title: Cell and Microvesicle Urine microRNA Deep Sequencing Profiles from Healthy Individuals: Observations with Potential Impact on Biomarker Studies.
abstract: BACKGROUND
  Urine is a potential source of biomarkers for diseases of the kidneys and urinary tract. RNA, including microRNA, is present in the urine enclosed in detached cells or in extracellular vesicles (EVs) or bound and protected by extracellular proteins. Detection of cell- and disease-specific microRNA in urine may aid early diagnosis of organ-specific pathology. In this study, we applied barcoded deep sequencing to profile microRNAs in urine of healthy volunteers, and characterized the effects of sex, urine fraction (cells vs. EVs) and repeated voids by the same individuals.
  
  
  RESULTS
  Compared to urine-cell-derived small RNA libraries, urine-EV-derived libraries were relatively enriched with miRNA, and accordingly had lesser content of other small RNA such as rRNA, tRNA and sn/snoRNA. Unsupervised clustering of specimens in relation to miRNA expression levels showed prominent bundling by specimen type (urine cells or EVs) and by sex, as well as a tendency of repeated (first and second void) samples to neighbor closely. Likewise, miRNA profile correlations between void repeats, as well as fraction counterparts (cells and EVs from the same specimen) were distinctly higher than correlations between miRNA profiles overall. Differential miRNA expression by sex was similar in cells and EVs.
  
  
  CONCLUSIONS
  miRNA profiling of both urine EVs and sediment cells can convey biologically important differences between individuals. However, to be useful as urine biomarkers, careful consideration is needed for biofluid fractionation and sex-specific analysis, while the time of voiding appears to be less important.
authors.affiliation: Nephrology and Hypertension, Hadassah-Hebrew University Medical Center, Jerusalem, Israel.
authors.forename: Iddo Z
authors.initials: IZ
authors.lastname: Ben-Dov
authors.affiliation: Rockefeller University Hospital, The Rockefeller University, New York, NY, United States of America.
authors.forename: Veronica M
authors.initials: VM
authors.lastname: Whalen
authors.affiliation: Pediatric Nephrology, Children's Hospital at Montefiore, Albert Einstein College of Medicine, Bronx, NY, United States of America.
authors.forename: Beatrice
authors.initials: B
authors.lastname: Goilav
authors.affiliation: Laboratory of RNA Molecular Biology, The Rockefeller University, New York, NY, United States of America.
authors.forename: Klaas E A
authors.initials: KE
authors.lastname: Max
authors.affiliation: Laboratory of RNA Molecular Biology, The Rockefeller University, New York, NY, United States of America.
authors.forename: Thomas
authors.initials: T
authors.lastname: Tuschl
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000652:urine*; D055252:Cell-Derived Microparticles / Q000235:genetics*; D000067128:Extracellular Vesicles / Q000235:genetics*; D005260:Female; D020869:Gene Expression Profiling; D064368:Healthy Volunteers; D059014:High-Throughput Nucleotide Sequencing / Q000379:methods*; D006801:Humans; D008297:Male; D035683:MicroRNAs / Q000235:genetics* / Q000652:urine*; D025341:Principal Component Analysis; D055815:Young Adult
chemical_list: D015415:Biomarkers; D035683:MicroRNAs