First Author | Jung JC | Year | 2002 |
Journal | Dev Dyn | Volume | 223 |
Issue | 3 | Pages | 402-13 |
PubMed ID | 11891989 | Mgi Jnum | J:75334 |
Mgi Id | MGI:2176339 | Doi | 10.1002/dvdy.10069 |
Citation | Jung JC, et al. (2002) Matrix metalloproteinases mediate the dismantling of mesenchymal structures in the tadpole tail during thyroid hormone-induced tail resorption. Dev Dyn 223(3):402-13 |
abstractText | It has been suggested that a family of tissue remodelling enzymes called matrix metalloproteinases (MMPs) play a causal role in the process of tail resorption during thyroid hormone-induced metamorphosis of the anuran tadpole; however, this hypothesis has never been directly substantiated. We cloned two new Xenopus MMPs, gelatinase A (MMP-2) and MT3-MMP (MMP-16), and the MMP inhibitor TIMP-2. These clones were used along with several others to perform a comprehensive expression study. We show that all MMPs and TIMP-2 are dramatically induced in the resorbing tail during spontaneous metamorphosis and are spatially coexpressed, primarily in the remodelling mesenchymal tissues. By Northern blotting, we show that all the examined MMPs/TIMP-2 are also induced by treatment of organ-cultured tails with thyroid hormone (T(3)). Using the organ culture model, we provide the first direct evidence that MMPs are required for T(3)-induced tail resorption by showing that a synthetic inhibitor of MMP activity/expression can specifically retard the resorption process. By gelatin zymography, we also show T(3) induction of a fifth MMP, preliminarily identified as gelatinase B (GelB; MMP-9). Moreover, T(3) not only induces MMP/TIMP expression but also MMP activation, and we provide evidence that TIMP-2 participates in the latter process. These findings suggest that MMPs and TIMPs act in concert to effect the dismantling of mesenchymal structures during T(3)-induced metamorphic tadpole tail resorption. Copyright 2002 Wiley-Liss, Inc. |