Toll-like receptors in pathophysiology of liver diseases

Affinity-purified targets screening facilitates active components discovery of Chinese formula -HuGan tablets as a case

ETHNOPHARMACOLOGICAL RELEVANCE

Alcoholic Liver Disease (ALD), a chronic condition caused by long-term heavy alcohol consumption, can progress to cirrhosis or liver failure. HuGan Tablets (HGT) is a compound preparation made of six Chinese herbs, which is used in clinic for the treatment of chronic hepatitis, with studies demonstrating its efficacy in alleviating alcohol-induced liver injury in rats. However, the active components and therapeutic targets of HGT remain unclear and require further investigation.

AIM OF THIS STUDY

The aim of this study was to develop a systematic pipeline based on the SPR fishing strategy to identify effective components and therapeutic targets in Chinese formulas, using HGT as a representative case.

MATERIALS AND METHODS

HRMS was employed to analyze HGT ingredients absorbed in rat blood, while network pharmacology, molecular docking and literature mining were utilized to identify potential targets of HGT for ALD alleviation. A systematic SPR-based fishing system was developed by evaluating protein target coupling efficiency, sample recovery rate, specificity of target-small molecule binding, and LOD, and candidate components screened and identified using this system were further screened by SPR affinity tests. Additionally, therapeutic efficacy of the selected compounds was validated in vitro using an ethanol-induced AML12 model and further confirmed in vivo using a mouse model of ALD by assessing markers such as ALT, AST, and oxidative stress indicators.

RESULTS

A total of 128 compounds were identified in HGT, with 29 metabolites detected in rat blood. MFN2, SOD2, mTOR, RXRA, and GSTP1 were identified as anti-ALD targets of HGT through integrated network pharmacology, molecular docking, and literature analysis. An SPR-based active component fishing system was successfully developed, capturing 15 candidate compounds. SPR affinity analysis revealed strong binding (KD: 3.41-221.7 μM) between (R,S)-goitrin, chlorogenic acid, saikosaponin B2, schisandrin, schisandrol B, schisandrin A, schisandrin C, and schisantherin A and the target proteins. Except for (R,S)-goitrin, the other seven compounds significantly reduced ALT, AST, TG, ROS, and MDA levels while enhancing SOD and GSH activities in cellular models, with comparable therapeutic effects observed in ALD mice.

CONCLUSION

This study scientifically established an integrated SPR-based pipeline to systematically characterize active ingredients and therapeutic targets in herbal formulations, which was successfully applied to reveal key therapeutic targets and pharmacodynamic components of HGT for ALD. This study provides a valuable framework for SPR-based screening of bioactive components in traditional formulas, as well as for understanding the material basis and mechanism of action of HGT in the treatment of ALD.

SPP1 + macrophages cause exhaustion of tumor-specific T cells in liver metastases

Functional tumor-specific CD8+ T cells are essential for effective anti-tumor immune response and immune checkpoint inhibitor therapy. Here we show that, compared to other organ sites, primary, metastatic liver tumors in murine models contain a higher number of tumor-specific CD8+ T cells which are also dysfunctional. High-dimensional, multi-omic analysis of patient samples reveals a higher frequency of exhausted tumor-reactive CD8+ T cells and enriched interactions between these cells and SPP1+ macrophages in profibrotic, alpha-SMA rich regions specifically in the liver. Differential pseudotime trajectory inference analysis reveals that extrahepatic signaling promotes an intermediate cell (IC) population in the liver, characterized by co-expression of VISG4, CSF1R, CD163, TGF-βR, IL-6R, and SPP1. Analysis of premetastatic adenocarcinoma patient samples reveals enrichment of this population may predict liver metastasis. These findings suggest a mechanism by which extrahepatic tumors drive liver metastasis by promoting an IC population that inhibits tumor-reactive CD8+ T cell function.

DNA methylation-driven genes in hepatocellular carcinoma patients: insights into immune infiltration and prognostic implications

Background

Hepatocellular carcinoma (HCC) poses a significant global burden as a highly prevalent and life-threatening malignant tumor that endangers human life and wellbeing. The purpose of this study was to examine how DNA methylation-driven genes impact the prognosis of HCC patients.

Methods

Differentially expressed genes from The Cancer Genome Atlas, GSE76427, GSE25097 and GSE14520 datasets were collected to perform differential expression analysis between HCC patients and controls. Weighted gene coexpression network analysis (WGCNA) was subsequently performed to create coexpression modules for the DEGs. Then, ssGSEA was employed to investigate the infiltration of immune cells in HCC. Enrichment analysis and methylation were carried out for the module genes. We utilized Kaplan-Meier survival analysis to assess patient prognosis.

Results

Eight coexpression modules were identified via WGCNA for 1927 upregulated and 1,231 downregulated DEGs, after which the hub genes of the modules were identified. Module 5 had high immune infiltration, and the hub gene SCAMP3 was positively associated with Tcm. Module 3 exhibited a low level of immune infiltration, and the expression of the hub gene HCLS1 was negatively correlated with T cells and dendritic cells. Furthermore, we obtained five hub genes (BOP1, BUB1B, NOTCH3, SCAMP3, and SNRPD2) as methylation-driven genes. BOP1 and BUB1B were found to be correlated with unfavorable overall survival in patients with HCC.

Conclusion

HCLS1 and SCAMP3 are associated with immunity, whereas BOP1 and BUB1B are modified by methylation and may serve as prognostic markers for HCC.

Unique clinical, morphological, and molecular characteristics of tumors associated with PSC-IBD

Primary sclerosing cholangitis (PSC) is a rare cholestatic liver disease characterized by chronic inflammation and progressive fibrosis of the biliary tree, leading to significant liver function impairment over time. There is a strong association with inflammatory bowel diseases (IBD), together representing a distinct and complex medical condition. Patients with PSC-IBD face a heightened risk of various cancers, particularly colorectal carcinoma (CRC) and cholangiocarcinoma (CCA) as the most common types. In this review, we aim to characterize the distinctive features of PSC-IBD-associated carcinomas. Cancer pathogenesis in PSC-IBD is shaped by various factors including dysregulated bile acid metabolism, gut dysbiosis, and unique immune responses. PSC-IBD-associated CRC is often right-sided and warrants vigilant monitoring due to its higher incidence and unique morphological features compared to CRC arising in the terrain of IBD alone. CCA shares substantial genetic similarities with extrahepatic CCA and poses diagnostic challenges since it is frequently detected at advanced stages due to symptom overlap with PSC. Besides, reliable predictive biomarkers for targeted therapy remain largely unexplored. The distinct molecular, genetic, and histopathological profiles of CRC and CCA in PSC-IBD underscore the complexity of these malignancies and highlight the need for continued research to develop precise therapeutic strategies.

Unraveling the link between metabolic dysfunction-associated steatotic liver disease and osteoporosis: a bridging function of gut microbiota

This review examines the strong association between metabolic dysfunction-associated steatotic liver disease (MASLD) and osteoporosis (OP), with a particular focus on the role of gut microbiota in linking these two disorders. Both MASLD and OP are closely linked to metabolic syndrome, and their pathogenesis involves multiple factors, such as inflammatory response, insulin resistance, altered intestinal permeability, and estrogen deficiency. Dysregulation of gut microbiota not only affects hepatic fat accumulation and bone metabolism disorders through metabolites, such as short-chain fatty acids, but also exacerbates systemic chronic inflammation by impairing the intestinal barrier function, thus accelerating the progression of both diseases. This article summarizes recent studies that highlight the central role of gut microbiota as a co-morbid factor in MASLD and OP, offering new perspectives for future diagnostic and therapeutic strategies.

Mechanisms of rifaximin inhibition of hepatic fibrosis in mice with metabolic dysfunction associated steatohepatitis through the TLR4/NFκB pathway

Metabolic dysfunction-associated steatohepatitis (MASH) has become a serious public health problem, posing an increasingly dangerous threat to human health owing to its increasing prevalence and accompanying intra- and extrahepatic adverse outcomes. Rifaximin is considered to have therapeutic potential for MASH; however, its efficacy remains controversial. Our study aimed to observe the ameliorative effects of rifaximin and explore its possible mechanisms at the cellular level. 1. 42 male C57BL/6J mice were divided into 3 groups, the CON group and MCD group were fed with normal feed and MCD feed for 12 weeks respectively, and the MCD + RFX group was treated with rifaximin by gavage for 4 weeks on the basis of MCD feed. Hematoxylin-eosin staining, Sirius red staining and immunohistochemical staining were used to observe the histopathological changes of liver and intestine. Differences in liver transaminases, inflammatory factors, fibrosis indexes and intestinal tight junction proteins were compared among the 3 groups of mice. 2. A MASH cell model was constructed by inducing HepG2 cells with free fatty acids to observe the effects of rifaximin on MASH in vitro. In addition, the effects of rifaximin on TLR4/NF-κB signaling pathway were explored by applying TLR4 agonist LPS and TLR4 inhibitor TAK-242. Hepatic histopathology was significantly improved in MASH mice after rifaximin treatment, and their serum alanine aminotransferase and aspartate aminotransferase levels were (72.72 ± 5.68) U/L and (222.8 ± 11.22) U/L, respectively, which were significantly lower than those in the MCD group [(293.3 ± 10.69) U/L and (414.1 ± 36.29) U/L, P < 0.05], and the levels of inflammatory factors and fibrosis indicators were reduced. Rifaximin ameliorated intestinal barrier injury with increased expression of intestinal tight junction protein ZO-1 in the MCD + RFX group of mice, and the concentration of LPS-binding proteins (4.92 ± 0.55 vs. 15.82 ± 1.71, P < 0.05) was lower than that in the MCD group. In the NASH cell model, rifaximin similarly exerted inhibitory effects on its inflammatory factors and TLR4/NF-κB signaling pathway. Application of TLR4 inhibitors weakened the inhibitory effect of rifaximin on MASH. Our study supports rifaximin as a potential treatment for MASH, with potential mechanisms related to improving intestinal barrier integrity and downregulating the TLR4/NF-κB signaling pathway.

Toll-like receptor upregulation in liver and peripheral blood mononuclear cells of patients with amoebic liver abscess

AIM

We aimed to understand the host and microbe interactions at the time of infection and inflammatory response in amoebic liver abscess (ALA) patients based on toll-like receptor (TLR) expression (mRNA), cytokine and IgG subtypes levels.

METHODS AND RESULTS

Liver aspirates from 100 ALA patients and 11 liver autopsy samples were used as negative controls. Blood samples from 100 ALA and 41 healthy individuals were collected. mRNA expression of TLR 1 to 9 genes was measured using reverse transcriptase polymerase chain reaction (RT-PCR). Serum cytokines level was quantified by flow cytometry. In-house ELISA for the analysis of IgG and its subtypes in the serum samples was performed. A total of 7 TLR genes (TLR1, TLR2, TLR4, TLR6, TLR7, TLR8 and TLR9) and 6 TLR genes (TLR1, TLR2, TLR3, TLR4, TLR5 and TLR8) were found to be elevated in liver aspirates and PBMCs respectively. Increased serum cytokine levels were observed in ALA patients vs. healthy controls. Interestingly, a significant increase in IgG and its subtypes (IgG1, IgG3 and IgG4) was found in the serum of ALA patients.

CONCLUSION

Increased levels of TLR, pro- and anti-inflammatory cytokines, IgG and its subtypes, are possibly linked with early-stage infection in ALA patients.

IMPACT STATEMENT

The role of TLRs in association with ALA might provide insights into new therapeutic strategies.

Research Progress on Anti-Inflammatory Mechanism of Inula cappa

The incidence of various inflammatory diseases has remained high. Inula cappa is a kind of Chinese herbal medicine with a wide range of pharmacological uses and application value. It has anti-inflammatory, antibacterial, antioxidant, hepatoprotective and other pharmacological activities. The monomeric compounds that have been confirmed to have anti-inflammatory effects are luteolin, chrysoerilol, artemetin, chlorogenic acid, neochlorogenic acid, cryptchlorogenic acid, isochlorogenic acid A, isochlorogenic acid B, isochlorogenic acid C and 1,3-O-dicaffeoylquinic acid. This article introduces the relationship between Inula cappa and inflammation, the anti-inflammatory components of I. cappa, the modulation of each component on the inflammatory transduction signal pathway, and the TLR2/MyD88/NF-KB anti-inflammatory signaling pathway, providing a theoretical basis for anti-inflammatory research on and clinical medication using Inula cappa.

The Impact of Toll-Like Receptor 5 on Liver Function in Age-Related Metabolic Disorders

Toll-like receptor 5 (TLR5) plays a critical role beyond its traditional function in innate immunity, significantly impacting metabolic regulation and liver health. Previously, we reported that TLR5 activation extends the healthspan and lifespan of aging mice. This study demonstrates that TLR5 deficiency leads to pronounced metabolic abnormalities with age, primarily affecting liver metabolic functions rather than intestinal inflammation. Comprehensive RNA sequencing analysis revealed that TLR5 deficiency induces gene expression changes in liver tissue similar to those caused by the methionine-choline deficient (MCD) diet, particularly affecting lipid metabolism and circadian rhythm-related genes. TLR5 knockout (TLR5 KO) mice displayed an increased propensity for liver fibrosis and lipid accumulation under the MCD diet, exacerbating liver pathology. Both hepatocytes and hepatic stellate cells in TLR5 KO mice were functionally impacted, leading to metabolic dysfunction and fibrosis. These findings suggest that TLR5 could be a significant target for addressing metabolic diseases that arise and worsen with aging. Furthermore, understanding the mechanisms by which TLR5 activation extends healthspan could provide valuable insights into therapeutic strategies for enhancing longevity and managing age-related metabolic disorders.

Expression of miR-15b-5p and toll-like receptor4 as potential novel diagnostic biomarkers for hepatitis C virus-induced hepatocellular carcinoma

Objectives

Globally, hepatocellular Carcinoma (HCC) ranks seventh in women's cancer and fifth in men's cancer. Early identification can minimize mortality and morbidity. MicroRNAs and Toll-like receptors have been suggested as potential new biomarkers for HCC; Therefore, we explored Toll-like receptor 4 (TLR-4) and miRNA 15b-5p as new non-invasive HCC biomarkers and early detection approaches.

Methodology

In this case-control study, four primary groups were formed from 400 patients who participated in this study: 100 hepatitis C (HCV) patients without cirrhosis or HCC, 100 HCV with cirrhosis patients, 100 HCC and HCV patients, and 100 healthy controls. The HCC diagnosis was confirmed according to the American Association for the Study of Liver Disease (AASLD) Practice Guidelines. Triphasic computed tomography was used to assess the HCC tumor size. Real-time PCR was used to analyze miRNA 15b-5p and Toll-like receptor 4 (TLR-4) expression profiles.

Results

Significant diagnostic performance was achieved by miRNA 15b-5p in differentiating the HCC group from the control group, with 90 % sensitivity and 88 % specificity (AUC] 0.935, p < 0.001), while TLR-4 had moderate diagnostic performance with 85 % sensitivity and 86 % specificity (AUC:0.885, p < 0.001).

Conclusions

The ability of miR-15b-5p to recognize HCC was positive and it outperformed Toll-like receptor4. MiR-15b-5p has the potential to be a more precise and predictive biological marker for HCC than Toll-like receptor4. Future studies exploring different miRNAs and HCC cases from various etiologies are required to better understand the role of miRNAs in this disease and allow for more effective strategies.

Microbiome interplays in the gut-liver axis: implications for liver cancer pathogenesis and therapeutic insights

Globally, primary liver cancer (PLC) ranks the most fatal malignancy. Most of the patients are in advanced stage of PLC at the very time they are diagnosed with it, accounting much for its poor prognosis. With the advancement of modern medical research and care system, the main etiology of PLC more and more switches from hepatitis viruses such as HAV, HBV, HCV, HEV to other causes like metabolism-associated steatohepatitis (MASH) and metabolic-associated fatty liver disease (MAFLD). As a result, it is of great necessity to find out new ways for treatment and early diagnosis to cope with this problem. Nowadays, as the mechanism of the Gut-Liver Axis in the formation of MAFLD, MASH and PLC has been gradually elucidated. The association between gut microbiome and the formation of PLC is of great significance to take an insight into. In this review, we present the concept of Gut-Liver Axis and its function in the mutual influence between gut microbiota and PLC from several aspects in which we will focus on the structure of gut barrier and the functional influences the gut microbiota have on the immune response and metabolic changes on human liver. Furthermore, we conclude the potential association of gut microbiota constitution with the PLC. Eventually, we hope this review can offer novel instructions for early diagnosis and treatment for liver cancer.

Human Liver MSCs Retain Their Basic Cellular Properties in Chronically Inflamed Liver Tissue

Every 25th death worldwide is associated with liver pathology. The development of novel approaches to liver diseases therapy and protocols for maintaining the vital functions of patients on the liver transplant waiting list are urgently needed. Resident mesenchymal stem cells (MSCs) play a significant role in supporting liver tissue integrity and improve the liver condition after infusion. However, it remains unclear whether MSCs isolated from chronically inflamed livers are similar in their basic cellular properties to MSCs obtained from healthy livers. We applied a large array of tests to compare resident MSCs isolated from apparently normal liver tissue and from chronically inflamed livers of patients with fibrosis, cirrhosis, and viral hepatitis. Chronic inflammatory environment did not alter the major cellular characteristics of MSCs, including the expression of MSC markers, stem cell markers, adhesion molecules, and the hallmarks of senescence, as well as cell proliferation, migration, and secretome. Only the expression of some immune checkpoints and toll-like receptors was different. Evidently, MSCs with unchanged cellular properties are present in human liver even at late stages of inflammatory diseases. These cells can be isolated and used as starting material in the development of cell therapies of liver diseases.

Gut microbes, diet, and genetics as drivers of metabolic liver disease: a narrative review outlining implications for precision medicine

Metabolic dysfunction-associated steatotic liver disease (MASLD) is rapidly increasing in prevalence, impacting over a third of the global population. The advanced form of MASLD, Metabolic dysfunction-associated steatohepatitis (MASH), is on track to become the number one indication for liver transplant. FDA-approved pharmacological agents are limited for MASH, despite over 400 ongoing clinical trials, with only a single drug (resmetirom) currently on the market. This is likely due to the heterogeneous nature of disease pathophysiology, which involves interactions between highly individualized genetic and environmental factors. To apply precision medicine approaches that overcome interpersonal variability, in-depth insights into interactions between genetics, nutrition, and the gut microbiome are needed, given that each have emerged as dynamic contributors to MASLD and MASH pathogenesis. Here, we discuss the associations and molecular underpinnings of several of these factors individually and outline their interactions in the context of both patient-based studies and preclinical animal model systems. Finally, we highlight gaps in knowledge that will require further investigation to aid in successfully implementing precision medicine to prevent and alleviate MASLD and MASH.

A Paradoxical Tumor Antigen Specific Response in the Liver

Functional tumor-specific CD8+ T cells are essential for an effective anti-tumor immune response and the efficacy of immune checkpoint inhibitor therapy. In comparison to other organ sites, we found higher numbers of tumor-specific CD8+ T cells in primary, metastatic liver tumors in murine tumor models. Despite their abundance, CD8+ T cells in the liver displayed an exhausted phenotype. Depletion of CD8+ T cells showed that liver tumor-reactive CD8+ T failed to control liver tumors but was effective against subcutaneous tumors. Similarly, analysis of single-cell RNA sequencing data from patients showed a higher frequency of exhausted tumor-reactive CD8+ T cells in liver metastasis compared to paired primary colon cancer. High-dimensional, multi-omic analysis combining proteomic CODEX and scRNA-seq data revealed enriched interaction of SPP1+ macrophages and CD8+ tumor-reactive T cells in profibrotic, alpha-SMA rich regions in the liver. Liver tumors grew less in Spp1-/- mice and the tumor-specific CD8+ T cells were less exhausted. Differential pseudotime trajectory inference analysis revealed extrahepatic signaling promoting an intermediate cell (IC) population in the liver, characterized by co-expression of VISG4, CSF1R, CD163, TGF-βR, IL-6R, SPP1. scRNA-seq of a third data set of premetastatic adenocarcinoma showed that enrichment of this population may predict liver metastasis. Our data suggests a mechanism by which extrahepatic tumors facilitate the formation of liver metastasis by promoting an IC population inhibiting tumor-reactive CD8+ T cell function.

Kupffer Cells and Hepatocytes: A Key Relation in the Context of Canine Leishmaniasis

Human zoonotic visceral leishmaniasis (ZVL) and canine leishmaniasis (CanL) constitute a major public and veterinary health concern and are both caused by the infection with the protozoan parasite Leishmania infantum. One of the main target organs in CanL is the liver. This complex organ, composed of various highly specialized cell types, has garnered significant attention from the scientific community as a crucial player in innate immune functions. In the context of CanL, liver infection by parasites and the host immune response generated strongly influence the disease outcome. Thus, taking advantage of a co-culture system involving canine hepatocytes and L. infantum-infected autologous Kupffer cells (KCs), allowing cell-to-cell interaction, the current report aims to shed light on the hepatocyte-KCs immune interaction. The co-culture of infected KCs with hepatocytes revealed a vital role of these cells in the activation of a local immune response against L. infantum parasites. Although KCs alone can be immunologically silenced by L. infantum infection, the cell-to-cell interaction with hepatocytes in co-culture can lead to local immune activation. In co-culture it was observed gene expression increased the number of innate immune receptors, specifically cell membrane TLR2 and cytoplasmatic NOD1 along with high TNF-α generation. Altogether, these results suggest that the immune response generated in co-culture could induce the recruitment of other circulating cells to contain and contribute to the resolution of the infection in the liver. This work also enhances our understanding of the liver as a vital organ in innate immunity within the context of CanL.

Special Issue "The Role of Toll-Like Receptors (TLRs) in Infection and Inflammation 2.0"

Toll-like receptors (TLRs) are key players in the innate immune system, in host' first-line defense against pathogens [...].

Microcrystal electron diffraction structure of Toll-like receptor 2 TIR-domain-nucleated MyD88 TIR-domain higher-order assembly

Eukaryotic TIR (Toll/interleukin-1 receptor protein) domains signal via TIR-TIR interactions, either by self-association or by interaction with other TIR domains. In mammals, TIR domains are found in Toll-like receptors (TLRs) and cytoplasmic adaptor proteins involved in pro-inflammatory signaling. Previous work revealed that the MAL TIR domain (MALTIR) nucleates the assembly of MyD88TIR into crystalline arrays in vitro. A microcrystal electron diffraction (MicroED) structure of the MyD88TIR assembly has previously been solved, revealing a two-stranded higher-order assembly of TIR domains. In this work, it is demonstrated that the TIR domain of TLR2, which is reported to signal as a heterodimer with either TLR1 or TLR6, induces the formation of crystalline higher-order assemblies of MyD88TIR in vitro, whereas TLR1TIR and TLR6TIR do not. Using an improved data-collection protocol, the MicroED structure of TLR2TIR-induced MyD88TIR microcrystals was determined at a higher resolution (2.85 Å) and with higher completeness (89%) compared with the previous structure of the MALTIR-induced MyD88TIR assembly. Both assemblies exhibit conformational differences in several areas that are important for signaling (for example the BB loop and CD loop) compared with their monomeric structures. These data suggest that TLR2TIR and MALTIR interact with MyD88 in an analogous manner during signaling, nucleating MyD88TIR assemblies unidirectionally.

Protective effects of 17-β-estradiol on liver injury: The role of TLR4 signaling pathway and inflammatory response

Liver injury, a major global health issue, stems from various causes such as alcohol consumption, nonalcoholic steatohepatitis, obesity, diabetes, metabolic syndrome, hepatitis, and certain medications. The liver's unique susceptibility to ischemia and hypoxia, coupled with the critical role of the gut-liver axis in inflammation, underscores the need for effective therapeutic interventions. The study highlights E2's interaction with estrogen receptors (ERs) and its modulation of the Toll-like receptor 4 (TLR4) signaling pathway as key mechanisms in mitigating liver injury. Activation of TLR4 leads to the release of pro-inflammatory cytokines and chemokines, exacerbating liver inflammation and injury. E2 down-regulates TLR4 expression, reduces oxidative stress, and inhibits pro-inflammatory cytokines, thereby protecting the liver. Both classic (ERα and ERβ) and non-classic [G protein-coupled estrogen receptor (GPER)] receptors are influenced by E2. ERα is particularly crucial for liver regeneration, preventing liver failure by promoting hepatocyte proliferation. Furthermore, E2 exerts anti-inflammatory, antioxidant, and anti-apoptotic effects by inhibiting cytokines such as IL-6, IL-1β, TNF-α, and IL-17, and by reducing lipid peroxidation and free radical damage. The article calls for further clinical research to validate these findings and to develop estrogen-based treatments for liver injuries. Overall, the research emphasizes the significant potential of E2 as a therapeutic agent for liver injuries. It advocates for extensive clinical studies to validate E2 hepatoprotective properties and develop effective estrogen-based treatments.

The effects of the combination therapy of chemotherapy drugs on the fluctuations of genes involved in the TLR signaling pathway in glioblastoma multiforme therapy

One of the most lethal and aggressive types of malignancies with a high mortality rate and poor response to treatment is glioblastoma multiforme (GBM). This means that modernizing the medications used in chemotherapy, in addition to medicines licensed for use in other illnesses and chosen using a rationale process, can be beneficial in treating this illness. Meaningly, drug combination therapy with chemical or herbal originations or implanting a drug wafer in tumors to control angiogenesis is of great importance. Importantly, the primary therapeutic hurdles in GBM are the development of angiogenesis and the blood-brain barrier (BBB), which keeps medications from getting to the tumor. This malignancy can be controlled if the drug's passage through the BBB and the VEGF (vascular endothelial growth factor), which promotes angiogenesis, are inhibited. In this way, the effect of combination therapy on the genes of different main signaling pathways like TLRs may be indicated as an impressive therapeutic strategy for treating GBM. This article aims to discuss the effects of chemotherapeutic drugs on the expression of various genes and associated translational factors involved in the TLR signaling pathway.

Repairing gut barrier by traditional Chinese medicine: roles of gut microbiota

Gut barrier is not only part of the digestive organ but also an important immunological organ for the hosts. The disruption of gut barrier can lead to various diseases such as obesity and colitis. In recent years, traditional Chinese medicine (TCM) has gained much attention for its rich clinical experiences enriched in thousands of years. After orally taken, TCM can interplay with gut microbiota. On one hand, TCM can modulate the composition and function of gut microbiota. On the other hand, gut microbiota can transform TCM compounds. The gut microbiota metabolites produced during the actions of these interplays exert noticeable pharmacological effects on the host especially gut barrier. Recently, a large number of studies have investigated the repairing and fortifying effects of TCM on gut barriers from the perspective of gut microbiota and its metabolites. However, no review has summarized the mechanism behand this beneficiary effects of TCM. In this review, we first briefly introduce the unique structure and specific function of gut barrier. Then, we summarize the interactions and relationship amidst gut microbiota, gut microbiota metabolites and TCM. Further, we summarize the regulative effects and mechanisms of TCM on gut barrier including physical barrier, chemical barrier, immunological barrier, and microbial barrier. At last, we discuss the effects of TCM on diseases that are associated gut barrier destruction such as ulcerative colitis and type 2 diabetes. Our review can provide insights into TCM, gut barrier and gut microbiota.

Exploring the potential of drug repurposing for liver diseases: A comprehensive study

Drug repurposing involves the investigation of existing drugs for new indications. It offers a great opportunity to quickly identify a new drug candidate at a lower cost than novel discovery and development. Despite the importance and potential role of drug repurposing, there is no specific definition that healthcare providers and the World Health Organization credit. Unfortunately, many similar and interchangeable concepts are being used in the literature, making it difficult to collect and analyze uniform data on repurposed drugs. This research was conducted based on understanding general criteria for drug repurposing, concentrating on liver diseases. Many drugs have been investigated for their effect on liver diseases even though they were originally approved (or on their way to being approved) for other diseases. Some of the hypotheses for drug repurposing were first captured from the literature and then processed further to test the hypothesis. Recently, with the revolution in bioinformatics techniques, scientists have started to use drug libraries and computer systems that can analyze hundreds of drugs to give a short list of candidates to be analyzed pharmacologically. However, this study revealed that drug repurposing is a potential aid that may help deal with liver diseases. It provides available or under-investigated drugs that could help treat hepatitis, liver cirrhosis, Wilson disease, liver cancer, and fatty liver. However, many further studies are needed to ensure the efficacy of these drugs on a large scale.

RNA m5C methylation: a potential modulator of innate immune pathways in hepatocellular carcinoma

RNA 5-methylcytosine (m5C) methylation plays a crucial role in hepatocellular carcinoma (HCC). As reported, aberrant m5C methylation is closely associated with the progression, therapeutic efficacy, and prognosis of HCC. The innate immune system functions as the primary defense mechanism in the body against pathogenic infections and tumors since it can activate innate immune pathways through pattern recognition receptors to exert anti-infection and anti-tumor effects. Recently, m5C methylation has been demonstrated to affect the activation of innate immune pathways including TLR, cGAS-STING, and RIG-I pathways by modulating RNA function, unveiling new mechanisms underlying the regulation of innate immune responses by tumor cells. However, research on m5C methylation and its interplay with innate immune pathways is still in its infancy. Therefore, this review details the biological significance of RNA m5C methylation in HCC and discusses its potential regulatory relationship with TLR, cGAS-STING, and RIG-I pathways, thereby providing fresh insights into the role of RNA methylation in the innate immune mechanisms and treatment of HCC.

Comprehensive bibliometric and visualized analysis of research on gut-liver axis published from 1998 to 2022

Background

The concept of the gut-liver axis was proposed by Marshall in 1998, and since then, this hypothesis has been gradually accepted by the academic community. Many publications have been published on the gut-liver axis, making it important to assess the scientific implications of these studies and the trends in this field.

Methods

Publications were retrieved from the Web of Science Core Collection. Microsoft Excel, CiteSpace, VOSviewer, and Scimago Graphica software were used for bibliometric analysis.

Results

A total of 776 publications from the Web of Science core database were included in this study. In the past 25 years, the number of publications on the gut-liver axis has shown an upward trend, particularly in the past 3 years (2020-2022). China had the highest number of publications (267 articles, 34.4%). However, the United States was at the top regarding influence and international cooperation in this field. The University of California San Diego had contributed the most publications. Suk, Ki Tae and Schnabl, Bernd were tied for the first rank in most publications. Thematic hotspots and frontiers were focused on gut microbiota, microbial metabolite, intestinal permeability, bacterial translocation, bile acid, non-alcoholic steatohepatitis, and alcoholic liver disease.

Conclusion

Our study is the first bibliometric analysis of literature using visualization software to present the current research status of the gut-liver axis over the past 25 years. The damage and repair of intestinal barrier function, as well as the disruption of gut microbiota and host metabolism, should be a focus of attention. This study can provide a reference for later researchers to understand the global research trends, hotspots, and frontiers in this field.

Network pharmacological analysis on the mechanism of Linggui Zhugan decoction for nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD), represents a chronic progressive disease that imposes a significant burden on patients and the healthcare system. Linggui Zhugan decoction (LGZGD) plays a substantial role in treating NAFLD, but its exact molecular mechanism is unknown. Using network pharmacology, this study aimed to investigate the mechanism of action of LGZGD in treating NAFLD. Active ingredients and targets were identified through the integration of data from the TCMSP, GEO, GeneCards, and OMIM databases. Cytoscape 3.9.1 software, in conjunction with the STRING platform, was employed to construct network diagrams and screen core targets. The enrichment analysis of gene ontology and the Kyoto Encyclopedia of Genes and Genomes pathways were conducted by using the R. Molecular docking of the active ingredients and core targets was performed with AutoDock Vina software. We obtained 93 and 112 active ingredients and potential targets using the bioinformatic analysis of LGZGD in treating NAFLD. The primary ingredients of LGZGD included quercetin, kaempferol, and naringenin. The core targets were identified AKT1, MYC, HSP90AA1, HIF1A, ESR1, TP53, and STAT3. Gene ontology function enrichment analysis revealed associations with responses to nutrient and oxygen levels, nuclear receptor activity, and ligand-activated transcription factor activity. Kyoto Encyclopedia of Genes and Genomes signaling pathway analysis implicated the involvement of the PI3K-Akt, IL-17, TNF, Th17 cell differentiation, HIF-1, and TLR signaling pathways. Molecular docking studies indicated strong binding affinities between active ingredients and targets. LGZGD intervenes in NAFLD through a multi-ingredient, multi-target, and multi-pathway approach. Treatment with LGZGD can improve insulin resistance, oxidative stress, inflammation, and lipid metabolism associated with NAFLD.

A study integrated metabolomics and network pharmacology to investigate the effects of Shicao in alleviating acute liver injury

ETHNOPHARMACOLOGICAL RELEVANCE

Shicao is the aerial part of Achillea alpina L., a common herb found mainly in Europe, Asia, and North America. Traditional Chinese medicine has a history of thousands of years and is widely used to treat various diseases.

AIM OF STUDY

To explore the hepatoprotective effects of Shicao on CCl4-induced acute liver injury.

METHODS

A rat model of acute liver injury was established and liver function indices were assessed to evaluate the protective effect of Shicao on the liver. Untargeted metabolomics of the serum and liver tissues was conducted using UPLC-Q-TOF/MS to identify differential metabolites related to acute liver injury. A network of metabolite-reaction-enzyme-gene constituents was constructed using network pharmacology. Hub targets and key components of the effect of Shicao on acute liver injury were screened from the network.

RESULTS

Compared to the model group, Shicao improved the degree of liver damage through the assessment of the liver index, ALT and AST levels, and hepatic pathology slices, demonstrating its hepatoprotective effect against acute liver injury in rats. 10 and 38 differential metabolites involved in acute liver injury were identified in serum and liver tissues, respectively. Most of these were regulated or restored following treatment with Shicao, which mainly consisted of bile acids, lipids, and nucleotides such as taurocholic acid, LysoPC (17:0), and adenosine diphosphate ribose. Through the network of metabolite-reaction-enzyme-gene-constituents, 10 key components and 5 hub genes, along with 7 crucial differential metabolites, were mainly involved in glycerophospholipid metabolism, purine metabolism, biosynthesis of unsaturated fatty acids, and primary bile acid biosynthesis, which may play important roles in the prevention of acute liver injury by Shicao.

CONCLUSION

This study revealed that Shicao had protective effects against CCl4-induced liver injury in rats. It was speculated that the ingredients of Shicao might be closely related to the hub targets, thereby regulating the levels of key metabolites, affecting inflammatory response and oxidative stress and attenuate the liver injury consequently. This study provides a basis for further investigation of its therapeutic potential and the mechanism of action.

Screening of Multitarget Compounds against Acetaminophen Hepatic Toxicity Using In Silico, In Vitro, and In Vivo Approaches

Combination therapy and multitarget drugs have recently attracted much attention as promising tools to fight against many challenging diseases and, thus, represent a new research focus area. The aim of the current project was to screen multitarget compounds and to study their individual and combined effects on acetaminophen-induced liver injury. In this study, 2 of the best hepatoprotective multitargeting compounds were selected from a pool of 40 major compounds present in Curcuma longa and Cinnamomum zeylanicum by using molecular docking, ADMET profiling, and Pfizer's rule of five. The two selected compounds, quercetin and curcumin, showed a high binding affinity for the CYP2E1 enzyme, MAPK, and TLR4 receptors that contribute to liver injury. The candidates caused the decreased viability of cancer cell lines (HepG2 and Huh7) but showed no effect on a normal cell line (Vero). Examination of biochemical parameters (ALT, AST, ALP, and bilirubin) showed the hepatoprotective effect of the candidate drugs in comparison with the control group, which was confirmed by histological findings. Taken together, quercetin and curcumin not only satisfied the drug-like assessment criterion and proved to be multitargeting by preventing liver damage but also showed anticancer activities.

Metabolic Dysfunction-Associated Fatty Liver Disease and Chronic Viral Hepatitis: The Interlink

Metabolic dysfunction-associated fatty liver disease (MAFLD) has now affected nearly one-third of the global population and has become the number one cause of chronic liver disease in the world because of the obesity pandemic. Chronic hepatitis resulting from hepatitis B virus (HBV) and hepatitis C virus (HCV) remain significant challenges to liver health even in the 21st century. The co-existence of MAFLD and chronic viral hepatitis can markedly alter the disease course of individual diseases and can complicate the management of each of these disorders. A thorough understanding of the pathobiological interactions between MAFLD and these two chronic viral infections is crucial for appropriately managing these patients. In this comprehensive clinical review, we discuss the various mechanisms of chronic viral hepatitis-mediated metabolic dysfunction and the impact of MAFLD on the progression of liver disease.

Breaking the barriers: the role of gut homeostasis in Metabolic-Associated Steatotic Liver Disease (MASLD)

Obesity, insulin resistance (IR), and the gut microbiome intricately interplay in Metabolic-associated Steatotic Liver Disease (MASLD), previously known as Non-Alcoholic Fatty Liver Disease (NAFLD), a growing health concern. The complex progression of MASLD extends beyond the liver, driven by "gut-liver axis," where diet, genetics, and gut-liver interactions influence disease development. The pathophysiology of MASLD involves excessive liver fat accumulation, hepatocyte dysfunction, inflammation, and fibrosis, with subsequent risk of hepatocellular carcinoma (HCC). The gut, a tripartite barrier, with mechanical, immune, and microbial components, engages in a constant communication with the liver. Recent evidence links dysbiosis and disrupted barriers to systemic inflammation and disease progression. Toll-like receptors (TLRs) mediate immunological crosstalk between the gut and liver, recognizing microbial structures and triggering immune responses. The "multiple hit model" of MASLD development involves factors like fat accumulation, insulin resistance, gut dysbiosis, and genetics/environmental elements disrupting the gut-liver axis, leading to impaired intestinal barrier function and increased gut permeability. Clinical management strategies encompass dietary interventions, physical exercise, pharmacotherapy targeting bile acid (BA) metabolism, and microbiome modulation approaches through prebiotics, probiotics, symbiotics, and fecal microbiota transplantation (FMT). This review underscores the complex interactions between diet, metabolism, microbiome, and their impact on MASLD pathophysiology and therapeutic prospects.

Revolutionizing medicine with toll-like receptors: A path to strengthening cellular immunity

Toll-like receptors play a vital role in cell-mediated immunity, which is crucial for the immune system's defense against pathogens and maintenance of homeostasis. The interaction between toll-like-receptor response and cell-mediated immunity is complex and essential for effectively eliminating pathogens and maintaining immune surveillance. In addition to pathogen recognition, toll-like receptors serve as adjuvants in vaccines, as molecular sensors, and recognize specific patterns associated with pathogens and danger signals. Incorporating toll-like receptor ligands into vaccines can enhance the immune response to antigens, making them potent adjuvants. Furthermore, they bridge the innate and adaptive immune systems and improve antigen-presenting cells' capacity to process and present antigens to T cells. The intricate signaling pathways and cross-talk between toll-like-receptor and T cell receptor (TCR) signaling emphasize their pivotal role in orchestrating effective immune responses against pathogens, thus facilitating the development of innovative vaccine strategies. This article provides an overview of the current understanding of toll-like receptor response and explores their potential clinical applications. By unraveling the complex mechanisms of toll-like-receptor signaling, we can gain novel insights into immune responses and potentially develop innovative therapeutic approaches. Ongoing investigations into the toll-like-receptor response hold promise in the future in enhancing our ability to combat infections, design effective vaccines, and improve clinical outcomes.

Mechanisms and Therapeutic Strategies for MAFLD Targeting TLR4 Signaling Pathways

BACKGROUND

Metabolic-associated fatty liver disease (MAFLD) is one of the most common chronic liver diseases. The underlying pathophysiological mechanisms are intricate and involve various factors. Unfortunately, there is currently a lack of available effective treatment options. Toll-like receptors (TLRs) are a group of pattern-recognition receptors that are responsible for activating the innate immune system. Research has demonstrated that TLR4 plays a pivotal role in the progression of MAFLD by facilitating the pathophysiological mechanisms.

SUMMARY

Lipid peroxidation, pro-inflammatory factors, insulin resistance (IR), and dysbiosis of intestinal microbiota are considered as the pathogenic mechanisms of MAFLD. This review summarizes the impact of TLR4 signaling pathways on the progression of MAFLD, specifically in relation to lipid metabolic disorders, IR, oxidative stress, and gut microbiota disorders. Additionally, we emphasize the potential therapeutic approaches for MAFLD that target TLR4 signaling pathways, including the use of plant extracts, traditional Chinese medicines, probiotics, pharmaceuticals such as peroxisome proliferator-activated receptor antagonists and farnesol X agonists, and lifestyle modifications such as dietary changes and exercise also considered. Furthermore, TLR4 signaling pathways have also been linked to the lean MAFLD.

KEY MESSAGES

TLR4 plays a crucial role in MAFLD by triggering IR, buildup of lipids, imbalance in gut microbiota, oxidative stress, and initiation of immune responses. The mitigation of MAFLD can be accomplished by suppressing the TLR4 signaling pathway. In the future, it could potentially emerge as a therapeutic target for the condition.

Gut-microbiota prompt activation of natural killer cell on alcoholic liver disease

The liver is rich in innate immune cells, such as natural killer (NK) cells, natural killer T cells, and Kupffer cells associated with the gut microbiome. These immune cells are dysfunctional owing to alcohol consumption. However, there is insufficient data on the association between immune cells and gut microbiome in alcoholic liver disease (ALD). Therefore, the purpose of this study was to evaluate the effects of probiotic strains on NK cells in ALD patients. In total, 125 human blood samples [control (n = 22), alcoholic hepatitis (n = 43), and alcoholic cirrhosis (n = 60]) were collected for flow cytometric analysis. C57BL/6J mice were divided into four groups (normal, EtOH-fed, and 2 EtOH+strain groups [Phocaeicola dorei and Lactobacillus helveticus]). Lymphocytes isolated from mouse livers were analyzed using flow cytometry. The frequency of NK cells increased in patients with alcoholic hepatitis and decreased in patients with alcoholic cirrhosis. The expression of NKp46, an NK cell-activating receptor, was decreased in patients with alcoholic hepatitis and increased in patients with alcoholic cirrhosis compared to that in the control group. The number of cytotoxic CD56dimCD16+ NK cells was significantly reduced in patients with alcoholic cirrhosis. We tested the effect of oral administration P. dorei and L. helveticus in EtOH-fed mice. P. dorei and L. helveticus improved liver inflammation and intestinal barrier damage caused by EtOH supply and increased NK cell activity. Therefore, these observations suggest that the gut microbiome may ameliorate ALD by regulating immune cells.

Acute Kidney Injury: Definition, Management, and Promising Therapeutic Target

Acute kidney injury (AKI) is caused by a sudden loss of renal function, resulting in the build-up of waste products and a significant increase in mortality and morbidity. It is commonly diagnosed in critically ill patients, with its occurrence estimated at up to 50% in patients hospitalized in the intensive critical unit. Despite ongoing efforts, the death rate associated with AKI has remained high over the past half-century. Thus, it is critical to investigate novel therapy options for preventing the epidemic. Many studies have found that inflammation and Toll-like receptor-4 (TLR-4) activation have a significant role in the pathogenesis of AKI. Noteworthy, challenges in the search for efficient pharmacological therapy for AKI have arisen due to the multifaceted origin and complexity of the clinical history of people with the disease. This article focuses on kidney injury's epidemiology, risk factors, and pathophysiological processes. Specifically, it focuses on the role of TLRs especially type 4 in disease development.

Chronic metabolic stress drives developmental programs and loss of tissue functions in non-transformed liver that mirror tumor states and stratify survival

Under chronic stress, cells must balance competing demands between cellular survival and tissue function. In metabolic dysfunction-associated steatotic liver disease (MASLD, formerly NAFLD/NASH), hepatocytes cooperate with structural and immune cells to perform crucial metabolic, synthetic, and detoxification functions despite nutrient imbalances. While prior work has emphasized stress-induced drivers of cell death, the dynamic adaptations of surviving cells and their functional repercussions remain unclear. Namely, we do not know which pathways and programs define cellular responses, what regulatory factors mediate (mal)adaptations, and how this aberrant activity connects to tissue-scale dysfunction and long-term disease outcomes. Here, by applying longitudinal single-cell multi -omics to a mouse model of chronic metabolic stress and extending to human cohorts, we show that stress drives survival-linked tradeoffs and metabolic rewiring, manifesting as shifts towards development-associated states in non-transformed hepatocytes with accompanying decreases in their professional functionality. Diet-induced adaptations occur significantly prior to tumorigenesis but parallel tumorigenesis-induced phenotypes and predict worsened human cancer survival. Through the development of a multi -omic computational gene regulatory inference framework and human in vitro and mouse in vivo genetic perturbations, we validate transcriptional (RELB, SOX4) and metabolic (HMGCS2) mediators that co-regulate and couple the balance between developmental state and hepatocyte functional identity programming. Our work defines cellular features of liver adaptation to chronic stress as well as their links to long-term disease outcomes and cancer hallmarks, unifying diverse axes of cellular dysfunction around core causal mechanisms.

Unveiling the role of gut dysbiosis in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is a multifactorial complicated condition, reflected by the accumulation of extra fat in the liver. A detailed study of literature throws light on the fascinating connection between gut dysbiosis and NAFLD. The term 'gut dysbiosis' describes an imbalance in the harmony and operation of the gut microflora, which can upshoot a number of metabolic disorders. To recognize the underlying mechanisms and determine treatment options, it is essential to comprehend the connection between gut dysbiosis and NAFLD. This in-depth review discusses the normal gut microflora composition and its role in health, alterations in the gut microflora composition that leads to disease state focusing on NAFLD. The potential mechanisms influencing the advent and aggravation of NAFLD suggested disturbance of microbial metabolites, changes in gut barrier integrity, and imbalances in the composition of the gut microflora. Furthermore, it was discovered that gut dysbiosis affected immune responses, liver inflammation, and metabolic pathways, aggravating NAFLD.

Benefit of using interaction effects for the analysis of high-dimensional time-response or dose-response data for two-group comparisons

High throughput RNA sequencing experiments are widely conducted and analyzed to identify differentially expressed genes (DEGs). The statistical models calculated for this task are often not clear to practitioners, and analyses may not be optimally tailored to the research hypothesis. Often, interaction effects (IEs) are the mathematical equivalent of the biological research question but are not considered for different reasons. We fill this gap by explaining and presenting the potential benefit of IEs in the search for DEGs using RNA-Seq data of mice that receive different diets for different time periods. Using an IE model leads to a smaller, but likely more biologically informative set of DEGs compared to a common approach that avoids the calculation of IEs.

Targeting the Adipose Tissue-Liver-Gut Microbiota Crosstalk to Cure MASLD

The gut microbiota is a complex system, playing a peculiar role in regulating innate and systemic immunity. Increasing evidence links dysfunctional gut microbiota to metabolic dysfunction-associated steatotic liver disease (MASLD) due to the activation of multiple pathways in the gut and in the liver, including those mediated by Toll-like receptors (TLRs), that sustain hepatic inflammation. Thus, many efforts have been made to unravel the role of microbiota-associated dysfunction in MASLD, with the final aim of finding novel strategies to improve liver steatosis and function. Moreover, recent evidence underlines the role of adipose tissue in sustaining hepatic inflammation during MASLD development. In this review, we focus on the recently discovered strategies proposed to improve the alteration of gut microbiota observed in MASLD patients, with a particular insight into those known to modulate gut microbiota-associated dysfunction and to affect the complex crosstalk between the gut, the adipose tissue, and the liver.

Synthetic 5-amino-6-D-ribitylaminouracil paired with inflammatory stimuli facilitates MAIT cell expansion in vivo

Introduction

Mucosal-associated invariant T (MAIT) cells are a population of innate-like T cells, which mediate host immunity to microbial infection by recognizing metabolite antigens derived from microbial riboflavin synthesis presented by the MHC-I-related protein 1 (MR1). Namely, the potent MAIT cell antigens, 5-(2-oxopropylideneamino)-6-D-ribitylaminouracil (5-OP-RU) and 5-(2-oxoethylideneamino)-6-D-ribitylaminouracil (5-OE-RU), form via the condensation of the riboflavin precursor 5-amino-6-D-ribitylaminouracil (5-A-RU) with the reactive carbonyl species (RCS) methylglyoxal (MG) and glyoxal (G), respectively. Although MAIT cells are abundant in humans, they are rare in mice, and increasing their abundance using expansion protocols with antigen and adjuvant has been shown to facilitate their study in mouse models of infection and disease.

Methods

Here, we outline three methods to increase the abundance of MAIT cells in C57BL/6 mice using a combination of inflammatory stimuli, 5-A-RU and MG.

Results

Our data demonstrate that the administration of synthetic 5-A-RU in combination with one of three different inflammatory stimuli is sufficient to increase the frequency and absolute numbers of MAIT cells in C57BL/6 mice. The resultant boosted MAIT cells are functional and can provide protection against a lethal infection of Legionella longbeachae.

Conclusion

These results provide alternative methods for expanding MAIT cells with high doses of commercially available 5-A-RU (± MG) in the presence of various danger signals.

Toll-like receptor 5 tunes hepatic and pancreatic stellate cells activation

OBJECTIVE

Stellate cells are responsible for liver and pancreas fibrosis and strictly correlate with tumourigenesis. Although their activation is reversible, an exacerbated signalling triggers chronic fibrosis. Toll-like receptors (TLRs) modulate stellate cells transition. TLR5 transduces the signal deriving by the binding to bacterial flagellin from invading mobile bacteria.

DESIGN

Human hepatic and pancreatic stellate cells were activated by the administration of transforming growth factor-beta (TGF-β). TLR5 was transiently knocked down by short-interference RNA transfection. Reverse Transcription-quantitativePCR and western blot were performed to analyse the transcript and protein level of TLR5 and the transition players. Fluorescence microscopy was performed to identify these targets in spheroids and in the sections of murine fibrotic liver.

RESULTS

TGF-β-activated human hepatic and pancreatic stellate cells showed an increase of TLR5 expression. TLR5 knockdown blocked the activation of those stellate cells. Furthermore, TLR5 busted during murine liver fibrosis and co-localised with the inducible Collagen I. Flagellin suppressed TLR5, COL1A1 and ACTA2 expression after the administration of TGF-β. Instead, the antagonist of TLR5 did not block the effect of TGF-β. Wortmannin, a specific AKT inhibitor, induced TLR5 but not COL1A1 and ACTA2 transcript and protein level.

CONCLUSION

TGF-β-mediated activation of hepatic and pancreatic stellate cells requires the over-expression of TLR5. Instead, its autonomous signalling inhibits the activation of the stellate cells, thus prompting a signalling through different regulatory pathways.

Differences in Bacterial Translocation and Liver Injury in Ethanol Versus Diet-Induced Liver Disease

BACKGROUND

Alcohol-associated liver disease (ALD) and non-alcoholic fatty liver disease (NAFLD)/non-alcoholic steatohepatitis (NASH) are two of the most common etiologies of chronic liver disease worldwide. Changes in intestinal permeability and increased gut microbial translocation have been posited as important contributors to inflammation in both ALD and NAFLD. However, gut microbial translocation has not been compared between the two etiologies and can lead to better understanding of the differences in their pathogenesis to liver disease.

METHODS

We compared serum and liver markers in the following five models of liver disease to understand the differences in the role of gut microbial translocation on liver disease progression caused by ethanol versus Western diet: (1) 8-week chronic ethanol feeding model. (2) 2-week chronic-plus-binge (National Institute on Alcohol Abuse and Alcoholism (NIAAA)) ethanol feeding model. (3) 2-week chronic-plus-binge (NIAAA) ethanol feeding model in microbiota-humanized gnotobiotic mice colonized with stool from patients with alcohol-associated hepatitis. (4) 20-week Western-diet-feeding model of NASH. (5) 20-week Western-diet-feeding model in microbiota-humanized gnotobiotic mice colonized with stool from NASH patients.

RESULTS

Translocation of bacterial lipopolysaccharide to the peripheral circulation was seen in both ethanol-induced and diet-induced liver disease, but translocation of bacteria itself was restricted to only ethanol-induced liver disease. Moreover, the diet-induced steatohepatitis models developed more significant liver injury, inflammation, and fibrosis compared with ethanol-induced liver disease models, and this positively correlated with the level of lipopolysaccharide translocation.

CONCLUSIONS

More significant liver injury, inflammation, and fibrosis are seen in diet-induced steatohepatitis, which positively correlates with translocation of bacterial components, but not intact bacteria.

Different TLR signaling pathways drive pathology in experimental cerebral malaria vs. malaria-driven liver and lung pathology

Malaria infection causes multiple organ-specific lethal pathologies, including cerebral malaria, and severe liver and lung pathologies by inducing strong inflammatory responses. Gene polymorphism studies suggest that TLR4 and TLR2 contribute to severe malaria, but the roles of these signaling molecules in malaria pathogenesis remain incompletely understood. We hypothesize that danger-associated molecular patterns produced in response to malaria activate TLR2 and TLR4 signaling and contribute to liver and lung pathologies. By using a mouse model of Plasmodium berghei NK65 infection, we show that the combined TLR2 and TLR4 signaling contributes to malaria liver and lung pathologies and mortality. Macrophages, neutrophils, natural killer cells, and T cells infiltrate to the livers and lungs of infected wild-type mice more than TLR2,4-/- mice. Additionally, endothelial barrier disruption, tissue necrosis, and hemorrhage were higher in the livers and lungs of infected wild-type mice than in those of TLR2,4-/- mice. Consistent with these results, the levels of chemokine production, chemokine receptor expression, and liver and lung pathologic markers were higher in infected wild-type mice than in TLR2,4-/- mice. In addition, the levels of HMGB1, a potent TLR2- and TLR4-activating danger-associated molecular pattern, were higher in livers and lungs of wild-type mice than TLR2,4-/- mice. Treatment with glycyrrhizin, an immunomodulatory agent known to inhibit HMGB1 activity, markedly reduced mortality in wild-type mice. These results suggest that TLR2 and TLR4 activation by HMGB1 and possibly other endogenously produced danger-associated molecular patterns contribute to malaria liver and lung injury via signaling mechanisms distinct from those involved in cerebral malaria pathogenesis.

The comparative performance of a custom Canine NanoString® panel on FFPE and snap frozen liver biopsies

Formalin-Fixed Paraffin Embedded (FFPE) biopsies would provide a critical mass of cases to allow investigation of canine liver disease, however their use is often limited by challenges typically associated with transcriptomic analysis. This study evaluates the capability of NanoString® to measure the expression of a broad panel of genes in FFPE liver samples. RNA was isolated from matched histopathologically normal liver samples using FFPE (n = 6) and snap frozen in liquid nitrogen (n = 6) and measured using a custom NanoString® panel. Out of the 40 targets on the panel, 27 and 23 targets were above threshold for non-diseased snap frozen and FFPE tissue respectively. The binding density and total counts were significantly reduced in the FFPE samples relative to the snap frozen samples (p = 0.005, p = 0.01, respectively), confirming a reduction in sensitivity. The concordance between the snap frozen and FFPE samples was high, with correlations (R) ranging between 0.88 and 0.99 between the paired samples. An additional 14 immune-related targets, undetectable the non-diseased FFPE liver, were above threshold when the technique was applied to a series of diseased samples, further supporting their inclusion on this panel. This use of NanoString® based analysis opens up huge opportunity for retrospective evaluation of gene signatures in larger caseloads through harnessing the capacity of archived FFPE samples This information used alongside clinical and histological data will not only afford a way to explore disease etiopathogenesis, it may also offer insight into sub-types of liver disease in dogs, which cannot be discerned using more traditional diagnostic methods.

Luteolin: A Phytochemical to Mitigate S. Typhimurium Flagellin-Induced Inflammation in a Chicken In Vitro Hepatic Model

The use of natural feed supplements is an alternative tool to diminish the damage caused by certain bacteria, improving animal health and productivity. The present research aimed to investigate the proinflammatory effect of flagellin released from the bacterial flagellum of Salmonella enterica serovar Typhimurium and to attenuate the induced inflammation with luteolin as a plant-derived flavonoid on a chicken primary hepatocyte-non-parenchymal cell co-culture. Cells were cultured in a medium supplemented with 250 ng/mL flagellin and 4 or 16 µg/mL luteolin for 24 h. Cellular metabolic activity, lactate dehydrogenase (LDH) activity, interleukin-6, 8, 10 (IL-6, IL-8, IL-10), interferon-α, γ (IFN-α, IFN-γ), hydrogen peroxide (H₂O₂) and malondialdehyde (MDA) concentrations were determined. Flagellin significantly increased the concentration of the proinflammatory cytokine IL-8 and the ratio of IFN-γ/IL-10, while it decreased the level of IL-10, indicating that the model served adequate to study inflammation in vitro. Luteolin treatment at 4 µg/mL did not prove to be cytotoxic, as reflected by metabolic activity and extracellular LDH activity, and significantly reduced the flagellin-triggered IL-8 release of the cultured cells. Further, it had a diminishing effect on the concentration of IFN-α, H₂O₂ and MDA and restored the level of IL-10 and the ratio of IFN-γ/IL-10 when applied in combination with flagellin. These results suggest that luteolin at lower concentrations may protect hepatic cells from an excessive inflammatory response and act as an antioxidant to attenuate oxidative damage.

The interactions between inflammation and insulin resistance: molecular mechanisms in insulin-producing and insulin-dependent tissues

In the modern world the prevalence of obesity and type 2 diabetes mellitus (T2DM) significantly increases. In this light the risks of obesity-associated complications also grow up. The crucial linkage between obesity and its metabolic and cardiovascular complications is inflammatory process. The mechanism of this linkage is similar in pancreas and insulin-dependent tissues both on cells, cell-to-cell communication and signaling pathway levels: the catalysts are different lipids (cholesterol, free fatty acids, triglycerides), which are able to activate Toll-like receptors of innate immunity and inflammation. Nextly, IKK- and JNK-dependent cascades activate the secretion of inflammatory cytokines TNFa, IL-1b, IL-6 and others, which act by paracrine and autocrine manner and support inflammation both in local and systemic levels. Thus, insulin-producing and insulin-dependent tissues, which are involved in T2DM pathogenesis, through the inflammatory process integrate in pathogenic and self-maintaining cycle, which leads to the suppression of insulin secretion, pancreatic β-cell failure and the development of insulin-dependent tissues insulin resistance.

Toll- like receptor 2 polymorphism and IL-6 profile in relation to disease progression in chronic HBV infection: a case control study in Egyptian patients

Chronic hepatitis B (CHB) has a wide range of outcomes depending on host immune responses mainly Toll-like receptors (TLRs) signaling and released cytokines. Toll-like receptor 2 (TLR2) single nucleotide polymorphisms (SNPs) and interleukin 6 (IL-6) may influence the course of CHB. We aimed to elucidate the relation between TLR-2 polymorphism, IL-6 profile, and CHB progression. We analyzed TLR-2 polymorphism (SNP; rs3804099) in 185 CHB patients and 60 controls using TaqMan allelic discrimination assay. Serum IL-6 levels were assessed by ELISA. IL-6 levels were considerably higher in active CHB and cirrhotic patients compared with inactive carriers and controls (P < 0.001). IL-6 showed positive correlation with ALT and advanced fibrosis in active CHB patients (r = 0.31, P = 0.02). A significant positive correlation was noticed between IL-6 and HBV DNA PCR in all CHB groups. TT genotype of rs3804099/TLR-2 was significantly more prevalent in inactive carriers compared to active hepatitis patients (P = 0.04, OR = 0.39 and 95% CI: 0.16-0.95). Both heterozygous CT and mutant TT genotypes were significantly more frequent among inactive carriers compared to cirrhotic patients (P = 0.01, OR = 0.33, 95% CI: 0.13-0.81 and P = 0.009, OR = 0.32, 95% CI: 0.13-0.77). TT genotype was significantly related to lower IL-6 levels in active hepatitis and cirrhotic groups (P = 0.005 and P = 0.001, respectively) showing that TLR mutations would be associated with milder hepatitis activity and lower possibility for disease progression. There may be a positive association between TLR2 rs3804099 polymorphism and hepatitis B activity. IL-6 is a good indicator of CHB disease progression.

NAFLD and HBV interplay - related mechanisms underlying liver disease progression

Non-alcoholic fatty liver disease (NAFLD) and Hepatitis B virus infection (HBV) constitute common chronic liver diseases with worldwide distribution. NAFLD burden is expected to grow in the coming decade, especially in western countries, considering the increased incidence of diabetes and obesity. Despite the organized HBV vaccinations and use of anti-viral therapies globally, HBV infection remains endemic and challenging public health issue. As both NAFLD and HBV have been associated with the development of progressive fibrosis, cirrhosis and hepatocellular carcinoma (HCC), the co-occurrence of both diseases has gained great research and clinical interest. The causative relationship between NAFLD and HBV infection has not been elucidated so far. Dysregulated fatty acid metabolism and lipotoxicity in NAFLD disease seems to initiate activation of signaling pathways that enhance pro-inflammatory responses and disrupt hepatocyte cell homeostasis, promoting progression of NAFLD disease to NASH, fibrosis and HCC and can affect HBV replication and immune encountering of HBV virus, which may further have impact on liver disease progression. Chronic HBV infection is suggested to have an influence on metabolic changes, which could lead to NAFLD development and the HBV-induced inflammatory responses and molecular pathways may constitute an aggravating factor in hepatic steatosis development. The observed altered immune homeostasis in both HBV infection and NAFLD could be associated with progression to HCC development. Elucidation of the possible mechanisms beyond HBV chronic infection and NAFLD diseases, which could lead to advanced liver disease or increase the risk for severe complications, in the case of HBV-NAFLD co-existence is of high clinical significance in the context of designing effective therapeutic targets.

Polyphenol-Rich Liupao Tea Extract Prevents High-Fat Diet-Induced MAFLD by Modulating the Gut Microbiota

The modulation of gut microbiota dysbiosis might regulate the progression of metabolic-associated fatty liver disease (MAFLD). Here, we found that polyphenol-rich Liupao tea extract (PLE) prevents high-fat diet (HFD)-induced MAFLD in ApoE^-/- male mice accompanied by protection of the intestinal barrier and downregulation of lipopolysaccharide (LPS)-related Toll-like receptor 4 (TLR4)-myeloid differentiation primary response 88 (MyD88) signaling in the liver. Fecal microbiome transplantation (FMT) from PLE-and-HFD-treated mice delayed MAFLD development significantly compared with FMT from HFD-treated mice. In this case, 16S rRNA gene sequencing revealed that Rikenellaceae and Odoribacter were significantly enriched and that Helicobacter was significantly decreased in not only the HFD+PLE group but also the HFD+PLE-FMT group. Furthermore, the level of 3-sulfodeoxycholic acid was significantly decreased in the HFD+PLE-FMT group compared with the HFD-FMT group. In conclusion, our data demonstrate that PLE could modulate the MAFLD phenotype in mice and that this effect is partly mediated through modulation of the gut microbiota.

Pathogenesis of Alcohol-Associated Liver Disease

Excessive alcohol consumption is a global healthcare problem with enormous social, economic, and clinical consequences. While chronic, heavy alcohol consumption causes structural damage and/or disrupts normal organ function in virtually every tissue of the body, the liver sustains the greatest damage. This is primarily because the liver is the first to see alcohol absorbed from the gastrointestinal tract via the portal circulation and second, because the liver is the principal site of ethanol metabolism. Alcohol-induced damage remains one of the most prevalent disorders of the liver and a leading cause of death or transplantation from liver disease. Despite extensive research on the pathophysiology of this disease, there are still no targeted therapies available. Given the multifactorial mechanisms for alcohol-associated liver disease pathogenesis, it is conceivable that a multitherapeutic regimen is needed to treat different stages in the spectrum of this disease.

Host-microbiome interactions: Gut-Liver axis and its connection with other organs

An understanding of connections between gut microbiome and liver has provided important insights into the pathophysiology of liver diseases. Since gut microbial dysbiosis increases gut permeability, the metabolites biosynthesized by them can reach the liver through portal circulation and affect hepatic immunity and inflammation. The immune cells activated by these metabolites can also reach liver through lymphatic circulation. Liver influences immunity and metabolism in multiple organs in the body, including gut. It releases bile acids and other metabolites into biliary tract from where they enter the systemic circulation. In this review, the bidirectional communication between the gut and the liver and the molecular cross talk between the host and the microbiome has been discussed. This review also provides details into the intricate level of communication and the role of microbiome in Gut-Liver-Brain, Gut-Liver-Kidney, Gut-Liver-Lung, and Gut-Liver-Heart axes. These observations indicate a complex network of interactions between host organs influenced by gut microbiome.