FAM3B Mediates The Molecular Mechanism Of Vascular Smooth Muscle Cell Proliferation And Migration Induced By Hyperglycemia

Under prolonged hyperglycemic condition,the incidence of vascular diseases is significantly increased in diabetic patients,which leads to serious cardiovascular disease(CVD).In this process,the proliferation and migration of vascular smooth muscle cells(VSMCs)play an essential role.Therefore,how to suppress the hyperglycemia-induced VSMC activation and decrease the incidence of diabetic CVD are most important issues in the public health.On the other hand,family with sequence similarity 3,member B(FAM3B),a protein with unique secondary structure(four-helix bundles with disulfide bridges),is co-secreted with insulin from the ?-cell upon glucose stimulation and regulates glucose homeostasis.However,in VSMCs,whether FAM3B is also responded to hyperglycemia and further regulates their physiological behaviors remain unknown.In the current study,to investigate the role of FAM3B in high glucose-induced VSMC proliferation and migration,we intend to take primary VSMCs as research objects,and then artificially regulate the expression of FAM3B via gain-/loss-of-function methods.5-Ethynyl-2'-deoxyuridine(EdU)incorporation and cell counting assays were used to determine cell proliferation rate.Cell cycle was detected by flow cytometry.Wound-healing and transwell assay were administered to detect cell migration rate.At the molecular level,the protein expression levels of cell cycle(PCNA,CDK2/6,CyclinE/D1,p27)and migration-associated proteins(MMP2/9,ICAM-1/VCAM-1)were analyzed by using western blot.Mechanically,we performed miRNAs microarray analysis,to screen out the potential downstream miRNAs of FAM3B.We found that glucose dose-and time-dependently increase FAM3B expression.In addition,the stability of FAM3B protein was increased by glucose stimulates,indicating that FAM3B may mediate high glucose induced VSMCs activation.FAM3B overexpression significantly advanced VSMC proliferation and migration,accelerated the cell cycle progression.At the protein level,overexpression of FAM3B increased cell cycle associated protein(PCNA,CDK2/6,Cyclin E/D1)and migration related protein(MMP2/9,ICAM-1/VCAM-1)expression.In contrast,the expression level of p27 was inhibited.On the other hand,knockdown of FAM3B by the siRNA transduction remarkably suppressed all the VSMC behaviors mentioned above.At the molecular level,through microarray analysis,we identified a downstream microRNA of the FAM3B,miR-322-5p.Enforced expression of miR-322-5p significantly antagonized FAM3B-induced VSMC proliferation and migration,suggesting that FAM3B facilitated VSMC pathological activation through inhibition of miR-322-5p.In summary,our study strongly suggested that FAM3B mediates high glucose-induced VSMCs proliferation and migration via inhibition of miR-322-5p.We first explore the role of FAM3B on VSMCs,enriched the current knowledge of FAM3B's function,and will provide a novel therapeutic target for diabetes-induced CVD.