Figure 2.

Fibrocyte ablation attenuated hepatic fibrogenesis. Fibrillar collagen distribution was visualized by (a) Sirius Red/Fast Green staining and (b) immunohistochemical staining of collagen I on formalin fixed, paraffin-embedded liver sections. TAA-treatment caused pronounced periportal and bridging fibrosis as well as faint chicken wire sinusoidal fibrosis in the control- and fibrocyte-ablated group. Dotted boxes are shown in enlarged panels on the right side. Magnification 200×, bars 100 and 25 µm. (c) Quantitative assessment of hepatic hydroxyproline content revealed a reduction of fibrillar collagens in mice lacking fibrocytes. The assay was performed three times. Mean values of each individual mouse are depicted by black triangles (control) or blue dots (fibrocyte ablation). The solid line depicts the group mean, the dotted line the mean hydroxyproline level in untreated supercontrols (SC). (d) Morphometric analysis of Sirius Red/Fast Green-stained sections displayed a comparable extent of red-stained areas in TAA-treated mice with and without fibrocyte ablation. A total of 1361 images were analyzed (2–134 per mouse). (e) The transcriptional levels of Col1a1 were equal throughout both groups. (f) Relative protein levels of MMP-2, MMP-8, MMP-9, MMP-12, TIMP-1, TIMP-4, and Serpin E1 were assessed utilizing a multiplex ELISA and remained constant as a result of fibrocyte ablation. Absolute concentrations and individual p-values are provided in Figure S4.