羟氯喹对IgA肾病大鼠肾脏病理和Toll样受体4表达的影响

Effect of hydroxychloroquine on renal pathology and Toll-like receptor 4 expression in a rat model of IgA nephropathy

目的探讨羟氯喹对IgA肾病(IgAN)大鼠Toll样受体4(TLR4)表达的影响及其对肾脏病理的改善作用。方法将24只Wistar大鼠随机分为对照组、IgAN组、羟氯喹治疗组(HCQ组),每组8只。IgAN组和HCQ组采用牛血清白蛋白+蓖麻油+脂多糖+CCl4的方法建立IgAN模型,9周后HCQ组大鼠每日给予羟氯喹灌胃,IgAN组和对照组大鼠每日给予蒸馏水灌胃,持续8周。第17周末处死大鼠,留取肾组织标本。肾组织切片行苏木素-伊红染色和Masson染色,观察羟氯喹治疗前后IgAN大鼠肾小球系膜细胞增生和肾组织纤维化情况;采用直接免疫荧光法检测肾小球系膜区IgA的沉积密度;采用免疫组织化学染色法观察肾组织中TLR4的表达。结果IgAN组与对照组相比,肾组织内炎症细胞浸润明显增多、系膜细胞明显增生、肾组织明显纤维化,系膜区IgA沉积密度和TLR4阳性表达率均明显增加,差异均有统计学意义(P<0.05)。HCQ组与Ig AN组相比,肾组织内炎症细胞浸润、系膜细胞增生、肾组织纤维化程度均减轻,系膜区Ig A沉积密度和TLR4阳性表达率均降低,差异均有统计学意义(P<0.05);HCQ组与对照组相比,肾脏病理损伤仍较明显,系膜区Ig A沉积密度和TLR4阳性表达率均明显增加(P<0.05)。结论羟氯喹对Ig AN大鼠的肾脏病理损伤有改善作用,可能通过降低TLR4表达进而减轻肾内系膜增生和纤维化,减少Ig A沉积,对Ig AN有治疗作用。

Objective To investigate the therapeutic effects of hydroxychloroquine(HCQ)on the expression of Toll-like receptor 4(TLR4)and the renal pathology in a rat model of IgA nephropathy(IgAN).Methods Twenty-four Wistar rats were divided into three groups(each n=8):the control,IgAN,and HCQ groups.The rats in the IgAN and HCQ groups were treated with bovine serum albumin,castor oil,lipopolysaccharide,and CCl4 for 9 weeks to establish the IgAN model.In the HCQ group,the rats were then administered HCQ for 8 weeks.At the end of week 17,the rats were sacrificed and renal tissue samples were collected.The proliferation of mesangial cells and the renal fibrosis were observed by hematoxylin-eosin staining and Masson staining.The intensity of IgA deposition and the expression of TLR4 were detected by using a direct immunofluorescence assay and immunohistochemical staining.Results Compared with the control group,the Ig AN group showed a significant increase in the infiltration of renal inflammatory cells,the proliferation of mesangial cells,the degree of renal fibrosis,and the intensity of IgA deposition and TLR4 expression in the mesangial region(P<0.05).Treatment with HCQ reduced the intensity of IgA deposition and TLR4 expression,alleviated the degree of renal fibrosis,and improved pathological changes compared with the IgAN group(P<0.05).There were significant differences in renal pathology,intensity of Ig A deposition,and TLR4 expression between the HCQ and control groups(P<0.05).Conclusion HCQ ameliorated the pathological changes in IgAN rats through the inhibition of TLR4 expression,which alleviated mesangial hyperplasia and fibrosis and reduced Ig A deposition to exert therapeutic effects.