基于脂肪棕色化探究大黄素对老龄小鼠脂质代谢的影响

Effect of emodin on lipid metabolism in aging mice

目的研究大黄素对老龄小鼠脂质代谢的影响及其潜在机制。方法40只10月龄SPF级C57BL/6J小鼠随机分为老龄组、大黄素40 mg·kg^(-1)组、大黄素80 mg·kg^(-1)组和罗格列酮10 mg·kg^(-1)组,另设10只8周龄C57BL/6J小鼠为非老龄组,各给药组连续灌胃给药6周。监测各组小鼠体质量,末次给药后取材,测定血清三酰甘油(TG)、总胆固醇(TC)、低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C)、游离脂肪酸(FFA)、瘦素(LEP)和脂联素(ADPN)含量;HE染色观察小鼠皮下脂肪组织及棕色脂肪组织形态变化;免疫组化法检测皮下白色脂肪组织和棕色脂肪组织解偶联蛋白1(UCP1)表达。结果大黄素干预可显著降低TC、TG、FFA含量(P<0.05),升高血清ADPN含量(P<0.05)。此外,大黄素干预组小鼠皮下白色脂肪细胞出现多室,细胞变小、变圆,具有棕色化趋势,同时白色脂肪组织(WAT)和棕色脂肪组织(BAT)中UCP1阳性细胞表达升高(P<0.05)。结论老龄小鼠可出现脂质代谢紊乱,白色脂肪组织比重增加,脂肪呈现白色化趋势。大黄素可改善老龄动物的脂质代谢紊乱,其作用可能与促进脂肪棕色化有关。

Objective To determine the effect and potential mechanism of emodin on lipid metabolism in aging mice.Methods Totally 40 ten-month-old C57BL/6J mice were randomly divided into 4 groups:an aging group,an emodin 40 mg·kg^(-1) group,an emodin 80 mg·kg^(-1) group,and an arosiglitazone 10 mg·kg^(-1) group.Another 10 eight-week-old C57BL/6J mice were used as the non-aging group.The drugs were orally administered to the mice for 6 weeks consecutively.Their body mass was monitored each week.After the last administration,parameters including the serum triglyceride(TG),cholesterol(TC),low density lipoprotein(LDL-C),high density lipoprotein(HDL-C),free fatty acid(FFA),leptin(LEP)and adiponectin(ADPN)were detected.The morphology of subcutaneous adipose tissue and brown adipose tissue were observed with H&E staining.The protein expression of UCP1 of white adipose tissue and polychromatic adipose tissue(BAT)was detected with immunohistochemistry.Results Emodin significantly reduced TC,TG and FFA(P<0.05),and increased the serum ADPN significantly(P<0.05).In addition,subcutaneous white adipose cells of the emodin treatment groups presented multilocular lipid drops.The cells became smaller and rounder,and tented to turn brown.Simultaneously,the expression of UCP1 positive cells in the WAT and the BAT(P<0.05)was increased.Conclusion Lipid disorders may appear in aging mice,including high levels of blood lipids,increased proportion of WAT ratio,and whiting of adipose.Emodin can relieve lipid disorders in aging mice,whose mechanism may be related to the browning of white adipose.