Urinary podocyte-associated mRNA profile in various stages of diabetic nephropathy

PLoS One. 2011;6(5):e20431. doi: 10.1371/journal.pone.0020431. Epub 2011 May 31.


Background: Podocyte injury and subsequent excretion in urine play a crucial role in the pathogenesis and progression of diabetic nephropathy (DN). Quantification of messenger RNA (mRNA) expression in urinary sediment by real-time PCR is emerging as a noninvasive method of screening DN-associated biomarkers. We hypothesized that the urinary mRNA profile of podocyte-associated molecules may provide important clinical insight into the different stages of diabetic nephropathy.

Methods: DN patients (N = 51) and healthy controls (N = 13) were enrolled in this study. DN patients were divided into a normoalbuminuria group (UAE<30 mg/g, n = 17), a microalbuminuria group (UAE 30∼300 mg/g, n = 15), and a macroalbuminuria group (UAE>300 mg/g, n = 19), according to their urinary albumin excretion (UAE). Relative mRNA abundance of synaptopodin, podocalyxin, CD2-AP, α-actin4, and podocin were quantified, and correlations between target mRNAs and clinical parameters were examined.

Results: The urinary mRNA levels of all genes studied were significantly higher in the DN group compared with controls (p<0.05), and mRNA levels increased with DN progression. Urinary mRNA levels of all target genes positively correlated with both UAE and BUN. The expression of podocalyxin, CD2-AP, α-actin4, and podocin mRNA correlated with serum creatinine (r = 0.457, p = 0.001; r = 0.329, p = 0.01; r = 0.286, p = 0.021; r = 0.357, p = 0.006, respectively). Furthermore, podocalyxin mRNA was found to negatively correlate with eGFR (r = -0.349, p = 0.01).

Conclusion: The urinary mRNA profiles of synaptopodin, podocalyxin, CD2-AP, α-actin4, and podocin were found to increase with the progression of DN, which suggested that quantification of podocyte-associated molecules will be useful biomarkers of DN.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actinin / genetics
  • Adaptor Proteins, Signal Transducing / genetics
  • Adult
  • Creatinine / blood
  • Cytoskeletal Proteins / genetics
  • Diabetic Nephropathies / blood
  • Diabetic Nephropathies / urine*
  • Female
  • Humans
  • Intracellular Signaling Peptides and Proteins / genetics
  • Male
  • Membrane Proteins / genetics
  • Microfilament Proteins / genetics
  • Middle Aged
  • Podocytes / metabolism*
  • RNA, Messenger / blood*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Sialoglycoproteins / genetics


  • ACTN4 protein, human
  • Adaptor Proteins, Signal Transducing
  • CD2-associated protein
  • Cytoskeletal Proteins
  • Intracellular Signaling Peptides and Proteins
  • Membrane Proteins
  • Microfilament Proteins
  • NPHS2 protein
  • RNA, Messenger
  • SYNPO protein, human
  • Sialoglycoproteins
  • podocalyxin
  • Actinin
  • Creatinine