虾青素对大鼠对比剂急性肾损伤的保护作用以及对SIRT1-P53通路的影响

Protective Effect of Astaxanthin on Contrast-induced Acute Kidney Injury via SIRT1-p53 Pathway in Rats

目的研究虾青素对对比剂急性肾损伤(CI-AKI)的保护作用及其与SIRT1-P53的通路关系和对NO、3-NT含量影响。方法 40只SD大鼠采用数字表法随机分为5组:对照组,虾青素对照组,造模组,iNOS抑制剂组,虾青素治疗组。每组8只,建立对比剂急性肾损伤模型72h后检测大鼠血清肌酐(Scr)、尿素氮(BUN)水平;HE染色观察肾组织病理改变;Tunel法检测肾小管细胞凋亡;氧化应激试剂盒法检测肾脏组及谷织丙二醛(MDA)含量,总超氧化物歧化酶(T-SOD)、谷胱甘肽过氧化物酶(GSH-Px)胱甘肽(GSH)活性;SIRT1试剂盒法检测SIRT1活性;Western blot法检测肾组织中SIRT1、P53及ac-P53的蛋白表达;NO试剂盒、3-硝基酪氨酸(3-NT)试剂盒测定肾组织中NO、3-NT含量。结果与对照组比较,造模组Scr、BUN水平显著升高;iNOS抑制剂组和虾青素治疗组较造模组均降低(P均<0.05);HE和Tunel染色可见造模组大鼠肾脏肾小管损伤严重,iNOS抑制剂组和虾青素治疗组上述病理改变减轻,肾损伤评分、凋亡指数(AI)降低(P均<0.05);与对照组比较,造模组肾组织中MDA含量显著增高,T-SOD、GSH、GSH-Px活性显著降低,差异有统计学意义(P<0.05),iNOS抑制剂组和虾青素治疗上述指标有明显改善(P均<0.05);与对照组比较,造模组SIRT1活性降低,SITR1、P53表达均上调,且ac-P53/P53比值升高;虾青素治疗组SIRT1活性升高、SIRT1表达上调,P53下调,且ac-P53/P53比值下降(P均<0.05)。与对照组比较,造模组肾组织NO、3-NT含量明显升高,而iNOS抑制剂组和虾青素对照组较造模组降低(P均<0.05)。结论虾青素对CI-AKI具有保护作用,其机制可能与SIRT1-P53通路有关。虾青素能够降低CI-AKI肾组织中NO、3-NT含量,减轻对比剂所致的肾损伤。

Objective To observe the protective effect of astaxanthin on contrast-induced acute kidney injury in rats and relationship between SIRT1-P53 passage and astaxanthin. Methods Forty SD rats were randomly divided into five groups：control group; control group of astaxanthin; model set; group of iNOS inhibitor. Treatment group of astaxanthin; there were eight rats in each group. 72h after building a contrast induced-nephropathy model,we tested the level of Scr and BUN in rats, observed pathologic change of nephridial tissue via H-E dye, tested the apoptosis of kidney tubules via Tunel method tested MDA content of kidney tissue, activity of T-SOD, GSH and GSH-Px via oxidative stress kit method, tested SIRT1 activity via colorimwetric kit method of SIRT1 activity; tested protein expression of SIRT1, P53 and ac-P53 in kidney tissue via Western blotting; tested NO and 3-NT content of kidney tissue in rats for groups respectively viaNO and 3-NT Kit. Results Compared with control group, level of Scr and BUN in model set significantly increased. Level of Scr and BUN iniNOS inhibitor group and treatment group of astaxanthin both reduced compared with model group （mean P〈0.05）. It could be seen that pathologic changes such as severe injury of kidney tubules, medulla congestion, structural damage of kidney tubules, falling of brush boarder in epithelial cell, vacuolar degeneration, necrocytosis and protein disposition, etc occurred in rats of model set via HE staining, and above pathologic changes mitigated in iNOS inhibitor group and treatment group of astaxanthin, so renal injury grade was reduced （P〈0.05）.It was indicated that number for positive cell of Tunel in model set via Tunel method obviously increased. Compared with model group, number for positive cell of Tunel in kidney tissue of rats significantly reduced in iNOS inhibitor group and treatment group of astaxanthin, and apoptotic index reduced （P〈0.05）.Compared with control group, MDA content in kidney tissue of model set significantly increased, and activity of T-SOD, CAT, GSH-Px significantly reduced, and there was statistical meaning of difference （P〈0.05）, and above indexes of 1400W group and treatment group of astaxanthin were significantly improved （mean P〈0.05）.Compared with control group,SIRT1 activity for model set significantly reduced （P〈0.01）.Expression of SITR1, P53 in model set all increased, and ratio of P53/ac-P53 increased. SIRT1 activity and expression ofSITR1 for treatment group of astaxanthin increased, P53 reduced, and ratio of P53/ac-P53 reduced （mean P〈0.05）. Compared with cnontrol group, contend of NO and 3-NT in model group increased, contend of NO and 3-NT in iNOS inhibitor group and treatment group of astaxanthin both reduced when compared with model group set. Conclusion Precondition with astaxanthin could have protective function on CI-AKI.The mechanism of which is partly via SIRT1-P53 pathway activation.Astaxanthin could relieve Atue Kidney Injury which was led by inhexol by reducing the content of NO and 3-NT in CI-AKI kidney tissue and had a protective effect on kidney.