Prostatic Acid Phosphatase Is Expressed in Peptidergic and Nonpeptidergic Nociceptive Neurons of Mice and Rats

Bonnie Taylor-Blake,Mark J Zylka

doi:10.1371/journal.pone.0008674

Bonnie Taylor-Blake, Mark J Zylka

Open Access

https://doi.org/10.1371/journal.pone.0008674

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Journal: PloS one	Publication Date: Jan 13, 2010
Citations: 60	License type: CC BY 4.0

Affiliation: University of North Carolina at Chapel Hill

Abstract

Thiamine monophosphatase (TMPase, also known as Fluoride-resistant acid phosphatase or FRAP) is a classic histochemical marker of small- to medium-diameter dorsal root ganglia (DRG) neurons and has primarily been studied in the rat. Previously, we found that TMPase was molecularly identical to Prostatic acid phosphatase (PAP) using mice. In addition, PAP was expressed in a majority of nonpeptidergic, isolectin B4-binding (IB4+) nociceptive neurons and a subset of peptidergic, calcitonin gene-related peptide-containing (CGRP+) nociceptive neurons. At the time, we were unable to determine if PAP was present in rat DRG neurons because the antibody we used did not cross-react with PAP in rat tissues. In our present study, we generated a chicken polyclonal antibody against the secretory isoform of mouse PAP. This antibody detects mouse, rat and human PAP protein on western blots. Additionally, this antibody detects PAP in mouse and rat small- to medium-diameter DRG neurons and axon terminals in lamina II of spinal cord. In the rat, 92.5% of all PAP+ cells bind the nonpeptidergic marker IB4 and 31.8% of all PAP+ cells contain the peptidergic marker CGRP. Although PAP is found in peptidergic and nonpeptidergic neurons of mice and rats, the percentage of PAP+ neurons that express these markers differs between species. Moreover, PAP+ axon terminals in the rat partially overlap with Protein kinase Cγ (PKCγ+) interneurons in dorsal spinal cord whereas PAP+ axon terminals in the mouse terminate dorsal to PKCγ+ interneurons. Collectively, our studies highlight similarities and differences in PAP localization within nociceptive neurons of mice and rats.

Highlights

It has long been known that small- to medium-diameter dorsal root ganglia (DRG) neurons contain an acid phosphatase called Thiamine monophosphatase (TMPase; known as Fluoride-resistant acid phosphatase or FRAP) [1,2,3,4,5,6]
We tested four commercially available antibodies directed against hPAP
While our research with Prostatic acid phosphatase (PAP) was in progress [17], Biømeda went out of business, making it impossible to obtain this antibody for further studies

Summary

Introduction

It has long been known that small- to medium-diameter DRG neurons contain an acid phosphatase called Thiamine monophosphatase (TMPase; known as Fluoride-resistant acid phosphatase or FRAP) [1,2,3,4,5,6]. TMPase was extensively co-localized in cells and axon terminals with the nonpeptidergic neuron marker IB4 and partially co-localized (30–50%) with CGRP, a more broadly expressed marker of peptidergic DRG neurons [14,15,16]. As part of our previous study, we used antibodies generated against the secretory isoform of human PAP to detect PAP in mouse DRG neurons and axon terminals in spinal cord [17].

Results

Conclusion