Gene expression-based functional differences between the bladder body and trigonal urothelium

The bladder body and the trigone are covered by a transitional urothelium differently involved in bladder filling and micturition. in the bladder functions. Aim. To study molecular differences between the bladder body and trigonal urothelium, we analyzed the urothelial transcriptomes and the profiles of urothelial and urinal microbiomes using massive sequencing of the total epithelial RNA and amplicons of the bacterial 16S rRNA gene, respectively, in 17 adolescent female patients with pain and micturition dysfunction. Results. RNA sequencing identified 10261 differentially expressed genes (DEGs) ( p. adj-value = 0.05), between the body and trigonal urothelium, of which the top 1000 DEGs were annotated to 36 and 77 the Reactome-related pathways formed in both locations, respectively. They represented 11 categories, (including the Extracellular matrix organization, Neuronal System, and Muscle contraction) and 15 categories (including the RHO GTPase effectors, Cell cycle, Formation of the cornified envelope and Neutrophil degranulation) enriched in the body urothelium and trigonal urothelium, respectively. There were no statistically significant differences in the bacterial taxa abundances, diversity, and richness indices neither between patients' bladder body and trigonal urothelia nor in the urine samples of patients compared to their healthy female family members. Five bacterial taxa in urine significantly differentiated healthy adolescent controls from the patients' group. Conclusion. On the transcriptome level, the body and trigonal urothelium appeared to be functionally different tissues. However, although our adolescent patients can be included in a bladder pain syndrome/interstitial cystitis, it is still not known which of the molecular differences found between the body and trigonal urothelium may be accompanied by clinical symptoms.