The effects of BclXL and Bax over-expression on stretch-injury induced neural cell death.
The Bcl-2 family of proteins has recently been implicated as a possible player in the complex cascade of neural cell death due to traumatic brain injuries. However, it is unclear if the Bcl-2 pathways are activated in mechanically injured neurons. Here we report the effects of BclX(L) and Bax over-expression on stretch-induced neural cell death using an in vitro uniaxial stretch model of traumatic axonal injury. Specifically, YFP, YFP-tagged Bax and YFP-tagged BclX(L) proteins were expressed in differentiated NG108-15 cells and stretch-injury assays were carried out at different strain and strain rate combinations. As a control, insults known to act within the Bcl-2 pathways were used to study cell viability and to compare with the results of cell death due to mechanical stretching. Surprisingly, under the stretch-injury conditions in this study, BclXL did not provide protection against cell death. Further, translocation of Bax could not be identified after stretch-injury. The implications of these findings to cell death pathways in traumatic brain injury are discussed.
Pfister
Bryan
B
Department of Neurosurgery, University of Pennsylvania, Philadelphia, PA 19104, USA.
Oyler
George
G
Betenbaugh
Michael
M
Bao
Gang
G
D000818:Animals; D017209:Apoptosis; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism; D002460:Cell Line; D002470:Cell Survival; D020833:Diffuse Axonal Injury / Q000209:etiology / Q000378:metabolism* / Q000473:pathology*; D004548:Elasticity; D015870:Gene Expression; D040542:Mechanotransduction, Cellular; D009474:Neurons / Q000378:metabolism* / Q000473:pathology*; D010812:Physical Stimulation / Q000009:adverse effects; D051381:Rats; D013314:Stress, Mechanical; D051028:bcl-2-Associated X Protein / Q000378:metabolism*; D051020:bcl-X Protein / Q000378:metabolism*
D051017:Apoptosis Regulatory Proteins; C494828:Bax protein, rat; C494813:Bcl2l1 protein, rat; D051028:bcl-2-Associated X Protein; D051020:bcl-X Protein