Vinculin and cellular retinol-binding protein-1 are markers for quiescent and activated hepatic stellate cells in formalin-fixed paraffin embedded human liver.

Hepatic stellate cells (HSCs) have important roles in the pathogenesis of liver fibrosis and cirrhosis. As response to chronic injury HSCs are activated and change from quiescent into myofibroblast-like cells. Several HSC-specific markers have been described in rat or mouse models. The aim of our work was to identify the best marker(s) for human HSCs. To this end we used the automated high throughput NexES IHC staining device (Ventana Medical Systems) to incubate sections under standardized conditions. Formalin fixed paraffin embedded (FFPE) normal and diseased human livers were studied. With immunohistochemistry we examined the expression of synemin, desmin, vimentin, vinculin, neurotrophin-3 (NT-3), alpha-smooth muscle actin (alpha-SMA), cellular retinol-binding protein-1 (CRBP-1), glial fibrillary acidic protein (GFAP), cysteine- and glycine-rich protein 2 (CRP2), and cytoglobin/stellate cell activation-associated protein (cygb/STAP). This is the first study in which a series of HSC markers is compared on serial FFPE human tissues. CRBP-1 clearly stains lobular HSCs without reacting with smooth muscle cells (SMCs) and shows variable cholangiocyte positivity. Vinculin has a similar staining pattern as CRBP-1 but additionally stains SMCs, and (myo)fibroblasts. In conclusion, we therefore propose to use CRBP-1 and/or vinculin to stain HSCs in human liver tissues.