Autophagy Activation in Peripheral Blood Mononuclear Cells of Peritoneal Dialysis Patients

Simona Granata; Maurizio Bruschi; Alberto Verlato; Paola Pontrelli; Loreto Gesualdo; Giovanni Stallone; Gianluigi Zaza

doi:10.1016/j.ekir.2023.06.017

Autophagy Activation in Peripheral Blood Mononuclear Cells of Peritoneal Dialysis Patients

Kidney Int Rep. 2023 Jun 26;8(9):1852-1863. doi: 10.1016/j.ekir.2023.06.017. eCollection 2023 Sep.

Authors

Simona Granata¹, Maurizio Bruschi^{2

3}, Alberto Verlato^{4

5}, Paola Pontrelli⁶, Loreto Gesualdo⁶, Giovanni Stallone¹, Gianluigi Zaza¹

Affiliations

¹ Nephrology, Dialysis and Transplantation Unit, Department of Medical and Surgical Sciences, University of Foggia, Foggia, Italy.
² Laboratory of Molecular Nephrology, IRCCS Istituto Giannina Gaslini, Genova, Italy.
³ Department of Experimental Medicine, University of Genoa, Genoa, Italy.
⁴ Renal Unit, Department of Medicine, University Hospital of Verona, Verona, Italy.
⁵ Department of Medicine, Nephrology, Icahn School of Medicine at Mount Sinai, New York, NY, United States.
⁶ Nephrology, Dialysis and Transplantation Unit, Department of Precision and Regenerative Medicine and Ionian Area, University of Bari, Bari, Italy.

Abstract

Introduction: The complete systemic deregulated biological network in patients on peritoneal dialysis (PD) is still only partially defined. High-throughput/omics techniques may offer the possibility to analyze the main biological fingerprints associated with this clinical condition.

Methods: We applied an innovative bioinformatic analysis of gene expression microarray data (mainly based on support vector machine (SVM) learning) to compare the transcriptomic profile of peripheral blood mononuclear cells (PBMCs) of healthy subjects (HS), chronic kidney disease (CKD) patients, and patients on PD divided into a microarray group (5 HS, 9 CKD, and 10 PD) and a validation group (10 HS, 15 CKD, and 15 PD). Classical well-standardized biomolecular approaches (western blotting and flow cytometry) were used to validate the transcriptomic results.

Results: Bioinformatics revealed a distinctive PBMC transcriptomic profiling for PD versus CKD and HS (n = 419 genes). Transcripts encoding for key elements of the autophagic pathway were significantly upregulated in PD, and the autophagy related 5 (ATG5) reached the top level of discrimination [-Log10 P-value = 11.3, variable importance in projection (VIP) score = 4.8, SVM rank:1]. Protein levels of ATG5 and microtubule associated protein 1 light chain 3 beta (LC3B), an important constituent of the autophagosome, validated microarray results. In addition, the incubation of PBMCs of HS with serum of patients on PD upregulated both proteins. Autophagy in PBMCs from patients on PD was attenuated by N-acetyl-cysteine or Resatorvid treatment.

Conclusions: Our data demonstrated, for the first time, that the autophagy pathway is activated in immune-cells of patients on PD, and this may represent a novel therapeutic target.

Keywords: autophagy; chronic kidney disease; peritoneal dialysis.