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OBJECTIVE To study the interventional effect and mechanism of 1，8-cineole on pancreatic β cell ferroptosis induced by type 2 diabetes. METHODS In vitro ferroptosis model was established in pancreatic β cells of mice by using high glucose. The effects of low-dose and high-dose 1，8-cineole （0.25， 0.5 μmol/L） on the level of Fe2+ in pancreatic β cells were investigated. The effects of 1，8-cineole （0.5 μmol/L） combined with ferroptosis inducer Erastin （20 μmol/L） and ferroptosis inhibitor Ferrostatin-1 （20 μmol/L） on the protein expressions of glutathione peroxidase-4 （GPX4） and cyclooxygenase-2 （COX2） were also detected. The type 2 diabetes model mice were established by feeding high-sugar and high-fat diet combined with intraperitoneal injection of streptozotocin. The effects of low-dose and high-dose 1，8-cineole （50， 200 mg/kg） on the pathological morphology of pancreatic tissue， the content of iron as well as the protein expressions of GPX4 and COX2 were investigated. RESULTS The results of the cell experiment showed that compared with the model group， pretreatment with 1，8-cineole significantly reduced intracellular Fe2+ levels and upregulated GPX4 protein expression， while downregulated COX2 protein expression in pancreatic β cells （P＜0.05）. After combining with Ferrostatin-1， the expression trends of the above two proteins were the same， while there was no statistically significant difference after combining with Erastin. The results of animal experiments showed that compared with the model group， after intervention with 1，8-cineole， the structure of the pancreatic islets in mice recovered intact and their morphology improved； the iron content of pancreatic tissue and protein expression of COX2 were decreased significantly （P＜0.05）， while protein expression of GPX4 was increased significantly （P＜0.05）. CONCLUSIONS 1，8-cineole could ameliorate pancreatic β cell injury induced by diabetes， the mechanism of which may be related to reducing intracellular iron deposition and regulating ferroptosis-related proteins.
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The Ca2+-activated monovalent cation selective transient receptor potential melastatin 4 (TRPM4) channel expressed in pancreatic β-cells is implicated in the β-cell function and insulin secretion, but how pharmacological function of TRPM4 channel affects membrane excitability of β-cells remains largely unknown. Here, we report that pharmacological inhibition of TRPM4 by specific inhibitor 9-phenanthrol attenuates electrical activities of pancreatic β-cells. In whole-cell current clamp recordings, 9-phenanthrol results in inhibition of action potential frequency induced by tolbutamide of the INS-1 pancreatic β-cells in a dose-dependent manner with an IC50 value of 14.99 ± 7.93 μmol·L-1. Similarly, 9-phenanthrol also inhibited action potential firing in INS-1 cells stimulated by current injection. Further recordings of β-cells demonstrate the significant inhibitory effects on action potential peak and action potential amplitude by 9-phenanthrol. Taken together, our results show the involvement of TRPM4 channel function in pancreatic β-cells depolarization and action potential, it provides pharmacological experimental methods and theoretical support for the study of TRPM4 channel in pancreatic β-cells.
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Cellular senescence is a state in which cells enter permanent cell cycle arrest, which is characterized by senescence-associated secretory phenotype secretion, macromolecular damage, metabolic dysregulation and so on. Recent studies have shown a close relationship between cellular senescence and type 2 diabetes. On the one hand, the glycolipotoxic microenvironment of type 2 diabetes can accelerate cell senescence and accumulation. On the other hand, cellular senescence can promote the development of type 2 diabetes. For example, senescence of pancreatic β-cells leads to β-cell dysfunction and adipocytes senescence results in the secretion of pro-inflammatory cytokines, causing disturbances in lipid metabolism and exacerbating insulin resistance. Moreover, senescence of endothelial cells, retinal endothelial cells, and other cell types contributes to the occurrence of chronic complications in diabetes. Cellular senescence is not only an important factor in the onset of type 2 diabetes but also a consequence of its progression. Targeting cellular senescence holds promise as a new strategy for the treatment of type 2 diabetes.
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Objective:To establish a method for detecting pancreatic β-cell dedifferentiation using flow cytometry.Methods:Experimental study. Min6 (mouse β cell line), αTC1-6 (mouse α cell line), HepG2 (human hepatocellular carcinoma cells) and mouse F9 cells (mouse teratocarcinoma cell) were cultured with conventional medium. Min6 cells were treated with interleukin-1β (IL-1β) in combined with tumor necrosis factor α (TNFα), or palmitic acid (PA) overnight and stained with anti-chromogranin A (ChgA), anti-insulin (Ins), anti-glucagon (Gcg), anti-SRY-box transcription factor 9 (Sox9) and anti-octamer binding transcription factor 4 (Oct4) antibodies, respectively. Flow cytometry was applied to detect the pression of ChgA, Ins, Gcg, Sox9, and Oct4 in the cells, respectively. Unpaired Student t test was used for statistical analysis. Results:Flow cytometry analyses showed that Ins and ChgA were highly expressed in Min6 cells, Gcg was highly expressed in αTC1-6, Sox9 was highly expressed in HepG2, and Oct4 was highly expressed in F9 cells, respectively (around 90%). Treatment of Min6 cells with IL-1β+TNFα significantly decreased Ins positive staining cells (92.775%±1.702% vs. 97.125%±0.246%, P=0.045), while increased Sox9 positive staining cells (41.675%±0.390% vs. 25.875%±3.348%, P=0.003). No significant changes in ChgA and Oct4 expression could be viewed (both P>0.05). PA treatment elevated the number of Gcg positive staining cells (54.500%±3.597% vs. 41.160%±3.007%, P=0.022). The levels of mRNA expression by qPCR of the above proteins were in consistent with the levels of protein expression by flow cytometry in Min6 cells. Conclusion:Flow cytometry can be used to detect proteins expressed in dedifferentiated models of β cells, which provides a new method for identify dedifferentiation of pancreatic β cells.
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Studies on diabetes have long been hampered by a lack of authentic disease models that, ideally, should be unlimited and able to recapitulate the abnormalities involved in the development, structure, and function of human pancreatic islets under pathological conditions. Stem cell-based islet organoids faithfully recapitulate islet development in vitro and provide large amounts of three-dimensional functional islet biomimetic materials with a morphological structure and cellular composition similar to those of native islets. Thus, islet organoids hold great promise for modeling islet development and function, deciphering the mechanisms underlying the onset of diabetes, providing an in vitro human organ model for infection of viruses such as SARS-CoV-2, and contributing to drug screening and autologous islet transplantation. However, the currently established islet organoids are generally immature compared with native islets, and further efforts should be made to improve the heterogeneity and functionality of islet organoids, making it an authentic and informative disease model for diabetes. Here, we review the advances and challenges in the generation of islet organoids, focusing on human pluripotent stem cell-derived islet organoids, and the potential applications of islet organoids as disease models and regenerative therapies for diabetes.
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Humans , COVID-19 , Diabetes Mellitus/therapy , Islets of Langerhans , Organoids , SARS-CoV-2ABSTRACT
Type 2 diabetes (T2D) is characterized by the malfunction of pancreatic β cells. Susceptibility and pathogenesis of T2D can be affected by multiple factors, including sex differences. However, the mechanisms underlying sex differences in T2D susceptibility and pathogenesis remain unclear. Using single-cell RNA sequencing (scRNA-seq), we demonstrate the presence of sexually dimorphic transcriptomes in mouse β cells. Using a high-fat diet-induced T2D mouse model, we identified sex-dependent T2D altered genes, suggesting sex-based differences in the pathological mechanisms of T2D. Furthermore, based on islet transplantation experiments, we found that compared to mice with sex-matched islet transplants, sex-mismatched islet transplants in healthy mice showed down-regulation of genes involved in the longevity regulating pathway of β cells. Moreover, the diabetic mice with sex-mismatched islet transplants showed impaired glucose tolerance. These data suggest sexual dimorphism in T2D pathogenicity, indicating that sex should be considered when treating T2D. We hope that our findings could provide new insights for the development of precision medicine in T2D.
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The present study investigated the therapeutic efficacy and potential mechanism of Jinqi Jiangtang Tablets(JQJT) on pancreatic β cell dysfunction based on network pharmacology and molecular docking technology. TCMSP platform was used to retrieve the chemical components and targets of the three Chinese herbal medicines of JQJT. The genes were converted to gene symbol by the UniProt, and its intersection with targets related to pancreatic β cell function in GeneCards and CTD databases was obtained. The drugs, active components and common targets were imported into Cytoscape 3.8.2 to plot the drug-component-target network. The main effective components and targets were obtained by software analysis. The drug targets and targets related to pancreatic β cell function were imported separately into the STRING platform for the construction of protein-protein interaction(PPI) networks. The two PPI networks were merged by Cytoscape 3.8.2 and the key targets were obtained by plug-in CytoNCA. The targets obtained from drug-component-target network and PPI networks were imported into DAVID for GO analysis and KEGG enrichment analysis. AutoDock was used to carry out molecular docking of main active components and core targets and Pymol was used to plot the molecular docking diagram. The results showed that there were 371 active components and 203 targets related to JQJT and 2 523 targets related to pancreatic β cell damage, covering 136 common targets. The results revealed core targets(such as PTGS2, PTGS1, NOS2, ESR1 and RXRA) and effective key components(such as quercetin, kaempferol, luteolin, β-carotene and β-sitosterol). KEGG enrichment analysis indicated that apoptosis, inflammation, and other signaling pathways were mainly involved. Molecular docking results showed that the main active components could spontaneously bind to the targets. This study preliminarily revealed the mechanism of JQJT in improving pancreatic β cell damage through multi-component, multi-target and multi-pathway, and provided a theoretical basis for JQJT in the treatment of pancreatic β cell dysfunction.
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Drugs, Chinese Herbal/pharmacology , Insulin-Secreting Cells , Medicine, Chinese Traditional , Molecular Docking Simulation , Tablets , TechnologyABSTRACT
Objective: To investigate the characteristics of insulin secretion function and sensitivity and blood glucose disposition capacity in the prediabetes populations. Methods: A total of 1 317 subjects were enrolled in this study, including 382 with normal glucose tolerance (NGT) and 935 with pre-diabetes. All pre-diabetes populations were divided into seven subgroups according to the cut-off points of 2010 American Diabetes Association standards. Homeostasis model assessment (HOMA) was used to access baseline insulin secretion (HOMA-β) and insulin sensitivity (HOMA-IR). Insulin secretion and sensitivity after glucose load were evaluated by area under curve (AUC) for insulin/AUC for glucose (AUCINS120/AUCGLU120) and insulin sensitivity index (ISI) calculated from Cederholm formula, respectively. Disposition index (DI) was used to reflect blood glucose disposition capacity. Results: The most common type of pre-diabetes was impaired fasting glucose (IFG) combined with impaired glucose tolerance (IGT) and glycated hemoglobin A1c (HbA1c ) 5.7%-6.4%, followed by isolated IGT, while the proportion of isolated IFG was the lowest. The insulin sensitivity of isolated HbA1c 5.7%-6.4% group was better than that of isolated IFG group, isolated IGT group, and IFG combined with IGT group (P<0.05). And its β-cell function was similar with the other subgroups. The DI value of isolated HbA1c 5.7%-6.4% group was about 1.5 times of that of isolated IGT group and IFG combined with IGT group (P=0.000), which was similar with isolated IFG group. The function of β cell or insulin sensitivity in the pre-diabetes subjects with HbA1c 5.7%-6.4% was further damaged compared with the pre-diabetes people whose HbA1c were lower than 5.7%. Conclusion: Different types of pre-diabetes are significantly heterogeneous under new diagnostic criteria, and further prospective studies with a larger sample size are needed to clarify whether HbA1c 5.7%-6.4% is suitable as a diagnostic criteria for pre-diabetes in Chinese population.
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Objective To study the function of Deptor gene on the regulation of diabetes mellitus in suc-cessfully constructed and identified islet β-cell conditionally DEPTOR knockout mice model. Method By cross-breeding Deptorflox/floxmice with Cre mice expressed conditional specifically in pancreatic β-cell,Deptorflox/+Cre+/-mice were acquired and their genotypic identification was then performed. As the mice model of this study, Deptorflox/floxCre+/-mice were generated by crossing Deptorflox/+Cre+/-mice with Deptorflox/floxmice.Genotypic identifica-tion was performed by PCR at the age of 3 weeks. Tamoxifen was administered through intraperitoneal injection to induce the activation of the Cre recombination in islet beta cells of 8 weeks mice.Double immunofluorescence label-ing was then applied to identify the knockout effect of DEPTOR gene. Results Ten Islets Deptor knockout mice models were successfully acquired after 10-month cross-breeding. Validated genotype by PCR analysis were Deptorflox/floxCre+/- and double immunofluorescence labeling showed a significant difference between knockout mice and rodent controls. Conclusion Our study successfully constructs the islets conditionally Deptor deleted mice model by using Cre-loxp recombination system,providing a promising appliable animal model for study of dia-betes mellitus pathogenetic mechanism.
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The main etiology of diabetes mellitus is loss of functional β cell mass, which is responsible for the secretion of the insulin hormone to reduce elevated plasma glucose and to maintain glucose homeostasis. Type 1 diabetes has traditionally been characterized by autoimmune-mediated β-cell death leading to insulin dependence, whereas type 2 diabetes has hallmarks of peripheral insulin resistance, accompanied by β cell dysfunction, and cell death. However, a growing body of evidence suggests that β cell dysfunction and defects of functional maturation in type 2 diabetes involve: (1 ) loss of cell identity, specifically proteins associated with mature cell function and transcription factors like Pdx1,MafA,Nkx6. 1,Glut2,and GK,and (2) de-differentiation,defined by regression to a progenitor or stem cell-like state. Moreover, ectopic expression of genes that are disallowed in β cells is also crucial to maintain the mature phenotype of β cells. In this review, we will combine our preliminary data and summarize the recent literature describing how β cell functional maturation is regulated. We hope that this perspective could shed some lights on possible avenues of new therapeutic intervention for diabetes mellitus.
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Diabetic peripheral neuropathy (DPN) seriously affects the quality of life in patients with type 2 diabetes mellitus. This paper reviews the role of Chinese medicine in the main treatment goal of DPN, including protecting pancreatic β-cells, in the use of antioxidation therapy to delay disease progression, and in the endpoint of neural repair and regeneration. We propose that protecting the body from injury caused by high glucose and oxidative stress, and promoting repair and regeneration of nerves should be the research direction for the prevention and treatment of DPN.
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Type 1 diabetes mellitus (T1DM) is an organ-specific autoimmune disease caused by absolute lack of insulin secretion and progressive pancreatic β cell damage.Patients require lifelong subcutaneous injection of insulin.However,this treatment could induce great pain without improving long-term prognosis.Along with the medicine development,comprehensive methods including genetic technology are adopted to achieve pancreatic β cell regeneration and transformation.Protecting the function of remaining pancreatic β cells for T1DM patients provides a new insight in prevention of acute and chronic T1DM complications.Currents studies of islet β cell reconstruction focus on islet transplantation,stem cell transplantation and immune regulator applications.Unfortunately,owing to their limitations,these methods cannot satisfy clinical application.While transdifferentiation of pancreatic islet δ cells has become a hope recently because of its unique advantages.In this paper,we will summarize the technical methods,influence factors and possible mechanisms of the transdifferentiation of pancreatic islet δ cells.
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To investigate the effects of metformin on pancreatic β-cell function and its possible mechanism, high fat diet-induced type 2 diabetic C57BL/6J mice were divided into two groups according to fasting blood glucose (FBG), glucose decreasing rate at 40 min of insulin tolerance test, triglycerides (TG), cholesterol (CHO) and body weight (BW). The C57 mice were gavaged with water or metformin for 58 days. β-Cell function was evaluated by oral glucose tolerance test and hyperglycemic clamp. Genes and proteins related to pancreas proliferation, lipid metabolism and endoplasmic reticulum stress were investigated. Compared with the model group, metformin group exhibited a reduction in the body weight (PPPPPPdx-1, Pβ (Lxr-β, PPPP<0.05) were also down-regulated. These results suggest that metformin could improve the insulin secretion function of type 2 diabetic C57BL/6J mice. The mechanism of the action may rely on its improvement of pancreas cell proliferation, lipid metabolism and amelioration of endoplasmic reticulum stress.
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BACKGROUND: Arsenic is known as an endocrine disruptor that people are exposed to through various sources such as drinking water and indigestion of marine products. Although some epidemiological and animal studies have reported a correlation between arsenic exposure and diabetes development, there are limited studies regarding the toxic effects of organic arsenic including arsenobetaine on the human body. Here, we analyzed the association between urine arsenobetaine and the homeostasis model assessment of β-cell function (HOMA-β), which is an index for predicting diabetes development and reflecting the function of pancreatic β-cells. METHODS: In the fourth Korea National Health and Nutrition Examination Survey (KNHANES), health and nutrition surveys and screening tests were performed. Of the total survey population, people with confirmed values for urine total arsenic and arsenobetaine were included, and known diabetic patients were excluded. A total 369 participants were finally included in the study. We collected surveys on health, height, body weight, body mass index, blood mercury level, fasting glucose level, and serum insulin level and calculated HOMA index. Owing to sexual discrepancy, we performed sexually stratified analysis. RESULTS: Urine total arsenic and total arsenic minus arsenobetaine was not associated with HOMA-IR and HOMA-β in univariate analysis or in sexually stratified analysis. However, urine arsenobetaine showed a statistically significant relationship with HOMA-β in univariate analysis, and only male participants showed a significant correlation in sexually stratified analysis. In the analysis adjusted for age, BMI, smoking, alcohol drinking, physical activity and blood mercury, the HOMA-β value in the group below the 25th percentile of arsenobetaine was significantly higher than the group between 50 and 75th percentile, while no difference was shown for HOMA-IR. In sexually stratified analysis, The value of HOMA-β was significantly higher in male participants with below the 25th percentile urine arsenobetaine than the group between 25 and 50th and between 50 and 75th, while no difference was shown for HOMA-IR. However, female participants did not demonstrate a relationship between HOMA–IR, HOMA-β and urine arsenobetaine. CONCLUSION: This study revealed the association between urine arsenobetaine and pancreatic β-cell function assessed by HOMA-β in the normal population (without diabetes), especially in males, despite adjusting for factors affecting pancreatic β-cell function and diabetes. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s40557-017-0181-0) contains supplementary material, which is available to authorized users.
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Animals , Female , Humans , Male , Alcohol Drinking , Arsenic , Body Height , Body Weight , Drinking Water , Dyspepsia , Fasting , Glucose , Homeostasis , Human Body , Insulin , Korea , Mass Screening , Motor Activity , Nutrition Surveys , Smoke , SmokingABSTRACT
Objective To investigate the relationship of pancreatic β-cell function and insulin resistance with microalbuminuria in a cross -sectional study of patients with type 2 diabetes.Methods A total of 524 partici-pants with type 2 diabetes were recruited in this cross -sectional study.All subjects'height,weight,waist circumfer-ence and blood pressure were measured.Venous blood samples were drawn to measure fasting plasma glucose (FPG), fasting lipids,glycated hemoglobin A1c (HbA1c),fasting C -peptide (FPC).24h -urine was collected to measure urinary albumin excretion rate (UAER).Homeostasis model assessment of pancreatic β-cell function (HOMA -B) and insulin resistance (HOMA -IR)were estimated using fasting plasma C -peptide.According to HOMA -B quar-tile,the subjects were divided into four groups,including q1 -q4.According to HOMA -IR,the subjects were also divided into four groups,including Q1 -Q4.We assessed the crude associations across quartiles of these data with demographic and clinical parameters using a nonparametric test for trend across ordered groups (trend using Stata software).Multivariable logistic regression analysis was performed to assess the relationships of pancreatic β-cell function and insulin resistance with microalbuminuria in patients with type 2 diabetes.Results Trend test showed that UAER gradually reduced with increase of HOMA -B.The UAER values in subjects with q1,q2,q3 and q4 were 8.92(5.53 -28.65),8.55(5.52 -20.95),7.57(4.79 -19.83)and 7.84(5.23 -14.38)μg/min,respectively, and the trend was statistically significant(z =-2.1,P <0.05 ).With HOMA -IR increasing,UAER gradually increased.The UAER values in subjects with Q1,Q2,Q3 and Q4 were 6.73(4.85 -16.52),8.61 (5.2 -20.37), 8.31(4.88 -27.04),8.75(6.03 -25.21)μg/min,respectively,and the trend was also statistically significant(z =2.41,P <0.05).Multivariable logistic regression analysis showed that subjects with the highest quartile of HOMA -B had lower possibility of microalbuminuria than patients with the lowest quartile of HOMA -B (adjusted OR q4 vs. q1 =0.39,95% CI:0.20 -0.76,Wald =7.59,P =0.006).Subjects with the highest quartile of HOMA -IR had higher risk of microalbuminuria than those with the lowest quartile of HOMA -IR (adjusted OR Q4 vs.Q1 =2.00, 95% CI:1.08 -3.72,Wald =4.84,P =0.028).Conclusion Insulin resistance is associated with an increased prevalence of microalbuminuria in type 2 diabetes,while improved pancreatic β-cell function is linked to decreased rates of microalbuminuria for those patients.
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Objective To investigate the effect of dipeptidyl peptidase-4 (DPP-4) inhibitor on lipopolysaccharide (LPS)-induced changes in the mass and function of pancreatic β-cells.Methods RINm cells were cultured and treated with LPS alone or combined with different concentrations of sitagliptin for 24 h.The proliferation of RINm cells was detected by CCK-8 assay.Apoptotic rate was determined by Annexin V-fluorescein isothiocyanate (FITC)/propidium iodide flow cytometry.Insulin secretion was measured by enzyme-linked immunosorbent assay.The expression of IL-6 mRNA was displayed by RT-PCR.Results LPS significantly stimulated the proliferation of RINm cells (0.89 ± 0.04 vs 1.14 ± 0.08,P＜0.01),while LPS+sitagliptin showed no significant difference compared with LPS group.The cell apoptotic rate in LPS + 10-1 mmol/L sitagliptin group was significantly lower than that in LPS group.There were no significant differences in basal insulin secretion among all groups,but after the high/low glucose stimulation,LPS increased insulin secretion as compared with the control.The IL-6 mRNA expression in LPS+sitagliptin group was significantly lower than that in LPS group (0.77 ± 0.33 vs 1.30 ± 0.41,P =0.006).Conclusions DPP-4 inhibitor has no influence on LPS-induced proliferation of pancreatic β-cell,but it can inhibit LPS-induced apoptosis and insulin secretion,and IL-6 may be involved in the process.
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[Summary] Epigenetics defines heritable changes in gene expression that are not coded in the DNA sequence itself.Three systems,including DNA methylation,RNA-associated silencing and histone modification,are used to initiate and sustain epigenetic silencing.Type 2 diabetes mellitus(T2DM) is a polygenic disorder,which is caused by both genetic and environmental factors.However,pathogenesis of T2DM has not been elucidated.Recent studies have indicated that epigenetics may play an important role in the pathogenesis of T2DM,which is involved in the development and differentiation of β cell,secretion of β cell,insulin sensitivity and so on.Researches related to epigenetics may provide a new measure and target to clarify the pathogenesis of T2DM as well as prevent and treat the disease.
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The development of diabetes is associated with parasecretion of insulin resulting from the mass loss and dysfunction of β-cell in pancreas. Autophagy is a process of high conservation, which can improve β-cell function impaired by inflammation, oxidative stress, and endoplasmic reticulum stress. That is beneficial to delaying the progression of diabetes. Thus, in this review we summarize the definition of autophagy, autophagy related proteins and modulation of autophagy signaling pathways, the protection of autophagy on the structure and function of β-cells, as well as autophagy in β-cells with inflammation, oxidative stress and endoplasmic reticulum stress.
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[Summary] The effects of lipid components on insulin secretion in patients with type 2 diabetes(T2DM) and control subjects were explored. The results demonstrated that in control group, disposal index( DI)0 was positively correlated with high density cholesterol(HDL-C), while DI30 was negatively correlated with total cholesterol(TC), triglycerides( TG) and low density cholesterol ( LDL-C), and DI120 was also negatively correlated with TC and LDL-C. In T2DM group, DI0 was negatively correlated with TC and LDL-C, DI30 was negatively correlated with TC, TG, LDL-C and TG/ HDL-C, DI120 was negatively correlated with TC, TG, LDL-C and TG/ HDL-C.
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<p><b>OBJECTIVE</b>Interferon-γ (IFN-γ) plays an important role in apoptosis and was shown to increase the risk of diabetes. Visfatin, an adipokine, has anti-diabetic, anti-tumor, and regulating inflammatory properties. In this study we investigated the effect of visfatin on IFN-γ-induced apoptosis in rat pancreatic β-cells.</p><p><b>METHODS</b>The RINm5F (rat insulinoma cell line) cells exposed to IFN-γ were treated with or without visfatin. The viability and apoptosis of the cells were assessed by using MTT and flow cytometry. The expressions of mRNA and protein were detected by using real-time PCR and western blot analysis.</p><p><b>RESULTS</b>The exposure of RINm5F cells to IFN-γ for 48 h led to increased apoptosis percentage of the cells. Visfatin pretreatment significantly increased the cell viability and reduced the cell apoptosis induced by IFN-γ. IFN-γ-induced increase in expression of p53 mRNA and cytochrome c protein, decrease in mRNA and protein levels of anti-apoptotic protein Bcl-2 were attenuated by visfatin pretreatment. Visfatin also increased AMPK and ERK1/2 phosphorylation and the anti-apoptotic action of visfatin was attenuated by the AMPK and ERK1/2 inhibitor.</p><p><b>CONCLUSION</b>These results suggested that visfatin protected pancreatic islet cells against IFN-γ-induced apoptosis via mitochondria-dependent apoptotic pathway. The anti-apoptotic action of visfatin is mediated by activation of AMPK and ERK1/2 signaling molecules.</p>