Production of platelet derived growth factor B chain (PDGF-B/c-sis) mRNA and immunoreactive PDGF B-like polypeptide by rheumatoid synovium: coexpression with heparin binding acidic fibroblast growth factor-1.
We present evidence supporting the hypothesis that locally produced platelet derived growth factor (PDGF) B-like polypeptides, as well as heparin binding growth factor-1 (HBGF-1), are involved in stimulating the pronounced hyperplasia of rheumatoid synovial stromal fibroblastlike cells. Explanted rheumatoid synovial tissues in vitro spontaneously secreted, in a time dependent manner, mitogenic activity for rheumatoid synoviocytes that was neutralizable by anti-PDGF antibody. PDGF B/c-sis mRNA transcripts were detected in synovium from patients with rheumatoid arthritis (RA) (n = 5). Spontaneous PDGF B-like synthesis was detected by immunoprecipitation of radiolabeled PDGF B-like polypeptides secreted by explanted tissues. Furthermore, rheumatoid synovial tissues, particularly macrophage-like cells, immunostained specifically with anti-PDGF B chain. The extent and intensity of staining and mononuclear cell infiltration were highly correlated. Immunostaining of osteoarthritic and normal synovial tissues was significantly less than RA synovium. PDGF-B immunostaining of synovial specimens previously characterized for expression of HBGF-1, the precursor of acidic fibroblast growth factor (aFGF), revealed that the extent and intensity of expression of HBGF-1 and PDGF-B were highly correlated.
Remmers
E F
EF
Arthritis and Rheumatism Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20892.
Sano
H
H
Lafyatis
R
R
Case
J P
JP
Kumkumian
G K
GK
Hla
T
T
Maciag
T
T
Wilder
R L
RL
D001172:Arthritis, Rheumatoid / Q000378:metabolism*; D016220:Fibroblast Growth Factor 1 / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D010003:Osteoarthritis / Q000378:metabolism*; D010982:Platelet-Derived Growth Factor / Q000096:biosynthesis / Q000235:genetics*; D012333:RNA, Messenger / Q000096:biosynthesis*; D013194:Staining and Labeling; D013583:Synovial Membrane / Q000378:metabolism*
D010982:Platelet-Derived Growth Factor; D012333:RNA, Messenger; D016220:Fibroblast Growth Factor 1