Expression of Pdx-1 in bone marrow mesenchymal stem cells promotes differentiation of islet-like cells in vitro.
Bone marrow mesenchymal stem cells (BMSCs) have the ability of self-renewal and multi-directional differentiation. Recent reports showed that BMSCs could differentiate into endocrine cells of pancreas. However, the differentiation is not efficient enough to produce insulin-producing cells for the future therapeutic use. Pdx-1 is a crucial regulator for pancreatic development. Therefore we constructed a eukaryotic expression vector containing Pdx-1 to determine the effect of Pdx-1 expression on differentiation of BMSCs in vitro. The results showed that BMSCs could self-assemble to form functional pancreatic islet-like structures after differentiation in vitro. The proportion of insulin-producing cells differentiated from Pdx-1+BMSCs was 28.23% +/- 2.56%, higher than that from BMSCs transfected with vacant vector and Pdx-1-BMSCs (7.23% +/- 1.56% and 4.08% +/- 2.69% respectively) by flow cytometry. Immunocytochemical examination also testified the expression of multiple beta-cells-specific genes such as insulin, glucagons, somatostatin in differentiated BMSCs. The results also revealed that the expressions of genes mentioned above in Pdx-1+BMSCs were higher than that in Pdx-1-BMSCs, which was confirmed by Western blotting analysis and RT-PCR. Glucose-induced insulin secretion from Pdx-1+BMSCs in 5 mmol/L and 25 mmol/L glocuse was (56.61 +/- 4.82) microU/mL and (115.29 +/- 2.56) microU/mL respectively, which were much higher than those from Pdx-1-BMSCs ((25.53 +/- 6.49) microU/mL and (53.26 +/- 7.56) microU/mL respectively). Grafted animals were able to maintain their body weight and survive for relatively longer periods of time than hyperglycemic sham-grafted controls, which demonstrated an overall beneficial effect of the grafted cells on the health of the animals. These findings thus suggested that exogenous expression of Pdx-1 should provide a promising approach for efficiently producing islet-like cells from BMSCs for the future therapeutic use in diabetic patients.
Sun
Jiping
J
Department of Pediatrics, Xiang-Ya Hospital, Central-South University, Changsha 410008, China.
Yang
Yujia
Y
Wang
Xiaoli
X
Song
Jianhui
J
Jia
Yanjie
Y
D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology / Q000378:metabolism*; D002454:Cell Differentiation; D002469:Cell Separation; D002478:Cells, Cultured; D003920:Diabetes Mellitus / Q000139:chemically induced; D015870:Gene Expression; D005822:Genetic Vectors / Q000235:genetics; D005947:Glucose / Q000378:metabolism / Q000494:pharmacology; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D006943:Hyperglycemia / Q000097:blood; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013311:Streptozocin / Q000494:pharmacology; D015996:Survival Rate; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*
D018398:Homeodomain Proteins; D007328:Insulin; D015534:Trans-Activators; C084010:pancreatic and duodenal homeobox 1 protein; D013311:Streptozocin; D005947:Glucose