Matrine inhibits disturbed flow-enhanced migration via downregulation of ERK1/2-MLCK signaling vascular smooth muscle cells.

Background: To investigate the effects of matrine on the vascular smooth muscle cell (VSMC) migration modulated by disturbed flow and their underlying molecular mechanisms in vitro.

Methods: Isolated rat aortic VSMCs were grown to confluence on 20- × 80-mm fibronectin-coated glass cover slides, and then, denuded zones were made at the position calculated to be the oscillating flow-reattachment zone and also in the downstream laminar flow region. VSMCs were treated with different doses of matrine (0, 10, 20, 30, and 40 mg/L), or PD98059 (30 μM), ML-7 (10 μM) combined with matrine (40 mg/L) for 30 minutes before and during the experiments. Then, the wounded monolayers were kept under static conditions or were subjected to laminar or disturbed flow for 21 hours or 10 hours. The VSMC migration was assessed by microscopic images. The extracellular signal-regulated kinase 1/2 (ERK1/2) and myosin light chain kinase (MLCK) proteins were determined by Western blot.

Results: Disturbed flow significantly increased phosphorylation of ERK1/2. Selective inhibition of ERK1/2 phosphorylation by inhibitor PD98059 and matrine significantly suppressed VSMC migration under disturbed flow. Disturbed flow significantly enhanced phosphorylation of MLCK, whereas both matrine and PD98059 inhibited the phosphorylation of MLCK under disturbed flow. The complete inhibition of MLCK phosphorylation using the selective MLCK inhibitor ML-7 significantly inhibited VSMC migration under disturbed flow.

Conclusion: Matrine inhibits VSMC migration under disturbed flow, in part, by downregulation of ERK1/2-MLCK signaling pathway.