Figure 7.

Western blot and quantitative RT-PCR show upregulated extracellular matrix remodeling pathways in DyW mice throughout postnatal development. (A) Western blot of total and phosphorylated Smad2/3 (pSmad2/3) shows an increase in transforming growth factor β (TGF-β) signaling as early as week 1. Additionally, we saw a decrease in Smad7 expression as early as week 2. (DyW is also referred to as KO, Knockout.) (B) Fibronectin 1 (Fn1) gene expression was found to be upregulated two- to fivefold in Lama2^DyW (DyW) animals at all four time points compared to age-matched wild-type (WT) mice (P < 0.0001 by two-way analysis of variance (ANOVA) and n = 5 for all groups). (C) Additionally, periostin (Postn) transcript levels showed massive upregulation at weeks 2, 3 and 4 (P < 0.05 for week 1, P < 0.005 for week 3 and P < 0.0001 for weeks 2 and 4, all by two-way ANOVA (n = 5 for all groups)). (D) Matrix metalloproteinase 2 (MMP-2) transcription levels became elevated by postnatal week 2 and remained that way through week 4 (P < 0.0005 by two-way ANOVA (n = 5)). (E) In contrast, MMP-9 expression was significantly upregulated at weeks 1, 2 and 3 (P < 0.005 by two-way ANOVA (n = 5)), but was comparable to the WT by week 4. (F) Gene expression of tissue inhibitor of matrix metalloproteinase 1 (TIMP-1) shows a several-fold upregulation starting as early as week 1 (P < 0.0005 by two-way ANOVA (n = 5)). Asterisks indicate statistical significance between age-matched DyW and WT animals, hash tags indicate significant changes within the DyW group and Deltas indicate significant changes within the WT group. *P < 0.05, **P < 0.01, ***P < 0.001 and ****P < 0.0001 These statistical representations also apply other symbols (Δ, #).