| First Author | Zhang L | Year | 2012 |
| Journal | J Biol Chem | Volume | 287 |
| Issue | 9 | Pages | 6177-86 |
| PubMed ID | 22210777 | Mgi Jnum | J:182436 |
| Mgi Id | MGI:5315639 | Doi | 10.1074/jbc.M111.292649 |
| Citation | Zhang L, et al. (2012) Role of integrin-beta3 protein in macrophage polarization and regeneration of injured muscle. J Biol Chem 287(9):6177-86 |
| abstractText | Following injury, skeletal muscle achieves repair by a highly coordinated, dynamic process resulting from interplay among numerous inflammatory, growth factors and myogenic regulators. To identify genes involved in muscle regeneration, we used a microarray analysis; there was a significant increase in the expression of a group of integrin genes. To verify these results, we used RT-PCR and Western blotting and found that 12 integrins were up-regulated from 3 h to 15 days following injury. Following muscle injury, integrin-beta3 was initially expressed, mainly in macrophages. In integrin-beta3 global KO mice, the expression of myogenic genes was decreased and muscle regeneration was impaired, whereas fibrosis was enhanced versus events in wild type (WT) mice. The mechanism for these responses in integrin-beta3 KO mice included an infiltration of macrophages that were polarized into the M2 phenotype. These macrophages produced more TGF-beta1 and increased TGF-beta1/Smad signaling. In vitro, we confirmed that M2 macrophages lacking integrin-beta3 produced more TGF-beta1. Furthermore, transplantation of bone marrow cells from integrin-beta3 KO mice into WT mice led to suppression of the infiltration and accumulation of macrophages into injured muscles. There was also impaired muscle regeneration with an increase in muscle fibrosis. Our results demonstrate that integrin-beta3 plays a fundamental role in muscle regeneration through a regulation of macrophage infiltration and polarization leading to suppressed TGF-beta1 production. This promotes efficient muscle regeneration. Thus, an improvement in integrin-beta3 function could stimulate muscle regeneration. |
