Recent studies have revealed the role of the pRb family members pRb and p130 in the response to
vascular injury. We evaluated the arterial injury response in the absence of p107, a
protein that shares a high degree of homology with the injury-controlling p130. Carotid artery
ligation and perivascular
electric injury of the femoral artery were applied to p107 knockout (p107 -/-) mice, and morphometric analysis was performed 3 wk after
ligation and
electric injury. Arterial vessels of p107 -/- mice were indistinguishable from controls under basal conditions. After carotid artery
ligation the p107 -/- mice (n = 7) did not display an enhanced
ligation response compared with controls (n = 9), which was studied over a distance of approximately 450 microm proximal and approximately 200 microm distal from the
ligation site, with regard to vessel wall area,
neointima area, and lumen area. Corresponding with this, morphometric data obtained from the perivascular
electric injury of the femoral artery confirmed the lack of enhanced
ligation and injury response in the absence of p107. We conclude that the pRb family member p107 is not a key regulator in
vascular injury response. These data, in conjunction with previously reported results, indicate that the control of
vascular injury response is not a redundant feature of pRb
proteins but primarily specific for p130. Further studies on functional domains of p130 and p107 will help to resolve the pathways in
vascular injury response.