| First Author | Chattopadhyay S | Year | 2009 |
| Journal | Glia | Volume | 57 |
| Issue | 12 | Pages | 1316-25 |
| PubMed ID | 19229995 | Mgi Jnum | J:156203 |
| Mgi Id | MGI:4419051 | Doi | 10.1002/glia.20851 |
| Citation | Chattopadhyay S, et al. (2009) MMP-9 controls Schwann cell proliferation and phenotypic remodeling via IGF-1 and ErbB receptor-mediated activation of MEK/ERK pathway. Glia 57(12):1316-25 |
| abstractText | Phenotypic remodeling of Schwann cells is required to ensure successful regeneration of damaged peripheral axons. After nerve damage, Schwann cells produce an over 100-fold increase in metalloproteinase-9 (MMP-9), and therapy with an MMP inhibitor increases the number of resident (but not infiltrating) cells in injured nerve. Here, we demonstrate that MMP-9 regulates proliferation and trophic signaling of Schwann cells. Using in vivo BrdU incorporation studies of axotomized sciatic nerves of MMP-9-/- mice, we found increased Schwann cell mitosis in regenerating (proximal) stump relative to wild-type mice. Treatment of cultured primary Schwann cells with recombinant MMP-9 suppressed their growth, mitogenic activity, and produced a dose-dependent, biphasic, and selective activation of ERK1/2, but not JNK and p38 MAPK. MMP-9 induced ERK1/2 signaling in both undifferentiated and differentiated (using dbcAMP) Schwann cells. Using inhibitors to MEK and trophic tyrosine kinase receptors, we established that MMP-9 regulates Ras/Raf/MEK-ERK pathways through IGF-1, ErbB, and PDGF receptors. We also report on the early changes of MMP-9 mRNA expression (within 24 h) after axotomy. These studies establish that MMP-9 controls critical trophic signal transduction pathways and phenotypic remodeling of Schwann cells. |
