Characterization of voiding function and structural bladder changes in a rat model of neurogenic underactive bladder...

Area of Science:

• Urology
• Regenerative Medicine
• Molecular Biology

Background:

• Neurogenic underactive bladder (UAB) disease presents a significant clinical challenge.
• Understanding the molecular mechanisms underlying myogenic changes in UAB is crucial for developing effective therapies.

Purpose of the Study:

• To establish an animal model for neurogenic UAB.
• To identify molecular markers indicative of secondary myogenic alterations in the bladder wall.

Main Methods:

• Male rats underwent pelvic nerve injury or sham surgery.
• Functional bladder evaluation included voiding pattern analysis, cystometry, and in-vitro contractility tests.
• Quantitative PCR and immunohistochemistry were used to assess smooth muscle cell (SMC) and extracellular matrix markers.

Main Results:

• Pelvic nerve injury led to increased bladder weight and absent voiding contractions, causing overflow incontinence.
• In-vitro bladder contractility was reduced post-injury.
• A shift in SMC phenotype was observed, with upregulation of synthetic markers (RBP1, MYH10, OPN) and downregulation of contractile markers (SMTL).
• The SMTL/OPN mRNA ratio significantly decreased in injured bladders.

Conclusions:

• Pelvic nerve injury induces a switch from contractile to synthetic SMC phenotype in the bladder wall, characterizing UAB.
• The SMTL/OPN mRNA ratio serves as a key marker for this phenotypical switch.
• Targeting this SMC phenotypical shift offers a potential therapeutic strategy for UAB.
• Identified markers can aid in evaluating therapeutic interventions for bladder wall structure improvement.