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P068 Increase of aerobic glycolysis mediated by activated t helper cells drives synovial fibroblasts towards an inflammatory phenotype
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  1. P Kvacskay1,
  2. M Souto-Carneiro1,
  3. R de Albuquerque Carvalho2,
  4. J-H Schnotz1,
  5. S Krienke1,
  6. KD Klika3,
  7. T Tretter1,
  8. H-M Lorenz1,
  9. L-O Tykocinski1
  1. 1Internal Medicine V – Division of Rheumatology, University Hospital Heidelberg, Heidelberg, Germany
  2. 2NMR Centre, Department of Biochemistry, University of Coimbra, Coimbra, Portugal
  3. 3Molecular Structure Analysis, German Cancer Research Centre (DKFZ), Heidelberg, Germany

Abstract

Introduction There is growing evidence for a dysregulated glucose metabolism of synovial fibroblasts (SF) in rheumatoid arthritis (RA) being a prerequisite for their aggressive phenotype. As yet, little is known about the influence of immune cells on the metabolism of SF although local infiltration of leucocytes constitutes a hallmark in the pathogenesis of RA.

Objectives In this study, we investigated the effect of T helper (Th) cells on the glucose metabolism and cytokine production of non-inflammatory and inflammatory SF in vitro.

Methods RASF as well as SF from patients with osteoarthritis (OA) were cultured in the presence of a stable glucose isotope (U-13C) and stimulated with culture supernatants (SN) of activated Th cells. Lactate production was measured by proton nuclear magnetic resonance spectroscopy (H-NMR). Secretion of interleukin (IL)−6, IL-8 and matrix metalloprotease (MMP)−3 was quantified by ELISA. The expression of hexokinase (HK)-II, pyruvate kinase (PK)-M2 and pyruvate dehydrogenase (PDH) was analysed by PCR, western blot and immunofluorescence. Janus kinases (JAKs) were blocked by Baricitinib or Tofacitinib, glycolysis was inhibited by 3-Bromopyruvate (3 BP) or Fx11.

Results In the absence of stimulation, RASF showed a significantly higher lactate production and IL-6 and MMP-3 secretion compared to OASF. Stimulation by Th cell SN strikingly changed the metabolic profile of both RASF and OASF by inducing a shift towards aerobic glycolysis with strongly increased lactate production. In parallel, a significant increase in IL-6 and MMP-3 secretion was induced. Interestingly, Bariticinib and Tofacitinib as well as glycolytic inhibitors significantly reduced both the production of lactate and the secretion of inflammatory cytokines. Finally, perpetual stimulation of non-inflammatory OASF by Th cell SN triggered an inflammatory phenotype characterised by significantly higher amounts of lactate, IL-6 and MMP-3 compared to non- or single stimulated SF.

Conclusions Chronic stimulation of non-inflammatory SF by activated Th cells provoked an aggressive phenotype with strongly increased glycolytic activity and upregulated secretion of inflammatory cytokines. This was blocked by both JAK- and glycolytic inhibitors. These observations suggest that the Th cell-mediated metabolic switch towards aerobic glycolysis in SF is an important step in the pathogenesis of RA. Targeting this mechanism could provide a new strategy in the therapy of RA.

Disclosure of interest None declared

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