Type 1 diabetes mellitus is an autoimmune disease,which results in the permanent destruction of β-cells of the pancreatic islets of Langerhans.While exogenous insulin therapy has dramatically improved the quality of ...Type 1 diabetes mellitus is an autoimmune disease,which results in the permanent destruction of β-cells of the pancreatic islets of Langerhans.While exogenous insulin therapy has dramatically improved the quality of life,chronic diabetic complications develop in a substantial proportion of subjects and these complications generally progress and worsen over time.Although intensive insulin therapy has proven effective to delay and sometimes prevent the progression of complications such as nephropathy,neuropathy or retinopathy,it is difficult to achieve and maintain long term in most subjects.Reasons for this diff iculty include compliance issues and the increased risk of severe hypoglycemic episodes,which are generally associated with intensification of exogenous insulin therapy.Clinical studies have shown that transplantation of pancreas or purified pancreatic islets can support glucose homeostasis in type 1 diabetic patients.Islet transplantation carries the special advantages of being less invasive and resulting in fewer complications compared with the traditional pancreas or pancreas-kidney transplantation.However,islet transplantation efforts have limitations including the short supply of donor pancreata,the paucity of experienced islet isolation teams,side effects of immunosuppressants and poor long-term results.The purpose of this article is to review recent progress in clinical islet transplantation for the treatment of diabetes.展开更多
Background The induced expression of heme oxygenase-1 （HO-1） in donor islets improves allograft survival. Cobalt protoporphyrin （CoPP） could significantly enhance the expression of HO-1 mRNA and protein in rat isl...Background The induced expression of heme oxygenase-1 （HO-1） in donor islets improves allograft survival. Cobalt protoporphyrin （CoPP） could significantly enhance the expression of HO-1 mRNA and protein in rat islet safely. Our work was to study how to protect pancreatic islet xenograft by CoPP-induction. Methods Islet xenografts treated with CoPP-induction and CoPP＋ Zinc protoporphyrin （ZnPP） in vitro and in vivo were randomly transplanted into murine subrenal capsule; then the graft survival time was compared by blood glucose level and pathological examination and meanwhile the interferon ~ （IFN-y）, tumor necrosis factor a （TNF-a）, interleukin 10 （IL-10） and IL-113 level in serum and their mRNA and HO-1 mRNA and protein expression were examined. Results Islets with CoPP-induction under low- and high-glucose stimulation exhibited much higher insulin secretion compared with other three groups. CoPP-induction could increase higher expression of HO-1 （mRNA： 3.33- and 76.09- fold in vitro and in vivo; protein： 2.85- and 58.72-fold）. The normoglycemia time in induction groups （（14.63±1.19） and （16.88±1.64） days） was significantly longer. The pathological examination showed less lymphocyte infiltration in induction groups. The IL-10 level and its mRNA in induction groups were significantly higher. Conclusions The HO-1 induced by CoPP would significantly improve function, prolong normoglycemia time and reduce lymphocyte infiltration. Meanwhile CoPP-induction in vivo had more beneficial effects than in vitro. Its mechanism could be related to immune-modulation of IL-10.展开更多
基金Supported by The All Saints Health Foundation (in part)
文摘Type 1 diabetes mellitus is an autoimmune disease,which results in the permanent destruction of β-cells of the pancreatic islets of Langerhans.While exogenous insulin therapy has dramatically improved the quality of life,chronic diabetic complications develop in a substantial proportion of subjects and these complications generally progress and worsen over time.Although intensive insulin therapy has proven effective to delay and sometimes prevent the progression of complications such as nephropathy,neuropathy or retinopathy,it is difficult to achieve and maintain long term in most subjects.Reasons for this diff iculty include compliance issues and the increased risk of severe hypoglycemic episodes,which are generally associated with intensification of exogenous insulin therapy.Clinical studies have shown that transplantation of pancreas or purified pancreatic islets can support glucose homeostasis in type 1 diabetic patients.Islet transplantation carries the special advantages of being less invasive and resulting in fewer complications compared with the traditional pancreas or pancreas-kidney transplantation.However,islet transplantation efforts have limitations including the short supply of donor pancreata,the paucity of experienced islet isolation teams,side effects of immunosuppressants and poor long-term results.The purpose of this article is to review recent progress in clinical islet transplantation for the treatment of diabetes.
文摘Background The induced expression of heme oxygenase-1 （HO-1） in donor islets improves allograft survival. Cobalt protoporphyrin （CoPP） could significantly enhance the expression of HO-1 mRNA and protein in rat islet safely. Our work was to study how to protect pancreatic islet xenograft by CoPP-induction. Methods Islet xenografts treated with CoPP-induction and CoPP＋ Zinc protoporphyrin （ZnPP） in vitro and in vivo were randomly transplanted into murine subrenal capsule; then the graft survival time was compared by blood glucose level and pathological examination and meanwhile the interferon ~ （IFN-y）, tumor necrosis factor a （TNF-a）, interleukin 10 （IL-10） and IL-113 level in serum and their mRNA and HO-1 mRNA and protein expression were examined. Results Islets with CoPP-induction under low- and high-glucose stimulation exhibited much higher insulin secretion compared with other three groups. CoPP-induction could increase higher expression of HO-1 （mRNA： 3.33- and 76.09- fold in vitro and in vivo; protein： 2.85- and 58.72-fold）. The normoglycemia time in induction groups （（14.63±1.19） and （16.88±1.64） days） was significantly longer. The pathological examination showed less lymphocyte infiltration in induction groups. The IL-10 level and its mRNA in induction groups were significantly higher. Conclusions The HO-1 induced by CoPP would significantly improve function, prolong normoglycemia time and reduce lymphocyte infiltration. Meanwhile CoPP-induction in vivo had more beneficial effects than in vitro. Its mechanism could be related to immune-modulation of IL-10.
