Macrophage reprogramming for therapy

VISTA deficiency exerts anti-tumor effects in breast cancer through regulating macrophage polarization

Growing evidence had showed that tumor-associated macrophages (TAMs) have a tumor-promoting M2 phenotype which could drive pathological phenomena. In breast cancer, TAMs are abundantly present and may play an important role in the development of breast cancer. V-domain immunoglobulin suppressor of T cell activation (VISTA) is a novel inhibitory checkpoint and immunotherapy target for tumor through regulating immune response. However, its effects on macrophages have not been investigated, which was also the focus of this study. Here, the scRNA-seq data further revealed that VISTA was highly expressed in multiple macrophage subclusters. In vitro experiments showed that the absence of VISTA enhanced the M1 polarization of macrophages, inhibited the M2 polarization of macrophages and the proliferation and phagocytosis of 4 T1 cells induced by M2-CM. VISTA regulated the activation of STAT1 and STAT6 signaling pathways in the process of macrophage polarization. In vivo experiments demonstrated that VISTA deficient mice exhibited reduced tumor growth, possibly due to the increase of M1 macrophages and the decrease of M2 macrophages. In summary, our study is the first to reveal the effect of VISTA on macrophages in breast cancer, which showed that VISTA affects tumor growth by critically regulating the macrophage polarization through the STAT pathway.

Naringenin modifies T-helper responses and macrophage activities in BALB/c mice

Objective

Naringenin is a naturally occurring flavonoid found in citrus fruits. This study was done to compare the oral immunomodulatory effects of naringenin and prednisolone.

Materials and Methods

The effect of one-month oral administration of naringenin (10, 20, and 40 mg/kg) and prednisolone (2 mg/kg) on peritoneal macrophage was compared in the first set of experiments. Separate evaluations were conducted on the effects of naringenin on in vivo and ex vivoT-helper (Th) lymphocyte responses and their subsets in mice immunized with ovalbumin (OVA). Animals challenged with OVA received oral doses of naringenin or prednisolone from two days prior to immunization to 28 days after immunization.

Results

Naringenin and prednisolone increased macrophages' respiratory burst, and nitric oxide and interleukin (IL)-10 production while decreasing IL-12 production. Macrophages isolated from mice administered with 40 mg/kg naringenin had greater phagocytic potential than those isolated from mice administered with prednisolone. OVA-challenged mice treated with 40 mg/kg naringenin or prednisolone had decreased delayed-type hypersensitivity comparable to control mice. The splenocyte proliferation index was lower in the prednisolone-treated group than the naringenin-treated group, even at 40 mg/kg. In the splenocyte cultures, both agents decreased T-bet expression. Naringenin, in contrast to prednisolone, did not affect GATA3expression. The 40 mg/kg naringenin dose reduced RORγt more effectively than prednisolone.

Conclusion

All these findings indicate the potential of naringenin as a modifying agent of immune responses. Consequently, naringenin may be beneficial in controlling some immunopathological conditions.

Macrophage phenotype is determinant for fibrosis development in keloid disease

Keloid refers to a fibroproliferative disorder characterized by an accumulation of extracellular matrix (ECM) components at the dermis level, overgrowth beyond initial wound, and formation of tumor-like nodule areas. Treating keloid is still an unmet clinical need and the lack of an efficient therapy is clearly related to limited knowledge about keloid etiology, despite the growing interest of the scientific community in this pathology. In past decades, keloids were often studied in vitro through the sole prism of fibroblasts considered as the major effector of ECM deposition. Nevertheless, development of keloids results from cross-interactions of keloid fibroblasts (KFs) and their surrounding microenvironment, including immune cells such as macrophages. Our study aimed to evaluate the effect of M1 and M2 monocyte-derived macrophages on KFs in vitro. We focused on the effects of the macrophage secretome on fibrosis-related criteria in KFs, including proliferation, migration, differentiation, and ECM synthesis. First, we demonstrated that M2-like macrophages enhanced the fibrogenic profile of KFs in culture. Then, we surprisingly founded that M1-like macrophages can have an anti-fibrogenic effect on KFs, even in a pro-fibrotic environment. These results demonstrate, for the first time, that M1 and M2 macrophage subsets differentially impact the fibrotic fate of KFs in vitro, and suggest that restoring the M1/M2 balance to favor M1 in keloids could be an efficient therapeutic lever to prevent or treat keloid fibrosis.

Siglec9 + tumor-associated macrophages predict prognosis and therapeutic vulnerability in patients with colon cancer

BACKGROUND

Siglec9 has been identified as an immune checkpoint molecule on tumor-associated macrophages (TAMs). Nevertheless, the expression profile and clinical significance of Siglec9 + TAMs in colon cancer (CC) are still not fully understood.

METHODS

Two clinical cohorts from distinct medical centers were retrospectively enrolled. Immunohistochemistry and immunofluorescence were conducted to evaluate the infiltration of immune cells. Single-cell RNA sequencing and flow cytometry were utilized to identify the impact of Siglec9 + TAMs on the tumor immune environment, which was subsequently validated through bioinformatics analysis of the TCGA database. Prognosis and the benefit of adjuvant chemotherapy (ACT) were also evaluated using Cox regression analysis and the Kaplan-Meier method.

RESULTS

High infiltration of Siglec9 + TAMs was associated with worse prognosis and better benefit from 6-month ACT. Siglec9 + TAMs contributed to immunoevasion by promoting the infiltration of immunosuppressive cells and the dysfunction process of CD8 + T cells. Additionally, high infiltration of Siglec9 + TAMs was associated with the mesenchymal-featured subtype and overexpression of the VEGF signaling pathway, which was validated by the strongest communication between Siglec9 + TAMs and vascular endothelial cells.

CONCLUSIONS

Siglec9 + TAMs may serve as a biomarker for prognosis and response to ACT in CC. Furthermore, the immunoevasive contexture and angiogenesis stimulated by Siglec9 + TAMs suggest potential treatment combinations for CC patients.

The promising role of tumor-associated macrophages in the treatment of cancer

Macrophages are important components of the immune system. Mature macrophages can be recruited to tumor microenvironment that affect tumor cell proliferation, invasion and metastasis, extracellular matrix remodeling, immune suppression, as well as chemotherapy resistance. Classically activated type I macrophages (M1) exhibited marked tumor killing and phagocytosis. Therefore, using macrophages for adoptive cell therapy has attracted attention and become one of the most effective strategies for cancer treatment. Through cytokines and/or chemokines, macrophage can inhibit myeloid cells recruitment, and activate anti-tumor and immune killing functions. Applying macrophages for anti-tumor delivery is one of the most promising approaches for cancer therapy. This review article introduces the role of macrophages in tumor development and drug resistance, and the possible clinical application of targeting macrophages for overcoming drug resistance and enhancing cancer therapeutics, as well as its challenges.

Diesel exhaust particles induce polarization state-dependent functional and transcriptional changes in human monocyte-derived macrophages

Macrophage populations exist on a spectrum between the proinflammatory M1 and proresolution M2 states and have demonstrated the ability to reprogram between them after exposure to opposing polarization stimuli. Particulate matter (PM) has been repeatedly linked to worsening morbidity and mortality following respiratory infections and has been demonstrated to modify macrophage function and polarization. The purpose of this study was to determine whether diesel exhaust particles (DEP), a key component of airborne PM, would demonstrate polarization state-dependent effects on human monocyte-derived macrophages (hMDMs) and whether DEP would modify macrophage reprogramming. CD14+CD16- monocytes were isolated from the blood of healthy human volunteers and differentiated into macrophages with macrophage colony-stimulating factor (M-CSF). Resulting macrophages were left unpolarized or polarized into the proresolution M2 state before being exposed to DEP, M1-polarizing conditions (IFN-γ and LPS), or both and tested for phagocytic function, secretory profile, gene expression patterns, and bioenergetic properties. Contrary to previous reports, we observed a mixed M1/M2 phenotype in reprogrammed M2 cells when considering the broader range of functional readouts. In addition, we determined that DEP exposure dampens phagocytic function in all polarization states while modifying bioenergetic properties in M1 macrophages preferentially. Together, these data suggest that DEP exposure of reprogrammed M2 macrophages results in a highly inflammatory, highly energetic subpopulation of macrophages that may contribute to the poor health outcomes following PM exposure during respiratory infections.NEW & NOTEWORTHY We determined that reprogramming M2 macrophages in the presence of diesel exhaust particles (DEP) results in a highly inflammatory mixed M1/M2 phenotype. We also demonstrated that M1 macrophages are particularly vulnerable to particulate matter (PM) exposure as seen by dampened phagocytic function and modified bioenergetics. Our study suggests that PM causes reprogrammed M2 macrophages to become a highly energetic, highly secretory subpopulation of macrophages that may contribute to negative health outcomes observed in humans after PM exposure.

Neuroinflammation in fetal alcohol spectrum disorders and related novel therapeutic approaches

Fetal alcohol spectrum disorders (FASD) is an umbrella term to describe the neurological effects of prenatal alcohol exposure (PAE). It has been extensively characterized that PAE causes cell proliferation disruption, heterotopias, and malformations in various brain regions and there is increasing evidence that neuroinflammation is responsible for some of these neurotoxic effects. Despite evidence of its importance, neuroinflammation is not usually considered at diagnosis or treatment for FASD. Here, we discuss the literature regarding anti- inflammatory drugs and nutraceuticals, which hold promise for future therapeutical interventions in these disorders.

Signaling pathways in macrophages: molecular mechanisms and therapeutic targets

Macrophages play diverse roles in development, homeostasis, and immunity. Accordingly, the dysfunction of macrophages is involved in the occurrence and progression of various diseases, such as coronavirus disease 2019 and atherosclerosis. The protective or pathogenic effect that macrophages exert in different conditions largely depends on their functional plasticity, which is regulated via signal transduction such as Janus kinase-signal transducer and activator of transcription, Wnt and Notch pathways, stimulated by environmental cues. Over the past few decades, the molecular mechanisms of signaling pathways in macrophages have been gradually elucidated, providing more alternative therapeutic targets for diseases treatment. Here, we provide an overview of the basic physiology of macrophages and expound the regulatory pathways within them. We also address the crucial role macrophages play in the pathogenesis of diseases, including autoimmune, neurodegenerative, metabolic, infectious diseases, and cancer, with a focus on advances in macrophage-targeted strategies exploring modulation of components and regulators of signaling pathways. Last, we discuss the challenges and possible solutions of macrophage-targeted therapy in clinical applications. We hope that this comprehensive review will provide directions for further research on therapeutic strategies targeting macrophage signaling pathways, which are promising to improve the efficacy of disease treatment.

Preliminary Study on the Effect and Molecular Mechanism of Tetrandrine in Alleviating Pulmonary Inflammation and Fibrosis Induced by Silicon Dioxide

This study aims to explore the molecular mechanism of tetrandrine (Tet) in alleviating pulmonary inflammation and fibrosis induced by silica (SiO2) from the perspective of autophagy. C57BL/6J mice were selected as experimental animals, and SiO2 was exposed by intranasal instillation. Tet was intervened by oral gavage. The mice were euthanized on the 7th and 42nd day of SiO2 exposure, and lung tissues were collected for histopathological, molecular biological, immunological, and transmission electron microscopy analysis. The results showed that SiO2 exposure could lead to significant lung inflammation and fibrosis, while Tet could significantly reduce SiO2 exposure-induced lung inflammation and fibrosis. Molecular mechanism research indicated that, compared with SiO2 expose group, Tet intervention could significantly reduce the expression levels of inflammatory cytokines and fibrosis markers (TNF-α, IL-1β, MCP-1, TGF-β1, HYP, Col-I, and Fn), and regulate the expression of key molecules ATG7, microtubule-associated protein 1 light chain 3B (LC3B), and P62 in the autophagy pathway to improve the blocking of autophagic flux, promote the recovery of autophagic lysosomal system function, and inhibit apoptosis. In summary, Tet can alleviate silica-induced lung inflammation and fibrosis, which may be achieved by regulating the expression of key molecules in the autophagy process and associated apoptotic pathway.

Macrophage Reprogramming via Targeted ROS Scavenging and COX-2 Downregulation for Alleviating Inflammation

Inflammation-related diseases affect large populations of people in the world and cause substantial healthcare burdens, which results in significant costs in time, material, and labor. Preventing or relieving uncontrolled inflammation is critical for the treatment of these diseases. Herein, we report a new strategy for alleviating inflammation by macrophage reprogramming via targeted reactive oxygen species (ROS) scavenging and cyclooxygenase-2 (COX-2) downregulation. As a proof of concept, we synthesize a multifunctional compound named MCI containing a mannose-based macrophage targeting moiety, an indomethacin (IMC)-based segment for inhibiting COX-2, and a caffeic acid (CAF)-based section for ROS clearance. As revealed by a series of in vitro experiments, MCI could significantly attenuate the expression of COX-2 and the level of ROS, leading to M1 to M2 macrophage reprogramming, as evidenced by the reduction and the elevation in the levels of pro-inflammatory M1 markers and anti-inflammatory M2 markers, respectively. Furthermore, in vivo experiments show MCI's promising therapeutic effects on rheumatoid arthritis (RA). Our work illustrates the success of targeted macrophage reprogramming for inflammation alleviation, which sheds light on the development of new anti-inflammatory drugs.

Atherosclerosis and Inflammation: Insights from the Theory of General Pathological Processes

Recent advances have greatly improved our understanding of the molecular mechanisms behind atherosclerosis pathogenesis. However, there is still a need to systematize this data from a general pathology perspective, particularly with regard to atherogenesis patterns in the context of both canonical and non-classical inflammation types. In this review, we analyze various typical phenomena and outcomes of cellular pro-inflammatory stress in atherosclerosis, as well as the role of endothelial dysfunction in local and systemic manifestations of low-grade inflammation. We also present the features of immune mechanisms in the development of productive inflammation in stable and unstable plaques, along with their similarities and differences compared to canonical inflammation. There are numerous factors that act as inducers of the inflammatory process in atherosclerosis, including vascular endothelium aging, metabolic dysfunctions, autoimmune, and in some cases, infectious damage factors. Life-critical complications of atherosclerosis, such as cardiogenic shock and severe strokes, are associated with the development of acute systemic hyperinflammation. Additionally, critical atherosclerotic ischemia of the lower extremities induces paracoagulation and the development of chronic systemic inflammation. Conversely, sepsis, other critical conditions, and severe systemic chronic diseases contribute to atherogenesis. In summary, atherosclerosis can be characterized as an independent form of inflammation, sharing similarities but also having fundamental differences from low-grade inflammation and various variants of canonical inflammation (classic vasculitis).

Therapeutic strategies targeting pro-fibrotic macrophages in interstitial lung disease

Idiopathic pulmonary fibrosis (IPF) is the representative phenotype of interstitial lung disease where severe scarring develops in the lung interstitium. Although antifibrotic treatments are available and have been shown to slow the progression of IPF, improved therapeutic options are still needed. Recent data indicate that macrophages play essential pro-fibrotic roles in the pathogenesis of pulmonary fibrosis. Historically, macrophages have been classified into two functional subtypes, "M1" and "M2," and it is well described that "M2" or "alternatively activated" macrophages contribute to fibrosis via the production of fibrotic mediators, such as TGF-β, CTGF, and CCL18. However, highly plastic macrophages may possess distinct functions and phenotypes in the fibrotic lung environment. Thus, M2-like macrophages in vitro and pro-fibrotic macrophages in vivo are not completely identical cell populations. Recent developments in transcriptome analysis, including single-cell RNA sequencing, have attempted to depict more detailed phenotypic characteristics of pro-fibrotic macrophages. This review will outline the role and characterization of pro-fibrotic macrophages in fibrotic lung diseases and discuss the possibility of treating lung fibrosis by preventing or reprogramming the polarity of macrophages. We also utilized a systematic approach to review the literature and identify novel and promising therapeutic agents that follow this treatment strategy.

Macrophages as potential targets in gene therapy for cancer treatment

Macrophages, as ubiquitous and functionally diverse immune cells, play a central role in innate immunity and initiate adaptive immunity. Especially, tumor-associated macrophages (TAMs) are crucial contributors to the tumorigenesis and development of cancer. Thus, macrophages are emerging potential targets for cancer treatment. Among the numerous targeted therapeutic options, gene therapy is one of the most potential therapeutic strategies via directly and specifically regulating biological functions of macrophages at the gene level for cancer treatment. This short review briefly introduces the characteristics of macrophage populations, the functions of TAM in the occurrence, and the progress of cancer. It also summarized some representative examples to highlight the current progress in TAM-targeted gene therapy. The review hopes to provide new insights into macrophage-targeted gene therapy for precision cancer therapy.

"Two birds with one stone" strategy for the lung cancer therapy with bioinspired AIE aggregates

Aggregation-induced emission luminogens (AIEgens) have emerged as novel phototherapeutic agents with high photostability and excellent performance to induce photodynamic and/or photothermal effects. In this study, a zwitterion-type NIR AIEgens C₄₁H₃₇N₂O₃S₂ (named BITT) with biomimetic modification was utilized for lung cancer therapy. The tumor-associated macrophage (TAM)-specific peptide (CRV) was engineered into the lung cancer cell-derived exosomes. The CRV-engineered exosome membranes (CRV-EM) were obtained to camouflage the BITT nanoparticles (CEB), which targeted both lung cancer cells and TAMs through homotypic targeting and TAM-specific peptide, respectively. The camouflage with CRV-EM ameliorated the surface function of BITT nanoparticles, which facilitated the cellular uptake in both cell lines and induced significant cell death in the presence of laser irradiations in vitro and in vivo. CEB showed improved circulation lifetime and accumulations in the tumor tissues in vivo, which induced efficient photodynamic and photothermal therapy. In addition, CEB induced the tumor microenvironment remodeling as indicated by the increase of CD8 + and CD4 + T cells, as well as a decrease of M2 TAM and Myeloid-derived suppressor cells (MDSCs). Our work developed a novel style of bioinspired AIE aggregates, which could eliminate both lung cancer cells and TAMs, and remodel the tumor environments to achieve an efficient lung cancer therapy. To the best of our knowledge, we are the first to use this style of bioinspired AIE aggregates for photo-mediated immunotherapy in lung cancer therapy.

GSK3β Inhibition Prevents Macrophage Reprogramming by High-Dose Methotrexate

Methotrexate (MTX) is an antifolate drug used as a chemotherapeutic agent for acute lymphoblastic leukemia, where MTX improves patients' prognosis. Macrophage reprogramming is being increasingly assessed as an antitumor therapeutic strategy. However, and although MTX limits the pathogenic action of macrophages in chronic inflammatory diseases, its effects on tumor-promoting macrophages have not been previously explored. We now report that MTX shapes the transcriptional and functional profile of M-CSF-dependent human macrophages, whose transcriptome is highly enriched in the gene signature that defines pathogenic tumor-associated macrophages ("large TAM"). Specifically, MTX prompted the acquisition of the gene signature of antitumoral "small TAM" and skewed macrophages toward an IL-6high IFNβ1high IL-10low phenotype upon subsequent stimulation. Mechanistically, the MTX-induced macrophage reprogramming effect correlated with a reduction of the M-CSF receptor CSF1R expression and function, as well as a diminished expression of MAF and MAFB transcription factors, primary determinants of pro-tumoral macrophages whose transcriptional activity is dependent on GSK3β. Indeed, the ability of MTX to transcriptionally reprogram macrophages toward an antitumoral phenotype was abrogated by inhibition of GSK3β. Globally, our results establish MTX as a macrophage reprogramming drug and indicate that its ability to modulate macrophage polarization may also underlie its therapeutic benefits. Since GSK3β inhibition abrogates the reprogramming action of MTX, our results suggest that the GSK3β-MAFB/MAF axis constitutes a target for the macrophage-centered antitumor strategies.

Roles of transducin-like enhancer of split (TLE) family proteins in tumorigenesis and immune regulation

Mammalian transducin-like enhancer of split family proteins (TLEs) are homologous to Drosophila Groucho (Gro) and are essential transcriptional repressors. Seven TLE family members, TLE1-7, have been identified to date. These proteins do not bind DNA directly; instead, they bind a set of transcription factors and thereby inhibit target gene expression. Loss of TLEs in mice usually leads to defective early development; however, TLE functions in developmentally mature cells are unclear. Recent studies have revealed that TLEs are dysregulated in certain human cancer types and may function as oncogenes or tumor suppressors in different contexts. TLE levels also affect the efficacy of cancer treatments and the development of drug resistance. In addition, TLEs play critical roles in the development and function of immune cells, including macrophages and lymphocytes. In this review, we provide updates on the expression, function, and mechanism of TLEs; discuss the roles played by TLEs in tumorigenesis and the inflammatory response; and elaborate on several TLE-associated signaling pathways, including the Notch, Wnt, and MAPK pathways. Finally, we discuss potential strategies for targeting TLEs in cancer therapy.

Therapeutic strategies for gastric cancer targeting immune cells: Future directions

Gastric cancer (GC) is a malignancy with a high incidence and mortality, and the emergence of immunotherapy has brought survival benefits to GC patients. Compared with traditional therapy, immunotherapy has the advantages of durable response, long-term survival benefits, and lower toxicity. Therefore, targeted immune cells are the most promising therapeutic strategy in the field of oncology. In this review, we introduce the role and significance of each immune cell in the tumor microenvironment of GC and summarize the current landscape of immunotherapy in GC, which includes immune checkpoint inhibitors, adoptive cell therapy (ACT), dendritic cell (DC) vaccines, reduction of M2 tumor-associated macrophages (M2 TAMs), N2 tumor-associated neutrophils (N2 TANs), myeloid-derived suppressor cells (MDSCs), effector regulatory T cells (eT_regs), and regulatory B cells (B_regs) in the tumor microenvironment and reprogram TAMs and TANs into tumor killer cells. The most widely used immunotherapy strategies are the immune checkpoint inhibitor programmed cell death 1/programmed death-ligand 1 (PD-1/PD-L1) antibody, cytotoxic T lymphocyte–associated protein 4 (CTLA-4) antibody, and chimeric antigen receptor T (CAR-T) in ACT, and these therapeutic strategies have significant anti-tumor efficacy in solid tumors and hematological tumors. Targeting other immune cells provides a new direction for the immunotherapy of GC despite the relatively weak clinical data, which have been confirmed to restore or enhance anti-tumor immune function in preclinical studies and some treatment strategies have entered the clinical trial stage, and it is expected that more and more effective immune cell–based therapeutic methods will be developed and applied.

New insights from the single-cell level: Tumor associated macrophages heterogeneity and personalized therapy

Tumor-associated macrophages (TAMs) are important immune cells in the tumor microenvironment, and their invasion in tumors is closely related to poor prognosis. Although TAMs are recognized as therapeutic targets, their heterogeneity makes studying tumor mechanism and developing drugs targeting TAMs difficult. The study of TAMs heterogeneity can be used to analyze the mechanism of tumor progression and drug resistance, and may provide possible treatment strategies for cancer patients. Single-cell RNA sequencing (scRNA-seq) can reveal the RNA expression profile for each TAM to distinguish heterogeneity, thereby providing a more efficient detection method and more accurate information for TAM-related studies. In this review, by summarizing the research progress in macrophage heterogeneity and other aspects of scRNA-seq over the past five years, we introduced the development of scRNA-seq technology and its application status in solid tumors, analyzed the advantages and selections of scRNA-seq in TAMs, and summarized the detailed specific research fields. To explore the mechanism of tumor progression and drug intervention from single cell level will provide new perspective for personalized treatment strategies targeting macrophages.

Inflammation: A New Look at an Old Problem

Pro-inflammatory stress is inherent in any cells that are subject to damage or threat of damage. It is defined by a number of universal components, including oxidative stress, cellular response to DNA damage, unfolded protein response to mitochondrial and endoplasmic reticulum stress, changes in autophagy, inflammasome formation, non-coding RNA response, formation of an inducible network of signaling pathways, and epigenetic changes. The presence of an inducible receptor and secretory phenotype in many cells is the cause of tissue pro-inflammatory stress. The key phenomenon determining the occurrence of a classical inflammatory focus is the microvascular inflammatory response (exudation, leukocyte migration to the alteration zone). This same reaction at the systemic level leads to the development of life-critical systemic inflammation. From this standpoint, we can characterize the common mechanisms of pathologies that differ in their clinical appearance. The division of inflammation into alternative variants has deep evolutionary roots. Evolutionary aspects of inflammation are also described in the review. The aim of the review is to provide theoretical arguments for the need for an up-to-date theory of the relationship between key human pathological processes based on the integrative role of the molecular mechanisms of cellular and tissue pro-inflammatory stress.

Single-Cell Transcriptome Analysis Reveals Inter-Tumor Heterogeneity in Bilateral Papillary Thyroid Carcinoma

Background

The tumor microenvironment (TME) plays a pivotal role in cancer progression in papillary thyroid carcinoma (PTC), yet the composition and the phenotype of cells within the TME in bilateral PTC are poorly understood.

Methods

We performed unbiased transcriptome-wide single-cell RNA sequencing (scRNA-seq) analysis on 29,561 cells from 3 pairs of bilateral PTC and 1 non-tumor thyroid sample. The results of the analysis were validated by a large-scale bulk transcriptomic dataset deposited in The Cancer Genome Atlas (TCGA) database.

Results

Our integrative analysis of thyroid follicular cells revealed 42 signaling pathways enriched in malignant follicular cells, including cytokine-cytokine receptor interaction, PI3K/Akt signaling pathway, mitogen-activated protein kinase (MAPK) signaling pathway, and tumor necrosis factor (TNF) signaling pathway. A 6-gene signature (CXCL3, CXCL1, IL1A, CCL5, TNFRSF12A, and IL18) in the cytokine-cytokine receptor interaction pathway was constructed to predict the prognosis of patients with PTC, with high risk scores being associated with decreased overall survival [hazard ratio (HR) = 3.863, 95% CI = 2.233-6.682, p < 0.001]. Gene set variation analysis (GSVA) indicated that the pathways enriched in bilateral PTC were significantly different, indicating great heterogeneity in bilateral PTC, even with the same BRAF V600E mutation. Comprehensive analysis of T cells revealed that the proportion of CD8+ tissue-resident memory T cells expressing IFNG decreased in tumor samples with advanced N stage. Within the myeloid compartment, the ratio of suppressive M2-like to pro-inflammatory M1-like macrophages increased with advanced disease stage, which was confirmed in the bulk dataset using transcriptomic profiles. In addition, we also identified numerous biologically critical interactions among myeloid cells, T cells, and follicular cells, which were related to T-cell recruitment, M2-like macrophage polarization, malignant follicular cell progression, and T-cell inhibitory signaling.

Conclusion

Our integrative analyses revealed great inter-tumor heterogeneity within the TME in bilateral PTC, which will offer assistance for precise diagnosis and treatment.

Joint synovial macrophages as a potential target for intra-articular treatment of osteoarthritis-related pain

Osteoarthritis is the most common form of joint disease and is one of the leading causes of chronic pain. Given the multi-factorial nature, numerous efforts have been made to clarify the multiple factors impacting the pain symptoms and joint pathology, including synovial macrophages in particular. Accumulating evidence from studies involving human participants and experimental animal models suggests that accumulating macrophages in synovial tissue are implicated in peripherally mediated pain sensitization of affected joints in osteoarthritis. Crosstalk between synovial macrophages and the innervating primary nociceptive neurons is thought to contribute to this facilitated pain processing by the peripheral nervous system. Due to high plasticity and complexity of synovial macrophages in the joint, safe therapies targeting single cells or molecules are currently lacking. Using advanced technologies (such as single-cell RNA sequencing and mass cytometry), studies have shown that diverse subpopulations of synovial macrophages exist in the distinct synovial microenvironments of specific osteoarthritis subtypes. Considerable progress has been made in delineating the molecular mechanisms of various subsets of synovial macrophages in the development of osteoarthritis. To develop a novel intra-articular treatment paradigm targeting synovial macrophages, we have summarized in this review the recent advances in identifying the functional consequences of synovial macrophage sub-populations and understanding of the molecular mechanisms driving macrophage-mediated remodeling.

Engineering Macrophages via Nanotechnology and Genetic Manipulation for Cancer Therapy

Macrophages play critical roles in tumor progression. In the tumor microenvironment, macrophages display highly diverse phenotypes and may perform antitumorigenic or protumorigenic functions in a context-dependent manner. Recent studies have shown that macrophages can be engineered to transport drug nanoparticles (NPs) to tumor sites in a targeted manner, thereby exerting significant anticancer effects. In addition, macrophages engineered to express chimeric antigen receptors (CARs) were shown to actively migrate to tumor sites and eliminate tumor cells through phagocytosis. Importantly, after reaching tumor sites, these engineered macrophages can significantly change the otherwise immune-suppressive tumor microenvironment and thereby enhance T cell-mediated anticancer immune responses. In this review, we first introduce the multifaceted activities of macrophages and the principles of nanotechnology in cancer therapy and then elaborate on macrophage engineering via nanotechnology or genetic approaches and discuss the effects, mechanisms, and limitations of such engineered macrophages, with a focus on using live macrophages as carriers to actively deliver NP drugs to tumor sites. Several new directions in macrophage engineering are reviewed, such as transporting NP drugs through macrophage cell membranes or extracellular vesicles, reprogramming tumor-associated macrophages (TAMs) by nanotechnology, and engineering macrophages with CARs. Finally, we discuss the possibility of combining engineered macrophages and other treatments to improve outcomes in cancer therapy.

Remodeling immune microenvironment in periodontitis using resveratrol liposomes as an antibiotic-free therapeutic strategy

BACKGROUND

Periodontitis is a complicated inflammatory disease that damages the tooth-supporting tissues, with limited pharmacotherapy available. Macrophage-targeting therapy is promising for inflammatory diseases. Resveratrol (RSV), a nonflavonoid polyphenol, is known for its anti-inflammatory and immunomodulatory effects. However, its medical application is limited by its poor stability and water-solubility, as well as its low bioavailability.

RESULT

A therapeutic resveratrol-loaded liposomal system (Lipo-RSV) was developed to treat periodontitis. The physical properties of Lipo-RSV and its ability to regulate macrophages were investigated. The results showed that Lipo-RSV had good biocompatibility and could re-educate the inflammatory macrophages from M1- to M2-like phenotype through activating p-STAT3 and downregulating p-STAT1. Besides, the Lipo-RSV could scavenge ROS and inhibit the NF-κB signal and inflammasomes, thereby reducing the pro-inflammatory cytokines IL-1β, IL-6, and TNF-α.

CONCLUSION

These results revealed that Lipo-RSV could be a potential therapeutic system for the antibiotic-free treatment for periodontal diseases.

Roles of Macrophage Polarization and Macrophage-Derived miRNAs in Pulmonary Fibrosis

This mini-review summarizes the current evidence for the role of macrophage activation and polarization in inflammation and immune response pertinent to interstitial lung disease, specifically pulmonary fibrosis. In the fibrosing lung, the production and function of inflammatory and fibrogenic mediators involved in the disease development have been reported to be regulated by the effects of polarized M1/M2 macrophage populations. The M1 and M2 macrophage phenotypes were suggested to correspond with the pro-inflammatory and pro-fibrogenic signatures, respectively. These responses towards tissue injury followed by the development and progression of lung fibrosis are further regulated by macrophage-derived microRNAs (miRNAs). Besides cellular miRNAs, extracellular exosomal-miRNAs derived from M2 macrophages have also been proposed to promote the progression of pulmonary fibrosis. In a future perspective, harnessing the noncoding miRNAs with a key role in the macrophage polarization is, therefore, suggested as a promising therapeutic strategy for this debilitating disease.

Defects in Macrophage Reprogramming in Cancer Therapy: The Negative Impact of PD-L1/PD-1

Classically activated M1 macrophages and alternatively activated M2 macrophages are two polarized subsets of macrophages at the extreme ends of a constructed continuum. In the field of cancer research, M2 macrophage reprogramming is defined as the repolarization of pro-tumoral M2 to anti-tumoral M1 macrophages. It is known that colony-stimulating factor 1 (CSF1)/CSF1 receptor (CSF1R) and CSF2/CSF2R signaling play important roles in macrophage polarization. Targeting CSF1/CSF1R for M2 macrophage reprogramming has been widely performed in clinical trials for cancer therapy. Other targets for M2 macrophage reprogramming include Toll-like receptor 7 (TLR7), TLR8, TLR9, CD40, histone deacetylase (HDAC), and PI3Kγ. Although macrophages are involved in innate and adaptive immune responses, M1 macrophages are less effective at phagocytosis and antigen presenting, which are required properties for the activation of T cells and eradication of cancer cells. Similar to T and dendritic cells, the “functionally exhausted” status might be attributed to the high expression of programmed death-ligand 1 (PD-L1) or programmed cell death protein 1 (PD-1). PD-L1 is expressed on both M1 and M2 macrophages. Macrophage reprogramming from M2 to M1 might increase the expression of PD-L1, which can be transcriptionally activated by STAT3. Macrophage reprogramming or PD-L1/PD-1 blockade alone is less effective in the treatment of most cancers. Since PD-L1/PD-1 blockade could make up for the defect in macrophage reprogramming, the combination of macrophage reprogramming and PD-L1/PD-1 blockade might be a novel treatment strategy for cancer therapy.

Macrophage Function in Calcium Oxalate Kidney Stone Formation: A Systematic Review of Literature

Background

The global prevalence and recurrence rate of kidney stones is very high. Recent studies of Randall plaques and urinary components in vivo, and in vitro including gene manipulation, have attempted to reveal the pathogenesis of kidney stones. However, the evidence remains insufficient to facilitate the development of novel curative therapies. The involvement of renal and peripheral macrophages in inflammatory processes offers promise that might lead to the development of therapeutic targets. The present systematic literature review aimed to determine current consensus about the functions of macrophages in renal crystal development and suppression, and to synthesize evidence to provide a basis for future immunotherapy.

Methods

We systematically reviewed the literature during February 2021 according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Articles investigating the relationship between macrophages and urolithiasis, particularly calcium oxalate (CaOx) stones, were extracted from PubMed, MEDLINE, Embase, and Scopus. Study subjects, languages, and publication dates were unrestricted. Two authors searched and screened the publications.

Results

Although several studies have applied mixed modalities, we selected 10, 12, and seven (total, n = 29) of 380 articles that respectively described cultured cells, animal models, and human samples.

The investigative trend has shifted to macrophage phenotypes and signaling pathways, including micro (m)-RNAs since the discovery of macrophage involvement in kidney stones in 1999. Earlier studies of mice-associated macrophages with the acceleration and suppression of renal crystal formation. Later studies found that pro-inflammatory M1- and anti-inflammatory M2-macrophages are involved. Studies of human-derived and other macrophages in vitro and ex vivo showed that M2-macrophages (stimulated by CSF-1, IL-4, and IL-13) can phagocytose CaOx crystals, which suppresses stone development. The signaling mechanisms that promote M2-like macrophage polarization toward CaOx nephrocalcinosis, include the NLRP3, PPARγ-miR-23-Irf1/Pknox1, miR-93-TLR4/IRF1, and miR-185-5p/CSF1 pathways.

Proteomic findings have indicated that patients who form kidney stones mainly express M1-like macrophage-related proteins, which might be due to CaOx stimulation of the macrophage exosomal pathway.

Conclusions

This systematic review provides an update regarding the current status of macrophage involvement in CaOx nephrolithiasis. Targeting M2-like macrophage function might offer a therapeutic strategy with which to prevent stones via crystal phagocytosis.

Can we treat inflammation by managing misbehaving monocytes?

When monocytes migrate from blood into tissues they differentiate into macrophage-like cells. The outcome of this differentiation process is strongly influenced by the tissue environment, and the macrophages produced help control the immunological properties of the tissue. The process of monocyte-macrophage differentiation is therefore potentially attractive when seeking therapeutic targets to amplify or modulate the inflammatory response. Here we highlight recent research in this area, identifying the gene Paqr11 as an important factor in monocyte differentiation, and therefore an important potential target for reducing macrophage-mediated inflammation in arthritis.