Purpose: To assess functional and structural changes in vascular and neural structures associated with diabetic bladder dysfunction (DBD) in the bladders of streptozotocin (STZ)-induced diabetic mice. Methods: Eight-week-old C57BL/6 mice were injected with STZ at 50 mg/kg daily for 5 consecutive days. Catheters were inserted 12 weeks later, and 5 days after catheter placement bladder functions were assessed by conscious cystometry. Neurovascular and extracellular matrix marker changes in harvested urinary bladders were investigated by immunofluorescent staining. Body weights and fasting and postprandial blood glucose levels were measured 12 weeks after STZ injection. Results: STZ-induced diabetic mice had significantly lower body weights and significantly higher blood glucose levels. Assessment of bladder function in STZ-induced diabetic mice revealed a nearly 3-fold increase in bladder capacity and intercontractile interval compared to controls. However, basal pressure, maximal bladder pressure, and threshold pressure were not significantly different. Morphological and structural analysis showed that STZ-induced diabetic mice had significantly reduced microvascular density in lamina propria (33% of the nondiabetic control values), and severely decreased nerve contents in the detrusor region (42% of the nondiabetic control values). Conclusions STZ-induced diabetic mice exhibit functional and structural derangements in urinary bladder. The present study provides a foundation and describes a useful means of evaluating the efficacies of therapeutic targets and exploring the detailed mechanism of DBD.

Purpose: To investigate the therapeutic potential of eliminating insulin-like growth factor-binding protein 5 (IGFBP5) expression in improving erectile function in mice with cavernous nerve injury (CNI)-induced erectile dysfunction (ED). Materials and Methods: Eight-week-old male C57BL/6 mice were divided into four groups: a sham-operated group and three CNI-induced ED groups. The CNI-induced ED groups were treated with intracavernous injections 3 days before the CNI procedure.These injections included phosphate-buffered saline, scrambled control short hairpin RNA (shRNA), or shRNA targeting mouse IGFBP5 lentiviral particles. One week after CNI, erectile function was evaluated and the penile tissue was then harvested for histological examination and western blot analysis. Additionally, the major pelvic ganglia (MPG) and dorsal root ganglia (DRG) were cultured for ex vivo neurite outgrowth assays. Results: Following CNI, IGFBP5 expression in the cavernous tissues significantly increased, reaching its peak at day 7. First, ablation of IGFBP5 expression promotes neurite sprouting in MPG and DRG when exposed to lipopolysaccharide. Second, ablating IGFBP5 expression in CNI-induced ED mice improved erectile function, likely owing to increased neurovascular contents, including endothelial cells, pericytes, and neuronal processes. Third, ablating IGFBP5 expression in CNI-induced ED mice promoted neurovascular regeneration by increasing cell proliferation, reducing apoptosis, and decreasing Reactive oxygen species production. Finally, western blot analysis demonstrated that IGFBP5 ablation attenuated the JNK/c-Jun signaling pathway, activated the PI3K/AKT signaling pathway, and increased vascular endothelial growth factor and neurotrophic factor expression. Conclusions Ablating IGFBP5 expression enhanced neurovascular regeneration and ultimately improved erectile function in CNI-induced ED mice.

Purpose: To determine whether the overexpression of the Argonaute RNA-induced silencing complex catalytic component 2 (Ago2) improves erectile function in mice after cavernous nerve injury (CNI). Materials and Methods: Lentiviruses containing Ago2 open reading frame (ORF) mouse clone (Ago2 O/E) were used to overexpress Ago2, and lentiviruses ORF negative control particles (NC) were used as a negative control. Three days before preparing the CNI model, we injected lentiviruses into the penises of 8-week-old male C57BL/6 mice. Animals were then divided into four groups: the sham operation control group and the CNI+phosphate-buffered saline, CNI+NC, and CNI+Ago2 O/E groups. One week later, erectile function was assessed by electrically stimulating cavernous nerves bilaterally and obtaining intracavernous pressure parameters. Penile tissue was also collected for molecular mechanism studies. Results: Ago2 overexpression improved erectile function in mice after CNI-induced erectile dysfunction (ED). Immunofluorescence staining and Western blot analysis showed that under Ago2 overexpressing conditions, the contents of endothelial cells, pericytes, and neuronal cells increased in the penile tissues of CNI mice, and this was attributed to reduced apoptosis and ROS production. In addition, we also found that Ago2 overexpression could restore penile mitochondrial function, thereby improving erectile function in CNI-induced ED mice. Conclusions Our findings demonstrate that Ago2 overexpression can reduce penile cell apoptosis, restore penile mitochondrial function, and improve erectile function in CNI-induced ED mice.