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Breaking the TRPV1‐Calcineurin Interaction as a Novel Means for Pain Control
Author(s) -
McAllister Stacy,
Zambelli Vanessa,
Gross Eric
Publication year - 2016
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.30.1_supplement.927.2
Subject(s) - trpv1 , calcineurin , transient receptor potential channel , pharmacology , nociception , in vitro , carica , chemistry , peptide , capsaicin , medicine , receptor , biochemistry , biology , transplantation , horticulture
Targeting the transient receptor potential vanilloid 1 (TRPV1) channel for pain control is complex. Previous efforts in drug discovery resulted in failure since TRPV1 agonists are painful and TRPV1 antagonists cause hyperthermia. Calcineurin is an important TRPV1 protein partner since an interaction of TRPV1 with calcineurin favors TRPV1 channel opening. Therefore as an alternative, we hypothesized by breaking the interaction between TRPV1 and calcineurin, we can indirectly modulate TRPV1 to reduce pain sensation. To test this hypothesis, we used methods including computational biology, peptide synthesis, in vitro , and behavioral pain assays. Based on computational analysis, we discovered a sequence within the TRPV1 C‐terminus that interacts with the calcineurin A subunit. The TRPV1 region forms an alpha coil‐coil, part of the TRPV1 channel inner pore unit, and is evolutionary conserved in mammals. Based on these findings, we synthesized a peptide against this region, linked it to TAT 47–57 and called it V1‐cal. In a competitive in vitro calcineurin activity assay, V1‐cal reduced the ability for calcineurin to dephosphorylate a calcineurin substrate as measured by free phosphate release in vitro . Further, we used a carrageenan‐induced inflammatory pain model in male Wistar rats of 10–14 weeks of age. Nociceptive threshold was assessed using the Randall‐Selitto method at baseline and 3 hours after administration of carrageenan. Ten minutes prior to carrageenan, rats were injected intraplantarly with the V1‐cal peptide or saline control. Relative to the control group, rats treated with the V1‐cal peptide had a higher mechanical pain threshold (55±8g vs 36±1g, mean±SEM, n=5/group). Together, these data suggest V1‐cal is an effective therapeutic for pain control by disrupting the TRPV1‐calcineurin interaction. Support or Funding Information This work was supported by NIH grant T32 GM089626 to SM.