The Effect Of Mitochondrial Cx43 On Atherosclerosis And Its Mechanisms

Objectives:To explore the effect of mitochondrial Cx43 on atherosclerosis(AS) and its signaling pathway mechanisms. Methods:Two experimental models were established. ① Rat VSMCs proliferation model was induced by Using PDGF-BB, VSMCs were randomly divided into 3 groups: a. control; b.PDGF-BB; c.PD98059+PDGF-BB. ② VSMCs-ECs Co-culture model was established to simulate AS in vitro. Cells were randomly divided into 2 groups: a.control, b.TNF-α.VSMCs activity was detected by MTT assay; Reactive oxygen species(ROS) was checked by Fluorescent probes; Expression of mitochondrial Cx43 was studied by western blot. Results:1. Rat VSMCs proliferation model:① MTT assay results showed that: The absorbance value(A value) of PDGF-BB group was increased compared with that of control group(P<0.05); A value of PD98059+PDGF-BB group was decreased compared with control group(P<0.05); A value of PD98059+PDGF-BB group was decreased compared with PDGF-BB group(P<0.01).② ROS was detected by Fluorescent probes.The results showed that the intensity of fluorescence was proportional to the amount of ROS. The green fluorescence of PDGF-BB group was stronger than that of control group, indicating that the amount of ROS increased. The green fluorescence of PD98059+PDGF-BB group was weaker than that of control and PDGF-BB group, indicating that the amount of ROS decreased.③ Compared with control group, mitochondrial Cx43 protein expression of PDGF-BB group was significantly increased(P<0.01) and mitochondrial Cx43 protein expression of PD98059+PDGF-BB group was significantly decreased(P<0.05). Compared with PDGF-BB group, mitochondrial Cx43 protein expression of PD98059+PDGF-BB group was significantly decreased(P<0.01).2. EC-VSMC Co-culture model:① MTT assay results showed that the A value of TNF-α group was increased compared with control group(P<0.05).② The green fluorescence of TNF-α group was stronger than that of control group, indicating that the amount of ROS increased.③ Compared with control group, mitochondrial Cx43 protein expression of TNF-α group was significantly increased(P<0.01). Conclusion:1. VSMCs proliferation are induced by PDGF-BB and VSMCs-ECs Co-culture model significantly. ROS formation is increased and expression of mitochondrial Cx43 is up-regulated.2. ERK1/2 pathway is involved in the increase of ROS formation and up-regulation of expression of mitochondrial Cx43.3. The results provide a new idea for the prevention and treatment of AS.