First Author | Kothapalli D | Year | 2007 |
Journal | J Cell Biol | Volume | 176 |
Issue | 4 | Pages | 535-44 |
PubMed ID | 17296798 | Mgi Jnum | J:119716 |
Mgi Id | MGI:3703182 | Doi | 10.1083/jcb.200611058 |
Citation | Kothapalli D, et al. (2007) Hyaluronan and CD44 antagonize mitogen-dependent cyclin D1 expression in mesenchymal cells. J Cell Biol 176(4):535-44 |
abstractText | High molecular weight (HMW) hyaluronan (HA) is widely distributed in the extracellular matrix, but its biological activities remain incompletely understood. We previously reported that HMW-HA binding to CD44 antagonizes mitogen-induced S-phase entry in vascular smooth muscle cells (SMCs; Cuff, C.A., D. Kothapalli, I. Azonobi, S. Chun, Y. Zhang, R. Belkin, C. Yeh, A. Secreto, R.K. Assoian, D.J. Rader, and E. Pure. 2001. J. Clin. Invest. 108:1031-1040); we now characterize the underlying molecular mechanism and document its relevance in vivo. HMW-HA inhibits the mitogen-dependent induction of cyclin D1 and down-regulation of p27(kip1) in vascular SMCs. p27(kip1) messenger RNA levels were unaffected by HMW-HA, but the expression of Skp2, the rate-limiting component of the SCF complex that degrades p27(kip1), was reduced. Rescue experiments identified cyclin D1 as the primary target of HMW-HA. Similar results were observed in fibroblasts, and these antimitogenic effects were not detected in CD44-null cells. Analysis of arteries from wild-type and CD44-null mice showed that the effects of HMW-HA/CD44 on cyclin D1 and Skp2 gene expression are detected in vivo and are associated with altered SMC proliferation after vascular injury. |