靶向于PDGFR-β的肉苁蓉苯乙醇苷类成分（CPhGs）脂质体在抗肝纤维化过程中的机制研究

Previous studies have shown that phenylethanoid glycosides from Cistanche (CPhGs) could effectively scavenge free radicals, regulate the expression of apoptotic gene Bcl-2/Bax, inhibit the expression of HBsAg and HBeAg and HBV DNA replication. In vivo and in vitro experiments showed that CPhGs different dose groups can significantly inhibit the proliferation of HSC, reduce collagen and ECM synthesis,.thus delaying and preventing the formation of liver fibrosis. Although in vitro and in vivo experiments some drugs showed anti-hepatic fibrosis effects, but it showed relatively low efficacy, a relatively short half-life and some serious side effects in clinical applications. This project aims to utilize pPB to modify sterically-stable liposomes(SSL) to prepare the pPB-SSL carrier, to establish the application,CPhGs was selected to be entrapped in pPB-SSL and study anti-hepatic fibrosis effect of CPhGs liposomes. The studies will reveal effect target of.CPhGs liposomes and clarify its molecular mechanism of anti-hepatic fibrosis by observing the influence of CPhGs liposomes on proliferation and apoptosis of HSC-T6,secretion of collagen, and PDGF involved in multiple signal transduction pathways. Expectations for more possible for clinical use of liver fibrosis targeting drug treatment.

前期研究显示传统补肾益气中药肉苁蓉所含的苯乙醇苷类成分(CPhGs)能有效清除自由基、调节凋亡基因Bcl-2/Bax的表达以及抑制HBsAg和HBeAg的表达和HBV DNA的复制，从而发挥抗肝炎作用，体外实验也表明CPhGs不同剂量组能有效抑制HSC活化、增殖，减少胶原合成，使ECM的合成减少，而达到抑制胶原的生成、抗肝纤维化的作用;虽然有许多药物在体内外实验中表现出一定的抗肝纤维化作用，但是在临床应用中却表现出相对低的疗效、相对短的半衰期和一些严重的副作用。本项目拟设计制备针对PDGFR-β的环肽修饰的包封CPhGs的立体稳定脂质体，并通过体外实验研究，观察CPhGs脂质体对HSC-T6增殖、凋亡和胶原表达的影响，以及对PDGF参与的多条信号转导通路的影响，从细胞分子水平阐明其抗肝纤维化的分子机制，期望寻求更可能为临床所用的抗肝纤维化的靶向药物治疗途径。

课题组前期研究显示肉苁蓉所含的苯乙醇苷类成分（CPhGs）在体内对牛血清白蛋白（BSA）诱导的大鼠肝纤维化具有显著的防治作用，并且体外实验结果也显示CPhGs可以通过 TGF-β/Smad 信号通路抑制 HSCs 的激活从而发挥抗肝纤维化作用。为提高CPhGs抗肝纤维化的药效和靶向性，本项目在前期研究基础上，研究制备了CPhGs新剂型CPhGs靶向脂质体，并对其体内药代动力学、组织分布及体外释放度进行了研究；采用BSA诱导的大鼠免疫性肝纤维化模型，在整体动物水平上考察CPhGs靶向脂质体以及CPhGs原料药对大鼠免疫性肝纤维化的防治作用及发挥药效的机制；选用HSC-T6细胞株，通过观察CPhGs靶向脂质体对HSC-T6细胞增殖、凋亡、周期和胶原分泌的作用，以及其对PDGF-BB/Fak/PI3K/Akt信号传导通路的影响，揭示其作用靶点，从细胞和分子水平阐明了其抗肝纤维化的分子机制。研究结果可为进一步拓展沙生植物肉苁蓉在医疗领域的应用以及对预防和治疗肝纤维化新药的开发提供理论依据。