Hypoxia-inducible factor-1α attenuates myocardial inflammatory injury in rats induced by coronary microembolization

Abstract

To investigated the role of HIF-1α in myocardial inflammatory injury in rats induced by CME and its possible mechanism. Forty SD rats were separated randomly and equally into four groups, i.e. CME+HIF-1α stabilizer dimethyloxalyl glycine (CME+DMOG) group, CME+HIF-1α inhibitor YC-1 (CME+YC-1) group, CME group, and Sham group. HBFP staining, myocardial enzyme assessment, and cardiac ultrasound were used to measure microinfarct, serum c-troponin I (cTnI) level, and Cardiac function. ELISA and western blot were applied for detecting NLRP3 inflammasome pathway and TLR4/MyD88/NF-κB signaling level.Pro-inflammatory factors of IL-18, IL-1β and TNF-α increased their expression levels after CME, which indicated inflammatory responses in the myocardium. Additionally, in the inflammatory process, NLRP3 inflammasome and TLR4/MyD88/NF-κB signaling were involved. DMOG reverses these effects of CME, whereas YC-1 aggravates these effects. HIF-1α may attenuate myocardial inflammatory injury induced by CME and improve cardiac function, which can perhaps be explained by the fact that TLR4/MyD88/NF-κB signaling pathway activation is inhibited.

Key words
HIF-1α; coronary microembolization; NLRP3 inflammasome; TLR4/MyD88/NF-κB