Characterization of Primary Bladder Neck Obstruction: Immunohistochemical and Gene Expression Analysis
Year: 2008
Type: article
Study design: Observational Study
Abstract: Background: Pathophysiology of primary bladder neck obstruction (PBNO) remains poorly understood. We postulated abnormal smooth muscle (SM) differentiation and disorganization of bladder neck musculature as key features of PBNO pathophysiology. Materials and Methods: Immunohistochemical analysis and gene expression profiles of bladder neck specimens derived from 11 patients urodynamically diagnosed with PBNO, 4 patients with benign prostatic hypertrophy (BPH) and 2 normal controls were performed. Consecutive sections were processed for immunohistochemical characterization using anti-SM a-actin, h-caldesmon, collagen type IV, and GAP-43 antibodies. cDNA, synthesized from isolated RNA of the specimens, were polymerase chain reaction amplified to assess for expression of smooth muscle myosin heavy chain, collagen types I and III, non-muscle myosin heavy chain, and a1A adrenergic receptor mRNA. Results: While SM disorganization in PBNO specimens compared with normal bladder neck tissue was observed, PBNO bladder neck specimens stained positively for SM markers: a-actin, h-caldesmon and collagen type IV, suggesting their SM origin. Staining for GAP-43, a phosphoprotein associated with the growth of axons and the modulation of new nerve/ muscle connection, was also positive in PBNO tissue. Reverse transcription and polymerase chain reaction measurements of SM related gene expression indicated extremely low levels of smooth muscle myosin heavy chain mRNA expression in PBNO specimens when compared to BPH or normal tissue. Expression of a1A adrenergic receptor was maintained in both PBNO and normal bladder neck specimens. Conclusion: Expression of SM specific markers in the PBNO tissue was diminished compared to bladder neck tissue from BPH or normal controls, suggesting SM dedifferentiation or transdifferentiation.
Source: Current Urology
DOI: 10.1159/000106542
Institution: The University of Texas Southwestern Medical Center
Language: English
Subfield: Urology
Field: Medicine
Domain: Health Sciences
Open Access status: diamond
OpenAlex ID: W2048265530