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Abstract: FR-PO983

Possible Role of Calpains 2 and 5 in CKD Progression and Renal Fibrosis

Session Information

  • CKD: Pathobiology - I
    November 04, 2022 | Location: Exhibit Hall, Orange County Convention Center‚ West Building
    Abstract Time: 10:00 AM - 12:00 PM

Category: CKD (Non-Dialysis)

  • 2203 CKD (Non-Dialysis): Mechanisms

Authors

  • Gutierrez Calabres, Elena, Department of Systems Biology, Physiology Unit, Universidad of Alcala, Alcala de Henares, Madrid, Spain
  • Campillo de Blas, Sofia, Department of Systems Biology, Physiology Unit, Universidad of Alcala, Alcala de Henares, Madrid, Spain
  • de la Serna, Mariano, Biomedical Research Foundation, Hospital Universitario Principe de Asturias, Alcala de Henares, Madrid, Spain
  • Canales Bueno, Natalia, NOVELREN, Instituto Ramon y Cajal de Investigacion Sanitaria (IRYCIS), Fundacion Renal Iñigo Alvarez de Toledo (FRIAT) and REDinREN, (ISCIII), Madrid, Madrid, Spain
  • González Valero, Cristina, Department of Systems Biology, Physiology Unit, Universidad of Alcala, Alcala de Henares, Madrid, Spain
  • Griera, Mercedes, Graphenano Medical Care S.L., NOVELREN, Instituto Ramon y Cajal de Investigacion Sanitaria (IRYCIS), Fundacion Renal Iñigo Alvarez de Toledo (FRIAT) and REDinREN, (ISCIII), Madrid, Madrid, Spain
  • De frutos garcia, Sergio, Graphenano Medical Care S.L., NOVELREN, Instituto Ramon y Cajal de Investigacion Sanitaria (IRYCIS), Fundacion Renal Iñigo Alvarez de Toledo (FRIAT) and REDinREN, (ISCIII), Madrid, Madrid, Spain
  • Calleros, Laura, Department of Systems Biology, Physiology Unit, Universidad of Alcala, Alcala de Henares, Madrid, Spain
  • Rodriguez puyol, Diego, Nephrology Unit and Biomedical Research Foundation, Hospital Universitario Principe de Asturias and Department of Medicine and Medical Specialties, Universidad de Alcala, Alcala de Henares, Madrid, Spain
Background

Calpains (CAPN) are intracellular cysteine proteases that play an important role in multiple biological processes linked to tissue damage and repair mechanisms, such as epithelial-mesenchymal transition and fibrosis. These two phenomena are critical in the development of chronic kidney disease (CKD), but a relationship between them and CAPN in CKD has not been definitively proved. The aim of this study was to investigate the possible role of CAPN in the development of CKD and renal fibrosis in an experimental model of CKD induced by adenine and in human kidney proximal tubular cells (HK-2).

Methods

Tubulointerstitial damage resembling that is observed in human CKD was induced in mice fed an adenine-rich diet (0.2%, for 5 days and 2 weeks). In vitro experiments were performed in TGF-b HK-2 treated cells (1 ng/ml, different times), and two CAPN inhibitors (calpeptin, calpain inhibitor III, 50 µM). Mice renal function was assessed by measuring plasma BUN and creatinine. Fibrosis markers (collagen type I and fibronectin) were determined by RT-qPCR. Protein content of CAPN 2 and 5 were analyzed by western blot. CAPN activity was analyzed by fluorescence assays.

Results

Our results show a progressive worsening of renal function and fibrosis in adenine-fed mice, with increased BUN, creatinine, COL I and FN mRNA expression, being significantly higher at 2 weeks of treatment. Protein content of CAPN 2 and 5 was significantly higher in animals that received adenine for 2 weeks when compared to control, together with a statistically significant increased renal CAPN activity. Our results point out that CAPN 2 and 5 content in renal tissue increases as CKD and fibrosis progresses. To verify this potential relationship, we induced fibrosis in HK-2 cells with TGF-b, that increased COL I and FN mRNA expression, as well as CAPN 2 and 5 levels. The two CAPN inhibitors prevented the TGF-b-induced increase in CAPN activity and COL I expression.

Conclusion

We suggest a direct relationship between the fibrosis observed in CKD and the cellular content of CAPN, which could be involved in the genesis or progression of kidney disease. Thus, effective CAPN blockade or downregulation could be useful as a therapeutic strategy to prevent CKD.

Funding

  • Other NIH Support