基于内质网应激机制探讨黄连煎剂对代谢综合征所致肾损害的影响

Results from clinical and experimental study indicate that Coptis is effective in the treatment of metabolic syndrome and metabolic syndrome related renal damage .Metabolic syndrome can cause and aggravate renal damage. Endoplasmic reticulum stress plays an important role in metabolic syndrome.Endoplasmic reticulum damage is one of the pathological mechanisms involved in kidney damage caused by metabolic syndrome. We found that the pathogenisis of fructose-fed rats is similar to metabolic syndrome with renal lesions, which showed glomerular focal segmental mesangial matrix increase,tubular cell swelling and vacuolar degeneration under light microscope,renal tubular epithelial cell swelling and decreased endoplasmic reticulum under transmission electron microscopy. In patients with metabolic syndrome related renal damage ,we found the mRNA expressions of GRP78 and CHOP in urine were increased,after the treatment of Coptis decoction,the mRNA expressions of GRP78 and CHOP were decreased.We will examine the presence of ER stress in fructose-feld rats and the correlation between effects of Coptis decoction on Metabolic syndrome related renal damage and defree of ER stress.The purpose of this is to understand the molecular mechanisms of Coptis decoction in treating renal injury caused by metabolic syndrome,and to examine the therapeutic targets and pathways of Coptis.

临床及基础研究表明黄连对改善代谢综合征及其肾损害有较好疗效。内质网应激是代谢综合征肾损害的重要分子机制。我们前期的研究发现，果糖喂养的大鼠代谢综合征模型，病理上呈现肾小球局灶节段性系膜基质增多及肾小管浊肿和空泡变性，透射电镜见肾小管上皮细胞肿胀，内质网减少；黄连治疗可以使代谢综合征肾损害患者尿液的GRP78mRNA、CHOPmRNA表达明显下降。本项目以内质网应激未折叠蛋白反应为切入点，以果糖喂养的大鼠代谢综合征模型和人肾小管上皮细胞为研究对象，采用分子生物学和细胞生物学等方法，从形态学、蛋白水平和基因水平等方面着手，研究黄连煎剂对代谢综合征所诱导的内质网应激肾脏细胞损伤的保护作用，阐明黄连煎剂防治代谢综合征所致肾损害的分子机制，寻找药物治疗靶点或途径，为黄连煎剂治疗代谢综合征肾损害奠定实验基础。

临床及基础研究表明黄连对改善代谢综合征及其肾损害有较好疗效，内质网应激是代谢综合征肾损害的重要分子机制，从分子机制上探讨黄连煎剂对代谢综合征及其所致肾损害的治疗靶点，对阐明代谢综合征肾损害的发病机制和采取合理干预措施具有重要意义。本课题在前期工作的基础上，以内质网应激未折叠蛋白反应（UPR）为切入点，以果糖喂养建立代谢综合征大鼠模型和人肾小管上皮细胞为研究对象，采用分子生物学和细胞生物学等方法，从形态学、蛋白水平和基因水平等方面着手，对黄连煎剂防治代谢综合征所致肾损害的分子机制进行研究。一方面通过果糖喂养建立大鼠代谢综合征模型，表现出血清CHO、TG、血压、体重升高及肾脏损害的组织病理学改变。采用黄连煎剂干预治疗后可降低代谢综合征合并肾损害大鼠的体重、血脂及血压水平，改善胰岛素抵抗，电镜下观察还能减轻肾脏病理损害；同时发现其可下调肾组织中GRP78和CHOP蛋白和基因表达水平。另一方面通过果糖（浓度25mM，时间为24h）刺激诱导人肾小管上皮细胞发生内质网应激，提高UPR反应多条信号通路的活性，而黄连煎剂可抑制这一改变。研究提示内质网应激反应存在于果糖诱导代谢综合征所致肾损害过程中，黄连煎剂可通过影响内质网应激反应的相关蛋白或基因的表达发挥其对内质网应激的调控作用。综合上述黄连煎剂可以通过减轻代谢综合征所诱导的内质网应激肾脏细胞损伤而发挥作用。本研究揭示了黄连煎剂治疗代谢综合征所致肾损害的机制和作用环节，为代谢综合征肾损害的治疗提供新的思路和方法。本项目资助发表核心论文6篇，培养硕士生3名，均已经取得硕士学位。