Reactive Oxygen Species in Macrophages: Sources and Targets

Anti-infective therapy of inhibiting Staphylococcus aureus ClpP by protocatechuic aldehyde

The increasing antibiotic resistance and widespread pathogenicity of Staphylococcus aureus (S. aureus) has resulted in severe infections in both human and animals, necessitating the urgent development of novel therapeutic agents. Targeting virulence factors has emerged as a promising approach to combat infections caused by drug-resistant bacteria. Protocatechuic aldehyde (PCA) was identified as an inhibitor of S. aureus ClpP through an enzyme activity inhibition assay. Treatment with PCA at concentrations of 64 and 128 μg/mL significantly reduced the proteolytic and hemolytic activities of S. aureus, as well as its adherence and invasion capabilities. Furthermore, S. aureus treated with PCA exhibited decreased persistence under adverse stress conditions, including elevated temperature, NaClO, and H₂O₂ stress. Furthermore, the bactericidal activity of tigecycline against S. aureus was enhanced when used in combination with PCA. Molecular simulations revealed that PCA directly binded to ClpP at the G107, V88, and I81 residues, thereby further inhibiting its activity. In vivo, PCA treatment improved survival rates and reduced inflammatory responses in a mouse model of S. aureus-induced pneumonia. Overall, PCA represents an effective therapeutic agent against S. aureus infections by inhibiting ClpP activity, providing a novel strategy to combat S. aureus.

Insight into the enhanced performance of the 1-phenylethyl segment in an aza-BODIPY system

Non-aryl substituted aza-BODIPYs exhibit extraordinary optical properties. 1-Phenylethyl-substituted aza-BODIPY PE-BDP was herein successfully prepared. Based on X-ray crystallographic analysis, 1-phenylethyl segments at 1,7-sites in PE-BDP as a stable mesomer were observed for the first time, and the plane of the phenyl group in the 1-phenylethyl segment is orthogonal to the core of PE-BDP. This orthogonal structure enhanced the spin-orbit charge transfer intersystem crossing (SOCT-ISC), and PE-BDP could induce type-I ROS generation. By the cyclic voltammetry test of PE-BDP, the reduction-oxidation processes remained electrochemically reversible. Under alkaline conditions, the new dianion species generated from PE-BDP can be monitored by spectroscopic redshift, and theoretical calculations also supported this result. Self-assembled PE-BDP nanoparticles under irradiation exhibited a good tumor-inhibition capability by inhibiting proliferation and migration, and promoting the apoptosis of glioma cells by type-I ROS and photothermal effects.

CD103+ T Cells Eliminate Damaged Alveolar Epithelial Type II Cells Under Oxidative Stress to Prevent Lung Tumorigenesis

The nexus between aging-associated immune deteriorations and tumorigenesis of lung cancers remains elusive. In a mouse model with Med23 depletion in T cells (Med23 -/-), it is found a strong association between the decline of CD103+ T cells and spontaneous alveolar epithelial type II cell (AT2 cell)-originated lung adenocarcinomas. The reduction of CD103+ T cells in the lung results in an accumulation of AT2 cells bearing oxidative damages, which appears to be the major origin of the lung adenocarcinoma. Functional experiments reveal CD103+ T cells can eradicate oxidative-damage-bearing AT2 cells as well as ROS-dependent, KRAS (G12D)-driven tumorigenesis. In vitro co-cultures prove CD103+ T cells, especially CD103+ CD8+ T cells, exhibit a killing capacity that matches the oxidative stress level in the target cells. In aged animals, it is found the abundance of CD103+ CD8+ T cells in the lung declines with age, accompanied by an accumulation of oxidative-damage-bearing AT2 cells. Collectively, the study establishes the vital function of CD103+ T cells in surveilling epithelial cells under oxidative stress to prevent malignancies, and unravels a potential immuno-dysregulation in the aged lung which contributes to tumorigenesis.

Cellular crosstalk in fibrosis: insights into macrophage and fibroblast dynamics

Pathological fibrosis, the excessive deposition of extracellular matrix and tissue stiffening that causes progressive organ dysfunction, underlies diverse chronic diseases. The fibrotic microenvironment is driven by the dynamic microenvironmental interaction between various cell types; macrophages and fibroblasts play central roles in fibrotic disease initiation, maintenance, and progression. Macrophage functional plasticity to microenvironmental stimuli modulates fibroblast functionality by releasing pro-inflammatory cytokines, growth factors, and matrix remodeling enzymes that promote fibroblast proliferation, activation, and differentiation into myofibroblasts. Activated fibroblasts and myofibroblasts serve as the fibrotic effector cells, secreting extracellular matrix components and initiating microenvironmental contracture. Fibroblasts also modulate macrophage function through the release of their own pro-inflammatory cytokines and growth factors, creating bidirectional crosstalk that reinforces the chronic fibrotic cycle. The intricate interplay between macrophages and fibroblasts, including their secretomes and signaling interactions, leads to tissue damage and pathological loss of tissue function. In this review, we examine macrophage-fibroblast reciprocal dynamic interactions in pathological fibrotic conditions. We discuss the specific lineages and functionality of macrophages and fibroblasts implicated in fibrotic progression, with focus on their signal transduction pathways and secretory signalling that enables their pro-fibrotic behaviour. We then finish with a set of recommendations for future experimentation with the goal of developing a set of potential targets for anti-fibrotic therapeutic candidates. Understanding the cellular interactions between macrophages and fibroblasts provides valuable insights into potential therapeutic strategies to mitigate fibrotic disease progression.

The antioxidant protein PntA coordinates with OmpW to resist oxidant stress in Actinobacillus pleuropneumoniae

Bacteria have evolved various strategies to combat oxidative stress caused by reactive oxygen species (ROS). Outer membrane proteins including OmpW play multiple roles in bacterial physiology, stress responses and virulence. In this study, the OmpW protein of Actinobacillus pleuropneumoniae, an important porcine respiratory tract pathogen, was found to contribute to virulence but concurrently to reduce resistance to oxidative stress. An ompW deletion (ΔompW) showed attenuation in mice, and decreased adherence to pig tracheal epithelial cells and resistance to hyperosmotic stress, compared to the wild-type (WT) strain. However, the ΔompW strain exhibited increased resistance to H2O2, enhanced survival ability within macrophages, and lower intracellular ROS level. OmpW may serve as a H2O2 channel. Further study showed that exposure to H2O2 significantly suppressed ompW transcription in the WT strain. Overexpression of these two proteins in WT and ΔompW increased the antioxidative properties of the bacteria. Furthermore, by construction of the double gene mutant ΔompWΔpntA, it was found that PntA could reverse the effects of OmpW on the bacterial survivability and intracellular ROS level after H2O2 treatment. Therefore, by interacting with OmpW, PntA alleviated the increased oxidative stress sensitivity caused by OmpW. These results suggest a mechanism whereby antioxidant proteins collaborate with OMPs to protect bacteria from oxidative stress.

Nutritional management of pediatric nephrotic syndrome regarding oxidative stress and antioxidant balance

Pediatric nephrotic syndrome remains a complex clinical entity, with incompletely elucidated pathogenetic mechanisms, in which oxidative stress appears to have a substantial etiopathogenic role. Recent evidence supports the involvement of redox imbalance in podocyte damage, impaired glomerular function, and systemic decline. All this suggests that antioxidant interventions can favorably modulate the course of the disease. This narrative review aims to synthesize the most relevant data from the current literature on the interaction between oxidative stress and nephrotic syndrome in children, with a focus on the therapeutic potential of antioxidants. The analysis focuses on the molecular mechanisms by which oxidative stress contributes to the progression of renal dysfunction, the role of oxidative biomarkers in disease monitoring, and the ability of antioxidants to reduce the need for immunosuppressants and corticosteroids, thus contributing to the decrease in associated morbidity. The translational perspectives of antioxidant therapy are also discussed, in the context of the urgent need for effective adjuvant strategies with a safety profile superior to conventional therapies. By integrating these data, the paper supports the valorization of antioxidant interventions as an emerging direction in the management of pediatric nephrotic syndrome and substantiates the need for controlled clinical trials, with rigorous design, in this field.

A novel calcium alginate hydrogel formulation to enhance monocyte/macrophage anti-inflammatory activity

Alginate hydrogels are biocompatible and present tunable properties making them ideal for biomedical applications. We designed a novel Ca2+-Alginate hydrogel and investigated its bioactivity on key component of the immune inflammatory process, the monocytes/macrophages. Our results demonstrate that the developed Ca2+-Alginate hydrogel downregulated the expression of inflammation-related markers CD36 and CD64, in both classical and intermediate monocyte subsets. Additionally, the hydrogel upregulated the expression of the anti-inflammatory marker CD206 in both subsets and reduced their capacity to produce TNFα. In macrophages, the hydrogel modulated the pro-inflammatory M1 towards an anti-inflammatory profile, as evidenced by an increased population of CD163+CD206+ macrophages, typically associated with anti-inflammatory/immunoregulatory activity, and a decreased production of TNFα. The hydrogel also affected mitochondrial function in M1-macrophages, increasing mitochondrial mass and reducing reactive oxygen species production. The translational potential of the hydrogel was evaluated on circulating monocytes from patients suffering from the severe skin disease recessive dystrophic epidermolysis bullosa. The hydrogel increased the anti-inflammatory classical monocyte subset at the expense of the intermediate inflammatory subset. It also reduced CD36 and CD64, and downregulated TNFα production. Collectively, our findings provide evidence of the anti-inflammatory potential of a Ca2+-Alginate hydrogel, suggesting its promising therapeutic application to modulate inflammation.

A historical perspective of Kupffer cells in the context of infection

The Kupffer cell was first discovered by Karl Wilhelm von Kupffer in 1876, labeling them as "Sternzellen." Since their discovery as the primary macrophages of the liver, researchers have gradually gained an in-depth understanding of the identity, functions, and influential role of Kupffer cells, particularly in infection. It is becoming clear that Kupffer cells perform important tissue-specific functions in homeostasis and disease. Stationary in the sinusoids of the liver, Kupffer cells have a high phagocytic capacity and are adept in clearing the bloodstream of foreign material, toxins, and pathogens. Thus, they are indispensable to host defense and prevent the dissemination of bacteria during infections. To highlight the importance of this cell, this review will explore the history of the Kupffer cell in the context of infection beginning with its discovery to the present day.

A nucleoside-based supramolecular hydrogel integrating localized self-delivery and immunomodulation for periodontitis treatment

Periodontitis is a highly prevalent oral disease characterized by bacterial-induced hyperactivation of the host immune system, leading to a sustained inflammatory response and osteoclastic activity, which ultimately results in periodontal destruction. In this work, an immunomodulatory supramolecular hydrogel for the topical treatment of periodontitis was synthesized using a simple one-pot method. This phenylboronate ester-based 8AGPB hydrogel exhibited excellent stability, self-healing properties, injectability, and biocompatibility. During degradation, the 8AGPB hydrogel releases immunomodulatory agent 8-aminoguanosine (8AG), which regulates MAPK and NF-κB signaling pathways by modulation of second messengers in macrophages. In combination with 1,4-phenylenediboronic acid (PBA), which possesses antioxidant properties, 8AG effectively inhibits ROS production and oxidative damage in LPS-stimulated macrophages, lowering the M1/M2 macrophage polarization ratio and reducing the secretion of pro-inflammatory factors. In an experimental periodontitis model using C57BL/6 mice, periodontal injection of the 8AGPB hydrogel reduced inflammatory infiltration and osteoclastic activity through immunomodulation and inhibition of osteoclast differentiation, thereby ameliorating periodontal destruction during periodontitis progression. Overall, the 8AGPB supramolecular hydrogel, serving as an injectable self-delivery platform for 8AG, may represent a promising novel strategy for periodontitis treatment and offer insights for the development of future topical anti-inflammatory systems.

An Antibody-Recruiting Molecule Enhances Fcγ Receptor-Mediated Uptake and Killing of Mycobacterial Pathogens by Macrophages

Mycobacteria, which include the infectious agents for tuberculosis (TB) and nontuberculous mycobacteria (NTM) disease, pose a critical health challenge due to traits that allow them to evade host immune clearance and antibiotic action. Toward a novel immunotherapy approach for mycobacteria, we previously reported an antibody-recruiting molecule (ARM) strategy to specifically modify the surface glycans of mycobacteria with exogenous haptens, marking the bacteria for opsonization by endogenous antibodies and enhancing the antibody-mediated immune response. We showed that the ARM, a trehalose-dinitrophenyl conjugate (Tre-DNP), exploited a conserved metabolic pathway to metabolically label the surface of nonpathogenic Mycobacterium smegmatis with DNP, recruited anti-DNP antibodies to the bacterial surface, and enhanced phagocytosis of the bacteria by THP-1 cells. Here, we extend these findings by investigating the ability of the Tre-DNP ARM strategy to increase macrophage-mediated phagocytosis and killing of different pathogenic mycobacterial species and interrogating mechanisms associated with the outcome. We show that Tre-DNP successfully modified the surface of multiple pathogens, including Mycobacterium tuberculosis and the NTM species Mycobacterium abscessus and Mycobacterium avium, and that phagocytosis and killing of intracellular bacteria by differentiated THP-1 cells is significantly enhanced for all species. Furthermore, we find that enhanced uptake is dependent upon the Fcγ receptor (FcγR) and enhanced killing correlates with sustained production of reactive oxygen species (ROS) and increased phagosome-lysosome fusion. Overall, our data demonstrate that Tre-DNP efficiently promotes ingestion of mycobacteria by human macrophages via the FcγR and enhances host effector responses against the pathogen. Thus, ARMs are tools that can be exploited for the purposes of (i) conducting mechanistic studies on immune recognition and elimination of mycobacterial pathogens and (ii) developing immune-targeting strategies against mycobacterial pathogens.

Nrf2-dependent effects of CDDO-Me on bactericidal activity in macrophage infection models

Introduction

Diabetes and chronic kidney disease (CKD) increase susceptibility to bacterial infections, particularly Staphylococcus aureus, which is associated with highmortality in CKD patients. Dysregulated macrophage activity and excessive oxidative stress exacerbate immune dysfunction and inflammation in these conditions. Nrf2 (nuclear factor erythroid 2-related factor 2) is a key regulator of antioxidant defenses and macrophage function. CDDO-Me, a synthetic triterpenoid, activates Nrf2, providing antioxidant and anti-inflammatoryeffects. However, its precise role in modulating macrophage activity, polarization, and bacterial clearance remains unclear.

Methods

The effects of CDDO-Me on macrophage function were evaluated in vitro (THP-1 and RAW 264.7 macrophages) and an in vivo Nrf2 knockout mouse model. Nrf2 activation was assessed via Western blot and luciferase reporter assays, oxidative stress was measured using CellROX reagent, and inflammatory responses were quantified by RT-qPCR. Intracellular S. aureus survival and macrophage polarization markers were analyzed to investigate the role of CDDO-Me in enhancing bactericidal activity.

Results

Our results showed that CDDO-Me activated the Nrf2 signaling pathway, reducing oxidative stress and inflammation in macrophages by downregulating pro-inflammatory cytokines (IL-1β, TNF-α). It modulated macrophage polarization, decreasing M1 and M2 marker expression, and significantly enhanced bactericidal activity against S. aureus. These effects were Nrf2-dependent, as demonstrated in knockout models.

Conclusion

The ability of CDDO-Me to regulate oxidative stress, inflammation, and bacterial clearance underscores its therapeutic potential for managing inflammatory and infectious diseases indiabetes and CKD.

Cytolethal distending toxin from Glaesserella parasuis induces ferroptosis in porcine alveolar macrophages and mice

Glaesserella parasuis cytolethal distending toxin (GpCDT) is a bacterial genotoxin whose main action is to activate DNA damage responses, induce cell cycle arrest, and induce the apoptosis of host cells. In our previous studies, we reported that cells incubated with GpCDT exhibited changes in the expression of ferroptosis-related proteins; thus, we hypothesized that, in addition to apoptosis, GpCDT may also cause ferroptosis, a novel mode of cell death. Here, we observed that treatment of 3D4/21 cells with GpCDT resulted in cytoplasmic iron overload, depletion of GSH (reduced glutathione), and overproduction of reactive oxygen species (ROS) and malondialdehyde (MDA), indicating that GpCDT disrupted iron metabolism and redox homeostasis in these cells. These phenomena were counteracted by the specific ferroptosis inhibitor ferrostatin-1 and the iron chelator deferoxamine mesylate. In vitro infection with the Glaesserella parasuis field isolate strain SC1401 (CDT positive) induced changes in the expression of ferroptosis biomarkers and proteins. Infection of C57BL/6 mice yielded similar results. Our results suggest that ferroptosis may play a substantial role in GpCDT-induced cellular injury.

An Electron Paramagnetic Resonance Study of the Superoxide-Scavenging and Redox-Modulating Effects of Lecithinized Superoxide Dismutase in the Bloodstream

Lecithinized superoxide dismutase (PC-SOD) was found to have a significantly improved half-life in the bloodstream and better pharmacological effects compared with unmodified SOD. However, there is no direct evidence that parenterally administered PC-SOD decreases superoxide levels in blood and tissues in vivo. In the present study, we investigated the ability of PC-SOD versus unmodified SOD as a superoxide scavenger in mice subjected to oxidative stress. Experiments were performed on a lipopolysaccharide (LPS) mouse model of acute inflammation known to be accompanied by the overproduction of superoxide in the blood. The mice were divided into four groups: untreated (healthy; n = 6), LPS-treated (n = 7), LPS/SOD-treated (n = 6), and LPS/PC-SOD-treated (n = 7) mice. SOD and PC-SOD were injected intravenously. Blood samples were collected at four time intervals and analyzed by electron paramagnetic resonance (EPR) spectroscopy using a nitroxide probe, 3-carbamoyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl (CMP). The following effects were observed: (i) In the blood of healthy mice, the EPR signal was significantly lower compared with the control (p < 0.001) and LPS-treated mice (p < 0.01); (ii) in the blood of LPS-treated mice, the EPR signal was identical to that of the control; and (iii) in the blood of LPS/SOD-treated mice collected immediately after enzyme injection, the EPR signal was significantly lower compared with the control (p < 0.01) and LPS-treated mice (p < 0.05). However, the effect disappeared in the samples collected 30 min and 1 h after enzyme injection. (iv) In LPS/PC-SOD-treated mice, the EPR signal was significantly lower compared with the control (p < 0.01) and LPS-treated mice (p < 0.05), even in the blood samples collected within 1 h after enzyme injection. The data indicate that the blood of healthy mice was characterized by a high reducing capacity, while the blood of LPS-treated mice was characterized by a high oxidative capacity. SOD decreased superoxide production immediately after enzyme injection. However, the effect was short-lived and disappeared within 30 min. PC-SOD effectively decreased superoxide production in the bloodstream of LPS-treated mice and restored the redox balance to the control level even two hours after enzyme injection. The effects of PC-SOD were more pronounced and long-lasting compared with those of SOD. The possible reason is the longer half-life of PC-SOD in the bloodstream, its better stability, and its slower clearance from the circulation due to the increased hydrophobicity of the enzyme and its interaction with plasma proteins. The data are discussed in the context of recent clinical trials showing that PC-SOD is a promising pharmaceutical product for adjuvant therapy of a variety of pathologies accompanied by inflammation, redox imbalance, and oxidative stress.

Nanoparticle delivery of CD68 siRNA inhibits neuroimmune responses by inhibiting activation of M1 macrophages

CD68 is a vital costimulatory molecule expressed on macrophages/microglia (M/Ms) and plays a critical role in their activation. By targeting this molecule, therapeutic interventions can potentially prevent the homing of M/Ms. to the lesion site. In this study, we developed a biomimetic nanoparticle-based system (siCD68/NPs) to deliver CD68 small interfering RNA (siCD68) more efficiently into M/Ms.Administration of siCD68/NPs was found to not only polarize M1 macrophages toward M2 phenotype, but also reduce the reactive oxygen species (ROS) levels in lipopolysaccharide (LPS) plus interferon-γ (IFN-γ) induced macrophages/microglia (M/Ms). Moreover, treatment with siCD68/NPs significantly extended the survival time in a mouse spinal cord injury (SCI) model.In summary, siCD68/NPs were found to activate an anti-neuroinflammatory immune response and reprogram the polarization of M/Ms., leading to a significant improvement in the recovery of spinal cord injury. This study contributes to the field of biomimetic nanoparticle-based therapies and offers novel insights into potential treatments for neuroinflammation-induced SCI.

Effect of high-altitude hypoxia on function and cytoarchitecture of rats' liver

The liver is central to metabolic, detoxification, and homeostatic functions. Exposure to hypobaric hypoxia at high altitudes causes detrimental effects on the liver, leading to injury. This study evaluated the effect of hypoxia-induced at high altitudes on liver function, oxidative stress, and histopathological changes in rats. This study used 24 male Wistar rats (aged 8-10 weeks). The hypoxia (hypobaric hypoxia) was inducted at a high altitude of 2,100 m above sea level. Normoxia is defined as 40 m above the sea level. The rats were randomly divided into two groups: a control group maintained at low altitudes and an experimental group exposed to high altitudes for eight weeks. Blood samples were collected from all rats through a cardiac puncture, and liver samples were taken through an abdominal approach. All samples were processed through standard methods and evaluated for liver function tests and histopathological assessment. Serum aspartate aminotransferase and alanine transaminase levels significantly increased by 25% and 30%, respectively, in the high-altitude group compared to controls (p < 0.01), indicating mild hepatocellular damage. Oxidative stress assessment indicated a significant elevation in malondialdehyde by 42% in the liver homogenates of high-altitude rats compared to controls (p < 0.001). Moreover, Superoxide dismutase activity and glutathione content decreased by 18% and 22% in the high-altitude group (p < 0.01), confirming the increased oxidative stress. Histologically, minimal inflammatory infiltration was observed in the rat livers at high altitudes, with no signs of necrosis or severe structural changes. Subclinical liver dysfunction, as evidenced by altered serum enzyme levels and increased oxidative stress with mild histological changes, is induced by high-altitude hypoxia in rats. This study's results support that a hypobaric hypoxic environment physiologically stresses the liver. Further research into the long-term implications of hypobaric hypoxia and the adaptive responses of the liver is warranted.

Immunomodulatory Effects of Symplectoteuthis oualaniensis Protamine and Its PEG Derivative on Macrophages: Involvement of PI3K/Akt Signaling, Redox Regulation, and Cell Cycle Modulation

Protamine is a promising marine-derived bioactive compound that is highly arginine-rich and has demonstrated unique advantages in medical and biological research. This study, for the first time, investigates the molecular mechanisms underlying the immunomodulatory effects of Salmon Protamine Sulfate (SPS), Symplectoteuthis oualaniensis Protamine (SOP), and its polyethylene glycol (PEG) derivative (SOP-PEG) on RAW264.7 macrophages. The results demonstrate that both SOP and SOP-PEG significantly enhance the proliferation of RAW264.7 cells by promoting the secretion of pro-inflammatory cytokines and nitric oxide (NO), increasing ROS production, and improving antioxidant capacity, in comparison to SPS. Elevated ROS levels play a crucial role in enhancing macrophage immune activity, while the enhanced antioxidant defense mechanisms help maintain redox homeostasis and protect against oxidative stress-induced cellular damage. A Western blot analysis reveals that SOP and SOP-PEG notably regulate the expression of key proteins associated with the PI3K/Akt signaling pathway and anti-apoptotic mechanisms. Furthermore, a flow cytometry analysis indicates a significant increase in the G2/M-phase cell population in the treatment groups, which is corroborated by Western blot data showing alterations in critical regulatory proteins. Notably, SOP-PEG exhibits the strongest effects in regulating macrophage immune activity, which can be attributed to the enhanced stability and prolonged bioactivity resulting from the PEGylation of SOP. This comprehensive study reveals how SOP and SOP-PEG enhance macrophage immune function through multiple mechanisms, including PI3K/Akt activation, redox regulation, and cell cycle modulation. It provides valuable insights and a theoretical foundation for their potential applications in immunotherapy and immune regulation.

Diverse Fluorescent Probe Concepts for Detection and Monitoring of Reactive Oxygen Species

World-wide research on reactive oxygen species (ROS) continues to reveal new information about the role and impact of ROS on human health and disease. ROS are generated in live cells as a byproduct of aerobic metabolism. Physiological concentrations of cellular ROS are important for signaling and homeostasis, but excessive generation of ROS causes apoptotic and necrotic cell death and various health disorders. Fluorescence technology is a powerful tool to detect, monitor, and image cellular ROS. The present review provides an overview of diverse organic dye-based fluorescent probe concepts that involve modifications of traditional fluorescent dyes utilizing basic principles of dye chemistry and photophysics. Fluorescence responses of the probes and their specificity towards ROS are discussed through analyses of their photophysical and photochemical parameters. We also provide an outlook on future directions of ROS-responsive fluorescent dyes, which could enable the design and development of advanced probes for gaining deeper insights into redox biology.

Innovative approaches to boost mesenchymal stem cells efficacy in myocardial infarction therapy

Stem cell-based therapy has emerged as a promising approach for heart repair, potentially regenerating damaged heart tissue and improving outcomes for patients with heart disease. However, the efficacy of stem cell-based therapies remains limited by several challenges, including poor cell survival, low retention rates, poor integration, and limited functional outcomes. This article reviews current enhancement strategies to optimize mesenchymal stem cell therapy for cardiac repair. Key approaches include optimizing cell delivery methods, enhancing cell engraftment, promoting cell functions through genetic and molecular modifications, enhancing the paracrine effects of stem cells, and leveraging biomaterials and tissue engineering techniques. By focusing on these enhancement techniques, the paper highlights innovative approaches that can potentially transform stem cell therapy into a more viable and effective treatment option for cardiac repair. The ongoing research and technological advancements continue to push the boundaries, hoping to make stem cell therapy a mainstream treatment for heart disease.

Phenothiazines boost host control of Mycobacterium avium infection in primary human macrophages

Mycobacterium avium (Mav) complex is the leading cause of pulmonary diseases associated with non-tuberculous mycobacterial (NTM) infections worldwide. The inherent and increasing acquired antibiotic resistance of Mav hampers the treatment of Mav infections and emphasizes the urgent need for alternative treatment strategies. A promising approach is host-directed therapy (HDT), which aims to boost the host's immune defenses to combat infections. In this study, we show that phenothiazines, particularly trifluoperazine (TFP) and chlorproethazine (CPE), restricted Mav survival in primary human macrophages. Notably, TFP and CPE did not directly inhibit mycobacterial growth at used concentrations, confirming these drugs function through host-dependent mechanisms. TFP and CPE induced a mild, albeit not statistically significant, increase in autophagic flux along with the nuclear intensity of transcription factor EB (TFEB), the master transcriptional regulator of autophagy. Inhibition of autophagic flux with bafilomycin, however, did not impair the improved host infection control by TFP and CPE, suggesting that the host (auto)phagolysosomal pathway is not causally involved in the mechanism of action of TFP and CPE. Additionally, TFP and CPE increased the production of both cellular and mitochondrial reactive oxygen species (ROS). Scavenging mitochondrial ROS did not impact, whereas inhibition of NADPH oxidase (NOX)-mediated ROS production partially impaired the HDT activity of TFP and CPE, indicating that oxidative burst may play a limited role in the improved host control of Mav infection by these drugs. Overall, our study demonstrates that phenothiazines are promising HDT candidates that enhance the antimicrobial response of macrophages against Mav, through mechanism(s) that were partially elucidated.

Myeloid FtH Regulates Macrophage Response to Kidney Injury by Modulating Snca and Ferroptosis

This study explored the role of myeloid ferritin heavy chain (FtH) in coordinating kidney iron trafficking in health and disease. Synuclein-α (Snca) was the sole iron-binding protein upregulated in response to myeloid FtH deletion (FtH Δ/Δ ). Following kidney injury, FtH Δ/Δ mice showed worsened kidney function. Transcriptome analysis revealed coupling of FtH deficiency with ferroptosis activation, a regulated cell death associated with iron accumulation. Adverse effects of ferroptosis were evidenced by upregulation of ferroptosis-related genes, increased oxidative stress markers, and significant iron deposition in kidney tissues. This iron buildup in FtH Δ/Δ kidneys stemmed from macrophage reprogramming into an iron-recycling phenotype, driven by Spic induction. Mechanistically, we establish that monomeric Snca functions as a ferrireductase catalyst, intensifying oxidative stress and triggering ferroptosis. Additionally, Snca accumulates in kidney diseases distinguished by leukocyte expansion across species. These findings position myeloid FtH as a pivotal orchestrator of the FtH-Snca-Spic axis driving macrophage reprogramming and kidney injury.

Highlights

Myeloid FtH deficiency drives kidney injury via activation of ferroptosisMΦ FtH deficiency induces Snca, linking iron dysregulation to MΦ function and response to kidney injuryFerrireductase activity of monomeric Snca augments oxidative stress, promoting lipid peroxidation and ferroptosis.

In brief

MΦ FtH modulates Snca and Spic to coordinate the injury response, linking iron trafficking to ferroptosis-induced kidney injury.

Modulation of pulmonary immune functions by the Pseudomonas aeruginosa secondary metabolite pyocyanin

Pseudomonas aeruginosa is a prevalent opportunistic Gram-negative bacterial pathogen. One of its key virulence factors is pyocyanin, a redox-active phenazine secondary metabolite that plays a crucial role in the establishment and persistence of chronic infections. This review provides a synopsis of the mechanisms through which pyocyanin exacerbates pulmonary infections. Pyocyanin induces oxidative stress by generating reactive oxygen and nitrogen species which disrupt essential defense mechanisms in respiratory epithelium. Pyocyanin increases airway barrier permeability and facilitates bacterial invasion. Pyocyanin also impairs mucociliary clearance by damaging ciliary function, resulting in mucus accumulation and airway obstruction. Furthermore, it modulates immune responses by promoting the production of pro-inflammatory cytokines, accelerating neutrophil apoptosis, and inducing excessive neutrophil extracellular trap formation, which exacerbates lung tissue damage. Additionally, pyocyanin disrupts macrophage phagocytic function, hindering the clearance of apoptotic cells and perpetuating inflammation. It also triggers mucus hypersecretion by inactivating the transcription factor FOXA2 and enhancing the IL-4/IL-13-STAT6 and EGFR-AKT/ERK1/2 signaling pathways, leading to goblet cell metaplasia and increased mucin production. Insights into the role of pyocyanin in P. aeruginosa infections may reveal potential therapeutic strategies to alleviate the severity of infections in chronic respiratory diseases including cystic fibrosis (CF) and chronic obstructive pulmonary disease (COPD).

Antioxidant Therapies as Emerging Adjuncts in Rheumatoid Arthritis: Targeting Oxidative Stress to Enhance Treatment Outcomes

Rheumatoid arthritis (RA) is a chronic autoimmune disorder characterized by persistent inflammation and progressive joint destruction. Recent data underscore oxidative stress as a primary factor in the pathophysiology of rheumatoid arthritis, intensifying inflammatory processes and tissue damage via the overproduction of reactive oxygen species (ROS) and compromised antioxidant defenses. Current therapies, including disease-modifying antirheumatic drugs (DMARDs), primarily target immune dysregulation but fail to address oxidative stress, necessitating novel adjunctive treatment strategies. This review explores the potential of antioxidant-based therapies as complementary approaches to RA management. Natural compounds such as curcumin, resveratrol, sulforaphane, and propolis exhibit strong anti-inflammatory and antioxidative properties by modulating redox-sensitive pathways, including nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and nuclear factor erythroid 2-related factor 2(Nrf2)/heme oxygenase (HO-1). N-acetylcysteine (NAC) replenishes intracellular glutathione, enhancing cellular resilience against oxidative stress. Additionally, molecular hydrogen (H2) selectively neutralizes harmful ROS, reducing oxidative damage and inflammation. The role of vitamin supplementation (D, B12, C, and K) in regulating immune responses and protecting joint structures is also discussed. This review aims to evaluate the efficacy and potential clinical applications of antioxidant therapies in RA, emphasizing their role in mitigating oxidative damage and improving treatment outcomes. While preliminary findings are promising, further clinical trials are needed to establish standardized dosing, long-term safety, and their integration into current RA treatment protocols.

Sesquiterpene lactones from Cichorium intybus exhibit potent anti-inflammatory and hepatoprotective effects by repression of NF-κB and enhancement of NRF2

ETHNOPHARMACOLOGICAL RELEVANCE

Cichorium intybus is a traditional medicinal herb for hepatitis treatment in China and Europe. Sesquiterpene lactones are the main active ingredients in C. intybus. However, their structure-activity relationship (SAR) and molecular mechanisms of anti-inflammatory and hepatoprotective effects require further elucidation.

AIM OF THE STUDY

To identify new sesquiterpene lactones from C. intybus, and further evaluate their anti-inflammatory effects, SAR, and mechanisms of anti-inflammatory and hepatoprotective properties.

METHODS

Identification of sesquiterpene lactones from C. intybus using chromatographic fractionation, NMR, and mass spectrometry. The repression of inflammation was evaluated in RAW264.7 macrophages incubated with LPS. Western blotting was employed to investigate the anti-inflammatory mechanisms. The hepatoprotective effect was measured in LPS/D-galactosamine (D-GalN)-induced acute hepatitis in mice.

RESULTS

We identified 3 new sesquiterpene lactones and 15 known analogues from C. intybus. SAR analysis showed that the α-methylene-γ-lactone moiety was essential for their anti-inflammatory properties. Furthermore, 8-deoxylactucin was identified as the most potent anti-inflammatory component in LPS-induced RAW264.7 macrophages by reduction of nitric oxide production via inhibiting iNOS expression, and suppression of IL-1β, IL-6, and TNF-α expression. Mechanistically, 8-deoxylactucin not only blocked LPS-induced IKKα/β phosphorylation, IκBα phosphorylation and degradation, and NF-κB nuclear accumulation, but also enhanced NRF2 expression and nuclear translocation, HO-1 and NQO1 expression, and reduced ROS generation in vitro. In vivo, 8-deoxylactucin mitigated LPS/D-GalN-induced acute hepatitis, which manifested as reduction in inflammatory infiltration, live injury, serum levels of AST and ALT, and production of pro-inflammatory cytokines and 4-hydroxynonenal.

CONCLUSION

8-Deoxylactucin, the sesquiterpene lactone isolated from C. intybus, exerted anti-inflammatory and hepatoprotective effects by blocking NF-κB activation and enhancing NRF2 activation.

Changes in Macrophages in Pulmonary Hypertension: A Focus on High-altitude Pulmonary Hypertension

High-altitude pulmonary hypertension (HAPH) is a condition characterized by elevated pulmonary arterial pressure exceeding normal physiological values, resulting from a combination of high-altitude low-pressure, hypoxic environments, genetic susceptibility, immune dysfunction, and neurogenic disturbances. This condition predominantly manifests as right heart failure, severely impacting quality of life and life expectancy. Macrophages, as one of the most prevalent innate immune cells, have been increasingly recognized for their crucial role in the pathogenesis of HAPH. The low-pressure and hypoxic environment, along with other etiological factors, lead to metabolic abnormalities in tissue cells and the microenvironment. This results in increased secretion of chemokines, cytokines, and growth factors in the microenvironment, which promote the proliferation of tissue-resident macrophages and the differentiation of monocytes recruited from the blood into macrophages. This exacerbates the inflammatory cascade, further promoting cell proliferation, tissue repair, and inhibition of apoptosis. These processes contribute to the migration and proliferation of pulmonary arterial smooth muscle cells, endothelial cells, and fibroblasts, leading to vascular remodeling and ultimately the development of pulmonary arterial hypertension. This review examines the role of macrophage-mediated immune responses in high-altitude pulmonary arterial hypertension, with a focus on hypoxia as a key feature.

Targeting Non-Eosinophilic Immunological Pathways in COPD and AECOPD: Current Insights and Therapeutic Strategies

COPD is a multifactorial illness characterized by a long-term restriction of airflow and an inflammatory reaction in the lungs. The associated emphysema leads to the breakdown of alveolar proteins and abnormal expansion of the lung air spaces. Chronic bronchitis caused by the same disease can result in increased deposition of structural proteins, narrowing of the airways, and excessive mucus secretion leading to acute exacerbation of COPD (AECOPD). The most commonly prescribed medications for it, such as glucocorticoids and bronchodilators, provide important therapeutic benefits, but they also have negative side effects, including immunosuppression and infection. Therefore, it is necessary to develop medications for the treatment of COPD that specifically target the immune system and molecular components. This review focuses on non-eosinophilic aspects of immunological modulation in COPD management. Since, existing literature extensively covers eosinophilic inflammation, this review aims to fill the gap by examining alternative immunological pathways and their therapeutic implications. The findings suggest that targeting specific immune responses may enhance treatment efficacy while minimizing adverse effects associated with traditional therapies. In summary, this review emphasizes the importance of advancing research into non-eosinophilic immunological mechanisms in COPD, prescribing for the development of novel therapies that can more effectively manage this disease.

Effects of aged garlic extract on macrophage functions: a short review of experimental evidence (Review)

Macrophages play crucial roles in both the innate and adaptive immune systems, contributing to the removal of pathogens and subsequent immune responses. Conversely, aberrant macrophage functions are associated with the onset and progression of various diseases, highlighting macrophages as potential therapeutic targets. Aged garlic extract (AGE) is derived from garlic that has undergone a maturation process of over 10 months in an ethanol solution and contains a variety of bioactive components which are produced in the aging process. Previous animal studies and clinical trials have demonstrated that AGE and its constituents exert a range of health benefits, including immune modulation and amelioration of disease conditions. Experimental studies indicate that AGE modulates macrophage functions associated with pathological conditions. To facilitate understanding of AGE's potential as a functional alleviation for macrophage-associated diseases, the present short review summarizes experimental evidence supporting the notion that AGE and its components modify macrophage functions, including phagocytosis, production of reactive oxygen species and polarization.

Engineering next-generation oxygen-generating scaffolds to enhance bone regeneration

In bone, an adequate oxygen (O2) supply is crucial during development, homeostasis, and healing. Oxygen-generating scaffolds (OGS) have demonstrated significant potential to enhance bone regeneration. However, the complexity of O2 delivery and signaling in vivo makes it challenging to tailor the design of OGS to precisely meet this biological requirement. We review recent advances in OGS and analyze persisting engineering and translational hurdles. We also discuss the potential of computational and machine learning (ML) models to facilitate the integration of novel imaging data with biological readouts and advanced biomanufacturing technologies. By elucidating how to tackle current challenges using cutting-edge technologies, we provide insights for transitioning from traditional to next-generation OGS to improve bone regeneration in patients.

Pro-Oxidative and Inflammatory Actions of Extracellular Hemoglobin and Heme: Molecular Events and Implications for Alzheimer's and Parkinson Disease

Hemoglobin (Hb) and heme, which are typically confined within red blood cells (RBCs), are essential for intravascular transport of gases and nutrients. However, these molecules acquire secondary functions upon exposure to the extracellular environment. Hb and heme generate reactive oxygen species (ROS), which are potent pro-inflammatory agents that contribute to oxidative stress and cellular damage. These events are relevant to neurodegenerative processes, where oxidative stress, irregular deposition of protein aggregates, and chronic inflammation are key pathological features. Extracellular Hb, heme, and oxidative stress derived from hemorrhagic events or RBC lysis may contribute to increased blood-brain barrier (BBB) permeability. These events allow Hb and heme to interact with neuroimmune cells and pathological protein aggregates, further amplifying pro-inflammatory signaling and the progression of Alzheimer's disease (AD) and Parkinson disease (PD). Chronic neuroinflammation, oxidative stress, and mitochondrial dysfunction lead to neuronal degeneration. Here, we sought to elucidate the pro-oxidative and inflammatory actions of extracellular Hb and heme, emphasizing their potential impact on AD and PD development.

An Activatable Chemiluminescent Self-Reporting Sulfur Dioxide Donor for Inflammatory Response and Regulation of Gaseous Vasodilation

Sulfur dioxide (SO2), being a novel gaseous signaling molecule, exhibits significant potential for application in the field of cardiovascular diseases. SO2 donors serve as crucial tools for the transportation and regulation of SO2 in vivo, facilitating the investigation of physiological roles associated with this molecule. However, the current therapeutic SO2 donors lack the capability to monitor the real-time release of SO2, thereby hindering accurate assessment of their therapeutic efficacy and target localization. Herein, we present an activatable chemiluminescent self-reporting SO2 donor (CL-SO2D) that can be selectively activated by peroxynitrite (ONOO-) to release SO2 and enable real-time visualization of the extent of release through chemiluminescent imaging. In vitro and cellular experiments demonstrate that CL-SO2D exhibits high selectivity and signal-to-noise ratio toward ONOO- and effectively facilitates the SO2 release process. Finally, CL-SO2D successfully achieved the response to the mouse inflammatory model and relieved vasoconstriction in zebrafish by releasing SO2 stimulated by ONOO-. The findings suggest that CL-SO2D exhibits impressive attributes in the diagnosis and treatment of SO2-related diseases, opening the gateway for developing low-background and high-sensitivity self-reporting SO2 donors.

Fractures Associated with Immune Checkpoint Inhibitors: A Disproportionality Analysis of the World Health Organization Pharmacovigilance Database

Background/Objectives: The risk of fractures associated with immune checkpoint inhibitors (ICIs) is increasing; however, the relationship between fracture risk and potential factors, such as osteoporosis and hyperthyroidism, remains unclear. Methods: Using VigiBase, the World Health Organization's global pharmacovigilance database, we investigated the signals for osteoporosis, hyperthyroidism, and fractures associated with ICIs (nivolumab, pembrolizumab, atezolizumab, durvalumab, ipilimumab, and tremelimumab) by calculating information components (ICs) and their 95% confidence intervals (CIs). Furthermore, we estimated the association between the occurrence of fractures in patients receiving ICIs and osteoporosis or hyperthyroidism. Results: Signals of hyperthyroidism (IC = 4.66, 95% CI: 4.58-4.73), but not osteoporosis (IC = -1.79, 95% CI: -2.22 to -1.36) or fractures (IC = -0.21, 95% CI: -0.36 to -0.06), were detected in patients using ICIs. Osteoporosis (odds ratio: 118.00, 95% CI: 61.00-230.00) was associated with an increased reporting frequency of fractures related to ICIs, whereas hyperthyroidism (odds ratio: 0.60, 95% CI: 0.19-1.87) was not associated with such an increase. Conclusions: The VigiBase analysis indicates that the use of ICIs does not increase the reporting frequency of osteoporosis or fractures. Additionally, hyperthyroidism did not increase the reporting frequency of fractures associated with ICIs.

NIR-Responsive Functionalized Nanoflower for Acute Spinal Cord Injury

Excessive accumulations of reactive oxygen species (ROS) and M1 macrophages are closely associated with the complex pathogenesis of spinal cord injury (SCI). Thus, therapeutics that synergistically exert the elimination of ROS and repolarization of pro-inflammation macrophages are gaining increasing notice. We developed a prussian blue-based nanoflower (KPBF) with near-infrared (NIR) photothermal and antioxidant properties. The KPBF's biofunctions were similar to those of other antioxidant enzymes, such as catalase and superoxide dismutase, which are capable of reducing ROS. With NIR irradiation, KPBF efficiently heated the injured spinal cord lesion. By modifying the CKLVFFAED peptide, KPBF remarkably penetrated through the blood-spinal cord barrier (BSCB) into the local lesion. Moreover, KPBF repolarized M1 macrophages and alleviated neuroinflammation in SCI mice. Overall, KPBF presented a universal nanotherapeutic system with immunoregulation and antioxidant activities for acute SCI recovery.

The role of oxidative stress-related genes in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is an age-related interstitial lung disease of unknown cause. Oxidative stress, an imbalance between oxidants and antioxidants, is implicated in IPF pathogenesis and prognosis but needs further study. We used transcriptome sequencing data (GSE70866) and oxidative stress-related genes from GeneCards. A prognostic risk model for IPF patients was constructed using LASSO. Functional and pathway differences were analyzed between risk score groups, along with comparisons of immune cells and functions. An IPF rat model with vitamin D3 (VD3) intervention was also established. Finally, we used IL-4 to induce M2 macrophages to explore the mechanism of action of CCL2. We identified 483 DEGs and 50 oxidative stress-related DEGs (OSDEGs). Single-factor COX regression identified 34 prognostic OSDEGs, and LASSO identified an 8-gene signature for the risk model. The high-risk group had more CD8 + T cells, macrophages, APC costimulation, and cytokine-cytokine receptor activity. CCL2 was significantly correlated with macrophages in IPF. VD3 inhibited the TGF-β signaling pathway and reduced macrophage M2 infiltration in the rat model. In the IL-4 induced M2 macrophage model, we found that M2 macrophages produced more CCL2, and the production of CCL2 was significantly reduced after VD3 intervention. We established prognostic markers of eight oxidative stress-related genes. The risk score effectively predicts adverse outcomes in IPF. VD3 may alleviate IPF by reducing macrophage infiltration and inhibiting the TGF-β signaling pathway.

Unveiling the Role of Selenium in Child Development: Impacts on Growth, Neurodevelopment and Immunity

Selenium (Se) is a vital trace element for children, playing a crucial role in numerous physiological processes, including antioxidant defense, immune regulation, thyroid function, and bone metabolism. Emerging evidence highlights its potential impact on child development and growth while also underscoring the complexity of its mechanisms and the global variations in Se intake. The aim of this review is to comprehensively elucidate the significance of Se in various biological processes within the human body, with a focus on its role in child development and growth; its biochemical effects on the nervous system, thyroid function, immune system, and bone tissue; and the implications of Se deficiency and toxicity. This review integrates findings from experimental models, epidemiological studies, and clinical trials to explore Se's role in neurodevelopment, growth regulation, and immune competence in children. Selenoproteins, which regulate oxidative stress and thyroid hormone and bone metabolism, are essential for normal growth and cognitive development in children. Se deficiency and toxicity has been linked to impaired immune function, growth retardation, and decreased immune function. The findings underscore Se's influence on various biological pathways that are critical for healthy child development and its broader importance for child health. Public health strategies aimed at optimizing selenium intake may play a pivotal role in improving pediatric health outcomes worldwide.

Functional Nanosheet Immunoswitches Reprogramming Innate Macrophages for Immunotherapy of Colorectal Cancer and Sepsis

Macrophages are involved in the immunopathogenesis of cancer and inflammatory diseases and are a primary target for immunotherapy to reprogram the M1 and M2 phenotypes in tumor and inflammatory microenvironments. Herein, functional nanosheet immunoswitches that can bidirectionally polarize macrophages in tumor and inflammatory microenvironments are designed for effective immunotherapy of colorectal cancer and sepsis. WSe2 nanosheets are functionalized with palmitic acid to obtain an M1 immunoswitch (PA-WSe2) that promotes the polarization of macrophages toward the M1 phenotype in the tumor microenvironment by activating the STAT1 signaling pathway. WS2 nanosheets bearing linoleic acid are synthesized as an M2 immunoswitch (LA-WS2) that effectively polarizes macrophages to the M2 phenotype in the septic microenvironment by activating the STAT3 signaling pathway. The PA-WSe2 M1 immunoswitch upregulates the secretion of pro-inflammatory cytokines and reactive oxygen and nitrogen species (ROS and RNS) via M1 polarization, leading to the effective immunotherapy for colorectal cancer in vivo. In contrast, the LA-WS2 M2 immunoswitch induces the elevated production of anti-inflammatory cytokines and scavenging of ROS and RNS through M2 polarization, resulting in superior immunotherapy for severe sepsis in mice. These nanosheet immunoswitches can provide a route to immunotherapy for various cancers and inflammatory diseases.

Anas barbariae 200K Modulates Cell Stiffness and Oxidative Stress in Microglial Cells In Vitro

Anas barbariae 200K, a homeopathic medicine, is traditionally used for influenza-like illnesses. We investigated the effects of Anas barbariae 200K on microglial cells, a subpopulation of macrophages specific to the central nervous system often used to study the inflammatory processes and oxidative stress generated during influenza-like episodes. The study demonstrates the effect of Anas barbariae 200K on cell stiffness and the reactive oxygen species production using atomic force microscopy and fluorescence microscopy techniques, respectively. Our results showed that Anas barbariae 200K rapidly increased cell stiffness in resting cells by 41% compared with the vehicle. In inflamed cells, cell stiffness was decreased by 21% when treated with Anas barbariae 200K compared with the vehicle. Finally, Anas barbariae 200K caused a reorganisation of filamentous actin, with marked relocation of actin at the cell extremities. Moreover, Anas barbariae 200K significantly decreased the reactive oxygen species (ROS) production in inflamed microglial cells by 40% (total intracellular ROS) and by 67% (mitochondrial ROS) compared with the vehicle. These results strongly suggest an effect of Anas barbariae 200K at a cellular level on cell stiffness and actin cytoskeleton. This sheds light on the biological mechanism of action of this homeopathic preparation.

Macrophage Responses to Multicore Encapsulated Iron Oxide Nanoparticles for Cancer Therapy

Macrophages are the primary cells responsible for nanoparticle processing and mediating host immunological biological outcomes. Their cellular response to nanoparticles is a vital constituent in the safety assessment of new designs for clinical application. An approach for the treatment of solid tumors was developed, based on magnetic hyperthermia, consisting of iron oxide multicore encapsulated nanoparticles named Sarah nanoparticles (SaNPs), and alternating magnetic field irradiation. SaNPs are intravenously injected, accumulate in the liver, spleen and in tumor tissue, where they are passively targeted to malignant cells via the Enhanced Permeability and Retention (EPR) effect and undergo selective heating. SaNP-induced responses after cellular uptake were investigated in murine RAW264.7 macrophages using a wide imaging approach. When activated, macrophages form different phenotypic populations with unique immune functions, however the mechanism/s by which these activated macrophages respond to nanoparticles is unclear. Unraveling these responses is important for the understanding of nanoparticle uptake, potential degradation, and clearance to address both toxicity and regulatory concerns, which was the aim of this study. The results demonstrated that SaNPs undergo internalization, localize within the lysosomal compartment while keeping their integrity, without intracellular toxic degradation, and are cleared with time. The production of tumor necrosis factor alpha (TNF-α) and reactive oxygen species (ROS), superoxide dismutase (SOD) activation, and cytokine secretion in macrophage conditioned medium (CM) were also evaluated. SaNPs effects were both time- and dose- dependent. High SaNP concentrations resulted in reduced RAW264.7 cell viability which correlated with SOD activation and was associated with ROS generation. Lower SaNP concentrations stimulated the time-dependent production of TNF-α. The expression of additional cytokines was also induced, potentially affecting cancer cell growth by CM from SaNP-activated macrophages supporting a potential antitumor effect. These results will help understand the fate of nanoparticles in vivo.

Shedding light on microglial dysregulation in Alzheimer's disease: exploring molecular mechanisms and therapeutic avenues

Alzheimer's disease (AD) stands out as the foremost prevalent neurodegenerative disorder, characterized by a complex etiology. Various mechanisms have been proposed to elucidate its onset, encompassing amyloid-beta (Aβ) toxicity, tau hyperphosphorylation, oxidative stress and reactive gliosis. The hallmark of AD comprises Aβ and tau aggregation. These misfolded protein aggregates trigger the activation of glial cells, primarily microglia. Microglial cells serve as a major source of inflammatory mediators and their cytotoxic activation has been implicated in various aspects of AD pathology. Activated microglia can adopt M1 or M2 phenotypes, where M1 promotes inflammation by increasing pro-inflammatory cytokines and M2 suppresses inflammation by boosting anti-inflammatory factors. Overexpressed pro-inflammatory cytokines include interleukin (IL)-1β, IL-6 and tumor necrosis factor-α (TNF-α) in adjacent brain regions. Furthermore, microglial signaling pathways dysregulated in AD are myeloid differentiation primary-response protein 88 (Myd 88), colony-stimulating factor-1 receptor (CSF1R) and dedicator of cytokinesis 2 (DOCK2), which alter the physiology. Despite numerous findings, the causative role of microglia-mediated neuroinflammation in AD remains elusive. This review concisely explores cellular and molecular mechanisms of activated microglia and their correlation with AD pathogenesis. Additionally, it highlights promising therapeutics targeting microglia modulation, currently undergoing preclinical and clinical studies, for developing effective treatment for AD.

Nutritional and inflammatory status dynamics reflect preoperative treatment response and predict prognosis in locally advanced rectal cancer: A retrospective multi-institutional analysis

BACKGROUND

Systemic inflammation, as an important host property, is the most representative tumor-host interactions in cancer, and the development of malignant neoplasms may contribute to impairment on nutritional status. This study aimed to investigate the potential ability of nutritional and inflammatory index in predicting neoadjuvant chemoradiotherapy efficacy and prognosis in locally advanced rectal cancer (LARC).

METHODS

This study was conducted using multi-institutional data. A total of 507 patients (262 in the training and 245 in the validation cohort) with stage IIA-IIIC LARC fit for neoadjuvant chemoradiotherapy were recruited from 2012 to 2014 were included in this study. Advanced lung cancer inflammation index (ALI) reflected nutritional and inflammatory status. The ALI was calculated as body mass index (BMI) × albumin × neutrophil/lymphocyte. Logistic regression model was used to identify predictive factors for preoperative treatment response. Cox multivariate regression models were used to analyze the factors affecting disease-free survival (DFS) and overall survival (OS).

RESULTS

In the training cohort, patients with high pretreatment ALI were observed to be associated with young patients, never smoked, relatively high BMI, and early-stage pathologic TNM staging. The receiver operating characteristic curve indicated that pretreatment ALI and its changing was the single most important factor determining outcomes than other inflammatory indicators. The 10-year DFS and OS rates of the whole group were 63.6% and 74.1% respectively. Patients with low pretreatment ALI and ALI change had significantly poorer 10-year DFS (P < .001 and P = .001) and 10-year OS (P = .002 and P = .025) rates than those with high ALI and ALI change. Similar findings were observed in the validation cohort. Multivariate analysis revealed that pretreatment ALI (P = .047 and P = .006) and ALI change (P = .027 and P = .041) were identified as independent prognostic factors for DFS. Meanwhile, high pretreatment ALI (P = .020 and P = .010), high systemic immune-inflammation index (SII) change (P = .040 and P = .012) and clinical stage T2-T3 were independent protective factors for OS. Furthermore, multivariate logistic regression analyses revealed that pretreatment ALI, ALI change, and SII change could independently predict efficacy of neoadjuvant chemoradiotherapy.

CONCLUSION

Our results suggest that as a feasible indicator of nutritional and inflammatory status, the ALI shows better efficiency than other inflammatory indicators in predicting efficacy of neoadjuvant chemoradiotherapy and prognosis.

Enhancement of Bone Tissue Regeneration with Multi-Functional Nanoparticles by Coordination of Immune, Osteogenic, and Angiogenic Responses

Inorganic nanoparticles are promising materials for bone tissue engineering due to their chemical resemblance to the native bone structure. However, most studies are unable to capture the entirety of the defective environment, providing limited bone regenerative abilities. Hence, this study aims to develop a multifunctional nanoparticle to collectively control the defective bone niche, including immune, angiogenic, and osteogenic systems. The nanoparticles, self-assembled by biomimetic mineralization and tannic acid (TA)-mediated metal-polyphenol network (MPN), are released sustainably after the incorporation within a gelatin cryogel. The released nanoparticles display a reduction in M1 macrophages by means of reactive oxygen species (ROS) elimination. Consequently, osteoclast maturation is also reduced, which is observed by the minimal formation of multinucleated cells (0.4%). Furthermore, the proportion of M2 macrophages, osteogenic differentiation, and angiogenic potential are consistently increased by the effects of magnesium from the nanoparticles. This orchestrated control of multiple systems influences the in vivo vascularized bone regeneration in which 80% of the critical-sized bone defect is regenerated with new bones with mature lamellar structure and arteriole-scale micro-vessels. Altogether, this study emphasizes the importance of the coordinated modulation of immune, osteogenic, and angiogenic systems at the bone defect site for robust bone regeneration.

The Role of mtDNA Mutations in Atherosclerosis: The Influence of Mitochondrial Dysfunction on Macrophage Polarization

Atherosclerosis is a complex inflammatory process associated with high-mortality cardiovascular diseases. Today, there is a growing body of evidence linking atherosclerosis to mutations of mitochondrial DNA (mtDNA). But the mechanism of this link is insufficiently studied. Atherosclerosis progression involves different cell types and macrophages are one of the most important. Due to their high plasticity, macrophages can demonstrate pro-inflammatory and pro-atherogenic (macrophage type M1) or anti-inflammatory and anti-atherogenic (macrophage type M2) effects. These two cell types, formed as a result of external stimuli, differ significantly in their metabolic profile, which suggests the central role of mitochondria in the implementation of the macrophage polarization route. According to this, we assume that mtDNA mutations causing mitochondrial disturbances can play the role of an internal trigger, leading to the formation of macrophage M1 or M2. This review provides a comparative analysis of the characteristics of mitochondrial function in different types of macrophages and their possible associations with mtDNA mutations linked with inflammation-based pathologies including atherosclerosis.

Anodized Ti6Al4V-ELI, electroplated with copper is bactericidal against Staphylococcus aureus and enhances macrophage phagocytosis

Implants aim to restore skeletal dysfunction associated with ageing and trauma, yet infection and ineffective immune responses can lead to failure. This project characterized the microbiological and host cell responses to titanium alloy with or without electroplated metallic copper. Bacterial viability counting and scanning electron microscopy quantified and visualized the direct and indirect bactericidal effects of the Cu-electroplated titanium (Cu-Ep-Ti) against two different Staphylococcus aureus strains. Human THP-1 macrophage adhesion and viability was analyzed, along with phagocytosis. Results showed potent antimicrobial activity alongside promising host-immunomodulatory properties. Direct and indirect exposure to Cu-Ep-Ti produced potent bactericidal effects resulting in 94-100% reductions in bacterial viability at 24 h, with complete eradication in some cases. As expected, cytotoxicity was observed in THP-1 macrophages without media exchange, though when media was exchanged at 8, 24 and 48 h cell viability was equivalent to Control-Ti. Interestingly macrophages adhered to the copper material or grown in the presence of copper ions showed 7-fold increase in phagocytosis of S. aureus bioparticles compared to Control-Ti, suggesting a dual bactericidal and host immunomodulatory mechanism. In conclusion, this Cu-electroplated Ti biomaterial can limit bacterial contamination on the implant surface, whilst simultaneously promoting a beneficial antimicrobial immune response.

Immunomodulatory activity of Trypanosoma cruzi recombinant antigen combination TSA-1-C4 and Tc24-C4 induce activation of macrophages and CD8+ T cells

Chagas disease is a chronic infection caused by the protozoan parasite, Trypanosoma cruzi, with limited benefits of the currently available anti-parasitic chemotherapeutic approaches to halt the progression of heart disease. Recombinant TSA-1-C4 and Tc24-C4 proteins have been developed as promising antigen candidates for therapeutic vaccines, leading to propose them in combination as a bivalent recombinant protein strategy. In this study, we evaluated the immunomodulatory effect of the combined TSA-1-C4 and Tc24-C4 recombinant proteins by in vitro assays using murine macrophages. Macrophages from naïve Balb/c mice were isolated and stimulated with TSA-1-C4 plus Tc24-C4 recombinant proteins, hence, supernatants were recovered to measure host NO, H2O2, as well as, TNF-α, IL-1β, IL-6 and IL-10 cytokine responses. Later, stimulated macrophages were co-cultured with CD8+ T cells from naïve mice, and inflammatory cytokine-profiles were measured from supernatants. We observed that combining both antigens promotes the activation of host macrophages by NO and H2O2 release; moreover, these macrophages also induced considerable pro-inflammatory immune-responses mediated by TNF-, IL-1β and IL-6 cytokines compared to either TSA-1-C4 or Tc24-C4 stimulated macrophages. In addition, naïve CD8+ T cells in presence of TSA-1-C4 plus Tc24-C4 stimulated-macrophages similarly boosted the pro-inflammatory immune profile by significant production of IFN-γ and TNF-α cytokines. These results support immunological advantages for the use of TSA-1-C4 and Tc24-C4 combination as vaccine candidates against T. cruzi.

Bioluminescent Probes for the Detection of Superoxide and Nitric Oxide

The regulation of reactive oxygen species (ROS) such as superoxide (SO) and nitric oxide (NO) is crucial in biology, influencing metabolism and signaling pathways. Imbalances in these species lead to oxidative stress and various diseases. Traditional methods for measuring SO and NO face challenges in terms of sensitivity and specificity, particularly in complex biological matrices. This report introduces bioluminescent probes that leverage the intrinsic sensitivity of bioluminescence for direct and selective detection of SO and NO. These probes release analogs of d-luciferin upon reaction with their target ROS. Following addition of luciferase, luminescence is generated proportional to the amount of accumulated luciferin, allowing for quantitation of SO or NO. Both probes exhibit high specificity, confirmed through cell-free assays and cell-based studies in macrophages, demonstrating their utility in measuring cellular SO and NO production. These assays offer a robust, high-throughput platform for studying ROS, providing direct insights into oxidative stress-related mechanisms.

Development and characterization of a chicory extract fermented by Akkermansia muciniphila: An in vitro study on its potential to modulate obesity-related inflammation

Obesity, the fifth leading cause of death globally and linked to chronic low-grade inflammation and development of numerous severe pathologies, is a major public health problem. Fermented foods, probiotics, and postbiotics emerge as promising avenues for combating obesity and inflammation. The aim of our study was to develop and characterize phyto-postbiotics corresponding to prebiotic compounds fermented by gut bacteria, which could act on obesity and related-inflammation. Chicory extract fermented by Akkermansia muciniphila (C-Akm) was selected as the most antioxidant of 20 fermented extracts. The identification of metabolites derived from C-Akm extract has enabled us to detect mostly amino acids, acids, and some polyphenols (daidzein and genistein). The anti-inflammatory and anti-obesity activities of C-Akm extract were studied by testing the extract (50 μg/mL) on the polarization of THP-1 into macrophages, the secretion of pro-inflammatory cytokines in LPS-stimulated PBMCs, and the secretion of leptin and adiponectin in adipospheroids derived from human adipose stem cells. Finally, the extract was examined in 3D co-culture model mimicking inflamed obese adipose tissue. We found that C-Akm extract decreased ROS generation, TNF-α and Il-6 gene expression in polarized macrophages, INFγ and IL-17A secretion in LPS-stimulated PBMCs stimulated with LPS. It also decreased leptin expression while increasing adiponectin and HSL expression levels in both adipocytes and co-cultures. In addition, C-Akm extract stimulated adiponectin secretion in the co-culture model. Finally, our in vitro investigations demonstrated the potential benefits of C-Akm extract in the prevention and treatment of obesity-related inflammation.

Regulation of nitric oxide generation and consumption

Nitric oxide (NO), originally discovered for its role in cardiovascular function, is a key molecule in physiological processes including metabolism, neurotransmission (including memory, learning, neuroprotection and synaptic plasticity), immunity, reproduction, and much more. NO can be synthesized by the catalytic activity of the enzyme nitric oxide synthase (NOS), which is found biologically in three isoforms, or nonenzymatically based on simple reduction of nitrate and nitrite or by the NO-donor S-nitrosothiol (R-SNO). Importantly, the deficiency of NO has been noted in a wide range of pathologies including cardiovascular disease, cancer, erectile dysfunction, male and female infertility, and mitochondrial disease. While there are several pathways that can lead to a reduction in the bioavailability of NO (i.e., consumption, inhibition, and substrate competition) it is the conclusion of the authors that multiple pathways co-exist in pathological states. This article outlines for the first time the major pathways of NO generation, the importance of NO in health, NO scavenging and enzyme inhibition, and the potential benefits of supplementation.

Bioactive Compounds from Vegetal Organs of Taraxacum Species (Dandelion) with Biomedical Applications: A Review

Taraxacum officinale (dandelion) is a perennial flowering plant of the Asteraceae family that has spread globally and is well-known for its traditional uses. The aim of this work is to provide a detailed review of scientific literature on the genus Taraxacum from the last two decades, with particular emphasis on the biological and pharmacological characteristics of dandelions. The traditional use of Taraxacum species and their potential use in medicine are assessed. In addition, individual papers describing principal pathways and molecules modulated by Taraxacum in antitumoral, anti-inflammatory, antidiabetic, hepatoprotective, immunomodulatory, antimicrobial, and antioxidant activities are presented. This review of phytochemical studies reveals that dandelions contain a wide range of bioactive compounds, such as polyphenols, phytosterols, flavonoids, carotenoids, terpene, and coumarins, whose biological activities are actively explored in various areas of human health, some constituents having synergistic activities, including antioxidant, antimicrobial, anti-inflammatory and anticancer activities. The study provides a screening of Taraxacum sp. chemical composition, an assessment of the main pharmacological properties, and a description of relevant studies supporting the use of dandelion for its particularly valuable and diversified therapeutic potential in different diseases.

Anti-inflammatory properties of ophioglonin derived from the fern Ophioglossum vulgatum L. via inactivating NF-κB and MAPK signaling pathways

Medicinal plants contain bioactive compounds that have therapeutic effects on human health. Ophioglossum vulgatum L. is a representative species of the fern genus Ophioglossum that has anti-inflammatory properties as recognized in folk medicine. Herein, we performed a nitric oxide (NO) assay-guided screening in RAW264.7 cells to investigate the active components of the plant. We found that ophioglonin (OPN), a characteristic homoflavonoid of the genus Ophioglossum, is one of the bioactive components. Therefore, we performed a comparative analysis of the isolated compounds and found that OPN has effects similar to those of isolated dihydroquercetin and luteolin at the concentrations tested. The antioxidant and anti-inflammatory activities of OPN were extensively validated using lipopolysaccharide -stimulated RAW264.7 cells, mouse bone marrow-derived macrophages (BMDMs), and peritoneal exudate macrophages (PEMs). In vivo experiments with a carrageenan-induced mouse paw edema model further confirmed the anti-inflammatory effect of OPN. Additionally, we found that OPN and Ophioglossum vulgatum extracts inhibit the activation of signal transducers, NF-ĸB p65, IĸBα, ERK, p38, and JNK, consistent with the findings of pathway enrichment analysis. This work reinforces the anti-inflammatory properties of Ophioglossum vulgatum and indicates that OPN is a promising therapeutic agent for inflammation-associated disorders. Further clinical evaluations, including clinical trials, would be beneficial to validate the anti-inflammatory properties of OPN.

Mechanistic insights into the anti-oxidative and anti-inflammatory functions of covalent-reactive cinnamyl compounds within Cinnamomum cassia

BACKGROUND

Cinnamomum cassia Presl (Lauraceae) is widely used as a medicinal plant in the folk medicine and pharmaceutic industry, for its promising anti-inflammatory, anti-oxidative, and anti-bacterial function. However, the major bioactive components were still in debate, and their underlying molecular mechanism was not yet fully understood.

PURPOSE

This study aimed to identify the bioactive ingredients of C. cassia and investigate the molecular mechanism using in vitro and in silico methods.

METHODS

UPLC-QTOF/MS/MS analysis was used to characterize the chemical constituents of alcoholic extract from C. cassia. Reduced glutathione was employed to deplete covalent active cinnamyl compounds. Subsequently, the anti-inflammatory and antioxidant effects of covalent reactive and non-covalent reactive ingredients from C. cassia extract were compared. Their molecular mechanisms were investigated using untargeted metabolomics, in vitro assays, surface plasmon resonance (SPR), and molecular modeling.

RESULTS

Chemical analysis and in vitro assays confirmed the covalent reactive cinnamyl compounds, such as cinnamaldehyde and 2-methoxycinnamaldehyde, exhibited anti-inflammatory and anti-oxidative activity on LPS-stimulated macrophages. Untargeted metabolomics revealed that cinnamaldehyde, one of the covalent reactive cinnamyl compounds, primarily affected amino acid metabolism, and glucose metabolism, promoted glutathione synthesis within LPS-stimulated macrophages, and affected the metabolic profile of M1 macrophages. Consistent with these findings, cinnamaldehyde significantly increased glutathione synthesis and induced glutathione efflux from murine macrophages. In contrast to the literature data, we observed that cinnamaldehyde did not cause GSH depletion, nor elevate the expression of glutamate-cysteine ligase (GCL) in proinflammatory macrophages at low concentrations. The SPR experiment and molecular modeling demonstrated that GCLC was the potential target of cinnamaldehyde.

CONCLUSIONS

Our study not only demonstrated the reactive cinnamyl species as the principal antioxidative component of C. cassia but also unveiled a novel molecular mechanism whereby covalent reactive compounds exert their antioxidative effects through covalent modification of GCLC at its active center.

Proteoglycan 4 (Lubricin) and regulation of xanthine oxidase in synovial macrophage as a mechanism of controlling synovitis

BACKGROUND

Synovial macrophages (SMs) are important effectors of joint health and disease. A novel Cx3CR1 + TREM2 + SM population expressing the tight junction protein claudin-5, was recently discovered in synovial lining. Ablation of these SMs was associated with onset of arthritis. Proteoglycan 4 (PRG4) is a mucinous glycoprotein that fulfills lubricating and homeostatic roles in the joint. The aim of this work is to study the role of PRG4 in modulating synovitis in the context of SM homeostasis and assess the contribution of xanthine oxidase (XO)-hypoxia inducible factor alpha (HIF-1a) axis to this regulation.

METHODS

We used Prg4FrtloxP/FrtloxP;R26FlpoER/+, a novel transgenic mouse, where the Prg4Frt allele normally expresses the PRG4 protein and was designed to flank the first two exons of Prg4 with a flippase recognition target and "LOXP" sites. Inducing flippase activity with tamoxifen (TAM) inactivates the Frt allele and thus creates a conditional knockout state. We studied anti-inflammatory SMs and XO by quantitative immunohistochemistry, isolated RNA and studied immune pathway activations by multiplexed assays and isolated SMs and studied PRG4 signaling dysfunction in relation to glycolytic switching due to pro-inflammatory activation. Prg4 inactivated mice were treated with oral febuxostat, a specific XO inhibitor, and quantification of Cx3CR1 + TREM2 + SMs, XO immunostaining and synovitis assessment were conducted.

RESULTS

Prg4 inactivation induced Cx3CR1 + TREM2 + SM loss (p < 0.001) and upregulated glycolysis and innate immune pathways in the synovium. In isolated SMs, Xdh (p < 0.01) and Hif1a (p < 0.05) were upregulated. Pro-inflammatory activation of SMs was evident by enhanced glycolytic flux and XO-generated reactive oxygen species (ROS). Febuxostat reduced glycolytic flux (p < 0.001) and HIF-1a levels (p < 0.0001) in SMs. Febuxostat also reduced systemic inflammation (p < 0.001), synovial hyperplasia (p < 0.001) and preserved Cx3CR1 + TREM2 + SMs (p < 0.0001) in synovia of Prg4 inactivated mice.

CONCLUSIONS

PRG4 is a biologically significant modulator of synovial homeostasis via inhibition of XO expression and downstream HIF-1a activation. PRG4 signaling is anti-inflammatory and promotes synovial homeostasis in chronic synovitis, where direct XO inhibition is potentially therapeutic in chronic synovitis.

Facts, Dogmas, and Unknowns About Mitochondrial Reactive Oxygen Species in Cancer

Cancer metabolism is sustained both by enhanced aerobic glycolysis, characteristic of the Warburg phenotype, and oxidative metabolism. Cell survival and proliferation depends on a dynamic equilibrium between mitochondrial function and glycolysis, which is heterogeneous between tumors and even within the same tumor. During oxidative phosphorylation, electrons from NADH and FADH2 originated in the tricarboxylic acid cycle flow through complexes of the electron transport chain. Single electron leaks at specific complexes of the electron transport chain generate reactive oxygen species (ROS). ROS are a concentration-dependent double-edged sword that plays multifaceted roles in cancer metabolism. ROS serve either as signaling molecules favoring cellular homeostasis and proliferation or damage DNA, protein and lipids, causing cell death. Several aspects of ROS biology still remain unsolved. Among the unknowns are the actual levels at which ROS become cytotoxic and if toxicity depends on specific ROS species or if it is caused by a cumulative effect of all of them. In this review, we describe mechanisms of mitochondrial ROS production, detoxification, ROS-induced cytotoxicity, and the use of antioxidants in cancer treatment. We also provide updated information about critical questions on the biology of ROS on cancer metabolism and discuss dogmas that lack adequate experimental demonstration. Overall, this review brings a comprehensive perspective of ROS as drivers of cancer progression, inducers of cell death, and the potential use of antioxidants as anticancer therapy.