Ping Chen, Xiaoling Dong, Jin Zhu, Jiahong Dong, Jiming Ding, Lin Zhang
Institute of Hepatobiliary Surgery, Southwest Hospital, The Third Military Medical University, Chongqing, China.
Arch Med Res. 2006 Jul;37(5):576-83. doi: 10.1016/j.arcmed.2005.12.004.
We undertook this study in rats to investigate the role of hepatic sinusoidal endothelial cells (SECs) in hepatocyte proliferation early after partial hepatectomy and the regulatory mechanisms involved.
The animal model of 70% hepatectomy was made. Hepatic SECs and hepatocytes were isolated and cultured according to the method of Braet et al. with some modifications. Levels of nitric oxide (NO), interleukin-6 (IL-6), and hepatic growth factor (HGF) in the supernatants of hepatic SEC cultures were measured, and the expression of HGF mRNA by hepatic SECs was analyzed. The relationship between the supernatants of hepatic SEC cultures and hepatocyte proliferation was probed. (3)H-thymidine incorporation and the proliferating cell nuclear antigen (PCNA) labeling index of hepatocytes were used as signs of hepatocyte proliferation.
Levels of NO, IL-6, and HGF in the supernatants of hepatic SECs cultures were increased markedly 6 and 24 h after hepatectomy and then were decreased gradually. The expression of HGF mRNA by cultured SECs was increased markedly 6 and 24 h after hepatectomy, with a peak 6 h after hepatectomy. The PCNA labeling index and (3)H-thymidine incorporation of hepatocytes started to increase 6 h after hepatectomy, with a peak at 24 h. Hepatic SECs were isolated from rats 24 h after partial hepatectomy and cultured for 24 h, and the culture supernatants were obtained. The supernatants not only significantly enhanced the PCNA labeling index and (3)H-thymidine incorporation of proliferating hepatocytes isolated from rats after partial hepatectomy but also obviously increased the DNA synthesis of quiescent hepatocytes from the control rats. The extent of hepatocyte proliferation was closely related to the amount of the SEC culture supernatants added in both rats after partial hepatectomy and control rats.
These results suggest that cytokines (such as IL-6, HGF and NO) secreted by SECs play important roles in liver regeneration early after partial hepatectomy. We speculate that activated hepatic SECs secrete some substances that induce or trigger liver regeneration after partial hepatectomy.
我们在大鼠中进行了这项研究，以探讨肝窦内皮细胞（SECs）在部分肝切除术后早期肝细胞增殖中的作用及其相关调控机制。
制作70%肝切除术的动物模型。参照Braet等人的方法并稍作修改，分离并培养肝SECs和肝细胞。检测肝SECs培养上清液中一氧化氮（NO）、白细胞介素-6（IL-6）和肝生长因子（HGF）的水平，并分析肝SECs中HGF mRNA的表达。探讨肝SECs培养上清液与肝细胞增殖之间的关系。采用（3）H-胸腺嘧啶核苷掺入法和增殖细胞核抗原（PCNA）标记指数作为肝细胞增殖的指标。
肝切除术后6小时和24小时，肝SECs培养上清液中NO、IL-6和HGF的水平显著升高，随后逐渐下降。肝切除术后6小时和24小时，培养的SECs中HGF mRNA的表达显著增加，在肝切除术后6小时达到峰值。肝细胞的PCNA标记指数和（3）H-胸腺嘧啶核苷掺入率在肝切除术后6小时开始增加，在24小时达到峰值。在部分肝切除术后24小时从大鼠分离肝SECs并培养24小时，获得培养上清液。该上清液不仅显著提高了从部分肝切除术后大鼠分离的增殖肝细胞的PCNA标记指数和（3）H-胸腺嘧啶核苷掺入率，还明显增加了对照大鼠静止肝细胞的DNA合成。在部分肝切除术后的大鼠和对照大鼠中，肝细胞增殖程度均与添加的SECs培养上清液量密切相关。
这些结果表明，SECs分泌的细胞因子（如IL-6、HGF和NO）在部分肝切除术后早期肝再生中起重要作用。我们推测，活化的肝SECs分泌某些物质，诱导或触发部分肝切除术后的肝再生。
