非酒精性脂肪肝（NAFLD）是导致动脉粥样硬化（AS）的重要原因之一。APN是脂肪组织分泌的唯一保护性细胞因子，是NAFLD与AS联系的纽带和防治心血管疾病的新靶点，其可抑制体内TLR4/NF-κB介导的多种炎症因子的表达，而正、负向调节蛋白的平衡是介导此通路的关键信号，但APN在NAFLD所致AS疾病中的表达水平及调控此平衡的具体机制尚不明确。前期工作表明，补肾抗衰片调脂抗炎、抗氧化应激作用显著，具有抗AS作用。本研究拟采用在体与离体实验相结合的方法，通过观察NAFLD所致AS体内内质网应激水平及加用通路抑制剂后TLR4/NF-κB通路正、负向调节蛋白平衡，探索补肾抗衰片调控APN表达的作用，并阐明其抑制NAFLD所致AS的免疫炎症反应的机制。

Nonalcoholic fatty liver disease(NAFLD) is one of the most important reasons which result in atherosclerosis(AS). APN, the unique protective cytokines secreted by adipose tissue, is the hinge of NAFLD and AS, and the new target of preventing and curing cardiovascular diseases. APN can inhibit the expression of various inflammatory factor caused by TLR4/NF-κB pathway, the balance of positive and negative regulatory proteins is the key signal which mediates this pathway. However, the mechanism of APN regulating the balance of positive and negative regulatory proteins in TLR4/NF-κB pathway and its expression level in AS induced by NAFLD is unclear. Preliminary studies show that the effect of Bushen Kangshuai tablets on reducing fat, anti-inflammation, resisting oxidative stress, preventing the process of AS is significant. In order to explain the influence of Bushen Kangshuai tablets regulating the abnormal expression of APN and TLR4/NF-κB pathway and the mechanism of Bushen Kangshuai tablets accuring AS caused by NAFLD, this study will observe the level of endoplasmic reticulum stress and the balance of positive and negative regulatory proteins after adding the pathway inhibitor in TLR4/NF-κB pathway in vivo and in vitro.

目前研究认为，非酒精性脂肪肝（NAFLD）不仅是动脉粥样硬化（AS）发病的独立危险因子，还是不依赖于心血管疾病传统危险因素的独立预测因素，其对心血管疾病的作用可能独立于肥胖和代谢综合症，已成为当前AS发病的重要原因之一。因此，尽早干预NAFLD可能有助于改善AS的进程和远期预后。AS的发病机制复杂，主要涉及脂质代谢紊乱、血管慢性炎症、血管平滑肌细胞异常增殖等方面。而脂质代谢紊乱和慢性炎症反应也是NAFLD发病的重要原因，提示NAFLD和AS之间存在发病的共同病理基础。脂联素（APN）是由脂肪组织作为内分泌器官表达和分泌的唯一的保护性细胞因子，具有胰岛素增敏、抗炎和抗AS等作用，其合成与脂肪组织的内质网应激密切相关。调节APN表达可能是干预NAFLD和AS的有效作用靶点。本研究在体实验表明，经补肾抗衰片干预后，高脂饲料喂养的ApoE-/-小鼠主动脉AS病变程度减轻。究其原因，一方面可能与补肾抗衰片抑制脂肪组织高炎症反应状态和内质网过度应激，升高血清APN表达水平，进而改善机体炎症反应状态有关。另一方面可能与补肾抗衰片上调肝脏和主动脉脂联素受体（AdipoR）表达，促进APN与其受体结合，改善肝脏APN抵抗，增加APN在主动脉组织的聚集利用，进而抑制肝脏和主动脉组织TLR4/NF-κB信号通路有关。与此同时，该结果也提示补肾抗衰片可能具有类似脂联素和脂联素受体激动剂样作用。对此，本研究离体实验发现，补肾抗衰片具有增强PDGF诱导的人主动脉平滑肌细胞（HASMC）上AdipoR1和AdipoR2蛋白表达的作用。这一作用能够通过上调PDGF诱导的HASMC上AMPKα的表达及其磷酸化水平，进而显著抑制PDGF诱导的mTOR以及其下游因子p70S6K的磷酸化，降低cyclin D1蛋白的表达，最终抑制HASMC的异常增殖。说明补肾抗衰片具有类似脂联素及其受体激动剂样作用。