title: Messenger RNA expression of podocyte-associated molecules in the urinary sediment of patients with diabetic nephropathy.
abstract: BACKGROUND
  Podocyte loss plays an important role in the pathogenesis of diabetic nephropathy. We hypothesize that messenger RNA expression of podocyte-associated molecules in urinary sediment may provide important clinical information in patients with diabetic nephropathy.
  
  
  METHODS
  We studied 21 patients with biopsy-proven diabetic nephropathy and 9 healthy controls. The mRNA expression of nephrin, podocin, synaptopodin, Wilms' tumor-1 (WT-1) and alpha-actinin-4 in urinary sediment were measured by real-time quantitative polymerase chain reaction. The degree of histological damage was quantified by morphometric analysis. Patients were then followed for an average of 25.63 +/- 10.76 months. The rate of glomerular filtration rate (GFR) decline was calculated by the least-square regression.
  
  
  RESULTS
  There were significant differences in nephrin, podocin, synaptopodin, alpha-actinin-4 (p < 0.01 for all comparisons) and WT-1 (p = 0.028) expression between patients and normal controls. Urinary nephrin expression was significantly correlated with proteinuria (r = 0.502, p = 0.020); urinary synaptopodin was significantly correlated with proteinuria (r = 0.585, p = 0.005), serum creatinine (r = 0.516, p = 0.017) and estimated GFR (r = -0.560, p = 0.008), and urinary WT-1 expression was significantly correlated with the degree of tubulointerstitial fibrosis (r = 0.558, p = 0.009). There was no significant correlation between GFR decline and urinary expression of target genes.
  
  
  CONCLUSIONS
  Urinary mRNA expressions of nephrin, podocin, synaptopodin, WT-1 and alpha-actinin-4 are higher in patients with diabetic nephropathy than in normal controls. Urinary nephrin and synaptopodin expressions are correlated with baseline clinical parameters such as proteinuria or renal function, while WT-1 expression is related to the degree of histological damage. Our results suggest that urinary mRNA expression of podocyte-associated molecules may be used for risk stratification of diabetic nephropathy.
authors.affiliation: Department of Medicine and Therapeutics, Prince of Wales Hospital, Chinese University of Hong Kong, Hong Kong, SAR, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Wang
authors.forename: Fernand Mac-Moune
authors.initials: FM
authors.lastname: Lai
authors.forename: Ka-Bik
authors.initials: KB
authors.lastname: Lai
authors.forename: Kai-Ming
authors.initials: KM
authors.lastname: Chow
authors.forename: Kam-Tao Philip
authors.initials: KT
authors.lastname: Li
authors.forename: Cheuk-Chun
authors.initials: CC
authors.lastname: Szeto
mesh_terms: D000328:Adult; D003928:Diabetic Nephropathies / Q000652:urine*; D005260:Female; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000652:urine*; D008297:Male; D008875:Middle Aged; D050199:Podocytes / Q000378:metabolism*; D012333:RNA, Messenger / Q000652:urine*
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D012333:RNA, Messenger