EDA-FN diminishes liver fibrosis.

<p>(A–B) Fibrosis was increased in cKO animals, as evidenced by enhanced matrix accumulation, shown using picro-sirius red staining of the matrix (A, middle), collagen I staining in red (A, right) (Bars represent 100 μm), and quantification of collagen biochemically (B, left), as well as by impaired liver function (alanine transaminase [ALT] is shown in B, right), <i>n</i> = 13/10/15/14 for collagen and 17/16/15/12 for ALT in three experiments. Fibrosis was induced by injecting CCl₄ over 6 wk. (C) In the absence of thymus-schooled T-cells, fibrosis is still increased in cKO animals, as evidenced by collagen accumulation, <i>n</i> = 8/10/16/14 in three experiments of 6 wk exposure to CCl₄. (D) CD11b⁺-cells isolated from the livers of healthy CT and cKO animals showed a change in arginase-1 mRNA expression similar to the changes in the myeloid cells in the bone marrow, <i>n</i> = 13/15 in four experiments. (E) The injury induced by short exposure to CCl₄ (72 h) is increased in cKO mice or after injection of cKO myeloid cells isolated from the bone marrow 24 h after injury induction (48 h prior to euthanasia and collagen quantification), <i>n</i> = 6/6/5/5. (F) CD11b⁺-cells differentiated from the bone marrow for 24 h in the presence of EDA result in decreased matrix accumulation when injected 24 h after CCl₄ exposure (and 48 h prior to euthanasia). This is not the case for pFN or EDB, <i>n</i> = 6/6/6. (G) In the short injury model, administration of CD11b⁺-cells exposed to an inhibitor of α5β1 integrin at the same time as EDA prevents the protective effect of EDA. An arginase inhibitor (nor-NOHA) added 1 h prior to injection of cells exposed to EDA for 24 h also prevents the beneficial effects of EDA on decreasing collagen accumulation, <i>n</i> = 4/6/6/6. ANOVA followed by <i>t</i> tests was used. Underlying data for B–G are provided in <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.1002562#pbio.1002562.s001" target="_blank">S1 Data</a>.