Grb2 is required for the development of neointima in response to vascular injury.
OBJECTIVE
Neointima formation occurs in arteries in response to mechanical or chemical injury and is responsible for substantial morbidity. In this work, the role of the intracellular linker protein Grb2 in the pathogenesis of neointima formation was examined. Grb2 is a critical signaling protein that facilitates the activation of the small GTPase ras by receptor tyrosine kinases.


RESULTS
Cultured rat aortic smooth muscle cells were treated with an antisense morpholino to Grb2 and these cells showed a reduced proliferative response to platelet-derived growth factor stimulation. Grb2-/- mice do not survive embryonic development. Grb2+/- mice appear normal at birth and are fertile but have defective signaling in several tissues. Cultured smooth muscle cells derived from Grb2+/- mice grew at a much slower rate than cells derived from Grb2+/+ mice. Grb2+/- and Grb2+/+ mice were subjected to carotid injury. After 21 days, Grb2+/+ mice developed robust neointima formation that, in some cases, resulted in an occlusive lesion. In contrast, Grb2+/- mice were resistant to the development of neointima


CONCLUSIONS
Grb2 is an essential component of the signaling cascade resulting in neointima formation after arterial injury.
Zhang
Shaosong
S
Center for Cardiovascular Research, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA.
Ren
Jie
J
Khan
M Faisal
MF
Cheng
Alec M
AM
Abendschein
Dana
D
Muslin
Anthony J
AJ
D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D001011:Aorta / Q000166:cytology; D001161:Arteriosclerosis; D002339:Carotid Arteries / Q000503:physiopathology; D020212:Carotid Artery Injuries / Q000503:physiopathology*; D002455:Cell Division / Q000502:physiology; D002478:Cells, Cultured; D004195:Disease Models, Animal; D051380:GRB2 Adaptor Protein; D051379:Mice; D018345:Mice, Knockout; D009131:Muscle, Smooth, Vascular / Q000166:cytology*; D011506:Proteins / Q000235:genetics / Q000502:physiology*; D051381:Rats; D015398:Signal Transduction; D017539:Tunica Intima / Q000502:physiology*; D014652:Vascular Diseases / Q000503:physiopathology*
D048868:Adaptor Proteins, Signal Transducing; D051380:GRB2 Adaptor Protein; C495949:Grb2 protein, mouse; C495950:Grb2 protein, rat; D011506:Proteins