Increased severity of inflammation correlates with elevated expression of TRPV1 nerve fibers and nerve growth factor on interstitial cystitis/bladder pain syndrome.
OBJECTIVE
Although evidence supports a role for inflammation in interstitial cystitis/bladder pain syndrome (IC/BPS), the mechanism remains unknown. We determined whether inflammation causes an elevated expression of nerve growth factor (NGF) and transient receptor potential vanilloid receptor subtype 1 (TRPV1) and correlated them with the symptoms.


METHODS
Bladder biopsies were obtained from 53 IC/BPS patients and 27 controls, and hematoxylin and eosin staining, immunostaining and Western blotting were performed to detect inflammation, TRPV1-immunoreactive and PGP9.5-immunoreactive nerve fibers, and NGF, respectively. Symptoms were assessed using the Pelvic Pain/Urgency/Frequency (PUF) questionnaire and pain visual analogue scale scores. Suburothelial nerve fiber density was quantified and correlated with PUF scores.


RESULTS
Increased severity of inflammation was correlated with a higher TRPV1-immunoreactive nerve fiber density (r = 0.4113, p = 0.0024) and higher NGF levels (r = 0.3775, p = 0.0052). Suburothelial TRPV1-immunoreactive nerve fiber density was significantly correlated with pain scores and urgency scores (r = 0.3320, p = 0.0145 and r = 0.3823, p = 0.0039, respectively). PGP9.5-immunoreactive nerve fibers were significantly increased in IC/BPS (p = 0.0193) and had a positive relationship with inflammation severity (r = 0.6138, p < 0.0001).


CONCLUSIONS
Our study revealed increased severity of inflammation correlated with a higher expression of TRPV1-immunoreactive nerve fibers and NGF in IC/BPS and correlated with clinical symptoms.
Department of Urology, The Third Affiliated Hospital of the Sun Yat-Sen University, Guangzhou, China.
Bo-long
BL
Liu
Fei
F
Yang
Hai-lun
HL
Zhan
Zhi-ying
ZY
Feng
Zhi-gang
ZG
Zhang
Wen-biao
WB
Li
Xiang-fu
XF
Zhou
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D018856:Cystitis, Interstitial / Q000378:metabolism*; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D007249:Inflammation; D008297:Male; D008875:Middle Aged; D020932:Nerve Growth Factor / Q000378:metabolism*; D010146:Pain / Q000378:metabolism*; D011446:Prospective Studies; D050916:TRPV Cation Channels / Q000378:metabolism*; D001745:Urinary Bladder Diseases / Q000378:metabolism*
D050916:TRPV Cation Channels; C494482:TRPV1 protein, human; D020932:Nerve Growth Factor