title: Lysine 63 ubiquitination is involved in the progression of tubular damage in diabetic nephropathy.
abstract: The purpose of our study was to evaluate how hyperglycemia (HG) influences Lys63 protein ubiquitination and its involvement in tubular damage and fibrosis in diabetic nephropathy (DN). Gene and protein expression of UBE2v1, a ubiquitin-conjugating E2-enzyme variant that mediates Lys63-linked ubiquitination, and Lys63-ubiquitinated proteins increased in HK2 tubular cells under HG. Matrix-assisted laser desorption/ionization-time of flight/tandem mass spectrometry identified 30 Lys63-ubiquitinated proteins, mainly involved in cellular organization, such as β-actin, whose Lys63 ubiquitination increased under HG, leading to cytoskeleton disorganization. This effect was reversed by the inhibitor of the Ubc13/UBE2v1 complex NSC697923. Western blot analysis confirmed that UBE2v1 silencing in HK2 under HG, restored Lys63-β-actin ubiquitination levels to the basal condition. Immunohistochemistry on patients with type 2 diabetic (T2D) revealed an increase in UBE2v1- and Lys63-ubiquitinated proteins, particularly in kidneys of patients with DN compared with control kidneys and other nondiabetic renal diseases, such as membranous nephropathy. Increased Lys63 ubiquitination both in vivo in patients with DN and in vitro, correlated with α-SMA expression, whereas UBE2v1 silencing reduced HG-induced α-SMA protein levels, returning them to basal expression. In conclusion, UBE2v1- and Lys63-ubiquitinated proteins increase in vitro under HG, as well as in vivo in T2D, is augmented in patients with DN, and may affect cytoskeleton organization and influence epithelial-to-mesenchymal transition. This process may drive the progression of tubular damage and interstitial fibrosis in patients with DN.-Pontrelli, P., Conserva, F., Papale, M., Oranger, A., Barozzino, M., Vocino, G., Rochetti, M. T., Gigante, M., Castellano, G., Rossini, M., Simone, S., Laviola, L., Giorgino, F., Grandaliano, G., Di Paolo, S., Gesualdo, L. Lysine 63 ubiquitination is involved in the progression of tubular damage in diabetic nephropathy.
authors.affiliation: Division of Nephrology, Dialysis, and Transplantation, Department of Emergency and Organ Transplantation, University of Bari, Bari, Italy; paola.pontrelli@uniba.it.
authors.forename: Paola
authors.initials: P
authors.lastname: Pontrelli
authors.affiliation: Division of Nephrology, Dialysis, and Transplantation, Department of Emergency and Organ Transplantation, University of Bari, Bari, Italy.|Department of Cardiology and Cardiac Rehabilitation, Scientific Clinical Institute of Maugeri, Bari, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Conserva
authors.affiliation: Division of Nephrology, Department of Medical and Surgical Sciences, University of Foggia, Foggia, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Papale
authors.affiliation: Division of Nephrology, Dialysis, and Transplantation, Department of Emergency and Organ Transplantation, University of Bari, Bari, Italy.
authors.forename: Annarita
authors.initials: A
authors.lastname: Oranger
authors.affiliation: Division of Nephrology, Dialysis, and Transplantation, Department of Emergency and Organ Transplantation, University of Bari, Bari, Italy.
authors.forename: Mariagrazia
authors.initials: M
authors.lastname: Barozzino
authors.affiliation: Division of Nephrology, Department of Medical and Surgical Sciences, University of Foggia, Foggia, Italy.
authors.forename: Grazia
authors.initials: G
authors.lastname: Vocino
authors.affiliation: Division of Nephrology, Dialysis, and Transplantation, Department of Emergency and Organ Transplantation, University of Bari, Bari, Italy.
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: Rocchetti
authors.affiliation: Division of Nephrology, Dialysis, and Transplantation, Department of Emergency and Organ Transplantation, University of Bari, Bari, Italy.
authors.forename: Margherita
authors.initials: M
authors.lastname: Gigante
authors.affiliation: Division of Nephrology, Dialysis, and Transplantation, Department of Emergency and Organ Transplantation, University of Bari, Bari, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Castellano
authors.affiliation: Division of Nephrology, Dialysis, and Transplantation, Department of Emergency and Organ Transplantation, University of Bari, Bari, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Rossini
authors.affiliation: Division of Nephrology, Dialysis, and Transplantation, Department of Emergency and Organ Transplantation, University of Bari, Bari, Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Simone
authors.affiliation: Division of Endocrinology, Department of Emergency and Organ Transplantation, University of Bari, Bari, Italy; and.
authors.forename: Luigi
authors.initials: L
authors.lastname: Laviola
authors.affiliation: Division of Endocrinology, Department of Emergency and Organ Transplantation, University of Bari, Bari, Italy; and.
authors.forename: Francesco
authors.initials: F
authors.lastname: Giorgino
authors.affiliation: Division of Nephrology, Department of Medical and Surgical Sciences, University of Foggia, Foggia, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Grandaliano
authors.affiliation: Nephrology Unit, Dimiccoli Hospital, Barletta, Italy.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Di Paolo
authors.affiliation: Division of Nephrology, Dialysis, and Transplantation, Department of Emergency and Organ Transplantation, University of Bari, Bari, Italy.
authors.forename: Loreto
authors.initials: L
authors.lastname: Gesualdo
mesh_terms: D000595:Amino Acid Sequence; D015415:Biomarkers; D002460:Cell Line; D003928:Diabetic Nephropathies / Q000378:metabolism*; D004847:Epithelial Cells / Q000378:metabolism; D005786:Gene Expression Regulation / Q000502:physiology*; D020868:Gene Silencing; D006801:Humans; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D044763:Ubiquitin-Conjugating Enzymes / Q000235:genetics / Q000378:metabolism*; D057149:Ubiquitinated Proteins; D054875:Ubiquitination / Q000502:physiology*
chemical_list: D015415:Biomarkers; D014157:Transcription Factors; D057149:Ubiquitinated Proteins; C471624:UBE2V1 protein, human; D044763:Ubiquitin-Conjugating Enzymes
keywords: EMT; diabetic kidney; hyperglycemia; post-translational modifications