Myeloperoxidase: friend and foe

Disinfectants and one health review: The role of reactive oxygen species in the bactericidal activity of chlorine against Salmonella

Salmonella are among the most common foodborne pathogens in humans, and they are associated with mild to severe diseases commonly referred to as salmonellosis. The genus resides in various animals' intestinal tracts, including humans. It is one of the most diverse genera of bacteria, including over 2500 serovars. Consumption of poultry products contaminated with Salmonella is a significant source of disease transmission in humans. Because of this food safety concern, the poultry industry and governments spend billions of dollars on Salmonella containment methods. However, a completely effective strategy is yet to be established. Chlorine has been commonly used as a disinfectant in the poultry industry. In humans, antibiotic therapy is the primary means for managing Salmonella infection. However, widespread use of both compounds at sub-inhibitory concentrations has allowed resistant strains to emerge and rapidly spread globally. Both antimicrobial compounds involve generating reactive oxygen species (ROS) as a bactericidal mechanism of action. However, ROS generation and its association with bacterial survival and growth inhibition have not been widely explored. Thus, a better understanding of ROS generation during antimicrobial treatments may help devise better Salmonella containment strategies.

Shared Phenotypes of Immune Cells Recruited to the Cornea and the Surface of the Lens in Response to Formation of Corneal Erosions

Injuries to the cornea can lead to recurrent corneal erosions, compromising its barrier function and increasing the risk of infection. Vital as corneal integrity is to the eye's optical power and homeostasis, the immune response to corneal erosions remains poorly understood. It is also unknown whether there is coordinated immune activation between the cornea and other regions of the anterior segment to protect against microbial invasion and limit the spread of inflammation when corneal erosions occur. Herein, a corneal debridement wounding model was used to characterize the immune cell phenotypes populating the cornea in response to erosion formation, and whether and which immune cells are concurrently recruited to the surface of the lens was investigated. The formation of corneal erosions induced an influx of myeloid lineage phenotypes, both M2 macrophages associated with tissue healing and wound repair, and Ly6G+ Ly6C+ myeloperoxidase+ cells resembling neutrophils/polymorphonuclear-myeloid-derived suppressor cells (PMN-MDSCs), with few regulatory T cells, into the corneal stroma under erosion sites. This leukocyte migration into the cornea when erosions develop was paralleled by the recruitment of immune cells, predominantly neutrophils/PMN-MDSCs, to the anterior, cornea-facing lens capsule. Both cornea-infiltrating and lens capsule-associated neutrophil/PMN-MDSC-like immune cells produce the anti-inflammatory cytokine IL-10. These findings suggest a collaborative role for the lens capsule-associated immune cells in preventing infections, controlling inflammation, and maintaining homeostasis of the anterior segment during recurrent corneal erosions.

From infection to infertility: a review of the role of human papillomavirus-induced oxidative stress on reproductive health and infertility

Infertility has emerged as a significant global health concern, affecting nearby 8-12% of couples in reproductive age worldwide. Increasing evidence suggests a potential link between human papillomavirus (HPV) and infertility in both men and women. Some research indicate that HPV can infect various components of semen, potentially affecting sperm quality by decreasing motility, viability, and increasing DNA fragmentation, all of which may contribute to male infertility. The virus can attach to the equatorial region of the sperm head, enabling infected sperm to transmit the virus to the oocyte or placenta. Consequently, HPV potentially induces apoptosis in trophoblastic cells and disrupts their adhesion to endometrial cells, which raises the risk of miscarriage. HPV may also affect ovarian reserve by causing chronic inflammation, which can impair granulosa cell function and lower serum anti-Müllerian hormone (AMH) levels. Besides, HPV-related immune responses also contribute to infertility by producing anti-sperm antibodies (ASAs), which cause sperm clumping, reduce motility through cervical mucus, activate the complement system that damages sperm in the female reproductive tract and interfere with sperm-egg interactions. Moreover, HPV infection has been linked to reduced success rates in assisted reproductive technologies (ART), potentially disrupting critical processes such as the acrosome reaction, sperm-oocyte interaction, and fusion. One potential mechanism through which HPV contributes to infertility is oxidative stress (OS). Triggered OS can negatively impact sperm quality and cause damage to the female reproductive system, ultimately contributing to infertility. Despite these associations, the precise mechanisms and the strength of the relationship remain uncertain. Thus, this review seeks to investigate the potential impact of HPV on infertility, particularly its effects on the reproductive system through OS. A clearer understanding of these processes could inform future health strategies for addressing HPV-related infertility.

The potential role of leukocytes cell population data (CPD) for diagnosing sepsis in adult patients admitted to the intensive care unit

OBJECTIVES

The aim of the study was to evaluate the predictive value of cell population data (CPD) parameters in comparison with procalcitonin (PCT) and C-reactive protein (CRP) for an early diagnosis of sepsis in intensive care unit (ICU). The effect of renal function on CPD, PCT and CRP, in septic and non-septic patients was also investigated.

METHODS

This is a retrospective, observational and single-center study, performed with data collected from patients consecutively admitted to the ICU of the Edoardo Bassini Hospital in Milan. Patients were divided in septic and non-septic according to Sepsis-III criteria. The control group was formed by critically ill patients without sepsis. Patients with sepsis were further divided in patients with sepsis and patients with septic shock.

RESULTS

A significant difference between septic and non-septic patients was found for neutrophils complexity (NE-SSC), neutrophils fluorescence intensity (NE-SFL), width of dispersion of neutrophils fluorescence (NE-WY), monocytes complexity (MO-X), monocytes fluorescence intensity (MO-Y), PCT and CRP parameters. PCT, neutrophils sixe (NE-FSC), NE-WY, width of dispersion of neutrophils size (NE-WZ) and MO-X discriminated sepsis and septic-shock patients. CPD parameters were not influenced by renal function. CPD, PCT and CRP had a heterogeneous diagnostic performance efficiency in the prediction of sepsis. Overall, NE-SSC, NE-SFL, width of dispersion of neutrophils complexity (NE-WX), MO-X, MO-Y, PCT and CRP displayed the best diagnostic performance for sepsis.

CONCLUSIONS

This study suggested that some CPD parameters (i.e., NE-SFL and MO-X) might provide useful information for diagnosis and management of sepsis.

A phenothiazine-based ratiometric fluorescent probe for detecting hypochlorite (ClO-) and its application in foods and water samples

As a significant reactive oxygen species (ROS), ClO- plays versatile roles in daily life and many biological events. However, its abnormal levels are responsible for serious harm to human health. Therefore, it is of crucial interest to develop effective methods for detecting ClO- in foods and living organisms. In this work, a novel fluorescent probe ethyl 2-(3-formyl-2-methoxy-10H-phenothiazin-10-yl)acetate (PEA) for detecting ClO- was presented. It shows the merits of rapid ratiometric response (within 10 s), high selectivity and very large Stokes shift (190 nm). The detection limit of PEA for ClO- was determined to be 0.47 μM. We not only successfully prepared paper test strips for efficient qualitative naked eye ClO- detection, but also demonstrated its potential for the valid detection of ClO- in natural water samples, beverages and foods. Furthermore, the probe PEA was also applied to the fluorescence imaging of ClO- in onion epidermal cells.

Electrophilic Susceptibility of Graphene Quantum Dots: Hypochlorous versus Hypobromous Acids-Experimental and Theoretical Study

Graphene quantum dots (GQDs) are water-soluble, are biocompatible, and exhibit low toxicity. These properties, along with their adjustable and efficient fluorescent emission, make GQDs valuable for biological applications, particularly as spectroscopic nanosensors. In this context, GQDs have been utilized to detect hypochlorous acid (HOCl). While HOCl is a well-known synthetic disinfectant, it is also naturally produced by the enzyme myeloperoxidase (MPO) in mammals. This heme-peroxidase also catalyzes the production of hypobromous acid (HOBr), a more potent halogenating agent. In our study, we compared the reactivity of HOCl and HOBr with GQDs. By monitoring the fluorescence bleaching of the GQDs, we demonstrated that HOBr is more reactive than HOCl. The increased reactivity was attributed to HOBr's higher electrophilicity. The electrophilic nature of the reaction was further confirmed by introducing nicotine as a chlorination catalyst. Anisole did not inhibit the electrophilic attack, confirming the high reactivity of GODs with HOBr. The enzyme MPO was used to generate HOBr through oxidation of Br- by H2O2. Thus, the enzymatic activity of MPO could be monitored by GQDs' fluorescence bleaching, and the efficiency of MPO inhibitors could be evaluated. We applied differential function theory (DFT) methodologies to support our experimental findings, proposing a transition state for the electrophilic attack. Consistent with our experimental results, the energetic barrier for the reaction with HOBr was lower than that for HOCl. Overall, our results indicate the susceptibility of GQDs to electrophilic attacks by hypohalous acids and highlight new opportunities for biological applications.

The interplay between the myeloperoxidase-hypochlorous acid system, heme oxygenase, and free iron in inflammatory diseases

Accumulated unbound free iron (Fe(II or III)) is a redox engine generating reactive oxygen species (ROS) that promote oxidative stress and inflammation. Iron is implicated in diseases with free radical pathology including cardiovascular, neurodegenerative, reproductive disorders, and some types of cancer. While many studies focus on iron overload disorders, few explore the potential link between the myeloperoxidase-hypochlorous acid (MPO-HOCl) system and localized iron accumulation through heme and iron‑sulfur (FeS) cluster protein destruction. Although inducible heme oxygenase (HO-1), the rate-limiting enzyme in heme catabolism, is frequently associated with these diseases, we hypothesize that HOCl also contributes to the generation of free iron and heme degradation products. Furthermore, HO-1 and HOCl may play a dual role in free iron accumulation by regulating the activity of key iron metabolism proteins. Enzymatic and non-enzymatic modulators, as well as scavengers of HOCl, can help prevent heme destruction and reduce the accumulation of free iron. Given iron's role in disease progression and severity, identifying the primary sources, mechanisms, and mediators involved in free iron generation is crucial for developing effective pharmacological treatments. Further investigation focusing on the specific contributions of the MPO-HOCl system and free iron is necessary to explore novel strategies to mitigate its harmful effects in biological systems.

A dual-responsive ratiometric fluorescent probe for the detection of hypochlorite and hydrazine in environmental samples, live cells, and plant tissues

Hypochlorite (ClO-), a potent oxidizer and disinfectant, and hydrazine, a powerful reducing agent, are widely used in daily life and various industries. However, their extensive use comes with significant risks, as they are highly toxic to both the environment and human health. They have been associated with various health issues and even linked to cancer. Therefore, the simultaneous detection of hypochlorite and hydrazine is crucial for assessing their impact and monitoring the onset and progression of related diseases. A phenanthroimidazole-indandione based colorimetric and ratiometric fluorescent probe PIID was designed and synthesized for dual channel detection of hypochlorite and hydrazine in environmental and biological samples. Probe PIID, which showed a strong yellow-orange emission at 640 nm with a massive Stokes shift of 220 nm, exhibited excellent fluorescence change from yellow-orange to green (526 nm) in the presence of ClO- and from yellow-orange to blue (424 nm) in the presence of hydrazine in an aqueous-THF solvent system. A strong ICT effect, which was acting in probe PIID, gets weakened through ClO- - mediated cleavage of the CC bridge bond to produce aldehyde PIB with a blue shift of 114 nm and hydrazine-induced hydrazinolysis of the indanedione moiety to form hydrazone compound PIBH with a blue shift of 216 nm and that was also confirmed by DFT studies. Not only that, the probe exhibits excellent selectivity over other ROS (reactive oxygen species) and amines with a very fast response time of 40 seconds for hypochlorite and 90 seconds for hydrazine, and high sensitivity was observed with detection limits of 32.75 nM for hypochlorite and 92 nM for hydrazine. Moreover, PIID was employed to monitor both the analytes successfully in environmental water samples and in a solid-state TLC strip study. Hypochlorite was monitored in commercial disinfectants, and by exogenous bioimaging in human breast cancer cells (MDA-MB 231) and endogenous bioimaging in RAW 264.7 macrophage cells with very low cytotoxicity and good cell viability. Meanwhile, hydrazine was tracked in soil samples, and confocal imaging was performed on onion tissue.

Effect of gamma-terpinene on the articular inflammatory response

This study investigates the anti-inflammatory and antinociceptive effects of gamma-terpinene (GT), a monoterpene present in essential oils, in models of acute joint inflammation and pain. GT was administered orally at doses of 25, 50, 75, and 100 mg/kg. Joint inflammation was induced by an intra-articular injection of zymosan to assess joint edema, leukocyte migration, and myeloperoxidase (MPO) enzyme activity. A carrageenan-induced paw edema model was used to evaluate edema and mechanical hyperalgesia, with measurements taken via plethysmometry and Von Frey testing. Results showed that GT significantly decreased leukocyte migration, joint edema, and MPO activity in the zymosan model, indicating an anti-inflammatory effect. In the carrageenan model, GT also demonstrated a dose-dependent reduction in paw edema and mechanical hyperalgesia, highlighting its analgesic potential. These findings support that GT possesses notable anti-inflammatory and antinociceptive properties, making it a promising candidate for natural therapeutic applications in managing inflammatory joint conditions. This suggests a potential role of GT as a natural alternative to NSAIDs and glucocorticoids (GCs), reducing inflammation while minimizing side effects. Future studies should explore its clinical applicability and long-term safety.

Preliminary study of neutrophils and neutrophil extracellular traps (NETs) in canine mammary tumors

Neutrophils play a complex role in cancer biology, can contributing to tumor progression and immune defense. Neutrophil extracellular traps (NETs) have emerged as key modulators within the tumor microenvironment. Herein, the association between molecular classification, histological grade, necrosis, tumor-infiltrating neutrophils, and NETs was assessed in 19 canine mammary malignant tumors. Immunohistochemistry using citrullinated histone-3 (cith3) and myeloperoxidase (MPO) antibodies were used to detect NETs. A fading and re-staining method was applied on the same sections. NETs were scored based on the presence of cith3 positive areas and compared with tumor grade. The neutrophil score numerically increased as the tumor grade increased. The NET score was slightly higher in grade I carcinomas compared to carcinomas with other grades. On contrary, the necrosis score was also higher in grade II and III tumors than grade I tumors. A low but non-significant negative correlation existed between tumor grade and NET score (r = -0.219). No statistically significant associations between the tumor markers (ER, PR, HER2) and molecular subtypes with tumor grade, NET score, neutrophil count, and necrosis. In this study, the presence of NETs in canine malignant mammary tumor of different histological subtypes and grades was reported. Preliminary evidence was gathered that NETs are negatively correlated with tumor grade, suggesting their potential role in prognostication.

To activate a G protein-coupled receptor permanently with cell surface photodynamic action in the gastrointestinal tract

Different from reversible agonist-stimulated receptor activation, singlet oxygen oxidation activates permanently G protein-coupled receptor (GPCR) cholecystokinin 1 (CCK1R) in type II photodynamic action, with soluble photosensitizer dyes (sulphonated aluminum phthalocyanine, λmax 675 nm) or genetically encoded protein photosensitizers (KillerRed λmax 585 nm; mini singlet oxygen generator λmax 450 nm), together with a pulse of light (37 mW/cm2, 1-2 minutes). Three lines of evidence shed light on the mechanism of GPCR activated by singlet oxygen (GPCR-ABSO): (1) CCK1R is quantitatively converted from dimer to monomer; (2) Transmembrane domain 3, a pharmacophore for permanent photodynamic CCK1R activation, can be transplanted to non-susceptible M3 acetylcholine receptor; and (3) Larger size of disordered region in intracellular loop 3 correlates with higher sensitivity to photodynamic CCK1R activation. GPCR-ABSO will add to the arsenal of engineered designer GPCR such as receptors activated solely by synthetic ligands and designer receptors exclusively activated by designer drugs, but show some clear advantages: Enhanced selectivity (double selectivity of localized photosensitizer and light illumination), long-lasting activation with no need for repeated drug administration, antagonist-binding site remains intact when needed, ease to apply to multiple GPCR. This type of permanent photodynamic activation may be applied to functional proteins other than GPCR.

Modulating Neutrophil Extracellular Trap Formation In Vivo with Locoregional Precision Using Differently Charged Self-Assembled Hydrogels

Neutrophil extracellular traps (NETs) are DNA networks released by neutrophils, first described as a defense response against pathogens but have since been associated with numerous inflammatory diseases. Diverse physical material properties have been shown to promote NET formation. Herein, we report the discovery that the charge of self-assembled peptide hydrogels predictably modulates the formation of NETs in vivo within the implanted material. Positively charged gels induce rapid NET release, whereas negatively charged gels do not. This differential immune response to our self-assembled peptide gels enabled the development of a material platform that allows rheostat-like modulation over the degree of NET formation with anatomical and locoregional control.

In-depth functional analysis of BRD9 in fetal hematopoiesis reveals context-dependent roles

The hierarchical organization of hematopoietic stem cells (HSCs) governing adult hematopoiesis has been extensively investigated. However, the dynamic epigenomic transition from fetal to adult hematopoiesis remains incompletely understood, particularly regarding the involvement of epigenetic factors. In this study, we investigate the roles of BRD9, an essential component of the non-canonical BAF (ncBAF) complex known to govern the fate of adult HSCs, in fetal hematopoiesis. Consistent with observations in adult hematopoiesis, BRD9 loss impairs fetal HSC stemness and disturbs erythroid maturation. Intriguingly, the impact on myeloid lineage was discrepant: BRD9 loss inhibited and promoted myeloid differentiation in fetal and adult models, respectively. Through comprehensive transcriptomic and epigenomic analysis, we elucidate the differential roles of BRD9 in a context- and lineage-dependent manner. Our data uncover how BRD9/ncBAF complex modulates transcription in a stage-specific manner, providing deeper insights into the epigenetic regulation underlying the transition from fetal to adult hematopoiesis.

Precise manipulation of iron spin states in single-atom catalytic membranes for singlet oxygen selective production

Heterogeneous single-atom catalysts are attracting substantial attention for selectively generating singlet oxygen (1O2). However, precise manipulation of atom coordination structures remains challenging. Here, the fine coordination structure of iron single-atom carbon-nitride catalysts (Fe-CNs) was manipulated by precisely tuning the heating rate with 1 °C min-1 difference. Multiple techniques in combination with density functional theory (DFT) calculations reveal that FeN6 coordination sites with high Fe spin states promote the adsorption, electron transfer, and dissociation of peroxymonosulfate (PMS), resulting in nearly 100% selection of 1O2 generation. A lamellar single atom catalytic membrane is constructed, exhibiting high permeance, high degradation, high-salinity resistance and sustained operation stability. This work provides ideas for regulating spin states of the metal site to fabricate catalysts with selective 1O2 generation for membrane separation and environment catalysis applications.

Kurarinone Attenuates LPS-Induced Pneumonia by Inhibiting MAPK and NF-κB Signaling Pathways

Kurarinone is a prenylated flavanone isolated from Sophora flavescens Aiton. This investigation aimed to elucidate whether kurarinone could ameliorate lipopolysaccharide (LPS)-induced pneumonia and explore the underlying mechanism. C57BL/6 mice were treated with LPS (50 μg/20 μL) to establish pneumonia models. Kurarinone (100 mg/kg) or dexamethasone (DEX, 5 mg/kg) was administered for 7 days before LPS inhalation. BEAS-2B cells were incubated with kurarinone at 1, 2, and 5 μM for 2 h before LPS stimulation for 24 h. We found that kurarinone ameliorated lung injury and inflammatory cell infiltration in the mouse lung (p < 0.001). Kurarinone decreased MPO activity (47.6%, p < 0.001) and alleviated the inflammatory response by reducing the levels of IL-1β (34.9%, p < 0.001), TNF-α (55.1%, p < 0.001), and IL-6 (36.2%, p < 0.001) in the lung. Kurarinone reduced the levels of IL-1β, TNF-α, IL-6, iNOS, and COX2 in LPS-treated BEAS-2B cells in a concentration-dependent manner (p < 0.05). Mechanistically, kurarinone restrained LPS-induced activation of MAPK and NF-κB pathways in vivo and in vitro (p < 0.05). Overall, kurarinone alleviates LPS-induced pneumonia in mice by reducing inflammation via MAPK and NF-κB pathways, suggesting that kurarinone might be a potential therapeutic agent for pneumonia. This study provides new research ideas for the discovery of natural flavonoids that can treat pneumonia.

Effects of aqueous extract of Waltheria indica (Sterculiaceae) leafy stems on acetic acid-induced ulcerative colitis in rats

Ulcerative colitis is one of the inflammatory bowel diseases that manifest itself by uncontrolled inflammation of colon. The objective of this work was to evaluate the effects of aqueous extract of Waltheria indica on acetic acid-induced ulcerative colitis in rats. Six (6) groups of five (5) rats each, were anesthetized with a ketamine (50 mg/kg)/valium (10 mg/kg) mixture after eighteen (18) fasting hours. Colitis was induced by intrarectal administration of 1 mL of acetic acid (5%) in animals. Five (5) hours later, the normal control (NC) and the colitis control (CC) received distilled water (10 mL/kg bw), the positive control (Pre5) received prednisolone (5 mg/kg) and the other three test groups received the W. indica extract at 50 (Wi50), 100 (Wi100) and 200 (Wi200) mg/kg bw, orally for 7 days. At the end of the treatment, the animals were sacrificed and the blood was collected from the carotid artery, part in the ethylenediaminetetraacetate (EDTA) tube for hematological analyzes and part in dry tubes for biochemical assays. The abdomen was then opened, the colon, liver, spleen, lungs and heart were removed, drained, weighed and the indexes of each organ were determined. The extract at 200 mg/kg reduced myeloperoxidase (MPO) and inhibited the production of interleukin-1 beta (IL-1β) and interleukin-6(IL-6) in the colon and serum. The extract significantly increased the blood platelet level of the colitis rats. Thus, these results suggest that Walthera indica extract may have therapeutic potential for the treatment of inflammatory bowel diseases.

Hypochlorous Acid-Activatable NIR Fluorescence/Photoacoustic Dual-Modal Probe with High Signal-to-Background Ratios for Imaging of Liver Injury and Plasma Diagnosis of Sepsis

Hypochlorous acid can be employed as a biomarker for blood infection (such as sepsis) and tissue damage (such as drug-induced liver injury, DILI), and the diagnosis of tissue damage or blood infection can be achieved through the detection of hypochlorous acid in relevant biological samples. Considering the complex environment and the diverse interferences in living organisms and blood plasma, developing new detection methods for HClO with high signal-to-background ratios is particularly important, and it can improve the accuracy of detection and quality of imaging based on a higher contrast, which makes the detection of HClO clearer and more accurate. Here, based on the advantages of the NIR fluorescence/photoacoustic dual-modal probe, we reported a hypochlorous acid-activatable NIR fluorescence/photoacoustic dual-modal probe (NIRF-PA-HClO) based on the spirolactam ring-opening strategy in this paper. NIRF-PA-HClO showed excellent NIRF/PA dual-modal responses with high SBRs for HClO in solution, cells, and mice. Moreover, NIRF-PA-HClO was successfully applied for high-contrast imaging of DILI. Finally, NIRF-PA-HClO was employed for the blood plasma diagnosis of sepsis with satisfactory results. In summary, the above results proved that NIRF-PA-HClO would be a potentially useful tool for the study of physiological and pathological roles of HClO, the investigation of the pathology and therapeutic mechanisms of hepatotoxicity, and the diagnosis of blood infection. Also, the development of NIRF-PA-HClO provides new design mentality for constructing other analyte-activatable NIRF/PA dual-modal probes with high SBRs.

Free Radical Scavenging Activity and Inhibition of Enzyme-Catalyzed Oxidation by trans-aryl-Palladium Complexes

Herein, nine square planar trans-arylbis(triphenylphosphine)palladium halides (PdX(PPh3)2Ar) were synthesized and fully characterized. The molecular structure of two complexes (1 and 2) have been determined by both X-ray diffraction and described thanks to Hirshfeld surface analysis. Investigation of the antioxidant activities showed that most of the complexes exhibit a strong dose-dependent radical scavenging activity towards DPPH radical as well as in the ABTS radical scavenging test. Complexes 1 [PdI(PPh3)2(4-MeOC6H4)] and 3 [PdCl(PPh3)2(4-MeOC6H4)] showed the highest activity in the DPPH assay with EC50 values of 1.14 ± 0.90 and 1.9 ± 0.87 µM, respectively. In contrast, for the ABTS assay, quercetin (5.56 ± 0.97 µM) was slightly more efficient than the three complexes 1 (5.78 ± 0.98 µM), 2 (7.01 ± 0.98 µM), and 3 (11.12 ± 0.94 µM). The use of kinetic studies as a powerful parameter shows that complexes 1, 2, and 3 displayed the best antioxidant efficiency. The antioxidant effect of the nine palladium complexes has been also evaluated on the enzyme-catalyzed oxidation of the L012 probe (using HRP/H2O2) by using a chemiluminescence technique. As with the last model, complexes 1, 2, and 3 showed the best activity, with EC50 values of 3.56 ± 1.87, 148 0.71, and 5.8 ± 2.60 µM, respectively. Interestingly, those complexes (1, 2, and 3) even exhibited a higher dose-dependent activity than the quercetin (7.06 ± 2.56 µM) used as a standard. Taken together, the combined results reveal that the antiradical and enzyme (HRP) inhibitory activity of complexes decrease following the ligand order of p-OMePh > p-OAcPh >> Ph.

Biodegradable semiconducting polymer nanoparticles for phototheranostics

Semiconducting polymer nanoparticles (SPNs) have been widely applied for phototheranostics. However, the disadvantage of in vivo long-term metabolism greatly suppresses the clinical application of SPNs. To improve the metabolic rate and minimize the long-term toxicity of SPNs, biodegradable semiconducting polymers (BSPs), whose backbones may be degraded under certain conditions, have been designed. This review summarizes recent advances in BSP-constructed nanoparticles (BSPNs) for phototheranostics. BSPs are divided into two categories: conjugated backbone degradable BSPs (CBD-BSPs) and non-conjugated backbone degradable BSPs (NCBD-BSPs), based on the feature of chemical structure. The biological applications, including cancer imaging and combination therapy, of these BSPNs are described. Finally, the conclusion and future perspectives of this field are discussed.

A novel multifunctional fluorescent probe with ESIPT and AIE effects for the detection of Co2+ and HClO

We developed a novel fluorescent probe featuring excited-state intramolecular proton transfer (ESIPT) and aggregation-induced emission (AIE) effects, which displayed dual-channel fluorescence emission. The probe detected both Co2+ and HClO with naked eye under daylight as well as through a fluorescence spectrophotometer. The probe exhibited a low detection limit for Co2+ at 2.823 μM, while the detection limit for HClO was 11.55 μM. When the probe (10 μM) was mixed with Co2+, the fluorescence intensity at 556 nm rapidly decreased within 10 minutes and stabilized after 40 minutes, while for HClO, it took 960 min to observe the same decrease in intensity within 960 min. The probe (10 μM) achieved naked-eye detection of Co2+ recognition under daylight; however, achieving naked-eye detection of HClO under daylight necessitated higher concentrations (500 μM). Thus, this probe shows promising potential for environmental monitoring and water quality detection.

"The NET effect": Neutrophil extracellular traps-a potential key component of the dysregulated host immune response in sepsis

Neutrophils release neutrophil extracellular traps (NETs) as part of a healthy host immune response. NETs physically trap and kill pathogens as well as activating and facilitating crosstalk between immune cells and complement. Excessive or inadequately resolved NETs are implicated in the underlying pathophysiology of sepsis and other inflammatory diseases, including amplification of the inflammatory response and inducing thrombotic complications. Here, we review the growing evidence implicating neutrophils and NETs as central players in the dysregulated host immune response. We discuss potential strategies for modifying NETs to improve patient outcomes and the need for careful patient selection.

Identification of EGR1 as a Key Diagnostic Biomarker in Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) Through Machine Learning and Immune Analysis

Background

Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD), as a common chronic liver condition globally, is experiencing an increasing incidence rate which poses significant health risks. Despite this, the detailed mechanisms underlying the disease's onset and progression remain poorly understood. In this study, we aim to identify effective diagnostic biomarkers for MASLD using microarray data combined with machine learning techniques, which will aid in further understanding the pathogenesis of MASLD.

Methods

We collected six datasets from the Gene Expression Omnibus (GEO) database, using five of them as training sets and one as a validation set. We employed three machine learning methods-LASSO, SVM, and Random Forest (RF)-to identify hub genes associated with MASLD. These genes were further validated using the external dataset GSE164760. Additionally, functional enrichment analysis, immune infiltration analysis, and immune function analysis were conducted. A TF-miRNA-mRNA network was constructed, and single-cell RNA sequencing was used to determine the distribution of key genes within key cell clusters. Finally, the expression of the key genes was further validated using the palmitic acid-induced AML-12 cell line and the MCD mouse model.

Results

In this study, through differential gene expression (DEGs) analysis and machine learning techniques, we successfully identified 10 hub genes. Among these, the key gene EGR1 was validated and screened using an external dataset, with an area under the curve (AUC) of 0.882. Enrichment analyses and immune infiltration assessments revealed multiple pathways involving EGR1 in the pathogenesis and progression of MASLD, showing significant correlations with various immune cells. Furthermore, additional cellular experiments and animal model validations confirmed that the expression trends of EGR1 are highly consistent with our analytical findings.

Conclusion

Our research has confirmed EGR1 as a key gene in MASLD, providing novel insights into the disease's pathogenesis and identifying new therapeutic targets for its treatment.

"Urinary tract infection: Conventional testing to developing Technologies"

Urinary tract infections (UTIs) present an escalating global health concern, precipitating increased hospitalizations and antibiotic utilization, thereby fostering the emergence of antimicrobial resistance. Current diagnostic modalities exhibit protracted timelines and substantial financial burdens, necessitating specialized infrastructures. Addressing these impediments mandates the development of a precise diagnostic paradigm to expedite identification and augment antibiotic stewardship. The application of biosensors, recognized for their transformative efficacy, emerges as a promising resolution. Recent strides in biosensor technologies have introduced pioneering methodologies, yielding pertinent biosensors and integrated systems with significant implications for point-of-care applications. This review delves into historical perspectives, furnishing a comprehensive delineation of advancements in UTI diagnostics, disease etiology, and biomarkers, underscoring the potential merits of these innovations for optimizing patient care.

NAC-Grafted ROS-Scavenging Polymer Nanoparticles for Modulation of Acute Lung Injury Microenvironment In Vivo

N-Acetyl cysteine (NAC) is an essential molecule that boosts acute lung injury (ALI) defense via its direct antioxidant capability. Nevertheless, the therapeutic use of NAC is limited due to its poor bioavailability and short half-life. In this study, NAC was grafted to the polyurethane consisting of poly(propylene fumarate), poly(thioketal), and 1,6-hexamethylene diisocyanate (PFTU) to reduce excessive oxidative stress and inflammatory factors in ALI. The NAC-grafted polymer nanoparticles (NPT@NPs) were prepared as a drug delivery system, which could effectively scavenge free radicals and reduce inflammation in vitro. The administration of NPT@NPs exhibited notable efficacy in ameliorating pulmonary edema, attenuating the presence of inflammatory cells, suppressing myeloperoxidase expression, diminishing the levels of pro-inflammatory cytokines, and reversing cell apoptosis in an ALI model induced by lipopolysaccharide (LPS). The NPT@NPs demonstrated significantly better efficacy compared to the free NAC in mitigating the deleterious effects of LPS on pulmonary tissue, thereby providing more effective protection against pulmonary inflammation.

Pathophysiological Role of Neutrophil Extracellular Traps in Diet-Induced Obesity and Metabolic Syndrome in Animal Models

The global pandemic of obesity poses a serious health, social, and economic burden. Patients living with obesity are at an increased risk of developing noncommunicable diseases or to die prematurely. Obesity is a state of chronic low-grade inflammation. Neutrophils are first to be recruited to sites of inflammation, where they contribute to host defense via phagocytosis, degranulation, and extrusion of neutrophil extracellular traps (NETs). NETs are web-like DNA structures of nuclear or mitochondrial DNA associated with cytosolic antimicrobial proteins. The primary function of NETosis is preventing the dissemination of pathogens. However, neutrophils may occasionally misidentify host molecules as danger-associated molecular patterns, triggering NET formation. This can lead to further recruitment of neutrophils, resulting in propagation and a vicious cycle of persistent systemic inflammation. This scenario may occur when neutrophils infiltrate expanded obese adipose tissue. Thus, NETosis is implicated in the pathophysiology of autoimmune and metabolic disorders, including obesity. This review explores the role of NETosis in obesity and two obesity-associated conditions-hypertension and liver steatosis. With the rising prevalence of obesity driving research into its pathophysiology, particularly through diet-induced obesity models in rodents, we discuss insights gained from both human and animal studies. Additionally, we highlight the potential offered by rodent models and the opportunities presented by genetically modified mouse strains for advancing our understanding of obesity-related inflammation.

Effects of Moringa oleifera extract on biochemical and histological parameters of sodium valproate induced lungs damage

Sodium valproate- a salt of valproic acid (VPA), is an anticonvulsant used in the treatment of epilepsy and a range of psychiatric conditions that include panic attacks, anxiety, post-traumatic stress, migraine and bipolar disorder etc. VPA can cause direct damage to many tissues due to accumulation of toxic metabolites. Nowadays, phytochemicals are amongst the best options for the treatment of diseases. Moringa oleifera is a popular plant in the tropics owing to its numerous pharmacological and phytochemical properties such as antiproliferative, hepatoprotective, anti-inflammatory, and cardioprotective effects. In the present study, the protective effects of Moringa ethanol extract on oxidative lung damage caused by VPA was assessed biochemically and histologically. Sprague Dawley female rats were divided into 4 groups: Control, Moringa extract (M), sodium valproate (V), and sodium valproate + Moringa extract (V + M). Doses of sodium valproate and Moringa extract (dissolved in physiological saline) were given at 500 mg/kg b.w. and 300 mg/kg b.w. for 15 days, respectively. The rats were sacrificed on the 16th day, lung tissues collected biochemical parameters (glutathione level, antioxidant enzyme activities, oxidative stress biomarker and inflammatory proteins) and histopathological findings obtained from the study indicated increased damage in lung tissue of the valproate administered group. The damage was prevented/decreased upon administration of Moringa to the valproate rats. The present findings revealed that Moringa extract had a protective and therapeutic effect against VPA induced lung damage. Moringa extract demonstrated an ameliorative effect on histopathological and biochemical parameters in valproate induced lung damage.

The Roles of Oxidative Stress and Red Blood Cells in the Pathology of the Varicose Vein

This review discusses sources of reactive oxygen species, enzymatic antioxidant systems, and low molecular weight antioxidants. We present the pathology of varicose veins (VVs), including factors such as hypoxia, inflammation, dysfunctional endothelial cells, risk factors in varicose veins, the role of RBCs in venous thrombus formation, the influence of reactive oxygen species (ROS) and RBCs on VV pathology, and the role of hemoglobin in the damage of particles and macromolecules in VVs. This review discusses the production of ROS, enzymatic and nonenzymatic antioxidants, the pathogenesis of varicose veins as a pathology based on hypoxia, inflammation, and oxidative stress, as well as the participation of red blood cells in the pathology of varicose veins.

Effect of emodin on acute lung injury: a meta-analysis of preclinical trials

BACKGROUND

Emodin has protective effects on acute lung injury (ALI) or acute respiratory distress syndrome (ARDS). This meta-analysis intended to illustrate the efficacy of emodin on ALI/ARDS animal models.

METHODS

Relevant preclinical studies were searched on PubMed, EMBASE, and Web of Science. Standardized mean differences (SMDs) with corresponding confidence intervals (CIs) were used to compare lung injury scores, lung wet-to-dry weight ratios (W/D), myeloperoxidase (MPO), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), IL-6, IL-18, PaO2, and PaCO2 between the treatment and control groups. The article quality was appraised using the SYRCLE tool.

RESULTS

Twenty one studies published between 2014 and 2023 were enrolled. Compared with the control group, emodin significantly reduced lung injury scores (SMD: -3.63; 95% CI: -4.36, -2.90; p < 0.00001), W/D ratios (SMD: -3.23; 95% CI: -4.29, -2.16; p < 0.00001), and MPO levels (SMD: -2.96; 95% CI: -3.92, -1.99; p < 0.00001). Furthermore, emodin downregulated TNF-α (SMD: -3.04; 95% CI: -3.62, -2.47; p < 0.00001), IL-1β (SMD: -3.76; 95% CI: -4.65, -2.87; p < 0.00001), IL-6 (SMD: -3.19; 95% CI: -3.95, -2.43; p < 0.00001), and IL-18 levels (SMD: -4.83; 95% CI: -6.10, -3.57; p < 0.00001). Emodin improved gas exchange dysfunction, increased PaO2 (SMD: 3.76; 95% CI: 2.41, 5.11; p < 0.00001), and decreased PaCO2 (SMD: -3.83; 95% CI: -4.90, -2.76; p < 0.00001). Sensitivity analyses and stratified analyses were conducted for outcome measures with heterogeneity.

CONCLUSIONS

Emodin treatment can effectively reduce the severity of ALI in animal models. Additional animal investigations and clinical trials involving human subjects are imperative.

Turning Neutrophil Cell Death Deadly in the Context of Hypertensive Vascular Disease

Hypertensive vascular disease (HVD) is a major health burden globally and is a comorbidity commonly associated with other metabolic diseases. Many factors are associated with HVD including obesity, diabetes, smoking, chronic kidney disease, and sterile inflammation. Increasing evidence points to neutrophils as an important component of the chronic inflammatory response in HVD. Neutrophils are abundant in the circulation and can respond rapidly upon stimulation to deploy an armament of antimicrobial effector functions. One of the outcomes of neutrophil activation is the generation of neutrophil extracellular traps (NETs), a regulated extrusion of chromatin and proteases. Although neutrophils and NETs are well described as components of the innate immune response to infection, recent evidence implicates them in HVD. Endothelial cell activation can trigger neutrophil adhesion, activation, and production of NETs promoting vascular dysfunction, vessel remodelling, and loss of resistance. The regulated release of NETs can be controlled by the pore-forming activities of distinct cell death pathways. The best characterized pathways in this context are apoptosis, pyroptosis, and necroptosis. In this review, we discuss how inflammatory cell death signalling and NET formation contribute to hypertensive disease. We also examine novel therapeutic approaches to limit NET production and their future potential as therapeutic drugs for cardiovascular disorders.

Amniotic fluid-derived mesenchymal stem cells reduce inflammation and improve lung function following transplantation in a porcine model

BACKGROUND

Lung transplantation is hindered by low donor lung utilization rates. Infectious complications are reasons to decline donor grafts due to fear of post-transplant primary graft dysfunction. Mesenchymal stem cells are a promising therapy currently investigated in treating lung injury. Full-term amniotic fluid-derived lung-specific mesenchymal stem cell treatment may regenerate damaged lungs. These cells have previously demonstrated inflammatory mediation in other respiratory diseases, and we hypothesized that treatment would improve donor lung quality and postoperative outcomes.

METHODS

In a transplantation model, donor pigs were stratified to either the treated or the nontreated group. Acute respiratory distress syndrome was induced in donor pigs and harvested lungs were placed on ex vivo lung perfusion (EVLP) before transplantation. Treatment consisted of 3 doses of 2 × 106 cells/kg: one during EVLP and 2 after transplantation. Donors and recipients were assessed on clinically relevant parameters and recipients were followed for 3 days before evaluation for primary graft dysfunction (PGD).

RESULTS

Repeated injection of the cell treatment showed reductions in inflammation seen through lowered immune cell counts, reduced histology signs of inflammation, and decreased cytokines in the plasma and bronchoalveolar lavage fluid. Treated recipients showed improved pulmonary function, including increased PaO2/FiO2 ratios and reduced incidence of PGD.

CONCLUSIONS

Repeated injection of lung-specific cell treatment during EVLP and post transplant was associated with improved function of previously damaged lungs. Cell treatment may be considered as a potential therapy to increase the number of lungs available for transplantation and the improvement of postoperative outcomes.

Myeloperoxidase enzyme-catalyzed breakdown of zero-dimension carbon quantum dots

Carbon quantum dots (CQDs) have shown considerable interest in multiple fields including bioimaging, biosensing, photocatalysis, ion sensing, heavy metal detection, and therapy due to highly tunable photoluminescence and good photostability. Apart from having optical properties CQDs offer several advantages such as low toxicity, environmental friendliness, affordability, and simple synthesis methods. Furthermore, by modifying their surface and functionality, it's possible to precisely control their physical and chemical characteristics. Nevertheless, the growing utilization of carbon-based nanomaterials (CNMs) requires thorough examination of their potential toxicity and long-term impacts on human health and biological systems. In this study, carbon quantum dots (CQDs) were synthesized via a microwave-assisted method using citric acid and urea as precursors, resulting in an average particle diameter of 10.73 nm. The CQDs were further characterized using SEM and FTIR analysis. The CQDs exhibited an excitation wavelength of 320 nm, displaying an emission peak at 430 nm. The enzymatic biodegradation of CQDs by human myeloperoxidase enzyme has been thoroughly investigated here. It is very crucial to understand how these carbon quantum dots interact with the innate immune system that plays a vital role in recognizing and clearing foreign particles. Human myeloperoxidase (MPO), a key enzyme highly expressed in neutrophil granulocytes during inflammatory responses, has been shown to facilitate the biodegradation of carbon quantum dots and various carbon-based nanomaterials through oxidative processes. As a member of the peroxidase family, MPO produces hypochlorous acid (HOCl) and a range of reactive intermediates to eliminate pathogens. Consequently, the study of the biodegradability of CQDs within biological systems is essential for accelerating technological advancements. Here, we have assessed breakdown of CQDs through an oxidative process facilitated by a myeloperoxidase (MPO)-based peroxide system. The human MPO enzyme acted as a catalyst for the CQD degradation, and the addition of hydrogen peroxide (H2O2) and sodium chloride (NaCl) was found to accelerate the reaction.

Topical histone deacetylase inhibitor remetinostat improves IMQ-induced psoriatic dermatitis via suppressing dendritic cell maturation and keratinocyte differentiation and inflammation

Psoriasis is a chronic inflammatory skin disease characterized by excessive proliferation of keratinocytes and infiltration of immune cells. Although psoriasis has entered the era of biological treatment, there is still a need to explore more effective therapeutic targets and drugs due to the presence of resistance and adverse reactions to biologics. Remetinostat, an HDAC inhibitor, can maintain its potency within the skin with minimal systemic effects, making it a promising topical medication for treating psoriasis. But its effectiveness in treating psoriasis has not been evaluated. In this study, the topical application of remetinostat significantly improved psoriasiform inflammation in an imiquimod-induced mice model by inhibiting CD86 expression of CD11C+I-A/I-E+ dendritic cells (DCs) in the skin. Moreover, remetinostat could dampen the maturation and activation of bone marrow-derived DCs in vitro, as well as the expression of psoriasis-related inflammatory mediators by keratinocytes. In addition, remetinostat could promote keratinocyte differentiation without affecting its proliferation. Our findings demonstrate that remetinostat improves psoriasis by inhibiting the maturation and activation of DCs and the differentiation and inflammation of keratinocytes, which may facilitate the potential application of remetinostat in anti-psoriasis therapy.

Two-Photon Cellular and Intravital Imaging of Hypochlorous Acid by Fluorescent Probes That Exhibit a Synergistic Excited-State Intramolecular Proton Transfer-Intramolecular Charge Transfer Mechanism Enabling Near-Infrared Emission with a Large Stokes Shift

To develop highly effective molecular tools for intravital imaging of hypochlorous acid (HOCl), in this study, we initially designed two-photon hybrid fluorophores, SDP and P-SDP, by conjugating the classical dye 2-(2'-hydroxyphenyl)benzothiazole with the two-photon hydroxylphenyl-butadienylpyridinium fluorophore. The designed fluorophores exhibit a synergistic interaction between excited-state intramolecular proton transfer and intramolecular charge transfer mechanisms, enabling near-infrared (NIR) emission and significant Stokes shifts. Subsequently, using these fluorophores, we developed two HOCl fluorescent probes, SDP-SN and P-SDP-SN, by further incorporating N,N-dimethylthiocarbamate as a specific recognition group for HOCl. Toward HOCl, both SDP-SN and P-SDP-SN demonstrate an ultrafast response (less than 3 s), NIR emission at wavelengths of 714 and 682 nm, and remarkable Stokes shifts of 303 and 271 nm, respectively. Leveraging these advantages in conjunction with their ability to cross the blood-brain barrier, the probes find successful application in two-photon cellular and intravital imaging of HOCl. This includes visualizing endogenous generation of HOCl in cellular models related to inflammation, hyperglycemia, and ferroptosis, as well as mapping in vivo generation of HOCl within the brain and abdominal cavity using a murine model of systemic inflammation.

A reactive oxygen species-triggerable theranostic prodrug system

Abnormally elevated levels of reactive oxygen species (ROS) are considered one of the characteristics of tumors and have been extensively employed in the construction of tumor-activated prodrugs. However, ideal ROS-activated molecular triggers that possess high sensitivity and easy functionalization for tailoring specific prodrugs, remain scarce. In this work, we developed a highly reactive oxygen species (hROS, such as •OH, ONOO- and HOCl)-responsive molecular trigger (namely FDROS-4) through the conjunction of methylene blue (MB) and 2, 6-bis (hydroxymethyl) aniline via urea bond, integrating imaging and therapeutic functions. FDROS-4 could be readily modified as multifunctional prodrugs and efficiently activated by hROS, leading to the release of near-infrared emissive MB and parent drugs. By using chlorambucil as a model drug and incorporating varying numbers of galactose as liver-targeting ligands, we designed and synthesized a series of prodrugs named FDROS-6, FDROS-7, and FDROS-8. The optimal prodrug, FDROS-7, could self-assemble into monocomponent nanoparticles, exhibiting enhanced biocompatibility and therapeutic efficacy compared to the parent drug. This hROS-activated molecular trigger holds promise for the development of stimulus-responsive prodrugs in chemotherapy.

Epilipidomics reveals lipid fatty acid and headgroup modification in gas plasma-oxidized biomembranes

Lipids, possessing unsaturated fatty acid chains and polar regions with nucleophilic heteroatoms, represent suitable oxidation targets for autologous and heterologous reactive species. Lipid peroxidation products (LPPs) are highly heterogeneous, including hydroperoxides, alkenals, chlorination, or glycation. Accordingly, delineation of lipid targets, species type, resulting products, and oxidation level remains challenging. To this end, liposomal biomimetic models incorporating a phosphatidylcholine, -ethanolamine, and a sphingomyelin were used to deconvolute effects on a single lipid scale to predict potential modification product outcomes. To introduce oxidative modifications, gas plasma technology, a powerful pro-oxidant tool to promote LPP formation by forming highly abundant reactive species in the gas and liquid phases, was employed to liposomes. The plasma parameters (gas type/combination) were modified to modulate the resulting species-profile and LPP formation by enriching specific reactive species types over others. HR-LC-MS (Münzel and et al., 2017) [2] was employed for LPP identification. Moreover, the heavy oxygen isotope 18O was used to trace O2-incorporation into LPPs, providing first information on the plasma-mediated lipid peroxidation mechanism. We found that combination of lipid class and gas composition predetermined the type of attack: admixture of O2 to the plasma and the presence of nitrogen atoms with free electrons in the molecule lead to chlorination of the amide bond and headgroup. Here, atomic oxygen driven formation of hypochlorite is the major reactive species. In contrast, POPC yields mainly to LPPs with oxidation of the oleic acid tail, especially truncations, epoxidation, and hydroperoxide formation. Here, singlet oxygen is assumingly the major driver. 18O labelling revealed that gas phase derived reactive species are dominantly incorporated into the LPPs, supporting previous findings on gas-liquid interface chemistry. In summary, we here provided the first insights into gas plasma-mediated lipid peroxidation, which, employed in more complex cell and tissue models, may support identifying mechanisms of actions in plasma medicine.

Exploring mammalian heme peroxidases: A comprehensive review on the structure and function of myeloperoxidase, lactoperoxidase, eosinophil peroxidase, thyroid peroxidase and peroxidasin

The peroxidase family of enzymes is a ubiquitous cluster of enzymes primarily responsible for the oxidation of organic and inorganic substrates. The mammalian heme peroxidase subfamily is characterized by a covalently linked heme prosthetic group which plays a key role in the oxidation of halides and psuedohalides into their respective hypohalous acid and hypothiocyanous acid under the influence of H2O2 as substrate. The members of the heme peroxidase family include Lactoperoxidase (LPO), Eosinophil peroxidase (EPO), Myeloperoxidase (MPO), Thyroid peroxidase (TPO) and Peroxidasin (PXDN). The biological activity of LPO, MPO and EPO pertains to antibacterial, antifungal and antiviral while TPO is involved in the biosynthesis of the thyroid hormone and PXDN helps maintain the ECM. While these enzymes play several immunomodulatory roles, aberrations in their activity have been implicated in diseases such as myocardial infarction, asthma and Alzheimer's amongst others. The sequence and structural similarities amongst the members of the family are strikingly high while the substrate specificities and subcellular locations vary. Hence, it becomes important to provide a consortium of information regarding the members to study their biochemical, pathological and clinical function.

Are Advanced Oxidation Protein Products (AOPPs) Levels Altered in Neuropsychiatric Disorders? An Integrative Review

Neuropsychiatric disorders such as major depressive disorder (MDD), bipolar disorder (BD), and schizophrenia (SZ) are considered a public health problem since it interferes in personal relationships and at work. The pathophysiological mechanisms of these mental disorders are still not completely understood. The variety and heterogeneity of symptoms, as well as the absence of biomarkers, make the diagnosis, prognosis, and treatment of these disorders difficult. However, oxidative stress appears to play a role in the pathophysiology of these diseases. In this context, advanced oxidation protein products (AOPPs) are considered a biomarker of protein oxidative damage and have been associated with neuroinflammatory diseases. In patients with neuropsychiatric disorders, increased levels of AOPPs were associated with the severity of symptoms and decreased quality of life. Thus, the objective of this integrative review is to investigate and discuss the relationship between AOPPs levels and MDD, BD, and SZ. Different databases were consulted and approximately 112 scientific articles were found relating AOPPs and psychiatric disorders. In the majority of studies, the blood levels of AOPPs were increased in MDD, BD, and SZ and associated with the severity of the disorders. Although the association of this marker with the risk of developing one of these mental disorders is more uncertain, some studies have suggested this relationship. Of the twenty-four studies highlighted, only four did not find significant differences in AOPPs levels in patients with the disorders mentioned. In summary, it may be suggested that the assessment of AOPPs levels can be a useful tool in the evaluation of neuropsychiatric disorders, at least for prognostic evaluation. However, the role of this biomarker in the pathophysiology of mental disorders is still unclear, as well as whether reducing its levels represents a potential therapeutic strategy.

The Promise of a Pointillist Perspective for Comparative Immunology

Most studies in comparative immunology involve investigations into the detailed mechanisms of the immune system of a nonmodel organism. Although this approach has been insightful, it has promoted a deep understanding of only a handful of species, thus inhibiting the recognition of broad taxonomic patterns. Here, we call for investigating the immune defenses of numerous species within a pointillist framework, that is, the meticulous, targeted collection of data from dozens of species and investigation of broad patterns of organismal, ecological, and evolutionary forces shaping those patterns. Without understanding basic immunological patterns across species, we are limited in our ability to extrapolate and/or translate our findings to other organisms, including humans. We illustrate this point by focusing predominantly on the biological scaling literature with some integrations of the pace of life literature, as these perspectives have been the most developed within this framework. We also highlight how the more traditional approach in comparative immunology works synergistically with a pointillist approach, with each approach feeding back into the other. We conclude that the pointillist approach promises to illuminate comprehensive theories about the immune system and enhance predictions in a wide variety of domains, including host-parasite dynamics and disease ecology.

Valproic acid alleviates total-body irradiation-induced small intestinal mucositis in mice

PURPOSE

Gastrointestinal (GI) injury is one of the serious problems of total-body irradiation (TBI). However, no fundamental treatment for TBI and other radiation-induced GI injury has yet been established. Valproic acid (VPA) administration reduces mortality in mice subjected to total-body irradiation (TBI) with X-rays. This study aimed to evaluate the effects of VPA on GI injury induced by TBI in mice.

MATERIALS AND METHODS

Mice were subjected to TBI with X-rays to induce GI injury. Changes in survival and weight were observed after VPA administration. The small intestine was then sampled at 0, 1, 3, 7, and 10 d after irradiation for histological and immunohistological evaluation and measurement of myeloperoxidase (MPO) activity and inflammatory cytokine levels (IL-1β).

RESULTS

VPA (200 and 600 mg/kg) increased survival rate and reduced weight loss in model mice. IL-1β expression 1 d after irradiation was significantly lower in the VPA group than that in the vehicle group. Furthermore, the increase in MPO activity at 3 and 7 d after irradiation was significantly suppressed by VPA administration. Histological examination (hematoxylin and eosin staining) revealed that 600 mg/kg VPA inhibited inflammatory cell infiltration. Immunostaining for the proliferating cell nuclear antigen involved in cell proliferation showed that VPA suppressed the irradiation-induced decrease in cell proliferative capacity.

CONCLUSIONS

Treatment with VPA in mice with GI injury caused by TBI suppressed inflammatory responses in small intestinal mucosal cells. These results suggest that VPA may be a useful therapeutic agent against TBI-induced small intestinal mucositis.

Signature Proteins in Small Extracellular Vesicles of Granulocytes and CD4+ T-Cell Subpopulations Identified by Comparative Proteomic Analysis

Several studies have described the proteomic profile of different immune cell types, but only a few have also analysed the content of their delivered small extracellular vesicles (sEVs). The aim of the present study was to compare the protein signature of sEVs delivered from granulocytes (i.e., neutrophils and eosinophils) and CD4+ T cells (i.e., TH1, TH2, and TH17) to identify potential biomarkers of the inflammatory profile in chronic inflammatory diseases. Qualitative (DDA) and quantitative (DIA-SWATH) analyses of in vitro-produced sEVs revealed proteome variations depending on the cell source. The main differences were found between granulocyte- and TH cell-derived sEVs, with a higher abundance of antimicrobial proteins (e.g., LCN2, LTF, MPO) in granulocyte-derived sEVs and an enrichment of ribosomal proteins (RPL and RPS proteins) in TH-derived sEVs. Additionally, we found differentially abundant proteins between neutrophil and eosinophil sEVs (e.g., ILF2, LTF, LCN2) and between sEVs from different TH subsets (e.g., ISG15, ITGA4, ITGB2, or NAMPT). A "proof-of-concept" assay was also performed, with TH2 biomarkers ITGA4 and ITGB2 displaying a differential abundance in sEVs from T2high and T2low asthma patients. Thus, our findings highlight the potential use of these sEVs as a source of biomarkers for diseases where the different immune cell subsets studied participate, particularly chronic inflammatory pathologies such as asthma or chronic obstructive pulmonary disease (COPD).

Impaired neutrophil-mediated cell death drives Ewing's Sarcoma in the background of Down syndrome

Introduction

Ewing Sarcoma (EWS) has been reported in seven children with Down syndrome (DS). To date, a detailed assessment of this solid tumour in DS patients is yet to be made.

Methods

Here, we characterise a chemo-resistant mediastinal EWS in a 2-year-old DS child, the youngest ever reported case, by exploiting sequencing approaches.

Results

The tumour showed a neuroectodermal development driven by the EWSR1-FLI1 fusion. The inherited myeloperoxidase deficiency of the patient caused failure of neutrophil-mediated cell death and promoted genomic instability.

Discussion

In this context, the tumour underwent genome-wide near haploidisation resulting in a massive overexpression of pro-inflammatory cytokines. Recruitment of defective neutrophils fostered rapid evolution of this EWS.

Simultaneously Controlling Inflammation and Infection by Smart Nanomedicine Responding to the Inflammatory Microenvironment

The overactivated immune cells in the infectious lesion may lead to irreversible organ damages under severe infections. However, clinically used immunosuppressive anti-inflammatory drugs will usually disturb immune homeostasis and conversely increase the risk of infections. Regulating the balance between anti-inflammation and anti-infection is thus critical in treating certain infectious diseases. Herein, considering that hydrogen peroxide (H2O2), myeloperoxidase (MPO), and neutrophils are upregulated in the inflammatory microenvironment and closely related to the severity of appendectomy patients, an inflammatory-microenvironment-responsive nanomedicine is designed by using poly(lactic-co-glycolic) acid (PLGA) nanoparticles to load chlorine E6 (Ce6), a photosensitizer, and luminal (Lum), a chemiluminescent agent. The obtained Lum/Ce6@PLGA nanoparticles, being non-toxic within normal physiological environment, can generate cytotoxic single oxygen via bioluminescence resonance energy transfer (BRET) in the inflammatory microenvironment with upregulated H2O2 and MPO, simultaneously killing pathogens and excessive inflammatory immune cells in the lesion, without disturbing immune homeostasis. As evidenced in various clinically relevant bacterial infection models and virus-induced pneumonia, Lum/Ce6@PLGA nanoparticles appeared to be rather effective in controlling both infection and inflammation, resulting in significantly improved animal survival. Therefore, the BRET-based nanoparticles by simultaneously controlling infections and inflammation may be promising nano-therapeutics for treatment of severe infectious diseases.

The pivotal role of neutrophil extracellular traps in cardiovascular diseases: Mechanisms and therapeutic implications

Cardiovascular diseases (CVDs) continue to pose a significant burden on global health, prominently contributing to morbidity and mortality rates worldwide. Recent years have witnessed an increasing recognition of the intricate involvement of neutrophil extracellular traps (NETs) in the pathology of diverse cardiovascular conditions. This review provides a comprehensive analysis of the multifaceted functions of NETs in cardiovascular diseases, shedding light on the impact on atherosclerosis, myocardial infarction, heart failure, myocarditis, atrial fibrillation, aortic stenosis, and the potential therapeutic avenues targeting NETs.

Pentoxifylline in patients with ulcerative colitis treated with mesalamine by modulation of IL-6/STAT3, ZO-1, and S1P pathways: a randomized controlled double-blinded study

BACKGROUND

Ulcerative colitis (UC) is an inflammatory bowel disease (IBD) that lasts a long time and has a variety of causes.

AIM

The primary aim of this study was to evaluate pentoxifylline's (PTX) essential function in patients with UC.

METHODS

Fifty-two mild to moderate UC patients who matched the eligibility requirements participated in this clinical study. One gram of mesalamine (t.i.d.) and a placebo were administered to the mesalamine group (n = 26) for a duration of 24 weeks. Mesalamine 1 g t.i.d. and PTX 400 mg two times daily were administered to the PTX group (n = 26) for 24 weeks. A gastroenterologist investigated patients at the start and 6 months after the medication was given to assess disease activity index (DAI) and numeric pain rating scale (NRS). Also, interleukin-6 (IL-6), sphingosine 1 phosphate (S1P), tumor necrosis factor-alpha (TNF-α), and fecal myeloperoxidase (MPO) were measured before and after therapy. Zonula occuldin-1 (ZO-1) and signal transducer and activator of transcription factor-3 (STAT-3) expression was assessed before and after therapy as well as histological assessment. Short Form 36 Health Survey (SF-36), was assessed for each patient before and after 6 months of treatment.

RESULTS

The PTX group showed statistically lower levels of serum SIP, TNF-α, IL-6, faecal MPO, gene expression of STAT-3, and a significant increase of ZO-1 in comparison with the mesalamine group. DAI and NRS significantly decreased whereas SF-36 significantly increased in the PTX group.

CONCLUSION

PTX could alleviate inflammation in patients with UC, so it might be promising adjunctive for patients with UC.

TRIAL REGISTRATION IDENTIFIER

NCT05558761.

Neutrophil trapping and nexocytosis, mast cell-mediated processes for inflammatory signal relay

Neutrophils are sentinel immune cells with essential roles for antimicrobial defense. Most of our knowledge on neutrophil tissue navigation derived from wounding and infection models, whereas allergic conditions remained largely neglected. Here, we analyzed allergen-challenged mouse tissues and discovered that degranulating mast cells (MCs) trap living neutrophils inside them. MCs release the attractant leukotriene B4 to re-route neutrophils toward them, thus exploiting a chemotactic system that neutrophils normally use for intercellular communication. After MC intracellular trap (MIT) formation, neutrophils die, but their undigested material remains inside MC vacuoles over days. MCs benefit from MIT formation, increasing their functional and metabolic fitness. Additionally, they are more pro-inflammatory and can exocytose active neutrophilic compounds with a time delay (nexocytosis), eliciting a type 1 interferon response in surrounding macrophages. Together, our study highlights neutrophil trapping and nexocytosis as MC-mediated processes, which may relay neutrophilic features over the course of chronic allergic inflammation.

Faecal biomarkers for diagnosis and prediction of disease course in treatment-naïve patients with IBD

BACKGROUND

Faecal biomarkers can be used to assess inflammatory bowel disease (IBD).

AIM

To explore the performance of some promising biomarkers in diagnosing and predicting disease course in IBD.

METHODS

We included 65 patients with treatment-naïve, new-onset Crohn's disease (CD), 90 with ulcerative colitis (UC), 67 symptomatic controls (SC) and 41 healthy controls (HC) in this prospective observational study. We analysed faecal samples for calprotectin (FC), myeloperoxidase (MPO), human neutrophil lipocalin (HNL), eosinophil cationic protein ECP and eosinophil-derived neurotoxin (EDN) and compared markers among groups. We assessed the diagnostic capability of biomarkers with receiver operating characteristic curves. Clinical disease course was determined for each patient with IBD and analysed the association with biomarkers by logistic regression.

RESULTS

All markers were elevated at inclusion in patients with IBD compared with HC (p < 0.001) and SC (p < 0.001). FC (AUC 0.85, 95% CI: 0.79-0.89) and MPO (AUC 0.85, 95% CI: 0.80-0.89) showed the highest diagnostic accuracy in distinguishing IBD from SC. The diagnostic ability of biomarkers differed between IBD subtypes with the highest performance for FC and MPO in CD. The diagnostic accuracy was further improved by combining FC and MPO (p = 0.02). Levels of FC, MPO and HNL at inclusion were predictive of an aggressive disease course with MPO showing the strongest association (p = 0.006).

CONCLUSIONS

This study provides new insight into the diagnostic and prognostic capability of neutrophil and eosinophil biomarkers in IBD and suggests that MPO, alone or in combination with FC, may add to the diagnostic power of faecal biomarkers.

Redox-dependent plasticity of oxMIF facilitates its interaction with CD74 and therapeutic antibodies

MIF is a ubiquitous protein involved in proinflammatory processes, which undergoes an oxidation-driven conformational change to oxidized (ox)MIF. We demonstrate that hypochlorous acid, produced by neutrophil-released myeloperoxidase (MPO) under inflammatory conditions, effectively oxidizes MIF into the oxMIF isoform, which is specifically recognized by the anti-oxMIF therapeutic antibody, ON104. NMR investigation of MIF oxidized by the MPO system revealed increased flexibility throughout the MIF structure, including at several catalytic and allosteric sites. Mass spectrometry of MPO-oxMIF revealed methionines as the primary site of oxidation, whereas Pro2 and Tyr99/100 remained almost unmodified. ELISA, SPR and cell-based assays demonstrated that structural changes caused by MPO-driven oxidation promoted binding of oxMIF to its receptor, CD74, which does not occur with native MIF. These data reveal the environment and modifications that facilitate interactions between MIF and its pro-inflammatory receptor, and a route for therapeutic intervention targeting the oxMIF isoform.

The mitochondrial translocator protein (TSPO, 18 kDa): A key multifunctional molecule in liver diseases

Translocator protein (TSPO, 18 kDa), previously known as peripheral-type benzodiazepine receptor, is an evolutionarily conserved and tryptophan-rich 169-amino-acid protein located on the outer mitochondrial membrane. TSPO plays a crucial role in various fundamental physiological functions and cellular processes. Its expression is altered in pathological conditions, thus rendering TSPO a potential tool for diagnostic imaging and an appealing therapeutic target. The investigation of synthetic TSPO ligands as both agonists and antagonists has provided valuable insights into the regulatory mechanisms and functional properties of TSPO. Recently, accumulating evidence has highlighted the significance of TSPO in liver diseases. However, a comprehensive summary of TSPO function in the normal liver and diverse liver diseases is lacking. This review aims to provide an overview of recent advances in understanding TSPO function in both normal liver cells and various liver diseases, with a particular emphasis on its involvement in liver fibrosis and inflammation and addresses the existing knowledge gaps in the field that require further investigation.

Ex Tenebris Lux: Illuminating Reactive Oxygen and Nitrogen Species with Small Molecule Probes

Reactive oxygen and nitrogen species are small reactive molecules derived from elements in the air─oxygen and nitrogen. They are produced in biological systems to mediate fundamental aspects of cellular signaling but must be very tightly balanced to prevent indiscriminate damage to biological molecules. Small molecule probes can transmute the specific nature of each reactive oxygen and nitrogen species into an observable luminescent signal (or even an acoustic wave) to offer sensitive and selective imaging in living cells and whole animals. This review focuses specifically on small molecule probes for superoxide, hydrogen peroxide, hypochlorite, nitric oxide, and peroxynitrite that provide a luminescent or photoacoustic signal. Important background information on general photophysical phenomena, common probe designs, mechanisms, and imaging modalities will be provided, and then, probes for each analyte will be thoroughly evaluated. A discussion of the successes of the field will be presented, followed by recommendations for improvement and a future outlook of emerging trends. Our objectives are to provide an informative, useful, and thorough field guide to small molecule probes for reactive oxygen and nitrogen species as well as important context to compare the ecosystem of chemistries and molecular scaffolds that has manifested within the field.