Novel inhibitor candidates of TRPV2 prevent damage of dystrophic myocytes and ameliorate against dilated cardiomyopathy in a hamster model

Abstract

Transient receptor potential cation channel, subfamily V, member 2 (TRPV2) is a principal candidate for abnormal Ca 2+ -entry pathways, which is a potential target for therapy of muscular dystrophy and cardiomyopathy. Here, an in silico drug screening and the following cell-based screening to measure the TRPV2 activation were carried out in HEK293 cells expressing TRPV2 using lead compounds (tranilast or SKF96365) and off-patent drug stocks. We identified 4 chemical compounds containing aminobenzoyl groups and 1 compound (lumin) containing an ethylquinolinium group as candidate TRPV2 inhibitors. Three of these compounds inhibited Ca 2+ entry through both mouse and human TRPV2, with IC 50 of less than 10 μM, but had no apparent effect on other members of TRP family such as TRPV1 and TRPC1. Particularly, lumin inhibited agonist-induced TRPV2 channel activity at a low dose. These compounds inhibited abnormally increased Ca 2+ influx and prevented stretch-induced skeletal muscle damage in cultured myocytes from dystrophic hamsters (J2N-k). Further, they ameliorated cardiac dysfunction, and prevented disease progression in vivo in the same J2N-k hamsters developing dilated cardiomyopathy as well as muscular dystrophy. The identified compounds described here are available as experimental tools and represent potential treatments for patients with cardiomyopathy and muscular dystrophy. www.impactjournals.com/oncotarget/

The Transient Receptor Potential Vanilloid Type-2 (TRPV2) Ion Channels in Neurogenesis and Gliomagenesis: Cross-Talk between Transcription Factors and Signaling Molecules

“…In addition, four new chemical compounds were recently identified as selective TRPV2 inhibitors [88]. They have been shown to ameliorate cardiac dysfunction and prevent disease progression in the animal model of cardiomyopathy, as well as muscular dystrophy, by inhibiting the abnormal Ca 2+ -entry.…”

Blockade of TRPV2 is a Novel Therapy for Cardiomyopathy in Muscular Dystrophy

“…Cannabidiol (CBD), probenecid, lysophosphatidylcholine (LPC), 2-APB, high temperature (> 52 °C), and stretch are known to activate TRPV2. However, these stimulations did not always produce a sufficient response nor reproducible results for the inhibitor assay [28]. We found that mouse TRPV2 activity could be reproducibly evaluated by 2-APB stimulation under acidic conditions (pH = 6.5).…”

“…We found that mouse TRPV2 activity could be reproducibly evaluated by 2-APB stimulation under acidic conditions (pH = 6.5). Using the above method, we found that SKF96369 and tranilast inhibit Ca 2+ influx through mouse TRPV2 [28]. Subsequently, tranilast and SKF96369 were used as lead compounds, and the novel compounds that inhibit TRPV2 channel activity at a lower concentration than tranilast were identified using an in silico search for analogous compounds based on interaction prediction and an inhibitor search using commercially available compounds.…”

“…Subsequently, tranilast and SKF96369 were used as lead compounds, and the novel compounds that inhibit TRPV2 channel activity at a lower concentration than tranilast were identified using an in silico search for analogous compounds based on interaction prediction and an inhibitor search using commercially available compounds. These novel compounds, including lumin (NK-4), inhibited TRPV2 activity and yielded a reduction in fibrosis and improved cardiac function in J2N-k hamsters [28].…”

“…It is necessary to develop human-specific inhibitory antibodies or inhibitors of TRPV2 for treating human patients. Before finding adequate inhibitors, we characterized the DMD myotubes and tested tranilast on them [34], because we previously found tranilast can block hTRPV2 [28]. In this study, the human control skeletal muscle cell line, KD3 (control), was compared with the DMD cell line, D4P4 (DMD), from DMD patients.…”