Myofibroblast-to-hepatocyte conversion as a therapy for alcoholic liver disease

描述(申请人提供)：酒精性肝病最终导致肝功能衰竭。治疗酒精性肝病所致肝功能衰竭的唯一治疗方法是肝移植。肝细胞疗法对这些患者无效，因为酒精性肝病总是与肝纤维化有关，肝纤维化会损害移植的植入。 细胞。由于供肝长期短缺，许多酒精性肝病患者在等待肝移植时死亡。为了改善这些患者的预后，我们建议绕过肝纤维化作为肝细胞治疗的障碍。我们假设，肝纤维化的功能可以通过体内转化组成肝脏的细胞来改善。 纤维组织转化为具有肝细胞功能的细胞。我们的假设基于最近发现的可以将成纤维细胞转化为治疗有效的肝细胞样细胞(IHEPS)的肝脏转录因子，并成功地在体内将纤维化的心脏组织转化为功能实质。为了建立体内产生IHEP作为治疗肝纤维化的方法，我们将追求两个目标：(1)在体内将肌成纤维细胞转化为iHEPS。我们将用腺病毒载体将肝脏转录因子转移到肌成纤维细胞，这已经被证明在大鼠和小鼠肝纤维化模型中有效地转导肌成纤维细胞。在晚期肝纤维化中，大多数肌成纤维细胞处于静止状态，这将防止在肌成纤维细胞向iHEPS转化完成之前非整合腺病毒载体的丢失。由于肌成纤维细胞是肝脏中胶原的主要来源，我们的策略有望不仅增加具有肝细胞功能的细胞的数量，而且还能防止进一步的胶原在肝脏中沉积。(2)建立非整合型腺相关病毒(AAV)载体在体内将肌成纤维细胞转化为iHEPS的方法。常规腺病毒载体具有高度的免疫原性，因此对人类应用是不安全的。由于AAV载体可以在宿主细胞中持续存在而不会产生毒性，也不会整合到基因组中，因此它们越来越多地被用于人类的基因治疗。为了确定AAV载体对肝脏肌成纤维细胞的靶向性，我们将筛选一个重排AAV衣壳的文库。为了支持这种方法的可行性，最近在这个文库中发现了针对胰腺细胞的衣壳。通过用一种被认为对人类安全的病毒载体增强功能和减少肝脏纤维化，拟议的策略有可能成为肝移植治疗肝脏的替代方案。 因酒精性肝病而失败。

DESCRIPTION (provided by applicant): Alcoholic liver disease eventually causes liver failure. The only curative therapy for patients with liver failure due to alcoholic liver disease is liver transplantation. Liver cell therapy is not effective in these patients because alcoholic liver disease is invariably associated with liver fibrosis, which impairs the engraftment of transplanted cells. Because of the long-standing shortage of donor livers, many patients with alcoholic liver disease die while waiting for liver transplantation. To improve the outcomes of these patients, we propose to work around liver fibrosis as a barrier to liver cell therapy. We hypothesize that the function of fibrotic livers can be improved by in vivo conversion of the cells that make up the fibrotic tissue into cells with hepatocyte function. Our hypothesis rests on the recent identification of hepatic transcription factors that can convert fibroblasts into therapeutically effective hepatocyte-like cells (iHeps) and success with in vivo conversion of fibrotic heart tissu into functional parenchyma. To establish in vivo iHep generation as a therapy for liver fibrosis, we will pursue 2 aims: (1) To convert myofibroblasts into iHeps in vivo. We will deliver the hepatic transcription factors to myofibroblasts with adenoviral vectors, which have been shown to efficiently transduce myofibroblasts in rat and mouse models of liver fibrosis. Most myofibroblasts are quiescent in advanced liver fibrosis, which will prevent loss of nonintegrating adenoviral vectors before conversion of myofibroblasts into iHeps is completed. Because myofibroblasts are the main source of collagen in the liver, our strategy is expected to not only increase the number of cells with hepatocyte function, but also prevent further collagen deposition in the liver. (2) To establish the use of nonintegrating adenoassociated viral (AAV) vectors for conversion of myofibroblasts into iHeps in vivo. Conventional adenoviral vectors are highly immunogenic and therefore not safe for human application. Because AAV vectors can persist in host cells without toxicity and integration into the genome, they are increasingly used for human gene therapy. To establish targeting of AAV vectors to liver myofibroblasts, we will screen a library of shuffled AAV capsids. In support of the feasibility of this approach, capsids targeting specifically pancreatic ¿-cells have recently been identified in this library. By improvig function and reducing fibrosis of the liver with a viral vector deemed safe for human application, the proposed strategy has potential as an alternative to liver transplantation for therapy of liver failure due to alcoholic liver disease.