NCX3 knockout mice exhibit increased hippocampal CA1 and CA2 neuronal damage compared to wild-type mice following global cerebral ischemia.
There is uncertainty as to whether the plasma membrane Na(+)/Ca(2+)exchanger (NCX) has a neuroprotective or neurodamaging role following cerebral ischemia. To address this issue we compared hippocampal neuronal injury in NCX3 knockout mice (Ncx3(-/-)) and wild-type mice (Ncx3(+/+)) following global cerebral ischemia. Using a bilateral common carotid artery occlusion (BCCAO) model of global ischemia we subjected NCX3 knockout and wild-type mice to 17 and 15 minutes of ischemia. Following the 17 minute period of ischemia, wild-type mice exhibited approximately 80% CA1 neuronal loss and approximately 40% CA2 neuronal loss. In contrast, NCX3 knockout mice displayed >95% CA1 neuronal loss and approximately 95% CA2 neuronal loss. Following the 15 minute period of ischemia, wild-type mice did not exhibit any significant hippocampal neuronal loss. In contrast, NCX3 knockout mice displayed approximately 45% CA1 neuronal loss and approximately 25% CA2 neuronal loss. The results clearly demonstrate that mice deficient in the NCX3 protein are more susceptible to global cerebral ischemia than wild-type mice. Our findings suggest NCX3 has a positive role in maintaining neuronal intracellular calcium homeostasis following ischemia, and that when exchanger function is compromised neurons are more susceptible to calcium deregulation and cell death.
Department of Neurosurgery/Sir Charles Gairdner Hospital, Centre for Neuromuscular and Neurological Disorders/University of Western Australia, Australia.
Graham J
GJ
Jeffs
Bruno P
BP
Meloni
Sophie
S
Sokolow
Andre
A
Herchuelz
Stéphane
S
Schurmans
Neville W
NW
Knuckey
D000818:Animals; D002545:Brain Ischemia / Q000235:genetics* / Q000473:pathology*; D002452:Cell Count; D004195:Disease Models, Animal; D006624:Hippocampus / Q000473:pathology*; D026901:Membrane Transport Proteins / Q000172:deficiency*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009474:Neurons / Q000473:pathology*; D019831:Sodium-Calcium Exchanger; D013997:Time Factors
D026901:Membrane Transport Proteins; C491101:Slc8a3 protein, mouse; D019831:Sodium-Calcium Exchanger