To investigate the effects of telmisartan tablets (Tel) on viral myocardialtis (VM) mice through microRNA-320 (miR-320) and its mechanism.

A total of 60 BALB/c mice were divided into control group, model group, experimental group, Tel+rAAV-NC group and Tel+rAAV-miR-320 group, with 12 mice in each group. Except for control group, VM mouse models were established by intraperitoneal injection of coxsackievirus B3 0.1 mL containing 100 TCID50. Experimental group was given 10 mg·kg^-1 Tel intragastrically for 7 days. Based on experimental group, rAAV-NC was injected into the tail vein (1×10¹¹ viral copy number, dissolved in PBS 100 μL) in Tel+rAAV-NC group; based on experimental group, rAAV-miR-320 was injected into the tail vein (1×10¹¹ viral copy number, dissolved in PBS 100 μL) in Tel+rAAV-miR-320 group. The relative expression levels of miR-320 were detected by quantitative real time polymerase chain reaction. Creatine kinase isoenzyme, myoglobin and troponin were detected by enzyme-linked immunosorbent assay. TdT-mediated dUTP nick end labeling was used to detect apoptosis. The relative expression levels of peroxiredoxin-like protein NOX1 (PKNOX1)/B-cell lymphoma 10 (BCL10)/mucosa associated lymphoid tissue lymphoma translocation gene 1 (MALT1) signaling pathway were detected by Western blot.

The relative expression levels of miR-320 in control group, model group, experimental group, Tel+rAAV-NC group and Tel+rAAV-miR-320 group were 1.00±0.18, 4.06±0.73, 1.82±0.34, 1.95±0.36 and 3.47±0.61, respectively; creatine kinase isoenzyme were (36.09±4.82), (125.18±19.67), (49.73±8.04), (55.62±8.25) and (103.56±17.49) U·mL^-1, respectively; myoglobin were (72.35±11.46), (368.29±61.83), (93.62±15.27), (90.74±16.18) and (316.51±57.92) μg·L^-1, respectively; troponin were (17.42±2.53), (64.74±10.90), (28.59±4.16), (32.45±5.98) and (53.91±9.64) μg·L^-1, respectively; the apoptosis rates were (3.17±0.52)%, (28.46±5.39)%, (6.97±1.24)%, (8.01±1.53)% and (24.89±4.16)%, respectively; the relative expression levels of PKNOX1 protein were 1.00±0.15, 2.07±0.36, 1.43±0.19, 1.39±0.20 and 1.91±0.32, respectively; the relative expression levels of BCL10 protein were 1.00±0.18, 1.95±0.34, 1.48±0.22, 1.41±0.21 and 1.84±0.35, respectively; the relative expression levels of MALT1 protein were 1.00±0.13, 1.90±0.32, 1.26±0.15, 1.37±0.18 and 1.69±0.27, respectively. Statistical comparisons revealed significant differences between model group and control group, as well as between experimental group and model group, and between Tel+rAAV-miR-320 group and Tel+rAAV-NC group (all P<0.05).

By inhibiting the expression of miR-320, Tel alleviates myocardial injury and inhibits apoptosis in VM mice, which may be achieved by inhibiting PKNOX1/BCL10/MALT1 signaling pathway.