Thy-1 is expressed in myofibroblasts but not found in hepatic stellate cells following liver injury

Abstract

Thy-1 (CD90) is an adhesion molecule induced in Wbroblast populations associated with wound healing and Wbrosis. In this study the question whether Thy-1-geneexpression can be induced in hepatic stellate cells (HSC) in vivo, under conditions of liver injury or liver regeneration was addressed. Acute and chronic rat liver injury was induced by the administration of CCl 4 . For comparison, cirrhotic human liver, and rat 67% partial hepatectomy (PH) was studied as well. Thy-1-gene-expression was examined also in isolated human liver myoWbroblasts. Thy-1-mRNA expression was signiWcantly upregulated in chronic liver injury. Thy-1 + cells were detected in the periportal area of rat liver specimens in normal-, injured-and regenerativeconditions. In chronic human and rat liver injury, Thy-1 + cells were located predominantly in scar tissue. In the pericentral necrotic zone after CCl 4 -treatment, no induction of Thy-1 was found. Gremlin and Thy-1 showed comparable localization in the periportal areas. Thy-1 was not detected in either normal or capillarized sinusoids, in isolated rat HSC, and was neither inducible by inXammatory cytokines in isolated HSC, nor upregulated in treated myoWbroblasts. Based upon these data Thy-1 is not a marker of "activated" sinusoidal HSC, but it is a marker of "activated" (myo)Wbroblasts found in portal areas and in scar tissue.

Cytoglobin is expressed in hepatic stellate cells, but not in myofibroblasts, in normal and fibrotic human liver

“…14 In accordance with this report, we detected Thy-1 positivity to a limited extent around the portal vein area in the intact human liver and in the extended fibrotic septum of the fibrotic human liver, where portal myofibroblasts are located. Culture experiments using mouse stellate cells confirmed that these cells express CYGB throughout the culture period until day 7 and a-SMA at days 4 and 7, whereas Thy-1 is not expressed throughout this period.…”

“…In addition, these cells express cellular retinol-binding protein-1 (CRBP-1) and participate in the metabolism of retinol and retinyl esters. 11 In contrast, thymocyte differentiation antigen 1 (Thy-1 or CD90) [12][13][14] and fibulin-2 (FBLN2) [15][16][17] have been utilized as markers of liver myofibroblasts. These cell type-specific markers of liver fibroblastic cells have been largely utilized in studies with rodents.…”

Hematopoietic Microenvironment in the Fetal Liver: Roles of Different Cell Populations

“…Portal myofibroblasts express smooth muscle actin and desmin and are morphologically similar to activated stellate cells [20,32]. However, they are not related by origin to hepatic stellate cells [19,32]; unlike the latter, they express CD90 [32,33], gremlin [33], fibulin-2, and interleukin-6 [34] but do not express reelin [35].…”

Mesothelin/mucin 16 signaling in activated portal fibroblasts regulates cholestatic liver fibrosis

“…aPFs are activated by taurocholic acid and IL-25, but unlike activated HSCs (aHSCs), are unresponsive to PDGF (4). aPFs can be distinguished from aHSCs by expression of Thy-1, fibulin 2, elastin, and the ecto-ATPase nucleoside triphosphate diphosphohydrolase 2 (NTPD2) and by their lack of aHSC markers (retinoid, desmin, glial fibrillary acidic protein [GFAP], p75NGFR) (15)(16)(17)(18). Gene expression profiling of freshly isolated aPFs/myofibroblasts has identified several novel markers of aPFs, including mesothelin (MSLN) and mucin 16 (MUC16) (4).…”