Maraviroc, a CCR5 antagonist, ameliorates the development of hepatic steatosis in a mouse model of non-alcoholic fatty liver disease (NAFLD)

MAVMET trial: maraviroc and/or metformin for metabolic dysfunction associated fatty liver disease in adults with suppressed HIV

OBJECTIVE

Metabolic dysfunction associated fatty liver disease (MAFLD) is over-represented in people with HIV (PWH). Maraviroc (MVC) and/or metformin (MET) may reduce MAFLD by influencing inflammatory pathways and fatty acid metabolism.

DESIGN

Open-label, 48-week randomized trial with a 2 x 2 factorial design.

SETTING

Multicenter HIV clinics.

PARTICIPANTS

Nondiabetic, virologically suppressed PLWH, aged at least 35 years, with confirmed/suspected MAFLD (≥1 biochemical/anthropometric/radiological/histological features).

INTERVENTION

Adjunctive MVC; MET; MVC+MET vs. antiretroviral therapy (ART) alone.

PRIMARY OUTCOME

Change in liver fat fraction (LFF) between baseline and week-48 using magnetic resonance proton density fat fraction (MR PDFF).

RESULTS

Six sites enrolled 90 participants (93% male; 81% white; median age 52 [interquartile range, IQR 47-57] years) between March 19, 2018, and November 11, 2019. Seventy percent had imaging/biopsy and at least one 1 MAFLD criteria. The analysis included 82/90 with week-0 and week-48 scans. Median baseline MR PDFF was 8.9 (4.6-17.1); 40, 38, 8, and 14% had grade zero, one, two, and three steatosis, respectively. Mean LFF increased slightly between baseline and follow-up scans: 2.22% MVC, 1.26% MET, 0.81% MVC+MET, and 1.39% ART alone. Prolonged intervention exposure (delayed week-48 scans) exhibited greater increases in MR PDFF (estimated difference 4.23% [95% confidence interval, 95% CI 2.97-5.48], P  < 0.001). There were no differences in predicted change for any intervention compared to ART alone: MVC (-0.42% [95% CI -1.53 to 0.68, P  = 0.45]), MET (-0.62 [-1.81 to 0.56, P  = 0.30]), and MVC+MET (-1.04 [-2.74 to 0.65, P  = 0.23]). Steatosis grade remained unchanged in 55% and increased in 24%.

CONCLUSION

Baseline levels of liver fat were lower than predicted. Contrary to our hypothesis, neither MVC, MET, or the combination significantly reduced liver fat as measured by MRPDFF compared to ART alone.

Protective alleles and precision healthcare in crewed spaceflight

Common and rare alleles are now being annotated across millions of human genomes, and omics technologies are increasingly being used to develop health and treatment recommendations. However, these alleles have not yet been systematically characterized relative to aerospace medicine. Here, we review published alleles naturally found in human cohorts that have a likely protective effect, which is linked to decreased cancer risk and improved bone, muscular, and cardiovascular health. Although some technical and ethical challenges remain, research into these protective mechanisms could translate into improved nutrition, exercise, and health recommendations for crew members during deep space missions.

Role of maraviroc and/or rapamycin in the liver of IL10 KO mice with frailty syndrome

Cellular senescence and low-grade inflammation favor the acceleration of aging. The liver is an essential metabolic organ because changes related to its function are related to age-related diseases. The objective of this study was to evaluate the effects of maraviroc (MVC) and/or rapamycin (RAPA) on liver tissue in an experimental model of frailty syndrome in mice, since MVC and RAPA are two molecules able to decrease CCR5 expression, which is overexpressed in patients with frailty. Methods: Eighty male homozygous IL10KO mice were randomly assigned to one of 4 groups (n = 20): i) IL10KO group; ii) MVC group, iii) RAPA group, and iv) MVC-RAPA group. Liver samples were analyzed. Gene expression quantification and western blotting were also performed. The proinflammatory cytokines IL-6 and IL-18 were decreased in MVC and MVC/RAPA groups, IL-12 was decreased in RAPA and MVC/RAPA groups and TNF-α was decreased in all therapeutic groups. P21 was decreased in RAPA and MVC/RAPA groups, Galactosidase beta-1, was also significantly reduced in all therapeutic groups, as were NF-kB1, NF-kB2 and STAT3. In all groups, mTOR and CCL5 were significantly reduced. CCR5 expression was decreased in the MVC and MVC/RAPA groups. Conclusion: MVC and RAPA may protect against some factors involved in liver aging. More studies will be necessary to verify their clinical applications.

Gene-regulation modules in nonalcoholic fatty liver disease revealed by single-nucleus ATAC-seq

We investigated the progression of nonalcoholic fatty liver disease from fatty liver to steatohepatitis using single-nucleus and bulk ATAC-seq on the livers of rats fed a high-fat diet (HFD). Rats fed HFD for 4 wk developed fatty liver, and those fed HFD for 8 wk further progressed to steatohepatitis. We observed an increase in the proportion of inflammatory macrophages, consistent with the pathological progression. Utilizing machine learning, we divided global gene regulation into modules, wherein transcription factors within a module could regulate genes within the same module, reaffirming known regulatory relationships between transcription factors and biological processes. We identified core genes-central to co-expression and protein-protein interaction-for the biological processes discovered. Notably, a large part of the core genes overlapped with genes previously implicated in nonalcoholic fatty liver disease. Single-nucleus ATAC-seq, combined with data-driven statistical analysis, offers insight into in vivo global gene regulation as a combination of modules and assists in identifying core genes of relevant biological processes.

Hepmarc: A 96 week randomised controlled feasibility trial of add-on maraviroc in people with HIV and non-alcoholic fatty liver disease

OBJECTIVES

Maraviroc may reduce hepatic inflammation in people with HIV and non-alcoholic fatty liver disease (HIV-NAFLD) through CCR5-receptor antagonism, which warrants further exploration.

METHODS

We performed an open-label 96-week randomised-controlled feasibility trial of maraviroc plus optimised background therapy (OBT) versus OBT alone, in a 1:1 ratio, for people with virologically-suppressed HIV-1 and NAFLD without cirrhosis. Dosing followed recommendations for HIV therapy in the Summary of Product Characteristics for maraviroc. The primary outcomes were safety, recruitment and retention rates, adherence and data completeness. Secondary outcomes included the change in Fibroscan-assessed liver stiffness measurements (LSM), controlled attenuation parameter (CAP) and Enhanced Liver Fibrosis (ELF) scores.

RESULTS

Fifty-three participants (53/60, 88% of target) were recruited; 23 received maraviroc plus OBT; 89% were male; 19% had type 2 diabetes mellitus. The median baseline LSM, CAP & ELF scores were 6.2 (IQR 4.6-7.8) kPa, 325 (IQR 279-351) dB/m and 9.1 (IQR 8.6-9.6) respectively. Primary outcomes: all individuals eligible after screening were randomised; there was 92% (SD 6.6%) adherence to maraviroc [target >90%]; 83% (95%CI 70%-92%) participant retention [target >65%]; 5.5% of data were missing [target <20%]. There were noo Serious Adverse Reactions; mild-moderate intensity Adverse Reactions were reported by five participants (5/23, 22% (95%CI 5%-49%)) [target <10%]. All Adverse Reactions resolved. Secondary outcomes: no important differences were seen by treatment group for the change from baseline in LSM, CAP or ELF scores.

CONCLUSIONS

This feasibility study provides preliminary evidence of maraviroc safety amongst people with HIV-NAFLD, and acceptable recruitment, retention, and adherence rates. These data support a definitive randomised-controlled trial assessing maraviroc impact on hepatic steatosis and fibrosis.

TRIAL REGISTRATION

Clinical trial registry: ISCRTN, registration number 31461655.

Roles of heterogenous hepatic macrophages in the progression of liver diseases

Hepatic macrophages are key immune cells associated with the broad ranges of liver diseases including steatosis, inflammation and fibrosis. Hepatic macrophages interact with other immune cells and orchestrate hepatic immune circumstances. Recently, the heterogenous populations of hepatic macrophages have been discovered termed residential Kupffer cells and monocyte-derived macrophages, and identified their distinct population dynamics during the progression of various liver diseases. Liver injury lead to Kupffer cells activation with induction of inflammatory cytokines and chemokines, which triggers recruitment of inflammatory monocyte-derived macrophages. To understand liver pathology, the functions of different subtypes of liver macrophages should be regarded with different perspectives. In this review, we summarize recent advances in the roles of hepatic macrophages under liver damages and suggest hepatic macrophages as promising therapeutic targets for treating liver diseases.

Immune-related pathogenesis and therapeutic strategies of nonalcoholic steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) is the hepatic manifestation of metabolic syndrome and has become prevalent in the adult population worldwide, given the ongoing obesity pandemic. NAFLD comprises several hepatic disorders, ranging from fatty liver to nonalcoholic steatohepatitis (NASH), cirrhosis, and carcinoma. Excessive fat accumulation in the liver can induce the development of fatty liver, whereas the progression of fatty liver to NASH involves various complex factors. The crucial difference between fatty liver and NASH is the presence of inflammation and fibrosis, the emergence of which is closely associated with the action of immune cells and immunological factors, such as chemokines and cytokines. Thus, expanding our understanding of immunological mechanisms contributing to NASH pathogenesis will lead to the identification of therapeutic targets and the development of viable therapeutics against NASH.

Evaluating the role of chemokines and chemokine receptors involved in coronavirus infection

INTRODUCTION

Coronaviruses are a large family of positive-stranded nonsegmented RNA viruses with genomes of 26-32 kilobases in length. Human coronaviruses are commonly associated with mild respiratory illness; however, the past three decades have seen the emergence of severe acute respiratory coronavirus (SARS-CoV), middle eastern respiratory coronavirus (MERS-CoV), and SARS-CoV-2 which is the etiologic agent for COVID-19. Severe forms of COVID-19 include acute respiratory distress syndrome (ARDS) associated with cytokine release syndrome that can culminate in multiorgan failure and death. Among the proinflammatory factors associated with severe COVID-19 are the chemokines CCL2, CCL3, CXCL8, and CXCL10. Infection of susceptible mice with murine coronaviruses, such as mouse hepatitis virus (MHV), elicits a similar chemokine response profile as observed in COVID-19 patients and these in vivo models have been informative and show that targeting chemokines reduces the severity of inflammation in target organs.

AREAS COVERED

PubMed was used using keywords: Chemokines and coronaviruses; Chemokines and mouse hepatitis virus; Chemokines and COVID-19. Clinicaltrials.gov was used using keywords: COVID-19 and chemokines; COVID-19 and cytokines; COVID-19 and neutrophil.

EXPERT OPINION

Chemokines and chemokine receptors are clinically relevant therapeutic targets for reducing coronavirus-induced inflammation.

CCL5/CCR5 axis in human diseases and related treatments

To defense harmful stimuli or maintain the immune homeostasis, the body produces and recruits a superfamily of cytokines such as interleukins, interferons, chemokines etc. Among them, chemokines act as crucial regulators in defense systems. CCL5/CCR5 combination is known for facilitating inflammatory responses, as well as inducing the adhesion and migration of different T cell subsets in immune responses. In addition, recent studies have shown that the interaction between CCL5 and CCR5 is involved in various pathological processes including inflammation, chronic diseases, cancers as well as the infection of COVID-19. This review focuses on how CCL5/CCR5 axis participates in the pathological processes of different diseases and their relevant signaling pathways for the regulation of the axis. Moreover, we highlighted the gene therapy and chemotherapy studies for treating CCR5-related diseases, including the ongoing clinical trials. The barriers and perspectives for future application and translational research were also summarized.

Macrophages as key regulators of liver health and disease

Macrophages are a heterogeneous population of innate immune cells and key cellular components of the liver. Hepatic macrophages consist of embryologically-derived resident Kupffer cells (KC), recruited monocyte-derived macrophages (MDM) and capsular macrophages. Both the diversity and plasticity of hepatic macrophage subsets explain their different functions in the maintenance of hepatic homeostasis and in injury processes in acute and chronic liver diseases. In this review, we assess the evidence for macrophage involvement in regulating both liver health and injury responses in liver diseases including acute liver injury (ALI), chronic liver disease (CLD) (including liver fibrosis) and hepatocellular carcinoma (HCC). In healthy livers, KC display critical functions such as phagocytosis, danger signal recognition, cytokine release, antigen processing and the ability to orchestrate immune responses and maintain immunological tolerance. However, in most liver diseases there is a striking hepatic MDM expansion, which orchestrate both disease progression and regression. Single-cell approaches have transformed our understanding of liver macrophage heterogeneity, dynamics, and functions in both human samples and preclinical models. We will further discuss the new insights provided by these approaches and how they are enabling high-fidelity work to specifically identify pathogenic macrophage subpopulations. Given the important role of macrophages in regulating injury responses in a broad range of settings, there is now a huge interest in developing new therapeutic strategies aimed at targeting macrophages. Therefore, we also review the current approaches being used to modulate macrophage function in liver diseases and discuss the therapeutic potential of targeting macrophage subpopulations as a novel treatment strategy for patients with liver disorders.

Targeting monocytes/macrophages in fibrosis and cancer diseases: Therapeutic approaches

Over almost 140 years since their identification, the knowledge about macrophages has unbelievably evolved. The 'big eaters' from being thought of as simple phagocytic cells have been recognized as master regulators in immunity, homeostasis, healing/repair and organ development. Long considered to originate exclusively from bone marrow-derived circulating monocytes, macrophages have been also demonstrated to be the first immune cells colonizing tissues in the developing embryo and persisting in adult life by self-renewal, as long-lived tissue resident macrophages. Therefore, heterogeneous populations of macrophages with different ontogeny and functions co-exist in tissues. Macrophages act as sentinels of homeostasis and are intrinsically programmed to lead the wound healing and repair processes that occur after injury. However, in certain pathological circumstances macrophages get dysfunctional, and impaired or aberrant macrophage activities become key features of diseases. For instance, in both fibrosis and cancer, that have been defined 'wounds that do not heal', dysfunctional monocyte-derived macrophages overall play a key detrimental role. On the other hand, due to their plasticity these cells can be 're-educated' and exert anti-fibrotic and anti-cancer functions. Therefore macrophages represent an important therapeutic target in both fibrosis and cancer diseases. The current review will illustrate new insights into the role of monocytes/macrophages in these devastating diseases and summarize new therapeutic strategies and applications of macrophage-targeted drug development in their clinical setting.

Targeting Gut–Liver Axis for Treatment of Liver Fibrosis and Portal Hypertension

Antifibrotic therapies for the treatment of liver fibrosis represent an unconquered area of drug development. The significant involvement of the gut microbiota as a driving force in a multitude of liver disease, be it pathogenesis or fibrotic progression, suggest that targeting the gut–liver axis, relevant signaling pathways, and/or manipulation of the gut’s commensal microbial composition and its metabolites may offer opportunities for biomarker discovery, novel therapies and personalized medicine development. Here, we review potential links between bacterial translocation and deficits of host-microbiome compartmentalization and liver fibrosis that occur in settings of advanced chronic liver disease. We discuss established and emerging therapeutic strategies, translated from our current knowledge of the gut–liver axis, targeted at restoring intestinal eubiosis, ameliorating hepatic fibrosis and rising portal hypertension that characterize and define the course of decompensated cirrhosis.

Regulation and functional roles of chemokines in liver diseases

Inflammation is a major contributor to the pathogenesis of almost all liver diseases. Low-molecular-weight proteins called chemokines are the main drivers of liver infiltration by immune cells such as macrophages, neutrophils and others during an inflammatory response. During the past 25 years, tremendous progress has been made in understanding the regulation and functions of chemokines in the liver. This Review summarizes three main aspects of the latest advances in the study of chemokine function in liver diseases. First, we provide an overview of chemokine biology, with a particular focus on the genetic and epigenetic regulation of chemokine transcription as well as on the cell type-specific production of chemokines by liver cells and liver-associated immune cells. Second, we highlight the functional roles of chemokines in liver homeostasis and their involvement in progression to disease in both human and animal models. Third, we discuss the therapeutic opportunities targeting chemokine production and signalling in the treatment of liver diseases, such as alcohol-associated liver disease and nonalcoholic steatohepatitis, including the relevant preclinical studies and ongoing clinical trials.

The CCR5 and CXCR3 Pathways in Hepatitis C Virus Liver Transplanted Recipients Treated by a Direct Antiviral Agent Regimen: Informative Kinetics Profiles

The CC5 and CXC3 chemokines (CK) pathways are involved in the pathogenesis and outcome of several disease states, including chronic hepatitis C (CHC). The kinetics of Regulated upon Activation Normal T cell Expressed and Secreted (RANTES) (CCL5) and IP-10 (CXCL10) during direct-acting antivirals (DAA) treatment was retrospectively analyzed in 18 liver transplant recipients (LT-R) compared with 20 patients with CHC and 49 healthy controls (HC). CK levels were determined at baseline, week 4, end of treatment, 24 weeks post-treatment (sustained virological response [SVR]), and later-on during follow-up (FU), 12 and 24 months post-DAA. At baseline, median RANTES levels were higher in HC than in both LT-R (p > 0.01) and CHC (p > 0.01), whereas IP-10 levels were higher in LT-R and CHC than in HC (p > 0.05 and p = 0.01), respectively. Mean RANTES values increased during DAA therapy to peak at SVR and FU with significantly higher levels than at baseline in LT-R (p < 0.01) and in CHC, but only at FU (p < 0.003). A subsequent return to baseline or lower levels was observed at extended FU. On the contrary, IP-10 values showed a significant decrease from baseline to SVR and FU in both LT-R (p < 0.03) and CHC (p < 0.01). RANTES profiles during the first 4 weeks of DAA treatment showed an increase or decrease from baseline according to baseline RANTES levels. CCR5 genotyping in LT-R showed the presence of 1 homozygous Δ32/Δ32 and 2 heterozygous WT/Δ32 haplotypes with a prevalence of 5.5% and 11.1%, respectively. In conclusion, although IP-10 showed the expected kinetics, the CC5 pathway appears extensively altered during CHC infection: monitoring these patients may be indicated as they may be at risk of other infections or immune-mediated disorders.

Liver Injury and the Macrophage Issue: Molecular and Mechanistic Facts and Their Clinical Relevance

The liver is an essential immunological organ due to its gatekeeper position to bypassing antigens from the intestinal blood flow and microbial products from the intestinal commensals. The tissue-resident liver macrophages, termed Kupffer cells, represent key phagocytes that closely interact with local parenchymal, interstitial and other immunological cells in the liver to maintain homeostasis and tolerance against harmless antigens. Upon liver injury, the pool of hepatic macrophages expands dramatically by infiltrating bone marrow-/monocyte-derived macrophages. The interplay of the injured microenvironment and altered macrophage pool skews the subsequent course of liver injuries. It may range from complete recovery to chronic inflammation, fibrosis, cirrhosis and eventually hepatocellular cancer. This review summarizes current knowledge on the classification and role of hepatic macrophages in the healthy and injured liver.

Macrophages in Chronic Liver Failure: Diversity, Plasticity and Therapeutic Targeting

Chronic liver injury results in immune-driven progressive fibrosis, with risk of cirrhosis development and impact on morbidity and mortality. Persistent liver cell damage and death causes immune cell activation and inflammation. Patients with advanced cirrhosis additionally experience pathological bacterial translocation, exposure to microbial products and chronic engagement of the immune system. Bacterial infections have a high incidence in cirrhosis, with spontaneous bacterial peritonitis being the most common, while the subsequent systemic inflammation, organ failure and immune dysregulation increase the mortality risk. Tissue-resident and recruited macrophages play a central part in the development of inflammation and fibrosis progression. In the liver, adipose tissue, peritoneum and intestines, diverse macrophage populations exhibit great phenotypic and functional plasticity determined by their ontogeny, epigenetic programming and local microenvironment. These changes can, at different times, promote or ameliorate disease states and therefore represent potential targets for macrophage-directed therapies. In this review, we discuss the evidence for macrophage phenotypic and functional alterations in tissue compartments during the development and progression of chronic liver failure in different aetiologies and highlight the potential of macrophage modulation as a therapeutic strategy for liver disease.

Pathogenesis of NASH and Promising Natural Products

Nonalcoholic steatohepatitis (NASH) is a common clinical condition that can lead to advanced liver diseases. The mechanism of the diaease progression, which is lacking effective therapy, remains obsure. Therefore, there is a need to understand the pathogenic mechanisms responsible for disease development and progression in order to develop innovative therapies. To accomplish this goal, experimental animal models that recapitulate the human disease are necessary. Currently, an increasing number of studies have focused on natural constituents from medicinal plants which have been emerged as a new hope for NASH. This review summarized the pathogenesis of NASH, animal models commonly used, and the promising targets for therapeutics. We also reviewed the natural constituents as potential NASH therapeutic agents.

Hepatic macrophages in liver homeostasis and diseases-diversity, plasticity and therapeutic opportunities

Macrophages, which are key cellular components of the liver, have emerged as essential players in the maintenance of hepatic homeostasis and in injury and repair processes in acute and chronic liver diseases. Upon liver injury, resident Kupffer cells (KCs) sense disturbances in homeostasis, interact with hepatic cell populations and release chemokines to recruit circulating leukocytes, including monocytes, which subsequently differentiate into monocyte-derived macrophages (MoMϕs) in the liver. Both KCs and MoMϕs contribute to both the progression and resolution of tissue inflammation and injury in various liver diseases. The diversity of hepatic macrophage subsets and their plasticity explain their different functional responses in distinct liver diseases. In this review, we highlight novel findings regarding the origins and functions of hepatic macrophages and discuss the potential of targeting macrophages as a therapeutic strategy for liver disease.

Impact of prolonged maraviroc treatment on non-AIDS-related comorbidities in HIV-positive patients: a retrospective cohort study

OBJECTIVES

This retrospective study evaluates the effect of maraviroc, the first CCR5 receptor antagonist, on non-AIDS-related comorbidity incidence and its impact on inflammatory and lipid parameters.

METHODS

Seventy-four HIV patients on maraviroc treatment were compared with 312 patients never exposed to maraviroc (matched for sex, age and CD4 nadir).

RESULTS

At baseline (T0), maraviroc patients presented a longer duration of HIV infection, a higher prevalence of comorbidities and a greater frequency of polypharmacy. Non-AIDS-defining disease incidence was lower in the maraviroc group than in the non-maraviroc group (without achieving statistical significance). Except triglycerides (TGL), which dropped only in the maraviroc group, inflammatory and immunological parameters did not significantly change in either group by the end of the study period (T3). At T3, high-sensitivity C-reactive protein (hsCRP) and high-density lipoprotein were inversely correlated in both groups (Spearman's rho: maraviroc -0.30, P = 0.05; non-maraviroc -0.23, P = 0.0003). Only in the non-maraviroc group was the positive correlation between hsCRP and lipids observed both at T0 (hsCRP/low-density lipoprotein (LDL) +0.17, P = 0.004; hsCRP/total cholesterol +0.20, P = 0.0007; hsCRP/TGL +0.12, P = 0.04) and T3 (hsCRP/LDL +0.26, P < 0.0001; hsCRP/total cholesterol +0.24, P = 0.0001; hsCRP/TGL +0.15, P = 0.02). These correlations were not found in the maraviroc group. A significant positive correlation was found at T0 and at T3 between hsCRP and D-dimer in both groups (maraviroc: T0 +0.46, P = 0.0007; T3 +0.41, P = 0.006; non-maraviroc: T0 +0.17, P = 0.02; T3: +0.17, P = 0.017).

CONCLUSIONS

These data suggest a possible protective role of maraviroc in the incidence of non-AIDS-related comorbidities in a population with longer-lasting infection and allow us to hypothesize its role in the modulation of lipid-dependent inflammation.

Protocol for a phase IV, open-label feasibility study investigating non-invasive markers of hepatic fibrosis in people living with HIV-1 and non-alcoholic fatty liver disease randomised to receiving optimised background therapy (OBT) plus maraviroc or OBT alone

INTRODUCTION

At least 30% of people living with HIV (PLWH) infection have non-alcoholic fatty liver disease (NAFLD), which has now become a leading cause of hepatic fibrosis and cirrhosis. Management is based largely on lifestyle modifications, which are difficult to achieve, and therapeutic options are urgently needed. Maraviroc (MVC), through antagonism of CCR5 receptors, may reduce hepatic fibrosis progression and could be an effective treatment for NAFLD. However, dosing is usually two times per day, unlike most currently recommended antiretroviral therapies. This study will investigate the feasibility and acceptability of addition of MVC to combination antiretroviral therapy in PLWH and NAFLD as a treatment for NAFLD.

METHODS AND ANALYSIS

This is a phase IV, randomised, open-label, non-invasive feasibility study. Sixty individuals with well-controlled HIV-1 and NAFLD will be recruited from UK HIV clinics and randomised 1:1 to receive either optimised background therapy (OBT) plus MVC or OBT alone. Follow-up will be every 24 weeks for 96 weeks. The primary outcome measures will include recruitment and retention rates, adverse events and adherence. Secondary outcomes will include changes in markers of hepatic fibrosis, including the Enhanced Liver Fibrosis score, median liver stiffness measurement and controlled attenuation parameter scores on Fibroscan, and quality of life assessments. Analyses will be performed according to intention-to-treat principles. For secondary outcomes, estimated differences and 95% CIs between the groups using a t-method will be presented for continuous variables and as exact 95% binomial CIs for categorical variables.

ETHICS AND DISSEMINATION

Ethical approval was obtained through the London Dulwich UK Research Ethics Committee (reference 17/LO/2093). Results will be disseminated both through community groups and peer-reviewed scientific literature.Trial registration number SRCTN31461655. EudraCT number 2017-004141-24; Pre-results.

The therapeutic potential of C-C chemokine receptor antagonists in nonalcoholic steatohepatitis

Pooled prevalence of nonalcoholic fatty liver disease (NAFLD) globally is about 25%. Nonalcoholic steatohepatitis (NASH) with advanced fibrosis has been linked with substantial morbidity and mortality, without having to-date any licensed treatment. C-C chemokine receptor (CCR) antagonists have been investigated as candidates for the treatment of NASH. Inhibition of CCR2 is expected to mitigate hepatic inflammation, through reducing the activation of Kupffer cells, as well as the infiltration of monocytes and macrophages into the liver. Inhibition of CCR5 is expected to mitigate hepatic fibrogenesis, through impairing the activation of hepatic stellate cells, as well as to mitigate hepatic inflammation, through impairing the activation of Kupffer cells and macrophages. Cenicriviroc (CVC) is the first in class, dual inhibitor of CCR2 and CCR5. After exhibiting favorable results in animal models, CVC was shown to be beneficial in NASH patients with more severe fibrosis at a phase 2b trial (CENTAUR) and is currently at a phase 3 clinical trial (AURORA). Apart from CVC, other CCR5 mono-antagonists, such as maraviroc, are under evaluation in clinical trials with human immunodeficiency virus patients with NAFLD. The aim of this review was to summarize existing evidence on CVC and other CCR antagonists in NASH patients, primarily focusing on their clinical efficacy and safety.

Crosstalk Between Liver Macrophages and Surrounding Cells in Nonalcoholic Steatohepatitis

Nonalcoholic steatohepatitis (NASH), the advanced stage of nonalcoholic fatty liver disease (NAFLD), is emerging as a leading cause of progressive liver fibrosis and end-stage liver disease. Liver macrophages, mainly composed of Kupffer cells (KCs) and monocyte-derived macrophages (MoMFs), play a vital role in NASH progression and regression. Recent advances suggest that cell–cell communication is a fundamental feature of hepatic microenvironment. The reprogramming of cell–cell signaling between macrophages and surrounding cells contributes to the pathogenesis of NASH. In this review, we summarize the current knowledge of NASH regarding the composition of liver macrophages and their communication with surrounding cells, which are composed of hepatocytes, hepatic stellate cells (HSCs), liver sinusoidal endothelial cells (LSECs) and other immune cells. We also discuss the potential therapeutic strategies based on the level of macrophages.

Autologous fecal transplantation from a lean state potentiates caloric restriction effects on body weight and adiposity in obese mice

Autologous fecal transplantation (FT-A) emerges as a promising strategy to modulate gut microbiota with minimal side effects since individual´s own feces are transplanted. With the premise of improving obesity and its associated disorders, we investigated if fecal microbiota transplantation (FMT), heterologous and autologous, potentiates the effects of a moderate caloric restriction (CR) in high-fat diet (HFD)-induced obese mice. Mice were randomized into control, HFD, CR (12 weeks on HFD and 6 weeks under CR), FT-H (similar to CR and FMT carried out with feces from controls, weeks 17 & 18), and FT-A (administration of their own feces before developing obesity at weeks 17 & 18). Our study demonstrated that FMT, and, especially, FT-A potentiates the effects of a moderate CR on weight loss and adiposity in the short term, by decreasing feed efficiency and increasing adipose tissue lipolysis. Although FT-A produced a significant increase in bacterial richness/diversity, FMT did not significantly modify gut microbiota composition compared to the CR at phyla and bacteria genera levels, and only significant increases in Bifidobacterium and Blautia genera were observed. These results could suggest that other mechanisms different from bacterial microbiota engraftment participates in these beneficial effects. Thus, FT-A represents a very positive synergetic approach for obese patients that do not respond well to moderate restrictive diets.

Implications of maraviroc and/or rapamycin in a mouse model of fragility

Background: As age increases, the risk of developing fragility also increases. Improving the knowledge of frailty could contribute to maintaining the functional ability of elderly people. Interleukin (IL)-10 homozygous knockout mice (IL-10^tm/tm [IL10KO]) constitute an excellent tool for the study of frailty. Because patients with frailty demonstrate an overexpression of CCR5, rapamycin (RAPA) and/or maraviroc (MVC), two molecules able to decrease CCR5 expression, were evaluated.

Results: Muscle myostatin was reduced in all the therapeutic groups but the MVC group (p <0.001 for RAPA and MVC-RAPA) and in serum samples (p <0.01 for all the groups). Serum CK levels were also significantly lower in MVC and RAPA groups (p <0.01 in both cases). Lower AST levels were observed in all the therapeutic groups (p <0.05 for all of them). The apoptotic effector caspase-3 was significantly lower in MVC and RAPA groups (p<0.05 in both cases). Combined treatment with MVC-RAPA showed a synergistic increase in p-AKT, p-mTOR and SIRT1 levels.

Conclusions: MVC and RAPA show a protective role in some factors involved in frailty. More studies are needed to prove their clinical applications.

Material and methods: Eighty male homozygous IL10KOs were randomly assigned to one of 4 groups (n= 20): i) IL10KO group (IL10KO); ii) IL10KO receiving MVC in drinking water (MVC group), iii) IL10KO receiving RAPA in drinking water (RAPA group), and finally, iv) MVC-RAPA group that received MVC and RAPA in drinking water. Blood and muscle samples were analysed. Survival analysis, frailty index calculation, and functional assessment were also performed.

Therapeutic Targeting of Hepatic Macrophages for the Treatment of Liver Diseases

Hepatic macrophages play a central role in maintaining homeostasis in the liver, as well as in the initiation and progression of liver diseases. Hepatic macrophages are mainly derived from resident hepatic macrophages called Kupffer cells or circulating bone marrow-derived monocytes. Kupffer cells are self-renewing and typically non-migrating macrophages in the liver and are stationed in the liver sinusoids in contrast to macrophages originating from circulating monocytes. Kupffer cells regulate liver homeostasis by mediating immunity against non-pathogenic blood-borne molecules, while participating in coordinated immune responses leading to pathogen clearance, leukocyte recruitment and antigen presentation to lymphocytes present in the vasculature. Monocyte-derived macrophages infiltrate into the liver tissue when metabolic or toxic damage instigates and are likely dispensable for replenishing the macrophage population in homeostasis. In recent years, different populations of hepatic macrophages have been identified with distinct phenotypes with discrete functions, far beyond the central dogma of M1 and M2 macrophages. Hepatic macrophages play a central role in the pathogenesis of acute and chronic liver failure, liver fibrosis, non-alcoholic fatty liver disease, alcoholic liver disease, viral hepatitis, and hepatocellular carcinoma, as well as in disease resolution. The understanding of the role of hepatic macrophages in liver diseases provides opportunities for the development of targeted therapeutics for respective malignancies. This review will summarize the current knowledge of the hepatic macrophages, their origin, functions, their critical role in maintaining homeostasis and in the progression or resolution of liver diseases. Furthermore, we will provide a comprehensive overview of the therapeutic targeting strategies against hepatic macrophages developed for the treatment of liver diseases.

Drug-induced liver steatosis in patients with HIV infection

Drug-induced liver injury (DILI) due to the use of prescription and non-prescription medication by HIV-positive and HIV-negative patients is one of the main causes of acute liver failure and transplantation in Western countries and, although rare, has to be considered a serious problem because of its unforeseeable nature and possibly fatal course. Drug-induced steatosis (DIS) and steatohepatitis (DISH) are infrequent but well-documented types of DILI. Although a number of commonly used drugs are associated with steatosis, it is not always easy to identify them as causative agents because of the weak temporal relationship between the administration of the drug and the clinical event, the lack of a confirmatory re-challenge, and the high prevalence of non-alcoholic fatty liver disease (NAFLD) in the general population, which often makes it difficult to make a differential diagnosis of DIS and DISH. The scenario is even more complex in HIV-positive patients not only because of the underlying disease, but also because the various anti-retroviral regimens have different effects on liver steatosis. Given the high prevalence of liver steatosis in HIV-positive patients and the increasing use of drugs associated with a potential steatotic risk, the identification of clinical signs suggesting liver damage should help to avoid the possible misdiagnosis of "primary" NAFLD in a patient with DIS or DISH. This review will therefore initially concentrate on the current diagnostic criteria for DIS/DISH and their differential diagnosis from NAFLD. Subsequently, it will consider the different clinical manifestations of iatrogenic liver steatosis in detail, with specific reference to HIV-positive patients. Finally, the last part of the review will be dedicated to the possible effects of liver steatosis on the bioavailability of antiretroviral and other drugs.

Deletion of C-C Motif Chemokine Ligand 5 Worsens Invariant Natural Killer T-Cell-Mediated Hepatitis via Compensatory Up-regulation of CXCR2-Related Chemokine Activity

BACKGROUND & AIMS

Chemokine-mediated immune cell recruitment plays pivotal roles in liver inflammation. C-C motif chemokine ligand 5 (CCL5) has been shown to be responsible for the recruitment of monocytes/macrophages and has been implicated in various liver diseases, including nonalcoholic fatty liver disease, fibrosis, and hepatocellular carcinoma. Previous studies have also shown that inhibition of CCL5 appears to be a promising therapeutic approach for several chronic liver diseases. However, whether blocking CCL5 could benefit immune cell-mediated hepatitis remains largely elusive.

METHODS

By adopting a specific agonist, alpha-galactosylceramide (α-Galcer), of invariant natural killer T cells (iNKTs), we investigated the function and mechanism of CCL5 in the iNKT induced murine hepatitis model.

RESULTS

We found significantly increased CCL5 expression in α-Galcer-induced hepatitis murine model. Such an increase in CCL5 is mainly enriched in non-parenchymal cells such as macrophages and iNKTs but not in hepatocytes. Surprisingly, CCL5 blockage by genetic deletion of Ccl5 does not affect the α-Galcer-induced iNKT activation but greatly worsens α-Galcer-induced liver injury accompanied by an increased hepatic neutrophil infiltration. Mechanistically, we demonstrated that greater neutrophil accumulation in the liver is responsible for the enhanced liver injury in Ccl5^-/- mice. Such an increased hepatic neutrophil infiltration is mainly caused by an enhanced CXCL1-CXCR2 signal in Ccl5^-/- mice. Therapeutically, either antibody-mediated neutrophil depletion or a CXCR2 antagonist, SB225002, mediated CXCR2 signaling blockage significantly ameliorated α-Galcer-induced liver injury in Ccl5^-/- mice.

CONCLUSIONS

Our present study demonstrates that (1) α-Galcer-induced murine hepatitis could greatly induce CCL5 production in macrophages and iNKT cells; (2) loss of CCL5 could enhance CXCL1 expression in hepatocytes and activate CXCL1-CXCR2 axis in neutrophils to augment their hepatic infiltration; and (3) neutrophil depletion or blockage of CXCL1-CXCR2 axis greatly improves α-Galcer-induced liver injury in Ccl5^-/- mice. This study suggests that clinical utilization of CCL5 blockage may compensatorily induce the activation of other chemokine pathways to enhance neutrophil recruitment and liver injury in hepatitis.

Function and therapeutic advances of chemokine and its receptor in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) represents a spectrum of hepatic pathology, ranging from simple accumulation of fat in its most benign form, steatohepatitis, to cirrhosis in its most advanced form. The prevalence of NAFLD is 20-30% in adults, and 10-20% of patients with NAFLD progress to nonalcoholic steatohepatitis (NASH) which is predicted to be the leading cause of liver transplantation over the next 10 years. Therefore, it is essential to explore effective diagnostic and treatment strategies for NAFLD patients. Chemokines are a family of small and highly conserved proteins (molecular weight ranging from 8 to 12 kDa) involved in regulating the migration and activities of hepatocytes, Kupffer cells (KCs), hepatic stellate cells (HSCs), endothelial cells and circulating immune cells. Accumulating data show that chemokine and its receptor act vital roles in the pathogenesis of NAFLD. Herein, we summarize the involvement of the chemokine and its receptor in the pathogenesis of NAFLD and explore the novel pharmacotherapeutic avenues for patients with NAFLD.

Chemokines and Chemokine Receptors in the Development of NAFLD

Chemokines are chemo-attractants for leukocyte trafficking, growth, and activation in injured and inflammatory tissues. The chemokine system is comprised of 50 chemokine ligands and 20 cognate chemokine receptors. In the context of liver diseases, leukocytes, hepatocytes, hepatic stellate cells, endothelial cells, and vascular smooth muscle cells are capable of producing chemokines. Chemokine receptors are typically expressed in various leukocyte subsets. Given that inflammation is a critical factor for the transition from simple steatosis to non-alcoholic steatohepatitis (NASH), and fibrosis, the chemokine system may play a prominent role in the pathogenesis of non-alcoholic fatty liver disease (NAFLD). Indeed, accumulating evidence shows elevated expression of chemokines and their receptors in the livers of obese patients with advanced steatosis and NASH. This chapter will discuss the underlying molecular mechanisms and the therapeutic potential of the chemokine systems in the pathogenesis of NAFLD. Among chemokines, we will highlight CCL2, CCL5, CXCL8-10, CX3CL1, and CXCL16 as pivotal mediators in the development of steatosis, NASH, and fibrosis.

Regulation, Communication, and Functional Roles of Adipose Tissue-Resident CD4+ T Cells in the Control of Metabolic Homeostasis

Evidence accumulated over the past few years has documented a critical role for adipose tissue (AT)-resident immune cells in the regulation of local and systemic metabolic homeostasis. In the lean state, visceral adipose tissue (VAT) is predominated by anti-inflammatory T-helper 2 (Th2) and regulatory T (Treg) cell subsets. As obesity progresses, the population of Th2 and Treg cells decreases while that of the T-helper 1 (Th1) and T-helper 17 (Th17) cells increases, leading to augmented inflammation and insulin resistance. Notably, recent studies also suggest a potential role of CD4⁺ T cells in the control of thermogenesis and energy homeostasis. In this review, we have summarized recent advances in understanding the characteristics and functional roles of AT CD4⁺ T cell subsets during obesity and energy expenditure. We have also discussed new findings on the crosstalk between CD4⁺ T cells and local antigen-presenting cells (APCs) including adipocytes, macrophages, and dendritic cells (DCs) to regulate AT function and metabolic homeostasis. Finally, we have highlighted the therapeutic potential of targeting CD4⁺ T cells as an effective strategy for the treatment of obesity and its associated metabolic diseases.

Maraviroc improves hepatic triglyceride content but not inflammation in a murine nonalcoholic fatty liver disease model induced by a chronic exposure to high-fat diet

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in the general population. Its severity ranges from simple steatosis to cirrhosis. C-C chemokine ligand type 5 or RANTES (Regulated upon Activation, Normal T-cell Expressed, and Secreted) plays an important role in the progression of hepatic inflammation and fibrosis. Our objective was to examine the preventive and therapeutic effects of maraviroc (MVC), a C-C chemokine receptor 5 antagonist, on liver pathology in an NAFLD mouse model. A total of 60 male C57BL/6 mice were randomly assigned to 1 of 4 groups: (1) high-fat diet (HFD) group or control group, (2) preventive group (HFD group plus MVC in drinking water since the beginning of the study), (3) early-therapeutic group (HFD group plus MVC in drinking starting at week 24 of the study), and (4) late-therapeutic group (HFD group plus MVC in drinking water starting at week 36 of the study). All mice were sacrificed at week 48. The hepatic triglyceride concentration in the HFD group was significantly higher than that in the groups treated with MVC at any time. Gene expression associated with lipogenesis (diacylglycerol acyltransferase 2 and proliferator-activated receptor-γ), insulin resistance (insulin receptor substrate-2), and β-oxidation (carnitine palmitoyltransferase 1A and acyl-CoA oxidase) was significantly reduced in all the groups treated with MVC. In summary, the beneficial effect of MVC on hepatic steatosis is maintained throughout the study.

Chemokine Receptor 5 Has No Major Role in the Severity of Hepatitis C Virus-Related Liver Damage

Total or partial inactivation of the chemokine 5 (CC5) pathway, as caused by the CC5 receptor Δ32 deletion (CCR5Δ32), may result in a profound manipulation of immune surveillance with significant consequences on the course and response to therapy of diverse human infections, including HIV. It has been postulated that in chronic hepatitis C (CHC), such a deregulation of CC5 pathway may compromise T cell-dependent antiviral immune responses, which in turn may favor viral persistence. To test this hypothesis, we investigated a cohort of 100 patients with CHC in whom 12 heterozygous and 1 homozygous CCR5Δ32 mutations were detected compared to 8 and none in 98 healthy controls (13% vs. 8.2%, p = 0.36). As patients with and without CCR5Δ32 mutations were similar in terms of histological activity (p = 0.84) and fibrosis stage (p = 0.20) as well as CCR5 tissue expression, we reasonably exclude that this CCR5 mutation is significantly involved in the pathogenesis of CHC and may be a potential therapeutic target. However, deleted patients showed a significantly higher response to pegylated interferon-alfa (PEG-IFN), suggesting that a dormant immune system is more readily primed by immunostimulation.

Blockade of the chemokine receptor, CCR5, reduces the growth of orthotopically injected colon cancer cells via limiting cancer-associated fibroblast accumulation

We previously demonstrated that cancer-associated fibroblasts (CAFs) accumulate at tumor sites through the interaction between a chemokine, CCL3, and its receptor, CCR5, in the late phase of colitis-associated colon carcinogenesis. Here we examined the effect of a CCR5 antagonist, maraviroc, on tumor growth arising from the orthotopic injection of mouse or human colon cancer cell lines into the cecal wall by focusing on CAFs. Orthotopic injection of either cell line caused tumor formation together with leukocyte infiltration and fibroblast accumulation. Concomitant oral administration of maraviroc reduced tumor formation with few effects on leukocyte infiltration. In contrast, maraviroc reduced the intratumor number of α-smooth muscle actin-positive fibroblasts, which express epidermal growth factor, a crucial growth factor for colon cancer cell growth. These observations suggest that maraviroc or other CCR5 antagonists might act as novel anti-CRC drugs to dampen CAFs, an essential cell component for tumor progression.

Differential impact of the dual CCR2/CCR5 inhibitor cenicriviroc on migration of monocyte and lymphocyte subsets in acute liver injury

A hallmark of acute hepatic injury is the recruitment of neutrophils, monocytes and lymphocytes, including natural killer (NK) or T cells, towards areas of inflammation. The recruitment of leukocytes from their reservoirs bone marrow or spleen into the liver is directed by chemokines such as CCL2 (for monocytes) and CCL5 (for lymphocytes). We herein elucidated the impact of chemokine receptor inhibition by the dual CCR2 and CCR5 inhibitor cenicriviroc (CVC) on the composition of myeloid and lymphoid immune cell populations in acute liver injury. CVC treatment effectively inhibited the migration of bone marrow monocytes and splenic lymphocytes (NK, CD4 T-cells) towards CCL2 or CCL5 in vitro. When liver injury was induced by an intraperitoneal injection of carbon tetrachloride (CCl₄) in mice, followed by repetitive oral application of CVC, flow cytometric and unbiased t-SNE analysis of intrahepatic leukocytes demonstrated that dual CCR2/CCR5 inhibition in vivo significantly decreased numbers of monocyte derived macrophages in acutely injured livers. CVC also reduced numbers of Kupffer cells (KC) or monocyte derived macrophages with a KC-like phenotype, respectively, after injury. In contrast to the inhibitory effects in vitro, CVC had no impact on the composition of hepatic lymphoid cell populations in vivo. Effective inhibition of monocyte recruitment was associated with reduced inflammatory macrophage markers and moderately ameliorated hepatic necroses at 36h after CCl₄. In conclusion, dual CCR2/CCR5 inhibition primarily translates into reduced monocyte recruitment in acute liver injury in vivo, suggesting that this strategy will be effective in reducing inflammatory macrophages in conditions of liver disease.

Functional role of CCL5/RANTES for HCC progression during chronic liver disease

BACKGROUND & AIMS

During liver inflammation, triggering fibrogenesis and carcinogenesis immune cells play a pivotal role. In the present study we investigated the role of CCL5 in human and in murine models of chronic liver inflammation leading to hepatocellular carcinoma (HCC) development.

METHODS

CCL5 expression and its receptors were studied in well-defined patients with chronic liver disease (CLD) and in two murine inflammation based HCC models. The role of CCL5 in inflammation, fibrosis, tumor initiation and progression was analyzed in different cell populations of NEMO^Δhepa/CCL5^-/- animals and after bone marrow transplantation (BMT). For therapeutic intervention Evasin-4 was injected for 24h or 8weeks.

RESULTS

In CLD patients, CCL5 and its receptor CCR5 are overexpressed - an observation confirmed in the Mdr2^-/- and NEMO^Δhepa model. CCL5 deletion in NEMO^Δhepa mice diminished hepatocyte apoptosis, compensatory proliferation and fibrogenesis due to reduced immune cell infiltration. Especially, CD45⁺/Ly6G⁺ granulocytes, CD45⁺/CD11b⁺/Gr1.1⁺/F4/80⁺ pro-inflammatory monocytes, CD4⁺ and CD8⁺ T cells were decreased. One year old NEMO^Δhepa/CCL5^-/- mice displayed smaller and less malignant tumors, characterized by reduced proliferative capacity and less pronounced angiogenesis. We identified hematopoietic cells as the main source of CCL5, while CCL5 deficiency did not sensitise NEMO^Δhepa hepatocytes towards TNFα induced apoptosis. Finally, therapeutic intervention with Evasin-4 over a period of 8weeks ameliorated liver disease progression.

CONCLUSION

We identified an important role of CCL5 in human and functionally in mice with disease progression, especially HCC development. A novel approach to inhibit CCL5 in vivo thus appears encouraging for patients with CLD.

LAY SUMMARY

Our present study identifies the essential role of the chemoattractive cytokine CCL5 for liver disease progression and especially hepatocellular carcinoma development in men and mice. Finally, the inhibition of CCL5 appears to be encouraging for therapy of human chronic liver disease.

Steatosis induced CCL5 contributes to early-stage liver fibrosis in nonalcoholic fatty liver disease progress

The rapidly increasing prevalence of nonalcoholic fatty liver disease (NAFLD) has become one of the major public health threats in China and worldwide. However, during the development of NAFLD, the key mechanism underlying the progression of related fibrosis remains unclear, which greatly impedes the development of optimal NAFLD therapy. In the current study, we were endeavored to characterize a proinflammatory cytokine, CCL5, as a major contributor for fibrosis in NAFLD. The results showed that CCL5 was highly expressed in fatty liver and NASH patients. In NAFLD rats induced by 8-week-HFD, CCL5 and its receptor, CCR5, were significantly up-regulated and liver fibrosis exclusively occurred in this group. In addition, we showed that hepatocytes are the major source contributing to this CCL5 elevation. Interestingly, a CCL5 inhibitor Met-CCL5, significantly decreased liver fibrosis but not hepatic steatosis. Using a cell model of hepatic steatosis, we found that the conditioned medium of lipid-overloaded hepatocytes (Fa2N-4 cells) which produced excessive CCL5 stimulated the profibrotic activities of hepatic stellate cells (LX-2) as manifested by increased migration rate, proliferation and collagen production of LX-2 cells. CCL5 knockdown in Fa2N-4 cells, Met-CCL5 or CCR5 antibody treatment on LX-2 cells all significantly inhibited the conditioned medium of FFA-treated Fa2N-4 cells to exert stimulatory effects on LX-2 cells. Consistently, the conditioned medium of Fa2N-4 cells with CCL5 over-expression significantly enhanced migration rate, cell proliferation and collagen production of LX-2 cells. All these results support that CCL5 produced by steatotic hepatocytes plays an essential role in fibrotic signaling machinery of NAFLD. In addition, we were able to identify C/EBP-β as the up-stream regulator of CCL5 gene transcription in hepatocytes treated with free fatty acid (FFA). Our data strongly supported that CCL5 plays a pivotal regulatory role in hepatic fibrosis during NAFLD, which constitutes a novel and exciting observation that may call for potential future development of specific CCL5-targeted NAFLD therapy.

Maraviroc ameliorates the increased adipose tissue macrophage recruitment induced by a high-fat diet in a mouse model of obesity

BACKGROUND

Any strategy designed to decrease the macrophage content in adipose tissue (AT) is of great value as a way to decrease inflammation in this fat depot and also as a way to prevent or treat obesity and associated disorders. Maraviroc (MVC), a CCR5 antagonist approved for the treatment of HIV-infected patients, has beneficial effects on metabolism. The objective of this study was to investigate the effects of MVC on AT macrophage recruitment in a mouse model of obesity. The plausible underlying mechanisms of action were also investigated.

METHODS

32 male C57BL/6 mice were randomly assigned to the following groups: control, MVC (300 mg/l MVC in drinking water), high-fat diet (HFD) or HFD+MVC. After 16 weeks of treatment, histopathological and molecular analyses were performed on epididymal fat.

RESULTS

Our results demonstrated that MVC reduced the presence of macrophages in epididymal fat despite the ingestion of an HFD. The inhibition of MCP-1 gene expression and JNK signalling pathway along with the upregulation of protective cytokines such as cardiotrophin-1 could contribute to these actions. MVC effects on AT macrophage recruitment were associated with a lower body weight gain and a partial improvement in insulin resistance despite an HFD.

CONCLUSIONS

We have demonstrated the ability of MVC to ameliorate the increased AT macrophage recruitment induced by an HFD in a mouse model of obesity. These actions could be of interest when designing antiretroviral treatments in HIV-patients.

Inflammation-associated upregulation of the sulfated steroid transporter Slc10a6 in mouse liver and macrophage cell lines

AIM

Slc10a6, an incompletely characterized member of the SLC10A bile acid transporter family, was one of the most highly induced RNA transcripts identified in a screen for inflammation-responsive genes in mouse liver. This study aimed to elucidate a role for Slc10a6 in hepatic inflammation.

METHODS

Mice were treated with lipopolysaccharide (LPS; 2 mg/kg) or interleukin (IL)-1β (5 mg/kg) for various time points. Cells were treated with LPS (1 μg/mL) at various time points, with cell signaling inhibitors, nuclear receptor ligands and Slc10a6 substrates. All mRNA levels were determined by quantitative polymerase chain reaction.

RESULTS

Slc10a6 mRNA levels were upregulated in mouse liver at 2 h (7-fold), 4 h (100-fold) and 16 h (50-fold) after LPS treatment, and 35-fold by the cytokine IL-1β (4 h). Both absence of the nuclear receptor Fxr and pretreating mice with the synthetic retinoid X receptor-α ligand LG268 attenuated the LPS upregulation of Slc10a6 mRNA by 60-75%. In vitro, Slc10a6 mRNA was induced 30-fold by LPS in mouse RAW264.7 macrophages in a time-dependent manner (maximum at 8 h). The Slc10a6 substrate dehydroepiandrosterone sulfate (DHEAS) enhanced LPS induction of CCL5 mRNA, a pro-inflammatory chemokine, by 50% in RAW264.7 cells. This effect was abrogated in the presence of anti-inflammatory nuclear receptor ligands 9-cis-retinoic acid and dexamethasone.

CONCLUSION

Dramatic upregulation of Slc10a6 mRNA by LPS combined with enhanced LPS stimulation of CCL5 expression by the Slc10a6 substrate DHEAS in macrophages suggests that Slc10a6 function contributes to the hepatic inflammatory response.

Anti-CD137 enhances anti-CD20 therapy of systemic B-cell lymphoma with altered immune homeostasis but negligible toxicity

Studies of sequential anti-CD137/anti-CD20 therapy have previously shown that the efficacy of anti-CD20 was heavily reliant upon anti-CD137; however, the exact mechanism of the anti-B-cell lymphoma efficacy, and whether this correlates with enhanced adverse effects or toxicity, had not been elucidated. Here, we observed that sequential anti-CD137 administration with anti-CD20 resulted in a synergistic therapy, largely dependent upon Fc receptors (FcR), to prolong survival in an experimental B-cell lymphoma therapy model. Tumor suppression was accompanied by B cell depletion, which was not dependent on one activating FcR. Surprisingly, the B-cell activating factor (BAFF) was elevated in the plasma of mice receiving anti-CD137 alone or in combination with anti-CD20, while a selective increase in some plasma cytokines was also noted and triggered by anti-CD137. These effects were independent of activating FcR. Sustained treatment of advanced lymphoma revealed increased lymphocyte infiltrates into the liver and a significant decrease in the metabolic capability of the liver in mice receiving anti-CD137. Importantly, these effects were not exacerbated in mice receiving the anti-CD20/CD137 combination, and elevations in classical liver damage markers such as alanine aminotransferase (ALT) were less than that caused by the lymphoma itself. Thus, combined anti-CD20/anti-CD137 treatment increases the therapeutic index of anti-CD20 or anti-CD137 alone. These mouse data were corroborated by ongoing clinical development studies to assess safety, tolerability and pharmacodynamic activity of human patients treated by this approach. Together, these data support the use of this sequential antibody therapeutic strategy to improve the efficacy of rituximab in B-cell lymphoma patients.

Hepatic safety of maraviroc in HIV-1-infected patients with hepatitis C and/or B co-infection. The Maraviroc Cohort Spanish Group

INTRODUCTION

Limited data is available regarding the hepatic safety of maraviroc in patients co-infected with HIV and HCV and/or HBV. Our objective was to compare the hepatic safety profile and fibrosis progression in HIV-mono-infected patients and co-infected with HCV and/or HBV treated with maraviroc.

METHODS

Retrospective multicentre cohort study of HIV-infected patients receiving treatment with a maraviroc-containing regimen in 27 hospitals in Spain.

RESULTS

A total of 667 patients were analyzed, of whom 313 were co-infected with HCV (n=282), HBV (n=14), or both (n=17). Maraviroc main indications were salvage therapy (52%) and drug toxicity (20%). Grade 3-4 hypertransaminasaemia (AST/ALT >5 times ULN) per 100 patient-years of maraviroc exposure, was 5.84 (95% CI, 4.04-8.16) and 1.23 (95% CI, 0.56-2.33) in co-infected and HIV-mono-infected patients, respectively (incidence rate ratio, 4.77; 95% CI, 2.35-10.5). However, the degree of aminotransferase abnormalities remained stable throughout the study in both groups, and no significant between-group differences were seen in the cumulative proportion of patients showing an increase in AST/ALT levels greater than 3.5 times baseline levels. No between-group differences were seen in liver fibrosis over time. With a maraviroc median exposure of 20 months (IQR, 12-41), two patients (0.3%) discontinued maraviroc because of grade 4 hepatitis, and other 2 died due to complications associated to end-stage-liver disease.

CONCLUSIONS

Maraviroc-containing regimens showed a low incidence of hepatitis in a large Spanish cohort of HIV-infected patients, including more than 300 patients co-infected with HCV and/or HBV. Co-infection did not influence the maximum liver enzyme level or the fibrosis progression throughout the study.

CCR1 antagonism attenuates T cell trafficking to omentum and liver in obesity-associated cancer

Obesity is a global health problem presenting serious risk of disease fuelled by chronic inflammation, including type 2 diabetes mellitus, cardiovascular disease, liver disease and cancer. Visceral fat, in particular the omentum and liver of obese individuals are sites of excessive inflammation. We propose that chemokine-mediated trafficking of pro-inflammatory cells to the omentum and liver contributes to local and subsequent systemic inflammation. Oesophagogastric adenocarcinoma (OAC) is an exemplar model of obesity and inflammation driven cancer. We have demonstrated that T cells actively migrate to the secreted factors from the omentum and liver of OAC patients and that both CD4(+) and CD8(+) T cells bearing the chemokine receptor CCR5 are significantly more prevalent in these tissues compared to matched blood. The CCR5 ligand and inflammatory chemokine MIP-1α is also secreted at significantly higher concentrations in the omentum and liver of our OAC patient cohort compared to matched serum. Furthermore, we report that MIP-1α receptor antagonism can significantly reduce T cell migration to the secreted factors from OAC omentum and liver. These novel data suggest that chemokine receptor antagonism may have therapeutic potential to reduce inflammatory T cell infiltration to the omentum and liver and in doing so, may ameliorate pathological inflammation in obesity and obesity-associated cancer.

Non-alcoholic steatohepatitis: emerging molecular targets and therapeutic strategies

Non-alcoholic fatty liver disease - the most common chronic liver disease - encompasses a histological spectrum ranging from simple steatosis to non-alcoholic steatohepatitis (NASH). Over the next decade, NASH is projected to be the most common indication for liver transplantation. The absence of an effective pharmacological therapy for NASH is a major incentive for research into novel therapeutic approaches for this condition. The current focus areas for research include the modulation of nuclear transcription factors; agents that target lipotoxicity and oxidative stress; and the modulation of cellular energy homeostasis, metabolism and the inflammatory response. Strategies to enhance resolution of inflammation and fibrosis also show promise to reverse the advanced stages of liver disease.

Opportunity and challenge for diagnosis and treatment of hepatic fibrosis

Hepatic fibrosis is a wound-healing response to all kinds of chronic liver injuries, which is characterized by extracellular matrix remodeling. Hepatic fibrosis ultimately leads to cirrhosis and even hepatic cell carcinoma. Thus, diagnosis and treatment of hepatic fibrosis are important for the management of chronic liver diseases. Recently, the study of hepatic fibrogenesis has witnessed tremendous progress, with many new diagnostic and therapeutic options emerging. This article mainly discusses the opportunity and challenge for diagnosis and treatment of hepatic fibrosis.

Pathophysiology and Mechanisms of Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) encompasses a spectrum of liver disorders characterized by abnormal hepatic fat accumulation, inflammation, and hepatocyte dysfunction. Importantly, it is also closely linked to obesity and the metabolic syndrome. NAFLD predisposes susceptible individuals to cirrhosis, hepatocellular carcinoma, and cardiovascular disease. Although the precise signals remain poorly understood, NAFLD pathogenesis likely involves actions of the different hepatic cell types and multiple extrahepatic signals. The complexity of this disease has been a major impediment to the development of appropriate metrics of its progression and effective therapies. Recent clinical data place increasing importance on identifying fibrosis, as it is a strong indicator of hepatic disease-related mortality. Preclinical modeling of the fibrotic process remains challenging, particularly in the contexts of obesity and the metabolic syndrome. Future studies are needed to define the molecular pathways determining the natural progression of NAFLD, including key determinants of fibrosis and disease-related outcomes. This review covers the evolving concepts of NAFLD from both human and animal studies. We discuss recent clinical and diagnostic methods assessing NAFLD diagnosis, progression, and outcomes; compare the features of genetic and dietary animal models of NAFLD; and highlight pharmacological approaches for disease treatment.

Rubratoxin-B-induced secretion of chemokine ligands of cysteine-cysteine motif chemokine receptor 5 (CCR5) and its dependence on heat shock protein 90 in HL60 cells

To elucidate the mechanism underlying rubratoxin B toxicity, the effects of rubratoxin B on the secretion of CCR5 chemokines, CCL3, CCL4, and CCL5, in a human promyelocytic leukemia cell line, HL60, were investigated. In addition, to examine whether the molecular chaperone 90-kDa heat shock protein (Hsp90) contributes to rubratoxin B toxicity, the effects of Hsp90-specific inhibitors, radicicol and geldanamycin, were investigated. Exposure to rubratoxin B for 24h induced secretion of each CCR5 chemokine, although the effect on CCL5 secretion was modest, and it enhanced secretion of proinflammatory cytokines tumor necrosis factor-α, CXCL8, and CCL2. Concomitant treatment with radicicol abolished the rubratoxin-induced secretion of all cytokines investigated. Geldanamycin antagonized the rubratoxin B-induced effects on CCL3 and CCL5, but not CCL4; the effects of geldanamycin were less than that of radicicol. Taken together, the results suggest that rubratoxin B, with the contribution of Hsp90, induces secretion of CCR5 chemokines.

Off-label use of maraviroc in clinical practice

Maraviroc is a first-in-class selective CCR5 antagonist only approved in combination with other antiretrovirals for the treatment of HIV-infection. However, sometimes, off-label prescribing is necessary. In this regard, interesting data have been obtained with maraviroc from studies using murine models. In human daily clinical practice there are many researching areas of interest where CCR5 could play an important role. Nowadays few clinical trials are evaluating maraviroc's role in non-HIV-infected patients but there are many open issues that need to be answered about CCR5 antagonists. In this article we review some of them.

Murine models provide insight to the development of non-alcoholic fatty liver disease

Associated with the obesity epidemic, non-alcoholic fatty liver disease (NAFLD) has become the leading liver disease in North America. Approximately 30 % of patients with NAFLD may develop non-alcoholic steatohepatitis (NASH) that can lead to cirrhosis and hepatocellular carcinoma (HCC). Frequently animal models are used to help identify underlying factors contributing to NAFLD including insulin resistance, dysregulated lipid metabolism and mitochondrial stress. However, studying the inflammatory, progressive nature of NASH in the context of obesity has proven to be a challenge in mice. Although the development of effective treatment strategies for NAFLD and NASH is gaining momentum, the field is hindered by a lack of a concise animal model that reflects the development of liver disease during obesity and the metabolic syndrome. Therefore, selecting an animal model to study NAFLD or NASH must be done carefully to ensure the optimal application. The most widely used animal models have been reviewed highlighting their advantages and disadvantages to studying NAFLD and NASH specifically in the context of obesity.

Maraviroc: a review of its use in HIV infection and beyond

The human immunodeficiency virus-1 (HIV-1) enters target cells by binding its envelope glycoprotein gp120 to the CD4 receptor and/or coreceptors such as C-C chemokine receptor type 5 (CCR5; R5) and C-X-C chemokine receptor type 4 (CXCR4; X4), and R5-tropic viruses predominate during the early stages of infection. CCR5 antagonists bind to CCR5 to prevent viral entry. Maraviroc (MVC) is the only CCR5 antagonist currently approved by the United States Food and Drug Administration, the European Commission, Health Canada, and several other countries for the treatment of patients infected with R5-tropic HIV-1. MVC has been shown to be effective at inhibiting HIV-1 entry into cells and is well tolerated. With expanding MVC use by HIV-1-infected humans, different clinical outcomes post-approval have been observed with MVC monotherapy or combination therapy with other antiretroviral drugs, with MVC use in humans infected with dual-R5- and X4-tropic HIV-1, infected with different HIV-1 genotype or infected with HIV-2. This review discuss the role of CCR5 in HIV-1 infection, the development of the CCR5 antagonist MVC, its pharmacokinetics, pharmacodynamics, drug–drug interactions, and the implications of these interactions on treatment outcomes, including viral mutations and drug resistance, and the mechanisms associated with the development of resistance to MVC. This review also discusses available studies investigating the use of MVC in the treatment of other diseases such as cancer, graft-versus-host disease, and inflammatory diseases.