Kidney Week

Abstract: FR-PO301

WWP2-Induced Pericytes to Myofibroblast Transition Contributes to the Progression of Fibrosis in CKD in Diabetes

Session Information

• Diabetic Kidney Disease: Basic - 1
  October 25, 2024 | Location: Exhibit Hall, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Diabetic Kidney Disease

• 701 Diabetic Kidney Disease: Basic

Authors

• Pontrelli, Paola, University of Bari Aldo Moro, Bari, BA, Italia / Italy, Italy

Paola Pontrelli, PhD

• Conserva, Francesca, University of Bari Aldo Moro, Bari, BA, Italia / Italy, Italy

Francesca Conserva, PhD

• Cicirelli, Antonella, University of Bari Aldo Moro, Bari, BA, Italia / Italy, Italy

Antonella Cicirelli, MSc

• Venneri, Maria, University of Bari Aldo Moro, Bari, BA, Italia / Italy, Italy

Maria Venneri, MS, PhD

• Franzin, Rossana, University of Bari Aldo Moro, Bari, BA, Italia / Italy, Italy

Rossana Franzin, PhD

• Stasi, Alessandra, University of Bari Aldo Moro, Bari, BA, Italia / Italy, Italy

Alessandra Stasi, PhD

• Sclavo, Giorgia, University of Bari Aldo Moro, Bari, BA, Italia / Italy, Italy

Giorgia Sclavo, MSc

• Squiccimarro, Elena, University of Bari Aldo Moro, Bari, BA, Italia / Italy, Italy

Elena Squiccimarro, MSc

• Gallone, Anna, University of Bari Aldo Moro, Bari, BA, Italia / Italy, Italy

Anna Gallone

• Pesce, Francesco, Universita Cattolica del Sacro Cuore Facolta di Medicina e Chirurgia, Roma, Lazio, Italy

Francesco Pesce, MD, PhD

• Fiorentino, Marco, University of Bari Aldo Moro, Bari, BA, Italia / Italy, Italy

Marco Fiorentino, MD

• Gesualdo, Loreto, University of Bari Aldo Moro, Bari, BA, Italia / Italy, Italy

Loreto Gesualdo, DrMed

Background

CKD in diabetes presents different histological phenotypes commonly classified as diabetic Nephropathy (DN), non-diabetic renal disease (NDRD) and mixed forms (DN+NDRD) and only true DN is characterized by activation of the lysine63 (K63-Ub) ubiquitination pathway involved in the progression of renal fibrosis. WWP2 is an E3 ligase enzyme that modulates myofibroblast activation in cardiac fibrosis and metabolic reprogramming in CKD. The aim of the study was to evaluate the role of WWP2 in renal fibrosis in diabetes and its involvement in K63-Ub.

Methods

The expression of WWP2, K-63Ub, a-sma, PDGFBR, vimentin, NG2 was evaluated by immunohistochemistry, immunofluorescence, qPCR, western blotting and/or flow cytometry in: i) renal biopsies of patients with DN (n=11) , nephroangiosclerosis or other renal damage in diabetic patients (NDRD) (n=8) and mixed forms DN+NDRD (n=3); ii) DBA/2J mice treated with streptozotocin in the presence or absence of a specific K63Ub inhibitor (NSC697923); iii) HK2 tubular cells, EAHY926 endothelial cells and pericytes.

Results

WWP2 was expressed at tubular, glomerular and vascular levels in both DN and DN+NDRD compared to NDRD (p<0.05 and p<0.01 respectively). Increased expression of WWP2 in DN was associated with the accumulation of K63Ub proteins in the tubular and vascular compartment, particularly in pericytes. In diabetic DBA/2J mice, K63Ub inhibition with NSC697923 significantly reduced WWP2 expression in the kidney (p < 0.05). Also in vitro, in HK2 cells, NSC697923 significantly reduced hyperglycemia-induced WWP2 and a-sma expression (p < 0.01). In pericytes, hyperglycemia induced the expression of WWP2 (RR>3), a-sma (RR>4), PDGFBR (RR>4), vimentin (RR>2) and reduced NG2 (RR>2) suggesting the transition from pericytes to myofibroblasts, and this effect was blocked by NSC697923 (p<0.05).

Conclusion

These findings suggest that WWP2 is involved in the K63-Ub pathway and promotes fibrosis progression in DN patients through pericytes to myofibroblasts transition. WWP2 could therefore represent a novel target in preventing the progression of renal damage in patients with DN.