Figure 1.

The expression of CD44 variants containing a single exon insert by untreated TGF-β₁and IL-1β-treated fibroblasts. Custom primers were designed to target variants that express one of the variable exons (6–14) between the common regions. Schematic (A) demonstrates the exon arrangement of CD44. Exons 1–5 and 15–19 are common to all CD44 variants. The variable region of CD44 is coded by exons 6–14 (labeled below exons). Corresponding variant nomenclature is highlighted in bold (labeled above exons 6–14). Primers were designed to span the exon boundary of the common region and the variant of interest. Forward primers overlapped the 3′ end of exon 5 in the common region with the 5′ end of the exon of interest. Reverse primers overlapped the 5′ end of exon 15 with the 3′ end of the exon of interest (B). Assessment of CD44 variants containing a single exon insert was carried out using qPCR. The expression of each CD44 variant in fibroblast (black circles) was compared with myofibroblasts (black squares) at 0 h and 72 h timepoints. (C–F) represent; CD44 (standard) (C), CD44v3 (D), CD44v6 (E), CD44v10 (F). The expression of each CD44 variant in fibroblasts (black circles) was compared with IL-1β (1.0 ng/ml) stimulated fibroblasts (black squares) at 0 h and 6 h timepoints. G–J represent; CD44 (standard) (G), CD44v3 (H), CD44v6 (I) and CD44v10 (J). For the mRNA expression of other CD44 variants in basal fibroblasts TGF-β₁ and IL1-β stimulation including CD44v2, CD44v4, CD44v7, CD44v8, and CD44v9, see Figures S1 and S2. CD44v5 was not expressed in fibroblasts or myofibroblasts. Data are shown as mean ± SD from three experimental repeats with statistical significance represented by; ∗p ≤ 0.05, ∗∗p ≤ 0.01, ∗∗∗p ≤ 0.001, and ∗∗∗∗p ≤ 0.0001.