Co-culture Of Macrophages Research Articles

Trophoblast cell-derived extracellular vesicles regulate the polarization of decidual macrophages by carrying miR-141-3p in the pathogenesis of preeclampsia

Dysregulation of macrophage polarization can prevent the invasion of trophoblast cells and further limit spiral artery remodeling in preeclampsia (PE). However, its mechanism is obscure. HTR8-/Svneo cells were cultured under normoxic or hypoxic conditions and extracellular vesicles (EVs) in the culture supernatants were extracted. Next, the cells were incubated with those EVs to investigate their effects on trophoblasts. A co-culture system consisting of HTR8-/Svneo cells and macrophages was used to reveal how the trophoblast-derived EVs affected the macrophage subtype. Finally, a PE mouse model and miR-141-3p knockout mice were used to verify the function of miR-141-3p in PE. Hypoxia induced abnormal increases in the levels of miR-141-3p in HTR8-/Svneo cells and EVs. EVs from hypoxia-treated HTR8-/Svneo cells could downregulate PTEN, a potential target of miR-141-3p, and inhibit trophoblast mitophagy and invasion. However, HTR8-/Svneo cells transfected with an miR-141-3p inhibitor could attenuate the influence of EVs. In an HTR8-/Svneo cell plus macrophage co-culture system, hypoxia-pretreated cells promoted the transformation of macrophages into the M1-phenotye, and HTR8-/Svneo invasion was inhibited by the macrophages. MiR-141 from EVs could target and downregulate dual specificity phosphatase 1 (DUSP1) expression in macrophages, induce formation of the M1 macrophage phenotype in THP-1 cells, downregulate DUSP1 expression, and upregulate TAB2/TAK1 signaling. These results were also demonstrated in normal pregnant mice and PE pregnant mice. A hypoxic environment could upregulate miR-141 expression in the EVs of HTR8-/Svneo cells, and THP-1-derived macrophages could uptake EVs releasing miR-141 to downregulate DUSP1 expression and induce the formation of M1 macrophages, which can lead to the development of PE.

Direct M2 macrophage co-culture overrides viscoelastic hydrogel mechanics to promote fibroblast activation.

Fibroblast activation drives fibrotic diseases such as pulmonary fibrosis. However, the complex interplay of how tissue mechanics and macrophage signals combine to influence fibroblast activation is not well understood. Here, we use hyaluronic acid hydrogels as a tunable cell culture system to mimic lung tissue stiffness and viscoelasticity. We applied this platform to investigate the influence of macrophage signaling on fibroblast activation. Fibroblasts cultured on stiff (50 kPa) hydrogels mimicking fibrotic tissue exhibit increased activation as measured by spreading as well as type I collagen and cadherin-11 expression compared to fibroblasts cultured on soft (1 kPa) viscoelastic hydrogels mimicking normal tissue. These trends were unchanged in fibroblasts cultured with macrophage-conditioned media. However, fibroblasts directly co-cultured with M2 macrophages show increased activation, even on soft viscoelastic hydrogels that normally suppress activation. Inhibition of interleukin 6 (IL6) signaling does not change activation in fibroblast-only cultures but ameliorates the pro-fibrotic effects of M2 macrophage co-culture. These results underscore the ability of direct M2 macrophage co-culture to override hydrogel viscoelasticity to promote fibroblast activation in an IL6-dependent manner. This work also highlights the utility of using hydrogels to deconstruct complex tissue microenvironments to better understand the interplay between microenvironmental mechanical and cellular cues.

Gene therapy for fat-1 prevents obesity-induced metabolic dysfunction, cellular senescence, and osteoarthritis

Obesity is one of the primary risk factors for osteoarthritis (OA), acting through cross talk among altered biomechanics, metabolism, adipokines, and dietary free fatty acid (FA) composition. Obesity and aging have been linked to cellular senescence in various tissues, resulting in increased local and systemic inflammation and immune dysfunction. We hypothesized that obesity and joint injury lead to cellular senescence that is typically associated with increased OA severity or with aging and that the ratio of omega-6 (ω-6) to omega-3 (ω-3) FAs regulates these pathologic effects. Mice were placed on an ω-6-rich high-fat diet or a lean control diet and underwent destabilization of the medial meniscus to induce OA. Obesity and joint injury significantly increased cellular senescence in subcutaneous and visceral fat as well as joint tissues such as synovium and cartilage. Using adeno-associated virus (AAV) gene therapy for fat-1, a fatty acid desaturase that converts ω-6 to ω-3 FAs, decreasing the serum ω-6:ω-3 FA ratio had a strong senomorphic and therapeutic effect, mitigating metabolic dysfunction, cellular senescence, and joint degeneration. In vitro coculture of bone marrow-derived macrophages and chondrocytes from control and AAV8-fat1-treated mice were used to examine the roles of various FA mediators in regulating chondrocyte senescence. Our results suggest that obesity and joint injury result in a premature "aging" of the joint as measured by senescence markers, and these changes can be ameliorated by altering FA composition using fat-1 gene therapy. These findings support the potential for fat-1 gene therapy to treat obesity- and/or injury-induced OA clinically.

Crosstalk between macrophages and mesenchymal stem cells shape patterns of osteogenesis and immunomodulation in mineralized collagen scaffolds

Mesenchymal stem cells (MSCs) are highly plastic, with the capacity to differentiate into a spectrum of tissue-specific stromal cells. In the field of bone regeneration, MSCs have largely been considered for their osteogenic differentiation capacity. MSCs are increasingly being appreciated for their immunomodulatory potential following exposure to pro-inflammatory stimuli (licensing). Pro-inflammatory environments arise following bone injury via activation of resident immune cells like macrophages. We describe the use of a mineralized collagen scaffold as a bone-mimetic in vitro model to study the influence of paracrine versus direct cell-to-cell contact of THP-1 macrophages on MSC osteogenic and immunomodulatory potential. Paracrine stimuli from macrophages enhance MSC osteogenic and immunomodulatory potential via upregulation of key transcriptomic markers as well as via soluble biomolecule production. Direct co-culture of MSCs and macrophages decreased immunomodulatory potential in MSCs, especially for licensed MSCs, but enhanced matrix remodeling and expression of genes related to macrophage chemotaxis. These data demonstrate the significant effect macrophage-derived paracrine factors and direct contact have on MSC activity in a biomaterial model of bone regeneration. This work illuminates a critical need to further understand these processes in more clinically relevant cell models to inform biomaterial design.

Glutamine Attenuates Inflammation and Stimulates Amniotic Cell Proliferation in Premature Rupture of Membranes-related in vitro Models.

Premature rupture of membranes (PROM), with a prevalence of 15.3% in China, frequently results in adverse pregnancy outcomes. In this study, we aimed to identify amino acid metabolites that were differentially expressed in PROM versus healthy controls (HC) using targeted metabolomics and further explored their mechanisms of action with in vitro models.Inclusion and exclusion criteria were established to recruit 50 PROM and 50 HC cases for targeted metabolomics analysis. Twenty-three amino acid metabolites were quantified in the secretions of the posterior vaginal fornix of pregnant women between 31 and 36 weeks of gestation. Glutamine (0.0216 vs. 0.037μg/mg, P = 0.003, AUC = 72.1%) was identified as the most differentially expressed amino acid metabolite between PROM and HC groups, and had a negative correlation with the abundance of Gardnerella (r=-0.3868, P = 0.0055), Megasphaera (r=-0.3130, P = 0.0269), and Prevotella (r=-0.2944, P = 0.0380), respectively.In amniotic epithelial cell and macrophage co-culture model, Glutamine reduced inflammatory cytokines and chemokines expression and suppressed macrophage chemotaxis. In LPS stimulated RAW 264.7 inflammation model, Glutamine inhibited the expression of inflammatory proteins iNOS and COX-2, down-regulated mRNA transcription of TNF, IL-6, and IL-1β, and reduced the production of reactive oxygen species through inhibiting NF-κB signaling pathway, and therefore demonstrated its anti-inflammatory effect. Furthermore, Glutamine protected amniotic epithelial cell from autophagy and stimulated its proliferation, therefore may intensify fetal membrane and prevent PROM in vivo.Our results suggested that low Glutamine level in vaginal secretion can be used as an indicator for PROM, and local Glutamine supplementation is a potential intervention and prevention strategy for PROM.

Astrocytes Can Be Key Players Against Cerebral Leishmaniasis: InVitro Co-Culture Model for the Assessment of Infection.

Leishmaniasis is a neglected tropical disease, caused by protozoan parasites of Leishmania (L.), and is transmitted by bite of phlebotomine sandflies. There are several studies on central nervous system infection to indicate that Leishmania can cross the blood-brain barrier, resulting in neurological manifestations, known as "cerebral leishmaniasis." This study highlighted the notions: (i) polarisation of bone marrow-derived macrophages (BMDM) incubated following stimulation with lipopolysaccharide (LPS) or soluble Leishmania antigen (SLA), (ii) quantification of parasites within co-culture of Leishmania-infected macrophages, and astrocytes, and (iii) effect of interferon-gamma (IFN-γ) on the infection rate of co-culture populations. Accordingly, 83% of overall macrophage population was identified on day 7 for CD11b and F4/80 macrophage markers. Flow cytometry analysis revealed significant increases in CD11b and F4/80 surface markers in LPS and SLA-stimulated BMDMs at 24 h, compared to untreated cells. TNF-α levels increased significantly in both LPS and SLA-treated BMDMs after 48 h. Additionally, SLA treatment induced a more elongated, spindle-like shape in the cells, indicative of M2 macrophage polarisation over the M1 phenotype. When non-infected astrocytes with/without stimulation with IFN-γ before co-culture, gp63 FITC-labelled parasite populations (%) in co-culture decreased to 25% at 72 h, thus indicating a lower infection rate in a time-dependent manner. IFN-γ and IL-6 levels significantly increased to 71.66 ± 3.51 and 184 ± 14.42 pg/mL, resulting in the inflammatory response in the co-culture system at 48 h (p ≤ 0.0001), when compared to the control (30 ± 2.52 pg/mL for IFN-γ and 8.66 ± 2.37 pg/mL for IL-6) at 0 h of the incubation. It is the first study to emphasize the communication between Leishmania-infected macrophages and astrocytes regarding Leishmania parasite load. The results suggest that astrocytes can lead to the reduction in Leishmania parasites, thereby controlling the incidence of cerebral leishmaniasis.

Trem2 acts as a non-classical receptor of interleukin-4 to promote diabetic wound healing.

The immunoglobulin superfamily protein Trem2 (triggering receptor expressed on myeloid cells 2) is primarily expressed on myeloid cells where it functions to regulate macrophage-related immune response induction. While macrophages are essential mediators of diabetic wound healing, the specific regulatory role that Trem2 plays in this setting remains to be established. This study was developed to explore the potential importance of Trem2 signalling in diabetic wound healing and to clarify the underlying mechanisms through which it functions. Following wound induction, diabetic model mice exhibited pronounced upregulation of Trem2 expression, which was primarily evident in macrophages. No cutaneous defects were evident in mice bearing a macrophage-specific knockout of Trem2 (T2-cKO), but they induced more pronounced inflammatory responses and failed to effectively repair cutaneous wounds, with lower levels of neovascularization, slower rates of wound closure, decreased collagen deposition following wounding. Mechanistically, we showed that interleukin (IL)-4 binds directly to Trem2, inactivating MAPK/AP-1 signalling to suppress the expression of inflammatory and chemoattractant factors. Co-culture of fibroblasts and macrophages showed that macrophages from T2-cKO mice suppressed the in vitro activation and proliferation of dermal fibroblasts through upregulation of leukaemia inhibitory factor (Lif). Injecting soluble Trem2 in vivo was also sufficient to significantly curtail inflammatory responses and to promote diabetic wound healing. These analyses offer novel insight into the role of IL-4/Trem2 signalling as a mediator of myeloid cell-fibroblast crosstalk that may represent a viable therapeutic target for efforts to enhance diabetic wound healing.

SGLT2 inhibitors ameliorate NAFLD in mice via downregulating PFKFB3, suppressing glycolysis and modulating macrophage polarization.

Sodium-glucose co-transporter 2 (SGLT2) inhibitor (SGLT2i) is a novel class of anti-diabetic drug, which has displayed a promising benefit for non-alcoholic fatty liver disease (NAFLD). In this study, we investigated the protective effects of SGLT2i against NAFLD and the underlying mechanisms. The db/db mice and western diet-induced NAFLD mice were treated with dapagliflozin (1 mg·kg-1·d-1, i.g.) or canagliflozin (10 mg·kg-1·d-1, i.g.) for 8 weeks. We showed that the SGLT2i significantly improved NAFLD-associated metabolic indexes, and attenuated hepatic steatosis and fibrosis. Notably, SGLT2i reduced the levels of pro-inflammatory cytokines and chemokines, downregulated M1 macrophage marker expression and upregulated M2 macrophage marker expression in liver tissues. In cultured mouse bone marrow-derived macrophages and human peripheral blood mononuclear cell-derived macrophages, the SGLT2i (10, 20 and 40 μmol/L) significantly promoted macrophage polarization from M1 to M2 phenotype. RNA sequencing, Seahorse analysis and liquid chromatography-tandem mass spectrometry analysis revealed that the SGLT2i suppressed glycolysis and triggered metabolic reprogramming in macrophages. By using genetic manipulation and pharmacological inhibition, we identified that the SGLT2i targeted PFKFB3, a key enzyme of glycolysis, to modulate the macrophage polarization of M1 to M2 phenotype. Using a co-culture of macrophages with hepatocytes, we demonstrated that the SGLT2i inhibited lipogenesis in hepatocytes via crosstalk with macrophages. In conclusion, this study highlights a potential therapeutic application for repurposing SGLT2i and identifying a potential target PFKFB3 for NAFLD treatment.

APP-CD74 axis mediates endothelial cell-macrophage communication to promote kidney injury and fibrosis.

Kidney injuries often carry a grim prognosis, marked by fibrosis development, renal function loss, and macrophage involvement. Despite extensive research on macrophage polarization and its effects on other cells, like fibroblasts, limited attention has been paid to the influence of non-immune cells on macrophages. This study aims to address this gap by shedding light on the intricate dynamics and diversity of macrophages during renal injury and repair. During the initial research phase, the complexity of intercellular communication in the context of kidney injury was revealed using a publicly available single-cell RNA sequencing library of the unilateral ureteral obstruction (UUO) model. Subsequently, we confirmed our findings using an independent dataset from a renal ischemia-reperfusion injury (IRI) model. We treated two different types of endothelial cells with TGF-β and co-cultured their supernatants with macrophages, establishing an endothelial cell and macrophage co-culture system. We also established a UUO and an IRI mouse model. Western blot analysis, flow cytometry, immunohistochemistry and immunofluorescence staining were used to validate our results at multiple levels. Our analysis revealed significant changes in the heterogeneity of macrophage subsets during both injury processes. Amyloid β precursor protein (APP)-CD74 axis mediated endothelial-macrophage intercellular communication plays a dominant role. In the in vitro co-culture system, TGF-β triggers endothelial APP expression, which subsequently enhances CD74 expression in macrophages. Flow cytometry corroborated these findings. Additionally, APP and CD74 expression were significantly increased in the UUO and IRI mouse models. Immunofluorescence techniques demonstrated the co-localization of F4/80 and CD74 in vivo. Our study unravels a compelling molecular mechanism, elucidating how endothelium-mediated regulation shapes macrophage function during renal repair. The identified APP-CD74 signaling axis emerges as a promising target for optimizing renal recovery post-injury and preventing the progression of chronic kidney disease.

Abstract A051: Innate immune cell dynamics and pancreatic tumor progression in alcoholic pancreatitis

Abstract Introduction: Persistent inflammation due to alcoholic chronic pancreatitis (ACP) is associated with pancreatic ductal adenocarcinoma (PDAC). Myeloid cell infiltration within the pancreas, particularly with oncogenic mutant KrasG12D/+ (*Kras), is crucial for driving PDAC carcinogenesis. Our previous work demonstrated that hyperactivation of cyclic AMP response element binding protein (CREB) accelerates ADM/PanIN progression with heightened fibroinflammation. However, the association between CREB in precursor neoplastic lesions and innate myeloid cells remains unclear. Methods: We established an ACP mouse model using an alcohol diet along with prolonged caerulein administration in Ptf1aCreERTM/+; LSL-KrasG12D/+ (KC), and CREB deleted [Crebfl/fl in KC (KCC-/-)] mice. Single-cell RNA sequencing (scRNA-seq) of the mouse pancreas, multiparametric immunophenotyping of tumor-infiltrating myeloid cells and chromatin immunoprecipitation (ChIP-seq) with CREB pulldown were performed. Cytokine arrays and qPCR studies followed co-culture assays using mouse neutrophils (J774M) and macrophages (RAW 264.7) with epithelial cell lines harboring *Kras with in vitro ACP induction were conducted. Results: ACP induction in KC mice led to increased infiltration of neutrophils and alternatively activated macrophages with the pancreas. Conversely, Creb-deleted mice exhibited significantly reduced myeloid cell infiltration despite ACP induction. ChIP-Seq and qPCR identified CREB-regulated chemokines and immunomodulators as mediators of myeloid cell trafficking. Co-culture of mouse neutrophils and macrophages with KC-ACP conditioned media significantly increased IL-1 receptor antagonist (Il-1ra) expression and secretion. Single-cell transcriptomic analysis revealed heightened Il1rn mRNA levels in neutrophils and macrophages in KC-ACP when compared with KC pancreatic tumors. Creb-deleted PDAC models showed strong downregulation of Il1rn in macrophages, confirming CREB’s role in modulating myeloid cell interactions via epithelial cell signaling. Conclusions: Our findings highlight that CREB activation in epithelial cells under ACP conditions facilitates crosstalk with myeloid cells, promoting IL-1ra upregulation in neutrophils and macrophages. This CREB-driven regulation of IL-1ra in myeloid cells contributes to inflammation-associated tumorigenesis. Targeting this axis may offer a novel therapeutic approach to curb pancreatic cancer progression. Citation Format: Siddharth Mehra, Sudhakar Jinka, Varun Krishnamoorthy, Supriya Srinivasan, Anna Bianchi, Andrew Adams, Haleh Amirian, Manan Patel, Jashodeep Datta, Nipun Merchant, Nagaraj Nagathihalli. Innate immune cell dynamics and pancreatic tumor progression in alcoholic pancreatitis [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr A051.

Melatonin downregulates angiogenesis and lymphangiogenesis by regulating tumor-associated macrophages via NLRP3 inflammasomes in lung adenocarcinoma.

Tumor-associated macrophages (TAMs), present within the tumor microenvironment (TME), strictly modulate tumor angiogenesis and lymphangiogenesis. Nevertheless, the associated signaling networks and candidate drug targets for these events remains to be elucidated. Given its antioxidative activities, we speculated that melatonin may reduce pyroptosis, and thereby modulate both angiogenesis and lymphangiogenesis. We revealed that a co-culture of A549 cells and THP-1 macrophages strongly enhanced expressions of the NLRP3 inflammasome axis members, and augmented angiogenesis and lymphangiogenesis. Next, we overexpressed NLRP3 in the A549 cells, and demonstrated that excess NLRP3 expression substantially upregulated VEGF and CXCL cytokine expressions, and enhanced lymphatic endothelial cells (LECs) tube formation. In contrast, NLRP3 inhibition produced the opposite effect. In addition, relative to controls, melatonin administration strongly inhibited the NLRP3 inflammasome axis, as well as angiogenesis and lymphangiogenesis in the co-culture system. Subsequent animal experiments using a Lewis Lung Carcinoma (LLC) subcutaneous tumor model in mice corroborate these findings. Melatonin treatment and NLRP3 knockdown significantly inhibit tumor growth and downregulate NLRP3 and IL-1β expression in tumor tissues. Furthermore, melatonin downregulates the expression of angiogenic and lymphangiogenic markers in tumor tissues. Taken together, the evidence suggested that a THP-1 macrophage and A549 cell co-culture stimulates angiogenesis and lymphangiogenesis via the NLRP3 axis. Melatonin protected against the TAMs- and NLRP3 axis-associated promotion of the aforementioned events in vitro and in vivo. Hence, melatonin is a promising candidate for managing for tumor-related angiogenesis and lymphangiogenesis in lung adenocarcinoma.

Eicosatetraynoic Acid Regulates Pro-Fibrotic Pathways in an Induced Pluripotent Stem Cell Derived Macrophage:Human Intestinal Organoid Model of Crohn's Disease.

We previously identified small molecules predicted to reverse an ileal gene signature for future Crohn's Disease (CD) strictures. Here we used a new human intestinal organoid (HIO) model system containing macrophages to test a lead candidate, eicosatetraynoic acid (ETYA). Induced pluripotent stem cell lines (iPSC) were derived from CD patients and differentiated into macrophages and HIOs. Macrophages and macrophage:HIO co-cultures were exposed to lipopolysaccharide (LPS) with and without ETYA pre-treatment. Cytospin and flow cytometry characterized macrophage morphology and activation markers, and RNA sequencing defined the global pattern of macrophage gene expression. TaqMan Low Density Array, Luminex multiplex assay, immunohistologic staining, and sirius red polarized light microscopy were performed to measure macrophage cytokine production and HIO pro-fibrotic gene expression and collagen content. iPSC-derived macrophages exhibited morphology similar to primary macrophages and expressed inflammatory macrophage cell surface markers including CD64 and CD68. LPS-stimulated macrophages expressed a global pattern of gene expression enriched in CD ileal inflammatory macrophages and matrisome secreted products, and produced cytokines and chemokines including CCL2, IL1B, and OSM implicated in refractory disease. ETYA suppressed CD64 abundance and pro-fibrotic gene expression pathways in LPS stimulated macrophages. Co-culture of LPS-primed macrophages with HIO led to up-regulation of fibroblast activation genes including ACTA2 and COL1A1, and an increase in HIO collagen content. ETYA pre-treatment prevented pro-fibrotic effects of LPS-primed macrophages. ETYA inhibits pro-fibrotic effects of LPS-primed macrophages upon co-cultured HIO. This model may be used in future untargeted screens for small molecules to treat refractory CD.

Therapeutically targeting the CALR/CD47 pathway in MPN to reactivate natural immunosurveillance mechanisms within the body to enhance treatment outcomes.

170 Background: MPNs are a group of related myeloid malignancies characterized by alterations in mature blood cell production/bone marrow environment and have a tendency to evolve into acute myeloid leukaemia. We demonstrated that CD47 blockade in combination with ruxolitinib, increased CALR expression enhancing cytotoxicity in vitro, promoting enhanced neoplastic clone clearance. With this study we describe a potential methodology for assessing effect of new compounds or combinations and the impact of modulating the immunoresponse upon myeloid malignant clones. Methods: Utilising HEL 92.1.7 and SET-2 cells (JAK2 mutated), Marimo cells (CALR mutated) and K562 cell line models; we will incubate with routine therapies (hydroxyurea, anagrelide, ruxolitinib) in combination with a range of anti-CD47 compounds (Anti-CD47 monocloncal antibodies, BET-1 inhibitors, SIRa inhibitor) and will determine the impact upon CD47 and CALR cell surface expression via flow cytometry. Monocyte derived macrophage (MDM) will be produced through Phorbol 12-myristate 13-acetate (PMA) differentiation of a monocytic Thp-1 cell line. Expression of macrophage cell surface markers (CD11b, CD14), as well as intracellular markers (CD68), will be detected by flow cytometry. MDM will then be polarized to either a pro-inflammatory M1, or anti-inflammatory M2 phenotype, with lipopolysaccharide/interferon gamma or interleukins 4 and 13, respectively. Co-culture experiments will then be undertaken to determine how different anti-CD47 therapy combination impact macrophage polarization and destruction of MPN cell lines. Results: We predict that CALR/CD47 levels on each cell line subtype will respond differently highlighting heterogeneity within MPNs and demonstrating the clear need for a more personalised immunotherapy approach. Alterations in JAK/STAT pathway and BET inhibition may hinder macrophage polarisation to the anti-tumorigenic M1 macrophage phenotype. We theorise that indirect co-culture of M1 macrophage with MPN suspension cells under different treatment modalities will enhance MPN cell death and decrease CD47 expression to a greater level than that which we expect to see in M2 polarised macrophage. We also anticipate that the M2 polarised macrophage, which dominate in the tumour microenvironment as MPN progresses, will fail to phagocytose MPN cells and may not be rescued by novel immunotherapeutics. Conclusions: Our group demonstrated the role of CD47 and CALR expression as a key mechanism and a potential target to enhance presentation of the cancer cell to the immune system, and we believe that understanding the interaction of CD47/CALR – macrophages, will drive new therapeutical approaches able to modulate the immune response and improve patients outcomes, potentially leading to complete MPN clone eradiation and cure.

Form-deprivation myopia promotes sclera M2-type macrophages polarization in mice

PurposeTo explore the phenotype of sclera macrophages in form-deprivation (FD) myopia mice and the effects of M2 macrophage in FD myopia development. MethodsC57BL/6 mice were under 2 weeks of unilateral FD treatment. and they were separated into two groups, including an intraperitoneally injected(IP) vehicle group and Panobinostat (LBH589) (10 mg/kg per body weight) treatment group. All biometric parameters were measured before and after treatments, and the type and density of sclera macrophages were identified by immunofluorescence and RT-qPCR. In vitro, we analyzed the M2 macrophage and primary human sclera fibroblast (HSF) co-culture system by using the transcriptome sequencing method. Gene ontology (GO) and KEGG enrichment analyses were used to pinpoint the biological functions and pathways associated with the identified Differentially Expressed Genes (DEGs). The hub genes were investigated using the STRING database and Cytoscape software and were confirmed using RT-qPCR. ResultsWe found that the M2-type sclera macrophage density and expression increased in FD-treated eyes. The results showed that LBH589 inhibited the M2 macrophage polarization, and reduced FDM development. GO and KEGG analyses revealed that the DEGs were predominantly involved in the synthesis and breakdown of the extracellular matrix (ECM), as well as in pathways related to ECM-receptor interaction and the PI3K-Akt signaling pathway. Five hub genes (FN-1, MMP-2, COL1A1, CD44, and IL6) were identified, and RT-qPCR validated the variation in expression levels among these genes. ConclusionM2 macrophage polarization occurred in the sclera in FDM mice. Panobinostat-mediated inhibition of M2 macrophage polarization may decrease FDM progression, as M2 macrophages are crucial in controlling ECM remodeling by HSFs.

Developing a Neuron and Macrophage Coculture In Vitro

Developing a Neuron and Macrophage Coculture In Vitro

Modulating tumor-associated macrophage polarization by anti-maRCO mAb exerts anti-osteosarcoma effects through regulating osteosarcoma cell proliferation, migration and apoptosis

PurposeOsteosarcoma is a primary bone tumor lacking optimal clinical treatment options. Tumor-associated macrophages in the tumor microenvironment are closely associated with tumor development and metastasis. Studies have identified the macrophage receptor with collagenous structure (MARCO) as a specific receptor expressed in macrophages. This study aimed to investigate whether anti-MARCO mAb treatment can induce macrophage polarization in the tumor microenvironment and elicit anti-tumor effects.MethodsTHP-1 cells were treated with 20 ng/mL phorbol 12-myristate 13-acetate and 80 ng/mL interleukin-4 for 48 h to induce macrophage polarization to alternatively activated macrophages (M2). Enzyme-linked immunosorbent assay, real-time quantitative polymerase chain reaction, flow cytometry, and bioinformatic analyses were performed to evaluate macrophage polarization. The co-culture groups included a blank group, an M2 macrophage and U2OS co-culture group, and an anti-MARCO mAb-treated M2 macrophage group. Cell viability assays, cell scratch tests, apoptosis, and cell cycle analyses were performed to determine the effects of anti-MARCO mAb-treated macrophages on osteosarcoma cells.ResultsIt was demonstrated that anti-MARCO mAb can drive macrophages toward classically activated macrophage (M1) polarization. Anti-MARCO mAb promoted the secretion of pro-inflammatory factors by macrophages, including tumor necrosis factor-alpha (TNF-α), interleukin-1beta, interleukin-6 and interleukin-23. Studies on in vitro co-culture models have revealed that macrophages treated with anti-MARCO mAb can suppress the growth and migration of osteosarcoma cells, induce cell apoptosis, and inhibit cell cycle progression of osteosarcoma cells through M1 polarization of macrophages in vitro.ConclusionAnti-MARCO mAb treatment exerts anti-osteosarcoma effects by affecting macrophage polarization toward M1 macrophages, offering a potential new therapeutic approach for treating osteosarcoma.

METTL14 derived from exosomes of M1 macrophages promotes high glucose-induced apoptosis, inflammation and oxidative stress in glomerular endothelial cells by mediating PAQR3 m6A modification.

Methyltransferase 14 (METTL14) mediated N6-methyladenine (m6A) RNA methylation and progestin and AdipoQ receptor family member 3 (PAQR3) are reported to be involved in diabetic nephropathy (DN) progression. Here, we explored whether the effects of PAQR3 on DN was associated with METTL14-induced m6A and their relationship with macrophage-related exosomes in DN progression. Human glomerular endothelial cells (GECs) were incubated in high glucose (HG) condition to mimic DN condition in vitro. Exosomes were isolated from M1 macrophages and co-cultured with GECs. qRT-PCR and western blotting detected the levels of genes and proteins. Cell functions were determined using cell counting kit-8 assay and flow cytometry. ELISA analysis detected inflammatory factors, and oxidative stress was evaluated by measuring reactive oxygen species and malondialdehyde. The m6A modification profile was determined by methylated RNA immunoprecipitation assay and the interaction was verified by dual-luciferase reporter assay. HG elevated PAQR3 expression levels in GECs. PAQR3 silencing reversed HG-induced viability arrest, apoptosis, inflammatory response, and oxidative stress. M1 macrophage co-culture could suppress HG-induced GEC injury. PAQR3 was packaged into M1 macrophage-derived exosomes, and M1 macrophages regulated HG-induced GEC injury by secreting PAQR3 into cells via exosomes. Mechanistically, METTL14 induced PAQR3 m6A modification. METTL14 was enriched in M1 macrophage-derived exosomes. METTL14 knockdown in M1 macrophage-derived exosomes protected GEC from HG-induced viability arrest, apoptosis, inflammation and oxidative stress by regulating PAQR3. Exosomal METTL14 derived from M1 macrophages promoted HG-induced apoptosis, inflammation and oxidative stress in GECs by mediating PAQR3 m6A modification.

Inhibition of SIRT1 relieves hepatocarcinogenesis via alleviating autophagy and inflammation

Imbalanced Sirtuin 1 (SIRT1) levels may lead to liver diseases through abnormal regulation of autophagy, but the roles of SIRT1-regulated autophagy in hepatocellular carcinoma are still controversial. In this study, we found that SIRT1 mRNA and protein levels were upregulated in hepatocellular carcinoma, and high SIRT1 expression hinted an advanced stage and a poor prognosis. The differentially expressed proteins were significantly elevated in autophagy, cellular response to stress, and immune signaling pathways. In a thioacetamide-induced hepatocellular carcinoma mouse model, we found that SIRT1 expression was highly increased with increased autophagy and excessive macrophage inflammatory response. Next, we established a Hepa 1–6 cells and macrophage co-culture system in vitro to model the alteration of tumor microenvironment, and found that the medium from CCl4-treated or SIRT1-overexpressing Hepa 1–6 cells triggered the polarization of macrophage M1, and the culture medium derived from M1 macrophage promoted Hepa 1–6 cells growth and intracellular oxidative stress. The progression of liver fibrosis in the CCl4-induced liver fibrosis mouse model showed that inhibition of SIRT1 alleviated inflammatory response and ameliorated liver fibrosis. These findings suggest that SIRT1-regulated autophagy and inflammation are oncogenic in hepatocarcinogenesis.

Fat Phagocytosis Promotes Anti-Inflammatory Responses of Macrophages in a Mouse Model of Osteonecrosis.

Osteonecrosis (ON) of the femoral head (ONFH) is a devastating bone disease affecting over 20 million people worldwide. ONFH is caused by a disruption of the blood supply, leading to necrotic cell death and increased inflammation. Macrophages are the key cells mediating the inflammatory responses in ON. It is unclear what the dynamic phenotypes of macrophages are and what mechanisms may affect macrophage polarization and, therefore, the healing process. In our preliminary study, we found that there is an invasion of macrophages into the repair tissue during ON healing. Interestingly, in both ONFH patients and a mouse ON model, fat was co-labeled within macrophages using immunofluorescence staining, indicating the phagocytosis of fat by macrophages. To study the effects of fat phagocytosis on the macrophage phenotype, we set up an in vitro macrophage and fat co-culture system. We found that fat phagocytosis significantly decreased M1 marker expression, such as IL1β and iNOS, in macrophages, whereas the expression of the M2 marker Arg1 was significantly increased with fat phagocytosis. To investigate whether the polarization change is indeed mediated by phagocytosis, we treated the cells with Latrunculin A (LA, which inhibits actin polymerization and phagocytosis). LA supplementation significantly reversed the polarization marker gene changes induced by fat phagocytosis. To provide an unbiased transcriptional gene analysis, we submitted the RNA for bulk RNA sequencing. Differential gene expression (DGE) analysis revealed that the top upregulated genes were related to anti-inflammatory responses, while proinflammatory genes were significantly downregulated. Additionally, using pathway enrichment and network analyses (Metascape), we confirmed that gene-enriched categories related to proinflammatory responses were significantly downregulated in macrophages with fat phagocytosis. Finally, we validated the similar macrophage phenotype changes in vivo. To summarize, we discovered that fat phagocytosis occurs in both ONFH patients and an ON mouse model, which inhibits proinflammatory responses with increased anabolic gene expression in macrophages. This fat-phagocytosis-induced macrophage phenotype is consistent with the in vivo changes shown in the ON mouse model. Our study reveals a novel phagocytosis-mediated macrophage polarization mechanism in ON, which fills in our knowledge gaps of macrophage functions and provides new concepts in macrophage immunomodulation as a promising treatment for ON.

Neutrophil extracellular traps are associated with airways inflammation and increased severity of lung disease in Cystic Fibrosis

BackgroundCystic Fibrosis (CF) is characterised by inflammatory lung disease and large numbers of airways neutrophils. In health, neutrophils undergo apoptosis and removal from the airway. Since CF neutrophils are known to engage in apoptosis less efficiently, we wanted to assess whether alternative forms of neutrophil clearance such as NETosis were prominent in the CF airway.MethodsSputum and blood were collected from 45 CF and 15 healthy control (HC) participants. Neutrophil morphology and biochemical properties were assessed in CF and HC sputum. Neutrophil Extracellular Traps (NETs) were measured by a novel histone-calprotectin ELISA. NET levels were compared to established measurements of airway inflammation. CF participants were followed up for one year and number of exacerbations recorded. Neutrophil and macrophage co-culture experiments were undertaken with cells from CF and HC.ResultsNeutrophil numbers were significantly higher in CF and associated with abnormal morphology. Several inflammatory mediators were elevated in CF sputum, as was cell-free DNA. This was highly correlated with sputum calprotectin, a known NET associated protein. Using a Histone/Calprotectin NETs ELISA, we demonstrated higher levels of NETs in the CF airway. CF participants treated with DNase had less sputum NETs, and in neutrophil/macrophage co-culture experiments, DNase effectively attenuated the pro-inflammatory potential of NETs, suggesting a previously unrecognised anti-inflammatory role for this treatment.ConclusionsNETs in the CF airway are associated with increased levels of inflammatory mediators and more severe lung disease. NETs effects on macrophages can be blocked by DNase, suggesting an anti-inflammatory role for this treatment in CF.