Real-Time Translocation and Function of PKCβII Isoform in Response to Nociceptive Signaling via the TRPV1 Pain Receptor.

Sravan Mandadi,Patricia J Armati,Basil D Roufogalis

doi:10.3390/ph4111503

Sravan Mandadi, Patricia J Armati + Show 1 more

Open Access

https://doi.org/10.3390/ph4111503

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Journal: Pharmaceuticals	Publication Date: Nov 11, 2011
Citations: 35	License type: CC BY 3.0

Affiliation: University of Calgary, University of Sydney

Abstract

Serine/threonine protein kinase C βII isoform (PKCβII) or the pain receptor transient receptor potential vanilloid 1 (TRPV1) have been separately implicated in mediating heat hyperalgesia during inflammation or diabetic neuropathy. However, detailed information on the role of PKC βII in nociceptive signaling mediated by TRPV1 is lacking. This study presents evidence for activation and translocation of the PKC βII isoform as a signaling event in nociception mediated by activation of TRPV1 by capsaicin. We show that capsaicin induces translocation of cytosolic PKCβII isoform fused with enhanced green fluorescence protein (PKCβII-EGFP) in dorsal root ganglion (DRG) neurons. We also show capsaicin-induced translocation in Chinese Hamster Ovarian (CHO) cells co-transfected with TRPV1 and PKCβII-EGFP, but not in CHO cells expressing PKCβII-EGFP alone. By contrast, the PKC activator phorbol-12-myristate-13-acetate (PMA) induced translocation of PKCβII-EGFP which was sustained and independent of calcium or TRPV1. In addition PMA-induced sensitization of TRPV1 to capsaicin response in DRG neurons was attenuated by PKCβII blocker CGP 53353. Capsaicin response via TRPV1 in the DRG neurons was confirmed by TRPV1 antagonist AMG 9810. These results suggested a novel and potential signaling link between PKCβII and TRPV1. These cell culture models provide a platform for investigating mechanisms of painful neuropathies mediated by nociceptors expressing the pain sensing gene TRPV1, and its regulation by the PKC isoform PKCβII.

Highlights

Hypersensitivity to nociception or hyperalgesia in many peripheral neuropathies is currently undertreated or requires complex drug treatment with significant side effects
As the methodological tools used in earlier studies could not delineate which molecules interacted during altered thermal sensitivity, we addressed this issue by characterizing changes in the localization and translocation of protein kinase C βII isoform (PKCβII) isoforms with respect to transient receptor potential vanilloid 1 (TRPV1) activation – the regulators known to be important in altered thermal sensitivity [24,26,27]
We have shown the activation, translocation and novel function of PKCβII isoform seen in the capsaicin-sensitive nociceptive dorsal root ganglion (DRG) neurons

Summary

Introduction

Hypersensitivity to nociception or hyperalgesia in many peripheral neuropathies is currently undertreated or requires complex drug treatment with significant side effects. These conditions represent a huge cost to health budgets worldwide. TRPV1 is the molecular integrator of noxious heat (>42 C), the hot chilli pepper ingredient capsaicin and tissue acidosis [3,4], and is characteristic of a nociceptive subset of dorsal root ganglion (DRG) neurons [5]. Nociceptive subsets of DRG neurons in culture have been a useful tool for the investigation of signaling mechanisms associated with hyperalgesia

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