BDNF overexpression in the bladder induces neuronal changes to mediate bladder overactivity.

Area of Science:

• Urology
• Neuroscience
• Molecular Biology

Background:

• Elevated urinary brain-derived neurotrophic factor (BDNF) correlates with overactive bladder (OAB) symptoms.
• The causal relationship between BDNF and OAB remains unclear.

Purpose of the Study:

• To investigate the functional role of BDNF overexpression in inducing bladder overactivity (BO).
• To establish a mechanistic link between urinary BDNF and dysfunctional voiding.

Main Methods:

• Rat bladder wall transfection with BDNF or luciferase transgenes.
• Transurethral open cystometry under anesthesia to assess bladder function.
• Analysis of gene and protein expression in bladder tissue and dorsal root ganglia.

Main Results:

• BDNF overexpression led to increased voiding pressure and reduced intercontractile intervals, mimicking BO.
• Upregulation of cholinergic transmission components and sensory channels (TRPV1, TRPA1) was observed.
• Elevated ATP and neurotrophins in bladder and dorsal root ganglia suggest afferent nerve sensitization.

Conclusions:

• BDNF overexpression directly induces a bladder overactivity phenotype in rats.
• Genomic changes in bladder efferent and afferent neurons establish a mechanistic link between BDNF and dysfunctional voiding.
• Findings support BDNF's role in OAB pathophysiology observed in animal models and human patients.