P2Y2 purinergic receptors are highly expressed in cardiac and diaphragm muscles of mdx mice, and their expression is decreased by suramin.

INTRODUCTION

In Duchenne muscular dystrophy (DMD) and in the mdx mouse model of DMD, the lack of dystrophin leads to increased calcium influx and muscle necrosis. Patients suffer progressive muscle loss, and cardiomyopathy is an important determinant of morbidity. P2 purinergic receptors participate in the increased calcium levels in dystrophic skeletal muscles.

METHODS

In this study, we evaluated whether P2 receptors are involved in cardiomyopathy in mdx mice at later stages of the disease.

RESULTS

Western blotting revealed that P2Y2 receptor levels were upregulated (54%) in dystrophic heart compared with a normal heart. Suramin reduced the levels of P2Y2 to almost normal values. Suramin also decreased heart necrosis (reduced CK-MB) and the expression of the stretch-activated calcium channel TRPC1.

CONCLUSIONS

This study suggests that P2Y2 may participate in cardiomyopathy in mdx mice. P2-selective drugs with specific actions in the dystrophic heart may ameliorate cardiomyopathy in dystrophinopathies. Muscle Nerve 55: 116-121, 2017.