Thank you, Chris. First of all, I would like to acknowledge the invitation by the chairs to participate in this SIG program. Well, I'm very proud to be here and try to make this appreciation to be mutual at the end of the presentation, if I wish to hope so. The topic that I will be defending is the therapeutic benefit of statin in chronic liver diseases. These are my disclosures. None of them has nothing to do with statin, so I feel quite free to continue on after that slide. So, why we are talking on statins for liver disease? So, you know that statins have long been used for this lipidemia, and the effects in cardiovascular diseases have excess in much the effects on serum cholesterol levels. So the beneficial effects go much beyond these lipid lowering effects. And this has been alluded to as the pleiotropic effects of statins, meaning that it has other beneficial effects on the vascular wall by which statins are really useful in cardiovascular diseases. So we thought that statins may also protect the liver. And why that? Because these pleiotropic effects exceed also to any kind of circulation, and the liver circulation is very important in the progression of liver diseases and in some of its complications, such as portal hypertension. So which are these pleiotropic effects of statins in the liver? This is summarized in this very busy slide that I will guide you through. But by saying, where I would like to show you that inhibition of the synthesis of mevalonate in the vascular wall leads to reduced activation of a small GTPases through inhibition of the formation of seraniopilophosphate. And these small GTPases include PrAT1 and RhoA. RhoA is essential for the contraction of pericytes and in the liver of the hepatic steroid cell, whereas PrAT1 acts on the synthesis of KLF2, which is a nuclear factor reporting the transduction of genes essential for maintaining a normal endothelial cell phenotype. As a result, the administration of statins gives in the liver an antifibrotic property, a pro-vascular phenotype, inhibition of contraction, inhibition of inflammation and cell death, and an improved vascularization. And these are all good effects for the liver. And so let's go a little bit further and examine to what extent these effects have been examined in liver disease. So here I summarize the molecular pathways that have been explored, the targeted cells, the underlying mechanisms, the improved pathogenic events, and in which preclinical and clinical models we have studied all these things, relating acute liver injury, chronic liver disease, and acute and chronic liver failure. So there are a multitude of studies that have been done during the past two decades, and I will try to summarize the main message, not entering into specific details, but the main messages that we have gone through all these studies. So this is to remind you on the key role of the KLF2 in maintaining an endothelial phenotype. The normal stimulus for KLF2 synthesis, which reports the transcription of genes conveying a normal phenotype to the endothelial cells, is shear stress. So the stress of blood flow over the endothelial surface. This is where statins act, because statins is the more powerful pharmacological agonist for the mechanoreceptor inducing the expression of KLF2. And this has led to a number of studies showing that this stimulation does indeed cause beneficial effects in the liver, including the enhancing of KLF2 expression, reversion of endothelial dysfunction, decreased fibrogenesis, protecting the liver from endotoxin shock and from ischemic lipid fusion injury, preventing acute and chronic liver failure, and reducing portal pressure in experimental models. So there is a full set of evidence showing that all these effects can be achieved. To make the story short, I would like to show you only a few studies. This is the first study showing that KLF2 can reverse the fibrogenic properties in the cirrhotic liver, either up regulating KLF2 expression by gene transfer or by synvastatin therapy. You can reduce fibrogenesis and reduce the expression of alpha-smooth mast cell actin and of procollagen 1, or even by giving synvastatin, deactivate the fatty cystoid cells, decrease fibrosis and portal pressure. And I'm showing here a picture of a serious red staining, showing how much fibrosis can be reduced by synvastatin in animals with chronic liver disease. And I'm putting here a study by Dr. Trevika in his lab. He has done a number of relevant studies on the effects of statins on liver function. And you see here also a very much decreased collagen content in another model of chronic liver disease. So this antifibrotic effect is, of course, very important and is in part responsible for the reduced portal pressure that we observed in animals with portal hypertension when treated with statins. This is another relevant mechanism that is influenced by statins in liver disease, which is preventing the consequences of hypovolemic shock. You see here normal animals or cirrhotic animals with bile duct ligation-induced cirrhosis, subject to bleeding and to resuscitation. And you see that there is an increase in transaminases in both models, especially in transfit cirrhosis. And how synvastatin pretreatment totally prevents this increase in transaminases that reflects liver injury during MRH and resuscitation. And as you see on the right panel, there is also an activation of inflammatory pathways with a marked increase in the cirrhotic rats after breathing and resuscitation. And this is totally abrogated by synvastatin therapy. So it means that the consequences of shock can be mitigated a lot by synvastatin pretreatment, thus protecting your liver when you have such an event. And also, we have shown that synvastatin pretreatment can prevent LPS-induced or sepsis-induced acute and chronic liver failure in cirrhotic rats. And this was done in two models of cirrhosis, the carbon-tet and the cerebellar cirrhotic model. And in these models, synvastatin reduced inflammatory reactions and liver damage, and also prevented mortality after LPS-induced shock. And you see here that in the vehicle-treated animals, there is a progressive mortality that is almost totally prevented by synvastatin pretreatment in both models of chronic liver injury. So this sets the background for clinical applications of statins in patients with chronic liver disease. So I will analyze that. The evidence we have up to now is limited. There are only a few randomized controlled trials and observational studies in patients with cirrhosis to provide objective evidence on the effects of statins in patients with cirrhosis. But I think that at least in some indications, the evidence we have up to now is quite firm. The first study that was published is that study that I summarized here. We published that 15 years ago. And this was a pilot study looking at the effects of acute synvastatin administration in patients with cirrhosis, looking at liver hemodynamics, and we observed an increased liver perfusion, an increased production of nitric oxide, which is reduced in cirrhosis. And this was accompanied by a decrease in hepatic sinusoidal resistance. So there were beneficial effects on the liver microcirculation after giving synvastatin, suggestive that we have improved endothelial function. You know, in cirrhosis, one of the basic mechanisms of increasing resistance in the liver is the existence of intrahepatic microcirculatory dysfunction, basically in the endothelial cells. So in the same paper, we had a second experiment that was a randomized controlled trial of acute, only two administrations of synvastatin in patients with cirrhosis that were studied before and after giving a test meal. So to explore whether an increased blood flow, the postprandial hyperemia of a test meal causes an increased blood flow, will elicit the normal mechanism of flow-induced vascular relaxation in patients with cirrhosis. And I show here in the slide, you see that in patients under placebo, this flow-induced increase in blood flow in the liver caused a marked increase in portal pressure that was not observed in patients pre-treated with synvastatin due to the fact that these patients were able to vasodilate their liver in response to the increased blood flow. So we reversed in these patients acutely the endothelial dysfunction that is contributing to the portal hypertension, and by this mechanism, we prevented the increase in portal pressure after a test meal. So the subsequent step we took was a phase two placebo-controlled clinical trial looking at the effects of chronic synvastatin administration in patients with cirrhosis treated for one month with statins or placebo on portal hypertension. And the main endpoint was HVPG, and as shown here, patients under placebo did not modify the HBPG, but the HBPG was significantly decreased by statins. And this effect was observed both in patients not taking beta blockers and in patients who already were on beta blockers. And this, so there was a clear additive effect over that of beta blockers. And this was accompanied by an unexpected finding that was an improved liver function. So even in cirrhosis, where you know that you think that liver function is limited by the extent of fibrosis and the hemodynamic alterations, we had in response to simvastatin administration, an increase in the hepatic clearance of ICG, which is an endopathic intrinsic clearance, which are objective quantitative tests of liver function. That's probably reflecting the antifibrotic effect of simvastatin, improving the availability of substrates to the liver cells. So in any case, these were clear favorable effects, suggesting that we could improve not only portal pressure, but also liver function. So there was a prospect for improving the prognosis in patients with advanced cirrhosis. And this was the aim of the subsequent study. There was a randomized phase three clinical trial with clinical endpoints that was preventing the compensation and death in patients who had already fled from viruses and that were receiving a standard therapy with beta blockers and endoscopic band ligation associated. And on top of that, we gave some simvastatin or placebo. And we couldn't prevent rebreeding, but we increased significantly survival in this population of patients. And this increase in survival was dramatic with an odds ratio of over a 60% improvement in the hazard of dying. So this was a dramatic improvement in prognosis in these patients. And the mechanism by reducing this was not preventing rebreeding, as I said, but preventing dying from rebreeding and dying from infections. And this is the moment to remind the experiments I showed before in rats, signaling that we could prevent with statins deterioration of liver function after a hemorrhagic shock and resuscitation, so bleeding, or after LPS injections, so after infections. So probably this is the underlying mechanism for this improved prognosis with simvastatin in patients with cirrhosis. Another important thing that we observed in this study was that two patients out of 60, which is much more than expected, out of 75, sorry, were developed hepatotoxicity and muscle toxicity with rhabdomyolysis after exposure to statins. And these were patients with a bilirubin over five and with child C cirrhosis. So this is indirect evidence that they get overexposure to statins. And actually, pharmacologists show us that in a modeling system, these patients' maximal dose should be of about half the standard dose and not greater than 20 milligrams per day. So in child C patients, you should be careful in dosing statins and reduce the dose by half. And I will come back to that point later on. So when we look into the future, in the absence of extra randomized controlled trials, I forget to mention a trial by Dr. Pedro Flores confirming our results in patients with portal hypertension. But in the absence of other controlled trials, we have to look at indirect evidence from observational studies. And just to make that things appear bright to you, there is a good prospect for the effects of statins raising on the horizon as new stars in the treatment of cirrhosis. Let's go to have a look at this evidence. There have been over 20 of these studies published. I will summarize it by examples. And the first that I am addressing is the use of statins in non-alcoholic steatohepatitis. And why this? Because patients with NASH, over 80% of them have an indication for statins. Yet, patients with these patients, very few of them are given statins. In this study from Italy, only 9% of these patients were under statins. And the study that they know with more patients being treated had only 30% of them treated. And so in this study, to make it short, the statins prevented the steatosis, NASH, and F2 to F4 fibrosis in these patients. And a subsequent study in patients with cirrhosis, evaluating the risk of cirrhosis in patients with chronic hepatitis C virus infection, suggested that this could be prevented by statins in such extensive way that it looks too good to be true. In high-dose statin treatment, the decrease in the odds ratio for cirrhosis was up to 0.13. So it's 80% protection from cirrhosis. This is almost impossible to be true. So there have been more studies, and this is a study using propensity score matching, very well conducted by the group of Dr. Garcia-Sal. And in this study, they confirm in patients with hep C infection in veterans that the hazard ratio for the compensation and death was decreased for almost 50% in statin users. So again, this looks almost too good to be true, but after so many studies, you begin to put a question mark in this too good to be true, and think that perhaps this will be true. Again, for hepatocellular carcinoma, there have been studies, this is a nationwide Swedish study, showing that lipophilic statins, such as simvastatin and atorvastatin, which concentrate more in the liver, will prevent liver cancer. While use of non-lipophilic statins, dihydrophilic statins, rosuvastatin, bravastatin, had no effect on that regard. So it looks like these beneficial effects in the liver are easier to obtain with simvastatin that has been the drug most used up to now. So, what else? Well, even in a very difficult situation, such as this PSC, which is a disease without a treatment, there has been evidence, indirect evidence, from this kind of a study, that progression to liver events, mortality, and death of liver transplantation can be prevented by the statin use. Again, there is something special in this study, which is that patients with more robust evidence of statin use had less clear protection. So the degree of protection was lower in patients with more statin exposure. And this is a little bit at odds with what one would predict, and probably points out to the problems with observational studies that have a very low transportability, which means that if you take situations with such kind of protective studies have been done, then when you go to examine in a randomized control trial, this is confirmed in very limited instances. And with the statins for other indications, non-liver indications, it's only two out of 60 studies, I think. So probably it's a problem. We have a problem with observational studies. And in that regard, I would like to show you that very recent studies have shown that this can be mitigated by adopting strategies in analysis emulating a randomized control trial. This is a study published in Nature Medicine very recently, showing that the flaws observed in cancer research on the protection afforded by statins can be very much mitigated by adopting such analysis strategy. This is illustrated in that slide that shows that an analysis that was very positive for statins, preventing cirrhosis using conventional strategies, totally disappear when you adopt that trial emulation strategy. And probably this is the way to go in observational studies to get more robust studies. Meanwhile, we are attending also the results of randomized control trials on CURS. There are three trials with clinical outcomes being conducted at present. One in Spain with simvastatin in very early cirrhosis. One in the States with simvastatin again in patients with compensated cirrhosis at risk of decompensation. And the liver hub project in Europe, which is in patients with decompensated advanced cirrhosis in order to prevent acute and chronic liver failure. So this will probably provide an answer to this. And my final slide is the precautions with the use of statins in patients with cirrhosis, which is, as I said, there is a risk for liver and muscle toxicity, which is usually self-limited and does not represent a problem. But in some cases, when you have marked transaminase elevations, this indicates true idiosyncratic reactions and severe cases have been reported, including mortal cases. So there is a problem which persists, but it's not particularly true for patients with liver disease. And this has been well-examined by the task force and the FDA, showing that the risk in patients with cirrhosis is not greater than in the general population. The only thing that you should remember is that doses should be halved in child sleep patients to avoid increased incidence of muscle toxicity. And for simvastatin, for instance, the dose should be not greater than 20 milligrams. So in summary, we are getting growing evidence of beneficial effects of statins in advanced chronic liver disease, reducing in portal pressure and in the complications of portal hypertension being a potential indication where we are close to get definitive evidence. We have several phase two studies and one phase three clinical trial double blind in favor. So we only need the second one to convert that into a firm indication. But the overall clinical evidence so far is limited, so we need further studies. And with that, I finish this by thanking you for your attention. Thank you. Thank you so much.

therapeutic benefits

statins

chronic liver diseases

pleiotropic effects

anti-fibrotic properties

liver function