Capturing the Kidney Transcriptome by Urinary Extracellular Vesicles—From Pre-Analytical Obstacles to Biomarker Research

Urinary extracellular vesicles (uEV) hold non-invasive RNA biomarkers for genitourinary tract diseases. However, missing knowledge about reference genes and effects of preanalytical choices hinder biomarker studies. We aimed to assess how variables (urine storage temperature, isolation workflow) affect diabetic kidney disease (DKD)—linked miRNAs or kidney—linked mRNAs (kidney-RNAs) in uEV isolates discover stable across diverse datasets. studied nine raw normalized sequencing datasets including healthy controls individuals with prostate cancer type 1 diabetes without albuminuria. focused on kidney-RNAs reviewing literature DKD-linked from tissue, cell culture uEV/urine experiments. RNAs were analyzed by expression heatmaps, hierarchical clustering selecting counts (>200) minimal coefficient variation. Kidney-RNAs decreased after urine at −20 °C vs. −80 °C. Isolation workflows captured different efficiencies. Ultracentrifugation DKD -linked that separated macroalbuminuria groups. Eleven stably expressed the Hence, pre-analytical had variable kidney-RNAs—analyzing complemented global correlation, which could fade differences some relevant RNAs. Replicating prior DKD-marker results discovery candidate encourages further