A concerted role of Na+ -K+ -Cl- cotransporter and Na+/Ca2+ exchanger in ischemic damage.
Na+-K+-Cl(-) cotransporter isoform 1 (NKCC1) and Na+/Ca2+ exchanger isoform 1 (NCX1) were expressed in cortical neurons. Three hours of oxygen and glucose deprivation (OGD) significantly increased expression of full-length NCX1 protein ( approximately 116 kDa), which remained elevated during 1 to 21 h reoxygenation (REOX) and was accompanied with concurrent cleavage of NCX1. Na+/Ca2+ exchanger isoform 1 heterozygous (NCX1+/-) neurons with approximately 50% less of NCX1 protein exhibited approximately 64% reduction in NCX-mediated Ca2+ influx. Expression of NCX1 and NKCC1 proteins was reduced in double heterozygous (NCX1+/-/NKCC1+/-) neurons. NCX-mediated Ca2+ influx was nearly abolished in these neurons. Three-hour OGD and 21-h REOX caused approximately 80% mortality rate in NCX1+/+ neurons and in NCX1+/- neurons. In contrast, NKCC1+/- neurons exhibited approximately 45% less cell death. The lowest mortality rate was found in NCX1+/-/NKCC1+/- neurons ( approximately 65% less neuronal death). The increased tolerance to ischemic damage was also observed in NCX1+/-/NKCC1+/- brains after transient cerebral ischemia. NCX1+/-/NKCC1+/- mice had a significantly reduced infarct volume at 24 and 72 h reperfusion. In conclusion, these data suggest that NKCC1 in conjunction with NCX1 plays a role in reperfusion-induced brain injury after ischemia.
Luo
Jing
J
Department of Neurological Surgery, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53792, USA.
Wang
Yanping
Y
Chen
Hai
H
Kintner
Douglas B
DB
Cramer
Sam W
SW
Gerdts
Josiah K
JK
Chen
Xinzhi
X
Shull
Gary E
GE
Philipson
Kenneth D
KD
Sun
Dandan
D
D000818:Animals; D015153:Blotting, Western; D002545:Brain Ischemia / Q000378:metabolism / Q000503:physiopathology*; D016923:Cell Death / Q000502:physiology; D002478:Cells, Cultured; D017403:In Situ Hybridization; D051379:Mice; D008822:Mice, Transgenic; D009474:Neurons / Q000378:metabolism*; D015424:Reperfusion; D015427:Reperfusion Injury / Q000378:metabolism / Q000503:physiopathology*; D019831:Sodium-Calcium Exchanger / Q000235:genetics / Q000378:metabolism*; D028021:Sodium-Potassium-Chloride Symporters / Q000235:genetics / Q000378:metabolism*; D064506:Solute Carrier Family 12, Member 2
C499849:NCX1 protein, mouse; C578878:Slc12a2 protein, mouse; D019831:Sodium-Calcium Exchanger; D028021:Sodium-Potassium-Chloride Symporters; D064506:Solute Carrier Family 12, Member 2