Prevention of renal ischemic injury by silencing the expression of renal caspase 3 and caspase 8.
BACKGROUND
Apoptotic pathways mediated by caspases play a critical role in renal ischemia-reperfusion injury (IRI). Downregulation of the caspase cascade, using small interfering RNA (siRNA) to silence the expression of caspase 3 and caspase 8, may have substantial therapeutic potential for limiting renal injury.


METHODS
IRI was induced in mice by clamping of the renal vein and artery for 25 or 35 min at 37 degrees C. Caspase 3 and caspase 8 (caspase 3/8) siRNA was administrated by hydrodynamic injection. Quantitative polymerase chain reaction (PCR) and immunohistochemistry were used to analyze the gene silencing efficacy, and the therapeutic effects of siRNA were evaluated by renal function analysis, histological examination, and overall survival of mice suffering from IRI.


RESULTS
In this study, we have shown, using quantitative PCR, that IRI is associated with increased levels of renal caspase 3/8 mRNA. Mice treated with caspase 3/8 siRNA showed a significant down-regulation in kidney expression of caspase 3/8 at both, transcriptional and protein levels. Kidney function in IRI was protected by siRNA therapy, as levels of blood urea nitrogen and creatinine were significantly reduced in mice treated with siRNA. Histological examination demonstrated that tissue injury caused by IRI was significantly reduced as a result of caspase 3/8 siRNA treatment. Furthermore, survival data showed that more than 70% of mice in siRNA-treated groups survived until the end of the eight-day observation period.


CONCLUSIONS
Herein, we have demonstrated the therapeutic potential of using siRNA to knock down the expression of caspases and prevent acute renal injury.
Zhang
Xusheng
X
Department of Surgery, University of Western Ontario, London, Ontario, Canada.
Zheng
Xiufen
X
Sun
Hongtao
H
Feng
Biao
B
Chen
Gang
G
Vladau
Costin
C
Li
Mu
M
Chen
Dong
D
Suzuki
Motohiko
M
Min
Lisa
L
Liu
Weihua
W
Garcia
Bertha
B
Zhong
Robert
R
Min
Wei-Ping
WP
D000818:Animals; D053148:Caspase 3 / Q000235:genetics; D053181:Caspase 8 / Q000235:genetics; D061945:Caspase Inhibitors; D007668:Kidney / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology; D051379:Mice; D008815:Mice, Inbred Strains; D012333:RNA, Messenger / Q000032:analysis; D034741:RNA, Small Interfering / Q000235:genetics / Q000494:pharmacology*; D015427:Reperfusion Injury / Q000473:pathology / Q000517:prevention & control*; D015854:Up-Regulation / Q000187:drug effects
D061945:Caspase Inhibitors; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D053148:Caspase 3; D053181:Caspase 8