Loss of dicer exacerbates cyclophosphamide-induced bladder overactivity by enhancing purinergic signaling

Area of Science:

• Urology
• Molecular Biology
• Genetics

Background:

• MicroRNAs (miRNAs) regulate gene expression in various pathologies.
• The role of miRNAs in the pathoetiology of overactive bladder (OAB) is largely unknown.

Purpose of the Study:

• To investigate the impact of miRNA processing on OAB development and characteristics.
• To elucidate the role of Dicer-dependent miRNAs in regulating detrusor function and OAB pathogenesis.

Main Methods:

• Generated a mouse model with inducible Dicer deletion in the detrusor muscle.
• Induced OAB using cyclophosphamide and assessed detrusor function, urodynamics, and macrophage infiltration.
• Analyzed miRNA targeting of P2x mRNAs and P2X expression in detrusor tissue.
• Examined human OAB patient bladder biopsies for similar molecular changes.

Main Results:

• Dicer deletion alone did not significantly alter detrusor function under physiological conditions.
• Loss of Dicer exacerbated cyclophosphamide-induced OAB, showing increased severity in contractile force, sensitivity, abnormal urodynamics, and macrophage infiltration.
• Dicer deficiency led to impaired miRNA expression targeting P2x mRNAs, resulting in enhanced P2X expression in the detrusor.
• Similar findings were observed in human OAB patient bladder biopsies, indicating conserved mechanisms.

Conclusions:

• miRNAs modulate OAB susceptibility by regulating purinergic signaling pathways.
• Loss of Dicer impairs miRNA-mediated suppression of P2X expression, predisposing to OAB.
• These findings suggest a protective role for specific miRNAs in suppressing OAB symptoms via purinergic signaling regulation.