肝纤维化进程中细胞间信息传递机制不清楚。有报道：肝细胞可分泌外泌体；肝细胞源神经因子能诱导HSCs凋亡。我们发现：肝细胞表达新型神经因子MANF与肝纤维化程度呈正相关，但HSCs中无MANF表达；肝细胞应激时分泌的外泌体含MANF；MANF能抑制炎症。推测：肝纤维化时肝细胞被诱导表达MANF，MANF以外泌体形式调节HSCs活性。为此，将检测病人血清中MANF水平，并分析其与肝纤维化程度相关性；制备肝细胞特异性MANF敲除小鼠模型，并用CCl4诱导慢性肝纤维化，证明MANF具有抗纤维化作用；分离肝细胞外泌体，证明外泌体和MANF能进入HSCs；利用细胞共培养、基因敲低和过表达等技术研究肝细胞源MANF对HSCs功能、增殖及凋亡的影响；进一步探讨SUMO1参与的MANF调节NF-κB机制。上述研究内容均属原始创新，该研究对了解细胞间信息传递方式、阐明肝纤维化机制及发现更有效干预手段奠定基础。

The mechanisms involved in liver fibrosis are complicated and unclear, especially the communication between the hepatocytes, the hepatic stellate cells (HSCs), and the Kupffer cells. It was recently reported that the hepatocytes excreted exosomes. The nerve growth factors (NGF) derived from hepatocytes induce HSCs apoptosis. We found that the new neurotrophic factor MANF, an ER stress inducible protein, was specifically expressed in hepatocytes and was closely associated with liver fibrosis. We also found that the exosome isolated from hepatocytes under treatment with tunicamycin or TNF-alpha contains MANF protein. Meanwhile, we have reported that MANF inhibited inflammation via blocking NF-kappa B activation. Therefore, we hypothesis that MANF expressed in the hepatocytes and excreted in the exosomes, may regulate HSCs activation during liver fibrosis. To verify this hypothesis, we will investigate the anti-fibrosis of MANF by using of the mice specifically knockouted MANF gene in hepatocytes. We will isolate the exosomes from the primarily culture hepatocytes after treatment with tunicamycin or TNF-alpha and detect MANF level. We also will test whether the exosomes are fused to HSCs. The methods, including cell co-culture, gene knockdown or knockout, gene over-expression will be used to test the effects of MANF derived from hepatocytes on the activation, proliferation and apoptosis of HSCs. We will explore the cellular mechanisms by which MANF regulates HSCs via exosomes delivery.