Dioscin ameliorates murine ulcerative colitis by regulating macrophage polarization

Dioscin alleviates aplastic anemia through regulatory T cells promotion

Objectives: Aplastic anemia (AA) is one of the immune-mediated bone marrow failure disorders caused by multiple factors, including the inability of CD4 + CD25 + regulatory T cells (Tregs) to negatively regulate cytotoxic T lymphocytes (CTLs). Dioscin is a natural steroid saponin that has a similar structure to steroid hormones. The purpose of this study is to look into the effect of Dioscin on the functions of CD4 + CD25+ Tregs in the AA mouse model and explore its underlying mechanism.Methods: To begin with, bone marrow failure was induced through total body irradiation and allogeneic lymphocyte infusion using male Balb/c mice. After 14 consecutive days of Dioscin orally administrated, the AA mouse model was tested for complete blood counts, HE Staining of the femur, Foxp3, IL-10 and TGF-β. Then CD4 + CD25+ Tregs were isolated from splenic lymphocytes of the AA mouse model, Tregs and the biomarkers and cytokines of Tregs were measured after 24 h of Dioscin intervention treatment in vitro.Results: Dioscin promotes the expression of Foxp3, IL-10, IL-35 and TGF-β, indicating its Tregs-promoting properties. Mechanistically, the administration of Dioscin resulted in the alteration of CD152, CD357, Perforin and CD73 on the surface of Tregs, and restored the expression of Foxp3.Conclusion: Dioscin markedly attenuated bone marrow failure, and promoted Tregs differentiation, suggesting the maintenance of theimmune balance effect of Dioscin. Dioscin attenuates pancytopenia and bone marrow failure via its Tregs promotion properties.

FoxO1-modulated macrophage polarization regulates osteogenesis via PPAR-γ signaling

Periodontitis, a common chronic inflammatory disease, epitomizes a significant impairment in the host immune system and an imbalance of bone metabolism. Macrophage polarization, a dynamic process dictated by the microenvironment, intricately contributes to the interplay between the immune system and bone remodeling, namely the osteoimmune system. Forkhead box protein O1 (FoxO1) has been shown to play a dramatic role in mediating oxidative stress, bone mass, as well as cellular metabolism. Nevertheless, the function and underlying mechanisms of FoxO1 in regulating macrophage polarization-mediated osteogenesis in periodontitis remain to be further elucidated. Here, we found that FoxO1 expression was closely linked to periodontitis, accompanied by aggravated inflammation. Notably, FoxO1 knockdown skewed macrophage polarization from M1 to the antiinflammatory M2 phenotype under inflammatory conditions, which rescued the impaired osteogenic potential. Mechanistically, we revealed that the enhancement of the transcription of peroxisome proliferator-activated receptor (PPAR) signaling in FoxO1-knockdown macrophages. In agreement with this contention, GW9662, a specific inhibitor of PPAR-γ signaling, greatly aggravated macrophage polarization from M2 to the M1 phenotype and attenuated osteogenic potential under inflammatory conditions. Additionally, PPAR-γ signaling agonist rosiglitazone (RSG) was applied to address ligature-induced periodontitis with attenuated inflammation. Our data lend conceptual credence to the function of FoxO1 in mediating macrophage polarization-regulated osteogenesis which serves as a novel therapeutic target for periodontitis.

Identification and experimental validation of immune-related gene PPARG is involved in ulcerative colitis

BACKGROUND

The pathophysiology of ulcerative colitis (UC) is believed to be heavily influenced by immunology, which presents challenges for both diagnosis and treatment. The main aims of this study are to deepen our understanding of the immunological characteristics associated with the disease and to identify valuable biomarkers for diagnosis and treatment.

METHODS

The UC datasets were sourced from the GEO database and were analyzed using unsupervised clustering to identify different subtypes of UC. Twelve machine learning algorithms and Deep learning model DNN were developed to identify potential UC biomarkers, with the LIME and SHAP methods used to explain the models' findings. PPI network is used to verify the identified key biomarkers, and then a network connecting super enhancers, transcription factors and genes is constructed. Single-cell sequencing technology was utilized to investigate the role of Peroxisome Proliferator Activated Receptor Gamma (PPARG) in UC and its correlation with macrophage infiltration. Furthermore, alterations in PPARG expression were validated through Western blot (WB) and immunohistochemistry (IHC) in both in vitro and in vivo experiments.

RESULT

By utilizing bioinformatics techniques, we were able to pinpoint PPARG as a key biomarker for UC. The expression of PPARG was significantly reduced in cell models, UC animal models, and colitis models induced by dextran sodium sulfate (DSS). Interestingly, overexpression of PPARG was able to restore intestinal barrier function in H2O2-induced IEC-6 cells. Additionally, immune-related differentially expressed genes (DEGs) allowed for efficient classification of UC samples into neutrophil and mitochondrial metabolic subtypes. A diagnostic model incorporating the three disease-specific genes PPARG, PLA2G2A, and IDO1 demonstrated high accuracy in distinguishing between the UC group and the control group. Furthermore, single-cell analysis revealed that decreased PPARG expression in colon tissue may contribute to the polarization of M1 macrophages through activation of inflammatory pathways.

CONCLUSION

In conclusion, PPARG, a gene related to immunity, has been established as a reliable potential biomarker for the diagnosis and treatment of UC. The immune response it controls plays a key role in the progression and development of UC by enabling interaction between characteristic biomarkers and immune infiltrating cells.

QingChang-XiaoPi decoction ameliorates intestinal inflammation of ulcerative colitis by regulating the pathogenicity of Th17 cells

BACKGROUND

QingChang-XiaoPi Decoction (QCXPY), a Chinese herbal prescription, has been employed in the treatment of ulcerative colitis (UC) in China. However, its molecular mechanism of action in UC remains unclear.

PURPOSE

To elucidate the therapeutic effects of QCXPY against UC and reveal its mechanism of action.

STUDY DESIGN

We conducted a single-arm observation to evaluate the clinical efficacy of QCXPY in patients with mild-to-moderate UC. Inclusion and exclusion criteria were established to ensure the eligibility of participants, with a focus on excluding patients with specific conditions or complications that could confound the results.

METHODS

The expression of inflammatory factors in patients' serum was detected using a Luminex assay. The main components of QCXPY were identified using UHPLC-Q-TOF-MS. Network pharmacology was employed to predict potential therapeutic targets and their mechanisms of action. The efficacy of QCXPY was evaluated using a dextran sulfate sodium (DSS)-induced mouse model. Disease activity index (DAI), histopathological score, cytokine detection by ELISA, T-helper 17 (Th17) cell proportion by flow cytometry, expression of the IL-23/IL-17 axis, and changes in the levels of its downstream effectors were detected by immunohistochemistry, immunofluorescence, and western blotting.

RESULTS

QCXPY could alleviate the symptoms of diarrhea, abdominal pain, abdominal distension, and purulent stool in patients with mild-to-moderate UC. Moreover, it reduced the expression of IL-6, IL-17, and IL-23 in serum; alleviated DSS-induced experimental colitis in mice; reduced DAI, pathological scores, and the expressions of IL-6, IL-17, and IL-23 in colon tissue; and decreased the proportion of pathogenic Th17 cells and the expression of STAT3 and phospho-STAT3.

CONCLUSION

This study confirmed for the first time that QCXPY could alleviate intestinal symptoms, reduce the levels of serum inflammatory factors, and improve the quality of life of patients with mild-to-moderate UC. Its mechanism of action may involve reducing the secretion of inflammatory cytokines, moderating the pathogenicity of Th17 cells, and inhibiting STAT3 phosphorylation, thereby alleviating intestinal inflammation in UC.

WTAP promotes the progression of ulcerative colitis by silencing the expression of CES2 through m6A modification

OBJECTIVE

This study will explore the function of WTAP, the critical segment of m6A methyltransferase complex, in UC and its regulation on immune response.

METHODS

The expression levels of key proteins were detected in colon tissues which were derived from UC patients and mice. Macrophage polarization and CD4+ T cell infiltration were detected by flow cytometry and IF staining. ELISA assay was utilized to analyze the level of the inflammatory cytokines. m6A-RIP-PCR, actinomycin D test, and RIP assays were utilized to detect the m6A level, stability, and bound proteins of CES2 mRNA. A dual luciferase reporter assay was conducted to confirm the transcriptional interactions between genes. A co-culture system of intestinal epithelium-like organs was constructed to detect the primary mouse intestinal epithelial cells (PMIEC) differentiation. The interaction between proteins was detected via Co-IP assay.

RESULTS

The expression of WTAP and CES2 in UC tissues was increased and decreased, respectively. Knockdown of WTAP inhibited the progression of UC in mice by inhibiting M1 macrophage polarization and CD4+ T cell infiltration. WTAP combined YTHDF2 to promote the m6A modification of CES2 mRNA and inhibited its expression. CES2 co-expressed with EPHX2 and overexpression of CES2 promoted the differentiation of PMIEC. The inhibitory effect of WTAP knockdown on the progress of UC was partially abrogated by CES2 knockdown.

CONCLUSION

WTAP/YTHDF2 silences CES2 by promoting its m6A modification and then promotes the progression of UC. WTAP could be a promoting therapy target of UC.

Quercetin restores respiratory mucosal barrier dysfunction in Mycoplasma gallisepticum-infected chicks by enhancing Th2 immune response

BACKGROUND

Mycoplasma gallisepticum (MG) has long been a pathogenic microorganism threatening the global poultry industry. Previous studies have demonstrated that the mechanism by which quercetin (QUE) inhibits the colonization of MG in chicks differs from that of antibiotics. However, the molecular mechanism by which QUE facilitates the clearance of MG remains unclear.

PURPOSE

The aim of this study was to investigate the molecular mechanism of MG clearance by QUE, with the expectation of providing new options for the treatment of MG.

METHODS

A model of MG infection in chicks and MG-induced M1 polarization in HD-11 cells were established. The mechanism of QUE clearance of MG was investigated by evaluating the relationship between tracheal mucosal barrier integrity, antibody levels, Th1/Th2 immune balance and macrophage metabolism and M1/M2 polarization balance. Furthermore, network pharmacology and molecular docking techniques were employed to explore the potential molecular pathways connecting QUE, M2 polarization, and fatty acid oxidation (FAO).

RESULTS

The findings indicate that QUE remodels tracheal mucosal barrier function by regulating tight junctions and secretory immunoglobulin A (sIgA) expression levels. This process entails the regulatory function of QUE on the Th1/Th2 immune imbalance that is induced by MG infection in the tracheal mucosa. Moreover, QUE intervention impeded the M1 polarization of HD-11 cells induced by MG infection, while simultaneously promoting M2 polarization through the induction of FAO. Conversely, inhibitors of the FAO pathway impede this effect. The results of computer network analysis suggest that QUE may induce FAO via the PI3K/AKT pathway to promote M2 polarization. Notably, inhibition of the PI3K/AKT pathway was found to effectively inhibit M2 polarization in HD-11 cells, while having a limited effect on FAO.

CONCLUSIONS

QUE promotes M2 polarization of HD-11 cells to enhance Th2 immune response through FAO and PI3K/AKT pathways, thereby restoring tracheal mucosal barrier function and ultimately inhibiting MG colonization.

Macrophage plasticity: signaling pathways, tissue repair, and regeneration

Macrophages are versatile immune cells with remarkable plasticity, enabling them to adapt to diverse tissue microenvironments and perform various functions. Traditionally categorized into classically activated (M1) and alternatively activated (M2) phenotypes, recent advances have revealed a spectrum of macrophage activation states that extend beyond this dichotomy. The complex interplay of signaling pathways, transcriptional regulators, and epigenetic modifications orchestrates macrophage polarization, allowing them to respond to various stimuli dynamically. Here, we provide a comprehensive overview of the signaling cascades governing macrophage plasticity, focusing on the roles of Toll-like receptors, signal transducer and activator of transcription proteins, nuclear receptors, and microRNAs. We also discuss the emerging concepts of macrophage metabolic reprogramming and trained immunity, contributing to their functional adaptability. Macrophage plasticity plays a pivotal role in tissue repair and regeneration, with macrophages coordinating inflammation, angiogenesis, and matrix remodeling to restore tissue homeostasis. By harnessing the potential of macrophage plasticity, novel therapeutic strategies targeting macrophage polarization could be developed for various diseases, including chronic wounds, fibrotic disorders, and inflammatory conditions. Ultimately, a deeper understanding of the molecular mechanisms underpinning macrophage plasticity will pave the way for innovative regenerative medicine and tissue engineering approaches.

Formyl peptide receptor 1 mitigates colon inflammation and maintains mucosal homeostasis through the inhibition of CREB-C/EBPβ-S100a8 signaling

Excessive inflammatory responses are the main characteristic of ulcerative colitis (UC). Activation of formyl peptide receptor 1 (FPR1) has been found to promote the proliferation and migration of epithelial cells, but its role and therapeutic potential in UC remain unclear. This study observed an increased expression of FPR1 in a mouse model of colitis. Interestingly, FPR1 deficiency exacerbated UC and increased the secretion of the proinflammatory mediator from immune cells (e.g. macrophages), S100a8, a member of the damage-associated molecular patterns. Notably, the administration of the FPR agonist Cmpd43 ameliorated colon injury in a preclinical mice model of UC, likely via inhibiting phosphorylation of cyclic adenosine monophosphate-response element-binding protein and expression of CCAAT/enhancer-binding protein β, which in turn suppressed the secretion of S100a8. In conclusion, these findings discovered a novel role of FPR1 in the development of colitis and will facilitate the development of FPR1-based pharmacotherapy to treat UC.

Autophagy: A potential target for natural products in the treatment of ulcerative colitis

Ulcerative colitis (UC) is a chronic inflammatory bowel disease primarily affecting the mucosa of the colon and rectum. UC is characterized by recurrent episodes, often necessitating lifelong medication use, imposing a significant burden on patients. Current conventional and advanced treatments for UC have the disadvantages of insufficient efficiency, susceptibility to drug resistance, and notable adverse effects. Therefore, developing effective and safe drugs has become an urgent need. Autophagy is an intracellular degradation process that plays an important role in intestinal homeostasis. Emerging evidence suggests that aberrant autophagy is involved in the development of UC, and modulating autophagy can effectively alleviate experimental colitis. A growing number of studies have established that autophagy can interplay with endoplasmic reticulum stress, gut microbiota, apoptosis, and the NLRP3 inflammasome, all of which contribute to the pathogenesis of UC. In addition, a variety of intestinal epithelial cells, including absorptive cells, goblet cells, and Paneth cells, as well as other cell types like neutrophils, antigen-presenting cells, and stem cells in the gut, mediate the development of UC through autophagy. To date, many studies have found that natural products hold the potential to exert therapeutic effects on UC by regulating autophagy. This review focuses on the possible effects and pharmacological mechanisms of natural products to alleviate UC with autophagy as a potential target in recent years, aiming to provide a basis for new drug development.

Protective effects of Amauroderma rugosum on dextran sulfate sodium-induced ulcerative colitis through the regulation of macrophage polarization and suppression of oxidative stress

BACKGROUND

Amauroderma rugosum (AR) is a medicinal mushroom commonly used to treat inflammation, gastric disorders, epilepsy, and cancers due to its remarkable anti-inflammatory and anti-oxidative properties. This study was designed to evaluate the pharmacological effects of AR and its underlying mechanism of action against ulcerative colitis (UC) in vitro and in vivo.

METHODS

A UC mouse model was established by administration of dextran sulfate sodium (DSS). AR extract was administered intragastrically to mice for 7 days. At the end of the experiment, histopathology, macrophage phenotype, oxidative stress, and inflammatory status were examined in vivo. Furthermore, RAW 264.7, THP-1, and Caco-2 cells were used to elucidate the mechanism of action of AR in vitro.

RESULTS

AR extract (0.5-2 mg/mL) significantly suppressed lipopolysaccharide (LPS) and interferon-gamma (IFN-γ)-induced M1 macrophage (pro-inflammatory) polarization in both RAW 264.7 and THP-1 cells. LPS-induced pro-inflammatory mediators (nitric oxide, TNF-α, IL-1β, MCP-1, and IL-6) were reduced by AR extract in a concentration-dependent manner. Similarly, AR extract downregulated MAPK signaling activity in LPS-stimulated RAW 264.7 cells. AR extract elicited a concentration-dependent increase in the mRNA expression of M2 (anti-inflammatory) phenotype markers (CD206, Arg-1, Fizz-1, and Ym-1) in RAW 264.7 cells. Moreover, AR extract suppressed DSS-induced ROS generation and mitochondrial dysfunction in Caco-2 cells. The in vivo experiment revealed that AR extract (200 mg/kg) increased colon length compared to the DSS-treated group. In addition, disease activity index, spleen ratio, body weight, oxidative stress, and colonic inflammation were markedly improved by AR treatment in DSS-induced UC mice. Finally, AR suppressed M1 and promoted M2 macrophage polarization in UC mice.

CONCLUSION

The AR extract protected against DSS-induced UC by regulating macrophage polarization and suppressing oxidative stress. These valuable findings suggest that adequate intake of AR can prevent and/or treat UC.

Constructing a screening model to obtain the functional herbs for the treatment of active ulcerative colitis based on herb-compound-target network and immuno-infiltration analysis

The therapeutic effect of most traditional Chinese medicines (TCM) on ulcerative colitis is unclear, The objective of this study was to develop a core herbal screening model aimed at facilitating the transition from active ulcerative colitis (UC) to inactive. We obtained the gene expression dataset GSE75214 for UC from the GEO database and analysed the differentially expressed genes (DEGs) between active and inactive groups. Gene modules associated with the active group were screened using WGCNA, and immune-related genes (IRGs) were obtained from the ImmPort database. The TCMSP database was utilized to acquire the herb-molecule-target network and identify the herb-related targets (HRT). We performed intersection operations on HRTs, DEGs, IRGs, and module genes to identify candidate genes and conducted enrichment analyses. Subsequently, three machine learning algorithms (SVM-REF analysis, Random Forest analysis, and LASSO regression analysis) were employed to refine the hubgene from the candidate genes. Based on the hub genes identified in this study, we conducted compound and herb matching and further screened herbs related to abdominal pain and blood in stool using the Symmap database.Besides, the stability between molecules and targets were assessed using molecular docking and molecular dynamic simulation methods. An intersection operation was performed on HRT, DEGs, IRGs, and module genes, leading to the identification of 23 candidate genes. Utilizing three algorithms (RandomForest, SVM-REF, and LASSO) for analyzing the candidate genes and identifying the intersection, we identified five core targets (CXCL2, DUOX2, LYZ, MMP9, and AGT) and 243 associated herbs. Hedysarum Multijugum Maxim. (Huangqi), Sophorae Flavescentis Radix (Kushen), Cotyledon Fimbriata Turcz. (Wasong), and Granati Pericarpium (Shiliupi) were found to be capable of relieving abdominal pain and hematochezia during active UC. Molecular docking demonstrated that the compounds of the four aforementioned herbs showed positive docking activity with their core targets. The results of molecular dynamic simulations indicated that well-docked active molecules had a more stable structure when bound to their target complexes. The study has shed light on the potential of TCMs in treating active UC from an immunomodulatory perspective, consequently, 5 core targets and 4 key herbs has been identified. These findings can provide a theoretical basis for subsequent management and treatment of active UC with TCM, as well as offer original ideas for further research and development of innovative drugs for alleviating UC.

Deciphering the shared mechanisms of Gegen Qinlian Decoction in treating type 2 diabetes and ulcerative colitis via bioinformatics and machine learning

Background

Although previous clinical studies and animal experiments have demonstrated the efficacy of Gegen Qinlian Decoction (GQD) in treating Type 2 Diabetes Mellitus (T2DM) and Ulcerative Colitis (UC), the underlying mechanisms of its therapeutic effects remain elusive.

Purpose

This study aims to investigate the shared pathogenic mechanisms between T2DM and UC and elucidate the mechanisms through which GQD modulates these diseases using bioinformatics approaches.

Methods

Data for this study were sourced from the Gene Expression Omnibus (GEO) database. Targets of GQD were identified using PharmMapper and SwissTargetPrediction, while targets associated with T2DM and UC were compiled from the DrugBank, GeneCards, Therapeutic Target Database (TTD), DisGeNET databases, and differentially expressed genes (DEGs). Our analysis encompassed six approaches: weighted gene co-expression network analysis (WGCNA), immune infiltration analysis, single-cell sequencing analysis, machine learning, DEG analysis, and network pharmacology.

Results

Through GO and KEGG analysis of weighted gene co-expression network analysis (WGCNA) modular genes and DEGs intersection, we found that the co-morbidity between T2DM and UC is primarily associated with immune-inflammatory pathways, including IL-17, TNF, chemokine, and toll-like receptor signaling pathways. Immune infiltration analysis supported these findings. Three distinct machine learning studies identified IGFBP3 as a biomarker for GQD in treating T2DM, while BACE2, EPHB4, and EPHA2 emerged as biomarkers for GQD in UC treatment. Network pharmacology revealed that GQD treatment for T2DM and UC mainly targets immune-inflammatory pathways like Toll-like receptor, IL-17, TNF, MAPK, and PI3K-Akt signaling pathways.

Conclusion

This study provides insights into the shared pathogenesis of T2DM and UC and clarifies the regulatory mechanisms of GQD on these conditions. It also proposes novel targets and therapeutic strategies for individuals suffering from T2DM and UC.

Traditional Chinese Medicine and renal regeneration: experimental evidence and future perspectives

Repair of acute kidney injury (AKI) is a typical example of renal regeneration. AKI is characterized by tubular cell death, peritubular capillary (PTC) thinning, and immune system activation. After renal tubule injury, resident renal progenitor cells, or renal tubule dedifferentiation, give rise to renal progenitor cells and repair the damaged renal tubule through proliferation and differentiation. Mesenchymal stem cells (MSCs) also play an important role in renal tubular repair. AKI leads to sparse PTC, affecting the supply of nutrients and oxygen and indirectly aggravating AKI. Therefore, repairing PTC is important for the prognosis of AKI. The activation of the immune system is conducive for the body to clear the necrotic cells and debris generated by AKI; however, if the immune activation is too strong or lengthy, it will cause damage to renal tubule cells or inhibit their repair. Macrophages have been shown to play an important role in the repair of kidney injury. Traditional Chinese medicine (TCM) has unique advantages in the treatment of AKI and a series of studies have been conducted on the topic in recent years. Herein, the role of TCM in promoting the repair of renal injury and its molecular mechanism is discussed from three perspectives: repair of renal tubular epithelial cells, repair of PTC, and regulation of macrophages to provide a reference for the treatment and mechanistic research of AKI.

Polysaccharides extracted from larvae of Lucilia sericata ameliorated ulcerative colitis by regulating the intestinal barrier and gut microbiota

Pest management technology has been a promising bioconversion method for waste resource utilization. Unlike many pests that consume waste, the larvae of Lucilia sericata, also known as maggots, have many outstanding advantages as following: with their strong adaption to environment and not easily infected and exhibiting a medicinal nutritional value. Herein, the potential efficacies of maggot polysaccharides (MP), as well as their underlying mechanisms, were explored in Dextran sulfate sodium (DSS)-induced colitis mice and TNF-α-elicited Caco-2 cells. We extracted two bioactive polysaccharides from maggots, MP-80 and MP-L, whose molecular weights were 4.25 × 103 and 2.28 × 103 g/mol, respectively. MP-80 and MP-L contained nine sugar residues: 1,4-α-Arap, 1,3-β-Galp, 1,4,6-β-Galp, 1,6-α-Glcp, 1-α-Glcp, 1,4-β-Glcp, 1-β-Xylp, 1,2-α-Manp, and 1-β-Manp. We demonstrated that MP-80 and MP-L significantly ameliorated DSS-induced symptoms and histopathological damage. Immuno-analysis revealed that compared with MP-L, MP-80 could better restore intestinal barrier and reduced inflammation by suppressing NLRP3/NF-κB pathways, which might be attributed to its enriched galactose fraction. Moreover, 16S rRNA sequencing revealed that MP-80 and MP-L both improved the dysbiosis and diversity of gut microbiota and acted on multiple microbial functions. Our study sheds new light on the possibility of using maggot polysaccharides as an alternative therapy for colitis.

Biomimetic Integrated Nanozyme for Flare and Recurrence of Gouty Arthritis

Flare and multiple recurrences pose significant challenges in gouty arthritis. Traditional treatments provide temporary relief from inflammation but fail to promptly alleviate patient pain or effectively prevent subsequent recurrences. It should also be noted that both anti-inflammation and metabolism of uric acid are necessary for gouty arthritis, calling for therapeutic systems to achieve these two goals simultaneously. In this study, we propose a biomimetic integrated nanozyme, HMPB-Pt@MM, comprising platinum nanozyme and hollow Prussian blue. It demonstrates anti-inflammatory properties by eliminating reactive oxygen species and reducing infiltration of inflammatory macrophages. Additionally, it rapidly targets inflamed ankles through the camouflage of macrophage membranes. Furthermore, HMPB-Pt@MM exhibits urate oxidase-like capabilities, continuously metabolizing locally elevated uric acid concentrations, ultimately inhibiting multiple recurrences of gouty arthritis. In summary, HMPB-Pt@MM integrates ROS clearance with uric acid metabolism, offering a promising platform for the treatment of gouty arthritis.

Opsonization Inveigles Macrophages Engulfing Carrier-Free Bilirubin/JPH203 Nanoparticles to Suppress Inflammation for Osteoarthritis Therapy

Osteoarthritis (OA) is a chronic inflammatory disease characterized by cartilage destruction, synovitis, and osteophyte formation. Disease-modifying treatments for OA are currently lacking. Because inflammation mediated by an imbalance of M1/M2 macrophages in the synovial cavities contributes to OA progression, regulating the M1 to M2 polarization of macrophages can be a potential therapeutic strategy. Basing on the inherent immune mechanism and pathological environment of OA, an immunoglobulin G-conjugated bilirubin/JPH203 self-assembled nanoparticle (IgG/BRJ) is developed, and its therapeutic potential for OA is evaluated. After intra-articular administration, IgG conjugation facilitates the recognition and engulfment of nanoparticles by the M1 macrophages. The internalized nanoparticles disassemble in response to the increased oxidative stress, and the released bilirubin (BR) and JPH203 scavenge reactive oxygen species (ROS), inhibit the nuclear factor kappa-B pathway, and suppress the activated mammalian target of rapamycin pathway, result in the repolarization of macrophages and enhance M2/M1 ratios. Suppression of the inflammatory environment by IgG/BRJ promotes cartilage protection and repair in an OA rat model, thereby improving therapeutic outcomes. This strategy of opsonization involving M1 macrophages to engulf carrier-free BR/JPH203 nanoparticles to suppress inflammation for OA therapy holds great potential for OA intervention and treatment.

Melatonin pretreatment improves endometrial regenerative cell-mediated therapeutic effects in experimental colitis

BACKGROUND

Endometrial regenerative cells (ERCs) have been proven to be an effective strategy for attenuating experimental colitis, but the complex in vivo microenvironment such as oxidative stress may largely limit and weaken ERC efficacy. Melatonin (MT) works as an anti-oxidative agent in a variety of preclinical diseases, and has been identified to promote mesenchymal stem cell-mediated therapeutic effects in different diseases. However, the ability of MT to enhance ERC-mediated effects in colitis is currently poorly understood.

METHODS

Menstrual blood was collected from healthy female volunteers to obtain ERCs and identified. In vitro, H2O2-induced oxidative stress was introduced to test if MT could prevent ERCs from damage through detection of intracellular reactive oxidative species (ROS) and apoptosis assay. In vivo, dextran sodium sulfate (DSS)-induced acute colitis was treated by ERCs and MT-primed ERCs, therapeutic effects were assayed by the disease activity index (DAI), histological features, and macrophage and CD4+ T cell in the spleen and colon, and cytokine profiles in the sera and colon were also measured.

RESULTS

In vitro, ERCs that underwent MT-precondition were found to possess more anti-oxidative potency in comparison to naïve ERCs, which were characterized by decreased apoptosis rate and intracellular ROS under H2O2 stimulation. In vivo, MT pretreatment can significantly enhance the therapeutic effects of ERCs in the attenuation of experimental colitis, including decreased DAI index and damage score. In addition, MT pretreatment was found to promote ERC-mediated inhibition of Th1, Th17, and M1 macrophage and pro-inflammatory cytokines, increase of Treg, and immunomodulation of cytokines in the spleen and colon.

CONCLUSIONS

MT pretreatment facilitates the promotion of cell viability under oxidative stress in vitro, while also enhancing ERC-mediated therapeutic effects in experimental colitis.

PANoptosis and Autophagy-Related Molecular Signature and Immune Landscape in Ulcerative Colitis: Integrated Analysis and Experimental Validation

Background

Ulcerative colitis (UC) is an autoimmune inflammatory disorder of the gastrointestinal tract. Programmed cell death (PCD), including PANoptosis and autophagy, plays roles in inflammation and immunity. This study aimed to investigate the molecular signature and immune landscape of the PANoptosis- and autophagy-related differentially expressed genes (DEGs) in UC.

Methods

Analyzing UC dataset GSE206285 yielded DEGs. Differentially expressed PANoptosis- and autophagy-related genes were identified using DEGs and relevant gene collections. Functional and pathway enrichment analyses were conducted. A protein-protein interaction (PPI) network was established to identify hub genes. TRRUST database predicted transcription factors (TFs), pivotal miRNAs, and drugs interacting with hub genes. Immune infiltration analysis, UC-associated single-cell sequencing data analysis, and construction of a competing endogenous RNA (ceRNA) network for hub genes were conducted. Machine learning identified key candidate genes, evaluated for diagnostic value via receiver operating characteristic (ROC) curves. A UC mice model verified expression of key candidate genes.

Results

Identifying ten PANoptosis-related hub DEGs and four autophagy-related hub DEGs associated them with cell chemotaxis, wound healing and positive MAPK cascade regulation. Immune infiltration analysis revealed increased immunocyte infiltration in UC patients, with hub genes closely linked to various immune cell infiltrations. Machine learning identified five key candidate genes, TIMP1, TIMP2, TIMP3, IL6, and CCL2, with strong diagnostic performance. At the single-cell level, these genes exhibited high expression in inflammatory fibroblasts (IAFs). They showed significant expression differences in the colon mucosa of both UC patients and UC mice model.

Conclusion

This study identified and validated novel molecular signatures associated with PANoptosis and autophagy in UC, potentially influencing immune dysregulation and wound healing, thus opening avenues for future research and therapeutic interventions.

Targeting lipid reprogramming in the tumor microenvironment by traditional Chinese medicines as a potential cancer treatment

In the last ten years, there has been a notable rise in the study of metabolic abnormalities in cancer cells. However, compared to glucose or glutamine metabolism, less attention has been paid to the importance of lipid metabolism in tumorigenesis. Recent developments in lipidomics technologies have allowed for detailed analysis of lipid profiles within cancer cells and other cellular players present within the tumor microenvironment (TME). Traditional Chinese medicine (TCM) and its bioactive components have a long history of use in cancer treatments and are also being studied for their potential role in regulating metabolic reprogramming within TME. This review focuses on four core abnormalities altered by lipid reprogramming in cancer cells: de novo synthesis and exogenous uptake of fatty acids (FAs), upregulated fatty acid oxidation (FAO), cholesterol accumulation, which offer benefits for tumor growth and metastasis. The review also discusses how altered lipid metabolism impacts infiltrating immune cell function and phenotype as these interactions between cancer-stromal become more pronounced during tumor progression. Finally, recent literature is highlighted regarding how cancer cells can be metabolically reprogrammed by specific Chinese herbal components with potential therapeutic benefits related to lipid metabolic and signaling pathways.

Metabolic Adaptations and Functional Activity of Macrophages in Homeostasis and Inflammation

In recent years, the role of cellular metabolism in immunity has come into the focus of many studies. These processes form a basis for the maintenance of tissue integrity and homeostasis, as well as represent an integral part of the immune response, in particular, inflammation. Metabolic adaptations not only ensure energy supply for immune response, but also affect the functions of immune cells by controlling transcriptional and post-transcriptional programs. Studying the immune cell metabolism facilitates the search for new treatment approaches, especially for metabolic disorders. Macrophages, innate immune cells, are characterized by a high functional plasticity and play a key role in homeostasis and inflammation. Depending on the phenotype and origin, they can either perform various regulatory functions or promote inflammation state, thus exacerbating the pathological condition. Furthermore, their adaptations to the tissue-specific microenvironment influence the intensity and type of immune response. The review examines the effect of metabolic reprogramming in macrophages on the functional activity of these cells and their polarization. The role of immunometabolic adaptations of myeloid cells in tissue homeostasis and in various pathological processes in the context of inflammatory and metabolic diseases is specifically discussed. Finally, modulation of the macrophage metabolism-related mechanisms reviewed as a potential therapeutic approach.

Construction of hyaluronic acid-functionalized magnolol nanoparticles for ulcerative colitis treatment

Oral targeted anti-inflammatory drugs have garnered significant interest in treating ulcerative colitis (UC) due to their potential in reducing medical costs and enhancing treatment efficacy. Magnolol (Mag), a natural anti-inflammatory compound, has demonstrated protective effects against UC. However, its application as an alternative therapeutic agent for UC is limited by poor gastrointestinal stability and inadequate accumulation at inflamed colonic lesions. This study introduces a novel nanoparticle (NPs) formulation based on Mag, functionalized with hyaluronic acid (HA) for targeted UC therapy. Bovine serum albumin (BSA) was modified with 2-thiamine hydrochloride to synthesize BSA·SH. Thiol-ene click reaction with Mag led to the formation of BSA·SH-Mag NPs, which were further modified with HA through dehydration condensation, regular spherical inflammation-targeting HA-BSA·SH-Mag nanoparticles with a charge of -23.6 mV and a particle size of 403 ± 4 nm were formed. In vitro studies revealed significant macrophage targeting and enhanced uptake by colon epithelial cells. Oral administration of HA-BSA·SH-Mag facilitated colon mucosal barrier repair by modulating pro-inflammatory cytokines (TNF-α, IL-6, IL-1β), anti-inflammatory cytokines (IL-10), and tight junction proteins (ZO-1, Claudin, Occludin). Crucially, HA-BSA·SH-Mag was found to inhibit the JAK2/STAT3/NF-κB signaling pathway, reducing DSS-induced colon tissue inflammation. This research provides valuable insights into the oral use of natural compounds in UC therapy, highlighting the therapeutic potential of HA-BSA·SH-Mag NPs.

Compound sophora decoction alleviates ulcerative colitis by regulating macrophage polarization through cGAS inhibition: network pharmacology and experimental validation

INTRODUCTION

Ulcerative colitis (UC) is a refractory disease with complex pathogenesis, and its pathogenesis is not clear. The present study aimed to investigate the potential target and related mechanism of Compound Sophora Decoction (CSD) in treating UC.

METHODS

A network pharmacology approach predicted the components and targets of CSD to treat UC, and cell and animal experiments confirmed the findings of the approach and a new target for CSD treatment of UC.

RESULTS

A total of 155 potential targets were identified for CSD treatment of UC, with some related to macrophage polarization, such as nitric oxide synthase (NOS2), also known as inducible nitric oxide synthase (iNOS). GO and KEGG enrichment analysis indicated that oxidative stress response and multiple inflammatory signaling pathways such as TNF-α may play a significant role. In vitro experiments revealed that Interferon-stimulated DNA (ISD) interference can cause polarization imbalances in Raw 264.7 and bone marrow-derived macrophages (BMDMs). Flow cytometry demonstrated that polarization of macrophages in the intestine, spleen, and lymph nodes in vivo was also unbalanced after dextran sulfate sodium (DSS) modeling with pathological intestinal injury. Both in vitro and in vivo studies indicated that after inducing inflammation, the levels of macrophage polarization-related markers (iNOS and Arg1) and inflammation-related factors (CCL17, IL10, TNF-α, and CXCL10) changed, accompanied by increased expression of cGAS. However, CSD treatment based on inflammation can inhibit the expression of cGAS protein and mRNA, lower the level of inflammatory factors, promote the expression of anti-inflammatory factors, and regulate macrophage polarization.

CONCLUSION

We concluded that CSD alleviated DSS-induced UC by inhibiting cGAS, thus regulating macrophage polarization.

Macrophage polarization: an important role in inflammatory diseases

Macrophages are crucial cells in the human body's innate immunity and are engaged in a variety of non-inflammatory reactions. Macrophages can develop into two kinds when stimulated by distinct internal environments: pro-inflammatory M1-like macrophages and anti-inflammatory M2-type macrophages. During inflammation, the two kinds of macrophages are activated alternatively, and maintaining a reasonably steady ratio is critical for maintaining homeostasis in vivo. M1 macrophages can induce inflammation, but M2 macrophages suppress it. The imbalance between the two kinds of macrophages will have a significant impact on the illness process. As a result, there are an increasing number of research being conducted on relieving or curing illnesses by altering the amount of macrophages. This review summarizes the role of macrophage polarization in various inflammatory diseases, including autoimmune diseases (RA, EAE, MS, AIH, IBD, CD), allergic diseases (allergic rhinitis, allergic dermatitis, allergic asthma), atherosclerosis, obesity and type 2 diabetes, metabolic homeostasis, and the compounds or drugs that have been discovered or applied to the treatment of these diseases by targeting macrophage polarization.

Potential application mechanism of traditional Chinese medicine in treating immune checkpoint inhibitor-induced colitis

Cancer ranks among the foremost causes of mortality worldwide, posing a significant threat to human lives. The advent of tumor immunotherapy has substantially transformed the therapeutic landscape for numerous advanced malignancies, notably non-small cell lung cancer and melanoma. However, as immune checkpoint inhibitors (ICIs) are increasingly applied in clinical settings, a spectrum of undesired reactions, termed immune-related adverse events (irAEs), has emerged. These adverse reactions are associated with immunotherapy and can result in varying degrees of harm to the human body. Among these reactions, Immune checkpoint inhibitor-induced colitis (ICIIC) stands out as one of the most prevalent clinical adverse events. In contemporary times, traditional Chinese medicine (TCM) has demonstrated remarkable efficacy in addressing various maladies. Consequently, investigating the potential application and mechanisms of Chinese medicine in countering immune checkpoint inhibitor-induced colitis assumes significant importance in the treatment of this condition.

IRF4 induces M1 macrophage polarization and aggravates ulcerative colitis progression by the Bcl6-dependent STAT3 pathway

Ulcerative colitis (UC) is an idiopathic chronic intestinal inflammation. An increasing body of evidence shows that macrophages play an important role in the pathogenesis of UC. Interferon regulatory factor 4 (IRF4) is crucial for the development of autoimmune diseases via regulating immune cells. This research was designed to explore the function of IRF4 in UC and its association with macrophage polarization. The in vitro model of UC was established by stimulating colonic epithelial cells with tumor necrosis factor α (TNF-α). A mouse model of UC was constructed by injecting C57BL/6 mice with dextran sulfate sodium salt. Flow cytometry was used to assess percentage of CD11b+ CD86+ and CD11b+ CD206+ cells in bone marrow macrophages. Occult blood tests were used to detect hematochezia. Hematoxylin and eosin staining assay was used to assess colon pathological changes. Enzyme-linked immunosorbent assay (ELISA) was used to detect concentrations of inflammatory cytokines. The interaction of IRF4 and B-cell lymphoma 6 (Bcl6) was confirmed using GST pull-down and coimmunoprecipitation assays. Our findings revealed that IRF4 promoted cell apoptosis and stimulated M1 macrophage polarization in vitro. Furthermore, IRF4 aggravated symptoms of the mouse model of UC and aggravated M1 macrophage polarization in vivo. IRF4 negatively regulated Bcl6 expression. Downregulation of Bcl6 promoted apoptosis and M1 macrophage polarization in the presence of IRF4 in vitro and in vivo. Moreover, Bcl6 positively mediated the Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling pathway. In conclusion, IRF4 aggravated UC progression through promoting M1 macrophage polarization via Bcl6/JAK2/STAT3 pathway. These findings suggested that IRF4 might be a good target to competitively inhibit or to treat with UC.

Systematic review of metabolomic alterations in ulcerative colitis: unveiling key metabolic signatures and pathways

Background

Despite numerous metabolomic studies on ulcerative colitis (UC), the results have been highly variable, making it challenging to identify key metabolic abnormalities in UC.

Objectives

This study aims to uncover key metabolites and metabolic pathways in UC by analyzing existing metabolomics data.

Design

A systematic review.

Data sources and methods

We conducted a comprehensive search in databases (PubMed, Cochrane Library, Embase, and Web of Science) and relevant study references for metabolomic research on UC up to 28 December 2022. Significant metabolite differences between UC patients and controls were identified, followed by an analysis of relevant metabolic pathways.

Results

This review incorporated 78 studies, identifying 2868 differentially expressed metabolites between UC patients and controls. The metabolites were predominantly from 'lipids and lipid-like molecules' and 'organic acids and derivatives' superclasses. We found 101 metabolites consistently altered in multiple datasets within the same sample type and 78 metabolites common across different sample types. Of these, 62 metabolites exhibited consistent regulatory trends across various datasets or sample types. Pathway analysis revealed 22 significantly altered metabolic pathways, with 6 pathways being recurrently enriched across different sample types.

Conclusion

This study elucidates key metabolic characteristics in UC, offering insights into molecular mechanisms and biomarker discovery for the disease. Future research could focus on validating these findings and exploring their clinical applications.

Crosstalk between hypoxia-inducible factor-1α and short-chain fatty acids in inflammatory bowel disease: key clues toward unraveling the mystery

The human intestinal tract constitutes a complex ecosystem, made up of countless gut microbiota, metabolites, and immune cells, with hypoxia being a fundamental environmental characteristic of this ecology. Under normal physiological conditions, a delicate balance exists among these complex "residents", with disruptions potentially leading to inflammatory bowel disease (IBD). The core pathology of IBD features a disrupted intestinal epithelial barrier, alongside evident immune and microecological disturbances. Central to these interconnected networks is hypoxia-inducible factor-1α (HIF-1α), which is a key regulator in gut cells for adapting to hypoxic conditions and maintaining gut homeostasis. Short-chain fatty acids (SCFAs), as pivotal gut metabolites, serve as vital mediators between the host and microbiota, and significantly influence intestinal ecosystem. Recent years have seen a surge in research on the roles and therapeutic potential of HIF-1α and SCFAs in IBD independently, yet reviews on HIF-1α-mediated SCFAs regulation of IBD under hypoxic conditions are scarce. This article summarizes evidence of the interplay and regulatory relationship between SCFAs and HIF-1α in IBD, pivotal for elucidating the disease's pathogenesis and offering promising therapeutic strategies.

Protective Effect of Mesenchymal Stem Cell Active Factor Combined with Alhagi maurorum Extract on Ulcerative Colitis and the Underlying Mechanism

Ulcerative colitis (UC) is a relapsing and reoccurring inflammatory bowel disease. The treatment effect of Alhagi maurorum and stem cell extracts on UC remains unclear. The aim of the present study was to investigate the protective role of Alhagi maurorum combined with stem cell extract on the intestinal mucosal barrier in an intestinal inflammation mouse model. Sixty mice were randomly divided into a control group, model group, Alhagi group, MSC group, and MSC/Alhagi group. MSC and Alhagi extract were found to reduce the disease activity index (DAI) scores in mice with colitis, alleviate weight loss, improve intestinal inflammation in mice (p < 0.05), preserve the integrity of the ileal wall and increase the number of goblet cells and mucin in colon tissues. Little inflammatory cell infiltration was observed in the Alhagi, MSC, or MSC/Alhagi groups, and the degree of inflammation was significantly alleviated compared with that in the model group. The distribution of PCNA and TNF-alpha in the colonic tissues of the model group was more disperse than that in the normal group (p < 0.05), and the fluorescence intensity was lower. After MSC/Alhagi intervention, PCNA and TNF-alpha were distributed along the cellular membrane in the MSC/Alhagi group (p < 0.05). Compared with that in the normal control group, the intensity was slightly reduced, but it was still stronger than that in the model group. In conclusion, MSC/Alhagi can alleviate inflammatory reactions in mouse colonic tissue, possibly by strengthening the protective effect of the intestinal mucosal barrier.

Eugenol Possesses Colitis Protective Effects: Impacts on the TLR4/MyD88/NF-[Formula: see text]B Pathway, Intestinal Epithelial Barrier, and Macrophage Polarization

Eugenol (EU) has been shown to ameliorate experimental colitis due to its anti-oxidant and anti-inflammatory bioactivities. In this study, DSS-induced acute colitis was established and applied to clarify the regulation efficacy of EU on intestinal barrier impairment and macrophage polarization imbalance along with the inflammatory response. Besides, the adjusting effect of EU on macrophages was further investigated in vitro. The results confirmed that EU intervention alleviated DSS-induced colitis through methods such as restraining weight loss and colonic shortening and decreasing DAI scores. Microscopic observation manifested that EU maintained the intestinal barrier integrity in line with the mucus barrier and tight junction protection. Furthermore, EU intervention significantly suppressed the activation of TLR4/MyD88/NF-[Formula: see text]B signaling pathways and pro-inflammatory cytokines gene expressions, while enhancing the expressions of anti-inflammatory cytokines. Simultaneously, WB and FCM analyses of the CD86 and CD206 showed that EU could regulate the DSS-induced macrophage polarization imbalance. Overall, our data further elucidated the mechanism of EU's defensive effect on experimental colitis, which is relevant to the protective efficacy of intestinal barriers, inhibition of oxidative stress and excessive inflammatory response, and reprogramming of macrophage polarization. Hence, this study may facilitate a better understanding of the protective action of the EU against UC.

Targeting Senescent Alveolar Epithelial Cells Using Engineered Mesenchymal Stem Cell-Derived Extracellular Vesicles To Treat Pulmonary Fibrosis

Type 2 alveolar epithelial cell (AEC2) senescence is crucial to the pathogenesis of pulmonary fibrosis (PF). The nicotinamide adenine dinucleotide (NAD+)-consuming enzyme cluster of differentiation 38 (CD38) is a marker of senescent cells and is highly expressed in AEC2s of patients with PF, thus rendering it a potential treatment target. Umbilical cord mesenchymal stem cell (MSC)-derived extracellular vesicles (MSC-EVs) have emerged as a cell-free treatment with clinical application prospects in antiaging and antifibrosis treatments. Herein, we constructed CD38 antigen receptor membrane-modified MSC-EVs (CD38-ARM-MSC-EVs) by transfecting MSCs with a lentivirus loaded with a CD38 antigen receptor-CD8 transmembrane fragment fusion plasmid to target AEC2s and alleviate PF. Compared with MSC-EVs, the CD38-ARM-MSC-EVs engineered in this study showed a higher expression of the CD38 antigen receptor and antifibrotic miRNAs and targeted senescent AEC2s cells highly expressing CD38 in vitro and in naturally aged mouse models after intraperitoneal administration. CD38-ARM-MSC-EVs effectively restored the NAD+ levels, reversed the epithelial-mesenchymal transition phenotype, and rejuvenated senescent A549 cells in vitro, thereby mitigating multiple age-associated phenotypes and alleviating PF in aged mice. Thus, this study provides a technology to engineer MSC-EVs and support our CD38-ARM-MSC-EVs to be developed as promising agents with high clinical potential against PF.

Emerging Roles of Macrophage Polarization in Osteoarthritis: Mechanisms and Therapeutic Strategies

Osteoarthritis (OA) is the most common chronic degenerative joint disease in middle-aged and elderly people, characterized by joint pain and dysfunction. Macrophages are key players in OA pathology, and their activation state has been studied extensively. Various studies have suggested that macrophages might respond to stimuli in their microenvironment by changing their phenotypes to pro-inflammatory or anti-inflammatory phenotypes, which is called macrophage polarization. Macrophages accumulate and become polarized (M1 or M2) in many tissues, such as synovium, adipose tissue, bone marrow, and bone mesenchymal tissues in joints, while resident macrophages as well as other stromal cells, including fibroblasts, chondrocytes, and osteoblasts, form the joint and function as an integrated unit. In this study, we focus exclusively on synovial macrophages, adipose tissue macrophages, and osteoclasts, to investigate their roles in the development of OA. We review recent key findings related to macrophage polarization and OA, including pathogenesis, molecular pathways, and therapeutics. We summarize several signaling pathways in macrophage reprogramming related to OA, including NF-κB, MAPK, TGF-β, JAK/STAT, PI3K/Akt/mTOR, and NLRP3. Of note, despite the increasing availability of treatments for osteoarthritis, like intra-articular injections, surgery, and cellular therapy, the demand for more effective clinical therapies has remained steady. Therefore, we also describe the current prospective therapeutic methods that deem macrophage polarization to be a therapeutic target, including physical stimulus, chemical compounds, and biological molecules, to enhance cartilage repair and alleviate the progression of OA.

The ERK-cPLA2-ACSL4 axis mediating M2 macrophages ferroptosis impedes mucosal healing in ulcerative colitis

Ulcerative colitis (UC) is a chronic gastrointestinal disease that can be managed with 5-aminosalicylic acid (5-ASA), the standard treatment for UC. However, the effectiveness of 5-ASA is not always optimal. Our study revealed that despite 5-ASA treatment, cells continued to experience excessive ferroptosis, which may hinder mucosal healing in UC and limit the success of this treatment approach in achieving disease remission. We found that combining 5-ASA with the ferroptosis inhibitor Fer-1 led to a significant inhibition of ferroptosis in macrophages present in the colon tissue, along with an increase in the proportion of M2 macrophages, suggesting that targeting ferroptosis in M2 macrophages could be a potential therapeutic strategy for alleviating UC. Our study also demonstrated that M2 macrophages are more susceptible to ferroptosis compared to M1 macrophages, and this susceptibility is associated with the activated arachidonic acid (AA) metabolism pathway mediated by ERK-cPLA2-ACSL4. Additionally, we found that the expression of cPLA2 gene pla2g4a was increased in the colon of UC patients compared to healthy controls. Furthermore, targeted metabolomics analysis revealed that the combination treatment group, as opposed to the 5-ASA treatment group, exhibited the ability to modulate AA metabolism. Overall, our findings emphasize the importance of addressing macrophage ferroptosis in order to enhance macrophage anti-inflammation, improve mucosal healing, and achieve better therapeutic outcomes for patients with UC.

Interpreting the chemical changes and therapeutic effect of Coptidis Rhizoma against ulcerative colitis before and after processing based on mathematical statistics and network pharmacology

INTRODUCTION

Coptidis Rhizoma (CR) is one of the most frequently used herbs to treat ulcerative colitis (UC) and is often processed before usage. However, the composition changes and therapeutic effects of CR before and after processing in the treatment of UC are still unclear.

OBJECTIVE

The purpose of the study is to explore the chemical components and therapeutic effects of crude and processed CR.

MATERIAL AND METHODS

CR was processed according to the 2020 version of the Chinese Pharmacopoeia. The liquid chromatography-mass spectrometry (LC-MS) and multivariate statistical analysis were used to screen the different compounds before and after processing. The network pharmacological prediction was carried out. The mechanism and therapeutic effects between crude and processed CR were verified by using dextran sulphate sodium-induced UC mice assay.

RESULTS

Ten compounds distinguish crude and processed CR based on multivariate statistical analysis. Network pharmacology predicts that the 10 compounds mainly play a role through TNF-α and IL-6 targets and PI3K/Akt and HIF-1 signalling pathways, and these results are verified by molecular biology experiments. For IL-6, IL-10 and TNF-α inflammatory factors, CR is not effective, while CR stir-fried with Evodiae Fructus (CRFE) and ginger juice (CRGJ) are. For PI3K/p-Akt, Cleaved caspase3, NF- κBp65 and HIF-1α signalling pathways, CR has therapeutic effects, while CRFE and CRGJ are significant.

CONCLUSION

Overall, CRFE and CRGJ show better effects in treating UC. The chemical changes of processing and the efficacy of processed CR are correlated, which provides a scientific basis for the clinical use of crude and processed CR.

Cerium-Luteolin Nanocomplexes in Managing Inflammation-Related Diseases by Antioxidant and Immunoregulation

Oxidative stress, characterized by an imbalance between reactive oxygen species (ROS) production and the antioxidant defense system, plays a pivotal role in inflammation-related diseases. Excessive ROS levels can induce cellular damage and impair normal physiological functions, triggering the release of inflammatory mediators and exacerbating the inflammatory response, ultimately leading to irreversible tissue damage. In this study, we synthesized cerium ion-luteolin nanocomplexes (CeLutNCs) by coordinating Ce ions with the natural product luteolin, aiming to develop a therapeutic agent with excellent antioxidant and immunoregulation properties for ROS-related inflammation treatment. In vitro experiments demonstrated that the prepared CeLutNCs effectively scavenged excess ROS, prevented cell apoptosis, down-regulated levels of important inflammatory cytokines, regulated the response of inflammatory macrophages, and suppressed the activation of the nuclear factor-κ-gene binding (NF-κB) pathway. In an acute kidney injury (AKI) animal model, CeLutNCs exhibited significant efficacy in improving kidney function, repairing damaged renal tissue, and reducing oxidative stress, inflammatory response, and cellular apoptosis. Moreover, the therapeutic potential of CeLutNCs in an acute lung injury (ALI) model was confirmed through the assessment of inflammatory responses and histopathological studies. This study emphasizes the effectiveness of these metal-natural product coordination nanocomplexes as a promising therapeutic approach for preventing AKI and other diseases associated with oxidative stress.

A Network Pharmacology and Molecular Dynamics Simulation-Based Study of Qing Run Hua Jie Decoction in Interstitial Pneumonia Treatment

Objective

This study is dedicated to revealing the potential mechanism of Qin Run Hua Jie (QRHJ) decoction in Interstitial pneumonia (IP) treatment.

Methods

The TCMSP database predicted the chemical components and targets of QRHJ decoction, and the IP-related genes were from the Genecards database. Cytoscape software was used to establish the interaction network. R package clusterProfiler was utilized for Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. The molecular docking analysis of target proteins and the corresponding active pharmaceutical ingredients in the core position of the interaction network was conducted. Then, molecular dynamics (MD) simulations of a potential active substance and its key targets were performed. The binding efficiency of EGFR and luteolin, HIF1A and diosgenin was detected by cellular thermal shift assay (CETSA), and protein expression was measured by Western blot. CCK-8 was used to detect cell activity.

Results

A total of 153 active ingredients, 127 targets and 362 IP-related genes were obtained. KEGG enrichment analysis identified IP-related signaling pathways including HIF-1 signaling pathway and TNF signaling pathway. The two key components luteolin and diosgenin stably bound to the key targets EGFR and HIF1A. Cell experiments further showed that EGFR and luteolin, HIF1A and diosgenin bound to exert anti-fibrotic effects.

Conclusion

As an active ingredient of QRHJ decoction, luteolin and diosgenin may exert therapeutic effect on IP through binding to the key target EGFR and HIF1A. This work initially revealed the key molecular mechanism of QRHJ decoction in IP treatment and offered theoretical evidence.

Diosgenin alters LPS-induced macrophage polarization by activating PPARγ/NF-κB signaling pathway

Diosgenin (DG) is a steroidal saponin derived from plants, and it exhibits anti-inflammatory properties. In this study, we employed an in vitro model of P.g.-LPS-stimulated mouse macrophage cell line RAW264.7 to investigate the anti-inflammatory effects and mechanism of DG under the condition of altered polarization of macrophages. The RAW264.7 cells were subjected to pre-treatment with DG with or without P.g.-LPS. In cultured macrophages, DG inhibited P.g.-LPS-induced pro-inflammatory M1 macrophages, and increased anti-inflammatory M2 macrophages. Notably, DG reduced the expression of phosphorylation levels of NF-κB p65 and IκB while increasing the expression of PPARγ. Further studies revealed that PPARγ inhibitor GW9662 or PPARγ siRNA reversed the inhibitory effect of DG on M1 phenotype. Collectively, the anti-inflammatory mechanism of DG is related to altering macrophage polarization by activating PPARγ and inhibiting NF-κB signaling pathways.

Pharmacological properties of Polygonatum and its active ingredients for the prevention and treatment of cardiovascular diseases

Despite continued advances in prevention and treatment strategies, cardiovascular diseases (CVDs) remain the leading cause of death worldwide, and more effective therapeutic methods are urgently needed. Polygonatum is a traditional Chinese herbal medicine with a variety of pharmacological applications and biological activities, such as antioxidant activity, anti-inflammation, antibacterial effect, immune-enhancing effect, glucose regulation, lipid-lowering and anti-atherosclerotic effects, treatment of diabetes and anticancer effect. There has also been more and more evidence to support the cardioprotective effect of Polygonatum in recent years. However, up to now, there has been a lack of comprehensive studies on the active ingredients and their pharmacotoxicological effects related to cardiovascular diseases. Therefore, the main active components of Polygonatum (including Polysaccharides, Flavonoids, Saponins) and their biological activities were firstly reviewed in this paper. Furthermore, we summarized the pharmacological effects of Polygonatum's active components in preventing and treating CVDs, and its relevant toxicological investigations. Finally, we emphasize the potential of Polygonatum in the prevention and treatment of CVDs.

N6-methyladenosine modification of TSC1 mRNA contributes to macrophage polarization regulated by Coptisine in DSS-induced ulcerative colitis

BACKGROUND AND PURPOSE

Ulcerative colitis (UC) is a global refractory disease characterized by recurrent episodes. Coptisine (COP) is an isoquinoline alkaloid derived from Coptis chinensis, which has strong anti-inflammatory activity. Macrophages are key cells mediating inflammation. It is reported that N6-methyladenosine (m6A) RNA methylation regulates the polarization of macrophages and affects the development of inflammation. COP exerts an exact inhibitory effect on macrophages inflammation, while the specific mechanism remains unclear. The current study is designed to conduct a further investigation into the protective mechanism of COP against dextran sulfate sodium (DSS) -induced UC in mice.

METHODS

Using a DSS-induced UC model, we evaluated the pharmacodynamic effect of COP on UC mice, and verified the regulatory mechanism of COP on macrophage polarization in vivo and in vitro. The methylation level of m6A was detected by methylated RNA immunoprecipitation sequence (MeRIP) -qPCR, and the expression level of Methyltransferase Like (METTL)14 was determined by western blotting. Then METTL14 was knocked down in macrophages, and its effects on Tuberous sclerosis complex (TSC1) mRNA and m6A methylation regulation were observed.

RESULTS

COP improved the symptoms, alleviated tissue damage and reduced inflammation levels in DSS-induced UC mice. COP increased TSC1 expression, inhibited the Mitogen-activated protein kinase (MEK) / Extracellular regulated protein kinases (ERK) signaling pathway, and thus inhibited macrophage M1 polarization, whereas COP increased CCAAT Enhancer Binding Protein beta (c/EBPβ) expression, and thus promoted macrophage M2 polarization. COP also significantly increased the expression of METTL14, which enhanced m6A methylation and ultimately improved the stability of TSC1 mRNA.

CONCLUSIONS

COP was effective in treating UC and could regulate the polarization of macrophages. The possible mechanisms might be related to m6A modification-mediated TSC1.

MiR-146b-5p enriched bioinspired exosomes derived from fucoidan-directed induction mesenchymal stem cells protect chondrocytes in osteoarthritis by targeting TRAF6

Osteoarthritis (OA) is a common degenerative joint disease characterized by progressive cartilage degradation and inflammation. In recent years, mesenchymal stem cells (MSCs) derived exosomes (MSCs-Exo) have attracted widespread attention for their potential role in modulating OA pathology. However, the unpredictable therapeutic effects of exosomes have been a significant barrier to their extensive clinical application. In this study, we investigated whether fucoidan-pretreated MSC-derived exosomes (F-MSCs-Exo) could better protect chondrocytes in osteoarthritic joints and elucidate its underlying mechanisms. In order to evaluate the role of F-MSCs-Exo in osteoarthritis, both in vitro and in vivo studies were conducted. MiRNA sequencing was employed to analyze MSCs-Exo and F-MSCs-Exo, enabling the identification of differentially expressed genes and the exploration of the underlying mechanisms behind the protective effects of F-MSCs-Exo in osteoarthritis. Compared to MSCs-Exo, F-MSCs-Exo demonstrated superior effectiveness in inhibiting inflammatory responses and extracellular matrix degradation in rat chondrocytes. Moreover, F-MSCs-Exo exhibited enhanced activation of autophagy in chondrocytes. MiRNA sequencing of both MSCs-Exo and F-MSCs-Exo revealed that miR-146b-5p emerged as a promising candidate mediator for the chondroprotective function of F-MSCs-Exo, with TRAF6 identified as its downstream target. In conclusion, our research results demonstrate that miR-146b-5p encapsulated in F-MSCs-Exo effectively inhibits TRAF6 activation, thereby suppressing inflammatory responses and extracellular matrix degradation, while promoting chondrocyte autophagy for the protection of osteoarthritic cartilage cells. Consequently, the development of a therapeutic approach combining fucoidan with MSC-derived exosomes provides a promising strategy for the clinical treatment of osteoarthritis.

Sea Cucumber Peptides Ameliorate DSS-Induced Ulcerative Colitis: The Role of the Gut Microbiota, the Intestinal Barrier, and Macrophage Polarization

The incidence of ulcerative colitis (UC) is increasing annually. There are few treatments for UC patients, and some drugs have serious side effects. Sea cucumber peptide (SCP) has anti-inflammatory, antioxidant and other biological activities, and various sea cucumber species are in pharmaceutical development. However, relevant studies on the effects of SCP on UC progression are still lacking. In this study, a mouse model of acute colitis was induced by 3% dextran sulfate (DSS), and the effect of 500 mg/kg SCP on colitis was investigated. The results showed that SCP can alleviate DSS-induced colon damage and intestinal barrier damage. SCP significantly inhibited the expression of inflammatory factors and oxidative stress in UC mice. SCP reversed the intestinal microbiota dysregulation induced by DSS, inhibited the growth of Sutterella, Prevotella_9 and Escherichia-Shigella harmful bacteria, and increased the abundance of Lachnospiraceae_NK4A136_group. At the same time, SCP treatment significantly inhibited the LPS-induced polarization of M1 macrophages, which may be mediated by two monopeptides, IPGAPGVP and TGPIGPPGSP, via FPR2. In conclusion, SCP can protect against colitis by modulating the intestinal microbiota composition and the intestinal barrier and inhibiting the polarization of M1 macrophages.

Dioscorea nipponica Makino: A comprehensive review of its chemical composition and pharmacology on chronic kidney disease

Chronic kidney disease (CKD) is a widespread ailment that significantly impacts global health. It is characterized by high prevalence, poor prognosis, and substantial healthcare costs, making it a major public health concern. The current clinical treatments for CKD are not entirely satisfactory, leading to a high demand for alternative therapeutic options. Chinese herbal medicine, with its long history, diverse varieties, and proven efficacy, offers a promising avenue for exploration. One such Chinese herbal medicine, Dioscorea nipponica Makino (DNM), is frequently used to treat kidney diseases. In this review, we have compiled studies examining the mechanisms of action of DNM in the context of CKD, focusing on five primary areas: improvement of oxidative stress, inhibition of renal fibrosis, regulation of metabolism, reduction of inflammatory response, and regulation of autophagy.

Berberine ameliorates collagen-induced arthritis in mice by restoring macrophage polarization via AMPK/mTORC1 pathway switching glycolytic reprogramming

Dysfunction of macrophage polarization majorly contributes to the progression of rheumatoid arthritis (RA). Polarization and functions of activated macrophages are closely associated with the reprogramming of intracellular metabolisms. Previously, we demonstrated that the anti-arthritis effect of berberine (BBR) in rats with adjuvant-induced arthritis (AA) may be related to AMP-activated protein kinase (AMPK) activation (a key regulator in the biological energy metabolism), and balanced macrophage polarization. However, the specific molecular mechanism of BBR in macrophage metabolism is yet to be elucidated. In this study, we clarified that BBR ameliorated articular inflammation and restored M1/M2 ratio in collagen-induced arthritis (CIA) mice in an AMPK-dependent manner. Mechanistically, BBR reversed the effects of mTORC1 agonist leucine (Leu) on regulating macrophage polarization through activation of AMPK to switch glycolytic reprogramming. Furthermore, BBR inhibition of mTORC1 rely on activation of AMPK to phosphorylate raptor and TSC2 instead of destroying its structure. Our study revealed that the activation of AMPK is required for the BBR-mediated anti-arthritis effect by downregulating mTORC1/HIF-1α and inhibiting the glycolysis in M1 macrophages.

Macrophage-Derived Extracellular Vesicles-Coated Palladium Nanoformulations Modulate Inflammatory and Immune Homeostasis for Targeting Therapy of Ulcerative Colitis

Ulcerative colitis (UC) is a chronic inflammatory bowel disease mainly involving the colon and rectum, which features recurrent mucosal inflammation. The excessive production of reactive oxygen species (ROS) is a trigger for pathological changes such as cell apoptosis and disordered immune microenvironments, which are crucial for the progression of UC and can be a promising therapeutic target. Nowadays, the development of targeted therapeutic strategies for UC is still in its infancy. Thus, developing effective therapies based on ROS scavenging and elucidating their molecular pathways are urgently needed. Herein, a biomimetic nanoformulation (Pd@M) with cubic palladium (Pd) as the core and macrophage-derived extracellular vesicles (MEVs) as the shell is synthesized for the treatment of UC. These Pd@M nanoformulations exhibit multienzyme-like activities for effective ROS scavenging, excellent targeting ability as well as good biocompatibility. It is verified that Pd@M can regulate the polarization state of macrophages by inhibiting glycolysis, and decrease neutrophil infiltration and recruitment. In this way, the colonic inflammatory and immune microenvironment is remodeled, and apoptosis is prevented, ultimately improving colonic mucosal barrier function and alleviating colitis in the mouse model. This finding provides a promising alternative option for the treatment of UC patients.

Identifying Macrophage-Related Genes in Ulcerative Colitis Using Weighted Coexpression Network Analysis and Machine Learning

Ulcerative colitis (UC) is an inflammatory bowel disease of unknown cause that typically affects the colon and rectum. Innate intestinal immunity, including macrophages, plays a significant role in the pathological development of UC. Using the CIBERSORT algorithm, we observed elevated levels of 22 types of immune cell infiltrates, as well as increased M1 and decreased M2 macrophages in UC compared to normal colonic mucosa. Weighted gene coexpression network analysis (WGCNA) was used to identify modules associated with macrophages and UC, resulting in the identification of 52 macrophage-related genes (MRGs) that were enriched in macrophages at single-cell resolution. Consensus clustering based on these 52 MRGs divided the integrated UC cohorts into three subtypes. Machine learning algorithms were used to identify ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1), sodium- and chloride-dependent neutral and basic amino acid transporter B(0+) (SLC6A14), and 3-hydroxy-3-methylglutaryl-CoA synthase 2 (HMGCS2) in the training set, and their diagnostic value was validated in independent validation sets. Gene set enrichment analysis (GSEA) and gene set variation analysis (GSVA) revealed the main biological effects, and that interleukin-17 was one of several signaling pathways enriched by the three genes. We also constructed a competitive endogenous RNA (CeRNA) network reflecting a potential posttranscriptional regulatory mechanism. Expression of diagnostic markers was validated in vivo and in biospecimens, and our immunohistochemistry (IHC) results confirmed that HMGCS2 gradually decreased during the transformation of UC to colorectal cancer. In conclusion, ENPP1, SLC6A14, and HMGCS2 are associated with macrophages and the progression of UC pathogenesis and have good diagnostic value for patients with UC.

Early depletion of M1 macrophages retards the progression of glucocorticoid-associated osteonecrosis of the femoral head

Inflammation stands as a pivotal factor in the pathogenesis of glucocorticoid-associated osteonecrosis of the femoral head (GA-ONFH). However, the vital role played by M1 macrophages, the principal constituents of the inflammatory process, remains largely underexplored. In this study, we employed reverse transcription-quantitative polymerase chain Reaction (RT-PCR), western blot, and flow cytometry to assess the impact of M1-conditioned medium on cultures of mouse bone marrow-derived mesenchymal stem cells (BMSCs) and Murine Long bone Osteocyte-Y4 (MLO-Y4) in vitro. Moreover, we quantified the levels of inflammatory cytokines in the M1-conditioned medium through the employment of an enzyme-linked immunosorbent assay (ELISA). For in vivo analysis, we examined M1 macrophages and investigated the NF-kB signaling pathway in specimens obtained from the femoral heads of animals and humans. We found that the number of M1 macrophages in the femoral head of GA-ONFH patients grew significantly, and in the mice remarkably increase, maintaining high levels in the intramedullary. In vitro, the M1 macrophage-conditioned medium elicited apoptosis in BMSCs and MLO-Y4 cells, shedding light on the intricate interplay between macrophages and these cell types. The presence of TNF-α within the M1-conditioned medium activated the NF-κB pathway, providing mechanistic insight into the apoptotic induction. Moreover, employing a robust rat macrophage clearance model and GA-ONFH model, we demonstrated a remarkable attenuation in TNF-α expression and NF-kB signaling subsequent to macrophage clearance. This pronounced reduction engenders diminished cellular apoptosis and engenders a decelerated trajectory of GA-ONFH progression. In conclusion, our study reveals the crucial involvement of M1 macrophages in the pathogenesis of GA-ONFH, highlighting their indispensable role in disease progression. Furthermore, early clearance emerges as a promising strategy for impeding the development of GA-ONFH.

Electroacupuncture alleviates ulcerative colitis by targeting CXCL1: evidence from the transcriptome and validation

Background

We aimed to use transcriptomics, bioinformatics analysis, and core gene validation to identify the core gene and potential mechanisms for electroacupuncture (EA) treatment of ulcerative colitis (UC).

Materials and methods

EA was performed in mice after induction of UC via dextran sodium sulfate. Body weight, disease activity index (DAI), colon length, and hematoxylin-eosin of the colon tissue were used to evaluate the effects of EA. Mice transcriptome samples were analyzed to identify the core genes, and further verified with human transcriptome database; the ImmuCellAI database was used to analyze the relationship between the core gene and immune infiltrating cells (IICs); and immunofluorescence was used to verify the results.

Results

EA could reduce DAI and histological colitis scores, increase bodyweight and colon length, and improve the expression of local and systemic proinflammatory factors in the serum and colon of UC mice. Eighteen co-differentially expressed genes were identified by joint bioinformatics analyses of mouse and human transcriptional data; Cxcl1 was the core gene. EA affected IICs by inhibiting Cxcl1 expression and regulated the polarization of macrophages by affecting the Th1 cytokine IFN-γ, inhibiting the expression of CXCL1.

Conclusions

CXCL1 is the target of EA, which is associated with the underlying immune mechanism related to Th1 cytokine IFN-γ.

M2 macrophage polarization: a potential target in pain relief

Pain imposes a significant urden on patients, affecting them physically, psychologically, and economically. Despite numerous studies on the pathogenesis of pain, its clinical management remains suboptimal, leading to the under-treatment of many pain patients. Recently, research on the role of macrophages in pain processes has been increasing, offering potential for novel therapeutic approaches. Macrophages, being indispensable immune cells in the innate immune system, exhibit remarkable diversity and plasticity. However, the majority of research has primarily focused on the contributions of M1 macrophages in promoting pain. During the late stage of tissue damage or inflammatory invasion, M1 macrophages typically transition into M2 macrophages. In recent years, growing evidence has highlighted the role of M2 macrophages in pain relief. In this review, we summarize the mechanisms involved in M2 macrophage polarization and discuss their emerging roles in pain relief. Notably, M2 macrophages appear to be key players in multiple endogenous pathways that promote pain relief. We further analyze potential pathways through which M2 macrophages may alleviate pain.

Treatment of Ulcerative Colitis by Cationic Liposome Delivered NLRP3 siRNA

Purpose

The abnormal activation of NLRP3 inflammasome is related to the occurrence and development of ulcerative colitis (UC). However, the ideal drug and delivery system remain important factors limiting the targeting of NLRP3 inflammasome in UC therapy. Gene therapy by delivering siRNA is effective in treating various diseases. Therefore, delivering siNLRP3 using an ideal vector for UC treatment is necessary.

Materials and Methods

Nanoparticles delivering siNLRP3 were developed based on cationic liposome (CLP/siNLRP3). Their ability to inhibit NLRP3 inflammasome activation was monitored using Western blot (WB) and Enzyme-linked Immunosorbent Assay (ELISA). The ASC oligomerization in LPS-primed peritoneal macrophages (PMs) was detected by WB and immunofluorescence. Moreover, we assessed the role of CLP/siNLRP3 on dextran sodium sulfate (DSS)-induced UC by examining NLRP3 levels, pro-inflammatory cytokines expression, and disease-associated index (DAI). Flow cytometry (FCM) was used to detect the contents of macrophages and T cells. Finally, we assessed the safety of CLP/siNLRP3.

Results

The prepared CLP was spherical, with a small particle size (94 nm) and low permeability. The CLP could efficiently protect siNLRP3 from degradation and then deliver siNLRP3 into PMs, inhibiting NLRP3 inflammasome activation. Also, the CLP/siNLRP3 could inhibit the secretion of mature IL-1β and IL-18 from PMs, thereby achieving a favorable anti-inflammation effect. In vivo, CLP/siNLRP3 could effectively alleviate intestinal injury in UC mice, which was attributed to down-regulating levels of IL-1β and IL-18, inhibiting infiltration of macrophages and other immune cells, and the polarization of M1 macrophages. Finally, pathological testing of tissue sections and blood biochemical tests showed no significant toxic effects of CLP/siNLRP3.

Conclusion

We introduced a prospective approach for the efficient delivery of siRNA in vitro and in vivo with high safety and stability, which was found to have great potential in treating NLRP3-driven diseases in an RNA-silencing manner.

Exosomal PPARγ derived from macrophages suppresses LPS-induced peritonitis by negative regulation of CD14/TLR4 axis

BACKGROUND

Intercellular communication between macrophages and peritoneal mesothelial cells (PMCs) has been suggested as a key factor regulating peritonitis development. Here, we explored whether PPARγ (peroxisome proliferator-activated receptor gamma) can be packaged into macrophage exosomes to mediate intercellular communication and regulate peritonitis.

METHODS

Macrophage exosomes were isolated by ultracentrifugation and identified by nanoparticle tracking analysis and transmission electron microscopy. Proteomic analysis of macrophage-derived exosomes was performed using mass spectrometry. Co-culture models of supernatants or exosomes with PMCs, as well as a mouse peritonitis model induced by lipopolysaccharide (LPS), were employed.

RESULTS

 In this study, using stable Raw264.7 cells overexpressing GFP-FLAG-PPARγ (OE-PPARγ), we found that PPARγ inhibited LPS-induced inflammatory responses in Raw264.7 cells and that PPARγ was incorporated into macrophage exosomes during this process. Overexpression of PPARγ mainly regulated the secretion of differentially expressed exosomal proteins involved in the biological processes of protein transport, lipid metabolic process, cell cycle, apoptotic process, DNA damage stimulus, as well as the KEGG pathway of salmonella infection. Using co-culture models and mouse peritonitis model, we showed that exosomes from Raw264.7 cells overexpressing PPARγ inhibited LPS-induced inflammation in co-cultured human PMCs and in mice through downregulating CD14 and TLR4, two key regulators of the salmonella infection pathway. Pretreatment of the PPARγ inhibitor GW9662 abolished the anti-inflammatory effect of exosomes from Raw264.7 OE-PPARγ cells on human PMCs.

CONCLUSIONS

These results suggested that overexpression of PPARγ largely altered the proteomic profile of macrophage exosomes and that exosomal PPARγ from macrophages acted as a regulator of intercellular communication to suppress LPS-induced inflammatory responses in vitro and in vivo via negatively regulating the CD14/TLR4 axis.

Immunometabolism changes in fibrosis: from mechanisms to therapeutic strategies

Immune cells are essential for initiating and developing the fibrotic process by releasing cytokines and growth factors that activate fibroblasts and promote extracellular matrix deposition. Immunometabolism describes how metabolic alterations affect the function of immune cells and how inflammation and immune responses regulate systemic metabolism. The disturbed immune cell function and their interactions with other cells in the tissue microenvironment lead to the origin and advancement of fibrosis. Understanding the dysregulated metabolic alterations and interactions between fibroblasts and the immune cells is critical for providing new therapeutic targets for fibrosis. This review provides an overview of recent advances in the pathophysiology of fibrosis from the immunometabolism aspect, highlighting the altered metabolic pathways in critical immune cell populations and the impact of inflammation on fibroblast metabolism during the development of fibrosis. We also discuss how this knowledge could be leveraged to develop novel therapeutic strategies for treating fibrotic diseases.