Therapeutic mTOR inhibition in autosomal dominant polycystic kidney disease: What is the appropriate serum level?
Autosomal dominant polycystic kidney disease (ADPKD) is the most common inherited renal disease, and sirolimus, a mammalian target of rapamycin (mTOR) inhibitor, has been shown to significantly retard cyst expansion in animal models. The optimal therapeutic dose of sirolimus is not yet defined. Here, we report the history of a previously unknown ADPKD deceased donor whose kidneys were engrafted in two different recipients. One of the two received an immunosuppressive regimen based on sirolimus for 5 years while the other did not. After transplantation, both patients developed severe transplant cystic disease. Donor DNA sequence identified a new hypomorphic mutation in PKD1. The rate of cyst growth was identical in the two patients regardless of the treatment. While sirolimus treatment reduced the activation of mTOR in peripheral blood mononuclear cells, it failed to prevent mTOR activation in kidney tubular cells, this could account for the inefficiency of treatment on cyst growth. Together, our results suggest that the dose of sirolimus required to inhibit mTOR varies according to the tissue.
Canaud
G
G
INSERM U, Centre de Recherche Croissance et Signalisation, Hôpital Necker Rue de Sèvres, Paris, France. guillaume.canaud@nck.aphp.fr
Knebelmann
B
B
Harris
P C
PC
Vrtovsnik
F
F
Correas
J-M
JM
Pallet
N
N
Heyer
C M
CM
Letavernier
E
E
Bienaimé
F
F
Thervet
E
E
Martinez
F
F
Terzi
F
F
Legendre
C
C
D000328:Adult; D015153:Blotting, Western; D003404:Creatinine / Q000097:blood; D005091:Exons / Q000235:genetics; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D047908:Intracellular Signaling Peptides and Proteins / Q000037:antagonists & inhibitors* / Q000097:blood; D007438:Introns / Q000235:genetics; D016030:Kidney Transplantation; D016031:Liver Transplantation; D008279:Magnetic Resonance Imaging; D008297:Male; D016891:Polycystic Kidney, Autosomal Dominant / Q000097:blood* / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors* / Q000097:blood; D020123:Sirolimus / Q000627:therapeutic use*; D058570:TOR Serine-Threonine Kinases; D050396:TRPP Cation Channels / Q000235:genetics
D003404:Creatinine; D007166:Immunosuppressive Agents; D047908:Intracellular Signaling Peptides and Proteins; D017346:Protein Serine-Threonine Kinases; D020123:Sirolimus; D058570:TOR Serine-Threonine Kinases; D050396:TRPP Cation Channels; C546842:MTOR protein, human