肥胖SD幼鼠脂肪组织血红素加氧酶-1表达与炎症状态和抗炎机制的探讨

HO-1 expression in adipose tissue of obese young SD rats and its role in inflammation and anti-inflammatory mechanism

目的探讨肥胖SD幼鼠内脏脂肪组织中血红素加氧酶(HO)-1表达的变化及其与脂肪组织巨噬细胞浸润、极化间的关系。方法 3周龄雄性SD大鼠24只,随机均分为对照组和实验组,分别给予标准饮食和高脂饮食,喂养至7周龄,检测三酰甘油(TG)、高密度脂蛋白胆固醇(HDL-C)、空腹血糖及胰岛素水平,定量PCR检测肾周脂肪组织中HO-1、白介素(IL)-6、IL-10、单核细胞趋化蛋白(MCP)-1基因表达变化,F4/80、CD206免疫组化观察脂肪组织中巨噬细胞浸润和极化情况。结果实验组幼鼠已经存在空腹血糖和胰岛素升高,胰岛素抵抗情况明显,HO-1表达明显高于对照组,炎症因子IL-6、MCP-1基因表达明显高于对照组,抗炎症因子IL-10低于对照组,差异有统计学意义(P<0.05)。实验组巨噬细胞浸润明显多于对照组(P<0.05),实验组F4/80免疫组化平均光密度(MOD)值与CD206免疫组化MOD值差异无统计学意义(P>0.05)。结论肥胖幼年SD大鼠的内脏脂肪组织出现炎症反应,伴有HO-1反应性的增加,后者影响巨噬细胞极化起到抗炎作用。

Objective To investigate the change of HO-1 expression in adipose tissue of obese young SD rats as well as its relationship with macrophage infiltration and polarization. Methods Three-week old SD rats （n=24） were randomly divided into 2 groups, routine diet group （NC） and high fat diet group （FC）. After feeding 4 weeks, triglyceride （TG）, high den？sity lipoprotein （HDL-C）, fasting glucose and insulin were compared between these two groups and the insulin resistance in？dex was calculated. The gene expressions of HO-1, IL-6, IL-10 and MCP-1 were assessed by quantitative PCR. Infiltration and polarization of macrophages and M2 macrophages in the visceral adipose tissue were examined by immunohistochemis？try. Results The levels of FINS, FBG and HOMA-IR in rats of FC group were higher than those of rats in NC group after 4 weeks feeding （P〈0.05）. The level of HO-1, IL-6, MCP-1 in rats from FC group were significantly higher while level of IL-10 were lower compared with those in rats from NC group after 4 weeks of feeding （P〈0.05）. In samples from FC groups, more macrophages were detected in adipose tissue by DAB staining than those from NC group. There was no significant dif？ference （P〉0.05） in MOD value of F4/80 and CD206 between these two groups （P〉0.05）. Conclusion The infiltration of macrophage in visceral adipose tissue of obese young SD rats significantly increased while HO-1 expression was reactively increased. This insinuated that HO-1 might play an important role in anti-inflammatory mechanism through regulating polar？ization of macrophages.