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
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
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 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 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
Excessive secretion of human islet amyloid polypeptide(hIAPP)is an important pathological basis of diabetic encephalopathy(DE).In this study,we aimed to investigate the potential implications of hIAPP in DE pathogenes...Excessive secretion of human islet amyloid polypeptide(hIAPP)is an important pathological basis of diabetic encephalopathy(DE).In this study,we aimed to investigate the potential implications of hIAPP in DE pathogenesis.Brain magnetic resonance imaging and cognitive scales were applied to evaluate white matter damage and cognitive function.We found that the concentration of serum hIAPP was positively correlated with white matter damage but negatively correlated with cognitive scores in patients with type 2 diabetes mellitus.In vitro assays revealed that oligodendrocytes,compared with neurons,were more prone to acidosis under exogenous hIAPP stimulation.Moreover,western blotting and co-immunoprecipitation indicated that hIAPP interfered with the binding process of monocarboxylate transporter(MCT)1 to its accessory protein CD147 but had no effect on the binding of MCT2 to its accessory protein gp70.Proteomic differential analysis of proteins co-immunoprecipitated with CD147 in oligodendrocytes revealed Yeast Rab GTPase-Interacting protein 2(YIPF2,which modulates the transfer of CD147 to the cell membrane)as a significant target.Furthermore,YIPF2 inhibition significantly improved hIAPP-induced acidosis in oligodendrocytes and alleviated cognitive dysfunction in DE model mice.These findings suggest that increased CD147 translocation by inhibition of YIPF2 optimizes MCT1 and CD147 binding,potentially ameliorating hIAPP-induced acidosis and the consequent DE-related demyelination.展开更多
Type 1 diabetes mellitus(T1DM) lacks insulin secretion due to autoimmune deficiency of pancreaticβ-cells.Protecting pancreatic islets and enhancing insulin secretion has been therapeutic approaches.Mannogalactoglucan...Type 1 diabetes mellitus(T1DM) lacks insulin secretion due to autoimmune deficiency of pancreaticβ-cells.Protecting pancreatic islets and enhancing insulin secretion has been therapeutic approaches.Mannogalactoglucan is the main type of polysaccharide from natural mushroom,which has potential medicinal prospects.Nevertheless,the antidiabetic property of mannogalactoglucan in T1DM has not been fully elucidated.In this study,we obtained the neutral fraction of alkali-soluble Armillaria mellea polysaccharide(AAMP-N) with the structure of mannogalactoglucan from the fruiting body of A.mellea and investigated the potential therapeutic value of AAMP-N in T1DM.We demonstrated that AAMP-N lowered blood glucose and improved diabetes symptoms in T1DM mice.AAMP-N activated unfolded protein response(UPR) signaling pathway to maintain ER protein folding homeostasis and promote insulin secretion in vivo.Besides that,AAMP-N promoted insulin synthesis via upregulating the expression of transcription factors,increased Ca^(2+) signals to stimulate intracellular insulin secretory vesicle transport via activating calcium/calmodulin-dependent kinase Ⅱ(CamkⅡ) and cAMP/PKA signals,and enhanced insulin secretory vesicle fusion with the plasma membrane via vesicle-associated membrane protein 2(VAMP2).Collectively,these studies demonstrated that the therapeutic potential of AAMP-N on pancreatic islets function,indicating that mannogalactoglucan could be natural nutraceutical used for the treatment of T1DM.展开更多
Imaging changes in the pancreas can provide valuable information about the status of islet beta-cell function in different pancreatic diseases,such as diabetes,pancreatitis,pancreatic cancer,fatty pancreas,and insulin...Imaging changes in the pancreas can provide valuable information about the status of islet beta-cell function in different pancreatic diseases,such as diabetes,pancreatitis,pancreatic cancer,fatty pancreas,and insulinoma.While imaging cannot directly measure beta-cell function;it can be used as a marker of disease progression and a tool to guide therapeutic interventions.As imaging techno-logies continue to advance,they will likely play an increasingly important role in diagnosing,monitoring,and managing diabetes.展开更多
AIM： To evaluate the recovery and function of isolated rat pancreatic islets during in vitro culture with small intestinal submucosa （SIS）. METHODS： Pancreatic islets were isolated from Wistar rats by standard sur...AIM： To evaluate the recovery and function of isolated rat pancreatic islets during in vitro culture with small intestinal submucosa （SIS）. METHODS： Pancreatic islets were isolated from Wistar rats by standard surgical procurement followed by intraductal collagenase distension, mechanical dissociation and Euroficoll purification. Purified islets were cultured in plates coated with multilayer SIS （SIS-treated group） or without multilayer SIS （standard cultured group） for 7 and 14 d in standard islet culture media of RPMI 1640. After isolation and culture, islets from both experimental groups were stained with dithizone and counted. Recovery of islets was determined by the ratio of counts after the culture to the yield of islets immediately following islet isolation. Viability of islets after the culture was assessed by the glucose challenge best with low （2.7 mmol/L） and high glucose （16.7 mmol/L） solution supplemented with 50 mmol/L 3-isobutyl-1- methylxanthine （IBMX） solution. Apoptosis of islet cells after the culture was measured by relative quantification of histone-complexed DNA fragments using ELISA. RESULTS： After 7 or 14 d of in vitro tissue culture, the recovery of islets in SIS-treated group was significantly higher than that cultured in plates without SIS coating. The recovery of islets in SIS-treated group was about twice more than that of in the control group. In SIS treated group, there was no significant difference in the recovery of islets between short- and long-term periods of culture （95.8±1.0% vs 90.8±1.5%, P〉0.05）. When incubated with high glucose （16.7 mmol/L） solution, insulin secretion in SIS-treated group showed a higher increase than that in control group after 14 d of culture （20.7±1.1 mU/L vs 11.8±1.1 mU/L, P〈0.05）. When islets were placed in high glucose solution containing IBMX, stimulated insulin secretion was higher in SlS-treated group than in control group. Calculated stimulation index of SlS-treated group was about 23 times of control group. In addition, the stimulation index of SlS-treated group remained constant regardless of short- and long- term periods of culture （9.5±0.2 vs 10.2±1.2, P〉0.05）. Much less apoptosis of islet cells occurred in SlS-treated group than in control group after the culture. CONCLUSION： Co-culture of isolated rat islets with native sheet-like SIS might build an extracellular matrix for islets and provide possible biotrophic and growth factors that promote the recovery and subsequent function of islets.展开更多
The purpose of the present study was to organize the parameters involved in experimental allotransplantation in rodents to elaborate the most suitable model to supply the scarcity of islet donors. We used the PubMed d...The purpose of the present study was to organize the parameters involved in experimental allotransplantation in rodents to elaborate the most suitable model to supply the scarcity of islet donors. We used the PubMed database to systematically search for published articles containing the keywords “rodent islet transplantation” to review. We included studies that involved allotransplantation experiments with rodents’ islets, and we reviewed the reference lists from the eligible publications that were retrieved. We excluded articles related to isotransplantation, autotransplantation and xenotransplantation, i.e., transplantation in other species. A total of 25 studies related to allotransplantation were selected for systematic review based on their relevance and updated data. Allotransplantation in rodents is promising and continues to develop. Survival rates of allografts have increased with the discovery of new immunosuppressive drugs and the use of different graft sites. These successes suggest that islet transplantation is a promising method to overcome the scarcity of islet donors and advance the treatment options for type 1 diabetes.展开更多
Islet transplantation could become an ideal treatment for severe diabetes to prevent hypoglycemia shock and irreversible diabetic complications, once some of the major and unresolved obstacles are overcome, including ...Islet transplantation could become an ideal treatment for severe diabetes to prevent hypoglycemia shock and irreversible diabetic complications, once some of the major and unresolved obstacles are overcome, including limited donor supplies and side effects caused by permanent immunosuppressant use. Approximately 30 years ago, some groups succeeded in improving the blood glucose of diabetic animals by transplanting encapsulated islets with semi-permeable membranes consisting of polymer. A semi-permeable membrane protects both the inner islets from mechanical stress and the recipient’s immune system (both cellular and humoral immunities), while allowing bidirectional diffusion of nutrients, oxygen, glucose, hormones and wastes, i.e., immune-isolation. This device, which enables immune-isolation, is called encapsulated islets or bio-artificial pancreas. Encapsulation with a semipermeable membrane can provide some advantages: (1) this device protects transplanted cells from the recipient’s immunity even if the xenogeneic islets (from large animals such as pig) or insulin-producing cells are derived from cells that have the potential for differentiation (some kinds of stem cells). In other words, the encapsulation technique can resolve the problem of limited donor supplies; and (2) encapsulation can reduce or prevent chronic administration of immunosuppressants and, therefore, important side effects otherwise induced by immunosuppressants. And now, many novel encapsulated islet systems have been developed and are being prepared for testing in a clinical setting.展开更多
The intra-islet microvasculature is a critical interface between the blood and islet endocrine cells governing a number of cellular and pathophysiological processes associated with the pancreatic tissue. A growing bod...The intra-islet microvasculature is a critical interface between the blood and islet endocrine cells governing a number of cellular and pathophysiological processes associated with the pancreatic tissue. A growing body of evidence indicates a strong functional and physical interdependency of β-cells with endothelial cells(ECs), the building blocks of islet microvasculature. Intra-islet ECs, actively regulate vascular permeability and appear to play a role in fine-tuning blood glucose sensing and regulation. These cells also tend to behave as "guardians", controlling the expression and movement of a number of important immune mediators, thereby strongly contributing to the physiology of islets. This review will focus on the molecular signalling and crosstalk between the intra-islet ECs and β-cells and how their relationship can be a potential target for intervention strategies in islet pathology and islet transplantation.展开更多
BACKGROUND: Type 1 diabets is an autoimmune disease caused by the destruction of pancreatic β-cell with an in- creased incidence worldwide in the closing decades of the 20th century. This study was to investigate the...BACKGROUND: Type 1 diabets is an autoimmune disease caused by the destruction of pancreatic β-cell with an in- creased incidence worldwide in the closing decades of the 20th century. This study was to investigate the effects of human umbilical cord serum (UCS) on the proliferation and function of human fetal islet-like cell clusters (ICCs) in vitro. METHODS: Eight fresh pancreatic glands obtained after in- duction of labor with water bag were mildly exposed to col- lagenase V, and the digested cells were cultured in a RPMI- 1640 medium plus 10% pooled UCS or fetal calf serum (FCS) to permit cells attachment and outgrowth of ICCs. RESULTS: In 8 consecutively explanted glands, develop- ment and proliferation of ICCs were observed. In the pre- sence of FCS, the outgrowth of ICC took place on the top of a flbroblast monocellular layer. UCS affected less growth of fibroblasts and increased the formation of ICCs about four-fold compared with explants from the same glands maintained in FCS. In both UCS and FCS, the insulin con- tent of the medium was variable to a certain extent and progressively declined from day 2 to day 6. Dithizone- stained ICCs in UCS suggested that most cell clusters were islet cells ( β-cells), and the purity of islets was estimated 80%-90%. The ultrastructure of the cultured cells showed a large number of granule-containing cells, most of which were identified as β-cells. CONCLUSION: We conclude that in comparison with ex- plants with FCS, the yield of ICCs and purification of islet cells are markedly increased by UCS and may facilitate the proliferation of pancreatic β-cells intended for islet trans- plantation.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
Total pancreatectomy and islet auto transplantation is a good option for chronic pancreatitis patients who suffer from significant pain, poor quality of life, and the potential of type 3C diabetes and pancreatic cance...Total pancreatectomy and islet auto transplantation is a good option for chronic pancreatitis patients who suffer from significant pain, poor quality of life, and the potential of type 3C diabetes and pancreatic cancer. Portal vein thrombosis is the most feared complication of the surgery and chances are increased if the patient has a hypercoagulable disorder. We present a challenging case of islet auto transplantation from our institution. A 29-year-old woman with plasminogen activator inhibitor-4G/4G variant and a clinical history of venous thrombosis was successfully managed with a precise peri- and postoperative anticoagulation protocol. In this paper we discuss the anti-coagulation protocol for safely and successfully caring out islet transplantation and associated risks and benefits.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.
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.
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.
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.
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 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.
基金supported by the National Natural Science Foundation of China (82100863)Hebei Natural Science Foundation (H2020206643 and H2020206105)+3 种基金Funding project for introducing overseas students of Hebei Province (C20210346)Medical Science Research Project of Hebei Province (20211628)Hebei Province Government-funded Excellent Talents Project in Clinical Medicine (ZF2023029)Spark Scientific Research Project of the First Hospital of Hebei Medical University (XH202004).
文摘Excessive secretion of human islet amyloid polypeptide(hIAPP)is an important pathological basis of diabetic encephalopathy(DE).In this study,we aimed to investigate the potential implications of hIAPP in DE pathogenesis.Brain magnetic resonance imaging and cognitive scales were applied to evaluate white matter damage and cognitive function.We found that the concentration of serum hIAPP was positively correlated with white matter damage but negatively correlated with cognitive scores in patients with type 2 diabetes mellitus.In vitro assays revealed that oligodendrocytes,compared with neurons,were more prone to acidosis under exogenous hIAPP stimulation.Moreover,western blotting and co-immunoprecipitation indicated that hIAPP interfered with the binding process of monocarboxylate transporter(MCT)1 to its accessory protein CD147 but had no effect on the binding of MCT2 to its accessory protein gp70.Proteomic differential analysis of proteins co-immunoprecipitated with CD147 in oligodendrocytes revealed Yeast Rab GTPase-Interacting protein 2(YIPF2,which modulates the transfer of CD147 to the cell membrane)as a significant target.Furthermore,YIPF2 inhibition significantly improved hIAPP-induced acidosis in oligodendrocytes and alleviated cognitive dysfunction in DE model mice.These findings suggest that increased CD147 translocation by inhibition of YIPF2 optimizes MCT1 and CD147 binding,potentially ameliorating hIAPP-induced acidosis and the consequent DE-related demyelination.
基金funded by the National Natural Science Foundation of China (32371341,31872674)the Scientific and Technologic Foundation of Jilin Province (20230202050NC)the Fundamental Research Funds for the Central Universities (CGZH202206)。
文摘Type 1 diabetes mellitus(T1DM) lacks insulin secretion due to autoimmune deficiency of pancreaticβ-cells.Protecting pancreatic islets and enhancing insulin secretion has been therapeutic approaches.Mannogalactoglucan is the main type of polysaccharide from natural mushroom,which has potential medicinal prospects.Nevertheless,the antidiabetic property of mannogalactoglucan in T1DM has not been fully elucidated.In this study,we obtained the neutral fraction of alkali-soluble Armillaria mellea polysaccharide(AAMP-N) with the structure of mannogalactoglucan from the fruiting body of A.mellea and investigated the potential therapeutic value of AAMP-N in T1DM.We demonstrated that AAMP-N lowered blood glucose and improved diabetes symptoms in T1DM mice.AAMP-N activated unfolded protein response(UPR) signaling pathway to maintain ER protein folding homeostasis and promote insulin secretion in vivo.Besides that,AAMP-N promoted insulin synthesis via upregulating the expression of transcription factors,increased Ca^(2+) signals to stimulate intracellular insulin secretory vesicle transport via activating calcium/calmodulin-dependent kinase Ⅱ(CamkⅡ) and cAMP/PKA signals,and enhanced insulin secretory vesicle fusion with the plasma membrane via vesicle-associated membrane protein 2(VAMP2).Collectively,these studies demonstrated that the therapeutic potential of AAMP-N on pancreatic islets function,indicating that mannogalactoglucan could be natural nutraceutical used for the treatment of T1DM.
文摘Imaging changes in the pancreas can provide valuable information about the status of islet beta-cell function in different pancreatic diseases,such as diabetes,pancreatitis,pancreatic cancer,fatty pancreas,and insulinoma.While imaging cannot directly measure beta-cell function;it can be used as a marker of disease progression and a tool to guide therapeutic interventions.As imaging techno-logies continue to advance,they will likely play an increasingly important role in diagnosing,monitoring,and managing diabetes.
基金Supported by the Key Program of Science and Technique of Ministry of Education of the People's Republic of China, No.104169
文摘AIM： To evaluate the recovery and function of isolated rat pancreatic islets during in vitro culture with small intestinal submucosa （SIS）. METHODS： Pancreatic islets were isolated from Wistar rats by standard surgical procurement followed by intraductal collagenase distension, mechanical dissociation and Euroficoll purification. Purified islets were cultured in plates coated with multilayer SIS （SIS-treated group） or without multilayer SIS （standard cultured group） for 7 and 14 d in standard islet culture media of RPMI 1640. After isolation and culture, islets from both experimental groups were stained with dithizone and counted. Recovery of islets was determined by the ratio of counts after the culture to the yield of islets immediately following islet isolation. Viability of islets after the culture was assessed by the glucose challenge best with low （2.7 mmol/L） and high glucose （16.7 mmol/L） solution supplemented with 50 mmol/L 3-isobutyl-1- methylxanthine （IBMX） solution. Apoptosis of islet cells after the culture was measured by relative quantification of histone-complexed DNA fragments using ELISA. RESULTS： After 7 or 14 d of in vitro tissue culture, the recovery of islets in SIS-treated group was significantly higher than that cultured in plates without SIS coating. The recovery of islets in SIS-treated group was about twice more than that of in the control group. In SIS treated group, there was no significant difference in the recovery of islets between short- and long-term periods of culture （95.8±1.0% vs 90.8±1.5%, P〉0.05）. When incubated with high glucose （16.7 mmol/L） solution, insulin secretion in SIS-treated group showed a higher increase than that in control group after 14 d of culture （20.7±1.1 mU/L vs 11.8±1.1 mU/L, P〈0.05）. When islets were placed in high glucose solution containing IBMX, stimulated insulin secretion was higher in SlS-treated group than in control group. Calculated stimulation index of SlS-treated group was about 23 times of control group. In addition, the stimulation index of SlS-treated group remained constant regardless of short- and long- term periods of culture （9.5±0.2 vs 10.2±1.2, P〉0.05）. Much less apoptosis of islet cells occurred in SlS-treated group than in control group after the culture. CONCLUSION： Co-culture of isolated rat islets with native sheet-like SIS might build an extracellular matrix for islets and provide possible biotrophic and growth factors that promote the recovery and subsequent function of islets.
文摘The purpose of the present study was to organize the parameters involved in experimental allotransplantation in rodents to elaborate the most suitable model to supply the scarcity of islet donors. We used the PubMed database to systematically search for published articles containing the keywords “rodent islet transplantation” to review. We included studies that involved allotransplantation experiments with rodents’ islets, and we reviewed the reference lists from the eligible publications that were retrieved. We excluded articles related to isotransplantation, autotransplantation and xenotransplantation, i.e., transplantation in other species. A total of 25 studies related to allotransplantation were selected for systematic review based on their relevance and updated data. Allotransplantation in rodents is promising and continues to develop. Survival rates of allografts have increased with the discovery of new immunosuppressive drugs and the use of different graft sites. These successes suggest that islet transplantation is a promising method to overcome the scarcity of islet donors and advance the treatment options for type 1 diabetes.
基金Supported by Research Seeds Quest Program in Japan Science and Technology Agency (NS)the Uehara Memorial Foundation (NS)Grant-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports Science and Technology of Japan, B: 22390253 (SE), C: 22591513 (NS)
文摘Islet transplantation could become an ideal treatment for severe diabetes to prevent hypoglycemia shock and irreversible diabetic complications, once some of the major and unresolved obstacles are overcome, including limited donor supplies and side effects caused by permanent immunosuppressant use. Approximately 30 years ago, some groups succeeded in improving the blood glucose of diabetic animals by transplanting encapsulated islets with semi-permeable membranes consisting of polymer. A semi-permeable membrane protects both the inner islets from mechanical stress and the recipient’s immune system (both cellular and humoral immunities), while allowing bidirectional diffusion of nutrients, oxygen, glucose, hormones and wastes, i.e., immune-isolation. This device, which enables immune-isolation, is called encapsulated islets or bio-artificial pancreas. Encapsulation with a semipermeable membrane can provide some advantages: (1) this device protects transplanted cells from the recipient’s immunity even if the xenogeneic islets (from large animals such as pig) or insulin-producing cells are derived from cells that have the potential for differentiation (some kinds of stem cells). In other words, the encapsulation technique can resolve the problem of limited donor supplies; and (2) encapsulation can reduce or prevent chronic administration of immunosuppressants and, therefore, important side effects otherwise induced by immunosuppressants. And now, many novel encapsulated islet systems have been developed and are being prepared for testing in a clinical setting.
文摘The intra-islet microvasculature is a critical interface between the blood and islet endocrine cells governing a number of cellular and pathophysiological processes associated with the pancreatic tissue. A growing body of evidence indicates a strong functional and physical interdependency of β-cells with endothelial cells(ECs), the building blocks of islet microvasculature. Intra-islet ECs, actively regulate vascular permeability and appear to play a role in fine-tuning blood glucose sensing and regulation. These cells also tend to behave as "guardians", controlling the expression and movement of a number of important immune mediators, thereby strongly contributing to the physiology of islets. This review will focus on the molecular signalling and crosstalk between the intra-islet ECs and β-cells and how their relationship can be a potential target for intervention strategies in islet pathology and islet transplantation.
文摘BACKGROUND: Type 1 diabets is an autoimmune disease caused by the destruction of pancreatic β-cell with an in- creased incidence worldwide in the closing decades of the 20th century. This study was to investigate the effects of human umbilical cord serum (UCS) on the proliferation and function of human fetal islet-like cell clusters (ICCs) in vitro. METHODS: Eight fresh pancreatic glands obtained after in- duction of labor with water bag were mildly exposed to col- lagenase V, and the digested cells were cultured in a RPMI- 1640 medium plus 10% pooled UCS or fetal calf serum (FCS) to permit cells attachment and outgrowth of ICCs. RESULTS: In 8 consecutively explanted glands, develop- ment and proliferation of ICCs were observed. In the pre- sence of FCS, the outgrowth of ICC took place on the top of a flbroblast monocellular layer. UCS affected less growth of fibroblasts and increased the formation of ICCs about four-fold compared with explants from the same glands maintained in FCS. In both UCS and FCS, the insulin con- tent of the medium was variable to a certain extent and progressively declined from day 2 to day 6. Dithizone- stained ICCs in UCS suggested that most cell clusters were islet cells ( β-cells), and the purity of islets was estimated 80%-90%. The ultrastructure of the cultured cells showed a large number of granule-containing cells, most of which were identified as β-cells. CONCLUSION: We conclude that in comparison with ex- plants with FCS, the yield of ICCs and purification of islet cells are markedly increased by UCS and may facilitate the proliferation of pancreatic β-cells intended for islet trans- plantation.
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.
文摘Total pancreatectomy and islet auto transplantation is a good option for chronic pancreatitis patients who suffer from significant pain, poor quality of life, and the potential of type 3C diabetes and pancreatic cancer. Portal vein thrombosis is the most feared complication of the surgery and chances are increased if the patient has a hypercoagulable disorder. We present a challenging case of islet auto transplantation from our institution. A 29-year-old woman with plasminogen activator inhibitor-4G/4G variant and a clinical history of venous thrombosis was successfully managed with a precise peri- and postoperative anticoagulation protocol. In this paper we discuss the anti-coagulation protocol for safely and successfully caring out islet transplantation and associated risks and benefits.
