M2-type Macrophage Polarization Research Articles

Targeting CCL5 Attenuates Fibrosis via Activation of PI3k/Akt Signaling Axis After Glaucoma Filtration Surgery

Purpose Glaucoma filtration surgery (GFS) stands as a paramount clinical intervention for glaucoma. Nonetheless, the prevalent cause of GFS failure is filtration bleb scarring, and the role of inflammation and immune response in contributing to fibrosis remains elusive. Methods The study employed 30 female Sprague-Dawley rats (8 weeks old, 200-250 g) to assess the anti-scarring impact of the Chemokine (C-C motif) receptor 5 (CCR5)-Chemokine (C-C motif) ligand 5 (CCL5) antibody after GFS. Additionally, anti-fibrotic effects on HConFs were examined, creating an intra-operative inflammatory response using damaged-HConFs supernatant medium (DHSM). In vitro and in vivo validation aimed to elucidate the potential anti-fibrotic molecular mechanism of the CCR5-CCL5 antibody. Results The CCR5-CCL5 antibody effectively prolonged filtration bleb duration and enhanced the functionality of the filtered bleb. Improved postoperative intraocular pressure values (IOP) and morphological images were observed in the CCR5-CCL5 antibody-treated group. Histochemical staining and cellular experiments confirmed the antifibrotic function of the CCR5-CCL5 antibody. Notably, M2-type macrophage polarization was reduced in the CCR5-CCL5 antibody-treated model. CCL5-induced fibrosis in HConFs was mediated through the PI3K/Akt signaling pathway. Consistently, inhibition of PI3K/Akt significantly attenuated the profibrotic effects of CCR5-CCL5. Mechanistically, the CCL5 antibody exerts its antifibrotic effect by targeting CCR5 on HConFs, leading to the inhibition of the PI3K/Akt mechanism. Conclusions This study unveils that CCR5-CCL5 promotes fibrosis in GFS through inflammatory stimulation of HConFs and enhanced activation of the PI3K/Akt signaling pathway. The findings suggest that intraoperative CCR5-CCL5 antibody treatment could serve as a cost-effective therapeutic agent or a useful adjuvant in preventing ocular bleb scar formation.

Huaxian formula prevents the progression of radiation-induced pulmonary fibrosis by inhibiting the pro-fibrotic effects of macrophages

Ethnopharmacological relevanceThe Huaxian formula (HXF), a traditional Chinese medicine (TCM) remedy, specifically targets the pathological factors of “heat toxicity” and “phlegm stasis” induced by radiation in radiation-induced pulmonary fibrosis (RIPF). It works by clearing heat and invigorating the blood, addressing these key factors in the development of RIPF. Aim of the studyThe HXF has demonstrated potential in preventing RIPF, although its underlying mechanisms remain unclear. This study aims to investigate the efficacy, molecular targets, and mechanisms of action of HXF. Materials and methodsThe major constituents of the HXF were identified by ultra performance liquid chromatography and tandem mass spectrometry (UPLC-MS). C57BL/6j mice were divided into four groups: control (Ctrl), HXF alone (HXF), 17Gy-irradiation alone (IR), and irradiation plus HXF (IR + HXF). Lung damage and fibrosis were assessed by histopathological staining, and the flow cytometry and immunohistochemistry (IHC) were used to detect the macrophages phenotype of lung tissues in vivo at 16 weeks post-irradiation. Transcriptomic sequencing and bioinformatics analyses identified key genes modulated by HXF. In vitro assays included flow cytometry, western bolt, and quantitative PCR (qPCR) explored the impact of HXF on macrophage polarization and fibrotic activity, while co-culture experiments of the macrophage conditional medium and mouse embryo fibroblast NIH/3T3 investigated macrophage-fibroblast interactions. Results20 major constituents of HXF were identified. And the in vivo results revealed significant lung damage and fibrosis in the IR group, which were notably mitigated in the IR + HXF group. And HXF has been shown to significantly inhibit the infiltration of M2-type macrophages in lung tissues. Transcriptomic analysis identified differentially expressed genes (DEGs) such as Arg1, Mmp10, and Fgf23. Bioinformatics enrichment analysis indicated that these DEGs are involved in pathways related to the inhibition of extracellular matrix formation and inflammation. In vitro, HXF-containing serum reduced M2-type macrophage polarization and decreased the secretion of Arginase1 and TGFβ1. Conditioned medium from HXF-treated macrophages suppressed fibroblast activation. ConclusionHXF's preventive effects on RIPF involve multiple targets and mechanisms, including the modulation of Arg1, Mmp10, and Fgf23 expression. By inhibiting the pro-fibrotic capacity of macrophages, HXF suppresses fibroblast activation and collagen production, thereby alleviating lung fibrosis. These findings underscore the potential of HXF as a preventive strategy in managing RIPF.

Xibining inhibition of the PI3K-AKT pathway reduces M1 macrophage polarization to ameliorate KOA synovial inflammation and nociceptive sensitization

BackgroundPain is the most critical symptom of knee osteoarthritis(KOA), which seriously affects the quality of life of patients. Xibining (XBN), a traditional herbal compound, has achieved good results in the clinical treatment of KOA, and its mechanism of action is worth exploring in depth. ObjectiveIn vivo and in vitro models of KOA were constructed, and the potential drug action mechanism of XBN in improving osteoarthritis pain was explored in combination with transcriptomics. MethodsIn vitro experiments were also conducted to explore the effects of different treatments of BMDMs on TRP channels in DRG neurons by constructing a coculture system of BMDMs and DRG neurons. The specific mechanism by which XBN affects BMDMs was explored via participatory transcriptomics. ResultsOur results showed that KOA aggravated macrophage infiltration in synovial tissues and DRG tissues and increased the transcriptional and translational levels of TRPA1, TRPV1, and TRPM8 in synovial tissues and DRG tissues; XBN treatment improved inflammation in synovial tissues and macrophage infiltration in DRG tissues, and it decreased the transcriptional and translational levels of TRPA1, TRPV1, and TRPM8, consistent with the results of behavioral tests to improve nociceptive sensitization induced by KOA. The results from in vitro experiments showed that promoting macrophage M1-type polarization exacerbated TRP channel activation in DRG neurons and that XBN acted by inhibiting macrophage M1-type polarization. A reference transcriptome study showed that XBN may play a role in inhibiting M1 macrophage-type polarization in KOA by suppressing the PI3K-AKT pathway in BMDMs. We verified the conclusions obtained from transcriptomics via in vitro experiments. We place greater emphasis on the role that the intrinsic immune system plays in the area of pain control in osteoarthritis. ConclusionXBN improve KOA nociceptive sensitization by modulating the PI3K/Akt signaling pathway, attenuating the level of synovial inflammation and inhibiting M1-type macrophage polarization in synovial and DRG tissues in KOA mice.

Time-Dependent Electrical Active and Ultrasound-Responsive Calcium Titanate Implant Coating with Immunomodulation, Osteogenesis, and Customized Antibacterial Activity.

Surgical site infection and insufficient osseointegration are notable risks factors associated with oral implant surgery. In this study, the development of a polarized calcium titanate (CT-P) coating for titanium surfaces is proposed as a solution to these problems. The coating generated electrical stimulation (ES) can inhibit pro-inflammatory M1-type macrophage polarization and promote anti-inflammatory M2-type macrophage polarization, resulting in favorable bone immunomodulation. The ES generated by the coating can match the physiological electrical potential that will change during bone repair, thereby promoting osseointegration in vivo. In addition, the system can also achieve on-demand antibacterial activity, mainly depending on the CT-P coating responding to ultrasound (US) irradiation to produce reactive oxygen species (ROS) and remove Staphylococcus aureus (S. aureus) on the surface of the implant. In conclusion, this work provides valuable insights for the development and clinical application of highly efficient electroactive coatings, as well as novel solutions for the selective treatment of bacterial infections in the surgical area.

SPI1+CD68+ macrophages as a biomarker for gastric cancer metastasis: a rationale for combined antiangiogenic and immunotherapy strategies

BackgroundTumor-associated macrophages (TAMs) have been demonstrated to be associated with tumor progression. However, the different subpopulations of TAMs and their roles in gastric cancer (GC) remain poorly understood. This study...

Enhancing Tumor-Specific immunity with SLdacA: A attenuated Salmonella-mediated c-di-AMP delivery system targeting the STING pathway

The STING agonist stimulates an anti-tumor immune response by activating T cells, but its limited tumor-targeting specificity poses risks of cytokine storms or autoimmune reactions. Conversely, attenuated Salmonella typhimurium △ppGpp (S.t△ppGpp) exhibits superior tumor-targeting specificity and potent anti-tumor immunogenicity. However, the anti-tumor effects of Salmonella carrying STING agonists remain underexplored. In this study, we engineered a strain called SLdacA, utilizing S.t△ppGpp as a carrier, to produce c-di-AMP. This engineered strain effectively enhances dendritic cell maturation and M1-type macrophage polarization by inducing type I interferon production, thereby recruiting and activating effector T cells against tumor progression. This process is regulated by the STING/type I interferon pathway. Our findings indicate that utilizing S.t△ppGpp as a delivery vehicle for STING agonists holds promise as a strategy for synergistic bacterial-mediated immunotherapy.

Insect Cuticle Protein Nanoassemblies without Nonspecific Immune Response for Acute Methicillin-Resistant Staphylococcus aureus Pneumonia Remission.

The emergence and proliferation of methicillin-resistant Staphylococcus aureus (MRSA) pneumonia poses a significant global public health threat. Herein, the significant remission effect against acute MRSA pneumonia was realized through the insect cuticle protein (OfCPH-2) nanoassemblies without nonspecific immune response. The lung repair results could be attributed to the transforming of M1-type to M2-type macrophage polarization and the repression of Th17 cell differentiation in mice spleens through the intervention of OfCPH-2 nanoassemblies. These findings offer a valuable insight into the application of insect protein-based materials as effective antidrug resistant strain agents as well as a powerful strategy for acute MRSA pneumonia.

Hyaluronic Acid/Gelatin-Based Multifunctional Bioadhesive Hydrogel Loaded with a Broad-Spectrum Bacteriocin for Enhancing Diabetic Wound Healing.

The development of multifunctional wound adhesives is critical in clinical settings due to the scarcity of dressings with effective adhesive properties while protecting against infection by drug-resistant bacteria. Polysaccharide and gelatin-based hydrogels, known for their biocompatibility and bioactivity, assist in wound healing. This study introduces a multifunctional bioadhesive hydrogel developed through dynamic covalent bonding and light-triggered covalent bonding, comprising oxidized hyaluronic acid, methacrylated gelatin, and the bacteriocin recently discovered by our lab, named jileicin (JC). The adhesion strength of the hydrogel, measured at 180 kPa, was 4.35 times higher than that of the fibrin glue. Furthermore, the hydrogel demonstrated robust platelet adhesion, procoagulant activity, and outstanding hemostatic properties in a mouse liver injury model. Incorporating JC significantly enhanced the phagocytosis and bactericidal capabilities of the macrophages. This immunomodulatory function on host cells, coupled with its potent bacterial membrane-disrupting ability, makes JC an effective killer against methicillin-resistant Staphylococcus aureus. In wound repair experiments on diabetic mice with infected full-thickness skin defects, the hydrogel treatment group showed a notable reduction in bacterial load, accelerated M2-type macrophage polarization, diminished inflammation, and hastened wound healing. Owing to its outstanding biocompatibility, antibacterial activity, and controlled adhesion, this hydrogel presents a promising therapeutic option for treating infected skin wounds.

Sulforaphane ameliorates non-alcoholic steatohepatitis by KLF4-mediated macrophage M2 polarization

Non-alcoholic fatty liver disease (NAFLD) has become a global issue and a severe threat to public health. However, to date, no approved therapeutic drugs have been developed. Dietary interventions with natural products have shown promise in preventing and treating NAFLD. Sulforaphane (SFN) is a phytocompound with antioxidant and anti-inflammatory properties, and previous research has demonstrated that SFN can ameliorate hepatic lipid accumulation and inflammation. However, the molecular mechanisms underlying these beneficial effects remain unclear. In this study, we confirmed the protective effects of SFN on excessive lipid accumulation and inflammatory injury in a high-fat, high-fructose diet-induced non-alcoholic steatohepatitis (NASH) mouse model. We found that SFN attenuates the inflammatory injury in a macrophage cell line and the liver of NASH mice, owing to the promotion of M1-type macrophage polarization toward the M2-type and the regulation of inflammatory mediators. Further analysis demonstrated that this SFN-induced macrophage M2-type polarization occurs in a Krüppel-like factor 4 (KLF4)-dependent manner. In summary, we uncovered a new mechanism of action underlying SFN activity and provide evidence that dietary intervention with SFN might be protective against NASH.

Esculin alleviates lipopolysaccharide (LPS)-induced pneumonia by regulating the USP7/MAPK14 axis.

Pneumonia is a serious and life-threatening lung inflammation with high morbidity and mortality. Accumulating evidence has suggested that esculin, a derivative of coumarin, possesses potent anti-inflammatory effects. This study is designed to explore the pharma role and underlying mechanism of esculin against lipopolysaccharides (LPS)-induced pneumonia. TC-1 cells were stimulated by LPS to mimic the inflammatory injury model in vitro. Cell viability, proliferation, and apoptosis were determined using MTT assay, 5-ethynyl-2'-deoxyuridine assay, and flow cytometry. Interleukin-1β and tumor necrosis factor α levels were analyzed using an enzyme-linked immunosorbent assay. Reactive oxygen species and superoxide dismutase were examined using special assay kits. Macrophage polarization was detected using flow cytometry. Mitogen-activated protein kinase 14 (MAPK14) level was detected by real-time quantitative polymerase chain reaction. MAPK14 and ubiquitin-specific protease 7 (USP7) protein levels were determined using western blot assay. After Ubibrowser database prediction, the interaction between USP7 and MAPK14 was verified using a Co-immunoprecipitation assay. The biological role of esculin was verified in LPS-challenged ALI mice in vivo. Here, we found that esculin significantly relieved LPS-induced TC-1 cell proliferation inhibition, and apoptosis, inflammatory response, oxidative stress, and M1-type macrophage polarization promotion. MAPK14 and USP7 expressions were enhanced in LPS-treated TC-1 cells, which was partly abolished by esculin treatment. Overexpressing MAPK14 attenuated the repression of esculin on LPS-triggered TC-1 cell injury. At the molecular level, USP7 interacted with MAPK14 and maintained its stability by removing ubiquitin. Moreover, esculin repressed the progression of pneumonia in vivo by regulating MAPK14. Taken together, esculin exposure could mitigate LPS-induced TC-1 cell injury partly by targeting the USP7/MAPK14 axis, providing a better understanding of the role of esculin in the anti-inflammatory therapeutics for pneumonia.

GO/Cu Nanosheet-Integrated Hydrogel Platform as a Bioactive and Biocompatible Scaffold for Enhanced Calvarial Bone Regeneration.

The treatment of craniofacial bone defects caused by trauma, tumors, and infectious and degenerative diseases is a significant issue in current clinical practice. Following the rapid development of bone tissue engineering (BTE) in the last decade, bioactive scaffolds coupled with multifunctional properties are in high demand with regard to effective therapy for bone defects. Herein, an innovative bone scaffold consisting of GO/Cu nanoderivatives and GelMA-based organic-inorganic hybrids was reported for repairing full-thickness calvarial bone defect. In this study, motivated by the versatile biological functions of nanomaterials and synthetic hydrogels, copper nanoparticle (CuNP)-decorated graphene oxide (GO) nanosheets (GO/Cu) were combined with methacrylated gelatin (GelMA)-based organic-inorganic hybrids to construct porous bone scaffolds that mimic the extracellular matrix (ECM) of bone tissues by photocrosslinking. The material characterizations, in vitro cytocompatibility, macrophage polarization and osteogenesis of the biohybrid hydrogel scaffolds were investigated, and two different animal models (BALB/c mice and SD rats) were established to further confirm the in vivo neovascularization, macrophage recruitment, biocompatibility, biosafety and bone regenerative potential. We found that GO/Cu-functionalized GelMA/β-TCP hydrogel scaffolds exhibited evidently promoted osteogenic activities, M2 type macrophage polarization, increased secretion of anti-inflammatory factors and excellent cytocompatibility, with favorable surface characteristics and sustainable release of Cu2+. Additionally, improved neovascularization, macrophage recruitment and tissue integration were found in mice implanted with the bioactive hydrogels. More importantly, the observations of microCT reconstruction and histological analysis in a calvarial bone defect model in rats treated with GO/Cu-incorporated hydrogel scaffolds demonstrated significantly increased bone morphometric values and newly formed bone tissues, indicating accelerated bone healing. Taken together, this BTE-based bone repair strategy provides a promising and feasible method for constructing multifunctional GO/Cu nanocomposite-incorporated biohybrid hydrogel scaffolds with facilitated osteogenesis, angiogenesis and immunoregulation in one system, with the optimization of material properties and biosafety, it thereby demonstrates great application potential for correcting craniofacial bone defects in future clinical scenarios.

ZIF-8@Pt Nanozyme Used for Scavenging Reactive Oxygen Species in the Treatment of Rheumatoid Arthritis

To formulate a ZIF-8 nano mimetic enzyme conjugated with platinum metal (ZIF-8@Pt) that can scavenge reactive oxygen species (ROS) and to explore its potential applications in the treatment of rheumatoid arthritis (RA). The ZIF-8@Pt nanozyme was created by in situ reduction. Characterization of the nanozyme was then performed and its ability to mimic enzymes was investigated. Cell experiments were conducted using RAW264.7 cells, which were divided into three groups, including the untreated group (UT), the positive control group receiving lipopolysaccharide (LPS), which was designated as the LPS group, and the ZIF-8@Pt group receiving ZIF-8@Pt and LPS treatment. The cell experiments were conducted to evaluate the anti-inflammatory properties of ZIF-8@Pt through scavenging intracellular ROS. On the other hand, a collagen-induced arthritis (CIA) model was induced in rats. Similar to the group designations in the cell experiments, the rats were assigned to three groups, including a healthy control group (the UT group), a positive control group receiving a local injection of PBS solution in the knee joint, which was referred to as the control group, and a treatment group receiving a local injection of ZIF-8@Pt solution in the knee joint, which was referred to as the ZIF-8@Pt group. General evaluation, imaging observation, assessment of inflammatory factors, and pathological evaluation were performed to assess the therapeutic efficacy of ZIF-8@Pt against RA. The in vitro experiment revealed significant difference in the levels of intracellular ROS and LPS-induced M1-type macrophage polarization between the LPS group and the ZIF-8@Pt group (P<0.05). The in vivo experiment showed that significant difference in the levels of inflammatory factors, including interleukin-1β (IL-1β), C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), and arginase-1 (Arg-1) in the knee joints of the CIA rats between the LPS group and the ZIF-8@Pt group (P<0.05). Comparing the findings for the ZIF-8@Pt group and the control group, pathology assessment revealed that ZIF-8@Pt reduced local hypoxia and suppressed osteoclastic activity, neovascularization, and M1-type macrophage polarization (P<0.05). The ZIF-8@Pt enzyme mimetic inhibits macrophage inflammatory polarization by ROS scavenging, thereby improving inflammation in RA. Furthermore, the ZIF-8@Pt nanozyme improves the hypoxic environment and inhibits angiogenesis and bone destruction, demonstrating promising therapeutic efficacy for RA.

Biological characteristics of tissue engineered-nerve grafts enhancing peripheral nerve regeneration

BackgroundA favorable regenerative microenvironment is essential for peripheral nerve regeneration. Neural tissue-specific extracellular matrix (ECM) is a natural material that helps direct cell behavior and promote axon regeneration. Both bone marrow-derived mesenchymal stem cells (BMSCs) and adipose-derived mesenchymal stem cells (ADSCs) transplantation are effective in repairing peripheral nerve injury (PNI). However, there is no study that characterizes the in vivo microenvironmental characteristics of these two MSCs for the early repair of PNI when combined with neural tissue-derived ECM materials, i.e., acellular nerve allograft (ANA).MethodsIn order to investigate biological characteristics, molecular mechanisms of early stage, and effectiveness of ADSCs- or BMSCs-injected into ANA for repairing PNI in vivo, a rat 10 mm long sciatic nerve defect model was used. We isolated primary BMSCs and ADSCs from bone marrow and adipose tissue, respectively. First, to investigate the in vivo response characteristics and underlying molecular mechanisms of ANA combined with BMSCs or ADSCs, eighty-four rats were randomly divided into three groups: ANA group, ANA+BMSC group, and ANA+ADSC group. We performed flow cytometry, RT-PCR, and immunofluorescence staining up to 4 weeks postoperatively. To further elucidate the underlying molecular mechanisms, changes in long noncoding RNAs (lncRNAs), circular RNAs (circRNAs), microRNAs (miRNAs), and messenger RNAs (mRNAs) were systematically investigated using whole transcriptome sequencing. We then constructed protein–protein interaction networks to find 10 top ranked hub genes among differentially expressed mRNAs. Second, in order to explore the effectiveness of BMSCs and ADSCs on neural tissue-derived ECM materials for repairing PNI, sixty-eight rats were randomized into four groups: ANA group, ANA+BMSC group, ANA+ADSC group, and AUTO group. In the ANA+BMSC and ANA+ADSC groups, ADSCs/BMSCs were equally injected along the long axis of the 10-mm ANA. Then, we performed histological and functional assessments up to 12 weeks postoperatively.ResultsThe results of flow cytometry and RT-PCR showed that ANA combined with BMSCs exhibited more significant immunomodulatory effects, as evidenced by the up-regulation of interleukin (IL)-10, down-regulation of IL-1β and tumor necrosis factor-alpha (TNF-α) expression, promotion of M1-type macrophage polarization to M2-type, and a significant increase in the number of regulatory T cells (Tregs). ANA combined with ADSCs exhibited more pronounced features of pro-myelination and angiogenesis, as evidenced by the up-regulation of myelin-associated protein gene (MBP and MPZ) and angiogenesis-related factors (TGF-β, VEGF). Moreover, differentially expressed genes from whole transcriptome sequencing results further indicated that ANA loaded with BMSCs exhibited notable immunomodulatory effects and ANA loaded with ADSCs was more associated with angiogenesis, axonal growth, and myelin formation. Notably, ANA infused with BMSCs or ADSCs enhanced peripheral nerve regeneration and motor function recovery with no statistically significant differences.ConclusionsThis study revealed that both ANA combined with BMSCs and ADSCs enhance peripheral nerve regeneration and motor function recovery, but their biological characteristics (mainly including immunomodulatory effects, pro-vascular regenerative effects, and pro-myelin regenerative effects) and underlying molecular mechanisms in the process of repairing PNI in vivo are different, providing new insights into MSC therapy for peripheral nerve injury and its clinical translation.

MiR-33a-5p in stored red blood cells regulates genes of innate immune response and promotes inflammation.

Blood transfusion is a common therapeutic procedure in hospitalized patients. Red blood cell (RBC) units undergo various biochemical and morphological changes during storage (storage lesion). miRNAs have been studied intensively regarding cellular metabolic processes, but the effect of miRNAs on blood storage is not well defined. We performed bioinformatics analysis on the public data set of miRNA expression of RBC based on R language, and performed the Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis on the target genes of differentially expressed miRNA. The expression of miRNA differential genes in blood samples stored at different times was verified by qRT-PCR. Next, we used ELISA and qRT-PCR to verify the expression of IL-1β, IL-6, IL-12 and TNF-α in blood at day 1 and day 42. In addition, in vitro, we transfected macrophages with overexpressed miRNA, and the effects of overexpressed miRNA on macrophage polarization and the release of inflammatory factors were verified by flow cytometry and qRT-PCR and ELISA. This study combined bioinformatics analysis and experiments to discover the differentially expressed miRNAs in long-term stored blood. The results showed that compared to fresh blood samples, the inflammatory factors were significantly doubled by ELISA, as well as the higher mRNA expression at 42 day. Experimentally verified that miR-33a-5p promoted the M1 type macrophage polarization and increased the release of related inflammatory factors through PPARα/ACC2/AMPK/CPT-1a axis regulation. This study elucidates a potential mechanism of inflammatory factor accumulation in long-term stored blood, providing a theoretical basis and a potential target to prevent transfusion-related adverse reactions.

Tanshinol ameliorates imiquimod-induced psoriasis by inhibiting M1 macrophage polarization through suppression of the notch signaling pathway

BackgroundPsoriasis is a common immune-related chronic inflammatory skin disease, often accompanied by significant itching, and once diseased, the course of the disease lasts for most of the lifetime. Tanshinol (TAN) is an active ingredient of Salvia miltiorrhiza, which possesses pharmacological effects such as anti-inflammatory and antioxidant properties. However, the effects of TAN on psoriasis have not been widely reported. Therefore, the aim of this study was to investigate the therapeutic effects and mechanisms of TAN in psoriasis.MethodsAn imiquimod (IMQ)-induced psoriasis mouse model was constructed and treated with different doses of TAN to observe the changes in skin lesion phenotype, macrophage polarization, inflammation and Notch signaling pathway in mice. Further removal of macrophages or inhibition or activation of Notch signaling pathway was performed to examine the changes in skin lesion phenotype, macrophage polarization, inflammation and Notch signaling pathway in mice. In addition, in vitro experiments verified that TAN regulates RAW264.7 macrophage polarization and cytokine secretion through the Notch pathway.ResultsThe results showed that TAN alleviated IMQ-induced skin lesions and pathological phenotypes in psoriasis mice and inhibited Notch signaling pathway and M1-type macrophage polarization. Moreover, macrophage clearance and Notch signaling pathway activation inhibited the effect of TAN on psoriasis. Further in vitro experiments showed that Notch agonists reversed the effects of TAN on macrophage polarization and inflammatory cytokines.ConclusionsCollectively, these findings suggest that TAN may exert a therapeutic effect on psoriasis by inhibiting the Notch signaling pathway and thus M1-type macrophage polarization.

The anti-inflammatory role of zDHHC23 through the promotion of macrophage M2 polarization and macrophage necroptosis in large yellow croaker (Larimichthys crocea).

Zinc finger Asp-His-His-Cys motif-containing (zDHHC) proteins, known for their palmitoyltransferase (PAT) activity, play crucial roles in diverse cellular processes, including immune regulation. However, their non-palmitoyltransferase immunomodulatory functions and involvement in teleost immune responses remain underexplored. In this study, we systematically characterized the zDHHC family in the large yellow croaker (Larimichthys crocea), identifying 22 members. Phylogenetic analysis unveiled that each of the 22 LczDHHCs formed distinct clusters with their orthologues from other teleost species. Furthermore, all LczDHHCs exhibited a highly conserved DHHC domain, as confirmed by tertiary structure prediction. Notably, LczDHHC23 exhibited the most pronounced upregulation following Pseudomonas plecoglossicida (P. plecoglossicida) infection of macrophage/monocyte cells (MO/MΦ). Silencing LczDHHC23 led to heightened pro-inflammatory cytokine expression and diminished anti-inflammatory cytokine levels in MO/MΦ during infection, indicating its anti-inflammatory role. Functionally, LczDHHC23 facilitated M2-type macrophage polarization, as evidenced by a significant skewing of MO/MΦ towards the pro-inflammatory M1 phenotype upon LczDHHC23 knockdown, along with the inhibition of MO/MΦ necroptosis induced by P. plecoglossicida infection. These findings highlight the non-PAT immunomodulatory function of LczDHHC23 in teleost immune regulation, broadening our understanding of zDHHC proteins in host-pathogen interactions, suggesting LczDHHC23 as a potential therapeutic target for immune modulation in aquatic species.

Cenicriviroc Suppresses and Reverses Steatohepatitis by Regulating Macrophage Infiltration and M2 Polarization in Mice.

The inhibition of hepatic macrophage and Kupfer cell recruitment and activation is a potential strategy for treating insulin resistance and nonalcoholic steatohepatitis (NASH). Cenicriviroc (CVC), a dual C-C chemokine receptor 2 (CCR2) and CCR5 antagonist, has shown antifibrotic activity in murine models of NASH and has been evaluated in clinical trials on patients with NASH. This study investigated the effects of CVC on macrophage infiltration and polarization in a lipotoxic model of NASH. C57BL/6 mice were fed a high-cholesterol, high-fat (CL) diet or a CL diet containing 0.015% CVC (CL + CVC) for 12 weeks. Macrophage recruitment and activation were assayed by immunohistochemistry and flow cytometry. CVC supplementation attenuated excessive hepatic lipid accumulation and peroxidation and alleviated glucose intolerance and hyperinsulinemia in the mice that were fed the CL diet. Flow cytometry analysis revealed that compared with the CL group, mice fed the CL + CVC diet had fewer M1-like macrophages, more M2-like macrophages, and fewer T cell counts, indicating that CVC caused an M2-dominant shift of macrophages in the liver. Similarly, CVC decreased lipopolysaccharide-stimulated M1-like macrophage activation, whereas it increased interleukin-4-induced M2-type macrophage polarization in vitro. In addition, CVC attenuated hepatic fibrosis by repressing hepatic stellate cell activation. Lastly, CVC reversed insulin resistance as well as steatosis, inflammation, and fibrosis of the liver in mice with pre-existing NASH. In conclusion, CVC prevented and reversed hepatic steatosis, insulin resistance, inflammation, and fibrogenesis in the liver of NASH mice via M2 macrophage polarization.

LDHA-mediated M2-type macrophage polarization via tumor-derived exosomal EPHA2 promotes renal cell carcinoma progression.

Lactate dehydrogenase A (LDHA) is known to promote the growth and invasion of various types of tumors, affects tumor resistance, and is associated with tumor immune escape. But how LDHA reshapes the tumor microenvironment and promotes the progression of renal cell carcinoma (RCC) remains unclear. In this study, we found that LDHA was highly expressed in clear cell RCC (ccRCC), and this high expression was associated with macrophage infiltration, while macrophages were highly infiltrated in ccRCC, affecting patient prognosis via M2-type polarization. Our in vivo and in vitro experiments demonstrated that LDHA and M2-type macrophages could enhance the proliferation, invasion, and migration abilities of ccRCC cells. Mechanistically, high expression of LDHA in ccRCC cells upregulated the expression of EPHA2 in exosomes derived from renal cancer. Exosomal EPHA2 promoted M2-type polarization of macrophages by promoting activation of the PI3K/AKT/mTOR pathway in macrophages, thereby promoting the progression of ccRCC. All these findings suggest that EPHA2 may prove to be a potential therapeutic target for advanced RCC.

Ganlu formula ethyl acetate extract (GLEE) blocked the development of experimental arthritis by inhibiting NLRP3 activation and reducing M1 type macrophage polarization

Ethnopharmacological relevanceThe Tibetan medicine Ganlu Formula, as a classic prescription, is widely used across the Qinghai-Tibet Plateau area of China, which has a significant effect on relieving the course of rheumatoid arthritis (RA). However, the active compounds and underlying mechanisms of Ganlu Formula in RA treatment remain largely unexplored. Aim of the studyThis study aimed to elucidate the active substances and potential mechanisms of the ethyl acetate extract of Ganlu Formula ethyl acetate extract (GLEE) in the treatment of RA. Materials and methodsUltra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) was utilized to analyze and identify the chemical constituents within GLEE. Discovery Studio molecular virtual docking technology was utilized to dock the interaction of GLEE with inflammation-related pathway proteins. The GLEE gene library was obtained by transcriptome sequencing. Collagen-induced arthritic（CIA) rats were utilized to assess the antiarthritic efficacy of GLEE. Micro-CT imaging was employed to visualize the rat paw, and ultrasound imaging revealed knee joint effusion. Evaluation of synovial tissue pathological changes was conducted through hematoxylin-eosin staining and saffranine solid green staining, while immunohistochemical staining was employed to assess NLRP3 expression along with inflammatory markers. Immunofluorescence staining was utilized to identify M1 macrophages. ResultsMetabolomic analysis via UPLC-Q-TOF-MS identified 28 potentially bioactive compounds in GLEE, which interacted with the active sites of key proteins such as NLRP3, NF-κB, and STAT3 through hydrogen bonds, C–H bonds, and electrostatic attractions. In vitro analyses demonstrated that GLEE significantly attenuated NLRP3 inflammasome activation and inhibited the polarization of bone marrow-derived macrophages (BMDMs) towards the M1 phenotype. In vivo, GLEE not only prevented bone mineral density (BMD) loss but also reduced ankle swelling in CIA rats. Furthermore, it decreased the expression of the NLRP3 inflammasome and curtailed the release of inflammatory mediators within the knee joint. ConclusionGLEE effectively mitigated inflammatory responses in both blood and knee synovial membranes of CIA rats, potentially through the down-regulation of the NLRP3/Caspase-1/IL-1β signaling pathway and reduction in M1 macrophage polarization.

Improving stroke prognosis by TLR4 KO to enhance N2 neutrophil infiltration and reduce M1 macrophage polarization.

Cerebral ischemic stroke remains a leading cause of mortality and morbidity worldwide. Toll-like receptor 4 (TLR4) has been implicated in neuroinflammatory responses poststroke, particularly in the infiltration of immune cells and polarization of macrophages. This study aimed to elucidate the impact of TLR4 deficiency on neutrophil infiltration and subsequent macrophage polarization after middle cerebral artery occlusion (MCAO), exploring its role in stroke prognosis. The objective was to investigate how TLR4 deficiency influences neutrophil behavior poststroke, its role in macrophage polarization, and its impact on stroke prognosis using murine models. Wild-type and TLR4-deficient adult male mice underwent MCAO induction, followed by various analyses, including flow cytometry to assess immune cell populations, bone marrow transplantation experiments to evaluate TLR4-deficient neutrophil behaviors, and enzyme-linked immunosorbent assay and Western blot analysis for cytokine and protein expression profiling. Neurobehavioral tests and infarct volume analysis were performed to assess the functional and anatomical prognosis poststroke. TLR4-deficient mice exhibited reduced infarct volumes, increased neutrophil infiltration, and reduced M1-type macrophage polarization post-MCAO compared to wild-type mice. Moreover, the depletion of neutrophils reversed the neuroprotective effects observed in TLR4-deficient mice, suggesting the involvement of neutrophils in mediating TLR4's protective role. Additionally, N1-type neutrophils were found to promote M1 macrophage polarization via neutrophil gelatinase-associated lipocalin (NGAL) secretion, a process blocked by TLR4 deficiency. The study underscores the protective role of TLR4 deficiency in ischemic stroke, delineating its association with increased N2-type neutrophil infiltration, diminished M1 macrophage polarization, and reduced neuroinflammatory responses. Understanding the interplay between TLR4, neutrophils, and macrophages sheds light on potential therapeutic targets for stroke management, highlighting TLR4 as a promising avenue for intervention in stroke-associated neuroinflammation and tissue damage.