白细胞介素34对巨噬细胞脂质摄取可能机制的研究

Mechanism of IL-34 underlying oxLDL uptake in macrophages

目的探讨白细胞介素34(IL-34)对巨噬细胞脂质摄取能力的影响及其可能机制。方法实验以小鼠巨噬细胞系RAW 246.7培养,氧化型低密度脂蛋白(oxLDL)诱导建立泡沫细胞模型,分为对照组、IL-34组(50ng/ml)、oxLDL组(40μg/ml)、联合组(oxLDL 40μg/ml+IL-34 50ng/ml)。油红O染色观察细胞内脂滴的形成;荧光标记oxLDL孵育后荧光显微镜观察细胞内脂质荧光强度;Western blot及RT-PCR检测清道夫受体A、CD36蛋白及转录水平的表达变化。结果对照组及IL-34组细胞内未见红染颗粒。与oxLDL组比较,联合组细胞内红染颗粒明显增多,荧光强度增加;CD36蛋白和mRNA明显升高(0.89±0.03 vs 0.56±0.11,1.25±0.17 vs 0.60±0.09,P<0.05)。结论 IL-34能够通过上调CD36而增加巨噬细胞对脂蛋白的摄取。

Objective To study the effect of IL-34 on oxLDL uptake in macrophages and its mecha-nism. Methods A model of foam cells was induced by oxLDL. The cultured macrophages RAW 246.7 from mice were divided into control group,50 ng/ml IL-34 group,40μg/ml oxLDL group, and 40μg/ml oxLDL＋50 ng/ml IL-34 group. Lipid droplets in RAW 246.7 were detected with oil red O staining. Fluorescence intensity in RAW 246.7 was detected by fluorescence microscopy after fluorescence-labled oxLDL was incubated. Expressions of CD36 and SR-A protein and mRNA were detected by Western blot and RT-PCR respectively. Results Oil red O stained particles in RAW 246.7 were not detected in control group and IL-34 group. The number and fluorescence intensity of oil red O stained particles were significantly greater and the expression level of CD36 protein and mRNA was significantly higher in 40 μg/ml oxLDL＋50 ng/ml IL-34 group than in 50 ng/ml IL-34 group and 40μg/ml oxLDL group （P〈0.05）. Conclusion IL-34 can increase the oxLDL uptake in macrophages by upregulating the CD36 expression level.