Objective:To discuss the effect of the combined therapy of levemir and acarbose on T cell subsets and function of isletβ cells in elder patients with early-onset type 2 Diabetes Mellitus. Methods:According to the num...Objective:To discuss the effect of the combined therapy of levemir and acarbose on T cell subsets and function of isletβ cells in elder patients with early-onset type 2 Diabetes Mellitus. Methods:According to the number parity of entry sequence, 100 cases of elder patients with early-onset type 2 Diabetes Mellitus are divided into the control group and the observation group of 50 cases. The control group was treated with novolin and acarbose, the observation group was given subcutaneous injection of levemir and acarbose treatment. Compare the T cell subsets and function of isletβ cells in two group of patients before the treatment (T0), treatment for 4 weeks (T1) ,treatment for 8 weeks (T2).Results:(1) The levels of T0, T1, T2CD3+, CD4+, CD4+/CD8+ were increased in both groups, and CD8+ decreased. Among them, the levels of T1, T2CD3+, CD4+, CD4+/CD8+ of the observation group were obviously higher than the control group, the level of CD8+ was lowly than the control group, the difference was statistically significant;(2) In the stage of T0, T1, T2, the levels of FPG, HbA1c, HOMA-IR were showed a downward trend, the levels of FIns, HOMA-B were increased. In these two groups, the levels of T1, T2FPG, HbA1c, HOMA-IR of the observation group were lower than the control group, and the levels of FIns, HOMA-B were higher than the control group, the difference was statistically significant;(3) In the control group occurred 3 cases of hypoglycemia, and the incidence of adverse reactions was 6%. However, in the observation group no occurred adverse reactions, the difference was statistically significant.Conclusions:The combined therapy of levemir and acarbose in elder patients with early-onset type 2 Diabetes Mellitus, It helps to improve immune function, protect the isletβ-cell function.展开更多
A century has passed since the Nobel Prize winning discovery of insulin,which still remains the mainstay treatment for type 1 diabetes mellitus(T1DM)to this day.True to the words of its discoverer Sir Frederick Banti...A century has passed since the Nobel Prize winning discovery of insulin,which still remains the mainstay treatment for type 1 diabetes mellitus(T1DM)to this day.True to the words of its discoverer Sir Frederick Banting,“insulin is not a cure for diabetes,it is a treatment”,millions of people with T1DM are dependent on daily insulin medications for life.Clinical donor islet transplantation has proven that T1DM is curable,however due to profound shortages of donor islets,it is not a mainstream treatment option for T1DM.Human pluripotent stem cell derived insulin-secreting cells,pervasively known as stem cell-derivedβcells(SC-βcells),are a promising alternative source and have the potential to become a T1DM treatment through cell replacement therapy.Here we briefly review how isletβcells develop and mature in vivo and several types of reported SC-βcells produced using different ex vivo protocols in the last decade.Although some markers of maturation were expressed and glucose stimulated insulin secretion was shown,the SC-βcells have not been directly compared to their in vivo counterparts,generally have limited glucose response,and are not yet fully matured.Due to the presence of extra-pancreatic insulin-expressing cells,and ethical and technological issues,further clarification of the true nature of these SC-βcells is required.展开更多
AIM： To investigate the role of endogenous γ-aminobutyric acid （GABA） in pancreatic exocrine secretion. METHODS： The isolated, vascularly perfused rat pancreas was employed in this study to eliminate the possible...AIM： To investigate the role of endogenous γ-aminobutyric acid （GABA） in pancreatic exocrine secretion. METHODS： The isolated, vascularly perfused rat pancreas was employed in this study to eliminate the possible influences of extrinsic nerves and hormones. Cholecystokinin （CCK; 10 pmol/L） was intra-arterially given to stimulate exocrine secretion of the pancreas. RESULTS： Glutamine, a major precursor of GABA, which was given intra-arterially at concentrations of 1, 4 and 10 mmol/L, dose-dependently elevated the CCK-stimulated secretions of fluid and amylase in the normal pancreas. Bicuculline （10 μmol/L）, a GABAA receptor antagonist, blocked the enhancing effect of glutamine （4 mmol/L） on the CCK-stimulated exocrine secretions. Glutamine, at concentrations of 1, 4 and 10 mmol/L, dose-dependently increased the GABA concentration in portal effluent of the normal pancreas. The effects of glutamine on the CCK-stimulated exocrine secretion as well as the GABA secretion were markedly reduced in the streptozotocintreated pancreas. CONCLUSION： GABA could be secreted from β-cells into the isletoacinar portal system after administration of glutainine, and could enhance the CCK-stimulated exocrine secretion through GABAA receptors. Thus, GABA in islet β-cells is a hormone modulating pancreatic exocrine secretion.展开更多
Objective: To elucidate the effect of Huanglian-Renshen-Decoction(HRD) on ameliorating type 2 diabetes mellitus by maintaining islet β-cell identity through regulating paracrine and endocrine glucagon-like peptide-1(...Objective: To elucidate the effect of Huanglian-Renshen-Decoction(HRD) on ameliorating type 2 diabetes mellitus by maintaining islet β-cell identity through regulating paracrine and endocrine glucagon-like peptide-1(GLP-1)/GLP-1 receptor(GLP-1R) in both islet and intestine. Methods: The db/db mice were divided into the model(distilled water), low-dose HRD(LHRD, 3 g/kg), high-dose HRD(HHRD, 6 g/kg), and liraglutide(400 μg/kg) groups using a random number table, 8 mice in each group. The db/m mice were used as the control group(n=8, distilled water). The entire treatment of mice lasted for 6 weeks. Blood insulin, glucose, and GLP-1levels were quantified using enzyme-linked immunosorbent assay kits. The proliferation and apoptosis factors of islet cells were determined by immunohistochemistry(IHC) and immunofluorescence(IF) staining. Then,GLP-1, GLP-1R, prohormone convertase 1/3(PC1/3), PC2, v-maf musculoaponeurotic fibrosarcoma oncogene homologue A(MafA), and pancreatic and duodenal homeobox 1(PDX1) were detected by Western blot, IHC,IF, and real-time quantitative polymerase chain reaction, respectively. Results: HRD reduced the weight and blood glucose of the db/db mice, and improved insulin sensitivity at the same time(P<0.05 or P<0.01). HRD also promoted mice to secrete more insulin and less glucagon(P<0.05 or P<0.01). Moreover, it also increased the number of islet β cell and decreased islet α cell mass(P<0.01). After HRD treatment, the levels of GLP-1,GLP-1R, PC1/3, PC2, MafA, and PDX1 in the pancreas and intestine significantly increased(P<0.05 or P<0.01).Conclusion: HRD can maintain the normal function and identity of islet β cell, and the underlying mechanism is related to promoting the paracrine and endocrine activation of GLP-1 in pancreas and intestine.展开更多
BACKGROUND Endogenous regeneration of pancreatic isletβ-cells is a path to cure both type 1 and advanced type 2 diabetes.Pancreatic cancer cell line-1(PANC-1),a human pancreatic islet progenitor cell line,can be indu...BACKGROUND Endogenous regeneration of pancreatic isletβ-cells is a path to cure both type 1 and advanced type 2 diabetes.Pancreatic cancer cell line-1(PANC-1),a human pancreatic islet progenitor cell line,can be induced by trypsin to differentiate into insulin-secreting islet-like aggregates(ILAs).However,the underlying mechanism has not been explored.AIM To explore the mechanism and signaling pathway of trypsin-induced differentiation of islet progenitor cells into insulin-secreting cells.METHODS PANC-1 cells were induced by trypsin to form ILAs and differentiate into insulinsecreting cells.Clustered regularly interspaced short palindromic repeats(CRISPR)-associated protein 9 knockout and small interfering RNA knockdown techniques were used to investigate membrane proteins and downstream signaling pathways involved in the process.RESULTS The extracellular domain of membrane receptor E-cadherin hydrolyzed by trypsin induced the aggregation of PANC-1 cells and stimulated E-cadherin-recruited casein kinase-1γ3,which specifically phosphorylated the Ser655/Thr658 site ofα-catenin in the cadherin-catenin complex,participating in the process of PANC-1 differentiation and affecting the maturation of differentiated ILAs.CONCLUSION The current study reveals the mechanism by which trypsin promotes PANC-1 cell differentiation into islet-like cells,providing a novel approach for endogenous isletβ-cell regeneration.展开更多
BACKGROUND Type 2 diabetes mellitus(T2DM)is a severe global health problem that causes prolonged disease exposure and an elevated risk for chronic complications,posing a substantial health burden.Although therapies,su...BACKGROUND Type 2 diabetes mellitus(T2DM)is a severe global health problem that causes prolonged disease exposure and an elevated risk for chronic complications,posing a substantial health burden.Although therapies,such as GLP-1 receptor agonists and SGLT2 inhibitors,have been successfully developed,new therapeutic options are still expected to offer better blood glucose control and decrease complications.AIM To elucidate the mechanism by which TERT/FOXO1 affects high glucose(HG)-induced dysfunction in isletβ-cells via the regulation of ATG9A-mediated autophagy.METHODS High-fat diet(HFD)-fed/streptozotocin(STZ)-treated mice or HG-treated MIN6 cells were used to establish T2DM models.Fasting blood glucose(FBG)and insulin levels in mice,as well as morphological changes in islet tissues,were assessed.Cell proliferation and the apoptosis rate were measured via EdU assays and flow cytometry,respectively.The expression levels of TERT,FOXO1,ATG9A and autophagy-related proteins(LC3B,p62)were analyzed via western blotting.The relationship between FOXO1 and ATG9A was assessed using dual-luciferase reporter gene assays and ChIP assays.RESULTS T2DM modeling in HFD-fed/STZ-treated mice and HG-treated MIN6 cells led to elevated TERT and FOXO1 expression and reduced ATG9A expression.Mice with T2DM were found to have decreased body weight,worsened morphology,elevated FBG and suppressed insulin levels.HG-treated MIN6 cells presented decreased viability and LC3B expression,in addition to increased p62 expression and apoptosis rates.FOXO1 knockdown both in vitro and in vivo protected mice and cells against isletβ-cell dysfunction via the activation of autophagy.The molecular mechanism involved the suppression of ATG9A expression by TERT through FOXO1 transcription activation.CONCLUSION Our results suggested that TERT/FOXO1 inhibits ATG9A expression to decrease isletβ-cell function in T2DM.展开更多
BACKGROUND Not all islet transplants desirably achieve insulin independence.This can be attributed to the microarchitecture and function of the islets influenced by their dimensions.Large islets enhance insulin secret...BACKGROUND Not all islet transplants desirably achieve insulin independence.This can be attributed to the microarchitecture and function of the islets influenced by their dimensions.Large islets enhance insulin secretion through paracrine effects but are more susceptible to hypoxic injury post-transplant,while small islets offer better viability and insulin independence.In vivo studies suggest large islets are essential for maintaining euglycemia,though smaller islets are typically preferred in transplantation for better outcomes.AIM To document the impact of islet dimension on clinical and preclinical transplant outcomes to optimize procedures.METHODS PubMed,Scopus and EMBASE platforms were searched for relevant literature up to 9 April 2024.Articles reported on either glucose-stimulated insulin-secreting(GSIS)capacity,islet viability and engraftment,or insulin independence based on the islet dimension were included.The risk of bias was measured using the Appraisal Tool for Cross-Sectional Studies.Extracted data was analyzed via a narrative synthesis.RESULTS Nineteen studies were included in the review.A total of sixteen studies reported the GSIS,of which nine documented the increased insulin secretion in the small islet,where the majority reported insulin secretion per islet equivalent(IEQ).Seven studies documented increased GSIS in large-sized islets that measure insulin secretion per cell or islet.All the articles that compared small and large islets reported poor viability and engraftment of large islets.CONCLUSION Small islets with a diameter<125μm have desired transplantation outcomes due to their better survival following isolation.Large-sized islets receive blood supply directly from arterioles in vivo to meet their higher metabolic demands.The large islet undergoes central necrosis soon after the isolation(devascularization);failing to maintain the viability and glucose stimuli leads to a decline in GSIS and the overall function of the islet.Improved preservation of large islets after islet isolation,enhances the islet yield(IEQ),thereby reducing the likelihood of failed islet isolation and potentially improves transplant outcome.展开更多
Objective:To investigate the relationship between Jiaotai pill(JTP),its main component berberine(BBR),and the serotonin(5-HT)system in regulating islet hormone secretion and alleviating pancreatic b-cell dysfunction d...Objective:To investigate the relationship between Jiaotai pill(JTP),its main component berberine(BBR),and the serotonin(5-HT)system in regulating islet hormone secretion and alleviating pancreatic b-cell dysfunction during type 2 diabetes mellitus(T2DM)progression.Methods:T2DM rat model was established using a high-fat diet and streptozotocin injection.JTP,BBR,and Metformin were intragastrically administered for 35 days.The analyzed indices included blood glucose,blood lipids,islet hormones,and proteins related to 5-HT synthesis,secretion,and transport.Additionally,an in vitro model of glucose injury in islet cells was established to study the effects of JTP and BBR on islet hormone secretion following tryptophan hydroxylase 1(TPH1)inhibition.Results:JTP and BBR significantly improved blood glucose and lipid levels and islet morphology in T2DM rats.Both models exhibited reduced islet 5-HT levels and impaired islet hormone secretion.However,the administration of JTP and BBR reversed these effects.Furthermore,JTP and BBR upregulated the expression of TPH1(P=.0194,P=.0413)transglutaminase 2(TGase2;P=.0492,P=.0349),serotonin transporter(SERT,P=.0090),and 5-hydroxytryptamine 1F receptor(5-HT1FR)in the islet 5-HT pathway(P=.0194).In the cell model,the regulatory effects of JTP and BBR on islet hormone levels were significantly weakened after TPH1 inhibition(P=.001),suggesting that JTP and BBR influence islet hormone secretion through the pancreatic 5-HT system.Conclusion:The islet 5-HT system is correlated with islet hormone secretion dysfunction in T2DM.JTP and BBR can improve islet hormone secretion by activating the TPH1/TGase2/SERT/5-HT1FR pathway in the islet 5-HT system in T2DM rats.展开更多
Type 1 diabetes(T1D)is a chronic,lifelong,autoimmune disease that is debilitating and life-threatening to those who suffer from severe hypoglycaemic events or the devastating chronic complications.Exogenous insulin re...Type 1 diabetes(T1D)is a chronic,lifelong,autoimmune disease that is debilitating and life-threatening to those who suffer from severe hypoglycaemic events or the devastating chronic complications.Exogenous insulin replacement,including the artificial pancreas,is the current mainstay of T1D therapy but cannot prevent the chronic vascular complications of the disease.They are also responsible for contributing to severe iatrogenic hypoglycaemia and impaired hypoglycaemic awareness.β-cell replacement with either pancreas or islet allotransplantation can reverse diabetes leading to better glycaemic control,prevention of hypoglycaemic events and improved quality of life for patients.The limited supply of cadaveric organ donors is a major barrier to this therapeutic option.Thus,alternative sources of islets are being actively explored,mainly human pluripotent stem-cell derived islets and xenogeneic porcine islets.Although these sources harbor their own risks and problems,various novel and innovative solutions are being perseveringly investigated across the globe to overcome these in the hopes that safe islet transplantation may one day be available to all T1D patients suffering from severe hypoglycaemic events.This review will concentrate on pre-clinical and clinical studies,in addition to the latest scientific discoveries relevant to T1D transplantation therapy using allogeneic or xenogeneic donor islet cells.展开更多
BACKGROUND Diabetes is characterized by insulin resistance as well as impaired insulin production,withβ-cell dysfunction playing a critical role in disease progression.Exercise is known to improve insulin sensitivity...BACKGROUND Diabetes is characterized by insulin resistance as well as impaired insulin production,withβ-cell dysfunction playing a critical role in disease progression.Exercise is known to improve insulin sensitivity,but its effects on pancreatic islet quality and function remain poorly understood.This work hypothesized that swimming training enhances glycemic control and insulin secretion by upregulating the insulin-like growth factor 1(IGF-1)/phosphatidylinositol 3-kinase/protein kinase B(PI3K/AKT)pathway in streptozotocin(STZ)-induced diabetic rats.AIM To investigate the effects of swimming on pancreatic islet quality and function in STZ-induced diabetic rats via the IGF-1/PI3K/AKT pathway.METHODS Twenty-six Sprague-Dawley rats were grouped into diabetic and control groups,with each group further split into exercise and sedentary subgroups.Diabetic rats were induced with STZ.The exercise groups underwent swimming training for 60 minutes/day,5 days/week,for 8 weeks.Body weight,food intake,blood glucose,insulin,lipids,and muscle glycogen were measured.Pancreatic islet morphology and the protein expression levels of IGF-1,PI3K,and AKT were analyzed.Data were analyzed using two-way repeated-measure ANOVA,followed by Tukey’s post-hoc test.RESULTS Exercise training significantly improved body weight[diabetic exercise group(D-Ex):390.66±50.14 g vs diabetic sedentary group(D-Sed):315.89±50.12 g,P<0.05],reduced blood glucose(D-Ex:12.21±4.43 mmol/L vs D-Sed:17.79±2.05 mmol/L,P<0.05),and increased insulin levels(D-Ex:53.50±15.31 pmol/L vs D-Sed:25.31±10.23 pmol/L,P<0.05)in diabetic rats.It also enhanced islet morphology,increased IGF-1 expression,and activated the PI3K/AKT pathway(P<0.05).In-vitro experiments confirmed that IGF-1 positively regulated insulin expression and inhibitedβ-cell apoptosis via the PI3K/AKT pathway.CONCLUSION Exercise training improves pancreatic islet quality and function in diabetic rats by modulating the IGF-1/PI3K/AKT pathway,highlighting its therapeutic potential for diabetes management.展开更多
To get recombinant antigen (Is/et Cell Autoantigen 69)ICA69 which was expressed in Escherichia coli strains (E.coli) by means of the gene engineering technique so that it can be used for early diagnosis of and screeni...To get recombinant antigen (Is/et Cell Autoantigen 69)ICA69 which was expressed in Escherichia coli strains (E.coli) by means of the gene engineering technique so that it can be used for early diagnosis of and screening in type Ⅰ diabetes mellitus, the cDNA fragment of human ICA69 was amplified by PCR, and then cloned into pSPORT 1 vector. After DNA sequencing, it was inserted into pGEX-2T between the sites of EcoR Ⅰ and Sma Ⅰ, then recombinant plasmid p2T-ICA69 was constructed and introduced into E.coli. The GST-ICA69 fusion protein was expressed by the induction of IPTG. The recombinant ICA69 proteins were used to detect the antibodies against hICA69 in 100 healthy subjects and type Ⅰ diabetic serum by the use of indirect ELISA. The sequence analysis showed that the amplified fragments contained 1449 bp, encoded 483 amino acids, and had been correctly inserted into pGEX-2T vector. The recombinant proteins expressed in the prokaryotic cells had immunogenicity and could be used to detect antibodies against ICA69 in type Ⅰ diabetic serum. Finally it can be concluded in this paper that the expression products obtained by the method of gene engineering are recombinant ICA69 antigen and may be used to improve the forecast rate and the diagnostic rate of type Ⅰ diabetes in combination with other tests.展开更多
Objective Isletαcells input is essential for insulin secretion fromβcells.The present study aims to investigate the association between 25-hydroxyvitamin D[25(OH)D]and islet function homeostasis in type-2 diabetes(T...Objective Isletαcells input is essential for insulin secretion fromβcells.The present study aims to investigate the association between 25-hydroxyvitamin D[25(OH)D]and islet function homeostasis in type-2 diabetes(T2D)patients.Methods A total of 4670 T2D patients from seven communities in Shanghai,China were enrolled.The anthropometric indices,biochemical parameters,serum 25(OH)D,and islet function[including C-peptide(C-p)and glucagon]were measured.Results The fasting plasma glucose(FPG),glycated hemoglobin(HbA1c),glucagon,and C-p levels exhibited a significantly decreasing trend in T2D patients as the 25(OH)D levels increased.Next,the population was divided into two groups:abdominal obesity and non-abdominal obesity groups.After adjustment,the 25(OH)D level was found to be associated with HbA1c,glucagon,and homeostasis model assessment ofβ(HOMA-β)in the non-abdominal obesity group.There was a significant relationship between 25(OH)D and HbA1c,glucagon,HOMA-IR,baseline insulin or C-p in the abdominal obesity group.In the abdominal obesity group,the ordinary least squares(OLS)regression and quantile regression revealed that 25(OH)D was obviously associated with glucagon and fasting C-p levels.In the abdominal obesity group,the moderate analysis revealed a significant interaction effect of 25(OH)D and glucagon on C-p(P=0.0124).Furthermore,the conditional indirect effect of 25(OH)D on the glucagon/C-p ratio was significantly lower at 1 standard deviation(SD)below the mean(P=0.0002),and lower at the mean of the course of diabetes(P=0.0007).Conclusion 25(OH)D was found to be negatively correlated to glucagon and C-p in T2D patients with abdominal obesity.The 25(OH)D influenced C-p in part by influencing glucagon.The effect of 25(OH)D on the glucagon/C-p ratio in T2D patients with abdominal obesity,in terms of islet homeostasis,is influenced by the course of diabetes.展开更多
Objective:To study the effect of mechanism of high glucose on apoptosis and cell cycle arrest of isletβcells via p27 pathway.Methods:Islet INS-1 cells were cultured and divided into groups.The control group was treat...Objective:To study the effect of mechanism of high glucose on apoptosis and cell cycle arrest of isletβcells via p27 pathway.Methods:Islet INS-1 cells were cultured and divided into groups.The control group was treated with ordinary medium,the high glucose group was treated with high glucose medium containing 25mmol/L glucose,the high glucose+si-NC group was treated with high glucose medium and transfected with NC siRNA,and the high glucose+si-P27 group was treated with high glucose medium and transfected with p27 siRNA.After 24 hours treatment,MTS assay was used to detect the cell viability A490,TUNEL assay was used to detect apoptosis rate,flow cytometry was used to detect the cell cycle distribution and western blot was used to detect the expression levels of P27,caspase-8 and cyclinD1.Results:Compared with those in the control group,the A490,the ratio of S phase and G2/M phase as well as the expression level of CyclinD1 decreased,while the apoptosis rate,the ratio of G0/G1 phase as well as the expression levels of P27 and caspase-8 increased in the high glucose group(P<0.05);compared with those in the high glucose group,the A490,cell cycle as well as the expression levels of P27,caspase-8 and cyclinD1 were not different from those in the high glucose+si-NC group(P>0.05);compared with those in the high glucose group and high glucose+si-NC group,the A490,the ratio of S phase and G2/M phase as well as the expression levels of cyclinD1 increased,while the apoptosis rate,the ratio of G0/G1 phase as well as the expression levels of p27 and caspase-8 decreased in the high glucose+si-P27 group(P<0.05).Conclusion:The apoptosis and cell cycle arrest induced by high glucose are related to P27 pathway activation.展开更多
The NSC-34 cell line is a widely recognized motor neuron model and various neuronal differentiation protocols have been exploited. Under previously reported experimental conditions, only part of the cells resemble dif...The NSC-34 cell line is a widely recognized motor neuron model and various neuronal differentiation protocols have been exploited. Under previously reported experimental conditions, only part of the cells resemble differentiated neurons;however, they do not exhibit extensive and time-prolonged neuritogenesis, and maintain their duplication capacity in culture. The aim of the present work was to facilitate long-term and more homogeneous neuronal differentiation in motor neuron–like NSC-34 cells. We found that the antimitotic drug cytosine arabinoside promoted robust and persistent neuronal differentiation in the entire cell population. Long and interconnecting neuronal processes with abundant growth cones were homogeneously induced and were durable for up to at least 6 weeks in culture. Moreover, cytosine arabinoside was permissive, dispensable, and mostly irreversible in priming NSC-34 cells for neurite initiation and regeneration after mechanical dislodgement. Finally, the expression of the cell proliferation antigen Ki67 was inhibited by cytosine arabinoside, whereas the expression levels of neuronal growth associated protein 43, vimentin, and motor neuron–specific p75, Islet2, homeobox 9 markers were upregulated, as confirmed by western blot and/or confocal immunofluorescence analysis. Overall, these findings support the use of NSC-34 cells as a motor neuron model for properly investigating neurodegenerative mechanisms and prospectively identifying neuroprotective strategies.展开更多
AIM:To investigate the antioxidant activity of chitooligosaccharides(COSs)on pancreatic islet cells in diabetic rats induced by streptozotocin. METHODS:The antioxidant effect of COSs on pancreatic islet cells was dete...AIM:To investigate the antioxidant activity of chitooligosaccharides(COSs)on pancreatic islet cells in diabetic rats induced by streptozotocin. METHODS:The antioxidant effect of COSs on pancreatic islet cells was detected under optical microscopy and with colorimetric assay and gel electrophoresis.The activities of glutathione peroxidase and superoxide dismutase,total antioxidant capacity,and content of malondialdehyde in serum and tissue slices of pancreas were examined after 60 d to determine the effect of COSs in streptozotocin-induced diabetes in rats. RESULTS:COSs can prohibit the apoptosis of pancreatic islet cells.All concentrations of COSs can improve the capability of total antioxidant capacity and activity of superoxide dismutase and decrease the content of malondialdehyde drastically.Morphological investigation in the pancreas showed that COSs have resulted in the reduction of islets,loss of pancreatic cells,and nuclear pyknosis of pancreatic cells. CONCLUSION:COSs possess various biological activities and can be used in the treatment of diabetes mellitus.展开更多
AIM: To study the capacity of bone marrow mesenchymal stem cells (BM-MSCs) trans-differentiating into islet-like cells and to observe the effect of portal vein transplantation of islet-like cells in the treatment of s...AIM: To study the capacity of bone marrow mesenchymal stem cells (BM-MSCs) trans-differentiating into islet-like cells and to observe the effect of portal vein transplantation of islet-like cells in the treatment of streptozotocin-induced diabetic rat. METHODS: BM-MSCs were isolated from SD rats and induced to differentiate into islet-like cells under defined conditions. Differentiation was evaluated with electron microscopy, RT-PCR, immunofluorescence and flow cytometry. insulin release after glucose challenge was tested with ELiSA. Then allogeneic islet-like cells were transplanted into diabetic rats via portal vein. Blood glucose levels were monitored and islet hormones were detected in the liver and pancreas of the recipient by immunohistochemistry. RESULTS: BM-MSCs were spheroid adherent monolayers with high CD90, CD29 and very low CD45 expression. Typical islet-like cells clusters were formed after induction. Electron microscopy revealed that secretory granules were densely packed within the cytoplasm of the differentiated cells. The spheroid cells expressed islet related genes and hormones. The insulin-positive cells accounted for 19.8% and mean fluorescence intensity increased by 2.6 fold after induction. The cells secreted a small amount of insulin that was increased 1.5 fold after glucose challenge. After transplantation, islet-like cells could locate in the liver expressing islet hormones and lower the glucose levels of diabetic rats during d 6 to d 20.CONCLUSION: Rat BM-MSCs could be transdifferentiated into islet-like cells in vitro . Portal vein transplantation of islet-like cells could alleviate the hyperglycemia of diabetic rats.展开更多
AIM： To observe the effect of berberine on insulin secretion in rat pancreatic islets and to explore its possible molecular mechanism. METHODS： Pdmary rat islets were isolated from male Sprague-Dawley rats by collag...AIM： To observe the effect of berberine on insulin secretion in rat pancreatic islets and to explore its possible molecular mechanism. METHODS： Pdmary rat islets were isolated from male Sprague-Dawley rats by collagenase digestion and treated with different concentrations （1, 3, 10 and 30 μmol/L） of berberine or 1 μmol/L Glibenclamide （GB） for 24 h. Glucose-stimulated insulin secretion （GSIS） assay was conducted and insulin was determined by radioimmunoassay. 3-（4,5-Dimethylthiazol-2-yl）- 2,5-diphenyltetrazolium bromide （MTT） assay was performed to evaluate cytotoxicity. The mRNA level of hepatic nuclear factor 4 alpha （HAIF4α） was determined by reverse transcription polymerase chain reaction （RT-PCR）. Indirect immunofluorescence staining and Western blot analysis were employed to detect protein expression of HNF4α in the islets. Glucokinase （GK） activity was measured by spectrophotometric method. RESULTS： Berberine enhanced GSIS rather than basal insulin secretion dose-dependently in rat islets and showed no significant cytotoxicity on islet cells at the concentration of 10 μmol/L. Both mRNA and protein expressions of HNF4α were up-regulated by berberine in a dose-dependent manner, and GK activity was also increased accordingly. However, GB demonstrated no regulatory effects on HNF4α expression or GK activity. CONCLUSION： Berberine can enhance GSIS in rat islets, and probably exerts the insulinotropic effect via a pathway involving HNF4α and GK, which is distinct from sulphonylureas （SUs）.展开更多
AIM: To investigate the effect of chitooligosaccharides on proliferation of pancreatic islet cells, release of insulin and 2 h plasma glucose in streptozotocin-induced diabetic rats.METHODS: In vitro, the effect of ch...AIM: To investigate the effect of chitooligosaccharides on proliferation of pancreatic islet cells, release of insulin and 2 h plasma glucose in streptozotocin-induced diabetic rats.METHODS: In vitro, the effect of chitooligosaccharides on proliferation of pancreatic islet cells and release of insulin was detected with optical microscopy, colorimetric assay, and radioimmunoassay respectively. In vivo, the general clinical symptoms, 2 h plasma glucose, urine glucose, oral glucose tolerance were examined after sixty days of feeding study to determine the effect of chitooligosaccharides in streptozotocin-induced diabetic rats. RESULTS: Chitooligosaccharides could effectively accelerate the proliferation of pancreatic islet cells. Chitooligosaccharides (100 mg/L) had direct and prominent effect on pancreastic β cells and insulin release from islet cells. All concentrations of chitooligosaccharides could improve the general clinical symptoms of diabetic rats, decrease the 2 h plasma glucose and urine glucose, and normalize the disorders of glucose tolerance.CONCLUSION: Chitooligosaccharides possess various biological activities and can be used in the treatment of diabetes mellitus.展开更多
文摘Objective:To discuss the effect of the combined therapy of levemir and acarbose on T cell subsets and function of isletβ cells in elder patients with early-onset type 2 Diabetes Mellitus. Methods:According to the number parity of entry sequence, 100 cases of elder patients with early-onset type 2 Diabetes Mellitus are divided into the control group and the observation group of 50 cases. The control group was treated with novolin and acarbose, the observation group was given subcutaneous injection of levemir and acarbose treatment. Compare the T cell subsets and function of isletβ cells in two group of patients before the treatment (T0), treatment for 4 weeks (T1) ,treatment for 8 weeks (T2).Results:(1) The levels of T0, T1, T2CD3+, CD4+, CD4+/CD8+ were increased in both groups, and CD8+ decreased. Among them, the levels of T1, T2CD3+, CD4+, CD4+/CD8+ of the observation group were obviously higher than the control group, the level of CD8+ was lowly than the control group, the difference was statistically significant;(2) In the stage of T0, T1, T2, the levels of FPG, HbA1c, HOMA-IR were showed a downward trend, the levels of FIns, HOMA-B were increased. In these two groups, the levels of T1, T2FPG, HbA1c, HOMA-IR of the observation group were lower than the control group, and the levels of FIns, HOMA-B were higher than the control group, the difference was statistically significant;(3) In the control group occurred 3 cases of hypoglycemia, and the incidence of adverse reactions was 6%. However, in the observation group no occurred adverse reactions, the difference was statistically significant.Conclusions:The combined therapy of levemir and acarbose in elder patients with early-onset type 2 Diabetes Mellitus, It helps to improve immune function, protect the isletβ-cell function.
基金Supported by the Juvenile Diabetes Research Foundation,No.4-2006-1025Diabetes Australia Research TrustTelethon Perth Children’s Hospital Research Fund(TPCHRF)grant to Jiang FX.
文摘A century has passed since the Nobel Prize winning discovery of insulin,which still remains the mainstay treatment for type 1 diabetes mellitus(T1DM)to this day.True to the words of its discoverer Sir Frederick Banting,“insulin is not a cure for diabetes,it is a treatment”,millions of people with T1DM are dependent on daily insulin medications for life.Clinical donor islet transplantation has proven that T1DM is curable,however due to profound shortages of donor islets,it is not a mainstream treatment option for T1DM.Human pluripotent stem cell derived insulin-secreting cells,pervasively known as stem cell-derivedβcells(SC-βcells),are a promising alternative source and have the potential to become a T1DM treatment through cell replacement therapy.Here we briefly review how isletβcells develop and mature in vivo and several types of reported SC-βcells produced using different ex vivo protocols in the last decade.Although some markers of maturation were expressed and glucose stimulated insulin secretion was shown,the SC-βcells have not been directly compared to their in vivo counterparts,generally have limited glucose response,and are not yet fully matured.Due to the presence of extra-pancreatic insulin-expressing cells,and ethical and technological issues,further clarification of the true nature of these SC-βcells is required.
基金Supported by the Hallym Academy of Sciences, Hallym University, Korea in 2001 (to HJ Park)
文摘AIM： To investigate the role of endogenous γ-aminobutyric acid （GABA） in pancreatic exocrine secretion. METHODS： The isolated, vascularly perfused rat pancreas was employed in this study to eliminate the possible influences of extrinsic nerves and hormones. Cholecystokinin （CCK; 10 pmol/L） was intra-arterially given to stimulate exocrine secretion of the pancreas. RESULTS： Glutamine, a major precursor of GABA, which was given intra-arterially at concentrations of 1, 4 and 10 mmol/L, dose-dependently elevated the CCK-stimulated secretions of fluid and amylase in the normal pancreas. Bicuculline （10 μmol/L）, a GABAA receptor antagonist, blocked the enhancing effect of glutamine （4 mmol/L） on the CCK-stimulated exocrine secretions. Glutamine, at concentrations of 1, 4 and 10 mmol/L, dose-dependently increased the GABA concentration in portal effluent of the normal pancreas. The effects of glutamine on the CCK-stimulated exocrine secretion as well as the GABA secretion were markedly reduced in the streptozotocintreated pancreas. CONCLUSION： GABA could be secreted from β-cells into the isletoacinar portal system after administration of glutainine, and could enhance the CCK-stimulated exocrine secretion through GABAA receptors. Thus, GABA in islet β-cells is a hormone modulating pancreatic exocrine secretion.
基金Supported by the National Natural Science Foundation of China(No.82004358)。
文摘Objective: To elucidate the effect of Huanglian-Renshen-Decoction(HRD) on ameliorating type 2 diabetes mellitus by maintaining islet β-cell identity through regulating paracrine and endocrine glucagon-like peptide-1(GLP-1)/GLP-1 receptor(GLP-1R) in both islet and intestine. Methods: The db/db mice were divided into the model(distilled water), low-dose HRD(LHRD, 3 g/kg), high-dose HRD(HHRD, 6 g/kg), and liraglutide(400 μg/kg) groups using a random number table, 8 mice in each group. The db/m mice were used as the control group(n=8, distilled water). The entire treatment of mice lasted for 6 weeks. Blood insulin, glucose, and GLP-1levels were quantified using enzyme-linked immunosorbent assay kits. The proliferation and apoptosis factors of islet cells were determined by immunohistochemistry(IHC) and immunofluorescence(IF) staining. Then,GLP-1, GLP-1R, prohormone convertase 1/3(PC1/3), PC2, v-maf musculoaponeurotic fibrosarcoma oncogene homologue A(MafA), and pancreatic and duodenal homeobox 1(PDX1) were detected by Western blot, IHC,IF, and real-time quantitative polymerase chain reaction, respectively. Results: HRD reduced the weight and blood glucose of the db/db mice, and improved insulin sensitivity at the same time(P<0.05 or P<0.01). HRD also promoted mice to secrete more insulin and less glucagon(P<0.05 or P<0.01). Moreover, it also increased the number of islet β cell and decreased islet α cell mass(P<0.01). After HRD treatment, the levels of GLP-1,GLP-1R, PC1/3, PC2, MafA, and PDX1 in the pancreas and intestine significantly increased(P<0.05 or P<0.01).Conclusion: HRD can maintain the normal function and identity of islet β cell, and the underlying mechanism is related to promoting the paracrine and endocrine activation of GLP-1 in pancreas and intestine.
基金Supported by the National Natural Science Foundation of China,No.82073908.
文摘BACKGROUND Endogenous regeneration of pancreatic isletβ-cells is a path to cure both type 1 and advanced type 2 diabetes.Pancreatic cancer cell line-1(PANC-1),a human pancreatic islet progenitor cell line,can be induced by trypsin to differentiate into insulin-secreting islet-like aggregates(ILAs).However,the underlying mechanism has not been explored.AIM To explore the mechanism and signaling pathway of trypsin-induced differentiation of islet progenitor cells into insulin-secreting cells.METHODS PANC-1 cells were induced by trypsin to form ILAs and differentiate into insulinsecreting cells.Clustered regularly interspaced short palindromic repeats(CRISPR)-associated protein 9 knockout and small interfering RNA knockdown techniques were used to investigate membrane proteins and downstream signaling pathways involved in the process.RESULTS The extracellular domain of membrane receptor E-cadherin hydrolyzed by trypsin induced the aggregation of PANC-1 cells and stimulated E-cadherin-recruited casein kinase-1γ3,which specifically phosphorylated the Ser655/Thr658 site ofα-catenin in the cadherin-catenin complex,participating in the process of PANC-1 differentiation and affecting the maturation of differentiated ILAs.CONCLUSION The current study reveals the mechanism by which trypsin promotes PANC-1 cell differentiation into islet-like cells,providing a novel approach for endogenous isletβ-cell regeneration.
基金Supported by National Natural Science Foundation of China,No.82000792General Project of Chongqing Natural Science Foundation,No.CSTB2023NSCQ-MSX0246 and No.CSTB2022NSCQ-MSX1271+1 种基金Research Project of the State Administration of Traditional Chinese Medicine on Collaborative Chronic Disease Management of Traditional Chinese Medicine and Western Medicine,No.CXZH2024087Science and Health Joint Project of Dazu District Science and Technology Bureau,No.DZKJ2024JSYJ-KWXM1002.
文摘BACKGROUND Type 2 diabetes mellitus(T2DM)is a severe global health problem that causes prolonged disease exposure and an elevated risk for chronic complications,posing a substantial health burden.Although therapies,such as GLP-1 receptor agonists and SGLT2 inhibitors,have been successfully developed,new therapeutic options are still expected to offer better blood glucose control and decrease complications.AIM To elucidate the mechanism by which TERT/FOXO1 affects high glucose(HG)-induced dysfunction in isletβ-cells via the regulation of ATG9A-mediated autophagy.METHODS High-fat diet(HFD)-fed/streptozotocin(STZ)-treated mice or HG-treated MIN6 cells were used to establish T2DM models.Fasting blood glucose(FBG)and insulin levels in mice,as well as morphological changes in islet tissues,were assessed.Cell proliferation and the apoptosis rate were measured via EdU assays and flow cytometry,respectively.The expression levels of TERT,FOXO1,ATG9A and autophagy-related proteins(LC3B,p62)were analyzed via western blotting.The relationship between FOXO1 and ATG9A was assessed using dual-luciferase reporter gene assays and ChIP assays.RESULTS T2DM modeling in HFD-fed/STZ-treated mice and HG-treated MIN6 cells led to elevated TERT and FOXO1 expression and reduced ATG9A expression.Mice with T2DM were found to have decreased body weight,worsened morphology,elevated FBG and suppressed insulin levels.HG-treated MIN6 cells presented decreased viability and LC3B expression,in addition to increased p62 expression and apoptosis rates.FOXO1 knockdown both in vitro and in vivo protected mice and cells against isletβ-cell dysfunction via the activation of autophagy.The molecular mechanism involved the suppression of ATG9A expression by TERT through FOXO1 transcription activation.CONCLUSION Our results suggested that TERT/FOXO1 inhibits ATG9A expression to decrease isletβ-cell function in T2DM.
文摘BACKGROUND Not all islet transplants desirably achieve insulin independence.This can be attributed to the microarchitecture and function of the islets influenced by their dimensions.Large islets enhance insulin secretion through paracrine effects but are more susceptible to hypoxic injury post-transplant,while small islets offer better viability and insulin independence.In vivo studies suggest large islets are essential for maintaining euglycemia,though smaller islets are typically preferred in transplantation for better outcomes.AIM To document the impact of islet dimension on clinical and preclinical transplant outcomes to optimize procedures.METHODS PubMed,Scopus and EMBASE platforms were searched for relevant literature up to 9 April 2024.Articles reported on either glucose-stimulated insulin-secreting(GSIS)capacity,islet viability and engraftment,or insulin independence based on the islet dimension were included.The risk of bias was measured using the Appraisal Tool for Cross-Sectional Studies.Extracted data was analyzed via a narrative synthesis.RESULTS Nineteen studies were included in the review.A total of sixteen studies reported the GSIS,of which nine documented the increased insulin secretion in the small islet,where the majority reported insulin secretion per islet equivalent(IEQ).Seven studies documented increased GSIS in large-sized islets that measure insulin secretion per cell or islet.All the articles that compared small and large islets reported poor viability and engraftment of large islets.CONCLUSION Small islets with a diameter<125μm have desired transplantation outcomes due to their better survival following isolation.Large-sized islets receive blood supply directly from arterioles in vivo to meet their higher metabolic demands.The large islet undergoes central necrosis soon after the isolation(devascularization);failing to maintain the viability and glucose stimuli leads to a decline in GSIS and the overall function of the islet.Improved preservation of large islets after islet isolation,enhances the islet yield(IEQ),thereby reducing the likelihood of failed islet isolation and potentially improves transplant outcome.
基金supported by the National Natural Science Foundation of China(81673680)the Fundamental Research Funds for the Central Public Welfare Research Institutes(YZX-202306).
文摘Objective:To investigate the relationship between Jiaotai pill(JTP),its main component berberine(BBR),and the serotonin(5-HT)system in regulating islet hormone secretion and alleviating pancreatic b-cell dysfunction during type 2 diabetes mellitus(T2DM)progression.Methods:T2DM rat model was established using a high-fat diet and streptozotocin injection.JTP,BBR,and Metformin were intragastrically administered for 35 days.The analyzed indices included blood glucose,blood lipids,islet hormones,and proteins related to 5-HT synthesis,secretion,and transport.Additionally,an in vitro model of glucose injury in islet cells was established to study the effects of JTP and BBR on islet hormone secretion following tryptophan hydroxylase 1(TPH1)inhibition.Results:JTP and BBR significantly improved blood glucose and lipid levels and islet morphology in T2DM rats.Both models exhibited reduced islet 5-HT levels and impaired islet hormone secretion.However,the administration of JTP and BBR reversed these effects.Furthermore,JTP and BBR upregulated the expression of TPH1(P=.0194,P=.0413)transglutaminase 2(TGase2;P=.0492,P=.0349),serotonin transporter(SERT,P=.0090),and 5-hydroxytryptamine 1F receptor(5-HT1FR)in the islet 5-HT pathway(P=.0194).In the cell model,the regulatory effects of JTP and BBR on islet hormone levels were significantly weakened after TPH1 inhibition(P=.001),suggesting that JTP and BBR influence islet hormone secretion through the pancreatic 5-HT system.Conclusion:The islet 5-HT system is correlated with islet hormone secretion dysfunction in T2DM.JTP and BBR can improve islet hormone secretion by activating the TPH1/TGase2/SERT/5-HT1FR pathway in the islet 5-HT system in T2DM rats.
文摘Type 1 diabetes(T1D)is a chronic,lifelong,autoimmune disease that is debilitating and life-threatening to those who suffer from severe hypoglycaemic events or the devastating chronic complications.Exogenous insulin replacement,including the artificial pancreas,is the current mainstay of T1D therapy but cannot prevent the chronic vascular complications of the disease.They are also responsible for contributing to severe iatrogenic hypoglycaemia and impaired hypoglycaemic awareness.β-cell replacement with either pancreas or islet allotransplantation can reverse diabetes leading to better glycaemic control,prevention of hypoglycaemic events and improved quality of life for patients.The limited supply of cadaveric organ donors is a major barrier to this therapeutic option.Thus,alternative sources of islets are being actively explored,mainly human pluripotent stem-cell derived islets and xenogeneic porcine islets.Although these sources harbor their own risks and problems,various novel and innovative solutions are being perseveringly investigated across the globe to overcome these in the hopes that safe islet transplantation may one day be available to all T1D patients suffering from severe hypoglycaemic events.This review will concentrate on pre-clinical and clinical studies,in addition to the latest scientific discoveries relevant to T1D transplantation therapy using allogeneic or xenogeneic donor islet cells.
文摘BACKGROUND Diabetes is characterized by insulin resistance as well as impaired insulin production,withβ-cell dysfunction playing a critical role in disease progression.Exercise is known to improve insulin sensitivity,but its effects on pancreatic islet quality and function remain poorly understood.This work hypothesized that swimming training enhances glycemic control and insulin secretion by upregulating the insulin-like growth factor 1(IGF-1)/phosphatidylinositol 3-kinase/protein kinase B(PI3K/AKT)pathway in streptozotocin(STZ)-induced diabetic rats.AIM To investigate the effects of swimming on pancreatic islet quality and function in STZ-induced diabetic rats via the IGF-1/PI3K/AKT pathway.METHODS Twenty-six Sprague-Dawley rats were grouped into diabetic and control groups,with each group further split into exercise and sedentary subgroups.Diabetic rats were induced with STZ.The exercise groups underwent swimming training for 60 minutes/day,5 days/week,for 8 weeks.Body weight,food intake,blood glucose,insulin,lipids,and muscle glycogen were measured.Pancreatic islet morphology and the protein expression levels of IGF-1,PI3K,and AKT were analyzed.Data were analyzed using two-way repeated-measure ANOVA,followed by Tukey’s post-hoc test.RESULTS Exercise training significantly improved body weight[diabetic exercise group(D-Ex):390.66±50.14 g vs diabetic sedentary group(D-Sed):315.89±50.12 g,P<0.05],reduced blood glucose(D-Ex:12.21±4.43 mmol/L vs D-Sed:17.79±2.05 mmol/L,P<0.05),and increased insulin levels(D-Ex:53.50±15.31 pmol/L vs D-Sed:25.31±10.23 pmol/L,P<0.05)in diabetic rats.It also enhanced islet morphology,increased IGF-1 expression,and activated the PI3K/AKT pathway(P<0.05).In-vitro experiments confirmed that IGF-1 positively regulated insulin expression and inhibitedβ-cell apoptosis via the PI3K/AKT pathway.CONCLUSION Exercise training improves pancreatic islet quality and function in diabetic rats by modulating the IGF-1/PI3K/AKT pathway,highlighting its therapeutic potential for diabetes management.
文摘To get recombinant antigen (Is/et Cell Autoantigen 69)ICA69 which was expressed in Escherichia coli strains (E.coli) by means of the gene engineering technique so that it can be used for early diagnosis of and screening in type Ⅰ diabetes mellitus, the cDNA fragment of human ICA69 was amplified by PCR, and then cloned into pSPORT 1 vector. After DNA sequencing, it was inserted into pGEX-2T between the sites of EcoR Ⅰ and Sma Ⅰ, then recombinant plasmid p2T-ICA69 was constructed and introduced into E.coli. The GST-ICA69 fusion protein was expressed by the induction of IPTG. The recombinant ICA69 proteins were used to detect the antibodies against hICA69 in 100 healthy subjects and type Ⅰ diabetic serum by the use of indirect ELISA. The sequence analysis showed that the amplified fragments contained 1449 bp, encoded 483 amino acids, and had been correctly inserted into pGEX-2T vector. The recombinant proteins expressed in the prokaryotic cells had immunogenicity and could be used to detect antibodies against ICA69 in type Ⅰ diabetic serum. Finally it can be concluded in this paper that the expression products obtained by the method of gene engineering are recombinant ICA69 antigen and may be used to improve the forecast rate and the diagnostic rate of type Ⅰ diabetes in combination with other tests.
基金supported by the National Natural Science Foundation of China(No.82120108008,No.91857117)the Project of Biobank(No.YBKA201909)from Shanghai Ninth People’s Hospital,Shanghai Jiaotong University School of Medicinea grant from Shanghai Jiaotong University School of Medicine(No.19XJ11007).
文摘Objective Isletαcells input is essential for insulin secretion fromβcells.The present study aims to investigate the association between 25-hydroxyvitamin D[25(OH)D]and islet function homeostasis in type-2 diabetes(T2D)patients.Methods A total of 4670 T2D patients from seven communities in Shanghai,China were enrolled.The anthropometric indices,biochemical parameters,serum 25(OH)D,and islet function[including C-peptide(C-p)and glucagon]were measured.Results The fasting plasma glucose(FPG),glycated hemoglobin(HbA1c),glucagon,and C-p levels exhibited a significantly decreasing trend in T2D patients as the 25(OH)D levels increased.Next,the population was divided into two groups:abdominal obesity and non-abdominal obesity groups.After adjustment,the 25(OH)D level was found to be associated with HbA1c,glucagon,and homeostasis model assessment ofβ(HOMA-β)in the non-abdominal obesity group.There was a significant relationship between 25(OH)D and HbA1c,glucagon,HOMA-IR,baseline insulin or C-p in the abdominal obesity group.In the abdominal obesity group,the ordinary least squares(OLS)regression and quantile regression revealed that 25(OH)D was obviously associated with glucagon and fasting C-p levels.In the abdominal obesity group,the moderate analysis revealed a significant interaction effect of 25(OH)D and glucagon on C-p(P=0.0124).Furthermore,the conditional indirect effect of 25(OH)D on the glucagon/C-p ratio was significantly lower at 1 standard deviation(SD)below the mean(P=0.0002),and lower at the mean of the course of diabetes(P=0.0007).Conclusion 25(OH)D was found to be negatively correlated to glucagon and C-p in T2D patients with abdominal obesity.The 25(OH)D influenced C-p in part by influencing glucagon.The effect of 25(OH)D on the glucagon/C-p ratio in T2D patients with abdominal obesity,in terms of islet homeostasis,is influenced by the course of diabetes.
基金National Natural Science Foundation of China(No.81970668)Shaanxi Science and Technology Planning Project(No.2019JM-116)。
文摘Objective:To study the effect of mechanism of high glucose on apoptosis and cell cycle arrest of isletβcells via p27 pathway.Methods:Islet INS-1 cells were cultured and divided into groups.The control group was treated with ordinary medium,the high glucose group was treated with high glucose medium containing 25mmol/L glucose,the high glucose+si-NC group was treated with high glucose medium and transfected with NC siRNA,and the high glucose+si-P27 group was treated with high glucose medium and transfected with p27 siRNA.After 24 hours treatment,MTS assay was used to detect the cell viability A490,TUNEL assay was used to detect apoptosis rate,flow cytometry was used to detect the cell cycle distribution and western blot was used to detect the expression levels of P27,caspase-8 and cyclinD1.Results:Compared with those in the control group,the A490,the ratio of S phase and G2/M phase as well as the expression level of CyclinD1 decreased,while the apoptosis rate,the ratio of G0/G1 phase as well as the expression levels of P27 and caspase-8 increased in the high glucose group(P<0.05);compared with those in the high glucose group,the A490,cell cycle as well as the expression levels of P27,caspase-8 and cyclinD1 were not different from those in the high glucose+si-NC group(P>0.05);compared with those in the high glucose group and high glucose+si-NC group,the A490,the ratio of S phase and G2/M phase as well as the expression levels of cyclinD1 increased,while the apoptosis rate,the ratio of G0/G1 phase as well as the expression levels of p27 and caspase-8 decreased in the high glucose+si-P27 group(P<0.05).Conclusion:The apoptosis and cell cycle arrest induced by high glucose are related to P27 pathway activation.
基金supported by FATALSDrug Project [Progetti di Ricerca@CNR SAC.AD002.173.058] from National Research Council,Italy (to CV)。
文摘The NSC-34 cell line is a widely recognized motor neuron model and various neuronal differentiation protocols have been exploited. Under previously reported experimental conditions, only part of the cells resemble differentiated neurons;however, they do not exhibit extensive and time-prolonged neuritogenesis, and maintain their duplication capacity in culture. The aim of the present work was to facilitate long-term and more homogeneous neuronal differentiation in motor neuron–like NSC-34 cells. We found that the antimitotic drug cytosine arabinoside promoted robust and persistent neuronal differentiation in the entire cell population. Long and interconnecting neuronal processes with abundant growth cones were homogeneously induced and were durable for up to at least 6 weeks in culture. Moreover, cytosine arabinoside was permissive, dispensable, and mostly irreversible in priming NSC-34 cells for neurite initiation and regeneration after mechanical dislodgement. Finally, the expression of the cell proliferation antigen Ki67 was inhibited by cytosine arabinoside, whereas the expression levels of neuronal growth associated protein 43, vimentin, and motor neuron–specific p75, Islet2, homeobox 9 markers were upregulated, as confirmed by western blot and/or confocal immunofluorescence analysis. Overall, these findings support the use of NSC-34 cells as a motor neuron model for properly investigating neurodegenerative mechanisms and prospectively identifying neuroprotective strategies.
基金Supported by The National Scientific Research Fund of China(2008JK007)the National Key Research and Development Program of China for the Tenth Five-Year Plan,No.2006BAD06A14
文摘AIM:To investigate the antioxidant activity of chitooligosaccharides(COSs)on pancreatic islet cells in diabetic rats induced by streptozotocin. METHODS:The antioxidant effect of COSs on pancreatic islet cells was detected under optical microscopy and with colorimetric assay and gel electrophoresis.The activities of glutathione peroxidase and superoxide dismutase,total antioxidant capacity,and content of malondialdehyde in serum and tissue slices of pancreas were examined after 60 d to determine the effect of COSs in streptozotocin-induced diabetes in rats. RESULTS:COSs can prohibit the apoptosis of pancreatic islet cells.All concentrations of COSs can improve the capability of total antioxidant capacity and activity of superoxide dismutase and decrease the content of malondialdehyde drastically.Morphological investigation in the pancreas showed that COSs have resulted in the reduction of islets,loss of pancreatic cells,and nuclear pyknosis of pancreatic cells. CONCLUSION:COSs possess various biological activities and can be used in the treatment of diabetes mellitus.
基金Supported by Medical Key Subject grants (2001-34) from Jiangsu Province of China
文摘AIM: To study the capacity of bone marrow mesenchymal stem cells (BM-MSCs) trans-differentiating into islet-like cells and to observe the effect of portal vein transplantation of islet-like cells in the treatment of streptozotocin-induced diabetic rat. METHODS: BM-MSCs were isolated from SD rats and induced to differentiate into islet-like cells under defined conditions. Differentiation was evaluated with electron microscopy, RT-PCR, immunofluorescence and flow cytometry. insulin release after glucose challenge was tested with ELiSA. Then allogeneic islet-like cells were transplanted into diabetic rats via portal vein. Blood glucose levels were monitored and islet hormones were detected in the liver and pancreas of the recipient by immunohistochemistry. RESULTS: BM-MSCs were spheroid adherent monolayers with high CD90, CD29 and very low CD45 expression. Typical islet-like cells clusters were formed after induction. Electron microscopy revealed that secretory granules were densely packed within the cytoplasm of the differentiated cells. The spheroid cells expressed islet related genes and hormones. The insulin-positive cells accounted for 19.8% and mean fluorescence intensity increased by 2.6 fold after induction. The cells secreted a small amount of insulin that was increased 1.5 fold after glucose challenge. After transplantation, islet-like cells could locate in the liver expressing islet hormones and lower the glucose levels of diabetic rats during d 6 to d 20.CONCLUSION: Rat BM-MSCs could be transdifferentiated into islet-like cells in vitro . Portal vein transplantation of islet-like cells could alleviate the hyperglycemia of diabetic rats.
基金The National Natural Science Foundation of China,No.30500685
文摘AIM： To observe the effect of berberine on insulin secretion in rat pancreatic islets and to explore its possible molecular mechanism. METHODS： Pdmary rat islets were isolated from male Sprague-Dawley rats by collagenase digestion and treated with different concentrations （1, 3, 10 and 30 μmol/L） of berberine or 1 μmol/L Glibenclamide （GB） for 24 h. Glucose-stimulated insulin secretion （GSIS） assay was conducted and insulin was determined by radioimmunoassay. 3-（4,5-Dimethylthiazol-2-yl）- 2,5-diphenyltetrazolium bromide （MTT） assay was performed to evaluate cytotoxicity. The mRNA level of hepatic nuclear factor 4 alpha （HAIF4α） was determined by reverse transcription polymerase chain reaction （RT-PCR）. Indirect immunofluorescence staining and Western blot analysis were employed to detect protein expression of HNF4α in the islets. Glucokinase （GK） activity was measured by spectrophotometric method. RESULTS： Berberine enhanced GSIS rather than basal insulin secretion dose-dependently in rat islets and showed no significant cytotoxicity on islet cells at the concentration of 10 μmol/L. Both mRNA and protein expressions of HNF4α were up-regulated by berberine in a dose-dependent manner, and GK activity was also increased accordingly. However, GB demonstrated no regulatory effects on HNF4α expression or GK activity. CONCLUSION： Berberine can enhance GSIS in rat islets, and probably exerts the insulinotropic effect via a pathway involving HNF4α and GK, which is distinct from sulphonylureas （SUs）.
基金Supported by the National High Technology Research and Development Program of China (863 Program, 2001AA625050) and the National Key Research and Development Program of China during the Tenth Five-Year Plan Period, No. 2001BA708B04-07
文摘AIM: To investigate the effect of chitooligosaccharides on proliferation of pancreatic islet cells, release of insulin and 2 h plasma glucose in streptozotocin-induced diabetic rats.METHODS: In vitro, the effect of chitooligosaccharides on proliferation of pancreatic islet cells and release of insulin was detected with optical microscopy, colorimetric assay, and radioimmunoassay respectively. In vivo, the general clinical symptoms, 2 h plasma glucose, urine glucose, oral glucose tolerance were examined after sixty days of feeding study to determine the effect of chitooligosaccharides in streptozotocin-induced diabetic rats. RESULTS: Chitooligosaccharides could effectively accelerate the proliferation of pancreatic islet cells. Chitooligosaccharides (100 mg/L) had direct and prominent effect on pancreastic β cells and insulin release from islet cells. All concentrations of chitooligosaccharides could improve the general clinical symptoms of diabetic rats, decrease the 2 h plasma glucose and urine glucose, and normalize the disorders of glucose tolerance.CONCLUSION: Chitooligosaccharides possess various biological activities and can be used in the treatment of diabetes mellitus.
