I _.
sake university, Toii-like receptors (TLRs) are members of t’ne interleukin-1 receptor (IL-1 R) family and have an IL-lR-like intracellular signaling in response to pathogens such as lipop~lysaccha~de and oligonucleotides. Recently several studies demonstrated that TLRs were also activated by endogenous signals such as oxidative stress and heat shock proteins. Oxidalive stress and heat shock proteins play pivotal roles in lefi ventricular (LV) remodeling after myocardial infarction (Ml). In this study, we examined whether TLR-2 was involved in cardiac remodeling after MI, MI was created by surgical left coronary artery ligation on TLR-2 knockout (KO) mice with a C57BLi6 background and normal C57BLi6 mice (WT). One and four weeks after the surgery, left ventricular function and histological parameters of cardiac remodeling were measured. .4t 4 weeks after operation, LV djmensions at end- diastole and end-systole and fractional showering were preserved in TLR-2 KO mice compared with WT mice. Fibrotic changes of noninfarct area in TLR-2 KO mice were smaller compared with WT mice. Furthermore, mortality of TLR-2 KO mice with MI was significantly less compared with WT mice. These data suggest that TLR-2 is linked to progression of ventricular remodeling after MI.
TRANSFER REDUCES ~YOCAR~IAL INFARCT SIZE IN RABBITS Xue-Hai Chen, Shinya Minatoguchi, Kenichiro Kosai”, Kentaro Yuge*, Minoru Nagano”, Tomoyuki Takahashi*, Masazumi Arai, Ningyuan Wang, Yu Misao, Chuanjiang Lu, Yoji Nagai, Genzou Takemura, Takako Fujiwara**, Hisayoshi Fujiwara, 2nd Department of Internal Medicine, *Department of Cardiovascular Regeneration , Gifu University School of Medicine, Gifu, Japan **Kyoto Women’s University, Kyoto, Japan
We aimed to clarify whether HGF-gene transfer reduces the myocardial infarct size and decreases the production of hydroxyl radicals during ischemia and reperfision. in male Japanese white rabbits, 1x10” particles of adenovirus AdHGF (HGF group) or adenovirus Ad-LacZ (control group) was injected into the myocardium. Three days after viral
infection, the anterolateral
coronary artery was occluded
for 30 min and reperfused.
The heart
was excised
4X hours
after reperfusion and the area at risk was determined by Evans blue dye and the infarct area was determined by TT’C staining.
The infarct
size as a percentage
of area at risk
was
obtained. In another rabbits, myocardial interstitiai 2,5DHBA levels, an indicator of hydroxyl radicals, were measured using a microdialysis technique before during and after ischemia. The infarct size was significantly reduced group
in the KGF group
(13.4i2.3
o/o) than
in the control
(36.5m2.0 %). The 2,SDHBA levels were increased during ischemia and reperfusion in the control group. However, this increase was inhibited in the HGF group. In conclusion, in viva adenovirus-mediated HGF gene transfer decreases hydroxyl radicals generation and reduces myocardiai infarct size in rabbits. O-16
O-15
1 GENE ~~a~oto shoji, Wiroshi Suzuki, Takatoshi Sate, Yos~~~~a Iso, ~asayuki Shibata, Masai Naka~n~, Shinji Koba, Eiichi Geshi, Takashi Katagiri Third repayment of ~ntemal Medicine Showa ~aive~s~ty, School of Medicine, Tokyo, Japan [Purpose; TNF-alpha is involved in the pa~ogenesis of myocar~al infarction, ~~obabIy through the occurrence of apoptosis. Recent studies have shown the effects of a~optosis-related factors, such as bcl-2 and bax, in myocardial infarction, but the precise role is not elucidated. To clarify the relationship bet~~een TNF-alpha and apoptosis, we investigated the expression of apoptosis after myo~ardial jnfarct~on in TNF-Alcoa deficient mice (KO) compared with that of wild type (FVT). [method] WT (CS7BLO) and KO mice were killed at 1, 3 and 7 days after ~igstion of left anterior descending coronary artery. ~h~rdio~raphy was performed to assess the left ventricular function. Apoptosis was detected by TUNEL staining. The expressions of bcl-2 and bax were examined using immunohistochem~stry. [~es~~t~ In the ultrasound study, left ventricular e~d~~astolic d~rne~s~o~ was si~ni~can~y smaller, and fractional shortening was si~~i~~a~tly higher in KO at 3 and 7 days. In light microscopic exam~natioa, many i~~ammator~ cells were observed at 1 day, and wall t~~n~in~ was apparent at 7 days, but there were no signi~~a~t differences in infarcted size between both groups. The number of TUNEL positive cells was tended to be smalfer in KO at 3 days, but the positive cells were rarely seen at 7 days in both groups. The expression of bcl-2 and bax was iocated in infarcted and peg-i~are~ted areas at 1 and 3 days, and were dominant in WT. [Conclusion1 We suggest that TNF-alpha is involved in the patl~oge~esis of myocardial infarction, possibly through apoptotic pathway.
A~L~V~A~ES
INF
After iscbe~a and repe~~ion, a significant amount of TNF- alpha is detected and ~~-TNF-alpha antibody improved myocardial recovery in vitro study. Soluble TNF- alpha receptor 1 (sTNFR1) is au ex~ceU~~ dom~n of TNFRl , and an ~~go~st to TNF-alpha. In the present study, we have examined whether sTNFR1 can reduce infarct size following ischemia and reperfusion. Male Wistar rats (2~~-3~g) were subjected to left coronary artery (LCA) ligation. After 30 tin of LCA ~cIns~o~, the tempor~y ligature on the LCA was released and blood flow was restored. Immediately after reclusion, a total of ZOCQ of sTNFR1 or LacZ plasmid was injected into 3 ~ffer~nt sites of the left ventricular waI1 (n=6, in each group). The TNF-alpha bioactivity in the myo~ardi~ si~fi~~y increased in rats receiving LacZ plasmid compared to that in she-operated rats, whereas treatment with the sTNFRl plasmid significantly reduced the bioactivity (LacZ plasmid; 701~72%, sTNFR1 plas~d; 273+25% vs sham-operated rats). The sTNFRl plasmid significantly reduced DNA fragmentation and caspase activity compared to the LacZ plasmid. Finally, tbe sTNFR1 expression-plasmid trea~ent s~g~~c~tl~ reduced the area of myocardiial infarction at 2 days after isch~~a-reclusion compared to LacZ plasmid. These findings showed for the first time that sT?IFRl could limit infarct size following ischemia-reperfusion injury possibly by decreasing the TNF-alph2 bioactivity in the rnyoc~~~.