Closed head injury induces upregulation of Beclin 1 at the cortical site of injury

T Diskin, P Tal-Or, S Erlich, L Mizrachy… - Journal of …, 2005 - liebertpub.com
T Diskin, P Tal-Or, S Erlich, L Mizrachy, A Alexandrovich, E Shohami, R Pinkas-Kramarski
Journal of neurotrauma, 2005liebertpub.com
Autophagy, a bulk degradation of subcellular constituents, is activated in several
neurodegenerative conditions. Beclin 1, a Bcl2 interacting protein, was found to promote
autophagy. The closed head injury model was used to investigate the possible role of
autophagy and Beclin 1 after traumatic brain injury. It is demonstrated that levels of Beclin-1
are dramatically increased near the site of injury. Neurons constitute the major population of
cells, with the highest Beclin 1 levels near the site of injury at early stages post injury …
Autophagy, a bulk degradation of subcellular constituents, is activated in several neurodegenerative conditions. Beclin 1, a Bcl2 interacting protein, was found to promote autophagy. The closed head injury model was used to investigate the possible role of autophagy and Beclin 1 after traumatic brain injury. It is demonstrated that levels of Beclin-1 are dramatically increased near the site of injury. Neurons constitute the major population of cells, with the highest Beclin 1 levels near the site of injury at early stages post injury. Elevated levels of Beclin 1 protein in neurons last for at least 3 weeks. In addition, Beclin-1 expression after injury is elevated also in astrocytes starting at 3 days after injury. Confocal microscopy analysis suggests that the high levels of Beclin 1 protein in astrocytes is confined to subcellular organelles, probably lysosomes or autophagosomes. Double staining of Beclin 1 and TUNEL indicate that most of the injured cells that exhibit double staining are neurons and not astrocytes. These findings show that Beclin 1 may play a role in brain responses to head trauma. Overexpression of Beclin 1 may be important for autophagy at the lesion site and may serve as a mechanism to discard injured cells and reduce damage to cells by disposing of injured components.
Mary Ann Liebert