title: Defect of suppression of inflammasome-independent interleukin-8 secretion from SW982 synovial sarcoma cells by familial Mediterranean fever-derived pyrin mutations.
abstract: Familial Mediterranean fever (FMF) is a recessive inherited autoinflammatory syndrome. Patients with FMF have symptoms such as recurrent fever and abdominal pain, sometimes accompanied by arthralgia. Biopsy specimens have revealed substantial neutrophil infiltration into synovia. FMF patients have a mutation in the Mediterranean fever gene, encoding pyrin, which is known to regulate the inflammasome, a platform for processing interleukin (IL)-1β. FMF patients heterozygous for E148Q mutation, heterozygous for M694I mutation, or combined heterozygous for E148Q and M694I mutations, which were found to be major mutations in an FMF study group in Japan, suffer from arthritis, the severity of which is likely to be lower than in FMF patients with M694V mutations. Expression plasmids of wild-type (WT) pyrin and mutated pyrin, such as E148Q, M694I, M694V, and E148Q+M694I, were constructed, and SW982 synovial sarcoma cells were transfected with these expression plasmids. IL-8 and IL-6 were spontaneously secreted from the culture supernatant of SW982 cells without any stimulation, whereas IL-1β and TNF-α could not be detected even when stimulated with lipopolysaccharide. Notably, two inflammasome components, ASC and caspase-1, could not be detected in SW982 cells by Western blotting. IL-8 but not IL-6 secretion from SW982 cells was largely suppressed by WT pyrin, but less suppressed by mutated pyrin, which appeared to become weaker in the order of E148Q, M694I, E148Q+M694I, and M694V mutations. As for IL-8 and IL-6, similar results were obtained using stable THP-1 cells expressing the WT pyrin or mutated pyrins, such as M694V or E148Q, when stimulated by LPS. In addition, IL-8 secretion from mononuclear cells of FMF patients was significantly higher than that of healthy volunteers when incubated on a culture plate. Thus, our results suggest that IL-8 secretion from SW982 synovial sarcoma cells suppressed by pyrin independently of inflammasome is affected by pyrin mutations, which may reflect the activity in FMF arthritis.
authors: Department of Molecular Pathology, Shinshu University Graduate School of Medicine, Matsumoto, Nagano, 390-8621, Japan.
authors: Rino
authors: R
authors: Sugiyama
authors: Kazunaga
authors: K
authors: Agematsu
authors: Kiyoshi
authors: K
authors: Migita
authors: Jun
authors: J
authors: Nakayama
authors: Sho
authors: S
authors: Mokuda
authors: Fumiya
authors: F
authors: Ogura
authors: Kaho
authors: K
authors: Haraikawa
authors: Chikara
authors: C
authors: Okumura
authors: Satomi
authors: S
authors: Suehiro
authors: Shinnosuke
authors: S
authors: Morikawa
authors: Yuki
authors: Y
authors: Ito
authors: Junya
authors: J
authors: Masumoto
mesh_terms: D053468:CARD Signaling Adaptor Proteins; D020170:Caspase 1 / Q000378:metabolism; D045744:Cell Line, Tumor; D016207:Cytokines / Q000378:metabolism; D003598:Cytoskeletal Proteins / Q000235:genetics* / Q000378:metabolism; D015536:Down-Regulation; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D010505:Familial Mediterranean Fever / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D056726:Genetic Association Studies; D057809:HEK293 Cells; D006801:Humans; D058847:Inflammasomes / Q000378:metabolism*; D016209:Interleukin-8 / Q000378:metabolism*; D007963:Leukocytes, Mononuclear / Q000378:metabolism; D020125:Mutation, Missense; D010766:Phosphorylation; D011499:Protein Processing, Post-Translational; D000071198:Pyrin; D013584:Sarcoma, Synovial; D012995:Solubility
chemical_list: D053468:CARD Signaling Adaptor Proteins; C508606:CXCL8 protein, human; D016207:Cytokines; D003598:Cytoskeletal Proteins; D058847:Inflammasomes; D016209:Interleukin-8; C000604192:MEFV protein, human; C402202:PYCARD protein, human; D000071198:Pyrin; D048049:Extracellular Signal-Regulated MAP Kinases; D020170:Caspase 1