Islet-like clusters derived from mesenchymal stem cells in Wharton's Jelly of the human umbilical cord for transplantation to control type 1 diabetes.
BACKGROUND
There is a widespread interest in developing renewable sources of islet-replacement tissue for type I diabetes mellitus. Human mesenchymal cells isolated from the Wharton's jelly of the umbilical cord (HUMSCs), which can be easily obtained and processed compared with embryonic and bone marrow stem cells, possess stem cell properties. HUMSCs may be a valuable source for the generation of islets.


RESULTS
HUMSCs were induced to transform into islet-like cell clusters in vitro through stepwise culturing in neuron-conditioned medium. To assess the functional stability of the islet-like cell clusters in vivo, these cell clusters were transplanted into the liver of streptozotocin-induced diabetic rats via laparotomy. Glucose tolerance was measured on week 12 after transplantation accompanied with immunohistochemistry and electron microscopy analysis. These islet-like cell clusters were shown to contain human C-peptide and release human insulin in response to physiological glucose levels. Real-time RT-PCR detected the expressions of insulin and other pancreatic beta-cell-related genes (Pdx1, Hlxb9, Nkx2.2, Nkx6.1, and Glut-2) in these islet-like cell clusters. The hyperglycemia and glucose intolerance in streptozotocin-induced diabetic rats was significantly alleviated after xenotransplantation of islet-like cell clusters, without the use of immunosuppressants. In addition to the existence of islet-like cell clusters in the liver, some special fused liver cells were also found, which characterized by human insulin and nuclei-positive staining and possessing secretory granules.


CONCLUSIONS
In this study, we successfully differentiate HUMSCs into mature islet-like cell clusters, and these islet-like cell clusters possess insulin-producing ability in vitro and in vivo. HUMSCs in Wharton's Jelly of the umbilical cord seem to be the preferential source of stem cells to convert into insulin-producing cells, because of the large potential donor pool, its rapid availability, no risk of discomfort for the donor, and low risk of rejection.
Chao
Kuo Ching
KC
Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan.
Chao
Kuo Fang
KF
Fu
Yu Show
YS
Liu
Shing Hwa
SH
D001483:Base Sequence; D001786:Blood Glucose / Q000378:metabolism; D002454:Cell Differentiation; D002460:Cell Line; D017690:Cell Transplantation; D017931:DNA Primers; D003922:Diabetes Mellitus, Type 1 / Q000601:surgery*; D000090322:Homeobox Protein Nkx-2.2; D018398:Homeodomain Proteins; D006801:Humans; D007150:Immunohistochemistry; D007328:Insulin / Q000097:blood; D007515:Islets of Langerhans / Q000166:cytology*; D009687:Nuclear Proteins; D014157:Transcription Factors; D014470:Umbilical Cord / Q000637:transplantation*
D001786:Blood Glucose; D017931:DNA Primers; D000090322:Homeobox Protein Nkx-2.2; D018398:Homeodomain Proteins; D007328:Insulin; C000715631:NKX2-2 protein, human; C000715628:Nkx2-2 protein, rat; D009687:Nuclear Proteins; D014157:Transcription Factors