Up-regulation of tissue-type transglutaminase after traumatic brain injury

Tolentino, Paul J
DeFord, S. Michelle
Notterpek, Lucia
Glenn, Christopher C
Pike, Brian R
Wang, Kevin K. W
Hayes, Ronald L

¹Department of Neuroscience Evelyn F. and William L. McKnight Brain Institute of the University of Florida Center for Traumatic Brain Injury Studies, Gainesville, Florida, USA
²Department of Neuroscience Therapeutics, Pfizer Inc., Ann Arbor, Michigan, USA

Received November, 2001.received 9 August, 2001.revised 7 November, 2001; accepted 8 November, 2001.

Address correspondence and reprint requests to Dr Ronald L. Hayes, Department of Neuroscience, University of Florida, 100 S. Newell Dr, Box 100244, Gainesville, FL 32611, USA. E-mail: [email protected]

Journal of Neurochemistry 80(4):p 579-588, February 2002.

Tissue-type transglutaminase (tTG, EC 2.3.2.13) has been implicated in various disease paradigms including neurodegenerative disease. In these studies, tTG induction after traumatic brain injury was studied using a rat cortical impact model. Using western blots, two forms of tTG protein expression were identified – a ∼79-kDa primary form (tTG-L) and a less abundant ∼70-kDa form (tTG-S). Both forms of tTG protein were elevated after injury. In ipsilateral cortex, peak induction of tTG-L protein [561% ± 80% of control (n = 5)] was observed five days after injury, with expression remaining elevated after two weeks. Peak induction of tTG-S protein [302% ± 81% of control (n = 5)] was observed three days after injury. Lesser tTG protein induction was observed in hippocampus. Northern blot analysis demonstrated two tTG transcripts in the ipsilateral cortex with peak induction of tTG-L mRNA three days after injury. However, tTG-S mRNA was not identified in control samples and only faintly detected in injured tissue. To facilitate analysis of low abundance transcripts in smaller tissue samples, a semiquantitative real-time PCR strategy was used. Semi-quantitative PCR analysis of tTG-L mRNA induction in ipsilateral cortex (peak after three days; 414% ± 21% of control, n = 3) confirmed tTG-L mRNA induction determined by northern blot (410% of control).