Focal Adhesion Kinase Pathway Regulates Migration And Adhesion Of Skeletal Muscle Satellite Cell In Swine

The objective of this study was to investigate the difference of satellite cell(SC)migration and adhesion abilities in Lantang and Landrace pigs. Wound healing and transwell assays were used to compare the migration of SCs derived from two species of pigs in vitro. The adhesion abilities of Lantang SC and Landrace SC were compared using ECM-cell adhesion assays. Immunofluorescence, Western blot and real-time RT-PCR analyses were performed to evaluate the expression of F-actin, focal adhesion and focal adhesion kinase(FAK) /paxillin signaling pathway. In addition, Lantang SCs were treated with a specific p-FAK inhibitor, PF-573228, to investigate the effect of p-FAK inhibition on SC migration, adhesion and functional protein expression, respectively.The results were showed as followed:(1) The migration and adhesion abilities of Lantang SCs were significantly greater than those of Landrace SCs(P<0.05).(2) Compared with Landrace SCs, Lantang SCs showed more focal adhesion sites, which were indicated by the presence of p-paxillin(Tyr118), and less F-actin reorganization at 24 h after seeding on fibronection.(3) These protein levels of p-FAK(Tyr397) and p-paxillin(Tyr118) were greater(P<0.05)in Lantang SCs than in Landrace SCs during migration. In addition, Lantang SCs presented much greater protein levels of p-FAK(Tyr397), p-paxillin(Tyr118) and p-Akt(Ser473)(P<0.05) compared with Landrace SCs at 2 h after adhesion, similar result in the m RNA abundances of ITGB3(P=0.053) were also been verified.(4) Lantang SCs were treated with 0, 5 and 10 ?mol/L FAK inhibitor(PF-573228) for 24 h, respectively. This drug was able to inhibit the auto-phosphorylation of FAK(Tyr397) in SCs. Treatment with 5 and 10 ?mol/L PF-573228 significantly inhibited Lantang SC migration and adhesion on fibronectin(P<0.05).(5) Compared with the control group, Treatment with 5 and 10 ?mol/L PF-573228 reduced the number of focal adhesion sites. The protein levels of p-paxillin(Tyr118) and p-Akt(Ser473) were significantly down-regulated in the 5 and 10 ?mol/L treatment groups compared with the control group,respectively(P<0.05).Collectively, the above results show that:The different migration and adhesion abilities of Lantang and Landrace SCs are associated with differences in the distribution and localization of F-actin and focal adhesion,which are regulated by the activation of the FAK-paxillin signaling pathway.