Abstract:
Objective To explore expression levels of integrin α5β1 in lesion tissues of patients with acute type A aortic dissection (AAAD) and human aortic smooth muscle cells (HASMC) and the possible regulatory mechanism.
Methods Immunohistochemistry was used to detect expression levels of integrin α5β1, phosphorylated focal adhesion kinase (p-FAK) and Caspase 3 proteins in the lesion tissues of AAAD patients. Immunofluorescence was used to detect integrins α5β1 and p-FAK expressions in HASMC. siRNA was used to downregulate integrin α5β1 in HASMC, CCK-8 and flow cytometry were used to detect the proliferation activity and apoptosis of HASMC, respectively.
Results The expression of integrin α5β1 at lesion tissues in AAAD patients was decreased (P < 0.05). Integrins α5β1 and FAK expressed in the same sites of normal HASMC. After down regulating expression of integrin α5β1 in HASMC, the smooth muscle cells showed decreased proliferation and increased apoptosis (P < 0.001). The expression of α5β1 and FAK proteins was downregulated (P < 0.001).
Conclusions Integrin α5β1/FAK signal pathway in the aorta of AAAD patients is down regulated, and the HASMC proliferation decreases and apoptosis increases after this signal pathway is inhibited.