Coronary microembolization (CME) is a common complication in percutaneous coronary intervention (PCI). Local myocardial inflammation caused by CME is the major cause of progressive cardiac dysfunction. High mobility group A1 (HMGA1)/nuclear factor-kappa B (NF-κB) signaling plays an important role in the development and progression of inflammation, but its role in CME remains unclear. This study evaluated the effect of HMGA1/NF-κB signaling on CME-induced myocardial inflammation and cardiac dysfunction.

Forty Sprague-Dawley rats were randomly divided into four groups: sham, CME, CME + HMGA1 small interfering RNA (HMGA1 siRNA), and CME + scrambled siRNA (control siRNA) groups, with 10 animals each. The CME model group was established by clamping the ascending aorta and injecting microspheres through the left ventricular apex for embolization, and the sham group was established by injecting the same amount of normal saline. The HMGA1 siRNA group was injected with HMGA1 siRNA transfection complexes into the tail vein 72 h before CME modeling, and the control siRNA group was caudally injected with the same amount of scrambled siRNA 72 h before CME modeling. Twelve hours after the operation, cardiac function, serum c-troponin I level, and microinfarct size were examined. The levels of HMGA1, NF-κB p65, TNF-α, and IL-1β were detected.

Myocardial dysfunction, enhanced serum c-troponin I, and microinfarct were induced following CME. Moreover, CME induced an increased expression of HMGA1, NF-κB p65, TNF-α, and IL-1β. The HMGA1 siRNA reversed these effects by CME, while the scrambled siRNA had no effect.

HMGA1/NF-κB signaling is involved in CME-induced myocardial inflammation. Inhibition of HMGA1/NF-κB signaling attenuated the CME-induced myocardial injury and improved cardiac function, suggesting a new potential target for the prevention and treatment of CME-induced myocardial injury.