title: CD2AP mRNA in urinary exosome as biomarker of kidney disease.
abstract: OBJECTIVE
  Podocyte injury plays an important role in the pathogenesis of kidney disease. Urinary exosomes are microvesicles released by tubular epithelial cells and podocytes containing information of their originated cells. This study investigated for the first time whether podocyte related mRNA in urinary exosome could serve as novel biomarkers for kidney disease.
  
  
  METHODS
  Urine samples were collected from 32 patients of kidney disease who underwent kidney biopsy and 7 controls. CD2AP, NPHS2 and synaptopodin were detected by real-time RT-PCR on RNA isolated from urinary exosome.
  
  
  RESULTS
  The pellet microvesicles were positively stained with exosome and podocyte marker, AQP2, CD9 and nephrin. CD2AP mRNA was lower (p=0.008) in kidney disease patients compared with controls and decreased with the increasing severity of proteinuria (p=0.06). CD2AP correlated with serum creatinine (r=-0.373, p=0.035), BUN (r=-0.445, p=0.009) and eGFR (r=0.351, p=0.046). Neither NPHS2 nor synaptopodin correlated with parameters of renal function. CD2AP mRNA correlated negatively with 24 hour urine protein (r=-0.403, p=0.022), severity of tubulointerstitial fibrosis (r=-0.394, p=0.026) and glomerulosclerosis (r=-0.389, p=0.031) and could discriminate kidney disease from controls with AUC of 0.821 (p=0.008).
  
  
  CONCLUSIONS
  Urinary exosome mRNA of CD2AP might be a non-invasive tool for detecting both renal function and fibrosis of kidney disease.
authors.affiliation: Institute of Nephrology, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, China. Electronic address: lvll46@gmail.com.
authors.forename: Lin-Li
authors.initials: LL
authors.lastname: Lv
authors.affiliation: Institute of Nephrology, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, China.
authors.forename: Yu-Han
authors.initials: YH
authors.lastname: Cao
authors.affiliation: Institute of Nephrology, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, China.
authors.forename: Ming-Ming
authors.initials: MM
authors.lastname: Pan
authors.affiliation: Institute of Nephrology, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Liu
authors.affiliation: Institute of Nephrology, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, China.
authors.forename: Ri-Ning
authors.initials: RN
authors.lastname: Tang
authors.affiliation: Institute of Nephrology, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, China.
authors.forename: Kun-Ling
authors.initials: KL
authors.lastname: Ma
authors.affiliation: Institute of Nephrology, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, China.
authors.forename: Ping-Sheng
authors.initials: PS
authors.lastname: Chen
authors.affiliation: Institute of Nephrology, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, China. Electronic address: liubc64@163.com.
authors.forename: Bi-Cheng
authors.initials: BC
authors.lastname: Liu
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics* / Q000652:urine; D000328:Adult; D015415:Biomarkers / Q000652:urine; D003598:Cytoskeletal Proteins / Q000235:genetics* / Q000652:urine; D055354:Exosomes / Q000235:genetics*; D005260:Female; D006801:Humans; D007674:Kidney Diseases / Q000235:genetics* / Q000652:urine*; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000235:genetics / Q000652:urine*; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D015415:Biomarkers; C114545:CD2-associated protein; D003598:Cytoskeletal Proteins; D012333:RNA, Messenger
keywords: Biomarker; Exosome; Podocyte; Renal fibrosis; Urine; mRNA