Expression and distribution of the transient receptor potential cationic channel ankyrin 1 (TRPA1) in the human vagina

Abstract

The transient receptor potential cationic channel type A1 (TRPA1), belonging to a superfamily of cationic membrane channels, has been suggested to act as mechano- and pain sensor and, thus, to play a role in neurotransmission in the human body, including the urogenital tract. While the expression of TRPA1 has been investigated in a variety of tissues, up until today, no study has addressed the expression and distribution in the female genital tract. The present study aimed to investigate the expression and distribution of TRPA1 protein in human vaginal tissue. Reverse transcriptase PCR (RT-PCR) was applied in order to identify messenger ribonuleic acid specifically encoding for TRPA/A1. The distribution of TRPA1 in relation to the neuronal nitric oxide synthase (nNOS) and the signaling peptide calcitonin gene-related peptide (CGRP) was examined by means of immunohistochemical methods (double-antibody technique, laser fluorescence microscopy). RT-PCR analysis revealed the expression of mRNA encoding sequences specific for TRPA in the vaginal wall and epithelium. Immunostaining related to TRPA1 was observed in the basal epithelium and in slender varicose nerve fibers transversing the subepithelial and stromal space of the vaginal sections. In addition, these fibers presented immunoreactivity specific for nNOS or CGRP. The smooth musculature of the vaginal wall and small vessels interspersing the tissue did not present signals related to TRPA1. The findings indicate that TRPA1 might be involved in afferent neurotransmission in the vagina and work synergistically together with the nitric oxide/cyclic guanosine monophosphate pathway.

A Novel Model of Cancer-Induced Peripheral Neuropathy and the Role of TRPA1 in Pain Transduction

“…Transient receptor potential ankyrin 1 (TRPA1) plays a role in cold, mechanical, and thermal pain recognition. It is produced in a wide variety of tissues such as those in the central (CNS) [8] and peripheral (PNS) [9][10][11][12] nervous systems, eye [13], lung [14], gastrointestinal tract [15], genital systems [16], skin [17], cardiovascular system [18], urinary system [9,10], and teeth [19,20]. In some inflammatory conditions, such as streptozotocin-induced type I diabetes in rats [9] and cyclophosphamide-induced cystitis and hyperalgesia in mice bladders [10], TRPA1 is overexpressed by DRG neurons.…”

Satellite glial cells in sensory ganglia express functional transient receptor potential ankyrin 1 that is sensitized in neuropathic and inflammatory pain

“…In this study, we chose a rabbit extracellular TRPA1 antibody for several reasons: (1) this antibody has been well characterized by the vendor, demonstrating a high specificity against an epitope (NSTGIINETSDHSE) corresponding to amino acid residues 747 to 760 in the first extracellular loop of TRPA1 ( Figure 1a); (2) the specificity has been verified in TRPA1 knockout tissue; 38 and (3) it consistently detects TRPA1 expression by IHC or immunoblot from DRGs and from nonneuronal tissues. 19,[36][37][38]40,[53][54][55][56][57][58][59][60][61][62][63] We also tested the specificity of this antibody in the detection of TRPA1 expression. By immunoblot, the antibody revealed a clean band at $120 KDa as the target protein in the homogenates of the DRGs from adult rats, and preincubation with excess immunogenic peptide completely eliminated the band (Figure 1b).…”

Redox-sensitive transient receptor potential channels in oxygen sensing and adaptation

“…This was particularly interesting as TRPM8 is different from TRPA1 in responding to mild cold temperatures as well as to different sets of organic compounds [ 97 ]. Since its discovery, TRPA1 has been reported in most sensory neurons targeting vital organs (see the non-extensive Table 1 below for TRPA1 expression in neuronal populations and nociception) [ 20 , 40 , 42 , 48 – 51 , 70 , 77 , 82 , 83 , 96 , 97 , 108 ]. To date, TRPA1 has been also detected in non-neuronal cells such as hair cells of the ear, urethra, skin, olfactory epithelium, dental pulp, uvea, vagina, and pulmonary epithelial cells, and this list is still growing (Table 2 ) [ 3 , 4 , 8 , 9 , 11 , 14 , 19 , 22 , 31 , 55 , 56 , 64 , 66 , 69 , 105 , 106 ].…”