基于Sonic hedgehog信号通路的eruberin A对胰腺星状细胞活化及慢性胰腺炎的影响

Chronic pancreatitis (CP) is one of the most strenuous diseases in clinical practice. Due to its elusive etiologies, no effective medical management of this disease has been developed. Activated pancreatic stellate cells (PSCs) have recently been implicated in the pathogenesis of pancreatic fibrosis, which is commonly associated with the development of CP and pancreatic ductal adenocarcinoma. Therefore, the suppression of PSC activation is believed to be a potential therapeutic strategy for CP. Our previous works have demonstrated that sonic hedgehog (Shh) signaling plays important roles in the activation of PSCs, by which production of extracellular matrix proteins and expression of α-smooth muscle actin was overwhelmed, in mice induced with CP. From our preliminary in vitro data, eruberin A, a folk medicine for the purpose of blood-nourishing has been used in the Chinese population for centuries, was found to significantly suppress the activation of cultured PSCs and such suppression was probably mediated through the attenuation of Shh signaling. This proposed study is aimed to investigate whether Shh signaling pathway components are important regulators for the development of pancreatic fibrosis and CP. Consequently, our objective is to clarify the role of Shh signaling in the suppression of PSC activation by eruberin A. The results of our study are of relevance to uncovering the mechanism of pancreatic fibrogenesis and obtaining patent claims toward new targets in therapeutic treatments of pancreatic fibrosis and CP.

慢性胰腺炎号称临床内外科最棘手的疾病之一。其发病机理不清，目前尚缺有效的治疗手段。新近的研究表明胰腺星状细胞异常活化是导致胰腺纤维化，慢性胰腺炎以及胰腺癌的关键，因此，抑制星状细胞活化应是当前治疗的新靶点。在慢性胰腺炎小鼠模型上，细胞外基质过度分泌，纤维结缔组织过度沉积，致胰腺结构改变，形成纤维化，并伴发炎症反应，我们近期的研究显示在胰腺星状细胞异常活化的同时，胰腺內在纤维化标志物的表达及刺蝟信号通路 (Shh)呈过度激活情况。通过前期的体外实验，我们发现eruberin A 能显著地减低胰腺星状细胞株上相关纤维化基因的表达，其机制与抑制Shh信号密切相关。本项目拟从动物和细胞分子水平来探讨并阐明eruberin A 阻断Shh信号通路的分子机制，及其干预胰腺纤维化和慢性胰腺炎的作用及相关机理。本项目为开拓治疗新靶点和开发具有自主知识产权的抗胰腺纤维化及慢性胰腺创新药物奠定理论基础。

项目背景：Eruberin A（2,3-脱氢黄酮类化合物）是一种从金星蕨科新月蕨属植物中分离出来的黄烷醇苷，已有数百年的历史，已被用作血液滋养的民间药物。然而，它确实具有多种其他促进健康的益处，包括抗纤维化活性。胰腺星状细胞（PSCs）的激活是胰腺纤维化的关键启动步骤，也是与慢性胰腺炎和胰腺腺癌相关的病理特征。..方法：通过实时聚合酶链式反应，Western-blot印迹和免疫染色检测eruberin A在胰腺星状细胞中抗纤维化的机制，因LTC-14细胞系保留原代星状细胞的基本特征和形态学特征，所以被用作体外实验模型。..重要结果：Eruberin A（20 μg/mL）有效抑制胰腺星状细胞的表型转换，减低纤维化介质即α-平滑肌肌动蛋白，纤连蛋白和I型胶原的表达水平，从而压制转化生长因子-β (5 ng/mL）的促纤维化刺激。胰腺星状细胞经Eruberin A处理后，Shh信号及其下端转录因子Gli1的表达显著降低。此外，核因子-κB（NF-κB）和磷酸肌醇3-激酶（PI3K）/丝氨酸 - 苏氨酸激酶（AKT）的磷酸化也被Eruberin A显著下调。Eruberin A对Shh信号通路的抑制效果与使用Shh干扰RNA类似，使用eruberin A亦能对抗Shh重组蛋白的刺激。..结论：我们的研究结果表明，eruberin A显著抑制胰腺星状细胞中纤维化介质的表达水平，我们认为其抗纤维化机制与Shh及PI3K信号通路密切相关。因此，eruberin A 可用作抗纤维化剂，以减少慢性胰腺炎造成的组织损伤，及减少发展腺腺癌的风险。