Author(s): Kampfl A, Posmantur R, Nixon R, Grynspan F, Zhao X, et al.
Increasing evidence suggests that excessive activation of the calcium-activated neutral protease mu-calpain could play a major role in calcium-mediated neuronal degeneration after acute brain injuries. To further investigate the changes of the in vivo activity of mu-calpain after unilateral cortical impact injury in vivo, the ratio of the 76-kDa activated isoform of mu-calpain to its 80-kDa precursor was measured by western blotting. This mu-calpain activation ratio increased to threefold in the pellet of cortical samples ipsilateral to the injury site at 15 min, 1 h, 3 h, and 6 h after injury and returned to control levels at 24-48 h after injury. We also investigated the effect of mu-calpain activation on proteolysis of the neuronal cytoskeletal protein alpha-spectrin. Immunoreactivity for alpha-spectrin breakdown products was detectable within 15 min after injury in cortical samples ipsilateral to the injury site. The levels of alpha-spectrin breakdown products increased in a biphasic manner, with a large increase between 15 min and 6 h after injury, followed by a smaller increase between 6 and 24 h after the insult. No further accumulation of alpha-spectrin breakdown products was observed between 24 and 48 h after injury. Histopathological examinations using hematoxylin and eosin staining demonstrated dark, shrunken neurons within 15 min after traumatic brain injury. No evidence of mu-calpain autolysis, calpain-mediated alpha-spectrin degradation, or hematoxylin and eosin neuronal pathology was detected in the contralateral cortex. Although mu-calpain autolysis and cytoskeletal proteolysis occurred concurrently with early morphological alterations, evidence of calpain-mediated proteolysis preceded the full expression of evolutionary histopathological changes. Our results indicate that rapid and persistent mu-calpain activation plays an important role in cortical neuronal degeneration after traumatic brain injury. Our data also suggest that specific inhibitors of calpain could be potential therapeutic agents for the treatment of traumatic brain injury in vivo.
Referred From: https://www.ncbi.nlm.nih.gov/pubmed/8858942
Author(s): Decuypere M, Klimo P Jr
Author(s): Blostein PA, Jones SJ, Buechler CM, Vandongen S
Author(s): Crevits L, Hanse MC, Tummers P, Van Maele G
Author(s): Bandtlow CE
Author(s): Brösamle C, Huber AB, Fiedler M, Skerra A, Schwab ME
Author(s): Mott TF, McConnon ML, Rieger BP
Author(s): McCrea M, Pliskin N, Barth J, Cox D, Fink J, et al.
Author(s): van Leeuwen N, Lingsma HF, Perel P, Lecky F, Roozenbeek B, et al.
Author(s): Zhou W, Xu D, Peng X, Zhang Q, Jia J, et al.
Author(s): Jager TE, Weiss HB, Coben JH, Pepe PE
Author(s): Shenton ME, Hamoda HM, Schneiderman JS, Bouix S, Pasternak O, et al.
Author(s): Bigler ED, Maxwell WL
Author(s): Königs M, de Kieviet JF, Oosterlaan J
Author(s): Rohling ML, Binder LM, Demakis GJ, Larrabee GJ, Ploetz DM, et al.
Author(s): Simmons AN, Matthews SC
Author(s): Panayiotou A, Jackson M, Crowe SF
Author(s): Caner H, Can A, Atalay B, Erdogan B, Albayrak AH, et al.
Author(s): Abu-Judeh HH, Parker R, Singh M, el-Zeftawy H, Atay S, et al.
Author(s): Atalay B, Caner H, Can A, Cekinmez M
Author(s): Tymianski M, Tator CH
Author(s): Abrous DN, Rodriguez J, le Moal M, Moser PC, Barnéoud P
Author(s): Büki A, Koizumi H, Povlishock JT
Author(s): Blumbergs PC, Scott G, Manavis J, Wainwright H, Simpson DA, et al.
Author(s): Büki A, Siman R, Trojanowski JQ, Povlishock JT
Author(s): Geddes JF, Vowles GH, Nicoll JA, Révész T
Author(s): Saatman KE, Zhang C, Bartus RT, McIntosh TK
Author(s): Posmantur R, Kampfl A, Siman R, Liu J, Zhao X, et al.
Author(s): Ercan M, Inci S, Kilinc K, Palaoglu S, Aypar U