脂多糖通过下调TANGO1/SCFD1轴破坏内质网-高尔基体稳定性加剧血管内皮细胞炎症损伤OA

AIM:To explore whether lipopolysaccharide(LPS)-induced inflammatory environment disrupts Sec1 family domain-containing 1(SCFD1)function via down-regulation of transport and Golgi organization protein 1(TANGO1),thereby leading to vascular endothelial cell dysfunction and aggravated inflammation.METHODS:Human umbilical vein endothelial cells were used as the cellular model,and the experimental groups were as follows:dimethyl sulfoxide(DMSO)group(0.1％DMSO was added to the culture medium),LPS group(1 mg/L LPS was added to the cul-ture medium),OE-NC group(the cells were transfected with an empty expression plasmid),and LPS+TANGO1 overex-pression group(the cells transfected with TANGO1 overexpression plasmid followed by 1 mg/L LPS treatment).Each group consisted of three replicate samples.The endoplasmic reticulum and Golgi apparatus fluorescence probes were used to assess the changes in fluorescence intensity.Actin-Tracker Red was used to determine the effect of TANGO1 overexpres-sion on cytoskeleton remodeling.Western blot was used to detect the expression of TANGO1,SCFD1,inositol-requiring enzyme 1,and spliced form of X-box binding protein 1.Flow cytometry was used to detect the apoptosis of the cells.The levels of reactive oxygen species(ROS),nitrogen oxide,superoxide dismutase and malondialdehyde were determined to evaluate the oxidative stress level of endothelial cells.The interaction relationship between TANGO1 and SCFD1 was pre-liminarily verified by the co-immunoprecipitation experiment and co-transfection experiment of SCFD1 knockdown and TANGO1 overexpression.RESULTS:Compared with DMSO group,LPS significantly promoted the level of cellular oxida-tive stress(P<0.01),and increased the apoptosis rate of cells(P<0.01).At the same time,LPS enhanced the fluores-cence intensity of the endoplasmic reticulum(P<0.01),decreased the fluorescence intensity of the Golgi apparatus(P<0.01),induced abnormal remodeling of the cell skeleton(pseudopod contraction),and down-regulated the protein expres-sion of TANGO1 and SCFD1(P<0.01).Overexpression of TANGO1 effectively mitigated these LPS-induced cellular inju-ries(P<0.01).The co-immunoprecipitation experiments confirmed a direct interaction between TANGO1 and SCFD1,overexpression of SCFD1 had no significant effect on the expression level of TANGO1,while after knockdown of SCFD1,the function of TANGO1 in alleviating endoplasmic reticulum stress was impaired(P<0.01).CONCLUSION:Treat-ment with LPS down-regulates the TANGO1/SCFD1 expression,thereby disrupting endoplasmic reticulum-Golgi homeosta-sis and promoting oxidative stress and apoptosis in vascular endothelial cells.In contrast,overexpression of TANGO1 maintains endoplasmic reticulum-Golgi homeostasis,reduces apoptosis,and exerts protective effects.