Cell Differentiation Unit, Diabetes Research Center, Vrije Universiteit Brussel, Brussels, Belgium.
Cell Transplant. 2013;22(5):821-30. doi: 10.3727/096368912X636812.
Development of β-cells from human embryonic stem cells (hESCs) could compensate for the shortage of islet donors required for diabetes therapy. Although pancreatic progenitors have been derived from hESCs using various protocols, no fully functional b-cells could be generated in vitro. We evaluated the in vivo growth and differentiation of PDX1+ pancreatic endoderm cells obtained from hESCs. Here we show site-specific survival and differentiation when comparing cells grafted in the epididymal fat pad or the subcutaneous space of NOD/SCID mice after 12 weeks follow-up. Subcutaneous grafts persisted and expressed PDX1 at all time points analyzed, showed PDX1 and NKX6.1 coexpression after 6 weeks, and contained NGN3+ cells after 12 weeks.These findings suggest that further specification along the pancreatic lineage occured at the subcutaneous site.In sharp contrast, in the fat pad grafts only a minority of PDX1+ cells remained after 2 weeks, and no further pancreatic differentiation was observed later on. In addition, contaminating mesenchymal cells present in the implants further developed into cartilage tissue after 6 weeks implantation in the fat pad, but not in the subcutaneous space. These findings indicate that the in vivo microenvironment plays a critical role in the further differentiation of transplanted pancreatic endoderm cells.
从人类胚胎干细胞 (hESC) 中开发β细胞可以弥补糖尿病治疗所需胰岛供体的短缺。尽管已经使用各种方案从 hESC 中获得了胰腺祖细胞，但在体外仍无法生成完全功能的β细胞。我们评估了从 hESC 获得的 PDX1+胰腺内胚层细胞在体内的生长和分化。在这里，我们比较了细胞在经过 12 周的后续观察后在 NOD/SCID 小鼠的附睾脂肪垫或皮下空间中的定植和分化情况。皮下移植物在所有分析的时间点都持续存在并表达 PDX1，在 6 周后显示 PDX1 和 NKX6.1 共表达，并且在 12 周后含有 NGN3+细胞。这些发现表明在皮下部位进一步沿着胰腺谱系特化。与此形成鲜明对比的是，在脂肪垫移植物中，只有少数 PDX1+细胞在 2 周后仍然存在，并且随后没有进一步的胰腺分化。此外，在脂肪垫中植入 6 周后，植入物中存在的混杂间充质细胞进一步发育为软骨组织，但在皮下空间中则不会。这些发现表明体内微环境在移植的胰腺内胚层细胞的进一步分化中起着关键作用。
