Fig. 4. Repeated hABCB4_v6 mRNA administration prevents liver fibrosis progression in BALB/c.Abcb4^−/− mice.

(A) Representative low-magnification images of connective tissue staining (Sirius Red, ×50, scale bar 200 μm). Blow-up magnification of portal tract matched by the calibre of portal vein in hABCB4_v6 mRNA-treated mice and eGFP controls (×200, portal vein marked by the asterisk). (B) Collagen morphometry (% of Picrosirius Red area, n = 3/5/10/11 per bar, average of 10 random HPF per animal). (C) Hepatic collagen content as determined biochemically via hydroxyproline (n = 10–15 for BALB/c.Abcb4^−/− mice, n = 5 for WT). (D) Portal venous pressure, as determined via direct cannulation of portal vein with microtip pressure monitor at study endpoint. (E,F) Hepatic transcript levels of key profibrogenic molecules COLIA1, TGFβ1, TIMP-1, and ITGB6 (E) and of matrix-degrading enzymes (MMP-2, −3, −9, −12) (F) in BALB/c.Abcb4^−/− mice treated with control eGFP or hABCB4_v6 mRNA (n = 7–9 per group). Data are mean ± SEM (all animals are males, t test p value as indicated on each graph). See also Figure S6 for additional bile duct morphology images. hABCB4, human ATP-binding cassette 4; HPF, high-power field; WT, wild-type.