大鼠体外肝细胞集落的建立及生长调控研究

目的研究建立体外培养肝细胞集落的关键条件,探讨肝细胞克隆生长的调控机制。方法采用原位预灌流和胶原酶循环灌流分离肝细胞,观察在化学限定培养条件下,肝细胞生长素(HPN)、二甲亚砜(DMSO)及尼克酰胺(NA)对肝细胞DNA合成、有丝分裂象、光镜形态和电镜超微结构的影响。结果肝细胞培养时间进程显示:10 mmol/L NA显著协同HPN促进肝细胞3H-TdR掺入作用,在60和84 h出现2个DNA合成峰;2% DMSO抑制3H-TdR掺入,但在NA共同作用下,肝细胞在132 h表现为DNA合成峰。有丝分裂象显示:HPN NA DMSO培养72 h时肝细胞为正常二级分裂,168 h后仍保持相当的有丝分裂活性。光镜下形态及电镜超微结构观察到培养28 d的肝细胞克隆生长特征及增殖潜在性。结论NA及DMSO加入-移除方案可交叉控制HPN作用的肝细胞增殖,所构建的肝细胞克隆生长系统可用于人肝细胞代谢、诱变、细胞中毒及生物转化等研究,并为实施体外克隆肝细胞治疗肝衰竭及遗传性肝疾病提供实验依据。

Establishment and growth regulation of rat hepatocyte colony in vitro

Objective To investigate the conditions essential for culturing hepatocytes colony in vitro, and to study the growth regulation mechanisms of hepatocyte colony. Methods Rat hepatocytes were isolated by two-step in situ preperfusion and collagenase circulatory perfusion. The effects of hepatopoietin (HPN), nicotinamide (NA) and dimethyl sulfoxide (DMSO) on DNA synthesis, mitotic activity, morphology (under inverted microscope) and utrastructure (under TEM) of the hepatocytes were investigated in chemically defined culture medium. Results The time course of DNA synthesis in cultured hepatocytes showed that 3 H-TdR incorporation was dramatically enhanced by 10 mmol/L NA, presenting 2 peaks at 60 and 84 h respectively. The plateau of DNA synthesis was diminished in the presence of DMSO, but a peak occurred again at 132 h upon NA treatment. After cell culture in the presence of HPN, NA, and DMSO for 72 h, the hepatocytes presented sustained regular bipolar mitosis, with considerable mitotic activity at 168 h. The growth characteristics of hepatocyte colony, in addition to its potential for expansion, were captured by both light and electron microscopy on day 28 of cell culture. Conclusion The reciprocal actions of NA and DMSO can control the proliferation of HPN-stimulated hepatocytes, which can be used for studying human hepatocyte metabolism, cytotoxicity, biotransformation and mutagenesis, and may provide experimental evidences for the treatment of liver failure and genetic liver diseases with in vitro hepatocyte clones.