Differential expression profile of cold (TRPA1) and cool (TRPM8) receptors in human urogenital organs.
OBJECTIVE
To examine the expressions of transient receptor potential (TRP) channel A1 and TRPM8 in the human urogenital organs (urinary bladder and prostate) and how these expressions change in association with bladder outlet obstruction (BOO) or benign prostatic hyperplasia (BPH). In addition to TRPM8, a cool receptor, TRPA1 is recently recognized as a cold receptor. TRPA1 is also a candidate for mechanosensor and/or nociceptor.


METHODS
Urinary bladder mucosa and muscular layer were taken from 9 controls and 9 patients with BOO. Prostatic specimens were obtained from 5 controls and 6 patients with BPH. Expressions of TRPA1 and TRPM8 messenger RNAs (mRNAs) were quantified by real-time revere transcriptase-polymerase chain reaction. Localization of TRPA1 protein was explored with immunohistochemistry.


RESULTS
The expression levels of TRPA1 mRNA in the bladder mucosa, bladder muscular layer, and prostate were in the ratio of 639:1:16. TRPA1 mRNA in the bladder mucosa with BOO was significantly upregulated to 2.32 times of control. TRPA1 protein was localized in the epithelial cells of both urinary bladder and prostate gland. The expression of TRPM8 mRNA in the prostate was much higher than that in the bladder mucosa (3024:1), but was not found in the bladder muscle layer. BPH or BOO did not significantly affect the expression of TRPM8.


CONCLUSIONS
TRPA1 and TRPM8 were differentially expressed in the human urinary bladder and prostate. TRPA1 in the bladder epithelium might be involved in the bladder sensory transduction and the induction process of overactive bladder by BOO.
Du
Shuqi
S
Department of Urology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Chuo, Yamanashi, Japan.
Araki
Isao
I
Kobayashi
Hideki
H
Zakoji
Hidenori
H
Sawada
Norifumi
N
Takeda
Masayuki
M
D000368:Aged; D000369:Aged, 80 and over; D015220:Calcium Channels / Q000096:biosynthesis*; D015870:Gene Expression; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009092:Mucous Membrane / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000096:biosynthesis*; D011467:Prostate / Q000378:metabolism*; D011470:Prostatic Hyperplasia / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000074025:TRPA1 Cation Channel; D050053:TRPM Cation Channels / Q000096:biosynthesis*; D050051:Transient Receptor Potential Channels / Q000096:biosynthesis*; D015854:Up-Regulation; D014524:Urethral Obstruction / Q000378:metabolism*; D001743:Urinary Bladder / Q000378:metabolism
D015220:Calcium Channels; D009419:Nerve Tissue Proteins; D000074025:TRPA1 Cation Channel; C473350:TRPA1 protein, human; D050053:TRPM Cation Channels; C425966:TRPM8 protein, human; D050051:Transient Receptor Potential Channels