Effects of simvastatin administration on rodents with lipopolysaccharide-induced liver microvascular dysfunction

Endothelial dysfunction: Pathophysiology and therapeutic targets for sepsis-induced multiple organ dysfunction syndrome

Sepsis and septic shock are critical medical conditions characterized by a systemic inflammatory response to infection, significantly contributing to global mortality rates. The progression to multiple organ dysfunction syndrome (MODS) represents the most severe complication of sepsis and markedly increases clinical mortality. Central to the pathophysiology of sepsis, endothelial cells play a crucial role in regulating microcirculation and maintaining barrier integrity across various organs and tissues. Recent studies have underscored the pivotal role of endothelial function in the development of sepsis-induced MODS. This review aims to provide a comprehensive overview of the pathophysiology of sepsis-induced MODS, with a specific focus on endothelial dysfunction. It also compiles compelling evidence regarding potential small molecules that could attenuate sepsis and subsequent multi-organ damage by modulating endothelial function. Thus, this review serves as an essential resource for clinical practitioners involved in the diagnosing, managing, and providing intensive care for sepsis and associated multi-organ injuries, emphasizing the importance of targeting endothelial cells to enhance outcomes of the patients.

Pathophysiology and therapeutic options for cirrhotic portal hypertension

Portal hypertension represents the primary non-neoplastic complication of liver cirrhosis and has life-threatening consequences, such as oesophageal variceal bleeding, ascites, and hepatic encephalopathy. Portal hypertension occurs due to increased resistance of the cirrhotic liver vasculature to portal blood flow and is further aggravated by the hyperdynamic circulatory syndrome. Existing knowledge indicates that the profibrogenic phenotype acquired by sinusoidal cells is the initial factor leading to increased hepatic vascular tone and fibrosis, which cause increased vascular resistance and portal hypertension. Data also suggest that the phenotype of hepatic cells could be further impaired due to the altered mechanical properties of the cirrhotic liver itself, creating a deleterious cycle that worsens portal hypertension in the advanced stages of liver disease. In this Review, we discuss recent discoveries in the pathophysiology and treatment of cirrhotic portal hypertension, a condition with few pharmacological treatment options.

Cellular Senescence in Acute Liver Injury: What Happens to the Young Liver?

Cellular senescence, characterized by irreversible cell cycle arrest, not only exists in age-related physiological states, but has been found to exist in various diseases. It plays a crucial role in both physiological and pathological processes and has become a trending topic in global research in recent years. Acute liver injury (ALI) has a high incidence worldwide, and recent studies have shown that hepatic senescence can be induced following ALI. Therefore, we reviewed the significance of cellular senescence in ALI. To minimize the potential confounding effects of aging on cellular senescence and ALI outcomes, we selected studies involving young individuals to identify the characteristics of senescent cells, the value of cellular senescence in liver repair, its regulation mechanisms in ALI, its potential as a biomarker for ALI, the prospect of treatment, and future research directions.

Vascular leak in sepsis: physiological basis and potential therapeutic advances

Sepsis is a life-threatening condition characterised by endothelial barrier dysfunction and impairment of normal microcirculatory function, resulting in a state of hypoperfusion and tissue oedema. No specific pharmacological therapies are currently used to attenuate microvascular injury. Given the prominent role of endothelial breakdown and microcirculatory dysfunction in sepsis, there is a need for effective strategies to protect the endothelium. In this review we will discuss key mechanisms and putative therapeutic agents relevant to endothelial barrier function.

Cardiomyopathy in cirrhosis: From pathophysiology to clinical care

Cirrhotic cardiomyopathy (CCM) is defined as systolic or diastolic dysfunction in the absence of prior heart disease or another identifiable cause in patients with cirrhosis, in whom it is an important determinant of outcome. Its underlying pathogenic/pathophysiological mechanisms are rooted in two distinct pathways: 1) factors associated with portal hypertension, hyperdynamic circulation, gut bacterial/endotoxin translocation and the resultant inflammatory phenotype; 2) hepatocellular insufficiency with altered synthesis or metabolism of substances such as proteins, lipids, carbohydrates, bile acids and hormones. Different criteria have been proposed to diagnose CCM; the first in 2005 by the World Congress of Gastroenterology, and more recently in 2019 by the Cirrhotic Cardiomyopathy Consortium. These criteria mainly utilised echocardiographic evaluation, with the latter refining the evaluation of diastolic function and integrating global longitudinal strain into the evaluation of systolic function, an important addition since the haemodynamic changes that occur in advanced cirrhosis may lead to overestimation of systolic function by left ventricular ejection fraction. Advances in cardiac imaging, such as cardiac magnetic resonance imaging and the incorporation of an exercise challenge, may help further refine the diagnosis of CCM. Over recent years, CCM has been shown to contribute to increased mortality and morbidity after major interventions, such as liver transplantation and transjugular intrahepatic portosystemic shunt insertion, and to play a pathophysiologic role in the genesis of hepatorenal syndrome. In this review, we discuss the pathogenesis/pathophysiology of CCM, its clinical implications, and the role of cardiac imaging modalities including MRI. We also compare diagnostic criteria and review the potential diagnostic role of electrocardiographic QT prolongation. At present, no definitive medical therapy exists, but some promising potential treatment strategies for CCM are reviewed.

Prophylactic simvastatin increased survival during endotoxemia and inhibited granulocyte trafficking in a cell-intrinsic manner

Cross sectional studies have shown that statin-users have improved odds of surviving severe sepsis. Meanwhile controlled clinical trials failed to demonstrate improved sepsis survival with acute statin administration following hospitalization. Here, a lethal murine peritoneal lipopolysaccharide (LPS) endotoxemia model was used to assess the efficacy of chronic versus acute simvastatin on survival. Mirroring clinical observations, chronic but not acute treatment with simvastatin significantly increased survival. At a pre-mortality time point in LPS-treated mice, chronic simvastatin suppressed granulocyte trafficking in to the lungs and peritoneum without otherwise suppressing emergency myelopoiesis, myeloid cells in circulation, or inflammatory cytokines. Chronic simvastatin treatment significantly downregulated inflammatory chemokine gene signature in the lungs of LPS-treated mice. Thus, it was unclear if simvastatin was inhibiting granulocyte chemotaxis in a cell intrinsic or extrinsic manner. Adoptive transfer of fluorescently labeled granulocytes from statin and vehicle treated mice into LPS-treated mice showed that simvastatin inhibited lung-granulocyte trafficking in a cell intrinsic manner. Congruent with this, chemotaxis experiments using in vitro macrophages and ex vivo granulocytes demonstrated that simvastatin inhibited chemotaxis in a cell-intrinsic manner. Collectively, chronic but not acute simvastatin treatment improved survival in murine endotoxemia, and this was associated with cell-intrinsic inhibition of granulocyte chemotaxis.

Baseline Severity and Inflammation Would Influence the Effect of Simvastatin on Clinical Outcomes in Cirrhosis Patients

BACKGROUND

Simvastatin administration to decompensated cirrhosis patients improved Child-Pugh (CP) at the end of a safety trial (EST).

AIM

To evaluate whether simvastatin reduces cirrhosis severity through a secondary analysis of the safety trial.

METHODS

Thirty patients CP class (CPc) CPc A (n = 6), CPc B (n = 22), and CPc C (n = 2) received simvastatin for one year.

PRIMARY ENDPOINT

cirrhosis severity. Secondary endpoints: health-related quality of life (HRQoL) and hospitalizations for cirrhosis complications.

RESULTS

Cirrhosis severity decreased baseline versus EST only across CP score (7.3 ± 1.3 versus 6.7 ± 1.7, P = 0.041), and CPc: 12 patients lessened from CPc B to CPc A, and three patients increased from CPc A to CPc B (P = 0.029). Due to cirrhosis severity changes and differences in clinical outcomes, 15 patients completed the trial as CPc A_EST and another 15 as CPc B/C. At baseline, CPc A_EST showed greater albumin and high-density lipoprotein cholesterol concentrations than CPc B/C (P = 0.036 and P = 0.028, respectively). Comparing EST versus baseline, only in CPc A_EST, there was a reduction in white-cell blood (P = 0.012), neutrophils (P = 0.029), monocytes (P = 0.035), and C-reactive protein (P = 0.046); an increase in albumin (P = 0.011); and a recovery in HRQoL (P < 0.030). Finally, admissions for cirrhosis complications decreased in CPc A_EST versus CPc B/C (P = 0.017).

CONCLUSIONS

Simvastatin would reduce cirrhosis severity only in CPc B at baseline in a suitable protein and lipid milieu, possibly due to its anti-inflammatory effects. Furthermore, only in CPc A_EST would improve HRQoL and reduce admissions by cirrhosis complications. However, as these outcomes were not primary endpoints, they require validation.

Understanding the Potential Role of Nanotechnology in Liver Fibrosis: A Paradigm in Therapeutics

The liver is a vital organ that plays a crucial role in the physiological operation of the human body. The liver controls the body's detoxification processes as well as the storage and breakdown of red blood cells, plasma protein and hormone production, and red blood cell destruction; therefore, it is vulnerable to their harmful effects, making it more prone to illness. The most frequent complications of chronic liver conditions include cirrhosis, fatty liver, liver fibrosis, hepatitis, and illnesses brought on by alcohol and drugs. Hepatic fibrosis involves the activation of hepatic stellate cells to cause persistent liver damage through the accumulation of cytosolic matrix proteins. The purpose of this review is to educate a concise discussion of the epidemiology of chronic liver disease, the pathogenesis and pathophysiology of liver fibrosis, the symptoms of liver fibrosis progression and regression, the clinical evaluation of liver fibrosis and the research into nanotechnology-based synthetic and herbal treatments for the liver fibrosis is summarized in this article. The herbal remedies summarized in this review article include epigallocathechin-3-gallate, silymarin, oxymatrine, curcumin, tetrandrine, glycyrrhetinic acid, salvianolic acid, plumbagin, Scutellaria baicalnsis Georgi, astragalosides, hawthorn extract, and andrographolides.

Improving Management of Portal Hypertension: The Potential Benefit of Non-Etiological Therapies in Cirrhosis

Portal hypertension is the consequence of cirrhosis and results from increased sinusoidal vascular resistance and hepatic blood inflow. Etiological therapies represent the first intervention to prevent a significant increase in portal pressure due to chronic liver damage. However, other superimposed pathophysiological drivers may worsen liver disease, including inflammation, bacterial translocation, endothelial dysfunction, and hyperactivation of hemostasis. These mechanisms can be targeted by a specific class of drugs already used in clinical practice. Albumin, rifaximin, statins, aspirin, and anticoagulants have been tested in cirrhosis and were a topic of discussion in the last Baveno consensus as non-etiological therapies. Based on the pathogenesis of portal hypertension in cirrhosis, our review summarizes the main mechanisms targeted by these drugs as well as the clinical evidence that considers them a valid complementary option to manage patients with cirrhosis and portal hypertension.

Protective effects of menthol against sepsis-induced hepatic injury: Role of mediators of hepatic inflammation, apoptosis, and regeneration

Liver dysfunction in sepsis is a major complication that amplifies multiple organ failure and increases the risk of death. Inflammation and oxidative stress are the main mediators in the pathophysiology of sepsis. Therefore, we investigated the role of menthol, a natural antioxidant, against sepsis-induced liver injury in female Wistar rats. Sepsis was induced by cecal ligation and puncture (CLP). Menthol (100 mg/kg) was given intragastric 2 h after CLP. Blood samples and liver tissues were collected 24 h after surgery. Menthol significantly (p < 0.05) attenuated the sepsis-induced elevation in serum liver enzymes and improved the hepatic histopathological changes. Menthol treatment significantly (p < 0.05) decreased hepatic levels of tumor necrosis factor-alpha, malondialdehyde, total nitrite, and cleaved caspase-3. It restored the hepatic levels of superoxide dismutase and reduced glutathione. Additionally, menthol significantly (p < 0.05) increased hepatic levels of B-cell lymphoma 2 (Bcl-2); an anti-apoptotic factor, and proliferating cell nuclear antigen (PCNA), a biomarker of regeneration and survival. Our results showed the therapeutic potential of menthol against liver injury induced by sepsis.

Early Diagnosis and Prevention of Infections in Cirrhosis

Strategies to prevent infection and improve outcomes in patients with cirrhosis. HAV, hepatitis A virus; HBV, hepatitis B virus; COVID-19, novel coronavirus disease 2019; NSBB, nonselective β-blocker; PPI, proton pump inhibitors.Cirrhosis is a risk factor for infections. Majority of hospital admissions in patients with cirrhosis are due to infections. Sepsis is an immunological response to an infectious process that leads to end-organ dysfunction and death. Preventing infections may avoid the downstream complications, and early diagnosis of infections may improve the outcomes. In this review, we discuss the pathogenesis, diagnosis, and biomarkers of infection; the incremental preventive strategies for infections and sepsi; and the consequent organ failures in cirrhosis. Strategies for primary prevention include reducing gut translocation by selective intestinal decontamination, avoiding unnecessary proton pump inhibitors' use, appropriate use of β-blockers, and vaccinations for viral diseases including novel coronavirus disease 2019. Secondary prevention includes early diagnosis and a timely and judicious use of antibiotics to prevent organ dysfunction. Organ failure support constitutes tertiary intervention in cirrhosis. In conclusion, infections in cirrhosis are potentially preventable with appropriate care strategies to then enable improved outcomes.

Statin use and risk of progression to liver cirrhosis in chronic hepatitis B independent of conventional risk factors: A nationwide study

Many studies have elucidated the protective associations of statin use with liver cancer or mortality, but studies examining statin's effect on the risk of progression to liver cirrhosis considering medical/metabolic conditions or lifestyle factors are lacking. We aimed to assess statin's benefit independent of conventional risk factors. We identified 25,033 pairs of statin users (using statins for ≥90 days) and nonusers among patients with chronic hepatitis B (CHB) in the Republic of Korea's National Health Insurance Service database from 2010 to 2018. The primary endpoint was progression to cirrhosis from an inactive carrier or simple CHB. The cumulative probability was plotted using the Kaplan-Meier method. Adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) were estimated using the multivariable Cox proportional hazard model. During a 218,472 person-year follow-up, 2210 incident cases of progression to cirrhosis occurred. The 5-year cumulative risks were 4.0% and 6.3% in statin users and nonusers, respectively (p < 0.001). Statin use was significantly associated with a decreased risk of progression to cirrhosis (aHR, 0.59; 95% CI, 0.55-0.65; p < 0.001), after adjusting for age, sex, hypertension, diabetes, dyslipidemia, antiviral therapy, aspirin use, metformin use, nonstatin medication for dyslipidemia, smoking, drinking, obesity, exercise, and liver dysfunction. This protective association was still significant in a dose-response manner and with different time lags for outcomes. Conclusion: Statin use is associated with a decreased risk of progression to cirrhosis among patients with CHB, independent of metabolic and lifestyle factors. Future studies are required to validate this observation.

Investigational drugs in early clinical development for portal hypertension

INTRODUCTION

Advanced chronic liver disease is considered a reversible condition after removal of the primary aetiological factor. This has led to a paradigm shift in which portal hypertension (PH) is a reversible complication of cirrhosis. The pharmacologic management of PH is centered on finding targets to modify the natural history of cirrhosis and PH.

AREAS COVERED

This paper offers an overview of the use of pharmacological strategies in early clinical development that modify PH. Papers included were selected from searching clinical trials sites and PubMed from the last 10 years.

EXPERT OPINION

A paradigm shift has generated a new concept of PH in cirrhosis as a reversible complication of a potentially curable disease. Decreasing portal pressure to prevent decompensation and further complications of cirrhosis that may lead liver transplantation or death is a goal. Therapeutic strategies also aspire achieve total or partial regression of fibrosis thus eliminating the need for treatment or screening of PH.

Pathogenesis-Related Gene Expression in Response to Trachyspermum ammi Supplementation Along With Probiotics in Chicken Salmonellosis and Insights in Drug Therapeutics

Salmonella enterica serovar typhimurium (S. typhimurium) is the leading cause of foodborne illness. Since Salmonella continues to have a detrimental effect on public health, there is an ongoing need to develop more advanced methods for combating Salmonellosis in foods before they reach consumers. In addition, the quest for alternative natural products has recently intensified due to increasingly stringent regulations regarding the use of antibiotics as growth promoters and consumer demand for antibiotic-free poultry products. This study evaluated the effect of Ajwain extract (AJE) on immune response and antioxidant status in broiler chicks challenged with Salmonella typhimurium. The chicks were infected with S. typhimurium and were divided into the different groups, except for the control group (CON). The challenged chicks received different treatments with 3 × 109 colony-forming unit (CFU) AciproTM-WS probiotic (PRO), 200 mg/kg Ajwain extract (AJE), 200 mg/100 kg of enrofloxacin (ENR), and a combination of 3 × 109 CFU AciproTM-WS probiotic and 200 mg/kg Ajwain extract (COM). Five days posttreatment, the tissue samples (liver and spleen) were analyzed. The results showed that basal diet supplemented with Ajwain extract (AJE) and a combination of probiotic and Ajwain extract (COM) significantly (P &lt; 0.0.5) reduced the cytokine expression in broiler chicks challenged with S. typhimurium. Our findings suggest that AJE can clear the bacterial infection, improve antioxidant status, and suppress the inflammation response. Additionally, AJE supplementation significantly mitigated the S. typhimurium-induced increase in the interleukin-6 (IL-6) (liver and spleen), interleukin-8 (IL-8) (liver and spleen), interleukin-17A (IL-17A) (liver and spleen), and inducible nitric oxide (iNOS) (spleen and liver) levels (P &lt; 0.05). We conclude that Ajwain is an efficient feed additive with antioxidant and anti-inflammatory properties. The interaction networks developed in this study provide a novel lead that could be targeted for anti-inflammatory and antioxidant properties.

Simvastatin Prevents Liver Microthrombosis and Sepsis Induced Coagulopathy in a Rat Model of Endotoxemia

Background: Endotoxemia causes endothelial dysfunction and microthrombosis, which are pathogenic mechanisms of coagulopathy and organ failure during sepsis. Simvastatin has potential anti-thrombotic effects on liver endothelial cells. We investigated the hemostatic changes induced by lipopolysaccharide (LPS) and explored the protective effects of simvastatin against liver vascular microthrombosis. Methods and results: We compared male Wistar rats exposed to LPS (5 mg/kg one i.p. dose) or saline in two experimental protocols—placebo (vehicle) and simvastatin (25 mg/kg die, orally, for 3 days before LPS). Morphological studies were performed by light- and electron-microscopy analyses to show intravascular fibrin deposition, vascular endothelial structure and liver damage. Peripheral- and organ-hemostatic profiles were analyzed using whole blood viscoelastometry by ROTEM, liver biopsy and western-blot/immunohistochemistry of thrombomodulin (TM), as well as immunohistochemistry of the von Willebrand factor (VWF). LPS-induced fibrin deposition and liver vascular microthrombosis were combined with a loss of sinusoidal endothelial TM expression and VWF-release. These changes were associated with parenchymal eosinophilia and necrosis. ROTEM analyses displayed hypo-coagulability in the peripheral blood that correlated with the degree of intrahepatic fibrin deposition (p < 0.05). Simvastatin prevented LPS-induced fibrin deposition by preserving TM expression in sinusoidal cells and completely reverted the peripheral hypo-coagulability caused by endotoxemia. These changes were associated with a significant reduction of liver cell necrosis without any effect on eosinophilia. Conclusions: Simvastatin preserves the antithrombotic properties of sinusoidal endothelial cells disrupted by LPS, deserving pharmacological properties to contrast sepsis-associated coagulopathy and hepatic failure elicited by endotoxemia

Simvastatin ameliorates oxidative stress levels in HepG2 cells and hyperlipidemic rats

Simvastatin is an established anti-hyperlipidemic drug and few studies have indicated its role in the mitigation of oxidative stress. However, a systematic study considering molecular binding/interaction of simvastatin with anti-oxidant enzymes followed by confirmational in vitro and in vivo studies have never been done. We investigated the molecular binding of simvastatin with multiple anti-oxidant enzymes and assessed their levels after the treatment of simvastatin in vitro and in vivo. This study is the first to show the molecular binding of simvastatin to catalase through molecular docking analysis. Moreover, the anti-oxidative properties of simvastatin have not been studied in Lipopolysaccharide (LPS) induced oxidative stress in HepG2 cells. We found that simvastatin effectively attenuated oxidative stress in LPS induced HepG2 cells and high-fat diet (HFD) fed hyperlipidemic rats by increasing the levels of antioxidant enzymes. The activity of catalase and superoxide dismutase (SOD) both increased significantly in oxidatively stressed HepG2 cells after the treatment with simvastatin (10 ​μM, 24 ​h). In addition to this, he original cell morphology of oxidatively stressed cells was restored by simvastatin, and an increase in antioxidant enzymes, catalase (0.08 U/cells to 0.12 U/cells), and SOD (0.57 U/cells to 0.74 U/cells) was also noted in HepG2 cells. Furthermore, a significant increase in the antioxidant enzymes such as Catalase, SOD, and reduced glutathione (GSH) was noted after simvastatin treatment in the HFD model. Moreover, we also observed degradation of by-products of lipid peroxidation thiobarbituric acid reactive substances (TBARs), nitric oxide (NO), and protein carbonyl levels. This indicates that simvastatin enhances anti-oxidant enzyme activities and can be repurposed for the treatment of oxidative stress in liver diseases in humans after extensive clinical trials.

•

In silico, molecular docking analysis shows that simvastatin binds to the active site of the catalase enzyme.

•

Simvastatin attenuates LPS induced oxidative stress in HepG2 cells by increasing the amount of antioxidant enzymes catalase and SOD.

•

Simvastatin significantly reduces triglycerides, cholesterol, LDL, VLDL, and increases HDL level in HFD induced oxidative stress in Wistar rats.

•

Simvastatin can be repurposed for the treatment of oxidative stress in liver diseases.

Incidence, predictors and outcome of sepsis-associated liver injury in children: a prospective observational study

Sepsis-associated liver injury (SALI) occurs as a result of the systemic and microcirculatory changes that happen because of sepsis. Its prognostic significance in the paediatric population is unclear. We enrolled all children < 19 years, admitted between July, 2020 and July, 2021 to the paediatric unit (ward or intensive care unit) with a diagnosis of sepsis for this study. Clinical and biochemical parameters of children with sepsis who developed SALI were compared with those without SALI to determine the risk factors of SALI and its impact on in-hospital mortality. A total of 127 children, median age 72 (1-204) months, 74 males were included. SALI developed in 45 (31.3%) at a median 1 (1-13) days after the diagnosis of sepsis. The SALI pattern was cholestatic in 18 (40%), hepatocellular in 17 (37.7%) and hypoxic hepatitis in 10 (22.3%). Paediatric sequential organ failure assessment (pSOFA) was an independent predictor of SALI - OR 1.17 (95% CI 1.067-1.302), p = 0.001. A pSOFA score of > 9.5 predicted the development of SALI with 66.7% sensitivity and 77.1% specificity. SALI was an independent predictor of mortality in children with sepsis - OR 1.9 (95% CI 1.3-3.4), p = 0.01.   Conclusions: SALI develops in 45 (31.3%) with sepsis. A higher pSOFA score is associated with SALI. Children who develop SALI have a ~ twofold higher risk of mortality than those without SALI. What is Known: • During the process of sepsis, the liver plays a role by scavenging bacteria and producing inflammatory mediators. However, at times the liver itself becomes a target of the dysregulated inflammatory response. This is known as sepsis-associated liver injury (SALI). • The incidence of sepsis-associated liver injury and its prognostic significance in children is not known.. What is New: • SALI develops in one-third children with sepsis and is associated with a higher pSOFA score. • Children who develop SALI have a higher risk of mortality.

The Hepatic Sinusoid in Chronic Liver Disease: The Optimal Milieu for Cancer

Simple Summary

During the development of chronic liver disease, the hepatic sinusoid undergoes major changes that further compromise the hepatic function, inducing persistent inflammation and the formation of scar tissue, together with alterations in liver hemodynamics. This diseased background may induce the formation and development of hepatocellular carcinoma (HCC), which is the most common form of primary liver cancer and a major cause of mortality. In this review, we describe the ways in which the dysregulation of hepatic sinusoidal cells—including liver sinusoidal cells, Kupffer cells, and hepatic stellate cells—may have an important role in the development of HCC. Our review summarizes all of the known sinusoidal processes in both health and disease, and possible treatments focusing on the dysregulation of the sinusoid; finally, we discuss how some of these alterations occurring during chronic injury are shared with the pathology of HCC and may contribute to its development.

Abstract

The liver sinusoids are a unique type of microvascular beds. The specialized phenotype of sinusoidal cells is essential for their communication, and for the function of all hepatic cell types, including hepatocytes. Liver sinusoidal endothelial cells (LSECs) conform the inner layer of the sinusoids, which is permeable due to the fenestrae across the cytoplasm; hepatic stellate cells (HSCs) surround LSECs, regulate the vascular tone, and synthetize the extracellular matrix, and Kupffer cells (KCs) are the liver-resident macrophages. Upon injury, the harmonic equilibrium in sinusoidal communication is disrupted, leading to phenotypic alterations that may affect the function of the whole liver if the damage persists. Understanding how the specialized sinusoidal cells work in coordination with each other in healthy livers and chronic liver disease is of the utmost importance for the discovery of new therapeutic targets and the design of novel pharmacological strategies. In this manuscript, we summarize the current knowledge on the role of sinusoidal cells and their communication both in health and chronic liver diseases, and their potential pharmacologic modulation. Finally, we discuss how alterations occurring during chronic injury may contribute to the development of hepatocellular carcinoma, which is usually developed in the background of chronic liver disease.

Prevention of Cirrhosis Complications: Looking for Potential Disease Modifying Agents

The current therapeutic strategies for the management of patients with cirrhosis rely on the prevention or treatment of specific complications. The removal of the causative agents (i.e., viruses or alcohol) prevents decompensation in the vast majority of patients with compensated cirrhosis. In contrast, even when etiological treatment has been effective, a significant proportion of patients with decompensated cirrhosis remains at risk of further disease progression. Therefore, therapies targeting specific key points in the complex pathophysiological cascade of decompensated cirrhosis could represent a new approach for the management of these severely ill patients. Some of the interventions currently employed for treating or preventing specific complications of cirrhosis or used in other diseases (i.e., poorly absorbable oral antibiotics, statins, albumin) have been proposed as potential disease-modifying agents in cirrhosis (DMAC) since clinical studies have shown their capacity of improving survival. Additional multicenter, large randomized clinical trials are awaited to confirm these promising results. Finally, new drugs able to antagonize key pathophysiological mechanisms are under pre-clinical development or at the initial stages of clinical assessment.

Role of liver sinusoidal endothelial cells in liver diseases

Liver sinusoidal endothelial cells (LSECs) form the wall of the hepatic sinusoids. Unlike other capillaries, they lack an organized basement membrane and have cytoplasm that is penetrated by open fenestrae, making the hepatic microvascular endothelium discontinuous. LSECs have essential roles in the maintenance of hepatic homeostasis, including regulation of the vascular tone, inflammation and thrombosis, and they are essential for control of the hepatic immune response. On a background of acute or chronic liver injury, LSECs modify their phenotype and negatively affect neighbouring cells and liver disease pathophysiology. This Review describes the main functions and phenotypic dysregulations of LSECs in liver diseases, specifically in the context of acute injury (ischaemia-reperfusion injury, drug-induced liver injury and bacterial and viral infection), chronic liver disease (metabolism-associated liver disease, alcoholic steatohepatitis and chronic hepatotoxic injury) and hepatocellular carcinoma, and provides a comprehensive update of the role of LSECs as therapeutic targets for liver disease. Finally, we discuss the open questions in the field of LSEC pathobiology and future avenues of research.

Individualized treatment options for patients with non-cirrhotic and cirrhotic liver disease

The obesity pandemic has led to a significant increase in patients with metabolic dysfunction-associated fatty liver disease (MAFLD). While dyslipidemia, type 2 diabetes mellitus and cardiovascular diseases guide treatment in patients without signs of liver fibrosis, liver related morbidity and mortality becomes relevant for MAFLD's progressive form, non-alcoholic steatohepatitis (NASH), and upon development of liver fibrosis. Statins should be prescribed in patients without significant fibrosis despite concomitant liver diseases but are underutilized in the real-world setting. Bariatric surgery, especially Y-Roux bypass, has been proven to be superior to conservative and/or medical treatment for weight loss and resolution of obesity-associated diseases, but comes at a low but existent risk of surgical complications, reoperations and very rarely, paradoxical progression of NASH. Once end-stage liver disease develops, obese patients benefit from liver transplantation (LT), but may be at increased risk of perioperative infectious complications. After LT, metabolic comorbidities are commonly observed, irrespective of the underlying liver disease, but MAFLD/NASH patients are at even higher risk of disease recurrence. Few studies with low patient numbers evaluated if, and when, bariatric surgery may be an option to avoid disease recurrence but more high-quality studies are needed to establish clear recommendations. In this review, we summarize the most recent literature on treatment options for MAFLD and NASH and highlight important considerations to tailor therapy to individual patient's needs in light of their risk profile.

SACRED: Effect of simvastatin on hepatic decompensation and death in subjects with high-risk compensated cirrhosis: Statins and Cirrhosis: Reducing Events of Decompensation

BACKGROUND/AIMS

The development of decompensation in cirrhosis demarcates a marked change in the natural history of chronic liver disease. HMG-CoA reductase inhibitors (statins) exert pleiotropic effects that reduce inflammation and fibrosis as well as improve vascular reactivity. Retrospective studies uniformly have associated statin utilization with improved outcomes for patients with cirrhosis. Prospective human studies have shown that statins reduce portal hypertension and reduce death in patients with decompensated cirrhosis after variceal hemorrhage when added to standard therapy with an acceptable safety profile. This proposal aims to extend these findings to demonstrate that simvastatin reduces incident hepatic decompensation events among cirrhotic patients at high risk for hepatic decompensation.

METHODS

We will perform the SACRED Trial (NCT03654053), a phase III, prospective, multi-center, double-blind, randomized clinical trial at 11 VA Medical Centers. Patients with compensated cirrhosis with clinically significant portal hypertension will be stratified based upon the concomitant use of nonselective beta-blockers and randomized to simvastatin 40 mg/day versus placebo for up to 24 months. Patients will be observed for the development of hepatic decompensation (variceal hemorrhage, ascites, encephalopathy), hepatocellular carcinoma, liver-related death, death from any cause, and/or complications of statin therapy. Ancillary studies will evaluate patient-reported outcomes and pharmacogenetic corollaries of safety and/or efficacy.

CONCLUSION

Statins have a long track-record of safety and tolerability. This class of medications is generic and inexpensive, and thus, if the hypothesis is proven, there will be few barriers to widespread acceptance of the role of statins to prevent decompensation in patients with compensated cirrhosis. ClinicalTrials.gov Identifier: NCT03654053.

Effect of Pravastatin Pretreatment and Hypercapnia on Intestinal Microvascular Oxygenation and Blood Flow During Sepsis

INTRODUCTION

In septic patients, adequate microvascular oxygenation (μHBO2) of the intestine is vital for their outcome. Recent studies suggest that statins can ameliorate septic microcirculation in a variety of tissues. However, the effect on intestinal microvascular oxygenation and blood flow is largely unknown. Furthermore, there are indications that statin therapy might not be beneficial in the presence of hypercapnia, as observed in septic acute respiratory distress syndrome (ARDS) patients. Therefore, the present study explores the effect of pravastatin with and without additional moderate acute hypercapnia on intestinal microvascular oxygenation and blood flow in experimental sepsis.

METHODS

Forty male Wistar rats were randomized into four groups. Half of the animals received 0.2 mg • kg pravastatin s.c., the other half received the same volume as vehicle (NaCl 0.9%). After 18 h, colon ascendens stent peritonitis surgery was conducted in all animals to induce sepsis. Twenty-four hours after surgery, baseline was established and the animals were subjected to either 120 min of normocapnic (pCO2 40 ± 6 mm Hg) or moderate hypercapnic (pCO2 72 ± 10 mm Hg) ventilation. Microcirculatory oxygenation (μHBO2) and perfusion (μflow) of the colon were continuously recorded using tissue reflectance spectrophotometry and laser Doppler, respectively.

RESULTS

In normocapnic septic animals μHBO2 decreased over time (-8.4 ± 8.7%; P < 0.05 vs. baseline), whereas after pravastatin pretreatment μHBO2 remained constant (-1.9 ± 5.7% vs. baseline). However, in hypercapnic septic animals pretreated with pravastatin μHBO2 declined significantly over time (-8.9 ± 11.8%; P < 0.05 vs. baseline) and was significantly lower compared with normocapnic pravastatin-pretreated animals. μflow did not change over time in any group.

CONCLUSION

Pravastatin pretreatment ameliorates the intestinal microvascular oxygenation in sepsis and thus seems to prevent intestinal hypoxia. Furthermore, we demonstrated that additional hypercapnia abolishes this effect, indicating why septic ARDS patients might not benefit from pravastatin therapy.

Ischemia/Reperfusion Injury in the Aged Liver: The Importance of the Sinusoidal Endothelium in Developing Therapeutic Strategies for the Elderly

The liver endothelium plays a key role in the progression and resolution of liver diseases in young and adult individuals. However, its role in older people remains unknown. We have herein evaluated the importance of the sinusoidal endothelium in the pathophysiology of acute liver injury, and investigated the applicability of simvastatin, in aged animals. Eighteen-months-old male Wistar rats underwent 60 minutes of partial warm ischemia followed by 2 hours of reperfusion (WIR). A group of aged rats received simvastatin for 3 days before WIR. Endothelial phenotype, parenchymal injury, oxidative and nitrosative stress, and fenestrae dynamics were analyzed. The effects of WIR and simvastatin were investigated in primary LSEC from aged animals. The results of this study demonstrated that WIR significantly damages the liver endothelium and its effects are markedly worse in old animals. WIR-aged livers exhibited reduced vasodilation and sinusoidal capillarization, associated with liver damage and cellular stress. Simvastatin prevented the detrimental effects of WIR in aged livers. In conclusion, the liver sinusoidal endothelium of old animals is highly vulnerable to acute insult, thus targeted protection is especially relevant in preventing liver damage. Simvastatin represents a useful therapeutic strategy in aging.

In situ self-assembled biosupramolecular porphyrin nanofibers for enhancing photodynamic therapy in tumors

Due to the complicated environment and high tissue hydraulic pressure in tumors that easily pumps the nanomedicines back to the systemic circulation, the concentration of released photosensitizers (PSs) retained in a tumor by a traditional nano-delivery system is very low, causing an unsatisfactory photodynamic therapy (PDT) effect. Therefore, we prepared a pH/H₂O₂-responsive nano-system (ZnP-OC-M) through modified porphyrin PS units with a long-unsaturated oleoyl chloride chain, and by the further introduction of hydrophilic hydroxyl groups and MnO₂ through a cis-addition reaction between the unsaturated double bonds of oleoyl chloride and dilute KMnO₄ solution. Making use of the sensitivity of MnO₂ to the H₂O₂ in the acid environment of tumor cells, ZnP-OC-M selectively realized responsive disintegration and O₂ generation. More importantly, the rich amphiphilic PS units were shedded simultaneously and spontaneously completed the self-assembly into nanofibers in situ by helical stacking, which displayed a 1.85-fold higher retention effect of PSs in vivo compared with free PS groups and showed a great tumor inhibition effect in enhancing PDT. This nanosystem effectively solves the problem of the low retention abilities leading to a poor PS concentration in a tumor, prolonging the treatment time window efficiently after only a single administration and achieving the purpose of PDT enhancement.

Cirrhosis as new indication for statins

In the recent years, there have been an increasing number of reports on favourable effects of statins in patients with advanced chronic liver disease. These include reduction in portal pressure, improved liver sinusoidal endothelial and hepatic microvascular dysfunction, decreased fibrogenesis, protection against ischaemia/reperfusion injury, safe prolongation of ex vivo liver graft preservation, reduced sensitivity to endotoxin-mediated liver damage, protection from acute-on-chronic liver failure, prevention of liver injury following hypovolaemic shock and preventing/delaying progression of cirrhosis of any aetiology. Moreover, statins have been shown to have potential beneficial effects in the progression of other liver diseases, such as chronic sclerosing cholangitis and in preventing hepatocellular carcinoma. Because of these many theoretically favourable effects, statins have evolved from being considered a risk to kind of wonder drugs for patients with chronic liver diseases. The present article reviews the current knowledge on the potential applications of statins in chronic liver diseases, from its mechanistic background to objective evidence from clinical studies.

Serum ammonia levels on admission for predicting sepsis patient mortality at D28 in the emergency department: A 2-center retrospective study

We assessed the predictive value of serum ammonia level on admission for the 28-day mortality of patients with sepsis.We retrospectively included septic patients admitted to the emergency department of West China Hospital, Sichuan University and The Fourth People's Hospital of Zigong city from June 2017 to May 2018. Patients were divided into 2 groups according to 28-day survival. Comparisons of serum ammonia level and sequential organ failure assessment (SOFA) score were made between 2 groups. Multivariate logistic regression models were employed to determine independent risk factors affecting 28-day mortality rate, and receiver operating characteristic (ROC) curve was also used to evaluate the efficacy of risk factors.Total of 316 patients were included into the study, 221 survived to 28 days and 95 were died before 28 days. The 28-day mortality rate was 30.06%. Multivariate logistic regression analyses revealed that the ammonia level, C reactive protein, SOFA score, and the leukocyte were independent risk factors for the 28-day mortality rate. In predicting the 28-day mortality rate, the SOFA score presented an area under the ROC curve (AUC) of 0.815, and the ammonia levels presented the AUC of 0.813.The ammonia level, C reactive protein, SOFA score, and the leukocyte are independent risk factors for 28-day mortality rate in septic patients. Moreover, the serum ammonia and SOFA score have similar predictive values. The serum ammonia level is also a suitable early indicator for prognostic evaluation of patients with sepsis as well.

Comprehensive evaluation of effects and safety of statin on the progression of liver cirrhosis: a systematic review and meta-analysis

Background

Statin has been more and more widely used in chronic liver disease, however, existed studies have attained contradictory results. According to the present study, we aimed to test the efficacy and safety of statin via a meta-analysis.

Methods

Different databases were searched for full-text publication based on inclusion and exclusion criteria. For data-pooling, fixed-effect model was applied if heterogeneity wasn’t detected. Otherwise, random-effect model was adopted. Heterogeneity was detected by I squire (I²) test. All results of analysis were illustrated as forest plots. Publication bias was assessed using the Begg’s adjusted rank correlation test. Standard mean difference (SMD) was calculated in continuous variables. Pooled hazard ratio or odds ratio was calculated in catergorical variables.

Results

Seventeen clinical studies were finally included. Hepatic portal hemodynamic parameters were improved in statin users for a short-term response. For a long-term follow-up, statin treatment surprisingly decreased mortality rate (HR = 0.782, 95% CI: 0.718–0.846, I² > 50%) and lower the occurrence of hepatocellular carcinoma (HR = 0.75, 95% CI: 0.64–0.86, I² > 50%) in liver cirrhosis. Statin seemed not to decrease the risk of esophageal variceal bleeding and spontaneous bacterial peritonitis. However, statin was proved to decrease the risk of hepatic encephalopathy and ascites. Incidence of drug related adverse events didn’t increase in statin users. Dose-dependent effects of statin on hepatocellular carcinoma development, decompensated cirrhosis events occurrence, and liver cirrhosis progression.

Conclusion

Statin influenced parameters of hepatic portal vessel pressure in short-term treatment. Prognosis of liver cirrhosis benefited from statin treatment in long term follow-up. The efficacy and safety of statin in liver cirrhosis treatment is confirmed. To date, similar study is hardly seen before.

Guideline-conform statin use reduces overall mortality in patients with compensated liver disease

Statins reduce cardiovascular risk. However, “real-life” data on statin use in patients with chronic liver disease and its impact on overall and liver-related survival are limited. Therefore, we assessed 1265 CLD patients stratified as advanced (ACLD) or non-advanced (non-ACLD) stage. Statin indication was evaluated according to the 2013 ACC/AHA guidelines and survival-status was verified by national death registry data. Overall, 122 (9.6%) patients had an indication for statin therapy but did not receive statins, 178 (14.1%) patients were on statins and 965 (76.3%) patients had no indication for statins. Statin underutilization was 34.2% in non-ACLD and 48.2% in ACLD patients. In non-ACLD patients, survival was worse without a statin despite indication as compared to patients on statin or without indication (log-rank p = 0.018). In ACLD patients, statin use did not significantly impact on survival (log-rank p = 0.264). Multivariate cox regression analysis confirmed improved overall survival in patients with statin as compared to patients with indication but no statin (HR 0.225; 95%CI 0.053–0.959; p = 0.044) and a trend towards reduced liver-related mortality (HR 0.088; 95%CI 0.006–1.200; p = 0.068). This was not observed in ACLD patients. In conclusion, guideline-confirm statin use is often withhold from  patients with liver disease and this underutilization is associated with impaired survival in non-ACLD patients.

Extracorporeal Perfusion in Vascularized Composite Allotransplantation: Current Concepts and Future Prospects

Severe injuries of the face and limbs remain a major challenge in today's reconstructive surgery. Vascularized composite allotransplantation (VCA) has emerged as a promising approach to restore these defects. Yet, there are major obstacles preventing VCA from broad clinical application. Two key restrictions are (1) the graft's limited possible ischemia time, keeping the potential donor radius extremely small, and (2) the graft's immunogenicity, making extensive lifelong monitoring and immunosuppressive treatment mandatory. Machine perfusion systems have demonstrated clinical success addressing these issues in solid organ transplantation by extending possible ischemia times and decreasing immunogenicity. Despite many recent promising preclinical trials, machine perfusion has not yet been utilized in clinical VCA. This review presents latest perfusion strategies in clinical solid organ transplantation and experimental VCA in light of the specific requirements by the vascularized composite allograft's unique tissue composition. It discusses optimal settings for temperature, oxygenation, and flow types, as well as perfusion solutions and the most promising additives. Moreover, it highlights the implications for the utility of VCA as therapeutic measure in plastic surgery, if machine perfusion can be successfully introduced in a clinical setting.

Ameliorative effects of autophagy inducer, simvastatin on alcohol-induced liver disease in a rat model

Alcoholic liver disease (ALD) encompasses a variety of liver injuries with various underlying mechanisms but still no effective treatment. So we aimed to monitor the influence of simvastatin on alcohol-induced liver injury and elucidate the underlying mechanisms of its cytoprotective effect. Thirty male albino rats were randomly divided into five equal groups. Group 1 (control): received a standard diet; group 2: received simvastatin (10 mg kg^-1  day ^-1 ) once a day orally for 8 weeks; group 3: received 20% ethanol (7.9 g kg ^-1  day ^-1 ) daily orally for 8 weeks; group 4: received 20% ethanol along with same simvastatin dose daily for 8 weeks; group 5: received 20% ethanol orally for 8 weeks then received the same simvastatin dose for the next 8 weeks. Serum alanine aminotransferase, aspartate aminotransferase, total cholesterol, triglycerides, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol were measured. Liver tissue malondialdehyde, reduced glutathione levels, and superoxide dismutase activity were estimated. B-cell lymphoma 2 and C/EBP homologous protein levels were evaluated by enzyme linked immunosorbent assay (ELISA). Light chain 3-II and peroxisome proliferation-activated receptor gamma messenger RNA expression was assessed by real-time polymerase chain reaction. Immunohistochemical staining was performed using anti-rat tumor necrosis factor-alpha antibody. Our results revealed that simvastatin treatment was able to ameliorate alcohol-induced liver damage; the improved biochemical data were confirmed by histopathological evaluation. Simvastatin being an autophagy inducer was able to prevent and reverse alcohol-induced liver changes via induction of autophagy, attenuation of oxidative stress, inflammation, and endoplasmic reticulum stress-induced apoptosis. Therefore, our findings suggest that treatment with simvastatin may be a useful approach in the management strategy of ALD.

Simvastatin Inhibits Endotoxin-Induced Apoptosis in Liver and Spleen Through Up-Regulation of Survivin/NF-κB/p65 Expression

Endotoxemia is associated by dysregulated apoptosis of immune and non-immune cells. We investigated whether simvastatin has anti-apoptotic effects, and induces hepatocytes and lymphocytes survival signaling in endotoxin-induced liver and spleen injuries. Wistar rats were divided into the groups pretreated with simvastatin (20 or 40 mg/kg, orally) prior to a non-lethal dose of lipopolysaccharide (LPS), the LPS group, and the control. The severity of tissue inflammatory injuries was expressed as hepatic damage scores (HDS) and spleen damage scores (SDS), respectively. The apoptotic cell was detected by TUNEL (Terminal deoxynucleotidyl transferase dUTP Nick End Labeling) and immunohistochemical staining (expression of cleaved caspase-3, and anti-apoptotic Bcl-xL, survivin and NF-κB/p65). Simvastatin dose-dependently abolished HDS and SDS induced by LPS (p < 0.01), respectively. Simvastatin 40 mg/kg significantly decreased apoptotic index and caspase-3 cleavage in hepatocytes and lymphocytes (p < 0.01 vs. LPS group, respectively), while Bcl-XL markedly increased accordingly with simvastatin doses. In the simvastatin, groups were determined markedly increased cytoplasmic expression of survivin associated with nuclear positivity of NF-κB, in both hepatocytes and lymphocytes (p < 0.01 vs. LPS group). Cell-protective effects of simvastatin against LPS seemed to be mediated by up-regulation of survivin, which leads to reduced caspase-3 activation and inhibition of hepatocytes and lymphocytes apoptosis.

Simvastatin Prevents Progression of Acute on Chronic Liver Failure in Rats With Cirrhosis and Portal Hypertension

BACKGROUND & AIMS

Cirrhosis and its clinical consequences can be aggravated by bacterial infections, ultimately leading to the development of acute on chronic liver failure (ACLF), characterized by acute decompensation, organ failure, and high mortality within 28 days. Little is known about cellular and molecular mechanisms of ACLF in patients with cirrhosis, so no therapeutic options are available. We developed a sepsis-associated preclinical model of ACLF to facilitate studies of pathogenesis and evaluate the protective effects of simvastatin.

METHODS

Male Wistar rats inhaled CCl₄ until they developed cirrhosis (at 10 weeks) or cirrhosis with ascites (at 15-16 weeks). Male Sprague-Dawley rats received bile-duct ligation for 28 days or intraperitoneal thioacetamide for 10 weeks to induce cirrhosis. After induction of cirrhosis, some rats received a single injection of lipopolysaccharide (LPS) to induce ACLF; some were given simvastatin or vehicle (control) 4 hours or 24 hours before induction of ACLF. We collected data on changes in hepatic and systemic hemodynamics, hepatic microvascular phenotype and function, and survival times. Liver tissues and plasma were collected and analyzed by immunoblots, quantitative polymerase chain reaction, immuno(fluoro)histochemistry and immunoassays.

RESULTS

Administration of LPS aggravated portal hypertension in rats with cirrhosis by increasing the severity of intrahepatic microvascular dysfunction, exacerbating hepatic inflammation, increasing oxidative stress, and recruiting hepatic stellate cells and neutrophils. Rats with cirrhosis given LPS had significantly shorter survival times than rats with cirrhosis given the control. Simvastatin prevented most of ACLF-derived complications and increased survival times. Simvastatin appeared to increase hepatic sinusoidal function and reduce portal hypertension and markers of inflammation and oxidation. The drug significantly reduced levels of transaminases, total bilirubin, and ammonia, as well as LPS-mediated activation of hepatic stellate cells in liver tissues of rats with cirrhosis.

CONCLUSIONS

In studies of rats with cirrhosis, we found administration of LPS to promote development of ACLF, aggravating the complications of chronic liver disease and decreasing survival times. Simvastatin reduced LPS-induced inflammation and liver damage in rats with ACLF, supporting its use in treatment of patients with advanced chronic liver disease.

Metformin inhibits mTOR-HIF-1α axis and profibrogenic and inflammatory biomarkers in thioacetamide-induced hepatic tissue alterations

The potential inhibitory effect of the antidiabetic and anti-inflammatory drug, metformin on thioacetamide (TAA)-induced hepatotoxicity associated with the inhibition of mammalian target of rapamycin (mTOR)-hypoxia-inducible factor-1α (HIF-1α) axis has not been investigated before. Therefore, we tested whether metformin can protect against liver injuries including fibrosis induced by TAA possibly via the downregulation of mTOR-HIF-1α axis and profibrogenic and inflammatory biomarkers. Rats either injected with TAA (200 mg/kg; twice a week for 8 weeks) before being killed after 10 weeks (model group) or were pretreated with metformin (200 mg/kg) daily for 2 weeks before TAA injections and continued receiving both agents until the end of the experiment, at Week 10 (protective group). Using light and electron microscopy examinations, we observed in the model group substantial damage to the hepatocytes and liver tissue such as collagen deposition, infiltration of inflammatory cells, and degenerative cellular changes with ballooned mitochondria that were substantially ameliorated by metformin. Metformin also significantly ( p < 0.05) inhibited TAA-induced HIF-1α, mTOR, the profibrogenic biomarker α-smooth muscle actin, tissue inhibitor of metalloproteinases-1, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), alanine aminotransferase (ALT) and aspartate aminotransferase in harvested liver homogenates and blood samples. In addition, a significant ( p < 0.01) positive correlation between hypoxia scoring (HIF-1α) and the serum levels of TNF-α ( r = 0.797), IL-6 ( r = 0.859), and ALT ( r = 0.760) was observed. We conclude that metformin protects against TAA-induced hepatic injuries in rats, which is associated with the inhibition of mTOR-HIF-1α axis and profibrogenic and inflammatory biomarkers; thus, may offer therapeutic potential in humans.

Simvastatin Protects Cardiomyocytes Against Endotoxin-induced Apoptosis and Up-regulates Survivin/NF-κB/p65 Expression

This study is aimed to investigate whether simvastatin induces cardiomyocytes survival signaling in endotoxin (lipopolysaccharide, LSP)-induced myocardial injury, and if so, further to determine a role of survivin in simvastatin-anti-apoptotic effect. Wistar rats were pretreated with simvastatin (10–40 mg/kg po) before a single non-lethal dose of LPS. In myocardial tissue, LPS induced structural disorganization of myofibrils with significant inflammatory infiltrate (cardiac damage score, CDS = 3.87 ± 0.51, p < 0.05), whereas simvastatin dose-dependently abolished structural changes induced by LPS (p < 0.01). Simvastatin in 20 mg/kg and 40 mg/kg pretreatment, dose dependently, attenuated myocardial apoptosis determined as apoptotic index (28.8 ± 4.5% and 18.9 ± 3.5, p < 0.05), decreased cleaved caspase-3 expression (32.1 ± 5.8%, p < 0.01), along with significant Bcl-xL expression in the simvastatin groups (p < 0.01). Interestingly, in the simvastatin groups were determined significantly increased expression of survivin (p < 0.01), but in negative correlation with cleaved caspase-3 and apoptotic indices (p < 0.01). Simvastatin has a cardioprotective effects against LPS induced apoptosis. The effect may be mediated by up-regulation of survivin via activation of NF-κB, which leads to reduced activation of caspase-3 and consequent apoptosis of cardiomyocytes in experimental sepsis.

Emodin Attenuates Lipopolysaccharide-Induced Acute Liver Injury via Inhibiting the TLR4 Signaling Pathway in vitro and in vivo

Aims: Emodin is an anthraquinone with potential anti-inflammatory properties. However, the possible molecular mechanisms and protective effects of emodin are not clear. The objective of this study was to investigate the possible molecular mechanisms and protective effects of emodin on lipopolysaccharide (LPS)-induced acute liver injury (ALI) via the Toll-like receptor 4 (TLR4) signaling pathway in the Raw264.7 cell line and in Balb/c mice. Methods: This study established an inflammatory cellular model and induced an ALI animal model. TLR4 was overexpressed by lentivirus and downregulated by small interfering RNA (siRNA) technology. The mRNA and protein levels of TLR4 and downstream molecules were detected in cells and liver tissue. The tumor necrosis factor-α (TNF-α) and interleukin (IL)-6 levels in supernatant and serum were determined by ELISA. The distribution and expression of mannose receptor C type 1 (CD206) and arginase 1 (ARG1) in the liver were tested by immunofluorescence. Mouse liver function and histopathological observations were assessed. Results: Administration of emodin reduced the protein and/or mRNA levels of TLR4 and its downstream molecules following LPS challenge in Raw264.7 cells and in an animal model. Additionally, emodin suppressed the expression of TNF-α and IL-6 in cell culture supernatant and serum. The inhibitory effect of emodin was also confirmed in RAW264.7 cells, in which TLR4 was overexpressed or knocked down. Additionally, ARG1 and CD206 were elevated in the emodin groups. Emodin also decreased serum ALT and AST levels and alleviated the liver histopathological damage induced by LPS. Conclusion: Emodin showed excellent hepatoprotective effects against LPS-induced ALI, possibly by inhibiting TLR4 signaling pathways.

Simvastatin protects against acetaminophen-induced liver injury in mice

The present study aimed to investigate the effect of simvastatin on acetaminophen (APAP) hepatotoxicity in a mouse model. Male C57BL/6 mice were allocated into the following groups: control, APAP, APAP+SIM10, APAP+SIM20, APAP+SIM100 and APAP+SIM200 groups. The mice in the APAP group were treated with saline intraperitoneally (i.p.) 72 h before and 24 h or 72 h after APAP challenge (i.p., 400 mg/kg of APAP). The simvastatin-treated groups were treated with different doses of simvastatin i.p. (10, 20, 100 and 200 mg/kg/day) as in the APAP group. After 24 h or 72 h of APAP challenge, blood and liver samples were collected to detect hepatic injury and liver regeneration. The results showed that low doses of simvastatin (10 and 20 mg/kg) could significantly reverse the histological change and decrease hepatic injury. Simvastatin also reduced the serum cytokine levels and transcriptional levels of tumor necrosis factor-α and interleukin-6 in the liver. The malonyldialdehyde and myeloperoxidase levels significantly decreased in the simvastatin treatment groups compared with the APAP group. Simvastatin restored the decrease in superoxide dismutase, catalase, glutathione and glutathione peroxidase activities induced by APAP hepatotoxicity. In addition, simvastatin inhibited hepatic C/EBP-homologous protein expression and hepatocyte apoptosis. However, simvastatin had no effect on liver regeneration after APAP hepatotoxicity. Moreover, high doses could aggravate APAP-induced liver injury. In conclusion, low doses of simvastatin had a significant therapeutic effect in APAP-induced liver injury by inhibiting oxidative stress, inflammation and apoptosis. However, high doses of simvastatin had adverse hepatotoxicity.

Impact of lipid modulation on the intestinal microcirculation in experimental sepsis

It has been observed, that patients who were treated medically for dyslipoproteinemia had a potentially lower risk of complications during infection and sepsis, regarding both morbidity and mortality. Aim of this study in experimental sepsis was to elucidate the impact of lipid metabolism modulation by simvastatin, HDL, or bezafibrate, respectively, on the intestinal microcirculation which plays a crucial role in the development of multiple organ failure in sepsis. Experimental sepsis was induced in Lewis rats by intravenous lipopolysaccharide (LPS) administration. Animals were treated with simvastatin, HDL or bezafibrate. By means of intestinal intravital microscopy (IVM), the inflammatory response in the microcirculation was studied by leukocyte adherence assessment (LA) and functional capillary density (FCD) measurements. In addition, plasma levels of pro-inflammatory cytokines were determined. Bezafibrate treatment led to a reduction in leukocyte adherence, improved functional capillary density (FCD), and a reduction in interleukin-1α (IL-1α), tumour necrosis factor α (TNF-α) and granulocyte macrophage colony stimulating factors (GM-CSF) plasma levels in experimental sepsis. Contrary to this, the administration of HDL increased leukocyte adherence as well as the number of rolling leukocytes. Only IL-1α plasma levels were decreased by HDL. No significant changes were observed following simvastatin treatment. In summary, only bezafibrate showed anti-inflammatory effects in endotoxemia. This effect cannot be explained by the HDL-enhancing effect of the bezafibrate, since the direct administration of HDL showed opposite effects. Bezafibrate induced reduction of inflammation in sepsis should be investigated in further studies.

Restoration of a healthy intestinal microbiota normalizes portal hypertension in a rat model of nonalcoholic steatohepatitis

Portal hypertension (PH) drives most of the clinical complications in chronic liver diseases. However, its progression in nonalcoholic steatohepatitis (NASH) and its association with the intestinal microbiota (IM) have been scarcely studied. Our aim was to investigate the role of the IM in the mechanisms leading to PH in early NASH. The experimental design was divided in two stages. In stage 1, Sprague-Dawley rats were fed for 8 weeks a high-fat, high-glucose/fructose diet (HFGFD) or a control diet/water (CD). Representative rats were selected as IM donors for stage 2. In stage 2, additional HFGFD and CD rats underwent intestinal decontamination, followed by IM transplantation with feces from opposite-diet donors (heterologous transplant) or autologous fecal transplant (as controls), generating four groups: CD-autotransplanted, CD-transplanted, HFGFD-autotransplanted, HFGFD-transplanted. After IM transplantation, the original diet was maintained for 12-14 days until death. HFGFD rats developed obesity, insulin resistance, NASH without fibrosis but with PH, intrahepatic endothelial dysfunction, and IM dysbiosis. In HFGFD rats, transplantation with feces from CD donors caused a significant reduction of PH to levels comparable to CD without significant changes in NASH histology. The reduction in PH was due to a 31% decrease of intrahepatic vascular resistance compared to the HFGFD-autotransplanted group (P < 0.05). This effect occurs through restoration of the sensitivity to insulin of the hepatic protein kinase B-dependent endothelial nitric oxide synthase signaling pathway.

CONCLUSION

The IM exerts a direct influence in the development of PH in rats with diet-induced NASH and dysbiosis; PH, insulin resistance, and endothelial dysfunction revert when a healthy IM is restored. (Hepatology 2018;67:1485-1498).

The Use of Statins in Patients With Chronic Liver Disease and Cirrhosis

PURPOSE OF REVIEW

Statins are drugs developed to treat hypercholesterolemia. Its use in patients with liver disease has been limited because one of its potential and most feared side effects is hepatotoxicity. However, there is robust evidence that supports the safety of statins in this population in the absence of severe liver dysfunction. In this review, we will summarize the efficacy and safety of statins in cirrhosis.

RECENT FINDINGS

Statins are effective in the treatment of dyslipidemia in patients with liver disease, because of their pleiotropic properties. These properties are independent of their effect on cholesterol levels, such as improving endothelial dysfunction or having antioxidant, antifibrotic, anti-inflammatory, antiproliferative, antiangiogenic, proapoptotic, or immunomodulation properties. Statins have been studied in other areas such as in treatment of portal hypertension, prevention of hepatocellular carcinoma, and/or protection against ischemia/reperfusion injury. Approved indications for statins in patients with cirrhosis are those of the general population, including dyslipidemia and increased cardiovascular risk. Compensated cirrhosis is not a contraindication. In patients with decompensated cirrhosis, statins should be prescribed with extreme caution at low doses, and with frequent monitoring of creatinine phosphokinase levels in order to detect adverse events in a timely fashion.

'Statins in retinal disease'

Statins are known for their blood cholesterol-lowering effect and are widely used in patients with cardiovascular and metabolic diseases. Research over the past three decades shows that statins have diverse effects on different pathophysiological pathways involved in angiogenesis, inflammation, apoptosis, and anti-oxidation, leading to new therapeutic options. Recently, statins have attracted considerable attention for their immunomodulatory effect. Since immune reactivity has been implicated in a number of retinal diseases, such as uveitis, age-related macular degeneration (AMD) and diabetic retinopathy, there is now a growing body of evidence supporting the beneficial effects of statins in these retinopathies. This review evaluates the relationship between statins and the pathophysiological basis of these diseases, focusing on their potential role in treatment. A PubMed database search and literature review was conducted. Among AMD patients, there is inconsistent evidence regarding protection against development of early AMD or delaying disease progression; though they have been found to reduce the risk of developing choroidal neovascular membranes (CNV). In patients with retinal vein occlusion, there was no evidence to support a therapeutic benefit or a protective role with statins. In patients with diabetic retinopathy, statins demonstrate a reduction in disease progression and improved resolution of diabetic macular oedema (DMO). Among patients with uveitis, statins have a protective effect by reducing the likelihood of uveitis development.

The NOX1 isoform of NADPH oxidase is involved in dysfunction of liver sinusoids in nonalcoholic fatty liver disease

The increased production of reactive oxygen species (ROS) has been postulated to play a key role in the progression of nonalcoholic fatty liver disease (NAFLD). However, the source of ROS and mechanisms underlying the development of NAFLD have yet to be established. We observed a significant up-regulation of a minor isoform of NADPH oxidase, NOX1, in the liver of nonalcoholic steatohepatitis (NASH) patients as well as of mice fed a high-fat and high-cholesterol (HFC) diet for 8 weeks. In mice deficient in Nox1 (Nox1KO), increased levels of serum alanine aminotransferase and hepatic cleaved caspase-3 demonstrated in HFC diet-fed wild-type mice (WT) were significantly attenuated. Concomitantly, increased protein nitrotyrosine adducts, a marker of peroxynitrite-induced injury detected in hepatic sinusoids of WT, were significantly suppressed in Nox1KO. The expression of NOX1 mRNA was much higher in the fractions of enriched liver sinusoidal endothelial cells (LSECs) than in those of hepatocytes. In primary cultured LSECs, palmitic acid (PA) up-regulated the mRNA level of NOX1, but not of NOX2 or NOX4. The production of nitric oxide by LSECs was significantly attenuated by PA-treatment in WT but not in Nox1KO. When the in vitro relaxation of TWNT1, a cell line that originated from hepatic stellate cells, was assessed by the gel contraction assay, the relaxation of stellate cells induced by LSECs was attenuated by PA treatment. In contrast, the relaxation effect of LSECs was preserved in cells isolated from Nox1KO. Taken together, the up-regulation of NOX1 in LSECs may elicit peroxynitrite-mediated cellular injury and impaired hepatic microcirculation through the reduced bioavailability of nitric oxide. ROS derived from NOX1 may therefore constitute a critical component in the progression of NAFLD.

Intrahepatic vascular changes in non-alcoholic fatty liver disease: Potential role of insulin-resistance and endothelial dysfunction

Metabolic syndrome is a cluster of several clinical conditions characterized by insulin-resistance and high cardiovascular risk. Non-alcoholic fatty liver disease is the liver expression of the metabolic syndrome, and insulin resistance can be a frequent comorbidity in several chronic liver diseases, in particular hepatitis C virus infection and/or cirrhosis. Several studies have demonstrated that insulin action is not only relevant for glucose control, but also for vascular homeostasis. Insulin regulates nitric oxide production, which mediates to a large degree the vasodilating, anti-inflammatory and antithrombotic properties of a healthy endothelium, guaranteeing organ perfusion. The effects of insulin on the liver microvasculature and the effects of IR on sinusoidal endothelial cells have been studied in animal models of non-alcoholic fatty liver disease. The hypotheses derived from these studies and the potential translation of these results into humans are critically discussed in this review.

Statin Use and Risk of Cirrhosis and Related Complications in Patients With Chronic Liver Diseases: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

Statins have been variably shown to decrease risk and complications of chronic liver diseases (CLDs). We performed a systematic review and meta-analysis to evaluate the association between statins and risk of cirrhosis and related complications in patients with CLDs.

METHODS

Through a systematic literature search up to March 2017, we identified 13 studies (3 randomized trials, 10 cohort studies) in adults with CLDs, reporting the association between statin use and risk of development of cirrhosis, decompensated cirrhosis, improvements in portal hypertension, or mortality. Pooled relative risk (RR) estimates with 95% confidence interval (CIs) were calculated using random effects model. Grading of Recommendations Assessment, Development and Evaluation criteria were used to assess quality of evidence.

RESULTS

Among 121,058 patients with CLDs (84.5% with hepatitis C), 46% were exposed to statins. In patients with cirrhosis, statin use was associated with 46% lower risk of hepatic decompensation (4 studies; RR, 0.54; 95% CI, 0.46-0.62; I2 = 0%; moderate-quality evidence), and 46% lower mortality (5 studies; RR, 0.54; 95% CI, 0.47-0.61; I2 = 10%; moderate-quality evidence). In patients with CLD without cirrhosis, statin use was associated with a nonsignificant (58% lower) risk of development of cirrhosis or fibrosis progression (5 studies; RR, 0.42; 95% CI, 0.16-1.11; I2 = 99%; very-low-quality evidence). In 3 randomized controlled trials, statin use was associated with 27% lower risk of variceal bleeding or progression of portal hypertension (hazard ratio, 0.73; 95% CI, 0.59-0.91; I2 = 0%; moderate-quality evidence).

CONCLUSIONS

Based on a systematic review and meta-analysis, statin use is probably associated with lower risk of hepatic decompensation and mortality, and might reduce portal hypertension, in patients with CLDs. Prospective observational studies and randomized controlled trials are needed to confirm this observation.

Liraglutide improves liver microvascular dysfunction in cirrhosis: Evidence from translational studies

Hepatic stellate cells (HSC) play a key role in the development of chronic liver disease (CLD). Liraglutide, well-established in type 2 diabetes, showed anti-inflammatory and anti-oxidant properties. We evaluated the effects of liraglutide on HSC phenotype and hepatic microvascular function using diverse pre-clinical models of CLD. Human and rat HSC were in vitro treated with liraglutide, or vehicle, and their phenotype, viability and proliferation were evaluated. In addition, liraglutide or vehicle was administered to rats with CLD. Liver microvascular function, fibrosis, HSC phenotype and sinusoidal endothelial phenotype were determined. Additionally, the effects of liraglutide on HSC phenotype were analysed in human precision-cut liver slices. Liraglutide markedly improved HSC phenotype and diminished cell proliferation. Cirrhotic rats receiving liraglutide exhibited significantly improved liver microvascular function, as evidenced by lower portal pressure, improved intrahepatic vascular resistance, and marked ameliorations in fibrosis, HSC phenotype and endothelial function. The anti-fibrotic effects of liraglutide were confirmed in human liver tissue and, although requiring further investigation, its underlying molecular mechanisms suggested a GLP1-R-independent and NF-κB-Sox9-dependent one. This study demonstrates for the first time that liraglutide improves the liver sinusoidal milieu in pre-clinical models of cirrhosis, encouraging its clinical evaluation in the treatment of chronic liver disease.