Bladder overactivity involves overexpression of MicroRNA 132 and nerve growth factor

Abstract

Aim Here, we assessed the expression of non-protein coding microRNAs (miRs), nerve growth factor and inflammatory molecules in the rat model of acetic acid induced bladder overactivity. Main Methods Under isoflurane anesthesia, adult female Sprague-Dawley rats were instilled for 30 min with either saline or NGF antisense oligonucleotides complexed with liposomes. 24h later, treated rats were exposed to either intravesical infusion of saline or saline containing 0.25% acetic acid at the rate of 0.04ml/min for 2h under urethane anesthesia (1g/kg; s.c). After CMG, bladder was harvested to study expression of NGF, cytokines and 8 specific miRNAs involved in bladder dysfunctions. The role of miR-132 in bladder overactivity was independently assessed through bladder wall transfection of plasmid encoding miR-132. Key Findings NGF overexpression in bladder overactivity was associated with ~2-fold upregulation and downregulation of miR-132 and miR-221, respectively. Pretreatment with NGF antisense restored the expression of miR-221 and miR-132 to control levels and also reduced the expression of cytokines (MCP-1 and sICAM-1). There was insignificant alteration in expression of miR-199a-5p, but expression of, miR-210, miR-212, miR-155, miR-134 and miR-206 remained similar across the experimental groups. Bladder wall transfection of miR-132 plasmid in absence of acetic acid exposure was able to independently induce bladder overactivity, bladder hypertrophy and upregulate the expression of NGF and other cytokines. Significance Overall, our work sheds light on the role of miR-132 in bladder overactivity, bladder hypertrophy, NGF signaling and expression of inflammatory mediators. Findings suggest that aberrant expression of miR-132 is involved in voiding dysfunctions.

Exploring biomarkers in the overactive bladder: Alterations in miRNA levels of a panel of genes in patients with OAB

“…In investigations of effective miRNAs in smooth muscle, Chiba et al suggested that miR‐133a may be a new treatment option in diseases with hypercontractility in the pathogenesis, such as asthma, by regulating contraction via RhoA expression in smooth muscle. Kashyap et al found that miR‐132 and miR‐221 were dysregulated in rat OAB models, and these miRNAs were effective in bladder hypertrophy and dysfunction. Chermansky et al also associated dysregulation of miR‐221 and miR‐125b with patients with OAB .…”

Role of Nerve Growth Factor (NGF) and miRNAs in Epithelial Ovarian Cancer

“…Firstly, NGF signaling through ERK protein increases miR-222 and miR-221 levels [4]; secondly, NGF overexpresses miR-221 levels, with consequences in neuronal differentiation [5]; thirdly, NGF raises miR-21 levels, supporting its signaling and protecting cells from neuronal degeneration [136]. While all of these studies have been done on a PC12 cell line, there are also a couple of reports done in bladder [137] and bronchial epithelium [138]. …”

MicroRNAs as potential biomarkers to predict the risk of urinary retention following intradetrusor onabotulinumtoxin‐A injection

“…The authors concluded that miR34a modulates OAB susceptibility by regulating the purinergic signaling. Our group recently reported on the changes in the expression of miR‐132 and miR221 in a rat model of bladder overactivity induced by acetic acid . These prior animal and clinical studies sparked our interest in studying miRs as potential biomarkers for OAB treatments.…”

“…Total RNA was isolated from biopsy tissue using Trizol reagent. Then, the total RNA was converted to cDNA using TaqMan MicroRNA Reverse Transcription Kit (Applied Biosystems, Foster city, CA) according to manufacturer's protocol . The TaqMan primers (Life Technologies, Foster city, CA) chosen were hsa‐miR206, hsa‐miR210, hsa‐miR221, hsa‐miR26a, hsa‐miR26b, hsa‐miR125b, hsa‐miR132, hsa‐miR16, hsa‐miR124a, hsa‐miR134, hsa‐miR153, hsa‐miR199a, and hsa‐miR212.…”

“…MiRs are believed to be necessary for smooth muscle growth, differentiation, and function . We recently reported on the dysregulation of miR‐132 and miR‐221 in a rat model of bladder overactivity . Another study reported on the pathological role of miR‐132 and miR‐212 (encoded from the same intron) in a rat model of bladder outlet obstruction .…”