D-mannose suppresses macrophage IL-1β production

New insights on metabolic reprogramming in macrophage plasticity

Macrophages are the first line of defense in the innate immune system. Macrophages have two subtypes: classically activated macrophages (M1) and alternatively activated macrophages (M2), with different phenotypes and functions. They play a critical role in defending against pathogens and maintaining internal homeostasis. Macrophages have great plasticity in their biological characteristics. Although the regulation of macrophage plasticity has not been fully elucidated, accumulated evidence supports that microenvironmental differences are the root cause for macrophage differentiation into different subtypes. These differences alter macrophage plasticity by modulating key metabolites, activating downstream gene transcription, and influencing phagocytosis, cytokine secretion, and immune regulation. Herein, we systematically summarize metabolic reprogramming, including glucose, lipid, amino acid, ion, vitamin, nucleotide, and butyrate metabolism, as key regulators affecting macrophage polarization, providing new insights for developing targeted drugs that modulate macrophage plasticity.

Research progress on edible mushroom polysaccharides as a novel therapeutic strategy for inflammatory bowel disease

Inflammatory bowel disease (IBD) is a complex condition linked to the gut microbiota, host metabolism, and the immune system. Edible mushroom polysaccharides (EMPs) are gaining attention for their benefits, particularly as prebiotics that help balance gut microbial, a key factor in IBD. With their scalable production, diverse hydrophilic properties, and demonstrated anti-inflammatory effects in both laboratory and animal studies, EMPs show promise for easing IBD symptoms. By supporting a healthy gut microbiome through various mechanisms, EMPs can play an important role in preventing and managing IBD, ultimately benefiting overall health and opening new treatment avenues. This review examines how EMPs affect IBD, focusing on their role in shaping gut microbiota, restoring gut barriers, regulating immune function, and influencing pathways related to colitis. It also explores their impact on the microbiota-gut-multi organ axis and overall host health, as well as the relationship between EMPs preparation, structure, and bioactivity, along with their potential applications in food and medicine. This investigation provides valuable insights into the intricate connections between the gut, immune system, and systemic inflammation system, highlighting how EMPs are key players in this complex interaction.

Isolation, structural characterization and multiple activity of a novel exopolysaccharide produced by Gelidibacter sp. PG-2

Microbial exopolysaccharides have been extensively explored due to their distinctive structural features and physiological activities, making them suitable for diverse applications in the food and environmental applications. Current studies mainly focus on the structural and functional characterization of exopolysaccharides from known strains, with limited exploration of novel strains. In this study, a novel exopolysaccharide was produced by Gelidibacter sp. PG-2 with a yield of 874 mg·L-1. The purified exopolysaccharides, termed as ZPS, had a molecular weight of 45,514 Da and contained numerous hydroxyl and carbonyl groups. ZPS was a heteropolysaccharide composed of mannose, glucosamine, glucuronic acid, galactonic acid, galactosamine, glucose, galactose, and fucose, with a molar ratio of 54.98: 4.05: 6.69: 1.00: 1.46: 2.95: 2.92: 1.55. ZPS linkage comprised Glcp-(1→, Manp-(1→, →2)-Manp-(1→, →4)-Galp-(1→, and →4)-Manp-(1→. The morphology of ZPS presented the smooth surface, spherical nanoparticle, and irregular network structure. ZPS demonstrated thermal stability and emulsification activity. ZPS potently stimulated macrophage phagocytic function and effectively inhibited the migration of cancer cells, thereby enhancing overall immunomodulatory activity. Additionally, ZPS featured cryoprotective activity and flocculation property. Overall, the multiple activity of ZPS hold tremendous potential in the food and pharmaceutical industries, offering new dimensions for novel microbial exopolysaccharides.

D-mannose suppresses the angiogenesis and progression of colorectal cancer

Angiogenesis is an important factor influencing the development of solid tumors, and vascular endothelial growth factor receptor-2 (VEGFR2) is a central regulator of angiogenesis. Antibodies and inhibitors against VEGFR2 have been widely used in various malignancies. However, the regulatory mechanism of VEGFR2 has not been fully clarified. Here, we show that D-mannose can significantly inhibit angiogenesis and tumor growth by degrading VEGFR2. Specifically, D-mannose inactivates GSK3β by promoting the phosphorylation of GSK3β at Ser9, enhances the nuclear translocation of TFE3, and promotes lysosomal biogenesis, thereby increasing the lysosome-mediated degradation of VEGFR2. Thus, D-mannose significantly inhibits the proliferation, migration, and capillary formation of human umbilical vein endothelial cells (HUVECs) in vitro. Oral administration of D-mannose dramatically inhibits angiogenesis and tumor growth in mice. Our findings reveal a previously unrecognized anti-tumor mechanism of D-mannose by destabilizing VEGFR2 and provide a new strategy for the clinical treatment of colorectal cancer (CRC).

The role of PKM2-mediated metabolic reprogramming in the osteogenic differentiation of BMSCs under diabetic periodontitis conditions

BACKGROUND

Diabetes mellitus (DM) and periodontitis have a bidirectional relationship, with each being a high-risk factor for the other. Prolonged hyperglycemia exacerbates periodontal inflammation and disrupts bone homeostasis. Pyruvate kinase M2 (PKM2), a key enzyme in glycolysis, is involved in metabolic reprogramming, but its role in osteogenesis under high-glucose (HG) inflammatory conditions remains largely unknown. This study aimed to investigate the effects of HG and inflammation on bone marrow mesenchymal stem cells (BMSCs) under indirect co-culture conditions and to explore how PKM2 regulates metabolism and mitochondrial function during osteogenic differentiation in HG inflammatory environments, elucidating its role in diabetic periodontitis (DP).

METHODS

Expose BMSCs to conditioned medium (CM) collected from RAW264.7 cells stimulated with HG and/or lipopolysaccharide (LPS). BMSCs functionality was assessed using CCK8, EdU, Annexin V-PI apoptosis assay, alkaline phosphatase (ALP), and Alizarin Red S (ARS) staining. Metabolic characteristics were evaluated through Seahorse assays, lactate production, glucose uptake, and ATP measurements. Mitochondrial function was assessed via JC-1, and ROS staining, Mito-Tracker staining, and transmission electron microscopy (TEM). Gene and protein expression were analyzed by quantitative real-time PCR and western blotting. In vivo therapeutic effects of shikonin were validated via micro-CT and histological staining in a diabetic periodontitis mouse model.

RESULTS

In vitro experiments demonstrated that HG inflammatory conditions impaired the survival of BMSCs, suppressed osteogenic differentiation, and induced metabolic reprogramming. This reprogramming was characterized by enhanced glycolysis, impaired oxidative phosphorylation (OXPHOS), abnormal upregulation of PKM2 expression, and mitochondrial dysfunction accompanied by morphological alterations. Shikonin effectively reversed these adverse effects by inhibiting PKM2 tetramerization, rescuing the loss of osteogenic function in BMSCs. The therapeutic potential of shikonin was confirmed in the diabetic periodontitis mouse model.

CONCLUSION

PKM2 impairs the osteogenesis of BMSCs by affecting metabolism and mitochondrial function, suggesting it as a potential therapeutic target for diabetic periodontitis.

Astragaloside IV alleviated bone loss in mice with ovariectomy-induced osteoporosis via modulating gut microbiota and fecal metabolism

Background

Astragaloside IV (AS-IV) is one of the most potent components of Astragalus. It has been reported to promote bone formation and inhibit osteoclastogenesis, suggesting its potential as a candidate for the prevention and treatment of postmenopausal osteoporosis (PMOP). The gut microbiota may play a crucial role in mediating the effects of AS-IV.

Objective

To investigate the impact of gut microbiota on the efficacy of AS-IV in treating PMOP.

Methods

Mice were randomly divided into three groups: Sham, ovariectomy (OVX), and AS-IV-treated OVX group (80 mg/kg). Bone loss was evaluated using Micro-CT and histopathology. Immunohistochemistry assessed specific bone markers. Inflammatory levels were measured by enzyme-linked immunosorbent assay (ELISA). Intestinal barrier function was examined via colonic histopathology and immunohistochemistry. Gut microbiota composition was analyzed by 16S rDNA sequencing, while metabolomic profiling identified key metabolites. Correlation analysis was performed to explore relationships between differential bacteria, key metabolites, and bone loss.

Results

AS-IV improved the femur microarchitecture and modulated bone turnover in OVX mice. AS-IV treatment strengthened the intestinal barrier function and decreased gut permeability. This compound reduced colonic oxidative stress and serum and bone marrow inflammatory cytokine production. 16S rDNA sequencing revealed that AS-IV modulated the gut microbiota composition, while metabolomic analysis showed its effects on pathways related to hormone biosynthesis, D-amino acid metabolism, and galactose metabolism.

Conclusion

This study provides new insights into the use of AS-IV for treating PMOP, highlighting the gut microbiota and its metabolites as key regulatory factors in AS-IV's therapeutic effects.

Mannose-Glycated Metal-Phenolic Microcapsules Orchestrate Phenotype Switch of Macrophages for Boosting Tumor Immunotherapy

Microcapsules are advancing in immunotherapy, with both their core and shell being capable of loading immunoregulatory substances. Notably, microcapsules with intrinsic bioactivities can more directly modulate the immune microenvironment, while current research in this area remains scarce. Herein, immunomodulatory metal-phenolic microcapsules (mMPMs) is developed through the one-step assembly of dopamine-modified hyaluronic acid (HADA) and FeIII onto mannose-glycated bovine serum albumin microbubbles (Man-BSA MBs). Specifically, Man-BSA formed during the early stages of the Maillard reaction is sonicated to produce microbubbles as templates for capsule preparation. Subsequently, HADA is rapidly coated on the templates and coordinates with FeIII to form microcapsules after air escapes from MBs. Mass spectrometry analysis identifies abundant lysine glycation sites on Man-BSA, with the highest glycation site percentage reaching 94.88%. Man-BSA within mMPMs effectively promotes macrophage internalization, induces the accumulation of pro-inflammatory mediators, and thereby results in the M1 polarization of macrophages, as further corroborated by proteomic analysis. Consequently, the compelling anti-tumor effects of mMPMs are demonstrated both in vitro and in vivo. Overall, this work presents an immunomodulatory microcapsule that activates pro-inflammatory phenotype macrophages, which is a promising microcarrier to improve immunotherapeutic effects.

Functional Polarization of Liver Macrophages by Glyco Gold Nanoparticles

Macrophages are crucial drivers of innate immunity. Reprogramming macrophages to a restorative phenotype in cancer or autoimmune diseases can stop their cancer-promoting activity or trigger anti-inflammatory immunity. Glycans have emerged as key components for immunity as they are involved in many pathophysiological disorders. Previous studies have demonstrated that supraphysiological amounts of mannose (Man) or sialic acid (Sia) can inhibit tumor growth and stimulate differentiation of regulatory T cells. Man is known to affect glucose metabolism in glycolysis by competing for the same intracellular transporters and affecting macrophage polarization, whereas Sia alters macrophage differentiation via signaling through Siglec-1. Herein, this work describes a macrophage targeting platform using gold nanoparticles (GNPs) functionalized with Man and Sia monosaccharides which exhibit high liver tropism. A single dose of glyco-GNPs can convert macrophages to a restorative phenotype in two completely different immune environments. Man promotes tumor-associated macrophages toward an antitumorigenic activity in a MC38 liver colorectal cancer model by secretion of TNF-α, IL -1β, and IL -6 in the tumor microenvironment. However, in a proinflammatory environment, as observed in a mouse model of autoimmune disease, primary biliary cholangitis, Man impairs the production of TNF-α, IL-1β, Arg1, and IL-6 cytokines. The results probe the dual role of Man in macrophage repolarization in response to the immune system. This study is a proof-of-concept that demonstrates that nanomedicine using specific glycans designed to target other immune cells such as myeloid cells, are a promising strategy not only against cancer but also against other pathologies such as autoimmune diseases.

The Intestinal Macrophage-Intestinal Stem Cell Axis in Inflammatory Bowel Diseases: From Pathogenesis to Therapy

The gut plays a crucial role in digestion and immunity, so its balance is essential to overall health. This balance relies on dynamic interactions between intestinal epithelial cells, immune cells, and crypt stem cells. Inflammatory bowel disease (IBD), which consists of ulcerative colitis and Crohn's disease, is a chronic relapsing inflammatory disease of the gastrointestinal tract closely related to immune dysfunction. Stem cells, known for their ability to self-renew and differentiate, play an important role in repairing damaged intestinal epithelium and maintaining homeostasis in vivo. Macrophages are key gatekeepers of intestinal immune homeostasis and have a significant impact on IBD. Current research has focused on the link between epithelial cells and stem cells, but interactions with macrophages, which have been recognized as attractive targets for the development of new therapeutic approaches to disease, have been less explored. Recently, the developing field of immunometabolism has reinforced that metabolic reprogramming is a key determinant of macrophage function and subsequent disease progression. The aim of this review is to explore the role of the macrophage-stem cell axis in the maintenance of intestinal homeostasis and to summarize potential approaches to treating IBD by manipulating the cellular metabolism of macrophages, as well as the main opportunities and challenges faced. In summary, our overview provides a framework for understanding the critical role of macrophage immunometabolism in maintaining gut health and potential therapeutic targets.

Mannose Promotes β-Amyloid Pathology by Regulating BACE1 Glycosylation in Alzheimer's Disease

Hyperglycemia accelerates Alzheimer's disease (AD) progression, yet the role of monosaccharides remains unclear. Here, it is demonstrated that mannose, a hexose, closely correlates with the pathological characteristics of AD, as confirmed by measuring mannose levels in the brains and serum of AD mice, as well as in the serum of AD patients. AD mice are given mannose by intra-cerebroventricular injection (ICV) or in drinking water to investigate the effects of mannose on cognition and AD pathological progression. Chronic mannose overload increases β-amyloid (Aβ) burdens and exacerbates cognitive impairments, which are reversed by a mannose-free diet or mannose transporter antagonists. Mechanistically, single-cell RNA sequencing and metabolomics suggested that mannose-mediated N-glycosylation of BACE1 and Nicastrin enhances their protein stability, promoting Aβ production. Additionally, reduced mannose intake decreased BACE1 and Nicastrin stability, ultimately lowering Aβ production and mitigating AD pathology. this results highlight that high-dose mannose consumption may exacerbate AD pathogenesis. Restricting dietary mannose may have therapeutic benefits.

Sweet regulation - The emerging immunoregulatory roles of hexoses

BACKGROUND

It is widely acknowledged that dietary habits have profound impacts on human health and diseases. As the most important sweeteners and energy sources in human diets, hexoses take part in a broad range of physiopathological processes. In recent years, emerging evidence has uncovered the crucial roles of hexoses, such as glucose, fructose, mannose, and galactose, in controlling the differentiation or function of immune cells.

AIM OF REVIEW

Herein, we reviewed the latest research progresses in the hexose-mediated modulation of immune responses, provided in-depth analyses of the underlying mechanisms, and discussed the unresolved issues in this field.

KEY SCIENTIFIC CONCEPTS OF REVIEW

Owing to their immunoregulatory effects, hexoses affect the onset and progression of various types of immune disorders, including inflammatory diseases, autoimmune diseases, and tumor immune evasion. Thus, targeting hexose metabolism is becoming a promising strategy for reversing immune abnormalities in diseases.

Interleukin-6 related signaling pathways as the intersection between chronic diseases and sepsis

Sepsis is associated with immune dysregulated and organ dysfunction due to severe infection. Clinicians aim to restore organ function, rather than prevent diseases that are prone to sepsis, resulting in high mortality and a heavy public health burden. Some chronic diseases can induce sepsis through inflammation cascade reaction and Cytokine Storm (CS). Interleukin (IL)-6, the core of CS, and its related signaling pathways have been considered as contributors to sepsis. Therefore, it is important to study the relationship between IL-6 and its related pathways in sepsis-related chronic diseases. This review generalized the mechanism of sepsis-related chronic diseases via IL-6 related pathways with the purpose to take rational management for these diseases. IL-6 related signaling pathways were sought in Kyoto Encyclopedia of Genes and Genomes (KEGG), and retrieved protein-protein interaction in the Search for Interaction Genes tool (STRING). In PubMed and Google Scholar, the studies were searched out, which correlating to IL-6 related pathways and associating with the pathological process of sepsis. Focused on the interactions of sepsis and IL-6 related pathways, some chronic diseases have been studied for association with sepsis, containing insulin resistance, Alcoholic liver disease (ALD), Alzheimer disease (AD), and atherosclerosis. This article summarized the inflammatory mechanisms of IL-6 cross-talked with other mediators of some chronic diseases in vitro, animal models, and human experiments, leading to the activation of pathways and accelerating the progression of sepsis. The clinicians should be highlight to this kind of diseases and more clinical trials are needed to provide more reliable theoretical basis for health policy formulation.

Mannose metabolism reshapes T cell differentiation to enhance anti-tumor immunity

Cellular metabolic status profoundly influences T cell differentiation, persistence, and anti-tumor efficacy. Our single-cell metabolic analyses of T cells reveal that diminished mannose metabolism is a prominent feature of T cell dysfunction. Conversely, experimental augmentation/restoration of mannose metabolism in adoptively transferred T cells via D-mannose supplementation enhances anti-tumor activity and restricts exhaustion differentiation both in vitro and in vivo. Mechanistically, D-mannose treatment induces intracellular metabolic programming and increases the O-GlcNAc transferase (OGT)-mediated O-GlcNAcylation of β-catenin, which preserves Tcf7 expression and epigenetic stemness, thereby promoting stem-like programs in T cells. Furthermore, in vitro expansion with D-mannose supplementation yields T cell products for adoptive therapy with stemness characteristics, even after extensive long-term expansion, that exhibits enhanced anti-tumor efficacy. These findings reveal cell-intrinsic mannose metabolism as a physiological regulator of CD8+ T cell fate, decoupling proliferation/expansion from differentiation, and underscoring the therapeutic potential of mannose modulation in cancer immunotherapy.

Metabolic Insights into Urinary Stone Formation: Evidence from Mendelian Randomization, Clinical, and in vivo Studies

Introduction

The global rise in urinary stone prevalence has become a significant health and economic challenge. Linked to metabolic disorders such as obesity and diabetes, urinary stones represent a complex systemic condition that requires a comprehensive understanding of metabolic profiles for effective management.

Methods

The methodological quality of this study was evaluated in accordance with the STROBE-MR checklist. Using genome-wide association study (GWAS) data for 1,091 blood and 1,172 urine metabolites, we conducted a two-sample Mendelian randomization (MR) analysis, validated by meta-analysis, to explore metabolic influences on stone formation. Multivariable and mediation MR analyses were performed to identify independent metabolite influences and their interaction with gut microbiota and metabolism-related genes. Clinical metabolomic analysis and further animal experiments substantiated our findings.

Results

Univariable MR identified 119 blood and 63 urine metabolites associated with urinary stones, with 16 blood and 2 urine metabolites showing robust associations post-correction. Notably, mannose and 3-aminoisobutyrate emerged as independent influencers of stone formation. Mediation MR suggested these metabolites as potential mediators in the gut microbiota's influence on stone formation. Clinical urine sample analysis indicates higher mannose levels in normal renal sides than stone sides. Animal studies confirmed mannose's protective role by reducing renal calcium oxalate crystal deposition.

Conclusion

Our study establishes causal links between specific metabolites and urinary stones, shedding light on the intricate biological mechanisms of stone formation. The discovery of mannose as a protective factor opens avenues for future research and clinical applications, offering promising directions for the prevention and treatment of stones.

Molecular mechanism of enhancing antitumor activity through the interaction between monosaccharides and human serum albumin

This study investigated the molecular mechanisms of the interactions between three antitumor active monosaccharides and human serum albumin (HSA) using spectroscopic and electrochemical analyses, supplemented by molecular docking simulations. The antitumor efficacy of these monosaccharides can be significantly enhanced by covalent drug coupling, while HSA, with its long half-life and low immunogenicity, provides new opportunities for the development of advanced antitumor drug delivery systems. The results showed that these monosaccharides effectively burst the fluorescence of HSA. Thermodynamic analysis revealed that Fucose undergoes a spontaneous, exothermic process that decreases entropy, while the binding of Mannose and Galactose is entropy-driven. Notably, the addition of these three monosaccharides slightly compacts the structure of HSA, stabilizing its transport and delivery in vivo, with the binding strength categorized as Fucose > Mannose > Galactose. These variations in binding constants explain the differences in efficacy and potential side effects in antitumor therapy. Further studies have shown that the interaction between monosaccharides and HSA improves drug stability and targeting, thereby enhancing antitumor activity. An in-depth study of these interactions may provide new insights into the design and optimization of antitumor drugs and the further development of novel antitumor therapies.

Genetically Confirmed Optimal Causal Association of Cerebrospinal Fluid Metabolites With Hemorrhagic Stroke

Hemorrhagic stroke (HS) mainly includes intracerebral hemorrhage (ICH) and subarachnoid hemorrhage (SAH), both of which seriously affect the patient's prognosis. Cerebrospinal fluid (CSF) metabolites and HS showed a link in observational studies. However, the causal association between them is not clear. We aimed to establish the optimal causality of CSF metabolites with HS. Mendelian randomization (MR) was employed to identify associations between CSF metabolites and different sources of HS. Univariable MR and false discovery rates (FDR) were used to identify initial causal associations. Linkage disequilibrium score regression determined genetic correlations. Multiple sensitive analyses ensured the reliability of the results. Multivariable MR and MR Bayesian Model Averaging were used to identify the optimal causal associations. The combined effects of metabolites and HS were assessed by meta-analyses. Pathway analyses were performed to identify potential pathways of action. Reverse MR was also conducted to identify reverse causal associations. Finally, Corresponding blood metabolites were used to explore the multiple roles of metabolites. We identified 20 CSF metabolites and six metabolic pathways associated with ICH; 15 CSF metabolites and three metabolic pathways associated with SAH. Nineteen and seven metabolites were causally associated with deep and lobar ICH, respectively. CSF levels of mannose (OR 0.63; 95% CI 0.45-0.88; Pcombined = 0.0059) and N-acetyltaurine (OR 0.68; 95% CI 0.47-0.98; Pcombined = 0.0395) may serve as the optimal exposures for ICH and SAH, respectively. Additionally, CSF ascorbic acid 3-sulfate levels significantly decrease the risk of deep ICH (OR 0.79; 95% CI 0.66-0.94; p = 0.0065; PFDR = 0.091). Supplemental analysis of blood metabolites suggested multiple roles for CSF and blood N-formylanthranilic acid and hippurate. There are significant causal associations between CSF metabolites and HS, which provides a further rationale for the prevention and monitoring of ICH and SAH.

Hydrolysates exhibited differential modulatory effects on macrophage compared to the raw polysaccharide (xyloglucomannan) isolated from Atractylodes macrocephala Koidz

It has been claimed that Atractylodes macrocephala applied as a traditional Chinese medicinal herb for centuries, owing to its excellent immunomodulatory and hepatic protective properties. This study aims to explore the immunomodulation of oligosaccharides obtained by gastrointestinal digestion after oral administration of A. macrocephala polysaccharide (xyloglucomannan, XGM). The analysis of chemistry showed that XGM consisted of D-glucose, D-mannose, and D-xylose in a molar ratio of 6.8:3.0:1.0, and the molecular weight was 5465 Da. Furthermore, HCl and pancreatic amylase were used to simulate digestive tract hydrolysis of polysaccharides, obtaining two XGM hydrolysates (XGM-AH and -EH). Oligosaccharide identification results indicated that both XGM-AH and XGM-EH contained glucans (degree of polymerization, DP = 2 ∼ 5). XGM-AH had a wider variety of oligosaccharides than XGM-EH, mainly glucomannans. In vitro immunostimulatory assay indicated that XGM could effectively stimulate the activation and enhance the phagocytosis of RAW264.7 cells. In contrast, XGM-AH and -EH exhibited anti-inflammatory effects, inhibited lipopolysaccharide (LPS)-induced aberrant activation of macrophages, reduced the release of cytokines of macrophages. Flow cytometry assay suggested that XGM-AH and -EH inhibited LPS-induced M1-type polarization of macrophages. In conclusion, XGM-derived oligosaccharides possess anti-inflammatory bioactivities and exhibit differential macrophage regulatory behaviors in contrast to the immune-activating effects exhibited by the prototype polysaccharides.

Agaricus bisporus Mannose-Binding Protein Stimulates the Innate Immune Cells

Purpose

A lectin-like protein from the mushroom Agaricus bisporus has been shown to slightly increase the proliferation of RAW 264.7 cells. Following its identification as a mannose-binding lectin, henceforth called A. bisporus mannose-binding protein (Abmb), the protein is hypothesized to stimulate the innate immune cells response. The present work was aimed to substantiate that hypothesis. Furthermore, this study complements Abmb exploration as a potential agent for anti-breast cancer, which its treatment is hampered with compromised immunity of patient receiving chemotherapy.

Methods

Abmb's effect on the phagocytic activity of the macrophage was measured with FACS. Nitric oxide (NO) production was checked using Griess test while expression of the cytokines in the RAW 264.7 cells was analysed at gene and protein level using polymerase chain reaction (PCR) and FACS, respectively. Abmb's effect on the expression of surface markers of the human immune cells in the peripheral blood mononuclear cells (PBMCs) was checked with specific antibodies for targeted cluster differentiation (CD) and analysed using FACS.

Results

Abmb increased the phagocytic activity of the macrophage and NO production. Abmb increased the expression of cytokines i.e. tumour necrosis factor (TNF)-α, interleukin (IL)-6, and IL-10. With the PBMCs, Abmb activated dendritic and natural killer (NK) cells, but not the B- or T-cells.

Conclusion

Abmb increased the activity of the macrophage cells and activated the immune cells that are related to the innate immune system, particularly the cellular immunity.

D-Mannose-Mediated metabolic pathways sustain the molecular signatures of sperm function and fertilization

INTRODUCTION

Mammalian sperm within a single ejaculate exhibit significant heterogeneity, with only a subset possessing the molecular characteristics required for successful fertilization. Identifying the defining traits of these high-fertility sperm remains an open question.

OBJECTIVES

To elucidate the molecular markers and mechanisms underlying the fertilization potential of sperm in both mice and humans, with a focus on the role of D-mannose.

METHODS

Sperm morphology and functionality were analyzed using flow cytometry, biochemical assays, and immunofluorescence. Multi-omics analyses, including proteomics, metabolomics, and lipidomics, were conducted to identify distinct molecular signatures. Pharmacological interventions were employed to validate the role of key pathways, particularly Akt/mTOR signaling.

RESULTS

Sperm with longer flagella demonstrated enhanced motility, mitochondrial activity, and fertilization potential in both mice and humans. Multi-omics analyses revealed distinct molecular profiles in high-fertility sperm, characterized by specific proteins, lipids, and metabolites. Notably, D-mannose supplementation enhanced sperm motility and fertilization capacity, even in asthenozoospermic sperm, by activating the Akt/mTOR pathway. This effect was not replicated by D-glucose or ATP supplementation. Mechanistically, D-mannose bypassed glycolytic rate-limiting steps, increasing ATP production and promoting mitochondrial and acrosomal integrity.

CONCLUSION

This study identifies key molecular signatures of fertilization-competent sperm and highlights D-mannose as a novel modulator of sperm quality and function. These findings provide valuable insights into sperm biology and propose innovative therapeutic strategies for treating male infertility and optimizing assisted reproduction technologies.

Decoding ferroptosis: transforming orthopedic disease management

As a mechanism of cell death, ferroptosis has gained popularity since 2012. The process is distinguished by iron toxicity and phospholipid accumulation, in contrast to autophagy, apoptosis, and other cell death mechanisms. It is implicated in the advancement of multiple diseases across the body. Researchers currently know that osteosarcoma, osteoporosis, and other orthopedic disorders are caused by NRF2, GPX4, and other ferroptosis star proteins. The effective relief of osteoarthritis symptoms from deterioration has been confirmed by clinical treatment with multiple ferroptosis inhibitors. At the same time, it should be reminded that the mechanisms involved in ferroptosis that regulate orthopedic diseases are not currently understood. In this manuscript, we present the discovery process of ferroptosis, the mechanisms involved in ferroptosis, and the role of ferroptosis in a variety of orthopedic diseases. We expect that this manuscript can provide a new perspective on clinical diagnosis and treatment of related diseases.

Casting NETs on Psoriasis: The modulation of inflammatory feedback targeting IL-36/IL-36R axis

NETosis happens when neutrophils are activated and neutrophil extracellular traps (NETs) are formed synchronously, which is a hallmark of psoriasis. However, the specific trigger that drives NET formation and the distinct contents and interaction with interleukin-36 receptor (IL-36R) of NETs remain to be further elucidated. This work identified NET formation driven by toll-like receptor (TLR) 3 ligand (especially polyinosinic-polycytidylic acid (Poly(I:C)) were enhanced by purinergic receptor P2X ligand-gated ion channel 7 receptor (P2X7R) ligands (especially adenosine 5'-triphosphate (ATP)). NET formation was accompanied by the secretion of inflammatory cytokines and characterized by IL-1β decoration. NET formation blockade decreased expressions of inflammatory cytokines and chemokines, which consequently improved inflammatory responses. Additionally, imiquimod (IMQ)-induced psoriasiform symptoms including neutrophilic infiltration tended to be time-sensitive. Mouse primary keratinocytes and mice deficient in Il1rl2, which encodes IL-36R, mitigated inflammatory responses and NET formation, thereby delaying the pathophysiology of psoriasis. Together, the findings provided the therapeutic potential for IL-36 targeting NET inhibitors in psoriasis treatment.

A Hypoxia-Inflammation Cycle and Multiple Sclerosis: Mechanisms and Therapeutic Implications

Purpose of Review

Multiple sclerosis (MS) is a complex neurodegenerative disease characterized by inflammation, demyelination, and neurodegeneration. Significant hypoxia exists in brain of people with MS (pwMS), likely contributing to inflammatory, neurodegenerative, and vascular impairments. In this review, we explore the concept of a negative feedback loop between hypoxia and inflammation, discussing its potential role in disease progression based on evidence of hypoxia, and its implications for therapeutic targets.

Recent Findings

In the experimental autoimmune encephalomyelitis (EAE) model, hypoxia has been detected in gray matter (GM) using histological stains, susceptibility MRI and implanted oxygen sensitive probes. In pwMS, hypoxia has been quantified using near-infrared spectroscopy (NIRS) to measure cortical tissue oxygen saturation (StO2), as well as through blood-based biomarkers such as Glucose Transporter-1 (GLUT-1). We outline the potential for the hypoxia-inflammation cycle to drive tissue damage even in the absence of plaques. Inflammation can drive hypoxia through blood-brain barrier (BBB) disruption and edema, mitochondrial dysfunction, oxidative stress, vessel blockage and vascular abnormalities. The hypoxia can, in turn, drive more inflammation.

Summary

The hypoxia-inflammation cycle could exacerbate neuroinflammation and disease progression. We explore therapeutic approaches that target this cycle, providing information about potential treatments in MS. There are many therapeutic approaches that could block this cycle, including inhibiting hypoxia-inducible factor 1-α (HIF-1α), blocking cell adhesion or using vasodilators or oxygen, which could reduce either inflammation or hypoxia. This review highlights the potential significance of the hypoxia-inflammation pathway in MS and suggests strategies to break the cycle. Such treatments could improve quality of life or reduce rates of progression.

Exploring the pharmacological mechanisms of the flower of Rhododendron molle in rheumatoid arthritis rats based on metabolomics integrated network pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

As a traditional Chinese medicine, the flower of Rhododendron molle G. Don (RMF) is record in the Chinese pharmacopoeia, and is commonly utilized for treating rheumatoid arthritis (RA) in clinical practice. However, its precise mechanisms necessitate further exploration.

AIM OF THE STUDY

To expound the effective components, targets, metabolites, and pathways participated in RMF's anti-RA effects by metabolomics integrated network pharmacology.

MATERIALS AND METHODS

CIA rats were intragastric administered RMF for 2 weeks, following which the therapeutic effects were comprehensively evaluated. Serum metabolomics was adopted to investigate the differential metabolites (DEMs). UHPLC-Q-Exactive-MS method was applied to identify the components of RMF, and then network pharmacology was utilize to select the component-RA-targets. Molecular docking and Western blotting were utilized to validate the key targets.

RESULTS

RA symptoms were alleviated by RMF through the inhibition secretion of pro-inflammatory factors IL-1β, IL-6 and TNF-α, along with relief in bone destruction observed in CIA rats. Four targets, namely AKR1B1, TPH1, CYP1A1, and CYP1A2, were identified, along with their corresponding metabolites, namely D-glucose, D-mannose, L-tryptophan, 11-deoxycorticosterone, and 17α-hydroxyprogesterone. These were found to be involved in three key metabolic pathways: steroid hormone biosynthesis, tryptophan metabolism, and galactose metabolism. Additionally, five significant anti-RA active components were identified from RMF, including Rhodojaponin (Rj)-Ⅱ, Rj-Ⅲ, Rj-Ⅴ, Rj-Ⅵ, and quercetin.

CONCLUSIONS

The anti-RA mechanisms of RMF were investigated in this study, focusing on active components, upstream targets, and downstream metabolites. These findings lay a foundation for the clinical practice and drug development of RMF.

Grifola frondosa polysaccharide's therapeutic potential in oxazolone-induced ulcerative colitis

Grifola frondosa polysaccharide (GFP) is a consumable fungus recognized for its potential health advantages. The present study aimed to investigate the development and potential etiologies of ulcerative colitis (UC) utilizing oxazolone (OXZ) as an inducer in mice, along with assessing the therapeutic effects of GFP at varying doses in UC mice, with sulfasalazine (SASP) serving as the positive control. The obtained results indicated that OXZ intervention in mice induced numerous physical manifestations of UC, including increased disease activity index (DAI), decreased goblet cell division, enhanced fibrosis, reduced expression of Claudin1 and Zona encludens protein1 (ZO-1), decreased proliferative activity of colonic mucosal epithelial cells, disturbed oxidation balance, and alterations in intestinal flora. Nonetheless, GFP intervention significantly ameliorated or even resolved these abnormal indicators to a considerable extent. Consequently, this study suggests that GFP might serve as a prebiotic to regulate intestinal flora, mitigate enterotoxin production, restore oxidative balance, thereby reducing the generation of inflammatory mediators, restoring the intestinal barrier, and ultimately improving OXZ-induced UC in mice. GFP demonstrates promising potential as a candidate drug for colitis treatment and as a dietary supplement for alleviating intestinal inflammatory issues.

D-mannose alleviates chronic periodontitis in rats by regulating the functions of neutrophils

BACKGROUND

Periodontitis is a chronic inflammatory disease characterized by the destruction of the components of the periodontium. It significantly impacts oral health and has been linked to systemic conditions like cardiovascular disease and diabetes. The critical role of neutrophils in the occurrence and development of chronic periodontitis has been paid increasing attention. The study aimed to explore the protective effects of D-mannose on chronic periodontitis and determine whether its underlying mechanisms is related to neutrophils.

METHODS

To explore the protective effects of D-mannose on chronic periodontitis, the eight-week-old Sprague Dawley rat model of lipopolysaccharide (LPS)-induced periodontitis was established, followed by D-mannose treatment by oral gavage. To evaluate the protective effects of D-mannose against periodontal bone loss, methylene blue staining, hematoxylin and eosin (H&E) staining, and micro-CT scanning were utilized. Then, immunofluorescence (IF), Western Blot, and RT-PCR were applied to assess the expression levels of pro-inflammatory cytokines (IL-1β, IL-6, and IL-17), anti-inflammatory cytokine (IL-10), tumor necrosis factor-alpha (TNF-α), granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), ten-eleven translocation 2 (TET2), and key glycolytic enzymes (HK1, HK2, PFKFB3), and to examine D-mannose's impact on the recruitment and activation of neutrophils in the gingiva. Additionally, neutrophils isolated from the peripheral blood of healthy rats were treated with LPS and D-mannose, and changes in the expression levels of myeloperoxidase (MPO), IL-1β, IL-6, IL-17, IL-10, and TET2 were observed via IF.

RESULTS

In vivo, D-mannose inhibited LPS-induced alveolar bone resorption in rats. After D-mannose treatment, the expression levels of IL-17 (p<0.01) and TET2 (p<0.01) were suppressed by IF, and the expression levels of IL-1β (p<0.05), IL-17 (p<0.05) and TET2 (p<0.01) were downregulated by WB. The results of qPCR showed that D-mannose reduced the expression levels of IL-1β (p<0.05), IL-6 (p<0.01), IL-17 (p<0.01), TNF-α (p<0.01), G-CSF (p<0.01), GM-CSF (p<0.01), TET2 (p<0.01), HK1 (p<0.01), HK2 (p<0.01), and PFKFB3 (p<0.01). D-mannose also inhibited the recruitment and activation of neutrophils in LPS-treated rat gingival tissues. In vitro, the results of IF showed that D-mannose inhibited the activation of neutrophils stimulated by LPS, downregulated the expression of IL-1β (p < 0.05), IL-6, IL-17 (p < 0.01), and TET2 (p < 0.01), and upregulated the expression of IL-10 (p < 0.01).

CONCLUSIONS

D-mannose can alleviate chronic periodontitis in rats by regulating the functions of neutrophils, potentially associated with the expression of TET2 and glycolysis, providing new insights into the potential application of D-mannose to chronic periodontitis.

Mannose coated selenium nanoparticles normalize intestinal homeostasis in mice and mitigate colitis by inhibiting NF-κB activation and enhancing glutathione peroxidase expression

Impaired intestinal homeostasis is a major pathological feature of inflammatory bowel diseases (IBD). Mannose and selenium (Se) both demonstrate potential anti-inflammatory and anti-oxidative properties. However, most lectin receptors bind free monosaccharide ligands with relatively low affinity and most Se species induce side effects beyond a very narrow range of dosage. This has contributed to a poorly explored therapies for IBD that combine mannose and Se to target intestinal epithelial cells (IECs) for normalization gut homeostasis. Herein, a facile and safe strategy for ulcerative colitis (UC) treatment was developed using optimized, mannose-functionalized Se nanoparticles (M-SeNPs) encapsulated within a colon-targeted hydrogel delivery system containing alginate (SA) and chitosan (CS). This biocompatible nanosystem was efficiently taken up by IECs and led to increased expression of Se-dependent glutathione peroxidases (GPXs), thereby modulating IECs' immune response. Using a mouse model of DSS-induced colitis, (CS/SA)-embedding M-SeNPs (C/S-MSe) were found to mitigate oxidative stress and inflammation through the inhibition of the NF-kB pathway in the colon. This stabilized mucosal homeostasis of IECs and ameliorated colitis-related symptoms, thereby providing a potential new approach for treatment of IBD.

Structural characterisation of a novel polysaccharide from pseudostellaria heterophylla fibrous root and its anti-inflammatory and antioxidant activities in vitro

A novel water-soluble polysaccharide, named PF90-1, with a molecular weight of 1.8 kDa, was isolated and purified from the fibrous root of Pseudostellaria heterophylla. PF90-1 is composed of Gal, Glc and Man in a molar ratio of 73.61: 19.11: 7.28. Methylation analysis revealed that PF90-1 comprises of T-Galp, 1,4-Galp, 1,3,4-Galp, 1,2,3,4-Galp, T-Glcp and 1,3-Manp in a molar ratio of 37.89: 9.37: 17.01: 12.01: 15.88: 7.83. Bioactivity experiments showed that PF90-1 significantly improved lipopolysaccharide (LPS)-induced inflammatory damage in RAW264.7 cells by inhibiting nitric oxide (NO) production and reducing the levels of pro-inflammatory factors (IL-1β and TNF-α). In addition, PF90-1 exhibited strong antioxidant effects, protecting PC12 cells from H2O2-induced oxidative damage. This findings suggest that PF90-1 holds potential therapeutic value for the treatment of inflammatory and oxidative injuries.

Unveiling the molecular mechanisms of Dendrobium officinale polysaccharides on intestinal immunity: An integrated study of network pharmacology, molecular dynamics and in vivo experiments

Intestinal immunity plays a pivotal role in overall immunological defenses, constructing mechanisms against pathogens while maintaining balance with commensal microbial communities. Existing therapeutic interventions may lead to drug resistance and potential toxicity when immune capacity is compromised. Dendrobium officinale, a traditional Chinese medicine, contains components identified to bolster immunity. Employing network pharmacology strategies, this study identified constituents of Dendrobium officinale and their action targets in the TCMSP and Swiss Target Prediction databases, and compared them with intestinal immunity-related targets. Protein-protein interaction networks revealed the core targets of Dendrobium officinale polysaccharides, encompassing key pathways such as cell proliferation, inflammatory response, and immune reactions, particularly in association with the Toll-like receptor 4. Molecular docking and molecular dynamics simulation further confirmed the high affinity and stability between Dendrobium officinale polysaccharides and Toll-like receptor 4. In vivo experiments demonstrated that Dendrobium officinale polysaccharides modulates the expression of Toll-like receptor 4 and its downstream key proteins in the colonic mucosa of mice. Consequently, these findings suggest that Dendrobium officinale polysaccharides may serve as a potential modulator for intestinal immune functions, with its mechanism potentially related to the Toll-like receptor 4.

α-Ketoglutarate plays an inflammatory inhibitory role by regulating scavenger receptor class a expression through N6-methyladenine methylation during sepsis

Sepsis arises from an uncontrolled inflammatory response triggered by infection or stress, accompanied by alteration in cellular energy metabolism, and a strong correlation exists between these factors. Alpha-ketoglutarate (α-KG), an intermediate product of the TCA cycle, has the potential to modulate the inflammatory response and is considered a crucial link between energy metabolism and inflammation. The scavenger receptor (SR-A5), a significant pattern recognition receptor, assumes a vital function in anti-inflammatory reactions. In the current investigation, we have successfully illustrated the ability of α-KG to mitigate inflammatory factors in the serum of septic mice and ameliorate tissue damage. Additionally, α-KG has been shown to modulate metabolic reprogramming and macrophage polarization. Moreover, our findings indicate that the regulatory influence of α-KG on sepsis is mediated through SR-A5. We also elucidated the mechanism by which α-KG regulates SR-A5 expression and found that α-KG reduced the N6-methyladenosine level of macrophages by up-regulating the m6A demethylase ALKBH5. α-KG plays a crucial role in inhibiting inflammation by regulating SR-A5 expression through m6A demethylation during sepsis. The outcomes of this research provide valuable insights into the relationship between energy metabolism and inflammation regulation, as well as the underlying molecular regulatory mechanism.

Establishing the link between D-mannose and juvenile grass carp (Ctenopharyngodon idella): Improved growth and intestinal structure associated with endoplasmic reticulum stress, mitophagy, and apical junctional complexes

D-mannose, essential for protein glycosylation, has been reported to have immunomodulatory effects and to maintain intestinal flora homeostasis. In addition to evaluating growth performance, we examined the impact of D-mannose on the structure of epithelial cells and apical junction complexes in the animal intestine. All 1800 grass carp (16.20 ± 0.01 g) were randomly divided into six treatments with six replicates of 50 fish each and fed with six different levels of D-mannose (0.52, 1.75, 3.02, 4.28, 5.50 and 6.78 g/kg diet) for 70 d. The study revealed that D-mannose increased feed intake (P < 0.001) but did not affect the percent weight gain (PWG), special growth rate, and feed conversion ratio (P > 0.05). D-mannose supplementation at 1.75 g/kg increased crude protein content in fish and lipid production value (P < 0.05). D-mannose supplementation at 4.28 g/kg increased intestinal length, intestinal weight and fold height of grass carp compared to the control group (P < 0.05). This improvement may be attributed to the phosphomannose isomerase (PMI)-mediated enhancement of glycolysis. This study found that D-mannose supplementation at 4.28 or 3.02 g/kg reduced serum diamine oxidase activity or D-lactate content (P < 0.05) and improved cellular and intercellular structures for the first time. The improvement of cellular redox homeostasis involves alleviating endoplasmic reticulum (ER) stress through the inositol-requiring enzyme 1 (IRE1), RNA-dependent protein kinase-like ER kinase (PERK), and activating transcription factor 6 (ATF6) signaling pathways. The alleviation of ER stress may be linked to the phosphomannomutase (PMM)-mediated enhancement of protein glycosylation. In addition, ubiquitin-dependent [PTEN-induced putative kinase 1 (PINK1)/Parkin] and ubiquitin-independent [BCL2-interacting protein 3-like (BNIP3L), BCL2-interacting protein 3 (BNIP3), and FUN14 domain containing 1 (FUNDC1)] mitophagy may play a role in maintaining cellular redox homeostasis. The enhancement of intercellular structures includes enhancing tight junction and adherent junction structures, which may be closely associated with the small Rho GTPase protein (RhoA)/the Rho-associated protein kinase (ROCK) signaling pathway. In conclusion, D-mannose improved intestinal cellular redox homeostasis associated with ER stress and mitophagy pathways, and enhanced intercellular structures related to tight junctions and adherent junctions. Furthermore, quadratic regression analysis of the PWG and intestinal reactive oxygen species content indicated that the optimal addition level of D-mannose for juvenile grass carp was 4.61 and 4.59 g/kg, respectively.

Anti-Inflammatory, Cytotoxic, and Genotoxic Effects of Soybean Oligopeptides Conjugated with Mannose

Soy protein is considered to be a high-quality protein with a range of important biological functions. However, the applications of soy protein are limited due to its poor solubility and high level of allergenicity. Its peptides have been of interest because they exert the same biological functions as soy protein, but are easier to absorb, more stable and soluble, and have a lower allergenicity. Moreover, recent research found that an attachment of chemical moieties to peptides could improve their properties including their biodistribution, pharmacokinetic, and biological activities with lower toxicity. This study therefore aimed to acquire scientific evidence to support the further application and safe use of the soybean oligopeptide (OT) conjugated with allulose (OT-AL) or D-mannose (OT-Man). The anti-inflammation, cytotoxicity, and genotoxicity of OT, OT-AL, and OT-Man were investigated. The results showed that OT, AL, Man, OT-AL, and OT-Man at doses of up to 1000 µg/mL were not toxic to HepG2 (liver cancer cells), HEK293 (kidney cells), LX-2 (hepatic stellate cells), and pre- and mature-3T3-L1 (fibroblasts and adipocytes, respectively), while slightly delaying the proliferation of RAW 264.7 cells (macrophages) at high doses. In addition, the oligopeptides at up to 800 µg/mL were not toxic to isolated human peripheral blood mononuclear cells (PBMCs) and did not induce hemolysis in human red blood cells (RBCs). OT-Man (200 and 400 µg/mL), but not OT, AL, Man, and OT-AL, significantly reduced the production of NO and the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX2) stimulated by lipopolysaccharide (LPS) in RAW 264.7 cells, suggesting that the mannose conjugation of soy peptide had an inhibitory effect against LPS-stimulated inflammation. In addition, the secretion of interleukin-6 (IL-6) stimulated by LPS was significantly reduced by OT-AL (200 and 400 µg/mL) and OT-Man (400 µg/mL). The tumor necrosis factor-α (TNF-α) level was significantly decreased by OT (400 µg/mL), AL (400 µg/mL), OT-AL (200 µg/mL), and OT-Man (200 and 400 µg/mL) in the LPS-stimulated cells. The conjugation of the peptides with either AL or Man is likely to be enhance the anti-inflammation ability to inhibit the secretion of cytokines. As OT-Man exhibited a high potential to inhibit LPS-induced inflammation in macrophages, its mutagenicity ability was then assessed in bacteria and Drosophila. These findings showed that OT-Man did not trigger DNA mutations and was genome-safe. This study provides possible insights into the health advantages and safe use of conjugated soybean peptides.

Polarized M2 macrophages induced by glycosylated nano-hydroxyapatites activate bone regeneration in periodontitis therapy

AIM

To investigate the association between periodontal macrophage polarization states and the alveolar bone levels, and to assess whether glycosylated nano-hydroxyapatites (GHANPs) could improve bone regeneration in periodontitis by inducing macrophage M2 polarization.

MATERIALS AND METHODS

The change of macrophage polarization state in inflammatory periodontal tissues (with bone loss) was examined using clinical gingival samples. The relationship between macrophage phenotype and bone level in periodontal bone loss and repair was evaluated using a mouse periodontitis model. The effect of GHANPs on macrophage polarization was assessed by the in vitro model of lipopolysaccharide (LPS)-stimulated inflammation. The polarization-related markers were detected by immunofluorescence staining, real-time polymerase chain reaction and enzyme-linked immunosorbent assay analysis. The therapeutic effect of GHANPs on alveolar bone loss was explored in experimental periodontitis by histological staining and micro-CT analysis.

RESULTS

A lower macrophage M2/M1 ratio was observed in periodontitis-affected human gingival tissues. The results of animal experiments demonstrated a positive correlation between a lower Arg-1/iNOS ratio and accelerated alveolar bone loss; also, the proportion of Arg-1-positive macrophages increased during bone repair and regeneration. The administration of GHANPs partially restored M2 macrophage polarization after LPS stimulation. GHANPs increased alveolar bone repair and regeneration in experimental periodontitis induced by ligation, potentially related to their macrophage M2 transition regulation.

CONCLUSIONS

The findings of this study indicate that the induction of macrophage M2 polarization can be considered a viable approach for enhancing inflammatory bone repair. Additionally, GHANPs show potential in the clinical treatment of periodontitis.

Macrophage metabolism impacts metabolic dysfunction-associated steatotic liver disease and its progression

Metabolic dysfunction-associated steatotic liver disease (MASLD), with a progressive form of metabolic dysfunction-associated steatohepatitis (MASH), is the leading chronic liver disease worldwide, which can progress to advanced liver disease and hepatocellular carcinoma. MASLD is tightly associated with metabolic disorders such as obesity, insulin resistance, and type 2 diabetes. Macrophages, as an innate immune component and a linker of adaptive immune response, play important roles in the pathogenesis and treatment of MASLD or MASH. Metabolic reprogramming can regulate macrophage activation and polarization to inhibit MASLD or MASH progression to advanced liver disease. Here, we summarize the underlying mechanisms of how different metabolites such as amino acids, glucose, and fatty acids can regulate macrophage function and phenotype, the factors that regulate macrophage metabolism, and potential treatment options to regulate macrophage function in MASLD or MASH, as well as other associated metabolic disorders.

Serum sickness-like reaction to D-supplement: a case report

BACKGROUND

Serum Sickness-Like Reaction (SSLR) is an immune response characterized by rash, polyarthralgias, inflammation, and fever. Serum sickness-like reaction is commonly attributed to antibiotics, anticonvulsants, and anti-inflammatory agents.

CASE PRESENTATION

A 16-year-old female with a history of overactive bladder and anemia presented with a diffuse urticarial rash, headaches, joint pain, and swelling for three days. Her medications included oral contraceptive pills, iron, mirabegron, UQora, and a probiotic. Physical examination revealed a diffuse urticarial rash, and her musculoskeletal exam revealed swelling and tenderness in her wrists. She was evaluated by her pediatrician and started on a 7-day course of prednisone, as well as antihistamines. Her CBC, basic metabolic panel, liver function panel, Lyme titers, and urinalysis were all within normal limits. With concern for hypersensitivity reaction to medication, all medications were discontinued. Nine days after symptom onset, the patient was evaluated by an allergist, who confirmed her presentation was consistent with serum sickness-like reaction. Her symptoms resolved, and her medications were re-introduced sequentially over several months. Restarting UQora, however, triggered a recurrence of her symptoms, and it was identified as the culprit medication. Consequently, UQora was permanently discontinued, and the patient has remained symptom-free.

CONCLUSIONS

This case report describes the first documented case of serum sickness-like reaction caused by UQora (active ingredient D-mannose). D-mannose is a monosaccharide, and it is frequently promoted to prevent urinary tract infections. While the clinical features and timeline in this case were typical of serum sickness-like reaction, UQora as the trigger was highly unusual. Clinicians should be aware of the diverse triggers of serum sickness-like reaction and the importance of prompt identification and management to enhance patient safety. Further research is necessary to better understand the potential therapeutic applications of D-mannose, as well as the potential risks and interactions.

Injectable Ozone-Rich Nanocomposite Hydrogel Loaded with D-Mannose for Anti-Inflammatory and Cartilage Protection in Osteoarthritis Treatment

Osteoarthritis (OA) is a dynamic condition characterized by cartilage damage and synovial inflammation. Ozone (O3) shows potential therapeutic effects owing to its anti-inflammatory properties; however, its high reactivity and short half-life substantially limit its effectiveness in OA treatment. In this study, an ozone-rich thermosensitive nanocomposite hydrogel loaded with D-mannose is developed for OA treatment. Briefly, O3 is encapsulated in nanoparticles (NPs) composed of perfluorotributylamine and fluorinated hyaluronic acid to improve its stability. Next, D-mannose is conjugated with α-amino of the hydroxypropyl chitin (HPCH) via Schiff base to prepare MHPCH. These nanoparticles are encapsulated in MHPCH to produce O3 NPs@MHPCH. In vitro cell experiments demonstrate that the O3 NPs@MHPCH treatment significantly reduced VEGF and inflammation levels, accompanied by a decrease in inflammatory factors such as IL-1β, IL-6, TNF-α, and iNOS. Furthermore, O3 NPs@MHPCH promotes the expression of collagen II and aggrecan and stimulates chondrocyte proliferation. Additionally, in vivo studies show that O3 NPs@MHPCH significantly alleviated OA by reducing synovial inflammation, cartilage destruction, and subchondral bone remodeling. O3 NPs@MHPCH offers a promising option for improving the efficacy of O3 therapy and reducing the risk of synovial inflammation and cartilage degeneration in OA.

d-mannose targets PD-1 to lysosomal degradation and enhances T cell-mediated anti-tumor immunity

High expression of programmed cell death protein 1 (PD-1), a typical immune checkpoint, results in dysfunction of T cells in tumor microenvironment. Antibodies and inhibitors against PD-1 or its ligand (PD-L1) have been widely used in various malignant tumors. However, the mechanisms by which PD-1 is regulated are not fully understood. Here, we report a mechanism of PD-1 degradation triggered by d-mannose and the universality of this mechanism in anti-tumor immunity. We show that d-mannose inactivates GSK3β via promoting phosphorylation of GSK3β at Ser9, thereby leading to TFE3 translocation to nucleus and subsequent PD-1 proteolysis induced by enhanced lysosome biogenesis. Notably, combination of d-mannose and PD-1 blockade exhibits remarkable tumor growth suppression attributed to elevated cytotoxicity activity of T cells in vivo. Furthermore, d-mannose treatment dramatically improves the therapeutic efficacy of MEK inhibitor (MEKi) trametinib in vivo. Our findings unveil a universally unrecognized anti-tumor mechanism of d-mannose by destabilizing PD-1 and provide strategies to enhance the efficacy of both immune checkpoint blockade (ICB) and MEKi -based therapies.

D-mannose alleviates intervertebral disc degeneration through glutamine metabolism

BACKGROUND

Intervertebral disc degeneration (IVDD) is a multifaceted condition characterized by heterogeneity, wherein the balance between catabolism and anabolism in the extracellular matrix of nucleus pulposus (NP) cells plays a central role. Presently, the available treatments primarily focus on relieving symptoms associated with IVDD without offering an effective cure targeting its underlying pathophysiological processes. D-mannose (referred to as mannose) has demonstrated anti-catabolic properties in various diseases. Nevertheless, its therapeutic potential in IVDD has yet to be explored.

METHODS

The study began with optimizing the mannose concentration for restoring NP cells. Transcriptomic analyses were employed to identify the mediators influenced by mannose, with the thioredoxin-interacting protein (Txnip) gene showing the most significant differences. Subsequently, small interfering RNA (siRNA) technology was used to demonstrate that Txnip is the key gene through which mannose exerts its effects. Techniques such as colocalization analysis, molecular docking, and overexpression assays further confirmed the direct regulatory relationship between mannose and TXNIP. To elucidate the mechanism of action of mannose, metabolomics techniques were employed to pinpoint glutamine as a core metabolite affected by mannose. Next, various methods, including integrated omics data and the Gene Expression Omnibus (GEO) database, were used to validate the one-way pathway through which TXNIP regulates glutamine. Finally, the therapeutic effect of mannose on IVDD was validated, elucidating the mechanistic role of TXNIP in glutamine metabolism in both intradiscal and orally treated rats.

RESULTS

In both in vivo and in vitro experiments, it was discovered that mannose has potent efficacy in alleviating IVDD by inhibiting catabolism. From a mechanistic standpoint, it was shown that mannose exerts its anti-catabolic effects by directly targeting the transcription factor max-like protein X-interacting protein (MondoA), resulting in the upregulation of TXNIP. This upregulation, in turn, inhibits glutamine metabolism, ultimately accomplishing its anti-catabolic effects by suppressing the mitogen-activated protein kinase (MAPK) pathway. More importantly, in vivo experiments have further demonstrated that compared with intradiscal injections, oral administration of mannose at safe concentrations can achieve effective therapeutic outcomes.

CONCLUSIONS

In summary, through integrated multiomics analysis, including both in vivo and in vitro experiments, this study demonstrated that mannose primarily exerts its anti-catabolic effects on IVDD through the TXNIP-glutamine axis. These findings provide strong evidence supporting the potential of the use of mannose in clinical applications for alleviating IVDD. Compared to existing clinically invasive or pain-relieving therapies for IVDD, the oral administration of mannose has characteristics that are more advantageous for clinical IVDD treatment.

The Application of Drugs and Nano-Therapies Targeting Immune Cells in Hypoxic Inflammation

Immune cells are pivotal in the dynamic interplay between hypoxia and inflammation. During hypoxic conditions, HIF-1α, a crucial transcription factor, facilitates the adaptation of immune cells to the hypoxic micro-environment. This adaptation includes regulating immune cell metabolism, significantly impacting inflammation development. Strategies for anti-inflammatory and hypoxic relief have been proposed, aiming to disrupt the hypoxia-inflammation nexus. Research extensively focuses on anti-inflammatory agents and materials that target immune cells. These primarily mitigate hypoxic inflammation by encouraging M2-macrophage polarization, restraining neutrophil proliferation and infiltration, and maintaining Treg/TH17 balance. Additionally, oxygen-releasing nano-materials play a significant role. By alleviating hypoxia and clearing reactive oxygen species (ROS), these nano-materials indirectly influence immune cell functions. This paper delves into the response of immune cells under hypoxic conditions and the resultant effects on inflammation. It provides a comprehensive overview of various therapies targeting specific immune cells for anti-inflammatory purposes and explores nano-materials that either carry or generate oxygen to alleviate anoxic micro-environments.

Bletilla striata polysaccharide attenuated the progression of pulmonary fibrosis by inhibiting TGF-β1/Smad signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Bletilla striata, a traditional medicinal plant, has been utilized as a folk medicine for many years because of its superior biological activity in China. However, Bletilla striata polysaccharide (BSP) has received less attention, and its specific mechanism for ameliorating pulmonary fibrosis is completely unclear.

AIMS OF THE STUDY

In this study, we aim to assess BSP on the treatment of PF and explore potential mechanisms.

MATERIALS AND METHODS

BSP was successfully extracted and purified from Bletilla striata. The mechanisms were assessed in bleomycin-induced pulmonary fibrosis model and lung fibroblasts activated by transforming growth factor-β1 (TGF-β1). Histological analysis, immunofluorescence, Western blot and flow cytometry were used to explore the alterations after BSP intervention.

RESULTS

The results in vivo showed an anti-PF effect of BSP treatment, which reduced pathogenic damages. Furthermore, TGF-β1-induced abnormal migration and upregulated expression of collagen I (COL1A1), vimentin and α-smooth muscle actin (α-SMA) were suppressed by BSP in L929 cells. Moreover, the abnormal proliferation was retarded by inhibiting the cell cycle of G1 to S phase. Immunofluorescence assay showed that BSP activated autophagy and played an antifibrotic role by inhibiting the expression of p62 and phospho-mammalian target of rapamycin (p-mTOR). Last but not least, the suppression of TGF-β1/Smad signaling pathway was critical for BSP to perform therapeutic effects in vitro and in vivo.

CONCLUSION

The possible mechanisms were involved in improving ECM deposition, regulating cell migration and proliferation, and promoting cellular autophagy. Briefly, all of the above revealed that BSP might be a novel therapy for treating pulmonary fibrosis.

Exopolysaccharide production by Lactobacillus plantarum T10 is responsible for the probiotic activity in enhancing intestinal barrier function in vitro and in vivo

Lactobacillus probiotics exert their effects in a strain-specific and metabolite-specific manner. This study aims to identify lactobacilli that can effectively enhance the intestinal barrier function both in vitro and in vivo and to investigate the underlying metabolite and molecular mechanisms involved. Nine Lactobacillus isolates were evaluated for their ability to enhance the IPEC-J2 cellular barrier function and for their anti-inflammatory and anti-apoptotic effects in IPEC-J2 cells after an enterotoxigenic Escherichia coli challenge. Of the nine isolates, L. plantarum T10 demonstrated significant advantages in enhancing the cellular barrier function and displayed anti-inflammatory and anti-apoptotic activities in vitro. The bioactivities of L. plantarum T10 were primarily attributed to the production of exopolysaccharides, which exerted their effects through the TLR-mediated p38 MAPK pathway in ETEC-challenged IPEC-J2 cells. Furthermore, the production of EPS by L. plantarum T10 led to the alleviation of dextran sulfate sodium-induced colitis by reducing intestinal damage and enhancing the intestinal barrier function in mice. The EPS is classified as a heteropolysaccharide with an average molecular weight of 23.0 kDa. It is primarily composed of mannose, glucose, and ribose. These findings have practical implications for the targeted screening of lactobacilli used in the production of probiotics and postbiotics with strain-specific features of exopolysaccharides.

ACSS2 controls PPARγ activity homeostasis to potentiate adipose-tissue plasticity

The appropriate transcriptional activity of PPARγ is indispensable for controlling inflammation, tumor and obesity. Therefore, the identification of key switch that couples PPARγ activation with degradation to sustain its activity homeostasis is extremely important. Unexpectedly, we here show that acetyl-CoA synthetase short-chain family member 2 (ACSS2) critically controls PPARγ activity homeostasis via SIRT1 to enhance adipose plasticity via promoting white adipose tissues beiging and brown adipose tissues thermogenesis. Mechanistically, ACSS2 binds directly acetylated PPARγ in the presence of ligand and recruits SIRT1 and PRDM16 to activate UCP1 expression. In turn, SIRT1 triggers ACSS2 translocation from deacetylated PPARγ to P300 and thereafter induces PPARγ polyubiquitination and degradation. Interestingly, D-mannose rapidly activates ACSS2-PPARγ-UCP1 axis to resist high fat diet induced obesity in mice. We thus reveal a novel ACSS2 function in coupling PPARγ activation with degradation via SIRT1 and suggest D-mannose as a novel adipose plasticity regulator via ACSS2 to prevent obesity.

Inhibition of bleomycin-induced pulmonary fibrosis in SD rats by sea cucumber peptides

BACKGROUND

Pulmonary fibrosis (PF) is the terminal manifestation of a type of pulmonary disease, which seriously affects the respiratory function of the body, and with no effective cure for treatment. This study evaluated the effect of sea cucumber peptides (SCP) on bleomycin-induced SD rat PF.

RESULTS

SCP can inhibit the PF induced by bleomycin. PF and SCP did not affect the food intake of rats, but PF reduced the body weight of rats, and SCP could improve the weight loss. SCP reduced lung index in PF rats in a dose-dependent manner. SCP significantly reduced IL-1β, IL-6, TNF-α, α-SMA and VIM expression levels in lung tissue (P < 0.05), significantly decreased TGF-β1 expression level in serum (P < 0.01) and the LSCP group and MSCP group had better inhibitory effects on PF than the HSCP group. Histomorphological results showed that SCP could ameliorate the structural damage of lung tissue, alveolar wall rupture, inflammatory cell infiltration, fibroblast proliferation and deposition of intercellular matrix and collagen fibers caused by PF. The improvement effect of the MSCP group was the most noteworthy in histomorphology. Metabolomics results showed that SCP significantly downregulated catechol, N-acetyl-l-histidine, acetylcarnitine, stearoylcarnitine, d-mannose, l-threonine, l-alanine, glycine, 3-guanidinopropionic acid, prostaglandin D2 and embelic acid d-(-)-β-hydroxybutyric acid expression levels in lung tissue.

CONCLUSION

SCP ameliorate bleomycin-induced SD rat PF. KEGG pathway analysis proved that SCP intervened in PF mainly via the lysosome pathway, with d-mannose as the key factor. © 2023 Society of Chemical Industry.

Aberrant Glycosylation in Pancreatic Ductal Adenocarcinoma 3D Organoids Is Mediated by KRAS Mutations

Aberrant glycosylation in tumor cells is a hallmark during carcinogenesis. KRAS gene mutations are the most well-known oncogenic abnormalities but their association with glycan alterations in pancreatic ductal adenocarcinoma (PDAC) is largely unknown. We employed patient-derived 3D organoids to culture pure live PDAC cells, excluding contamination by fibroblasts and immune cells, to gasp the comprehensive cancer cell surface glycan expression profile using lectin microarray and transcriptomic analyses. Surgical specimens from 24 PDAC patients were digested and embedded into a 3D culture system. Surface-bound glycans of 3D organoids were analyzed by high-density, 96-lectin microarrays. KRAS mutation status and expression of various glycosyltransferases were analyzed by RNA-seq. We successfully established 16 3D organoids: 14 PDAC, 1 intraductal papillary mucinous neoplasm (IPMN), and 1 normal pancreatic duct. KRAS was mutated in 13 (7 G12V, 5 G12D, 1 Q61L) and wild in 3 organoids (1 normal duct, 1 IPMN, 1 PDAC). Lectin reactivity of AAL (Aleuria aurantia) and AOL (Aspergillus oryzae) with binding activity to α1-3 fucose was higher in organoids with KRAS mutants than those with KRAS wild-type. FUT6 (α1-3fucosyltransferase 6) and FUT3 (α1-3/4 fucosyltransferase 3) expression was also higher in KRAS mutants than wild-type. Meanwhile, mannose-binding lectin (rRSL [Ralstonia solanacearum] and rBC2LA [Burkholderia cenocepacia]) signals were higher while those of galactose-binding lectins (rGal3C and rCGL2) were lower in the KRAS mutants. We demonstrated here that PDAC 3D-cultured organoids with KRAS mutations were dominantly covered in increased fucosylated glycans, pointing towards novel treatment targets and/or tumor markers.

Mannose enhances intestinal immune barrier function and dextran sulfate sodium salt-induced colitis in mice by regulating intestinal microbiota

Background

Inflammatory bowel disease (IBD) greatly affects human quality of life. Mannose has been reported to be used to treat IBD, but the mechanism is currently unknown.

Methods

C57/BL mice were used as research subjects, and the mouse acute colitis model was induced using dextran sulfate sodium salt (DSS). After oral administration of mannose, the body weights and disease activity index (DAI) scores of the mice were observed. The colon lengths, histopathological sections, fecal content microbial sequencing, colon epithelial inflammatory genes, and tight junction protein Occludin-1 expression levels were measured. We further used the feces of mice that had been orally administered mannose to perform fecal bacterial transplantation on the mice with DSS-induced colitis and detected the colitis-related indicators.

Results

Oral administration of mannose increased body weights and colon lengths and reduced DAI scores in mice with DSS-induced colitis. In addition, it reduced the expression of colon inflammatory genes and the levels of serum inflammatory factors (TNF-α, IL-6, and IL-1β), further enhancing the expression level of the colonic Occludin-1 protein and alleviating the toxic response of DSS to the intestinal epithelium of the mice. In addition, gut microbial sequencing revealed that mannose increased the abundance and diversity of intestinal flora. Additionally, after using the feces of the mannose-treated mice to perform fecal bacterial transplantation on the mice with DSS-induced colitis, they showed the same phenotype as the mannose-treated mice, and both of them alleviated the intestinal toxic reaction induced by the DSS. It also reduced the expression of intestinal inflammatory genes (TNF-α, IL-6, and IL-1β) and enhanced the expression level of the colonic Occludin-1 protein.

Conclusion

Mannose can treat DSS-induced colitis in mice, possibly by regulating intestinal microorganisms to enhance the intestinal immune barrier function and reduce the intestinal inflammatory response.

PMI-controlled mannose metabolism and glycosylation determines tissue tolerance and virus fitness

Host survival depends on the elimination of virus and mitigation of tissue damage. Herein, we report the modulation of D-mannose flux rewires the virus-triggered immunometabolic response cascade and reduces tissue damage. Safe and inexpensive D-mannose can compete with glucose for the same transporter and hexokinase. Such competitions suppress glycolysis, reduce mitochondrial reactive-oxygen-species and succinate-mediated hypoxia-inducible factor-1α, and thus reduce virus-induced proinflammatory cytokine production. The combinatorial treatment by D-mannose and antiviral monotherapy exhibits in vivo synergy despite delayed antiviral treatment in mouse model of virus infections. Phosphomannose isomerase (PMI) knockout cells are viable, whereas addition of D-mannose to the PMI knockout cells blocks cell proliferation, indicating that PMI activity determines the beneficial effect of D-mannose. PMI inhibition suppress a panel of virus replication via affecting host and viral surface protein glycosylation. However, D-mannose does not suppress PMI activity or virus fitness. Taken together, PMI-centered therapeutic strategy clears virus infection while D-mannose treatment reprograms glycolysis for control of collateral damage.

Macrophage: Hidden Criminal in Therapy Resistance

BACKGROUND

Although substantial efforts have been made by researchers to develop drugs, a disappointing reality is that the emergence of drug resistance is an unavoidable reality for the majority of patients. In recent years, emerging evidence suggests a connection between drug resistance and immune dysregulation.

SUMMARY

As a ubiquitously distributed, versatile innate immune cell, macrophages play essential roles in maintaining tissue homeostasis in a steady state. Nevertheless, it is becoming aware that macrophages undermine the action of therapeutic drugs across various disease types. Reprogramming macrophage function has been proven to be effective in restoring patient responsiveness to treatment. Herein, we comprehensively reviewed how macrophages respond to drugs and the mechanisms by which they contribute to treatment unresponsiveness in cancer, inflammatory diseases, and metabolic diseases. In addition, future prospects in macrophage-based combination therapy were discussed.

KEY MESSAGES

Targeting macrophages is a promising strategy for overcoming drug resistance in immune disorders.

Acetyl-11-keto-beta-boswellic acid modulates macrophage polarization and Schwann cell migration to accelerate spinal cord injury repair in rats

BACKGROUND

Inhibiting secondary inflammatory damage caused by glial cells and creating a stable microenvironment is one of the main strategies to investigate drugs for the treatment of spinal cord injury. Acetyl-11-keto-beta-boswellic acid (AKBA) is the active component of the natural drug boswellia, which has anti-inflammatory and antioxidant effects and offers a possible therapeutic option for spinal cord injury.

METHODS

In this study, a spinal cord injury model was established by crushing spinal cord, respectively, to detect the M1 macrophage inflammatory markers: iNOS, TNF-α, IL-1β, and the M2 macrophage markers CD206, ARG-1, IL-10, and the detection of antioxidant enzymes and MDA. In vitro, macrophages were cultured to verify the main mechanism of the macrophage switch from Nrf2/HO-1 to M2 type by flow cytometry, immunofluorescence, and other techniques. Macrophage and Schwann cell co-culture validated the migration mechanism of Schwann cells promoted by AKBA.

RESULTS

AKBA significantly enhanced the antioxidant enzyme activities of CAT, GSH-Px, T-AOC, and SOD, reduced MDA content, and reduced oxidative damage caused by spinal cord injury via the Nrf2/HO-1 signaling pathway; AKBA mediates Nrf2/HO-1/IL-10, converts macrophages from M1 to M2 type, reduces inflammation, and promotes Schwann cell migration, thereby accelerating the repair of spinal cord injury in rats.

CONCLUSIONS

Our work demonstrates that AKBA can attenuate oxidative stress as well as the secondary inflammatory injury caused by macrophages after SCI, promote Schwann cell migration to the injury site, and thus accelerate the repair of the injured spinal cord.

Multi-omics revealed rumen microbiota metabolism and host immune regulation in Tibetan sheep of different ages

The rumen microbiota and metabolites play an important role in energy metabolism and immune regulation of the host. However, the regulatory mechanism of rumen microbiota and metabolite interactions with host on Tibetan sheep's plateau adaptability is still unclear. We analyzed the ruminal microbiome and metabolome, host transcriptome and serum metabolome characteristics of Tibetan sheep at different ages. Biomarkers Butyrivibrio, Lachnospiraceae_XPB1014_group, Prevotella, and Rikenellaceae_RC9_gut_group were found in 4 months, 1.5 years, 3.5 years, and 6 years Tibetan sheep, respectively. The rumen microbial metabolites were mainly enriched in galactose metabolism, unsaturated fatty acid biosynthesis and fatty acid degradation pathways, and had significant correlation with microbiota. These metabolites further interact with mRNA, and are co-enriched in arginine and proline metabolism, metabolism of xenobiotics by cytochrome P450, propanoate metabolism, starch and sucrose metabolism, gap junction pathway. Meanwhile, serum metabolites also have a similar function, such as chemical carcinogenesis - reactive oxygen species, limonene and pinene degradation, and cutin, suberine and wax biosynthesis, thus participating in the regulation of the body's immune and energy-related metabolic processes. This study systematically revealed that rumen microbiota, metabolites, mRNA and serum metabolites of Tibetan sheep were involved in the regulation of fermentation metabolic function and immune level of Tibetan sheep at different ages, which provided a new perspective for plateau adaptability research of Tibetan sheep at different ages.

The Bisdioxopiperazine ICRF-193 Attenuates LPS-induced IL-1β Secretion by Macrophages

Inhibiting pathological secretion of Interleukin-1β has shown beneficial effects in disease models and in the clinic and thus there is interest in finding inhibitors that can reduce its release from macrophages in response to their activation by foreign pathogens. We used an in vitro human macrophage model to investigate whether ICRF-193, a Topoisomerase II inhibitor could modulate IL1B mRNA expression and IL-1β secretion. These macrophage-like cells readily secrete IL-1β in response to Lipopolysaccharide (LPS). Upon exposure to a non-toxic dose of ICRF-193, IL-1β secretion was diminished by ~ 40%; however, level of transcription of IL1B was unaffected. We show that there was no Topoisomerase 2B (TOP2B) binding to several IL1B gene sites, which may explain why ICRF-193 does not alter IL1B mRNA levels. Hence, we show for the first time that ICRF-193 can reduce IL-1β secretion. Its low cost and the development of water-soluble prodrugs of ICRF-193 warrants its further investigation in the modulation of pathological secretion of this cytokine for the treatment of inflammatory disorders. (165 words).

ACOD1 deficiency offers protection in a mouse model of diet-induced obesity by maintaining a healthy gut microbiota

Aconitate decarboxylase 1 (ACOD1) is the enzyme synthesizing itaconate, an immuno-regulatory metabolite tuning host-pathogen interactions. Such functions are achieved by affecting metabolic pathways regulating inflammation and microbe survival. However, at the whole-body level, metabolic roles of itaconate remain largely unresolved. By using multiomics-integrated approaches, here we show that ACOD1 responds to high-fat diet consumption in mice by promoting gut microbiota alterations supporting metabolic disease. Genetic disruption of itaconate biosynthesis protects mice against obesity, alterations in glucose homeostasis and liver metabolic dysfunctions by decreasing meta-inflammatory responses to dietary lipid overload. Mechanistically, fecal metagenomics and microbiota transplantation experiments demonstrate such effects are dependent on an amelioration of the intestinal ecosystem composition, skewed by high-fat diet feeding towards obesogenic phenotype. In particular, unbiased fecal microbiota profiling and axenic culture experiments point towards a primary role for itaconate in inhibiting growth of Bacteroidaceae and Bacteroides, family and genus of Bacteroidetes phylum, the major gut microbial taxon associated with metabolic health. Specularly to the effects imposed by Acod1 deficiency on fecal microbiota, oral itaconate consumption enhances diet-induced gut dysbiosis and associated obesogenic responses in mice. Unveiling an unrecognized role of itaconate, either endogenously produced or exogenously administered, in supporting microbiota alterations underlying diet-induced obesity in mice, our study points ACOD1 as a target against inflammatory consequences of overnutrition.