Interferon-alpha 2 but not Interferon-gamma serum levels are associated with intramuscular fat in obese patients with nonalcoholic fatty liver disease

The role of inflammation induced by necroptosis in the development of fibrosis and liver cancer in novel knockin mouse models fed a western diet

Non-resolving, chronic inflammation (inflammaging) is believed to play an important role in aging and age-related diseases. The goal of this study was to determine if inflammation induced by necroptosis arising from the liver plays a role in chronic liver disease (CLD) and liver cancer in mice fed a western diet (WD). Necroptosis was induced in liver using two knockin (KI) mouse models that overexpress genes involved in necroptosis (Ripk3 or Mlkl) specifically in liver (i.e., hRipk3-KI and hMlkl-KI mice). These mice and control mice (not overexpressing Ripk3 or Mlkl) were fed a WD (high in fat, sucrose, and cholesterol) starting at 2 months of age for 3, 6, and 12 months. Feeding the WD induced necroptosis in the control mice, which was further elevated in the hRipk3-KI and hMlkl-KI mice and was associated with a significant increase in inflammation in the livers of the hRipk3-KI and hMlkl-KI mice compared to control mice fed the WD. Overexpressing Ripk3 or Mlkl significantly increased steatosis and fibrosis compared to control mice fed the WD. Mice fed the WD for 12 months developed liver tumors (hepatocellular adenomas): 28% of the control mice developing tumors compared to 62% of the hRipk3-KI and hMlkl-KI mice. The hRipk3-KI and hMlkl-KI mice showed significantly more and larger tumor nodules. Our study provides the first direct evidence that inflammation induced by necroptosis arising from hepatocytes can lead to the progression of hepatic steatosis to fibrosis in obese mice that eventually results in an increased incidence in hepatocellular adenomas.

Sonographic Features of Rectus Femoris Muscle in Patients with Metabolic Dysfunction-Associated Fatty Liver Disease and Their Correlation with Body Composition Parameters and Muscle Strength: Results of a Single-Center Cross-Sectional Study

This study aimed to describe sonographic features of rectus femoris muscle (RFM) in patients with metabolic dysfunction-associated fatty liver disease (MASLD) and their correlation with body composition parameters and muscle strength. A total of 67 patients with MASLD underwent dual-energy X-ray absorptiometry (DEXA), bioimpedance analysis (BIA), muscle strength measurement (grip strength [GS] and chair stand test [CST]), and ultrasound (US) investigation of the RFM in the dominant thigh using a 4 to 18 MHz linear probe. MASLD patients exhibited increased RFM echogenicity, possibly due to fatty infiltration. We confirmed that the greater the subcutaneous fat thickness, the smaller was the muscle mass (p < 0.001), and the lower was the muscle strength (p < 0.001 for GS and p = 0.002 for CST). On the contrary, the greater the anteroposterior diameter (APD) of RFM, the higher was the muscle mass (p < 0.001), and the greater was the muscle strength (p < 0.001 for GS and p = 0.007 for CST). In addition, APD of the RFM and stiffness of RFM exhibited direct correlation with bone mineral density values of the lumbar spine (p = 0.005 for both GS and CST). We concluded that US investigation of the RFM in the dominant thigh can be helpful in identifying MASLD patients at a high risk of musculoskeletal disorders given repeated point-of-care clinical evaluations.

Observational study of effects of HIV acquisition and antiretroviral treatment on biomarkers of systemic immune activation

To assess whether biomarkers of systemic inflammation are associated with HIV acquisition or with the timing of ART initiation ("immediate", at diagnosis, versus "deferred", at 24 weeks post-diagnosis) in men-who-have-sex-with-men (MSM) and transgender women, we conducted a retrospective study comparing inflammatory biomarkers in participants' specimens collected before infection and after ≥2 years of effective ART. We measured biomarkers in four longitudinally collected plasma, including two specimens collected from each participant before and two after HIV acquisition and confirmed ART-suppression. Biomarkers were quantified by enzyme-linked immuno-assay or Meso Scale Discovery. When evaluating systematic variation in these markers over time, we found that multiple biomarkers consistently varied across participants' two pre-infection or two post-ART-suppression specimens. Additionally, we compared changes in biomarkers after vs before HIV acquisition. Across 47 participants, the levels of C-reactive protein (CRP), monocyte chemo-attractant protein-1, tumor necrosis factor-α and interferon gamma-induced protein-10 significantly increased while leptin and lipopolysaccharide binding protein (LBP) significantly decreased following HIV infection. Randomization to deferred-ART initiation was associated with greater increases in CRP and no decrease in LBP. Acquisition of HIV appeared to induce systemic inflammation, with elevation of biomarkers previously associated with infections and cardiovascular disease. Initiation of ART during the early weeks of infection tempered the increase in pro-inflammatory biomarkers compared to delaying ART for ~24 weeks after HIV diagnosis. These findings provide insight into potential mediators by which immediate-ART initiation improves health outcomes, perhaps because immediate-ART limits the size of the HIV reservoir or limits immune dysregulation that in turn trigger systemic inflammation.

Myosteatosis: Diagnosis, pathophysiology and consequences in metabolic dysfunction-associated steatotic liver disease

Metabolic dysfunction-associated steatotic liver disease (MASLD) is associated with an increased risk of multisystemic complications, including muscle changes such as sarcopenia and myosteatosis that can reciprocally affect liver function. We conducted a systematic review to highlight innovative assessment tools, pathophysiological mechanisms and metabolic consequences related to myosteatosis in MASLD, based on original articles screened from PUBMED, EMBASE and COCHRANE databases. Forty-six original manuscripts (14 pre-clinical and 32 clinical studies) were included. Microscopy (8/14) and tissue lipid extraction (8/14) are the two main assessment techniques used to measure muscle lipid content in pre-clinical studies. In clinical studies, imaging is the most used assessment tool and included CT (14/32), MRI (12/32) and ultrasound (4/32). Assessed muscles varied across studies but mainly included paravertebral (4/14 in pre-clinical; 13/32 in clinical studies) and lower limb muscles (10/14 in preclinical; 13/32 in clinical studies). Myosteatosis is already highly prevalent in non-cirrhotic stages of MASLD and correlates with disease activity when using muscle density assessed by CT. Numerous pathophysiological mechanisms were found and included: high-fat and high-fructose diet, dysregulation in fatty acid transport and ketogenesis, endocrine disorders and impaired microRNA122 pathway signalling. In this review we also uncover several potential consequences of myosteatosis in MASLD, such as insulin resistance, MASLD progression from steatosis to metabolic steatohepatitis and loss of muscle strength. In conclusion, data on myosteatosis in MASLD are already available. Screening for myosteatosis could be highly relevant in the context of MASLD, considering its correlation with MASLD activity as well as its related consequences.

Graphislactone A, a Fungal Antioxidant Metabolite, Reduces Lipogenesis and Protects against Diet-Induced Hepatic Steatosis in Mice

Graphislactone A (GPA), a secondary metabolite derived from a mycobiont found in the lichens of the genus Graphis, exhibits antioxidant properties. However, the potential biological functions and therapeutic applications of GPA at the cellular and animal levels have not yet been investigated. In the present study, we explored the therapeutic potential of GPA in mitigating non-alcoholic fatty liver disease (NAFLD) and its underlying mechanisms through a series of experiments using various cell lines and animal models. GPA demonstrated antioxidant capacity on a par with that of vitamin C in cultured hepatocytes and reduced the inflammatory response induced by lipopolysaccharide in primary macrophages. However, in animal studies using an NAFLD mouse model, GPA had a milder impact on liver inflammation while markedly attenuating hepatic steatosis. This effect was confirmed in an animal model of early fatty liver disease without inflammation. Mechanistically, GPA inhibited lipogenesis rather than fat oxidation in cultured hepatocytes. Similarly, RNA sequencing data revealed intriguing associations between GPA and the adipogenic pathways during adipocyte differentiation. GPA effectively reduced lipid accumulation and suppressed lipogenic gene expression in AML12 hepatocytes and 3T3-L1 adipocytes. In summary, our study demonstrates the potential application of GPA to protect against hepatic steatosis in vivo and suggests a novel role for GPA as an underlying mechanism in lipogenesis, paving the way for future exploration of its therapeutic potential.

Effects of Feeding Corn Distillers Dried Grains with Solubles on Muscle Quality Traits and Lipidomics Profiling of Finishing Pigs

This study investigated the effects of adding corn distillers dried grains with solubles (DDGS) to the diet on the meat quality, chemical composition, fatty acid composition, and lipidomics profiling in the longissimus thoracis (LT) of finishing pigs. Twenty-four healthy crossbred pigs (average body weight 61.23 ± 3.25 kg) were randomly divided into two groups with three replicates per group and four pigs per pen. The control group (CON) was fed a basal diet, and the DDGS group was fed an experimental diet with 30% DDGS. The results show that adding DDGS to the diet increases the yellowness (b*), chroma (C*), linoleic acid (C18:2n-6) percentages, polyunsaturated fatty acid (PUFA) percentages and iodine value of LT (p < 0.05). Based on LC-ESI-MS/MS, 1456 lipids from 6 classes or 44 subclasses in LT were analyzed, and 50 differential lipids were observed. Triglyceride (TG) with C18:2n-6 side chains and ceramide alpha-hydroxy fatty acid-sphingosine (Cer-AS) contents increased significantly, and the decrease in multiple glycerophospholipids (GPs) content may be related to differences in the glycerophospholipid metabolic pathway. Correlation analysis suggests that triglycerides with C18:2n-6 side chains may be one of the reasons for the changes in b* and C* values in the LT. In conclusion, feeding DDGS affects the meat quality and fatty acid composition and may affect the lipid profile in the LT of finishing pigs by regulating lipid metabolism.

Observational study of effects of HIV Acquisition and Antiretroviral Treatment on Biomarkers of Systemic Immune Activation

Objective

Assess whether biomarkers of systemic inflammation are associated with HIV acquisition or with the timing of ART initiation ("immediate", at diagnosis, versus "deferred", at 24 weeks post-diagnosis) in men-who-have-sex-with-men (MSM) and transgender women.

Design

A retrospective study comparing inflammatory biomarkers in participants' specimens collected before and after ≥2 years of effective ART.

Methods

Inflammatory biomarkers were measured in four longitudinally collected plasma specimens, including two plasma specimens collected from each participant before and two after HIV acquisition and confirmed ART-suppression. Biomarkers were quantified by enzyme-linked immuno-assay or Meso Scale Discovery. Statistical measures compared intra-participant and between-group changes in biomarkers.

Results

Across 50 participants, the levels of C-reactive protein (CRP), monocyte chemo-attractant protein-1, tumor necrosis factor-α and interferon gamma-induced protein-10 significantly increased while leptin and lipopolysaccharide binding protein (LBP) significantly decreased following HIV infection. Randomization to deferred-ART initiation was associated with greater increases in CRP and no decreases in LBP. Multiple biomarkers varied significantly within participants' two pre-infection or two post-ART-suppression specimens.

Conclusions

Acquisition of HIV appeared to induce systemic inflammation, with elevation of biomarkers previously associated with infections and cardiovascular disease. Initiation of ART during the early weeks of infection tempered the increase in pro-inflammatory biomarkers compared to those who delayed ART for ~24 weeks after HIV diagnosis, perhaps because immediate-ART limited the size of the HIV reservoir or limited immune dysregulation. Some but not all biomarkers appeared sufficiently stable to assess intraparticipant changes over time. Given that pro-inflammatory biomarkers predict multiple co-morbidities, our findings suggest that immediate-ART initiation may improve health outcomes.

New Insights into the Identification of Metabolites and Cytokines Predictive of Outcome for Patients with Severe SARS-CoV-2 Infection Showed Similarity with Cancer

SARS-CoV-2 infection is characterized by several clinical manifestations, ranging from the absence of symptoms to severe forms that necessitate intensive care treatment. It is known that the patients with the highest rate of mortality develop increased levels of proinflammatory cytokines, called the "cytokine storm", which is similar to inflammatory processes that occur in cancer. Additionally, SARS-CoV-2 infection induces modifications in host metabolism leading to metabolic reprogramming, which is closely linked to metabolic changes in cancer. A better understanding of the correlation between perturbed metabolism and inflammatory responses is necessary. We evaluated untargeted plasma metabolomics and cytokine profiling via ¹H-NMR (proton nuclear magnetic resonance) and multiplex Luminex assay, respectively, in a training set of a limited number of patients with severe SARS-CoV-2 infection classified on the basis of their outcome. Univariate analysis and Kaplan-Meier curves related to hospitalization time showed that lower levels of several metabolites and cytokines/growth factors, correlated with a good outcome in these patients and these data were confirmed in a validation set of patients with similar characteristics. However, after the multivariate analysis, only the growth factor HGF, lactate and phenylalanine retained a significant prediction of survival. Finally, the combined analysis of lactate and phenylalanine levels correctly predicted the outcome of 83.3% of patients in both the training and the validation set. We highlighted that the cytokines and metabolites involved in COVID-19 patients' poor outcomes are similar to those responsible for cancer development and progression, suggesting the possibility of targeting them by repurposing anticancer drugs as a therapeutic strategy against severe SARS-CoV-2 infection.

From Beneath the Skin to the Airway Wall: Understanding the Pathological Role of Adipose Tissue in Comorbid Asthma-Obesity

This article provides a contemporary report on the role of adipose tissue in respiratory dysfunction. Adipose tissue is distributed throughout the body, accumulating beneath the skin (subcutaneous), around organs (visceral), and importantly in the context of respiratory disease, has recently been shown to accumulate within the airway wall: "airway-associated adipose tissue." Excessive adipose tissue deposition compromises respiratory function and increases the severity of diseases such as asthma. The mechanisms of respiratory impairment are inflammatory, structural, and mechanical in nature, vary depending on the anatomical site of deposition and adipose tissue subtype, and likely contribute to different phenotypes of comorbid asthma-obesity. An understanding of adipose tissue-driven pathophysiology provides an opportunity for diagnostic advancement and patient-specific treatment. As an exemplar, the potential impact of airway-associated adipose tissue is highlighted, and how this may change the management of a patient with asthma who is also obese. © 2023 American Physiological Society. Compr Physiol 13:4321-4353, 2023.

The Role of Interferon Regulatory Factors in Non-Alcoholic Fatty Liver Disease and Non-Alcoholic Steatohepatitis

Non-alcoholic fatty liver disease (NAFLD) is becoming the most common chronic liver disease with many metabolic comorbidities, such as obesity, diabetes, and cardiovascular diseases. Non-alcoholic steatohepatitis (NASH), an advanced form of NAFLD, accompanies the progression of hepatic steatosis, inflammation, cell death, and varying degree of liver fibrosis. Interferons (IFNs) have been shown to play important roles in the pathogenesis of NAFLD and NASH. Their regulating transcriptional factors such as interferon regulatory factors (IRFs) can regulate IFN expression, as well as genes involved in macrophage polarization, which are implicated in the pathogenesis of NAFLD and advanced liver disease. In this review, the roles of IRF-involved signaling pathways in hepatic inflammation, insulin resistance, and immune cell activation are reviewed. IRFs such as IRF1 and IRF4 are also involved in the polarization of macrophages that contribute to critical roles in NAFLD or NASH pathogenesis. In addition, IRFs have been shown to be regulated by treatments including microRNAs, PPAR modulators, anti-inflammatory agents, and TLR agonists or antagonists. Modulating IRF-mediated factors through these treatments in chronic liver disease can ameliorate the progression of NAFLD to NASH. Furthermore, adenoviruses and CRISPR activation plasmids can also be applied to regulate IRF-mediated effects in chronic liver disease. Pre-clinical and clinical trials for evaluating IRF regulators in NAFLD treatment are essential in the future direction.

Immunoediting in SARS-CoV-2: Mutual relationship between the virus and the host

Immunoediting is a well-known concept that occurs in cancer through three steps of elimination, equilibrium, and escape (3Es), where the immune system first suppresses the growth of tumor cells and then promotes them towards the malignancy. This phenomenon has been conceptualized in some chronic viral infections such as HTLV-1 and HIV by obtaining the resistance to elimination and making a persistent form of infected cells especially in untreated patients. Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a heterogeneous disease characterizing from mild/asymptomatic to severe/critical courses with some behavioral aspects in an immunoediting setting. In this context, a coordinated effort between innate and adaptive immune system leads to detection and destruction of early infection followed by equilibrium between virus-specific responses and infected cells, which eventually ends up with an uncontrolled inflammatory response in severe/critical patients. Although the SARS-CoV-2 applies several escape strategies such as mutations in viral epitopes, modulating the interferon response and inhibiting the MHC I molecules similar to the cancer cells, the 3Es hallmark may not occur in all clinical conditions. Here, we discuss how the lesson learnt from cancer immunoediting and accurate understanding of these pathophysiological mechanisms helps to develop more effective therapeutic strategies for COVID-19.

Hepcidin expression levels involve efficacy of pegylated interferon-α treatment in hepatitis B-infected liver

BACKGROUND

Hepcidin is the master iron regulator hormone produced by the liver. The association of serum hepcidin with pegylated interferon therapy in patients with chronic hepatitis C infection has been studied. However, the role of serum hepcidin level in predicting the effect of pegylated interferon treatment in patients with chronic hepatitis B (CHB) infection is yet to be elucidated. Our study aims to investigate the correlation between hepcidin expression levels and the curative effect of interferon-alpha therapy in patients with CHB.

METHODS

A total of 47 patients with CHB who accepted pegylated interferon-α (PEG-IFN- α) treatment were recruited. The serum level of hepcidin was estimated by ELISA. The alternation in the gene expression level of hepcidin was detected by RT-PCR, and immunofluorescence cell staining was performed to detect hepcidin peptide. The induction of antiviral proteins was analyzed by Western blotting. The predictive value of early on-treatment variation in serum hepcidin during treatment progress was assessed by receiver operating characteristic analysis.

RESULTS

High levels of early on-treatment serum hepcidin were observed in patients who achieved a decline in HBsAg > 1 log10 IU/mL or HBV DNA > 1 log10 IU/mL. In vitro, an elevation of the hepcidin expression in HepG2.2.15 cells induced by PEG-IFN-α treatment was noted. Furthermore, combined treatment with hepcidin and PEG-IFN-α increased the levels of antiviral proteins. The predictive cut-off value of hepcidin for HBsAg decline > 1 log10 IU/mL was 239 pg/mL, and the sensitivity and specificity were 72.73% and 70.97%, respectively. The predictive cut-off value of hepcidin for the decline in HBV DNA > 1 log10 IU/mL was 190.4 pg/mL, and the sensitivity and specificity were 72.73% and 61.11%, respectively. Early-on treatment changes in the hepcidin level signified the predictive value of the PEG-IFN-α curative effect.

CONCLUSIONS

A higher early-on treatment hepcidin level indicates a higher possibility of HBsAg and HBV DNA decline in patients with CHB during PEG-IFN-α treatment. A high early-on treatment serum hepcidin level is significant in predicting the PEG-IFN-α therapeutic effect in patients with CHB.

Orally administered melanin from Sepiapharaonis ink ameliorates depression-anxiety-like behaviors in DSS-induced colitis by mediating inflammation pathway and regulating apoptosis

The effects of intestinal inflammation on the brain and behavior have received a lot of attention. Melanin (MSI) from Sepiapharaonis ink as an emerging functional food, it exhibited a significant protective effect on dextran sulfate sodium (DSS) induced colitis in previous study. In present study, C57BL/6J mice were free to drink 2.5% DSS solution to establish the colitis model. During the DSS treatment, mice were orally administrated with MSI once per day (75, 150, and 300 mg/kg, respectively). The results showed that MSI treatment ameliorated the depression and anxiety symptoms of colitis mice. Further mechanism studies indicated that MSI alleviated inflammatory response by adjusting cytokines TNF-α, IL-1β, IFN-γ, and IL-10, and proteins NLRP3/ASC/caspase-1 inflammasome), inhibited the activation of microglia, restored brain synaptic density, reduced oxidative stress (SOD, MDA) and regulated apoptosis (tunel staining, caspase-3). MSI could modulate depression-anxiety states by targeting inflammation, nerve tissue, oxidative stress and apoptosis. MSI administration could serve as an emerging blue food and nutrition strategy for the prevention of digestive tract inflammation and behavioral disorders.

Association of IFNA16 and TNFRSF19 Polymorphisms with Intramuscular Fat Content and Fatty Acid Composition in Pigs

Interferon-alpha-16 (IFNA16) and tumor necrosis factor receptor superfamily member 19 (TNFRSF19) are cytokines that may play a role in adipogenesis and fatness. Single nucleotide polymorphisms (SNPs) of the porcine IFNA16 and TNFRSF19 genes were verified and their association with intramuscular fat (IMF) content and fatty acid (FA) composition were evaluated in commercial crossbred pigs. Two non-synonymous SNPs of the porcine IFNA16 c.413G > A and TNFRSF19 c.860G > C loci were detected in commercial crossbred pigs. The porcine IFNA16 c.413G >A polymorphism was significantly associated with stearic acid, total saturated FAs (SFAs), and the ratio of monounsaturated FAs (MUFAs) to SFAs (p < 0.05). Furthermore, the porcine TNFRSF19 c.860G > C polymorphism was found to be significantly associated with IMF content and arachidic acid levels (p < 0.05). The results revealed that porcine IFNA16 and TNFRSF19 polymorphisms are related to IMF content and/or FA composition and affirmed the importance of these cytokine genes as potential candidate genes for lipid deposition and FA composition in the muscle tissue of pigs.

Findings from Studies Are Congruent with Obesity Having a Viral Origin, but What about Obesity-Related NAFLD?

Infection has recently started receiving greater attention as an unusual causative/inducing factor of obesity. Indeed, the biological plausibility of infectobesity includes direct roles of some viruses to reprogram host metabolism toward a more lipogenic and adipogenic status. Furthermore, the probability that humans may exchange microbiota components (virome/virobiota) points out that the altered response of IFN and other cytokines, which surfaces as a central mechanism for adipogenesis and obesity-associated immune suppression, is due to the fact that gut microbiota uphold intrinsic IFN signaling. Last but not least, the adaptation of both host immune and metabolic system under persistent viral infections play a central role in these phenomena. We hereby discuss the possible link between adenovirus and obesity-related nonalcoholic fatty liver disease (NAFLD). The mechanisms of adenovirus-36 (Ad-36) involvement in hepatic steatosis/NAFLD consist in reducing leptin gene expression and insulin sensitivity, augmenting glucose uptake, activating the lipogenic and pro-inflammatory pathways in adipose tissue, and increasing the level of macrophage chemoattractant protein-1, all of these ultimately leading to chronic inflammation and altered lipid metabolism. Moreover, by reducing leptin expression and secretion Ad-36 may have in turn an obesogenic effect through increased food intake or decreased energy expenditure via altered fat metabolism. Finally, Ad-36 is involved in upregulation of cAMP, phosphatidylinositol 3-kinase, and p38 signaling pathways, downregulation of Wnt10b expression, increased expression of CCAAT/enhancer binding protein-beta, and peroxisome proliferator-activated receptor gamma 2 with consequential lipid accumulation.

Flame Retardants-Mediated Interferon Signaling in the Pathogenesis of Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is a growing concern worldwide, affecting 25% of the global population. NAFLD is a multifactorial disease with a broad spectrum of pathology includes steatosis, which gradually progresses to a more severe condition such as nonalcoholic steatohepatitis (NASH), fibrosis, cirrhosis, and eventually leads to hepatic cancer. Several risk factors, including exposure to environmental toxicants, are involved in the development and progression of NAFLD. Environmental factors may promote the development and progression of NAFLD by various biological alterations, including mitochondrial dysfunction, reactive oxygen species production, nuclear receptors dysregulation, and interference in inflammatory and immune-mediated signaling. Moreover, environmental contaminants can influence immune responses by impairing the immune system’s components and, ultimately, disease susceptibility. Flame retardants (FRs) are anthropogenic chemicals or mixtures that are being used to inhibit or delay the spread of fire. FRs have been employed in several household and outdoor products; therefore, human exposure is unavoidable. In this review, we summarized the potential mechanisms of FRs-associated immune and inflammatory signaling and their possible contribution to the development and progression of NAFLD, with an emphasis on FRs-mediated interferon signaling. Knowledge gaps are identified, and emerging pharmacotherapeutic molecules targeting the immune and inflammatory signaling for NAFLD are also discussed.

Inflammation and fibrosis in chronic liver diseases including non-alcoholic fatty liver disease and hepatitis C

At present chronic liver disease (CLD), the third commonest cause of premature death in the United Kingdom is detected late, when interventions are ineffective, resulting in considerable morbidity and mortality. Injury to the liver, the largest solid organ in the body, leads to a cascade of inflammatory events. Chronic inflammation leads to the activation of hepatic stellate cells that undergo trans-differentiation to become myofibroblasts, the main extra-cellular matrix producing cells in the liver; over time increased extra-cellular matrix production results in the formation of liver fibrosis. Although fibrogenesis may be viewed as having evolved as a “wound healing” process that preserves tissue integrity, sustained chronic fibrosis can become pathogenic culminating in CLD, cirrhosis and its associated complications. As the reference standard for detecting liver fibrosis, liver biopsy, is invasive and has an associated morbidity, the diagnostic assessment of CLD by non-invasive testing is attractive. Accordingly, in this review the mechanisms by which liver inflammation and fibrosis develop in chronic liver diseases are explored to identify appropriate and meaningful diagnostic targets for clinical practice. Due to differing disease prevalence and treatment efficacy, disease specific diagnostic targets are required to optimally manage individual CLDs such as non-alcoholic fatty liver disease and chronic hepatitis C infection. To facilitate this, a review of the pathogenesis of both conditions is also conducted. Finally, the evidence for hepatic fibrosis regression and the mechanisms by which this occurs are discussed, including the current use of antifibrotic therapy.

Association of Serum Fibroblast Growth Factor 23 Levels with the Presence and Severity of Hepatic Steatosis Is Independent of Sleep Duration in Patients with Diabetes

PURPOSE

Fibroblast growth factor (FGF) 23 is currently recognized to be involved in the occurrence and development of metabolic diseases. The present study aimed to investigate the association between serum FGF23 levels and hepatic steatosis, as well as the influence of sleep duration.

PATIENTS AND METHODS

The present study population was selected from patients with diagnosed diabetes hospitalized during February 2018 to April 2019. Serum FGF23 levels were assessed by two-side sandwich enzyme-linked immunosorbent assay. The presence and severity of hepatic steatosis were determined by controlled attenuation parameter (CAP). Hepatic steatosis was determined as CAP≥302 dB/m.

RESULTS

Serum FGF23 levels were significantly higher in individuals with hepatic steatosis than in those without hepatic steatosis (P=0.004). The present study population was divided into Q1-Q4 according to serum FGF23 quartiles. The risks of hepatic steatosis were increased more than 3 folds in Q2-Q4 (all P<0.01) compared to Q1. CAP showed an uptrend from Q1 to Q4 (P=0.005), even after adjustment for gender and age (P=0.001). Multivariate variance analyses showed significant differences in CAP among Q1-Q4 (P=0.008) and between individuals with short and long sleep duration (P=0.023), which were independent of each other. Serum FGF23 levels were positively associated with CAP independent of gender, age, total metabolic traits, and sleep duration (P=0.042).

CONCLUSION

Serum FGF23 levels were independently and positively associated with the severity of hepatic steatosis. The associations of serum FGF23 levels and sleep duration with hepatic steatosis were independent of each other.

Nonalcoholic Fatty Liver Disease: A Challenge from Mechanisms to Therapy

Focusing on previously published mechanisms of non-alcoholic fatty liver disease (NAFLD), their uncertainty does not always permit a clear elucidation of the grassroot alterations that are at the basis of the wide-spread illness, and thus curing it is still a challenge. There is somehow exceptional progress, but many controversies persist in NAFLD research and clinical investigation. It is likely that hidden mechanisms will be brought to light in the near future. Hereby, the authors present, with some criticism, classical mechanisms that stand at the basis of NAFLD, and consider contextually different emerging processes. Without ascertaining these complex interactions, investigators have a long way left ahead before finding an effective therapy for NAFLD beyond diet and exercise.

Scutellaria baicalensis Alleviates Insulin Resistance in Diet-Induced Obese Mice by Modulating Inflammation

Insulin resistance is strongly associated with the metabolic syndrome, and chronic inflammation is known to be a major mechanism of insulin resistance and is a therapeutic target. This study was designed to evaluate the effect of Scutellaria baicalensis (SB) in high-fat diet (HFD)-induced insulin-resistant mice and to investigate its mechanism based on inflammatory responses. Mice were fed a HFD to induce insulin resistance and then administered SB for nine weeks. Body weight, glucose, lipid, insulin, epididymal fat pad and liver weights, and histologic characteristics were evaluated to determine the effect on insulin resistance. In order to evaluate the effects on the inflammatory process, we analyzed the proportions of macrophages in liver and epididymal fat and measured inflammatory gene expression. Fasting and postprandial glucose, fasting insulin, HOMA-IR, triglycerides, and low density lipoprotein cholesterol levels were significantly decreased by SB administration. The epididymal fat and liver showed significant weight decreases and histological improvements. Total adipose tissue macrophages (ATMs) decreased (27.71 ± 3.47% vs. 45.26 ± 7.26%, p < 0.05), M2 ATMs increased (47.02 ± 6.63% vs. 24.28 ± 8.00%, p < 0.05), and CD11b⁺ Kupffer cells decreased. The expression levels of tumor necrosis factor alpha and F4/80 in the liver were significantly decreased (12.03 ± 1.47% vs. 25.88 ± 4.57%, p < 0.05) compared to HFD group. These results suggest that SB improved insulin resistance through inhibition of macrophage-mediated inflammation.