Effect of propranolol on myocardial cell apoptosis in rats with autoimmune myocardioptis by regulating the SDF-1/CXCR4 signaling axis

AIM To investigate the effect of propranolol (Pro) on myocardial cell apoptosis in rats with autoimmune myocardioptis (AM) by regulating the stromal cell-derived factor 1 (SDF-1)/chemokine receptor 4 (CXCR4) signal axis.

METHODS Sixty rats were randomly selected and assigned to a blank group (n=12, CON group) and AM rat model was constructed in the rest of the rats. The rats with successfully constructed AM model were randomly grouped into AM group, Pro group, SDF-1/CXCR4 signal axis inhibitor (WZ811) group, and Pro+WZ811 group, with 12 rats in each group and received treatment once a day for 2 continuous weeks. ELISA method was applied to detect levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), H&E staining was applied to observe pathological changes in myocardial tissue, TUNEL method was applied to detect apoptosis in myocardial tissue and Western blot was applied to detect the expressions of BCL-2 associated X protein (Bax), B-cell lymphoma/leukemia 2 protein (Bcl-2), cleaved Caspase‐3, and SDF-1/CXCR4 pathway proteins.

RESULTS Compared with those of the CON group, the myocardial tissue structure of the AM group showed abnormal, with extensive necrosis, edema and inflammatory cell infiltration, and the pathological score of myocardial tissue, contents of IL-6 and TNF-α, myocardial cell apoptosis rate and the expressions of Bax and cleaved Caspase-3 were increased (P<0.05) and the protein levels of Bcl-2, SDF-1 and CXCR4 were obviously down-regulated (P<0.05). Compared with those in the AM group, the necrosis and edema of myocardial tissue cells in Pro group improved, and inflammatory cell infiltration decreased, the pathological score of myocardial tissue, contents of IL-6 and TNF-α, myocardial cell apoptosis rate, and the protein levels of Bax and cleaved Caspase-3 were obviously reduced (P<0.05), and the protein levels of Bcl-2, SDF-1 and CXCR4 were obviously increased (P<0.05). All the above indicators in the WZ811 group showed an opposite trend and WZ811 reversed the improvement effect of propranolol on myocardial cell apoptosis in AM rats.

CONCLUSION Propranolol alleviates myocardial cell apoptosis in AM rats by activating the SDF-1/CXCR4 signaling pathway.