Respiratory Burst Research Articles

Physiological and biochemical responses of Labeo rohita to neonicotinoids imidacloprid, clothianidin, and their mixture.

Neonicotinoids, widely used insecticides, pose severe environmental risks due to their persistence in soil and water, adversely affecting non-target organisms and ecosystem integrity. The present study examined the 56days effects of imidacloprid (66.6mg/l), clothianidin (30mg/l), and their combination (33.3mg/l and 15mg/l) on Labeo rohita, using one-third of the LC50 sub-lethal concentrations. Survival, weight gain, and the hepatosomatic index decreased insignificantly in the IMI group and significantly in the CLO and Mix groups. Haematological indicators, including erythrocyte counts, haemoglobin, and haematocrit values, were also significantly reduced. Blood glucose and serum creatinine levels increased, while serum albumin, globulin, and plasma total proteins decreased. White blood cell counts elevated, while immunoglobulin (IgM), respiratory burst, and lysozyme activities were significantly inhibited. Liver, brain and muscle lactate and malate dehydrogenases were elevated, whereas succinate and glutamate dehydrogenases were decreased. Liver aspartate aminotransferase activity was substantially higher than that of brain and muscle, which had considerably higher levels of alanine aminotransferase in muscle than in the brain and liver. Additionally, muscle alkaline phosphatase activity was significantly higher than in the liver and brain, whereas liver acid phosphatase showed a greater elevation than in the muscle and brain. The physiological, haematological, and biochemical indices peaked on day 28 and slight recovery was observed on day 56 (IMI > CLO > Mix). The study highlights that the mixture of insecticides poses greater hazards compared to a single active compound, and the indiscriminate use of these insecticides jeopardizes non-target organisms, ecosystems, and public health.

Genome-Wide Identification, Classification, Expression Analysis, and Screening of Drought and Heat Resistance-Related Candidates of the Rboh Gene Family in Wheat

Plant respiratory burst oxidase homologs (Rbohs) are key enzymes that produce reactive oxygen species (ROS), which serve as signaling molecules regulating plant growth and stress responses. In this study, 39 TaRboh genes (TaRboh01–TaRboh39) were identified. These genes were distributed unevenly among the wheat genome’s fourteen chromosomes, with the exception of homoeologous group 2 and 7 and chromosomes 4A, as well as one unidentified linkage group (Un). TaRbohs were classified into ten distinct clades, each sharing similar motif compositions and gene structures. The promoter regions of TaRbohs contained cis-elements related to hormones, growth and development, and stresses. Furthermore, five TaRboh genes (TaRboh26, TaRboh27, TaRboh31, TaRboh32, and TaRboh34) exhibited strong evolutionary conservation. Additionally, a Ka/Ks analysis confirmed that purifying selection was the predominant force driving the evolution of these genes. Expression profiling and qPCR results further indicated differential expression patterns of TaRboh genes between heat and drought stresses. TaRboh11, TaRboh20, TaRboh22, TaRboh24, TaRboh29, and TaRboh34 were significantly upregulated under multiple stress conditions, whereas TaRboh30 was only elevated in response to drought stress. Collectively, our findings provide a systematic analysis of the wheat Rboh gene family and establish a theoretical framework for our future research on the role of Rboh genes in response to heat and drought stress.

The benefits of astaxanthin-rich microalgal powder on growth, health, and disease resistance against Fusarium solani in Pacific white shrimp

In shrimp aquaculture, enhancing health and disease resistance is crucial for sustainable production. This study investigates the pioneering effects of astaxanthin-enriched microalgal powder from Haematococcus pluvialis (HP) on Pacific white shrimp (Litopenaeus vannamei), focusing on growth efficiency, body composition, immune and antioxidant responses, intestinal health, histopathology, gene expression, and resistance against Fusarium solani. Shrimp (initial weight 5.27 ± 0.12 g) were separated into four groups and fed diets supplemented with HP at concentrations of 0, 0.5, 1, and 1.5 g/kg feed (control, HP 0.5, HP1, and HP1.5), respectively, for 8 weeks. The outcomes revealed marked improvements in growth, feed utilization, and survival rate of the HP-fed groups. The improvement was dose-dependent. The protein and ash content increased and the lipid decreased with HP supplementation. A dose-dependent augmented antioxidant-immune response was obvious in the HP-fed groups. This is proven by the high level of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase, total hemocyte count, respiratory burst, lysozyme (LYZ), phenoloxidase (PO), and phagocytic activity with up-regulation of proPO, LYZ, SOD, and CAT genes. Dietary HP influenced the intestinal bacterial community, where it reduced total aerobic and fecal bacteria and rose total probiotic bacteria and Clostridium counts. Histological investigation showed increased secretory vesicles within B-cells in the hepato-pancreas and larger muscle fibers in the HP-fed groups. Additionally, dietary HP notably lowered mortality rates upon the F. solani challenge, with a reduction from 65.00 % in the control to 45.00 %, 35.00%, and 35.00 % in the HP 0.5, HP1, and HP1.5 groups, respectively. Our study recommends adopting dietary HP at the optimal dose of 1.2 g/kg diet relying on the broken line regression model. This study provides valuable insights into the potential of HP as a dietary supplement to improve the health, growth, and disease resistance of L. vannamei, marking a significant advancement in shrimp aquaculture.

Catechol-derived Mannich bases: radical regulatory properties, cytotoxicity and interaction with biomolecules

Free radicals are ubiquitous in biological systems, being responsible for pathogenesis of degenerative diseases and participating in vitally important biochemical processes, which are mediated by radical regulatory agents. The effects of the aliphatic amine substituents in the catechol-derived Mannich bases on their antioxidant and pro-oxidant activity were investigated. It has been found that the presence of catechol moiety in the structure of Mannich bases allows them to act as Cu(II) reductants, efficient Fe(II) chelators and potent DPPH radical scavengers. It has been found that the plausible mechanism of the DPPH radical scavenging proceeds via quinone formation, followed by their interaction with ethanol via the Michael addition reaction. In the neutrophil respiratory burst assay, several compounds have demonstrated a weak antioxidant activity at the micromolar level (0.1–10 µM), whereas at the millimolar level (0.1 mМ) a strong pro-oxidant effect has been observed. Additionally, at the highest used concentrations a pronounced cytotoxicity against dermal fibroblasts DF-2 and an immunosuppressive effect against T-lymphocytes have been observed for all the synthesized compounds. It has been demonstrated that the oxidation of catechols in the presence of low-molecular thiols results in the formation of covalent adducts, which provides an insight into their cytotoxicity and detoxification pathways.

The transcription factor FcMYB3 responds to 60Co γ-ray irradiation of axillary buds in Ficus carica L. by activating the expression of the NADPH oxidase, FcRbohD

Plant irradiation has been used to induce genetic variation in crop germplasm. However, the underlying mechanisms of plant responses to ionizing radiation stress are still unclear. In plants, reactive oxygen species (ROS) are produced with abiotic stress. Respiratory burst oxidative homologs (Rboh) genes are important regulators of plant ROS stress responses, but little is known of their involvement in the response to ionizing radiation stress. In this study, young branches of Ficus carica L. were irradiated with 60Co γ-rays and axillary buds were collected after 3- 48 h after irradiation. The differentially expressed genes (DEGs; p< 0.05) detected included an early (6 h) and sustained increase in member of the MAPK signaling pathway. The activities of superoxide dismutase SOD, POD and CAT in fig axillary buds showed a trend of first decrease and then increase with time, while the contents of MDA and H2O2 maintained an overall upward trend. The analysis of differentially expressed genes (DEGs; p < 0.05) indicated an early (6 h) and sustained increase in member of the MAPK signaling pathway. DEGs for glutathione-s-transferase and genes involved in phenylpropanoid and flavonoid biosynthesis pathways were detected at all time points, indicating that γ-irradiation induced an increased capacity for in ROS-scavenging. Substantial changes in the expression of MYB, NAC and bHLH transcription factor family members were also seen to occur within 6 h after irradiation. Taking Rboh-derived ROS signaling pathway as the entry point, the MYB transcription factor, FcMYB3, was identified as an potential upstream regulator of FcRbohD in a yeast one hybrid assay and this interaction verified by LUC and EMSA experiments. The knock-down and overexpression of FcMYB3 indicated that FcMYB3 is a positive regulator of ROS accumulation in response to γ-ray radiation stress responses in fig. Our results will provide a better understanding of the mechanisms of radiation tolerance in plant materials.

Immunological Responses, Expression of Immune-Related Genes, and Disease Resistance of Rainbow Trout (Oncorhynchus mykiss) Fed Diets Supplied with Capsicum (Capsicum annuum) Oleoresin

A 45-day feeding study was carried out to assess the immune-stimulatory effects of capsicum oleoresin when added to rainbow trout diets. A total of 450 fish (mean weight: 155.20 ± 1.96 g) were distributed into 400 L tanks (30 fish/tank) across five experimental groups: control (CT, 0%), C7 (0.7%), C14 (1.4%), C21 (2.1%), and C28 (2.8%). Each group consisted of three replicate tanks. At the end of this period, hemato-biochemical parameters, innate immune responses, and immune-related gene expression levels were evaluated, and a histological examination of head kidney and liver sections was conducted. Finally, fish in all groups were challenged with Lactococcus garvieae and observed for an additional 20 days. The results revealed that oleoresin supplementation enhanced the immune responses of the treated fish, which was evidenced by the increased globulin, total protein, respiratory burst activity, and total immunoglobulin levels. The highest expression levels of the il-8, il-1β, TGF-β, and SAA genes was noticed in the C7 group, as compared with the results for the other groups. The IgT gene expression levels were higher in all experimental groups than in the CT group, and this increase was at the highest level in the C28 group. Following the bacterial challenge, all experimental groups displayed higher survival rates compared to that of the CT group. These values were 75.93, 72.22, 46.30, 33.33, and 29.63% in the C7, C14, C21, C28, and CT groups, respectively, with the C7 group displaying the highest survival rate among the groups. The histological examination of liver and head kidney tissues revealed that higher doses (in the C21 and C28 groups) showed an increase in cytoplasmic vacuolization, which causes adverse effects on fish health. However, the C7 group displayed normal histological structure in both tissues. Taken together, the most favorable immune responses were achieved in the C7 group, suggesting that 0.7% oleoresin could be applied to rainbow trout to boost immunity and protect the fish from diseases.

Combined effects of vitamin E and temperature on the growth, biochemistry, and natural immune response of juveniles snubnose pompano (Trachinotus blochii)

This study investigates the combined effects of Vitamin E and temperature on the growth, biochemical composition, and immune responses of juvenile snubnose pompano (Trachinotus blochii). A 70-day experiment was conducted with six treatments combining two levels of dietary Vitamin E (0 and 400 mg/kg) and three temperature levels (28°C, 31°C, and 34°C). The results revealed that both temperature and Vitamin E significantly influenced growth performance, feed utilization efficiency, protein and lipid content, and certain immune parameters (P < 0.05). Fish reared at 34°C with 400 mg/kg vitamin E demonstrated the highest growth indicators (SGRL, SGRW), protein efficiency, hepatosomatic index (HSI), and immune response, as indicated by elevated serum lysozyme levels, phagocytic activity, and white blood cells. Temperature notably affected lysozyme and respiratory burst activity, with values increasing at higher temperatures. Vitamin E supplementation improved these metrics regardless of temperature, increasing protein efficiency and reducing feed intake and feed conversion ratio (FCR). Moreover, Vitamin E enhanced immune responses, including increased white blood cell (WBC) counts and phagocytic activity. No interactive effects between Vitamin E and temperature were observed (P > 0.05). Overall, Vitamin E (400 mg/kg) positively influenced growth, biochemical composition, and immunity in snubnose pompano, particularly at elevated temperatures. The findings demonstrate that dietary vitamin E can enhance growth and immune performance, particularly under elevated temperatures, providing a basis for optimizing vitamin E use in snubnose pompano aquaculture.

Nitric oxide-mediated PpRAP2.2 regulates the transcription of PpRbohA/D to enhance resistance to Monilinia fructicola in peach fruit

Nitric oxide (NO), a critical signaling molecule, plays key roles in plant cell physiological processes, particularly in redox system. To investigate the resistance of exogenous NO to brown rot (Monilinia fructicola) in peach fruit during storage, postharvest peaches were treated with NO and c-PTIO (an NO scavenger), exploring the mechanism of NO enhancing disease resistance in peach fruit through reactive oxygen species (ROS) metabolism. The results indicated that NO significantly inhibited brown rot in postharvest peach fruit, evidenced by reduced disease incidence and smaller lesion diameters. Additionally, exogenous NO treatment decreased the expression of respiratory burst oxidase homologs (PpRbohs), which is a crucial factor in ROS metabolism. The transcription factor PpRAP2.2 was identified through yeast one-hybrid (Y1H) screening with the promoter of PpRbohD. The expression pattern of PpRAP2.2 was closely associated with superoxide anion (O2-) content and peach fruit disease resistance. PpRAP2.2, a nuclear-localized transcription factor, activated the expression of PpRbohA and PpRbohD by directly binding to their promoter. The virus-induced gene silencing (VIGS) assay showed that silencing of PpRAP2.2 facilitated peach disease resistance by reducing the transcription of PpRbohA and PpRbohD. Furthermore, the overexpression of PpRAP2.2 resulted in a significant reduction in disease incidence and conidiophores in transgenic tomatoes relative to control group under M. fructicola, suggesting that PpRAP2.2 effectively enhanced the resistance of tomatoes to M. fructicola. These results indicate that PpRAP2.2 enhances NO-mediated disease resistance in peach by regulating the expression of PpRbohA and PpRbohD. These finding provide a basis for further studies on function and regulatory mechanisms of peach fruit disease resistance.

The OXI1 kinase regulates plant immunity by linking microbial pattern-induced ROS burst to MAPK activation.

Plant cell-surface-localized pattern recognition receptors (PRRs) recognize microbial patterns and activate pattern-triggered immunity (PTI). Typical PTI responses include reactive oxygen species (ROS) burst controlled by the NADPH oxidase RESPIRATORY BURST OXIDASE HOMOLOGUE D (RbohD) and activation of the mitogen-activated protein kinase (MAPK) cascade composed of MAPKKK3/5-MKK4/5-MPK3/6. However, the mechanisms through which PRRs regulate and coordinate these immune responses are not fully understood. Here, we showed that Arabidopsis thaliana OXIDATIVE SIGNAL-INDUCIBLE1 (OXI1), a kinase known to be activated by ROS, is involved in the LYK5-CERK1 receptor complex, which recognizes fungal cell wall-derived chitin. The oxi1 mutant exhibits enhanced susceptibility to various pathogens and reduced chitin-induced MAPK activation and ROS burst. We showed that chitin induces the phosphorylation of OXI1 in an RbohD-dependent manner. H2O2 and chitin treatment causes the oxidation of OXI1 at Cys104 and Cys205, which is essential for the kinase activity of OXI1. These oxidation sites are required for chitin-induced MAPK activation and disease resistance. Activated OXI1 directly phosphorylates MAPKKK5 to regulate MAPK activation. Additionally, OXI1 phosphorylates RbohD, suggesting that it may activate RbohD to promote ROS burst to further enhance the long-term MAPK activation. Together, our findings reveal a pathway linking PRR-mediated ROS production to MAPK activation through OXI1.

Melatonin: dual players mitigating drought-induced stress in tomatoes via modulation of phytohormones and antioxidant signaling cascades

Drought stress significantly retards the plant production. Melatonin is a vital hormone, signaling molecule, and bio-regulator of diverse physiological growth and development processes. Its role in boosting agronomic traits under diverse stress conditions has received considerable attention. However, the underlying molecular mechanism of action and how they increase drought stress tolerance has not been fully interpreted. The current study aimed to ascertain the protective role of melatonin in fortifying the antioxidant defense system, modulating the phytohormone profile, and improving agronomic traits of tomato seedlings under drought stress. After the V1 stage (1st leaf fully emerged), tomato seedlings were exposed to PEG-6000 to mimic drought-induced stress (DR 10% and DR 20%), followed by exogenous application of 100 µM soil drench. Drought-induced stress negatively impacted tomato seedlings by reducing growth and development and biomass accumulation, diminishing salicylic acid (SA) and chlorophyll levels, and dramatically lowering the antioxidant defense ability. However, melatonin protected them by activating the defense system, which decreased the oxidative burst and increased the activities of SOD, CAT, and APX. Administration of 100 µM melatonin by soil drench most remarkably downregulated the transcription factors of SlDREB3 and SlNCED3. This study has validated the moderating potential of melatonin against drought-induced stress by maintaining plant growth and development, enhancing hormone levels, elevating antioxidant enzyme activities, and suppressing the relative expression of drought-responsive genes. These findings also provide a basis for the potential use of MT in agricultural research and other relevant fields of study.

Evaluation of biofloc system effects on water quality, growth, innate immunity, physiological status, and immune- and growth-related gene expressions in early growth stages of thin-lipped mullet (Liza ramada)

AbstractA 90-day experiment was carried out to study the influence of biofloc system on water quality, growth, feed utilization, survivability, bacteria in fish gut, and physiological and immunological responses of thin-lipped mullet (Liza ramada). Two treatments, clear water (CW) and biofloc (BFS), were each designed in triplicates. Both treatments were stocked with Liza ramada (mean weight of 1.18 ± 0.02 g). BFS group showed the highest final body weight, weight gain, average daily weight gain, and specific growth rate, the lowest feed conversion ratio, and the highest protein efficiency ratio and survivability. The proximate analysis of biofloc samples showed that percent crude protein and lipid were 26.17 and 7.75% respectively with the presence of essential minerals required for fish growth. The total body chemical composition of fish demonstrated improved crude protein and fat in Liza ramada stocked in BFS compared to CW. The highest total bacterial count and Bacillus number were recorded in the intestine of fish kept under BFS. Protease, lipase, and amylase levels significantly increased in fish stocked in BFS. The highest antioxidant activity was observed in fish kept under BFS treatment, while cortisol, alanine aminotransferase, and serum aspartate aminotransferase showed the lowest activity. Significantly high serum total protein, serum albumin, serum globulin, phagocytic activity, lysozymes, respiratory burst activity, and immunoglobulin M were observed in fish raised in BFS compared to CW. The intestinal histomorphometry examination showed a significantly high villi length and width, crypt depth, high number of intraepithelial lymphocytes, and goblet cells in BFS group. BFS resulted in a significantly up-regulation of the immune genes in the liver (IL-1β, TNF-α, IL-8, and IL-10) and the growth-related genes in the liver (IGF-1 and GH) compared to CW treatment. These results revealed that applying biofloc system in the rearing of Liza ramada resulted in many advantages including growth improvement, high survivability, enhanced activity of digestive enzymes, antioxidant system, immunological response, gut health, and decreased stress enzymes.

Effect of elevated ammonium on biotic and abiotic stress defense responses and expression of related genes in cucumber (Cucumis sativus L.) plants

Ammonium (NH4+) enhances plant defense mechanisms but can be phytotoxic as the sole nitrogen source. To investigate the impact of a balanced NH4+ and NO3− ratio on plant defense parameters without adverse effects, cucumber plants (Cucumis sativus L.) were grown under control (14 mM NO3− + 2 mM NH4+) and elevated level of NH4+ (eNH4+, 8 mM NO3−+ 8 mM NH4+). Plants subjected to eNH4+ showed significantly increased shoot and root biomass by about 41% and 47%, respectively. Among the antioxidant enzymes studied, ascorbate peroxidase (EC 1.11.1.11) activity was increased up to 3.3 fold in eNH4+ compared with control plants, which was associated with enhanced resistance to paraquat. Upregulation of PATHOGENESIS RELATED PROTEIN 4 (PR4) and LIPOXYGENASE 1 (LOX1), accompanied by increased concentrations of salicylic acid and nitric oxide, conferred more excellent resistance of eNH4+ plants to powdery mildew infection. However, the expression levels of ACC OXIDASE 1 (ACO1) and RESPIRATORY BURST OXIDASE HOMOLOGS B (RBOHB) were lower in eNH4+ plants, which was consistent with decreased NADPH oxidase activity and lower leaf H2O2 levels. The biosynthesis of phenolics was enhanced, whereas the activities of polymerizing enzymes and lignin deposition were reduced by half in eNH4+ plants. Besides, a significant effect on plant biomass under salt or drought stress has not been observed between control and eNH4+ plants. These results showed that different defense pathways are distinctively affected by eNH4+ treatment, and the NH4+ to NO3− ratio may play a role in fine-tuning the plant defense response.

SYNLAC prime probiotics enhances growth performance, and resistance of white shrimp, Penaeus vannamei to Enterocytozoon hepatopenaei and Vibrio alginollyticus: Insights into immune and metabolic pathway modulations

This study explores the impact of SYNLAC Prime probiotics on the growth performance, health status, and metabolic profile of white shrimp, Penaeus vannamei. Shrimp fed with the experimental diets, including the control diet without probiotic supplementation, and the diets supplemented with SYNLAC Prime probiotics at concentrations of 105 CFU (g diet)−1 (P5) and 106 CFU (g diet)−1 (P6) for 56 days. Results indicated a significant enhancement in growth performance in probiotic-treated shrimp relative to the control group, attributed to structural improvements in the digestive tract, particularly the increased abundances of B cells in the hepatopancreas. The administration of dietary probiotics markedly reduced the severity of Enterocytozoon hepatopenaei (EHP) infection and decreased cumulative mortalities following Vibrio alginolyticus challenge. Shrimp in the P6 group exhibited significant elevations in phenoloxidase activity, respiratory burst, lysozyme activity and phagocytic activity compared to control group. Furthermore, there was an upregulation of several immune-related genes in hepatopancreas, including serine protease (SP), prophenoloxidase (proPO) I, proPO II, and penaeidin 3a. Additionally, the expression of β-1, 3-glucan binding protein and SP mRNA was significantly increased in hemocytes. Untargeted metabolomics analysis using LC-MS/MS revealed significant changes in the hepatopancreas metabolic profile, highlighting alterations in energy metabolisms pathways, such as citrate cycle and nicotinate and nicotinamide metabolism, as well as amino acid metabolisms pathways including arginine and proline metabolism, taurine and hypotaurine metabolism, and histidine metabolism. These findings underscore the potential of SYNLAC Prime probiotics in enhancing shrimp growth, immune function, and metabolic pathways, offering valuable insights for advancing health management strategies in shrimp aquaculture.

EpiFusion: Joint inference of the effective reproduction number by integrating phylodynamic and epidemiological modelling with particle filtering.

Accurately estimating the effective reproduction number (Rt) of a circulating pathogen is a fundamental challenge in the study of infectious disease. The fields of epidemiology and pathogen phylodynamics both share this goal, but to date, methodologies and data employed by each remain largely distinct. Here we present EpiFusion: a joint approach that can be used to harness the complementary strengths of each field to improve estimation of outbreak dynamics for large and poorly sampled epidemics, such as arboviral or respiratory virus outbreaks, and validate it for retrospective analysis. We propose a model of Rt that estimates outbreak trajectories conditional upon both phylodynamic (time-scaled trees estimated from genetic sequences) and epidemiological (case incidence) data. We simulate stochastic outbreak trajectories that are weighted according to epidemiological and phylodynamic observation models and fit using particle Markov Chain Monte Carlo. To assess performance, we test EpiFusion on simulated outbreaks in which transmission and/or surveillance rapidly changes and find that using EpiFusion to combine epidemiological and phylodynamic data maintains accuracy and increases certainty in trajectory and Rt estimates, compared to when each data type is used alone. We benchmark EpiFusion's performance against existing methods to estimate Rt and demonstrate advances in speed and accuracy. Importantly, our approach scales efficiently with dataset size. Finally, we apply our model to estimate Rt during the 2014 Ebola outbreak in Sierra Leone. EpiFusion is designed to accommodate future extensions that will improve its utility, such as explicitly modelling population structure, accommodations for phylogenetic uncertainty, and the ability to weight the contributions of genomic or case incidence to the inference.

Transcription factor PagWRKY33 regulates gibberellin signaling and immune receptor pathways in Populus.

Enhanced autoimmunity often leads to impaired plant growth and development, and the coordination of immunity and growth in Populus remains elusive. In this study, we have identified the transcription factors PagWRKY33a/b as key regulators of immune response and growth maintenance in Populus. The disruption of PagWRKY33a/b causes growth issues and autoimmunity while conferring resistance to anthracnose caused by Colletotrichum gloeosporioides. PagWRKY33a/b binds to the promoters of N requirement gene 1.1 (NRG1.1) and Gibberellic Acid-Stimulated in Arabidopsis (GASA14)during infection, activating their transcription. This process maintains disease resistance and engages in GA signaling to reduce growth costs from immune activation. The oxPagWRKY33a/nrg1.1 mutant results in reduced resistance to C. gloeosporioides. Further, PagWRKY33a/b is phosphorylated and activated by Mitogen-Activated Protein Kinase Kinase 1 (MKK1), which inhibits Respiratory Burst Oxidase Homolog D (RBOHD) and Respiratory Burst Oxidase Homolog I (RBOHI) transcription, causing ROS bursts in wrky33a/b double mutants. This leads to an upregulation of PagNRG1.1 in the absence of pathogens. However, the wrky33a/b/nrg1.1 and wrky33a/b/rbohd triple mutants show compromised defense responses, underscoring the complexity of WRKY33 regulation. Additionally, the stability of PagWRKY33 is modulated by Ring Finger Protein 5 (PagRNF5)-mediated ubiquitination, balancing plant immunity and growth. Together, our results provide key insights into the complex function of WRKY33 in Populus autoimmunity and its impact on growth and development.

Tumor integrin-targeted glucose oxidase enzyme promotes ROS-mediated cell death that combines with interferon alpha therapy for tumor control.

While heightened intratumoral levels of reactive oxygen species (ROS) are typically associated with a suppressive tumor microenvironment, under certain conditions ROS contribute to tumor elimination. Treatment approaches, including some chemotherapy and radiation protocols, increase cancer cell ROS levels that influence their mechanism of cell death and subsequent recognition by the immune system. Furthermore, activated myeloid cells rapidly generate ROS upon encounter with pathogens or infected cells to eliminate disease, and recently, this effector function has been noted in cancer contexts as well. Collectively, ROS-induced cancer cell death may help initiate adaptive anti-tumor immune responses that could synergize with current approved immunotherapies, for improved control of solid tumors. In this work, we explore the use of glucose oxidase, an enzyme which produces hydrogen peroxide, a type of ROS, to therapeutically mimic the endogenous oxidative burst from myeloid cells to promote antigen generation within the tumor microenvironment. We engineer the enzyme to target pan-tumor expressed integrins both as a tumor-agnostic therapeutic approach, but also as a strategy to prolong local enzyme activity following intratumoral administration. We found the targeted enzyme potently induced cancer cell death and enhanced cross-presentation by dendritic cells in vitro, and further combined with interferon alpha for long-term tumor control in murine MC38 tumors in vivo. Optimizing the single-dose administration of this enzyme overcomes limitations with immunogenicity noted for other pro-oxidant enzyme approaches. Overall, our results suggest ROS-induced cell death can be harnessed for tumor control, and highlight the potential use of designed enzyme therapies alongside immunotherapy against cancer.

Phytochemical properties of Cyrtocarpa edulis peel exert antimicrobial activity and enhance immunobiological parameters in Almaco jack Seriola rivoliana cells

Fish aquaculture has increased but also disease problems related to it, along with antimicrobial resistance. The use of medicinal plants containing phytochemicals with antimicrobial, antioxidant, and immunomodulatory activities has been proposed. In this study, C. edulis “peel” was investigated for its phytochemical composition, antioxidant capacity, antimicrobial activities, and immunostimulant properties in leukocytes from Almaco Jack, S. rivoliana. The proximal composition of peel indicated 4.10 % protein 5.37 % ash and 6.93 % crude fiber, whereas total phenolic and flavonoid contents were 180 mg and 50 mg per gram of dry sample, respectively. Superoxide radical scavenging, total antioxidant, and iron chelation activities were also detected. In vitro, Almaco Jack S. rivoliana leukocytes treated with peel extract showed no cytotoxicity, whereas respiratory burst, myeloperoxidase, and SOD activities, as well as nitric oxide production, were enhanced. Most bacterial strains were inhibited 70 % at a concentration of 1 mg/mL C. edulis peel extract, except for Salmonella Enteritidis (40 %) and Vibrio parahaemolyticus (25 %). In conclusion, peel has phytochemicals with antioxidant capacity, immunostimulatory effects for Almaco Jack, Seriola rivoliana, and antimicrobial activity against Gram-positive and Gram-negative pathogens. Future experiments in fish must be conducted using C. edulis peel in diets to confirm their immunostimulant, antioxidant, and antimicrobial properties.

Respiratory Disease Surveillance in the Middle East and Latin America during the COVID-19 Pandemic, 2020-2022.

Characterizing the epidemiology of circulating respiratory pathogens during the COVID-19 pandemic could clarify the burden of acute respiratory infections and monitor outbreaks of public health and military relevance. The US Department of Defense supported 2 regions for influenza-like illness and severe acute respiratory infections surveillance, one in the Middle East through US Naval Medical Research Unit EURAFCENT, and another in Latin America through US Naval Medical Research Unit SOUTH. During 2020‒2022, coinciding with the COVID-19 pandemic, we collected a total of 16,146 nasopharyngeal and oropharyngeal swab samples from sentinel sites in Jordan (n = 11,305) and Latin America (n = 4,841). Samples were tested for SARS-CoV-2, influenza, and other respiratory pathogens. SARS-CoV-2 was the most frequently detected pathogen during 2020; other respiratory pathogens had distinct temporal and frequency distributions according to geographic location. Our findings support the need for continued sentinel surveillance as a vital tool for assessing the burden of respiratory diseases globally.

Antiviral efficacy of Andrographis paniculata and andrographolides: A narrative review

The rise of emerging infectious diseases has become notably prominent due to ecological changes and mutations in pathogens. The respiratory illness outbreak caused by the COVID-19 pandemic has spread globally. Natural products contain numerous structures and biological activities, offering ample options for discovering new antiviral drugs with unique targets and mechanisms. Andrographis paniculata has been utilized in Indian Ayurvedic, Swedish, Traditional Thai, and Chinese medicine to alleviate coughs, colds, and influenza symptoms. Early-stage laboratory studies indicate that this herbal extract may reduce inflammation and fever, and boost the body’s natural defenses against viruses, potentially leading to symptom relief. This review aims to systematically present clinical trial data about antiviral herbal formulations derived from Andrographis paniculata, delineating the antiviral effects of both natural and synthetic derivatives, along with in silico analyses.

Metabolic rate and mitochondrial physiology adjustments in Arctic char (Salvelinus alpinus) during cyclic hypoxia.

Diel fluctuations of oxygen levels characterize cyclic hypoxia and pose a significant challenge to wild fish populations. Although recent research has been conducted on the effects of hypoxia and reoxygenation, mechanisms by which fish acclimatize to cyclic hypoxia remain unclear, especially in hypoxia-sensitive species. We hypothesized that acclimation to cyclic hypoxia requires a downregulation of aerobic metabolic rate and an upregulation of mitochondrial respiratory capacities to mitigate constraints on aerobic metabolism and the elevated risk of oxidative stress upon reoxygenation. We exposed Arctic char (Salvelinus alpinus) to 10days of cyclic hypoxia and measured their metabolic rate and mitochondrial physiology to determine how they cope with fluctuating oxygen concentrations. We measured oxygen consumption as a proxy of metabolic rate and observed that Arctic char defend their standard metabolic rate but decrease their routine metabolic rate during hypoxic phases, presumably through the repression of spontaneous swimming activities. At the mitochondrial level, acute cyclic hypoxia increases oxygen consumption without ADP (CI-LEAK) in the liver and heart. Respiration in the presence of ADP (OXPHOS) temporarily increases in the liver and decreases in the heart. Cytochrome c oxidase oxygen affinity also increases at day 3 in the liver. However, no change occurs in the brain, which is likely primarily preserved through preferential perfusion (albeit not measured in this study). Finally, in vivo measurements of reactive oxygen species revealed the absence of an oxidative burst in mitochondria in the cyclic hypoxia group. Our study shows that Arctic char acclimatize to cyclic hypoxia through organ-specific mitochondrial adjustments.