Respiratory Burst Research Articles

Glucose transporter 1 is essential for the resolution of methicillin-resistant S. aureus skin and soft tissue infections

Skin/soft tissue infections (SSTIs) caused by methicillin-resistant Staphylococcus aureus (MRSA) pose a major healthcare burden. Distinct inflammatory and resolution phases comprise the host immune response to SSTIs. Resolution is a myeloid PPARγ-dependent anti-inflammatory phase that is essential for the clearance of MRSA. However, the signals activating PPARγ to induce resolution remain unknown. Here, we demonstrate that myeloid glucose transporter 1 (GLUT-1) is essential for the onset of resolution. MRSA-challenged macrophages are unsuccessful in generating an oxidative burst or immune radicals in the absence of GLUT-1 due to a reduction in the cellular NADPH pool. This translates invivo as a significant reduction in lipid peroxidation products required for the activation of PPARγ in MRSA-infected mice lacking myeloid GLUT-1. Chemical induction of PPARγ during infection circumvents this GLUT-1 requirement and improves resolution. Thus, GLUT-1-dependent oxidative burst is essential for the activation of PPARγ and subsequent resolution of SSTIs.

Understanding the Cardiovascular Fallout of E-cigarettes: A Comprehensive Review of the Literature.

E-cigarettes (ECs) deliver chemicals, including nicotine. They can cause respiratory distress, addiction, cardiovascular effects, and death. More research is needed, especially regarding their impact on the cardiovascular system(CVS) and during pregnancy. Our article aims to fill this gap by summarizing studies elaborating upon the current impact of ECs and the components thereof on the CVS. Acute respiratory distress outbreaks, nicotine addiction, CVS effects, and deaths have been occasionally reported within this cohort, although these events are not uncommon with neighboring age groups. Randomized control trials implying ECs have some contribution towardquitting smoking have been studied. To regulate EC distribution, the Food and Drug Administration (FDA) and Centers for Disease Control and Prevention (CDC) have created key checkpoints. Additionally, taxation, pricing, age restriction, and media campaigns could be modulated to significantly reduce illicit sales. Education to the users, distributors, and regulators about this product can also play an aiding role in promoting responsible EC use.Another strategy about licensing could be employed, which could incentivize genuine resellers. The effects on CVS and child-bearing by ECs are grim, which calls for strict regulation, awareness, and avoidance by the teetotaler public. They may help individuals stop smoking butnot without harming themselves. Strict regulations are necessary to prevent non-judicious use of these devices.

Clinical presentation, diagnosis, and treatment of chronic granulomatous disease.

Chronic granulomatous disease (CGD) is caused by an impaired respiratory burst reaction in phagocytes. CGD is an X-linked (XL) (caused by pathogenic variants in CYBB) or autosomal recessive inborn error of immunity (caused by pathogenic variants in CYBA, NCF1, NCF2, or CYBC1). Female carriers of XL-CGD and unfavorable lyonization may present with the partial or full picture of CGD. Patients with CGD are at increased risk for invasive bacterial and fungal infections of potentially any organ, but especially the lymph nodes, liver, and lungs. Pathogens most frequently isolated are S. aureus and Aspergillus spp. Autoinflammation is difficult to control with immunosuppression, and patients frequently remain dependent on steroids. To diagnose CGD, reactive oxygen intermediates (O2 - or H2O2) generated by the NADPH oxidase in peripheral blood phagocytes are measured upon in vitro activation with either phorbol-12-myristate-13-acetate (PMA) and/or TLR4 ligands (E. coli or LPS). Conservative treatment requires strict hygienic conduct and adherence to antibiotic prophylaxis against bacteria and fungi, comprising cotrimoxazole and triazoles. The prognosis of patients treated conservatively is impaired: for the majority of patients, recurrent and/or persistent infections, autoinflammation, and failure to thrive remain lifelong challenges. In contrast, cellular therapies (allogeneic stem cell transplantation or gene therapy) can cure CGD. Optimal outcomes in cellular therapies are observed in individuals without ongoing infections or inflammation. Yet cellular therapies are the only curative option for patients with persistent fungal infections or autoinflammation.

Mitigating salinity stress and improving cotton productivity through integrative use of gypsum and compost amendments with exogenous proline

Abiotic constraints, such as salinity, significantly damage crop yields worldwide. Cotton, though moderately salt-tolerant, suffers from reduced growth and yield under saline-sodic soil conditions. Effective integrated mitigation strategies are crucial to address this challenge. Our study, conducted in Lodhran, Punjab, Pakistan, investigated six treatments using an integrated strategy such as gypsum, compost and exogenous proline combining effect in improving cotton productivity under salinity stress. We assessed plant growth, agronomic traits, physio-chemical parameters, cotton yield, and soil characteristics. Our experimental results showed that the combined application of amendments such as T5: gypsum + proline and T6: compost + proline gave better results as compared to individual treatments (T2, T3 & T4) over the control (T1). A significant improvement was observed in plant length and dry weights of shoot and root by 64 %, 81 % and 47 %, respectively under the effect of T5, also increased cotton yield up to 2 folds (888 kg) over control (324 kg ha−1). Likewise, significant improvement in the plant physio-chemical parameters was recorded such as high activities of antioxidant enzymes and the maximum accumulation of malondialdehyde (MDA) content by 60–71 %, as well as reduction in the oxidative burst by 55–65 % after the integrated treatments (T5 & T6) as compared to salt-stressed plants (control). Likewise, contents of nutrients are improved in plants viz., N: 70; P: 61 %; K: 33 % and Mg: 86 % under the positive effect of gypsum + proline over control. Results of soil analysis showed that the soil was moderately saline-sodic. Furthermore, soil analysis revealed that there was a significant improvement in NPK, S and Mg content in the soil after treated salt-stressed soil with gypsum and compost (T2, T3, T5 and T6) while a significant reduction was observed in Ca (17 %) and Na content (28 %), as well as EC (dSm−1) was decreased by 38 % and SAR (mmol/L)1/2 by 27 % under the effect of gypsum + proline over the control treatment. The outcomes of the current study reveal that the reclamation potential of gypsum and compost applied individually or together with exogenous proline improved plant growth, yield and plant defense system under salinity stress.

Stimulatory Effects of Phyllanthus amarus Extract on the Growth Performance, Hematobiochemical Activity, Antioxidative Status and Immune Response of Clarias gariepinus

This study investigated the antibacterial activity of Phyllanthus amarus extracts and its influence on the performance of Clarias gariepinus fingerlings. The fish were fed diets containing 0.0, 0.5, 1.0, 1.5 or 2.0 g P. amarus methanol extract (PAE) / kg basal diet for 84 days. Thereafter, blood samples were collected for hematological and biochemical analyses. At the end of the 84-day feeding trial, fish were challenged with Aeromonas hydrophila, after which immune response parameters were measured. The data obtained were analyzed using one-way analysis of variance at p<0.05. The results showed significant antibacterial activity of PAE against A. hydrophila, and its application at 0.5-1.5 g significantly promoted growth performance, with the highest at 1.0 g. Hematocrit, hemoglobin and lymphocytes were enhanced at 0.5-1.5 g PAE. All the fishes fed PAE-supplemented diets had lower concentrations of serum liver enzymes; while the values of creatinine, glucose and total bilirubin did not differ among the treatments. Glutathione peroxidase, glutathione‐S‐transferase, lysozyme, phagocytic and respiratory burst activities increased in all PAE-fortified treatments, with highest fish survival in 1.0 g PAE treatment. Therefore, the inclusion of 1.0 g Phyllanthus amarus extract is recommended as a dietary supplement for Clarias gariepinus.

LECT2 mediates antibacterial immune response induced by Nocardia seriolae infection in the northern snakehead

Leukocyte-derived chemotaxin-2 (LECT2) is a multifunctional immunoregulator that plays several pivotal roles in the host's defense against pathogens. This study aimed to elucidate the specific functions and mechanisms of LECT2 (CaLECT2) in the northern snakehead (Channa argus) during infections with pathogens such as Nocardia seriolae (N. seriolae). We identified CaLECT2 in the northern snakehead, demonstrating its participation in the immune response to N. seriolae infection. CaLECT2 contains an open reading frame (ORF) of 459 bp, encoding a peptide of 152 amino acids featuring a conserved peptidase M23 domain. The CaLECT2 protein shares 62%–84 % identities with proteins from various other fish species. Transcriptional expression analysis revealed that CaLECT2 was constitutively expressed in all examined tissues, with the highest expression observed in the liver. Following intraperitoneal infection with N. seriolae, CaLECT2 transcription increased in the spleen, trunk kidney, and liver. In vivo challenge experiments showed that injecting recombinant CaLECT2 (rCaLECT2) could protect the snakehead against N. seriolae infection by reducing bacterial load, enhancing serum antibacterial activity and antioxidant capacity, and minimizing tissue damage. Moreover, in vitro analysis indicated that rCaLECT2 significantly enhanced the migration, respiratory burst, and microbicidal activity of the head kidney-derived phagocytes. These findings provide new insights into the role of LECT2 in the antibacterial immunity of fish.

Imaging kidney inflammation using an oxidatively activated MRI probe

Imaging tools for kidney inflammation could improve care for patients suffering inflammatory kidney diseases by lessening reliance on percutaneous biopsy or biochemical tests alone. During kidney inflammation, infiltration of myeloid immune cells generates a kidney microenvironment that is oxidizing relative to normal kidney. Here, we evaluated whether magnetic resonance imaging (MRI) using the redox-active iron (Fe) complex Fe-PyC3A as an oxidatively activated probe could serve as a marker of kidney inflammation using mouse models of unilateral ischemia-reperfusion injury (IRI) and lupus nephritis (MRL-lpr mice). We imaged unilateral IRI in gp91phox knockout mice, which are deficient in the nicotinamide oxidase II (NOX2) enzyme required for myeloid oxidative burst, as loss of function control, and imaged MRL/MpJ mice as non-kidney involved lupus control. Gadoterate meglumine was used as a non-oxidatively activated control MRI probe. Fe-PyC3A safety was preliminarily examined following a single acute dose. Fe-PyC3A generated significantly greater MRI signal enhancement in the IRI kidney compared to the contralateral kidney in wild-type mice, but the effect was not observed in the NOX2-deficient control. Fe-PyC3A also generated significantly greater kidney enhancement in MRL-lpr mice compared to MRL/MpJ control. Gadoterate meglumine did not differentially enhance the IRI kidney over the contralateral kidney and did not differentially enhance the kidneys of MRL-lpr over MRL/MpJ mice. Fe-PyC3A was well tolerated at the highest dose evaluated, which was a 40-fold greater than required for imaging. Thus, our data indicate that MRI using Fe-PyC3A is specific to an oxidizing kidney environment shaped by activity of myeloid immune cells and support further evaluation of Fe-PyC3A for imaging kidney inflammation.

Untying arsenite tolerance mechanisms in contrasting maize genotypes attributed to NIPs-mediated controlled influx and root-to-shoot translocation, redox homeostasis and phytochelatin-mediated detoxification pathway

Contamination of ground water and soil with toxic metalloids like arsenic (As) poses a serious hazard to the global agricultural food production. One of the best ways to restrict entry of As into the food chain is selection of germplasms which accrue extremely low level of As in grains. Here, we screened diverse maize genotypes under high arsenite (100 μM AsIII) stress and identified PMI-PV-9 and PMI-PV-3 as AsIII-tolerant and -sensitive maize genotype respectively. Expression of genes associated with As uptake, vacuolar sequestration, biosynthesis of phytochelatins, root-to-shoot translocation, in vivo ROS generation, fine tuning of antioxidant defense system, DNA and membrane damage, H2O2 and superoxide anion (O2•-) levels were compared among the selected genotypes. PMI-PV-9 plants performed much better than PMI-PV-3 in terms of plant growth with no visible symptom of As toxicity. Susceptibility of PMI-PV-3 to AsIII stress may be attributed to comparatively low expression of genes involved in phytochelatins (PCs) biosynthesis. Concomitant decrease in ABCC1 expression might be another key factor for futile sequestration of AsIII into root vacuoles. Moreover, up-regulation of ZmNIP3;1 might contribute in high root-to-leaf As translocation. Substantial spike in H2O2, O2•- and MDA levels indicates that PMI-PV-3 plants have experienced more oxidative stress than PMI-PV-9 plants. Appearance of prominent deep brown and dark blue spots/stripes on leaves as revealed after DAB and NBT staining respectively suggest severe oxidative burst in PMI-PV-3 plants. Marked reduction in DHAR and MDAR activity rendered PMI-PV-3 cells to recycle ascorbate pool ineffectively, which might have exacerbated their susceptibility to AsIII stress. In a nutshell, incompetent PCs mediated detoxification system and disruption of cellular redox homeostasis owing to feeble antioxidant defence system resulting oxidative burst might be the prime reasons behind reduced performance of PMI-PV-3 plants under AsIII stress.

Neutrophil Oxidative Burst Profile Is Related to a Satisfactory Response to Itraconazole and Clinical Cure in Feline Sporotrichosis.

Despite the central role of cats in the transmission and amplification of Sporothrix, studies regarding immune response in feline sporotrichosis are scarce. In cats with sporotrichosis, neutrophil-rich lesions are usually associated to good general condition and lower fungal burden. However, the role of neutrophils in anti-Sporothrix immunity has been little explored in cats. Thus, the aim of this study was to evaluate the neutrophil oxidative burst in the blood of cats with sporotrichosis. Cats with sporotrichosis included in the study were treated with itraconazole (ITZ) alone or combined with potassium iodide (KI). The neutrophil oxidative burst was evaluated through a flow-cytometry-based assay using dihydrorhodamine 123 (background) and stimulation with Zymosan and heat-killed Sporothrix yeasts. The cure rate was 50.0% in cats under treatment with ITZ monotherapy and 90.9% in cats treated with ITZ + KI (p = 0.014), endorsing the combination therapy as an excellent alternative for the treatment of feline sporotrichosis. Higher percentages of Sporothrix-stimulated neutrophils were associated with good general condition (p = 0.003). Higher percentages of Sporothrix- (p = 0.05) and Zymosan-activated (p = 0.014) neutrophils before and early in the treatment were related to clinical cure in ITZ-treated cats. The correlation between oxidative burst and successful use of KI could not be properly assessed given the low number of failures (n = 2) in this treatment group. Nasal mucosa involvement, typically linked to treatment failure, was related to lower percentages of activated neutrophils in the background at the treatment outcome (p = 0.02). Our results suggest a beneficial role of neutrophils in feline sporotrichosis and a positive correlation between neutrophil activation and the cure process in ITZ-treated cats.

Exogenous application of melatonin attenuates waterlogging stress through adopting quiescence adaptation technique in tomato seedlings

Waterlogging (WL) is a major limiting factor in global crop production and seriously limits growth and yield improvement in low-lying rainfed regions. Melatonin (MT) is a vital phytohormone that functions as a "master regulator" in multiple facets related to plant growth and development, in addition to maintaining a potential role in response to stresses. However, the pharmacological role of MT in attenuating waterlogging stress in tomato largely remains elucidated. The objective of the current investigation is to justify the physiological regulatory mechanism of tomato seedlings exposed to WL and the putative functions of MT to mitigate the adverse effects of WL. Tomato seedlings were grown on substrate (peat: vermiculite, 2:1, v/v) and at the 4th leaf stage subjected to waterlogging stress for 10 days and seedlings were foliar sprayed with melatonin during waterlogging stress. The results revealed that WL significantly arrested tomato seedlings growth, and reduced pigment content coincided with enhanced leaf senescence. MT supplementation attenuated WL-induced oxidative damage through increasing osmoprotectants activity, elevating antioxidant enzyme functioning synchronized with inhibiting excess reactive oxygen species (ROS) production. The concentrations of MT (28 %), abscisic acid (ABA, 170 %), and 1-aminocyclopropane-1-carboxylic acid (ACC, 129 %) were increased, while indole acetic acid (IAA, 15 %), jasmonic acid (JA, 55 %) and gibberellic acid (GA3, 26 %) content were decreased in only WL seedlings roots relative to control seedlings. The core anaerobic respiration enzyme alcohol dehydrogenase (ADH) and pyruvate decarboxylase (PDC) activity were elevated by 127 % and 163 %, respectively at day 10 in WL+MT received seedlings than control. WL treatment varyingly contributed on nutrient content, as evidenced that N+, K+, and Ca2+ content decreased, whereas Mn2+, Fe2+, and Mg2+ content increased and MT addition reversed their concentrations under similar stress conditions. Exogenous MT promoted WL-tolerance of tomato by positively suppressing respiratory burst oxidase homologs (RBOH)-regulating gene expression while up-regulating ethylene biosynthesis gene transcription. Most importantly, programmed cell death (PCD) regulated enzyme caspase-3 activity concurred with PCD-induced gene (caspase-3, pirin, TBN1) expression significantly inhibited by MT application. In general, these findings reveal that external supplementation with MT can improve plant tolerance to WL through complex processes and multifaceted mechanisms.

CDPK5 and CDPK13 play key roles in acclimation to low oxygen through the control of RBOH-mediated ROS production in rice

Abstract CALCIUM-DEPENDENT PROTEIN KINASE (CDPK) stimulates reactive oxygen species (ROS)-dependent signaling by activating RESPIRATORY BURST OXIDASE HOMOLOG (RBOH). The lysigenous aerenchyma is a gas space created by cortical cell death that facilitates oxygen diffusion from the shoot to the root tips. Previously, we showed that RBOHH is indispensable for the induction of aerenchyma formation in rice (Oryza sativa) roots under low-oxygen conditions. Here, we showed that CDPK5 and CDPK13 localize to the plasma membrane where RBOHH functions. Mutation analysis of the serine at residues 92 and 107 of RBOHH revealed that these residues are required for CDPK5- and CDPK13-mediated activation of ROS production. The requirement of Ca2+ for CDPK5 and CDPK13 function was confirmed using in vitro kinase assays. CRISPR/Cas9-based mutagenesis of CDPK5 and/or CDPK13 revealed that the double knockout almost completely suppressed inducible aerenchyma formation, whereas the effects were limited in the single knockout of either CDPK5 or CDPK13. Interestingly, the double knockout almost suppressed the induction of adventitious root formation, which is widely conserved in vascular plants, under low-oxygen conditions. Our results suggest that CDPKs are essential for the acclimation of rice to low-oxygen conditions and also for many other plant species conserving CDPK-targeted phosphorylation sites in RBOH homologs.

FTY720 ameliorates experimental MPO-ANCA-associated vasculitis by regulating fatty acid oxidation via the neutrophil PPARα-CPT1a pathway.

Increasing studies demonstrated the importance of C5a and anti-neutrophil cytoplasmic antibody (ANCA)-induced neutrophil activation in the pathogenesis of ANCA-associated vasculitis (AAV). Sphingosine-1-phosphate (S1P) acts as a downstream effector molecule of C5a and enhances neutrophil activation induced by C5a and ANCA. The current study investigated the role of a S1P receptor modulator, FTY720, in experimental autoimmune vasculitis (EAV) and explored the immunometabolism-related mechanisms of FTY720 in modulating ANCA-induced neutrophil activation. The effects of FTY720 in EAV were evaluated by quantifying haematuria, proteinuria, crescent formation, tubulointerstitial injury and pulmonary haemorrhage. RNA sequencing of renal cortex and gene enrichment analysis were performed. The proteins of key identified pathways were analysed in neutrophils isolated from peripheral blood of patients with active AAV and normal controls. We assessed the effects of FTY720 on ANCA-induced neutrophil respiratory burst and neutrophil extracellular traps formation (NETosis). FTY720 treatment significantly attenuated renal injury and pulmonary haemorrhage in EAV. RNA sequencing analyses of renal cortex demonstrated enhanced fatty acid oxidation (FAO) and peroxisome proliferator-activated receptor (PPAR) signalling in FTY720-treated rats. Compared with normal controls, patients with active AAV showed decreased FAO in neutrophils. FTY720-treated differentiated HL-60 cells showed increased expression of carnitine palmitoyltransferase 1a (CPT1a) and PPARα. Blocking or knockdown of CPT1a or PPARα in isolated human neutrophils and HL-60 cells reversed the inhibitory effects of FTY720 on ANCA-induced neutrophil respiratory burst and NETosis. FTY720 attenuated renal injury in EAV through upregulating FAO via the PPARα-CPT1a pathway in neutrophils, offering potential immunometabolic targets in AAV treatment.

Fermented mahua oil cake in the diet of Labeo rohita: effects on growth performance, digestive enzyme activity and immune response

Market instability, increased competition, escalating price and reduced availability of conventional ingredients warrants the researchers to rely on alternative feed ingredients. This approach may help in producing aqua feeds in a sustainable and cost-effective way to accomplish the global food and nutritional securities. Mahua oil cake (Bassia latifolia) is an underutilized non-conventional ingredient that holds promise for incorporation into aqua feed following nutrient enhancement by solid-state fermentation. A five-month pond feeding trial was carried out to investigate the effects of Sachharomyces cerevisiae and Bacillus subtilis fermented mahua oil cake (MOC) on the production performance, nutrient utilization, digestive capacity, and innate immunological responses of Labeo rohita fingerlings. For this, two iso-nitrogenous feed were formulated and prepared incorporating fermented MOC at different levels i.e. 0 and 40 percentage replacing soybean meal and other feed ingredients and fed to rohu fingerlings of two treatment groups in pond culture for 5 months duration. Improved growth performance, feed conversion ratio, feed intake, protein efficiency ratio and digestive capacity were observed in fish fed diets with 40 percent of fermented MOC compared to control. Innate immune responses parameters (respiratory burst activity, myeloperoxidase, lysozyme and hemaglutination activities) were significantly higher (P < 0.05) in fishes fed with fermented MOC. Therefore, we conclude incorporation of solid state fermented mahua oil cake up to 40% level in diet of L. rohita fingerlings in pond culture without any adverse effects on growth, nutrient utilization and innate immune response.

The calcium-dependent protein kinase CPK16 regulates hypoxia-induced ROS production by phosphorylating the NADPH oxidase RBOHD in Arabidopsis.

Reactive oxygen species (ROS) production is a key event in modulating plant responses to hypoxia and post-hypoxia reoxygenation. However, the molecular mechanism by which hypoxia-associated ROS homeostasis is controlled remains largely unknown. Here, we showed that the calcium-dependent protein kinase CPK16 regulates plant hypoxia tolerance by phosphorylating the plasma membrane-anchored NADPH oxidase respiratory burst oxidase homolog D (RBOHD) to regulate ROS production in Arabidopsis (Arabidopsis thaliana). In response to hypoxia or reoxygenation, CPK16 was activated through phosphorylation of its Ser274 residue. The cpk16 knockout mutant displayed enhanced hypoxia tolerance, whereas CPK16-overexpressing (CPK16-OE) lines showed increased sensitivity to hypoxic stress. In agreement with these observations, hypoxia and reoxygenation both induced ROS accumulation in the rosettes of CPK16-OEs more strongly than in the rosettes of the cpk16-1 mutant or the wild type. Moreover, CPK16 interacted with and phosphorylated the N-terminus of RBOHD at 4 serine residues (Ser133, Ser148, Ser163, and Ser347) that were necessary for hypoxia- and reoxygenation-induced ROS accumulation. Furthermore, the hypoxia-tolerant phenotype of cpk16-1 was fully abolished in the cpk16 rbohd double mutant. Thus, we have uncovered a regulatory mechanism by which the CPK16-RBOHD module shapes the ROS production during hypoxia and reoxygenation in Arabidopsis.

Effect of dietary mannan oligosaccharide inclusion on production parameters of Farfantepenaeus aztecus cultured in a biofloc system

AbstractThe effects of dietary mannan oligosaccharide (MOS) supplementation in a biofloc system on growth performance, whole‐body proximate composition, whole‐body fatty acids, nonspecific immune parameters, antioxidant enzyme activities, digestive enzyme activity, and gut microbiota of brown shrimp, Farfantepenaeus aztecus, were investigated. Shrimp were fed five diets containing different levels of MOS doses (MOS0: basal diet, MOS1: 0.1%, MOS2: 0.2%, MOS3: 0.3%, and MOS4: 0.4%) during the 90‐day trial. The results indicated that all MOS‐supplemented shrimp showed significantly higher growth rates and better feed utilization than shrimp fed the control diet. Experimental diets had varying effects on the nonspecific immune parameters and antioxidant enzyme activities, indicating that MOS supplementation resulted in significant differences in the parameters except for respiratory burst activity. Significantly higher protease activity was observed in shrimp fed MOS1 and MOS2 diets compared with MOS0, MOS3, and MOS4 diets. Shrimps fed MOS2 and MOS3 diets had the highest lipase and amylase activities among all groups. Proteobacteria were the most abundant phylum in all groups and were higher at increasing MOS doses. In conclusion, these results suggest that supplementing the diet of brown shrimp in the biofloc system with 3 g kg−1 of MOS may improve production parameters.

PECULIARITIES OF NEUTROPHIL EXTRACELLULAR TRAPS FORMATION IN CHINCHILLA RABBITS

Neutrophil extracellular traps (NETs) are decondensed nuclear chromatin, decorated with bactericidal proteins of various cell organelles and performing an eff ector function aimed to combat pathogens at the site of infl ammation. At the same time, NETs play an important role in the pathogenesis of many autoimmune and infl ammatory diseases as well as malignancies. Rabbits are one of the most commonly used species of laboratory animals in medical and biological research. A large number of models of various diseases of the cardiovascular, immune and other human systems have been developed in rabbits. However, there is no information in the scientifi c literature about the ability of rabbit neutrophils to undergo NETosis in response to well-known pharmacological stimuli. The purpose of the present work was to study in in vitro system the ability of neutrophils of Soviet chinchilla rabbit to form NETs in response to mimetic of diacylglycerol phorbol 12-myristate 13-acetate (PMA) and calcium ionophore A23187. To isolate rabbit neutrophils, the one-step density gradient centrifugation on Ficoll-Hypaque method with modifi cations was used. Oxidative burst was assessed with luminol-amplifi ed chemiluminescence method, and NET formation was assessed with immunofl uorescence analysis. The work shows for the fi rst time that neutrophils of Soviet chinchilla rabbit do not form NETs in response to PMA, but form traps in response to A23187, as well as have a low level of oxidative burst in response to PMA, A23187 and chemoattractant N-formyl-methionylleucyl-phenylalanine.

PECULIARITIES OF NEUTROPHIL EXTRACELLULAR TRAPS FORMATION IN CHINCHILLA RABBITS

Neutrophil extracellular traps (NETs) are decondensed nuclear chromatin, decorated with bactericidal proteins of various cell organelles and performing an eff ector function aimed to combat pathogens at the site of infl ammation. At the same time, NETs play an important role in the pathogenesis of many autoimmune and infl ammatory diseases as well as malignancies. Rabbits are one of the most commonly used species of laboratory animals in medical and biological research. A large number of models of various diseases of the cardiovascular, immune and other human systems have been developed in rabbits. However, there is no information in the scientifi c literature about the ability of rabbit neutrophils to undergo NETosis in response to well-known pharmacological stimuli. The purpose of the present work was to study in in vitro system the ability of neutrophils of Soviet chinchilla rabbit to form NETs in response to mimetic of diacylglycerol phorbol 12-myristate 13-acetate (PMA) and calcium ionophore A23187. To isolate rabbit neutrophils, the one-step density gradient centrifugation on Ficoll-Hypaque method with modifi cations was used. Oxidative burst was assessed with luminol-amplifi ed chemiluminescence method, and NET formation was assessed with immunofl uorescence analysis. The work shows for the fi rst time that neutrophils of Soviet chinchilla rabbit do not form NETs in response to PMA, but form traps in response to A23187, as well as have a low level of oxidative burst in response to PMA, A23187 and chemoattractant N-formyl-methionylleucyl-phenylalanine.

Alterations of pathogen transmission patterns and attenuated immune stimulation might be the cause of increased adult respiratory infections cases in 2023, results from a multi-center study in mainland China

BackgroundSeveral respiratory infections outbreaks have been observed in mainland China after reduction of non-pharmaceutical interventions. Other countries have seen increases in respiratory infections outside typical seasons post-COVID-19, warranting investigation into underlying causes. MethodsWe established monitoring networks for suspected respiratory infection in 14 tertiary hospitals nationwide. PCR for SARS-CoV-2, influenza A and B were performed on 3708 respiratory specimens and deep sequencing were conducted to identify co-infections or newly emerging microbes in 2023. Viral evolutionary analysis was completed. We retrospectively detected serum antibody level for various respiratory pathogens from 4324 adults without respiratory infections over 7 years to observe its dynamic curves. FindingsSARS-CoV-2 and influenza A were the main pathogens during outbreaks in 2023, bacterial-virus and bacterial-bacterial co-infections were most detected, but community co-infections didn't significantly increase pneumonia incidence. Different SARS-CoV-2 and influenza variants were present in different outbreaks, and no novel pathogens were found. The epidemiological patterns of influenza A, COVID-19 and etc. were altered, exhibiting characteristics of being "staggered" compared to most global regions, and potentially led to "overlapping prevalence". Binding antibody testing showed regular fluctuation, without significant decrease against common respiratory pathogens in adults. Influenza A antibody stimulation was attenuated during the 2023 outbreak. Conclusions"Misaligned" alteration in seasonal respiratory disease patterns possibly caused combined epidemics, leading to cases spike in China, 2023. In adults, antibody levels didn't show significant decline, but reduced immune response to influenza during 2020–2023 emphasizes the need for consistent vaccination during pandemics.

Manipulated C5aR1 over/down-expression associates with IL-6 expression during bacterial inflammation in half-smooth tongue sole (Cynoglossus semilaevis)

The complement component 5a/complement component 5 receptor 1 (C5a/C5aR1) pathway plays a crucial role in the onset and development of inflammation, but relevant studies in fish are lacking. In this study, we successfully characterized the relationship between half-smooth tongue sole (Cynoglossus semilaevis) C5aR1 (CsC5aR1) and bacterial inflammation. First, we showed that the overexpression of CsC5aR1 significantly increased bacterial pathological damage in the liver and intestine, whereas inhibition attenuated the damage. The in vitro experiments suggested that CsC5aR1 was able to positively regulate the phagocytic activity and respiratory burst of tongue sole macrophages. In terms of both transcriptional and translational levels, overexpression/inhibition of CsC5aR1 was followed by a highly consistent up-regulation/decrease of its downstream canonical inflammatory factor interleukin-6 (CsIL-6). Furthermore, we stimulated macrophages by lipopolysaccharide (LPS) and lipoteichoic acid (LTA) and found a broad-spectrum response to bacterial infections by the C5a/C5aR1 complement pathway together with the downstream inflammatory factor CsIL-6. Subsequently, we directly elucidated that CsIL-6 is an indicator of C5a/C5aR1-mediated inflammation at different infection concentrations, different infectious bacteria (Vibrio anguillarum and Mycobacterium marinum), and different detection levels. These results might provide a new inflammation bio-marker for early warning of bacteria-induced hyperinflammation leading to fish mortality and a promising target for the treatment of bacterial inflammation in teleost.

Phospholipid Signaling in Crop Plants: A Field to Explore.

In plant models such as Arabidopsis thaliana, phosphatidic acid (PA), a key molecule of lipid signaling, was shown not only to be involved in stress responses, but also in plant development and nutrition. In this article, we highlight lipid signaling existing in crop species. Based on open access databases, we update the list of sequences encoding phospholipases D, phosphoinositide-dependent phospholipases C, and diacylglycerol-kinases, enzymes that lead to the production of PA. We show that structural features of these enzymes from model plants are conserved in equivalent proteins from selected crop species. We then present an in-depth discussion of the structural characteristics of these proteins before focusing on PA binding proteins. For the purpose of this article, we consider RESPIRATORY BURST OXIDASE HOMOLOGUEs (RBOHs), the most documented PA target proteins. Finally, we present pioneering experiments that show, by different approaches such as monitoring of gene expression, use of pharmacological agents, ectopic over-expression of genes, and the creation of silenced mutants, that lipid signaling plays major roles in crop species. Finally, we present major open questions that require attention since we have only a perception of the peak of the iceberg when it comes to the exciting field of phospholipid signaling in plants.