The anti-fibrotic effect of mycophenolic acid-induced neutral endopeptidase.
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.
Dell'Oglio
Maria Pia
MP
Renal, Dialysis and Transplantation Unit, Department of Emergency and Organ Transplantation, University of Bari, Bari, Italy.
Zaza
Gianluigi
G
Rossini
Michele
M
Divella
Chiara
C
Pontrelli
Paola
P
Verrienti
Raffaella
R
Rutigliano
Monica
M
Ditonno
Pasquale
P
Stifanelli
Patrizia
P
Ancona
Nicola
N
Schena
Francesco Paolo
FP
Grandaliano
Giuseppe
G
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
D007166:Immunosuppressive Agents; D013608:Tablets, Enteric-Coated; D016572:Cyclosporine; D015260:Neprilysin; D009173:Mycophenolic Acid; D001379:Azathioprine