title: Effects of tofacitinib on nucleic acid metabolism in human articular chondrocytes.
abstract: OBJECTIVE
  In our previous screening of chondrocyte protein profiles, the amount of adenosine monophosphate deaminase (AMPD) 2 was found to be decreased by tofacitinib. Extending the study, here we confirmed the decrease of AMPD2 by tofacitinib and further investigated effects of tofacitinib on purine nucleotide metabolism.
  
  
  METHODS
  Human articular chondrocytes and a chondrosarcoma cell line: OUMS-27 were stimulated with tofacitinib. Then the levels of AMPD2 and its related enzymes were investigated by Western blot. The levels of AMP and adenosine were assessed by mass spectrometry.
  
  
  RESULTS
  We confirmed the significant decrease of AMPD2 by tofacitinib in chondrocytes (p = 0.025). The levels of adenosine kinase and 5'-nucleotidase were decreased in chondrocytes, although they did not meet statistical significance (p = 0.067 and p = 0.074, respectively). The results from OUMS-27 were similar to those from the chondrocytes. The cellular adenosine levels were significantly decreased by tofacitinib in OUMS-27 (p = 0.014). The cellular AMP levels were increased, although they did not meet statistical significance in OUMS-27 (p = 0.066).
  
  
  CONCLUSIONS
  Our data indicate that tofacitinib increases the cellular levels of adenosine, which is known to have anti-inflammatory activity, through the downregulation of AMPD2. This would be a novel functional aspect of tofacitinib.
authors.affiliation: Clinical Proteomics & Molecular Medicine, St. Marianna University Graduate School of Medicine , Sugao, Miyamae, Kawasaki, Kanagawa , Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Koizumi
authors.forename: Mitsumi
authors.initials: M
authors.lastname: Arito
authors.forename: Wataru
authors.initials: W
authors.lastname: Endo
authors.forename: Manae S
authors.initials: MS
authors.lastname: Kurokawa
authors.forename: Kazuki
authors.initials: K
authors.lastname: Okamoto
authors.forename: Kazuki
authors.initials: K
authors.lastname: Omoteyama
authors.forename: Naoya
authors.initials: N
authors.lastname: Suematsu
authors.forename: Moroe
authors.initials: M
authors.lastname: Beppu
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Kato
mesh_terms: D000659:AMP Deaminase / Q000096:biosynthesis / Q000235:genetics*; D000368:Aged; D000369:Aged, 80 and over; D015153:Blotting, Western; D002478:Cells, Cultured; D019902:Chondrocytes / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D053616:Janus Kinase 3 / Q000037:antagonists & inhibitors; D008297:Male; D009696:Nucleic Acids / Q000187:drug effects / Q000378:metabolism*; D020370:Osteoarthritis, Knee / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism; D010880:Piperidines / Q000494:pharmacology*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D011743:Pyrimidines / Q000494:pharmacology*; D011758:Pyrroles / Q000494:pharmacology*; D012313:RNA / Q000235:genetics*; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D009696:Nucleic Acids; D010880:Piperidines; D047428:Protein Kinase Inhibitors; D011743:Pyrimidines; D011758:Pyrroles; D012313:RNA; C479163:tofacitinib; D053616:Janus Kinase 3; D000659:AMP Deaminase; C475566:AMPD2 protein, human
keywords: AMP deaminase; Adenosine; Chondrocytes; Tofacitinib