Study on Strategies for Non-Heart Beating Liver

肝窦内皮细胞（SEC）损伤是非心脏供者肝移植的主要异常。在原代培养中，血管内皮生长因子是维持和增殖血管内皮生长因子的重要因素。我们发现VEGF也通过上调SECs的孔隙度而发挥无血管通透性因子的作用。此外，VEGF可抑制肝窦星状细胞、周细胞的收缩，提示VEGF可调节肝窦微循环。UW溶液冷保存后，大鼠肝脏肝细胞中VEGF表达增加，但在SEC形成之前，VBGFR-1和VEGFR-1 mRNA表达减少。这可能表明VEGF不能有效作用于冷保存肝脏中的SEC，外源VBGF不能阻止SEC的损伤。这种激活导致了这种肝脏原位移植后的SEC损伤。我们发现活化的Kupffer细胞表达骨桥蛋白，这是Th1免疫反应启动的必要细胞因子。此外，我们利用具有不同骨桥蛋白基因等位基因的小鼠，证明骨桥蛋白作为一种趋化因子在巨噬细胞向肝脏迁移中发挥了重要作用，这表明调节Kupffer细胞中骨桥蛋白的表达可能是保护SECs的另一种策略。我们利用人血清淀粉样蛋白P组分启动子作为肝细胞特异性载体，制备了在肝脏中高度表达骨桥蛋白的转基因小鼠，以证明我们的假设的研究正在进行中

Sinusoidal endothelial cell (SEC) injury is a major abnormality in the liver transplanted from non-heart beating donors. It is important to protect SECs for the establishment of non-heartbcating liver transplantationVEGF is a factor essential for maintenance as well as proliferation of SECs in primary culture. We demonstrated that VEGF also acted as avascular permeability factor through up-regulation of the porosity on SECs. Furthermore, VEGF inhibited contraction of stellate cells, pericytes of SECs, suggesting that VEGF can regulate microcirculation in the hepatic sinusoids. VEGF expression in hepatocytes was increased in rat liver after cold preservation in UW solution, but mRNA expressions of VBGFR-1 and VEGFR-1 were decreased prior to the development of SEC in jury These results may suggest that VEGF cannot work effectively on SECs in the cold preserved liver, and also that exogenous VBGF cannot prevent SEC from injuryKupffer cells were markedly activated in the cold preserved liver, and this activation contributed to SEC injury after orthotopic transplantation of such livers. We found that activated Kupffer cells expressed osteopontin an essential cytokine for initiation of Th1 immune response. Also, we demonstrated that osteopontin played a major role as a chemokine in macrophage migration into the liver using mice with different alleles of osteopontin gene, suggesting that the modulation of osteopontin expression in Kupffer cells may be another strategy for protection of the SECs. We made transgenic mice expressing osteopontin very highly in the liver using human serum amyloid P component promotor as a vector specific for hepatocytes Investigations to prove our hypothesis are now in progress