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Activation of TRPM2 and TRPV1 Channels in Dorsal Root Ganglion by NADPH Oxidase and Protein Kinase C Molecular Pathways: a Patch Clamp Study.
J Mol Neurosci. 2017 Mar; 61(3):425-435.JM

Abstract

Despite considerable research, the mechanisms of neuropathic pain induced by excessive oxidative stress production and overload calcium ion (Ca2+) entry in dorsal root ganglion (DRG) remain substantially unidentified. The transient receptor potential melastatin 2 (TRPM2) and vanilloid 1 (TRPV1) channels are activated with different stimuli including oxidative stress. TRPM2 and TRPV1 have been shown to be involved in induction of neuropathic pain. However, the activation mechanisms of TRPM2 and TRPV1 via NADPH oxidase and protein kinase C (PKC) pathways are poorly understood. In this study, I investigated the roles of NADPH oxidase and PKC on Ca2+ entry through TRPM2 and TRPV1 channels in in vitro DRG neurons of rats. Rat DRG neurons were used in whole-cell patch clamp experiments. The H2O2-induced TRPM2 current densities were decreased by N-(p-amylcinnamoyl)anthranilic acid (ACA), and dose-dependent capsaicin (CAP) and H2O2-induced TRPV1 currents were inhibited by capsazepine (CPZ). The TRPV1 channel is activated in the DRG neurons by 0.01 mM capsaicin but not 0.001 mM or 0.05 mM capsaicin. TRPM2 and TRPV1 currents were increased by the PKC activator, phorbol myristate acetate (PMA), although the currents were decreased by ACA, CPZ, and the PKC inhibitor, bisindolylmaleimide I (BIM). Both channel currents were further increased by PMA + H2O2 as compared to H2O2 only. In the combined presence of PMA + BIM, no TRPM2 or TRPV1 currents were observed. The CAP and H2O2-induced TRPM2 current densities were also decreased by the NADPH oxidase inhibitors apocynin and N-Acetylcysteine. In conclusion, these results demonstrate a protective role for NADPH oxidase and PKC inhibitors on Ca2+ entry through TRPM2 and TRPV1 channels in DRG neurons. Since excessive oxidative stress production and Ca2+ entry are implicated in the pathophysiology of neuropathic pain, the findings may be relevant to the etiology and treatment of neuropathology in DRG neurons.

Authors+Show Affiliations

Neuroscience Research Center, Süleyman Demirel University, Isparta, Turkey. mustafanaziroglu@sdu.edu.tr. Tıp Fakültesi, Biyofizik Anabilim Dalı Başkanı, Süleyman Demirel University, 32260, Isparta, TR, Turkey. mustafanaziroglu@sdu.edu.tr.

Pub Type(s)

Journal Article

Language

eng

PubMed ID

28097492

Citation

Nazıroğlu, Mustafa. "Activation of TRPM2 and TRPV1 Channels in Dorsal Root Ganglion By NADPH Oxidase and Protein Kinase C Molecular Pathways: a Patch Clamp Study." Journal of Molecular Neuroscience : MN, vol. 61, no. 3, 2017, pp. 425-435.
Nazıroğlu M. Activation of TRPM2 and TRPV1 Channels in Dorsal Root Ganglion by NADPH Oxidase and Protein Kinase C Molecular Pathways: a Patch Clamp Study. J Mol Neurosci. 2017;61(3):425-435.
Nazıroğlu, M. (2017). Activation of TRPM2 and TRPV1 Channels in Dorsal Root Ganglion by NADPH Oxidase and Protein Kinase C Molecular Pathways: a Patch Clamp Study. Journal of Molecular Neuroscience : MN, 61(3), 425-435. https://doi.org/10.1007/s12031-017-0882-4
Nazıroğlu M. Activation of TRPM2 and TRPV1 Channels in Dorsal Root Ganglion By NADPH Oxidase and Protein Kinase C Molecular Pathways: a Patch Clamp Study. J Mol Neurosci. 2017;61(3):425-435. PubMed PMID: 28097492.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Activation of TRPM2 and TRPV1 Channels in Dorsal Root Ganglion by NADPH Oxidase and Protein Kinase C Molecular Pathways: a Patch Clamp Study. A1 - Nazıroğlu,Mustafa, Y1 - 2017/01/17/ PY - 2016/10/21/received PY - 2017/01/06/accepted PY - 2017/1/18/pubmed PY - 2017/7/1/medline PY - 2017/1/19/entrez KW - N acetyl cysteine KW - NADPH oxidase KW - Protein kinase C KW - Sensory neurons KW - TRPM2 channel KW - TRPV1 channel SP - 425 EP - 435 JF - Journal of molecular neuroscience : MN JO - J Mol Neurosci VL - 61 IS - 3 N2 - Despite considerable research, the mechanisms of neuropathic pain induced by excessive oxidative stress production and overload calcium ion (Ca2+) entry in dorsal root ganglion (DRG) remain substantially unidentified. The transient receptor potential melastatin 2 (TRPM2) and vanilloid 1 (TRPV1) channels are activated with different stimuli including oxidative stress. TRPM2 and TRPV1 have been shown to be involved in induction of neuropathic pain. However, the activation mechanisms of TRPM2 and TRPV1 via NADPH oxidase and protein kinase C (PKC) pathways are poorly understood. In this study, I investigated the roles of NADPH oxidase and PKC on Ca2+ entry through TRPM2 and TRPV1 channels in in vitro DRG neurons of rats. Rat DRG neurons were used in whole-cell patch clamp experiments. The H2O2-induced TRPM2 current densities were decreased by N-(p-amylcinnamoyl)anthranilic acid (ACA), and dose-dependent capsaicin (CAP) and H2O2-induced TRPV1 currents were inhibited by capsazepine (CPZ). The TRPV1 channel is activated in the DRG neurons by 0.01 mM capsaicin but not 0.001 mM or 0.05 mM capsaicin. TRPM2 and TRPV1 currents were increased by the PKC activator, phorbol myristate acetate (PMA), although the currents were decreased by ACA, CPZ, and the PKC inhibitor, bisindolylmaleimide I (BIM). Both channel currents were further increased by PMA + H2O2 as compared to H2O2 only. In the combined presence of PMA + BIM, no TRPM2 or TRPV1 currents were observed. The CAP and H2O2-induced TRPM2 current densities were also decreased by the NADPH oxidase inhibitors apocynin and N-Acetylcysteine. In conclusion, these results demonstrate a protective role for NADPH oxidase and PKC inhibitors on Ca2+ entry through TRPM2 and TRPV1 channels in DRG neurons. Since excessive oxidative stress production and Ca2+ entry are implicated in the pathophysiology of neuropathic pain, the findings may be relevant to the etiology and treatment of neuropathology in DRG neurons. SN - 1559-1166 UR - https://www.unboundmedicine.com/medline/citation/28097492/Activation_of_TRPM2_and_TRPV1_Channels_in_Dorsal_Root_Ganglion_by_NADPH_Oxidase_and_Protein_Kinase_C_Molecular_Pathways:_a_Patch_Clamp_Study_ DB - PRIME DP - Unbound Medicine ER -