Loading…

Leishmanial lipid suppresses tumor necrosis factor α, interleukin‐1β, and nitric oxide production by adherent synovial fluid mononuclear cells in rheumatoid arthritis patients and induces apoptosis through the mitochondrial‐mediated pathway

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 antiinflamma...

Full description

Saved in:
Bibliographic Details
Published in:Arthritis and rheumatism 2008-03, Vol.58 (3), p.696-706
Main Authors: Majumdar, Kajal Nayan, Banerjee, Aditi, Ratha, Jagnyeswar, Mandal, Mriganka, Sarkar, Rathindra Nath, Saha, Krishna Das
Format: Article
Language:English
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary: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‐κB, 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‐κB 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 α, interleukin‐1β, and NO in the culture, decreased their cytosolic protein levels, and decreased NF‐κB 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. Conclusion 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.
ISSN:0004-3591
1529-0131
DOI:10.1002/art.23295