Objective To explore the mechanisms of differentiation and development of pancreatic endocrine cells as well as pancreatic regeneration.Methods Human embryonic pancreatic tissue at 7-14 weeks of gestation was collecte...Objective To explore the mechanisms of differentiation and development of pancreatic endocrine cells as well as pancreatic regeneration.Methods Human embryonic pancreatic tissue at 7-14 weeks of gestation was collected.Diabetes mellitus rat model was induced with 65 mg/kg of streptozotocin.Insulin, glucagon, somatostatin, nestin, and cytokeratin 19 (CK19) of pancreatic tissues were observed by immunohistochemistry.Results At 9 weeks of gestation, pancreatic epithelial cells began to co-express insulin, glucagon, somatostatin, and CK19 before migration.Islet cells gradually congregated along with the increase of aging, and at 14 weeks of gestation histological examination showed islet formation.At 12 weeks of gestation, nestin-positive cells could be seen in the pancreatic mesenchyme.During early embryogenesis, islet cells of pancreatic ducts co-expressed insulin, glucagon, and somatostatin.During pancreatic regeneration after damage, nestin expression of islet cells increased.Conclusion In the early stage of embryogenesis, islet cells of primary pancreatic ducts can be differentiated to multipotential endocrine cells before migration.During tissue regeneration, pancreatic stem cells may differentiate and proliferate to form pancreatic islet.展开更多
The pancreas became one of the first objects of regenerative medicine,since other possibilities of dealing with the pancreatic endocrine insufficiency were clearly exhausted.The number of people living with diabetes m...The pancreas became one of the first objects of regenerative medicine,since other possibilities of dealing with the pancreatic endocrine insufficiency were clearly exhausted.The number of people living with diabetes mellitus is currently approaching half a billion,hence the crucial relevance of new methods to stimulate regeneration of the insulin-secretingβ-cells of the islets of Langerhans.Natural restrictions on the islet regeneration are very tight;nevertheless,the islets are capable of physiological regeneration viaβ-cell self-replication,direct differentiation of multipotent progenitor cells and spontaneousα-toβ-orδ-toβ-cell conversion(trans-differentiation).The existing preclinical models ofβ-cell dysfunction or ablation(induced surgically,chemically or genetically)have significantly expanded our understanding of reparative regeneration of the islets and possible ways of its stimulation.The ultimate goal,sufficient level of functional activity ofβ-cells or their substitutes can be achieved by two prospective broad strategies:β-cell replacement andβ-cell regeneration.The“regeneration”strategy aims to maintain a preserved population ofβ-cells through in situ exposure to biologically active substances that improveβ-cell survival,replication and insulin secretion,or to evoke the intrinsic adaptive mechanisms triggering the spontaneous non-β-toβ-cell conversion.The“replacement”strategy implies transplantation ofβ-cells(as non-disintegrated pancreatic material or isolated donor islets)orβ-like cells obtained ex vivo from progenitors or mature somatic cells(for example,hepatocytes orα-cells)under the action of small-molecule inducers or by genetic modification.We believe that the huge volume of experimental and clinical studies will finally allow a safe and effective solution to a seemingly simple goal-restoration of the functionally activeβ-cells,the innermost hope of millions of people globally.展开更多
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
Neuregulin-1 type Ⅲ is a key regulator in Schwann cell proliferation, committing to a myelinat- ing fate and regulating myelin sheath thickness. However, the expression pattern of neuregulin- 1 type III in the periph...Neuregulin-1 type Ⅲ is a key regulator in Schwann cell proliferation, committing to a myelinat- ing fate and regulating myelin sheath thickness. However, the expression pattern of neuregulin- 1 type III in the peripheral nervous system during developmental periods （such as the premyelin- ating stage, myelinating stage and postmyelinating stage） has rarely been studied. In this study, dorsal root ganglia were isolated from rats between postnatal day 1 and postnatal day 56. The expression pattern of neuregulin-1 type III in dorsal root ganglia neurons at various develop- mental stages were compared by quantitative real-time polymerase chain reaction, western blot assay and immunofluorescent staining. The expression of neuregulin-I type Ⅲ mRNA reached its peak at postnatal day 3 and then stabilized at a relative high expression level from postnatal day 3 to postnatal day 56. The expression of neuregulin-1 type III protein increased gradually from postnatal day 1, reached a peak at postnatal day 28, and then decreased at postnatal day 56. Immunofluorescent staining results showed a similar tendency to western blot assay results. Experimental findings indicate that the expression of neuregulin-1 type III in rat dorsal root ganglion was increased during the premyelinating （from postnatal day 2 to postnatal day 5） and myelinating stage （from postnatal day 5 to postnatal day 10）, but remained at a high level in the postmyelinating stage （after postnatal day 10）.展开更多
Diabetes mellitus remains a major burden.More than 200 million people are affected worldwide,which represents 6%of the world’s population.Type 1 diabetes mellitus is an autoimmune disease,which induces the permanent ...Diabetes mellitus remains a major burden.More than 200 million people are affected worldwide,which represents 6%of the world’s population.Type 1 diabetes mellitus is an autoimmune disease,which induces the permanent destruction of theβ-cells of the pancreatic islets of Langerhans.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.The successes achieved over the last few decades by the transplantation of whole pancreas and isolated islets suggest that diabetes can be cured by the replenishment of deficientβcells.However,islet transplantation efforts have various limitations,including the limited 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 the recent progress in clinical islet transplantation for the treatment of diabetes and to describe the recent progress on pancreatic stem/progenitor cell research,which has opened up several possibilities for the development of new treatments for diabetes.展开更多
Pancreatic stem cells were isolated and cultured from aborted human fetal pancreases of gestational age 14-20 weeks. They were seeded at a density of 1 × 104 in serum-free media for differentiation into neuron-li...Pancreatic stem cells were isolated and cultured from aborted human fetal pancreases of gestational age 14-20 weeks. They were seeded at a density of 1 × 104 in serum-free media for differentiation into neuron-like cells, expressing β-tubulin III and glial fibrillary acidic protein. These neuron-like cells displayed a synapse-like morphology and appeared to form a neuronal network. Pancreatic stem cells were also seeded at a density of 1 × 105 for differentiation into islet-like cells, expressing insulin and glucagon, with an islet-like morphology. These cells had glucose-stimulated secretion of human insulin and C-peptide. Results suggest that pancreatic stem cells can be differentiated into neuron-like and islet-like cells.展开更多
During the pathogenesis of type 1 diabetes(T1D) and type 2 diabetes(T2D), pancreatic islets, especially the β cells, face significant challenges. These insulin-producing cells adopt a regeneration strategy to compens...During the pathogenesis of type 1 diabetes(T1D) and type 2 diabetes(T2D), pancreatic islets, especially the β cells, face significant challenges. These insulin-producing cells adopt a regeneration strategy to compensate for the shortage of insulin, but the exact mechanism needs to be defined. High-fat diet(HFD) and streptozotocin(STZ) treatment are well-established models to study islet damage in T2D and T1D respectively. Therefore, we applied these two diabetic mouse models, triggered at different ages, to pursue the cell fate transition of isletβ cells. Cre-LoxP systems were used to generate islet cell type-specific(α, β, or δ) green fluorescent protein(GFP)-labeled mice for genetic lineage tracing, thereinto β-cell GFP-labeled mice were tamoxifen induced. Single-cell RNA sequencing(scRNA-seq) was used to investigate the evolutionary trajectories and molecular mechanisms of the GFP-labeled β cells in STZ-treated mice. STZ-induced diabetes caused extensive dedifferentiation of β cells and some of which transdifferentiated into α or δ cells in both youth-and adulthood-initiated mice while this phenomenon was barely observed in HFD models. β cells in HFD mice were expanded via self-replication rather than via transdifferentiation from α or δ cells, in contrast, α or δ cells were induced to transdifferentiate into β cells in STZ-treated mice(both youthand adulthood-initiated). In addition to the re-dedifferentiation of β cells, it is also highly likely that these “α or δ” cells transdifferentiated from pre-existing β cells could also re-trans-differentiate into insulin-producing β cells and be beneficial to islet recovery. The analysis of ScRNA-seq revealed that several pathways including mitochondrial function, chromatin modification, and remodeling are crucial in the dynamic transition of β cells. Our findings shed light on how islet β cells overcome the deficit of insulin and the molecular mechanism of islet recovery in T1D and T2D pathogenesis.展开更多
文摘Objective To explore the mechanisms of differentiation and development of pancreatic endocrine cells as well as pancreatic regeneration.Methods Human embryonic pancreatic tissue at 7-14 weeks of gestation was collected.Diabetes mellitus rat model was induced with 65 mg/kg of streptozotocin.Insulin, glucagon, somatostatin, nestin, and cytokeratin 19 (CK19) of pancreatic tissues were observed by immunohistochemistry.Results At 9 weeks of gestation, pancreatic epithelial cells began to co-express insulin, glucagon, somatostatin, and CK19 before migration.Islet cells gradually congregated along with the increase of aging, and at 14 weeks of gestation histological examination showed islet formation.At 12 weeks of gestation, nestin-positive cells could be seen in the pancreatic mesenchyme.During early embryogenesis, islet cells of pancreatic ducts co-expressed insulin, glucagon, and somatostatin.During pancreatic regeneration after damage, nestin expression of islet cells increased.Conclusion In the early stage of embryogenesis, islet cells of primary pancreatic ducts can be differentiated to multipotential endocrine cells before migration.During tissue regeneration, pancreatic stem cells may differentiate and proliferate to form pancreatic islet.
基金Supported by the President Grant for Government Support of Young Russian Scientists,No.075-15-2019-1120.
文摘The pancreas became one of the first objects of regenerative medicine,since other possibilities of dealing with the pancreatic endocrine insufficiency were clearly exhausted.The number of people living with diabetes mellitus is currently approaching half a billion,hence the crucial relevance of new methods to stimulate regeneration of the insulin-secretingβ-cells of the islets of Langerhans.Natural restrictions on the islet regeneration are very tight;nevertheless,the islets are capable of physiological regeneration viaβ-cell self-replication,direct differentiation of multipotent progenitor cells and spontaneousα-toβ-orδ-toβ-cell conversion(trans-differentiation).The existing preclinical models ofβ-cell dysfunction or ablation(induced surgically,chemically or genetically)have significantly expanded our understanding of reparative regeneration of the islets and possible ways of its stimulation.The ultimate goal,sufficient level of functional activity ofβ-cells or their substitutes can be achieved by two prospective broad strategies:β-cell replacement andβ-cell regeneration.The“regeneration”strategy aims to maintain a preserved population ofβ-cells through in situ exposure to biologically active substances that improveβ-cell survival,replication and insulin secretion,or to evoke the intrinsic adaptive mechanisms triggering the spontaneous non-β-toβ-cell conversion.The“replacement”strategy implies transplantation ofβ-cells(as non-disintegrated pancreatic material or isolated donor islets)orβ-like cells obtained ex vivo from progenitors or mature somatic cells(for example,hepatocytes orα-cells)under the action of small-molecule inducers or by genetic modification.We believe that the huge volume of experimental and clinical studies will finally allow a safe and effective solution to a seemingly simple goal-restoration of the functionally activeβ-cells,the innermost hope of millions of people globally.
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.
基金supported by grants from the National Program on Key Basic Research Project of China(973 Program),No.2014CB542206the National Natural Science Foundation of China,No.81201389,30973052Program for Changjiang Scholars and Innovative Research Team in University of Ministry of Education of China,No.IRT13051
文摘Neuregulin-1 type Ⅲ is a key regulator in Schwann cell proliferation, committing to a myelinat- ing fate and regulating myelin sheath thickness. However, the expression pattern of neuregulin- 1 type III in the peripheral nervous system during developmental periods （such as the premyelin- ating stage, myelinating stage and postmyelinating stage） has rarely been studied. In this study, dorsal root ganglia were isolated from rats between postnatal day 1 and postnatal day 56. The expression pattern of neuregulin-1 type III in dorsal root ganglia neurons at various develop- mental stages were compared by quantitative real-time polymerase chain reaction, western blot assay and immunofluorescent staining. The expression of neuregulin-I type Ⅲ mRNA reached its peak at postnatal day 3 and then stabilized at a relative high expression level from postnatal day 3 to postnatal day 56. The expression of neuregulin-1 type III protein increased gradually from postnatal day 1, reached a peak at postnatal day 28, and then decreased at postnatal day 56. Immunofluorescent staining results showed a similar tendency to western blot assay results. Experimental findings indicate that the expression of neuregulin-1 type III in rat dorsal root ganglion was increased during the premyelinating （from postnatal day 2 to postnatal day 5） and myelinating stage （from postnatal day 5 to postnatal day 10）, but remained at a high level in the postmyelinating stage （after postnatal day 10）.
文摘Diabetes mellitus remains a major burden.More than 200 million people are affected worldwide,which represents 6%of the world’s population.Type 1 diabetes mellitus is an autoimmune disease,which induces the permanent destruction of theβ-cells of the pancreatic islets of Langerhans.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.The successes achieved over the last few decades by the transplantation of whole pancreas and isolated islets suggest that diabetes can be cured by the replenishment of deficientβcells.However,islet transplantation efforts have various limitations,including the limited 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 the recent progress in clinical islet transplantation for the treatment of diabetes and to describe the recent progress on pancreatic stem/progenitor cell research,which has opened up several possibilities for the development of new treatments for diabetes.
基金supported by the Science and Technology Plan Project of Yantai City (Transplantation of pancreatic islet cells induced from human embryonic stem cells into diabetic animals in vitro), No. 2008142-9
文摘Pancreatic stem cells were isolated and cultured from aborted human fetal pancreases of gestational age 14-20 weeks. They were seeded at a density of 1 × 104 in serum-free media for differentiation into neuron-like cells, expressing β-tubulin III and glial fibrillary acidic protein. These neuron-like cells displayed a synapse-like morphology and appeared to form a neuronal network. Pancreatic stem cells were also seeded at a density of 1 × 105 for differentiation into islet-like cells, expressing insulin and glucagon, with an islet-like morphology. These cells had glucose-stimulated secretion of human insulin and C-peptide. Results suggest that pancreatic stem cells can be differentiated into neuron-like and islet-like cells.
基金supported by the National Natural Science Foundation of China(81830023,82070803,82100838,82100837,81900708)。
文摘During the pathogenesis of type 1 diabetes(T1D) and type 2 diabetes(T2D), pancreatic islets, especially the β cells, face significant challenges. These insulin-producing cells adopt a regeneration strategy to compensate for the shortage of insulin, but the exact mechanism needs to be defined. High-fat diet(HFD) and streptozotocin(STZ) treatment are well-established models to study islet damage in T2D and T1D respectively. Therefore, we applied these two diabetic mouse models, triggered at different ages, to pursue the cell fate transition of isletβ cells. Cre-LoxP systems were used to generate islet cell type-specific(α, β, or δ) green fluorescent protein(GFP)-labeled mice for genetic lineage tracing, thereinto β-cell GFP-labeled mice were tamoxifen induced. Single-cell RNA sequencing(scRNA-seq) was used to investigate the evolutionary trajectories and molecular mechanisms of the GFP-labeled β cells in STZ-treated mice. STZ-induced diabetes caused extensive dedifferentiation of β cells and some of which transdifferentiated into α or δ cells in both youth-and adulthood-initiated mice while this phenomenon was barely observed in HFD models. β cells in HFD mice were expanded via self-replication rather than via transdifferentiation from α or δ cells, in contrast, α or δ cells were induced to transdifferentiate into β cells in STZ-treated mice(both youthand adulthood-initiated). In addition to the re-dedifferentiation of β cells, it is also highly likely that these “α or δ” cells transdifferentiated from pre-existing β cells could also re-trans-differentiate into insulin-producing β cells and be beneficial to islet recovery. The analysis of ScRNA-seq revealed that several pathways including mitochondrial function, chromatin modification, and remodeling are crucial in the dynamic transition of β cells. Our findings shed light on how islet β cells overcome the deficit of insulin and the molecular mechanism of islet recovery in T1D and T2D pathogenesis.
