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
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
Regenerative medicine, including cell-replacement strategies, may have an important role in the treatment of type 1 diabetes which is associated with decreased islet cell mass. To date, significant progress has been m...Regenerative medicine, including cell-replacement strategies, may have an important role in the treatment of type 1 diabetes which is associated with decreased islet cell mass. To date, significant progress has been made in generating insulin-secreting 13 cells from pluripotent mouse embryonic stem cells （ESCs）.The aim of this study is to explore the potential of regulating the differentiation of ESCs into pancreatic endocrine cells capable of synthesizing the pancreatic hormones including insulin, glucagon, somatostatin and pancreatic polypeptide under proper conditions. Undifferentiated ES cell line was stably transfected with mouse RIP-YFP plasmid construction in serum-free medium using LipofectamineTM 2000 Reagents. We tested pancreatic specific gene expression and characterized these ESC-derived pancreatic endocrine cells. Most of these insulin-secreting cells co-expressed many of the phenotypic markers characteristic of 13 cells such as insulinl, insulin2, Isletl, MafA, insulinoma-associated antigen 1 （IA1） and so on, indicating a similar gene expression pattern to adult islet 13 cells in vivo. Characterization of this population revealed that it consisted predominantly of pancreatic endocrine cells that were able to undergo pancreatic specification under the appropriate conditions. We also demonstrated that zinc supplementation mediated up-regulation of insulin-secreting cells as an effective inducer promoted the development of ESC-derived diabetes therapy. In conclusion, this work not only established an efficient pancreatic differentiation strategy from ESCs to pancreatic endocrine lineage in vitro, but also leaded to the development of new strategies to derive transplantable islet-replacement 13 cells from embryonic stem cells for the future applications of a stem cell based therapy of diabetes.展开更多
AIM: To explore the bioactivity of an ethanolic extract of Schizandra arisanensis (SA-Et) and isolated constituents against interleukin-1 β and interferon-γ-mediated β cell death and abolition of insulin secretion....AIM: To explore the bioactivity of an ethanolic extract of Schizandra arisanensis (SA-Et) and isolated constituents against interleukin-1 β and interferon-γ-mediated β cell death and abolition of insulin secretion. METHODS: By employing BRIN-BD11 cells, the effects of SA-Et administration on cytokine-mediated cell death and abolition of insulin secretion were evaluated by a viability assay, cell cycle analysis, and insulin assay. The associated gene and protein expressions were also measured. In addition, the bioactivities of several peak compounds collected from the SA-Et were tested against cytokine-mediated β cell death.RESULTS: Our Results revealed that SA-Et dose-dependently ameliorated cytokine-mediated β cell death and apoptosis. Instead of suppressing inducible nitric oxide synthase/nitric oxide cascade or p38MAPK activity, suppression of stress-activated protein kinase/c-Jun NH2-terminal kinase activity appeared to be the target for SA-Et against the cytokine mix. In addition, SA-Et provided some insulinotropic effects which re-activated the abolished insulin exocytosis in cytokine-treated BRIN-BD11 cells. Finally, schiarisanrin A and B isolated from the SA-Et showed a dose-dependent protective effect against cytokine-mediated β cell death. CONCLUSION: This is the first report on SA-Et ameliorating cytokine-mediated β cell death and dysfunction via anti-apoptotic and insulinotropic actions.展开更多
OBJECTIVE： To evaluate the effect of Nelumbo Nucifera leaf water extract （NNLE） on insulinoma （RIN） cells induced by interleukin-1β （1L-1β） and interferon-g （IFN-γ）, and injured pancreatic β-cells induced...OBJECTIVE： To evaluate the effect of Nelumbo Nucifera leaf water extract （NNLE） on insulinoma （RIN） cells induced by interleukin-1β （1L-1β） and interferon-g （IFN-γ）, and injured pancreatic β-cells induced by Streptozotocin （STZ） in rats. METHODS： The anti-oxidative effects of NNLE were assessed using 1,1 -diphenyl-2-picryl hydrazyl （DPPH） and nitric oxide （NO） scavenging assays. The inhibitory effect of NNLE on a-glucosidase and DPP （dipeptidyl peptidase）-IV was measured in vitro. Pancreatic 1β-cell protective and insulin secretory effects were assessed, using 1L-1β and IFN-γ-inducedrat RIN cells. STZ-induced diabetic rats were treated with 50, 100, and 400 mg/kg NNLE for 4 weeks. The effects of NNLE on blood glucose （BG）, body weight （BW）, and lipid profiles were measured. RESULTS： NNLE inhibited DPPH, NO, aglucosidase, and DPP-Ⅳ which were directly linked to the function of β-cells. Furthermore, NNLE protected RIN cells from toxicity induced by 11-11β and IFN-γ, decreased NO production, and increased insulin secretion. NNLE caused a significant reduction in blood glucose, triglyceride （TG）, total cholesterol （TC）, blood urea nitrogen （BUN）, and creatinine in STZ-induced diabetic rats. Furthermore, it significantly decreased BW loss in STZ-induced diabetic rats. CONCLUSION： Our results suggest that NNLE reduced the toxicity in insulinoma cells and increased insulin secretion in pancreatic β-cells in STZ-induced diabetic rats.展开更多
Pluripotent stem cells(PSCs) are able to differentiate into several cell types, including pancreatic β cells. Differentiation of pancreatic β cells depends on certain transcription factors, which function in a coord...Pluripotent stem cells(PSCs) are able to differentiate into several cell types, including pancreatic β cells. Differentiation of pancreatic β cells depends on certain transcription factors, which function in a coordinated way during pancreas development. The existing protocols for in vitro differentiation produce pancreatic β cells, which are not highly responsive to glucose stimulation except after their transplantation into immune-compromised mice and allowing several weeks for further differentiation to ensure the maturation of these cells in vivo. Thus, although the substantial improvement that has been made for the differentiation of induced PSCs and embryonic stem cells toward pancreatic β cells, several challenges still hindering their full generation. Here, we summarize recent advances in the differentiation of PSCs into pancreatic β cells and discuss the challenges facing their differentiation as well as the different applications of these potential PSC-derived β cells.展开更多
AIM： To identify and compare the profile of Ca^2＋ channel subunit expression in INS-1 and rat pancreatic β cells.METHODS： The rat insulin-secreting INS-1 cell line was cultured in RPMI-1640 with Wistar rats employ...AIM： To identify and compare the profile of Ca^2＋ channel subunit expression in INS-1 and rat pancreatic β cells.METHODS： The rat insulin-secreting INS-1 cell line was cultured in RPMI-1640 with Wistar rats employed as islet donors. Ca^2＋ channel subunit expression in INS-1 and isolated rat β cells were examined by reverse transcription polymerase chain reaction （RT-PCR）. Absolute real-time quantitative PCR was performed in a Bio-Rad iQ5 Gradient Real Time PCR system and the data analyzed using an iQ5 system to identify the expression level of the Ca^2＋ channel subunits. RESULTS： In INS-1 cells, the L-type Ca^2＋ channel 1C subunit had the highest expression level and the TPRM2 subunit had the second highest expression. In rat β cells, the TPRC4β subunit expression was dominant and the expression of the L-type lC subunit exceeded the 1D subunit expression about two-fold. This result agreed with other studies, confirming the important role of the L-type lC subunit in insulinsecreting cells, and suggested that non-voltage-operated Ca^2＋ channels may have an important role in biphasic insulin secretion. CONCLUSION： Twelve major Ca^2＋ channel subunit types were identified in INS-1 and rat β cells and significant differences were observed in the expression of certain subunits between these cells.展开更多
Objective To investigate the effect of ferulic acid,a natural compound,on pancreatic beta cell viability,Ca^(2+)channels,and insulin secretion.Methods We studied the effects of ferulic acid on rat insulinoma cell line...Objective To investigate the effect of ferulic acid,a natural compound,on pancreatic beta cell viability,Ca^(2+)channels,and insulin secretion.Methods We studied the effects of ferulic acid on rat insulinoma cell line viability using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide viability assay.The whole-cell patch-clamp technique and enzyme-linked immunosorbent assay were also used to examine the action of ferulic acid on Ca^(2+)channels and insulin secretion,respectively.Results Ferulic acid did not affect cell viability during exposures up to 72 h.The electrophysiological study demonstrated that ferulic acid rapidly and concentration-dependently increased L-type Ca^(2+)channel current,shifting its activation curve in the hyperpolarizing direction with a decreased slope factor,while the voltage dependence of inactivation was not affected.On the other hand,ferulic acid have no effect on T-type Ca^(2+)channels.Furthermore,ferulic acid significantly increased insulin secretion,an effect inhibited by nifedipine and Ca^(2+)-free extracellular fluid,confirming that ferulic acid-induced insulin secretion in these cells was mediated by augmenting Ca^(2+)influx through L-type Ca^(2+)channel.Our data also suggest that this may be a direct,nongenomic action.Conclusion This is the first electrophysiological demonstration that acute ferulic acid treatment could increase L-type Ca^(2+)channel current in pancreaticβcells by enhancing its voltage dependence of activation,leading to insulin secretion.展开更多
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.
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Regenerative medicine, including cell-replacement strategies, may have an important role in the treatment of type 1 diabetes which is associated with decreased islet cell mass. To date, significant progress has been made in generating insulin-secreting 13 cells from pluripotent mouse embryonic stem cells （ESCs）.The aim of this study is to explore the potential of regulating the differentiation of ESCs into pancreatic endocrine cells capable of synthesizing the pancreatic hormones including insulin, glucagon, somatostatin and pancreatic polypeptide under proper conditions. Undifferentiated ES cell line was stably transfected with mouse RIP-YFP plasmid construction in serum-free medium using LipofectamineTM 2000 Reagents. We tested pancreatic specific gene expression and characterized these ESC-derived pancreatic endocrine cells. Most of these insulin-secreting cells co-expressed many of the phenotypic markers characteristic of 13 cells such as insulinl, insulin2, Isletl, MafA, insulinoma-associated antigen 1 （IA1） and so on, indicating a similar gene expression pattern to adult islet 13 cells in vivo. Characterization of this population revealed that it consisted predominantly of pancreatic endocrine cells that were able to undergo pancreatic specification under the appropriate conditions. We also demonstrated that zinc supplementation mediated up-regulation of insulin-secreting cells as an effective inducer promoted the development of ESC-derived diabetes therapy. In conclusion, this work not only established an efficient pancreatic differentiation strategy from ESCs to pancreatic endocrine lineage in vitro, but also leaded to the development of new strategies to derive transplantable islet-replacement 13 cells from embryonic stem cells for the future applications of a stem cell based therapy of diabetes.
基金Supported by National Science Council, No. NSC94-2314-B-077-001, No. NSC101-2320-B-077-003-MY2National Research Institute of Chinese Medicine, No. NRICM95-DHM-04
文摘AIM: To explore the bioactivity of an ethanolic extract of Schizandra arisanensis (SA-Et) and isolated constituents against interleukin-1 β and interferon-γ-mediated β cell death and abolition of insulin secretion. METHODS: By employing BRIN-BD11 cells, the effects of SA-Et administration on cytokine-mediated cell death and abolition of insulin secretion were evaluated by a viability assay, cell cycle analysis, and insulin assay. The associated gene and protein expressions were also measured. In addition, the bioactivities of several peak compounds collected from the SA-Et were tested against cytokine-mediated β cell death.RESULTS: Our Results revealed that SA-Et dose-dependently ameliorated cytokine-mediated β cell death and apoptosis. Instead of suppressing inducible nitric oxide synthase/nitric oxide cascade or p38MAPK activity, suppression of stress-activated protein kinase/c-Jun NH2-terminal kinase activity appeared to be the target for SA-Et against the cytokine mix. In addition, SA-Et provided some insulinotropic effects which re-activated the abolished insulin exocytosis in cytokine-treated BRIN-BD11 cells. Finally, schiarisanrin A and B isolated from the SA-Et showed a dose-dependent protective effect against cytokine-mediated β cell death. CONCLUSION: This is the first report on SA-Et ameliorating cytokine-mediated β cell death and dysfunction via anti-apoptotic and insulinotropic actions.
文摘OBJECTIVE： To evaluate the effect of Nelumbo Nucifera leaf water extract （NNLE） on insulinoma （RIN） cells induced by interleukin-1β （1L-1β） and interferon-g （IFN-γ）, and injured pancreatic β-cells induced by Streptozotocin （STZ） in rats. METHODS： The anti-oxidative effects of NNLE were assessed using 1,1 -diphenyl-2-picryl hydrazyl （DPPH） and nitric oxide （NO） scavenging assays. The inhibitory effect of NNLE on a-glucosidase and DPP （dipeptidyl peptidase）-IV was measured in vitro. Pancreatic 1β-cell protective and insulin secretory effects were assessed, using 1L-1β and IFN-γ-inducedrat RIN cells. STZ-induced diabetic rats were treated with 50, 100, and 400 mg/kg NNLE for 4 weeks. The effects of NNLE on blood glucose （BG）, body weight （BW）, and lipid profiles were measured. RESULTS： NNLE inhibited DPPH, NO, aglucosidase, and DPP-Ⅳ which were directly linked to the function of β-cells. Furthermore, NNLE protected RIN cells from toxicity induced by 11-11β and IFN-γ, decreased NO production, and increased insulin secretion. NNLE caused a significant reduction in blood glucose, triglyceride （TG）, total cholesterol （TC）, blood urea nitrogen （BUN）, and creatinine in STZ-induced diabetic rats. Furthermore, it significantly decreased BW loss in STZ-induced diabetic rats. CONCLUSION： Our results suggest that NNLE reduced the toxicity in insulinoma cells and increased insulin secretion in pancreatic β-cells in STZ-induced diabetic rats.
文摘Pluripotent stem cells(PSCs) are able to differentiate into several cell types, including pancreatic β cells. Differentiation of pancreatic β cells depends on certain transcription factors, which function in a coordinated way during pancreas development. The existing protocols for in vitro differentiation produce pancreatic β cells, which are not highly responsive to glucose stimulation except after their transplantation into immune-compromised mice and allowing several weeks for further differentiation to ensure the maturation of these cells in vivo. Thus, although the substantial improvement that has been made for the differentiation of induced PSCs and embryonic stem cells toward pancreatic β cells, several challenges still hindering their full generation. Here, we summarize recent advances in the differentiation of PSCs into pancreatic β cells and discuss the challenges facing their differentiation as well as the different applications of these potential PSC-derived β cells.
基金Supported by The Tsinghua-Yue-Yuan Medical Science Fund,No20240000568
文摘AIM： To identify and compare the profile of Ca^2＋ channel subunit expression in INS-1 and rat pancreatic β cells.METHODS： The rat insulin-secreting INS-1 cell line was cultured in RPMI-1640 with Wistar rats employed as islet donors. Ca^2＋ channel subunit expression in INS-1 and isolated rat β cells were examined by reverse transcription polymerase chain reaction （RT-PCR）. Absolute real-time quantitative PCR was performed in a Bio-Rad iQ5 Gradient Real Time PCR system and the data analyzed using an iQ5 system to identify the expression level of the Ca^2＋ channel subunits. RESULTS： In INS-1 cells, the L-type Ca^2＋ channel 1C subunit had the highest expression level and the TPRM2 subunit had the second highest expression. In rat β cells, the TPRC4β subunit expression was dominant and the expression of the L-type lC subunit exceeded the 1D subunit expression about two-fold. This result agreed with other studies, confirming the important role of the L-type lC subunit in insulinsecreting cells, and suggested that non-voltage-operated Ca^2＋ channels may have an important role in biphasic insulin secretion. CONCLUSION： Twelve major Ca^2＋ channel subunit types were identified in INS-1 and rat β cells and significant differences were observed in the expression of certain subunits between these cells.
基金This research project was supported by Mahidol University,Thailand.We also thank the Faculty of Medicine Siriraj Hospital,Mahidol University,for additional financial support to K.R.and W.B.W。
文摘Objective To investigate the effect of ferulic acid,a natural compound,on pancreatic beta cell viability,Ca^(2+)channels,and insulin secretion.Methods We studied the effects of ferulic acid on rat insulinoma cell line viability using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide viability assay.The whole-cell patch-clamp technique and enzyme-linked immunosorbent assay were also used to examine the action of ferulic acid on Ca^(2+)channels and insulin secretion,respectively.Results Ferulic acid did not affect cell viability during exposures up to 72 h.The electrophysiological study demonstrated that ferulic acid rapidly and concentration-dependently increased L-type Ca^(2+)channel current,shifting its activation curve in the hyperpolarizing direction with a decreased slope factor,while the voltage dependence of inactivation was not affected.On the other hand,ferulic acid have no effect on T-type Ca^(2+)channels.Furthermore,ferulic acid significantly increased insulin secretion,an effect inhibited by nifedipine and Ca^(2+)-free extracellular fluid,confirming that ferulic acid-induced insulin secretion in these cells was mediated by augmenting Ca^(2+)influx through L-type Ca^(2+)channel.Our data also suggest that this may be a direct,nongenomic action.Conclusion This is the first electrophysiological demonstration that acute ferulic acid treatment could increase L-type Ca^(2+)channel current in pancreaticβcells by enhancing its voltage dependence of activation,leading to insulin secretion.
