Combined effects of mechanical and ischemic injury to cortical cells: Secondary ischemia increases damage and decreases effects of neuroprotective agents

Traumatic brain injury (TBI) involves direct mechanical damage, which may be aggravated by secondary insults such as ischemia. We utilized an in vitro model of stretch-induced injury to investigate the effects of mechanical and combined mechanical/ischemic insults to cultured mouse cortical cells. Stretch injury alone caused significant neuronal loss and increased uptake of the dye, propidium iodide, suggesting cellular membrane damage to both glia and neurons. Exposure of cultures to ischemic conditions for 24h, or a combination of stretch and 24h of ischemia, caused greater neuronal loss compared to stretch injury alone. Next, we tested the neuroprotective effects of superoxide dismutase (SOD), and the nitric oxide (NO) synthase inhibitors 7-nitroindazole (7-NINA) and lubeluzole. In general, these agents decreased neuronal loss following stretch injury alone, but were relatively ineffective against the combined injury paradigm. A combination of SOD with 7-NINA or lubeluzole offered no additional protection than single drug treatment against stretch alone or combined injury. These results suggest that the effects of primary mechanical damage and secondary ischemia to cortical neurons are cumulative, and drugs that scavenge superoxide or reduce NO production may not be effective for treating the secondary ischemia that often accompanies TBI.

[1]  C. Epstein,et al.  Effects of Nitric Oxide Synthase Inhibition on Brain Infarction in SOD-1-Transgenic Mice following Transient Focal Cerebral Ischemia , 1996, Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism.

[2]  J. Weber,et al.  Alterations in calcium-mediated signal transduction after traumatic injury of cortical neurons. , 1999, Cell calcium.

[3]  E. Steyerberg,et al.  Brain tissue oxygen response in severe traumatic brain injury , 2003, Acta Neurochirurgica.

[4]  F. Sharp,et al.  Modeling both the mechanical and hypoxic features of traumatic brain injury in vitro in rats , 2002, Neuroscience Letters.

[5]  J. Steeves,et al.  Modulating astrogliosis after neurotrauma , 2001, Journal of neuroscience research.

[6]  R. Raghupathi,et al.  Pharmacotherapy for traumatic brain injury: a review. , 1998, Proceedings of the Western Pharmacology Society.

[7]  L. Longo,et al.  Free radical-induced elevation of ornithine decarboxylase activity in developing rat brain slices , 1997, Brain Research.

[8]  J. Grotta,et al.  Lubeluzole in Acute Ischemic Stroke Treatment: A Double-Blind Study With an 8-Hour Inclusion Window Comparing a 10-mg Daily Dose of Lubeluzole With Placebo , 2000, Stroke.

[9]  M. Ross,et al.  Obligatory Role of Inducible Nitric Oxide Synthase in Ischemic Preconditioning , 2005, Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism.

[10]  R. Busto,et al.  Role of nitric oxide in traumatic brain injury in the rat. , 1998, Journal of neurosurgery.

[11]  C. Robertson,et al.  The Association Between Neuronal Nitric Oxide Synthase and Neuronal Sensitivity in the Brain After Brain Injury , 2002, Annals of the New York Academy of Sciences.

[12]  I. Morita,et al.  Involvement of nitric oxide and free radical (O2-) in neuronal injury induced by deprivation of oxygen and glucose in vitro. , 1994, Acta neurochirurgica. Supplementum.

[13]  M. Aschner,et al.  Methylmercury-induced reactive oxygen species formation in neonatal cerebral astrocytic cultures is attenuated by antioxidants. , 2003, Brain research. Molecular brain research.

[14]  W. Hoffman,et al.  Brain tissue oxygen pressure, carbon dioxide pressure and pH during ischemia. , 1996, Neurological research.

[15]  C. I. Zeeuw,et al.  Cell death, glial protein alterations and elevated S-100β release in cerebellar cell cultures following mechanically induced trauma , 2004, Neurobiology of Disease.

[16]  T. Dawson,et al.  Nitric Oxide in Neuronal Degeneration , 1996, Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine.

[17]  E W Steyerberg,et al.  Brain oxygen tension in severe head injury. , 2000, Neurosurgery.

[18]  C. D. De Zeeuw,et al.  Repeated mild injury causes cumulative damage to hippocampal cells. , 2002, Brain : a journal of neurology.

[19]  E. Shohami,et al.  Cerebral ischemia and trauma—different etiologies yet similar mechanisms: neuroprotective opportunities , 2002, Brain Research Reviews.

[20]  P. Kochanek,et al.  Early neuropathologic effects of mild or moderate hypoxemia after controlled cortical impact injury in rats. , 1997, Journal of neurotrauma.

[21]  M. Bähr,et al.  Neuronal death after brain injury , 1999, Cell and Tissue Research.

[22]  R. Busto,et al.  Effects of L-NAME and 7-NI on NOS catalytic activity and behavioral outcome after traumatic brain injury in the rat. , 1999, Journal of neurotrauma.

[23]  K. Maiese,et al.  Neuroprotection of Lubeluzole Is Mediated Through the Signal Transduction Pathways of Nitric Oxide , 1997, Journal of neurochemistry.

[24]  E C Toescu,et al.  Apoptosis and cell death in neuronal cells: where does Ca2+ fit in? , 1998, Cell calcium.

[25]  E. Ellis,et al.  Stretch-induced injury of cultured neuronal, glial, and endothelial cells. Effect of polyethylene glycol-conjugated superoxide dismutase. , 1996, Stroke.

[26]  T. Dawson,et al.  Nitric oxide synthase in models of focal ischemia. , 1997, Stroke.

[27]  G. Schneider,et al.  Lubeluzole following traumatic brain injury in the rat. , 1999, Journal of Neurotrauma.

[28]  J. Povlishock,et al.  A new model for rapid stretch-induced injury of cells in culture: characterization of the model using astrocytes. , 1995, Journal of neurotrauma.

[29]  J. Weber.  Calcium homeostasis following traumatic neuronal injury. , 2004, Current neurovascular research.

[30]  A. Maas,et al.  Current recommendations for neurotrauma , 2000, Current opinion in critical care.

[31]  V. Dawson.  Potent neuroprotectants linked to bifunctional inhibition. , 1999, Proceedings of the National Academy of Sciences of the United States of America.

[32]  J. Rafols,et al.  Attenuation of iNOS mRNA exacerbates hypoperfusion and upregulates endothelin-1 expression in hippocampus and cortex after brain trauma. , 2004, Nitric oxide : biology and chemistry.

[33]  J. Disterhoft,et al.  Lubeluzole and conditioned learning after cerebral ischemia , 2003, Experimental Brain Research.

[34]  B. Pike,et al.  Novel Characteristics of Glutamate-Induced Cell Death in Primary Septohippocampal Cultures: Relationship to Calpain and Caspase-3 Protease Activation , 2000, Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism.

[35]  H. Ou,et al.  Neuroprotective MK801 is associated with nitric oxide synthase during hypoxia/reoxygenation in rat cortical cell cultures , 2002, Journal of cellular biochemistry.

[36]  C. Culmsee,et al.  Lubeluzole protects hippocampal neurons from excitotoxicity in vitro and reduces brain damage caused by ischemia. , 1998, European journal of pharmacology.

[37]  E. W. Steyerberg,et al.  Serial Transcranial Doppler Measurements in Traumatic Brain Injury with Special Focus on the Early Posttraumatic Period , 2002, Acta Neurochirurgica.

[38]  E. Hall,et al.  Peroxynitrite-mediated protein nitration and lipid peroxidation in a mouse model of traumatic brain injury. , 2004, Journal of neurotrauma.

[39]  B. Pike,et al.  Stretch injury causes calpain and caspase-3 activation and necrotic and apoptotic cell death in septo-hippocampal cell cultures. , 2000, Journal of neurotrauma.