VEGF signaling mediates bladder neuroplasticity and inflammation in response to BCG

• Type: Article in International Scientific Journal
• Date: 2011

Authors

Saban, MR (Author) Other; Davis, CA (Author) Other; António Avelino Silva (Author) FMUP; Francisco Cruz (Author) FMUP; Maier, J (Author) Other; Bjorling, DE (Author) Other; Sferra, TJ (Author) Other; Hurst, RE (Author) Other; Saban, R (Author) Other

Journal

The Journal is awaiting validation by the Administrative Services.

Title: BMC Physiology

Vol. 11

Final page: 16

ISSN: 1472-6793

Indexing

Scopus - 23 Citations

Other information

Authenticus ID: P-008-0ZF

DOI: 10.1186/1472-6793-11-16

Abstract (EN): Background: This work tests the hypothesis that increased levels of vascular endothelial growth factor (VEGF) observed during bladder inflammation modulates nerve plasticity. Methods. Chronic inflammation was induced by intravesical instillations of Bacillus Calmette-Guérin (BCG) into the urinary bladder and the density of nerves expressing the transient receptor potential vanilloid subfamily 1 (TRPV1) or pan-neuronal marker PGP9.5 was used to quantify alterations in peripheral nerve plasticity. Some mice were treated with B20, a VEGF neutralizing antibody to reduce the participation of VEGF. Additional mice were treated systemically with antibodies engineered to specifically block the binding of VEGF to NRP1 (anti-NRP1B) and NRP2 (NRP2B), or the binding of semaphorins to NRP1 (anti-NRP1 A) to diminish activity of axon guidance molecules such as neuropilins (NRPs) and semaphorins (SEMAs). To confirm that VEGF is capable of inducing inflammation and neuronal plasticity, another group of mice was instilled with recombinant VEGF165or VEGF121into the urinary bladder. Results: The major finding of this work was that chronic BCG instillation resulted in inflammation and an overwhelming increase in both PGP9.5 and TRPV1 immunoreactivity, primarily in the sub-urothelium of the urinary bladder. Treatment of mice with anti-VEGF neutralizing antibody (B20) abolished the effect of BCG on inflammation and nerve density. NRP1A and NRP1B antibodies, known to reduce BCG-induced inflammation, failed to block BCG-induced increase in nerve fibers. However, the NRP2 B antibody dramatically potentiated the effects of BCG in increasing PGP9.5-, TRPV1-, substance P (SP)-, and calcitonin gene-related peptide (CGRP)-immunoreactivity (IR). Finally, instillation of VEGF121or VEGF165into the mouse bladder recapitulated the effects of BCG and resulted in a significant inflammation and increase in nerve density. Conclusions: For the first time, evidence is being presented supporting that chronic BCG instillation into the mouse bladder promotes a significant increase in peripheral nerve density that was mimicked by VEGF instillation. Effects of BCG were abolished by pre-treatment with neutralizing VEGF antibody. The present results implicate the VEGF pathway as a key modulator of inflammation and nerve plasticity, introduces a new animal model for investigation of VEGF-induced nerve plasticity, and suggests putative mechanisms underlying this phenomenon. © 2011 Saban et al; licensee BioMed Central Ltd.

Language: English

Type (Professor's evaluation): Scientific