猪胚胎干细胞研究进展

Current Progress in Procine Embryonic Stem Cells

胚胎干细胞是一类具有在体外无限自我复制和分化为体内任何种类细胞的多潜能细胞。目前,公认的胚胎干细胞全能性判断标准包括:体内及体外向三胚层细胞分化和二倍体嵌合后能形成生殖细胞。从1981年Kaufman等第一次分离小鼠胚胎干细胞至今,能满足这些标准的只有小鼠、大鼠和鸡的胚胎干细胞系。猪作为一种生理结构和器官的三维结构和人都比较相似的传统药物实验模型,其胚胎干细胞系的建立一直受到广泛的关注,但是迄今为止真正的猪胚胎干细胞系(即满足上述判定标准)还未被建立起来。本文将从多个方面阐述猪胚胎干细胞系的研究进展及亟待解决的问题。猪的全基因组序列已经测序完成,相信随着干细胞研究的深入开展,对维持多能性的转录因子和细胞信号通路认识的逐步加深,建立真正的猪胚胎干细胞系将成为可能。

Embryonic stem cells can be maintained indefinitely in vitro and yet maintain the competence to produce all the cells within a fetus.The well-accepted criteria for totipotency of embryonic stem cells inculde 1） differentiating into three germ layers in vitro;2） teratoma formation ability;3） germline transmission and/or tetrap-loid -complementation.Only mouse,rat and chicken embryonic stem cell lines could satisfy all the standards since Kaufman MH and Evans MJ derived the first mouse embryonic stem cell line in 1981.Pigs are widely used as drug experimental models because of the physiologically similarity with humans.Although the derivation of porcine embryonic stem cells are highly needed,no convincing embryonic stem cell lines have been produced in this species to date.In this review,we discuss the recent progress in this field,especially oriented on possible reasons and obstacles why establishment of porcine embryonic stem cell lines is still unsuccessful.The identification of appropriate stem cell markers,functional cytokine pathways,and key pluripotency-maintaining factors along with the accomplishment of porcine genomes,provide encouragement for establishment of porcine embryonic stem cell lines in the near future.