Islet-Like Clusters Derived from Mesenchymal Stem Cells in Wharton's Jelly of the Human Umbilical Cord for Transplantation to Control Type 1 Diabetes

Yu Show Fu,Kuo Ching Chao,Kuo Fang Chao,Kathrin Maedler,Shing Hwa Liu

doi:10.1371/journal.pone.0001451

Abstract

BackgroundThere 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.Methodology and Principal FindingsHUMSCs 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 β-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 and SignificanceIn 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.

Highlights

Type 1 diabetes accounts for only about 5–10% of all cases of diabetes; its incidence continues to increase worldwide and it has serious short-term and long-term implications [1]
There was no human insulin and human nuclei immunostaining in the sham liver of STZ-diabetic rat without transplantation of cell clusters (Fig. 7B-h-j). These findings indicated that implanted islet-like cell clusters and human insulin and nuclei-positive staining liver cells are simultaneously existed in the liver after transplantation of stage 4 islet-like cell clusters for 3 months
We explored the possibility of using HUMSCs in Wharton’s Jelly of the umbilical cord as a source for cellular differentiation into insulin-producing cell clusters under de novo culture conditions

Summary

Introduction

Type 1 diabetes accounts for only about 5–10% of all cases of diabetes; its incidence continues to increase worldwide and it has serious short-term and long-term implications [1]. All commonly used immunosuppressive drugs (steroids, calcineurin inhibitors, and rapamycin) have been reported to have adverse effects on pancreatic b-cells [7] These factors motivate efforts to develop renewable sources of islet-replacement tissue. 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. 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. 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

Methods

Results

Conclusion