cyclin-d1 and Diabetes-Mellitus

Diabetes and metabolic perturbation are global health challenges. Sleep insufficiency may trigger metabolic dysregulation leading to diabetes. However, the intergenerational transmission of this environmental information is not clearly understood. The research objective was to determine the possible effect of paternal sleep deprivation on the metabolic phenotype of the offspring and to investigate the underlying mechanism of epigenetic inheritance. Male offspring of sleep-deprived fathers exhibit glucose intolerance, insulin resistance, and impaired insulin secretion. In these SD-F1 offspring, a reduction in beta cell mass and proliferation of beta cells were observed. Mechanistically, in pancreatic islets of SD-F1 offspring, we identified alterations in DNA methylation at the promoter region of the LRP5 (LDL receptor related protein 5) gene, a coreceptor of Wnt signaling, resulting in downregulation of downstream effectors cyclin D1, cyclin D2, and Ctnnb1. Restoration of Lrp5 in the pancreas of SD-F1 male mice could improve impaired glucose tolerance and expression of cyclin D1, cyclin D2, and Ctnnb1. This study might significantly contribute to our understanding of the effects of sleeplessness on health and metabolic disease risk from the perspective of the heritable epigenome.

Topics: Animals; Cyclin D1; Cyclin D2; Diabetes Mellitus; DNA Methylation; Fathers; Glucose Intolerance; Humans; Islets of Langerhans; Low Density Lipoprotein Receptor-Related Protein-5; Male; Melatonin; Mice; Sleep Deprivation

Diabetes mellitus is a metabolic disorder caused by insufficient insulin secretion. The expression of microRNA (miR)‑532‑5P is downregulated in diabetes, but its specific role in diabetes has not yet been elucidated. The present study aimed to investigate the specific mechanism underlying the effects of miR‑532‑5p on diabetes. Cell viability was determined using an MTT assay. The expression levels of miR‑532‑5P, cyclin D1 (CCND1), Insulin1 and Insulin2 were detected using reverse transcription‑quantitative PCR. The expression of miR‑532‑5p and CCND1 were overexpressed in cells by cell transfection. ELISA was used to detect insulin secretion. 2',7'‑dichlorodihydrofluorescein diacetate was used to quantify reactive oxygen species levels in cells. Apoptosis was detected using a TUNEL assay. Western blotting was performed to detect the expression of apoptosis‑related proteins, CCND1 and p53. A dual‑luciferase reporter assay was conducted, and verified the targeted binding of miR‑532‑5p and CCND1. The expression of miR‑532‑5p was downregulated in high glucose (HG)‑induced MIN6 cells. Overexpression of miR‑532‑5p could improve the HG‑induced decline in insulin secretion and inhibit HG‑induced oxidative stress and apoptosis in cells. miR‑532‑5p can target and regulate the expression of CCND1. Overexpression of miR‑532‑5p downregulated HG‑induced cell insulin secretion, oxidative stress and apoptosis by downregulating CCND1, which is involved in regulating the expression of p53. To conclude, miR‑532‑5p regulated oxidative stress and insulin secretion damage in HG‑induced pancreatic β cells by downregulating the expression of CCND1, which is involved in the upregulation of the expression of p53.

Topics: Apoptosis; Cell Line; Cell Proliferation; Cell Survival; China; Cyclin D1; Diabetes Mellitus; Glucose; Humans; Insulin Secretion; Insulin-Secreting Cells; MicroRNAs; Oxidative Stress; Reactive Oxygen Species; Signal Transduction

LncRNAs are reported to participate in the progression of various diseases including diabetic nephropathy. Currently, we reported that SNHG16 was obviously upregulated in db/db mice and high glucose-treated mice mesangial cells. Then, functional experiments showed that SNHG16 silencing significantly inhibited proliferation of mice mesangial cells, which induced the apoptosis and triggered cell cycle arrest. Meanwhile, proliferation-related biomarkers PCNA and Cyclin D1 (CCND1) were greatly repressed. Furthermore, western blot analysis was conducted to test fibrogenesis-associated genes Fibronectin and α-SMA. Meanwhile, the increased protein expression levels of Fibronectin and α-SMA under high glucose conditions were reversed by loss of SNHG16. miR-141-3p has been reported to be involved in various diseases. Then, RNA immunoprecipitation assay revealed the relation between SNHG16 and miR-141-3p. Downregulation of SNHG16 was able to induce expression of miR-141-3p, which was obviously reduced in db/db diabetic nephropathy mice. In addition, CCND1 is a crucial cell cycle master in human diseases. CCND1 was speculated as the target of miR-141-3p and miR-141-3p inhibited CCND1 expression significantly. Meanwhile, we observed that loss of CCND1 greatly repressed mice mesangial cell proliferation and induced cell apoptosis. Taken these together, we revealed for the first time that SNHG16 induced proliferation and fibrogenesis via modulating miR-141-3p and CCND1 in diabetic nephropathy. SNHG16/miR-141-3p/CCND1 axis can suggest a pathological mechanism of progression of diabetic nephropathy.

Topics: Animals; Cell Proliferation; Cyclin D1; Diabetes Mellitus; Diabetic Nephropathies; Humans; Mice; MicroRNAs; RNA, Long Noncoding

Epidemiological studies have indicated diabetes mellitus (DM) as a risk of cholangiocarcinoma (CCA), however, the effects and mechanisms of high glucose on progression of CCA remain unclear. This study reports for the first time of the enhancing effects of high glucose on aggressive phenotypes of CCA cells via STAT3 activation. CCA cells cultured in high glucose media exerted significantly higher rates of cell proliferation, adhesion, migration and invasion than those cultured in normal glucose. The phosphokinase array revealed STAT3 as the dominant signal activated in response to high glucose. Increased nuclear STAT3, p-STAT3 and its downstream target proteins, cyclin D1, vimentin and MMP2, were shown to be underling mechanisms of high glucose stimulation. The link of high glucose and STAT3 activation was confirmed in tumor tissues from CCA patients with DM that exhibited higher STAT3 activation than those without DM. Moreover, the levels of STAT3 activation were correlated with the levels of blood glucose. Finally, decreasing the level of glucose or using a STAT3 inhibitor could reduce the effects of high glucose. These findings suggest that controlling blood glucose or using a STAT3 inhibitor as an alternative approach may improve the therapeutic outcome of CCA patients with DM.

Topics: Adult; Aged; Bile Duct Neoplasms; Cell Adhesion; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cholangiocarcinoma; Cyclin D1; Diabetes Complications; Diabetes Mellitus; Female; Gene Expression Regulation, Neoplastic; Glucose; Humans; Male; Matrix Metalloproteinase 2; Microtomy; Middle Aged; Signal Transduction; STAT3 Transcription Factor; Tissue Embedding; Vimentin

The initiation of β-cell proliferation to recover reduced β-cell mass is considered as one of the attractive therapeutic approaches for type 1 and 2 diabetes. In this study, we investigated the involvement of miRNAs in β-cell proliferation.. Global miRNA array analysis of pancreas tissue was carried out using a 60% partial pancreatectomy (PPx) rodent model, which is a well-characterized model for pancreatic regeneration with accelerated proliferation of β-cells. To explore miRNAs with mitogenic activity on β-cells, precursors and antisense oligonucleotides (ASOs) for miRNAs were transfected into a primary islet monolayer cell cultures isolated from adult rats in order to modify their expression and proliferation of β-cells.. We found that miR-199b-5p, which was up-regulated 2.6 times in the pancreas of the PPx treated group, significantly enhanced the proliferation of β-cells when its precursor was over-expressed. Target genes of miR-199b-5p were investigated and Mixed lineage kinase-3 (MLK3) was identified as one of the candidates since its expression was down-regulated through an interaction with miR-199b-5p and siRNA treatment for MLK3 enhanced the proliferation of β-cells.. Our data suggest that the up-regulation of miR-199b-5p enhances proliferation of β-cells at least in part through down-regulation of MLK3.

Topics: Animals; Cell Proliferation; Cells, Cultured; Cyclin D1; Cyclin E; Diabetes Mellitus; Down-Regulation; Gene Expression Regulation; Insulin-Secreting Cells; Male; MAP Kinase Kinase Kinases; MicroRNAs; Mitogen-Activated Protein Kinase Kinase Kinase 11; Oligonucleotides, Antisense; Rats; Rats, Wistar; Real-Time Polymerase Chain Reaction; RNA Interference; RNA, Small Interfering

Insulin constitutes a principal evolutionarily conserved hormonal axis for maintaining glucose homeostasis; dysregulation of this axis causes diabetes. PGC-1α (peroxisome-proliferator-activated receptor-γ coactivator-1α) links insulin signalling to the expression of glucose and lipid metabolic genes. The histone acetyltransferase GCN5 (general control non-repressed protein 5) acetylates PGC-1α and suppresses its transcriptional activity, whereas sirtuin 1 deacetylates and activates PGC-1α. Although insulin is a mitogenic signal in proliferative cells, whether components of the cell cycle machinery contribute to its metabolic action is poorly understood. Here we report that in mice insulin activates cyclin D1-cyclin-dependent kinase 4 (Cdk4), which, in turn, increases GCN5 acetyltransferase activity and suppresses hepatic glucose production independently of cell cycle progression. Through a cell-based high-throughput chemical screen, we identify a Cdk4 inhibitor that potently decreases PGC-1α acetylation. Insulin/GSK-3β (glycogen synthase kinase 3-beta) signalling induces cyclin D1 protein stability by sequestering cyclin D1 in the nucleus. In parallel, dietary amino acids increase hepatic cyclin D1 messenger RNA transcripts. Activated cyclin D1-Cdk4 kinase phosphorylates and activates GCN5, which then acetylates and inhibits PGC-1α activity on gluconeogenic genes. Loss of hepatic cyclin D1 results in increased gluconeogenesis and hyperglycaemia. In diabetic models, cyclin D1-Cdk4 is chronically elevated and refractory to fasting/feeding transitions; nevertheless further activation of this kinase normalizes glycaemia. Our findings show that insulin uses components of the cell cycle machinery in post-mitotic cells to control glucose homeostasis independently of cell division.

Topics: Acetylation; Amino Acids; Animals; Cell Cycle; Cell Line, Tumor; Cell Nucleus; Cells, Cultured; Cyclin D1; Cyclin-Dependent Kinase 4; Diabetes Mellitus; Enzyme Activation; Fasting; Gene Deletion; Gluconeogenesis; Glucose; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Hepatocytes; Histone Acetyltransferases; Homeostasis; Humans; Hyperglycemia; Hyperinsulinism; Insulin; Male; Mice; Phosphorylation; RNA, Messenger; Signal Transduction; Transcription Factors; Transcription, Genetic

Germ line PERK mutations are associated with diabetes mellitus and growth retardation in both rodents and humans. In contrast, late embryonic excision of PERK permits islet development and was found to prevent onset of diabetes, suggesting that PERK may be dispensable in the adult pancreas. To definitively establish the functional role of PERK in adult pancreata, we generated mice harboring a conditional PERK allele in which excision is regulated by tamoxifen administration. Deletion of PERK in either young adult or mature adult mice resulted in hyperglycemia associated with loss of islet and β cell architecture. PERK excision triggered intracellular accumulation of proinsulin and Glut2, massive endoplasmic reticulum (ER) expansion, and compensatory activation of the remaining unfolded-protein response (UPR) signaling pathways specifically in pancreatic tissue. Although PERK excision increased β cell death, this was not a result of decreased proliferation as previously reported. In contrast, a significant and specific increase in β cell proliferation was observed, a result reflecting increased cyclin D1 accumulation. This work demonstrates that contrary to expectations, PERK is required for secretory homeostasis and β cell survival in adult mice.

Topics: Animals; Base Sequence; Cell Proliferation; Cyclin D1; Diabetes Mellitus; eIF-2 Kinase; Endoplasmic Reticulum; Gene Knockout Techniques; Glucose; Homeostasis; Hyperglycemia; Insulin-Secreting Cells; Islets of Langerhans; Mice; Mice, Knockout; Pancreas; RNA, Messenger; Unfolded Protein Response

Cyclins drive cell-cycle progression by associating with their kinase partners, cyclin-dependent kinases (CDK). We investigated cyclin D1/CDK6, cyclin E/CDK2 complexes, and the cell-cycle negative regulators p15 and p27 in an incisional skin wound model.. Wounds were produced on the back of female diabetic mice and their normoglycemic littermates. Animals were treated with polydeoxyribonucleotide (PDRN, 8 mg/kg/i.p.), an agonist of adenosine A2(A) receptors, or its vehicle daily. Granulation tissue proliferation by Ki67 immunostaining, cyclin D/CDK6 and cyclin E/CDK2 complexes, and p21 and p16 proteins (Western blot analysis), and the histologic changes were assessed at different days (3, 6, and 12 days after injury).. Numerous Ki67 positive cells were observed at day 3 and day 6 in the granulation tissue of normoglycemic mice. Ki67 positive cells were fewer in diabetic than in normoglycemic mice. PDRN increased Ki67 positive cells in diabetic mice. Normoglycemic mice showed the greatest upregulation of cyclin D1, CDK6, cyclin E, and CDK2 at day 6. Diabetic mice had a markedly lower expression of cyclin D1, CDK6, cyclin E, and CDK2 at day 6. They also showed a greater expression of p15 and p27 at day 6. PDRN administration in diabetic mice increased cyclin D1/CDK6 and cyclin E/CDK2 expression and reduced p15 and p27 inhibitors at day 6 after injury; moreover, it improved the impaired wound healing at day 12.. Our results suggest that adenosine A2(A) receptor activation by PDRN might represent a therapeutic strategy to overcome the diabetes-impaired cell-cycle machinery.

Topics: Animals; Cell Cycle; Cell Proliferation; Cyclin D1; Cyclin E; Cyclin-Dependent Kinase 2; Cyclin-Dependent Kinase 6; Cyclin-Dependent Kinase Inhibitor p27; Diabetes Mellitus; Female; Granulation Tissue; Intracellular Signaling Peptides and Proteins; Mice; Mice, Inbred C57BL; Polydeoxyribonucleotides; Receptor, Adenosine A2A; Wound Healing

Diabetic patients have a strong predilection for atherosclerosis and postangioplasty restenosis. Accelerated cell proliferation and excessive extracellular matrix deposition are believed to contribute to the development of atherosclerotic plaques and neointima. We investigated the effect of diabetes on cell cycle, proliferation signaling, and the activation of matrix metalloproteinases (MMPs). Segments of internal mammary arteries from 26 type 2 diabetic and 26 non-diabetic patients undergoing coronary artery bypass grafting surgery were compared. Increased levels of cyclin D1 mRNA (by 135+/-14%) and protein expression (by 93.8+/-7.0%), retinoblastoma protein phosphorylation (by 45.9+/-4.8%), and beta-catenin nuclear localization (by 176+/-16%) indicated the enhanced cell cycle entry in the diabetic arteries. Diabetes increased phosphorylation of extracellular signal-regulated kinase-1/2 and p-38-mitogen-activated protein kinase (MAPK) by 76.0+/-6.8 and 62.3+/-4.3%. Increased collagen deposition was evidenced in the diabetic arteries. mRNA levels of MMP-1 and MMP-3 were decreased in the diabetic tissue to 55 and 82%, respectively, compared to the non-diabetic group; protein levels were also decreased accompanied with decreased enzymatic activities by 21 and 50%, respectively. In conclusion, enhanced cell cycle entry, increased MAPK signaling, and downregulated MMP-1 and MMP-3 were characteristic of diabetic arterial vasculature, and could contribute to the progressive atherosclerosis and postangioplasty restenosis in diabetic patients.

Topics: Aged; Angioplasty; Arteries; Cell Cycle; Cell Proliferation; Cyclin D1; Diabetes Complications; Diabetes Mellitus; Gene Expression Regulation, Enzymologic; Humans; MAP Kinase Signaling System; Matrix Metalloproteinase 1; Matrix Metalloproteinase 3; Middle Aged; p38 Mitogen-Activated Protein Kinases

Regulation of adult beta-cell mass in pancreatic islets is essential to preserve sufficient insulin secretion in order to appropriately regulate glucose homeostasis. In many tissues mitogens influence development by stimulating D-type cyclins (D1, D2, or D3) and activating cyclin-dependent kinases (CDK4 or CDK6), which results in progression through the G(1) phase of the cell cycle. Here we show that cyclins D2 and D1 are essential for normal postnatal islet growth. In adult murine islets basal cyclin D2 mRNA expression was easily detected, while cyclin D1 was expressed at lower levels and cyclin D3 was nearly undetectable. Prenatal islet development occurred normally in cyclin D2(-/-) or cyclin D1(+/-) D2(-/-) mice. However, beta-cell proliferation, adult mass, and glucose tolerance were decreased in adult cyclin D2(-/-) mice, causing glucose intolerance that progressed to diabetes by 12 months of age. Although cyclin D1(+/-) mice never developed diabetes, life-threatening diabetes developed in 3-month-old cyclin D1(-/+) D2(-/-) mice as beta-cell mass decreased after birth. Thus, cyclins D2 and D1 were essential for beta-cell expansion in adult mice. Strategies to tightly regulate D-type cyclin activity in beta cells could prevent or cure diabetes.

Topics: Animals; Blood Glucose; Cell Proliferation; Cyclin D1; Cyclin D2; Cyclins; Diabetes Mellitus; Gene Expression; Glucagon; Glucose Intolerance; Insulin; Islets of Langerhans; Male; Mice; Mice, Knockout

One major limitation in pancreatic islet transplantation is availability of donor tissue. Donor shortage is exacerbated by islet apoptosis from the stresses of islet isolation and transplantation. Furthermore, the side effects of immunosuppressive drugs preclude transplants into patients whose diabetes is controlled by parenteral insulin. We hypothesised that over-expressing anti-apoptotic Bcl-2 or secretion of immunomodulatory CTLA4Ig molecules in islet beta cells would enhance survival of transplanted islets while minimizing systemic side effects. Over-expression of Bcl-2 neither significantly increased preservation of islet cell mass after transplantation into immunocompromised recipients nor decreased cytokine-mediated apoptosis in vitro. Although Bcl-2 over-expression alone was insufficient in protecting islet allografts from rejection, its beneficence was shown by the enhancement of protection when the adaptive immune response was inhibited by locally produced CTLA4Ig. Thus, the combination of anti-apoptotic and immunosuppressive intervention has additive or synergistic efficacy and may reduce the level of systemic immunosuppression or quantity of donor tissue required.

Topics: Abatacept; Animals; Apoptosis; Cyclin D1; Cytoprotection; Diabetes Mellitus; Graft Survival; Immunoconjugates; Islets of Langerhans Transplantation; Mice; Mice, Inbred Strains; Mice, Transgenic; Transplantation, Homologous