免疫蛋白酶体β2i亚基在DOCA/盐敏感小鼠血管炎症反应中的作用

摘要

目的:探讨免疫蛋白酶体β2i亚基在醋酸脱氧皮质酮(DOCA)/盐敏感小鼠血管炎症反应中的作用.方法:将β2i基因敲除小鼠和同窝对照野生雄性小鼠的右侧肾脏切除并在皮下植入DOCA 药片,然后饮用NaCl 溶液(1%)3周,建立盐敏感高血压小鼠模型.3周后分别提取各实验组新鲜胸主动脉组织中总的RNA和蛋白,或用福尔马林固定和石蜡包埋组织后进行切片.采用Western blot、实时荧光定量PCR和免疫组化法分别检测胸主动脉中β2i、巨噬细胞标志物Mac-2、NF-κB及促炎症因子(IL-1β、IL-6和TNF-α)的表达水平.结果:与假手术组相比,DOCA/盐处理明显增高血管组织中β2i 的mRNA和蛋白表达水平、巨噬细胞浸润数、NF-κB及促炎症因子IL-1β、IL-6和TNF-α的mRNA表达水平;相反,敲除β2i基因明显抑制了DOCA/盐诱导的这些改变.结论:免疫蛋白酶体β2i亚基可能通过激活NF-κB信号通路促进DOCA/盐诱导的血管炎症反应.%AIM:To investigate the role of immunoproteasome subunit β2i in deoxycorticosterone acetate (DOCA)/salt-induced vascular inflammation in mice.METHODS:Wild-type and β2i knockout male mice were used.The right kidney was removed and DOCA pellet was subcutaneously implanted in the mice.The mice were then received 1% NaCl as drinking water for 3 weeks.The total RNA and protein were isolated from thoracic aorta 3 weeks later.The aortic tissues were fixed in formalin, embedded in paraffin and sectioned.Western blot, real-time PCR and immunohistochemistry were performed to detect the expression of β2i, macrophage marker Mac-2, NF-κB, and proinflammatory cytokines IL-1β, IL-6 and TNF-α in thoracic aorta.RESULTS:Compared with sham group, DOCA/salt treatment significantly increased the expression of β2i at mRNA and protein levels, increased the infiltration of macrophages and expression of Mac-2, and upregulated the expression of NF-κB and proinflammatory cytokines including IL-1β, IL-6 and TNF-α in wild-type group, whereas theses effects were markedly attenuated in β2i knockout mice.CONCLUSION:Immuneproteasome subunit β2i is involved in DOCA/salt-induced vascular inflammation through activation of NF-κB signaling in the mice.