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Objective@#Glucagon-like peptide-1(GLP-1) and gastrin synergistically promote the differentiation of insulin-producing cells which differentiated from rat bone marrow mesenchymal stem cells (BMSCs).@*Methods@#(1)Prepare IPCs model: pancreatic duodenal homeobox 1 (Pdx-1), neurogenin 3 (Ngn3) combined with V-type tendon fibrosarcoma oncogene homolog A (MafA) co-transfected BMSCs differentiation into IPCs; (2)IPCs were divided into 4 groups: Group A(uninduced group), group B(GLP-1 induction group), group C(gastrin induction group), and group D(GLP-1 combined with gastrin induction group). Cultured in high glucose medium for 7 days, the expression levels of insulin2, Pdx-1, GK, nestin, and glucagon mRNA were detected by RT-PCR. The insulin secretion of each group was detected by ELISA.@*Results@#After cultured for 7 days under high glucose conditions, the morphology of IPCs in each induction group changed significantly, gradually aggregated and formed scattered cell masses, and the combined induction group formed large cell masses. The staining of disulfide brown was reddish brown; The levels of insulin secretion increased gradually on the 0, 3rd, 5th, 7th, and 9th day after induction, and the increase was the most significant in the combined induction group (P<0.05). Compared with group A, the expression of insulin2 and GK in group B and D was significantly up-regulated, the expression of glucagon was down-regulated in group D, the expression of Pdx-1 was down-regulated in group C, and the expression of glucagon was up-regulated (P<0.05). Compared with group B, The expression of insulin2 was down-regulated in group C, and the expression level of glucagon was up-regulated. The expression levels of Pdx-1 and Insulin2 were significantly up-regulated in group D, and the expression level of glucagon was down-regulated (P<0.05). Compared with group C, the expression level of Pdx-1, insulin2 and GK was significantly up-regulated in group D, and the expression level of glucagon was down-regulated (P<0.05).@*Conclusion@#GLP-1 and gastrin synergistically promote the differentiation of IPCs into islet β cells by up-regulating GK and insulin2 and down-regulating glucagon.
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Diabetes constitutes a worldwide epidemic that affects all ethnic groups. Cell therapy is one of the best alternatives of treatment, by providing an effective way to regenerate insulin-producing cells lost during the course of the disease, but many issues remain to be solved. Several groups have been working in the development of a protocol capable of differentiating Mesenchymal Stem Cells (MSCs) into physiologically sound Insulin Producing Cells (IPCs). In order to obtain a simple, fast and direct method, we propose in this manuscript the induction of MSCs to express NESTIN in a short time period (2 h), proceeded by incubation in a low glucose induced medium (24 h) and lastly by incubation in a high glucose medium. Samples from cell cultures incubated in high glucose medium from 12 to 168 h were obtained to detect the expression of INSULIN-1, INSULIN -2, PDX-1 and GLUT-2 genes. Induced cells were exposed to a glucose challenge, in order to assess the production of insulin. This method allowed us to obtain cells expressing PDX-1, which resembles a progenitor insulin-producing cell.
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Humans , Cell Culture Techniques , Cell- and Tissue-Based Therapy , Ethnicity , Glucose , Insulin , Mesenchymal Stem Cells , Methods , NestinABSTRACT
Objective To study and explore Glucose-reducing effect of induced human bone mes-enchymal stem cells on diabetic mice.Methods The diabetic model of rats was duplicated by injection of STZ intraperitoneally.The induced cells were implanted into diabetic mice.Blood glucose levels were moni-tored every 3 days after implantation for 14 days.Results The mice receiving the treated Cells began to decrease their blood glucose levels after 3days.But control Animals that did not receive induced cells exhib-ited persistent hyperglycemia.Conclusions Induced cells by hBMSCs can decrease blood glucose levels on diabetic mice.
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Aims: Mesenchymal stem cells (MSCs) can differentiate into multiple cell types including insulinproducing cells. However, these cells usually cannot be directed to efficiently differentiate into β cells in vitro. The present study aimed to explore whether the pancreatic microenvironment could induce bone marrow-derived (BM)-MSCs to differentiate into β cells to compensate for insufficient β-cells. Methodology: We directly transplanted male enhanced green fluorescence protein (EGFP)- expressing BM-MSCs into the pancreas of female diabetic Sprague-Dawley rats by multi-point injection. Results: BM-MSCs could restore serum insulin and C-peptide levels and reverse hyperglycemia by intra-pancreatic transplantation. BM-MSCs from male donors could differentiate into pancreatic stem/progenitor cells and β cells under female pancreas micro-environment. Neogenesis islets derived from BM-MSCs were verified in pancreatic tissue by histology and the expression of genes related to β cell gene biomarker was determined by RT-PCR and quantitative real time-PCR. Ychromosome SRY and PDX-1 mRNA have expressed simultaneously in neogenesis β cells. Polyploidy and aneuploid DNA were not observed. Conclusion: This study showed that transplanted BM-MSCs did not fuse with pancreatic cells and could contribute to repair, paracrine and differentiation into new islet β cells in the pancreatic microenvironment.
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Fontes alternativas de células ß têm sido estudadas para o tratamento de Diabetes mellitus tipo 1, dentre as quais a mais promissora consiste das células-tronco diferenciadas em células produtoras de insulina (IPCs). Alguns trabalhos demonstram a capacidade de células-tronco embrionárias murinas (mESCs) de formarem estruturas semelhantes a ilhotas pancreáticas, porém, os níveis de produção de insulina são insuficientes para a reversão do diabetes em camundongos diabetizados. Este trabalho visa desenvolver um protocolo adequado para geração de IPCs e contribuir para a identificação e caracterização funcional de novos genes associados à organogênese pancreática. Logo no início da diferenciação das mESCs em IPCs, foi possível verificar o surgimento de células progenitoras, evidenciado pela expressão de marcadores importantes da diferenciação beta-pancreática. Ao final do processo de diferenciação in vitro, ocorreu a formação de agrupamentos (clusters) semelhantes a ilhotas, corando positivamente por ditizona, que é específica para células ß-pancreáticas. Para avaliar seu potencial in vivo, estes clusters foram microencapsulados em Biodritina® e transplantados em camundongos diabetizados. Apesar dos níveis de insulina produzidos não serem suficientes para estabelecer a normoglicemia, os animais tratados com IPCs apresentaram melhores condições, quando comparados ao grupo controle, tendo melhor controle glicêmico, ganho de massa corpórea e melhor aparência da pelagem, na ausência de apatia. Além disso, análise dos clusters transplantados nestes animais indicou aumento da expressão de genes relacionados à maturação das células ß. Porém, quando estes clusters foram microencapsuladas em Bioprotect® e submetidos à maturação in vivo em animais normais, ocorreu um aumento drástico na expressão de todos os genes analisados, indicando sua maturação completa em células beta. O transplante destas células completamente maturadas em animais diabetizados, tornou-os normoglicêmicos e capazes de responder ao teste de tolerância à glicose (OGTT) de forma semelhante aos animais normais. A segunda parte do trabalho visou analisar genes diferencialmente expressos identificados em estudo anterior do nosso grupo, comparando, através de DNA microarray, mESCs indiferenciadas e diferenciadas em IPCs. Um dos genes diferencialmente expressos é aquele que codifica para a Purkinge cell protein 4 (Pcp4), sendo 3.700 vezes mais expresso em IPCs. Para investigar o possível papel do gene Pcp4 em células ß e no processo de diferenciação ß-pancreática, adotou-se o enfoque de genômica funcional, superexpressando e inibindo sua expressão em células MIN-6 e mESCs. Apesar da alteração na expressão de Pcp4 em células MIN-6 não ter interferido de forma expressiva na expressão dos genes analisados, quando inibido, modificou o perfil da curva de crescimento celular, aumentando seu tempo de dobramento de forma significativa e diminuindo da viabilidade celular em ensaios de indução de apoptose. Já na diferenciação de mESCs em IPCs, a superexpressão de Pcp4 interferiu de forma positiva apresentando uma tendência a aumentar a expressão dos genes relacionado à diferenciaçãoß-pancreática. Concluindo, desenvolvemos um novo protocolo de diferenciação de mESCs em IPCs as quais foram capazes de reverter o diabetes em camundongos diabetizados e descrevemos, pela primeira vez, o gene Pcp4 como sendo expresso em células ß-pancreáticas, podendo estar relacionado à manutenção da viabilidade celular e maturação destas células
New cellular sources for type 1 Diabetes mellitus treatment have been previously investigated, the most promising of which seems to be the insulin producing cells (IPCs), obtained by stem cells differentiation. Some reports show that murine embryonic stem cells (mESCs) are able to form islet-like structures, however, their insulin production is insufficient to render diabetic mice normoglycemic. This work aims at developing an adequate protocol for generation of IPCs and searching for new genes which could be involved in the pancreatic organogenesis process. Early on during mESCs differentiation into IPCs, we observed the presence of progenitor cells, which were able to express pancreatic ß-cell markers. At the end of the differentiation process, the islet-like clusters positively stained for the insulin-specific dithizone. These clusters were microencapsulated in Biodritin® microcapsules, and then transplanted into diabetized mice. Although the levels of insulin production were insufficient for the animals to achieve normoglycemia, those which received IPCs displayed improved conditions, when compared to the control group, as judged by a better glycemic control, body weight gain and healthy fur appearance, in the absence of apathy. In addition, when these transplantated clusters were retrieved, high levels of expression of the genes related to ß-cell maturation were detected. IPCs were also microencapsulated in Bioprotect® and subjected to in vivo maturation in normal animals. A dramatic increase of the analyzed genes expression was observed, indicating complete maturation of the differentiated cells. When these cells were transplanted into diabetized mice, these animals achieved normoglycemia and were able to display glucose tolerance test (OGTT) response very similar to that of normal mice. In the second part of this work, we analyzed upregulated genes described in previous work from our group, comparing undifferentiated mESCs to IPCs using a microarray platform. One of these genes is that coding for the Purkinje cell protein 4 (Pcp4), which is 3,700 more expressed than in undifferentiated mESC cells. We adopted a functional genomics approach to investigate the role played by the Pcp4 gene in ß-cells and in ß-cell differentiation, by inducing overexpression and knocking down this gene in MIN-6 and mESC cells. Although the differential expression of Pcp4 in MIN-6 was not able to interfere with the expression of the genes analyzed, we observed different cell growth rates, with increased doubling time and decreased cell viability when its expression was knocked down. In addition, overexpression of Pcp4 in mESCs subjected to differentiation into IPCs apparently increases the expression of genes related to ß-cell differentiation. In conclusion, we developed a new protocol for ESCs differentiation into IPCs, which is able to revert diabetes in diabetized mice, and we also describe here, for the first time, the Pcp4 gene as being expressed in pancreatic ß-cells and possibly being related to maintenance of cell viability and ß-cell maturation
Subject(s)
Mice , Genes , Insulin/physiology , Diabetes Mellitus, Type 1/prevention & control , Embryonic Stem Cells/classification , Gene Expression , Islets of Langerhans , Molecular Biology , Mouse Embryonic Stem Cells/metabolism , Organogenesis , Pancreas , Purkinje Cells/classificationABSTRACT
ObjectiveTo investigate the effects of liraglutide on the differentiation of human bone marrow mesenchymal stem cells (hBM-MSCs) into insulin-producing cells (IPCs).MethodsIn vitro,hBM-MSCs were induced into IPCs by three-stage induction procedure containing high glucose,nicotinamide,and liraglutide.The morphological change of cells was observed by inverted microscope during induction and the induced cells were confirmed by dithizone(DTZ) staining.The protein expressions of pancreatic and duodenal homeobox-1 (PDX-1),glucose transporter 2 (GLUT2),glucokinase(GK),and insulin in each stage of the induced cells were detected by Western blot.Insulin secretion was measured by ELISA.ResultsThe induced effect was pronounced after adding 10 nmol/L liraglutide for 7 days.Cells began to aggregate and get round gradually during induction,and the morphology of most cells appeared as grape-like aggregation and clustered islet-like cells by the end of induction.The number of DTZ positive cells and the protein expressions of PDX-1,GLUT2,GK,and insulin were increased gradually( P＜0.05 ).The basal and glucose-stimulated insulin secretion from induced cells was also increased gradually(P＜0.05).Conclusion BM-MSCs could be induced into IPCs by high glucose,nicotinamide,and liraglutide in vitro.
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Diabetes mellitus impacts patient survival and quality of life mainly due to its acute and chronic complications.Pancreas transplantation may restore normoglycemia and reduce the complication of insulin-dependent diabetes,thus improving the quality of life and prolonging patient's survival.Although pancreas transplantation requires major surgery and life-long immunosuppression therapy,it currently remains the gold stand for patients with type 1 diabetes mellitus,who do not respond to conventional therapy.Meanwhile,potential of the islet transplantation,insulin-producing cells replacement therapy,and artificial pancreas as the alternative to pancreas transplantation are under investigation.
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Objective To investigate the influence of Zhenqing Recipe(ZQR)and Ligustri Lucidi Fructus(LLF)on diabetic rats and its possible mechanism.Methods The model of type 2 diabetic rats was established by feeding a high-sucrose-high-fat diet and injecting a low dose of Streptozotocin in Wistar rats.The model rats were randomly divided into three groups: diabetic model,ZQR-treated,and LLF-treated groups for 8-weeks treatment.The normal Wistar rats were as a normal control group.Results The level of fasting blood glucose in ZQR and LLF groups was decreased compared with model group(P < 0.01,0.05,respectively).Both ZQR and LLF markedly reduced serum triglycerides(P < 0.01,0.05,respectively),and increased the insulin sensitivity index(P < 0.05).Histopathology revealed that ZQR and LLF reduced pancreatic damage.Immunohistochemistry evaluation showed that the percentage of insulin positive cells in pancreatic island was higher than model group(P < 0.01,0.05,respectively).The mRNA and protein expression of SREBP-1c in pancreas were significantly decreased in ZQR and FLL group(P < 0.01).Conclusion ZQR has therapeutic effect on type 2 diabetes,it ameliorates the histopathologlcal changes of pancreas,protects β cells,improves insulin resistance,and attenuates the expression of SREBP-1c.This study also provides the anti-diabetic evidence of FLL even its effects are weaker than ZQR.
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AIM: To explore the possibility of differentiating functional insulin-producing cells from human BM-derived stem cells. METHODS: Mesenchymal stem cells were isolated from human bone marrow. Then these cells were induced with epidermal growth factor, β-mercaptoethanol and high concentration of glucose. The gene expression related to islet β cells was detected by RT-PCR. Insulin in the treated cells was examined by immunocytochemistry. In addition, the levels of insulin secretion and glucose-stimulated insulin release were examined by microparticle enzyme immunoassay. Finally, the induced cells were implanted into the right renal subcapsular space of diabetic mice. Blood glucose levels were monitored 16 d after implantation. The right kidneys of the treated mice were harvested for immunohistochemistry. RESULTS: The key genes related to pancreatic β cells had been confirmed to express by PCR and insulin was detected by immunocytochemistry in differentiated human BM-derived stem cells induced by high glucose, which responded to glucose challenge. Furthermore, implantation of the cells in renal subcapsular space was able to lower the glucose levels in hyperglycemic mice. After 16 days, the implanted cells were determined still to be insulin positive cells by immunohistochemistry. CONCLUSION: These results indicate human BM-derived stem cells are capable of differentiating into functional insulin-producing cells and may represent a pool of cells for the treatment of diabetes.
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PURPOSE: Here we showed that human umbilical cord blood (hUCB)-derived cells, when cultured under defined conditions, generated insulin-producing cells (IPCs). METHODS: hUCB mononuclear cells (MNCs) were cultured in serum-free low (5.5 mM glucose) DMEM at a cell density of 3x10(6)/cm2 in the presence of 1% DMSO for 3 days followed by high (25 mM glucose) DMEM supplemented with 10% FBS for 7 additional days. They were plated in plastic six well plates on slide coverslips (22x22 mm2) coated with 0.006% type I collagen. RESULTS: These IPCs formed clusters similar to islets of Langerhans. We confirmed these clusters were positive for insulin and C-peptide by immunohistochemistry. CONCLUSION: Our data demonstrated that in vitro hUCB-derived cells generated IPCs, which can be a potential source for the treatment of diabetes via a stem cell therapy approach.
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Humans , C-Peptide , Cell Count , Collagen Type I , Dimethyl Sulfoxide , Fetal Blood , Immunohistochemistry , Insulin , Islets of Langerhans , Plastics , Stem Cells , Umbilical CordABSTRACT
The reactive oxygen species (ROS) are considered to be an important mediator in pancreatic beta cell destruction, thereby triggering the development of insulin-dependent diabetes mellitus. In the present study, HIV-1 Tat-mediated transduction of Cu, Zn-superoxide dismutase (SOD) was investigated to evaluate its protective potential against streptozotocin (STZ) -induced cytotoxicity in insulin-producing MIN6N cells. Tat-SOD fusion protein was successfully delivered into MIN6N cells in a dose-dependent manner and the transduced fusion protein was enzymatically active for 48 h. The STZ induced-cell destruction, superoxide anion radical production, and DNA fragmentation of MIN6N cells were significantly decreased in the cells pretreated with Tat-SOD for 1 h. Furthermore, the transduction of Tat-SOD increased Bcl-2 and heat shock protein 70 (hsp70) expressions in cells exposed to STZ, which might be partly responsible for the effect of Tat-SOD. These results suggest that an increased of free radical scavenging activity by transduction of Tat-SOD enhanced the tolerance of the cell against oxidative stress in STZ-treated MIN6N cells. Therefore, this Tat-SOD transduction technique may provide a new strategy to protect the pancreatic beta cell destruction in ROS-mediated diabetes.