Journal articles on the topic 'Nox4 overexpression'
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Kim, Young-Mee, Seok-Jo Kim, Ryosuke Tatsunami, Hisao Yamamura, Tohru Fukai, and Masuko Ushio-Fukai. "ROS-induced ROS release orchestrated by Nox4, Nox2, and mitochondria in VEGF signaling and angiogenesis." American Journal of Physiology-Cell Physiology 312, no. 6 (June 1, 2017): C749—C764. http://dx.doi.org/10.1152/ajpcell.00346.2016.
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Reactive oxygen species (ROS) derived from NADPH oxidase (NOX) and mitochondria play a critical role in growth factor-induced switch from a quiescent to an angiogenic phenotype in endothelial cells (ECs). However, how highly diffusible ROS produced from different sources can coordinate to stimulate VEGF signaling and drive the angiogenic process remains unknown. Using the cytosol- and mitochondria-targeted redox-sensitive RoGFP biosensors with real-time imaging, here we show that VEGF stimulation in human ECs rapidly increases cytosolic RoGFP oxidation within 1 min, followed by mitochondrial RoGFP oxidation within 5 min, which continues at least for 60 min. Silencing of Nox4 or Nox2 or overexpression of mitochondria-targeted catalase significantly inhibits VEGF-induced tyrosine phosphorylation of VEGF receptor type 2 (VEGFR2-pY), EC migration and proliferation at the similar extent. Exogenous hydrogen peroxide (H2O2) or overexpression of Nox4, which produces H2O2, increases mitochondrial ROS (mtROS), which is prevented by Nox2 siRNA, suggesting that Nox2 senses Nox4-derived H2O2 to promote mtROS production. Mechanistically, H2O2 increases S36 phosphorylation of p66Shc, a key mtROS regulator, which is inhibited by siNox2, but not by siNox4. Moreover, Nox2 or Nox4 knockdown or overexpression of S36 phosphorylation-defective mutant p66Shc(S36A) inhibits VEGF-induced mtROS, VEGFR2-pY, EC migration, and proliferation. In summary, Nox4-derived H2O2 in part activates Nox2 to increase mtROS via pSer36-p66Shc, thereby enhancing VEGFR2 signaling and angiogenesis in ECs. This may represent a novel feed-forward mechanism of ROS-induced ROS release orchestrated by the Nox4/Nox2/pSer36-p66Shc/mtROS axis, which drives sustained activation of angiogenesis signaling program.
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Moon, Joon Hwan, Tae Hoon Kim, Heung Man Lee, Seung Hoon Lee, Whan Choe, Ha Kyun Kim, Jung Hoon Lee, Kyoung Ho Oh, and Sang Hag Lee. "Overexpression of the Superoxide Anion and NADPH Oxidase Isoforms 1 and 4 (NOX1 and NOX4) in Allergic Nasal Mucosa." American Journal of Rhinology & Allergy 23, no. 4 (July 2009): 370–76. http://dx.doi.org/10.2500/ajra.2009.23.3340.
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Background The purpose of this study was to investigate the expression and distribution of superoxide anion, NADPH oxidase (NOX)1, and NOX4 in healthy, allergic nasal mucosa and nasal polyps to evaluate the possible influence of oxidative stress on the development of allergic rhinitis and nasal polyps. Methods The expression and distribution of superoxide anion, NOX1 and NOX4 were evaluated in healthy and allergic nasal mucosa and nasal polyps, using dihydroethidium fluorescence, semiquantitative reverse transcriptase-polymerase chain reaction, immunohistochemistry, and Western blot. Results NOX1 and NOX4 were localized mainly in the epithelial layer, submucosal glands, vascular endothelium, and inflammatory cells in healthy and allergic nasal mucosa and nasal polyps. The cellular source that generated superoxide anion is also localized in the epithelial cells, submucosal glands, vascular endothelium, and inflammatory cells, demonstrating the similar sites of expression of NOX1 and NOX4 in healthy and allergic nasal mucosa and nasal polyps. NOX1 and NOX4 mRNA and proteins and superoxide anions had increased levels of expression in allergic nasal mucosa and nasal polyps compared with healthy nasal mucosa. Conclusions These results indicate that NOX1 and NOX4 may play an important role in reactive oxygen species production, contributing to the oxidative stress in allergic rhinitis and nasal polyp tissues.
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Nadworny, Alyson S., Mallik R. Guruju, Daniel Poor, Robert M. Doran, Ram V. Sharma, Michael I. Kotlikoff, and Robin L. Davisson. "Nox2 and Nox4 influence neonatal c-kit+ cardiac precursor cell status and differentiation." American Journal of Physiology-Heart and Circulatory Physiology 305, no. 6 (September 15, 2013): H829—H842. http://dx.doi.org/10.1152/ajpheart.00761.2012.
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Redox status has emerged as critical in modulating stemness and lineage commitment in several precursor cell types. However, a role for redox genes, specifically NADPH oxidases (Nox), in cardiac precursor cells (CPCs) has not been established. We tested whether CPCs marked by type III receptor tyrosine kinase c-kit (c-kit+) exhibit a unique NADPH oxidase signature that confers precursor status and whether alterations in this profile are functionally linked to changes in lineage specification. Dihydroethidium (DHE) microfluorography indicated reduced basal reactive oxygen species (ROS) formation within early postnatal c-kit+ CPCs. Real-time quantitative PCR revealed downregulation of ROS generator Nox2 and its subunit p67phox in c-kit+ CPCs under basal conditions but upregulation of Nox2 and Nox4 over the course of differentiation. Adenoviral silencing of Nox2 and Nox4 increased expression of CPC markers c-kit and Flk-1 and blunted smooth and cardiac muscle differentiation, respectively, while overexpression of Nox2 and Nox4 significantly reduced c-kit expression. These changes were accompanied by altered expression of transcription factors regulating cardiac lineage commitment, Gata6 and Gata4, and cytokine transforming growth factor (TGF)-β1. Similar to other precursor cell types, RT2Profiler PCR Arrays revealed that c-kit+ CPCs also exhibit enhanced antioxidant capacity at the mRNA level. In conclusion, we report that c-kit+ CPCs demonstrate reduced Nox2 expression and ROS levels and that increases in Nox2 and Nox4 influence their differentiation into mature cells. We speculate that ROS generators Nox2 and Nox4, along with the antioxidant genes identified by PCR Arrays, may be novel targets in CPCs that could prove useful in cell-based therapy of the heart.
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Hu, Fang, Meng Xue, Yang Li, Yi-Jie Jia, Zong-Ji Zheng, Yan-Lin Yang, Mei-Ping Guan, Liao Sun, and Yao-Ming Xue. "Early Growth Response 1 (Egr1) Is a Transcriptional Activator of NOX4 in Oxidative Stress of Diabetic Kidney Disease." Journal of Diabetes Research 2018 (2018): 1–10. http://dx.doi.org/10.1155/2018/3405695.
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Background. NADPH oxidase 4 (NOX4) plays a major role in renal oxidative stress of diabetic kidney disease (DKD). NOX4 was significantly increased in Egr1-expressing fibroblasts, but the relationship between Egr1 and NOX4 in DKD is unclear. Methods. For the evaluation of the potential relationship between Egr1 and NOX4, both were detected in HFD/STZ-induced mice and HK-2 cells treated with TGF-β1. Then, changes in NOX4 expression were detected in HK-2 cells and mice with overexpression and knockdown of Egr1. The direct relationship between Egr1 and NOX4 was explored via chromatin immunoprecipitation (ChIP). Results. We found increased levels of Egr1, NOX4, and α-SMA in the kidney cortices of diabetic mice and in TGF-β1-treated HK-2 cells. Overexpression or silencing of Egr1 in HK-2 cells could upregulate or downregulate NOX4 and α-SMA. ChIP assays revealed that TGF-β1 induced Egr1 to bind to the NOX4 promoter. Finally, Egr1 overexpression or knockdown in diabetic mice could upregulate or downregulate the expression of NOX4 and ROS, and α-SMA was also changed. Conclusion. Our study provides strong evidence that Egr1 is a transcriptional activator of NOX4 in oxidative stress of DKD. Egr1 contributes to DKD by enhancing EMT, in part by targeting NOX4.
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Gusan, Svetlana, and Madhu B. Anand-Srivastava. "cAMP attenuates the enhanced expression of Gi proteins and hyperproliferation of vascular smooth muscle cells from SHR: role of ROS and ROS-mediated signaling." American Journal of Physiology-Cell Physiology 304, no. 12 (June 15, 2013): C1198—C1209. http://dx.doi.org/10.1152/ajpcell.00269.2012.
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We previously showed that angiotensin II (ANG II)-induced overexpression of inhibitory G proteins (Gi) was attenuated by dibutyryl-cAMP (db-cAMP) in A10 vascular smooth muscle cells (VSMC). Since enhanced levels of endogenous ANG II contributed to the overexpression of Gi protein and hyperproliferation of VSMC from spontaneously hypertensive rats (SHR), the present study was therefore undertaken to examine if cAMP could also attenuate the overexpression of Gi proteins and hyperproliferation of VSMC from SHR and to explore the underlying molecular mechanisms responsible for this response. The enhanced expression of Giα proteins in VSMC from SHR and Nω-nitro-l-arginine methyl ester hypertensive rats was decreased by db-cAMP. In addition, enhanced inhibition of adenylyl cyclase by inhibitory hormones and forskolin-stimulated adenylyl cyclase activity by low concentration of GTPγS in VSMC from SHR was also restored to Wistar-Kyoto (WKY) levels by db-cAMP. Furthermore, db-cAMP also attenuated the hyperproliferation and the increased production of superoxide anion, NAD(P)H oxidase activity, overexpression of Nox1/Nox2/Nox4 and p47phox proteins, increased phosphorylation of PDGF-receptor (R), EGF-R, c-Src, and ERK1/2 to control levels. In addition, the protein kinase A (PKA) inhibitor reversed the effects of db-cAMP on the expression of Nox4 and Giα proteins and hyperproliferation of VSMC from SHR to WKY levels, while stimulation of the exchange protein directly activated by cAMP did not have any effect on these parameters. These results suggest that cAMP via PKA pathway attenuates the overexpression of Gi proteins and hyperproliferation of VSMC from SHR through the inhibition of ROS and ROS-mediated transactivation of EGF-R/PDGF-R and MAPK signaling pathways.
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Chen, Dan, Ying-Hao Zang, Yun Qiu, Feng Zhang, Ai-Dong Chen, Jue-Jin Wang, Qi Chen, Yue-Hua Li, Yu-Ming Kang, and Guo-Qing Zhu. "BCL6 Attenuates Proliferation and Oxidative Stress of Vascular Smooth Muscle Cells in Hypertension." Oxidative Medicine and Cellular Longevity 2019 (January 22, 2019): 1–9. http://dx.doi.org/10.1155/2019/5018410.
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Proliferation and oxidative stress of vascular smooth muscle cells (VSMCs) contribute to vascular remodeling in hypertension and several major vascular diseases. B-cell lymphoma 6 (BCL6) functions as a transcriptional repressor. The present study is designed to determine the roles of BCL6 in VSMC proliferation and oxidative stress and underlying mechanism. Angiotensin (Ang) II was used to induce VSMC proliferation and oxidative stress in human VSMCs. Effects of BCL6 overexpression and knockdown were, respectively, investigated in Ang II-treated human VSMCs. Therapeutical effects of BCL6 overexpression on vascular remodeling, oxidative stress, and proliferation were determined in the aorta of spontaneously hypertensive rats (SHR). Ang II reduced BCL6 expression in human VSMCs. BCL6 overexpression attenuated while BCL6 knockdown enhanced the Ang II-induced upregulation of NADPH oxidase 4 (NOX4), production of reactive oxygen species (ROS), and proliferation of VSMCs. BCL6 expression was downregulated in SHR. BCL6 overexpression in SHR reduced NOX4 expression, ROS production, and proliferation of the aortic media of SHR. Moreover, BCL6 overexpression attenuated vascular remodeling and hypertension in SHR. However, BCL6 overexpression had no significant effects on NOX2 expression in human VSMCs or in SHR. We conclude that BCL6 attenuates proliferation and oxidative stress of VSMCs in hypertension.
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Nishimura, Ataru, Tetsuro Ago, Junya Kuroda, Koichi Arimura, Masaki Tachibana, Kuniyuki Nakamura, Yoshinobu Wakisaka, Junichi Sadoshima, Koji Iihara, and Takanari Kitazono. "Detrimental role of pericyte Nox4 in the acute phase of brain ischemia." Journal of Cerebral Blood Flow & Metabolism 36, no. 6 (October 13, 2015): 1143–54. http://dx.doi.org/10.1177/0271678x15606456.
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Pericytes are mural cells abundantly present in cerebral microvessels and play important roles, including the formation and maintenance of the blood–brain barrier. Nox4 is a major source of reactive oxygen species in cardiovascular cells and modulate cellular functions, particularly under pathological conditions. In the present study, we found that the expression of Nox4 was markedly induced in microvascular cells, including pericytes, in peri-infarct areas after middle cerebral artery occlusion stroke models in mice. The upregulation of Nox4 was greater in a permanent middle cerebral artery occlusion model compared with an ischemia/reperfusion transient middle cerebral artery occlusion model. We performed permanent middle cerebral artery occlusion on mice with Nox4 overexpression in pericytes (Tg-Nox4). Infarct volume was significantly greater with enhanced reactive oxygen species production and blood–brain barrier breakdown in peri-infarct areas in Tg-Nox4, compared with littermate controls. In cultured brain pericytes, Nox4 was significantly upregulated by hypoxia and was promptly downregulated by reoxygenation. Phosphorylation of NFκB and production of matrix metalloproteinase 9 were significantly increased in both cultured pericytes overexpressing Nox4 and in peri-infarct areas in Tg-Nox4. Collectively, Nox4 is upregulated in pericytes in peri-infarct areas after acute brain ischemia and may enhance blood–brain barrier breakdown through activation of NFκB and matrix metalloproteinase 9, thereby causing enlargement of infarct volume.
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Chen, Yen-Hao, Chih-Yen Chien, Fu-Min Fang, Tai-Lin Huang, Yan-Ye Su, Sheng-Dean Luo, Chao-Cheng Huang, Wei-Che Lin, and Shau-Hsuan Li. "Nox4 Overexpression as a Poor Prognostic Factor in Patients with Oral Tongue Squamous Cell Carcinoma Receiving Surgical Resection." Journal of Clinical Medicine 7, no. 12 (December 1, 2018): 497. http://dx.doi.org/10.3390/jcm7120497.
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Background: Nox4 has been reported to promote tumor progression of various types of cancer through many different pathways. The current study was designed to evaluate the prognostic significance of Nox4 in patients with oral tongue squamous cell carcinoma (OTSCC) receiving surgical resection. Methods: We retrospectively analyzed the 161 patients with OTSCC treated with surgical resection, including 81 patients with high expression of Nox4 and 80 patients with low expression of Nox4. Two OTSCC cell lines, SAS and SCC4, were used to investigate the proliferation activity. Results: The univariate and multivariable analyses showed that negative nodal metastasis and low expression of Nox4 were significantly associated with superior disease-free survival (DFS) and overall survival (OS). Western blotting analysis indicated that Nox4 was highly expressed in these two OTSCC cell lines and knockdown of Nox4 was successful by transfecting with Nox4 shRNA. In addition, these cell lines were also treated with a Nox4 inhibitor (GKT-137831) and the results showed GKT-137831 could inhibit the proliferation of OTSCC tumor cells in a dose-dependent manner. Conclusion: Our study suggests that Nox4 plays an important role in disease progression of OTSCC and Nox4 overexpression is a poor prognostic factor for patients with OTSCC who received surgical resection.
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Wang, Xi-Ling, Li-Long Pan, Fen Long, Wei-Jun Wu, Di Yan, Peng Xu, Si-Yu Liu, et al. "Endogenous Hydrogen Sulfide Ameliorates NOX4 Induced Oxidative Stress in LPS-Stimulated Macrophages and Mice." Cellular Physiology and Biochemistry 47, no. 2 (2018): 458–74. http://dx.doi.org/10.1159/000489980.
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Background/Aims: Sepsis is a severe and complicated syndrome that is characterized by dysregulation of host inflammatory responses and organ failure. Cystathionine-γ-lyase (CSE)/ hydrogen sulfide (H2S) has potential anti-inflammatory activities in a variety of inflammatory diseases. NADPH oxidase 4 (Nox4), a member of the NADPH oxidases, is the major source of reactive oxygen species (ROS) and its expression is increased in sepsis, but its function in CSE-mediated anti-inflammatory activities remains unknown. Methods: Macrophages were either transfected with CSE, Nox4 siRNA or transduced with lentiviral vector encoding CSE or Nox4, and then stimulated with lipopolysaccharide (LPS). The expression of inflammatory mediators and signaling pathway activation were measured by quantitative PCR (qPCR), ELISA, and immunoblotting. LPS-induced shock severity in WT, Nox4 knockdown and CSE knockout (CSE-/-) mice was assessed. Results: Here we showed that CSE and Nox4 were upregulated in macrophage and mouse in response to LPS. After LPS stimulation, the inflammatory responses were significantly ameliorated by lentiviral Nox4 shRNA knockdown, but were exacerbated by lentiviral overexpressing Nox4. Furthermore, Nox4 mediated inflammation through PI3K/Akt and p-p38 mitogen-activated protein kinase signal pathway. Notably, CSE knockout served to amplify the inflammatory cascade by increasing Nox4-ROS signaling activation in septic mice and macrophage. Similarly, the enhanced production of inflammatory mediators by macrophages was reduced by CSE overexpression. Conclusion: Thus, we demonstrated that CSE/H2S attenuated LPS-induced sepsis against oxidative stress and inflammation damage probably largely through mediated Nox4 pathway.
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Fang, Lijun, Wei Wang, Jiazheng Chen, Anju Zuo, Hongmei Gao, Tao Yan, Pengqi Wang, et al. "Osthole Attenuates Bleomycin-Induced Pulmonary Fibrosis by Modulating NADPH Oxidase 4-Derived Oxidative Stress in Mice." Oxidative Medicine and Cellular Longevity 2021 (September 4, 2021): 1–12. http://dx.doi.org/10.1155/2021/3309944.
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Idiopathic pulmonary fibrosis (IPF) is a chronic progressive lung disease characterized by the extensive accumulation of myofibroblasts and collagens. However, the exact mechanism that underlies this condition is unclear. Growing evidence suggests that NADPH oxidases (NOXs), especially NOX4-derived oxidative stress, play an important role in the development of lung fibrosis. Bleomycin (BLM) is a tumor chemotherapeutic agent, which has been widely employed to establish IPF animal models. Osthole (OST) is an active constituent of the fruit of Cnidium ninidium. Here, we used an in vivo mouse model and found that OST suppressed BLM-induced body weight loss, lung injury, pulmonary index increase, fibroblast differentiation, and pulmonary fibrosis. OST also significantly downregulated BLM-induced NOX4 expression and oxidative stress in the lungs. In vitro, OST could inhibit TGF-β1-induced Smad3 phosphorylation, differentiation, proliferation, collagen synthesis, NOX4 expression, and ROS generation in human lung fibroblasts in a concentration-dependent manner. Moreover, NOX4 overexpression could prevent the above effects of OST. We came to the conclusion that OST could significantly attenuate BLM-induced pulmonary fibrosis in mice, via the mechanism that involved downregulating TGF-β1/NOX4-mediated oxidative stress in lung fibroblasts.
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Dong, Qingqing, Xiaohong Zhang, and Min Zhang. "Long Noncoding RNA-5657 Inhibits the Proliferation of Pancreatic Cells and Insulin Secretion in Gestational Diabetes by Inhibiting the NADPH Oxidase 4 (NOX4)." Journal of Biomaterials and Tissue Engineering 12, no. 9 (September 1, 2022): 1825–30. http://dx.doi.org/10.1166/jbt.2022.3113.
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Multiple comorbidities are observed during pregnancy and there are many challenges for pregnant women with a previous history of diabetes. Pancreatic β-cell dysfunction is associated with gestational diabetes mellitus (GDM). This study intends to explore LncRNA-5657’s effect on proapoptotic cell proliferation and insulin secretion in gestational diabetes. Real-time quantitative fluorescence PCR measured LncRNA-5657 expression in GDM patient placental tissues along with analysis of cell activity, proliferation and insulin secretion by MTT assay, BrdU staining and ELISA. The relation between LncRNA-5657 and NOX4 was assessed by dual luciferase reporter assay. LncRNA-5657 was overexpressed in placental tissue of GDM patients compared to normal pregnant women. LncRNA-5657 overexpression promoted cell proliferation and insulin secretion, which was reversed by LncRNA-5657 downregulation. In addition, LncRNA-5657 negatively regulated NOX4 expression. Overexpression of NOX4 abolished the effect of LncRNA-5657 mimics on pancreatic β-cells, and knockdown of LncRNA-5657 promoted insulin secretion by upregulating NOX4 expression. In conclusion, LncRNA-5657 inhibits insulin secretion and β-cell proliferation by targeting NOX4, indicating that LncRNA-5657 might be a novel target for the treatment of GDM.
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Ma, Jia, Qian Cai, Dandan Yang, Jiali Yang, Jing Xue, Miao Yu, Yingxue Liu, Fucheng Ma, Feng Li, and Xiaoming Liu. "A Positive Feed Forward Loop between Wnt/β-Catenin and NOX4 Promotes Silicon Dioxide-Induced Epithelial-Mesenchymal Transition of Lung Epithelial Cells." Oxidative Medicine and Cellular Longevity 2020 (December 8, 2020): 1–16. http://dx.doi.org/10.1155/2020/3404168.
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Silicosis is a chronic fibrotic lung disease caused by the accumulation of silica dust in the distal lung. Canonical Wnt signaling and NADPH oxidase 4 (NOX4) have been demonstrated to play a crucial role in the pathogenesis of pulmonary fibrosis including silicosis. However, the underlying mechanisms of crosstalk between these two signalings are not fully understood. In the present study, we aimed to explore the interaction of Wnt/β-catenin and NOX4 of human epithelial cells in response to an exposure of silica dust. Results demonstrated an elevated expression of key components of Wnt/β-catenin signaling and NOX4 in the lungs of silicon dioxide- (SiO2-) induced silicosis mice. Furthermore, the activated Wnt/β-catenin and NOX4 signaling are accompanied by an inhibition of cell proliferation, an increase of ROS production and cell apoptosis, and an upregulation of profibrogenic factors in BEAS-2B human lung epithelial cells exposed to SiO2. A mechanistic study further demonstrated that the Wnt3a-mediated activation of canonical Wnt signaling could augment the SiO2-induced NOX4 expression and reactive oxygen species (ROS) production but reduced glutathione (GSH), while Wnt inhibitor DKK1 exhibited an opposite effect to Wnt3a. Vice versa, an overexpression of NOX4 further activated SiO2-induced Wnt/β-catenin signaling and NFE2-related factor 2 (Nrf2) antioxidant response along with a reduction of GSH, whereas the shRNA-mediated knockdown of NOX4 showed an opposite effect to NOX4 overexpression. These results imply a positive feed forward loop between Wnt/β-catenin and NOX4 signaling that may promote epithelial-mesenchymal transition (EMT) of lung epithelial cells in response to an exposure of silica dust, which may thus provide an insight into the profibrogenic role of Wnt/β-catenin and NOX4 crosstalk in lung epithelial cell injury and pathogenesis of silicosis.
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Xu, Ning, Hao Meng, Tianyi Liu, Yingli Feng, Yuan Qi, and Honglei Wang. "TRPC1 Deficiency Exacerbates Cerebral Ischemia/Reperfusion-Induced Neurological Injury by Potentiating Nox4-Derived Reactive Oxygen Species Generation." Cellular Physiology and Biochemistry 51, no. 4 (2018): 1723–38. http://dx.doi.org/10.1159/000495676.
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Background/Aims: Transient receptor potential cation channel 1 (TRPC1)-mediated the calcium (Ca2+) influx plays an important role in several brain disorders. However, the function of TRPC1 in ischemia/reperfusion (I/R)-induced neurological injury is unclear. Methods: Wild-type or TRPC1 knockout mice underwent middle cerebral artery occlusion for 90 min followed by 24 h of reperfusion. In an in vitro study, neuronal cells were treated with oxygen–glucose deprivation and reoxygenation (OGD/R) to mimic I/R. The intracellular Ca2+ concentration [Ca2+]i was measured by Fura 2-AM under a microscope. Cerebral infarct volume was measured by triphenyltetrazolium chloride staining. Neurological function was examined by neurological severity score, Morris water maze test, rotarod test and string test. Oxidative parameters were detected by malondialdehyde, glutathione peroxidase, and superoxide dismutase commercially available kits. The protein expression levels of TRPC1, Nox4, p22phox, p47phox, and p67phox were analyzed by western blotting. Results: Brain tissues from cerebral I/R mice showed decreased TRPC1 expression. Similarly, TRPC1 expression was reduced in HT22 cells upon exposure to OGD/R treatment, followed by decreased Ca2+ influx. However, TRPC1 overexpression reversed the OGD/R-induced decrease in [Ca2+]i. TRPC1 knockout significantly exacerbated I/R-induced brain infarction, edema, neurological severity score, memory impairment, neurological deficits, and oxidative stress. In contrast, TRPC1 upregulation inhibited the increase in reactive oxygen species (ROS) generation induced by OGD/R. Analysis of key subunits of the Nox family and mitochondrial ROS revealed that the effects of TRPC1 downregulation on oxidative stress were associated with activation of Nox4-containing NADPH oxidase. TRPC1 interacted with Nox4 and facilitated Nox4 protein degradation under OGD/R conditions. In addition, TRPC1 inhibition potentiated the OGD/R-induced translocation of p47phox and p67phox as well as the interaction between Nox4 and p47phox or p67phox, whereas TRPC1 overexpression had the opposite effects. Conclusion: TRPC1 deficiency potentiates ROS generation via Nox4-containing NADPH oxidase, which exacerbates cerebral I/R injury. TRPC1 may be a promising molecular target for the treatment of stroke.
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Santana-Garrido, Álvaro, Claudia Reyes-Goya, Pablo Espinosa-Martín, Luis Sobrevia, Luis M. Beltrán, Carmen M. Vázquez, and Alfonso Mate. "Oxidative and Inflammatory Imbalance in Placenta and Kidney of sFlt1-Induced Early-Onset Preeclampsia Rat Model." Antioxidants 11, no. 8 (August 19, 2022): 1608. http://dx.doi.org/10.3390/antiox11081608.
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Preeclampsia (PE) is a pregnancy-specific disorder characterized by the new onset of hypertension plus proteinuria and/or end-organ dysfunction. Here, we investigate the role of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase system as a major component of reactive oxygen species generation, in a rodent model of early-onset preeclampsia induced by excess sFlt1 (soluble fms-like tyrosine kinase 1). Placenta and kidney samples were obtained from normal pregnant and PE rats to measure the sFlt1/PlGF (placental growth factor) ratio in addition to oxidative stress-related parameters, including the activities and expressions of NADPH oxidase isoforms (NOX1, NOX2, and NOX4), components of nitric oxide (NO) metabolism, and antioxidant enzymes. Peroxisome proliferator-activated receptors (PPARα, PPARγ) and cytokines IL1β, IL3, IL6, IL10, and IL18 were also measured to evaluate the inflammation status in our experimental setting. Excessive O2●− production was found in rats that were treated with sFlt1; interestingly, this alteration appears to be mediated mainly by NOX2 in the placenta and by NOX4 in the kidney. Altered NO metabolism and antioxidant defense systems, together with mitochondrial dysfunction, were observed in this model of PE. Preeclamptic animals also exhibited overexpression of proinflammatory biomarkers as well as increased collagen deposition. Our results highlight the role of NADPH oxidase in mediating oxidative stress and possibly inflammatory processes in the placenta and kidney of an sFlt1-based model of early-onset preeclampsia.
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Diebold, Isabel, Andreas Petry, John Hess, and Agnes Görlach. "The NADPH Oxidase Subunit NOX4 Is a New Target Gene of the Hypoxia-inducible Factor-1." Molecular Biology of the Cell 21, no. 12 (June 15, 2010): 2087–96. http://dx.doi.org/10.1091/mbc.e09-12-1003.
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NADPH oxidases are important sources of reactive oxygen species (ROS), possibly contributing to various disorders associated with enhanced proliferation. NOX4 appears to be involved in vascular signaling and may contribute to the response to hypoxia. However, the exact mechanisms controlling NOX4 levels under hypoxia are not resolved. We found that hypoxia rapidly enhanced NOX4 mRNA and protein levels in pulmonary artery smooth-muscle cells (PASMCs) as well as in pulmonary vessels from mice exposed to hypoxia. This response was dependent on the hypoxia-inducible transcription factor HIF-1α because overexpression of HIF-1α increased NOX4 expression, whereas HIF-1α depletion prevented this response. Mutation of a putative hypoxia-responsive element in the NOX4 promoter abolished hypoxic and HIF-1α–induced activation of the NOX4 promoter. Chromatin immunoprecipitation confirmed HIF-1α binding to the NOX4 gene. Induction of NOX4 by HIF-1α contributed to maintain ROS levels after hypoxia and hypoxia-induced proliferation of PASMCs. These findings show that NOX4 is a new target gene of HIF-1α involved in the response to hypoxia. Together with our previous findings that NOX4 mediates HIF-1α induction under normoxia, these data suggest an important role of the signaling axis between NOX4 and HIF-1α in various cardiovascular disorders under hypoxic and also nonhypoxic conditions.
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Haurani, Mounir J., M. Eugenia Cifuentes, Alexander D. Shepard, and Patrick J. Pagano. "Nox4 Oxidase Overexpression Specifically Decreases Endogenous Nox4 mRNA and Inhibits Angiotensin II–Induced Adventitial Myofibroblast Migration." Hypertension 52, no. 1 (July 2008): 143–49. http://dx.doi.org/10.1161/hypertensionaha.107.101667.
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Leclerc, Joan, Debeissat Christelle, Socco-Lucca Marion, Ducrocq Elfi, Gouilleux Fabrice, Stasia Marie José, and Olivier Herault. "Influence of NADPH Oxidase Activity On the Reactive Oxygen Species Level in Human Leukemic Cells." Blood 120, no. 21 (November 16, 2012): 4801. http://dx.doi.org/10.1182/blood.v120.21.4801.4801.
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Abstract Abstract 4801 Redox metabolism plays an important role in self-renewal and differentiation of hematopoietic and leukemic cells. Reactive oxygen species (ROS) level is highly regulated. This regulation involves antioxydative enzymes and it has been recently described that leukemic stem cells (LSC) overexpress glutathione peroxydase 3 (Herault O et al, J. Exp. Med, 2012). This overexpression is associated with a decrease in ROS level and p38MAPK inactivation. ROS level in leukemic cells could be also regulated by the activity of ROS producers, such as NADPH oxidase, known to catalyze an electron transfer from NADPH to oxygen producing superoxides which could generate other downstream ROS. The expression of this enzymatic complex (NOX family, 6 isoforms) has been established in the plasma cell membrane of normal CD34+ hematopoietic progenitors (Piccoli C et al, Biochem. Biophys. Res. Commun., 2007). The aim of this study was to decipher the expression of NADPH oxydase components in various human acute myeloid leukemia (AML) Different leukemic cell lines were used according FAB classification: KG1a (MO/M1), KG1 (M1), HL60 (M2), Kasumi 1 (M2), NB4 (M3), ML2 (M4), THP1 (M5), U937 (M5), MV4–11 (M5), K562 (M6). The cells were cultured (2.105 cells/mL, 37°C in 95% humidified air and 5% CO2) in RPMI 1640 with 20mmoL/L L-glutamine supplemented with 10% FCS, 100 units/mL penicillin G, and 100mg/mL streptomycin. The expression of NOX1, NOX2, NOX3, NOX4, NOX5, DUOX1, DUOX2, P22phox and P40phox, P47phox, P67phox, NOXO1, NOXA1 was quantified by RT-qPCR (Universal Probe Library, Roche). NOX2 and its regulatory subunits expression was quantified by SDS-PAGE and western-blot experiments. The effects of diphenylene iodonium (DPI), a specific NOX inhibitor, were evaluated by ROS quantification using dichlorodihydrofluorescein diacetate (DCF-DA) staining followed by fluorimetry and flow cytometry analyses. The cells were washed twice in the physiological saline buffer (PBS) without calcium and magnesium, then incubated in PBS complemented with 0.5M MgCl2, 0.9M CaCl2, 20mM glucose (Picciocchi A et al, J. Biol. Chem., 2011) with or without 20μM DPI for 1 hour. The cells were distributed at 106cells per 200μL well in 96 wells plates. DCF-DA (10μM) was added to quantify the ROS level (flow cytometry) and to monitor ROS production kinetic (fluorimetry). NOX family genes expression showed that phagocyte oxidase NOX2 is expressed in all leukemic cell lines. Conversely the NOX2 isoforms were not expressed, or very weakly expressed in leukemic cell lines (NOX3 in KG1a; NOX4 in K562; DUOX1 in KG1a, KG1; DUOX2 in KG1a, KG1, HL60). P22phox, the second cytochrome b558 component was also expressed in all cell lines, this expression being higher than NOX2. The cytochrome b558 components were more expressed in differentiated leukemic cells (granulocytic and monocytic) than in undifferentiated cells (KG1a, KG1). NOX2 regulatory subunits were expressed in all leukemic cell lines, the lower level (especially P40phox, P47phox) being observed in KG1a. Proteins quantification confirmed RNA results. Cytochrome b558 components and regulatory subunits were expressed in all cell lines with a higher level in differentiated leukemias. Interestingly, the regulatory subunits were not observed in KG1a cells. Functional flow cytometry and fluorimetry studies revealed a decrease in ROS production in DPI exposed leukemic cell lines. This effect was higher in monocytic cell lines than in granulocytic and undifferentiated leukemias. In conclusion, NADPH oxidases are present in the AML cell membrane, and NOX contribution to the ROS level is higher in differentiated cells than in immature leukemias. Altogether these results suggest that NADPH oxidase is constitutively active in leukemic cells and influences the ROS level, suggesting a role in the pathophysiology of AML. Disclosures: No relevant conflicts of interest to declare.
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Stas, Sameer, Adam Whaley-Connell, Javad Habibi, Lama Appesh, Melvin R. Hayden, Poorna R. Karuparthi, Mahnaz Qazi, et al. "Mineralocorticoid Receptor Blockade Attenuates Chronic Overexpression of the Renin-Angiotensin-Aldosterone System Stimulation of Reduced Nicotinamide Adenine Dinucleotide Phosphate Oxidase and Cardiac Remodeling." Endocrinology 148, no. 8 (August 1, 2007): 3773–80. http://dx.doi.org/10.1210/en.2006-1691.
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The renin-angiotensin-aldosterone system contributes to cardiac remodeling, hypertrophy, and left ventricular dysfunction. Angiotensin II and aldosterone (corticosterone in rodents) together generate reactive oxygen species (ROS) via reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, which likely facilitate this hypertrophy and remodeling. This investigation sought to determine whether cardiac oxidative stress and cellular remodeling could be attenuated by in vivo mineralocorticoid receptor (MR) blockade in a rodent model of the chronically elevated tissue renin-angiotensin-aldosterone system, the transgenic TG (mRen2) 27 rat (Ren2). The Ren2 overexpresses the mouse renin transgene with resultant hypertension, insulin resistance, proteinuria, and cardiovascular damage. Young (6- to 7-wk-old) male Ren2 and age-matched Sprague-Dawley rats were treated with spironolactone or placebo for 3 wk. Heart tissue ROS, immunohistochemical analysis of 3-nitrotyrosine, and NADPH oxidase (NOX) subunits (gp91phox recently renamed NOX2, p22phox, Rac1, NOX1, and NOX4) were measured. Structural changes were assessed with cine-magnetic resonance imaging, transmission electron microscopy, and light microscopy. Significant increases in Ren2 septal wall thickness (cine-magnetic resonance imaging) were accompanied by perivascular fibrosis, increased mitochondria, and other ultrastructural changes visible by light microscopy and transmission electron microscopy. Although there was no significant reduction in systolic blood pressure, significant improvements were seen with MR blockade on ROS formation and NOX subunits (each P < 0.05). Collectively, these data suggest that MR blockade, independent of systolic blood pressure reduction, improves cardiac oxidative stress-induced structural and functional changes, which are driven, in part, by angiotensin type 1 receptor-mediated increases in NOX.
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Li, Jingming, Joshua J. Wang, and Sarah X. Zhang. "NADPH Oxidase 4-Derived H2O2Promotes Aberrant Retinal Neovascularization via Activation of VEGF Receptor 2 Pathway in Oxygen-Induced Retinopathy." Journal of Diabetes Research 2015 (2015): 1–13. http://dx.doi.org/10.1155/2015/963289.
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NADPH oxidase 4 (Nox4) is a major isoform of NADPH oxidase in retinal endothelial cells. Our previous study suggests that upregulation of Nox4 in retinal endothelial cells contributes to retinal vascular leakage in diabetes. In the current study, we investigated the role and mechanism of Nox4 in regulation of retinal neovascularization (NV), a hallmark of proliferative diabetic retinopathy (PDR), using a mouse model of oxygen-induced retinopathy (OIR). Our results confirmed that Nox4 was expressed predominantly in retinal vasculature of mouse retina. Retinal expression of Nox4 was markedly increased in OIR, in parallel with enhanced phosphorylation of ERK. In human retinal microvascular endothelial cells (HRECs), overexpression of Nox4 by adenovirus significantly increased extracellular H2O2generation, resulting in intensified VEGFR2 activation and exacerbated angiogenesis upon VEGF stimulation. In contrast, silencing Nox4 expression or scavenging H2O2by polyethylene glycol- (PEG-) conjugated catalase inhibited endothelial migration, tube formation, and VEGF-induced activation of VEGFR2 signaling. Importantly, knockdown of retinal Nox4 by adenovirus-delivered siRNA significantly reduced ERK activation and attenuated retinal NV formation in OIR. Taken together, our data indicate that Nox4 promotes retinal NV formation through H2O2/VEGFR2/ERK signaling pathway. Reducing retinal Nox4 expression may represent a promising therapeutic approach for neovascular retinal diseases such as PDR.
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Qi, Jie, Xue Luo, Zhichao Ma, Bo Zhang, Shuyan Li, Xuyang Duan, Bo Yang, and Jun Zhang. "Swimming Exercise Protects against Insulin Resistance via Regulating Oxidative Stress through Nox4 and AKT Signaling in High-Fat Diet-Fed Mice." Journal of Diabetes Research 2020 (January 21, 2020): 1–9. http://dx.doi.org/10.1155/2020/2521590.
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Nonpharmaceutical therapies such as exercise training and diet intervention are widely used for the treatment of insulin resistance (IR). Although the skeletal muscle is the major peripheral tissue of glucose metabolism under insulin stimulation, the mechanism underlying muscle IR is poorly understood. Using a high-fat diet-induced IR mouse model, we here show that NADPH oxidase 4 (Nox4) upregulation mediates the production of reactive oxygen species (ROS) that causes metabolic syndrome featuring IR. The Nox4 expression level was markedly elevated in IR mice, and Nox4 overexpression was sufficient to trigger IR. Conversely, downregulation of Nox4 expression through exercise training prevented diet-induced IR by reducing the production of ROS and enhancing the AKT signaling pathway. Thus, this study indicates that exercise might improve IR through a reduction of Nox4-induced ROS in the skeletal muscle and enhancement of AKT signal transduction.
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Velimirović, Milica, Gordana Jevtić Dožudić, Vesna Selaković, Tihomir Stojković, Nela Puškaš, Ivan Zaletel, Milica Živković, et al. "Effects of Vitamin D3 on the NADPH Oxidase and Matrix Metalloproteinase 9 in an Animal Model of Global Cerebral Ischemia." Oxidative Medicine and Cellular Longevity 2018 (2018): 1–14. http://dx.doi.org/10.1155/2018/3273654.
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Decreased blood flow in the brain leads to a rapid increase in reactive oxygen species (ROS). NADPH oxidase (NOX) is an enzyme family that has the physiological function to produce ROS. NOX2 and NOX4 overexpression is associated with aggravated ischemic injury, while NOX2/4-deficient mice had reduced stroke size. Dysregulation of matrix metalloproteinases (MMPs) contributes to tissue damage. The active form of vitamin D3 expresses neuroprotective, immunomodulatory, and anti-inflammatory effects in the CNS. The present study examines the effects of the vitamin D3 pretreatment on the oxidative stress parameters and the expression of NOX subunits, MMP9, microglial marker Iba1, and vitamin D receptor (VDR), in the cortex and hippocampus of Mongolian gerbils subjected to ten minutes of global cerebral ischemia, followed by 24 hours of reperfusion. The ischemia/reperfusion procedure has induced oxidative stress, changes in the expression of NOX2 subunits and MMP9 in the brain, and increased MMP9 activity in the serum of experimental animals. Pretreatment with vitamin D3 was especially effective on NOX2 subunits, MMP9, and the level of malondialdehyde and superoxide anion. These results outline the significance of the NOX and MMP9 investigation in brain ischemia and the importance of adequate vitamin D supplementation in ameliorating the injury caused by I/R.
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Xiao, Qingzhong, Zhenling Luo, Anna Elena Pepe, Andriani Margariti, Lingfang Zeng, and Qingbo Xu. "Embryonic stem cell differentiation into smooth muscle cells is mediated by Nox4-produced H2O2." American Journal of Physiology-Cell Physiology 296, no. 4 (April 2009): C711—C723. http://dx.doi.org/10.1152/ajpcell.00442.2008.
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NADPH oxidase (Nox4) produces reactive oxygen species (ROS) that are important for vascular smooth muscle cell (SMC) behavior, but the potential impact of Nox4 in stem cell differentiation is unknown. When mouse embryonic stem (ES) cells were plated on collagen IV-coated dishes/flasks, a panel of SMC-specific genes was significantly and consistently upregulated. Nox4 expression was markedly correlated with such a gene induction as confirmed by real-time PCR, immunofluorescence, and Western blot analysis. Overexpression of Nox4 specifically resulted in increased SMC marker production, whereas knockdown of Nox4 induced a decrease. Furthermore, SMC-specific transcription factors, including serum response factor (SRF) and myocardin were activated by Nox4 gene expression. Moreover, Nox4 was demonstrated to drive SMC differentiation through generation of H2O2. Confocal microscopy analysis indicates that SRF was translocated into the nucleus during SMC differentiation in which SRF was phosphorylated. Additionally, autosecreted transforming growth factor (TGF)-β1 activated Nox4 and promoted SMC differentiation. Interestingly, cell lines generated from stem cells by Nox4 transfection and G418 selection displayed a characteristic of mature SMCs, including expression of SMC markers and cells with contractile function. Thus we demonstrate for the first time that Nox4 is crucial for SMC differentiation from ES cells, and enforced Nox4 expression can maintain differentiation status and functional features of stem cell-derived SMCs, highlighting its impact on vessel formation in vivo and vascular tissue engineering in the future.
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Balzamino, Bijorn Omar, Lucia Dinice, Andrea Cacciamani, Agnese Re, Fabio Scarinci, Luca Bruno, Pamela Cosimi, and Alessandra Micera. "Short-Term In Vitro ROS Detection and Oxidative Stress Regulators in Epiretinal Membranes and Vitreous from Idiopathic Vitreoretinal Diseases." BioMed Research International 2022 (December 16, 2022): 1–12. http://dx.doi.org/10.1155/2022/7497816.
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Background. A plethora of inflammatory, angiogenic, and tissue remodeling factors has been reported in idiopathic epiretinal membranes (ERMs). Herein we focused on the expression of a few mediators (oxidative, inflammatory, and angiogenic/vascular factors) by means of short-term vitreal cell cultures and biomolecular analysis. Methods. Thirty-nine (39) ERMs and vitreal samples were collected at the time of vitreoretinal surgery and biomolecular analyses were performed in clear vitreous, vitreal cell pellets, and ERMs. ROS products and iNOS were investigated in adherent vitreal cells and/or ERMs, and iNOS, VEGF, Ang-2, IFNγ, IL18, and IL22 were quantified in vitreous (ELISA/Ella, IF/WB); transcripts specific for iNOS, p65NFkB, KEAP1, NRF2, and NOX1/NOX4 were detected in ERMs (PCR). Biomolecular changes were analyzed and correlated with disease severity. Results. The higher ROS production was observed in vitreal cells at stage 4, and iNOS was found in ERMs and increased in the vitreous as early as at stage 3. Both iNOS and NOX4 were upregulated at all stages, while p65NFkB was increased at stage 3. iNOS and NOX1 were positively and inversely related with p65NFkB. While NOX4 transcripts were always upregulated, NRF2 was upregulated at stage 3 and inverted at stage 4. No significant changes occurred in the release of angiogenic (VEGF, Ang-2) and proinflammatory (IL18, IL22 and IFNγ) mediators between all stages investigated. Conclusions. ROS production was strictly associated with iNOS and NOX4 overexpression and increased depending on ERM stadiation. The higher iNOS expression occurred as early as stage 3, with respect to p65NFkB and NRF2. These last mediators might have potential prognostic values in ERMs as representative of an underneath retinal damage.
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Lu, Xianghuai, Tamara C. Murphy, Mark S. Nanes, and C. Michael Hart. "PPARγ regulates hypoxia-induced Nox4 expression in human pulmonary artery smooth muscle cells through NF-κB." American Journal of Physiology-Lung Cellular and Molecular Physiology 299, no. 4 (October 2010): L559—L566. http://dx.doi.org/10.1152/ajplung.00090.2010.
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NADPH oxidases are a major source of superoxide production in the vasculature. The constitutively active Nox4 subunit, which is selectively upregulated in the lungs of human subjects and experimental animals with pulmonary hypertension, is highly expressed in vascular wall cells. We demonstrated that rosiglitazone, a synthetic agonist of the peroxisome proliferator-activated receptor-γ (PPARγ), attenuated hypoxia-induced pulmonary hypertension, vascular remodeling, Nox4 induction, and reactive oxygen species generation in the mouse lung. The current study examined the molecular mechanisms involved in PPARγ-regulated, hypoxia-induced Nox4 expression in human pulmonary artery smooth muscle cells (HPASMC). Exposing HPASMC to 1% oxygen for 72 h increased Nox4 gene expression and H2O2 production, both of which were reduced by treatment with rosiglitazone during the last 24 h of hypoxia exposure or by treatment with small interfering RNA (siRNA) to Nox4. Hypoxia also increased HPASMC proliferation as well as the activity of a Nox4 promoter luciferase reporter, and these increases were attenuated by rosiglitazone. Chromatin immunoprecipitation assays demonstrated that hypoxia increased binding of the NF-κB subunit, p65, to the Nox4 promoter and that binding was attenuated by rosiglitazone treatment. The role of NF-κB in Nox4 regulation was further supported by demonstrating that overexpression of p65 stimulated Nox4 promoter activity, whereas siRNA to p50 or p65 attenuated hypoxic stimulation of Nox4 promoter activity. These results provide novel evidence for NF-κB-mediated stimulation of Nox4 expression in HPASMC that can be negatively regulated by PPARγ. These data provide new insights into potential mechanisms by which PPARγ activation inhibits Nox4 upregulation and the proliferation of cells in the pulmonary vascular wall to ameliorate pulmonary hypertension and vascular remodeling in response to hypoxia.
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Huang, Jianhua, Li Li, Weifeng Yuan, Linxin Zheng, Zhenhui Guo, and Wenjie Huang. "NEMO-Binding Domain Peptide Attenuates Lipopolysaccharide-Induced Acute Lung Injury by Inhibiting the NF-κB Signaling Pathway." Mediators of Inflammation 2016 (2016): 1–11. http://dx.doi.org/10.1155/2016/7349603.
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The aim of the present study is to investigate the protective effects and relevant mechanisms exerted by NEMO-binding domain peptide (NBD) against lipopolysaccharide- (LPS-) induced acute lung injury (ALI) in mice. The ALI model was induced by intratracheally administered atomized LPS (5 mg/kg) to BABL/c mice. Half an hour before LPS administration, we treated the mice with increasing concentrations of intratracheally administered NBD or saline aerosol. Two hours after LPS administration, each group of mice was sacrificed. We observed that NBD pretreatment significantly attenuated LPS-induced lung histopathological injury in a dose-dependent manner. Western blotting established that NBD pretreatment obviously attenuated LPS-induced IκB-αand NF-κBp65 activation and NOX1, NOX2, and NOX4 overexpression. Furthermore, NBD pretreatment increased SOD and T-AOC activity and decreased MDA levels in lung tissue. In addition, NBD also inhibited TNF-αand IL-1βsecretion in BALF after LPS challenge. In conclusion, NBD protects against LPS-induced ALI in mice.
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Datla, Srinivasa Raju, Daniel J. McGrail, Sasa Vukelic, Lauren P. Huff, Alicia N. Lyle, Lily Pounkova, Minyoung Lee, et al. "Poldip2 controls vascular smooth muscle cell migration by regulating focal adhesion turnover and force polarization." American Journal of Physiology-Heart and Circulatory Physiology 307, no. 7 (October 1, 2014): H945—H957. http://dx.doi.org/10.1152/ajpheart.00918.2013.
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Polymerase-δ-interacting protein 2 (Poldip2) interacts with NADPH oxidase 4 (Nox4) and regulates migration; however, the precise underlying mechanisms are unclear. Here, we investigated the role of Poldip2 in focal adhesion turnover, as well as traction force generation and polarization. Poldip2 overexpression (AdPoldip2) in vascular smooth muscle cells (VSMCs) impairs PDGF-induced migration and induces a characteristic phenotype of long cytoplasmic extensions. AdPoldip2 also prevents the decrease in spreading and increased aspect ratio observed in response to PDGF and slightly impairs cell contraction. Moreover, AdPoldip2 blocks focal adhesion dissolution and sustains H2O2 levels in focal adhesions, whereas Poldip2 knockdown (siPoldip2) significantly decreases the number of focal adhesions. RhoA activity is unchanged when focal adhesion dissolution is stimulated in control cells but increases in AdPoldip2-treated cells. Inhibition of RhoA blocks Poldip2-mediated attenuation of focal adhesion dissolution, and overexpression of RhoA or focal adhesion kinase (FAK) reverses the loss of focal adhesions induced by siPoldip2, indicating that RhoA and FAK mediate the effect of Poldip2 on focal adhesions. Nox4 silencing prevents focal adhesion stabilization by AdPoldip2 and induces a phenotype similar to siPoldip2, suggesting a role for Nox4 in Poldip2-induced focal adhesion stability. As a consequence of impaired focal adhesion turnover, PDGF-treated AdPoldip2 cells are unable to reduce and polarize traction forces, a necessary first step in migration. These results implicate Poldip2 in VSMC migration via regulation of focal adhesion turnover and traction force generation in a Nox4/RhoA/FAK-dependent manner.
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Su, Xiangsheng, Yihang Yang, Changfa Guo, Rui Zhang, Shicheng Sun, Yanjun Wang, Qiujiang Qiao, Yibing Fu, and Qi Pang. "NOX4-Derived ROS Mediates TGF-β1-Induced Metabolic Reprogramming during Epithelial-Mesenchymal Transition through the PI3K/AKT/HIF-1α Pathway in Glioblastoma." Oxidative Medicine and Cellular Longevity 2021 (June 27, 2021): 1–30. http://dx.doi.org/10.1155/2021/5549047.
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Current studies on tumor progression focus on the roles of cytokines in the tumor microenvironment (TME), and recent research shows that transforming growth factor-β1 (TGF-β1) released from TME plays a pivotal role in tumor development and malignant transformation. The alteration in cellular metabolism is a hallmark of cancer, which not only provides cancer cells with ATP for fuel cellular reactions, but also generates metabolic intermediates for the synthesis of essential cellular ingredients, to support cell proliferation, migration, and invasion. Interestingly, we found a distinct metabolic change during TGF-β1-induced epithelial-mesenchymal transition (EMT) in glioblastoma cells. Indeed, TGF-β1 participates in metabolic reprogramming, and the molecular basis is still not well understood. NADPH oxidases 4 (NOX4), a member of the Nox family, also plays a key role in the biological effects of glioblastoma. However, the relationship between NOX4, TGF-β1, and cellular metabolic changes during EMT in glioblastoma remains obscure. Here, our findings demonstrated that TGF-β1 upregulated NOX4 expression accompanied by reactive oxygen species (ROS) through Smad-dependent signaling and then induced hypoxia-inducible factor 1α (HIF-1α) overexpression and nuclear accumulation resulting in metabolic reprogramming and promoting EMT. Besides, inhibition of glycolysis reversed EMT suggesting a causal relationship between TGF-β1-induced metabolic changes and tumorigenesis. Moreover, TGF-β1-induced metabolic reprogramming and EMT which modulated by NOX4/ROS were blocked when the phosphoinositide3-kinase (PI3K)/AKT/HIF-1α signaling pathways were inhibited. In conclusion, these suggest that NOX4/ROS induction by TGF-β1 can be one of the main mechanisms mediating the metabolic reprogramming during EMT of glioblastoma cells and provide promising strategies for cancer therapy.
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Chai, DongDong, Lei Zhang, SiWei Xi, YanYong Cheng, Hong Jiang, and Rong Hu. "Nrf2 Activation Induced by Sirt1 Ameliorates Acute Lung Injury After Intestinal Ischemia/Reperfusion Through NOX4-Mediated Gene Regulation." Cellular Physiology and Biochemistry 46, no. 2 (2018): 781–92. http://dx.doi.org/10.1159/000488736.
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Background/Aims: Nuclear erythroid 2-related factor-2 (Nrf2) is a major stress-response transcription factor that has been implicated in regulating ischemic angiogenesis. We investigated the effects of Nrf2 in regulating revascularization and modulating acute lung injury. Methods: The expression of Nrf2 and sirtuin1 (Sirt1) was assessed in lung tissue by western blotting and immunofluorescence staining after intestinal ischemia/reperfusion (IIR) in Nrf2–/– and wild-type (WT) mice. The involvement of Nrf2 in angiogenesis, cell viability, and migration was investigated in human pulmonary microvascular endothelial cells (PMVECs). Additionally, the influence of Nrf2 expression on NOX pathway activation was measured in PMVECs after oxygen–glucose deprivation/reoxygenation. Results: We found activation and nuclear accumulation of Nrf2 in lung tissue after IIR. Compared to IIR in WT mice, IIR in Nrf2–/– mice significantly enhanced leukocyte infiltration and collagen deposit, and inhibited endothelial cell marker CD31 expression. Nrf2 upregulation and translocation into the nucleus stimulated by Sirt1 overexpression exhibited remission of histopathologic changes and enhanced CD31 expression. Nrf2 knockdown repressed non-phagocytic cell oxidase 4 (NOX4), hypoxia-inducible factor (HIF-1α) and vascular endothelial growth factor (VEGF) expression after IIR. Nrf2 upregulation by Sirt1 enhances NOX4, HIF-1α and VEGF expression after IIR in WT mice. Furthermore, Nrf2 knockdown suppressed cell viability, capillary tube formation and cell migration in PMVECs after oxygen–glucose deprivation/reoxygenation and also inhibited NOX4, HIF-1 and VEGF expression. Moreover, NOX4 knockdown in PMVECs decreased the levels of VEGF, HIF-1α and angiogenesis. Conclusion: Nrf2 stimulation by Sirt1 plays an important role in sustaining angiogenic potential through NOX4-mediated gene regulation.
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Huang, Yongpan, Jiayu Tang, Xiaojuan Li, Xian Long, Yansong Huang, and Xi Zhang. "miR-92b-3p Exerts Neuroprotective Effects on Ischemia/Reperfusion-Induced Cerebral Injury via Targeting NOX4 in a Rat Model." Oxidative Medicine and Cellular Longevity 2022 (March 30, 2022): 1–16. http://dx.doi.org/10.1155/2022/3494262.
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The necessity to increase the efficiency of organ preservation has pushed researchers to consider the mechanisms to minimize cerebral ischemia/reperfusion (I/R) injury. Hence, we evaluated the role of the miR-92b-3p/NOX4 pathway in cerebral I/R injury. A cerebral I/R injury model was established by blocking the left middle cerebral artery for 2 h and reperfusion for 24 h, and a hypoxia/reoxygenation (H/R) model was established. Thereafter, cerebral I/R increased obvious neurobiological function and brain injury (such as cerebral infarction, apoptosis, and cell morphology changes). In addition, we noted a significant decrease in the expression of miR-92b-3p, as well as increases in apoptosis and oxidative stress and an increase in NOX4. Furthermore, overexpression of miR-92b-3p blocked the inhibitory effect of miR-92b-3p on the expression of NOX4 and the accumulation of oxygen-free radicals. Bioinformatics analysis found that NOX4 may be the target gene regulated by miR-92b-3p. In conclusion, the involvement of the miR-92b-3p/NOX4 pathway ameliorated cerebral I/R injury through the prevention of apoptosis and oxidative stress. The miR-92b-3p/NOX4 pathway could be considered a potential therapeutic target to alleviate cerebral I/R injury.
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Gao, Jie, Ying Meng, Xin Ge, Chen-Xing Hou, Qing-Hai Zhu, Yi-Zhou Wang, Li-Fan Sun, et al. "SATB2 overexpression promotes oral squamous cell carcinoma progression by up-regulating NOX4." Cellular Signalling 82 (June 2021): 109968. http://dx.doi.org/10.1016/j.cellsig.2021.109968.
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Mahadev, Kalyankar, Hiroyuki Motoshima, Xiangdong Wu, Jean Marie Ruddy, Rebecca S. Arnold, Guangjie Cheng, J. David Lambeth, and Barry J. Goldstein. "The NAD(P)H Oxidase Homolog Nox4 Modulates Insulin-Stimulated Generation of H2O2 and Plays an Integral Role in Insulin Signal Transduction." Molecular and Cellular Biology 24, no. 5 (March 1, 2004): 1844–54. http://dx.doi.org/10.1128/mcb.24.5.1844-1854.2004.
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ABSTRACT Insulin stimulation of target cells elicits a burst of H2O2 that enhances tyrosine phosphorylation of the insulin receptor and its cellular substrate proteins as well as distal signaling events in the insulin action cascade. The molecular mechanism coupling the insulin receptor with the cellular oxidant-generating apparatus has not been elucidated. Using reverse transcription-PCR and Northern blot analyses, we found that Nox4, a homolog of gp91phox, the phagocytic NAD(P)H oxidase catalytic subunit, is prominently expressed in insulin-sensitive adipose cells. Adenovirus-mediated expression of Nox4 deletion constructs lacking NAD(P)H or FAD/NAD(P)H cofactor binding domains acted in a dominant-negative fashion in differentiated 3T3-L1 adipocytes and attenuated insulin-stimulated H2O2 generation, insulin receptor (IR) and IRS-1 tyrosine phosphorylation, activation of downstream serine kinases, and glucose uptake. Transfection of specific small interfering RNA oligonucleotides reduced Nox4 protein abundance and also inhibited the insulin signaling cascade. Overexpression of Nox4 also significantly reversed the inhibition of insulin-stimulated IR tyrosine phosphorylation induced by coexpression of PTP1B by inhibiting PTP1B catalytic activity. These data suggest that Nox4 provides a novel link between the IR and the generation of cellular reactive oxygen species that enhance insulin signal transduction, at least in part via the oxidative inhibition of cellular protein-tyrosine phosphatases (PTPases), including PTP1B, a PTPase that has been previously implicated in the regulation of insulin action.
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Zhang, M., Y. H. Looi, A. C. Brewer, and A. M. Shah. "010 Cardiomyocyte-specific overexpression of Nox4 attenuates adverse cardiac remodelling after myocardial infarction." Heart 96, no. 4 (February 1, 2010): e3-e4. http://dx.doi.org/10.1136/hrt.2009.191049j.
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Goettsch, Claudia, Winfried Goettsch, Gregor Muller, Jochen Seebach, Hans-Joachim Schnittler, and Henning Morawietz. "Nox4 overexpression activates reactive oxygen species and p38 MAPK in human endothelial cells." Biochemical and Biophysical Research Communications 380, no. 2 (March 2009): 355–60. http://dx.doi.org/10.1016/j.bbrc.2009.01.107.
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Wang, Jinju, Shuzhen Chen, and Ji Bihl. "Exosome-Mediated Transfer of ACE2 (Angiotensin-Converting Enzyme 2) from Endothelial Progenitor Cells Promotes Survival and Function of Endothelial Cell." Oxidative Medicine and Cellular Longevity 2020 (January 20, 2020): 1–11. http://dx.doi.org/10.1155/2020/4213541.
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Angiotensin-converting enzyme 2 (ACE2) is an emerging cardiovascular protective target that mediates the metabolism of angiotensin (Ang) II into Ang (1–7). Our group has demonstrated that ACE2 overexpression enhances the function of endothelial progenitor cells (EPCs). Here, we investigated whether ACE2-primed EPCs (ACE2-EPCs) can protect cerebral microvascular endothelial cells (ECs) against injury and dysfunction in an in vitro model, with focusing on their exosomal and cytokine paracrine effects on endothelial mitochondria. Human EPCs were transfected with lentivirus containing null or human ACE2 cDNA (denoted as Null-EPCs and ACE2-EPCs, respectively). Their conditioned culture media, w/wo depletion of exosomes (ACE2-EPC-CMEX-, Null-EPC-CMEX-, ACE2-EPC-CM, and Null-EPC-CM), were used for coculture experiments. EC injury and dysfunction model was induced by Ang II before coculture. Apoptosis, angiogenic ability, mitochondrion functions (ROS production, membrane potential, fragmentation), and gene expressions (ACE2, Nox2, and Nox4) of ECs were analyzed. The supernatant was collected for measuring the levels of ACE2, Ang II/Ang-(1–7), and growth factors (VEGF and IGF). Our results showed that (1) ACE2-EPC-CM had higher levels of ACE2, Ang (1–7), VEGF, and IGF than that of Null-EPC-CM. (2) Ang II-injured ECs displayed an increase of apoptotic rate and reduction in tube formation and migration abilities, which were associated with ACE2 downregulation, Ang II/Ang (1–7) imbalance, Nox2/Nox4 upregulation, ROS overproduction, an increase of mitochondrion fragmentation, and a decrease of membrane potential. (3) ACE2-EPC-CM had better protective effects than Null-EPC-CM on Ang II-injured ECs, which were associated with the improvements on ACE2 expression, Ang II/Ang (1–7) balance, and mitochondrial functions. (4) ACE2-EPC-CMEX- and Null-EPC-CMEX- showed reduced effects as compared to ACE2-EPCs-CM and Null-EPCs-CM. In conclusion, our data demonstrate that ACE2 overexpression can enhance the protective effects of EPCs on ECs injury, majorly through the exosomal effects on mitochondrial function.
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Craps, Julie, Virginie Joris, Lelio Baldeschi, Chantal Daumerie, Alessandra Camboni, Antoine Buemi, Benoit Lengelé, et al. "miR-199a Downregulation as a Driver of the NOX4/HIF-1α/VEGF-A Pathway in Thyroid and Orbital Adipose Tissues from Graves′ Patients." International Journal of Molecular Sciences 23, no. 1 (December 23, 2021): 153. http://dx.doi.org/10.3390/ijms23010153.
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Graves’ disease (GD) is an autoimmune thyroiditis often associated with Graves’ orbitopathy (GO). GD thyroid and GO orbital fat share high oxidative stress (OS) and hypervascularization. We investigated the metabolic pathways leading to OS and angiogenesis, aiming to further decipher the link between local and systemic GD manifestations. Plasma and thyroid samples were obtained from patients operated on for multinodular goiters (controls) or GD. Orbital fats were from GO or control patients. The NADPH-oxidase-4 (NOX4)/HIF-1α/VEGF-A signaling pathway was investigated by Western blotting and immunostaining. miR-199a family expression was evaluated following quantitative real-time PCR and/or in situ hybridization. In GD thyroids and GO orbital fats, NOX4 was upregulated and correlated with HIF-1α stabilization and VEGF-A overexpression. The biotin assay identified NOX4, HIF-1α and VEGF-A as direct targets of miR-199a-5p in cultured thyrocytes. Interestingly, GD thyroids, GD plasmas and GO orbital fats showed a downregulation of miR-199a-3p/-5p. Our results also highlighted an activation of STAT-3 signaling in GD thyroids and GO orbital fats, a transcription factor known to negatively regulate miR-199a expression. We identified NOX4/HIF-1α/VEGF-A as critical actors in GD and GO. STAT-3-dependent regulation of miR-199a is proposed as a common driver leading to these events in GD thyroids and GO orbital fats.
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Lin, Xiao-Lu, Li Yang, Seng-Wang Fu, Wen-Feng Lin, Yun-Jie Gao, Hao-Yan Chen, and Zhi-Zheng Ge. "Overexpression of NOX4 predicts poor prognosis and promotes tumor progression in human colorectal cancer." Oncotarget 8, no. 20 (April 4, 2017): 33586–600. http://dx.doi.org/10.18632/oncotarget.16829.
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Xue, Jiahong, Jiali Fan, Yuan Li, Wenhuan Wu, Qing Yan, and Qiangsun Zheng. "ABCG1 Attenuates Oxidative Stress Induced by H2O2 through the Inhibition of NADPH Oxidase and the Upregulation of Nrf2-Mediated Antioxidant Defense in Endothelial Cells." Analytical Cellular Pathology 2020 (December 3, 2020): 1–11. http://dx.doi.org/10.1155/2020/2095645.
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Summary. Oxidative stress is an important factor that is related to endothelial dysfunction. ATP-binding cassette transporter G1 (ABCG1), a regulator of intracellular cholesterol efflux, has been found to prevent endothelial activation in vessel walls. To explore the role of ABCG1 in oxidative stress production in endothelial cells, HUAECs were exposed to H2O2 and transfected with the specific ABCG1 siRNA or ABCG1 overexpression plasmid. The results showed that overexpression of ABCG1 by ABCG1 plasmid or liver X receptor (LXR) agonist T0901317 treatment inhibited ROS production and MDA content induced by H2O2 in HUAECs. Furthermore, ABCG1 upregulation blunted the activity of prooxidant NADPH oxidase and the expression of Nox4, one of the NADPH oxidase subunits. Moreover, the increased migration of Nrf2 from the cytoplasm to the nucleus and antioxidant HO-1 expression were detected in HUAECs with upregulation of ABCG1. Conversely, ABCG1 downregulation by ABCG1 siRNA increased NADPH oxidase activity and Nox4 expression and abrogated the increase at Nrf2 nuclear protein levels. In addition, intracellular cholesterol load interfered with the balance between NADPH oxidase activity and HO-1 expression. It was suggested that ABCG1 attenuated oxidative stress induced by H2O2 in endothelial cells, which might be involved in the balance between decreased NADPH oxidase activity and increased Nrf2/OH-1 antioxidant defense signaling via its regulation for intracellular cholesterol accumulation.
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Gomes, Pedro, Sónia Simão, Elisabete Silva, Vanda Pinto, João S. Amaral, Joana Afonso, Maria Paula Serrão, Maria João Pinho, and Patrício Soares-da-Silva. "Aging increases Oxidative Stress and Renal Expression of Oxidant and Antioxidant Enzymes that Are Associated with an Increased Trend in Systolic Blood Pressure." Oxidative Medicine and Cellular Longevity 2, no. 3 (2009): 138–45. http://dx.doi.org/10.4161/oxim.2.3.8819.
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The aim of this study was to investigate whether the effects of aging on oxidative stress markers and expression of major oxidant and antioxidant enzymes associate with impairment of renal function and increases in blood pressure. To explore this, we determined age-associated changes in lipid peroxidation (urinary malondialdehyde), plasma and urinary hydrogen peroxide (H2O2) levels, as well as renal H2O2production, and the expression of oxidant and antioxidant enzymes in young (13 weeks) and old (52 weeks) male Wistar Kyoto (WKY) rats. Urinary lipid peroxidation levels and H2O2production by the renal cortex and medulla of old rats were higher than their young counterparts. This was accompanied by overexpression of NADPH oxidase components Nox4 and p22phoxin the renal cortex of old rats. Similarly, expression of superoxide dismutase (SOD) isoforms 2 and 3 and catalase were increased in the renal cortex from old rats. Renal function parameters (creatinine clearance and fractional excretion of sodium), diastolic blood pressure and heart rate were not affected by aging, although slight increases in systolic blood pressure were observed during this 52-week period. It is concluded that overexpression of renal Nox4 and p22phoxand the increases in renal H2O2levels in aged WKY does not associate with renal functional impairment or marked increases in blood pressure. It is hypothesized that lack of oxidative stress-associated effects in aged WKY rats may result from increases in antioxidant defenses that counteract the damaging effects of H2O2.
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Kim, Ha-Rim, and Seon-Young Kim. "Perilla frutescens Sprout Extract Protect Renal Mesangial Cell Dysfunction against High Glucose by Modulating AMPK and NADPH Oxidase Signaling." Nutrients 11, no. 2 (February 8, 2019): 356. http://dx.doi.org/10.3390/nu11020356.
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Perilla frutescens (L.) Britt. var. japonica (Hassk.) Hara (PF), is a medical herb of the Lamiaceae family. We have previously reported that the PF sprout extract (PFSE) is effective in treating hyperglycemia. However, the role of PFSE on glomerular mesangial cells (MCs) proliferation and the extracellular matrix (ECM) accumulation in a diabetic condition are still unclear. Therefore, in this study, we have investigated the role of PFSE on cell proliferation and ECM accumulation in murine glomerular MCs (MMCs), cultured under a high glucose (HG) condition. PFSE treatment attenuated HG-induced MMCs proliferation and hypertrophy. Moreover, the HG-induced ECM protein, collagen IV and fibronectin, overexpression was abolished by the PFFSE treatment. In addition, PFSE inhibited reactive oxygen species (ROS) overproduction and NOX2 and NOX4 expression in MMCs under a HG condition. Our data further revealed the involvement of mesangial cell damage in AMP-activated kinase (AMPK) activation. PFSE strongly activated AMPK in MMCs under hyperglycemic conditions. These results suggest that PFSE inhibits HG-medicated MC fibrosis through suppressing the activation of NOX2/4 and the AMPK activation mechanism. PFSE may be useful for the prevention or treatment of diabetic nephropathy.
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Cao, Xinran, Shiran Yu, Yuanyuan Wang, Min Yang, Jie Xiong, Haitao Yuan, and Bo Dong. "Effects of the (Pro)renin Receptor on Cardiac Remodeling and Function in a Rat Alcoholic Cardiomyopathy Model via the PRR-ERK1/2-NOX4 Pathway." Oxidative Medicine and Cellular Longevity 2019 (March 13, 2019): 1–13. http://dx.doi.org/10.1155/2019/4546975.
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Alcoholic cardiomyopathy (ACM) caused by alcohol consumption manifests mainly as by maladaptive myocardial function, which eventually leads to heart failure and causes serious public health problems. The (pro)renin receptor (PRR) is an important member of the local tissue renin-angiotensin system and plays a vital role in many cardiovascular diseases. However, the mechanism responsible for the effects of PRR on ACM remains unclear. The purpose of this study was to determine the role of PRR in myocardial fibrosis and the deterioration of cardiac function in alcoholic cardiomyopathy. Wistar rats were fed a liquid diet containing 9% v/v alcohol to establish an alcoholic cardiomyopathy model. Eight weeks later, rats were injected with 1×109v.g./100 μl of recombinant adenovirus containing EGFP (scramble-shRNA), PRR, and PRR-shRNA via the tail vein. Cardiac function was assessed by echocardiography. Cardiac histopathology was measured by Masson’s trichrome staining, immunohistochemical staining, and dihydroethidium staining. In addition, cardiac fibroblasts (CFs) were cultured to evaluate the effects of alcohol stimulation on the production of the extracellular matrix and their underlying mechanisms. Our results indicated that overexpression of PRR in rats with alcoholic cardiomyopathy exacerbates myocardial oxidative stress and myocardial fibrosis. Silencing of PRR expression with short hairpin RNA (shRNA) technology reversed the myocardial damage mediated by PRR. Additionally, PRR activated phosphorylation of ERK1/2 and increased NOX4-derived reactive oxygen species and collagen expression in CFs with alcohol stimulation. Administration of the ERK kinase inhibitor (PD98059) significantly reduced NOX4 protein expression and collagen production, which indicated that PRR increases collagen production primarily through the PRR-ERK1/2-NOX4 pathway in CFs. In conclusion, our study demonstrated that PRR induces myocardial fibrosis and deteriorates cardiac function through ROS from the PRR-ERK1/2-NOX4 pathway during ACM development.
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Huff, Lauren Parker, Daniel Seicho Kikuchi, Elizabeth Faidley, Steven J. Forrester, Michelle Z. Tsai, Bernard Lassègue, and Kathy K. Griendling. "Polymerase-δ-interacting protein 2 activates the RhoGEF epithelial cell transforming sequence 2 in vascular smooth muscle cells." American Journal of Physiology-Cell Physiology 316, no. 5 (May 1, 2019): C621—C631. http://dx.doi.org/10.1152/ajpcell.00208.2018.
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Polymerase-δ-interacting protein 2 (Poldip2) controls a wide variety of cellular functions and vascular pathologies. To mediate these effects, Poldip2 interacts with numerous proteins and generates reactive oxygen species via the enzyme NADPH oxidase 4 (Nox4). We have previously shown that Poldip2 can activate the Rho family GTPase RhoA, another signaling node within the cell. In this study, we aimed to better understand how Poldip2 activates Rho family GTPases and the functions of the involved proteins in vascular smooth muscle cells (VSMCs). RhoA is activated by guanine nucleotide exchange factors. Using nucleotide-free RhoA (isolated from bacteria) to pulldown active RhoGEFs, we found that the RhoGEF epithelial cell transforming sequence 2 (Ect2) is activated by Poldip2. Ect2 is a critical RhoGEF for Poldip2-mediated RhoA activation, because siRNA against Ect2 prevented Poldip2-mediated RhoA activity (measured by rhotekin pulldowns). Surprisingly, we were unable to detect a direct interaction between Poldip2 and Ect2, as they did not coimmunoprecipitate. Nox4 is not required for Poldip2-driven Ect2 activation, as Poldip2 overexpression induced Ect2 activation in Nox4 knockout VSMCs similar to wild-type cells. However, antioxidant treatment blocked Poldip2-induced Ect2 activation. This indicates a novel reactive oxygen species-driven mechanism by which Poldip2 regulates Rho family GTPases. Finally, we examined the function of these proteins in VSMCs, using siRNA against Poldip2 or Ect2 and determined that Poldip2 and Ect2 are both essential for vascular smooth muscle cell cytokinesis and proliferation.
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Chen, Yen-Hao, Hung-I. Lu, Chien-Ming Lo, Chang-Chun Hsiao, and Shau-Hsuan Li. "NOX4 overexpression is a poor prognostic factor in patients undergoing curative esophagectomy for esophageal squamous cell carcinoma." Surgery 167, no. 3 (March 2020): 620–27. http://dx.doi.org/10.1016/j.surg.2019.11.017.
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Friis, Martin Barfred, Katrine Gribel Vorum, and Ian Henry Lambert. "Volume-sensitive NADPH oxidase activity and taurine efflux in NIH3T3 mouse fibroblasts." American Journal of Physiology-Cell Physiology 294, no. 6 (June 2008): C1552—C1565. http://dx.doi.org/10.1152/ajpcell.00571.2007.
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Reactive oxygen species (ROS) are produced in NIH3T3 fibroblasts during hypotonic stress, and H2O2 potentiates the concomitant release of the organic osmolyte taurine (Lambert IH. J Membr Biol 192: 19–32, 2003). The increase in ROS production [5-(and-6)-carboxy-2′, 7′-dichlorodihydrofluorescein diacetate fluorescence] is detectable after a reduction in the extracellular osmolarity from 335 mosM (isotonic) to 300 mosM and reaches a maximal value after a reduction to 260 mosM. The swelling-induced ROS production is reduced by the flavoprotein inhibitor diphenylene iodonium chloride (25 μM) but is unaffected by the nitric oxide synthase inhibitor Nω-nitro-l-arginine methyl ester, indicating that the volume-sensitive ROS production is NADPH oxidase dependent. NIH3T3 cells express the NADPH oxidase components: p22phox, a NOX4 isotype; p47phox; and p67phox (real-time PCR). Exposure to the Ca2+-mobilizing agonist ATP (10 μM) potentiates the release of taurine but has no effect on ROS production under hypotonic conditions. On the other hand, addition of the protein kinase C (PKC) activator phorbol 12-myristate 13-acetate (PMA, 100 nM) or the lipid messenger lysophosphatidic acid (LPA, 10 nM) potentiates the swelling-induced taurine release as well as the ROS production. Overexpression of Rac1 or p47phox or p47phox knockdown [small interfering (si)RNA] had no effect on the swelling-induced ROS production or taurine release. NOX4 knockdown (siRNA) impairs the increase in the ROS production and the concomitant taurine release following osmotic exposure. It is suggested that a NOX4 isotype plus p22phox account for the swelling-induced increase in the ROS production in NIH3T3 cells and that the oxidase activity is potentiated by PKC and LPA but not by Ca2+.
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Wang, Dong, Shi-Ping Li, Jin-Sheng Fu, Sheng Zhang, Lin Bai, and Li Guo. "Resveratrol defends blood-brain barrier integrity in experimental autoimmune encephalomyelitis mice." Journal of Neurophysiology 116, no. 5 (November 1, 2016): 2173–79. http://dx.doi.org/10.1152/jn.00510.2016.
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The mouse autoimmune encephalomyelitis (EAE), an experimental model of multiple sclerosis (MS), is primarily characterized as dysfunction of the blood-brain barrier (BBB). Resveratrol exhibits anti-inflammatory, antioxidative, and neuroprotective activities. We investigated the beneficial effects of resveratrol in protecting the integrity of the BBB in EAE mice and observed improved clinical outcome in the EAE mice after resveratrol treatment. Evans blue (EB) extravasation was used to detect the disruption of BBB. Western blot were used to detected the tight junction proteins and adhesion molecules zonula occludens-1 (ZO-1), occludin, ICAM-1, and VCAM-1. Inflammatory factors inducible nitric oxide synthase (iNOS), IL-1β, and arginase 1 were evaluated by quantitative RT-PCR (qPCR) and IL-10 by ELISA. NADPH oxidase (NOX) levels were evaluated by qPCR, and its activity was analyzed by lucigenin-derived chemiluminescence. Resveratrol at doses of 25 and 50 mg/kg produced a dose-dependent decrease in EAE paralysis and EB leakage, ameliorated EAE-induced loss of tight junction proteins ZO-1, occludin, and claudin-5, as well as repressed the EAE-induced increase in adhesion proteins ICAM-1 and VCAM-1. In addition, resveratrol suppressed the EAE-induced overexpression of proinflammatory transcripts iNOS and IL-1β and upregulated the expression of anti-inflammatory transcripts arginase 1 and IL-10 cytokine in the brain. Furthermore, resveratrol downregulated the overexpressed NOX2 and NOX4 in the brain and suppressed NADPH activity. Resveratrol ameliorates the clinical severity of MS through maintaining the BBB integrity in EAE mice.
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Kim, Hyun Jik, Chang-Hoon Kim, Ji-Hwan Ryu, Jung Hee Joo, Sang-Nam Lee, Min-Ji Kim, Jeung-Gweon Lee, Yun Soo Bae, and Joo-Heon Yoon. "Crosstalk between platelet-derived growth factor-induced Nox4 activation and MUC8 gene overexpression in human airway epithelial cells." Free Radical Biology and Medicine 50, no. 9 (May 2011): 1039–52. http://dx.doi.org/10.1016/j.freeradbiomed.2011.01.014.
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Alves, Renata, Camila Liyoko Suehiro, Flavia Garcia de Oliveira, Eliete Dalla Corte Frantz, Renata Frauches de Medeiros, Rodolfo de Paula Vieira, Milton de Arruda Martins, Chin Jia Lin, Antonio Claudio Lucas da Nobrega, and Alessandra Choqueta de Toledo-Arruda. "Aerobic exercise modulates cardiac NAD(P)H oxidase and the NRF2/KEAP1 pathway in a mouse model of chronic fructose consumption." Journal of Applied Physiology 128, no. 1 (January 1, 2020): 59–69. http://dx.doi.org/10.1152/japplphysiol.00201.2019.
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The present study investigated the effects of exercise on the cardiac nuclear factor (erythroid-derived 2) factor 2 (NRF2)/Kelch-like ECH-associated protein 1 (KEAP1) pathway in an experimental model of chronic fructose consumption. Male C57BL/6 mice were assigned to Control, Fructose (20% fructose in drinking water), Exercise (treadmill exercise at moderate intensity), and Fructose + Exercise groups ( n = 10). After 12 wk, the energy intake and body weight in the groups were similar. Maximum exercise testing, resting energy expenditure, resting oxygen consumption, and carbon dioxide production increased in the exercise groups (Exercise and Fructose + Exercise vs. Control and Fructose groups, P < 0.05). Chronic fructose intake induced circulating hypercholesterolemia, hypertriglyceridemia, and hyperleptinemia and increased white adipose tissue depots, with no changes in blood pressure. This metabolic environment increased circulating IL-6, IL-1β, IL-10, cardiac hypertrophy, and cardiac NF-κB-p65 and TNF-α expression, which were reduced by exercise ( P < 0.05). Cardiac ANG II type 1 receptor and NAD(P)H oxidase 2 (NOX2) were increased by fructose intake and exercise decreased this response ( P < 0.05). Exercise increased the cardiac expression of the NRF2-to-KEAP1 ratio and phase II antioxidants in fructose-fed mice ( P < 0.05). NOX4, glutathione reductase, and catalase protein expression were similar between the groups. These findings suggest that exercise confers modulatory cardiac effects, improving antioxidant defenses through the NRF2/KEAP1 pathway and decreasing oxidative stress, representing a potential nonpharmacological approach to protect against fructose-induced cardiometabolic diseases. NEW & NOTEWORTHY This is the first study to evaluate the cardiac modulation of NAD(P)H oxidase (NOX), the NRF2/Kelch-like ECH-associated protein 1 pathway (KEAP), and the thioredoxin (TRX1) system through exercise in the presence of moderate fructose intake. We demonstrated a novel mechanism by which exercise improves cardiac antioxidant defenses in an experimental model of chronic fructose intake, which involves NRF2-to-KEAP1 ratio modulation, enhancing the local phase II antioxidants hemoxygenase-1, thioredoxin reductase (TXNRD1), and peroxiredoxin1B (PDRX1), and inhibiting cardiac NOX2 overexpression.
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Dou, Fangfang, Beiling Wu, Lin Sun, Jiulin Chen, Te Liu, Zhihua Yu, and Chuan Chen. "Identification of a novel regulatory pathway for PPARα by RNA-seq characterization of the endothelial cell lipid peroxidative injury transcriptome." Open Biology 9, no. 12 (December 2019): 190141. http://dx.doi.org/10.1098/rsob.190141.
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Endothelial dysfunction caused by endothelial cell injuries is the initiating factor for atherosclerosis (AS), and lipid peroxidative injury is one of a dominant factor for AS pathogenesis. Using RNA-seq, we compared changes in transcriptome expression before and after endothelial cell injury, and found 311 differentially expressed genes (DEGs), of which 258 genes were upregulated and 53 genes were downregulated. The protein–protein interactions (PPIs) between the genes were analysed using the STRING database, and a PPI network of DEGs was constructed. The relationship distributions among these PPIs were analysed by performing network node statistics. We found that in the top 20 DEGs with high connected protein nodes in the PPI network, 16 were upregulated and 4 were downregulated. Gene ontology (GO) functional enrichment analysis and KEGG pathway enrichment analysis on the DEGs were also performed. By comparing the upregulated expressed genes with high connected protein nodes in the PPI network to those related to endothelial cell lipid damage and repair in the GO analysis, we identified seven genes (NOX4, PPARA, CCL2, PDGFB, IL8, VWF, CD36) and verified their expression levels by real-time polymerase chain reaction. The protein interactions between the seven genes were then analysed using the STRING database. The results predicted that CCL2 interacts with NOX4, PPARα, PDGFβ and VWF individually. Thus, we examined the protein expression levels of CCL2, NOX4, PPARα, PDGFβ and VWF, and found that the expression levels of all proteins were significantly upregulated after the lipid peroxidative injury, with CCL2 and PPARα exhibiting the highest expression levels. Therefore, we investigated the interregulatory relationship between CCL2 and PPARα and their roles in the repair of endothelial cell injury. With the help of gene overexpression and knockdown techniques, we discovered that PPARα promotes the repair of endothelial cell injury by upregulating CCL2 expression in human umbilical vein endothelial cells but that CCL2 cannot regulate PPARα expression. Therefore, we believe that PPARα participates in the repair of endothelial cell lipid peroxidative injury through regulating the expression of CCL2.
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Bai, Yangqiu, Jinying Liu, Xiaoke Jiang, Xiuling Li, Bingyong Zhang, and Xiaoying Luo. "Nucleophagic Degradation of Progerin Ameliorates Defenestration in Liver Sinusoidal Endothelium Due to SIRT1-Mediated Deacetylation of Nuclear LC3." Cells 11, no. 23 (December 3, 2022): 3918. http://dx.doi.org/10.3390/cells11233918.
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Progerin, a permanently farnesylated prelamin A protein in cell nuclei, is potentially implicated in the defenestration of liver sinusoidal endothelial cells (LSECs) and liver fibrogenesis. Autophagy regulates the degradation of nuclear components, called nucleophagy, in response to damage. However, little is known about the role of nucleophagy in LSEC defenestration. Herein, we aim to dissect the underlying mechanism of progerin and nucleophagy in LSEC phenotype. We found an abnormal accumulation of progerin and a loss of SIRT1 in the nucleus of intrahepatic cells in human fibrotic liver tissue. In vivo, nuclear progerin abnormally accumulated in defenestrated LSECs, along with a depletion of SIRT1 and Cav-1 during liver fibrogenesis, whereas these effects were reversed by the overexpression of SIRT1 with the adenovirus vector. In vitro, H2O2 induced the excessive accumulation of progeirn, with the depletion of Lamin B1 and Cav-1 to aggravate LSEC defenestration. NAC and mito-TEMPO, classical antioxidants, inhibited NOX2- and NOX4-dependent oxidative stress to improve the depletion of Lamin B1 and Cav-1 and promoted progerin-related nucleophagy, leading to a reverse in H2O2-induced LSEC defenestration. However, rapamycin aggravated the H2O2-induced depletion of Lamin B1 and Cav-1 due to excessive autophagy, despite promoting progerin nucleophagic degradation. In addition, overexpressing SIRT1 with the adenovirus vector inhibited oxidative stress to rescue the production of Lamin B1 and Cav-1. Moreover, the SIRT1-mediated deacetylation of nuclear LC3 promoted progerin nucleophagic degradation and subsequently inhibited the degradation of Lamin B1 and Cav-1, as well as improved F-actin remodeling, contributing to maintaining LSEC fenestrae. Hence, our findings indicate a new strategy for reversing LSEC defenestration by promoting progerin clearance via the SIRT1-mediated deacetylation of nuclear LC3.
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Adesina, Sherry E., Brandy E. Wade, Kaiser M. Bijli, Bum-Yong Kang, Clintoria R. Williams, Jing Ma, Young-Mi Go, C. Michael Hart, and Roy L. Sutliff. "Hypoxia inhibits expression and function of mitochondrial thioredoxin 2 to promote pulmonary hypertension." American Journal of Physiology-Lung Cellular and Molecular Physiology 312, no. 5 (May 1, 2017): L599—L608. http://dx.doi.org/10.1152/ajplung.00258.2016.
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Pulmonary hypertension (PH) is characterized by increased pulmonary vascular resistance, pulmonary vascular remodeling, and increased pulmonary vascular pressures that often result in right ventricular dysfunction, leading to right heart failure. Evidence suggests that reactive oxygen species (ROS) contribute to PH pathogenesis by altering pulmonary vascular cell proliferation and intracellular signaling pathways. However, the role of mitochondrial antioxidants and oxidant-derived stress signaling in the development of hypoxia-induced PH is largely unknown. Therefore, we examined the role of the major mitochondrial redox regulator thioredoxin 2 (Trx2). Levels of Trx2 mRNA and protein were examined in human pulmonary arterial endothelial cells (HPAECs) and smooth muscle cells (HPASMCs) exposed to hypoxia, a common stimulus for PH, for 72 h. Hypoxia decreased Trx2 mRNA and protein levels. In vitro overexpression of Trx2 reduced hypoxia-induced H2O2 production. The effects of increased Trx2 protein level were examined in transgenic mice expressing human Trx2 (TghTrx2) that were exposed to hypoxia (10% O2) for 3 wk. TghTrx2 mice exposed to hypoxia had exacerbated increases in right ventricular systolic pressures, right ventricular hypertrophy, and increased ROS in the lung tissue. Trx2 overexpression did not attenuate hypoxia-induced increases in Trx2 oxidation or Nox4 expression. Expression of a dominant negative C93S Trx2 mutant that mimics Trx2 oxidation exacerbated hypoxia-induced increases in HPASMC H2O2 levels and cell proliferation. In conclusion, Trx2 overexpression failed to attenuate hypoxia-induced HPASMC proliferation in vitro or hypoxia-induced PH in vivo. These findings indicate that strategies to enhance Trx2 expression are unlikely to exert therapeutic effects in PH pathogenesis.
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Gu, Yanting, Yuewen Gong, Haojun Zhang, Xi Dong, Tingting Zhao, Frank J. Burczynski, Guqi Wang, et al. "Regulation of transforming growth factor beta 1 gene expression by dihydropteridine reductase in kidney 293T cells." Biochemistry and Cell Biology 91, no. 3 (June 2013): 187–93. http://dx.doi.org/10.1139/bcb-2012-0087.
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Quinoid dihydropteridine reductase (QDPR) is an enzyme involved in the metabolic pathway of tetrahydrobiopterin (BH4). BH4 is an essential cofactor of nitric oxide synthase (NOS) and can catalyze arginine to citrulline to release nitric oxide. Point mutations of QDPR have been found in the renal cortex of spontaneous Otsuka Long Evans Tokushima Fatty (OLETF) diabetic rats. However, the role of QDPR in DN is not clear. This study investigates the effects of QDPR overexpression and knockdown on gene expression in the kidney. Rat QDPR cDNA was cloned into pcDNA3.1 vector and transfected in human kidney cells (293T). The expression of NOS, transforming growth factor beta 1 (TGF-β1), Smad3, and NADPH oxidase were examined by RT–PCR and Western blot analyses. BH4 was assayed by using ELISA. Expression of QDPR was significantly decreased and TGF-β1 and Smad3 were increased in the renal cortex of diabetic rats. Transfection of QDPR into 293T cells increased the abundance of QDPR in cytoplasm and significantly reduced the expression of TGF-β1, Smad3, and the NADPH oxidases NOX1 and NOX4. Moreover, abundance of neuronal NOS (nNOS) mRNA and BH4 content were significantly increased. Furthermore, inhibition of QDPR resulted in a significant increase in TGF-β1 expression. In conclusion, QDPR might be an important factor mediating diabetic nephropathy through its regulation of TGF-β1/Smad3 signaling and NADPH oxidase.