TY - JOUR
T1 - Acquired resistance of a mammalian cell line to hypoxia-reoxygenation through cotransfection of Kir6.2 and SUR1 clones
AU - Jovanovic, Aleksandar
AU - Jovanovic, Sofija
AU - Carrasco, Antonio J.
AU - Terzic, Andre
PY - 1998/9
Y1 - 1998/9
N2 - Reoxygenation after transient hypoxia is a common clinical condition that often causes greater tissue damage than persistent hypoxia itself. This warrants the development of a means to protect cells against hypoxia- reoxygenation injury. Adenosine triphosphate (ATP)-sensitive K+ (K(ATP)) channels have been proposed to play an essential role in the mechanisms of endogenous cellular protection. Thus far, however, K(ATP) channel proteins have not been exploited to generate an injury-resistant cellular phenotype by delivering K(ATP) channel genes into injury-prone cells. A first step in this direction is the evaluation of the outcome of transferring genes encoding K(ATP), channels into a K(ATP) channel-deficient cell type exposed to metabolic stress. Untransfected COS-7 monkey kidney cells, which natively lack K(ATP) channels, were found to be vulnerable to hypoxia-reoxygenation injury, which induced cytosolic Ca2+ loading, as measured by digital epifluorescent imaging. COS-7 cells cotransfected with K(ATP) channel genes, Kir6.2 and SUR1, gained resistance to hypoxia-reoxygenation. This acquired resistance was abolished by glyburide; the K(ATP) channel antagonist. We have previously shown that Kir6.2 and SUR1 physically associate to form a functional K(ATP) channel, not reconstituted by either of the subunits alone. Transfection with individual channel subunits Kir6.2 or SUR1, failed to produce resistance to hypoxia-reoxygenation induced Ca2+ loading. This is a first demonstration that transfer of K(ATP) channel subunits can generate an injury-resistant cellular phenotype. The findings from this study may, thus, provide a framework for future therapeutic strategies based on gene delivery of K(ATP) channel subunits in cells and tissues vulnerable to hypoxia- reoxygenation insults.
AB - Reoxygenation after transient hypoxia is a common clinical condition that often causes greater tissue damage than persistent hypoxia itself. This warrants the development of a means to protect cells against hypoxia- reoxygenation injury. Adenosine triphosphate (ATP)-sensitive K+ (K(ATP)) channels have been proposed to play an essential role in the mechanisms of endogenous cellular protection. Thus far, however, K(ATP) channel proteins have not been exploited to generate an injury-resistant cellular phenotype by delivering K(ATP) channel genes into injury-prone cells. A first step in this direction is the evaluation of the outcome of transferring genes encoding K(ATP), channels into a K(ATP) channel-deficient cell type exposed to metabolic stress. Untransfected COS-7 monkey kidney cells, which natively lack K(ATP) channels, were found to be vulnerable to hypoxia-reoxygenation injury, which induced cytosolic Ca2+ loading, as measured by digital epifluorescent imaging. COS-7 cells cotransfected with K(ATP) channel genes, Kir6.2 and SUR1, gained resistance to hypoxia-reoxygenation. This acquired resistance was abolished by glyburide; the K(ATP) channel antagonist. We have previously shown that Kir6.2 and SUR1 physically associate to form a functional K(ATP) channel, not reconstituted by either of the subunits alone. Transfection with individual channel subunits Kir6.2 or SUR1, failed to produce resistance to hypoxia-reoxygenation induced Ca2+ loading. This is a first demonstration that transfer of K(ATP) channel subunits can generate an injury-resistant cellular phenotype. The findings from this study may, thus, provide a framework for future therapeutic strategies based on gene delivery of K(ATP) channel subunits in cells and tissues vulnerable to hypoxia- reoxygenation insults.
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M3 - Article
C2 - 9759654
AN - SCOPUS:0031704523
SN - 0023-6837
VL - 78
SP - 1101
EP - 1107
JO - Laboratory Investigation
JF - Laboratory Investigation
IS - 9
ER -