Macrophage activation by endogenous danger signals

Targeting alveolar macrophages: a promising intervention for pulmonary infection and acute lung injury

Pulmonary infections are common respiratory diseases caused by a variety of pathogens, some of which can lead to epidemics. When they progress to acute lung injury or acute respiratory distress syndrome, the mortality rate is high and effective treatment options are lacking. Macrophages play a crucial role in the development and progression of lung injury, and serve as core components of immune regulation in the lungs. Therefore, regulation of macrophages to intervene in the progression of infection-induced lung injury is a promising research direction. However, the existence of different macrophage subsets and their inherent heterogeneity has led to the failure of many studies to achieve effective results, thereby limiting their clinical applications. We believe that interventions targeting macrophages must consider factors, such as macrophage subsets, timing of interventions, patients' varying immune states, and clinical stages, rather than simply focusing on regulating their phenotypes. This distinction is the key to the success of macrophage-targeted therapies. In this review, we summarize the characteristics of two distinct macrophage subpopulations, lung-tissue-resident alveolar macrophages and monocyte-derived macrophages, along with intervention strategies and research progress at various time points, with the aim of providing insights and directions for future research.

Evaluation of the association between serum danger molecules at diagnosis and survival outcomes in patients with diffuse large B cell lymphoma

When cellular stress or tissue injury occurs, molecules known as damage-associated molecular patterns are generated. The aim of the present was to examine the association between serum danger molecules and survival outcomes in patients with diffuse large B cell lymphoma (DLBCL) at the time of diagnosis. The present study was carried out retrospectively. An evaluation was conducted on 122 patients with DLBCL who were diagnosed at a tertiary care center between 2011 and 2024. The laboratory results of the patients diagnosed with DLBCL, which were examined in detail at diagnosis, were examined retrospectively. The median age of the patients was 59 years (range, 22-87 years) and 56.6% (n=69) of the patients were female. The 5-year overall survival (OS) rates of the patients who had a fibrinogen level ≤424 mg/dl and of those who had a fibrinogen level >424 mg/dl at the time of diagnosis were 82 and 41%, respectively (P<0.001). The 5-year progression-free survival (PFS) rates of the patients with a fibrinogen level ≤424 mg/dl and of those with a fibrinogen level >424 mg/dl at the time of diagnosis were 91 and 63%, respectively (P=0.002). The 5-year OS rates of patients with a uric acid level ≤5 mg/dl and those with a uric acid level >5 mg/dl at the time of diagnosis were 74 and 44%, respectively (P=0.008). The 5-year PFS rates of patients with a uric acid level ≤5 mg/dl and those with a uric acid level >5 mg/dl at the time of diagnosis were 83 and 71%, respectively (P=0.95). On the whole, the present study demonstrates that high uric acid and fibrinogen levels are negative prognostic factors for the OS and PFS of patients with DLBCL. These data may indicate that uric acid and fibrinogen levels at the time of diagnosis may provide predictive information to the existing library of clinical risk prediction tools in DLBCL.

Itaconate: A Potential Therapeutic Strategy for Autoimmune Disease

Itaconate is a metabolite of the Krebs cycle, and endogenous itaconate is driven by a variety of innate signals that inhibit the production of inflammatory cytokines. The key mechanism of action of itaconate was initially found to be the competitive inhibition of succinate dehydrogenase (SDH), which inhibits the production of inflammatory factors, as well as its antioxidant effects. With increasing research, it was discovered that it modifies cysteine residues of related proteins through the Michael addition, such as modifying the Kelch-like ECH-associated protein 1 (KEAP1) protein and activating the nuclear factor erythroid 2-related factor 2 (NRF2) signalling pathway, as well as glycolytic enzymes and cellular pathway-associated factors that attenuate inflammatory responses and oxidative stress. It also acts on a variety of immune cells, affecting their function and activity, and has been increasingly shown to play a therapeutic role in a variety of inflammatory and autoimmune diseases through a combination of these mechanisms. In conclusion, there has been a great breakthrough in the research of itaconate, from the initial industrial application to the redefinition of the biological functions of itaconate. However, with the deepening of the research, we also found that there are more questions: the mechanism of action of itaconate, more functions of itaconate, clinical application of itaconate, and the use of itaconate still needs to be solved.

The origin and polarization of Macrophages and their role in the formation of the Pre-Metastatic niche in osteosarcoma

Osteosarcoma, a primary malignant bone tumor commonly found in adolescents, is highly aggressive, with a high rate of disability and mortality. It has a profound negative impact on both the physical and psychological well-being of patients. The standard treatment approach, comprising surgery and chemotherapy, has seen little improvement in patient outcomes over the past several decades. Once relapse or metastasis occurs, prognosis worsens significantly. Therefore, there is an urgent need to explore new therapeutic approaches. In recent years, the successful application of immunotherapy in certain cancers has demonstrated its potential in the field of cancer treatment. Macrophages are the predominant components of the immune microenvironment in osteosarcoma and represent critical targets for immunotherapy. Macrophages exhibit dual characteristics; while they play a key role in maintaining tumor-promoting properties within the microenvironment, such as inflammation, angiogenesis, and immune suppression, they also possess antitumor potential as part of the innate immune system. A deeper understanding of macrophages and their relationship with osteosarcoma is essential for the development of novel therapeutic strategies.

Development of a macrophage polarization-modulating therapeutic agent for osteoarthritis treatment

Osteoarthritis (OA) is a common chronic degenerative joint disease. Recent studies have emphasized the crucial role of macrophages, particularly tissue-resident macrophages (Tissue-Resident Macrophages, TRMs), in the pathogenesis and progression of OA. Under physiological conditions, TRMs maintain joint homeostasis, but under various stimuli, they can polarize into pro-inflammatory M1 or anti-inflammatory M2 phenotypes. An imbalance in macrophage polarization, favoring the M1 phenotype, leads to sustained inflammation, cartilage degradation, and osteophyte formation, further exacerbating OA symptoms and structural damage. This article reviews the current understanding of macrophage polarization in OA, with a particular emphasis on the mechanisms by which TRMs influence the joint microenvironment. It explores the therapeutic potential of drug molecular platforms aimed at regulating macrophage polarization, shifting the balance from pro-inflammatory M1 to anti-inflammatory M2. The discussion includes various pharmacological agents such as corticosteroids, hyaluronic acid derivatives, monoclonal antibodies, and bioactive molecules like Squid Type II Collagen (SCII) in modulating macrophage function and slowing OA progression. Additionally, the article examines advancements in gene therapy methods targeting macrophages, utilizing nanotechnology-based delivery systems to enhance the specificity and efficiency of macrophage phenotype regulation. Targeting TRMs through sophisticated drug molecular platforms presents a promising strategy for developing novel diagnostic and therapeutic interventions for osteoarthritis.

Immune-enhancing effects of enzymatic hydrolysates of peanut sprouts in RAW 264.7 macrophages and cyclophosphamide-induced immunosuppressed mouse model

Immune deficiency is associated with the development of various diseases. Resveratrol, the main bioactive component of peanut sprouts, exerts immunomodulatory effects. Enzymatic hydrolysis increases the yield of bioactive components from plant resources. In this study, the immune-enhancing effects of three types of peanut sprout extracts (peanut sprout non-enzyme extract (PSNE), peanut sprout cellulase extract (PSCE), and peanut sprout pectinase extract (PSPE)) were evaluated to confirm the effectiveness of enzymatic hydrolysis extract of peanut sprouts. The immune-boosting potency of the extracts was assessed by measuring proinflammatory mediators (nitric oxide (NO), and prostaglandin E2 (PGE2)), inflammatory cytokines (tumor necrosis factor-α (TNF-α), interleukin (IL)-6, IL-1β, and monocyte chemoattractant protein-1 (MCP-1)) in RAW 264.7 cells. To evaluate the immune-boosting efficacy of the extract in an in vivo model, immune organ indices and total leukocyte and natural killer (NK) cell populations were measured in a cyclophosphamide-induced immunosuppressed mouse model. PSCE had a significantly higher resveratrol content than PSNE and PSPE. Moreover, PSCE actively increased NO and PGE2 production in RAW 264.7 cells in a concentration-dependent manner, indicating its immune-promoting potential. PSCE significantly increased the expression of inflammatory cytokines and promoted the phosphorylation and nuclear translocation of nuclear factor kappa-light-chain-enhancer of activated B cells, thereby enhancing immunity. In the mouse model, oral administration of PSCE enhanced immunity by suppressing the cyclophosphamide-induced loss of immune organ index and decline of leukocyte population in the blood and NK cell population in the spleen. Our results suggest that hydrolysis using cellulase can promote the immune-enhancing effects of peanut sprout extract by increasing the extraction of resveratrol.

Atrophic C2C12 Myotubes Activate Inflammatory Response of Macrophages In Vitro

BACKGROUND

Skeletal muscle wasting is commonly observed in aging, immobility, and chronic diseases. In pathological conditions, the impairment of skeletal muscle and immune system often occurs simultaneously. Recent studies have highlighted the initiative role of skeletal muscle in interactions with immune cells. However, the impact of skeletal muscle wasting on macrophage inflammatory responses remains poorly understood.

METHODS

To investigate the effect of atrophic myotubes on the inflammatory response of macrophages, we established two in vitro models to induce myotube atrophy: one induced by D-galactose and the other by starvation. Conditioned medium (CM) from normal and atrophic myotubes were collected and administered to bone marrow-derived macrophages (BMDMs) from mice. Subsequently, lipopolysaccharide (LPS) stimulation was applied, and the expression of inflammatory cytokines was measured via RT-qPCR.

RESULTS

Both D-galactose and starvation treatments reduced myotube diameter and upregulated muscle atrophy-related gene expression. CM from both atrophic myotubes models augmented the gene expression of pro-inflammatory factors in BMDMs following LPS stimulation, including Il6, Il1b, and Nfkb1. Notably, CM from starvation-induced atrophic myotubes also enhanced Il12b, Tnf, and Nos2 expression in BMDMs after stimulation, a response not observed in D-galactose-induced atrophic myotubes.

CONCLUSIONS

These findings suggest that CM from atrophic myotubes enhanced the expression of LPS-induced pro-inflammatory mediators in macrophages.

Glycerol metabolism is activated in both palmitic acid-stimulated and adipose tissue macrophages from a murine model of cardiometabolic heart failure

Macrophages chronically exposed to saturated fatty acids, such as those encountered in adipose tissue, present a pro-inflammatory phenotype with a characteristic foamy morphology. This feature is caused by the excess uptake of circulating lipids, yielding large cytoplasmic lipid bodies formed by triacylglycerols and cholesteryl derivatives. Palmitic acid (PA) is a potent inflammatory inducer in macrophages after chronic exposure to this fatty acid. However, acute exposure to this fatty acid is unable to activate a pro-inflammatory phenotype, although it is sufficient to induce metabolic reprogramming including the formation of small lipid bodies. In the present study, we used an in vitro model of human monocyte-derived macrophages to unravel the early stages of metabolic reprogramming observed in macrophages exposed to PA. We observed that partial inhibition of the glycerol 3-phosphate shuttle is necessary for supplying glycerol 3-phosphate for triacylglycerol biosynthesis. Furthermore, we characterized an alternative pathway to increase the concentration of glycerol 3-phosphate involving an aquaporin and glycerol kinase. Our results suggested that early lipid bodies biogenesis rises as a response mechanism to buffer excessive PA without inducing a pro-inflammatory program. Additionally, we observed that macrophages chronically exposed to PA eventually upregulate the production of inflammatory cytokines. Finally, our in vitro observations were confirmed in adipose tissue macrophages derived from a preclinical mouse model of cardiometabolic heart failure with preserved ejection fraction characterized by heightened adiposity and inflammation. KEY POINTS: The glycerol 3-phosphate shuttle is partially inhibited in palmitic acid-activated macrophages. Aquaporin 3 expression is upregulated in macrophages exposed to palmitic acid and in adipose tissue macrophages from a murine model of cardiometabolic heart failure. Aquaporin 3 participates in the biosynthesis of triacylglycerols by supplying extracellular glycerol.

Hallmarks of aging: A user's guide for comparative biologists

Since the first description of a set of characteristics of aging as so-called hallmarks or pillars in 2013/2014, these characteristics have served as guideposts for the research in aging biology. They have been examined in a range of contexts, across tissues, in response to disease conditions or environmental factors, and served as a benchmark for various anti-aging interventions. While the hallmarks of aging were intended to capture generalizable characteristics of aging, they are derived mostly from studies of rodents and humans. Comparative studies of aging including species from across the animal tree of life have great promise to reveal new insights into the mechanistic foundations of aging, as there is a great diversity in lifespan and age-associated physiological changes. However, it is unclear how well the defined hallmarks of aging apply across diverse species. Here, we review each of the twelve hallmarks of aging defined by Lopez-Otin in 2023 with respect to the availability of data from diverse species. We evaluate the current methods used to assess these hallmarks for their potential to be adapted for comparative studies. Not unexpectedly, we find that the data supporting the described hallmarks of aging are restricted mostly to humans and a few model systems and that no data are available for many animal clades. Similarly, not all hallmarks can be easily assessed in diverse species. However, for at least half of the hallmarks, there are methods available today that can be employed to fill this gap in knowledge, suggesting that these studies can be prioritized while methods are developed for comparative study of the remaining hallmarks.

Haloxylon salicornicum Phytochemicals Suppress NF-κB, iNOS and Pro-Inflammatory Cytokines in Lipopolysaccharide-Induced Macrophages

Haloxylon salicornicum is traditionally used for the treatment of several disorders associated with inflammation. Despite it is a defense response against tissue injury and infections, inflammation can become a chronic condition that can negatively impact the body. This study investigated the effect of H. salicornicum phytochemicals nuclear factor-kappaB (NF-κB), inducible nitric oxide synthase (iNOS) and cytokines release by lipopolysaccharide (LPS)-challenged macrophages in vitro. The binding affinity of the tested phytochemical towards NF-κB and iNOS was investigated using molecular docking. Ten compounds (four coumarins, three sterols and three flavonoids) were isolated from the ethanolic extract of H. salicornicum. Treatment of LPS-challenged macrophages with the compounds resulted in remarkable decrease in NF-κB p65 and iNOS mRNA abundance. All compounds suppressed the production of nitric oxide (NO) and the pro-inflammatory cytokines (tumor necrosis factor (TNF)-α and interleukin (IL)-6) from macrophages challenged with LPS. Molecular docking revealed the ability of the isolated phytochemicals to bind NF-κB p65 and iNOS. In conclusion, H. salicornicum is a rich source of phytochemicals with anti-inflammatory properties. The anti-inflammatory efficacy of H. salicornicum phytoconstituents is mediated via their ability to modulate NF-κB and iNOS, and suppress the release of NO, TNF-α, and IL-6 from macrophages.

The role of macrophage polarization in ulcerative colitis and its treatment

Macrophages have great plasticity. Typically, there are two of activated macrophages: M1 macrophages and M2 macrophages. Of them, M1 macrophages play a major role in responses that are pro-inflammatory, while M2 macrophages play an important part in responses that are anti-inflammatory. Ulcerative colitis (UC) is a chronic, non-specific inflammatory disease of the intestine. The pathophysiology and course of UC are significantly influenced by the inflammatory response triggered by macrophage activation. M1 is a possible cause of increased inflammation in UC whereas M2 has a significant function in the healing of inflammation. The polarization imbalance of intestinal M1/M2 macrophages is closely linked to UC. Thus, by suppressing M1 polarization, encouraging M2 polarization, and reestablishing macrophage polarization balance, the treatment of UC based on macrophage polarization is beneficial for UC. Not only chemical drugs, but also traditional Chinese medicine compounds and herbal extracts have been shown to restore the balance of macrophage polarization, providing a new idea in the treatment of UC.

Positive feedback loop involving AMPK and CLYBL acetylation links metabolic rewiring and inflammatory responses

Metabolic rewiring underlies effective macrophages defense to respond disease microenvironment. However, the underlying mechanisms driving metabolic rewiring to enhance macrophage effector functions remain unclear. Here, we demonstrated that the metabolic reprogramming in inflammatory macrophages depended on the acetylation of CLYBL, a citramalyl-CoA lyase, at lysine 154 (K154), and blocking CLYBL-K154 acetylation restricted the release of pro-inflammatory factors. Mechanistically, we found a crucial AMPK-CLYBL acetylation positive feedback loop, triggered by toll-like receptors (TLRs), involving AMPK hypophosphorylation and CLYBL hyperacetylation. The deacetylase enzyme SIRT2 acted as the bridge between AMPK phosphorylation and CLYBL acetylation, thereby regulating macrophage polarization and the release of pro-inflammatory cytokines. Furthermore, CLYBL hypoacetylation decreased monocyte infiltration, thereby alleviating cardiac remodeling. These findings suggest that the AMPK-CLYBL acetylation positive feedback loop serves as a metabolic switch driving inflammatory response and inhibiting CLYBL-K154 acetylation may offer a promising therapeutic strategy for inflammatory response-related disorders.

The neurorepellent SLIT2 inhibits LPS-induced proinflammatory signaling in macrophages

Macrophages are important mediators of immune responses with critical roles in the recognition and clearance of pathogens, as well as in the resolution of inflammation and wound healing. The neuronal guidance cue SLIT2 has been widely studied for its effects on immune cell functions, most notably directional cell migration. Recently, SLIT2 has been shown to directly enhance bacterial killing by macrophages, but the effects of SLIT2 on inflammatory activation of macrophages are less known. Using RNA sequencing analysis, quantitative polymerase chain reaction, and enzyme-linked immunosorbent assay, we determined that in murine bone marrow-derived macrophages challenged with the potent proinflammatory mediator lipopolysaccharide (LPS), exposure to the bioactive N-terminal fragment of SLIT2 (NSLIT2) suppressed production of proinflammatory cytokines interleukin (IL)-6 and IL-12 and concurrently increased the anti-inflammatory cytokine IL-10. We found that NSLIT2 inhibited LPS-induced MyD88- and TRIF-mediated signaling cascades and did not inhibit LPS-induced internalization of Toll-like receptor 4 (TLR4), but instead inhibited LPS-induced upregulation of macropinocytosis. Inhibition of macropinocytosis in macrophages attenuated LPS-induced production of proinflammatory IL-6 and IL-12 and concurrently enhanced anti-inflammatory IL-10. Taken together, our results indicate that SLIT2 can selectively modulate macrophage response to potent proinflammatory stimuli, such as LPS, by attenuating proinflammatory activation and simultaneously enhancing anti-inflammatory activity. Our results highlight the role of macropinocytosis in proinflammatory activation of macrophages exposed to LPS. Given that LPS-producing bacteria cause host illness through synergistic direct bacterial infection and excessive LPS-induced systemic inflammation, our work suggests a novel therapeutic role for SLIT2 in combatting the significant morbidity and mortality of patients with Gram-negative bacterial sepsis.

Development of immunocompetent full thickness skin tissue constructs to model skin fibrosis for high-throughput drug screening

The lack of the immune component in most of the engineered skin models remains a challenge to study the interplay between different immune and non-immune cell types of the skin. Immunocompetent humanin vitroskin models offer potential advantages in recapitulatingin vivolike behavior which can serve to accelerate translational research and therapeutics development for skin diseases. Here we describe a three-dimensional human full-thickness skin (FTS) equivalent incorporating polarized M1 and M2 macrophages from human peripheral CD14+monocytes. This macrophage-incorporated FTS model demonstrates discernible immune responses with physiologically relevant cytokine production and macrophage plasticity under homeostatic and lipopolysaccharide stimulation conditions. M2-incorporated FTS recapitulates skin fibrosis phenotypes with transforming growth factor-β1 treatment as reflected by significant collagen deposition and myofibroblast expression, demonstrating a M2 potentiation effect. In conclusion, we successfully biofabricated an immunocompetent FTS with functional macrophages in a high-throughput (HT) amenable format. This model is the first step towards a HT-assay platform to develop new therapeutics for skin diseases.

Mast Cells as a Component of Spermatogonial Stem Cells' Microenvironment

The formation of mature spermatozoa originates from spermatogonial stem cells (SSCs) located near the basement membrane of the seminiferous tubules. This developmental process, known as spermatogenesis, is tightly regulated to ensure continuous sperm production. A critical aspect of this regulation is the balance between SSC differentiation and self-renewal, which is directed by various factors guiding SSCs in either of these two directions. The SSC niche, defined functionally rather than anatomically, includes all factors necessary for SSC maintenance. These factors are produced by cells surrounding the SSC niche, collectively creating the microenvironment of the seminiferous tubules. Coordination between the cells in this microenvironment is essential for the proper function of the SSC niche and successful spermatogenesis. Testicular mast cells (MCs) significantly influence the regulation of this niche, as they contain various biologically active substances that regulate a wide range of physiological processes and contribute to different pathological conditions affecting fertility. This review explores the effects of testicular MCs on SSCs, their role in regulating spermatogenesis under normal and pathological conditions, and their interactions with other components of the testicular microenvironment, with a focus on their potentially critical impact on spermatogenesis and male fertility.

Anti-Inflammatory Effects of Apostichopus japonicus Extract in Porphyromonas gingivalis-Stimulated RAW 264.7 Cells

Apostichopus japonicus has been used both as a food and in traditional medicine. However, its anti-inflammatory effects in periodontal diseases have not been studied. We examined the anti-inflammatory properties of Apostichopus japonicus extract in RAW 264.7 cells stimulated by Porphyromonas gingivalis. The cytotoxicity of Apostichopus japonicus extract was evaluated using the MTS assay. Its effect on NO production was then measured using the NO assay. The mRNA expression of inducible nitric oxide synthase (iNOS) and the pro-inflammatory cytokines IL-1β and IL-6 were assessed using quantitative real-time PCR (qRT-PCR). Western blotting was performed to investigate the expression of regulatory proteins involved in the NF-κB and MAPK signaling pathways. Apostichopus japonicus extract significantly inhibited NO production without cytotoxicity in RAW 264.7 cells. Following Porphyromonas gingivalis stimulation, treatment with the extract decreased iNOS mRNA expression and protein levels, which are responsible for NO production. The extract also suppressed the mRNA expression of pro-inflammatory cytokines. Additionally, Apostichopus japonicus extract inhibited NF-κB activation by regulating signaling molecules such as IKK and IκBα, while also preventing the phosphorylation of MAPK, including ERK, p38, and JNK, showing anti-inflammatory potential. Therefore, it may be a promising natural candidate for the development of new preventive and therapeutic strategies for periodontitis.

Unraveling the complex interplay of sex, endocrinology, and inflammation in post-Injury articular cartilage breakdown through in silico modeling

The onset of degenerative joint diseases such as post-traumatic osteoarthritis (PTOA) are associated with joint injury, biomechanical changes, and synovial biochemical anomalies. Sex and reproductive endocrinology have been emerging as potential risk factors, with epidemiological evidence revealing that female's exhibit higher PTOA risk and poorer outcomes post-injury compared to males. Sex hormones, including estradiol, progesterone, and testosterone, have been shown to regulate inflammatory signaling in immune and synovial cells, yet their collective impact on injury-induced joint inflammation and catabolism is poorly understood. Using an in silico kinetic model, we investigated the effects of sex-specific endocrine states on post-injury mechanisms in the human synovial joint. Our model results reveal that heightened estradiol levels in pre-menopausal females during the peri-ovulatory phase increase interleukin (IL)-1β expression and suppress IL-10 expression within the synovium after a simulated injury. Conversely, elevated testosterone levels in males decrease post-injury IL-1β, tumor necrosis factor alpha (TNF)-α, and stromelysin (MMP)-3 expression while increasing IL-10 production compared to females. Gaining insight into the effects of sex hormones on injury-induced inflammation and cartilage degradation provides a basis for designing future experimental and clinical studies to explore their effects on the synovial system, with a particular focus on the female sex.

In silico assessment of CAR macrophages activity against SARS-CoV-2 infection

Macrophage engineering with chimeric antigen receptor is a promising technique first applied to the treatment of tumours and recently suggested as a possible immunotherapeutic route against the COVID-19 disease. Four immunotherapies based on engineered macrophages have been tested in vitro revealing promising, with one of them acting without increasing the cytokines level. We present a mathematical model aimed at the evaluation of both the SARS-CoV-2 virions dynamics and the cytokines production induced, while such newly developed constructs interact with the immune system once administered. The importance of the study lies both in monitoring the dynamics of the infection and in evaluating the cytokine production, since clinical studies show that in critical COVID-19 patients an abnormal cytokines production occurs, a concern to be accounted for in designing appropriate therapeutic strategies. The mathematical model was built in the context of the continuum approach of the mass conservation, while the numerical simulations have been performed introducing parameters deduced from the experiments, using the finite element method. The model simulations allow to analyse and to compare the immune mechanisms underlying the virus dynamics, deepening the investigation for two selected immunotherapies, suggesting that a synergistic work of involved cytokines with phagocytic activity of macrophages occurs. The best SARS-CoV-2 clearance relies not only on the phagocytic capacity of the engineered macrophages, but also on the production of T-lymphocytes, pro- and anti-inflammatory cytokines which in the two cases examined in depth can decrease by 99.7 %, 99.6 % and 69 % respectively, passing from the most effective immunotherapy to the least effective one. This study is the first mathematical model that analyses the dynamics of macrophages engineered to fight the COVID-19, and paves the way for their possible exploitation against such a challenging disease, going beyond existing models involving other immune cells.

An overview of the functions and mechanisms of APOBEC3A in tumorigenesis

The APOBEC3 (A3) family plays a pivotal role in the immune system by performing DNA/RNA single-strand deamination. Cancers mostly arise from the accumulation of chronic mutations in somatic cells, and recent research has highlighted the A3 family as a major contributor to tumor-associated mutations, with A3A being a key driver gene leading to cancer-related mutations. A3A helps to defend the host against virus-induced tumors by editing the genome of cancer-associated viruses that invade the host. However, when it is abnormally expressed, it leads to persistent, chronic mutations in the genome, thereby fueling tumorigenesis. Notably, A3A is prominently expressed in innate immune cells, particularly macrophages, thereby affecting the functional state of tumor-infiltrating immune cells and tumor growth. Furthermore, the expression of A3A in tumor cells may directly affect their proliferation and migration. A growing body of research has unveiled that A3A is closely related to various cancers, which signifies the potential significance of A3A in cancer therapy. This paper mainly classifies and summarizes the evidence of the relationship between A3A and tumorigenesis based on the potential mechanisms, aiming to provide valuable references for further research on the functions of A3A and its development in the area of cancer therapy.

Co-delivery of Interferon Regulatory Factor 5 (IRF5) siRNA and dasatinib by a disulfide bond bearing polymeric carrier for enhanced anti-inflammatory effects

Co-delivery of chemical drugs and nucleic acids has attracted a great interest recently for treatment of inflammatory diseases. Dasatinib (DB), a tyrosine kinase inhibitor with anti-cancer effects, and Interferon Regulatory Factor 5 (IRF5) siRNA have shown anti-inflammatory effects. In the present study, a novel redox-responsive polymeric micelle was designed for co-delivery of DB and IRF5 siRNA-expressing plasmid (psiRF5) to enhance anti-inflammatory effects on macrophages. psiRF5 was condensed efficiently to redox-responsive micelles of DB-conjugated chitosan (CN) composed of disulfide bond, from different molecular weights of CN to form CN-SS-DB/psiRF5 micelles. The micelles with optimum N/P ratios had particle sizes of 287.8 and 245.4 nm and positive zeta potentials. The disulfide bond bearing micelles showed a redox-responsive drug release, protected the plasmid from being dissociated or degraded in exposure with heparin, serum and DNase I, and significantly enhanced the transfection efficiency and IRF5-gene silencing compared to naked psiRF5. The optimum micelles exhibited a dramatic reduction in IRF5 expression and revealed a notably higher anti-inflammatory effect than either DB or psiRF5, as indicated by more IL-10 and less IL-6 and TNF-α production by LPS-stimulated RAW264.7 macrophages incubated with the co-delivery system. The resultant nanocarriers might be promising for more effective treatment of inflammatory diseases.

Biosynthetic enzyme analysis identifies a protective role for TLR4-acting gut microbial sulfonolipids in inflammatory bowel disease

The trillions of microorganisms inhabiting the human gut are intricately linked to human health. While specific microbes have been associated with diseases, microbial abundance alone cannot reveal the molecular mechanisms involved. One such important mechanism is the biosynthesis of functional metabolites. Here, we develop a biosynthetic enzyme-guided disease correlation approach to uncover microbial functional metabolites linked to disease. Applying this approach, we negatively correlate the expression of gut microbial sulfonolipid (SoL) biosynthetic enzymes to inflammatory bowel disease (IBD). Targeted chemoinformatics and metabolomics then confirm that SoL abundance is significantly decreased in IBD patient data and samples. In a mouse model of IBD, we further validate that SoL abundance is decreased while inflammation is increased in diseased mice. We show that SoLs consistently contribute to the immunoregulatory activity of different SoL-producing human microbes. We further reveal that sulfobacins A and B, representative SoLs, act on Toll-like receptor 4 (TLR4) and block lipopolysaccharide (LPS) binding, suppressing both LPS-induced inflammation and macrophage M1 polarization. Together, these results suggest that SoLs mediate a protective effect against IBD through TLR4 signaling and showcase a widely applicable biosynthetic enzyme-guided disease correlation approach to directly link the biosynthesis of gut microbial functional metabolites to human health.

Targeting Inflammatory Lesions Facilitated by Galactosylation Modified Delivery System Eudragit/Gal-PLGA@Honokiol for the treatment of Ulcerative Colitis

Honokiol (HNK) is one of the bioactive ingredients from the well-known Chinese herbal medicine Magnolia officinalis, and its research interests is rising for its extensive pharmacological activities, including novel therapeutic effect on ulcerative colitis (UC). However, further application of HNK is largely limited by its unique physicochemical properties, such as poor water solubility, low bioavailability, as well as unsatisfied targeting efficacy for inflammatory lesions. In this study, we constructed galactosylation modified PLGA nanoparticles delivery system for efficient target delivery of HNK to the colitic lesions, which could lay a research foundation for the deep development of HNK for the treatment of UC. D-galactose was grafted by chemical coupling reactions with PLGA to prepare Gal-PLGA, which was used as a carrier for HNK (Gal-PLGA@HNK nanoparticles (NPs)). To improve the colon targeting efficiency by oral administration of the NPs, Eudragit S100 was used for wrapping on the surface of Gal-PLGA@HNK NPs (E/Gal-PLGA@HNK NPs). Our results showed that the encapsulation efficiency and drug loading capacity of E/Gal-PLGA@HNK NPs were 90.72 ± 0.54% and 8.41 ± 0.02%, respectively. Its average particle size was 242.24 ± 8.42 nm, with a PDI value of 0.135 ± 0.06 and zeta-potential of -16.83 ± 1.89 mV. The release rate of HNK from E/Gal-PLGA@HNK NPs was significantly decreased when compared with that of free HNK in simulated gastric and intestinal fluids, which displayed a slow-releasing property. It was also found that the cellular uptake of E/Gal-PLGA@HNK NPs was significantly increased when compared with that of free HNK in RAW264.7 cells, which was facilitated by D-galactose grafting on the PLGA carrier. Additionally, our results showed that E/Gal-PLGA@HNK NPs significantly improved colonic atrophy, body weight loss, as well as reducing disease activity index (DAI) score and pro-inflammatory cytokine levels in UC mice induced by DSS. Besides, the retention time of E/Gal-PLGA@HNK NPs in the colon was significantly increased when compared with that of other preparations, suggesting that these NPs could prolong the interaction between HNK and the injured colon. Taken together, the efficiency for target delivery of HNK to the inflammatory lesions was significantly improved by galactosylation modification on the PLGA carrier, which provided great benefits for the alleviation of colonic inflammation and injury in mice.

Multiple site inflammation and acute kidney injury in crush syndrome

Crush syndrome, which frequently occurs in earthquake disasters, often leads to rhabdomyolysis induced acute kidney injury (RIAKI). Recent findings indicate that systemic inflammatory response syndrome (SIRS) exacerbates muscle collapse, contributing to RIAKI. The purpose of this study is to investigate the involvement of multiple site inflammation, including intraperitoneal, in crush syndrome. In a mouse model of RIAKI, elevated levels of inflammatory mediators such as TNFα, IL-6, myoglobin, and dsDNA were observed in serum and the peritoneal cavity, peaking earlier in the intraperitoneal cavity than in serum or urine. Our previously developed novel peptide inhibiting leukocyte extracellular traps was administered intraperitoneally and blocked all of these mediators in the intraperitoneal cavity and serum, ameliorating muscle damage and consequent RIAKI. Although further studies are needed to determine whether intraperitoneal inflammation associated with muscle collapse can lead to systemic inflammation, resulting in more severe and prolonged muscle damage and renal injury, early suppression of multiple site inflammation, including intraperitoneal, might be an effective therapeutic target.

Reduction of Pro-Inflammatory Markers in RAW264.7 Macrophages by Polyethylenimines

The physiological problem of chronic inflammation and its associated pathologies attract ongoing attention with regard to methods for their control. Current systemic pharmacological treatments present problematic side effects. Thus, the possibility of new anti-inflammatory compounds with differing mechanisms of action or biophysical properties is enticing. Cationic polymers, with their ability to act as carriers for other molecules or to form bio-compatible materials, present one such possibility. Although not well described, several polycations such as chitosan and polyarginine, have displayed anti-inflammatory properties. The present work shows the ubiquitous laboratory transfection reagent, polyethylenimine (PEI) and more specifically low molecular weight branched PEI (B-PEI) as also possessing such properties. Using a RAW264.7 murine cell line macrophage as an inflammation model, it is found the B-PEI 700 Da as being capable of reducing the production of several pro-inflammatory molecules induced by the endotoxin lipopolysaccharide. Although further studies are required for elucidation of its mechanisms, the revelation that such a common lab reagent may present these effects has wide-ranging implications, as well as an abundance of possibilities.

Mesenchymal Stromal Cells: New Generation Treatment of Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a chronic inflammatory disease of the gastrointestinal tract, which has a high recurrence rate and is incurable due to a lack of effective treatment. Mesenchymal stromal cells (MSCs) are a class of pluripotent stem cells that have recently received a lot of attention due to their strong self-renewal ability and immunomodulatory effects, and a large number of experimental and clinical models have confirmed the positive therapeutic effect of MSCs on IBD. In preclinical studies, MSC treatment for IBD relies on MSCs paracrine effects, cell-to-cell contact, and its mediated mitochondrial transfer for immune regulation. It also plays a therapeutic role in restoring the intestinal mucosal barrier through the homing effect, regulation of the intestinal microbiome, and repair of intestinal epithelial cells. In the latest clinical trials, the safety and efficacy of MSCs in the treatment of IBD have been confirmed by transfusion of autologous or allogeneic bone marrow, umbilical cord, and adipose MSCs, as well as their derived extracellular vesicles. However, regarding the stable and effective clinical use of MSCs, several concerns emerge, including the cell sources, clinical management (dose, route and frequency of administration, and pretreatment of MSCs) and adverse reactions. This article comprehensively summarizes the effects and mechanisms of MSCs in the treatment of IBD and its advantages over conventional drugs, as well as the latest clinical trial progress of MSCs in the treatment of IBD. The current challenges and future directions are also discussed. This review would add knowledge into the understanding of IBD treatment by applying MSCs.

Monocytes and macrophages: Origin, homing, differentiation, and functionality during inflammation

Monocytes and macrophages are essential components of innate immune system and have versatile roles in homeostasis and immunity. These phenotypically distinguishable mononuclear phagocytes play distinct roles in different stages, contributing to the pathophysiology in various forms making them a potentially attractive therapeutic target in inflammatory conditions. Several pieces of evidence have supported the role of different cell surface receptors expressed on these cells and their downstream signaling molecules in initiating and perpetuating the inflammatory response. In this review, we discuss the current understanding of the monocyte and macrophage biology in inflammation, highlighting the role of chemoattractants, inflammasomes, and integrins in the function of monocytes and macrophages during events of inflammation. This review also covers the recent therapeutic interventions targeting these mononuclear phagocytes at the cellular and molecular levels.

The guardians of pulmonary harmony: alveolar macrophages orchestrating the symphony of lung inflammation and tissue homeostasis

Recent breakthroughs in single-cell sequencing, advancements in cellular and tissue imaging techniques, innovations in cell lineage tracing, and insights into the epigenome collectively illuminate the enigmatic landscape of alveolar macrophages in the lung under homeostasis and disease conditions. Our current knowledge reveals the cellular and functional diversity of alveolar macrophages within the respiratory system, emphasising their remarkable adaptability. By synthesising insights from classical cell and developmental biology studies, we provide a comprehensive perspective on alveolar macrophage functional plasticity. This includes an examination of their ontology-related features, their role in maintaining tissue homeostasis under steady-state conditions and the distinct contribution of bone marrow-derived macrophages (BMDMs) in promoting tissue regeneration and restoring respiratory system homeostasis in response to injuries. Elucidating the signalling pathways within inflammatory conditions, the impact of various triggers on tissue-resident alveolar macrophages (TR-AMs), as well as the recruitment and polarisation of macrophages originating from the bone marrow, presents an opportunity to propose innovative therapeutic approaches aimed at modulating the equilibrium between phenotypes to induce programmes associated with a pro-regenerative or homeostasis phenotype of BMDMs or TR-AMs. This, in turn, can lead to the amelioration of disease outcomes and the attenuation of detrimental inflammation. This review comprehensively addresses the pivotal role of macrophages in the orchestration of inflammation and resolution phases after lung injury, as well as ageing-related shifts and the influence of clonal haematopoiesis of indeterminate potential mutations on alveolar macrophages, exploring altered signalling pathways and transcriptional profiles, with implications for respiratory homeostasis.

L-AP Alleviates Liver Injury in Septic Mice by Inhibiting Macrophage Activation via Suppressing NF-κB and NLRP3 Inflammasome/Caspase-1 Signal Pathways

Liver injury and progressive liver failure are severe life-threatening complications in sepsis, further worsening the disease and leading to death. Macrophages and their mediated inflammatory cytokine storm are critical regulators in the occurrence and progression of liver injury in sepsis, for which effective treatments are still lacking. l-Ascorbic acid 6-palmitate (L-AP), a food additive, can inhibit neuroinflammation by modulating the phenotype of the microglia, but its pharmacological action in septic liver damage has not been fully explored. We aimed to investigate L-AP's antisepticemia action and the possible pharmacological mechanisms in attenuating septic liver damage by modulating macrophage function. We observed that L-AP treatment significantly increased survival in cecal ligation and puncture-induced WT mice and attenuated hepatic inflammatory injury, including the histopathology of the liver tissues, hepatocyte apoptosis, and the liver enzyme levels in plasma, which were comparable to NLRP3-deficiency in septic mice. L-AP supplementation significantly attenuated the excessive inflammatory response in hepatic tissues of septic mice in vivo and in cultured macrophages challenged by both LPS and ATP in vitro, by reducing the levels of NLRP3, pro-IL-1β, and pro-IL-18 mRNA expression, as well as the levels of proteins for p-I-κB-α, p-NF-κB-p65, NLRP3, cleaved-caspase-1, IL-1β, and IL-18. Additionally, it impaired the inflammasome ASC spot activation and reduced the inflammatory factor contents, including IL-1β and IL-18 in plasma/cultured superannuants. It also prevented the infiltration/migration of macrophages and their M1-like inflammatory polarization while improving their M2-like polarization. Overall, our findings revealed that L-AP protected against sepsis by reducing macrophage activation and inflammatory cytokine production by suppressing their activation in NF-κB and NLRP3 inflammasome signal pathways in septic liver.

Enzyme-treated red rice (Oryza sativa L.) bran extracts mitigate inflammatory markers in RAW 264.7 macrophage cells and exhibit anti-inflammatory efficacy greater/comparable to ferulic acid, catechin, γ-tocopherol, and γ-oryzanol

ETHNOPHARMACOLOGICAL RELEVANCE

Rice (Oryza sativa L.), a staple food for a significant portion of the global population, has been recognized for its traditional medicinal properties for centuries. Rice bran, a by-product of rice milling, contains many bioactive compounds with potential pharmaceutical and therapeutic benefits. In recent years, research has highlighted the anti-inflammatory potential of rice bran, contributed by the bioactive components concentrated in their bran but, unfortunately, entrapped in the bran matrix, with limited bioavailability. Previous studies have reported that the enzymatic treatment of rice bran improves the bran's bioactive compound profile but did not investigate its impact on chronic conditions such as inflammation.

AIM OF THE STUDY

This study investigates the anti-inflammatory effects of endo-1,4-β-xylanase (ERB) and Viscozyme (VRB) treated red rice bran extracts against lipopolysaccharide-induced inflammation in RAW264.7 macrophages in comparison with non-enzyme-treated bran (CRB). Further established their efficacy with known anti-inflammatory compounds-ferulic acid (FA), catechin (CAT), γ-tocopherol (GTP), and γ-oryzanol (ORZ).

MATERIALS AND METHODS

The RAW 264.7 macrophage cells were pre-treated with non-toxic concentrations (10-200 μg/mL) of FA, CAT, GTP, ORZ, CRB, ERB, and VRB, followed by inflammatory stimulation with LPS for 24 h. Further, the cell supernatant and pellets were harvested to study the anti-inflammatory effects by evaluating and measuring their efficacy in inhibiting pro-inflammatory cytokines (TNF-α, IL-6, IL-10, IL-1β) and mediators (ROS, NO, PGE2, COX2, iNOS) through biochemical, ELISA, and mRNA expression studies.

RESULTS

The findings showed that both ERB and VRB effectively inhibited the production of pro-inflammatory markers (TNF-α, IL-6) and mediators (ROS, NO, PGE2) by downregulating mRNA expressions of inflammatory genes (TNF-α, IL-1β, IL-6, IL-10, COX2, iNOS) and demonstrated anti-inflammatory efficacy higher than CRB. On comparison, ERB demonstrated exceptional efficacy by causing a reduction of 48% in ROS, 20% in TNF-α, and 23% in PGE2 at 10 μg/mL, surpassing the anti-inflammatory capabilities of all the bioactive compounds, FA and ORZ, respectively. At the same time, VRB exhibited remarkable efficacy by reducing NO production by 52% at 200 μg/mL and IL-6 by 66% at 10 μg/mL, surpassing FA, CAT, ORZ, and GTP. Further, ERB downregulated the mRNA expression of IL-10 and iNOS, while VRB downregulated TNF-α, IL-1β, and COX2 expression. Both extracts equally downregulated IL-6 expression at 10 μg/mL, demonstrating the efficacy more remarkable/on par with established anti-inflammatory compounds.

CONCLUSIONS

Overall, enzyme-treated rice bran/extract, particularly ERB, possesses excellent anti-inflammatory properties, making them promising agents for alternatives to contemporary nutraceuticals/functional food against inflammatory diseases.

Potential Targets and Signaling Mechanisms of Cinnamaldehyde Enhancing Intestinal Function and Nutritional Regulation in Fat Greenling (Hexagrammos otakii)

Cinnamaldehyde is an ideal feed additive with good immune enhancement and anti-inflammatory regulation effects. However, the anti-inflammatory regulation mechanism in fat greenling (Hexagrammos otakii, H. otakii) remains unclear. The nine targets of cinnamaldehyde were gathered in identified by the Traditional Chinese Medicine Systems Pharmacology database and Uniprot database, and 1,320 intestinal inflammation disease (IIF)-related proteins were screened from DrugBank, Online Mendelian Inheritance in Man (OMIM), Genecards, and Pharmacogenetics and Pharmacogenomics Knowledge Base (PHARMGKB) Databases. According to the Gene Ontology enrichment results and Kyoto Encyclopedia of Genes and Genomes pathway results, cinnamaldehyde may regulated the responses to bacteria, lipopolysaccharide, an inflammatory cytokine, and external stimuli via the nuclear factor kappa-B (NFκB) signaling pathway within on inflammatory network. In addition, the protein-protein interaction analysis assisted in obtaining the closely related inflammatory regulatory proteins, including the C5a anaphylatoxin chemotactic receptor 1 (C5aR1), transcription factor p65 (RELA), prostaglandin G/H synthase 2 (PTGS2), and toll-like receptor 4 (TLR4), which were confirmed as the bottleneck nodes of the network to be more deeply verified via the molecular docking. Moreover, a cinnamaldehyde feeding model was established for evaluating the anti-inflammatory effect of cinnamaldehyde in vivo. According to the current findings implied that cinnamaldehyde may play a protective role against IIF H. otakii by reducing inflammation through the C5 complement (C5)/C5aR1/interleukin-6 (IL-6) and TLR4/NFκB/PTGS2 pathway. The study focused on investigating the action mechanism of cinnamaldehyde on IIF through combining pharmacology and experimental verification in vivo, which provided a fresh perspective on the promoting effect of cinnamaldehyde on IIF in fish.

Ferulic Acid Derivatives Ameliorate Intestine Barrier Destruction by Alleviating Inflammatory Responses in Dextran Sulfate Sodium-Induced Inflammatory Bowel Disease

Inflammatory bowel disease (IBD), a chronic disorder affecting the colon and rectum, involves the overproduction of pro-inflammatory cytokines causing damage to tight junctions (TJ) in the intestinal epithelial cells and chronic inflammation. The current mainstay of treatment, sulfasalazine, often causes adverse effects, thereby necessitating the exploration of alternative herbal medicines with fewer side effects. Portulaca oleracea L. (P. oleracea), a traditional medicinal herb, contains feruloyl amide compounds. We synthesized new compounds by conjugating ferulic acid (FA) with (±)-octopamine. Our study focused on novel FA derivatives that demonstrate protective effects against the intestinal epithelial barrier and inflammatory responses. In lipopolysaccharide-induced cells, C1 and C1a inhibited the production of inflammatory mediators. In Caco-2 cells, these compounds maintained the TJ protein expression, thereby demonstrating their protective effects on the epithelial barrier. In a mouse model of dextran sulfate sodium-induced IBD, a treatment with these compounds ameliorated features including a body weight reduction, colon shortening, an increased disease activity index, and histopathological changes. Furthermore, C1a demonstrated greater efficacy than C1 at the same concentration. These findings suggest that the novel FA derivative (C1a) effectively alleviates clinical signs and inflammatory mediators in IBD, making these compounds potential candidates as natural medicines for the treatment of IBD.

Extracellular vesicles from Candida albicans modulate immune cells function and play a protective role in fungal keratitis

Fungal keratitis (FK) is a highly blinding infectious corneal disease caused by pathogenic fungi. Candida albicans (C. albicans) is one of the main pathogens of fungal keratitis. Extracellular vesicles (EVs), lipid bilayer compartments released by almost all living cells, including fungi, have garnered attention for their role in pathogenic microbial infection and host immune responses in recent years. Studies have reported that pretreating the host with fungal EVs can reduce the inflammatory response of the host when attacked by fungi and reduce the lethality of fungal infection. However, there are no studies that have evaluated whether C. albicans EVs can modulate the inflammatory response associated with C. albicans keratitis. Our study revealed that C. albicans EVs could activate the polymorphonuclear cells (PMNs) and promote their secretion of proinflammatory cytokines and nitric oxide (NO), enhance their phagocytic and fungicidal abilities against C. albicans. C. albicans EVs also induced a proinflammatory response in RAW264.7 cells, which was characterized by increased production of inflammatory cytokines and elevated expression of the chemokine CCL2. Similarly, stimulation of C. albicans EVs to RAW264.7 cells also enhanced the phagocytosis and killing ability of cells against C. albicans. Besides, in our in vivo experiments, after receiving subconjunctival injection of C. albicans EVs, C57BL/6 mice were infected with C. albicans. The results demonstrated that pre-exposure to C. albicans EVs could effectively diminish the severity of keratitis, reduce fungal load and improve prognosis. Overall, we conclude that C. albicans EVs can modulate the function of immune cells and play a protective role in C. albicans keratitis.

Immune Evasion in Cancer Is Regulated by Tumor-Asociated Macrophages (TAMs): Targeting TAMs

Recent advancements in cancer treatment have explored a variety of approaches to address the needs of patients. Recently, immunotherapy has evolved as an efficacious treatment for various cancers resistant to conventional therapies. Hence, significant milestones in immunotherapy were achieved clinically in a large subset of cancer patients. Unfortunately, some cancer types do not respond to treatment, and among the responsive cancers, some patients remain unresponsive to treatment. Consequently, there is a critical need to examine the mechanisms of immune resistance and devise strategies to target immune suppressor cells or factors, thereby allowing for tumor sensitivity to immune cytotoxic cells. M2 macrophages, also known as tumor-associated macrophages (TAMs), are of interest due to their role in suppressing the immune system and influencing antitumor immune responses through modulating T cell activity and immune checkpoint expression. TAMs are associated with signaling pathways that modulate the tumor microenvironment (TME), contributing to immune evasion. One approach targets TAMs, focusing on preventing the polarization of M1 macrophages into the protumoral M2 phenotype. Other strategies focus on direct or indirect targeting of M2 macrophages through understanding the interaction of TAMs with immune factors or signaling pathways. Clinically, biomarkers associated with TAMs' immune resistance in cancer patients have been identified, opening avenues for intervention using pharmacological agents or immunotherapeutic approaches. Ultimately, these multifaceted approaches are promising in overcoming immune resistance and improving cancer treatment outcomes.

Multifunctional and theranostic hydrogels for wound healing acceleration: An emphasis on diabetic-related chronic wounds

Hydrogels represent intricate three-dimensional polymeric structures, renowned for their compatibility with living systems and their ability to naturally degrade. These networks stand as promising and viable foundations for a range of biomedical uses. The practical feasibility of employing hydrogels in clinical trials has been well-demonstrated. Among the prevalent biomedical uses of hydrogels, a significant application arises in the context of wound healing. This intricate progression involves distinct phases of inflammation, proliferation, and remodeling, often triggered by trauma, skin injuries, and various diseases. Metabolic conditions like diabetes have the potential to give rise to persistent wounds, leading to delayed healing processes. This current review consolidates a collection of experiments focused on the utilization of hydrogels to expedite the recovery of wounds. Hydrogels have the capacity to improve the inflammatory conditions at the wound site, and they achieve this by diminishing levels of reactive oxygen species (ROS), thereby exhibiting antioxidant effects. Hydrogels have the potential to enhance the growth of fibroblasts and keratinocytes at the wound site. They also possess the capability to inhibit both Gram-positive and Gram-negative bacteria, effectively managing wounds infected by drug-resistant bacteria. Hydrogels can trigger angiogenesis and neovascularization processes, while also promoting the M2 polarization of macrophages, which in turn mitigates inflammation at the wound site. Intelligent and versatile hydrogels, encompassing features such as pH sensitivity, reactivity to reactive oxygen species (ROS), and responsiveness to light and temperature, have proven advantageous in expediting wound healing. Furthermore, hydrogels synthesized using environmentally friendly methods, characterized by high levels of biocompatibility and biodegradability, hold the potential for enhancing the wound healing process. Hydrogels can facilitate the controlled discharge of bioactive substances. More recently, there has been progress in the creation of conductive hydrogels, which, when subjected to electrical stimulation, contribute to the enhancement of wound healing. Diabetes mellitus, a metabolic disorder, leads to a slowdown in the wound healing process, often resulting in the formation of persistent wounds. Hydrogels have the capability to expedite the healing of diabetic wounds, facilitating the transition from the inflammatory phase to the proliferative stage. The current review sheds light on the biological functionalities of hydrogels, encompassing their role in modulating diverse mechanisms and cell types, including inflammation, oxidative stress, macrophages, and bacteriology. Additionally, this review emphasizes the significance of smart hydrogels with responsiveness to external stimuli, as well as conductive hydrogels for promoting wound healing. Lastly, the discussion delves into the advancement of environmentally friendly hydrogels with high biocompatibility, aimed at accelerating the wound healing process.

Advancing CAR-based immunotherapies in solid tumors: CAR- macrophages and neutrophils

Macrophages and neutrophils are the main components of the innate immune system and play important roles in promoting angiogenesis, extracellular matrix remodeling, cancer cell proliferation, and metastasis in the tumor microenvironment (TME). They can also be harnessed to mediate cytotoxic tumor killing effects and orchestrate effective anti-tumor immune responses with proper stimulation and modification. Therefore, macrophages and neutrophils have strong potential in cancer immunotherapy. In this review, we briefly outlined the applications of macrophages or neutrophils in adoptive cell therapies, and focused on chimeric antigen receptor (CAR)-engineered macrophages (CAR-Ms) and neutrophils (CAR-Ns). We summarized the construction strategies, the preclinical and clinical studies of CAR-Ms and CAR-Ns. In the end, we briefly discussed the limitations and challenges of CAR-Ms and CAR-Ns, as well as future research directions to extend their applications in treating solid tumors.

Biomimetic Systems Involving Macrophages and Their Potential for Targeted Drug Delivery

The concept of targeted drug delivery can be described in terms of the drug systems' ability to mimic the biological objects' property to localize to target cells or tissues. For example, drug delivery systems based on red blood cells or mimicking some of their useful features, such as long circulation in stealth mode, have been known for decades. On the contrary, therapeutic strategies based on macrophages have gained very limited attention until recently. Here, we review two biomimetic strategies associated with macrophages that can be used to develop new therapeutic modalities: first, the mimicry of certain types of macrophages (i.e., the use of macrophages, including tumor-associated or macrophage-derived particles as a carrier for the targeted delivery of therapeutic agents); second, the mimicry of ligands, naturally absorbed by macrophages (i.e., the use of therapeutic agents specifically targeted at macrophages). We discuss the potential applications of biomimetic systems involving macrophages for new advancements in the treatment of infections, inflammatory diseases, and cancer.

The role of type II esophageal microbiota in achalasia: Activation of macrophages and degeneration of myenteric neurons

OBJECTIVE

The gut microbiota plays a critical role in the appropriate development and maintenance of the enteric nervous system (ENS). Esophageal achalasia (EA) is a rare motility disorder characterized by the selective degeneration of inhibitory neurons in the esophageal myenteric plexus. This study aimed to evaluate the composition of the esophageal microbiota in achalasia and explore the potential microbial mechanisms involved in its pathogenesis.

DESIGN

The lower esophageal mucosal microbiota was analyzed in patients with achalasia and control participants using 16 S rRNA sequencing. The association between the esophageal microbiota and achalasia was validated by inducing esophageal dysbiosis in C57BL/10 J and C57BL/10ScNJ (TLR4KO) mice via chronic exposure to ampicillin sodium in their drinking water.

RESULTS

The esophageal microbiota in EA patients had lower diversity and a predominance of Gram-negative bacteria (Type II microbiota) compared to that in the healthy controls. Additionally, the relative abundance of Rhodobacter decreased significantly in patients with achalasia, which correlated with an enrichment of lipopolysaccharide (LPS) biosynthesis based on the COG database. Antibiotic-treated mice showed an esophageal microbiota characterized by increased abundance of Gram-negative bacteria (Type II microbiome), decreased abundance of Rhodobacter, and enriched LPS biosynthesis. Compared to the control and TLR4KO mice, the antibiotic-treated wild-type mice had higher LES resting pressure, increased LES contraction rate after carbachol stimulation, and decreased relaxation response to L-arginine. Moreover, the number of myenteric neurons decreased, while the number of lamina propria macrophages (LpMs) increased after antibiotic exposure. Furthermore, the TLR4-MYD88-NF-κB pathway was up-regulated, and the production of TNF-α, IL-1β, and IL-6 increased in the antibiotic-treated mice.

CONCLUSIONS

Patients with achalasia exhibit esophageal dysbiosis, which may induce aberrant esophageal motility.

PSGL-1 Blockade Induces Classical Activation of Human Tumor-associated Macrophages

The immune suppressive microenvironment is a major culprit for difficult-to-treat solid cancers. Particularly, inhibitory tumor-associated macrophages (TAM) define the resistant nature of the tumor milieu. To define tumor-enabling mechanisms of TAMs, we analyzed molecular clinical datasets correlating cell surface receptors with the TAM infiltrate. Though P-selectin glycoprotein ligand-1 (PSGL-1) is found on other immune cells and functions as an adhesion molecule, PSGL-1 is highly expressed on TAMs across multiple tumor types. siRNA-mediated knockdown and antibody-mediated inhibition revealed a role for PSGL-1 in maintaining an immune suppressed macrophage state. PSGL-1 knockdown or inhibition enhanced proinflammatory mediator release across assays and donors in vitro. In several syngeneic mouse models, PSGL-1 blockade alone and in combination with PD-1 blockade reduced tumor growth. Using a humanized tumor model, we observed the proinflammatory TAM switch following treatment with an anti-PSGL-1 antibody. In ex vivo patient-derived tumor cultures, a PSGL-1 blocking antibody increased expression of macrophage-derived proinflammatory cytokines, as well as IFNγ, indicative of T-cell activation. Our data demonstrate that PSGL-1 blockade reprograms TAMs, offering a new therapeutic avenue to patients not responding to T-cell immunotherapies, as well as patients with tumors devoid of T cells.

SIGNIFICANCE

This work is a significant and actionable advance, as it offers a novel approach to treating patients with cancer who do not respond to T-cell checkpoint inhibitors, as well as to patients with tumors lacking T-cell infiltration. We expect that this mechanism will be applicable in multiple indications characterized by infiltration of TAMs.

Differential gene expression of immunity and inflammation genes in colorectal cancer using targeted RNA sequencing

Introduction

Colorectal cancer (CRC) is a heterogeneous disease caused by molecular changes, as driver mutations, gene methylations, etc., and influenced by tumor microenvironment (TME) pervaded with immune cells with both pro- and anti-tumor effects. The studying of interactions between the immune system (IS) and the TME is important for developing effective immunotherapeutic strategies for CRC. In our study, we focused on the analysis of expression profiles of inflammatory and immune-relevant genes to identify aberrant signaling pathways included in carcinogenesis, metastatic potential of tumors, and association of Kirsten rat sarcoma virus (KRAS) gene mutation.

Methods

A total of 91 patients were enrolled in the study. Using NGS, differential gene expression analysis of 11 tumor samples and 11 matching non-tumor controls was carried out by applying a targeted RNA panel for inflammation and immunity genes containing 475 target genes. The obtained data were evaluated by the CLC Genomics Workbench and R library. The significantly differentially expressed genes (DEGs) were analyzed in Reactome GSA software, and some selected DEGs were used for real-time PCR validation.

Results

After prioritization, the most significant differences in gene expression were shown by the genes TNFRSF4, IRF7, IL6R, NR3CI, EIF2AK2, MIF, CCL5, TNFSF10, CCL20, CXCL11, RIPK2, and BLNK. Validation analyses on 91 samples showed a correlation between RNA-seq data and qPCR for TNFSF10, RIPK2, and BLNK gene expression. The top differently regulated signaling pathways between the studied groups (cancer vs. control, metastatic vs. primary CRC and KRAS positive and negative CRC) belong to immune system, signal transduction, disease, gene expression, DNA repair, and programmed cell death.

Conclusion

Analyzed data suggest the changes at more levels of CRC carcinogenesis, including surface receptors of epithelial or immune cells, its signal transduction pathways, programmed cell death modifications, alterations in DNA repair machinery, and cell cycle control leading to uncontrolled proliferation. This study indicates only basic molecular pathways that enabled the formation of metastatic cancer stem cells and may contribute to clarifying the function of the IS in the TME of CRC. A precise identification of signaling pathways responsible for CRC may help in the selection of personalized pharmacological treatment.

Immune microenvironment of cervical cancer and the role of IL-2 in tumor promotion

The tumor microenvironment (TME) is a heterogeneous mixture of resident and tumor cells that maintain close communication through their secretion products. The composition of the TME is dynamic and complex among the different types of cancer, where the immune cells play a relevant role in the elimination of tumor cells, however, under certain circumstances they contribute to tumor development. In cervical cancer (CC) the human papilloma virus (HPV) shapes the microenvironment in order to mediate persistent infections that favors transformation and tumor development. Interleukin-2 (IL-2) is an important TME cytokine that induces CD8+ effector T cells and NKs to eliminate tumor cells, however, IL-2 can also suppress the immune response through Treg cells. Recent studies have shown that CC cells express the IL-2 receptor (IL-2R), that are induced to proliferate at low concentrations of exogenous IL-2 through alterations in the JAK/STAT pathway. This review provides an overview of the main immune cells that make up the TME in CC, as well as the participation of IL-2 in the tumor promotion. Finally, it is proposed that the low density of IL-2 produced by immunocompetent cells is used by tumor cells through its IL-2R as a mechanism to proliferate simultaneously depleting this molecule in order to evade immune response.

New insights into intestinal macrophages in necrotizing enterocolitis: the multi-functional role and promising therapeutic application

Necrotizing enterocolitis (NEC) is an inflammatory intestinal disease that profoundly affects preterm infants. Currently, the pathogenesis of NEC remains controversial, resulting in limited treatment strategies. The preterm infants are thought to be susceptible to gut inflammatory disorders because of their immature immune system. In early life, intestinal macrophages (IMφs), crucial components of innate immunity, demonstrate functional plasticity and diversity in intestinal development, resistance to pathogens, maintenance of the intestinal barrier, and regulation of gut microbiota. When the stimulations of environmental, dietary, and bacterial factors interrupt the homeostatic processes of IMφs, they will lead to intestinal disease, such as NEC. This review focuses on the IMφs related pathogenesis in NEC, discusses the multi-functional roles and relevant molecular mechanisms of IMφs in preterm infants, and explores promising therapeutic application for NEC.

Macrophages in the Inflammatory Phase following Myocardial Infarction: Role of Exogenous Ubiquitin

Cardiovascular disease (CVD) is one of the leading causes of death worldwide. One of the most common implications of CVD is myocardial infarction (MI). Following MI, the repair of the infarcted heart occurs through three distinct, yet overlapping phases of inflammation, proliferation, and maturation. Macrophages are essential to the resolution of the inflammatory phase due to their role in phagocytosis and efferocytosis. However, excessive and long-term macrophage accumulation at the area of injury and dysregulated function can induce adverse cardiac remodeling post-MI. Ubiquitin (UB) is a highly evolutionarily conserved small protein and is a normal constituent of plasma. Levels of UB are increased in the plasma during a variety of pathological conditions, including ischemic heart disease. Treatment of mice with UB associates with decreased inflammatory response and improved heart function following ischemia/reperfusion injury. This review summarizes the role of macrophages in the infarct healing process of the heart post-MI, and discusses the role of exogenous UB in myocardial remodeling post-MI and in the modulation of macrophage phenotype and function.

Subversion of the Complement System by Pseudomonas aeruginosa

Pseudomonas aeruginosa is an opportunistic pathogen heavily implicated in chronic diseases. Immunocompromised patients that become infected with P. aeruginosa usually are afflicted with a lifelong chronic infection, leading to worsened patient outcomes. The complement system is an integral piece of the first line of defense against invading microorganisms. Gram-negative bacteria are thought to be generally susceptible to attack from complement; however, P. aeruginosa can be an exception, with certain strains being serum resistant. Various molecular mechanisms have been described that confer P. aeruginosa unique resistance to numerous aspects of the complement response. In this review, we summarize the current published literature regarding the interactions of P. aeruginosa and complement, as well as the mechanisms used by P. aeruginosa to exploit various complement deficiencies and the strategies used to disrupt or hijack normal complement activities.

Cellular heterogeneity and plasticity during NAFLD progression

Nonalcoholic fatty liver disease (NAFLD) is a progressive liver disease that can progress to nonalcoholic steatohepatitis (NASH), NASH-related cirrhosis, and hepatocellular carcinoma (HCC). NAFLD ranges from simple steatosis (or nonalcoholic fatty liver [NAFL]) to NASH as a progressive form of NAFL, which is characterized by steatosis, lobular inflammation, and hepatocellular ballooning with or without fibrosis. Because of the complex pathophysiological mechanism and the heterogeneity of NAFLD, including its wide spectrum of clinical and histological characteristics, no specific therapeutic drugs have been approved for NAFLD. The heterogeneity of NAFLD is closely associated with cellular plasticity, which describes the ability of cells to acquire new identities or change their phenotypes in response to environmental stimuli. The liver consists of parenchymal cells including hepatocytes and cholangiocytes and nonparenchymal cells including Kupffer cells, hepatic stellate cells, and endothelial cells, all of which have specialized functions. This heterogeneous cell population has cellular plasticity to adapt to environmental changes. During NAFLD progression, these cells can exert diverse and complex responses at multiple levels following exposure to a variety of stimuli, including fatty acids, inflammation, and oxidative stress. Therefore, this review provides insights into NAFLD heterogeneity by addressing the cellular plasticity and metabolic adaptation of hepatocytes, cholangiocytes, hepatic stellate cells, and Kupffer cells during NAFLD progression.

Investigating the link between miR-34a-5p and TLR6 signaling in sepsis-induced ARDS

Acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) are lung complications diagnosed by impaired gaseous exchanges leading to mortality. From the diverse etiologies, sepsis is a prominent contributor to ALI/ARDS. In the present study, we retrieved sepsis-induced ARDS mRNA expression profile and identified 883 differentially expressed genes (DEGs). Next, we established an ARDS-specific weighted gene co-expression network (WGCN) and picked the blue module as our hub module based on highly correlated network properties. Later we subjected all hub module DEGs to form an ARDS-specific 3-node feed-forward loop (FFL) whose highest-order subnetwork motif revealed one TF (STAT6), one miRNA (miR-34a-5p), and one mRNA (TLR6). Thereafter, we screened a natural product library and identified three lead molecules that showed promising binding affinity against TLR6. We then performed molecular dynamics simulations to evaluate the stability and binding free energy of the TLR6-lead molecule complexes. Our results suggest these lead molecules may be potential therapeutic candidates for treating sepsis-induced ALI/ARDS. In-silico studies on clinical datasets for sepsis-induced ARDS indicate a possible positive interaction between miR-34a and TLR6 and an antagonizing effect on STAT6 to promote inflammation. Also, the translational study on septic mice lungs by IHC staining reveals a hike in the expression of TLR6. We report here that miR-34a actively augments the effect of sepsis on lung epithelial cell apoptosis. This study suggests that miR-34a promotes TLR6 to heighten inflammation in sepsis-induced ALI/ARDS.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-023-03700-1.

Traditional Chinese medicine invigorating the spleen and kidney promotes HBsAg seroclearance in the mouse model

Traditional Chinese medicine (TCM) is often used as an adjuvant or alternative therapy for abnormal liver biochemistry or liver fibrosis associated with chronic hepatitis B (CHB). However, the role of TCM in HBsAg seroclearance remains unclear. We aimed at exploring the role and possible mechanisms of TCM in HBsAg seroclearance. Fifteen widely used TCM granules invigorating the spleen and kidneys were screened. C57BL/6J mice were administered daily with TCM granules by gavage for 1 week. The effect of TCM on the M1 polarization of macrophages was measured using a CD86 assay. According to the principles of formulating prescriptions, three single TCM with the most noticeable effect on M1 polarization, accompanied by two other TCM granules, were used to develop a TCM formula. The hepatitis B virus-expressing mouse model was constructed by hydrodynamic injection of the pAAV/HBV1.2 plasmid. Hepatitis B virus-expressing mice were gavaged daily with phosphate-buffered saline (PBS), TCM formula, or Codonopsis Radix, for 1 week. HBsAg, HBeAg, and hepatitis B virus DNA levels were measured. In addition, gut microbiota was profiled using 16S rDNA sequencing. Several TCM granules showed significant effects on M1 polarization. The TCM formula accelerated HBsAg seroclearance compared with the Codonopsis Radix and PBS groups. Intrahepatic M1 polarization, as indicated by flow cytometry and immunohistochemistry, was induced in the TCM formula and Codonopsis Radix groups. The abundance of Alloprevotella significantly increased in the TCM formula and Codonopsis Radix groups. These results demonstrate that the TCM formula for invigorating the spleen and kidney can accelerate HBsAg seroclearance. This effect can be attributed, at least in part, to M1 polarization of intrahepatic macrophages.

Macrophages Provide Essential Support for Erythropoiesis, and Extracellular ATP Contributes to a Erythropoiesis-Supportive Microenvironment during Repeated Psychological Stress

Psychological stress is a significant contributor to various chronic diseases and affects multiple physiological processes including erythropoiesis. This study aimed to examine the tissue-specific contributions of macrophages and extracellular ATP, as a signal of disturbed tissue homeostasis, to erythropoiesis under conditions of repeated psychological stress. Adult male BALB/c mice were subjected to 2 h daily restraint stress for seven consecutive days. Clodronate-liposomes were used to deplete resident macrophages from the bone marrow and spleen two days prior to the first restraint procedure, as well as newly recruited macrophages, every third day for the duration of the experiment. Repeated stress induced a considerable increase in the number of erythroid progenitor cells as well as in the percentage of CD71+/Ter119+ and CD71-/Ter119+ cells in the bone marrow and spleen. Macrophage depletion completely abolished the stimulative effect of repeated stress on immature erythroid cells, and prevented stress-induced increases in ATP levels, P2X7 receptor (P2X7R) expression, and ectonucleotidase CD39 activity and expression in the bone marrow and spleen. The obtained results demonstrate the stimulative effects of repeated stress on erythroid cells, extracellular ATP levels, P2X7R expression, CD39 activity and expression within the bone marrow and spleen, as well as the essential role of macrophages in stress-induced changes.

A positive feedback cycle between the alarmin S100A8/A9 and NLRP3 inflammasome-GSDMD signalling reinforces the innate immune response in Candida albicans keratitis

OBJECTIVE

Fungal keratitis is a severe sight-threatening ocular infection, without effective treatment strategies available now. Calprotectin S100A8/A9 has recently attracted great attention as a critical alarmin modulating the innate immune response against microbial challenges. However, the unique role of S100A8/A9 in fungal keratitis is poorly understood.

METHODS

Experimental fungal keratitis was established in wild-type and gene knockout (TLR4^-/- and GSDMD^-/-) mice by infecting mouse corneas with Candida albicans. The degree of mouse cornea injuries was evaluated by clinical scoring. To interrogate the molecular mechanism in vitro, macrophage RAW264.7 cell line was challenged with Candida albicans or recombinant S100A8/A9 protein. Label-free quantitative proteomics, quantitative real-time PCR, Western blotting, and immunohistochemistry were conducted in this research.

RESULTS

Herein, we characterized the proteome of mouse corneas infected with Candida albicans and found that S100A8/A9 was robustly expressed at the early stage of the disease. S100A8/A9 significantly enhanced disease progression by promoting NLRP3 inflammasome activation and Caspase-1 maturation, accompanied by increased accumulation of macrophages in infected corneas. In response to Candida albicans infection, toll-like receptor 4 (TLR4) sensed extracellular S100A8/A9 and acted as a bridge between S100A8/A9 and NLRP3 inflammasome activation in mouse corneas. Furthermore, the deletion of TLR4 resulted in noticeable improvement in fungal keratitis. Remarkably, NLRP3/GSDMD-mediated macrophage pyroptosis in turn facilitates S100A8/A9 secretion during Candida albicans keratitis, thus forming a positive feedback cycle that amplifies the proinflammatory response in corneas.

CONCLUSIONS

The present study is the first to reveal the critical roles of the alarmin S100A8/A9 in the immunopathology of Candida albicans keratitis, highlighting a promising approach for therapeutic intervention in the future.

Portable Handheld "SkinPen" Loaded with Biomaterial Ink for In Situ Wound Healing

In situ bioprinting has emerged as an attractive tool for directly depositing therapy ink at the defective area to adapt to the irregular wound shape. However, traditional bioprinting exhibits an obvious limitation in terms of an unsatisfactory bioadhesive effect. Here, a portable handheld bioprinter loaded with biomaterial ink is designed and named "SkinPen". Gelatin methacrylate (GelMA) and Cu-containing bioactive glass nanoparticles (Cu-BGn) serve as the main components to form the hydrogel ink, which displays excellent biocompatibility and antibacterial and angiogenic properties. More importantly, by introducing ultrasound and ultraviolet in a sequential programmed manner, the SkinPen achieves in situ instant gelation and amplified (more than threefold) bioadhesive shear strength. It is suggested that ultrasound-induced cavitation and the resulting topological entanglement contribute to the enhanced bioadhesive performance together. Combining the ultrasound-enhanced bioadhesion with the curative role of the hydrogel, the SkinPen shows a satisfactory wound-healing effect in diabetic rats. Given the detachable property of the SkinPen, the whole device can be put in a first-aid kit. Therefore, the application scenarios can be expanded to many kinds of accidents. Overall, this work presents a portable handheld SkinPen that might provide a facile but effective approach for clinical wound management.