Research On The Mechanism Of Lactic Acid On Phenotypic Switch Of Human Vascular Smooth Muscle Cells

Objective: To explore the effect of lactic acid on the phenotypic switch of Human Vascular Smooth Muscle Cells(HVSMC).Methods: This study combined clinical and basic research to explore the effects of lactic acid on vascular smooth muscle phenotypic switch in patients with peripheral arterial disease.1)Clinical research: Including patients with peripheral arterial disease and normal medical examination adults admitted to Chongqing Medical University in 2018,collecting the patient’s current medical history,past history,basic vital signs,laboratory test results and other data,and applying statistical methods to analyze each data.2)Basic research: HVSMC was cultured in a three-gas incubator,and human vascular smooth muscle cells were stimulated with different concentrations of lactic acid(0m M,4m M,8m M)for 0h,12 h,24h,and 48 h,and the cells were collected.RT-PCR,Western Blot and ELISA methods were used to detect phenotypic switch and inflammatory factor related gene and protein expression changes,and to screen the most suitable lactate concentration and stimulation time point.According to the selected lacticacid concentration and treatment time,the cultured HVSMC were treated with AKT inhibitor IV(10 μM)and adenovirus silencing AKT.RT-PCR,Western Blot,and ELISA methods were used to detect phenotypic switch and expression of inflammatory factor-related genes and proteins.Using RT-PCR and Western Blot to detect the expression of AKT-related signaling pathway genes and proteinsResults: 1)Clinical studies found that compared with the control group,there were significant statistical differences in gender,smoking habits,and serum lactic acid in patients with peripheral arterial disease.There are more men with peripheral arterial disease,more previous smoking history,and serum lactic acid increased significantly.2)Basic experiment,after stimulating human vascular smooth muscle cells at different concentrations of lactic acid(0m M,4m M,8m M)for 0h,12 h,24h,and 48 h,according to RT-PCR and Western Blot results,it was found that Smooth Muscle Protein-22α(SM-22α)and α-smooth muscle actin(α-SMA)(a contractile phenotype marker protein)decreased with increasing lactic acid concentration,and decreased with increasing culture time.The inflammatory factors: inflammatory factors Interleukin-6(IL-6)and recombinant Human cxc motif chemokine 8(CXCL-8)gene and protein expression increased,with the increasing concentration of lactic acid and the increasing of the cultivation time.Under the stimulation of 8m M lactic acid,phosphorylation-AKT(p-AKT)peaked at 12 h,suggesting that AKTmay be involved in the regulation of HVSMC phenotype switch by lactic acid.Compared with the lactic acid model group,AKT adenovirus silencing group and AKT inhibitor group,AKT pathway protein was significantly inhibited.The gene expression and protein expression of SM-22α and α-SMA were increased compared with the model group,while the gene and protein expression of IL-6 and CXCL-8 related inflammatory factors were decreased compared with the model group.Conclusion: The inflammatory phenotypic switch of HVSMC is significantly correlated with lactic acid,and the degree of inflammatory phenotypic switch is significantly time-dependent and concentrationdependent;lactic acid may affect the phenotypic switch of HVSMC through the AKT pathway,and may be peripheral arteries in the future The treatment of diseases and atherosclerosis provides certain ideas.