[Kindlin-2 regulates migration and adhesion of vascular smooth muscle cells via β1-integrin].

OBJECTIVE: To explore the effects of Kindlin-2 RNA interference on vascular smooth muscle cells (VSMCs) migration, adhesion and β1-integrin as well as the relationship between Kindlin-2 and β1-integrin.

METHODS: Primary VSMCs were cultured, infected with Kindlin-2 siRNA lentiviral vectors.VSMCs were divided into three groups:the blank control group, the negative control group and the Kindlin-2 siRNA group. The ability of VSMCs migration was measured by Transwell experiment and wound healing assay. The ability of VSMCs adhesion to extracelluar matrix was determined by cell-extracelluar matrix adhesion assay. The Kindlin-2 and β1-integrin mRNA and protein expression levels were detected by real-time quantitative PCR and Western blot. Total β1-integrin and active β1-integrin expression on the surface of VSMCs was evaluated by flow cytometry.

RESULTS: The efficiency of Kindlin-2 siRNA lentivirus infected VSMCs was more than 90%. The number of VSMCs migration in the Kindlin-2 siRNA group was significantly lower than that of the blank control group and the negative group (all P < 0.05). Moreover, the distance of VSMCs migration was shorter than that of the blank control group and the negative group (all P < 0.05). The number of VSMCs adhesion to collagen I was less than that of the blank control group and the negative group (all P < 0.05). A(590 nm) of the Kindlin-2 siRNA group was also lower than that of the blank control group and the negative group (all P < 0.05). Compared with the blank control group, the expression level of Kindlin-2 mRNA in the Kindlin-2 siRNA group decreased 47% (P < 0.05), but the expression level of β1-integrin mRNA remained unchanged. The Kindlin-2 protein level in the Kindlin-2 siRNA group was lower than that of the blank control group and the negative group (all P < 0.05). β1-integrin protein level was similar among the three groups. Activated β1-integrin on the surface of VSMCs in the Kindlin-2 siRNA group was lower than that of the blank control group and the negative group (all P < 0.05).However, the expression level of total β1-integrin on the VSMCs surface was similar among the three groups.

CONCLUSION: Kindin-2 can regulate VSMCs migration and adhesion and activate β1-integrin on the surface of VSMCs.