title: The anti-fibrotic effect of mycophenolic acid-induced neutral endopeptidase.
abstract: Mycophenolic acid (MPA) appears to have anti-fibrotic effects, but the molecular mechanisms underlying this are unknown. We prospectively studied 35 stable kidney transplant recipients maintained on cyclosporine and azathioprine. We converted 20 patients from azathioprine to enteric-coated mycophenolate sodium (EC-MPS) and continued the remaining 15 patients on azathioprine. Exploratory mRNA expression profiling, performed on five randomly selected EC-MPS patients, revealed significant upregulation of neutral endopeptidase (NEP), which is an enzyme that degrades angiotensin II. We confirmed these microarray data by measuring levels of NEP expression in all subjects; in addition, we found that NEP gene expression correlated inversely with proteinuria. In an additional 33 patients, glomerular and tubular NEP protein levels from renal graft biopsies were significantly higher among the 13 patients receiving cyclosporine + EC-MPS than among the 12 patients receiving cyclosporine + azathioprine or 8 patients receiving cyclosporine alone. Glomerular NEP expression inversely correlated with glomerulosclerosis and proteinuria, and tubular NEP expression inversely correlated with interstitial fibrosis. Incubation of human proximal tubular cells with MPA increased NEP gene expression in a dose- and time-dependent manner. Moreover, MPA reduced angiotensin II-induced expression of the profibrotic factor plasminogen activator inhibitor-1, and a specific NEP inhibitor completely reversed this effect. Taken together, our data suggest that MPA directly induces expression of neutral endopeptidase, which may reduce proteinuria and slow the progression of renal damage in kidney transplant recipients.
authors.affiliation: Renal, Dialysis and Transplantation Unit, Department of Emergency and Organ Transplantation, University of Bari, Bari, Italy.
authors.forename: Maria Pia
authors.initials: MP
authors.lastname: Dell'Oglio
authors.forename: Gianluigi
authors.initials: G
authors.lastname: Zaza
authors.forename: Michele
authors.initials: M
authors.lastname: Rossini
authors.forename: Chiara
authors.initials: C
authors.lastname: Divella
authors.forename: Paola
authors.initials: P
authors.lastname: Pontrelli
authors.forename: Raffaella
authors.initials: R
authors.lastname: Verrienti
authors.forename: Monica
authors.initials: M
authors.lastname: Rutigliano
authors.forename: Pasquale
authors.initials: P
authors.lastname: Ditonno
authors.forename: Patrizia
authors.initials: P
authors.lastname: Stifanelli
authors.forename: Nicola
authors.initials: N
authors.lastname: Ancona
authors.forename: Francesco Paolo
authors.initials: FP
authors.lastname: Schena
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Grandaliano
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000368:Aged; D001379:Azathioprine / Q000008:administration & dosage; D016572:Cyclosporine / Q000008:administration & dosage; D004305:Dose-Response Relationship, Drug; D004359:Drug Therapy, Combination; D005260:Female; D005355:Fibrosis / Q000517:prevention & control; D005500:Follow-Up Studies; D005786:Gene Expression Regulation; D006084:Graft Rejection / Q000517:prevention & control; D006085:Graft Survival; D006801:Humans; D007166:Immunosuppressive Agents / Q000008:administration & dosage*; D016030:Kidney Transplantation / Q000276:immunology* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009173:Mycophenolic Acid / Q000008:administration & dosage*; D015260:Neprilysin / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D011446:Prospective Studies; D018570:Risk Assessment; D013608:Tablets, Enteric-Coated; D014181:Transplantation Immunology; D016896:Treatment Outcome
chemical_list: D007166:Immunosuppressive Agents; D013608:Tablets, Enteric-Coated; D016572:Cyclosporine; D015260:Neprilysin; D009173:Mycophenolic Acid; D001379:Azathioprine