Apoptosis of hepatic stellate cells in carbon tetrachloride induced acute liver injury of the rat: Analysis of isolated hepatic stellate cells

Background/Aims: Analysis of isolated hepatic stellate cells (HSCs) from the injured liver may provide direct information on HSC apoptosis. However, it has not been established whether apoptotic HSCs would be isolated using the usual density gradient centrifugation method. The aim of this study was to observe the serial pattern of proliferation and apoptosis in isolated HSCs in comparison with that of liver tissue sections in CCl₄ induced acute liver injury. Methods: Male Sprague-Dawley rats were treated with a single intraperitoneal injection of carbon tetrachloride (CCl₄) and were killed at various time points after the treatment. Results: HSC proliferation showed a maximal increase at 32 h after CCl₄ injection. Apoptosis of HSC, examined by quantitative analysis of annexin-V-fluorescein isothiocyanate (FITC)staining, showed the maximal increase at 64 h. Apoptosis of HSC in liver tissue sections examined by counting desmin and Tdt-mediated-dUTP biotin nick end labeling (TUNEL) double staining cells, peaked at 64 h. The number of TUNEL positive HSCs in liver tissue sections correlated significantly with annexin-V-FITC binding of isolated HSC. Conclusions: Studying apoptosis using apoptotic HSCs isolated by a usual density gradient centrifugation method from injured tissue sections would be feasible since it correlated with in vivo apoptosis of HSC.