title: Successful treatment of animal models of rheumatoid arthritis with small-molecule cyclin-dependent kinase inhibitors.
abstract: Intraarticular gene transfer of cyclin-dependent kinase (CDK) inhibitors to suppress synovial cell cycling has shown efficacy in treating animal models of rheumatoid arthritis. Endogenous CDK inhibitors also modulate immune function via a CDK-independent pathway. Accordingly, systemic administration of small molecules that inhibit CDK may or may not ameliorate arthritis. To address this issue, alvocidib (flavopiridol), known to be tolerated clinically for treating cancers, and a newly synthesized CDK4/6-selective inhibitor were tested for antiarthritic effects. In vitro, they inhibited proliferation of human and mouse synovial fibroblasts without inducing apoptosis. In vivo, treatment of collagen-induced arthritis mice with alvocidib suppressed synovial hyperplasia and joint destruction, whereas serum concentrations of anti-collagen type II (CII) Abs and proliferative responses to CII were maintained. Treatment was effective even when therapeutically administered. Treated mice developed arthritis after termination of treatment. Thus, immune responses to CII were unimpaired. The same treatment ameliorated arthritis induced by K/BxN serum transfer to lymphocyte-deficient mice. Similarly, the CDK4/6-selective inhibitor suppressed collagen-induced arthritis. Both small-molecule CDK inhibitors were effective in treating animal models of rheumatoid arthritis not by suppressing lymphocyte function. Thus, the two small-molecule CDK inhibitors ameliorated arthritis models in a distinctive way, compared with other immunosuppressive drugs.
authors.affiliation: Clinical Immunology, RIKEN Research Center of Allergy and Immunology, Yokohama, Japan.
authors.forename: Chiyoko
authors.initials: C
authors.lastname: Sekine
authors.forename: Takahiko
authors.initials: T
authors.lastname: Sugihara
authors.forename: Sachiko
authors.initials: S
authors.lastname: Miyake
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hirai
authors.forename: Mitsuaki
authors.initials: M
authors.lastname: Yoshida
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Miyasaka
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Kohsaka
mesh_terms: D000818:Animals; D001169:Arthritis, Experimental / Q000188:drug therapy* / Q000473:pathology; D001172:Arthritis, Rheumatoid / Q000188:drug therapy* / Q000473:pathology; D001323:Autoantibodies / Q000097:blood; D049109:Cell Proliferation / Q000187:drug effects; D024043:Collagen Type II / Q000276:immunology; D051358:Cyclin-Dependent Kinase 4 / Q000627:therapeutic use*; D051361:Cyclin-Dependent Kinase 6 / Q000627:therapeutic use*; D018844:Cyclin-Dependent Kinases / Q000037:antagonists & inhibitors*; D004195:Disease Models, Animal; D005347:Fibroblasts / Q000187:drug effects; D005419:Flavonoids / Q000494:pharmacology / Q000627:therapeutic use*; D051379:Mice; D008815:Mice, Inbred Strains; D010880:Piperidines / Q000494:pharmacology / Q000627:therapeutic use*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology / Q000627:therapeutic use*; D013583:Synovial Membrane / Q000166:cytology / Q000187:drug effects; D016896:Treatment Outcome
chemical_list: D001323:Autoantibodies; D024043:Collagen Type II; D005419:Flavonoids; D010880:Piperidines; D047428:Protein Kinase Inhibitors; C077990:alvocidib; D051358:Cyclin-Dependent Kinase 4; D051361:Cyclin-Dependent Kinase 6; D018844:Cyclin-Dependent Kinases