| The morphological evidence for limb regeneration of certain amphibians has been known for many decades. However, the prospective wound healing and tissue regeneration molecular pathways within these amphibians and any equivalent capability possessed by mammals still remains largely unknown. In this study, data mining analyses are carried out on the total microarray gene expression data and selected important wound healing and tissue regeneration genes for both newt limb amputations and mouse digit amputations, and mouse muscle crush injury experiments using the 'Superhealer' MRL mice compared to the 'normal' B6 mice. The experimental portions of the analyses were done previously by our collaborators in a DARPA funded limb regeneration project. In the newt limb amputation analysis, MMP13, CXCL10, COL12A1, HOXD10 and CCNB1 exhibited expression change signatures discriminating de-differentiation and blastemal stages of the response to limb amputation while MMP9, TIMP1 and MMP3/10a showed their ability to discriminate various amputation sites. As for the mouse muscle crush injury analysis, it demonstrates that keratins (Krts) and keratin associated proteins (Krtaps) show no significant difference between MRL versus B6. However, the result from mouse digit amputation analysis indicates that gene activities for Krt6, Krt16 and other Krts/Krtaps exhibit different behavior in MRL versus B6. These observations imply that the different behavior observed for Krts and Krtaps in MRL versus B6 is more due to a response to tissue regeneration following direct digit amputation, than it is a response to the tissue repair following wound injury. |
