Figure 3
Interleukin-1 receptor 1 is highly expressed on infra-patellar pad derived fibroblasts.
Fibroblasts isolated from the infra-patellar fat pad and synovial membrane (both n = 5) were cultured in vitro and the relative gene expression of TLR1-10, RIG-1, RAGE and IL-1R1 quantified by qRT-PCR. (a) TLR expression was restricted mainly to TLR3 and TLR4 with little or no expression of other TLRs. (b) There was no detectable expression of RAGE but RIG-1 was expressed at levels comparable to TLR3 and TLR4. In contrast IL-1R1 expression was 100–150 fold greater than other receptors. Results are normalised to GAPDH as a loading control. Data is presented as mean ± standard error of the mean. Fibroblasts isolated from the infra-patellar fat pad were investigated for the expression of TLR3, TLR4 and IL-1R1 protein by Western Blotting (n = 4) (c) and flow cytometry (n = 6) (d). Cells expressed TLR3 and TLR4 at comparable levels at the cell surface. In contrast, expression of IL-1R1 was significantly higher than other receptors (red traces). β-actin was used as a loading control (c). Unstained cells (filled traces) and IgG controls (black traces) were used as flow cytometry controls (d).
