| First Author | Zhu B | Year | 2001 |
| Journal | Endocrinology | Volume | 142 |
| Issue | 8 | Pages | 3598-606 |
| PubMed ID | 11459808 | Mgi Jnum | J:132785 |
| Mgi Id | MGI:3776953 | Doi | 10.1210/endo.142.8.8331 |
| Citation | Zhu B, et al. (2001) Targeted overexpression of IGF-I in smooth muscle cells of transgenic mice enhances neointimal formation through increased proliferation and cell migration after intraarterial injury. Endocrinology 142(8):3598-606 |
| abstractText | The response of arterial smooth muscle cells to injury is governed by a complex series of events. Significant among them is the paracrine production of peptide growth factors. To determine the impact of local IGF-I gene expression on vascular injury, the left carotid arteries of SMP8-IGF-I mice (in which IGF-I is selectively overexpressed in smooth muscle cells by means of a smooth muscle alpha-actin promoter) and wild-type controls were injured mechanically with an epon resin probe. After 7 and 14 d, a progressive increase in medial area was seen in both SMP8-IGF-I and wild-type mice, but they were not significantly different from each other. However, by 14 d there was a more than 4-fold increase in neointimal area in transgenic vs. wild-type. The intima/media ratios were also strikingly increased at 14 d in the IGF-I-overexpressing animals. The mitotic index, determined in animals injected daily with bromodeoxyuridine for 3 d before death, was markedly elevated in both the media and neointima 7 d after injury in SMP8-IGF-I mice, but the effect had subsided by 14 d. Despite a higher rate of cell division, the relative increase in medial area was less in the SMP8-IGF-I mice than in wild-type mice at both 7 and 14 d, consistent with a stimulation of cell migration to the neointima. The experiments reported here provide compelling evidence that paracrine expression of IGF-I is a powerful stimulus for smooth muscle cell proliferation and migration in vivo. |
