Academic literature on the topic 'Ay Murine Model'

SummaryDiabetic nephropathy, a major complication of diabetes mellitus that leads to mortality, has been shown to involve a dysregulation of the coagulation system. Annexin-2, a co-receptor for plasminogen and tissue plasminogen activator on endothelial cells, is one of the molecules required to maintain the antithrombogenic properties of endothelial cells. Previously, we showed that recombinant annexin-2 protein (rAN II) modulated impaired fibrinolytic activity in the carotid arteries of rats. In the present study, to investigate its protective effects against diabetic nephropathy, rAN II was administered to KK-Ay mice, a murine model of type 2 diabetes, for eight weeks, and albuminuria, kidney size, and histological glomerular lesions were investigated. The mean weight of kidneys from KK-Ay mice treated with rAN II was significantly less than that of those treated with PBS (control) (p<0.02). Furthermore, the level of albuminuria observed in rAN II-treated KK-Ay mice was significantly less than that of the control group (rAN II, 0.90+/-0.12 µg/day; PBS, 1.55+/-0.31 µg/day; p<0.01); also, the area of diffuse glomerular lesions was significantly smaller (rAN II, 41.51+/-4.54%; PBS, 81.81+/-8.10%; p<0.01). Bleeding time, prothrombin time (PT), and active partial thromboplastin time (APTT) did not significantly differ between the two groups. Our results suggest that rAN II may inhibit the progression of diabetic nephropathy in KK-Ay mice without influencing the coagulation system, indicating that annexin-2 may be considered as a possible new therapeutic tool for patients with diabetic nephropathy.

Abstract To identify genes involved in the central regulation of energy balance, we compared hypothalamic mRNA from lean and obese Psammomys obesus, a polygenic model of obesity, using differential display PCR. One mRNA transcript was observed to be elevated in obese, and obese diabetic, P. obesus compared with lean animals and was subsequently found to be increased 4-fold in the hypothalamus of lethal yellow agouti (Ay/a) mice, a murine model of obesity and diabetes. Intracerebroventricular infusion of antisense oligonucleotide targeted to this transcript selectively suppressed its hypothalamic mRNA levels and resulted in loss of body weight in both P. obesus and Sprague Dawley rats. Reductions in body weight were mediated by profoundly reduced food intake without a concomitant reduction in metabolic rate. Yeast two-hybrid screening, and confirmation in mammalian cells by bioluminescence resonance energy transfer analysis, demonstrated that the protein it encodes interacts with endophilins, mediators of synaptic vesicle recycling and receptor endocytosis in the brain. We therefore named this transcript Src homology 3-domain growth factor receptor-bound 2-like (endophilin) interacting protein 1 (SGIP1). SGIP1 encodes a large proline-rich protein that is expressed predominantly in the brain and is highly conserved between species. Together these data suggest that SGIP1 is an important and novel member of the group of neuronal molecules required for the regulation of energy homeostasis.

Antidiabetic effects ofMorinda citrifolia(aka Noni) fermented byCheonggukjang(fast-fermented soybean paste) were evaluated using a T2DM (type 2 diabetes mellitus) murine model. Six-week-old KK-Ay/TaJcl mice were randomly divided into four groups: (1) the diabetic control (DC) group, provided with a normal mouse diet; (2) the positive control (PC) group, provided with a functional health food diet; (3) theM. citrifolia(MC) group, provided with an MC-based diet; (4) the fermentedM. citrifolia(FMC) group, provided with an FMC-based diet. Over a testing period of 90 days, food and water intake decreased significantly in the FMC and PC groups compared with the DC group. Blood glucose levels in the FMC group were 211.60–252.20 mg/dL after 90 days, while those in the control group were over 400 mg/dL after 20 days. In addition, FMC supplementation reduced glycosylated hemoglobin (HbA1c) levels, enhanced insulin sensitivity, and significantly decreased serum triglycerides and low-density lipoprotein (LDL) cholesterol. Furthermore, a fermentedM. citrifolia70% ethanolic extract (FMCE) activated peroxisome proliferator-activated receptor-(PPAR-)γand stimulated glucose uptake via stimulation of AMP-activated protein kinase (AMPK) in cultured C2C12 cells. These results suggest that FMC can be employed as a functional health food for T2DM management.

Abstract The Acute Myeloid Leukemia (AML) subtype characterised by translocations of the Mixed-Lineage Leukemia gene, MLL (t11q23; MLL-AML), is a particularly devastating disease with a median overall survival of only 9 months with current standard therapy. Cyclin dependent kinase (CDK) 9 inhibitors (CDK9i) directly target the CDK9/cyclin T complex (pTEFb) that is essential for activity of the MLL-fusion proteins and for transcriptional elongation, and therefore leads to reduction of transcript levels for multiple key leukemic oncogenes e.g. HOXA9, MYC and MCL1. Several observations suggest that utilising CDK9i to simultaneously target these oncogenes will be an effective strategy for AML, and MLL-AML in particular: (i) Leukemic stem cell (LSC) fractions of AML cells express a high level of MCL1, (ii) Targeting MCL1 has been demonstrated to reduce leukaemia cell survival in a murine model of MLL-ENL, (iii) MCL1 is consistently elevated in AML patients at relapse, (iv) HOXA9 is critical for leukemogenesis in many AMLs, in particular MLL-AML, (v) MYC has been shown to be a critical oncogene in MLL-AML, and (vi) CDK9 function has been shown to be important for MYC-driven tumorigenesis. Our in vitro and in vivo data support the clinical potential of a novel orally bioavailable inhibitor of CDK9, CDKI-73, as an effective therapy for MLL-AML patients. CDKI-73 is a potent inhibitor of CDK9 (Ki 3.5nM)1 and has been shown to induce down-regulation of MCL1, and cell death of Chronic Lymphocytic Leukemia (CLL) B-cells2 and Ovarian Cancer (OvCa) cells3 with nanomolar potency. At doses that are highly toxic for tumour cells, CDKI-73 shows limited toxicity for normal T- and B- Lymphocytes, Bone Marrow Mononuclear cells (BMMNC) and normal colony forming cells (CFC) from the BMMNC fraction. CDKI-73 has many favorable properties also making it an excellent clinical candidate for AML when compared to other CDK9i; in particular, CDKI-73 is (i) unique in its spectrum of inhibition, including targeting CDK6 (IC50 = 0.038 µM; a critical kinase for MLL-AML4), and is (ii) orally bioavailable (F = 56%)2, facilitating sustained in vivo target inhibition. Here we present data showing that in MLL-AML cell lines, CDKI-73 induces growth suppression and apoptosis associated with rapid loss of Myc and MCL1, and activation of PARP. In primary AML patient samples treated with 200nM CDKI-73, we have observed a similar decrease in MCL1 protein levels, with increased 7AAD uptake and Annexin-V staining, consistent with apoptotic cell death. Using a subcutaneous MV4;11 nude mouse xenograft model, we have shown that oral dosing of CDKI-73 (100 mg/kg once every 3 days for 18 days) resulted in a high level of anti-tumour efficacy (p<0.0001 compared to vehicle-treated mice), with minimal toxicity. Moreover, for an established MLL-AML patient-derived xenograft (PDX) generated in NOD/SCID-IL2RG-/- (NSG) mice we also observed significant inhibition of human AML in peripheral blood (p<0.0001), BM (p<0.05) and spleen (p<0.001) with administration of CDKI-73 at 75 mg/kg every 3 days for 15 days. In both models CDKI-73 was well-tolerated at these doses, consistent with our published and preliminary data showing differential effects of CDKI-73 on tumour versus normal cell populations. Given this data, our priority now is to establish the effectiveness of CDKI-73 across a larger panel of primary MLL-AML samples, in further patient derived AML xenografts, and as a combination treatment with AML chemotherapy. REFERENCES: 1. Shao H, Shi S, et al. (2013). J Med Chem. 56(3):640-59. 2. Walsby E, Pratt G, et al. (2014). Oncotarget. 5(2):375-85. 3. Lam F, Abbas AY, et al. (2014). Oncotarget. 5(17):7691-704. 4. Placke T, Faber K, et al. (2014). Blood. 124(1):13-23. Disclosures No relevant conflicts of interest to declare.

The nuclear hormone receptor farnesoid X receptor (FXR) plays a critical role in the regulation of bile acid, triglyceride (TG), and cholesterol homeostasis. WAY-362450 (FXR-450/XL335) is a potent synthetic FXR agonist as characterized in luciferase reporter assays and in mediating FXR target gene regulation in primary human and immortalized mouse hepatocytes. In vivo, WAY-362450 dose dependently decreased serum TG levels after 7 days of oral dosing in western diet-fed low-density lipoprotein receptor−/− mice and in the diabetic mouse strains KK-Ay and db/db comparable to that achieved with the peroxisome proliferator activated receptor-α agonist, fenofibrate. WAY-362450 treatment also reduced serum cholesterol levels via reductions in LDLc, VLDLc, and HDLc lipoprotein fractions that were not accompanied by hepatic cholesterol accumulation. This cholesterol lowering was dependent on FXR as demonstrated in a hypothyroid-induced hypercholesterolemia setting in FXR−/− mice. In fructose-fed models, WAY-362450 also decreased TG and VLDLc levels in rats and hamsters but significantly increased HDLc levels in rats while reducing HDLc levels in hamsters. The differential effect of WAY-362450 on HDLc is likely due to a murine-specific induction of endothelial lipase and scavenger receptor-BI that does not occur in rats. These studies demonstrate a consistent ability of WAY-362450 to lower both serum TG and cholesterol levels and suggest that synthetic FXR agonists may have clinical utility in the treatment of mixed dyslipidemia.

BackgroundThe clinical success of PD-1- and CTLA-4- immune checkpoint inhibitors highlights the key contribution of immunosuppression to limiting effective anti-tumor responses. However, as many patients do not respond to anti-PD1 or CTLA4 therapy1-3 novel therapeutics that target additional immune-suppressive mechanisms are needed. Regulatory T cells (Tregs) inhibit immune responses in the tumor microenvironment via multiple suppressive mechanisms.4 5 Existing Treg-targeting agents lack specificity for intratumoral Tregs and can also deplete effector cells, a property that has likely contributed to the lack of clinical activity observed to date. CCR8 (C-C chemokine receptor 8) is selectively expressed on highly activated intratumoral Tregs, its high expression correlates with poor prognosis in multiple human tumor types6 7 and depletion of CCR8+ Tregs in preclinical models elicited potent anti-tumor activity. These observations provided rationale for the development of a CCR8-specific human depleting antibody.MethodsHuman FOXP3 and CCR8 expression was correlated across multiple tumor types using TCGA datasets and expression of CCR8 evaluated in primary tumor explants and PBMCs by flow cytometry. The efficacy of anti-CCR8 antibody treatment was evaluated in the MC38 and CT26 murine tumor models. The depletion of Tregs following anti-CCR8 treatment was assessed by flow cytometry. Flow cytometric-based binding assays were performed using cell lines expressing human or cynomolgus CCR8. Purified human NK cells were co-cultured with CCR8+ target cells and flow cytometry used to evaluate antibody-dependent killing activity.ResultsCCR8 expression was highly correlated with FoxP3 across multiple cancer subtypes and was low to absent on effector T cells. Importantly, CCR8 was not detected on any peripheral human leukocyte subset. In murine tumor models, anti-CCR8 antibody treatment reduced tumor growth in a dose- and Fc-gamma-receptor-dependent manner and resulted in complete regressions and the development of memory. Tumor shrinkage was associated with a reduction in intratumoral Tregs and increased representation of intratumoral CD8 T cells. FPA157 is a highly specific human and cynomolgus crossreactive CCR8 antibody that does not bind closely related chemokine receptors. FPA157 was engineered to enhance antibody-dependent cell-mediated cytotoxicity (eADCC) and elicited potent NK-mediated killing of target cells expressing CCR8 at levels observed on human intratumoralTregs.ConclusionsFPA157 is a CCR8-specific monoclonal antibody with eADCC activity that is being developed for the treatment of cancer. Depletion of CCR8+ Tregs induced substantial anti-tumor activity in pre-clinical models, thus supporting the clinical evaluation of FPA157 as a novel approach to alleviate immune suppression in the microenvironment of human solid tumors.ReferencesHellmann MD, Ciuleanu TE, Pluzanski A, Lee JS, Otterson GA, Audigier-Valette C, Minenza E, Linardou H, Burgers S, Salman P, Borghaei H, Ramalingam SS, Brahmer J, Reck M, O’Byrne KJ, Geese WJ, Green G, Chang H, Szustakowski J, Bhagavatheeswaran P, Healey D, Fu Y, Nathan F, Paz-Ares L. Nivolumab plus Ipilimumab in lung cancer with a high tumor mutational burden. 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