Project description:Murine pancreatic beta cell line MIN6 was growth at two different concentrations of glucose (22,2 and 5,5 mM of glucose), 37ºC, 5% CO2 and was treated at four different concentrations of human amylin (0, 1, 10 and 20 uM) during three different times (2, 12 and 24 hours) Keywords = pancreatic beta cell Keywords = amylin Keywords = glucose Keywords: time-course
Project description:Murine pancreatic beta cell line MIN6 was growth at two different concentrations of glucose (22,2 and 5,5 mM of glucose), 37ºC, 5% CO2 and was treated at four different concentrations of human amylin (0, 1, 10 and 20 uM) during three different times (2, 12 and 24 hours)
Project description:In this study, we investigated the molecular and cellular mechanisms of verapamil treatment on β-cell function and survival using MIN6 cells. Verapamil's molecular processes were studied using transcriptomic data. MTT, cell count, and flow cytometry assessed cell proliferation, growth, and cycle. MIN6 cell function was assessed by glucose-stimulated insulin release and total insulin content. Seahorse and metabolic stress kits examined metabolic activity and oxygen consumption rate. The protective impact of verapamil on MIN6 cells was evaluated by challenging the verapamil treated cell with streptozotocin, T1D-cytomix, or T2D-cytomix cocktail. Our results demonstrate that verapamil treatment induced higher proliferation of MIN6 cells, altered expression of various proteins and genes, improved insulin secretion in hyperglycemic conditions, increased basal and maximal respiration levels, along with β-cell survival against streptozotocin, T1D-, or T2D-cytomix-induced toxicity, and rendered a protective effect.
Project description:There is a need for greater understanding of the molecular mechanism underlying the development of insulin resistance in type 2 diabetes, and new models in which to study this. The hormone amylin is postulated to be involved in the development of this disease, as human amylin (hA) forms amyloid in the pancreases of diabetic patients, and wild-type hA oligomers have been shown to be cytotoxic to β-cells. By contrast, rodent amylin is non-amyloidogenic, so mice expressing wild-type hA have been developed. However, amylin-evoked β-cell loss in these models limits the secretion of amylin and insulin. We have developed transgenic mice that overexpress [25, 28, 29triprolyl]human amylin, a non-amyloidogenic variant of amylin, designated the Line 44 (L44) model. These mice develop obesity and hyperglycaemia. We examined the expression of 43 genes involved in amylin, insulin and leptin signalling in the brain of this model, at different disease stages, using the NanoString nCounter (NanoString Technologies, Seattle, WA, USA). After onset of diabetes, mice remained hyperglycaemic for a period of time but blood glucose levels eventually returned to normoglycaemia. The incidence of diabetes (defined as having blood glucose measurements > 11 mM over 3 consecutive weeks) was gene-dose dependent; 81% of homozygous mice and 59% of hemizygous mice developed diabetes over 400 days. A proportion of nontransgenic mice (33%) also developed diabetes. As these were bred from hemizygous pairs this may be the result of epigenetic or environmental factors.
Project description:Glucose-stimulated insulin secretion (GSIS) is suppressed through α-adrenergic receptor stimulation by catecholamines, epinephrine and norepinephrine, in pancreatic β-cells. Previous work has elucidated a bevy of adrenergic regulatory mechanisms beyond traditional Gi-coupled signaling including regulation of ion channels and interactions with exocytotic machinery. Glucose oxidation may also be an important site for adrenergic regulation of GSIS, but the link between epinephrine and glucose oxidation in β-cells is undefined. Here, we evaluate whether adrenergic stimulation decreases oxidative metabolism in β cells. Oxygen consumption rates were determined for Min6 and isolated rat islets in 20mM glucose complete media, then epinephrine was added at either 0 nM (vehicle control) or 100nM, followed by 10uM yohimbine (a selective Adrα2A antagonist). To identify glucose oxidation as the primary metabolic pathway affected by epinephrine, oxidation of 14C(U)-labeled glucose was determined in Min6 cells with epinephrine or vehicle. Oxygen consumption and glucose oxidation experiments were conducted in the presence of cAMP and insulin secretion blockers, respectively. Proteomics was performed on Min6 cells exposed to epinephrine for 4 hours and compared to controls. Epinephrine, but not vehicle, reduced (P<0.01) oxygen consumption rates in rat islets and Min6 cells to 64 ± 6% and 65 ± 1% of baseline, respectively, and yohimbine restored oxygen consumption to rates not different from baseline. In Min6 cells incubated with epinephrine rates of 14C glucose oxidation were reduced (P<0.01) 66 ± 4% compared to vehicle controls. These results demonstrate that acute epinephrine exposure suppresses glucose oxidation in β cells via the specific adrenergic receptor, Adrα2A, and indicate a new role for adrenergic regulation in GSIS.
Project description:We compare global gene expression changes in the Min6 cell line in response to altered glucose flux and pharmacological manipulation of the O-GlcNAc postranslational protein modification. Min6 cells were treated for 1hr in the following conditions: Low glucose (LG), high glucose (HG) and LG+GlcNAcstatin (LG+GNS). After treatment, total RNA was extracted and used for sequencing.
Project description:We previously isolated a subclone, MIN6 clone 4, from the parental MIN6 cells, that shows well-regulated insulin secretion in response to glucose, glybenclamide, and KCl, even after prolonged culture. To investigate the molecular mechanisms responsible for preserving GSIS in this subclone, we compared four groups of MIN6 cells: Pr-LP (parental MIN6, low passage number), Pr-HP (parental MIN6, high passage number), C4-LP (MIN6 clone 4, low passage number), and C4-HP (MIN6 clone 4, high passage number). Based on their capacity for GSIS, we designated the Pr-LP, C4-LP, and C4-HP cells as M-bM-^@M-^\responder cells.M-bM-^@M-^] In a DNA microarray analysis, we identified a group of genes with high expression in responder cells (M-bM-^@M-^\responder genesM-bM-^@M-^]), but extremely low expression in the Pr-HP cells. MIN6 clone 4 cells are a subclone isolated from low-passage-number parental MIN6 cells by the limiting dilution method (JM, unpublished). This subclone was maintained in the same culture conditions as the parental cells, and retained good GSIS even after 6 months of continuous culture. For the low-passage-number parental MIN6 cells (Pr-LP), we used cells passaged 17-20 times; for the high-passage-number MIN6 cells (Pr-HP), we used cells passaged 35-40 times. Seventeen to 20 passages were also used for the low-passage-number MIN6 clone 4 cells (C4-LP), and the high-passage ones (C4-HP) were used after 40 to 50 passages.
Project description:14 human Non-Small Cell Lung cancer (NSCLC) cell lines were treated with Transforming Growth Factor beta-1 (TGFβ-1) to induce epithelial-to-mesenchymal transition. Microarrays measured gene expression at baseline and at different times after treatment.
Project description:To define the senescence-associated secretory phenotype (SASP) of beta-cells, we used conditioned media (CM) generated from bleomycin-treated MIN6 cells and from senescent (beta-Gal-positive) primary beta-cells. In order to culture senescent beta-cells, we isolated islet, FACS-sorted them into beta-Gal-positive and negative populations, excluding immune cells through negative selection of CD45-positive and CD11beta-positive cells. For both the MIN6 and primary beta-cell models, we cultured cells in serum-free media to generate CM for proteomic analysis using the aptamer-based SomaScan platform.
Project description:This study provides an evaluation of changes in gene expression associated with beta-naphthaflavone treatment of rat hepatocytes in vitro. Primary rat hepatocytes were treated for 24 and 48 hours with two doses 1 uM and 100 mM) of beta-naphthaflavone and 1% DMSO vehicle control. Five replicates of each treatment were performed. Cells were then extracted and RNA processed for microarray analysis. This series is part of a SuperSeries in which primary rat hepatocytes were treated with two doses of ten chemical compounds (and corresponding vehicle controls) for 24 and 48 hours. Each compound/vehicle treatment group was an individual study performed at different times. Each study was analyzed separately and themes common between studies were reported. Time Course/Dose Response