Fig. 1: The unfolded protein response (UPR) is an early event during in vitro hepatic stellate cell (HSC) activation.
From: Unfolded protein response is an early, non-critical event during hepatic stellate cell activation
a Bright-field images of freshly isolated mouse HSCs (mHSCs), plated on plastic culture dishes, were taken after 2, 10 and 24 h and 4, 7 and 10 days in culture (upper right panel). At the same time points, expression of HSC activation markers Acta2 and Lox was determined at the mRNA level by quantitative real-time polymerase chain reaction (qPCR; upper left panel). The lower panel shows mRNA levels of UPR genes Bip, Chop, Xbp1s, Atf4 and Herpud1 at the indicated time points during HSC culture; n = 3. b Immunofluorescent staining for Bip (green) of HSCs fixed at different time points during cultivation. 4′,6-Diamidino-2-phenylindole (DAPI; blue) was used as a nuclear staining. Graph representing the quantification of % mean intensity in at least 25 cells for each time point. c Western blot analysis of HSC activation markers PDGFRβ and α-smooth muscle actin (α-SMA) and of UPR marker BIP. GAPDH was used as a loading control. Cells were collected at the indicated time points, and samples for the 0 h time point were not seeded, but lysed immediately after cell isolation. Images and graphics are representatives of at least two different HSC isolations. *P < 0.05, **P < 0.01 and ***P < 0.001 versus 0 h
