Hepatic Zbtb18 (Zinc Finger and BTB Domain Containing 18) alleviates hepatic steatohepatitis via FXR (Farnesoid X Receptor)

Buyang Huanwu Decoction stabilizes atherosclerotic vulnerable plaques by regulating intestinal flora, TLR4-NF-κB-NLRP3 inflammatory pathway and mitophagy

OBJECTIVE

This study explores the anti-atherosclerosis (AS) effects of Buyang Huanwu Decoction (BYHWD), focusing on its regulatory effects on the TLR4/NF-κB/NLRP3 inflammatory pathway, gut microbiota metabolites, and mitochondrial autophagy. Through the triple regulatory mechanisms of gut microbiota, the TLR4/NF-κB/NLRP3 inflammatory pathway, and mitochondrial autophagy, this study explores a novel strategy for stabilizing vulnerable AS plaques.

MATERIALS AND METHODS

The active components of Buyang Huanwu Decoction (BYHWD) were detected using LC-MS/MS. By feeding a high-fat diet (HFD) and adding 1.3 % choline chloride to the drinking water to induce ApoE-/- mice gut microbiota dysbiosis, an AS mouse model with vulnerable plaques was established. The treatment groups were administered low, medium, and high doses of BYHWD, as well as broad-spectrum antibiotics. The effects of BYHWD on the vulnerable plaque area in the aorta, collagen content, macrophage and α-SMA protein expression, levels of inflammatory cytokines, reactive oxygen species (ROS), LC3 and NLRP3 expression, gut microbiota composition and abundance, serum trimethylamine-N-oxide (TMAO) levels, and the total bile acid content in the liver, serum, and gallbladder, as well as mitochondrial autophagy, were evaluated applying hematoxylin-eosin (HE) staining, Oil Red O staining, Sirius Red staining, immunohistochemistry, ELISA, immunofluorescence, 16S rRNA sequencing, biochemical analysis, and LC-MS detection. Western blot for TLR4, MyD88, ASC, pro-caspase-1, caspase-1, NLRP3, p-NF-κB/NF-κB, GPR41, GPR43, CYP7A1, CYP27A1, FMO3, FXR, TGR5, NIX, BNIP3, FUNDC1, PINK1, and Parkin proteins expression level.

RESULTS

A total of 31 major active components were identified in Buyang Huanwu Decoction (BYHWD). BYHWD significantly reduced the vulnerable plaque area in the ApoE-/- mouse model of AS, decreased the expression of inflammatory cytokines, inhibited the protein expression of TLR4, MyD88, p-NF-κB/NF-κB, ASC, pro-caspase-1, NLRP3, FMO3, NIX, BNIP3, FUNDC1, and PINK1/Parkin in aortic tissues, downregulated ROS levels and mitochondrial autophagy activity, regulated gut microbiota abundance, reduced serum TMAO levels, and up-regulated the expression of gut microbiota-related proteins, including GPR41, GPR43, CYP7A1, CYP27A1, FXR, and TGR5.

CONCLUSION

BYHWD exerts anti-AS effects through the inhibition of the TLR4/NF-κB/NLRP3 inflammatory pathway, modulating the gut microbiota, and stabilizing mitochondrial autophagy. The in-depth investigation of this mechanism effectively expands the therapeutic potential of BYHWD in the prevention and treatment of cardiovascular diseases and provides new theoretical insights and therapeutic targets for AS-related research.

FXR protects against neonatal sepsis by enhancing the immunosuppressive function of MDSCs

Myeloid-derived suppressor cells (MDSCs) play a protective role against neonatal inflammation during the early postnatal period. However, the mechanisms regulating neonatal MDSC function remain to be fully elucidated. In this study, we report that the bile acid receptor farnesoid X receptor (FXR) acts as a positive regulator of neonatal MDSC function. The FDA-approved FXR agonist obeticholic acid (OCA) protects against neonatal sepsis in an FXR-dependent manner. Genetic deficiency of FXR impairs the immunosuppressive and antibacterial functions of MDSCs, thereby exacerbating the severity of neonatal sepsis. Adoptive transfer of MDSCs alleviates sepsis in both Fxr-/- and Fxrfl/flMrp8-Cre+ pups. Mechanistic studies revealed that Hif1α, a well-established regulator of MDSCs, is a direct transcriptional target of FXR. In patients with neonatal sepsis, downregulation of FXR and HIF-1α in MDSCs was observed, which was inversely correlated with clinical parameters. These observations demonstrate the importance of FXR in neonatal MDSC function and its therapeutic potential in neonatal sepsis.

FXR activation suppresses NF-κB signaling, proliferation and migration in cervical cancer cells

Background

The Farnesoid X receptor (FXR) is a nuclear receptor known for its role in inflammation regulation and tumor suppression in various cancers. However, its functional significance and underlying mechanisms in cervical cancer (CC) remain unclear. The persistent activation of the nuclear factor kappa B (NF-κB) signaling pathway due to inflammation is a key driver of cancer progression. This study investigates the effects of FXR activation in CC and its interaction with the NF-κB pathway.

Methods

CC cells were treated with GW4064, an FXR agonist (3 µM), and xenograft tumor models were assigned to receive 30 mg/kg GW4064. NF-κB-mediated transcriptional activity was assessed using a dual-luciferase reporter assay. Gene expression in CC cells and mouse tissues was analyzed via quantitative real-time polymerase chain reaction (qRT-PCR), while key proteins in the NF-κB and STAT3 signaling pathways were examined using Western blotting. Cell proliferation, migration, and invasion were evaluated through methylthiazolyldiphenyl-tetrazolium bromide (MTT), wound healing, and real-time cellular analysis (RTCA), respectively. Apoptosis was measured using a fluorescein isothiocyanate (FITC) Annexin V Apoptosis Detection Kit I.

Results

FXR deletion in 6- to 8-week-old C57B/6 female mice led to abnormal upregulation of inflammatory genes in the cervix and aberrant NF-κB activation. Treatment with GW4064 suppressed NF-κB-regulated gene expression in Hela and Siha CC cells and inhibited NF-κB activity at the transcriptional level. Mechanistically, FXR activation suppressed tumor necrosis factor alpha (TNFα)-induced phosphorylation of NF-κB inhibitor alpha (IκBα) by directly binding to the promoter of inhibitor of nuclear factor kappa B kinase regulatory subunit gamma (IKBKG), thereby inhibiting its transcription. Additionally, FXR activation reduced CC cell proliferation and migration. In vivo, xenograft experiments in Hela cell-bearing Bagg's albino (BALB/c) nude female mice confirmed that FXR activation significantly suppressed tumor growth.

Conclusions

These findings highlight FXR activation as a potential therapeutic strategy for CC by targeting the NF-κB pathway as shown in both in vitro and in vivo.

Crosstalk Between Bile Acids and Intestinal Epithelium: Multidimensional Roles of Farnesoid X Receptor and Takeda G Protein Receptor 5

Bile acids and their corresponding intestinal epithelial receptors, the farnesoid X receptor (FXR), the G protein-coupled bile acid receptor (TGR5), play crucial roles in the physiological and pathological processes of intestinal epithelial cells. These acids and receptors are involved in the regulation of intestinal absorption, signal transduction, cellular proliferation and repair, cellular senescence, energy metabolism, and the modulation of gut microbiota. A comprehensive literature search was conducted using PubMed, employing keywords such as bile acid, bile acid receptor, FXR (nr1h4), TGR5 (gpbar1), intestinal epithelial cells, proliferation, differentiation, senescence, energy metabolism, gut microbiota, inflammatory bowel disease (IBD), colorectal cancer (CRC), and irritable bowel syndrome (IBS), with a focus on publications available in English. This review examines the diverse effects of bile acid signaling and bile receptor pathways on the proliferation, differentiation, senescence, and energy metabolism of intestinal epithelial cells. Additionally, it explores the interactions between bile acids, their receptors, and the microbiota, as well as the implications of these interactions for host health, particularly in relation to prevalent intestinal diseases. Finally, the review highlights the importance of developing highly specific ligands for FXR and TGR5 receptors in the context of metabolic and intestinal disorders.

Tissue macrophages: origin, heterogenity, biological functions, diseases and therapeutic targets

Macrophages are immune cells belonging to the mononuclear phagocyte system. They play crucial roles in immune defense, surveillance, and homeostasis. This review systematically discusses the types of hematopoietic progenitors that give rise to macrophages, including primitive hematopoietic progenitors, erythro-myeloid progenitors, and hematopoietic stem cells. These progenitors have distinct genetic backgrounds and developmental processes. Accordingly, macrophages exhibit complex and diverse functions in the body, including phagocytosis and clearance of cellular debris, antigen presentation, and immune response, regulation of inflammation and cytokine production, tissue remodeling and repair, and multi-level regulatory signaling pathways/crosstalk involved in homeostasis and physiology. Besides, tumor-associated macrophages are a key component of the TME, exhibiting both anti-tumor and pro-tumor properties. Furthermore, the functional status of macrophages is closely linked to the development of various diseases, including cancer, autoimmune disorders, cardiovascular disease, neurodegenerative diseases, metabolic conditions, and trauma. Targeting macrophages has emerged as a promising therapeutic strategy in these contexts. Clinical trials of macrophage-based targeted drugs, macrophage-based immunotherapies, and nanoparticle-based therapy were comprehensively summarized. Potential challenges and future directions in targeting macrophages have also been discussed. Overall, our review highlights the significance of this versatile immune cell in human health and disease, which is expected to inform future research and clinical practice.

Minocycline prevents early age-related cognitive decline in a mouse model of intellectual disability caused by ZBTB18/RP58 haploinsufficiency

Haploinsufficiency of the transcriptional repressor ZBTB18/RP58 is associated with intellectual disability. However, the mechanisms causing this disability are unknown, and preventative measures and treatments are not available. Here, we assessed multiple behaviors in Zbtb18/Rp58 heterozygous-knockout mice, and examined local field potentials, DNA fragmentation, mitochondrial morphology, and performed histochemical and transcriptome analyses in the hippocampus to evaluate chronic inflammation. In wild-type mice, object location memory was present at a similar level at 2 and 4-5 months of age, and became impaired at 12-18 months. In contrast, Zbtb18/Rp58 heterozygous-knockout mice displayed early onset impairments in object location memory by 4-5 months of age. These mice also exhibited earlier accumulation of DNA and mitochondrial damage, and activated microglia in the dentate gyrus, which are associated with defective DNA repair. Notably, chronic minocycline therapy, which has neuroprotective and anti-inflammatory effects, attenuated age-related phenotypes, including accumulation of DNA damage, increased microglial activation, and impairment of object location memory. Our results suggest that Zbtb18/Rp58 activity is required for DNA repair and its reduction results in DNA and mitochondrial damage, increased activation of microglia, and inflammation, leading to accelerated declines in cognitive functions. Minocycline has potential as a therapeutic agent for the treatment of ZBTB18/RP58 haploinsufficiency-associated cognitive dysfunction.

Examining the Pathogenesis of MAFLD and the Medicinal Properties of Natural Products from a Metabolic Perspective

Metabolic-associated fatty liver disease (MAFLD), characterized primarily by hepatic steatosis, has become the most prevalent liver disease worldwide, affecting approximately two-fifths of the global population. The pathogenesis of MAFLD is extremely complex, and to date, there are no approved therapeutic drugs for clinical use. Considerable evidence indicates that various metabolic disorders play a pivotal role in the progression of MAFLD, including lipids, carbohydrates, amino acids, and micronutrients. In recent years, the medicinal properties of natural products have attracted widespread attention, and numerous studies have reported their efficacy in ameliorating metabolic disorders and subsequently alleviating MAFLD. This review aims to summarize the metabolic-associated pathological mechanisms of MAFLD, as well as the natural products that regulate metabolic pathways to alleviate MAFLD.

The lack of PPARα exacerbated the progression of non-alcoholic steatohepatitis in mice with spleen deficiency syndrome by triggering an inflammatory response

Background

In addition to abnormal liver inflammation, the main symptoms of non-alcoholic steatohepatitis (NASH) are often accompanied by gastrointestinal digestive dysfunction, consistent with the concept of spleen deficiency (SD) in traditional Chinese medicine. As an important metabolic sensor, whether peroxisome proliferator-activated receptor alpha (PPARα) participates in regulating the occurrence and development of NASH with SD (NASH-SD) remains to be explored.

Methods

Clinical liver samples were collected for RNA-seq analysis. C57BL/6J mice induced by folium sennae (SE) were used as an SD model. qPCR analysis was conducted to evaluate the inflammation and metabolic levels of mice. PPARα knockout mice (PPARαko) were subjected to SE and methionine-choline-deficient (MCD) diet to establish the NASH-SD model. The phenotype of NASH and the inflammatory indicators were measured using histopathologic analysis and qPCR as well.

Results

The abnormal expression of PPARα signaling, coupled with metabolism and inflammation, was found in the results of RNA-seq analysis from clinical samples. SD mice showed a more severe inflammatory response in the liver evidenced by the increases in macrophage biomarkers, inflammatory factors, and fibrotic indicators in the liver. qPCR results also showed differences in PPARα between SD mice and control mice. In PPARαko mice, further evidence was found that the lack of PPARα exacerbated the inflammatory response phenotype as well as the lipid metabolism disorder in NASH-SD mice.

Conclusion

The abnormal NR signaling accelerated the vicious cycle between lipotoxicity and inflammatory response in NAFLD with SD. Our results provide new evidence for nuclear receptors as potential therapeutic targets for NAFLD with spleen deficiency.