Figure 4. TWEAK regulates chemokine expression in the skin.

(a,b) Naive WT or Fn14-deficient mice were injected with rTWEAK or IgG, administered once s.c. After 4 days expression of mRNA for indicated chemokines was measured in skin biopsies. (a, left) RNAseq heatmap of chemokine expression from 3 to 4 animals/group. (right) Mean (AV) fold increase and SD calculated from RNAseq data of the comparisons of rTWEAK into WT versus Fn-deficient mice, rTWEAK versus IgG into WT mice, and rTWEAK versus no injection into WT mice. (b) qPCR mRNA expression of indicated chemokines relative to GAPDH. Combined results from two experiments. Each data point one mouse. (c–f) naive WT mice were injected with rTWEAK or IgG (s.c.) twice weekly over 14 days as in Fig. 3a, with either a combination of blocking antibodies to CCL2, CCL5 and CCL7, or a combination of control antibodies (i.p). Combined results from two experiments. (c) Masson's trichrome staining of representative skin sections. Scale bar, 200 μm. (d,e) Quantification of epidermal and dermal thickness. (f) Total numbers of CD45⁺ cells and SigF⁺CD45⁺CD11b⁺Ly6G⁻ eosinophils from skin biopsies. (g,h) WT and TWEAK-deficient animals were treated with HDM for 23 days (g) and IMQ for 8 days (h) and mRNA for indicated chemokines assessed in skin, relative to GAPDH expression. Combined from two experiments. Each data point one mouse. Bars represent mean values. The Mann–Whitney U-test was performed to compare the groups. Asterisks indicate P<0.05. qPCR, quantitative PCR.