Temporal characterisation of pro- and anti-apoptotic mechanisms following diffuse traumatic brain injury in rats
Cernak, Ibolja, Chapman, Sarah M., Hamlin, Gary P., and Vink, Robert (2002) Temporal characterisation of pro- and anti-apoptotic mechanisms following diffuse traumatic brain injury in rats. Journal of Clinical Neuroscience, 9 (5). pp. 565-572.
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View at Publisher Website: http://dx.doi.org/10.1054/jocn.2002.1132
Few studies have characterised apoptosis in a brain injury model that causes a significant degree of diffuse axonal injury. Such characterisation is essential from a clinical viewpoint since diffuse axonal injury is a major component of human head injury. The present study therefore, examines the expression of active and proactive caspase-3, and the bax, bcl-2 and bcl-x members of the bcl-2 family, to characterise the temporal profile of apoptosis in a model of traumatic brain injury in rats that produces significant diffuse axonal injury. Pentobarbital anaesthetised male Sprague–Dawley rats were injured using the 2 m impact-acceleration model of diffuse traumatic brain injury. After injury, diffuse trauma resulted in an increased bax expression followed by induction of caspase-3. The increase in caspase-3 was simultaneous with an increase in anti-apoptotic bcl-2 expression. Bcl-x levels were increased after induction of caspase-3 and the increased levels of bcl-x were sustained to the end of the 5-day observation period. Increased active caspase-3 expression was associated with the appearance of TUNEL positive cells. These cells were detected in different brain regions at different times, with some regions showing no apoptotic cells until 3 days after injury. No TUNEL positive cells were detected at 7 and 14 days after injury. DNA electrophoresis confirmed that DNA fragmentation was maximal at 3 days after injury. Increased active caspase-3 levels were also significantly correlated with increased bcl-2 levels (r=0.80; P<0.001) suggesting that the apoptotic cascade after diffuse traumatic brain injury is a carefully controlled cellular homeostatic response. Pharmacological manipulation of this balance may offer a therapeutic approach for preventing cell death and improving outcome after diffuse traumatic brain injury.
|Item Type:||Article (Refereed Research - C1)|
|Keywords:||apoptosis; caspases; diffuse axonal injury; neurotrauma|
|FoR Codes:||11 MEDICAL AND HEALTH SCIENCES > 1109 Neurosciences > 110999 Neurosciences not elsewhere classified @ 51%|
11 MEDICAL AND HEALTH SCIENCES > 1109 Neurosciences > 110903 Central Nervous System @ 49%
|SEO Codes:||97 EXPANDING KNOWLEDGE @ 100%|
|Deposited On:||08 Dec 2010 11:03|
|Last Modified:||12 Feb 2011 20:20|
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