Loss of the serum response factor cofactor, cysteine-rich protein 1, attenuates neointima formation in the mouse.
OBJECTIVE
Cysteine-rich protein (CRP) 1 and 2 are cytoskeletal lin-11 isl-1 mec-3 (LIM)-domain proteins thought to be critical for smooth muscle differentiation. Loss of murine CRP2 does not overtly affect smooth muscle differentiation or vascular function but does exacerbate neointima formation in response to vascular injury. Because CRPs 1 and 2 are coexpressed in the vasculature, we hypothesize that CRPs 1 and 2 act redundantly in smooth muscle differentiation.


RESULTS
We generated Csrp1 (gene name for CRP1) null mice by genetic ablation of the Csrp1 gene and found that mice lacking CRP1 are viable and fertile. Smooth muscle-containing tissues from Csrp1-null mice are morphologically indistinguishable from wild-type mice and have normal contractile properties. Mice lacking CRPs 1 and 2 are viable and fertile, ruling out functional redundancy between these 2 highly related proteins as a cause for the lack of an overt phenotype in the Csrp1-null mice. Csrp1-null mice challenged by wire-induced arterial injury display reduced neointima formation, opposite to that seen in Csrp2-null mice, whereas Csrp1/Csrp2 double-null mice produce a wild-type response.


CONCLUSIONS
Smooth muscle CRPs are not essential for normal smooth muscle differentiation during development, but may act antagonistically to modulate the smooth muscle response to pathophysiological stress.
Lilly
Brenda
B
Huntsman Cancer Institute, Department of Biology, University of Utah, 2000 Circle of Hope, Salt Lake City, UT 84112, USA.
Clark
Kathleen A
KA
Yoshigi
Masaaki
M
Pronovost
Stephen
S
Wu
Meng-Ling
ML
Periasamy
Muthu
M
Chi
Mei
M
Paul
Richard J
RJ
Yet
Shaw-Fang
SF
Beckerle
Mary C
MC
D000818:Animals; D017209:Apoptosis; D002454:Cell Differentiation; D002465:Cell Movement; D049109:Cell Proliferation; D002478:Cells, Cultured; D005263:Femoral Artery / Q000378:metabolism / Q000473:pathology; D005838:Genotype; D006965:Hyperplasia; D060588:LIM Domain Proteins; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D023421:Models, Animal; D009124:Muscle Proteins / Q000172:deficiency / Q000235:genetics; D009131:Muscle, Smooth, Vascular / Q000293:injuries / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D032389:Myocytes, Smooth Muscle / Q000378:metabolism* / Q000473:pathology; D009687:Nuclear Proteins / Q000172:deficiency* / Q000235:genetics; D010641:Phenotype; D013997:Time Factors; D014162:Transfection; D017539:Tunica Intima / Q000293:injuries / Q000378:metabolism* / Q000473:pathology; D014661:Vasoconstriction
C486177:Csrp1 protein, mouse; C484376:Csrp2 protein, mouse; D060588:LIM Domain Proteins; D009124:Muscle Proteins; D009687:Nuclear Proteins