Urine

Recent findings suggest that human microbiome can influence the development of cancer, but the role of microorganisms in bladder cancer pathogenesis has not been explored yet. The aim of this study was to characterize and compare the urinary microbiome of bladder cancer patients with those of healthy controls. Bacterial communities present in urine specimens collected from 12 male patients diagnosed with bladder cancer, and from 11 healthy, age-matched individuals were analysed using 16S sequencing. Our results show that the most abundant phylum in both groups was Firmicutes, followed by Actinobacteria, Bacteroidetes and Proteobacteria. While microbial diversity and overall microbiome composition were not significantly different between groups, we could identify operational taxonomic units (OTUs) that were more abundant in either group. Among those that were significantly enriched in the bladder cancer group, we identified an OTU belonging to genus Fusobacterium, a possible protumorigenic pathogen. In an independent sample of 42 bladder cancer tissues, 11 had Fusobacterium nucleatum sequences detected by PCR. Three OTUs from genera Veillonella, Streptococcus and Corynebacterium were more abundant in healthy urines. However, due to the limited number of participants additional studies are needed to determine if urinary microbiome is associated with bladder cancer.

Artificial urine has many advantages over human urine for research and educational purposes. By closely mimicking healthy individuals' urine, it may also be important in discovering novel biomarkers. However, up until now, there has not been any specific protocol to prove the similarity in terms of the chemical composition at the molecular level. In this study, a new artificial urine protocol is established to mimics the urine of healthy individuals. The multi-purpose artificial urine (MP-AU) presented here is compared with two other protocols most cited in literature. Furthermore, these three protocols are also compared with samples from 28 healthy young individuals. To do so, attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) is used, according to which MP-AU shows a significantly close similarity with human urine. In formulating MP-AU, the infrared spectra of nine compounds is provided, making possible the band assignment of some absorption bands to certain compounds. Given its properties, the MP-AU protocol introduced here is both economical and practical, making it useful when designing comparative-controlled experiments.

Extracellular vesicles (EVs) provide an invaluable tool to analyse physiological processes because they transport, in biological fluids, biomolecules secreted from diverse tissues of an individual. EV biomarker detection requires highly sensitive techniques able to identify individual molecules. However, the lack of widespread, affordable methodologies for high-throughput EV analyses means that studies on biomarkers have not been done in large patient cohorts. To develop tools for EV analysis in biological samples, we evaluated here the critical parameters to optimise an assay based on immunocapture of EVs followed by flow cytometry. We describe a straightforward method for EV detection using general EV markers like the tetraspanins CD9, CD63 and CD81, that allowed highly sensitive detection of urinary EVs without prior enrichment. In proof-of-concept experiments, an epithelial marker enriched in carcinoma cells, EpCAM, was identified in EVs from cell lines and directly in urine samples. However, whereas EVs isolated from 5-10 ml of urine were required for western blot detection of EpCAM, only 500 μl of urine were sufficient to visualise EpCAM expression by flow cytometry. This method has the potential to allow any laboratory with access to conventional flow cytometry to identify surface markers on EVs, even non-abundant proteins, using minimally processed biological samples.

Urine-derived stem cells (UDSCs) have emerged as a promising cell source for regenerative medicine due to their non-invasive procurement, high proliferative capacity, and potential relevance to kidney-specific repair. Unlike conventional mesenchymal stem cells (MSCs) obtained from bone marrow or adipose tissue, UDSCs originate from multiple regions of the urinary tract and exhibit a unique biological profile that combines MSC characteristics with features of renal progenitor populations. This review provides a comprehensive overview of the current understanding of UDSC biology, including their origin, isolation strategies, morphology, immunophenotypic characteristics, differentiation potential, and secretory profile. Particular attention is given to the expression of renal lineage-associated markers and pluripotency-related factors that may contribute to their regenerative capacity. The bioactive mediators of UDSCs regulate inflammation, oxidative stress, angiogenesis, and extracellular matrix remodeling, thereby influencing key pathways implicated in chronic kidney disease (CKD)-associated fibrosis. Furthermore, the intrinsic renal progenitor signature of UDSCs may provide advantages in renal homing and tissue-specific repair compared with conventional MSC populations. Despite encouraging preclinical findings, significant challenges remain, including cellular heterogeneity, inconsistent isolation efficiency, lack of standardized characterization criteria, and limited clinical validation. Collectively, current evidence positions UDSCs as a biologically distinct and therapeutically attractive platform for kidney regeneration.