Preconditioning by toll-like receptor 2 agonist Pam3CSK4 reduces CXCL1-dependent leukocyte recruitment in murine myocardial ischemia/reperfusion injury.
OBJECTIVE
To test whether preconditioning with a toll-like receptor (TLR) 2 agonist protects against myocardial ischemia and reperfusion by interfering with chemokine CXCL1 release from cardiomyocytes.


METHODS
C3H mice were challenged with vehicle or synthetic TLR2 agonist Pam3Cys-Ser-Lys4 (Pam3CSK4; 1 mg/kg) 24 hrs before myocardial ischemia (20 mins) and reperfusion (2 hrs or 24 hrs). Infarct size, troponin T release, and leukocyte recruitment were quantified. In murine cardiomyocytes (HL-1), we studied the expression/activation profile of TLR2 in response to stimulation with Pam3CSK4 (0.01-1 mg/mL). Furthermore, we studied the chemokine ligand 1 (CXCL1) response to Pam3CSK4 and ischemia/reperfusion in vivo and in vitro.


METHODS
University hospital research laboratory.


METHODS
Anesthetized male mice and murine cardiomyocytes.


RESULTS
Preconditioning by Pam3CSK4 reduced infarct size and troponin T release. This was accompanied by a decreased recruitment of leukocytes into the ischemic area and an improved cardiac function. In HL-1 cells, TLR2 activation amplified the expression of the receptor in a time-dependent manner and led to CXCL1 release in a concentration-dependent manner. Preconditioning by Pam3CSK4 impaired CXCL1 release in response to a second inflammatory stimulus in vivo and in vitro.


CONCLUSIONS
Preconditioning by TLR2 agonist Pam3CSK4 reduces myocardial infarct size after myocardial ischemia/reperfusion. One of the mechanisms involved is a diminished chemokine release from cardiomyocytes, which subsequently limits leukocyte infiltration.
Mersmann
Jan
J
Clinic of Anesthesiology, Intensive Care Medicine, and Pain Management, JW Goethe University, Frankfurt, Germany.
Berkels
Reinhard
R
Zacharowski
Paula
P
Tran
Nguyen
N
Koch
Alexander
A
Iekushi
Kazuma
K
Dimmeler
Stefanie
S
Granja
Tiago F
TF
Boehm
Olaf
O
Claycomb
William C
WC
Zacharowski
Kai
K
D000818:Animals; D002460:Cell Line; D054360:Chemokine CXCL1 / Q000037:antagonists & inhibitors / Q000502:physiology*; D018925:Chemokines / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D019157:Ischemic Preconditioning, Myocardial; D007962:Leukocytes / Q000276:immunology*; D055666:Lipopeptides / Q000494:pharmacology*; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D009203:Myocardial Infarction / Q000276:immunology; D015428:Myocardial Reperfusion Injury / Q000235:genetics* / Q000276:immunology*; D032383:Myocytes, Cardiac / Q000187:drug effects* / Q000276:immunology*; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics; D051195:Toll-Like Receptor 2 / Q000819:agonists* / Q000235:genetics*; D020107:Troponin T / Q000378:metabolism
D054360:Chemokine CXCL1; D018925:Chemokines; C475895:Cxcl1 protein, mouse; D055666:Lipopeptides; C508075:Pam(3)CSK(4) peptide; D012333:RNA, Messenger; C493486:Tlr2 protein, mouse; D051195:Toll-Like Receptor 2; D020107:Troponin T