Improvement of peripheral blood lymphocyte subsets in primary biliary cirrhosis after ursodeoxycholic acid therapy

Anti-apoptotic therapeutic approaches in liver diseases: do they really make sense?

A variety of data suggesting apoptotic cell death as a key feature of liver injury stimulated researchers to investigate the therapeutic potential of anti-apoptotic strategies in experimental models. However, the overestimated role of apoptotic cell death in liver injury has tempered the clinical translation of the protection afforded by anti-apoptotic regimes in experimental models. Thus, the hope for apoptosis modulation as potential treatment strategy for injured liver in humans could not be confirmed. Herein, we evaluated the degree of apoptosis in different hepatic stress models which are relevant for the human pathophysiology. Using morphological criteria of apoptosis, caspase-3 activation as well as TUNEL assay in combination with a positive control of apoptosis in liver injury, we quantified apoptotic cell death discriminating between parenchymal and non-parenchymal cells and confirmed these results by cleaved caspase-3 and PARP-1 protein expression. Discussing our findings and relating them to the existing literature on the potential role of apoptotic cell death, we strongly recommend reconsidering anti-apoptotic strategies to ameliorate liver injury efficiently.

Suppressive effect of ursodeoxycholic acid on type IIA phospholipase A2 expression in HepG2 cells

Phospholipase A(2) IIA (PLA(2)IIA), which plays a crucial role in arachidonic acid metabolism and in inflammation, is upregulated under various pathological conditions, including in the gallbladder and gallbladder bile from patients with multiple cholesterol gallstones, in the liver and kidney of rats with cirrhosis, as well as in the colonic tissue of animals treated with a chemical carcinogen. The administration of ursodeoxycholic acid (UDCA) partially attenuated the PLA(2)IIA expression level in these different models. The aim of this study was to investigate the modulatory effect of UDCA on the PLA(2)IIA expression level at the cellular level. The HepG2 cells were selected to investigate the direct inhibitory effect of UDCA on PLA(2)IIA expression level. The proinflammatory cytokines (interleukin-6 and tumor necrosis factor alpha) -induced PLA(2)IIA expression in HepG2 cells was partially inhibited by the presence of UDCA in a dose-dependent fashion. The effect of UDCA on proinflammatory cytokines-induced PLA(2)IIA expression occurred at the transcriptional level. In addition, among the bile acids tested, this inhibitory effect was UDCA-specific. In conclusion, this study supports the possible alteration of arachidonic acid metabolism and PLA(2)IIA expression level, in particular, as the protective action of UDCA in patients with chronic liver disease.