TRPV-mediated capsaicin-induced feeding promotion and growth enhancement in sea cucumber Apostichopus japonicus: First evidence in echinoderms

The transient receptor potential vanilloid (TRPV) subfamily plays crucial roles in sensory transduction and physiological regulation in mammals, yet its functional mechanisms remain poorly understood in marine invertebrates, particularly in echinoderms. Here, we investigated the signaling mechanisms and physiological functions of TRPV channels in sea cucumber Apostichopus japonicus . Two TRPV channels (AjTRPVA and AjTRPVB) were identified in A. japonicus , and phylogenetic analysis revealed that these channels are evolutionarily conserved. We confirmed that both AjTRPVA and AjTRPVB function as capsaicin receptors, with AjTRPVB exhibiting more significant responses to capsaicin stimulation. Furthermore, in vivo pharmacological experiments further demonstrated that AjTRPV channels mediate capsaicin-induced feeding promotion and growth enhancement by regulating the expression of CCK and orexin precursor genes and growth factors including Megf6, Igf and GDF-8. To our knowledge, this is the first study to demonstrate that TRPV channels are involved in feeding and growth regulation in echinoderms. Given the economic importance of A. japonicus in aquaculture, the discovery of capsaicin-AjTRPV signaling as a potential regulator of feeding and growth in A. japonicus provides novel strategies for optimizing aquaculture practices for this species, and advances our understanding of TRPV channel functions in marine invertebrates. • This is the first study to characterize TRPV channels in echinoderms. • TRPVA and TRPVB are identified as capsaicin receptors in A. japonicus . • Capsaicin promotes A. japonicus feeding and growth via activating TRPV channels.