Journal articles: 'THF and THP synthesis'

1

Tejo, Ciputra, Yang Feng Anders See, Mitch Mathiew, and Philip Wai Hong Chan. "Synthesis of 1,4-amino alcohols by Grignard reagent addition to THF and N-tosyliminobenzyliodinane." Organic & Biomolecular Chemistry 14, no. 3 (2016): 844–48. http://dx.doi.org/10.1039/c5ob02302e.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Tsukigawa, Kenji, Shuhei Imoto, Keishi Yamasaki, Koji Nishi, Toshihiko Tsutsumi, Shoko Yokoyama, Yu Ishima, and Masaki Otagiri. "Synthesis and In Vitro Assessment of pH-Sensitive Human Serum Albumin Conjugates of Pirarubicin." Pharmaceuticals 14, no. 1 (December 30, 2020): 22. http://dx.doi.org/10.3390/ph14010022.

Full text

Abstract:

In a previous study, we reported on the development of a synthetic polymer conjugate of pirarubicin (THP) that was formed via an acid-labile hydrazone bond between the polymer and the THP. However, the synthetic polymer itself was non-biodegradable, which could lead to unexpected adverse effects. Human serum albumin (HSA), which has a high biocompatibility and good biodegradability, is also a potent carrier for delivering antitumor drugs. The objective of this study was to develop pH-sensitive HSA conjugates of THP (HSA-THP), and investigate the release of THP and the cytotoxicity under acidic conditions in vitro for further clinical development. HSA-THP was synthesized by conjugating maleimide hydrazone derivatives of THP with poly-thiolated HSA using 2-iminothiolane, via a thiol-maleimide coupling reaction. We synthesized two types of HSA-THP that contained different amounts of THP (HSA-THP2 and HSA-THP4). Free THP was released from both of the HSA conjugates more rapidly at an acidic pH, and the rates of release for HSA-THP2 and HSA-THP4 were similar. Moreover, both HSA-THPs exhibited a higher cytotoxicity at acidic pH than at neutral pH, which is consistent with the effective liberation of free THP under acidic conditions. These findings suggest that these types of HSA-THPs are promising candidates for further development.

APA, Harvard, Vancouver, ISO, and other styles

3

Floresta, Giuseppe, George P. Keeling, Siham Memdouh, Levente K. Meszaros, Rafael T. M. de Rosales, and Vincenzo Abbate. "NHS-Functionalized THP Derivative for Efficient Synthesis of Kit-Based Precursors for 68Ga Labeled PET Probes." Biomedicines 9, no. 4 (April 1, 2021): 367. http://dx.doi.org/10.3390/biomedicines9040367.

Full text

Abstract:

Hexadentate tris(3,4-hydroxypyridinone) ligands (THP) complex Fe3+ at very low iron concentrations and their high affinities for oxophilic trivalent metal ions have led to their development for new applications as bifunctional chelators for the radiometal gallium-68 (68Ga). THP-peptide bioconjugates rapidly and quantitatively complex 68Ga at room temperature, neutral pH, and micromolar ligand concentrations, making them amenable to kit-based radiosynthesis of 68Ga PET radiopharmaceuticals. With the aim to produce an N-hydroxysuccinimide-(NHS)-THP reagent for kit-based 68Ga-labeling and PET imaging, THP-derivatives were designed and synthesized to exploit the advantages of NHS chemistry for coupling with peptides, proteins, and antibodies. The more stable five-carbon atoms linker product was selected for a proof-of-concept conjugation and radiolabeling study with an anti-programmed death ligand 1 (PD-L1) camelid single domain antibody (sdAb) under mild conditions and further evaluated for site-specific amide bond formation with a synthesized glucagon-like peptide-1 (GLP-1) targeting peptide using solid-phase synthesis. The obtained THP-GLP-1 conjugate was tested for its 68Ga chelating ability, demonstrating to be a promising candidate for the detection and monitoring of GLP-1 aberrant malignancies. The obtained sdAb-THP conjugate was radiolabeled with 68Ga under mild conditions, providing sufficient labeling yields after 5 min, demonstrating that the novel NHS-THP bifunctional chelator can be widely used to easily conjugate the THP moiety to different targeting molecules (e.g., antibodies, anticalins, or peptides) under mild conditions, paving the way to the synthesis of different imaging probes with all the advantages of THP radiochemistry.

APA, Harvard, Vancouver, ISO, and other styles

4

Su, S. J., K. L. Chang, T. M. Lin, Y. H. Huang, and T. M. Yeh. "Uromodulin and Tamm-Horsfall protein induce human monocytes to secrete TNF and express tissue factor." Journal of Immunology 158, no. 7 (April 1, 1997): 3449–56. http://dx.doi.org/10.4049/jimmunol.158.7.3449.

Full text

Abstract:

Abstract Effects of uromodulin (URO) and Tamm-Horsfall protein (THP), the most abundant proteins in the urine of pregnant and normal women, respectively, on the induction of TNF-alpha secretion and tissue factor (TF) expression of human monocytes were studied. THP, URO, and its fragments stimulated human mononuclear cells to proliferate and secrete TNF-alpha. The release of URO and THP-induced TNF-alpha in monocytes was dependent upon protein tyrosine kinase activation that results in tyrosine phosphorylation. URO and THP also induced TF expression of human monocytes and monocytic cell line U937 in a dose-dependent manner. TF expression was transient, reached its peak at 6 h and declined toward basal levels by 24 h. Reverse transcriptase-PCR and dot-blot analysis confirmed the induction of TF mRNA synthesis. URO and THP-induced TF expression were inhibited by actinomycin D and pentoxifylline further supporting the requirement of de novo TF mRNA synthesis. The possibility of LPS contamination of URO and THP was excluded because: 1) URO and THP-induced TF expression were inhibited by specific Ab; 2) URO was less capable of inducing TF in HUVEC as compared with LPS; 3) polymyxin B blocked the induction of Limulus clotting by LPS but not by URO and THP; 4) both LPS-sensitive (C3H/HeN) and -resistant (C3H/HeJ) mice produced little or no TNF-alpha after URO challenge. Therefore, our findings suggest that URO and THP play a significant role in the innate immunity of the urinary system and that the immunostimulatory activity of URO is potentially useful for immunotherapy.

APA, Harvard, Vancouver, ISO, and other styles

5

Kawai, Nobuyuki, Yuhei Fujikura, Jun Takita, and Jun'ichi Uenishi. "Stereoselective synthesis of contiguous THF–THF and THF–THP units via PdII-catalyzed tandem reaction with 1,3-chirality transfer." Tetrahedron 69, no. 51 (December 2013): 11017–24. http://dx.doi.org/10.1016/j.tet.2013.09.067.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Mallavadhani, Uppuluri V., Banita Pattnaik, Nitasha Suri, and Ajit K. Saxena. "Novel C-ring Analogs of Ursolic acid: Synthesis and Cytotoxic Evaluation." Natural Product Communications 9, no. 12 (December 2014): 1934578X1400901. http://dx.doi.org/10.1177/1934578x1400901206.

Full text

Abstract:

Ursolic acid (1), a natural pentacyclic triterpenic acid, afforded a variety of ring-C transformed products (5–11) when treated with N-bromosuccinimide under the influence of a range of protective groups and solvents. The synthesized compounds have been evaluated for cytotoxic activity against prostate PC 3, leukemia THP 1, cervical Hela and lung A-549 cancer cell lines. Among the tested analogs, compounds 5, 8, 9 and 10 showed potent activity against PC 3, THP 1 and Hela cell lines. Especially, compound 10 showed enhanced activity against the Hela cell line than the parent compound. Compounds 5, 8 and 9 showed comparable activities against PC 3 and THP 1 cell lines.

APA, Harvard, Vancouver, ISO, and other styles

7

Nasir, Nadiah Mad, Kristaps Ermanis, and Paul A. Clarke. "Strategies for the construction of tetrahydropyran rings in the synthesis of natural products." Org. Biomol. Chem. 12, no. 21 (2014): 3323–35. http://dx.doi.org/10.1039/c4ob00423j.

Full text

APA, Harvard, Vancouver, ISO, and other styles

8

Tajbakhsh, Mahmood, Iraj Mohammadpoor-Baltork, and Farhad Ramzanian-Lehmali. "Benzyltriphenylphosphonium Peroxodisulfate: A Mild and Inexpensive Reagent for Selective Oxidative Deprotection of Trimethylsilyl and Tetrahydropyranyl Ethers, Ethylene Acetals and Ketals under Non-Aqueous and Aprotic Conditions." Journal of Chemical Research 2001, no. 5 (May 2001): 185–87. http://dx.doi.org/10.3184/030823401103169577.

Full text

Abstract:

Benzyltriphenylphosphonium peroxodisulfate has been found to be an effective reagent for the oxidative deprotection of trimethylsilyl (TMS) and tetrahydropyranyl (THP) ethers, ethylene acetals and ketals to their corresponding carbonyl compounds in excellent yields. Selective oxidative deprotection of TMS ethers in the presence of THP ethers and ethylene acetals (ketals) makes this method a useful and practical procedure in organic synthesis.

APA, Harvard, Vancouver, ISO, and other styles

9

Spurr, Ian, and Richard C. Brown. "Total Synthesis of Annonaceous Acetogenins Belonging to the Non-Adjacent Bis-THF and Non-Adjacent THF-THP Sub-Classes." Molecules 15, no. 1 (January 21, 2010): 460–501. http://dx.doi.org/10.3390/molecules15010460.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Kawai, Nobuyuki, Yuhei Fujikura, Jun Takita, and Jun'ichi Uenishi. "ChemInform Abstract: Stereoselective Synthesis of Contiguous THF-THF and THF-THP Units via PdII-Catalyzed Tandem Reaction with 1,3-Chirality Transfer." ChemInform 45, no. 22 (May 15, 2014): no. http://dx.doi.org/10.1002/chin.201422114.

Full text

APA, Harvard, Vancouver, ISO, and other styles

11

Yadav, J. S., U. V. Subba Reddy, and B. V. Subba Reddy. "Stereoselective synthesis of tetrahydropyran–tetrahydrofuran (THP–THF) core of (+)-muconin via Prins cyclization." Tetrahedron Letters 55, no. 29 (July 2014): 3860–63. http://dx.doi.org/10.1016/j.tetlet.2014.02.096.

Full text

APA, Harvard, Vancouver, ISO, and other styles

12

Harkat, Hassina, Jean-Marc Weibel, and Patrick Pale. "Synthesis of functionalized THF and THP through Au-catalyzed cyclization of acetylenic alcohols." Tetrahedron Letters 48, no. 8 (February 2007): 1439–42. http://dx.doi.org/10.1016/j.tetlet.2006.12.100.

Full text

APA, Harvard, Vancouver, ISO, and other styles

13

Spurr, Ian B., and Richard C. D. Brown. "ChemInform Abstract: Total Synthesis of Annonaceous Acetogenins Belonging to the Non-Adjacent bis-THF and Non-Adjacent THF-THP Subclasses." ChemInform 41, no. 22 (June 1, 2010): no. http://dx.doi.org/10.1002/chin.201022204.

Full text

APA, Harvard, Vancouver, ISO, and other styles

14

Cindrić, Marina, Alen Bjelopetrović, Gordana Pavlović, Vladimir Damjanović, Jasna Lovrić, Dubravka Matković-Čalogović, and Višnja Vrdoljak. "Copper(ii) complexes with benzhydrazone-related ligands: synthesis, structural studies and cytotoxicity assay." New Journal of Chemistry 41, no. 6 (2017): 2425–35. http://dx.doi.org/10.1039/c6nj03827a.

Full text

Abstract:

The present study reports the synthesis and characterization of copper(ii) complexes with benzhydrazone-related ligands. They were screened for their cytotoxic activityin vitroin THP-1 and HepG2 human cancer cell lines.

APA, Harvard, Vancouver, ISO, and other styles

15

Schmidt, J. A., and E. Abdulla. "Down-regulation of IL-1 beta biosynthesis by inducers of the heat-shock response." Journal of Immunology 141, no. 6 (September 15, 1988): 2027–34. http://dx.doi.org/10.4049/jimmunol.141.6.2027.

Full text

Abstract:

Abstract The effect of heat on IL-1 beta biosynthesis was investigated in both THP-1 cells, a myelomonocytic cell line which can be induced to make IL-1 alpha and beta, and human peripheral blood adherent monocytes (PBMC). Induction of THP-1 cells with LPS at 39 to 41 degrees C for 2 to 4 h resulted in the expected increased synthesis of the heat-shock proteins hsp 70 and hsp 90 but decreased synthesis of the IL-1 beta precursor protein, p35 (and its mRNA), compared with control cells at 37 degrees C. This appeared to be a direct effect on p35 synthesis rather than a block in LPS induction because heat also acted on preinduced cells. PBMC similarly incubated for 4 h with LPS required a temperature of 41 to 42 degrees C to induce hsp and show a decrease in p35 synthesis. Chemical inducers of the heat-shock response (heavy metals, sulphydryl reagents) were also effective inhibitors of IL-1 beta biosynthesis. A correlation was seen between the extent of IL-1 beta reduction and the level of hsp induction by chemical inducers in both THP-1 cells and PBMC which suggests that the two responses are linked. In addition, a gold salt currently used for therapy of chronic inflammation, auranofin, induced hsp and inhibited IL-1 beta biosynthesis, whereas a second salt, sodium aurothiomalate, did neither. These results support the hypothesis that elevated temperature is one of the physiologic signals for down-regulation of IL-1 beta biosynthesis through a mechanism related to the induction of hsp.

APA, Harvard, Vancouver, ISO, and other styles

16

Hocek, Michal, and Antonín Holý. "A Facile Synthesis of 6-Cyanopurine Bases." Collection of Czechoslovak Chemical Communications 60, no. 8 (1995): 1386–89. http://dx.doi.org/10.1135/cccc19951386.

Full text

Abstract:

A facile method of preparation of 6-cyanopurine bases from commercially available 6-chloropurines is reported. The 6-chloropurines were selectively protected by THP-functions and the protected derivatives reacted smoothly with tetraethylammonium cyanide and DABCO to give 6-cyanopurine derivatives that were easily deprotected to afford the title compounds.

APA, Harvard, Vancouver, ISO, and other styles

17

Chaudhury, Aritra, and Balaram Mukhopadhyay. "Synthesis of the pentasaccharide repeating unit of the O-antigen from Enterobacter cloacae C4115 containing the rare α-d-FucNAc." RSC Advances 10, no. 9 (2020): 4942–48. http://dx.doi.org/10.1039/c9ra09807k.

Full text

Abstract:

Pentasaccharide repeating unit of the O-antigen of Enterobacter cloacae C4115 is accomplished through rational protecting group manipulations. For the synthesis of α-d-FucNAc, it was established that the methoxymethyl (MOM) group is advantageous over the earlier reported tetrahydro pyran (THP) protection.

APA, Harvard, Vancouver, ISO, and other styles

18

Vögeli, Isabelle, Hans H. Jung, Bernhard Dick, Sandra K. Erickson, Robert Escher, John W. Funder, Felix J. Frey, and Geneviève Escher. "Evidence for a role of sterol 27-hydroxylase in glucocorticoid metabolism in vivo." Journal of Endocrinology 219, no. 2 (November 2013): 119–29. http://dx.doi.org/10.1530/joe-13-0141.

Full text

Abstract:

The intracellular availability of glucocorticoids is regulated by the enzymes 11β-hydroxysteroid dehydrogenase 1 (HSD11B1) and 11β-hydroxysteroid dehydrogenase 2 (HSD11B2). The activity of HSD11B1 is measured in the urine based on the (tetrahydrocortisol+5α-tetrahydrocortisol)/tetrahydrocortisone ((THF+5α-THF)/THE) ratio in humans and the (tetrahydrocorticosterone+5α-tetrahydrocorticosterone)/tetrahydrodehydrocorticosterone ((THB+5α-THB)/THA) ratio in mice. The cortisol/cortisone (F/E) ratio in humans and the corticosterone/11-dehydrocorticosterone (B/A) ratio in mice are markers of the activity of HSD11B2.In vitroagonist treatment of liver X receptor (LXR) down-regulates the activity of HSD11B1. Sterol 27-hydroxylase (CYP27A1) catalyses the first step in the alternative pathway of bile acid synthesis by hydroxylating cholesterol to 27-hydroxycholesterol (27-OHC). Since 27-OHC is a natural ligand for LXR, we hypothesised thatCYP27A1deficiency may up-regulate the activity of HSD11B1. In a patient with cerebrotendinous xanthomatosis carrying a loss-of-function mutation inCYP27A1, the plasma concentrations of 27-OHC were dramatically reduced (3.8 vs 90–140 ng/ml in healthy controls) and the urinary ratios of (THF+5α-THF)/THE and F/E were increased, demonstrating enhanced HSD11B1 and diminished HSD11B2 activities. Similarly, inCyp27a1knockout (KO) mice, the plasma concentrations of 27-OHC were undetectable (<1 vs 25–120 ng/ml inCyp27a1WT mice). The urinary ratio of (THB+5α-THB)/THA was fourfold and that of B/A was twofold higher in KO mice than in their WT littermates. The (THB+5α-THB)/THA ratio was also significantly increased in the plasma, liver and kidney of KO mice. In the liver of these mice, the increase in the concentrations of active glucocorticoids was due to increased liver weight as a consequence ofCyp27a1deficiency.In vitro, 27-OHC acts as an inhibitor of the activity of HSD11B1. Our studies suggest that the expression of CYP27A1 modulates the concentrations of active glucocorticoids in both humans and mice andin vitro.

APA, Harvard, Vancouver, ISO, and other styles

19

Foster, Gregory H., Cassandra S. Armstrong, Ramesh Sakiri, and Vernon L. Tesh. "Shiga Toxin-Induced Tumor Necrosis Factor Alpha Expression: Requirement for Toxin Enzymatic Activity and Monocyte Protein Kinase C and Protein Tyrosine Kinases." Infection and Immunity 68, no. 9 (September 1, 2000): 5183–89. http://dx.doi.org/10.1128/iai.68.9.5183-5189.2000.

Full text

Abstract:

ABSTRACT Infections with Shiga toxin (Stx)-producing bacteria cause bloody diarrhea which may progress to life-threatening complications, including acute renal failure and neurological abnormalities. The precise mechanism of disease progression is unclear, although evidence suggests that the localized production of the host proinflammatory cytokines tumor necrosis factor alpha (TNF-α) and interleukin-1 may exacerbate toxin-mediated vascular damage. Purified Stxs have been demonstrated to elicit proinflammatory cytokine synthesis from human peripheral blood mononuclear cells and monocytic cell lines in vitro. To understand toxin-monocyte interactions required for cytokine synthesis, we have treated differentiated THP-1 cells with purified wild-type toxins, enzymatic mutants, or B subunits and measured TNF-α production. Our data suggest that A subunit enzymatic activity is essential for cytokine production. THP-1 cells were treated with a series of protein kinase C (PKC), PKA, and protein tyrosine kinase inhibitors to examine the role of intracellular signaling molecules in Stx-mediated cytokine production. Treatment of cells with PKC and tyrosine kinase inhibitors blocked TNF-α secretion by Stx-stimulated THP-1 cells. Stx treatment directly activated PKC, which occurred at a point upstream of transcriptional activation of the gene encoding TNF-α.

APA, Harvard, Vancouver, ISO, and other styles

20

Colden-Stanfield, Margaret, and Elaine K. Gallin. "Modulation of K+ currents in monocytes by VCAM-1 and E-selectin on activated human endothelium." American Journal of Physiology-Cell Physiology 275, no. 1 (July 1, 1998): C267—C277. http://dx.doi.org/10.1152/ajpcell.1998.275.1.c267.

Full text

Abstract:

Resting membrane potential (RMP) and whole cell currents were recorded in human THP-1 monocytes adherent to polystyrene, unstimulated human umbilical vein endothelial cells (HUVECs), lipopolysaccharide (LPS)-treated HUVECs, immobilized E-selectin, or vascular cell adhesion molecule 1 (VCAM-1) using the patch-clamp technique. RMP after 5 h on polystyrene was −24.3 ± 1.7 mV ( n = 42) with delayed rectifier K+( I dr) and Cl− currents ( I Cl) present in >75% of the cells. Inwardly rectifying K+ currents ( I ir) were present in only 14% of THP-1 cells. Adherence to unstimulated HUVECs or E-selectin for 5 h had no effect on I ir or I Cl but decreased I dr. Five hours after adherence to LPS-treated HUVECs, outward currents were unchanged, but I ir was present in 81% of THP-1 cells. A twofold increase in I ir and a hyperpolarization (−41.3 ± 3.7 mV, n = 16) were abolished by pretreatment of THP-1 cells with cycloheximide, a protein synthesis inhibitor, or herbimycin A, a tyrosine kinase inhibitor, or by pretreatment of the LPS-treated HUVECs with anti-VCAM-1. Only a brief (15-min) interaction between THP-1 cells and LPS-treated HUVECs was required to induce I irexpression 5 h later. THP-1 cells adherent to VCAM-1 exhibited similar conductances to cells adherent to LPS-treated HUVECs. Thus engagement of specific integrins results in selective modulation of different K+ conductances.

APA, Harvard, Vancouver, ISO, and other styles

21

Mahato, Manohar, Santosh Yadav, Pradeep Kumar, and Ashwani Kumar Sharma. "Synthesis and Evaluation of Tetramethylguanidinium-Polyethylenimine Polymers as Efficient Gene Delivery Vectors." BioMed Research International 2014 (2014): 1–11. http://dx.doi.org/10.1155/2014/459736.

Full text

Abstract:

Previously, we demonstrated that 6-(N,N,N′,N′-tetramethylguanidinium chloride)-hexanoyl-polyethylenimine (THP) polymers exhibited significantly enhanced transfection efficiency and cell viability. Here, in the present study, we have synthesized a series of N,N,N′,N′-tetramethylguanidinium-polyethylenimine (TP1-TP5) polymers via a single-step reaction involving peripheral primary amines of bPEI and varying amounts of 2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate (HBTU). These polymers were found to interact efficiently with negatively charged pDNA and formed stable complexes in the size range of ~240–450 nm. Acid-base titration profiles revealed improved buffering capacity of TP polymers as compared to bPEI. Transfection and cytotoxicity assays performed with TP/pDNA complexes on HEK293, CHO, and HeLa cells showed significantly higher transfection efficiency and cell viability with one of the complexes, TP2/pDNA complex, exhibited the highest transfection efficiency (~1.4–2.3-fold) outcompeting native bPEI and the commercially available transfection reagent, Lipofectamine 2000. Compared to previously reported THP polymers, the transfection efficiency of TP/pDNA complexes was found to be lower, as examined by flow cytometry. These results highlight the importance of the hydrophobic C-6 linker in THP polymers in forming compact nanostructures with pDNA, which might lead to efficient uptake and internalization of the complexes; however, the projected TP polymers offer an advantage of their rapid and economical one-step synthesis.

APA, Harvard, Vancouver, ISO, and other styles

22

PANG, Jong-Hwei S., Chia-Jung WU, and Lee-Young CHAU. "Post-transcriptional regulation of H-ferritin gene expression in human monocytic THP-1 cells by protein kinase C." Biochemical Journal 319, no. 1 (October 1, 1996): 185–89. http://dx.doi.org/10.1042/bj3190185.

Full text

Abstract:

The mRNA coding for H-ferritin was highly induced in human monocytic THP-1 cells following treatment with phorbol 12-myristate 13-acetate (PMA). The induction was detected at 3 h, reached maximal levels at 12 h, and was sustained for up to 48 h subsequent to PMA exposure. PMA-induced up-regulation of H-ferritin gene expression was also observed in other leukaemic cell lines, HL60 and U937, but not in non-leukaemic cell types, including human fibroblasts, endothelial cells and smooth muscle cells. The effect of PMA could be completely blocked by the protein kinase C inhibitor, H-7. Furthermore, treatment of THP-1 cells with bacterial phospholipase C also produced a marked increase in expression of H-ferritin mRNA, suggesting the activation of protein kinase C was responsible for the accumulation of mRNA. Nuclear run-off experiments demonstrated that PMA did not increase the transcriptional rate of the H-ferritin gene. In contrast, the half-life of the H-ferritin mRNA measured in the presence of actinomycin D was greatly prolonged in PMA-treated cells. The induction of H-ferritin mRNA by PMA required no protein synthesis. Conversely, treatment of THP-1 cells with protein synthesis inhibitor, cycloheximide, resulted in a 4–5-fold increase in H-ferritin mRNA. The increase in the stability of the H-ferritin mRNA was also observed in cells treated with cycloheximide. Taken together, these results suggest that the stability of H-ferritin mRNA in THP-1 is subjected to regulation via a protein kinase C-mediated phosphorylation on existing putative protein factor(s).

APA, Harvard, Vancouver, ISO, and other styles

23

Serio, Kenneth J., Colin Luo, Linda Luo, and Jenny T. Mao. "TNF-α downregulates the leukotriene C4 synthase gene in mononuclear phagocytes." American Journal of Physiology-Lung Cellular and Molecular Physiology 292, no. 1 (January 2007): L215—L222. http://dx.doi.org/10.1152/ajplung.00023.2006.

Full text

Abstract:

We studied the effect of tumor necrosis factor (TNF)-α exposure on cysteinyl leukotriene (LT) synthesis by cells of monocyte/macrophage lineage. TNF-α conditioning of monocytic THP-1 cells and primary human monocytes resulted in a decreased capacity for LTC4 release. TNF-α exposure (for 16–24 h) decreased LTC4 synthase mRNA in THP-1 cells, primary mouse bone marrow-derived macrophages, and eosinophilic AML14.3D10 cells. TNF-α downregulated LTC4 synthase mRNA in THP-1 cells in a dose- and time-dependent manner, with downregulation observed as early as 4 h. The effect of TNF-α on LTC4 synthase mRNA expression was mediated via the MEK/ERK pathway, but not via cyclooxygenase or nitric oxide synthase pathways. Conditioning of actinomycin D-treated cells with TNF-α did not accelerate degradation of LTC4 synthase mRNA. TNF-α produced sustained activation of p50 and p65, which were previously reported by our group to decrease LTC4 synthase promoter activity. In transiently transfected THP-1 cells, TNF-α decreased promoter activity via an element located within the first 620 bp of the promoter. We conclude that TNF-α exposure downregulates the synthetic capacity for cysteinyl LT release and LTC4 synthase gene expression in monocytes/macrophages via a transcriptional mechanism.

APA, Harvard, Vancouver, ISO, and other styles

24

Oda, Tomoyuki, Kiichi Hirota, Kenichiro Nishi, Satoshi Takabuchi, Seiko Oda, Hiroko Yamada, Toshiyuki Arai, et al. "Activation of hypoxia-inducible factor 1 during macrophage differentiation." American Journal of Physiology-Cell Physiology 291, no. 1 (July 2006): C104—C113. http://dx.doi.org/10.1152/ajpcell.00614.2005.

Full text

Abstract:

Monocytes/macrophages of the myeloid lineage are the main cellular effectors of innate immunity. Hypoxia-inducible factor 1 (HIF-1) is essential for myeloid cell activation in response to inflammatory stimuli. However, it has not been established whether HIF-1 activity is induced during differentiation from monocyte to macrophage. We demonstrate that macrophage differentiation of THP-1 cells or monocytes from peripheral blood induces increased expression of both HIF-1α and HIF-1β as well as increased HIF-1 transcriptional activity leading to increased expression of HIF-1 target genes. The increased HIF-1 activity in differentiated THP-1 cells resulted from the combined effect of increased HIF-1α mRNA levels and increased HIF-1α protein synthesis. Differentiation-induced HIF-1α protein and mRNA and HIF-1-dependent gene expression was blocked by treating cells with an inhibitor of the protein kinase C or MAP kinase signaling pathway. THP-1 cell differentiation was also associated with increased phosphorylation of the translational regulatory proteins p70 S6 kinase, S6 ribosomal protein, eukaryotic initiation factor 4E, and 4E binding protein 1, thus providing a possible mechanism for the modulation of HIF-1α protein synthesis. RNA interference studies demonstrated that HIF-1α is dispensable for macrophage differentiation but is required for functional maturation.

APA, Harvard, Vancouver, ISO, and other styles

25

Tang, Yaling, Xinglian Xu, Jiang Li, Lulu Deng, and Shuzhen Mu. "Synthesis and Antileukemia Activity Evaluation of Benzophenanthridine Alkaloid Derivatives." Molecules 27, no. 12 (June 19, 2022): 3934. http://dx.doi.org/10.3390/molecules27123934.

Full text

Abstract:

Thirty-three benzophenanthridine alkaloid derivatives (1a–1u and 2a–2l) were synthesized, and their cytotoxic activities against two leukemia cell lines (Jurkat Clone E6-1 and THP-1) were evaluated in vitro using a Cell Counting Kit-8 (CCK-8) assay. Nine of these derivatives (1i–l, 2a, and 2i–l) with IC50 values in the range of 0.18–7.94 μM showed significant inhibitory effects on the proliferation of both cancer cell lines. Analysis of the primary structure–activity relationships revealed that different substituent groups at the C-6 position might have an effect on the antileukemia activity of the corresponding compounds. In addition, the groups at the C-7 and C-8 positions could influence the antileukemia activity. Among these compounds, 2j showed the strongest in vitro antiproliferative activity against Jurkat Clone E6-1 and THP-1 cells with good IC50 values (0.52 ± 0.03 μM and 0.48 ± 0.03 μM, respectively), slightly induced apoptosis, and arrested the cell-cycle, all of which suggests that compound 2j may represent a potentially useful start point to undergo further optimization toward a lead compound.

APA, Harvard, Vancouver, ISO, and other styles

26

Weiss, Taly, Itamar Shalit, Hannah Blau, Sara Werber, Drora Halperin, Avital Levitov, and Ina Fabian. "Anti-Inflammatory Effects of Moxifloxacin on Activated Human Monocytic Cells: Inhibition of NF-κB and Mitogen-Activated Protein Kinase Activation and of Synthesis of Proinflammatory Cytokines." Antimicrobial Agents and Chemotherapy 48, no. 6 (June 2004): 1974–82. http://dx.doi.org/10.1128/aac.48.6.1974-1982.2004.

Full text

Abstract:

ABSTRACT We previously showed that moxifloxacin (MXF) exerts protective anti-inflammatory effects in immunosuppressed mice infected with Candida albicans by inhibiting interleukin-8 (IL-8) and tumor necrosis factor alpha (TNF-α) production in the lung. Immunohistochemistry demonstrated inhibition of nuclear factor (NF)-κB translocation in lung epithelium and macrophages in MXF-treated mice. In the present study we investigated the effects of MXF on the production of proinflammatory cytokines (i.e., IL-8, TNF-α, and IL-1β) by activated human peripheral blood monocytes and THP-1 cells and analyzed the effects of the drug on the major signal transduction pathways associated with inflammation: NF-κB and the mitogen-activated protein kinases ERK and c-Jun N-terminal kinase (JNK). The levels of IL-8, TNF-α, and IL-1β secretion rose 20- and 6.7-fold in lipopolysaccharide (LPS)-activated monocytes and THP-1 cells, respectively. MXF (5 to 20 μg/ml) significantly inhibited cytokine production by 14 to 80% and 15 to 73% in monocytes and THP-1 cells, respectively. In THP-1 cells, the level of NF-κB nuclear translocation increased fourfold following stimulation with LPS-phorbol myristate acetate (PMA), and this was inhibited (38%) by 10 μg of MXF per ml. We then assayed the degradation of inhibitor (I)-κB by Western blotting. LPS-PMA induced degradation of I-κB by 73%, while addition of MXF (5 μg/ml) inhibited I-κB degradation by 49%. Activation of ERK1/2 and the 46-kDa p-JNK protein was enhanced by LPS and LPS-PMA and was significantly inhibited by MXF (54 and 42%, respectively, with MXF at 10 μg/ml). We conclude that MXF suppresses the secretion of proinflammatory cytokines in human monocytes and THP-1 cells and that it exerts its anti-inflammatory effects in THP-1 cells by inhibiting NF-κB, ERK, and JNK activation. Its anti-inflammatory properties should be further assessed in clinical settings.

APA, Harvard, Vancouver, ISO, and other styles

27

Collado, Isidro, José Botubol-Ares, María Durán-Peña, James Hanson, and Rosario Hernández-Galán. "Cp2Ti(III)Cl and Analogues as Sustainable Templates in Organic Synthesis." Synthesis 50, no. 11 (May 3, 2018): 2163–80. http://dx.doi.org/10.1055/s-0036-1591986.

Full text

Abstract:

This short review aims to provide an overview of the use of Cp2Ti(III)Cl and other related titanocene(III) species as coordinating reagents in template reactions in the selective preparation of C–C and C–O bonds. These complexes are able to assemble two components to produce powerful reactions possessing high regio-, chemo-, diastereo-, and enantioselectivity. The titanocene templates are divided into five structural types. The chemical transformations by these valuable templates, the substrate scope and mechanistic insights will also be described.1 Introduction2 Precedents for the Coordination of Ti(III) Species to Heteroatoms2.1 Coordination of Compounds with Hydrogen–Heteroatom Bonds to Ti(III) Species2.2 Coordination of Halogens to Ti(III) Species3 Types of Titanocene Templates4 Template Type I Mediated Organic Reactions4.1 Methylenecyclopropanation of Allylic Alcohols4.2 Base-Free O-Acylation of Alcohols and Phenol4.3 Epoxidation of Allylic Alcohols5 Template Type II Mediated Organic Reactions5.1 Ketone–Nitrile Cross-Coupling Reactions5.2 Imine–Nitrile Cross-Coupling Reactions5.3 Reductive Alkylation of Enones with Activated Alkenes6 Template Type III Mediated Organic Reactions6.1 Pinacol Coupling of Ketones7 Template Type IV Mediated Organic Reactions7.1 Michael-Type Addition of Aldehydes to Conjugated Enals7.2 Allylation, Crotylation, and Prenylation7.3 Barbier-Type Progargylation and Allenylation8 Template Type V Mediated Organic Reactions8.1 Protection of Alcohols as 2-O-THF and 2-O-THP Ethers8.2 Pinacol Coupling of Aldehydes8.3 McMurry Couplings9 Conclusions and Perspectives

APA, Harvard, Vancouver, ISO, and other styles

28

Lv, Yaying, Qi Qu, Caiwen Li, and Tao Zhu. "Acrylamide-Modified 3-Aminopropyltriethoxysilanes Hybrid Monomer for Highly Selective Imprinting Recognition of Theophylline." Journal of Chromatographic Science 58, no. 1 (December 27, 2019): 75–82. http://dx.doi.org/10.1093/chromsci/bmz106.

Full text

Abstract:

Abstract The hybrid monomer synthesized with 3-aminopropyltriethoxysilanes and acrylamide was applied for synthesis of molecularly imprinting polymers, and the obtained polymers were used as sorbent in solid-phase extraction for purification of theophylline (THP) in green tea. The static adsorption curves showed better molecular recognition ability and binding capability of the polymers for the target. On the optimized condition, a method was developed for increasing extraction of THP with satisfactory recovery of 93.7%. Good calibration linearity obtained in a range of 5–500 μg·mL−1. The recoveries at three spiked levels ranged from 86.7% to 100.7% with relative standard deviations ≤6.6% (n = 3). The result showed that the obtained polymers exhibited highly selective imprinting recognition to the analyte, and the number of templates was an important factor affecting the selective recognition ability of polymers. The proposed method with hybrid monomer imprinting polymers was successfully applied for purification of THP in green tea.

APA, Harvard, Vancouver, ISO, and other styles

29

McKenzie, Jordan A., Reham F. Barghash, Azhaar T. Alsaggaf, Omkar Kulkarni, Kalun Boudreau, Frederic Menard, Edward G. Neeland, and Andis Klegeris. "Synthesis and Evaluation of Novel Pyrazole Ethandiamide Compounds as Inhibitors of Human THP-1 Monocytic Cell Neurotoxicity." Cells 8, no. 7 (June 29, 2019): 655. http://dx.doi.org/10.3390/cells8070655.

Full text

Abstract:

Neuroinflammation and microglia-mediated neurotoxicity contribute to the pathogenesis of a broad range of neurodegenerative diseases; therefore, identifying novel compounds that can suppress adverse activation of glia is an important goal. We have previously identified a class of trisubstituted pyrazoles that possess neuroprotective and anti-inflammatory properties. Here, we describe a second generation of pyrazole analogs that were designed to improve their neuroprotective activity toward neurons under inflammatory conditions. Pyrazolyl oxalamide derivatives were designed to explore the effects of steric and electronic factors. Three in vitro assays were performed to evaluate the compounds’ anti-neurotoxic, neuroprotective, and cytotoxic activity using human THP-1, PC-3, and SH-SY5Y cells. Five compounds significantly reduced the neurotoxic secretions from immune-stimulated microglia-like human THP-1 monocytic cells. One of these compounds was also found to protect SH-SY5Y neuronal cells when they were exposed to cytotoxic THP-1 cell supernatants. While one of the analogs was discarded due to its interference with the cell viability assay, most compounds were innocuous to the cultured cells at the concentrations used (1–100 μM). The new compounds reported herein provide a design template for the future development of lead candidates as novel inhibitors of neuroinflammation and neuroprotective drugs.

APA, Harvard, Vancouver, ISO, and other styles

30

Ramachandran, G., A. Raman, S. Easwaramoorthi, R. S. Rathore, and K. Sathiyanarayanan. "Four component domino reaction for the synthesis of highly functionalized dimeric tetracyclic dilactam fluorophores: H-bond aided self-assembly." RSC Adv. 4, no. 55 (2014): 29276–80. http://dx.doi.org/10.1039/c4ra03622k.

Full text

Abstract:

A series of new dimeric tetracyclic dilactam fluorophores (DTDF) consisting of diazabicyclooctane-dione (DBOD) fused to tetrahydronaphthalene (THP) was designed and synthesized from a simple precursor.

APA, Harvard, Vancouver, ISO, and other styles

31

Batista, Poliane K., João Marcos G. de O. Ferreira, Fabio P. L. Silva, Mario L. A. A. Vasconcellos, and Juliana A. Vale. "The Role Ionic Liquid [BMIM][PF6] in One-Pot Synthesis of Tetrahydropyran Rings through Tandem Barbier–Prins Reaction." Molecules 24, no. 11 (May 31, 2019): 2084. http://dx.doi.org/10.3390/molecules24112084.

Full text

Abstract:

Tetrahydropyran (THP) rings are common in several natural products, therefore, various strategies are being developed to synthesize these rings. The present work described the study of a one-pot synthesis of 2,4,6-trisubstituted tetrahydropyran compounds promoted by the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate [BMIM][PF6] through a Barbier–Prins reaction between allyl bromide and aldehydes. The use of [BMIM][PF6] gave Prins products from several aldehydes in good yields and reaction times. We also found that the anion, PF6-, accelerates the Barbier reaction when used alone, and the excess SnBr2 from the reaction conditions of the Barbier reaction leads to the formation of the THP rings, thus acting as a catalyst for Prins cyclization. Additionally, we demonstrate that ionic liquid can be recovered and reused five times in the preparation of 4-bromo-tetrahydro-2,6-diphenyl-2H-pyran without significant yield loss.

APA, Harvard, Vancouver, ISO, and other styles

32

Morita, Toshiko, Kuniaki Saito, Masao Takemura, Naoya Maekawa, Suwako Fujigaki, Hidehiko Fujii, Hisayasu Wada, Shoji Takeuchi, Akio Noma, and Mitsuru Seishima. "3-Hydroxyanthranilic acid, an L-tryptophan metabolite, induces apoptosis in monocyte-derived cells stimulated by interferon- γ." Annals of Clinical Biochemistry: International Journal of Laboratory Medicine 38, no. 3 (May 1, 2001): 242–51. http://dx.doi.org/10.1258/0004563011900461.

Full text

Abstract:

3-Hydroxyanthranilic acid (3-HAA), a metabolite of L-tryptophan, accumulates in monocyte-derived cells (THP-1),but not in other celllines tested(MRC9, H4, U373MG, Wil-NS), following immune stimulation that induces indoleamine 2,3-dioxygenase (IDO), a rate-limiting enzyme in the L-tryptophan-kynurenine pathway. We examined whether metabolites of the L-tryptophan-kynurenine pathway act to induce apoptosis in monocytes/macrophages. Of the L-tryptophan metabolites tested, only 3-HAA at a concentration of 200µmol/L was found to induce apoptosis in THP-1 and U937 cells. The addition of ferrous or manganese ions further enhanced apoptosis and free radical formation by 3-HAA in these two types of cells. The apoptotic response induced by 3-HAA was significantly attenuated by the addition of antioxidant, α-tocopherol or Trolox (a water-soluble analogue of vitamin E), and the xanthine oxidase inhibitor, allopurinol. In addition, the 3-HAA-induced apoptotic response was slightly attenuated by catalase, but not by superoxide dismutase (SOD), indicating that generation of hydrogen peroxide is involved in this response. Interferon-γ (IFN-γ), an inducer of IDO, potently induced apoptosis in THP-1 cells, but not in U937 cells, in the presence of ferrous or manganese ions. This different susceptibility to apoptosis inducer between THP-1 and U937 cells may depend on the capacity of the cells for 3-HAA synthesis following IDO induction by IFN-γ. Furthermore, apoptosis was suppressed by cycloheximide in THP-1 cells, suggesting that newly synthesized proteins may be essential for apoptotic events. These results suggest that 3-HAA induces apoptosis in monocytes/macrophages under inflammatory or other pathophysiological conditions.

APA, Harvard, Vancouver, ISO, and other styles

33

Ring, William L., Carl A. Riddick, Joseph R. Baker, Christopher K. Glass, and Timothy D. Bigby. "Activated lymphocytes increase expression of 5-lipoxygenase and its activating protein in THP-1 cells." American Journal of Physiology-Cell Physiology 273, no. 6 (December 1, 1997): C2057—C2064. http://dx.doi.org/10.1152/ajpcell.1997.273.6.c2057.

Full text

Abstract:

The aim of this study was to investigate the regulation of the 5-lipoxygenase pathway of arachidonic acid metabolism by lymphocytes using the monocyte-like cell line, THP-1. When THP-1 cells were incubated over 4–7 days in 10% supernatant from lectin-activated human lymphocytes, their capacity to synthesize 5-lipoxygenase products was significantly increased. In contrast, the supernatant from nonactivated lymphocytes had no effect. The increase in capacity to synthesize 5-lipoxygenase products was mimicked by the addition of either granulocyte macrophage colony-stimulating factor (GM-CSF) or interleukin-3. These increases in synthetic capacity reflected increased enzymatic activity. Increased immunoreactive protein and mRNA for the enzymes 5-lipoxygenase and 5-lipoxygenase-activating protein were also found in cells conditioned with activated lymphocyte supernatants. Furthermore, the increase in mRNA for both enzymes was not blocked by cycloheximide, suggesting that the effect on steady-state mRNA levels does not require the synthesis of new protein. The increase in mRNA could be reproduced by GM-CSF. We conclude that lymphocytes can regulate the expression of 5-lipoxygenase in THP-1 cells over a period of days via the release of soluble factors.

APA, Harvard, Vancouver, ISO, and other styles

34

He, Fang, Felix Umrath, Christiane von Ohle, Siegmar Reinert, and Dorothea Alexander. "Analysis of the Influence of Jaw Periosteal Cells on Macrophages Phenotype Using an Innovative Horizontal Coculture System." Biomedicines 9, no. 12 (November 24, 2021): 1753. http://dx.doi.org/10.3390/biomedicines9121753.

Full text

Abstract:

Jaw periosteum-derived mesenchymal stem cells (JPCs) represent a promising cell source for bone tissue engineering in oral and maxillofacial surgery due to their high osteogenic potential and good accessibility. Our previous work demonstrated that JPCs are able to regulate THP-1-derived macrophage polarization in a direct coculture model. In the present study, we used an innovative horizontal coculture system in order to understand the underlying paracrine effects of JPCs on macrophage phenotype polarization. Therefore, JPCs and THP-1-derived M1/M2 macrophages were cocultured in parallel chambers under the same conditions. After five days of horizontal coculture, flow cytometric, gene and protein expression analyses revealed inhibitory effects on costimulatory and proinflammatory molecules/factors as well as activating effects on anti-inflammatory factors in M1 macrophages, originating from multiple cytokines/chemokines released by untreated and osteogenically induced JPCs. A flow cytometric assessment of DNA synthesis reflected significantly decreased numbers of proliferating M1/M2 cells when cocultured with JPCs. In this study, we demonstrated that untreated and osteogenically induced JPCs are able to switch macrophage polarization from a classical M1 to an alternative M2-specific phenotype by paracrine secretion, and by inhibition of THP-1-derived M1/M2 macrophage proliferation.

APA, Harvard, Vancouver, ISO, and other styles

35

Pandur, Edina, Kitti Tamási, Ramóna Pap, Gergely Jánosa, and Katalin Sipos. "Modulatory Effects of Fractalkine on Inflammatory Response and Iron Metabolism of Lipopolysaccharide and Lipoteichoic Acid-Activated THP-1 Macrophages." International Journal of Molecular Sciences 23, no. 5 (February 27, 2022): 2629. http://dx.doi.org/10.3390/ijms23052629.

Full text

Abstract:

Fractalkine (CX3CL1) acts as a chemokine as well as a regulator of iron metabolism. Fractalkine binds CX3CR1, the fractalkine receptor on the surface of monocytes/macrophages regulating different intracellular signalling pathways such as mitogen-activated protein kinase (MAPK), phospholipase C (PLC) and NFκB contributing to the production of pro-inflammatory cytokine synthesis, and the regulation of cell growth, differentiation, proliferation and metabolism. In this study, we focused on the modulatory effects of fractalkine on the immune response and on the iron metabolism of Escherichia coli and Pseudomonas aeruginosa lipopolysaccharides (LPS) and Staphylococcus aureus lipoteichoic acid (LTA) activated THP-1 cells to get a deeper insight into the role of soluble fractalkine in the regulation of the innate immune system. Pro-inflammatory cytokine secretions of the fractalkine-treated, LPS/LTA-treated, and co-treated THP-1 cells were determined using ELISArray and ELISA measurements. We analysed the protein expression levels of signalling molecules regulated by CX3CR1 as well as hepcidin, the major iron regulatory hormone, the iron transporters, the iron storage proteins and mitochondrial iron utilization. The results showed that fractalkine treatment alone did not affect the pro-inflammatory cytokine secretion, but it was proposed to act as a regulator of the iron metabolism of THP-1 cells. In the case of two different LPS and one type of LTA with fractalkine co-treatments, fractalkine was able to alter the levels of signalling proteins (NFκB, PSTAT3, Nrf2/Keap-1) regulating the expression of pro-inflammatory cytokines as well as hepcidin, and the iron storage and utilization of the THP-1 cells.

APA, Harvard, Vancouver, ISO, and other styles

36

Yukimasa, Nobuyasu, Yuna Kanaoka, Misaki Okito, Wataru Oboshi, Shoichi Sato, Mirai Yamazaki, and Takehiro Nakamura. "Differences in Cytokine Gene Expression after a Stimulation with Escherichia Coli and Porphyromonas Gingivalis or Lipopolysaccharides Derived from these Bacteria." Journal of Life Sciences Research 7, no. 1 (August 21, 2020): 13–20. http://dx.doi.org/10.20448/journal.504.2020.71.13.20.

Full text

Abstract:

Monocytes are important cells in innate immunity. The early stage of the innate immunity is regulated by various cytokines produced by monocytes. We conducted a preliminary study to investigate TNFα expression by stimulating THP-1 cells with several bacterial species. The TNFα mRNA levels significantly varied, with the most potent stimulatory effects observed with P. gingivalis. In the present study, we focused on P. gingivalis and compared differences in cytokine expression profiles after the stimulation of THP-1 with E. coli. Bacterial antigen stimulation increased various cytokine gene expressions in THP-1. P. gingivalis had significantly more potent effects on the mRNA expressions of TNFα, IL-1β, and IL-10, but not of IL-12p40, than E. coli. This result suggests the potent ability of P. gingivalis to induce inflammation. THP-1 stimulated with LPS derived from both bacterial species showed that E. coli had significantly more potent effects on the expressions of TNFα, IL-1β, and IL-12p40 than P. gingivalis. The differences in the bacterial antigens and the LPS stimulation effects suggest involvements of different receptors, such as TLR-2 and -4, which recognize bacterial components. The present results suggest that the P. gingivalis somatic cell antigen stimulates a number of pattern recognition receptors at the same time as the synthesis of bacterial components, except LPS. The potent virulence of P. gingivalis and persistence of infection might be affected by differences in cytokine production. Pro-inflammatory responses are dependent not only on the bacterial type, but also bacterial components.

APA, Harvard, Vancouver, ISO, and other styles

37

Sanceau, J., J. Wijdenes, M. Revel, and J. Wietzerbin. "IL-6 and IL-6 receptor modulation by IFN-gamma and tumor necrosis factor-alpha in human monocytic cell line (THP-1). Priming effect of IFN-gamma." Journal of Immunology 147, no. 8 (October 15, 1991): 2630–37. http://dx.doi.org/10.4049/jimmunol.147.8.2630.

Full text

Abstract:

Abstract The present work is a detailed study of the mechanism of IFN-gamma- and TNF-alpha-triggered IL-6 secretion and IL-6 gene expression in human monocytic THP-1 cells and of the effect of these cytokines on the expression of IL-6 surface receptor and IL-6R gene. Although TNF-alpha was shown to stimulate IL-6 expression in fibroblasts in monocytic THP-1 cells, IFN-gamma is required for TNF to induce IL-6 expression. The results reported here demonstrate that combined treatment of THP-1 cells with IFN-gamma + TNF-alpha induced IL-6 mRNA expression, whereas no significant induction was obtained by either cytokine alone. Nuclear run-on transcription assay showed that the increased level of IL-6 mRNA induced by IFN-gamma + TNF-alpha was associated with induction of gene transcription. Sequential stimulation of THP-1 cells by IFN-gamma and subsequently by TNF-alpha did not allow IL-6 gene induction, suggesting that IFN-gamma and TNF-alpha induced or activated different signaling factors which should act together to trigger IL-6 gene transcription. IFN-gamma pretreatment followed by IFN-gamma + TNF-alpha restimulation led to superinduction of the IL-6 gene expression with a concomitant increase in IL-6-secreted activity. This priming effect of IFN-gamma is dependent on active protein synthesis. Biochemical characterization of IL-6 proteins secreted by THP-1 cells by Western blotting and affinity chromatography allowed identification of a major IL-6 molecular species of 42 kDa and a minor one of 23 kDa. Furthermore, we showed here that IFN-gamma increased the IL-6R mRNA level with a concomitant increase in IL-6-specific binding to surface receptors. On the contrary, treatment with IFN-gamma + TNF-alpha reduced the level of IL-6R mRNA and IL-6 binding to THP-1 cells probably due to a ligand-mediated effect. Taken together, results reported here provide evidence that functional interaction between IFN-gamma and TNF-alpha is involved in the regulation of IL-6 and IL-6R expression in monocytic cells. Control of IL-6 production and IL-6R expression may be one of the important homeostatic properties of IFN-gamma.

APA, Harvard, Vancouver, ISO, and other styles

38

WEISS, Günter, Ivo GRAZIADEI, Martina URBANEK, Kurt GRÜNEWALD, and Wolfgang VOGEL. "Divergent effects of α1-antitrypsin on the regulation of iron metabolism in human erythroleukaemic (K562) and myelomonocytic (THP-1) cells." Biochemical Journal 319, no. 3 (November 1, 1996): 897–902. http://dx.doi.org/10.1042/bj3190897.

Full text

Abstract:

The acute-phase protein α1-antitrypsin (α1-AT) has been shown to inhibit the binding of transferrin to its cell-surface receptor. Here we demonstrate that in human erythroleukaemic cells (K562) α1-AT enhances the binding affinity of iron-regulatory protein (IRP), the central regulator of cellular iron metabolism, to iron-responsive elements. Activation of IRP by α1-AT is associated with a marked increase in transferrin receptor (trf-rec) mRNA levels in K562 and enhanced cell-surface expression of transferrin-binding sites, whereas ferritin production is decreased, although ferritin mRNA levels remain unchanged. In agreement with the well-established mechanism of cellular iron regulation, α1-AT seems to modulate trf-rec and ferritin expression primarily post-transcriptionally/translationally by influencing IRP activity. In contrast, α1-AT produces only minor changes in IRP activity, and subsequently in trf-rec expression and ferritin synthesis in THP-1 cells. Moreover the effects of α1-AT on iron homeostasis in K562 cannot be overcome by the addition of iron salts, whereas concomitant treatment of THP-1 with iron and α1-AT results in the same metabolic changes as the addition of iron alone. Because α1-AT blocks transferrin binding on K562 as well as on THP-1 cells, it is suggested, on the basis of the results presented here, (1) that erythroid and monocytic cells might differ in their dependence on transferrin-mediated iron supply and (2) that THP-1 might be able to acquire iron by a transferrin-independent iron uptake system. α1-AT might therefore be involved in the diversion of iron traffic between various cellular compartments under inflammatory conditions.

APA, Harvard, Vancouver, ISO, and other styles

39

Wise, Lyn, Catherine McCaughan, Chee Keong Tan, Andrew A. Mercer, and Stephen B. Fleming. "Orf virus interleukin-10 inhibits cytokine synthesis in activated human THP-1 monocytes, but only partially impairs their proliferation." Journal of General Virology 88, no. 6 (June 1, 2007): 1677–82. http://dx.doi.org/10.1099/vir.0.82765-0.

Full text

Abstract:

The sheep parapoxvirus orf virus (ORFV) induces acute, pustular skin lesions in humans. ORFV encodes an orthologue of interleukin-10 (IL-10) that, whilst it closely resembles ovine IL-10 (91 % amino acid identity), shows only 75 % amino acid identity to human IL-10 (hIL-10). The anti-inflammatory potential of ORFV IL-10 in human ORFV infection was investigated by examining its immunosuppressive effects on THP-1 monocytes. ORFV IL-10 and hIL-10 were shown to have equivalent inhibitory effects on the synthesis of proinflammatory cytokines in lipopolysaccharide-activated monocytes, but differed in their abilities to inhibit monocyte proliferation. Structural modelling of ORFV IL-10 revealed differences from hIL-10 in residues predicted to interact with IL-10 co-receptor 2 (IL-10R2), whereas there were very few differences in the residues predicted to interact with IL-10R1. These findings suggest that the partial ability of ORFV IL-10 to inhibit THP-1 monocyte proliferation may be due to the absence of critical residues that mediate the interaction with human IL-10R2.

APA, Harvard, Vancouver, ISO, and other styles

40

Lee, Sang-Yun, Rama P. Cherla, and Vernon L. Tesh. "Simultaneous Induction of Apoptotic and Survival Signaling Pathways in Macrophage-Like THP-1 Cells by Shiga Toxin 1." Infection and Immunity 75, no. 3 (December 28, 2006): 1291–302. http://dx.doi.org/10.1128/iai.01700-06.

Full text

Abstract:

ABSTRACT Shiga toxins have been shown to induce apoptosis in many cell types. However, Shiga toxin 1 (Stx1) induced only limited apoptosis of macrophage-like THP-1 cells in vitro. The mechanisms regulating macrophage death or survival following toxin challenge are unknown. Differentiated THP-1 cells expressed tumor necrosis factor receptors and membrane-associated tumor necrosis factor alpha (TNF-α) and produced soluble TNF-α after exposure to Stx1. However, the cells were refractory to apoptosis induced by TNF-α, although the cytokine modestly increased apoptosis in the presence of Stx1. Despite the partial resistance of macrophage-like THP-1 cells to Stx1-mediated killing, treatment of these cells with Stx1 activated a broad array of caspases, disrupted the mitochondrial membrane potential (ΔΨm), and released cytochrome c into the cytoplasm. The ΔΨm values were greatest in cells that had detached from plastic surfaces. Specific caspase inhibitors revealed that caspase-3, caspase-6, caspase-8, and caspase-9 were primarily involved in apoptosis induction. The antiapoptotic factors involved in macrophage survival following toxin challenge include inhibitors of apoptosis proteins and X-linked inhibitor of apoptosis protein. NF-κB and JNK mitogen-activated protein kinases (MAPKs) appeared to activate survival pathways, while p38 MAPK was involved in proapoptotic signaling. The JNK and p38 MAPKs were shown to be upstream signaling pathways which may regulate caspase activation. Finally, the protein synthesis inhibitors Stx1 and anisomycin triggered limited apoptosis and prolonged JNK and p38 MAPK activation, while macrophage-like cells treated with cycloheximide remained viable and showed transient activation of MAPKs. Collectively, these data suggest that Stx1 activates both apoptotic and cell survival signaling pathways in macrophage-like THP-1 cells.

APA, Harvard, Vancouver, ISO, and other styles

41

Dellacasagrande, Jérôme, Eric Ghigo, Sarah Machergui-El, Hammami, Rudolf Toman, Didier Raoult, Christian Capo, and Jean-Louis Mege. "αvβ3 Integrin and Bacterial Lipopolysaccharide Are Involved in Coxiella burnetii-Stimulated Production of Tumor Necrosis Factor by Human Monocytes." Infection and Immunity 68, no. 10 (October 1, 2000): 5673–78. http://dx.doi.org/10.1128/iai.68.10.5673-5678.2000.

Full text

Abstract:

ABSTRACT Coxiella burnetii, the agent of Q fever, enters human monocytes through αvβ3 integrin and survives inside host cells. In addition, C. burnetiistimulates the synthesis of inflammatory cytokines including tumor necrosis factor (TNF) by monocytes. We studied the role of the interaction of C. burnetii with THP-1 monocytes in TNF production. TNF transcripts and TNF release reached maximum values within 4 h. Almost all monocytes bound C. burnetiiafter 4 h, while the percentage of phagocytosing monocytes did not exceed 20%. Cytochalasin D, which prevented the uptake of C. burnetii without interfering with its binding, did not affect the expression of TNF mRNA. Thus, bacterial adherence, but not phagocytosis, is necessary for TNF production by monocytes. The monocyte αvβ3 integrin was involved in TNF synthesis since peptides containing RGD sequences and blocking antibodies against αvβ3 integrin inhibited TNF transcripts induced by C. burnetii. Nevertheless, the cross-linking of αvβ3 integrin by specific antibodies was not sufficient to induce TNF synthesis. The signal delivered by C. burnetii was triggered by bacterial lipopolysaccharide (LPS). Polymyxin B inhibited the TNF production stimulated by C. burnetii, and soluble LPS isolated fromC. burnetii largely mimicked viable bacteria. On the other hand, avirulent variants of C. burnetii induced TNF production through an increased binding to monocytes rather than through the potency of their LPS. We suggest that the adherence ofC. burnetii to monocytes via αvβ3 integrin enables surface LPS to stimulate TNF production in THP-1 monocytes.

APA, Harvard, Vancouver, ISO, and other styles

42

Knight, E., and B. Cordova. "IFN-induced 15-kDa protein is released from human lymphocytes and monocytes." Journal of Immunology 146, no. 7 (April 1, 1991): 2280–84. http://dx.doi.org/10.4049/jimmunol.146.7.2280.

Full text

Abstract:

Abstract The enhancement or inhibition of synthesis of specific proteins by IFN is believed to cause subsequent IFN-induced biological responses. The roles of most of these proteins in the biological responses induced by the IFNs, for example, inhibition of virus replication and inhibition of cell growth, remain largely unknown. Our recent research has focused on the induction and synthesis of an IFN-induced 15-kDa protein. In this report we show that human lymphocytes and monocytes, after treatment with IFN-beta, release into the medium an IFN-induced 15-kDa protein. At 24 h after induction of the 15-kDa protein in lymphocytes or monocytes, more than 50% of the total 15-kDa protein is in the medium. The human monocytic cell line THP-1 also releases 15-kDa protein into the medium after its induction by IFN-beta. An intracellular half-life of 12 h has been calculated for the 15-kDa protein in monocytes and THP-1 cells. The exocellular release of the 15-kDa protein by lymphocytes and monocytes suggests that 1) it may have an intercellular signaling role and 2) it may be an in vivo mediator of some of the biological responses induced by IFN.

APA, Harvard, Vancouver, ISO, and other styles

43

Serio, Kenneth J., K. Veera Reddy, and Timothy D. Bigby. "Lipopolysaccharide induces 5-lipoxygenase-activating protein gene expression in THP-1 cells via a NF-κB and C/EBP-mediated mechanism." American Journal of Physiology-Cell Physiology 288, no. 5 (May 2005): C1125—C1133. http://dx.doi.org/10.1152/ajpcell.00296.2004.

Full text

Abstract:

We examined induced expression of the 5-lipoxygenase-activating protein (FLAP), which is critical for leukotriene synthesis in mononuclear phagocytes. Prolonged exposure to the bacterial component, lipopolysaccharide (LPS), increased FLAP gene transcription, mRNA expression, and protein expression in the human monocyte-like THP-1 cell line. Activation and inhibition of the NF-κB pathway modulated LPS induction of FLAP gene expression. An NF-κB-mediated mechanism of action was supported by overexpression of dominant-negative IκBα and p50/p65 proteins. EMSA/supershift and DNase I footprint analyses revealed that p50 binds to an NF-κB site located in the proximal FLAP promoter, while chromatin immunoprecipitation assays demonstrated that LPS induced binding of p50 but not of p65. Moreover, EMSA/supershift analyses demonstrated that LPS induced time-dependent binding of THP-1 nuclear extracts (containing p50) to this promoter region. Mutation of the NF-κB site decreased basal promoter activity and abolished the p50- and p65-associated induction. EMSA/supershift analyses also demonstrated that LPS induced binding of THP-1 nuclear extracts [containing CCAAT/enhancer binding protein (C/EBP)-α, -δ, and -ε] to a C/EBP site located adjacent to the NF-κB site in the FLAP promoter. We conclude that LPS enhances FLAP gene expression via both NF-κB- and C/EBP-mediated transcriptional mechanisms in mononuclear phagocytes.

APA, Harvard, Vancouver, ISO, and other styles

44

Aman, MJ, G. Rudolf, J. Goldschmitt, WE Aulitzky, C. Lam, C. Huber, and C. Peschel. "Type-I interferons are potent inhibitors of interleukin-8 production in hematopoietic and bone marrow stromal cells." Blood 82, no. 8 (October 15, 1993): 2371–78. http://dx.doi.org/10.1182/blood.v82.8.2371.2371.

Full text

Abstract:

Abstract nterleukin-8 (IL-8) is produced by many cell types upon stimulation with bacterial products or inflammation-associated cytokines such as tumor necrosis factor-alpha and IL-1. Interferons (IFNs) represent another group of cytokines that are induced by similar stimuli in inflammatory reactions. We show now that type-I IFNs are potent inhibitors of IL-8 expression in vitro and in vivo. A significant reduction of both secretion of IL-8 protein and accumulation of IL-8 mRNA in vitro was observed in several cell types comprising peripheral blood mononuclear cells (PBMNC) from healthy donors and from patients with chronic myelogenous leukemia (CML), the myelomonocytic cell line THP-1, and bone marrow (BM) stromal cells as a representative model for BM microenvironment. By contrast, in lipopolysaccharide-stimulated polymorphonuclear phagocytes IFN failed to suppress IL-8 expression. In untreated patients with CML, a constitutive expression of IL-8 mRNA was detected in freshly isolated PBMNC that was markedly reduced 5 hours after therapeutic application of IFN-alpha. The mechanism of IL-8 downregulation was studied more in detail in the THP-1 cell line. The experiments showed that de novo protein synthesis was not required for the inhibitory effect. RNA decay analysis and nuclear run-on assays suggest that in THP-1 cell line the inhibition of IL-8 expression is predominantly regulated at the posttranscriptional level.

APA, Harvard, Vancouver, ISO, and other styles

45

Aman, MJ, G. Rudolf, J. Goldschmitt, WE Aulitzky, C. Lam, C. Huber, and C. Peschel. "Type-I interferons are potent inhibitors of interleukin-8 production in hematopoietic and bone marrow stromal cells." Blood 82, no. 8 (October 15, 1993): 2371–78. http://dx.doi.org/10.1182/blood.v82.8.2371.bloodjournal8282371.

Full text

Abstract:

nterleukin-8 (IL-8) is produced by many cell types upon stimulation with bacterial products or inflammation-associated cytokines such as tumor necrosis factor-alpha and IL-1. Interferons (IFNs) represent another group of cytokines that are induced by similar stimuli in inflammatory reactions. We show now that type-I IFNs are potent inhibitors of IL-8 expression in vitro and in vivo. A significant reduction of both secretion of IL-8 protein and accumulation of IL-8 mRNA in vitro was observed in several cell types comprising peripheral blood mononuclear cells (PBMNC) from healthy donors and from patients with chronic myelogenous leukemia (CML), the myelomonocytic cell line THP-1, and bone marrow (BM) stromal cells as a representative model for BM microenvironment. By contrast, in lipopolysaccharide-stimulated polymorphonuclear phagocytes IFN failed to suppress IL-8 expression. In untreated patients with CML, a constitutive expression of IL-8 mRNA was detected in freshly isolated PBMNC that was markedly reduced 5 hours after therapeutic application of IFN-alpha. The mechanism of IL-8 downregulation was studied more in detail in the THP-1 cell line. The experiments showed that de novo protein synthesis was not required for the inhibitory effect. RNA decay analysis and nuclear run-on assays suggest that in THP-1 cell line the inhibition of IL-8 expression is predominantly regulated at the posttranscriptional level.

APA, Harvard, Vancouver, ISO, and other styles

46

Frenzel, Laurent, Noha Semaan, Ghada Alsaleh, Dominique Wachsmann, Jacques-Eric Gottenberg, and Jean Sibilia. "A new mode of TNF-[alpha] inhibition by microRNA (99.26)." Journal of Immunology 182, no. 1_Supplement (April 1, 2009): 99.26. http://dx.doi.org/10.4049/jimmunol.182.supp.99.26.

Full text

Abstract:

Abstract TNF-α, is a major cytokine implicated in rheumatoid arthritis (RA). TNF-α expression is regulated both at the transcriptional and the postranscriptional levels and recent data demonstrated that miRNAs are implicated in TNF-α response in macrophages. LPS-activated synoviocytes fibroblast-like (FLS) isolated from RA patients express TNF-α mRNA but they do not release TNF-α. This inhibition is due to a rapid degradation of TNF-α mRNA. We demonstrated previously that miR-346, which is overexpressed in LPS-activated FLS inhibits Bruton's tyrosine kinase (Btk) expression, which controls TNF-α stability. In fact, transfection of antisense oligonucleotides targeting miR-346 reestablished Btk and TNF-α expression in activated FLS. We also showed that transfection of miR-346 in THP-1 cells, inhibited TNF-α secretion in response to LPS. Tristetraprolin (TTP) is a protein which inhibited TNF-α synthesis by binding to AU rich elements of TNF-α mRNA. We demonstrated in LPS-activated RA FLS, that inhibition of miR-346 decreases TTP expression. In parallel we also showed that inhibition of Btk by LFMA13 or miR-346, increases the expression of TTP in LPS-activated THP-1 cells which results in inhibition of TNF-α synthesis. These results indicate that Btk controls TNF-α synthesis by regulating TTP expression. In conclusion, our findings provide evidence that miR-346 can act as a negative regulator of inflammation.

APA, Harvard, Vancouver, ISO, and other styles

47

Gheorghe, Gheorghe I., and Liliana Laura Badita. "Improving Tribological Characteristics of Hip Prostheses Using Biocompatible Nanocoatings." Advanced Materials Research 741 (August 2013): 67–72. http://dx.doi.org/10.4028/www.scientific.net/amr.741.67.

Full text

Abstract:

Total hip prosthesis (THP) is the most success of the 20th century in orthopaedic biomedical engineering. However due to difficult conditions within the human body its durability is generally limited to 15-16 years. THP is a bio-tribosystem, on which many mechanical, thermal, chemical and biological factors act. This paper presents the results of an analysis regarding the topography and tribological parameters of femoral heads structures before and after TiN coating. We report on the synthesis of TiN thin films on steel substrates by pulsed laser deposition (PLD) method for improving the mechanical characteristics of the structures. Adhesion resistance of the coating on the sub-layer was evaluated by scratching tests accompanied by Optical Microscopy (OM), Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM). As a principal result, this work points out that TiN protective coatings deposited by PLD technique with the maximum number of pulses can represent an alternative technology to ensure adhesion and scratch resistance of TiN coatings on femoral heads.

APA, Harvard, Vancouver, ISO, and other styles

48

Watanabe, Masatada, Shuji Ohno, and Hiroshi Wachi. "Effect of β-agonist on the dexamethasone-induced expression of aromatase by the human monocyte cells." Endocrine Connections 6, no. 2 (February 2017): 82–88. http://dx.doi.org/10.1530/ec-16-0099.

Full text

Abstract:

Emerging evidence suggests that sex steroids are important for human skin health. In particular, estrogen improves skin thickness, elasticity and moisture of older women. The major source of circulating estrogen is the ovary; however, local estrogen synthesis and secretion have important roles in, for example, bone metabolism and breast cancer development. We hypothesized that infiltrated peripheral monocytes are one of the sources of estrogen in skin tissues. We also hypothesized that, during atopic dermatitis under stress, a decline in the hypothalamus–pituitary–adrenal axis (HPA) and facilitation of the (hypothalamus)–sympathetic–adrenomedullary system (SAM) attenuates estrogen secretion from monocytes. Based on this hypothesis, we tested aromatase expression in the human peripheral monocyte-derived cell line THP-1 in response to the synthetic glucocorticoid dexamethasone (Dex), the synthetic β-agonist isoproterenol (Iso) and the β-antagonist propranolol (Pro). Dex mimics glucocorticoid secreted during excitation of the HPA, and Iso mimics catecholamine secreted during excitation of the SAM. We found that aromatase activity and the CYP19A1 gene transcript were both upregulated in THP-1 cells in the presence of Dex. Addition of Iso induced their downregulation and further addition of Pro rescued aromatase expression. These results may suggest that attenuation of estrogen secretion from peripheral monocytes could be a part of the pathology of stress-caused deterioration of atopic dermatitis. Further examination using an in vitro human skin model including THP-1 cells might be a valuable tool for investigating the therapeutic efficacy and mechanism of estrogen treatment for skin health.

APA, Harvard, Vancouver, ISO, and other styles

49

Budakoti, Asha, Pradip Kumar Mondal, Prachi Verma, and Jagadish Khamrai. "Prins cyclization-mediated stereoselective synthesis of tetrahydropyrans and dihydropyrans: an inspection of twenty years." Beilstein Journal of Organic Chemistry 17 (April 29, 2021): 932–63. http://dx.doi.org/10.3762/bjoc.17.77.

Full text

Abstract:

Functionalized tetrahydropyran (THP) rings are important building blocks and ubiquitous scaffolds in many natural products and active pharmaceutical ingredients (API). Among various established methods, the Prins reaction has emerged as a powerful technique in the stereoselective synthesis of the tetrahydropyran skeleton with various substituents, and the strategy has further been successfully applied in the total synthesis of bioactive macrocycles and related natural products. In this context, hundreds of valuable contributions have already been made in this area, and the present review is intended to provide the systematic assortment of diverse Prins cyclization strategies, covering the literature reports of the last twenty years (from 2000 to 2019), with an aim to give an overview on exciting advancements in this area and designing new strategies for the total synthesis of related natural products.

APA, Harvard, Vancouver, ISO, and other styles

50

MENSHIKOV, Mikhail, Eugenia ELIZAROVA, Karina PLAKIDA, Angelika TIMOFEEVA, Georgy KHASPEKOV, Robert BEABEALASHVILLI, Alex BOBIK, and Vsevolod TKACHUK. "Urokinase upregulates matrix metalloproteinase-9 expression in THP-1 monocytes via gene transcription and protein synthesis." Biochemical Journal 367, no. 3 (November 1, 2002): 833–39. http://dx.doi.org/10.1042/bj20020663.

Full text

Abstract:

Urokinase-type plasminogen activator (uPA) is suggested to exert its proliferatory, migratory and invasive action through binding with its membrane receptor, promoting pericellular proteolysis and mediating cell signal transduction. One of the possible actions of urokinase can be related to the regulation of activity and/or the expression of proteolytic enzymes participating in extracellular matrix degradation. In the present study, the role of uPA in regulating matrix metalloproteinase (MMP) expression and release by the monocyte cell line THP-1 was investigated. Recombinant uPA induced the release of MMP9/gelatinase B, as detected by zymography and Western blotting, and this release was abolished by actinomycin D and cycloheximide (inhibitors of DNA transcription and protein synthesis) and partially suppressed by monensin (an inhibitor of secretion). Proteolytically inactive urokinase with substitution of His204 for Gln was able to reproduce about 70% of the effect induced by the wild-type recombinant uPA. The reverse transcription-PCR and Northern blot data indicated that the action of r-uPA on THP-1 cells resulted in formation of MMP9 mRNA, which depended on time, within 6—48h, of the cell incubation with r-uPA. These results suggest that urokinase upregulates MMP9 expression in monocytes via MMP9 gene transcription and protein biosynthesis.

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'THF and THP synthesis'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles