壮观霉素B1抑制过氧化物增殖激活受体共激活子类泛素修饰促高糖内皮细胞自愈

Spectomycin B1 promotes self-healing of endothelial cells in DM patients by inhibiting SUMOylation of PGC-1α

目的探讨过氧化物酶体增殖物激活受体γ辅激活因子1α(PGC-1α)的小泛素相关修饰蛋白(SUMO)在糖尿病患者血管内皮修复能力下降过程中的作用,并寻找新的治疗方法。方法选取人脐静脉内皮细胞(HUVEC)第3~6代细胞随机分对照组、高糖组及壮观霉素B1治疗组(治疗组)3组(n=4),分别于1.0 g/L葡萄糖、4.5 g/L葡萄糖、4.5 g/L葡萄糖+20μmol/L壮观霉素B1培养液中作用48 h,用Western blot检测SUMO2/3、PGC-1α蛋白表达,RT-PCR方法检测核呼吸因子-2α(NRF-2α)和核受体雌激素受体相关受体α(ERRα)mRNA表达,细胞划痕实验检测HUVEC损伤修复功能,模拟血管形成实验检测HUVEC血管形成能力。结果高糖组和治疗组共价态SUMO2/3蛋白表达水平明显高于对照组,NRF-2α和ERRαmRNA表达水平明显低于对照组(P<0.05,P<0.01);治疗组共价态SUMO2/3蛋白表达水平明显低于高糖组,NRF-2α和ERRαmRNA表达水平明显高于高糖组(P<0.05)。高糖组游离态SUMO2/3水平低于对照组和治疗组(P<0.05)。3组PGC-1α蛋白表达水平比较,无统计学差异(P>0.05)。细胞划痕实验显示,高糖组和治疗组细胞迁移距离明显低于对照组[(19.47±4.04)μm vs(57.35±5.59)μm,P=0.017;(31.98±6.05)μm vs(57.35±5.59)μm,P=0.032],治疗组细胞迁移距离明显高于高糖组(P=0.037)。细胞模拟血管形成实验显示,治疗组能够改善网状交联情况,形成少量类血管结构。结论壮观霉素B1能够通过抑制PGC-1α蛋白的SUMO化修饰增加血管内皮细胞在高糖环境下的自愈能力。

Objective To study the role of PPAR-γcoactivator-1α(PGC-1α)-SUMOylation in reducing the repair capacity of endothelial cells in DM patients.Methods The 3-6 passage HUVEC were divided into control group,high glucose group,spectomycin B1 treatment group(4 in each group)and cultured for 48 h in 1.0 g/L glucose,4.5 g/L glucose,4.5 g/L glucose+20μmol/L spectinomycin B1 respectively.The expressions of SUMO 2/3 and PGC-1αprotein were detected by Western blot and those of NRF-2αmRNA and ERRαmRNA were detected by RT-PCR.The repair of HUVEC injury was tested in scratch test and the angiogenesis of HUVEC was assayed in simulated angiogenesis test.Results The expression levels of covalent SUMO2/3 protein were significantly higher while those of NRF-2αmRNA and ERRαmRNA were significantly lower in high glucose group and spectomycin B1 treatment group than in control group(P<0.05,P<0.01).The expression levels of free SUMO 2/3 were significantly lower in high glucose group than in control group and spectomycin B1 treatment group(P<0.05).No significant difference was detected in expression levels of PGC-1αprotein among the 3 groups(P>0.05).Scratch test showed that the migration distance of HUVEC was significantly shorter in high glucose group and spectomycin B1 treatment group than in control group(19.47±4.04μm vs 57.35±5.59μm,P=0.017;31.98±6.05μm vs 57.35±5.59μm,P=0.032)and was significantly longer in spectomycin B1 treatment group than in high glucose group(P=0.037).Simulated angiogenesis test showed that spectomycin B1 treatment could improve the network cross-linking with a small number of vascular structures formed.Conclusion Spectinomycin B1 can improve the self-healing of HUVEC by inhibiting the PGC-1α-SUMOylation in DM patients.