基于调控PGC-1α促进腹膜间皮细胞线粒体生物合成:黄芪抗腹膜纤维化的机制研究

As we know ，Long-term peritoneal exposure to biological incompatibility of peritoneal dialysis fluid resulted in peritoneal mesothelial cell hypertrophy, aging, regeneration failure repair, cell cycle arrest and can induce apoptosis and necrosis, developed into a peritoneal fibrosis.PMCs causes mitochondrial dysfunction of cellular redox signal transduction abnormalities, leading to apoptosis, oxidative stress as determinants of peritoneal injury.PGC-1αas an important intracellular nuclear receptor transcription coactivator, is a major regulator of mitochondrial oxidative metabolism and biosynthesis .Our previous study found that Astragalus can inhibit PMCs cell apoptosis, oxygen free radical scavenging effect. We put forward the hypothesis on the basis of Astragalus: promote the repair and regeneration of PMCs, the protective effect of peritoneal.The molecular mechanism is regulation of PGC-1αnuclear receptor transcription auxiliary activator, promote mitochondrial biogenesis, regulation, inhibit excessive ROS, PMCs inhibit apoptosis, thereby preventing and curing PF.This study is based on the previous work, with the help of animal and cell model, using conventional cells, molecular biology and gene transfection technology,to evaluate the effect of Astragalus anti peritoneal fibrosis by regulating PGC-1 alpha PMCs promotes mitochondrial biogenesis - reduced ROS- apoptosis pathway to achieve.The implementation of the research may reveal new molecular mechanism of protection of Astragalus PMCs, is expected to slow down or even reverse the peritoneal fibrosis and provide a new strategy.

腹膜长期暴露于生物不相容性的腹透液中导致腹膜间皮细胞（peritoneal mesothelial cells，PMCs）肥大、衰老、细胞周期停滞，而后可致凋亡、坏死，发展成腹膜纤维化（peritoneal fibrillation，PF）。PMCs线粒体功能障碍导致细胞氧化应激、凋亡成为腹膜损伤的决定因素。PGC-1α是细胞线粒体生物合成及氧化代谢的主要调节者。我们前期研究发现黄芪有抑制PMCs凋亡、清除氧自由基作用。由此我们提出假说：黄芪促进PMCs的修复与再生，其分子机制在于调控PGC-1α，促进线粒体生物合成，抑制过量的ROS，阻抑PMCs凋亡，从而防治PF。本研究借助动物、细胞模型，采用细胞、分子生物学以及基因转染等技术，阐明黄芪抗PF是通过调控PGC-1α促进PMCs线粒体生物合成途径来实现。该研究的实施可能揭示黄芪保护PMCs新的分子机制，有望为延缓甚至逆转PF提供新的策略。

腹膜透析是治疗终末期肾病的有效方法之一。同血液透析相比，腹膜透析具有良好的保护残肾功能、较高的早期生存率、血流动力学稳定及操作简便等诸多优势。但由于腹膜透析液中存在的高糖、低pH值等介导腹膜纤维化，最终导致腹膜超滤衰竭已成为患者退出腹膜透析的重要原因。因此，阐明腹膜透析相关性PF的发生机制以及探索如何保护腹膜间皮细胞功能已成为肾脏替代治疗领域面临的重大挑战。本研究通过构建体内高糖腹透液诱导的大鼠腹膜纤维化模型，以及体外高糖腹透液诱导的大鼠腹膜间皮细胞（MPMCs）线粒体损伤，观察黄芪注射液及黄芪甲苷IV在腹膜纤维化过程中对细胞线粒体损伤的影响及线粒体合成相关蛋白PGC-1α及其下游基因调控机制影响。最终得出结论：.1.高糖腹透液能够诱导大鼠腹膜纤维化模型建立。.2.黄芪注射液干预后能明显增加MPMCs中Collagen I、Collagen III、FN和cytochrome C的表达，黄芪注射液能够改善高糖腹透液诱导的腹膜纤维化。.3.黄芪甲苷IV调控MPMCs线粒体生物合成机制在于能够增强PGC-1α及其下游转录因子 NRF-l和TFAM的蛋白和基因的表达，进而对氧化损伤的线粒体进行合成、修复，达到阻抑MPMCs凋亡的目的。.4.通过RNAi干扰技术构建干扰PGC-1α的表达载体，Si-PGC-1α组PGC-1α、NRF-1和NRF-2的表达量较NC对照组降低，而Si-PGC-1α+黄芪甲苷IV组表达量有所上升，进一步阐明黄芪甲苷IV激活了PGC-1α通路。