The Low Molecular Weight Hyaluronan Fragment HA35 Serves as a Dual Antagonist of Pain-Related Calcium Channels TRPV1 and TRPA1

Abstract

Background: Pain, especially chronic pain, remains a major health challenge worldwide. Transient receptor potential (TRP) channels, particularly TRPV1 and TRPA1, play crucial roles in pain perception. Hyaluronic acid (HA), whose bioactivity varies by molecular weight, has shown potential in modulating pain-related TRP channels. However, the effects of low-molecular-weight HA (LMWHA, ＜100 kDa), such as 35 kDa HA (HA35), compared to high-molecular-weight HA (HMWHA, ˃1000kDa), on TRPV1 and TRPA1 are understudied. Methods: This study was performed in vitro using HEK293 cells transiently transfected with human TRPV1, TRPA1, and TRPV3 channels. Patch-clamp electrophysiology was used to assess ion currents before and after treatment with HA35 and 1600 kDa HMWHA (HA1600). Data from 12 independent replicates per condition were analyzed to determine inhibition rates. Results: Both HA35 and HA1600 significantly inhibited TRPV1 and TRPA1 currents, with HA35 showing greater potency. Specifically, HA35 reduced capsaicin-induced TRPV1 currents by 34.46% (P < 0.0001) and AITC-induced TRPA1 currents by 29.27% (P < 0.001), compared to 22.33% (P < 0.0001) and 22.32% (P < 0.001) for HA1600, respectively. Neither agent affected TRPV3 currents (P > 0.05). These findings indicate that although LMWHA and HMWHA exert comparable modulatory actions on pain-related ion channels, their degrees of inhibition differ. Conclusion: HA35, as a LMWHA, selectively and more potently inhibits TRPV1 and TRPA1 channels compared to HMWHA. This study illustrates the distinct pharmacological properties of LMWHA versus HMWHA, supporting HA35’s potential as a dual-target analgesic with superior tissue permeability for TRP-mediated pain management.