BNIP3与LC3B在椎间盘退行性变过程中的作用

Role of BNIP3 and LC3B in process of intervertebral disc degeneration

目的研究BCL2/腺病毒E1B19k Da相互作用蛋白3(BNIP3)基因及微管相关蛋白轻链3B(LC3B)基因在退变椎间盘中的表达情况,探讨其与椎间盘退行性变分级之间的相关性。方法收集2016年4月—2016年7月因腰椎椎间盘突出症于本院接受手术治疗的21例患者的退变腰椎椎间盘标本25个,依据Pfirrmann分级分成5组,分别采用实时荧光定量PCR技术和蛋白质印迹法检测BNIP3、LC3B的m RNA和蛋白表达量,用实时荧光定量PCR技术检测Bcl-2、Bax、Caspase-3的mRNA表达量,并分析BNIP3表达量、LC3B表达量、细胞自噬、细胞凋亡与Pfirrmann分级之间的关系。结果退变椎间盘组织中BNIP3、LC3B在mRNA和蛋白水平的表达均随椎间盘退行性变程度加重而减少。Bcl-2 m RNA的表达随椎间盘退行性变程度加重而减少,Bax与Casepase-3 mRNA的表达随椎间盘退行性变程度加重而增多。结论随着椎间盘退行性变程度的加重,BNIP3与LC3B的表达减少,组织内细胞凋亡水平升高,细胞自噬对组织的保护作用逐渐下降。提示BNIP3与LC3B在腰椎椎间盘退行性变过程中具有重要的调节作用,可能是细胞自噬和凋亡之间的桥梁蛋白。

Objective To investigate the expressions of BCL2/adenovirus E1B19kDa protein-interacting protein3(BNIP3)and microtubule-associated protein light chain3B(LC3B)genes in degenerated intervertebral disc tissue,and explore the correlation between the Pfirrmann grading of lumbar intervertebral disc degeneration and their expression.Methods From April2016to July2016,25intervertebral disc tissues from21patients with lumbar disc herniation were harvested.The samples were divided into5groups by Pfirrmann grading of lumbar intervertebral disc degeneration.The expressions of BNIP3and LC3B mRNA and proteins in intervertebral disc tissues were assayed by real-time PCR and Western blotting.And the expressions of Bcl-2,Bax and Caspase-3mRNA were examined by real-time PCR.The correlation between the BNIP3,LC3B,autophagy,apoptosis and the Pfirrmann grading was analyzed.Results The mRNA and protein expressions of BNIP3and LC3B were down-regulated along with the severity of intervertebral disc degeneration.The mRNA expression of Bcl-2was down-regulated,and the mRNA expressions of Bax and Caspase-3were up-regulated along with the severity of intervertebral disc degeneration.Conclusion With gradual aggravation of the intervertebral disc degeneration,the expressions of BNIP3and LC3B would gradually decline;the apoptosis level would graually elevate;the protective effect of autophagy on the tissue would gradually decline.It suggests that BNIP3and LC3B play an important role in the regulation of lumbar disc degeneration,and BNIP3may be the“bridge protein”between apoptosis and autophagy.