Simulated ischemia induces renal tubular cell apoptosis through a nuclear factor-kappaB dependent mechanism.
OBJECTIVE
Ischemia-reperfusion injury is a relatively common cause of renal tubular cell death and acute renal failure. While nuclear factor-kappaB has been implicated in the pathophysiology of renal ischemia-reperfusion injury, the effect of nuclear factor-kappaB inhibition on ischemia induced renal tubular cell death remains unknown.


METHODS
Renal tubular cells (LLC-PK1) were exposed to simulated ischemia in the presence or absence of 10 microM. pyrrolidine dithiocarbamate (nuclear factor-kappaB inhibitor). Nuclear factor-kappaB activation (electrophoretic mobility shift assay and immunohistochemistry) and the effect of pyrrolidine dithiocarbamate on nuclear factor-kappaB activation (electrophoretic mobility shift assay) and ischemia induced apoptosis (terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling) were determined.


RESULTS
Simulated ischemia induced nuclear factor-kappaB activation and renal tubular cell apoptosis versus controls (mean plus or minus standard error of mean 62 +/- 5.2 versus 0.4 +/- 0.3 apoptotic nuclei per high power field, p <0.05). In contrast, previous cellular exposure to pyrrolidine dithiocarbamate effectively inhibited nuclear factor-kappaB activation and prevented ischemia induced apoptosis (mean 14 +/- 6 apoptotic nuclei per high power field).


CONCLUSIONS
Simulated ischemia induces nuclear factor-kappaB intranuclear translocation and activation in renal tubular cells. Furthermore, nuclear factor-kappaB mediates ischemia induced renal tubular cell apoptosis. Further elucidation of the complex role of nuclear factor-kappaB in inflammatory injury may lead to the development of targeted therapeutic strategies that ameliorate ischemic renal injury.
Meldrum
K K
KK
Department of Urology, Johns Hopkins University, Baltimore, Maryland, USA.
Hile
K
K
Meldrum
D R
DR
Crone
J A
JA
Gearhart
J P
JP
Burnett
A L
AL
D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D007683:Kidney Tubular Necrosis, Acute / Q000503:physiopathology*; D007684:Kidney Tubules / Q000098:blood supply*; D018374:LLC-PK1 Cells; D016328:NF-kappa B / Q000502:physiology*; D015427:Reperfusion Injury / Q000503:physiopathology*; D013552:Swine
D016328:NF-kappa B