Figure 3.

Temporal characterization of liver injury and intestinal permeability changes in a murine dietary nonalcoholic steatohepatitis (NASH) model. C57BL/6 mice (N = 5 mice/group) were fed a diet deficient in methionine and choline (MCD) and were sacrificed at multiple time points up to 21 days. We found evidence for significant MCD-induced liver injury as early as day 6 based on both (A) serum alanine aminotransferase (ALT) and (B, C) H&E liver histology (original magnification: 20×) that progressed to a peak value at day 21. Specifically, liver histologic examination revealed a progressively increasing number of inflammatory foci and steatosis throughout the experiment. In parallel, hepatic mRNA expression and systemic levels of tumor necrosis factor-α (TNF-α) were elevated at an early phase of the diet (D, E).Temporal evaluation of intestinal permeability changes, based on (F) fluorescein isothiocyanate (FITC) dextran serum measurements, and tight junction architecture based on (G) immunofluorescence staining for zona-occludens-1 (ZO-1), revealed evidence for a significant increase in intestinal permeability and disruption of normal tight junction architecture (loss of chicken-wire appearance of ZO-1: arrows) at day 10. DAPI, 4′,6-diamidino-2-phenylindole.