Effect ofα1-antitrypsin Z variant overexpression on autophagy regulation / 中国药理学通报

Aim To investigate the effect of α1-anti-trypsin Z variant (ATZ)overexpression on cell autoph-agy.Methods HEK 293T cells were transfected with pcDNA3.1 zeo+/ATM or pcDNA3.1 zeo+/ATZ,e-qual amount of empty vector was used as control.Cells were treated with NH4Cl for 4 hours and processed for detecting ATZ,LC3 and p62 by immunoblot.Mean-while ,expression and intracellular localization of ATZ, LC3 in 293 T cells were observed with double labeled immunofluorescence.The mRNA levels of autophagy-related genes were measured by real-time PCR.Immu-nohistochemistry was used to observe the morphology of ATZ-positive cells.Results Compared with the control,higher LC3Ⅱ levels and LC3 puncta were observed in ATZ transfected cells.Meanwhile,the levelsof p62 were decreased in ATZ transfected cells,andreversed by NH4 Cl (25 mmol·L -1 )treatment.Overexpression of ATZ increased the mRNA levels of Atg5and Atg12,but had no obvious influence on Beclin1.ATZoverexpressing cells presented abnormal morphologies.The nuclei became reduced,condensed,and even disappeared in ATZpositive cells.Conclusion ATZ overexpression increases autophagy activity whichmay be related to increasing Atg5 and Atg12 levels.