Platelets strongly induce hepatocyte proliferation with IGF-1 and HGF in vitro
Platelets strongly induce hepatocyte proliferation with IGF-1 and HGF in vitro
复制标题
DOI：
10.1016/j.jss.2007.02.035
复制
发表时间：
2008-04-01
影响因子：
2.2
通讯作者：
Ozaki, Michitaka
中科院分区：
文献类型：
--
作者：
Matsuo, Ryota;Ohkohchi, Nobuhiro;Ozaki, Michitaka
背景众所周知，血小板具有血栓形成作用。然而，血小板不仅在止血中而且在伤口愈合和组织再生中发挥重要作用。有报道称，扩大肝切除术后，血小板在肝脏中积聚并促进肝再生，但其机制尚不清楚。本研究旨在阐明血小板在体外对肝细胞有直接增殖作用的机制。使用通过胶原酶消化从雄性BALB/c小鼠获得的肝细胞和永生化肝细胞（TLR 2）。为了阐明血小板增殖作用的机制，在各种条件下测定肝细胞DNA合成并分析相关的细胞信号。同时进行色谱分析以明确血小板中哪些成分具有促有丝分裂活性。与血小板共同培养的肝细胞DNA合成显著增加（P < 0.001）。然而，当血小板和肝细胞分离时，血小板没有增殖作用。整个破碎的血小板，上清液部分，和新鲜分离的血小板有类似的增殖作用，而膜部分没有。加入血小板后，Akt和细胞外信号调节激酶ERK 1/2均被激活，但细胞外信号调节激酶STAT 3未被激活。凝胶排阻色谱法分离血小板提取物中的促有丝分裂组分，这些组分富含肝细胞生长因子和IGF-1。血小板和肝细胞之间的直接接触是增殖效应所必需的。直接接触启动了参与生长因子激活的信号转导。肝细胞生长因子、血管内皮生长因子和胰岛素样生长因子-1，而不是血小板衍生生长因子，主要促进肝细胞增殖。(C)2008年爱思唯尔公司All rights reserved.
Background. It is well known that platelets have a thrombotic effect. However, platelets play an important role not only in hemostasis but also in wound healing and tissue regeneration. Platelets have been reported to accumulate in the liver and promote liver regeneration after an extended hepatectomy, but the mechanism is unclear. The present study was designed to clarify the mechanism by which platelets have a direct proliferative effect on hepatocytes in vitro.Materials and methods. Hepatocytes obtained from male BALB/c mice by collagenase digestion and immortalized hepatocytes (TLR2) were used. To elucidate the mechanism of the proliferative effect of platelets, DNA synthesis of hepatocytes was measured under various conditions and the related cellular signals were analyzed. Chromatographic analysis was also performed to clarify which elements of platelets have mitogenic activity.Results. DNA synthesis significantly increased in the hepatocytes cultured with platelets (P < 0.001). However, when the platelets and hepatocytes were separated, the platelets did not have a proliferative effect. Whole disrupted platelets, the supernatant fraction, and fresh isolated platelets had a similar proliferative effect, while the membrane fraction did not. After the addition of platelets, both Akt and extracellular signal-regulated kinases ERK1/2 were activated, but extracellular signal-regulated kinase STAT3 was not activated. Some mitogenic fractions were obtained from the platelet extracts by gel exclusion chromatography; the fractions were rich in hepatocyte growth factor and IGF-1.Conclusions. Direct contact between platelets and hepatocytes was necessary for the proliferative effect. The direct contact initiated signal transduction involved in growth factor activation. Hepatocyte growth factor, vascular endothelial growth factor, and insulin-like growth factor-1, rather than platelet-derived growth factor, mainly contributed to hepatocyte proliferation. (C) 2008 Elsevier Inc. All rights reserved.