GSK-3beta inhibitor modulates TLR2/NF-kappaB signaling following myocardial ischemia-reperfusion.
OBJECTIVE
The present study defines the expression of Toll-like Receptor 2 (TLR2), and the modulatory role of Glycogen synthase kinase (GSK)-3beta inhibitor on TLR2/Nuclear Factor-kappa B (NF-kappaB) signaling following myocardial ischemia-reperfusion (MI-R) injury in rats.


METHODS
Real-time reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemistry (IHC) were used to analyze the presence and quantity of TLR2 mRNA and protein. Tumor necrosis factor (TNF)-alpha mRNA and interleukin-6 (IL-6) mRNA were analyzed by RT-PCR. The activation of NF-kappaB was detected by Western Blot and the myocardial infarct size by Evans blue-TTC staining.


RESULTS
Following 30 min of myocardial ischemia, a significant up-regulation of TLR2 mRNA was revealed by RT-PCR from 1 to 24 h post reperfusion. IHC demonstrated high protein expression levels of TLR2. Administration of the GSK-3beta inhibitor 4-benzyl-2-methyl-1, 2, 4-thiadiazolidine-3, 5-dione (TDZD-8) 5 min prior to reperfusion following 1 h reperfusion down-regulated mRNA levels of TLR2 and downstream proinflammatory cytokines (P < 0.05 vs. MI-R), decreased the activity of NF-kappaB and the size of the myocardial infarct (P < 0.05 vs. MI-R).


CONCLUSIONS
Our results demonstrate that TLR2 and its signaling components are activated by MI-R. TDZD-8 administration attenuates TLR2/NF-kappaB signaling, suggesting a possible mechanism whereby GSK-3beta inhibition improves the outcome of MI-R.
Gao
Hao-Kao
HK
Department of Cardiology, Xi Jing Hospital, Fourth Military Medical University, Xi'an, China.
Yin
Zhong
Z
Zhang
Rong-Qing
RQ
Zhang
Jun
J
Gao
Feng
F
Wang
Hai-Chang
HC
D000818:Animals; D038362:Glycogen Synthase Kinase 3 / Q000037:antagonists & inhibitors*; D000071679:Glycogen Synthase Kinase 3 beta; D015850:Interleukin-6 / Q000235:genetics; D008297:Male; D015428:Myocardial Reperfusion Injury / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D016328:NF-kappa B / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013830:Thiadiazoles / Q000494:pharmacology* / Q000627:therapeutic use; D051195:Toll-Like Receptor 2 / Q000235:genetics / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics
C494356:4-benzyl-2-methyl-1,2,4-thiadiazolidine-3,5-dione; D015850:Interleukin-6; D016328:NF-kappa B; D012333:RNA, Messenger; D013830:Thiadiazoles; C495343:Tlr2 protein, rat; D051195:Toll-Like Receptor 2; D014409:Tumor Necrosis Factor-alpha; D000071679:Glycogen Synthase Kinase 3 beta; C000605508:Gsk3b protein, rat; D038362:Glycogen Synthase Kinase 3