Differentiation of human umbilical cord blood-derived mononuclear cells to endocrine pancreatic lineage.
Generation of insulin-producing cells remains a major limitation for cellular replacement therapy in treatment of diabetes. To understand the potential of human umbilical cord blood (hUCB)-derived mononuclear cells (MNCs) in cell replacement therapy for diabetes, we studied MNCs isolated from 270 human umbilical cord blood samples. We characterized these by immunostaining and real-time PCR and studied their ability to differentiate into insulin-producing cells. We observe that freshly isolated MNCs as well as mesenchymal-like cells grown out by in vitro culture of isolated MNCs express key pancreatic transcription factors: pdx1, ngn3, isl1, brn4 and pax6. However, after 32-fold expansion, MNCs show decreased abundance of pdx1 and ngn3, indicating that islet/pancreatic progenitors detected in freshly isolated MNCs die or are diluted out during in vitro expansion. We therefore transplanted freshly isolated MNCs in NOD/SCID (immuno-incompetent) or FVB/NJ (immuno-competent) mice to check their ability to differentiate into insulin-producing cells. We observe that after 9 weeks of transplantation, approximately 25% grafts exhibit human insulin-producing (16% immunopositive) cells. The number and abundance of pro-insulin transcript-containing cells increased when the animals underwent partial pancreatectomy, 15 days after transplantation. Our results indicate that such hUCB-derived MNC population contains a subset of "pancreas-committed" cells that have the potential to differentiate into insulin-producing cells in vivo. Further studies in understanding the differentiation potential of this subset of pancreas-committed hUCB-derived MNCs will provide us with an autologous source of "lineage-committed" progenitors for cell replacement therapy in diabetes.
Parekh
Vishal S
VS
Stem Cells and Diabetes Section, Lab #12, National Center for Cell Science, Ganeshkhind Road, Pune, MH 411007, India.
Joglekar
Mugdha V
MV
Hardikar
Anandwardhan A
AA
D000818:Animals; D002454:Cell Differentiation; D019070:Cell Lineage; D002478:Cells, Cultured; D005312:Fetal Blood / Q000166:cytology*; D006801:Humans; D007150:Immunohistochemistry; D050417:Insulin-Secreting Cells / Q000378:metabolism*; D007515:Islets of Langerhans / Q000166:cytology* / Q000378:metabolism; D051379:Mice; D008815:Mice, Inbred Strains; D016513:Mice, SCID; D009000:Monocytes / Q000166:cytology*; D010180:Pancreatectomy; D013997:Time Factors; D014183:Transplantation, Heterologous