Fig. 1

Elevated CXCL1 expression contributes to IL-6 expression in OASFs and RASFs. a, b The expression levels of CXCL1 and IL-6 were investigated using the qPCR assay. c–e The protein secretion levels of CXCL1 (c) and IL-6 (d) were analyzed by using ELISA assay. The correlation between CXCL1 and IL-6 secretion levels from the same specimens was shown in e. f, g SFs isolated from all study participants were incubated with various concentrations (0, 1, 5, and 10 ng/mL) of CXCL1 for 24 h. Total RNA and cell lysates were extracted from SFs and assessed for IL-6 expression using qPCR and Western blot assays. The quantification of Western blot is provided in the lower panel. h, i OASFs and RASFs were treated with CXCL1 (10 ng/mL) for different time intervals (control, 6, 12, and 24 h), and IL-6 expression levels were determined by qPCR and Western blot. The quantification of Western blot is provided in the lower panel. j–m OASFs and RASFs were transduced with CXCL1 overexpressing or shRNA plasmids for 24 h, then CXCL1 and IL-6 expression were determined by qPCR. k OASFs and RASFs were treated with CXCL1 neutralized antibody (100 and 200 ng/mL) for 24 h, and IL-6 expression levels were analyzed by qPCR. (In the above experiments, NSFs; n = 8, OASFs; n = 10, RASFs; n = 10). Results are expressed as the mean ± SEM. In experiments involving more than two groups, statistical analysis was conducted by using one-way ANOVA followed by Fisher’s LSD post hoc comparisons tests. *p < 0.05 compared with the NSF group (a–d), control group (f–i). In experiments involving two groups, *p < 0.05 compared with vector group (j, k), control shR group (l, m), or IgG group (n)