Premium
Contributions of TRPA1, TRPV1 and ROS to Neuronal Activation Following Mitochondrial Modulation with Antimycin A
Author(s) -
Stanford Katherine,
Barannikov Ivan,
TaylorClark Thomas
Publication year - 2018
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.2018.32.1_supplement.864.2
Subject(s) - trpv1 , nociception , transient receptor potential channel , microbiology and biotechnology , chemistry , mitochondrion , uniporter , calcium imaging , trpv , mitochondrial ros , neuroscience , calcium , biology , receptor , biochemistry , cytosol , organic chemistry , enzyme
Mitochondrial dysfunction is linked to inflammatory nociceptive disorders which involve sensory nerve hyperexcitability. Inflammatory signaling pathways including interleukin‐1beta and tumor necrosis factor alpha induce mitochondrial dysfunction, resulting in mitochondrial reactive oxygen species (ROS) production, mitochondrial depolarization, and calcium release which influence cellular signaling. However, it is not known how these mitochondrial signaling events may influence nociception. Transient receptor potential channels (TRP) Ankyrin 1 (TRPA1) and vanilloid 1 (TRPV1) are selectively expressed in nociceptive subtypes of vagal, trigeminal and dorsal root afferents and play critical roles in inflammation‐associated nociception. However, the mechanism by which TRPA1 and TRPV1 contribute to nociception downstream of mitochondrial dysfunction is unknown. Our lab has previously demonstrated that Antimycin A, a mitochondrial electron transport chain complex III inhibitor, activates bronchopulmonary C‐fibers through the gating of TRPA1 and TRPV1. Here we evaluated the contributions of TRPA1, TRPV1 and ROS to neuronal activation during treatment with Antimycin A using live cell imaging of dissociated vagal mouse neurons and transfected HEK293 cells. We used calcium imaging (FURA‐2AM) to determine the activation of these non‐selective cation channels. Antimycin A selectively activated a portion of nociceptive wild‐type neurons while failing to activate non‐nociceptive neurons. With TRPV1 inhibition (iodoresiniferatoxin) or knockout the magnitude of calcium flux in responding neurons was unchanged while the percentage on neurons responding was decreased. Conversely, with TRPA1 inhibition (A967079) or knockout, the magnitude of calcium flux in responding neurons was decreased while the percentage of neurons responding was unchanged. Using both the TRPA1 and TRPV1 inhibitors together or a combination of knockout and inhibitor, responses to Antimycin A were abolished. In both TRPA1 and TRPV1 transfected HEK293 cells, a substantial portion of cells exhibited a significant increase in cytosolic calcium. To evaluate the contribution of ROS to the mitochondrial dysfunction‐evoked TRP channel activation, we scavenged ROS with dithiothreitol (DTT), a reducing agent. DTT diminished the calcium response in TRPA1 but not TRPV1 transfected HEK293 cells. In vagal neurons, MnTMPyP (cell permeable superoxide dismutase/catalase mimetic) and Tempol (superoxide dismutase mimetic) largely abolished the response to Antimycin A in TRPA1 knockout neurons. These data suggest that modulation of mitochondrial function activates nociceptive neurons via TRPA1 through a ROS‐mediated and TRPV1 through a ROS‐independent mechanism. Support or Funding Information National Heart Lung and Blood Institute This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .