Comparison of rheumatoid articular adipose and synovial tissue reactivity to proinflammatory stimuli: contribution to adipocytokine network
- Ewa Kontny1,
- Magdalena Plebanczyk1,
- Barbara Lisowska2,
- Malgorzata Olszewska2,
- Pawel Maldyk3,
- Włodzimierz Maslinski1
- 1Department of Pathophysiology and Immunology, Institute of Rheumatology, Warsaw, Poland
- 2Department of Anaesthesiology and Intensive Care, Institute of Rheumatology, Warsaw, Poland
- 3Department of Rheumoorthopaedic Surgery, Institute of Rheumatology, Warsaw, Poland
- Correspondence to Ewa Kontny, Department of Pathophysiology and Immunology, Institute of Rheumatology, Spartanska 1, 02-637, Warsaw, Poland;
Contributors EK designed the study, analysed and interpreted the data, wrote the manuscript draft. MP, MO analysed and interpreted the data. BL analysed the data and participated in the elaboration and discussion of the manuscript. PM participated in the elaboration and discussion of the manuscript. WM participated in drafting the article and revised it critically for important intellectual content. All the authors revised and approved the final submitted version.
- Received 5 May 2011
- Accepted 11 September 2011
- Published Online First 11 October 2011
Objectives (1) To compare spontaneous and stimuli-induced adipocytokine secretion by articular adipose tissue (AAT) and synovial membrane (SM) explants obtained from patients with rheumatoid arthritis (RA). (2) To investigate the biological activity of AAT and SM released factors.
Methods Tissues were obtained from patients undergoing joint replacement surgery. Tissue explants were treated with proinflammatory cytokines relevant to RA pathogenesis (interleukin 1β (IL-1β), tumour necrosis factor (TNF), interferon γ, IL-15, IL-17, IL-23). Selected adipocytokine (TNF, IL-6, IL-8, IL-1β, IL-1Ra, adiponectin, leptin) concentrations were measured in culture supernatants using ELISA. The biological activity of tissue-conditioned media was evaluated by measuring production of selected factors (IL-6, IL-8, Dickkopf-1, osteoprotegerin) by fibroblast-like synoviocytes (FLS).
Results Spontaneous cytokine release from AAT was ≤12% of that produced by SM, while leptin was secreted in similar amounts. AAT was highly reactive to proinflammatory cytokines (IL-1β>TNF). AAT treated with IL-1β released four times more leptin, similar amounts of IL-6 and IL-8 and about 20% of TNF, as compared with SM. Upon activation, the IL-1 receptor antagonist (IL-1Ra)/IL-1β ratio was higher in AAT than in SM cultures. Irrespective of activation status, SM produced twice as much adiponectin as AAT. Conditioned media from AAT and SM cultures similarly upregulated IL-6, IL-8, Dickkopf-1 and osteoprotegerin production by rheumatoid FLS.
Conclusion Rheumatoid AAT is highly reactive tissue which upon stimulation secretes considerable amounts of proinflammatory (IL-6, IL-8, TNF) and anti-inflammatory (IL-1Ra) cytokines and classical adipokines. This tissue releases biologically active factors that intensify pathogenic activities of rheumatoid FLS. Thus, AAT should be considered an important contributor to the pathological processes taking place in the RA joint.
Funding This work was sponsored by grant No N N402 369938 from the Polish Ministry of Science and Higher Education.
Competing interests None.
Patient consent Obtained.
Ethics approval The Institute of Rheumatology Ethics Committee.
Provenance and peer review Not commissioned; externally peer reviewed.