Up-regulation of reactivity and survival genes in astrocytes after exposure to short duration overpressure.
Gurdjian et al. proposed decades ago that pressure gradients played a major factor in neuronal injury due to impact. In the late 1950s, their experiments on concussion demonstrated that the principal factor in the production of concussion in animals was the sudden increase of intracranial pressure accompanying head injury. They reported the increase in pressure severity correlated with an increase in 'altered cells' resulting in animal death. More recently, Hardy et al. (2006) demonstrated the presence of transient pressure pulses with impact conditions. These studies indicate that short duration overpressure should be further examined as a mechanism of traumatic brain injury (TBI). In the present study, we designed and fabricated a barochamber that simulated overpressure noted in various head injury studies. We tested the effect of overpressure on astrocytes. Expressions of apoptotic, reactivity and survival genes were examined at 24, 48 and 72 h post-overpressure exposure. At 24 h, we found elevated levels of reactivity and survival gene expression. By 48 h, a decreased expression of apoptotic genes was demonstrated. This study reinforces the hypothesis that transient pressure acts to instigate the cellular response displayed following TBI.
Vandevord
Pamela J
PJ
Department of Biomedical Engineering, Wayne State University, 818 West Hancock, Detroit, MI 48202, USA. pvord@wayne.edu
Leung
Lai Yee
LY
Hardy
Warren
W
Mason
Matthew
M
Yang
King H
KH
King
Albert I
AI
D000818:Animals; D017209:Apoptosis / Q000235:genetics*; D051017:Apoptosis Regulatory Proteins / Q000235:genetics; D001253:Astrocytes / Q000378:metabolism* / Q000473:pathology; D001930:Brain Injuries / Q000235:genetics* / Q000378:metabolism* / Q000503:physiopathology; D002470:Cell Survival / Q000235:genetics; D005786:Gene Expression Regulation / Q000235:genetics*; D007378:Interleukins / Q000235:genetics; D009410:Nerve Degeneration / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology; D011312:Pressure / Q000009:adverse effects; D051381:Rats; D015398:Signal Transduction / Q000235:genetics; D013997:Time Factors; D015533:Transcriptional Activation; D015854:Up-Regulation / Q000235:genetics*
D051017:Apoptosis Regulatory Proteins; D007378:Interleukins