Mammalian Target of Rapamycin Complex 1 Activation Disrupts the Low-Density Lipoprotein Receptor Pathway: A Novel Mechanism for Extracellular Matrix Accumulation in Human Peritoneal Mesothelial Cells
Mammalian Target of Rapamycin Complex 1 Activation Disrupts the Low-Density Lipoprotein Receptor Pathway: A Novel Mechanism for Extracellular Matrix Accumulation in Human Peritoneal Mesothelial Cells
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雷帕霉素复合物 1 激活的哺乳动物靶点破坏低密度脂蛋白受体途径：人腹膜间皮细胞细胞外基质积累的新机制
DOI：
10.1159/000494144
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发表时间：
2018-11
期刊：
影响因子：
--
通讯作者：
Zhang M
中科院分区：
文献类型：
--
作者：
Liu J;Zhu W;Jiang CM;Feng Y;Xia YY;Zhang QY;Xu PF;Zhang M
腹膜纤维化（PF）以进行性细胞外基质（ECM）积累为特征。越来越多的证据表明，在高糖条件下，人腹膜间皮细胞（HPMCs）的ECM合成增加，但高糖腹膜透析液（PDS）对ECM合成的影响尚未完全阐明。本研究的目的是探讨高糖pds诱导hpmc产生ECM的潜在机制。高糖PDS刺激hpmc。哺乳动物雷帕霉素靶蛋白复合物1 （mTORC1）的活性可被雷帕霉素或mTOR (raptor) siRNA调控相关蛋白抑制。倒置显微镜下观察细胞形态学变化。油红O、filipin染色和高效液相色谱法检测脂质积累。实时聚合酶链反应和western blot分析低密度脂蛋白受体（LDLr）调控、mTORC1通路和ecm相关标志物的表达。结果表明，经PDS处理后，hpmc呈现与肌成纤维细胞形态一致的明显伸长，α-平滑肌肌动蛋白、成纤维细胞特异性蛋白-1、I型胶原等ECM蛋白表达增加。此外，ECM和脂质积累也有平行增加。此外，细胞内脂质沉积的影响与LDLr的失调密切相关，LDLr的失调是通过上调LDLr、甾醇调节元件结合蛋白（SREBP）、裂解激活蛋白（SCAP）和SREBP-2以及SCAP与Golgin的共表达增强介导的。进一步分析表明，PDS增强了mTOR、真核起始因子4e结合蛋白1和p70 S6激酶的蛋白磷酸化。有趣的是，即使在PDS存在的情况下，阻断mTORC1活性也能逆转LDLr的失调。这些影响还伴随着ECM成分表达的减少。我们的研究结果表明，mTORC1活性的增加通过破坏LDLr的调节而加剧了hpmc中ECM的形成，这导致了脂质紊乱介导的PF。
Peritoneal fibrosis (PF) is characterized by progressive extracellular matrix (ECM) accumulation. Increasing evidence has suggested that ECM synthesis was increased in human peritoneal mesothelial cells (HPMCs) under high-glucose conditions, but the effects of high-glucose peritoneal dialysis solution (PDS) on ECM synthesis have not been fully elucidated. The aim of this study was to explore the potential mechanisms of high-glucose PDS-induced production of ECM in HPMCs. HPMCs were stimulated by high-glucose PDS. The activity of mammalian target of rapamycin complex 1 (mTORC1) was inhibited by rapamycin or regulatory-associated protein of mTOR (raptor) siRNA. Morphological changes in the cells were observed under an inverted microscope. Oil red O, filipin staining and high-performance liquid chromatography were used to examine lipid accumulation. The expression of low-density lipoprotein receptor (LDLr) regulation, the mTORC1 pathway and ECM-associated markers were assessed by real-time polymerase chain reaction and western blot analysis. The results showed that after treatment with PDS, HPMCs showed notable elongation consistent with the morphology of myofibroblasts, and the expression of ECM proteins such as α-smooth muscle actin, fibroblast specific protein-1 and collagen I was increased. In addition, there was a parallel increase in the ECM and lipid accumulation. Moreover, the effect of intracellular lipid deposition was closely correlated with the dysregulation of LDLr, which was mediated through the upregulation of LDLr, sterol regulatory element-binding protein (SREBP) cleavage-activating protein (SCAP), and SREBP-2 and through the enhanced coexpression of the SCAP with the Golgin. Further analysis showed that PDS enhanced the protein phosphorylation of mTOR, eukaryotic initiation factor 4E-binding protein 1, and p70 S6 kinase. Interestingly, blocking mTORC1 activity reversed the dysregulation of LDLr, even in the presence of PDS. These effects were also accompanied by a decrease in the expression of ECM components. Our findings demonstrated that increased mTORC1 activity exacerbated ECM formation in HPMCs by disrupting LDLr regulation, which contributed to lipid disorder-mediated PF.
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影响因子：
3.8
作者：
Zhang Yang;Ma Kun Ling;Liu Jing;Wu Yu;Hu Ze Bo;Liu Liang;Lu Jian;Zhang Xiao Liang;Liu Bi Cheng;Ma KL
通讯作者：
Ma KL
影响因子：
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影响因子：
7.3
作者：
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通讯作者：
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影响因子：
5.6
作者：
Rabanal-Ruiz Y;Korolchuk VI
通讯作者：
Korolchuk VI
影响因子：
15.9
作者：
Ai, Ding;Chen, Chiyuan;Tall, Alan R.
通讯作者：
Tall, Alan R.