M2 Macrophage Phenotype Research Articles

Macrophage co-culture promotes cell reprogramming and prevents ferroptosis in aging fibroblasts for neurodegeneration therapy.

Ferroptosis, a form of programmed cell death associated with lipid peroxidation and iron dependency, plays a critical role in affecting neuronal function in the aging-related neurodegenerative diseases. Macrophages, influenced by these changes, contribute significantly to the progression of aging nerve diseases. Induced neuronal reprogramming is an advanced technology, which can direct convert somatic cells, such as fibroblasts, into neurons, and offers a promising approach for drug screening aimed at correcting ferroptosis and combating aging-related nerve diseases. However, the efficiency of this reprogramming process remains a significant challenge. In this study, we aimed to manipulate macrophage phenotypes to enhance the direct conversion of fibroblasts into neurons. Specifically, we sought to correct ferroptosis through screening natural compounds using aged fibroblasts and utilizing macrophages to promote induced neuronal (iN) reprogramming. Our findings demonstrate that M2 macrophages effectively promote the direct reprogramming of fibroblasts into iNs. In a novel macrophage-fibroblast co-culture system, M2 macrophages facilitate iN reprogramming by reducing fibroblast adhesion forces and promoting asymmetric cell division. Furthermore, we discovered that manipulating matrix stiffness can induce polarization of macrophages towards the M2 phenotype, thereby enhancing fibroblast reprogramming into iNs. To facilitate these findings, we developed a mechano-cue-based drug screening chip, where soft hydrogels induced and maintained the phenotype of M2 macrophages and effectively promoted cell reprogramming. Using a combinatorial approach with 36 such chips, we screened natural compounds for their anti-aging properties, focusing on reversing fibroblast aging and inducing their conversion into neuronal cells. Notably, Vitexin, an apigenin flavone glycoside with a role as a platelet aggregation inhibitor, emerged as a promising candidate to achieve our therapeutic goals. This study highlights the potential of macrophage-mediated modulation of fibroblast reprogramming as a strategy to address ferroptosis-induced neuronal dysfunction in aging-related nerve diseases. KEY MESSAGE: This study highlights the potential of macrophage-mediated modulation of fibroblast reprogramming as a strategy to address ferroptosis-induced neuronal dysfunction in aging-related nerve diseases.

Effectively alleviate rheumatoid arthritis via maintaining redox balance, inducing macrophage repolarization and restoring homeostasis of fibroblast-like synoviocytes by metformin-derived carbon dots

Overproduction of reactive oxygen species (ROS), elevated synovial inflammation, synovial hyperplasia and fibrosis are the main characteristic of microenvironment in rheumatoid arthritis (RA). Macrophages and fibroblast-like synoviocytes (FLSs) play crucial roles in the progression of RA. Hence, synergistic combination of ROS scavenging, macrophage polarization from pro-inflammatory M1 phenotype towards M2 anti-inflammatory phenotype, and restoring homeostasis of FLSs will provide a promising therapeutic strategy for RA. In this study, we successfully synthesized metformin-derived carbon dots (MCDs), and investigated the antirheumatic effect in vivo and in vitro. Designed MCDs could target inflamed cells and accumulate at the inflammatory joints of collagen-induced arthritis (CIA) rats. In vivo therapeutic investigation suggested that MCDs reduced synovial inflammation and hyperplasia, ultimately prevented cartilage destruction, bone erosion, and synovial fibrosis in CIA rats. In addition, MCDs eliminated the cellular ROS in M1 phenotype macrophages in RA microenvironment through the enzyme-like catalytic activity as well as inhibiting NOD-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome signaling pathway, effectively polarizing them into the M2 phenotype to realize the anti-inflammatory effect. Furthermore, MCDs could inhibit the proliferation, migration, and fibrosis of inflamed FLSs. Mechanistically, MCDs restored the homeostasis of FLSs while reducing the level of synovial inflammation by blocking IL-6/gp130 signaling pathway. Combined with preferable biocompatibility, MCDs offer a prospective treatment approach for RA.

A detoxified TLR4 agonist inhibits tumour growth and lung metastasis of osteosarcoma by promoting CD8+ cytotoxic lymphocyte infiltration

BackgroundOsteosarcoma is the most common malignant bone tumour with limited treatment options and poor outcomes in advanced metastatic cases. Current immunotherapies show limited efficacy, highlighting the need for novel therapeutic approaches. Systemic immune activation by Toll-like receptor 4 (TLR4) immunostimulants has shown great promise; however, current TLR4 agonists’ toxicity hinders this systemic approach in patients with osteosarcoma.MethodsWe compared the antitumour effect of lipopolysaccharides (LPS) with that of an innovative chemically detoxified TLR4 agonist (Lipo-MP-LPS) in a syngeneic metastatic osteosarcoma mouse model. Lipo-MP-LPS exhibited an optimal safety and solubility profile for systemic administration at an effective dose. We evaluated tumour growth, lung metastases, and immune cell infiltration in wild-type and TLR4-mutant mice and performed selective immunodepletion.ResultsLipo-MP-LPS exhibited antitumour effects against localised osteosarcoma tumours and lung metastases, like those of natural LPS. Lipo-MP-LPS promoted CD8+ T cells and M1 macrophages infiltration in primary tumours and CD8+ T cells in metastases, with an M1-phenotype macrophage shift. The Lipo-MP-LPS antitumour effects were found to depend on TLR4 and CD8+ T cells, but not on macrophages.ConclusionLipo-MP-LPS inhibited tumour growth and lung metastasis of osteosarcoma by promoting CD8 + T cell infiltration, indicating its therapeutic potential for advanced osteosarcoma.

Neutrophil-macrophage hybrid membrane-coated prussian blue nanozyme for ulcerative colitis treatment and mechanistic insights

BackgroundUlcerative colitis (UC) is a chronic and recurrent digestive tract disease that can lead to significant morbidity and mortality. The pathogenesis of UC is intricately associated with the presence of reactive oxygen species (ROS). Prussian blue (PB), an inorganic nanozyme with potent antioxidant properties, has been extensively applied in the treatment of various inflammatory conditions and tumors. However, despite the explicit antioxidant properties, the underlying molecular mechanism of PB nanozyme in the treatment of UC remains poorly understood. Furthermore, there is a deficiency in antioxidants that possess specific targeting capabilities towards UC lesions. The present study pioneered the fabrication of neutrophil (N)-macrophage (M) hybrid membrane-coated PB (NM-PB) nanozyme for the treatment of UC and investigated its underlying molecular mechanism.ResultsWe have successfully constructed PB, N-PB, M-PB, and NM-PB nanozymes. In both the colitis cell model and UC mouse model, compared with PB, N-PB, and M-PB nanozymes, NM-PB nanozymes exhibited remarkable targeting capabilities, significantly enhancing the localization and uptake of PB nanozymes at the lesion site. NM-PB nanozymes significantly reduced levels of ROS (•OH, •OOH, and H2O2) and decreased the production of proinflammatory cytokines (TNF-α, IL-6, IL-1β). Meanwhile, these nanozymes regulated the expression of intestinal mucosal barrier-related proteins (ZO-1, E-cadherin, and Occludin) and apoptosis-related proteins (Bcl2, Bax). Furthermore, NM-PB nanozymes facilitated the polarization of proinflammatory M1-phenotype macrophage towards an anti-inflammatory M2-phenotype. The mechanistic studies demonstrated that NM-PB nanozymes mitigated the progression of UC by inhibiting the pathway of cytokine-cytokine receptor interaction.ConclusionThe NM-PB nanozymes provide a promising and innovative alternative for the treatment of UC, offering enhanced targeting and efficacy through their unique design and mechanism of action.Graphical

Folic acid-modified ginger-derived extracellular vesicles for targeted treatment of rheumatoid arthritis by remodeling immune microenvironment via the PI3K-AKT pathway

Rheumatoid arthritis (RA), a form of autoimmune inflammation, is marked by enduring synovial inflammation and the subsequent impairment of joint function. Despite the availability of conventional treatments, they are often marred by significant side effects and the associated high costs. Plant-derived extracellular vesicles (PEVs) offer a compelling alternative, owing to their abundant availability, affordability, low immunogenicity, high biocompatibility, and feasibility for large-scale production. These vesicles enhance intercellular communication by transferring intrinsic bioactive molecules. In our research, we delve into the capacity of PEVs to treat RA, highlighting the role of ginger-derived extracellular vesicles (GDEVs). By conjugating GDEVs with folic acid (FA), we have developed FA-GDEVs that maintain their inherent immunomodulatory properties. FA-GDEVs are designed to selectively target M1 macrophages in inflamed joints via the folate receptors (FRs). Our in vitro findings indicate that FA-GDEVs promote the polarization towards a reparative M2 macrophage phenotype by modulating the PI3K-AKT pathway. Further corroboration comes from in vivo studies, which demonstrate that FA-GDEVs not only concentrate efficiently in the affected joints but also markedly reduce the manifestations of RA. Synthesizing these findings, it is evident that FA-GDEVs emerge as a hopeful candidate for RA treatment, offering benefits such as safety, affordability, and therapeutic efficacy.Graphical abstract

Mycobacterium tuberculosis resisters despite HIV exhibit activated T cells and macrophages in their pulmonary alveoli.

Natural resistance to Mycobacterium tuberculosis (Mtb) infection in some people with HIV (PWH) is unexplained. We performed single cell RNA-sequencing of bronchoalveolar lavage cells, unstimulated or ex vivo stimulated with Mtb, for 7 PWH who were TST & IGRA positive (called LTBI) and 6 who were persistently TST & IGRA negative (called resisters). Alveolar macrophages (AM) from resisters displayed a baseline M1 macrophage phenotype while AM from LTBI did not. Resisters displayed alveolar lymphocytosis, with enrichment of all T cell subpopulations including IFNG-expressing cells. In both groups, mycobactericidal granulysin was expressed almost exclusively by a T cell subtype that co-expressed granzyme B, perforin and NK cell receptors. These poly-cytotoxic T lymphocytes (CTL) over-expressed activating NK cell receptors and were increased in resister BAL. Following challenge with Mtb, only Intraepithelial Lymphocytes-like cells from LTBI participants responded with increased transcription of IFNG. AM from resisters responded with a stronger TNF signature at 6h post-infection while at 24h post-infection AM from LTBI displayed a stronger IFN-γ signature. Conversely, at 24h post-infection only AM from resisters displayed a significant upregulation of MICA transcripts which encode an activating ligand for poly-CTL. These results suggest that poly-CTL and AM mediate the resister phenotype in PWH.

A Review of Immunological Evaluation of Patients with Recurrent Spontaneous Abortion (RSA).

In approximately half of the recurrent spontaneous abortion (RSA) cases, the underlying cause is unknown. However, most unexplained miscarriages are thought to be linked to immune dysfunction. This review summarizes the current evidence regarding the immunological evaluations of patients with RSA, with potential implications for clinical research. The immune system plays a crucial role in the successful outcome of pregnancy, as it tolerates the semi-allogeneic fetus while offering protection to both the mother and fetus from pathogens. The maternal-fetal interface is the place where the crosstalk between various immune cells such as macrophages, dendritic cells, natural killer (NK) cells, and T cells takes place. An adequate balance is required between these immune cells for pregnancy to progress. In RSA, a dysregulation between these immune players is witnessed. For example, in RSA, NK cells are not increased but also undergo a change in their activity, manifested as cytotoxic decidual NK. Similarly, regulatory T cells, which are crucial for fostering a tolerant immune environment, are decreased in RSA women. Similarly, imbalances between T-helper (Th1, Th2, Th17) cell subsets have been implicated in RSA. Furthermore, the imbalance between pro-inflammatory M1 and anti-inflammatory M2 macrophage phenotypes has been documented, with studies indicating a predominance of M1 macrophages in RSA patients. Targeting immune imbalances with therapies such as immunoglobulin administration, TNF inhibitors, and anticoagulants may improve pregnancy outcomes in women with RSA.

Bioinspired Adhesive Hydrogel Platform with Photothermal Antimicrobial, Antioxidant, and Angiogenic Properties for Whole-Process Management of Diabetic Wounds.

Diabetic wound healing remains a major challenge in modern medicine. The persistent inflammation and immune dysfunction hinder angiogenesis by producing excessive ROS and increasing the susceptibility to bacterial infection. In this study, we developed an integrated strategy for whole-process management of diabetic wounds based on a bioinspired adhesive hydrogel platform with hemostasis, photothermal antimicrobial, antioxidant, anti-inflammatory, and angiogenic properties. A composite hydrogel (termed AQTGF) using poly(acrylic acid) (PAA) and quaternized chitosan (QCS) as the backbone materials and loaded with a TA-Gd/Fe-bimetallic-phenolic coordination polymer was prepared. The AQTGF hydrogel displayed favorable mechanical properties, self-healing capabilities, adhesion characteristics, and photothermal response performance. In vitro experiments demonstrated that the AQTGF hydrogel exhibits excellent photothermal antimicrobial capacity and antioxidant, angiogenic, and M2 macrophage phenotype polarizing properties. In addition, the rat tail amputation and liver hemostasis experiments demonstrated that the AQTGF hydrogel had excellent hemostasis performance. Moreover, in vivo studies have indicated that AQTGF hydrogel can facilitate diabetic wound healing by accelerating epidermal growth, promoting collagen deposition, modulating macrophage M2 polarization, inhibiting inflammation, and promoting angiogenesis. In conclusion, this study provides an adaptable hydrogel that holds promise for the treatment of chronic diabetic wounds.

Backpack-carrying macrophage immunotherapy for periodontitis.

Cell immunotherapy is a promising therapeutic modality to combat unmet medical needs. Macrophages offer a prominent cell therapy modality since their phenotypic plasticity allows them to perform a variety of roles including defending against pathogens, inducing/suppressing adaptive immunity, and aiding in wound healing. At the same time, this plasticity is a major hurdle in implementation of macrophage therapy. This hurdle can be overcome by cellular backpacks (BPs), discoidal particles that adhere on the macrophage surface and regulate M1/M2 phenotypic shift in an environment-independent manner. In this study, we engineered IL-4 BPs for maintaining macrophages in the M2 phenotype to regulate excess inflammation in periodontitis, a major oral infectious disease. IL-4 BPs induced and maintained M2 phenotype in macrophages in vitro for several days. After injection of macrophages carrying IL-4 BPs into the gingiva, the cells stayed in the tissue for over 5days and maintained the M2 phenotype in the disease sites. Furthermore, treatment with IL-4 BP-macrophages significantly suppressed the disease progression. Altogether, a treatment with BP-carrying macrophages offers a promising local therapy against periodontitis.

Extracellular vesicles in dry eye disease and Sjögren's syndrome: A systematic review on their diagnostic and therapeutic role.

Extracellular vesicles (EVs), defined as membrane-bound vesicles released from all cells, are being explored for their diagnostic and therapeutic role in dry eye disease (DED). We systematically shortlisted 32 articles on the role of EVs in diagnosing and treating DED. We cover the progress in the last 2 decades on the classification and isolation of EVs and their role in DED. The diagnostic predictability of exosomes was evaluated in Sjögren syndrome (SS) patients' tears, plasma, and saliva, where upregulation of inflammatory proteins was reported uniformly across studies. Also, we evaluate the therapeutic effects of MSC-derived EVs in in vitro and in vivo studies of SS and DED mouse models. A significant response occurs at a functional level with improved tear production and saliva flow rate and at a cellular level with reduced lymphocyte infiltration, improved corneal structural integrity, decreased epithelial cell apoptosis, and dampening of the inflammatory cytokine response. The proposed mechanisms of EV action include PD-L1, PRDM, NLRP-3, and Nf-kb pathways, and an increase in M2 macrophage phenotype. Current use of exosomes in DED is limited due to their cumbersome isolation techniqus. Further research on human subjects is needed, in addition to optimizing exosome isolation and delivery methods.

RETRACTION: "Diosmetin Inhibits the Growth and Invasion of Gastric Cancer by Interfering With M2 Phenotype Macrophage Polarization".

F. Zhang and H. Luo, "Diosmetin Inhibits the Growth and Invasion of Gastric Cancer by Interfering With M2 Phenotype Macrophage Polarization," Journal of Biochemical and Molecular Toxicology 37, no. 10 (2023): e23431, https://doi.org/10.1002/jbt.23431. The above article, published online on 28 June 2023, in Wiley Online Library (http://onlinelibrary.wiley.com/), has been retracted by agreement between the journal Editor-in-Chief, Dr. Hari K. Bhat; and Wiley Periodicles LLC. A third party notified the publisher that an image in Figure 6 F in this article had been re-used and manipulated from another article by a diferent set of authors (Zhou, et. al. 2022 [https://doi.org/10.1080/21655979.2022.2036914]). In addition, the third party reported that an image in Figure 3D in this article had been reused from another article by a different set of authors (Cui, et al 2022 [https://doi.org/10.1080/0886022X.2022.2092001]). The authors responded to an inquiry by the publisher and provided what was labelled as original data. However, the data provided did not fully correspond to the images published in the article, and the authors did not provide an explanation for the evidence of image duplications with other articles. The retraction has been agreed to because the evidence of image duplications across different articles, each of which reports on different experimental conditions, fundamentally compromises the conclusions of this article. The authors did not respond to our notice regarding the retraction.

One arrow two eagles: multifunctional nano-system for macrophage reprogramming and osteoclastogenesis inhibition against inflammatory osteolysis

Inflammatory osteolysis poses a significant worldwide threat to public health. However, current monotherapies, which target either the prevention of the inflammatory response or the attenuation of osteoclast (OC) formation, have limited efficacy due to the complexity of the bone immune system being overlooked. Herein, by means of modifying salmon calcitonin (sCT), a multifunctional nano-system (AuNDs-sCT) was designed to synergistically inhibit OC differentiation and reverse the inflammatory microenvironment against inflammatory osteolysis. On the one hand, AuNDs-sCT effectively restrained OC differentiation by binding to the calcitonin receptors on the surface of OC precursors, resulting in the down-regulation of OC-specific genes and proteins. The targeted capacity of AuNDs-sCT provided a more durable and precise therapeutic effect. On the other hand, AuNDs-sCT exhibited antioxidant and anti-inflammatory effects, which regulated the polarization “switch” from the pro-inflammatory M1 phenotype to the anti-inflammatory M2 phenotype in macrophages by the inhibition of NF-κB p65 phosphorylation, thereby effectively reversed the local inflammatory microenvironment. Additionally, AuNDs-sCT served as a promising fluorescent probe, enabling real-time visualization of the therapeutic process. This capability is expected to optimize drug administration and evaluate therapeutic effects. In summary, by inhibiting OC differentiation and reprogramming macrophages, AuNDs-sCT successfully realized drug repurposing and achieved the “one arrow two eagles” therapeutic strategy, which offers a synergistic and effective treatment option for the clinical management of inflammatory osteolysis.

Construction of a prognostic survival model with tumor immune-related genes for breast cancer.

Numerous studies have demonstrated that immune cell infiltration is a significant predictor in the prognosis of those with breast cancer. This study aimed to develop a prognostic model for undifferentiated breast cancer using immune-related markers. Differentially expressed genes (DEGs) and prognostic factors were identified from The Cancer Genome Atlas (TCGA) database. Cancer immune-associated genes were filtered using the GeneCards database. Least absolute shrinkage and selection operator (LASSO) and Cox proportional hazards regression were employed to select prognostic indicators. The single-sample gene set enrichment analysis (ssGSEA) algorithm and the CIBERSORT algorithm were used to analyze the correlation of prognostic indicators with immune cells in breast cancer. We identified six tumor immune-related genes, including zic family member 2 (ZIC2), solute carrier family 7 member 5 (SLC7A5), forkhead box J1 (FOXJ1), C-X-C motif chemokine ligand 9 (CXCL9), tumor necrosis factor receptor superfamily member 18 (TNFRSF18), and serine protease 2 (PRSS2), for the development of a prognostic model for patients with breast cancer. Notably, the results of the correlation analysis indicated that CXCL9 was associated with antitumor immune cells, including CD8+ T cells, cytotoxic cells, M1 macrophages, and activated memory CD4 T cells, and with the enrichment of natural killer (NK) CD56dim cells. Furthermore, CXCL9 exhibited a significant negative association with the tumor-promoting M2 macrophage phenotype. Our study established a six-gene model for predicting breast cancer prognosis. Furthermore, we unexpectedly discovered that CXCL9 is integral to immune infiltration in breast cancer and may serve as a critical biomarker for evaluating immune response and therapeutic efficacy in breast cancer treatment.

Cocktail strategy-based nanomedicine: A synergistic cascade of starvation, NIR-II photothermal, and gas therapy for enhanced tumor immunotherapy.

Immunotherapy has emerged as a highly promising strategy in the realm of cancer treatment, wherein immunogenic cell death (ICD) is considered a potential trigger for anti-tumor immunity by inducing adaptive immunity to dying cell antigens. This process is often accompanied by the exposure, active secretion, or passive release of a large number of damage-associated molecular patterns (DAMPs), which activate dendritic cells (DCs) and enhance their antigen-presenting capacity. Subsequently, it promotes the recruitment and activation of cytotoxic T lymphocytes, ultimately leading to tumor growth inhibition. In addition, polarizing the M2 phenotype of tumor-associated macrophages (TAMs) to the M1 phenotype is another way to activate anti-tumor immunity, which can further enhance the effect of anti-tumor immunotherapy. In this study, we engineered a composite nanoparticle of UiO-66-NH2@Gold nanoshells@GOx-P-Arg (denoted as UGsGP). The gold nano shells in UGsGP exhibit a broad Near-Infrared-II (NIR-II) absorption to give a high photothermal conversion efficiency and achieve photothermal therapy (PTT). The GOx in UGsGP involves the breakdown of glucose, which results in a decrease in ATP levels and an inhibition of HSP90 and HSP70 production, ultimately enhancing the heat sensitivity of the tumor for PTT. In addition, GOx-mediated starvation therapy by glucose exhaustion produces a substantial amount of hydrogen peroxide (H2O2), which can then react with P-Arg to produce intratumoral NO Thus, the synergistic effect of PTT resensitization, the photothermally-enhanced GOx-mediated starvation, and NO-based gas therapy promote the induction of ICD and the polarization of TAMs. The combination therapy exhibits significant antitumor effects both in vitro and in vivo. STATEMENT OF SIGNIFICANCE: (1) Gold nanoshells on the surface of UiO-66-NH2 display a broad absorption spectrum ranging from 900 to 1700 nm, combined with a high photothermal conversion efficiency of 74.0 %, demonstrating their remarkable ability to harness and convert light energy into heat for effective tumor ablation. (2) Under laser irradiation, GOx within the UGsGPs effectively consumes glucose, increasing intratumoral H2O2 levels, which then reacts with P-Arg to produce NO within the tumor. Concurrently, the reduction in ATP levels suppresses HSP90 and HSP70 production, thereby enhancing the tumor's sensitivity to photothermal therapy. (3) The synergistic combination of NO gas therapy, starvation therapy, and PTT promotes ICD induction and TAM polarization, thereby improving the therapeutic outcomes for primary and distant tumors.

Sirt3-Mediated Opa1 Deacetylation Protects Against Sepsis-Induced Acute Lung Injury by Inhibiting Alveolar Macrophage Pro-Inflammatory Polarization.

Aims: Mitochondrial dynamics in alveolar macrophages (AMs) are associated with sepsis-induced acute lung injury (ALI). In this study, we aimed to investigate whether changes in mitochondrial dynamics could alter the polarization of AMs in sepsis-induced ALI and to explore the regulatory mechanism of mitochondrial dynamics by focusing on sirtuin (SIRT)3-induced optic atrophy protein 1 (OPA1) deacetylation. Results: The AMs of sepsis-induced ALI showed imbalanced mitochondrial dynamics and polarization to the M1 macrophage phenotype. In sepsis, SIRT3 overexpression promotes mitochondrial dynamic equilibrium in AMs. However, 3-(1H-1, 2, 3-triazol-4-yl) pyridine (3TYP)-specific inhibition of SIRT3 increased the mitochondrial dynamic imbalance and pro-inflammatory polarization of AMs and further aggravated sepsis-induced ALI. OPA1 is directly bound to and deacetylated by SIRT3 in AMs. In AMs of sepsis-induced ALI, SIRT3 protein expression was decreased and OPA1 acetylation was increased. OPA1 acetylation at the lysine 792 amino acid residue (OPA1-K792) promotes self-cleavage and is associated with an imbalance in mitochondrial dynamics. However, decreased acetylation of OPA1-K792 reversed the pro-inflammatory polarization of AMs and protected the barrier function of alveolar epithelial cells in sepsis-induced ALI. Innovation: Our study revealed, for the first time, the regulation of mitochondrial dynamics and AM polarization by SIRT3-mediated deacetylation of OPA1 in sepsis-induced ALI, which may serve as an intervention target for precision therapy of the disease. Conclusions: Our data suggest that imbalanced mitochondrial dynamics promote pro-inflammatory polarization of AMs in sepsis-induced ALI and that deacetylation of OPA1 mediated by SIRT3 improves mitochondrial dynamic equilibrium, thereby ameliorating lung injury. Antioxid. Redox Signal. 41, 1014-1030.

Mincle Maintains M1 Polarization of Macrophages and Contributes to Renal Aging Through the Syk/NF-κB Pathway.

Kidney is a classic organ undergoing senescence, and chronic inflammation has an important effect in cellular senescence. Mincle has been shown to be vital for maintaining the M1 phenotype of macrophages, but its role in regulating renal aging has yet to be explored. Young (2 months of age) and old (24 months of age) mice were used to analyze the changes of kidney damage during natural aging. Mice were subcutaneously injected with D-galactose (D-gal) to establish a renal aging model, and miR-6948-3p mimic and Mincle siRNA were administered via the tail vein every 3 days. Aged kidney and experimental aging kidney were characterized by decreased renal function and structural damage, and upregulated expression of senescence-related proteins and SPAP components. The ratio of M1 macrophages was increased in the aged kidney, and Mincle accumulated in the aged kidney macrophages. Administration of miR-6948-3p mimic or Mincle siRNA alleviated D-gal-induced renal senescence. LPS was used to induce M1 polarization of bone marrow-derived macrophages, and a coculture system of M1 macrophages and mouse renal tubular epithelial cells (TCMK-1) was established. Mincle was upregulated in LPS-induced M1 macrophages in vitro, and silencing Mincle in M1 macrophages attenuated M1 macrophage-induced TCMK-1 cell senescence. Mechanistically, Mincle was regulated by miR-6948-3p and maintained the M1 phenotype of macrophages through the Syk/NF-κB pathway. In conclusion, Mincle, posttranscriptionally suppressed by miR-6948-3p, modulated renal senescence by maintaining the phenotype of M1 macrophages through the Syk/NF-κB pathway.

Rational Design of Advanced Gene Delivery Carriers: Macrophage Phenotype Matters.

Nucleic acid delivery in hard-to-transfect macrophages have attracted increasing attention in diverse applications such as defence against bacterial infection. Regulated by microenvironments in specific applications, macrophages have a heterogenous nature and exist in different phenotypes with diverse functions, e.g., pro-inflammatory and anti-inflammatory. However, it is not clear whether macrophage phenotype affects nucleic acid delivery, and which one is harder to transfect, and the design of nucleic acid carriers in harder-to-transfect macrophage phenotypes is largely unexplored. Herein, it is first revealed that nucleic acid delivery efficacy in macrophages is influenced by phenotype: IL-4-treated "M2-like" macrophages with suppressed mammalian target of rapamycin complex 1 (mTORC1) levels are harder-to-transfect than "M1-like" macrophages for mRNA and DNA. This knowledge is then translated to the purpose-design of gene delivery carriers for harder-to-transfect M2 phenotype macrophages dominant upon bacteria immune evasion. By loading chloroquine in tetrasulfide bond-containing organosilica nanoparticles, the resultant composite promotes macrophage M2 polarization to M1 and increases mTORC1 levels for enhanced translation. The design is demonstrated in vitro and in vivo for pathogenic Escherichia coli (E. coli) and methicillin-resistant Staphylococcus aureus (MRSA) infections. It is expected that the findings may provide new knowledge and gene delivery solutions in other applications where the M2 phenotype macrophage is dominant.

Polyinosinic/Polycytidylic Lipid Nanoparticles Enhance Immune Cell Infiltration and Improve Survival in the Glioblastoma Mouse Model.

Glioblastoma (GBM) immunotherapy is particularly challenging due to the pro-tumorigenic microenvironment, marked by low levels and inactive immune cells. Toll-like receptor (TLR) agonists have emerged as potent immune adjuvants but failed to show improved outcomes in clinical trials when administered as a monotherapy. We hypothesize that a combined nanoparticulate formulation of TLR agonist and immunogenic cell death-inducing drug (doxorubicin) will synergize to induce improved GBM immunotherapy. Lipid nanoparticle (LNP) formulations of the TLR agonists CpG and polyinosinic/polycytidylic (pIpC), with and without Dox, were first prepared, achieving an encapsulation efficiency >75% and a size <140 nm. In vitro studies identified that LNP pIpC was superior to CpG at activating bone marrow-derived immune cell populations (dendritic cells and macrophages) with minimal toxicity. It was also observed that the pIpC formulation can skew macrophage polarization toward the antitumorigenic M1 phenotype and increase macrophage phagocytosis of cancer cells. Upon intratumoral administration, pIpC Dox LNPs led to significant immune cell infiltration and activation. In survival models, the inclusion of Dox into pIpC LNP improved mice survival compared to control. However, addition of Dox did not show significant improvement in mice's survival compared to singly formulated pIpC LNP. This study has illustrated the potential of pIpC LNP formulations in prospective GBM immunotherapeutic regimes. Future studies will focus on optimizing dosage regimen and/or combination with other modalities, including the standard of care (temozolomide), immune checkpoint blockade, or cancer vaccines.

Cyclophosphamide ameliorates membranous nephropathy by upregulating miR-223 expression, promoting M2 macrophage polarization and inhibiting inflammation.

Membranous nephropathy (MN), also known as membranous glomerulonephritis, is a leading cause of adult nephrotic syndrome. The main pathological features encompass the deposition of immune complexes within the glomerular basement membrane epithelial cells, thickening of the basement membrane, and fusion of the foot process. This study aims to investigate the role of the immune and inflammatory modulator miR-223 in the immunosuppressive and anti-inflammatory effects of cyclophosphamide (CTX) on membranous nephropathy (MN). miR-223 mimetics or inhibitors was used to regulate miR-223 levels. LPS induced inflammatory cell model and cell polarization. CTX was used to treat Lipopolysaccharides (LPS) induced inflammatory response and polarization. Cationic bovine serum albumin (c-BSA) induced BALB/c mouse MN model, while CTX was used to treat c-BSA induced MN. The miR-223 level in LPS induced inflammatory model cells was lower than that in control cells. The levels of inflammatory factors in LPS+miR-223 mimetics and CTX+miR-223i cells were lower than those in LPS and miR-223i cells. The protein levels of LPS+miR-223 mimic, CTX+miR-223i macrophage M2 phenotype markers Arginase-1 (Arg1), transforming growth factor β1 (TGF-β1), anti-inflammatory factors interleukin-4 (IL4) and interleukin-13 (IL13) were significantly higher than those of LPS and miR-223i. The effect of CTX was confirmed in a BALB/c mouse MN model induced by cationic bovine serum albumin (c-BSA). CTX upregulates the expression of miR-223, promotes polarization of M2 macrophages, alleviates the inflammatory response and renal injury of MN.

IL-33/ST2 Signaling and its Correlation with Macrophage Heterogeneity and Clinicopathologic Features in Human Intrahepatic Cholangiocarcinoma.

IL-33/ST2 signaling plays crucial roles in the development and progression of various human malignancies. However, its significance in intrahepatic cholangiocarcinoma (ICC) still remains unclear. This study aimed to investigate the expression of IL-33/ST2 signaling and its correlations with macrophage heterogeneity and ICC patients' clinicopathologic features. The expression of different phenotype macrophage markers and IL-33/ST2 signalingrelated markers was detected. The correlation between L-33/ST2 signaling and different phenotype macrophage markers as well as ICC patients' clinicopathologic data was evaluated. Massive heterogeneous cancer cells and PAS-positive cells were observed in tumor tissues. CD68-positive cells accumulated in tumor tissues and expression of both M1 phenotype markers and M2 phenotype macrophage markers was higher in tumor samples than para-carcinoma samples. However, M2 phenotype macrophages represented the dominant macrophage population in ICC tissues. Plasma levels of IL-33, ST2, and MIF were evidently enhanced in ICC patients compared to healthy controls. IL-33/ST2 signaling-related markers exhibited a massive increase in tumor samples than para-carcinoma samples. IL-33 and ST2 expression in ICC tissues was positively associated with M1 and M2 phenotype macrophages. Plasma levels of IL-33, ST2, and MIF were correlated with the diameter of tumor lesions, lymph node metastasis, TNM stage, and tumor differentiation degree. Multivariate analysis demonstrated IL-33 expression to exhibit a correlation with the diameter of tumor lesions, lymph node metastasis, and TNM stage. Additionally, there was a relationship observed between ST2, MIF expression, and diameter of tumor lesions plus TNM stage. IL-33/ST2 signaling exhibited a positive relationship with macrophage heterogeneity in ICC tissues, and upregulated levels of IL-33, ST2, and MIF were associated with aggressive clinicopathologic characteristics. These findings may provide promising diagnostic biomarkers and potential therapeutic strategies for ICC patients targeting IL-33/ST2 signaling.