Are reactive oxygen species always detrimental to pathogens?

Type-I IFNs induce GBPs and lysosomal defense in hepatocytes to control malaria

Plasmodium parasites undergo development and replication within the hepatocytes before infecting the erythrocytes and initiating clinical malaria. Although type-I interferons (IFNs) are known to hinder Plasmodium infection within the liver, the underlying mechanisms remain unclear. Here, we describe two IFN-I-driven hepatocyte antimicrobial programs controlling liver-stage malaria. First, oxidative defense by NADPH oxidases 2 and 4 triggers a pathway of lysosomal fusion with the parasitophorous vacuole (PV) to help clear Plasmodium . Second, guanylate-binding protein (GBP) 1 disruption of the PV activates caspase-1 inflammasome, inducing pyroptosis to remove the infected host cells. Remarkably, both human and mouse hepatocytes enlist these cell-autonomous immune programs to eliminate Plasmodium ; their pharmacologic or genetic inhibition led to profound malarial susceptibility, and are essential in vivo . In addition to identifying the IFN-I-mediated cell-autonomous immune circuits controlling Plasmodium infection in the hepatocytes, this study extends our understanding of how non-immune cells are integral to protective immunity against malaria.

Oncolytic vaccinia virus harboring aphrocallistes vastus lectin exerts anti-tumor effects by directly oncolysis and inducing immune response through enhancing ROS in human ovarian cancer

Aphrocallistes vastus lectin (AVL) is a Ca2+ dependent C-type lectin produced by sponges. Previous studies have demonstrated that oncolytic vaccinia virus harboring AVL (oncoVV-AVL) effectively triggers cell death in various tumors. However, the effects of oncoVV-AVL on human ovarian cancer (OV) remain unknown. This study aims to investigate the mechanism-of-action of oncoVV-AVL in human OV cell lines and in tumor-bearing nude mice. We found that oncoVV-AVL could directly induce apoptosis and autophagy in ovarian cancer cells. Additionally, our results showed that oncoVV-AVL increased the serum levels of mouse IFN-γ (mIFN-γ), leading to the activation of M1-polarized macrophages. Conversely, NADPH, a reducing agent by providing reducing equivalents, reduced the production of mIFN-γ, and suppressed M1-polarization of macrophage. Based on these findings, we propose that oncoVV-AVL not only contributes to direct cytolysis, but also enhances host immune response by promoting ROS levels.

Role of Mitofusin 1 in mediating reactive oxygen species in alveolar macrophages during Streptococcuspneumoniae

Alveolar macrophages (AM) are key effectors of the immune response and are essential for host responses to S. pneumoniae. Mitochondria are highly dynamic organelles whose function aids in regulating the cell cycle, innate immunity, autophagy, redox signaling, calcium homeostasis, and mitochondrial quality control in AM. In response to cellular stress, mitochondria can engage in stress-induced mitochondrial hyperfusion (SIMH). The current study aimed to investigate the role of Mfn1 on mitochondrial control of reactive oxygen species (ROS) in AMs and the role of Mfn1 deficiency on immune responses to S. pneumoniae. Compared to Mfn1FloxCre- controls, there were distinct histological differences in lung tissue collected from Mfn1Floxed; CreLysM mice, with less injury and inflammation observed in mice with Mfn1 deficient myeloid cells. There was a significant decrease in lipid peroxidation and ROS production in Mfn1 deficient AM that was associated with increased superoxide dismutase (SOD) and antioxidant activity. Our findings demonstrate that Mfn1 deficiency in myeloid cells decreased inflammation and lung tissue injury during S. pneumoniae infection.

The mitochondrial uncoupler 2,4-dinitrophenol modulates inflammatory and oxidative responses in Trypanosoma cruzi-induced acute myocarditis in mice

By uncoupling oxidative phosphorylation, 2,4-dinitrophenol (DNP) attenuates reactive oxygen species (ROS) biosynthesis, which are known to aggravate infectious myocarditis in Chagas disease. Thus, the impact of DNP-based chemotherapy on Trypanosoma cruzi-induced acute myocarditis was investigated. C56BL/6 mice uninfected and infected untreated and treated daily with 100 mg/kg benznidazole (Bz, reference drug), 5 and 10 mg/kg DNP by gavage for 11 days after confirmation of T. cruzi infection were investigated. Twenty-four hours ​after the last treatment, the animals were euthanized and the heart was collected for microstructural, immunological and biochemical analyses. T. cruzi inoculation induced systemic inflammation (e.g., cytokines and anti-T. cruzi IgG upregulation), cardiac infection (T. cruzi DNA), oxidative stress, inflammatory infiltrate and microstructural myocardial damage in untreated mice. DNP treatment aggravated heart infection and microstructural damage, which were markedly attenuated by Bz. DNP (10 mg/kg) was also effective in attenuating ROS (total ROS, H2O2, and O2-), nitric oxide (NO), lipid (malondialdehyde - MDA) and protein (protein carbonyl - PCn) oxidation, TNF, IFN-γ, IL-10, and MCP-1/CCL2, anti-T. cruzi IgG, cardiac troponin I levels, as well as inflammatory infiltrate and cardiac damage in T. cruzi-infected mice. Our findings indicate that DNP aggravated heart infection and microstructural cardiomyocytes damage in infected mice. These responses were related to the antioxidant and anti-inflammatory properties of DNP, which favors infection by weakening the pro-oxidant and pro-inflammatory protective mechanisms of the infected host. Conversely, Bz-induced cardioprotective effects combined effective anti-inflammatory and antiparasitic responses, which protect against heart infection, oxidative stress, and microstructural damage in Chagas disease.

Assessing the physico-mechanical, anti-bacterial, and anti-demineralization properties of orthodontic resin composite containing different concentrations of photoactivated zinc oxide nanoparticles on Streptococcus mutans biofilm around ceramic and metal orthodontic brackets: An ex vivo study

BACKGROUND AND PURPOSE

The aim of this study was to evaluate the physico-mechanical, anti-bacterial, and anti-demineralization properties of orthodontic resin composite containing photoactivated zinc oxide nanoparticles (ZnONPs) on Streptococcus mutans biofilm around ceramic and metal brackets.

MATERIAL AND METHODS

Following the minimum inhibitory concentration (MIC) determination for ZnONPs, shear bond strength (SBS) was tested for composites containing different concentrations of ZnONPs. The chosen concentration was used to evaluate the microleakage, anti-bacterial, and anti-demineralization properties.

RESULTS

Adding 50μg/mL of ZnONPs to the orthodontic composite did not negatively affect its physico-mechanical properties. ZnONPs (50μg/mL)-mediated aPDT and 0.2% chlorhexidine significantly (P=0.000) reduced S. mutans biofilms compared to the phosphate-buffered saline (PBS) groups (metal/PBS=7.47±0.7×106, and ceramic/PBS=7.47±0.7×106), with the lowest colony count observed in these groups (metal/chlorhexidine=1.06±0.4×105, ceramic/chlorhexidine=1±0.2×105, metal/ZnONPs-mediated aPDT=1.33±0.3×105, and ceramic/ZnONPs-mediated aPDT=1.2±0.3×105). Sodium fluoride varnish and ZnONPs-mediated aPDT showed the highest efficacy in anti-demineralization and significantly improving the enamel surface microhardness compared to the artificial saliva, especially in ceramic bracket groups (524.17±42.78N and 441.00±29.48N, 394.17±46.83N, P=0.000, and P=0.003, respectively).

CONCLUSION

ZnONPs (50μg/mL)-mediated aPDT effectively inhibited S. mutans biofilm and promoted anti-demineralization without adverse effects on the physico-mechanical properties of the composite resin. These results suggest the potential of this method in preventing white spot lesions during orthodontic treatment.

Vanadium and strontium co-doped hydroxyapatite enriched polycaprolactone matrices for effective bone tissue engineering: A synergistic approach

Scientific research targeted at enhancing scaffold qualities has increased significantly during the last few decades. This emphasis frequently centres on adding different functions to scaffolds in order to increase their usefulness as instruments in the field of regenerative medicine. This study aims to investigate the efficacy of a multifunctional sustainable polymer scaffold, specifically Polycaprolactone (PCL) embedded with hydroxyapatite co-doped with vanadium and strontium (HVS), for bone tissue engineering applications. Polycaprolactone was used to fabricate the scaffold, while hydroxyapatite co-doped with vanadium and strontium (HVS) served as the nanofiller. A thorough investigation of the physicochemical and biological characteristics of the HVS nanofiller was carried out using cutting-edge techniques including Dynamic Light Scattering (DLS), and X-ray Photoelectron Spectroscopy (XPS) and in vitro cell studies. A cell viability rate of more than 70 % demonstrated that the synthesised nanofiller was cytotoxic, but in an acceptable range. The mechanical, biological, and physicochemical properties of the scaffold were extensively evaluated after the nanofiller was integrated. The water absorption characteristics of scaffold were enhanced by the addition of HVS nanofillers, leading to increased swelling, porosity, and hydrophilicity. These improvements speed up the flow of nutrients and the infiltration of cells into the scaffold. The scaffold has been shown to have important properties that stimulate bone cell activity, including better biodegradability and improved mechanical strength, which increased from 5.30 ± 0.37 to 10.58 ± 0.42 MPa. Further, its considerable antimicrobial qualities, blood-compatible nature, and capacity to promote biomineralization strengthen its appropriateness for usage in biomedical applications. Mainly, enhanced Alkaline phosphatase (ALP) activity, Alizarin Red Staining (ARS) activity, and excellent cell adhesive properties, indicating the outstanding osteogenic potential observed in rat bone marrow-derived stromal cells (rBMSC). These combined attributes highlight the pivotal role of these nanocomposite scaffolds in the field of bone tissue engineering.

Sulforaphane Inhibits Oxidative Stress and May Exert Anti-Pyroptotic Effects by Modulating NRF2/NLRP3 Signaling Pathway in Mycobacterium tuberculosis-Infected Macrophages

Sulforaphane (SFN) is a natural isothiocyanate derived from cruciferous vegetables such as broccoli, Brussels sprouts, and cabbage. SFN plays a crucial role in maintaining redox homeostasis by interacting with the active cysteine residues of Keap1, leading to the dissociation and activation of NRF2 in various diseases. In this study, our objective was to investigate the impact of SFN on oxidative stress and pyroptosis in Mycobacterium tuberculosis (Mtb)-infected macrophages. Our findings demonstrated that Mtb infection significantly increased the production of iNOS and ROS, indicating the induction of oxidative stress in macrophages. However, treatment with SFN effectively suppressed the expression of iNOS and COX-2 and reduced MDA and ROS levels, while enhancing GSH content as well as upregulating NRF2, HO-1, and NQO-1 expression in Mtb-infected RAW264.7 macrophages and primary peritoneal macrophages from WT mice. These results suggest that SFN mitigates oxidative stress by activating the NRF2 signaling pathway in Mtb-infected macrophages. Furthermore, excessive ROS production activates the NLRP3 signaling pathway, thereby promoting pyroptosis onset. Further investigations revealed that SFN effectively suppressed the expression of NLRP3, Caspase-1, and GSDMD, IL-1β, and IL-18 levels, as well as the production of LDH, suggesting that it may exhibit anti-pyroptotic effects through activation of the NRF2 signaling pathway and reductions in ROS production during Mtb infection. Moreover, we observed that SFN also inhibited the expression of NLRP3, ASC, Caspase1, and IL-1β along with LDH production in Mtb-infected primary peritoneal macrophages from NFR2-/- mice. This indicates that SFN can directly suppress NLRP3 activation and possibly inhibit pyroptosis initiation in an NRF2-independent manner. In summary, our findings demonstrate that SFN exerts its inhibitory effects on oxidative stress by activating the NRF2 signaling pathway in Mtb-infected macrophages, while it may simultaneously exert anti-pyroptotic properties through both NRF2-dependent and independent mechanisms targeting the NLRP3 signaling pathway.

Antimicrobial nanocomposite coatings for rapid intervention against catheter-associated urinary tract infections

Catheter-associated urinary tract infections (CAUTIs) pose a significant challenge in hospital settings. Current solutions available on the market involve incorporating antimicrobials and antiseptics into catheters. However, challenges such as uncontrolled release leading to undesirable toxicity, as well as the prevalence of antimicrobial resistance reduce the effectiveness of these solutions. Additionally, conventional antibiotics fail to effectively eradicate entrenched bacteria and metabolically suppressed bacteria present in the biofilm, necessitating the exploration of alternative strategies. Here, we introduce a novel polymer-nanocomposite coating that imparts rapid antimicrobial and anti-biofilm properties to coated urinary catheters. We have coated silicone-based urinary catheters with an organo-soluble antimicrobial polymer nanocomposite (APN), containing hydrophobic quaternized polyethyleneimine and zinc oxide nanoparticles, in a single step coating process. The coated surfaces exhibited rapid eradication of drug-resistant bacteria within 10-15 min, including E. coli, K. pneumoniae, MRSA, and S. epidermidis, as well as drug-resistant C. albicans fungi. APN coated catheters exhibited potent bactericidal activity against uropathogenic strains of E. coli, even when incubated in human urine. Furthermore, the stability of the coating and retention of antimicrobial activity was validated even after multiple washes. More importantly, this coating deterred biofilm formation on the catheter surface, and displayed rapid inactivation of metabolically repressed stationary phase and persister cells. The ability of the coated surfaces to disrupt bacterial membranes and induce the generation of intracellular reactive oxygen species (ROS) was assessed through different techniques, such as electron microscopy imaging, flow cytometry as well as fluorescence spectroscopy and microscopy. The surface coatings were found to be biocompatible in an in vivo mice model. Our simple one-step coating approach for catheters holds significant potential owing to its ability to tackle multidrug resistant bacteria and fungi, and the challenge of biofilm formation. This work brings us one step closer to enhancing patient care and safety in hospitals.

Double-Edged Sword: Exploring the Mitochondria-Complement Bidirectional Connection in Cellular Response and Disease

Mitochondria serve an ultimate purpose that seeks to balance the life and death of cells, a role that extends well beyond the tissue and organ systems to impact not only normal physiology but also the pathogenesis of diverse diseases. Theorized to have originated from ancient proto-bacteria, mitochondria share similarities with bacterial cells, including their own circular DNA, double-membrane structures, and fission dynamics. It is no surprise, then, that mitochondria interact with a bacterium-targeting immune pathway known as a complement system. The complement system is an ancient and sophisticated arm of the immune response that serves as the body's first line of defense against microbial invaders. It operates through a complex cascade of protein activations, rapidly identifying and neutralizing pathogens, and even aiding in the clearance of damaged cells and immune complexes. This dynamic system, intertwining innate and adaptive immunity, holds secrets to understanding numerous diseases. In this review, we explore the bidirectional interplay between mitochondrial dysfunction and the complement system through the release of mitochondrial damage-associated molecular patterns. Additionally, we explore several mitochondria- and complement-related diseases and the potential for new therapeutic strategies.

A critical review of Ginger's (Zingiber officinale) antioxidant, anti-inflammatory, and immunomodulatory activities

Ginger (Zingiber officinale) is a rhizome that has been used as a healthy herbal plant for years. Ginger's chemical components are recognized to provide beneficial health effects, namely as antioxidants and anti-inflammatory agents with the potential to operate as immunomodulators. This literature review covers numerous publications concerning ginger's immunomodulatory potential, associated with antioxidant and anti-inflammatory effects in modifying the body's immune system. Pathophysiology of oxidative stress and inflammation were introduced before diving deep down into the herbal plants as an immunomodulator. Ginger's antioxidant and anti-inflammatory properties are provided by gingerol, shogaols, paradol, and zingerone. Ginger's antioxidant mechanism is linked to Nrf2 signaling pathway activation. Its anti-inflammatory mechanism is linked to Akt inhibition and NF-KB activation, triggering the release of anti-inflammatory cytokines while reducing proinflammatory cytokines. Ginger consumption as food and drink was also explored. Overall, ginger and its active components have been shown to have strong antioxidant properties and the potential to reduce inflammation. Challenges and future prospects of ginger are also elaborated for future development. Future collaborations between researchers from various fields, including chemists, biologists, clinicians, pharmacists, and the food industry, are required further to investigate the effect of ginger on human immunity. Collaboration between researchers and industry can help accelerate the advancement of ginger applications.

Oxidative stress responses in biofilms

Oxidizing agents are low-molecular-weight molecules that oxidize other substances by accepting electrons from them. They include reactive oxygen species (ROS), such as superoxide anions (O2-), hydrogen peroxide (H2O2), and hydroxyl radicals (HO-), and reactive chlorine species (RCS) including sodium hypochlorite (NaOCl) and its active ingredient hypochlorous acid (HOCl), and chloramines. Bacteria encounter oxidizing agents in many different environments and from diverse sources. Among them, they can be produced endogenously by aerobic respiration or exogenously by the use of disinfectants and cleaning agents, as well as by the mammalian immune system. Furthermore, human activities like industrial effluent pollution, agricultural runoff, and environmental activities like volcanic eruptions and photosynthesis are also sources of oxidants. Despite their antimicrobial effects, bacteria have developed many mechanisms to resist the damage caused by these toxic molecules. Previous research has demonstrated that growing as a biofilm particularly enhances bacterial survival against oxidizing agents. This review aims to summarize the current knowledge on the resistance mechanisms employed by bacterial biofilms against ROS and RCS, focussing on the most important mechanisms, including the formation of biofilms in response to oxidative stressors, the biofilm matrix as a protective barrier, the importance of detoxifying enzymes, and increased protection within multi-species biofilm communities. Understanding the complexity of bacterial responses against oxidative stress will provide valuable insights for potential therapeutic interventions and biofilm control strategies in diverse bacterial species.

Hepatocytes and the art of killing Plasmodium softly

The Plasmodium parasites that cause malaria undergo asymptomatic development in the parenchymal cells of the liver, the hepatocytes, prior to infecting erythrocytes and causing clinical disease. Traditionally, hepatocytes have been perceived as passive bystanders that allow hepatotropic pathogens such as Plasmodium to develop relatively unchallenged. However, now there is emerging evidence suggesting that hepatocytes can mount robust cell-autonomous immune responses that target Plasmodium, limiting its progression to the blood and reducing the incidence and severity of clinical malaria. Here we discuss our current understanding of hepatocyte cell-intrinsic immune responses that target Plasmodium and how these pathways impact malaria.

Insights into the effect of guanylate-binding protein 1 on the survival of Brucella intracellularly

Brucellosis is a zoonotic disease that affects wild and domestic animals. It is caused by members of the bacterial genus Brucella. Guanylate-binding protein 1 (GBP1) is associated with microbial infections. However, the role of GBP1 during Brucella infection remains unclear. This investigation aimed to identify the association of GBP1 with brucellosis. Results showed that Brucella infection induced GBP1 upregulation in RAW 264.7 murine macrophages. Small interfering GBP1 targeting RNAs were utilized to explore how GBP1 regulates the survival of Brucella intracellularly. Results revealed that GBP1 knockdown promoted Brucella's survival ability, activated Nod-like receptor (NLR) containing a pyrin domain 3 (NLRP3) and absent in melanoma 2 (AIM2) inflammatory corpuscles, and induced pro-inflammatory cytokines IFN-γ and IL-1β. Furthermore, Brucella stimulated the expression of GBP1 in bone marrow-derived macrophages (BMDMs) and mice. During the inhibition of GBP1 in BMDMs, the intracellular growth of Brucella increased. In comparison, GBP1 downregulation enhanced the accumulation of Brucella-induced reactive oxygen species (ROS) in macrophages. Overall, the data indicate a significant role of GBP1 in regulating brucellosis and suggest the function underlying its suppressive effect on the survival and growth of Brucella intracellularly.

The combination of high temperature and Vibrio infection worsens summer mortality in the clam Meretrix petechialis by increasing apoptosis and oxidative stress

The interaction between environmental factors and Vibrio in bivalves is not well understood, despite the widely held belief that pathogen infection and seawater temperature significantly impact summer mortality. In the present study, we conducted simulated experiments to explore the effects of high temperature and Vibrio infection on the clam Meretrix petechialis. The survival curve analysis revealed that the combined challenge of high temperature and Vibrio infection (31°C-vibrio) led to significantly higher clam mortality compared to the groups exposed solely to Vibrio (27°C-vibrio), high temperature (31°C-control), and the control condition (27°C-control). Furthermore, PCoA analysis of 11 immune genes indicated that Vibrio infection predominated during the incubation period, with a gradual equilibrium between these factors emerging during the course of the infection. Additionally, our investigations into apoptosis and autophagy processes exhibited significant induction of mTOR and Bcl2 of the 31°C-vibrio group in the early challenge stage, followed by inhibition in the later stage. Oxidative stress analysis demonstrated a substantial additive effect on malondialdehyde (MDA) and glutathione (GSH) content in the combined challenge group compared to the control group. Comparative transcriptome analysis revealed a significant increase in differentially expressed genes related to immunity, such as complement C1q-like protein, C-type lectin, big defensin, and lysozyme, in the 31°C-vibrio group, suggesting that the synergistic effect of high temperature and Vibrio infection triggers more robust antibacterial immune responses. These findings provide critical insights for understanding the infection process and uncovering the causes of summer mortality.

Precise modulation and use of reactive oxygen species for immunotherapy

Reactive oxygen species (ROS) play an important role in regulating the immune system by affecting pathogens, cancer cells, and immune cells. Recent advances in biomaterials have leveraged this mechanism to precisely modulate ROS levels in target tissues for improving the effectiveness of immunotherapies in infectious diseases, cancer, and autoimmune diseases. Moreover, ROS-responsive biomaterials can trigger the release of immunotherapeutics and provide tunable release kinetics, which can further boost their efficacy. This review will discuss the latest biomaterial-based approaches for both precise modulation of ROS levels and using ROS as a stimulus to control the release kinetics of immunotherapeutics. Finally, we will discuss the existing challenges and potential solutions for clinical translation of ROS-modulating and ROS-responsive approaches for immunotherapy, and provide an outlook for future research.

The prostaglandin D2 antagonist asapiprant ameliorates clinical severity in young hosts infected with invasive Streptococcus pneumoniae

Streptococcus pneumoniae (pneumococcus) remains a serious cause of pulmonary and systemic infections globally, and host-directed therapies are lacking. The aim of this study was to test the therapeutic efficacy of asapiprant, an inhibitor of prostaglandin D2 signaling, against pneumococcal infection. Treatment of young mice with asapiprant after pulmonary infection with invasive pneumococci significantly reduced systemic spread, disease severity, and host death. Protection was specific against bacterial dissemination from the lung to the blood but had no effect on pulmonary bacterial burden. Asapiprant-treated mice had enhanced antimicrobial activity in circulating neutrophils, elevated levels of reactive oxygen species (ROS) in lung macrophages/monocytes, and improved pulmonary barrier integrity indicated by significantly reduced diffusion of fluorescein isothiocyanate (FITC)-dextran from lungs into the circulation. These findings suggest that asapiprant protects the host against pneumococcal dissemination by enhancing the antimicrobial activity of immune cells and maintaining epithelial/endothelial barrier integrity in the lungs.

Host-parasite interaction in severe and uncomplicated malaria infection in ghanaian children

PURPOSE

During malarial infection, both parasites and host red blood cells (RBCs) come under severe oxidative stress due to the production of free radicals. The host system responds in protecting the RBCs against the oxidative damage caused by these free radicals by producing antioxidants. In this study, we investigated the antioxidant enzyme; superoxide dismutase (SOD) activity and cytokine interactions with parasitaemia in Ghanaian children with severe and uncomplicated malaria.

METHODOLOGY

One hundred and fifty participants aged 0-12 years were administered with structured questionnaires. Active case finding approach was used in participating hospitals to identify and interview cases before treatment was applied. Blood samples were taken from each participant and used to quantify malaria parasitaemia, measure haematological parameters and SOD activity. Cytokine levels were measured by commercial ELISA kits. DNA comet assay was used to evaluate the extent of parasite DNA damage due to oxidative stress.

RESULTS

Seventy - Nine (79) and Twenty- Six (26) participants who were positive with malaria parasites were categorized as severe (56.75 × 103 ± 57.69 parasites/µl) and uncomplicated malaria (5.87 × 103 ± 2.87 parasites/µl) respectively, showing significant difference in parasitaemia (p < 0.0001). Significant negative correlation was found between parasitaemia and SOD activity levels among severe malaria study participants (p = 0.0428). Difference in cytokine levels (IL-10) amongst the control, uncomplicated and severe malaria groups was significant (p < 0.0001). The IFN-γ/IL-10 /TNF-α/IL-10 ratio differed significantly between the malaria infected and non- malaria infected study participants. DNA comet assay revealed damage to Plasmodium parasite DNA.

CONCLUSION

Critical roles played by SOD activity and cytokines as anti-parasitic defense during P. falciparum malaria infection in children were established.

Loss of TRIM29 mitigates viral myocarditis by attenuating PERK-driven ER stress response in male mice

Viral myocarditis, an inflammatory disease of the myocardium, is a significant cause of sudden death in children and young adults. The current coronavirus disease 19 pandemic emphasizes the need to understand the pathogenesis mechanisms and potential treatment strategies for viral myocarditis. Here, we found that TRIM29 was highly induced by cardiotropic viruses and promoted protein kinase RNA-like endoplasmic reticulum kinase (PERK)-mediated endoplasmic reticulum (ER) stress, apoptosis, and reactive oxygen species (ROS) responses that promote viral replication in cardiomyocytes in vitro. TRIM29 deficiency protected mice from viral myocarditis by promoting cardiac antiviral functions and reducing PERK-mediated inflammation and immunosuppressive monocytic myeloid-derived suppressor cells (mMDSC) in vivo. Mechanistically, TRIM29 interacted with PERK to promote SUMOylation of PERK to maintain its stability, thereby promoting PERK-mediated signaling pathways. Finally, we demonstrated that the PERK inhibitor GSK2656157 mitigated viral myocarditis by disrupting the TRIM29-PERK connection, thereby bolstering cardiac function, enhancing cardiac antiviral responses, and curbing inflammation and immunosuppressive mMDSC in vivo. Our findings offer insight into how cardiotropic viruses exploit TRIM29-regulated PERK signaling pathways to instigate viral myocarditis, suggesting that targeting the TRIM29-PERK axis could mitigate disease severity.

The Zanthoxylum armatum fruit's oil exterminates Candida cells by inhibiting ergosterol biosynthesis without generating reactive oxygen species

Candida spp. is a significant cause of topical and fungal infections in humans. In addition to Candida albicans, many non-albicans species such as C. krusei, C. glabrata, C. parapsilosis, C. tropicalis, C. guilliermondii cause severe infections. The main antifungal agents belong to three different classes, including azoles, polyenes, and echinocandins. However, resistance to all three categories of drugs has been reported. Therefore, there is an urgent need to search for other alternatives with antifungal activity. Many herbal extracts and compounds from natural sources show excellent antifungal activity. In this study, we used an oil extract from the fruits of Zanthoxylum armatum, which showed significant antifungal activity against various Candida spp. by two different methods-minimum inhibitory concentration (MIC) and agar diffusion. In addition, we attempted to explore the possible mechanism of action in C. albicans. It was found that the antifungal activity of Z. armatum oil is fungicidal and involves a decrease in the level of ergosterol in the cell membrane. The decrease in ergosterol level resulted in increased passive diffusion of a fluorescent molecule, rhodamine6G, across the plasma membrane, indicating increased membrane fluidity. The oil-treated cells showed decreased germ tube formation, an important indicator of C. albicans' virulence. The fungal cells also exhibited decreased attachment to the buccal epithelium, the first step toward invasion, biofilm formation, and damage to oral epithelial cells. Interestingly, unlike most antifungal agents, in which the generation of reactive oxygen species is responsible for killing, no significant effect was observed in the present study.

Application of antimicrobial sonodynamic therapy as a potential treatment modality in dentistry: A literature review

The accumulation of dental plaque is a precursor to various dental infections, including lesions, inflammation around dental implants, and inflammation under dentures. Traditional cleaning methods involving physical removal and chemical agents often fall short of eliminating bacteria and their protective biofilms. These methods can also inadvertently lead to bacteria that resist drugs and upset the mouth's microbial harmony. To counter these issues, a new approach is needed that can target and clear away dental plaque, minimize biofilms and bacteria, and thus support sustained dental health. Enter antimicrobial sonodynamic therapy (aSDT), a supplementary treatment that uses gentle ultrasound waves to trigger a sonosensitizer compound, destroying bacterial cells. This process works by generating heat, mechanical pressure, initiating chemical reactions, and producing reactive oxygen species (ROS), offering a fresh tactic for managing dental plaque and biofilms. The study reviews how aSDT could serve as an innovative dental treatment option to enhance oral health.

Serine metabolism is crucial for cGAS-STING signaling and viral defense control in the gut

Inflammatory bowel diseases are characterized by the chronic relapsing inflammation of the gastrointestinal tract. While the molecular causality between endoplasmic reticulum (ER) stress and intestinal inflammation is widely accepted, the metabolic consequences of chronic ER stress on the pathophysiology of IBD remain unclear. By using in vitro, in vivo models, and patient datasets, we identified a distinct polarization of the mitochondrial one-carbon metabolism and a fine-tuning of the amino acid uptake in intestinal epithelial cells tailored to support GSH and NADPH metabolism upon ER stress. This metabolic phenotype strongly correlates with IBD severity and therapy response. Mechanistically, we uncover that both chronic ER stress and serine limitation disrupt cGAS-STING signaling, impairing the epithelial response against viral and bacterial infection and fueling experimental enteritis. Consequently, the antioxidant treatment restores STING function and virus control. Collectively, our data highlight the importance of serine metabolism to allow proper cGAS-STING signaling and innate immune responses upon gut inflammation.

Drosophila melanogaster Sting mediates Coxiella burnetii infection by reducing accumulation of reactive oxygen species

The Gram-negative bacterium Coxiella burnetii is the causative agent of query fever in humans and coxiellosis in livestock. C. burnetii infects a variety of cell types, tissues, and animal species including mammals and arthropods, but there is much left to be understood about the molecular mechanisms at play during infection in distinct species. Human stimulator of interferon genes (STING) induces an innate immune response through the induction of type I interferons (IFNs), and IFN promotes or suppresses C. burnetii replication, depending on tissue type. Drosophila melanogaster contains a functional STING ortholog (Sting) which activates NF-κB signaling and autophagy. Here, we sought to address the role of D. melanogaster Sting during C. burnetii infection to uncover how Sting regulates C. burnetii infection in flies. We show that Sting-null flies exhibit higher mortality and reduced induction of antimicrobial peptides following C. burnetii infection compared to control flies. Additionally, Sting-null flies induce lower levels of oxidative stress genes during infection, but the provision of N-acetyl-cysteine (NAC) in food rescues Sting-null host survival. Lastly, we find that reactive oxygen species levels during C. burnetii infection are higher in Drosophila S2 cells knocked down for Sting compared to control cells. Our results show that at the host level, NAC provides protection against C. burnetii infection in the absence of Sting, thus establishing a role for Sting in protection against oxidative stress during C. burnetii infection.

Effects of Dietary Zinc on Growth, Haematological Indices, Digestive Enzyme Activity, Tissue Mineralization, Antioxidant and Immune Status of Fingerling Heteropneustes fossilis

A 12 week feeding trial was conducted to evaluate the effects of dietary zinc levels on Heteropneustes fossilis. Triplicate groups of fish were fed isoproteic (CP; 400 g/kg) and isocaloric (GE; 17.89 kJ/g) diets increasing levels of zinc (0, 5, 10, 15, 20, 25, 30 mg/kg) achieved by supplementing zinc sulphate heptahydrate to basal diet. Analysed concentrations of zinc in diets were 10.68, 15.83, 21.34, 26.74, 30.61, 34.91 and 41.34 mg/kg. Growth indices increased linearly (P<0.05) up to 26.74 mg/kg Zn. The protein and ash content of whole body also improved significantly up to 26.74 mg/kg Zn. Whole body fat content showed inverse pattern. Haematological parameters also showed an improving trend with the increase in dietary zinc up to 26.74 mg/kg and then levelled off. Activities of antioxidant enzymes were improved with the increase in dietary zinc level up to 26.74 mg/kg followed by no significant change (P>0.05). Serum lysozyme activity also exhibited the similar pattern. Immune response in terms of the activities of lysozyme, alkaline phosphatase and myeloperoxidase was also improved with the increase in dietary zinc levels up to 26.74 mg/kg. Dietary zinc levels affected significantly the whole body as well as vertebrae mineralization. Broken-line regression analysis of weight gain, vertebrae zinc activity, serum superoxide dismutase and protease activity against increasing amounts of dietary zinc revealed that the inclusion of zinc in diet in the range of 26.82-29.84 mg/kg is optimum for growth, haematological indices, antioxidant status, immune response and tissue mineralization in fingerling H. fossilis. The information obtained from present study would be helpful in formulating the zinc-balanced commercial feeds to improve the growth and health status of this important fish, thus contributing to aquaculture production and strengthening the food security.

Scs system links copper and redox homeostasis in bacterial pathogens

The bacterial envelope is an essential compartment involved in metabolism and metabolites transport, virulence, and stress defense. Its roles become more evident when homeostasis is challenged during host-pathogen interactions. In particular, the presence of free radical groups and excess copper in the periplasm causes noxious reactions, such as sulfhydryl group oxidation leading to enzymatic inactivation and protein denaturation. In response to this, canonical and accessory oxidoreductase systems are induced, performing quality control of thiol groups, and therefore contributing to restoring homeostasis and preserving survival under these conditions. Here, we examine recent advances in the characterization of the Dsb-like, Salmonella-specific Scs system. This system includes the ScsC/ScsB pair of Cu+-binding proteins with thiol-oxidoreductase activity, an alternative ScsB-partner, the membrane-linked ScsD, and a likely associated protein, ScsA, with a role in peroxide resistance. We discuss the acquisition of the scsABCD locus and its integration into a global regulatory pathway directing envelope response to Cu stress during the evolution of pathogens that also harbor the canonical Dsb systems. The evidence suggests that the canonical Dsb systems cannot satisfy the extra demands that the host-pathogen interface imposes to preserve functional thiol groups. This resulted in the acquisition of the Scs system by Salmonella. We propose that the ScsABCD complex evolved to connect Cu and redox stress responses in this pathogen as well as in other bacterial pathogens.

Oxidative stress governs mosquito innate immune signalling to reduce chikungunya virus infection in Aedes-derived cells

Arboviruses such as chikungunya, dengue and zika viruses cause debilitating diseases in humans. The principal vector species that transmits these viruses is the Aedes mosquito. Lack of substantial knowledge of the vector species hinders the advancement of strategies for controlling the spread of arboviruses. To supplement our information on mosquitoes' responses to virus infection, we utilized Aedes aegypti-derived Aag2 cells to study changes at the transcriptional level during infection with chikungunya virus (CHIKV). We observed that genes belonging to the redox pathway were significantly differentially regulated. Upon quantifying reactive oxygen species (ROS) in the cells during viral infection, we further discovered that ROS levels are considerably higher during the early hours of infection; however, as the infection progresses, an increase in antioxidant gene expression suppresses the oxidative stress in cells. Our study also suggests that ROS is a critical regulator of viral replication in cells and inhibits intracellular and extracellular viral replication by promoting the Rel2-mediated Imd immune signalling pathway. In conclusion, our study provides evidence for a regulatory role of oxidative stress in infected Aedes-derived cells.

A pilot study of mitochondrial response to an in vivo prosthetic joint Staphylococcus aureus infection model

Prosthetic joint infections (PJI) are associated with orthopaedic morbidity and mortality. Mitochondria, the "cell's powerhouses," are thought to play crucial roles in infection response and in increased risk of sepsis mortality. No current research discusses PJI's effect on mitochondrial function and a lack of understanding of immune-infection interactions potentially hinders patient care. The purpose of this pilot study was to evaluate the impact of simulated PJI on local tissue mitochondrial function. Using an established prosthetic implant-associated in vivo model, tissues were harvested from the surgical limb of a methicillin-sensitive Staphylococcus aureus implant-associated infection group (n = 6) and compared to a noninfected group (n = 6) at postoperative day (POD) 21. Using mitochondrial coupling assays, oxygen consumption rate and extracellular acidification rate were assessed in each group. Electron flow through mitochondrial complexes reflected group activity. Electron Paramagnetic Resonance (EPR) spectrometry measured the oxidizing potential of serum samples from infected versus noninfected groups. On POD21, colony-forming units per gram of tissue showed 5 × 109 in the infected group and 101 in the noninfected group (p < 0.0001). Maximal respiration and oxygen consumption due to adenosine triphosphate synthesis were significantly lower in isolated mitochondria from infected limbs (p = 0.04). Both groups had similar complex I, III, IV, and V activity (p > 0.1). Infected group EPR signal intensity reflecting reactive oxygen species levels was 1.31 ± 0.30 compared to 1.16 ± 0.28 (p = 0.73) in the noninfected group. This study highlights PJI's role in mammalian cell mitochondrial dysfunction and oxidative tissue damage, which can help develop interventions to combat PJI.

Antimicrobial photodynamic therapy for the management of gingivitis and white spot lesions in fixed orthodontic patients: A systematic review

AIM

We conducted this review to evaluate the safety and efficacy of antimicrobial photodynamic therapy (aPDT) for the management of gingivitis and white spot lesions (WSLs) in fixed orthodontic patients.

METHODS

The PubMed/MEDLINE, Cochrane Library, Scopus, and Google Scholar databases were searched for randomized controlled trials and clinical trials assessing the clinical effectiveness of aPDT for the management of gingivitis and WSLs in fixed orthodontic patients without time limitation. Primary outcomes were the changes in clinical parameters such as DIAGNOdent, plaque index (PI), bleeding on probing (BOP), and gingival index (GI). Secondary outcomes included measurements of microbial and inflammatory factors, such as cytokine levels (tumor necrosis factor alpha [TNF-α], interleukin-1 beta [IL-1β], and interleukin-6 [IL-6]), and bacterial counts.

RESULTS

Our search yielded a total of 12 studies that met the inclusion criteria. Among the 11 studies that evaluated gingivitis, the majority employed a diode laser (670nm, 150 mW, 22J/cm2, 60seconds) as the light source and methylene blue at a concentration of 0.0005% (applied for 3minutes) as the photosensitizer in a single treatment session. The included studies reported positive effects of aPDT on gingivitis management, with more improvements observed in PI, BOP, and GI following aPDT treatment. Additionally, aPDT was found to reduce the counts of periopathogens such as Porphyromonas gingivalis, as well as inflammatory factors (TNF-α, IL-1β, and IL-6). Two studies demonstrated that aPDT, particularly when administered in multiple sessions, effectively controlled the extent of WSLs during orthodontic treatment and yielded favorable outcomes that persisted for several months after treatment.

CONCLUSION

Based on the available evidence, aPDT appears to be a safe and effective treatment option for managing WSLs and gingivitis in patients with fixed orthodontic appliances. However, further high-quality RCTs are necessary to investigate the impact of potential confounding factors on the efficacy of aPDT.

Anti-bacterial and anti-biofilm activities of arachidonic acid against the cariogenic bacterium Streptococcus mutans

Streptococcus mutans is a Gram-positive, facultative anaerobic bacterium, which causes dental caries after forming biofilms on the tooth surface while producing organic acids that demineralize enamel and dentin. We observed that the polyunsaturated arachidonic acid (AA) (ω-6; 20:4) had an anti-bacterial activity against S. mutans, which prompted us to investigate its mechanism of action. The minimum inhibitory concentration (MIC) of AA on S. mutans was 25 μg/ml in the presence of 5% CO2, while it was reduced to 6.25-12.5 μg/ml in the absence of CO2 supplementation. The anti-bacterial action was due to a combination of bactericidal and bacteriostatic effects. The minimum biofilm inhibitory concentration (MBIC) was the same as the MIC, suggesting that part of the anti-biofilm effect was due to the anti-bacterial activity. Gene expression studies showed decreased expression of biofilm-related genes, suggesting that AA also has a specific anti-biofilm effect. Flow cytometric analyses using potentiometric DiOC2(3) dye, fluorescent efflux pump substrates, and live/dead SYTO 9/propidium iodide staining showed that AA leads to immediate membrane hyperpolarization, altered membrane transport and efflux pump activities, and increased membrane permeability with subsequent membrane perforation. High-resolution scanning electron microscopy (HR-SEM) showed remnants of burst bacteria. Furthermore, flow cytometric analysis using the redox probe 2',7'-dichlorofluorescein diacetate (DCFHDA) showed that AA acts as an antioxidant in a dose-dependent manner. α-Tocopherol, an antioxidant that terminates the radical chain, counteracted the anti-bacterial activity of AA, suggesting that oxidation of AA in bacteria leads to the production of cytotoxic radicals that contribute to bacterial growth arrest and death. Importantly, AA was not toxic to normal Vero epithelial cells even at 100 μg/ml, and it did not cause hemolysis of erythrocytes. In conclusion, our study shows that AA is a potentially safe drug that can be used to reduce the bacterial burden of cariogenic S. mutans.

Gut toxicity of polystyrene microplastics and polychlorinated biphenyls to Eisenia fetida: Single and co-exposure effects with a focus on links between gut bacteria and bacterial translocation stemming from gut barrier damage

Microplastics' (MPs) ability to sorb and transport polychlorinated biphenyls (PCBs) in soil ecosystems warrants significant attention. Although organisms mainly encounter pollutants through the gut, the combined pollution impact of MPs and PCBs on soil fauna gut toxicity remains incompletely understood. Consequently, this study examined the gut toxicity of polystyrene MPs (PS-MPs) and PCB126 on Eisenia fetida, emphasizing the links between gut bacteria and bacterial translocation instigated by gut barrier impairment. Our findings underscored that E. fetida could ingest PS-MPs, which mitigated the PCB126 accumulation in E. fetida by 9.43 %. Exposure to PCB126 inhibited the expression of gut tight junction (TJ) protein genes. Although the presence of PS-MPs attenuated this suppression, it didn't alleviate gut barrier damage and bacterial translocation in the co-exposure group. This group demonstrated a significantly increased level of gut bacterial load (BLT, ANOVA, p = 0.005 vs control group) and lipopolysaccharide-binding protein (LBP, ANOVA, all p < 0.001 vs control, PCB, and PS groups), both of which displayed significant positive correlations with antibacterial defense. Furthermore, exposure to PS-MPs and PCB126, particularly within the co-exposure group, results in a marked decline in the dispersal ability of gut bacteria. This leads to dysbiosis (Adonis, R2 = 0.294, p = 0.001), with remarkable signature taxa such as Janthinobacterium, Microbacterium and Pseudomonas, being implicated in gut barrier dysfunction. This research illuminates the mechanism of gut toxicity induced by PS-MPs and PCB126 combined pollution in earthworms, providing novel insights for the ecological risk assessment of soil.

Elongation on aliphatic chain improves selectivity of 2-hydroxy-3,4,6-trimethoxyphenyl chalcone on Trypanosoma cruzi

Aim: Our objective was to investigate the trypanocidal effect of the chalcone (2E,4E)-1-(2-hydroxy-3,4,6-trimethoxyphenyl)-5-phenylpenta-2,4-dien-1-one (CPNC). Material & methods: Cytotoxicity toward LLC-MK2 host cells was assessed by MTT assay, and the effect on Trypanosoma cruzi life forms (epimastigotes, trypomastigotes and amastigotes) was evaluated by counting. Flow cytometry analysis was performed to evaluate the possible mechanisms of action. Finally, molecular docking simulations were performed to evaluate interactions between CPNC and T. cruzi enzymes. Results: CPNC showed activity against epimastigote, trypomastigote and amastigote life forms, induced membrane damage, increased cytoplasmic reactive oxygen species and mitochondrial dysfunction on T. cruzi. Regarding molecular docking, CPNC interacted with both trypanothione reductase and TcCr enzymes. Conclusion: CPNC presented a trypanocidal effect, and its effect is related to oxidative stress, mitochondrial impairment and necrosis.

Photobiomodulation Effects on Periodontal Ligament Stem Cells: A Systematic Review of In Vitro Studies

BACKGROUND

Stem cell therapy has been considered to play a paramount role in the treatment modalities available for regenerative dentistry. The established beneficial effects of photobiomodulation (PBM) at the cellular level have led to the combined use of these two factors (PBM and stem cells). The main goal of this study was firstly to critically appraise the effects of PBM on periodontal ligament stem cells (PDLSCs), and secondly to explore the most effective PBM protocols applied.

METHODS

Pubmed, Cochrane, Scopus, Science Direct, and Google Scholar search engines were used to identify experimental in vitro studies in which PBM was applied to cultured PDLSCs. After applying specific keywords, additional filters, and inclusion/exclusion criteria, a preliminary number of 245 articles were narrowed down to 11 in which lasers and LEDs were used within the 630 - 1064 nm wavelength range. Selected articles were further assessed by three independent reviewers for strict compliance with PRISMA guidelines, and a modified Cochrane risk of bias to determine eligibility.

STATISTICAL ANALYSIS

The dataset analysed was extracted from the studies with sufficient and clearly presented PBM protocols. Simple univariate regression analysis was performed to explore the significance of contributions of potential quantitative predictor variables toward study outcomes, and a one-way ANOVA model was employed for testing differences between the laser or LED sources of the treatments. The significance level for testing was set at α = 0.05.

RESULTS

The proliferation rate, osteogenic differentiation, and expression of different indicative genes for osteogenesis and inflammation suppression were found to be positively affected by the application of various types of lasers and LEDs. With regard to the PBM protocol, only the wavelength variable appeared to affect the treatment outcome; indeed, the 940 nm wavelength parameter was found not to exert a favourable effect.

CONCLUSIONS

Photobiomodulation can enhance the stemness and differentiation capacities of periodontal ligament stem cells. Therefore, for PBM protocols, there remains no consensus amongst the scientific community. Statistical analyses performed here indicated that the employment of a near-infrared (NIR) wavelength of 940 nm may not yield a significant favourable outcome, although those within the 630 - 830 nm range did so. Concerning the fluence, it should not exceed 8 J/cm2 when therapy is applied by LED devices, and 4 J/cm2 when applied by lasers, respectively.

Intrinsic factors driving mosquito vector competence and viral evolution: a review

Mosquitoes are responsible for the transmission of numerous viruses of global health significance. The term "vector competence" describes the intrinsic ability of an arthropod vector to transmit an infectious agent. Prior to transmission, the mosquito itself presents a complex and hostile environment through which a virus must transit to ensure propagation and transmission to the next host. Viruses imbibed in an infectious blood meal must pass in and out of the mosquito midgut, traffic through the body cavity or hemocoel, invade the salivary glands, and be expelled with the saliva when the vector takes a subsequent blood meal. Viruses encounter physical, cellular, microbial, and immunological barriers, which are influenced by the genetic background of the mosquito vector as well as environmental conditions. Collectively, these factors place significant selective pressure on the virus that impact its evolution and transmission. Here, we provide an overview of the current state of the field in understanding the mosquito-specific factors that underpin vector competence and how each of these mechanisms may influence virus evolution.

Zirconium-Coated β-Cyclodextrin Nanomaterials for Biofilm Eradication

Under alkaline treatment, zirconyl chloride (ZrOCl2.8H2O) became a zirconia gel and formed a stable complex with beta-cyclodextrin (βCD). This complex was highly active in reactive oxygen species (ROS) formation via H2O2 decomposition. Its surface with numerous hydroxyl groups acts as an ionic sponge to capture the charged reaction intermediates, including superoxide (O2-•) and the hydroxyl radical (•OH). ROS, especially •OH radicals, are harmful to living microorganisms because of their kinetic instability, high oxidation potential, and chemical nonselectivity. Therefore, •OH radicals can engage in fast reactions with virtually any adjacent biomolecule. With H2O2, the complex with cationic and hydrophobic moieties interacted with the anionic bacterial membrane of two Gram-positive (Staphylococcus aureus and S. epidermidis) and two Gram-negative (Escherichia coli and Klebsiella pneumoniae) strains. The Zr-βCD-H2O2 also eradicated more than 99% of the biofilm of these four pathogens. Considering the difficult acquisition of resistance to the oxidation of •OH, the results suggested that this βCD-based nanomaterial might be a promising agent to target both drug-resistant pathogens with no cytotoxicity and exceptional antimicrobial activity.

Dietary supplementation of Polygonum chinense improves the immunity of Asian seabass, Lates calcarifer (Bloch, 1790) against Vibrio harveyi infection

Aquaculture plays a significant role in the overall fish production in Malaysia, contributing a substantial quantity of food-fish amounting to roughly 573,683 tonnes with an estimated economic value of US$860 million in 2022. However, diseases have become a significant limitation for aquaculture production. Therefore, herbal immunostimulant has been considered a natural and practical approach of preventing disease infection in fish. The ability of Polygonum chinense extract (PCE) on haemato-biochemistry parameters, immunomodulatory properties, and disease resistance of Lates calcarifer (Asian seabass) under Vibrio harveyi challenge was evaluated in this study, with a focus on dose-response associations and variability over various exposure durations (0-, 7- and 14-day post-infection). A total of 480 Asian seabass (9.5 ± 0.2 g) were distributed in 12 aquaria and fed four diets supplemented with 0 (control), 2, 5 and 10 g/kg diet for 60 days before being challenged with V. harveyi. Dietary PCE significantly improved (P < 0.05) survival, with the dose of 10 g/kg showing the highest survival rate (90 %) when compared to the control (60 %). Additionally, hematological (red and white blood cell counts, hemoglobulin, packed cell volume, and mean corpuscular volume) and immunological (activities of lysozyme, phagocytic activity and respiratory burst, and serum total immunoglobulin) properties were significantly increased (P < 0.05) in comparison to the control group. In contrast, serum aspartate aminotransferase and alanine aminotransferase levels, as well as glucose level were significantly reduced (P < 0.05) in PCE-fed fish compared to the control group. Conclusively, the current study discovered that supplementing fish feed with P. chinense extract improves fish haemato-biochemical profile, immunocompetence and disease resistance to V. harveyi infection.

Bilirubin in wound healing: A double-edged sword

The impact of bilirubin levels on wound healing remains a topic of controversy. The present study is a literature review that examines the impact of increased levels of bilirubin in the bloodstream on the process of wound healing. The physiological pathways and their interrelationships, as well as the relevant research publications, were comprehensively addressed in our discussion. The present study undertook a comprehensive review of the extant literature pertaining to the impact of bilirubin concentration on the process of wound healing, with particular emphasis on its association with reactive oxygen species. This scholarly article provides an overview of several studies that elucidate the mechanisms and correlation between bilirubin and the process of wound healing. The impact of bilirubin on wound healing has been observed, and it appears to function as a modulator. This review demonstrates that there exists a spectrum of bilirubin concentrations that can function as precise regulators, although this range falls under pathological hyperbilirubinemia. Further research is required to determine the precise boundary of this range. Within a certain range, bilirubin serves as a positive regulator in the process of wound healing. Beyond this range, it has the potential to function as a negative regulator.

Cerium oxide nanoparticles: Synthesis methods and applications in wound healing

Wound care and treatment can be critical from a clinical standpoint. While different strategies for the management and treatment of skin wounds have been developed, the limitations inherent in the current approaches necessitate the development of more effective alternative strategies. Advances in tissue engineering have resulted in the development of novel promising approaches for accelerating wound healing. The use of various biomaterials capable of accelerating the regeneration of damaged tissue is critical in tissue engineering. In this regard, cerium oxide nanoparticles (CeO2 NPs) have recently received much attention because of their excellent biological properties, such as antibacterial, anti-inflammatory, antioxidant, and angiogenic features. The incorporation of CeO2 NPs into various polymer-based scaffolds developed for wound healing applications has led to accelerated wound healing due to the presence of CeO2 NPs. This paper discusses the structure and functions of the skin, the wound healing process, different methods for the synthesis of CeO2 NPs, the biological properties of CeO2 NPs, the role of CeO2 NPs in wound healing, the use of scaffolds containing CeO2 NPs for wound healing applications, and the potential toxicity of CeO2 NPs.

Exposure to cooking fumes is associated with perturbations in nasal microbiota composition: A pilot study

Air pollution is one of the leading causes of overall mortality globally. Cooking emissions are a major source of fine particulate matter (PM2.5). However, studies on their potential perturbations on the nasal microbiota as well as their association with respiratory health are lacking. This pilot study aims to assess the environmental air quality among occupational cooks and its associations with nasal microbiota and respiratory symptoms. A total of 20 cooks (exposed) and 20 unexposed controls (mainly office workers), were recruited in Singapore from 2019 to 2021. Information on sociodemographic factors, cooking methods, and self-reported respiratory symptoms were collected using a questionnaire. Personal PM2.5 concentrations and reactive oxygen species (ROS) levels were measured using portable sensors and filter samplers. DNA was extracted from nasal swabs and sequenced using 16s sequencing. Alpha-diversity and beta-diversity were calculated, and between-group variation analysis of species was performed. Multivariable logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for associations between exposure groups and self-reported respiratory symptoms. Higher daily mean PM2.5 (P = 2 × 10-7) and environmental ROS exposure (P = 3.25 × 10-7) were observed in the exposed group. Alpha diversity of the nasal microbiota between the two groups was not significantly different. However, beta diversity was significantly different (unweighted UniFrac P = 1.11 × 10-5, weighted UniFrac P = 5.42 × 10-6) between the two exposure groups. In addition, certain taxa of bacteria were slightly more abundant in the exposed group compared to unexposed controls. There were no significant associations between the exposure groups and self-reported respiratory symptoms. In summary, the exposed group had higher PM2.5 and ROS exposure levels and altered nasal microbiotas as compared to unexposed controls, though further studies are required to replicate these findings in a larger population.

Reactive Oxygen Species-Dependent Activation of EGFR/Akt/p38 Mitogen-Activated Protein Kinase and JNK1/2/FoxO1 and AP-1 Pathways in Human Pulmonary Alveolar Epithelial Cells Leads to Up-Regulation of COX-2/PGE2 Induced by Silica Nanoparticles

The risk of lung exposure to silica nanoparticles (SiNPs) and related lung inflammatory injury is increasing with the wide application of SiNPs in a variety of industries. A growing body of research has revealed that cyclooxygenase (COX)-2/prostaglandin E2 (PGE2) up-regulated by SiNP toxicity has a role during pulmonary inflammation. The detailed mechanisms underlying SiNP-induced COX-2 expression and PGE2 synthesis remain unknown. The present study aims to dissect the molecular components involved in COX-2/PGE2 up-regulated by SiNPs in human pulmonary alveolar epithelial cells (HPAEpiCs) which are one of the major targets while SiNPs are inhaled. In the present study, we demonstrated that SiNPs induced COX-2 expression and PGE2 release, which were inhibited by pretreatment with a reactive oxygen species (ROS) scavenger (edaravone) or the inhibitors of proline-rich tyrosine kinase 2 (Pyk2, PF-431396), epidermal growth factor receptor (EGFR, AG1478), phosphatidylinositol 3-kinase (PI3K, LY294002), protein kinase B (Akt, Akt inhibitor VIII), p38 mitogen-activated protein kinase (MAPK) (p38 MAPK inhibitor VIII), c-Jun N-terminal kinases (JNK)1/2 (SP600125), Forkhead Box O1 (FoxO1, AS1842856), and activator protein 1 (AP-1, Tanshinone IIA). In addition, we also found that SiNPs induced ROS-dependent Pyk2, EGFR, Akt, p38 MAPK, and JNK1/2 activation in these cells. These signaling pathways induced by SiNPs could further cause c-Jun and FoxO1 activation and translocation from the cytosol to the nucleus. AP-1 and FoxO1 activation could increase COX-2 and PGE2 levels induced by SiNPs. Finally, the COX-2/PGE2 axis might promote the inflammatory responses in HPAEpiCs. In conclusion, we suggested that SiNPs induced COX-2 expression accompanied by PGE2 synthesis mediated via ROS/Pyk2/EGFR/PI3K/Akt/p38 MAPK- and JNK1/2-dependent FoxO1 and AP-1 activation in HPAEpiCs.

Murine Mast Cells That Are Deficient in IFNAR-Signaling Respond to Viral Infection by Producing a Large Amount of Inflammatory Cytokines, a Low Level of Reactive Oxygen Species, and a High Rate of Cell Death

Mat cells (MCs) are located in the skin and mucous membranes at points where the body meets the environment. When activated, MCs release inflammatory cytokines, which help the immune system to fight viruses. MCs produce, and have receptors for interferons (IFNs), which belong to a family of cytokines recognized for their antiviral properties. Previously, we reported that MCs produced proinflammatory cytokines in response to a recombinant vesicular stomatitis virus (rVSVΔm51) and that IFNAR signaling was required to down-modulate these responses. Here, we have demonstrated that UV-irradiated rVSVΔm51 did not cause any inflammatory cytokines in either in vitro cultured mouse IFNAR-intact (IFNAR+/+), or in IFNAR-knockout (IFNAR-/-) MCs. However, the non-irradiated virus was able to replicate more effectively in IFNAR-/- MCs and produced a higher level of inflammatory cytokines compared with the IFNAR+/+ MCs. Interestingly, MCs lacking IFNAR expression displayed reduced levels of reactive oxygen species (ROS) compared with IFNAR+/+ MCs. Additionally, upon the viral infection, these IFNAR-/- MCs were found to coexist with many dying cells within the cell population. Based on our findings, IFNAR-intact MCs exhibit a lower rate of rVSVΔm51 infectivity and lower levels of cytokines while demonstrating higher levels of ROS. This suggests that MCs with intact IFNAR signaling may survive viral infections by producing cell-protective ROS mechanisms and are less likely to die than IFNAR-/- cells.

Anti-multispecies microbial biofilms and anti-inflammatory effects of antimicrobial photo-sonodynamic therapy based on acrylic resin containing nano-resveratrol

BACKGROUND

Polymethylmethacrylate (PMMA)-based removable orthodontic appliances are susceptible to microbial colonization due to the surface porosity, and accumulating the biofilms causes denture stomatitis. the present study evaluated the anti-biofilm and antiinflammatory effects of antimicrobial photo-sonodynamic therapy (aPSDT) against multispecies microbial biofilms (Candida albicans, Staphylococcus aureus, Streptococcus sobrinus, and Actinomyces naeslundii) formed on acrylic resin modified with nanoresveratrol (NR).

MATERIALS AND METHODS

Following the determination of the minimum biofilm inhibitory concentration (MBIC) of NR, in vitro anti-biofilm activity of NR was evaluated. The antibiofilm efficacy against multispecies microbial biofilm including C. albicans, S. aureus, S. sobrinus, and A. naeslundii, were assessed by biofilm inhibition test and the results were measured. To reveal the anti-inflammatory effects of aPSDT on human gingival fibroblast (HGF) cells, the gene expression levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were evaluated via quantitative real-time polymerase chain reaction (qRT-PCR).

RESULTS

According to the results, the MBIC dose of NR against multispecies microbial biofilm was considered 512 µg/mL. The highest biofilm reduction activity was observed in MBIC treated with aPSDT and 2 × MBIC exposed to light emitting diode (LED) and ultrasound waves (UW). The expression level of TNF-α and IL-6 genes were significantly increased when HGF cells were exposed to multispecies microbial biofilms (P<0.05), while after treatment with aPSDT, the expression levels of genes were significantly downregulated in all groups (P<0.05).

CONCLUSION

Overall, NR-mediated aPSDT reduced the growth of the multispecies microbial biofilm and downregulated the expression of TNF-α and IL-6 genes. Therefore, modified PMMA with NR can be serving as a promising new orthodontic acrylic resin against multispecies microbial biofilms and the effect of this new material is amplified when exposed to LED and UW.

Molecular and Cellular Mechanisms of Action of Cannabidiol

Cannabidiol (CBD) is the primary non-psychoactive chemical from Cannabis Sativa, a plant used for centuries for both recreational and medicinal purposes. CBD lacks the psychotropic effects of Δ9-tetrahydrocannabinol (Δ9-THC) and has shown great therapeutic potential. CBD exerts a wide spectrum of effects at a molecular, cellular, and organ level, affecting inflammation, oxidative damage, cell survival, pain, vasodilation, and excitability, among others, modifying many physiological and pathophysiological processes. There is evidence that CBD may be effective in treating several human disorders, like anxiety, chronic pain, psychiatric pathologies, cardiovascular diseases, and even cancer. Multiple cellular and pre-clinical studies using animal models of disease and several human trials have shown that CBD has an overall safe profile. In this review article, we summarize the pharmacokinetics data, the putative mechanisms of action of CBD, and the physiological effects reported in pre-clinical studies to give a comprehensive list of the findings and major effects attributed to this compound.

Mesosphaerum suaveolens Essential Oil Attenuates Inflammatory Response and Oxidative Stress in LPS-Stimulated RAW 264.7 Macrophages by Regulating NF-κB Signaling Pathway

Mesosphaerum suaveolens (L.) Kuntze (Syn. Hyptis suaveolens (L.) Poit.) is a wild essential-oil-bearing plant having multiple uses in traditional medicine, perfumery, food, agriculture, and pharmaceutical industries. The present paper is the first report on the in vitro anti-inflammatory effects of the leaf essential oil of M. suaveolens (MSLEO) and unravels its molecular mechanism in LPS-stimulated RAW 264.7 macrophage cells. GC-MS analysis of the essential oil (EO) isolated from the leaves by hydro-distillation led to the identification of 48 constituents, accounting for 90.55% of the total oil, and β-caryophyllene (16.17%), phyllocladene (11.85%), abietatriene (11.46%), and spathulenol (7.89%) were found to be the major components. MSLEO treatment had no effect on the viability of RAW 264.7 cells up to a concentration of 100 μg/mL, and the EO was responsible for a reduction in proinflammatory cytokines like IL-6, IL-1β, and TNF-α, a decrease in intracellular ROS production, and the restoration of oxidative damage by elevating the levels of endogenous antioxidative enzymes like CAT, SOD, GPx, and GSH. RT-qPCR analysis indicated that MSLEO reduced the mRNA expression levels of iNOS and COX-2 as compared to the LPS-induced group. In addition, a confocal microscopy analysis showed that MSLEO inhibited the translocation of NF-κB from the cytosol to the nucleus. The results of this experiment demonstrate that MSLEO possesses significant anti-inflammatory potential by preventing the activation of NF-κB, which, in turn, inhibits the downstream expression of other inflammatory mediators associated with the activation of the NF-κB pathway in LPS-induced RAW 264.7 cells. Thus, the leaf essential oil of M. suaveolens may prove to be a promising therapeutic agent for the treatment of inflammation, and targeting the NF-κB signaling pathway may be considered as an attractive approach for anti-inflammatory therapies.

Dataset on the phagocytic and oxidative capacity of monocytes and granulocytes in the combined therapy of S.aureus infection in mice

The aim of this study was to evaluate phagocytic and oxidative activities of monocytes and granulocytes during combined therapy of mice infected by drug-resistant Staphylococcus aureus SCAID OTT1-2022. The treatment of the infected mice was conducted by using an iodine-containing coordination compound CC-195, antibiotic cefazolin and by a combined therapy with CC-195 and cefazolin. The PHAGOTEST and BURSTTEST kits (BD Biosciences, USA) were used to determine the phagocytic and oxidative activities. The samples were analyzed on a FACSCalibur flow cytometer (BD Biosciences, United States). It was found that the different treatment regiments applied on the infected animals caused a statistically significant differentiation in numbers and activity of monocytes and granulocytes in comparison to the negative and positive control animals (intact and infected but untreated mice, respectively).

Nanosilver: An Old Antibacterial Agent with Great Promise in the Fight against Antibiotic Resistance

Antibiotic resistance in bacteria is a major problem worldwide that costs 55 billion USD annually for extended hospitalization, resource utilization, and additional treatment expenditures in the United States. This review examines the roles and forms of silver (e.g., bulk Ag, silver salts (AgNO3), and colloidal Ag) from antiquity to the present, and its eventual incorporation as silver nanoparticles (AgNPs) in numerous antibacterial consumer products and biomedical applications. The AgNP fabrication methods, physicochemical properties, and antibacterial mechanisms in Gram-positive and Gram-negative bacterial models are covered. The emphasis is on the problematic ESKAPE pathogens and the antibiotic-resistant pathogens of the greatest human health concern according to the World Health Organization. This review delineates the differences between each bacterial model, the role of the physicochemical properties of AgNPs in the interaction with pathogens, and the subsequent damage of AgNPs and Ag+ released by AgNPs on structural cellular components. In closing, the processes of antibiotic resistance attainment and how novel AgNP-antibiotic conjugates may synergistically reduce the growth of antibiotic-resistant pathogens are presented in light of promising examples, where antibiotic efficacy alone is decreased.

Roles of Oxidative Stress and Nrf2 Signaling in Pathogenic and Non-Pathogenic Cells: A Possible General Mechanism of Resistance to Therapy

The coordinating role of nuclear factor erythroid-2-related factor 2 (Nrf2) in cellular function is undeniable. Evidence indicates that this transcription factor exerts massive regulatory functions in multiple signaling pathways concerning redox homeostasis and xenobiotics, macromolecules, and iron metabolism. Being the master regulator of antioxidant system, Nrf2 controls cellular fate, influencing cell proliferation, differentiation, apoptosis, resistance to therapy, and senescence processes, as well as infection disease success. Because Nrf2 is the key coordinator of cell defence mechanisms, dysregulation of its signaling has been associated with carcinogenic phenomena and infectious and age-related diseases. Deregulation of this cytoprotective system may also interfere with immune response. Oxidative burst, one of the main microbicidal mechanisms, could be impaired during the initial phagocytosis of pathogens, which could lead to the successful establishment of infection and promote susceptibility to infectious diseases. There is still a knowledge gap to fill regarding the molecular mechanisms by which Nrf2 orchestrates such complex networks involving multiple pathways. This review describes the role of Nrf2 in non-pathogenic and pathogenic cells.

In Vitro Antioxidant and Antitrypanosomal Activities of Extract and Fractions of Terminalia catappa

Chagas disease is a severe infectious and parasitic disease caused by the protozoan Trypanosoma cruzi and considered a public health problem. Chemotherapeutics are still the main means of control and treatment of the disease, however with some limitations. As an alternative treatment, plants have been pointed out due to their proven pharmacological properties. Many studies carried out with Terminalia catappa have shown several biological activities, but its effect against T. cruzi is still unknown. The objective of this work is to evaluate the therapeutic potential of extracts and fractions obtained from T. catappa on the parasite T. cruzi, in addition to analyzing its antioxidant activity. T. catappa ethyl acetate fraction were produced and submitted the chemical characterization by Liquid Chromatography Coupled to Mass Spectrometry (LC-MS). From all T. catappa extracts and fractions evaluated, the ethyl acetate and the aqueous fraction displayed the best antioxidant activity by the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging method (IC₅₀ of 7.77 ± 1.61 and 5.26 ± 1.26 µg/mL respectively), and by ferric ion reducing (FRAP) method (687.61 ± 0.26 and 1009.32 ± 0.13 µM of Trolox equivalent/mg extract, respectively). The ethyl acetate fraction showed remarkable T. cruzi inhibitory activity with IC₅₀ of 8.86 ± 1.13, 24.91 ± 1.15 and 85.01 ± 1.21 µg/mL against epimastigotes, trypomastigotes and intracellular amastigotes, respectively, and showed no cytotoxicity for Vero cells (CC₅₀ > 1000 µg/mL). The treatment of epimastigotes with the ethyl acetate fraction led to drastic ultrastructural changes such as the loss of cytoplasm organelles, cell disorganization, nucleus damage and the loss of integrity of the parasite. This effect could be due to secondary compounds present in this extract, such as luteolin, kaempferol, quercetin, ellagic acid and derivatives. The ethyl acetate fraction obtained from T. catappa leaves can be an effective alternative in the treatment and control of Chagas disease, and material for further investigations.

Wolbachia-induced inhibition of O'nyong nyong virus in Anopheles mosquitoes is mediated by Toll signaling and modulated by cholesterol

Enhanced host immunity and competition for metabolic resources are two main competing hypotheses for the mechanism of Wolbachia-mediated pathogen inhibition in arthropods. Using an Anopheles mosquito - somatic Wolbachia infection - O'nyong nyong virus (ONNV) model, we demonstrate that the mechanism underpinning Wolbachia-mediated virus inhibition is up-regulation of the Toll innate immune pathway. However, the viral inhibitory properties of Wolbachia were abolished by cholesterol supplementation. This result was due to Wolbachia-dependent cholesterol-mediated suppression of Toll signaling rather than competition for cholesterol between Wolbachia and virus. The inhibitory effect of cholesterol was specific to Wolbachia-infected Anopheles mosquitoes and cells. These data indicate that both Wolbachia and cholesterol influence Toll immune signaling in Anopheles mosquitoes in a complex manner and provide a functional link between the host immunity and metabolic competition hypotheses for explaining Wolbachia-mediated pathogen interference in mosquitoes. In addition, these results provide a mechanistic understanding of the mode of action of Wolbachia-induced pathogen blocking in Anophelines, which is critical to evaluate the long-term efficacy of control strategies for malaria and Anopheles-transmitted arboviruses.

Chemistry Related to the Catalytic Cycle of the Antioxidant Ebselen

The antioxidant drug ebselen has been widely studied in both laboratories and in clinical trials. The catalytic mechanism by which it destroys hydrogen peroxide via reduction with glutathione or other thiols is complex and has been the subject of considerable debate. During reinvestigations of several key steps, we found that the seleninamide that comprises the first oxidation product of ebselen underwent facile reversible methanolysis to an unstable seleninate ester and two dimeric products. In its reaction with benzyl alcohol, the seleninamide produced a benzyl ester that reacted readily by selenoxide elimination, with formation of benzaldehyde. Oxidation of ebselen seleninic acid did not afford a selenonium seleninate salt as previously observed with benzene seleninic acid, but instead generated a mixture of the seleninic and selenonic acids. Thiolysis of ebselen with benzyl thiol was faster than oxidation by ca. an order of magnitude and produced a stable selenenyl sulfide. When glutathione was employed, the product rapidly disproportionated to glutathione disulfide and ebselen diselenide. Oxidation of the S-benzyl selenenyl sulfide, or thiolysis of the seleninamide with benzyl thiol, afforded a transient thiolseleninate that also readily underwent selenoxide elimination. The S-benzyl derivative disproportionated readily when catalyzed by the simultaneous presence of both the thiol and triethylamine. The phenylthio analogue disproportionated when exposed to ambient or UV (360 nm) light by a proposed radical mechanism. These observations provide additional insight into several reactions and intermediates related to ebselen.

Bioactive Compounds of the Mediterranean Diet as Nutritional Support to Fight Neurodegenerative Disease

Neurodegenerative disorders are a widespread cause of morbidity and mortality worldwide, characterized by neuroinflammation, oxidative stress, and neuronal depletion. They include selective malfunction and progressive loss of neurons, glial cells, and neural networks in the brain and spinal cord. There is an urgent need to develop new and more effective therapeutic strategies to combat these devastating diseases because, today, there is no treatment that can cure degenerative diseases; however, we have many symptomatic treatments. Current nutritional approaches are beginning to reflect a fundamental change in our understanding of health. The Mediterranean diet may have a protective effect on the neurodegenerative process because it is rich in antioxidants, fiber, and omega-3 polyunsaturated fatty acids. Increasing knowledge regarding the impact of diet on regulation at the genetic and molecular levels is changing the way we consider the role of nutrition, resulting in new dietary strategies. Natural products, thanks to their bioactive compounds, have recently undergone extensive exploration and study for their therapeutic potential for a variety of diseases. Targeting simultaneous multiple mechanisms of action and a neuroprotection approach with the diet could prevent cell death and restore function to damaged neurons. For these reasons, this review will be focused on the therapeutic potential of natural products and the associations between the Mediterranean-style diet (MD), neurodegenerative diseases, and markers and mechanisms of neurodegeneration.

Pathophysiology and mechanisms of hearing impairment related to neonatal infection diseases

The inner ear, the organ of equilibrium and hearing, has an extraordinarily complex and intricate arrangement. It contains highly specialized structures meticulously tailored to permit auditory processing. However, hearing also relies on both peripheral and central pathways responsible for the neuronal transmission of auditory information from the cochlea to the corresponding cortical regions. Understanding the anatomy and physiology of all components forming the auditory system is key to better comprehending the pathophysiology of each disease that causes hearing impairment. In this narrative review, the authors focus on the pathophysiology as well as on cellular and molecular mechanisms that lead to hearing loss in different neonatal infectious diseases. To accomplish this objective, the morphology and function of the main structures responsible for auditory processing and the immune response leading to hearing loss were explored. Altogether, this information permits the proper understanding of each infectious disease discussed.