Study Of The Docking Protein GAB1 In The Regulation Of Vascular Smooth Muscle Cell Autophagy In Atherosclerosis

Objective:To investigate the level of GAB1 and state of autophagy in vascular smooth muscle cells from arteriosclerosis obliterans.And exploring the role and mechanisms of GAB1 in regulating vascular smooth muscle cells’ autophagy.Methods:1.Analysing the expression of GAB1,LC3 Ⅱ and P62 in vascular smooth muscle cells from arteriosclerosis patients and healthy controls via immunofluorescence(IF),Quantitative real time polymerase chain reaction(QPCR)and Western blot.2.The si RNA and plasmid DNA were used to knockdown and overexpress the level of GAB1 in vascular smooth muscle cells,investigating the role fo GAB1 in autophagy which was induced by cell starvation by adding 1X HBS 3.The expression of p-JNK,p-p38,p-AKT,p-ERK1/2 were detected by Western blot in vascular smooth muscle cells from arteriosclerosis patients or healthy controls.After that,corresponding signal pathway inhibitors were applied during the induction of autophagy in vascular smooth muscle cells to verify specific mechanisms.Results:1.There was a GAB1 deficiency in vascular smooth muscle cells from arteriosclerosis patients(p<0.01),and the expression of LC3 Ⅱ and p62 also was downregulated(p<0.01、p<0.01).2.Gene sliencing the GAB1 in vascular smooth muscle cells would downregulate the expression of LC3 Ⅱ and p62(p<0.01、p<0.01),promoting the autophagy in vascular smooth muscles cells,and the opposite result was approved by overexperssing the GBA1.3.The expression of p-JNK and p-p38 were activated in vascular smooth muscle cells from arteriosclerosis patients(p<0.01、p<0.01),and its autophagy could be inhibited by adding the specific JNK and p-p38 inhibitors,with the drowregulating of LC3 Ⅱ and p62(p<0.05、p<0.05).Conclusions:The decline of GAB1 in vascular smooth muscle cells from arteriosclerosis patients may be associated with the downregulating expression of LC3 Ⅱ and p62.GBA1 negatively regulates the vascular smooth muscle cells’ autophagy through the JNK and p38 pathways.