Transcriptomic Remodeling of the Spinal Cord-Injured Bladder and Its Modulation by Inosine Treatment
Neurogenic detrusor overactivity (NDO) is a frequent complication of spinal cord injury (SCI), often accompanied by profound structural and functional changes in the bladder. While inosine has previously been shown to improve bladder function in SCI models, its molecular effects on the bladder remain largely unexplored. In this study, we performed transcriptomic profiling of bladder tissues from SCI rats treated with inosine or vehicle. Bladder compartments were microdissected into detrusor and mucosa to capture compartment-specific changes. SCI induced widespread transcriptional alterations in both compartments, with inosine treatment partially restoring gene expression patterns toward those observed in non-injured controls. Unsupervised clustering and principal component analyses confirmed distinct transcriptional profiles associated with injury and treatment. Notably, inosine influenced a set of genes consistently altered by SCI, suggesting a protective or regulatory role at the molecular level. These findings reveal a compartment-specific transcriptomic response to spinal cord injury and provide insight into the mechanisms by which inosine may exert its therapeutic effects on the injured bladder. Overall design: Complete spinal cord transection was performed at the T8 vertebral level in male Sprague Dawley rats (6–7 weeks old, approximately 250 grams; Charles River Laboratories, Wilmington, MA) under isoflurane anesthesia, as previously described. The spinal cord was exposed between T8–T10 using bony and vascular landmarks and transected completely at T8. Following injury, rats received daily intraperitoneal injections of either inosine (225 mg/kg/day) or vehicle control (12 mM sodium bicarbonate buffer, pH 9.2) for 8 weeks. At the end of the treatment period, animals were euthanized, bladders were harvested, weighed, and microdissected into two distinct tissue compartments: detrusor (smooth muscle layer) and mucosa (urothelium and lamina propria). Tissues were flash-frozen in liquid nitrogen and stored at -80°C until RNA extraction and sequencing. RNA-seq was performed to assess transcriptomic changes in response to spinal cord injury and inosine treatment across bladder compartments.