Publicação
Mesenchymal stem cells for the cell-based therapy of type 1 diabetes : an experimental approach
| Resumo: | Human adult mesenchymal stem cells (hMSC) represent a potential source for cellbased therapies in Diabetes Mellitus. Yet, till now, no definitive data exist for clinical application. Aims 1. Evaluation of the pancreatic endocrine differentiation potential of humanmesenchymal stem-cells, immortalized with telomerase (hMSC-TERT); 2. Comparative analysis of the plasticity and molecular signature of human-islet-derived pancreatic cells (hIPC) and bone-marrow-derived hMSC (hBM-MSC). Research strategies: 1. In vitro differentiation of hMSC-TERT into insulin producing cells through: a) Endocrine-promoting culture conditions; b) Ectopic expression of two key regulatory genes of human endocrine pancreas, neurogenin3 (hNGN3) and pancreatic-duodenal homeobox 1 (/hPDX-1) genes in hMSC-TERT. 2. Comparison of the functional signature of hIPC and hBM-MSC by: a) Immunophenotype characterization; b) In vitro mesenchymal and endocrine differentiation of primary hBM-MSC and hIPC; c) Transcriptome analysis for detection of mesenchymal and adult stem-cell related gene markers. Identification of target genes, related to the origin and function of hBM-MSC and hIPC. Results We could demonstrate that hMSC-TERT can be differentiated in vitro into pancreatic endocrine phenotypes with the ability to synthesise and store insulin. Similar to pancreatic development, in hMSC-TERT, NGN3 contributes to the activation of PDX-1 promoter. Insulin secretion in a glucose-sensing manner was not detected in our cell system, which indicates that a mature state of beta-cell was not attained in these phenotypes; hIPC and hBM-MSC display very similar MSC phenotypes. However, our data suggest distinct functions of these populations, which are related to a “mesodermal tissue specification” and “positional memory” of these cells. In hIPC, we confirmed a state of epithelial-mesenchymal transition. Conclusions MSC populations are adult stem cells with distinct levels of plasticity and commitment. Future studies will help to identify those MSC populations with greater potential to replace or regenerate beta cells in type 1 Diabetes. |
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| Autores principais: | Limbert, Catarina de Castro Sobral Blanco, 1964- |
| Assunto: | Diabetes mellitus Diabetes mellitus tipo 1 Células-tronco mesenquimais Células estaminais Fisiopatologia Terapia tecidual Teses de doutoramento - 2011 |
| Ano: | 2011 |
| País: | Portugal |
| Tipo de documento: | tese de doutoramento |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade de Lisboa |
| Idioma: | inglês |
| Origem: | Repositório da Universidade de Lisboa |
| Resumo: | Human adult mesenchymal stem cells (hMSC) represent a potential source for cellbased therapies in Diabetes Mellitus. Yet, till now, no definitive data exist for clinical application. Aims 1. Evaluation of the pancreatic endocrine differentiation potential of humanmesenchymal stem-cells, immortalized with telomerase (hMSC-TERT); 2. Comparative analysis of the plasticity and molecular signature of human-islet-derived pancreatic cells (hIPC) and bone-marrow-derived hMSC (hBM-MSC). Research strategies: 1. In vitro differentiation of hMSC-TERT into insulin producing cells through: a) Endocrine-promoting culture conditions; b) Ectopic expression of two key regulatory genes of human endocrine pancreas, neurogenin3 (hNGN3) and pancreatic-duodenal homeobox 1 (/hPDX-1) genes in hMSC-TERT. 2. Comparison of the functional signature of hIPC and hBM-MSC by: a) Immunophenotype characterization; b) In vitro mesenchymal and endocrine differentiation of primary hBM-MSC and hIPC; c) Transcriptome analysis for detection of mesenchymal and adult stem-cell related gene markers. Identification of target genes, related to the origin and function of hBM-MSC and hIPC. Results We could demonstrate that hMSC-TERT can be differentiated in vitro into pancreatic endocrine phenotypes with the ability to synthesise and store insulin. Similar to pancreatic development, in hMSC-TERT, NGN3 contributes to the activation of PDX-1 promoter. Insulin secretion in a glucose-sensing manner was not detected in our cell system, which indicates that a mature state of beta-cell was not attained in these phenotypes; hIPC and hBM-MSC display very similar MSC phenotypes. However, our data suggest distinct functions of these populations, which are related to a “mesodermal tissue specification” and “positional memory” of these cells. In hIPC, we confirmed a state of epithelial-mesenchymal transition. Conclusions MSC populations are adult stem cells with distinct levels of plasticity and commitment. Future studies will help to identify those MSC populations with greater potential to replace or regenerate beta cells in type 1 Diabetes. |
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