Abstract: TH-PO698

Urinary Ubiquitinated Factor XII and Beta-2-Glycoprotein-1 May Identify Different Histological Patterns of Diabetic Kidney Disease

Session Information

Category: Diabetes

  • 501 Diabetes Mellitus and Obesity: Basic - Experimental

Authors

  • Papale, Massimo, University of Bari-Dept. of Emergency and Organ Transplantation, Bari, Italy
  • Giorgino, Francesco, University of Bari-Dept. of Emergency and Organ Transplantation, Bari, Italy
  • Laviola, Luigi, University of Bari-Dept. of Emergency and Organ Transplantation, Bari, Italy
  • Simone, Simona, University of Bari-Dept. of Emergency and Organ Transplantation, Bari, Italy
  • Trischitta, Vincenzo, Casa Sollievo della Sofferenza Hospital, San Giovanni Rotondo (Fg), Italy
  • De Cosmo, Salvatore, Casa Sollievo della Sofferenza Hospital, San Giovanni Rotondo (Fg), Italy
  • Grandaliano, Giuseppe, University of Foggia , Foggia, Italy
  • Gesualdo, Loreto, University of Bari-Dept. of Emergency and Organ Transplantation, Bari, Italy
  • Divella, Chiara, University of Bari-Dept. of Emergency and Organ Transplantation, Bari, Italy
  • Conserva, Francesca, University of Bari-Dept. of Emergency and Organ Transplantation, Bari, Italy
  • Castellano, Giuseppe, University of Bari-Dept. of Emergency and Organ Transplantation, Bari, Italy
  • Pontrelli, Paola, University of Bari-Dept. of Emergency and Organ Transplantation, Bari, Italy
  • Di Franco, Antonella, University of Bari-Dept. of Emergency and Organ Transplantation, Bari, Italy
  • Barozzino, Mariagrazia, University of Bari-Dept. of Emergency and Organ Transplantation, Bari, Italy
  • Pesce, Francesco, University of Bari-Dept. of Emergency and Organ Transplantation, Bari, Italy
  • Oranger, Annarita, University of Bari-Dept. of Emergency and Organ Transplantation, Bari, Italy
Background

Diabetic Kidney Disease (DKD) is a heterogeneous disease with distinct histopathological phenotypes spanning from the typical nodular Kimmelstiel-Wilson lesions (DN) observed in ≈ 40% of the cases to the arteriolosclerotic changes and other primitive glomerulonephropathies (non DN-CKD) reported in the remaining cases. Recent studies (PMID: 20671095; 27881486) suggest a role of protein ubiquitination in DKD thus we tested the usefulness of urinary ubiquitinated proteins (ubi-prot) as novel biomarkers for DKD.

Methods

Sixty-four Type 2 Diabetes Mellitus patients (pts) with normoalbuminuria (NORMO), microalbuminuria (MICRO), and micro or macroalbuminuria with biopsy-proven DN or non DN-CKD were enrolled. Urinary ubi-prot were purified by Immunoprecipitation with specific anti-ubiquitin antibody and identified by LTQ Orbitrap XL™ Mass Spectrometry (MS) analysis. Protein Pattern Analysis (PPA) allowed the recognition of specific molecular patterns in each group and the most confident biomarkers were then validated by IF and ELISA or immunoblotting in tissue and urine samples, respectively.

Results

MS analysis identified 79 ubi-prot in NORMO, 111 in MICRO, 135 in non DN-CKD and 116 in DN, respectively. PPA analysis associated differentially excreted ubi-prot to the activation of the classical pathway of complement system in DKD. Urinary C5b9, measured in an independent set of pts, was significantly more excreted (P < 0.01) in DKD Vs. non proteinuric T2DM and pts with Lupus Nephritis and correlated, in the DN subset, with an increased deposition in proximal tubuli. Furthermore, 5 unique ubi-prot namely Factor XII, Ig K and Lambda chains, Beta-2-glycoprotein-1 (B2GP-1) and C6 were excreted in DN group only. Independent validation in 8 DN Vs 8 non DN-CKD pts confirmed that urinary ubiquitinated Factor XII and B2GP-1 were significantly more excreted in DN Vs. non DN-CKD (P< 0.001 and P < 0.0001, respectively).

Conclusion

Combined evaluation of urinary C5b9, ubiquitinated Factor XII and B2GP-1 may allow noninvasive
stratification of pts with DKD

Funding

  • Government Support - Non-U.S.