角膜基质诱导胚胎干细胞定向分化的初步实验研究

目的:探索角膜基质接触诱导胚胎干细胞(embryonic stem cells,ES.细胞)定向分化的可能性。方法:分别在去上皮的新西兰白兔表层角膜缘基质上、晶状体上皮细胞饲养层上培养ES-D_3细胞,裸鼠皮下移植使其形成复层细胞,一段时间后,行扫描电镜和光镜观察。结果:I.ES细胞在新鲜表层角膜缘基质上增殖缓慢,2～3周形成较大细胞集落,光镜下细胞形态单一,体积较正常ES细胞大,电镜下细胞核已演变为细长形,移植到裸鼠皮下2周形成上皮样细胞复层,电镜下可见微绒毛,而角膜基质非上皮面的ES细胞仍保持其小细胞状态不变。2.晶状体上皮细胞与ES细胞共培养只能延缓其分化时间,不能诱导其定向分化。结论:表层角膜缘基质具有诱导ES细胞定向分化的潜能,体外培养条件下可能不发生晶状体诱导的第三级胚胎诱导。眼科学报1999;15:195-198。

Preliminary Experimental Study on Commitment Differentiation of Embryonic Stem Cells Induced by Corneal Limbal Stroma in Vitro

Purpose: To investigate the possibility of commitment differentiation of embryonic stem cells (ES cells) induced by corneal limbal stroma. Methods: Superficial corneal limbal stroma and lentis epithelium from New Zealand white rabbit were used for feeder layer for ES-Ds cells culture to induce the ES cells differentiation into corneal limbal stem cells. The differentiated ES cells were determined by light microscope and electronic microscope. Results: 1. The proliferation of differentiating ES cells which cultured on corneal surface stroma layer around the corneal limbus was slow. The appearance of induced ES cells were uniform cells with much larger size than undifferentiated ES cells, and the nucleoli become long and thin under electronic: microscope, but the size of ES cells cultured on deep stroma maintain as small as undifferentiated ES cells. The ES cells cultivated on surface stroma layer around the corneal limbus appeared microvilli 2 weeks after grafting into subcutaneous of athymic mice. 2. Lentis epithelium can only delay but not induce the ES cells differentiation to corned limbal stem celluloid. Conclusion: These results suggest that the superficial corneal limbal stroma has a potential ability to induce ES cells commitment differentiation. The tertiary embryo induction may not occur in vitro. Eye Science 1999; 15: 195 - 198.