Tumor necrosis factor-alpha induces interleukin-6 mRNA and protein in human granulosa luteinizing cells via protein tyrosine kinase without involving ceramide.
This study examines how interleukin-6 (IL-6) expression by human luteinizing granulosa cells is regulated. IL-6 was assayed in culture supernatants, mRNA in cells by in situ hybridization and by a competitive reverse-transcriptase polymerase chain reaction (RT-PCR). TNF alpha (100 pg-1 ng/ml) induced IL-6 mRNA and protein. Phorbol 12-myristate 13-acetate (PMA) (50 nM) mimicked this effect. DibutyrylcAMP (1 mM) and 10 microM forskolin. C2-, C6- and C8-ceramide (15 microM), all had no effect. The inhibitor of protein tyrosine kinase (PTK), genistein (100 micrograms/ml) reduced tumor necrosis factor (TNF) effects. The inhibitors of protein kinase C (PKC) (staurosporine, 10 nM), of phospholipase C (U73122, 2 microM), of phospholipase A2 (PLA2), (indomethacin 30 microM, mepacrin 50 microM, nordihydroguaiaretic acid 10 microM, ONO-RS-082 3,5 microM), none prevented it. Hence, IL-6 is induced by TNF alpha via activation of PTK. Protein kinase A, phosphoinositide and conventional PKC, sphingomyelin and PLA2 pathways are not implicated.
Machelon
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V
Institut National de la Santè et de la Recherche Médicale (INSERM), U-355, Clamart, France.
Nomé
F
F
Durand-Gasselin
I
I
Emilie
D
D
D002478:Cells, Cultured; D002518:Ceramides / Q000378:metabolism; D005260:Female; D006107:Granulosa Cells / Q000378:metabolism*; D006801:Humans; D015850:Interleukin-6 / Q000096:biosynthesis*; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis; D015398:Signal Transduction / Q000187:drug effects*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D002518:Ceramides; D015850:Interleukin-6; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D011505:Protein-Tyrosine Kinases