Chemical Hypoxia Brings to Light Altered Autocrine Sphingosine-1-Phosphate Signalling in Rheumatoid Arthritis Synovial Fibroblasts

Figure 3

Differential involvement of S1P receptors in S1P- and CoCl₂-mediated chemokine secretion by normal FLS and RAFLS. Human primary FLS from normal () and RA () donors were incubated with 5 μM S1P (a, b) or 200 μM CoCl₂ (c, d). Where indicated, cells were pretreated with S1P₃ antagonist CAY10444 (5 μM) or S1P₂ antagonist JTE-013 (5 μM) for 30 min before stimulation with S1P or CoCl₂. The amounts of chemokines released in the supernatants were monitored after 24 h. Data are expressed as percentage of chemokine production induced by S1P (a, b) or CoCl₂ (c, d). The data are the means ± SE from four experiments (4 different donors) performed in triplicate (3 independent experiments). For statistical comparative analyses, the samples stimulated with S1P (a, b) or CoCl₂ (c, d) were compared to those stimulated in the presence of CAY10444 or JTE-013, respectively. ; .

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