姜黄素通过调节PCSK9促进肝细胞摄取血浆LDL-C

Increased LDL-C uptakes of hepatocytes treated by curcumin via downregulating PCSK9 expression

目的明确姜黄素调节PCSK9促进肝细胞摄取LDL的作用。方法利用实验室现有的慢病毒感染HepG2和LO2两种细胞,分别构建过表达PCSK9(RNAi-PCSK9)和干扰PCSK9(OE-PCSK9)细胞模型,通过倒置荧光显微镜检测慢病毒转染效率;Western blot检测蛋白表达;油红O染色分析姜黄素对细胞中脂质摄取情况;酶法检测细胞内胆固醇含量。结果镜下观察细胞内可见清晰绿色荧光。Western blot结果显示干扰PCSK9组降低PCSK9表达,升高LDLR表达;过表达PCSK9组增加PCSK9表达,降低LDLR表达。油红O结果显示姜黄素/瑞舒伐他汀处理24 h后RNAi/OEPCSK9组细胞内脂质含量均增加。胆固醇含量测定姜黄素/瑞舒伐他汀处理24 h后RNAi-PCSK9组总胆固醇(total cholesterol,TC)/游离胆固醇(free cholesterol,FC)含量升高,OEPCSK9组TC/FC含量均下降。结论姜黄素特异性降低PCSK9表达继而促进肝细胞摄取LDL-C。

Aim To confirm the role of curcumin in promoting uptake LDL of hepatocytes via regulating PCSK9.Methods The models of PCSK9(RNAi-PCSK9)and PCSK9(OE-PCSK9)were constructed on HepG2 and LO2 cells by using the existing lentivirus in laboratory.The ratio of lentivirus infection was detected by inverted fluorescence microscopy.The effect of overexpression and RNA interference PCSK9 was detected by Western blot;lipid depositional effect of curcumin on cells was detected by oil red O staining analysis,and cholesterol levels in cells were analyzed by enzymatic detection.Results Clear green fluorescence was observed in RNAi/OE-PCSK9 group under inverted fluorescence microscopy.The results of Western blot showed that compared with control group,PCSK9 protein expression significantly decreased and LDLR expression increased in RNAi-PCSK9 group.PCSK9 protein expression in OE-PCSK9 significantly increased and LDLR expression increased,indicating that the model was successfully constructed.Oil red O staining results showed that the intracellular lipid content of RNAi/OE-PCSK9 group increased after treatment with curcumin and rosuvastatin(positive drug group)for 24 h.The results of cholesterol content showed that the content of total cholesterol(TC)and free cholesterol(FC)increased after 24 h treatment with curcumin in RNAi-PCSK9 group,and RNAi-PCSK9 group TC after rosuvastatin treatment for 24 h.The FC content increased,and the TC content in OE-PCSK9 group decreased.Conclusion Curcumin specifically reduces PCSK9 expression,accordingly promoting hepatocyte uptake of LDL-C.