题名：Enrichment of human embryonic stem cell-derived NKX6.1-expressing pancreatic progenitor cells accelerates the maturation of insulin-secreting cells in vivo.
作者：REZANIA A; BRUIN JE; XU J; NARAYAN K; FOX JK; O'NEIL JJ; KIEFFER TJ;
来源：Stem Cells. 2013 Jul 29. doi: 10.1002/stem.1489. [ IF= 0.00 ] ]
摘要：Human embryonic stem cells (hESCs) are considered a potential alternative to
cadaveric islets as a source of transplantable cells for treating patients with
diabetes. We previously described a differentiation protocol to generate
pancreatic progenitor cells from hESCs, composed of mainly pancreatic endoderm
(PDX1/NKX6.1-positive), endocrine precursors (NKX2.2/synaptophysin-positive,
hormone/NKX6.1-negative) and polyhormonal cells (insulin/glucagon-positive,
NKX6.1-negative). However, the relative contributions of NKX6.1-negative versus
NKX6.1-positive cell fractions to the maturation of functional beta-cells
remained unclear. To address this question we generated two distinct pancreatic
progenitor cell populations using modified differentiation protocols. Prior to
transplant both populations contained a high proportion of PDX1-expressing cells
(~85-90%), but were distinguished by their relatively high (~80%) or low (~25%)
expression of NKX6.1. NKX6.1-high and NKX6.1-low progenitor populations were
transplanted subcutaneously within macroencapsulation devices into diabetic mice.
Mice transplanted with NKX6.1-low cells remained hyperglycemic throughout the
5-month post-transplant period whereas diabetes was reversed in NKX6.1-high
recipients within 3 months. Fasting human C-peptide levels were similar between
groups throughout the study, but only NKX6.1-high grafts displayed robust meal-,
glucose- and arginine-responsive insulin secretion as early as 3 months
post-transplant. NKX6.1-low recipients displayed elevated fasting glucagon
levels. TheracyteTM devices from both groups contained almost exclusively
pancreatic endocrine tissue, but NKX6.1-high grafts contained a greater
proportion of insulin-positive and somatostatin-positive cells, whereas
NKX6.1-low grafts contained mainly glucagon-expressing cells. Insulin-positive
cells in NKX6.1-high, but not NKX6.1-low grafts expressed nuclear MAFA.
Collectively, this study demonstrates that a pancreatic endoderm-enriched
population can mature into highly functional beta-cells with only a minor
contribution from the endocrine subpopulation. Stem Cells 2013.