Toll-like receptor 2 plays a critical role in cardiac dysfunction during polymicrobial sepsis.
OBJECTIVE
To determine the role of toll-like receptor 2 in cardiac dysfunction during polymicrobial sepsis.


METHODS
Controlled animal study.


METHODS
University hospital research laboratory.


METHODS
Male C57BL/6, wild-type, toll-like receptor 2-/-.


METHODS
Polymicrobial peritonitis, a clinically relevant model of sepsis, was generated by cecum ligation and puncture. Wild-type and toll-like receptor 2-/- mice were divided into sham and cecum ligation and puncture groups. The sham animals underwent laparotomy but without cecum ligation and puncture. Twenty-four hours after surgeries, the cardiac function was assessed by serial echocardiography in vivo, a pressure transducer catheter was inserted into the left ventricles of isolated hearts (Langendorff model), and in vitro measurement of Ca2+ transients and sarcomere shortening in adult cardiomyocytes were isolated from the sham and septic animals. In addition, myocardial and serum cytokines, blood white blood cell counts, peritoneal neutrophil recruitment, chemokine receptor expression, and survival rates were examined.


RESULTS
Compared to septic wild-type mice, toll-like receptor 2-/- mice had markedly improved cardiac function during sepsis, as demonstrated by in vivo tissue Doppler imaging, better-preserved left ventricle function in isolated heart, and improved sarcomere shortening measured in single cardiomyocytes. There was also a significant survival benefit in toll-like receptor 2-/- mice compared to wild-type mice. These favorable outcomes in toll-like receptor 2-/- mice were associated with attenuated cardiodepressant cytokine levels in the myocardium and serum and enhanced neutrophil migratory function.


CONCLUSIONS
These studies suggest that toll-like receptor 2 signaling plays a critical role in mediating cardiomyopathy, deleterious myocardial and systemic inflammation, and high mortality during polymicrobial sepsis.
Department of Anesthesia and Critical Care, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA.
Lin
L
Zou
Yan
Y
Feng
Yu-Jung
YJ
Chen
Rui
R
Si
Shiqian
S
Shen
Qichang
Q
Zhou
Fumito
F
Ichinose
Marielle
M
Scherrer-Crosbie
Wei
W
Chao
D000818:Animals; D002465:Cell Movement; D016207:Cytokines / Q000096:biosynthesis; D006331:Heart Diseases / Q000209:etiology / Q000378:metabolism / Q000503:physiopathology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009206:Myocardium / Q000378:metabolism*; D032383:Myocytes, Cardiac / Q000502:physiology; D009504:Neutrophils / Q000502:physiology; D010538:Peritonitis / Q000150:complications* / Q000276:immunology / Q000382:microbiology; D018805:Sepsis / Q000150:complications* / Q000276:immunology / Q000382:microbiology; D051195:Toll-Like Receptor 2 / Q000235:genetics / Q000502:physiology*
D016207:Cytokines; D051195:Toll-Like Receptor 2