Bile acid-induced IRF3 phosphorylation mediates cell death, inflammatory responses, and fibrosis in cholestasis-induced liver and kidney injury via regulation of ZBP1

Helicobacter pylori infection induces DNA double-strand breaks through the ACVR1/IRF3/POLD1 signaling axis to drive gastric tumorigenesis

Helicobacter pylori (H. pylori) infection plays a pivotal role in gastric carcinogenesis through inflammation-related mechanisms. Activin A receptor type I (ACVR1), known for encoding the type I receptor for bone morphogenetic proteins (BMPs), has been identified as a cancer diver gene across various tumors. However, the specific role of AVCR1 in H. pylori-induced gastric tumorigenesis remains incompletely understood. We conducted a comprehensive analysis of the clinical relevance of ACVR1 by integrating data from public databases and our local collection of human gastric tissues. In vitro cell cultures, patient-derived gastric organoids, and transgenic INS-GAS mouse models were used for Western blot, qRT-PCR, immunofluorescence, immunohistochemistry, luciferase assays, ChIP, and comet assays. Furthermore, to investigate the therapeutic potential, we utilized the ACVR1 inhibitor DM3189 in our in vivo studies. H. pylori infection led to increased expression of ACVR1 in gastric epithelial cells, gastric organoid and gastric mucosa of INS-GAS mice. ACVR1 activation led to DNA double-strand break (DSB) accumulation by inhibiting POLD1, a crucial DNA repair enzyme. The activation of POLD1 was facilitated by the transcription factor IRF3, with identified binding sites. Additionally, treatment with the ACVR1 inhibitor DM3189 significantly ameliorated H. pylori-induced gastric pathology and reduced DNA damage in INS-GAS mice. Immunohistochemistry analysis showed elevated levels of ACVR1 in H. pylori-positive gastritis tissues, showing a negative correlation with POLD1 expression. This study uncovers a novel signaling axis of AVCR1/IRF3/POLD1 in the pathogenesis of H. pylori infection. The upregulation of ACVR1 and the suppression of POLD1 upon H. pylori infection establish a connection between the infection, genomic instability, and the development of gastric carcinogenesis.

Causal Association of Primary Biliary Cholangitis with Adverse Pregnancy and Neonatal Outcomes: A Two-Sample Mendelian Randomization Study

Background

Primary biliary cholangitis (PBC) is associated with multiple adverse pregnancy events and neonatal outcomes. However, the available observational study evidence results are inconsistent, and causality is unclear.

Methods

We used a two-sample Mendelian randomization (MR) analysis to assess the association between PBC and multiple adverse pregnancy events and neonatal outcomes in a European population. Independent SNPs associated with PBC from genome-wide association studies (GWAS) were selected as instrumental variables. The inverse variance weighting (IVW) method was used as the primary analysis method, supplemented by the remaining four MR analysis methods. Heterogeneity and sensitivity analyses of instrumental variables were examined using Cochrane's Q, MR-PRESSO, MR-Egger, and leave-one-out methods.

Results

IVW estimates indicated that genetically predicted increased PBC was associated with lower birth weight (OR 0.991, 95% CI 0.983 ~ 0.998, P=0.018), decreased gestational age (OR 0.992, 95% CI 0.987 ~ 0.998, P=0.007), and increased risk of preterm birth (OR 1.043, 95% CI 1.007 ~ 1.081, P=0.019) were associated. For birth weight, the OR estimates obtained by weighted median (OR 0.988, 95% CI 0.980 ~ 0.996, P= 0.006) were consistent with IVW. In addition, no significant causal associations were found between genetically predicted PBC and preeclampsia or eclampsia, miscarriage, placental abruption, gestational diabetes mellitus, and postpartum hemorrhage.

Conclusion

Our study reveals that genetically predicted PBC is associated with low birth weight, decreased gestational age, and increased risk of preterm labor in a European population. However, current research does not establish a causal relationship between PBC and adverse pregnancy outcomes.

Sensitive and Deep Coverage Phosphoproteome Detection Method Reveals Spleen as a More Sensitive Organ than Liver in Early Detection of Liver Fibrosis-Related Signaling Protein Dysregulation

Although cathepsin S is transported from the spleen to the liver, where it cleaves collagen XVIII to produce endostatin and plays a critical role in the onset of early liver fibrosis, the relationship between liver fibrosis and spleen function remains underexplored. Given the roles of phosphorylation in disease, understanding its regulatory mechanism in early liver fibrosis is crucial. Despite advances in mass spectrometry enhancing phosphoproteomics, its application is limited by small clinical samples and subtle protein changes. We optimized a phosphoproteomic workflow, adjusting the protein amounts and using different enrichment beads and varied mass spectrometers, achieving deep phosphoproteomic coverage from minimal samples. We identified over 46,000 phosphosites in HepG2 cells and over 29,000 phosphosites in mouse liver samples using just 500 μg of proteins. Even with as little as 50 μg of 293T proteins, we detected over 11,000 phosphosites, 1.2 times more than the recently reported RUPE-phospho. Using the Sensitive and Deep Coverage Phosphoproteome Detection method, abbreviated as SDC-PhosDet, we demonstrated that in early liver fibrosis, the spleen exhibits more rapid and sensitive phosphorylation changes than the liver, affecting proteins closely linked to signaling and metabolism such as STAT1, JUN, CBL, ATP7B, and PTPN2. These findings highlight the spleen's role and offer new avenues for investigating the molecular mechanisms of early liver fibrosis, diagnosis, and intervention beyond the liver itself. Moreover, this method holds promise for applying phosphoproteomics to early-stage liver fibrosis using clinical microsamples.

Exploration of the Combined Mechanism of Direct and Indirect Effects of Paeoniflorin in the Treatment of Cholestasis

Cholestasis is a multifactorial hepatobiliary disorder, characterized by obstruction of bile flow and accumulation of bile, which in turn causes damage to liver cells and other tissues. In severe cases, it can result in the development of life-threatening conditions, including cirrhosis and liver cancer. Paeoniflorin (PF) has been demonstrated to possess favourable therapeutic potential for the treatment of cholestasis. The objective of this research was to examine the molecular mechanism of PF in the treatment of ANIT-induced cholestasis and to propose novel avenues for further research on the pharmacological effects of PF. In vivo and in vitro models of cholestasis were developed. The histopathological changes in the bile ducts and liver were evaluated through the use of hematoxylin and eosin (HE) staining. The extent of apoptosis was evaluated through the use of immunofluorescence (IF), immunoblotting (WB), and electron microscopy. The JNK signalling pathway was identified as the direct mechanism of action of PF through the utilisation of HuProt™ 20 K chips and other technologies. The present study demonstrated that PF markedly alleviated liver injury in an ANIT-induced cholestasis model. Specifically, PF was observed to attenuate cholestasis-induced liver injury by reducing the abnormal elevation of liver function indices and suppressing the expression of inflammatory mediators. Furthermore, PF exhibited anti-apoptotic properties in both in vivo and in vitro experiments, thereby mitigating cholestasis-induced hepatocyte apoptosis. These protective effects are attributable to the fact that PF exerts its action through direct interaction with the JNK pathway. It has been demonstrated that PF is capable of binding directly to MAPK8 (JNK1) and MAPK9 (JNK2), thereby inhibiting JNK activation and reducing apoptosis. With regard to the protection of bile ducts, PF may indirectly inhibit hepatocyte apoptosis by maintaining the structural integrity and tight junctions of bile duct cells. PF improved cholestasis by inhibiting hepatocyte apoptosis directly by targeting the JNK signaling pathway and indirectly inhibited hepatocyte apoptosis by improving the tight junctions of bile duct cells to regulate the bile duct microenvironment.

Hyodeoxycholic acid inhibits colorectal cancer proliferation through the FXR/EREG/EGFR axis

Background

The high morbidity and mortality rates of colorectal cancer (CRC) have been a public health concern globally, and the search for additional therapeutic options is imminent. Hyodeoxycholic acid (HDCA) has been receiving attention in recent years and has demonstrated potent efficacy in several diseases. Nonetheless, the antitumor effects and molecular pathways of HDCA in CRC remain largely unexplored.

Methods

In this study, we investigated how HDCA influences the growth potential of CRC cells using techniques such as flow cytometry, Edu assay, CCK-8, colony formation assay, Western blot analysis, and animal experiments.

Results

It was found that HDCA treatment of CRC cells was able to significantly inhibit the proliferative capacity of the cells. Furthermore, it was discovered that HDCA primarily stimulated Farnesoid X Receptor (FXR) rather than Takeda G protein coupled receptor 5 (TGR5) to suppress CRC growth. It was also confirmed that HDCA inhibited the Epiregulin (EREG)/Epidermal Growth Factor Receptor (EGFR) pathway by activating FXR, and a negative correlation between FXR and EREG was analyzed in CRC tissue samples. Finally, in vivo animal studies confirmed that HDCA inhibited CRC proliferation without hepatotoxicity.

Conclusion

Our findings indicate that HDCA suppresses the EREG/EGFR signaling route by activating FXR, thereby hindering the growth of CRC cells and demonstrating a tumor-inhibiting effect in CRC. This study may provide a new therapeutic strategy to improve the prognosis of CRC.

Role of VDAC1 in hepatocyte apoptosis during acute liver injury in rats induced by obstructive jaundice

Objectives

Exploring the role of VDAC1 in hepatocyte apoptosis during acute liver injury induced by obstructive jaundice.

Materials and Methods

Animal and cell models were established to investigate possible mechanisms during acute liver injury induced by OJ. Blood was collected for liver function assessment. H&E and TEM were employed to observe pathological changes in the liver tissues. Flow cytometry was used to measure the hepatocyte apoptosis. The mitochondrial MPTP assay was employed to assess the mitochondrial function of hepatocytes. IHC, western blot, and qRT-PCR were employed to determine the expression levels of VDAC1. Then, VDAC-siRNA was used to establish a knockdown model. Flow cytometry was used again to measure hepatocyte apoptosis following VDAC1 knockdown.

Results

The serum of rats in the OJ group exhibited a significant increase in liver function. Irregular tissue structure and mitochondrial morphology were observed in the liver tissues of OJ rats. A significant increase in mitochondrial permeability in hepatocytes. The expression levels of VDAC1 were significantly increased in the liver tissue of OJ rats. They were also significantly increased in the hepatocytes, primarily within mitochondrial membranes, determined by western blot in vivo and in vitro. Significant increases in the rates of hepatocyte apoptosis, particularly early apoptosis, were observed in the OJ groups. However, there was a reverse in the rates of hepatocyte apoptosis after knockdown regulation of VDAC1 only within the cells of the OJ group.

Conclusion

The up-regulation of VDAC in liver injury caused by obstructive jaundice may lead to increased early apoptosis of hepatocytes.

Gasdermin D deletion prevents liver injury and exacerbates extrahepatic damage in a murine model of alcohol-induced ACLF

Background

Gasdermin D (GSDM-D), a key executor of pyroptosis, is increased in various liver diseases and contributes to disease progression. Alcohol induces inflammasome activation and cell death, which are both linked to GSDM-D activation. However, its role in alcohol-induced acute-on-chronic liver failure (ACLF) remains unclear.

Methods

ACLF was induced in GSDM-D-deficient or wild-type (WT) mice by 28-day bile duct ligation surgery plus a single 5 g/kg alcohol binge leading to acute decompensation. Nine hours after the alcohol binge, blood, liver, kidney and cerebellum specimens were collected for analysis.

Results

Active GSDM-D was significantly increased in humans and mice ACLF livers compared with both healthy controls and cirrhotic livers. GSDM-D-deficient mice with ACLF showed decreased inflammation, neutrophil infiltration and fibrosis in the liver, together with a reduction in pyroptotic, apoptotic and necroptotic death, compared with WT ACLF mice. Notably, GSDM-D-deficient mice also showed decreased liver regeneration and hepatocyte function. This was associated with an increase in senescence and expression of stem-like/cholangiocyte markers in the liver. Interestingly, in the kidney, GSDM-D-deficient mice showed an increase in histopathological damage score, decreased function and increased expression of necroptosis-related genes. In the cerebellum, GSDM-D deficiency increased the expression of neuroinflammation markers, astrocyte activation and apoptosis-related genes.

Conclusion

Our data indicate that GSDM-D deficiency has organ-specific effects in ACLF. While it reduces inflammation, neutrophil activation, cell death and fibrosis in the liver, GSDM-D deficiency impairs the synthetic function and increases senescence in hepatocytes. GSDM-D deficiency also increases kidney injury and neuroinflammation in ACLF.

A Novel Multi-organ Male Model of Alcohol-induced Acute-on-chronic Liver Failure Reveals NET-mediated Hepatocellular Death, Which is Prevented by RIPK3 Inhibition

BACKGROUND & AIMS

Alcohol abuse is the most frequent precipitating factor of acute-on-chronic liver failure (ACLF). We aimed at developing an alcohol-induced ACLF model and dissecting its underlying molecular mechanisms.

METHODS

ACLF was triggered by a single alcohol binge (5 g/kg) in a bile duct ligation (BDL) liver fibrosis murine model. Liver, kidney, and brain tissues and behavior were assessed in mice. Livers from patients with sclerosing cholangitis with and without ACLF were also evaluated.

RESULTS

In advanced fibrosis induced by BDL, an alcohol binge induced features of ACLF, including significant liver damage, systemic inflammation (increased endotoxin and pro-inflammatory cytokines), and hepatocyte dysfunction compared with BDL alone. ACLF was associated with extrahepatic manifestations, including increased blood urea nitrogen and creatinine, impaired coagulation, and features of encephalopathy. We discovered significantly increased neutrophil count and neutrophil extracellular traps (NETs) in the liver, kidney, and brain in murine ACLF. Livers from ACLF mice showed increased pyroptosis (gasdermin D) and necroptosis (receptor-interacting protein kinase 3 [RIPK3]), when compared with BDL. In vitro, cell-free NETs were induced by alcohol and/or bile acids and triggered pyro-/necroptotic death in hepatocytes. NETosis, pyroptosis, and RIPK3 activation were validated in human livers with ACLF. Moreover, pharmacological inhibition of necroptosis with a RIPK3 inhibitor-ameliorated inflammation, NETs, and liver fibrosis, improving multi-organ ACLF pathophysiology.

CONCLUSIONS

Our novel ACLF model triggered by alcohol binge mimics key features of pathophysiology and multi-organ impairment in human ACLF. Our results indicate that neutrophil infiltration and NETs contribute to hepatocyte cell death via pyroptosis and necroptosis in ACLF, identifying RIPK3 as a potential therapeutic target.

bcIRF5 activates bcTBK1 phosphorylation to enhance PANoptosis during GCRV infection

TBK1 is an important IFN antiviral signalling factor, and in previous work black carp TBK1 (bcTBK1) and black carp IRF5 (bcIRF5) together promoted cell death in GCRV-infected cells. In this research, bcTBK1 and bcIRF5 were investigated both in vivo and in vitro to delineate their individual and combined functions. This study demonstrated that both bcTBK1 and bcIRF5 expressions were modulated in response to GCRV infection across the intestine, gill, kidney and spleen. In bcgill cells, overexpression of bcTBK1 and bcIRF5 initially suppressed the expression of cell death-related genes, including RIPK1, caspase1, caspase3 and bax, but this suppression was negated upon GCRV infection. In vivo, mRNA expression levels of RIPK1 and related genes varied by tissue following bcTBK1 or bcIRF5 overexpression and GCRV infection. Notably, intracellular co-overexpression of bcTBK1 and bcIRF5 led to significant upregulation of caspase3, caspase1, bax, and IL1β, along with enhanced caspase3 activity post-GCRV infection. This co-expression correlated with higher survival rates in black carp during GCRV infection and increased caspase3 mRNA in the spleen and gills. Hematoxylin-eosin (HE) staining indicated disorganized spleen tissue and edematous, hyperplastic gill changes in co-transfected groups after infection. TUNEL staining of tissue sections showed that DNA breakage was significantly stronger in the co-transfected group than in the other groups during GCRV infection. Further phosphorylation experiments showed that bcIRF5 promoted phosphorylation modification of bcTBK1. Thus, these data suggest that bcIRF5 activates bcTBK1 by enhancing its phosphorylation and promotes PANoptosis in GCRV-infected cells.

The multiple roles of interferon regulatory factor family in health and disease

Interferon Regulatory Factors (IRFs), a family of transcription factors, profoundly influence the immune system, impacting both physiological and pathological processes. This review explores the diverse functions of nine mammalian IRF members, each featuring conserved domains essential for interactions with other transcription factors and cofactors. These interactions allow IRFs to modulate a broad spectrum of physiological processes, encompassing host defense, immune response, and cell development. Conversely, their pivotal role in immune regulation implicates them in the pathophysiology of various diseases, such as infectious diseases, autoimmune disorders, metabolic diseases, and cancers. In this context, IRFs display a dichotomous nature, functioning as both tumor suppressors and promoters, contingent upon the specific disease milieu. Post-translational modifications of IRFs, including phosphorylation and ubiquitination, play a crucial role in modulating their function, stability, and activation. As prospective biomarkers and therapeutic targets, IRFs present promising opportunities for disease intervention. Further research is needed to elucidate the precise mechanisms governing IRF regulation, potentially pioneering innovative therapeutic strategies, particularly in cancer treatment, where the equilibrium of IRF activities is of paramount importance.

Role of gut/liver metabolites and gut microbiota in liver fibrosis caused by cholestasis

AIM OF THE STUDY

Cholestasis induces severe liver injury and subsequent liver fibrosis. However, a comprehensive understanding of the relationships between liver fibrosis and cholestasis-induced changes in metabolites in the gut and fibrotic liver tissue and in the gut microbiota is insufficient.

METHODS

Common bile duct ligation (BDL) was employed to establish a cholestatic liver fibrosis model in mice for 26 days. Fibrotic liver tissue and the gut contents were collected. Untargeted metabolomics was conducted for the determination of metabolites in the gut contents and liver tissues. Metagenomics was adopted to explore the gut microbiota.

RESULTS

The metabolites in the gut contents and liver tissues between normal and cholestatic liver fibrosis mice were highly distinct. Beta-alanine metabolism and glutathione metabolism were downregulated in the gut of the BDL group. Galactose metabolism, biosynthesis of unsaturated fatty acids, and ABC transporters were upregulated in the gut and downregulated in the liver of the BDL group. Arginine biosynthesis, taurine and hypotaurine metabolism, arginine and proline metabolism, and primary bile acid biosynthesis were downregulated in the gut and upregulated in the liver of the BDL group. Metagenomic analysis revealed that the alpha diversity of the microbiota in the BDL group decreased. The altered structure of the gut microbiota in the BDL group led to the hypofunction of important metabolic pathways (such as folate biosynthesis, histidine metabolism, thiamine metabolism, biotin metabolism, and phenylalanine, tyrosine and tryptophan biosynthesis) and enzymes (such as NADH, DNA helicase, and DNA-directed DNA polymerase). Correlation analyses indicated that certain gut microbes were associated with gut and liver metabolites.

CONCLUSIONS

Untargeted metabolomics and metagenomics provided comprehensive information on gut and liver metabolism and gut microbiota in mice with cholestatic liver fibrosis. Therefore, significantly altered bacteria and metabolites may help provide some targets against cholestatic liver fibrosis in the future.

IRF3 regulates neuroinflammatory responses and the expression of genes associated with Alzheimer's disease

The pathological role of interferon signaling is emerging in neuroinflammatory disorders, yet, the specific role of Interferon Regulatory Factor 3 (IRF3) in neuroinflammation remains poorly understood. Here, we show that global IRF3 deficiency delays TLR4-mediated signaling in microglia and attenuates the hallmark features of LPS-induced inflammation such as cytokine release, microglial reactivity, astrocyte activation, myeloid cell infiltration, and inflammasome activation. Moreover, expression of a constitutively active IRF3 (S388D/S390D: IRF3-2D) in microglia induces a transcriptional program reminiscent of the Activated Response Microglia and the expression of genes associated with Alzheimer's disease, notably apolipoprotein-e. Using bulk-RNAseq of IRF3-2D brain myeloid cells, we identified Z-DNA binding protein-1 (ZBP1) as a target of IRF3 that is relevant across various neuroinflammatory disorders. Lastly, we show IRF3 phosphorylation and IRF3-dependent ZBP1 induction in response to Aβ in primary microglia cultures. Together, our results identify IRF3 as an important regulator of LPS and Aβ -mediated neuroinflammatory responses and highlight IRF3 as a central regulator of disease-specific gene activation in different neuroinflammatory diseases.

IRF3 inhibits inflammatory signaling pathways in macrophages to prevent viral pathogenesis

Viral inflammation contributes to pathogenesis and mortality during respiratory virus infections. IRF3, a critical component of innate antiviral immune responses, interacts with pro-inflammatory transcription factor NF-κB, and inhibits its activity. This mechanism helps suppress inflammatory gene expression in virus-infected cells and mice. We evaluated the cells responsible for IRF3-mediated suppression of viral inflammation using newly engineered conditional Irf3Δ/Δ mice. Irf3Δ/Δ mice, upon respiratory virus infection, showed increased susceptibility and mortality. Irf3 deficiency caused enhanced inflammatory gene expression, lung inflammation, immunopathology, and damage, accompanied by increased infiltration of pro-inflammatory macrophages. Deletion of Irf3 in macrophages (Irf3MKO) displayed, similar to Irf3Δ/Δ mice, increased inflammatory responses, macrophage infiltration, lung damage, and lethality, indicating that IRF3 in these cells suppressed lung inflammation. RNA-seq analyses revealed enhanced NF-κB-dependent gene expression along with activation of inflammatory signaling pathways in infected Irf3MKO lungs. Targeted analyses revealed activated MAPK signaling in Irf3MKO lungs. Therefore, IRF3 inhibited inflammatory signaling pathways in macrophages to prevent viral inflammation and pathogenesis.

The Role of Interferon Regulatory Factors in Liver Diseases

The interferon regulatory factors (IRFs) family comprises 11 members that are involved in various biological processes such as antiviral defense, cell proliferation regulation, differentiation, and apoptosis. Recent studies have highlighted the roles of IRF1-9 in a range of liver diseases, including hepatic ischemia-reperfusion injury (IRI), alcohol-induced liver injury, Con A-induced liver injury, nonalcoholic fatty liver disease (NAFLD), cirrhosis, and hepatocellular carcinoma (HCC). IRF1 is involved in the progression of hepatic IRI through signaling pathways such as PIAS1/NFATc1/HDAC1/IRF1/p38 MAPK and IRF1/JNK. The regulation of downstream IL-12, IL-15, p21, p38, HMGB1, JNK, Beclin1, β-catenin, caspase 3, caspase 8, IFN-γ, IFN-β and other genes are involved in the progression of hepatic IRI, and in the development of HCC through the regulation of PD-L1, IL-6, IL-8, CXCL1, CXCL10, and CXCR3. In addition, IRF3-PPP2R1B and IRF4-FSTL1-DIP2A/CD14 pathways are involved in the development of NAFLD. Other members of the IRF family also play moderately important functions in different liver diseases. Therefore, given the significance of IRFs in liver diseases and the lack of a comprehensive compilation of their molecular mechanisms in different liver diseases, this review is dedicated to exploring the molecular mechanisms of IRFs in various liver diseases.

Z-DNA binding protein 1 orchestrates innate immunity and inflammatory cell death

Innate immunity is not only the first line of host defense against microbial infections but is also crucial for the host responses against a variety of noxious stimuli. Z-DNA binding protein 1 (ZBP1) is a cytosolic nucleic acid sensor that can induce inflammatory cell death in both immune and nonimmune cells upon sensing of incursive virus-derived Z-form nucleic acids and self-nucleic acids via its Zα domain. Mechanistically, aberrantly expressed or activated ZBP1 induced by pathogens or noxious stimuli enables recruitment of TANK binding kinase 1 (TBK1), interferon regulatory factor 3 (IRF3), receptor-interacting serine/threonine-protein kinase 1 (RIPK1) and RIPK3 to drive type I interferon (IFN-I) responses and activation of nuclear factor kappa B (NF-κB) signaling. Meanwhile, ZBP1 promotes the assembly of ZBP1- and absent in melanoma 2 (AIM2)-PANoptosome, which ultimately triggers PANoptosis through caspase 3-mediated apoptosis, mixed lineage kinase domain like pseudokinase (MLKL)-mediated necroptosis, and gasdermin D (GSDMD)-mediated pyroptosis. In response to damaged mitochondrial DNA, ZBP1 can interact with cyclic GMP-AMP synthase to augment IFN-I responses but inhibits toll like receptor 9-mediated inflammatory responses. This review summarizes the structure and expression pattern of ZBP1, discusses its roles in human diseases through immune-dependent (e.g., the production of IFN-I and pro-inflammatory cytokines) and -independent (e.g., the activation of cell death) functions, and highlights the attractive prospect of manipulating ZBP1 as a promising therapeutic target in diseases.

Highly Expressed Z-DNA Binding Protein 1 in Esophageal Cancer Promotes Tumor Growth

BACKGROUND

Esophageal cancer (ESCA) is a common malignant tumor of the digestive tract, and its poor prognosis is mainly attributed to the occurrence of invasion and metastasis. Z-DNA binding protein 1 (ZBP1), as a mRNA regulatory factor, plays an important role in the occurrence and development of various tumors. However, the role of ZBP1 in ESCA is not yet understood.

AIMS

This study aims to explore the expression of ZBP1 in ESCA and its role in the development of ESCA.

METHODS

Using bioinformatics analysis and immunohistochemistry staining, we detected the expression of ZBP1 in ESCA and normal tissues. The potential mechanism of ZBP1 in ESCA was analyzed from the aspects of genetic mutations, protein interaction networks, and pathway enrichment. We performed functional experiments in vitro to elucidate the effect of ZBP1 on ESCA cells.

RESULTS

ZBP1 was found to be significantly upregulated in ESCA compared to adjacent noncancerous tissues, and its expression is closely related to gender, age, and lymph node metastasis. In ESCA, the genetic variation rate of ZBP1 is 8%, and its expression is positively correlated with immune cell infiltration. The ZBP1 co-expressed gene is mainly involved in processes such as lymph node proliferation and intercellular adhesion. In vitro experiments have confirmed that downregulation of ZBP1 significantly inhibited the proliferation, migration, and invasion of ESCA cells.

CONCLUSION

This research proves that downregulation of ZBP1 can inhibit the progression of ESCA. This finding indicates that ZBP1 may be a novel biomarker to improve the diagnosis and treatment of ESCA.

Mitochondrial (mt)DNA-cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) signaling promotes pyroptosis of macrophages via interferon regulatory factor (IRF)7/IRF3 activation to aggravate lung injury during severe acute pancreatitis

BACKGROUND

Macrophage proinflammatory activation contributes to the pathology of severe acute pancreatitis (SAP) and, simultaneously, macrophage functional changes, and increased pyroptosis/necrosis can further exacerbate the cellular immune suppression during the process of SAP, where cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) plays an important role. However, the function and mechanism of cGAS-STING in SAP-induced lung injury (LI) remains unknown.

METHODS

Lipopolysaccharide (LPS) was combined with caerulein-induced SAP in wild type, cGAS -/- and sting -/- mice. Primary macrophages were extracted via bronchoalveolar lavage and peritoneal lavage. Ana-1 cells were pretreated with LPS and stimulated with nigericin sodium salt to induce pyroptosis in vitro.

RESULTS

SAP triggered NOD-, LRR-, and pyrin domain-containing protein 3 (NLRP3) inflammasome activation-mediated pyroptosis of alveolar and peritoneal macrophages in mouse model. Knockout of cGAS/STING could ameliorate NLRP3 activation and macrophage pyroptosis. In addition, mitochondrial (mt)DNA released from damaged mitochondria further induced macrophage STING activation in a cGAS- and dose-dependent manner. Upregulated STING signal can promote NLRP3 inflammasome-mediated macrophage pyroptosis and increase serum interleukin (IL)-6, IL-1β, and tumor necrosis factor (TNF)-α levels and, thus, exacerbate SAP-associated LI (SAP-ALI). Downstream molecules of STING, IRF7, and IRF3 connect the mtDNA-cGAS-STING axis and the NLRP3-pyroptosis axis.

CONCLUSIONS

Negative regulation of any molecule in the mtDNA-cGAS-STING-IRF7/IRF3 pathway can affect the activation of NLRP3 inflammasomes, thereby reducing macrophage pyroptosis and improving SAP-ALI in mouse model.

IRF3 regulates neuroinflammatory responses and the expression of genes associated with Alzheimer's disease

The pathological role of interferon signaling is emerging in neuroinflammatory disorders, yet, the specific role of Interferon Regulatory Factor 3 (IRF3) in neuroinflammation remains poorly understood. Here, we show that global IRF3 deficiency delays TLR4-mediated signaling in microglia and attenuates the hallmark features of LPS-induced inflammation such as cytokine release, microglial reactivity, astrocyte activation, myeloid cell infiltration, and inflammasome activation. Moreover, expression of a constitutively active IRF3 (S388D/S390D:IRF3-2D) in microglia induces a transcriptional program reminiscent of the Activated Response Microglia and the expression of genes associated with Alzheimer's Disease, notably apolipoprotein-e. Lastly, using bulk-RNAseq of IRF3-2D brain myeloid cells, we identified Z-DNA binding protein-1 as a target of IRF3 that is relevant across various neuroinflammatory disorders. Together, our results identify IRF3 as an important regulator of LPS-mediated neuroinflammatory responses and highlight IRF3 as a central regulator of disease-specific gene activation in different neuroinflammatory diseases.

Quantitative proteomics reveals the protective effects of Yinchenzhufu decoction against cholestatic liver fibrosis in mice by inhibiting the PDGFRβ/PI3K/AKT pathway

Introduction: Yinchenzhufu decoction (YCZFD) is a traditional Chinese medicine formula with hepatoprotective effects. In this study, the protective effects of YCZFD against cholestatic liver fibrosis (CLF) and its underlying mechanisms were evaluated. Methods: A 3, 5-diethoxycarbonyl-1, 4-dihydro-collidine (DDC)-induced cholestatic mouse model was used to investigate the amelioration of YCZFD on CLF. Data-independent acquisition-based mass spectrometry was performed to investigate proteomic changes in the livers of mice in three groups: control, model, and model treated with high-dose YCZFD. The effects of YCZFD on the expression of key proteins were confirmed in mice and cell models. Results: YCZFD significantly decreased the levels of serum biochemical, liver injury, and fibrosis indicators of cholestatic mice. The proteomics indicated that 460 differentially expressed proteins (DEPs) were identified among control, model, and model treated with high-dose YCZFD groups. Enrichment analyses of these DEPs revealed that YCZFD influenced multiple pathways, including PI3K-Akt, focal adhesion, ECM-receptor interaction, glutathione metabolism, and steroid biosynthesis pathways. The expression of platelet derived growth factor receptor beta (PDGFRβ), a receptor associated with the PI3K/AKT and focal adhesion pathways, was upregulated in the livers of cholestatic mice but downregulated by YCZFD. The effects of YCZFD on the expression of key proteins in the PDGFRβ/PI3K/AKT pathway were further confirmed in mice and transforming growth factor-β-induced hepatic stellate cells. We uncovered seven plant metabolites (chlorogenic acid, scoparone, isoliquiritigenin, glycyrrhetinic acid, formononetin, atractylenolide I, and benzoylaconitine) of YCZFD that may regulate PDGFRβ expression. Conclusion: YCZFD substantially protects against DDC-induced CLF mainly through regulating the PDGFRβ/PI3K/AKT signaling pathway.

G-CSF increases calprotectin expression, liver damage and neuroinflammation in a murine model of alcohol-induced ACLF

Background and aims: Granulocyte colony-stimulating factor (G-CSF) has been proposed as a therapeutic option for patients with ACLF, however clinical outcomes are controversial. We aimed at dissecting the role of G-CSF in an alcohol-induced murine model of ACLF. Methods: ACLF was triggered by a single alcohol binge (5 g/kg) in a bile duct ligation (BDL) liver fibrosis model. A subgroup of mice received two G-CSF (200 μg/kg) or vehicle injections prior to acute decompensation with alcohol. Liver, blood and brain tissues were assessed. Results: Alcohol binge administered to BDL-fibrotic mice resulted in features of ACLF indicated by a significant increase in liver damage and systemic inflammation compared to BDL alone. G-CSF treatment in ACLF mice induced an increase in liver regeneration and neutrophil infiltration in the liver compared to vehicle-treated ACLF mice. Moreover, liver-infiltrating neutrophils in G-CSF-treated mice exhibited an activated phenotype indicated by increased expression of CXC motif chemokine receptor 2, leukotriene B4 receptor 1, and calprotectin. In the liver, G-CSF triggered increased oxidative stress, type I interferon response, extracellular matrix remodeling and inflammasome activation. Circulating IL-1β was also increased after G-CSF treatment. In the cerebellum, G-CSF increased neutrophil infiltration and S100a8/9 expression, induced microglia proliferation and reactive astrocytes, which was accompanied by oxidative stress, and inflammasome activation compared to vehicle-treated ACLF mice. Conclusion: In our novel ACLF model triggered by alcohol binge that mimics ACLF pathophysiology, neutrophil infiltration and S100a8/9 expression in the liver and brain indicate increased tissue damage, accompanied by oxidative stress and inflammasome activation after G-CSF treatment.

The Role of Inflammation in Cholestatic Liver Injury

Cholestasis is a common clinical event in which bile formation and excretion are blocked, leading to retention of bile acids or bile salts; whether it occurs intra- or extrahepatically, primary or secondary, its pathogenesis is still unclear and is influenced by a combination of factors. In a variety of inflammatory and immune cells such as neutrophils, macrophages (intrahepatic macrophages are also known as Kupffer cells), mast cells, NK cells, and even T cells in humoral immunity and B cells in cellular immunity, inflammation can be a "second strike" against cholestatic liver injury. These cells, stimulated by a variety of factors such as bile acids, inflammatory chemokines, and complement, can be activated and accumulate in the cholestatic liver, and with the involvement of inflammatory mediators and modulation by cytokines, can lead to destruction of hepatocytes and bile duct epithelial cells and exacerbate (and occasionally retard) the progression of cholestatic liver disease. In this paper, we summarized the new research advances proposed so far regarding the relationship between inflammation and cholestasis, aiming to provide reference for researchers and clinicians in the field of cholestatic liver injury research.