Ablation of MEK kinase 1 suppresses intimal hyperplasia by impairing smooth muscle cell migration and urokinase plasminogen activator expression in a mouse blood-flow cessation model

Circulation. 2005 Apr 5;111(13):1672-8. doi: 10.1161/01.CIR.0000160350.20810.0F. Epub 2005 Mar 28.

Abstract

Background: Migration, proliferation, and matrix-degrading protease expression of smooth muscle cells (SMCs) are major features of intimal hyperplasia after vascular injury. Although MEK kinase 1 (MEKK1) has been shown to regulate cell migration and urokinase plasminogen activator (uPA) expression, the precise role of MEKK1 in this process remains unknown.

Methods and results: We triggered a vascular remodeling model by complete ligation of the right common carotid artery in wild-type (WT) and MEKK1-null (MEKK1-/-) mice. The intimal areas 28 days after ligation were significantly decreased in the ligated MEKK1-/- arteries compared with WT arteries (28+/-8 versus 65+/-17 microm2, P<0.05). There were no differences in the ratios of proliferating cell nuclear antigen (PCNA)-positive cells to total cells within the arterial wall between WT and MEKK1-/- arteries. Proliferation capacity also did not differ between WT and MEKK1-/- cultured aortic smooth muscle cells (AoSMCs). In contrast, the number of intimal PCNA-positive cells 7 days after ligation was significantly smaller in MEKK1-/- arteries. Three different migration assays revealed that migration and invasion of MEKK1-/- AoSMCs were markedly impaired. Addition of full-length MEKK1 restored the migration capacity of MEKK1-/- AoSMCs. The number of MEKK1-/- AoSMCs showing lamellipodia formation by epithelial growth factor was significantly smaller compared with those of WT SMCs. Furthermore, uPA expression after ligation was markedly decreased in MEKK1-/- arteries.

Conclusions: MEKK1 is implicated in vascular remodeling after blood-flow cessation by regulating the migration and uPA expression of SMCs. MEKK1 is a potential target for drug development to prevent vascular remodeling.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Aorta / cytology
  • Carotid Stenosis*
  • Cell Movement*
  • Cells, Cultured
  • Disease Models, Animal
  • Gene Expression Regulation
  • Hyperplasia / etiology*
  • MAP Kinase Kinase Kinase 1 / deficiency
  • MAP Kinase Kinase Kinase 1 / physiology*
  • Mice
  • Mice, Knockout
  • Muscle, Smooth, Vascular / cytology*
  • Myocytes, Smooth Muscle / metabolism
  • Myocytes, Smooth Muscle / physiology
  • Tunica Intima / pathology*
  • Urokinase-Type Plasminogen Activator / genetics*

Substances

  • MAP Kinase Kinase Kinase 1
  • Urokinase-Type Plasminogen Activator