Role of periostin in inducing inflammatory responses in vivo.

A-B: Gelfoam patches containing PBS (Control, n = 6) or recombinant periostin (rPeriostin, n = 7) were placed into periaortic spaces of mice for 7 days. Representative images show mouse aortic walls, stained with hematoxylin/eosin (HE) or with antibodies against periostin, phosphorylated FAK (pFAK), or MCP-1 (A). Infiltrating cells were counted in 5-10 high-power fields (B). Data are mean ± SE. *p<0.05 compared to Control. C: Schematic diagram represents the proposed vicious cycle of periostin upregulation driven by mechanical strain through activation of FAK, resulting in the maintenance of inflammation in AAA.