Hepatic Inflammation In Mice Research Articles

Polysaccharide of Atractylodes macrocephala Koidz alleviates NAFLD-induced hepatic inflammation in mice by modulating the TLR4/MyD88/NF-κB pathway

Non-alcoholic fatty liver disease (NAFLD) not only could cause abnormal lipid metabolism in the liver, but also could cause liver inflammation. Previous studies have shown that Polysaccharide of Atractylodes macrocephala Koidz (PAMK) could alleviate animal liver inflammatory damage and alleviate NAFLD in mice caused by high-fat diet(HFD), but regulation of liver inflammation caused by NAFLD has rarely been reported. In this study, an animal model of non-alcoholic fatty liver inflammation in the liver of mice was established to explore the protective effect of PAMK on the liver of mice. The results showed that PAMK could alleviate the abnormal increase of body weight and liver weight of mice caused by HFD, alleviate the abnormal liver structure of mice, reduce the level of oxidative stress and cytokine secretion in the liver of mice, and downregulate the mRNA expression of TLR4, MyD88, NF-κB and protein expression of P-IκB, P-NF-κB-P65, TLR4, MyD88, NF-κB in the liver. These results indicate that PAMK could alleviate hepatocyte fatty degeneration and damage, oxidative stress and inflammatory response of the liver caused by NAFLD in mice.

Inhibiting CD44-ICD Attenuates LPS-Induced Initiation of Hepatic Inflammation in Septic Mice.

Sepsis is a severe condition induced by microbial infection. It elicits a systemic inflammatory response, leading to multi-organ failure, and the liver, as a scavenger, plays a significant role in this process. Controlling hepatic inflammation and maintaining liver function is crucial in managing sepsis. CD44-ICD, as a CD44 signal transductor, is involved in multiple inflammatory responses. However, the role of CD44-ICD in lipopolysaccharide (LPS)-induced hepatic inflammation has not been investigated. Therefore, we aimed to examine whether CD44-ICD initiates hepatic inflammation in septic mice. We induced hepatic inflammation in mice by administering LPS. DAPT, a CD44-ICD inhibitor, was given to mice or Chang cells 30 min or 1 h before LPS administration (10 mg/kg, i.p., or 100 ng/mL, respectively). Inhibition of CD44-ICD decreased the level of aspartate aminotransferase (AST), alanine aminotransferase (ALT), hepatic necrosis, inflammatory cell infiltration, interleukin (IL)-1β, inducible NO synthase (iNOS), nitric oxide (NO) production, nuclear factor (NF)κB signaling pathway proteins, and CD44 expression in mice. CD44-ICD inhibition also decreased IL-1β and CD44 expression levels in Chang cells. CD44-ICD may be a primary regulatory function in CD44-associated LPS-induced initiation of hepatic inflammation in mice.

A bioactive compound digested chia protein is capable of modulating NFκB mediated hepatic inflammation in mice fed a high-fat diet

The consumption of diets high in saturated fat can induce damages in liver morphology and function, which leads to increased inflammation, oxidative stress, and hepatic steatosis. Chia seed (Salvia hispanica L.) is rich in protein, which provides bioactive peptides with potential benefits, including antioxidant and anti-inflammatory functions. Then, this study aimed to analyze the effect of digested total protein (DTP) of chia on inflammation, oxidative stress, and morphological changes in liver of C57BL/6 mice fed a diet rich in saturated fat. Male C57BL/6 mice (n = 8/group), 8 weeks old, were fed standard diet (AIN), high-fat diet (HF), standard diet added digested protein (AIN + DTP) or high-fat diet added digested protein (HF + DTP) for 8 weeks. In animals fed a high-fat diet, chia DTP was able to reduce weight gain, food efficiency ratio and hepatosomatic index. In addition, it presented antioxidant capacity, which reduced catalase activity and lipid peroxidation. DTP was also able to reduce hepatic inflammation by reducing p65-NFκB expression and IL-1β expression and quantification. The APSPPVLGPP peptide present in chia DTP presented binding capacity with PPAR-α, which contributed to the reduction of hepatic fat accumulation evidenced by histological analysis. Thus, chia DTP improved hepatic inflammatory and histological parameters, being an effective food in reducing the liver damage caused by a high-fat diet.

1574-P: FoxO1 Links Insulin Resistance to Hepatic Inflammation and Catalyzes the Evolution of Benign Steatosis to Nonalcoholic Steatohepatitis

Hepatic inflammation is intertwined with insulin resistance and is a causative factor for the transition of benign steatosis to nonalcoholic steatohepatitis (NASH). We found that FoxO1 was markedly upregulated in hepatic macrophages, coinciding with hepatic inflammation and steatosis in dietary obese mice. We generated myeloid-conditional FoxO1-transgenic and FoxO1-knockout mice, two complementary models for determining the effect of FoxO1 gain- vs. loss-of-function on macrophage activation in response to insulin resistance. We found that myeloid FoxO1 gain-of-function aggravated hepatic inflammation in mice in response to overnutrition or endotoxin. In contrast, myeloid FoxO1 loss-of-function skewed macrophage polarization from pro-inflammatory M1 to anti-inflammatory M2 phenotypes, accompanied by the reduction of macrophage infiltration in liver. This effect contributed to the suppression of hepatic inflammation and improvement of insulin sensitivity. Despite fat-induced obesity, myeloid-conditional FoxO1-deficient mice were protected from developing hyperglycemia, hyperinsulinemia and glucose intolerance. Furthermore, the improvement in hepatic inflammation and insulin resistance translated into a significant beneficial effect on NASH, culminating in the reduction of hepatic steatosis and fibrosis in myeloid FoxO1-deficient mice on NASH-inducing diet. Human FOXO1 expression was upregulated in inflammatory macrophages in liver, correlating with hepatic inflammation, steatosis and fibrosis in patients with NASH. Mechanistically, FoxO1 counteracts Stat6 to skew macrophage polarization from M2 toward M1 signatures with pro-inflammatory profiles. We concluded that myeloid FoxO1 dysregulation is culpable for linking insulin resistance to abnormal macrophage activation. This effect perpetuates hepatic inflammation and catalyzes the evolution of simple steatosis to NASH. Disclosure S.Lee: None. T.Usman: None. G.Chhetri: None. X.Wang: None. H.Dong: None.

The Presence of Periodontitis Exacerbates Non-Alcoholic Fatty Liver Disease via Sphingolipid Metabolism-Associated Insulin Resistance and Hepatic Inflammation in Mice with Metabolic Syndrome.

Clinical studies have shown that periodontitis is associated with non-alcoholic fatty liver disease (NAFLD). However, it remains unclear if periodontitis contributes to the progression of NAFLD. In this study, we generated a mouse model with high-fat diet (HFD)-induced metabolic syndrome (MetS) and NAFLD and oral P. gingivalis inoculation-induced periodontitis. Results showed that the presence of periodontitis increased insulin resistance and hepatic inflammation and exacerbated the progression of NAFLD. To determine the role of sphingolipid metabolism in the association between NAFLD and periodontitis, we also treated mice with imipramine, an inhibitor of acid sphingomyelinase (ASMase), and demonstrated that imipramine treatment significantly alleviated insulin resistance and hepatic inflammation, and improved NAFLD. Studies performed in vitro showed that lipopolysaccharide (LPS) and palmitic acid (PA), a major saturated fatty acid associated with MetS and NAFLD, synergistically increased the production of ceramide, a bioactive sphingolipid involved in NAFLD progression in macrophages but imipramine effectively reversed the ceramide production stimulated by LPS and PA. Taken together, this study showed for the first time that the presence of periodontitis contributed to the progression of NAFLD, likely due to alterations in sphingolipid metabolism that led to exacerbated insulin resistance and hepatic inflammation. This study also showed that targeting ASMase with imipramine improves NAFLD by reducing insulin resistance and hepatic inflammation.

비알코올성 지방간에서 지질대사와 간 염증에 대한 fenofibrate와 수영운동 조합의 유익한 효과

The study analyzed the effects of combination of fenofibrate and swimming exercise on the improvement of fatty liver and hepatic inflammation in mice with non-alcoholic fatty liver by consuming a high-fat diet. High-fat diet fed male mice were divided into high-fat diet (H), high-fat diet+fenofibrate (H/F), high-fat diet+swimming exercise (H/Ex), and high-fat diet+ fenofibrate+swimming exercise (H/F/Ex) and raised for 8 weeks. Compared to H, H/F and H/Ex decreased body weight, adipose tissue weight, hepatic lipid accumulation, and serum ALT and AST. H/F/Ex reduced these factors more effectively than H/F. The expression of the fatty acid β-oxidation and inflammatory cytokine genes in liver was decreased in both H/F and H/Ex compared to H. In particular, the expression of these genes in H/F/Ex was further decreased compared to H/F. Thus, this suggests that the combination of fenofibrate and swimming exercise is more effective lipid metabolism and liver inflammation improvement than fenofibrate alone in non-alcoholic fatty liver.

Red yeast rice ameliorates non-alcoholic fatty liver disease through inhibiting lipid synthesis and NF-\u03baB/NLRP3 inflammasome-mediated hepatic inflammation in mice

BackgroundRed yeast rice (RYR), a nutraceutical with a profound cholesterol-lowering effect, was found to attenuate non-alcoholic fatty liver disease (NAFLD) in mice. Despite monacolin K in RYR being a specific inhibitor of hydroxymethylglutaryl-coenzyme A reductase (HMCGR), the mechanisms underlying the protective effects of RYR against NAFLD are not fully elucidated.MethodsUsing a mouse model of high-fat diet (HFD) feeding and a cellular model of HepG2 cells challenged by lipopolysaccharide (LPS) and palmitic acid (PA), the possible molecular mechanisms were exploited in the aspects of NF-κB/NLRP3 inflammasome and mTORC1-SREBPs signaling pathways by examining the relevant gene/protein expressions. Subsequently, the correlation between these two signals was also verified using cellular experiments.ResultsRYR ameliorated lipid accumulation and hepatic inflammation in vivo and in vitro. RYR improved lipid metabolism through modulating mTORC1-SREBPs and their target genes related to triglyceride and cholesterol synthesis. Furthermore, RYR suppressed hepatic inflammation by inhibiting the NF-κB/NLRP3 inflammasome signaling. Interestingly, the treatment with RYR or MCC950, a specific NLRP3 inhibitor, resulted in the reduced lipid accumulation in HepG2 cells challenged by LPS plus PA, suggesting that the inhibitory effects of RYR on NLRP3 inflammasome-mediated hepatic inflammation may partially, in turn, contribute to the lipid-lowering effect of RYR.ConclusionsThe modulation of NF-κB/NLRP3 inflammasome and lipid synthesis may contribute to the ameliorative effects of RYR against HFD-induced NAFLD.

A novel therapeutic approach to NASH: Both polyethylene glycol 3350 and lactulose reduce hepatic inflammation in C57BL/6J mice.

The gut-liver axis is one of the most emphasized topics in the pathogenesis of non-alcoholic fatty liver disease (NAFLD). Intestinal microbiota dysbiosis has been shown to be a predictor of disease severity and progression to fatty liver disease. Therefore, research addressing gut-based therapies has become popular. To investigate the effect of lactulose and polyethylene glycol 3350 (PEG 3350) in mice with induced obesity and NAFLD at a non-diarrheal dose. Thirty-six C57BL/6J male mice were divided into 6 groups. The first 2 groups (n = 6 each) were used as an induced obesity model (group A) and NAFLD model (group B) for 8 weeks. The remaining 24 animals were categorized into control diet group, high-fat diet (HFD) group, HFD + lactulose group, and HFD + PEG 3350 group. Serum and liver tissue samples were obtained for biochemical and histopathological analyses, respectively. The HFD + lactulose treatment group displayed a significant decrease in liver weight (1.3 (1.3-1.4) kg compared to 1.8 (1.6-1.9) kg) and NAFLD activity score (NAS) (1.5 (1.0-3.0) compared to 5.0 (4.0-5.0), respectively; p = 0.0043, p = 0.0021) when compared with the HFD group. However, a decrease in body weight (35.0 (34.6-36.0) kg compared to 40.9 (34.7-41.9) kg) and hepatosteatosis (HS) rate (33.3% compared to 100.0%) were not statistically significant (p = 0.1796, p = 0.0606, respectively). The HFD + PEG 3350 treatment group showed a statistically significant decrease in body weight (32.4 (30.2-33.9) kg compared to 40.9 (34.7-41.9) kg), liver weight (1.5 (1.3-1.5) kg compared to 1.8 (1.6-1.9) kg), HS rate (16.7% compared to 100.0%) and NAS (0.5 (0.0-1.0) compared to 5.0 (4.0-5.0); p = 0.0086, p = 0.0086, p = 0.0151, and p = 0.0021, respectively) when compared with the HFD group. We demonstrated that non-diarrheal dose of lactulose and PEG 3350 reduced hepatic inflammation in mice with induced NAFLD. It was also observed that PEG 3350 decreased HS and body weight. We believe these mechanisms can be utilized as novel therapeutic approaches in NAFLD in prospective human studies.

Leukocyte-Derived High-Mobility Group Box 1 Governs Hepatic Immune Responses to Listeria monocytogenes.

High‐mobility group box 1 (HMGB1) is a nucleoprotein with proinflammatory functions following cellular release during tissue damage. Moreover, antibody‐mediated HMGB1 neutralization alleviates lipopolysaccharide (LPS)‐induced shock, suggesting a role for HMGB1 as a superordinate therapeutic target for inflammatory and infectious diseases. Recent genetic studies have indicated cell‐intrinsic functions of HMGB1 in phagocytes as critical elements of immune responses to infections, yet the role of extracellular HMGB1 signaling in this context remains elusive. We performed antibody‐mediated and genetic HMGB1 deletion studies accompanied by in vitro experiments to discern context‐dependent cellular sources and functions of extracellular HMGB1 during murine bloodstream infection with Listeria monocytogenes. Antibody‐mediated neutralization of extracellular HMGB1 favors bacterial dissemination and hepatic inflammation in mice. Hepatocyte HMGB1, a key driver of postnecrotic inflammation in the liver, does not affect Listeria‐induced inflammation or mortality. While we confirm that leukocyte HMGB1 deficiency effectuates disseminated listeriosis, we observed no evidence of dysfunctional autophagy, xenophagy, intracellular bacterial degradation, or inflammatory gene induction in primary HMGB1‐deficient phagocytes or altered immune responses to LPS administration. Instead, we demonstrate that mice devoid of leukocyte HMGB1 exhibit impaired hepatic recruitment of inflammatory monocytes early during listeriosis, resulting in alterations of the transcriptional hepatic immune response and insufficient control of bacterial dissemination. Bone marrow chimera indicate that HMGB1 from both liver‐resident and circulating immune cells contributes to effective pathogen control. Conclusion: Leukocyte‐derived extracellular HMGB1 is a critical cofactor in the immunologic control of bloodstream listeriosis. HMGB1 neutralization strategies preclude an efficient host immune response against Listeria.

Hepatoprotective Effects of Indole, a Gut Microbial Metabolite, in Leptin-Deficient Obese Mice.

ABSTRACTBackgroundThe gut microbiota plays a role in the occurrence of nonalcoholic fatty liver disease (NAFLD), notably through the production of bioactive metabolites. Indole, a bacterial metabolite of tryptophan, has been proposed as a pivotal metabolite modulating inflammation, metabolism, and behavior.ObjectivesThe aim of our study was to mimic an upregulation of intestinal bacterial indole production and to evaluate its potential effect in vivo in 2 models of NAFLD.MethodsEight-week-old leptin-deficient male ob/ob compared with control ob/+ mice (experiment 1), and 4–5-wk-old C57BL/6JRj male mice fed a low-fat (LF, 10 kJ%) compared with a high-fat (HF, 60 kJ%) diet (experiment 2), were given plain water or water supplemented with a physiological dose of indole (0.5 mM, n ≥6/group) for 3 wk and 3 d, respectively. The effect of the treatments on the liver, intestine, adipose tissue, brain, and behavior was assessed.ResultsIndole reduced hepatic expression of genes involved in inflammation [C-C motif chemokine ligand 2 (Ccl2), C-X-C motif chemokine ligand 2 (Cxcl2); 3.3- compared with 5.0-fold, and 2.4- compared with 3.3-fold of control ob/+ mice, respectively, P < 0.05], and in macrophage activation [Cd68, integrin subunit α X (Itgax); 2.1- compared with 2.5-fold, and 5.0- compared with 6.4-fold of control ob/+ mice, respectively, P < 0.01] as well as markers of hepatic damage (alaninine aminotransferase; −32%, P < 0.001) regardless of genotype in experiment 1. Indole had no effect on hepatic inflammation in mice fed the LF or HF diet in experiment 2. Indole did not change hepatic lipid content, anxiety-like behavior, or inflammation in the ileum, adipose tissue, and brain in experiment 1.ConclusionsOur results support the efficacy of indole to reduce hepatic damage and associated inflammatory response and macrophage activation in ob/ob mice. These modifications appear to be attributable to direct effects of indole on the liver, rather than through effects on the adipose tissue or intestinal barrier.

Essential Role of IFN-γ in Regulating Gut Antimicrobial Peptides and Microbiota to Protect Against Alcohol-Induced Bacterial Translocation and Hepatic Inflammation in Mice.

The mechanisms by which alcohol provokes bacterial translocation in the development of alcoholic liver disease (ALD) remain incompletely defined. Our previous study demonstrates that impaired gut epithelial antimicrobial defense is critically involved in the pathogenesis of ALD. The study was set to determine the mechanisms of how alcohol inhibits the antimicrobial ability of intestinal epithelial cells (IECs) and to explore possible solutions to this issue. C57BL/6J mice were fed either alcohol or isocaloric dextrin liquid diet for 8 weeks, and intestinal IFN-γ-signal transducer and activator of transcription (STAT) signaling was analyzed. We found that chronic alcohol exposure led to a significant reduction in intestinal IFN-γ levels compared to a control; the protein levels of phosphorylated STAT1 (p-STAT1) and p-STAT3 were both declined by alcohol. We then tested the effects of IFN-γ-STAT signaling on regulating antimicrobial peptides (AMPs), gut microbiota, and disease progression of ALD in a mouse model of chronic alcohol feeding, time-course acute IFN-γ treatment, and in vivo and in vitro IEC-specific STAT1 or STAT3 knockout mouse models, respectively. Administration of IFN-γ activated intestinal STAT1 and STAT3, upregulated the expression of Reg3 and α-defensins, orchestrated gut microbiota, and reversed alcohol-induced intestinal ZO-1 disruption and systemic endotoxin elevation as well as hepatic inflammation. Meanwhile, acute IFN-γ treatment time-dependently induced AMP expression and α-defensin activation. We then dissected the roles of STAT1 and STAT3 in this progress. Lack of IEC-specific STAT3 inhibited IFN-γ-induced expression of Reg3 and α-defensins and hindered activation of α-defensins via inactivating matrix metallopeptidase 7 (MMP7), whereas lack of IEC-specific STAT1 impaired IFN-γ-stimulated expression of α-defensins and the IEC marker, sodium-hydrogen exchanger 3. Lastly, we found that interleukin (IL)-18, a known IFN-γ inducer, was also reduced by alcohol in mice. IL-18 treatment to alcohol-fed mice normalized gut IFN-γ levels and ameliorated organ damages in both the intestine and liver. Taken together, the study reveals that IFN-γ is critically involved in the regulation of AMPs through regulation of STAT1 and STAT3; impaired IFN-γ-STAT signaling provides an explanation for alcohol-induced gut antimicrobial dysfunction and microbial dysbiosis. Therefore, IFN-γ remains a promising host defense-enhancing cytokine with unexplored clinical potential in ALD therapy.

Gigantol ameliorates CCl4-induced liver injury via preventing activation of JNK/cPLA2/12-LOX inflammatory pathway

Arachidonic acid (AA) signaling pathway is an important constituent of inflammatory processes. In our previous study, it was found that dihydro-stilbene gigantol relieved hepatic inflammation in mice with CCl4-induced acute liver injury. This study aimed to investigate the involvement of arachidonate metabolic cascade in this process. Our results showed CCl4 activated AA metabolism with the evidence of cPLA2 phosphorylation, which was dependent on the MAPK/JNK activation. Pretreatment with JNK inhibitor SU3327 or gigantol abolished the cPLA2 activation, along with the attenuation of liver damage. Besides, gigantol markedly decreased immune cells activation. Metabolomic analysis revealed that gigantol universally reversed the upregulation of major AA metabolites in injured mouse livers induced by CCl4, especially 12-hydroxyeicosatetraenoic acid (12-HETE). Gigantol also decreased the mRNA and protein expression of platelet-, and leukocyte-type 12-lipoxxygenase (LOX) in the liver. Furthermore, pan-LOX inhibitor nordihydroguaiaretic acid (NDGA) and specific 12-LOX inhibitors baicalein and ML351 attenuated the liver injury to the same extent as gigantol. Overall, our study elucidated a comprehensive profile of AA metabolites during hepatic inflammation caused by CCl4, highlighting the role of 12-LOX-12-HETE pathway in this process. And gigantol alleviated liver inflammation partly through inhibiting the JNK/cPLA2/12-LOX pathway.

Oral Exposure to 1,4-Dioxane Induces Hepatic Inflammation in Mice: The Potential Promoting Effect of the Gut Microbiome.

1,4-Dioxane is a widely used industrial solvent that has been frequently detected in aquatic environments. However, the hepatotoxicity of long-term dioxane exposure at environmentally relevant concentrations and underlying mechanisms of liver damage remain unclear. In this study, male mice were exposed to dioxane at concentrations of 0.5, 5, 50, and 500 ppm for 12 weeks, followed by histopathological examination of liver sections and multiomics investigation of the hepatic transcriptome, serum metabolome, and gut microbiome. Results showed that dioxane exposure at environmentally relevant concentrations induced hepatic inflammation and caused changes in the hepatic transcriptome and serum metabolic profiles. However, no inflammatory response was observed after in vitro exposure to all concentrations of dioxane and its in vivo metabolites. The gut microbiome was considered to be contributing to this apparently contradictory response. Increased levels of lipopolysaccharide (LPS) may be produced by some gut microbiota, such as Porphyromonadaceae and Helicobacteraceae, after in vivo 500 ppm of dioxane exposure. LPS may enter the blood circulation through an impaired intestinal wall and aggravate hepatic inflammation in mice. This study provides novel insight into the underlying mechanisms of hepatic inflammation induced by dioxane and highlights the need for concerns about environmentally relevant concentrations of dioxane exposure.

Berbamine ameliorates ethanol-induced liver injury by inhibition of hepatic inflammation in mice.

Alcoholic liver disease (ALD) has become one of the leading causes of death in the world. Berbamine (BM), a natural product mainly derived from Berberis vulgaris L, possesses multiple bioactivities as a traditional medicine. However, the protective effect of BM on ALD remains unknown. In this study, we investigated the effect of BM on ethanol-induced hepatic injury in mice and its underlying mechanism. It was shown that BM at 0.3125-40 μmol·L-1had no effect on macrophages and hepatocytes proliferation. BM at 5-20 μmol·L-1 significantly inhibited lipopolysaccharide (LPS) or acetate-induced IL-1β and IL-6 mRNA expression in RAW264.7 cells. Moreover, BM treatment significantly inhibited LPS-induced p65 and STAT3 phosphorylation in RAW264.7 cells. Hepatic histopathology analysis showed that inflammatory cells infiltration and lipid accumulation were suppressed by 25 and 50 mg·kg-1 BM administration in ethanol-induced hepatic injury mouse model. Meanwhile, BM treatment significantly inhibited serum ALT and AST levels in ethanol-fed mice. Oil red O staining results showed that BM administration ameliorated hepatic lipid accumulation in ethanol-fed mice. Preventions of ethanol-induced hepatic injury by BM were reflected by markedly decreased serum and hepatic triglyceride (TG) and total cholesterol (TC) contents. Real-time PCR results showed that BM treatment significantly inhibited pro-inflammatory cytokines mRNA expression in ethanol-fed mouse liver. Remarkably, the mechanism of action of BM was related to the reduction of ethanol-induced NF-κB and STAT3 phosphorylation levels in liver. In addition, BM treatment significantly inhibited ERK phosphorylation but not JNK and p38 of MAPK pathway. Taken together, our results demonstrate a beneficial effect of BM on ethanol-induced liver injury via a mechanism associated with inactivation of NF-κB, STAT3 and ERK pathway, which gives insight into the further evaluation of the therapeutic potential of BM for ALD.

Polyphenolic extracts from Wushan tea leaves attenuate hepatic injury in CCl4-treated mice

The polyphenol extracts from Wushan tea leaves (WST-PE) attenuate CCl 4 -induced liver damage by enhancing the levels of antioxidant indicators and inactivating NF-κB signaling-mediated inflammation. Solid red arrow represents the changes induced by CCl 4 . Green dotted arrow represents the changes induced by CCl 4 + WST-PE treatment. • WST-PE consisted mainly of flavonoids, flavanones and flavonols. • WST-PE protected CCl 4 -treated mice from liver damage. • WST-PE improved the antioxidant ability of CCl 4 -intoxicated mice. • WST-PE suppressed NF-κB signaling-mediated inflammation induced by CCl 4 . The current study aimed to investigate the protective effects of polyphenolic extracts from Wushan tea leaves (WST-PE) on the liver of Kunming mice subjected to CCl 4 . Flavonoids, flavanones, and flavonols were major components of WST-PE that improved the elevation in serum AST and ALT and reduced the liver coefficient and pathological change in mice treated with CCl 4 . The CCl 4 -induced increase in MDA and decrease in antioxidases (SOD, CAT, and GSH-Px) were reversed by WST-PE. In mice treated with WST-PE, the mRNA expression levels of hepatic SOD1, SOD2, CAT, and GSH-Px increased, whereas the serum concentrations of IL-6, IL-1β, IFN-γ, and TNF-α decreased relative to those in the CCl 4 -treated mice. WST-PE reduced hepatic inflammation in mice by enhancing the protein expression of IκBα and suppressing the expression of NF-κB, COX-2, and iNOS. The hepatoprotective effects of WST-PE were partly attributed to the improvement of anti-oxidation and suppression of NF-κB signaling-mediated inflammation.

Unique cellular interaction of macrophage-targeted liposomes potentiates anti-inflammatory activity.

Nanomedicines that suppress macrophage-mediated chronic inflammation are important therapeutics for many inflammatory diseases. The small-sized (<100 nm) apoptotic-cell-mimetic macrophage-targeted liposomes served as a long-lasting immunosuppressive agent through preferential association with CD300a receptor, unlike larger liposomes, enabling the amelioration of hepatic inflammation in mice.

Oral Administration of Hoodia parviflora Alleviates Insulin Resistance and Nonalcoholic Steatohepatitis.

Metabolic syndrome is recognized as a proinflammatory condition leading to hepatic steatosis and nonalcoholic steatohepatitis (NASH). We tested the effects of a succulent species Hoodia parviflora N.E. Br., of the genus Hoodia sweetex Dence, on animal models of NASH and insulin resistance (ob/ob mouse and the sand rat Psammomys obesus). IL6 secretion was evaluated by ELISA and hepatic signal transducer and activator of transcription 3 by Western blot. We followed liver enzymes, weight, glucose, hepatic histology, hepatic triglycerides (TGs), and total fat and serum insulin. Oral administration of extracts derived from H. parviflora alleviated the insulin resistance manifested by improved glucose tolerance tests. Treatment alleviated the liver injury noted by a decrease in liver enzyme levels, improved intrahepatic TG content, total hepatic fat, and improved hepatic histology. Similarly, treatment with H. parviflora reduced hepatic inflammation in mice with Concanavalin A-induced hepatitis. These effects were independent of food consumption and weight. H. parviflora was associated with alleviated insulin resistance, hepatic steatosis, and liver injury. The data support its use as a liver protector.

Regulatory Effects of Stachyose on Colonic and Hepatic Inflammation, Gut Microbiota Dysbiosis, and Peripheral CD4+ T Cell Distribution Abnormality in High-Fat Diet-Fed Mice.

A long-term high-fat diet (HFD) can cause a range of health problems. Gut microbiota plays a decisive role in the development of HFD-associated inflammation, involved in function of T cells. This study was designed to probe the regulative effects of dietary stachyose, a functional oligosaccharide, on HFD-induced weight gain, inflammation, gut microbiota dysbiosis, and T cell abnormality in C57Bl/6 mice. Mice were divided into three groups which received normal chow, HFD and HFD plus stachyose (400 mg/kg), respectively. Results showed that administration of stachyose diminished the HFD-induced upregulation of serum TNF-α level and elevation of peripheral blood leukocyte populations to alleviate the HFD-caused colonic and hepatic inflammation in mice. Analysis of gut microbiota revealed that stachyose improved the intestinal homeostasis of HFD-fed mice by improving the bacterial diversity with the increases in the relative abundances of the Prevotellaceae_NK3B31_group, Parasutterella, Christensenellaceae_R-7_group, and Anaerovorax, as well as the fecal level of butanoic acid, while decreasing the ratio of Firmicutes-to-Bacteroidetes and the abundances of the Lachnospiraceae_NK4A136_group, Desulfovibrio, Anaerotruncus, Mucispirillum, Roseburia, and Odoribacter. Flow cytometric analysis showed that stachyose antagonized the HFD-induced decrease of peripheral CD4+ T cell population in mice. Conclusively, these findings suggest that long-term consumption of stachyose can ameliorate the HFD-associated colonic and hepatic inflammation and its complications by modulating gut microbiota.

Advanced Liver Steatosis Accompanies an Increase in the Level of Colonic Pro-inflammatory Bile Acids and Hepatic Inflammation in C57BL/6 Mice Fed a High-fat Diet (P15-027-19)

ObjectivesThe gut-liver axis is implicated in the pathogenesis of liver diseases; however, the mechanistic link between the gut and fatty liver disease severity remains to be characterized. We tested the hypothesis that advanced liver-steatosis accompanies an increase in the concentrations of colonic proinflammatory bile acids and hepatic inflammation in mice fed a high fat (HF) diet. MethodsFour-week-old male C57BL/6 mice (n = 14/group) were fed a HF (45% energy fat) or a low-fat (LF) (10% energy fat) diet for 21 wks. We used biochemical, immunohistological, gas & liquid chromatography with mass spectrometry, RNA sequencing and real-time PCR methods to examine the level of colonic proinflammatory bile acids and hepatic inflammation. ResultsAt the end of the study, body weight and body fat percentage in the HF group were 0.23- and 0.41- fold greater than the LF group, respectively. Compared with the LF group, the HF group exhibited an increase in hepatic lipid droplets, inflammatory cell infiltration, inducible nitric oxide synthase, and hepatocellular ballooning cells (without hepatic Mallory bodies) which are key histological features of advanced hepatic steatosis. Furthermore, nicotinamide n-methyltransferase and selenoprotein P, two hepatic proinflammation-related genes, were upregulated in the HF group. With unique colonic bile acid profiles, the levels of colonic hydrophobic (secondary) bile acids (lithocholic acids and deoxycholic acids) were at least 0.5- fold greater in the HF group compared with the LF group. It is known that these hydrophobic bile acids induce proinflammatory cytokine production (TNF-α and IL-6) in the colon, and exacerbate hepatic inflammation via portal venous circulation. This potential colon-liver axis is consistent with results that the plasma concentrations of TNF-α and IL-6 were 0.5-fold greater in the HF group compared the LF group. ConclusionsOur results demonstrate that advanced liver-steatosis accompanies an increase in colonic proinflammatory bile acid levels and hepatic inflammation, which suggests a cross-talk between colon and liver in mice fed a HF diet. Funding SourcesThis work was funded by the US Department of Agriculture, Agricultural Research Service, CRIS project 3062-51000-050-00D.

The immunoregulatory effects of CD8 T-cell-derived perforin on diet-induced nonalcoholic steatohepatitis.

The liver is a central immunologic organ with a high density of myeloid and lymphoid immune cells that play important roles in the development and progression of nonalcoholic steatohepatitis (NASH). However, the immune-cell-mediated regulation of NASH and its underlying mechanisms remain obscure. In this study, Prf1null mice showed significantly higher plasma alanine transaminase levels, with increased liver fat accumulation, lobular inflammation, and focal necrosis compared with wild-type (WT) mice after 4 wk of feeding on a methionine- and choline-deficient diet (MCD) or 16 wk of feeding on a high-fat diet. Perforin deficiency promoted the M1 polarization of infiltrated monocytes. Moreover, MCD-fed Prf1null mice exhibited increased accumulation, survival, activation, and proinflammatory cytokine production of CD8 T cells but not NK cells or CD4 T cells. Adoptive transfer of CD8 T cells or NK cells from WT or Prf1null mice, together with non-CD8 cells or non-NK cells from WT mice, indicated that CD8 T-cell-derived perforin participates in the mechanism regulating liver inflammation and thus plays a protective role in the development of NASH. Perforin-deficient CD8 T cells exhibited decreased cytotoxicity toward bone marrow-derived M1 monocytes and macrophages. According to the RNA sequencing data, the perforin deficiency inhibited cell apoptosis and enhanced the activation, migration, and proinflammatory cytokine production of CD8 T cells in mice with NASH. Furthermore, we found higher plasma soluble perforin levels and hepatic perforin expression in NASH patients, suggesting clinical relevance of the findings. We have elucidated an important role for the cytotoxic immune effector molecule perforin from CD8 T cells in restricting hepatic inflammation in mice with NASH and suggest that therapies designed to maximize the function of endogenous perforin in CD8 T cells might have potential benefits as NASH treatments.-Wang, T., Sun, G., Wang, Y., Li, S., Zhao, X., Zhang, C., Jin, H., Tian, D., Liu, K., Shi, W., Tian, Y., Zhang, D. The immunoregulatory effects of CD8 T-cell-derived perforin on diet-induced nonalcoholic steatohepatitis.