Prevention of in vitro hepatic stellate cells activation by the adenosine derivative compound IFC305.

We have previously shown that adenosine and the aspartate salt of adenosine (IFC305) reverse pre-established CCl(4)-induced cirrhosis in rats. However, their molecular mechanism of action is not clearly understood. Hepatic stellate cells (HSC) play a pivotal role in liver fibrogenesis leading to cirrhosis, mainly through their activation, changing from a quiescent adipogenic state to a proliferative myofibrogenic condition. Therefore, we decided to investigate the effect of IFC305 on primary cultured rat HSC. Our results reveal that this compound suppressed the activation of HSC, as demonstrated by the maintenance of a quiescent cell morphology, including lipid droplets content, inhibition of α-smooth muscle actin (α-SMA) and collagen α1(I) expression, and up-regulation of MMP-13, Smad7, and PPARγ expression, three key antifibrogenic genes. Furthermore, IFC305 was able to repress the platelet-derived growth factor (PDGF)-induced proliferation of HSC. This inhibition was independent of adenosine receptors stimulation; instead, IFC305 was incorporated into cells by adenosine transporters and converted to AMP by adenosine kinase. On the other hand, addition of pyrimidine ribonucleoside as uridine reversed the suppressive effect of IFC305 on the proliferation and activation of HSC, suggesting that intracellular pyrimidine starvation would be involved in the molecular mechanism of action of IFC305. In conclusion, IFC305 inhibits HSC activation and maintains their quiescence in vitro; these results could explain in part the antifibrotic liver beneficial effect previously described for this compound on the animal model.

An adenosine derivative compound, IFC305, reverses fibrosis and alters gene expression in a pre-established CCl(4)-induced rat cirrhosis.

Cirrhosis is a complex process that involves a dynamic modification of liver cell phenotype associated to gene expression changes. This study investigates the reversing capacity of an adenosine derivative compound (IFC305) on a rat model of liver cirrhosis and gene expression changes associated with it. Rats were treated with IFC305 or saline for 5 or 10 weeks after cirrhosis induction (CCl(4) treatment for 10 weeks). Fibrosis score, collagenase activity and amount of hepatic stellate cells (HSC, activated and with a lipid-storing phenotype) were measured in livers. In addition, gene expression analysis was performed using 5K DNA microarrays and quantitative RT-PCR. Treatment of cirrhotic rats with IFC305 for 5 or 10 weeks compared to saline control, induced: (1) reduction of fibrosis (50-70%) and of collagen, of alpha-SMA and desmin proteins, as well as of activated HSCs in liver, (2) increased collagenase activity and cell number of lipid-storing HSC, (3) improved serum parameters of liver function, such as reduced activity of aminotransferases and bilirubin. Expression of 413 differential genes, deregulated in cirrhotic samples, tended to be normalized by IFC305 treatment. Some genes modulated at transcript level by IFC305 were Tgfb1, Fn1, Col1a1, C9, Apoa1, Ass1, Cps1, and Pparg. The present study shows that IFC305 reverses liver fibrosis through modulation of adipogenic and fibrosis-related genes and by ameliorating hepatic function. Thus, understanding of the anti-cirrhotic effect of IFC305 might have therapeutical potential in patients with cirrhosis.