The number of patients worldwide suffering from the chronic disease diabetes mellitus is growing at an alarming rate. Insulin-secreting beta-cells in the islet of Langerhans are damaged to different extents in diabetic patients, either through an autoimmune reaction present in type 1 diabetic patients or through inherent changes within beta-cells that affect their function in patients suffering from type 2 diabetes. Cell replacement strategies via islet transplantation offer potential therapeutic options for diabetic patients. However, the discrepancy between the limited number of donor islets and the high number of patients who could benefit from such a treatment reflects the dire need for renewable sources of high-quality beta-cells. Human embryonic stem cells (hESCs) are capable of self-renewal and can differentiate into components of all three germ layers, including all pancreatic lineages. The ability to differentiate hESCs into beta-cells highlights a promising strategy to meet the shortage of beta-cells. Here, we review the different approaches that have been used to direct differentiation of hESCs into pancreatic and beta-cells. We will focus on recent progress in the understanding of signaling pathways and transcription factors during embryonic pancreas development and how this knowledge has helped to improve the methodology for high-efficiency beta-cell differentiation in vitro.
"However, an acute shortage of deceased organ donors currently limits the wider application of islet transplantation. One approach to overcome the limited supply of donor pancreases is to generate IPCs from stem cells with high proliferative and differentiating potential . hESCs have the potential to differentiate into specialized cells of all three primary germ-layers, including pancreatic IPCs , . "
[Show abstract][Hide abstract] ABSTRACT: Background
Human pancreatic islet transplantation is a prospective curative treatment for diabetes. However, the lack of donor pancreases greatly limits this approach. One approach to overcome the limited supply of donor pancreases is to generate functional islets from human embryonic stem cells (hESCs), a cell line with unlimited proliferative capacity, through rapid directed differentiation. This study investigated whether pancreatic insulin-producing cells (IPCs) differentiated from hESCs could correct hyperglycemia in severe combined immunodeficient (SCID)/non-obese diabetic (NOD) mice, an animal model of diabetes.
We generated pancreatic IPCs from two hESC lines, YT1 and YT2, using an optimized four-stage differentiation protocol in a chemically defined culture system. Then, about 5–7×106 differentiated cells were transplanted into the epididymal fat pad of SCID/NOD mice (n = 20). The control group were transplanted with undifferentiated hESCs (n = 6). Graft survival and function were assessed using immunohistochemistry, and measuring serum human C-peptide and blood glucose levels.
The pancreatic IPCs were generated by the four-stage differentiation protocol using hESCs. About 17.1% of differentiated cells expressed insulin, as determined by flow cytometry. These cells secreted insulin/C-peptide following glucose stimulation, similarly to adult human islets. Most of these IPCs co-expressed mature β cell-specific markers, including human C-peptide, GLUT2, PDX1, insulin, and glucagon. After implantation into the epididymal fat pad of SCID/NOD mice, the hESC-derived pancreatic IPCs corrected hyperglycemia for ≥8 weeks. None of the animals transplanted with pancreatic IPCs developed tumors during the time. The mean survival of recipients was increased by implanted IPCs as compared to implanted undifferentiated hESCs (P<0.0001).
The results of this study confirmed that human terminally differentiated pancreatic IPCs derived from hESCs can correct hyperglycemia in SCID/NOD mice for ≥8 weeks.
PLoS ONE 07/2014; 9(7):e102198. DOI:10.1371/journal.pone.0102198 · 3.23 Impact Factor
"Human pluripotent stem cells (hPSCs), including human embryonic stem cells (hESCs) and induced pluripotent stem cells (iPSCs)45, have replication competence and the ability to differentiate into many cell types. Furthermore, they are reported to be a potential source of β cells for cell therapy67. hPSCs may also be used as tools in drug discovery research, such as development of new drugs using disease model cells derived from disease-specific iPSCs891011. For the realization of such therapies it is crucial to efficiently generate insulin-producing cells (IPCs) from PSCs. "
[Show abstract][Hide abstract] ABSTRACT: Insulin-producing cells (IPCs) derived from human pluripotent stem cells (hPSCs) may be useful in cell therapy and drug discovery for diabetes. Here, we examined various growth factors and small molecules including those previously reported to develop a robust differentiation method for induction of mature IPCs from hPSCs. We established a protocol that induced PDX1-positive pancreatic progenitor cells at high efficiency, and further induced mature IPCs by treatment with forskolin, dexamethasone, Alk5 inhibitor II and nicotinamide in 3D culture. The cells that differentiated into INSULIN-positive and C-PEPTIDE-positive cells secreted insulin in response to glucose stimulation, indicating a functional IPC phenotype. We also found that this method was applicable to different types of hPSCs.
"Using this approach, the approximately three stage framework for forming pancreatic endocrine competent progenitor cells from hESCs has become TGF-beta signalling (Activin A) dependent induction of definitive endoderm [19,20], FGF7 or FGF10 enhanced patterning to endodermal gut tube [5,6], and retinoic acid dependent induction of PDX1 [5,21,22] with concurrent BMP and sonic hedgehog inhibition [5,14,15,21]. A considerable range of signalling molecules has been applied to coax endocrine cell development from endocrine-competent progenitors; these include exendin-4, IGF1, HGF, noggin, bFGF, BMP4, VEGF, WNT and various inhibitors of sonic hedgehog, TGF-beta, and NOTCH signalling pathways [5,14,23]. "
[Show abstract][Hide abstract] ABSTRACT: Human embryonic stem cells (hESCs) have the ability to form cells derived from all three germ layers, and as such have received significant attention as a possible source for insulin-secreting pancreatic beta-cells for diabetes treatment. While considerable advances have been made in generating hESC-derived insulin-producing cells, to date in vitro-derived glucose-responsive beta-cells have remained an elusive goal. With the objective of increasing the in vitro formation of pancreatic endocrine cells, we examined the effect of varying initial cell seeding density from 1.3 x 10(4) cells/cm(2) to 5.3 x 10(4) cells/cm(2) followed by a 21-day pancreatic endocrine differentiation protocol. Low density-seeded cells were found to be biased toward the G2/M phases of the cell cycle and failed to efficiently differentiate into SOX17-CXCR4 co-positive definitive endoderm cells leaving increased numbers of OCT4 positive cells in day 4 cultures. Moderate density cultures effectively formed definitive endoderm and progressed to express PDX1 in approximately 20% of the culture. High density cultures contained approximately double the numbers of PDX1 positive pancreatic progenitor cells and also showed increased expression of MNX1, PTF1a, NGN3, ARX, and PAX4 compared to cultures seeded at moderate density. The cultures seeded at high density displayed increased formation of polyhormonal pancreatic endocrine cell populations co-expressing insulin, glucagon and somatostatin. The maturation process giving rise to these endocrine cell populations followed the expected cascade of pancreatic progenitor marker (PDX1 and MNX1) expression, followed by pancreatic endocrine specification marker expression (BRN4, PAX4, ARX, NEUROD1, NKX6.1 and NKX2.2) and then pancreatic hormone expression (insulin, glucagon and somatostatin). Taken together these data suggest that initial cell seeding density plays an important role in both germ layer specification and pancreatic progenitor commitment, which precedes pancreatic endocrine cell formation. This work highlights the need to examine standard culture variables such as seeding density when optimizing hESC differentiation protocols.
PLoS ONE 12/2013; 8(12):e82076. DOI:10.1371/journal.pone.0082076 · 3.23 Impact Factor
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.