Calponin phosphorylation in cerebral cortex microvessels mediates sustained vasoconstriction after brain trauma.
OBJECTIVE
The purpose of this study was to determine the molecular and biochemical changes in the contractile protein, calponin (Cp), which temporally coincide with a previously reported state of sustained contractility following traumatic brain injury (TBI).


METHODS
Double immunofluorescence, western analysis and two-dimensional non-equilibrium pH gradient gel electrophoresis (NEPHGE)/SDS-PAGE techniques were utilized to determine both the location and extent of Cp within smooth muscle cells (SM) and the phosphorylation state of Cp following TBI, as induced using a weight drop acceleration impact model.


RESULTS
Double immunofluorescence for Cp and SM indicate that following injury, Cp migrates from the cytosol to a location subjacent to the SM membrane. Western analysis revealed a significant increase in Cp protein expression following injury that was maintained up to 48 hours post-injury. Combined Western analysis and NEPHGE indicated that Cp is phosphorylated following TBI.


CONCLUSIONS
Cp migration and phosphorylation may underlie the mechanism for increased vasoreactivity leading to hypoperfusion following TBI.
Kreipke
Christian W
CW
Department of Anatomy and Cell Biology, Scott Hall, Room No. 9312, Wayne State University School of Medicine, 540 E. Canfield, Detroit, MI 48201, USA.
Morgan
Randy
R
Roberts
George
G
Bagchi
Mihir
M
Rafols
José A
JA
D000199:Actins / Q000378:metabolism; D000818:Animals; D001930:Brain Injuries / Q000473:pathology* / Q000503:physiopathology*; D002135:Calcium-Binding Proteins / Q000378:metabolism*; D002540:Cerebral Cortex / Q000378:metabolism / Q000473:pathology*; D004195:Disease Models, Animal; D015180:Electrophoresis, Gel, Two-Dimensional / Q000379:methods; D008297:Male; D008833:Microcirculation / Q000378:metabolism*; D008840:Microfilament Proteins / Q000378:metabolism*; D008954:Models, Biological; D010766:Phosphorylation; D021381:Protein Transport / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors; D014661:Vasoconstriction / Q000502:physiology*; D000096985:Calponins
D000199:Actins; D002135:Calcium-Binding Proteins; D008840:Microfilament Proteins; D000096985:Calponins; C498862:Acta2 protein, rat