A role for p38(MAPK)/HSP27 pathway in smooth muscle cell migration

Area of Science:

• Cell Biology
• Molecular Biology
• Physiology

Background:

• Smooth muscle cells (SMCs) are involved in pathological conditions such as airway hyperresponsiveness, atherosclerosis, and angiogenesis.
• SMC migration beyond organ boundaries is a common feature in several diseases.
• Signaling pathways controlling SMC migration are not well-defined.

Purpose of the Study:

• To investigate the role of signaling pathways in regulating smooth muscle cell migration.
• To identify key molecular mediators of SMC migration induced by growth factors and cytokines.

Main Methods:

• Cultured tracheal myocytes were stimulated with platelet-derived growth factor, interleukin-1beta, and transforming growth factor-beta.
• Cell migration was assessed using migration assays.
• p38 mitogen-activated protein kinase (MAPK) activation and heat shock protein 27 (HSP27) phosphorylation were measured.
• Adenovirus-mediated gene expression of MAPK pathway components was utilized.

Main Results:

• Platelet-derived growth factor, interleukin-1beta, and transforming growth factor-beta induced tracheal myocyte migration.
• SB203580, a p38(MAPK) inhibitor, blocked cell migration.
• p38(MAPK) activation led to HSP27 phosphorylation, modulating F-actin polymerization.
• Overexpression of activated MAPK kinase 6b(E) increased migration, while dominant-negative p38alpha MAPK and HSP27 mutants inhibited it.

Conclusions:

• The p38(MAPK) pathway is a critical regulator of smooth muscle cell migration.
• Growth factor and cytokine-induced SMC migration is mediated through p38(MAPK) activation and subsequent HSP27 phosphorylation.
• Targeting the p38(MAPK) pathway may offer therapeutic strategies for diseases involving SMC dysfunction.