Talbot N C, Rexroad C E, Powell A M, Pursel V G, Caperna T J, Ogg S L, Nel N D
U.S. Department of Agriculture, Beltsville Agricultural Research Center, Maryland 20705.
In Vitro Cell Dev Biol Anim. 1994 Dec;30A(12):843-50. doi: 10.1007/BF02639394.
Continuous cultures of pluripotent parenchymal hepatocytes were derived from the epiblasts of 8-day-old pig blastocysts. The cells were polygonal and had phase-contrast dark, granular cytoplasm with prominent nuclei and nucleoli. These feeder-dependent cell cultures differentiated into large, multicellular, secretory, duct-like structures or formed small canaliculi between individual cells. Alternatively, the cells accumulated droplets that stained intensely with Oil Red O, a lipid-specific stain. Alpha-fetoprotein (AFP), albumin, and beta-fibrinogen mRNAs were expressed as the cells differentiated in culture. Serum-free medium that was conditioned by the cells contained transferrin, AFP, and albumin. The growth and viability of the cells were inhibited by transforming growth factor beta 1 (TGF beta 1) at concentrations > or = 1 ng/ml. The cell cultures grew slowly with doubling times of 2 to 3 d. One of the cultures, pig inner cell mass-19 (PICM-19), was passaged continuously for over 2 yr [> 100 population doublings (PD)] and appears to be an infinitely self-renewing cell population. The stem cell characteristics of the epiblast-derived fetal hepatocytes indicate that the cells may be unique for investigations of liver differentiation and organogenesis.
多能实质肝细胞的连续培养物源自8日龄猪囊胚的上胚层。细胞呈多边形，在相差显微镜下可见细胞质暗黑、呈颗粒状，细胞核和核仁突出。这些依赖饲养层细胞的培养物分化为大型、多细胞、分泌性、导管样结构，或在单个细胞之间形成小的胆小管。另外，细胞积累了用脂类特异性染料油红O强烈染色的脂滴。随着细胞在培养中分化，甲胎蛋白（AFP）、白蛋白和β-纤维蛋白原信使核糖核酸得以表达。细胞条件培养液中含有转铁蛋白、AFP和白蛋白。当转化生长因子β1（TGFβ1）浓度≥1纳克/毫升时，细胞的生长和活力受到抑制。细胞培养生长缓慢，倍增时间为2至3天。其中一种培养物，猪内细胞团-19（PICM-19），连续传代超过2年[>100次群体倍增（PD）]，似乎是一个无限自我更新的细胞群体。上胚层来源的胎儿肝细胞的干细胞特性表明，这些细胞对于肝脏分化和器官发生的研究可能具有独特性。
