title: Leishmanial lipid suppresses tumor necrosis factor alpha, interleukin-1beta, and nitric oxide production by adherent synovial fluid mononuclear cells in rheumatoid arthritis patients and induces apoptosis through the mitochondrial-mediated pathway.
abstract: OBJECTIVE
  Leishmanial lipid is a strong immunosuppressor of host cells. Inhibition of the inflammatory responses of synovial cells through induction of apoptosis is one of the main targets of therapeutic intervention in rheumatoid arthritis (RA). This study was undertaken to examine the antiinflammatory and apoptosis-inducing effects of leishmanial lipid on adherent synovial fluid mononuclear cells (SFMCs) in patients with RA.
  
  
  METHODS
  Lipid was extracted from a Leishmania donovani promastigote (MHO/IN/1978/UR6) by the Bligh and Dyer method. Nitric oxide (NO) was measured using the Griess reaction, and enzyme-linked immunosorbent assays for cytokines, NF-kappaB, and cytochrome c were performed. Levels of cytokines, inducible nitric oxide synthase, caspases, Bcl-2, Bax, t-Bid, and cytochrome c in the cell lysate and of NF-kappaB p65 in the nucleus were determined by Western blotting. Microscopic analysis, nuclear staining, DNA fragmentation assay, fluorescence-activated cell sorting, colorimetric assay for caspases, and fluorescent probe for measurement of mitochondrial membrane potential were used to study the leishmanial lipid-induced apoptotic pathway in SFMCs.
  
  
  RESULTS
  Leishmanial lipid inhibited the release of tumor necrosis factor alpha, interleukin-1beta, and NO in the culture, decreased their cytosolic protein levels, and decreased NF-kappaB p65 levels in SFMCs, in a dose-dependent manner. It had the reverse effect on interleukin-10 levels. Leishmanial lipid-induced apoptosis involved the activation of caspase 3, caspase 9, and Bax, the release of cytochrome c, the alteration of mitochondrial membrane potential, and the down-regulation of Bcl-2.
  
  
  CONCLUSIONS
  These results suggest that leishmanial lipid has strong antiinflammatory and apoptosis-inducing effects on SFMCs from patients with RA, and that apoptosis occurs via the mitochondrial pathway.
authors.affiliation: Indian Institute of Chemical Biology, Kolkata, India.
authors.forename: Kajal Nayan
authors.initials: KN
authors.lastname: Majumdar
authors.forename: Aditi
authors.initials: A
authors.lastname: Banerjee
authors.forename: Jagnyeswar
authors.initials: J
authors.lastname: Ratha
authors.forename: Mriganka
authors.initials: M
authors.lastname: Mandal
authors.forename: Rathindra Nath
authors.initials: RN
authors.lastname: Sarkar
authors.forename: Krishna Das
authors.initials: KD
authors.lastname: Saha
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001172:Arthritis, Rheumatoid / Q000378:metabolism* / Q000473:pathology; D053148:Caspase 3 / Q000378:metabolism; D053453:Caspase 9; D002478:Cells, Cultured; D005260:Female; D006801:Humans; D016753:Interleukin-10 / Q000378:metabolism; D053583:Interleukin-1beta / Q000378:metabolism*; D007893:Leishmania donovani / Q000378:metabolism*; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D008055:Lipids / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D008928:Mitochondria / Q000502:physiology; D016328:NF-kappa B / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D051381:Rats; D015398:Signal Transduction / Q000502:physiology; D013582:Synovial Fluid / Q000166:cytology / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
chemical_list: D053583:Interleukin-1beta; D008055:Lipids; D016328:NF-kappa B; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10; D009569:Nitric Oxide; D053148:Caspase 3; D053453:Caspase 9