Regulation Mechanism of Proliferation in Regenerating Liver Cells

当成熟的肝细胞通过外科手术被部分切除时，剩余的肝细胞开始快速增殖，直到它们再生到原来的重量。目前认为，肝部分切除术后肝脏再生受表皮生长因子、肝细胞生长因子、细胞表面调节剂、胰岛素受体等多种因素的影响。然而，如何控制增殖和如何刺激再生生长尚不完全清楚。为了明确肝脏再生的机制，我们利用高分辨率二维电泳技术研究了肝部分切除术后肝细胞和血清中蛋白质的变化，发现一些特异性蛋白质在再生阶段数量急剧增加或新出现。因此，我们研究了这些蛋白在再生阶段的特性和功能。所得结果如下：1。采用多种色谱法（硫酸铵分离、deae - sepharose色谱柱、凝胶过滤、等电聚焦、制备凝胶电泳和Con - sepharose色谱柱）从肝部分切除后3 ~ 24 h的大鼠肝脏中纯化出一种特异性蛋白，并对其分子特性进行了研究。纯化后的产物在sds - page上呈单条带。制备了兔抗血清。免疫电泳证实了抗血清的纯度。该抗血清对再生大鼠肝脏匀浆只有一条沉淀线。利用火箭免疫电泳技术，建立了一种能够测定特异蛋白的分析方法。特异性蛋白在肝部分切除术后2-3h出现，6-24h达到最大值，随后逐渐降低。在假手术大鼠肝脏中未检测到该蛋白。因此，我们认为该特异性蛋白在肝部分切除术后较早阶段促进了肝细胞的增殖。少

When mature liver cells are partially removed by a surgical operation, remnant liver cells begin rapid proliferation until they are regenerated to their original weight. It has been considered that liver regeneration after partial hepatectomy is affected by various factors such as epidermal growth factor, hepatocyto growth factor, cell surface modulator and insulin receptor. However, how controls the proliferation and how the regenerative growth is stimulated are not fully clear. In order to define the mechanism of liver regeneration, we investigated the changes of proteins in liver cells and serum after partial hepatectomy using high-resolution two dimensional electrophoresis, and detected some specific proteins which drastically increased in amount or newly appeared at a regenerating stage. Therefore, we investigated the characteristics and the function of these proteins under regenerating stage. Results obtained were listed below.1. One of the specific protein was purified by variou … More s chromatography (ammonium sulfate fractionation, DEAE-Separose column, gel filtration, isoelectric focusing, preparative gel electrophoresis and Con A-Sepharose column), from rat liver at regenerating stage (3-24 hours after partial hepatectomy) and some molecular characteristics were investigated. The purified preparation showed a single band on SDS-PAGE.2. Rabbit antiserum against the purified preparation was prepared. The purity of antiserum was confirmed by immunoelectrophoresis. This antiserum showed only one precipitin line against homogenate of regenerating rat liver.3. An analytical method capable of measuring for the specific protein was established using rocket immunoelectrophoresis.4. The specific protein appeared at 2-3h after partial hepatectomy, was at a maximum at 6-24h, and then gradually decreased. This protein was not detected in sham-operated rat liver. Therefore, it was considered that the specific protein contributed to the proliferation of liver cells at a relatively early stage after partial hepatectomy. Less