Feeding Cycle Research Articles

Natural Magnetite Minerals Enhance 1,2-Dichloroethane Reductive Dechlorination

Contamination of soil and groundwater by chlorinated solvents is an environmental issue of primary concern. Recently, electrically conductive iron particles have been proposed as a novel approach to accelerate anaerobic bioremediation processes. In fact, it was demonstrated that conductive particles facilitate the exchange of electrons between microorganisms via Direct Interspecies Electron Transfer (DIET) processes, thus enhancing the pollutant-degrading potential of the microbial community. However, the use of natural minerals in this context has not been reported so far. In this study, we applied, for the first time, natural magnetite and hematite to accelerate the reductive dechlorination of 1,2-dichloroethane by an enrichment culture in lab-scale anaerobic microcosms. After four feeding cycles, low magnetite-amended microcosms (13 mg/L) yielded the highest rate of 1,2-DCA reductive dechlorination and reduced methanogenic activity. By contrast, hematite did not display any apparent stimulatory effect. Surprisingly, in the presence of higher amounts of iron oxides, a weaker effect was obtained, probably because iron(III) present in the minerals competed for the electrons necessary for reductive dechlorination. For all microcosms, the concentration of the toxic byproduct vinyl chloride was negligible throughout the whole study. The SEM/EDS analysis confirmed the close interaction between the conductive iron oxide particles and the dechlorinating bacteria. This work opens the possibility of using natural conductive minerals for bioremediation applications as well as shedding light on the previously unrecognized role of such minerals in contaminated ecosystems.

318-OR: Intermittent Fasting Improves ß-cell Function in Nonobese KATP-Induced Neonatal Diabetes through Reduction of Cellular Stress and Enhanced Autophagy

Diabetes progression is characterized by loss of functional β-cell mass. Non-obese KATP-GOF mouse models of human neonatal diabetes developed severe diabetes due to lack of insulin secretion; with a marked loss of β-cell mass/identity and dedifferentiation as diabetes progresses. Intermittent fasting (IF) reduces body weight, improves diabetes and autophagy in humans and obese mice, but the mechanisms underlying this in lean individuals remains elusive. Upon diabetes development, non-obese KATP-GOF mice were divided in two groups: i) fed chow diet ad libitum (AL) , ii) subjected to IF (24h fast/24hr feed cycles) . IF-KATP-GOF mice showed reduced blood glucose without changes in body weight or lean-fat mass compared to AL-KATP-GOF mice. The markedly reduced insulin and increased proinsulin levels in islets from AL-KATP-GOF mice were restored to normal levels in IF-KATP-GOF islets. IF-KATP-GOF islets showed reduced ATF6 and sXBP1 message levels and decreased sXBP1 and TXNIP protein levels compared to AL-KATP-GOF islets, suggesting reduced oxidative and ER stress. Strikingly, the markedly increased autophagy markers LC3II and P62 in AL-KATP-GOF islets were reduced to control levels in IF-KATP-GOF, suggesting improved autophagy. Electron microscopy confirmed increased insulin granules, reduced mitochondrial and ER damage, and decreased autophagosome accumulation in IF-KATP-GOF. While liver G6PC and PCK1 (gluconeogenesis) , FAS (lypogenesis/lipolysis) , and CPT1 and ATGL (β-oxidation/lipolysis) messages were increased, CRCT2 and FOXO1 (gluconeogenesis) , GCK (glycolysis) and PPARα (β-oxidation) were decreased. PPARγ and PPARα were decreased in brown adipose tissue. In conclusion, our studies in KATP-GOF mice indicate the beneficial effects of IF not only on improving functional β-cell mass through decreasing oxidative and ER stress and enhancing autophagy, but also improving liver and adipose tissue function. Disclosure E.Castelblanco: None. Z.A.Shyr: None. Z.Yan: None. A.Diwan: Consultant; Biomedical systems (ERT) , Dewpoint Therapeutics. M.S.Remedi: None. Funding National Institutes of Health (GDK123163)

1365-P: Intermittent Fasting Modifies Pancreatic Glucosensor Mechanism In Diabetic Mice

Background: A specific feature in type-2 diabetes is beta-cell dysfunction, associated to reduction in glucose-stimulated insulin secretion. This function is high-regulated by the glucose sensor mechanism, conformed by GLUT2 and glucokinase, and their expresión is decreased in type-2 diabetes. Intermittent fasting is a recent option in diet control, with alternate cycles of fasting and feeding. In this study we evaluated intermittent fasting in diabetic mice, and its long-term effect in pancreatic GLUT2 and glucokinase expression. Methods: C57BL6 mice were fed with high fat diet for eight weeks, and then intermittent fasting cycles among four weeks. Weight, total caloric intake, fasting and glucose tolerance were determinated. Changes in insulin and glucokinase expression were evatualed by immunohistochemistry assays. Glucose-stimulated insulin secretion, and PDX1, insulin, GLUT2 and glucokinase mRNAs were analyzed in isolated islets. Results: Intermittent fasting caused weight loss, reduction in total caloric intake decrease and enhanced glucose tolerance. In diabetic mice, glucose-stimulated insulin secretion was restored after intermittent fasting, without significant changes in hormone content. Treated groups with fasting increased gene expression of PDX1, insulin and GLUT2, but decreased glucokinase mRNA and localization in beta-cells, but enhanced alpha-cell possitive presence. Conclusion: Intermittent fasting modifies glucosensor mechanism in pancreatic islets from diabetic mice, through GLUT2, PDX1 and insulin expression, but glucokinase. On future studies we will determine changes glucokinase enzymatic activity, and another transcription factors involved in these effects. Disclosure A.Vilches-flores: None. Y.Padilla-romero: None. Funding UNAM PAPIIT IN225819

Interaction Between Cecal Metabolites and Liver Lipid Metabolism Pathways During Induced Molting in Laying Hens.

Moult is a normal physiological phenomenon in poultry. Induced molting (IM) is the most widely used and economical molting technique. By inducing moult, the laying hens can grow new feathers during the next laying cycle and improve laying performance. However, the lack of energy supply has a huge impact on both the liver and intestines and acts on the intestines and liver through the “gut-liver axis”. More importantly, lipid metabolism in the liver is closely related to the laying performance of laying hens. Therefore, in this study, cecal metabolites and liver transcriptome data during IM of laying hens at the late stage of laying (stop feeding method) were analyzed together to reveal the regulatory mechanism of “gut-liver axis” affecting the laying performance of laying hens from the perspective of lipid metabolism. Transcriptome analysis revealed that 4,796 genes were obtained, among which 2,784 genes had significant differences (p < 0.05). Forty-nine genes were associated with lipid metabolism, and five core genes (AGPAT2, SGPL1, SPTLC1, PISD, and CYP51A1) were identified by WGCNA. Most of these differential genes are enriched in steroid biosynthesis, cholesterol metabolism, drug metabolism—cytochrome P450, synthesis and degradation of ketone bodies, PPAR signaling pathway, and bile secretion. A total of 96 differential metabolites were obtained by correlating them with metabolome data. Induced moult affects laying performance by regulating genes related to lipid metabolism, and the cecal metabolites associated with these genes are likely to regulate the expression of these genes through the “enterohepatic circulation”. This experiment enriched the theoretical basis of induced moult and provided the basis for prolonging the feeding cycle of laying hens.

Circadian alignment of early onset caloric restriction promotes longevity in male C57BL/6J mice.

Caloric restriction (CR) prolongs lifespan, yet the mechanisms by which it does so remain poorly understood. Under CR, mice self-impose chronic cycles of 2-hour-feeding and 22-hour-fasting, raising the question whether calories, fasting, or time of day are causal. We show that 30%-CR is sufficient to extend lifespan 10%; however, a daily fasting interval and circadian-alignment of feeding act together to extend lifespan 35% in male C57BL/6J mice. These effects are independent of body weight. Aging induces widespread increases in gene expression associated with inflammation and decreases in expression of genes encoding components of metabolic pathways in liver from ad lib fed mice. CR at night ameliorates these aging-related changes. Thus, circadian interventions promote longevity and provide a perspective to further explore mechanisms of aging.

Nano-bio interfacial interactions determined the contact toxicity of nTiO2 to nematodes in various soils

The biological effect of soilborne nanoparticles (NPs) is a manifestation of soil-NMs-bio interactions. Soil factors are known to restructure NPs surfaces and thus influence the nanotoxicity. However, the mechanisms by which environmental factors affecting nano-bio interactions to aggravate or alleviate nanotoxicities are poorly understood. Herein, we compared the toxicity of TiO2 NPs (nTiO2) in five soils using the model nematode (Caenorhabditis elegans), and investigated the variation of nano-bio interactions under different conditions. A correlation analysis showed that pH and dissolved organic matter (DOM) were dominant regulators of nTiO2 toxicity. At the nano-bio interface, low pH (5.0) led to nTiO2 adhesion to micron-sized furrows and aggravated dermal wrinkling, while humid acid (HA) alleviated these impacts. Mechanically, low pH increased nTiO2 adhesion through enhanced electrostatic attraction and subsequent stimulation of mucin and collagen synthesis, resulting in a positive feed cycle of pH-dependent contact nanotoxicity. HA not only prevented nTiO2 adhesion onto the epidermis due to its negative charge, but also relieved the overstimulation of stress response pathways, thereby alleviating nanotoxicity. These findings broaden our knowledge of how NPs induce contact toxicity in soil invertebrates through specific biointerfacial interactions, and highlight the important role of DOM in alleviating the combined hazards of NPs and soil acidification.

Image Processing Algorithm for In Situ Monitoring Fiber Laser Remote Cutting by a High-Speed Camera.

We present an in situ process monitoring approach for remote fiber laser cutting, which is based on evaluating images from a high-speed camera. A specifically designed image processing algorithm allows the distinction between complete and incomplete cuts by analyzing spectral and geometric information of the melt pool from the captured images of the high-speed camera. The camera-based monitoring system itself is fit to a conventional laser deflection unit for use with high-power fiber lasers, with the optical detection path being coaxially aligned to the incident laser. Without external illumination, the radiation of the melt from the process zone is recorded in the visible spectral range from the top view and spatially and temporally resolved. The melt pool size and emitted sparks are evaluated in dependence of machining parameters such as feed rate, cycles, and focus position during cutting electrical sheets.

2D and 3D visualizations of archosaur jaw muscle mechanics, ontogeny and phylogeny using ternary diagrams and 3D modeling.

Comparing patterns of performance and kinematics across behavior, development and phylogeny is crucial to understand the evolution of complex musculoskeletal systems such as the feeding apparatus. However, conveying 3D spatial data of muscle orientation throughout a feeding cycle, ontogenetic pathway or phylogenetic lineage is essential to understanding the function and evolution of the skull in vertebrates. Here, we detail the use of ternary plots for displaying and comparing the 3D orientation of muscle data. First, we illustrate changes in 3D jaw muscle resultants during jaw closing taxa the American alligator (Alligator mississippiensis). Second, we show changes in 3D muscle resultants of jaw muscles across an ontogenetic series of alligators. Third, we compare 3D resultants of jaw muscles of avian-line dinosaurs, including extant (Struthio camelus, Gallus gallus, Psittacus erithacus) and extinct (Tyrannosaurus rex) species to outline the reorganization of jaw muscles that occurred along the line to modern birds. Finally, we compare 3D resultants of jaw muscles of the hard-biting species in our sample (A. mississippiensis, T. rex, P. erithacus) to illustrate how disparate jaw muscle resultants are employed in convergent behaviors in archosaurs. Our findings show that these visualizations of 3D components of jaw muscles are immensely helpful towards identifying patterns of cranial performance, growth and diversity. These tools will prove useful for testing other hypotheses in functional morphology, comparative biomechanics, ecomorphology and organismal evolution.

Lutein production by microalgae using corn starch wastewater pretreated with rapid enzymatic hydrolysis

The main purpose of this study was to explore the pretreatment process of corn starch wastewater (CSW) and engineered microalgae cultivation strategy to improve the nutrient recovery from wastewater and the yield of microalgae lutein. One-stage enzymatic hydrolysis utilizing α-amylase and glucoamylase simultaneously was established to efficiently harvest a maximum concentration of reducing sugar content of 7.26 g/L from CSW in 50 min. Lutein yield of 10.96 mg/L was obtained under 24 h continuous illumination with 2200 Lux light intensity. Furthermore, a cyclic feeding cultivation strategy was developed to improve lutein accumulation and COD removal up to 25.9 mg/L and 50.7%, respectively, after three cultivation cycles. Lutein yield of 14.86 mg/L and COD removal efficiency of 73.2% was achieved with further implementation in actual wastewater. This work provided a new perspective in developing the potential of cultivating microalgae with corn starch wastewater to produce high-value lutein.

Prediction of Wall Heat Fluxes in a Rocket Engine with Conjugate Heat Transfer Based on Large-Eddy Simulation.

Although a lot of research and development has been done to understand and master the major physics involved in cryogenic rocket engines (combustion, feeding systems, heat transfer, stability, efficiency, etc.), the injection system and wall heat transfer remain critical issues due to complex physics, leading to atomization in the subcritical regime and the interactions of hot gases with walls. In such regimes, the fuel is usually injected through a coaxial annulus and triggers the atomization of the central liquid oxidizer jet. This type of injector is often referred to as air-assisted, or coaxial shear, injector, and has been extensively studied experimentally. Including such injection in numerical simulations requires specific models as simulating the atomization process is still out of reach in practical industrial systems. The effect of the injection model on the flame stabilization process and thus on wall heat fluxes is of critical importance when it comes to the design of wall-cooling systems. Indeed, maximizing the heat flux extracted from the chamber can lead to serious gain for the cooling and feeding systems for expander-type feeding cycles where the thermal energy absorbed by the coolant is converted into kinetic energy to drive the turbo-pumps of the feeding system. The methodology proposed in this work to numerically predict the flame topology and associated heat fluxes is based on state-of-the-art methods for turbulent reactive flow field predictions for rocket engines, including liquid injection, combustion model, and wall treatment. For this purpose, high-fidelity Large Eddy Simulation Conjugate Heat Transfer, along with a reduced kinetic mechanism for the prediction of chemistry, liquid injection model LOx sprays, and the use of a specific wall modeling to correctly predict heat flux for large temperature ratio between the bulk flow and the chamber walls, is used. A smooth and a longitudinally ribbed combustor configuration from JAXA are simulated. The coupling strategy ensures a rapid convergence for a limited additional cost compared to a fluid-only simulation, and the wall heat fluxes display a healthy trend compared to the experimental measurements. An increase of heat transfer coherent with the literature is observed when walls are equipped with ribs, compared to smooth walls. The heat transfer enhancement of the ribbed configuration with respect to the smooth walls is coherent with results from the literature, with an increase of around of wall heat flux extracted for the same chamber diameter.

Analysis of research concepts for the use of alternative fuels in diesels

The subject of the research is the analysis of the concepts of the use of alternative fuels (AT) in diesel engines. The main purpose of this work is to determine the degree of study of the scientific problems of the use of AT in diesel engines and to define the concept of further research. To achieve this goal, a review of studies on the use of AT in diesels was conducted and further ways of their implementation in this area were determined. In addition, the values of the cyclic feeds of mixed fuels (ST) consisting of diesel fuel (DT) and AT were determined, and the developed design of the system of quantitative and qualitative regulation of diesel ST was presented. Keywords alternative fuel, diesel fuel, mixed fuel, diesel, control system, cyclic feed

Restricting feeding to dark phase fails to entrain circadian activity and energy expenditure oscillations in Pitx3-mutant Aphakia mice.

Metabolic homeostasis is under circadian regulation to adapt energy requirements to light-dark cycles. Feeding cycles are regulated by photic stimuli reaching the suprachiasmatic nucleus via retinohypothalamic axons and by nutritional information involving dopaminergic neurotransmission. Previously, we reported that Pitx3-mutant Aphakia mice with altered development of the retinohypothalamic tract and the dopaminergic neurons projecting to the striatum, are resistant to locomotor and metabolic entrainment by time-restricted feeding. In their Matters Arising article, Scarpa etal. (2022) challenge this conclusion using mice from the same strain but following a different experimental paradigm involving calorie restriction. Here, we address their concerns by extending the analyses of our previous data, by identifying important differences in the experimental design between both studies and by presenting additional results on the dopaminergic deficit in the brain of Aphakia mice. This Matters Arising Response article addresses the Matters Arising article by Scarpa etal. (2022), published concurrently in Cell Reports.

A study on changing regularity of temperature of aluminum reduction cell

The stability of aluminum reduction cell is the fundamental guarantee for high efficiency and low energy consumption of aluminum electrolytic production. Temperature stability is an essential feature of and basic guarantee for the stability of a cell. In this paper, based on industrial tests on the 300kA industrial cells and a large number of data mining research on it, some regularities of periodic fluctuation of the cell temperature are found along with the feeding circles and the seasons. The relationship among cell temperature, feeding cycles and local air temperature has been studied. In the end, some suggestions for primary aluminum production are provided to improve daily temperature measurement, alumina feeding control strategies and energy balance according to local meteorological data in different region.

Deletion of Npas2 in the liver alters the functional gut microbiome at light/dark timepoints

In utero exposure of a maternal high fat diet (mHFD) results in the targeted epigenetic reprograming and disruption of circadian clock genes in the fetal liver. However, it is unclear if this disruption of the circadian clock exacerbates the effect of the offspring’s post-weaning high fat diet (oHFD) on the function of its gut microbiome. To understand the interaction of the circadian clock and the offspring gut microbiome with HFD feeding, we disrupted liver Npas2 expression and analyzed the resultant microbiome in light and dark cycles of feeding.

Novel biomarkers in healthy aging: Tongue and jaw kinematics as a potential way to further explore Alzheimer’s‐induced biological changes

AbstractBackgroundMany age‐related oral health problems, such as masticatory dysfunction and dysphagia, have been associated with Alzheimer’s Disease (AD). However, how oromotor dysfunctions in healthy aging differ from those found in AD is still largely unknown. Here, we aim to assess changes in tongue and jaw kinematics in healthy aging to understand how these biomarkers may provide early signatures of AD.MethodData were collected from two male monkeys (Macaca mulatta), one young (8 years) and one older (20 years). Using high‐resolution bilateral videoradiography (200 frames/s) and the X‐Ray Reconstruction of Moving Morphology (XROMM) workflow, we quantified the 3D position of tongue and jaw radio‐opaque markers while monkeys engaged in a natural feeding behavior. To evaluate age‐related changes, we analyzed tongue and jaw kinematics relative to specific events in the feeding cycle during 10‐s feeding trials (20‐60 trials). All protocols were approved by the University of Chicago Animal Care and Use Committee and complied with the National Institutes of Health Guide for the Care and Use of Laboratory Animals. ResultDuring chews and swallows, both monkeys exhibited cyclical tongue motions, however, the tongue motions in the older monkey were substantially less stereotyped. The distributions of x‐y‐z positions of the tongue during start/end of chews and swallows were tightly clustered in the young monkey but were more spread out in the older (Fig. 1). In addition, tongue movements in the rostro‐caudal direction lagged behind jaw movements to a greater degree in the older monkey than in the younger (Fig. 2). Indeed, in the young monkey, tongue movements in the rostro‐caudal direction were highly correlated with supero‐inferior jaw movements, with peak correlations occurring at zero lag (Fig. 3).ConclusionThese results show that tongue and jaw kinematics may change with age, particularly with regards to stereotypy of tongue movement and tongue‐jaw coordination. Understanding oromotor changes in healthy aging may serve as diagnostic measures that may be helpful in treating or delaying AD progression and in reducing the severity of debilitating oromotor dysfunctions.

AGN feeding and feedback in Fornax A

We present a multi-wavelength study of the gaseous medium surrounding the nearby active galactic nucleus (AGN), Fornax A. Using MeerKAT, ALMA, and MUSE observations, we reveal a complex distribution of the atomic (H I), molecular (CO), and ionised gas in its centre and along the radio jets. By studying the multi-scale kinematics of the multi-phase gas, we reveal the presence of concurrent AGN feeding and feedback phenomena. Several clouds and an extended 3 kpc filament – perpendicular to the radio jets and the inner disk (r ≲ 4.5 kpc) – show highly-turbulent kinematics, which likely induces non-linear condensation and subsequent chaotic cold accretion (CCA) onto the AGN. In the wake of the radio jets and in an external (r ≳ 4.5 kpc) ring, we identify an entrained massive (∼107M⊙) multi-phase outflow (vOUT ∼ 2000 km s−1). The rapid flickering of the nuclear activity of Fornax A (∼3 Myr) and the gas experiencing turbulent condensation raining onto the AGN provide quantitative evidence that a recurrent, tight feeding and feedback cycle may be self-regulating the activity of Fornax A, in agreement with CCA simulations. To date, this is one of the most in-depth probes of such a mechanism, paving the way to apply these precise diagnostics to a larger sample of nearby AGN hosts and their multi-phase inter stellar medium.

Sophistication in a seemingly simple creature: a review of wild holothurian nutrition in marine ecosystems.

ABSTRACTHolothurians are marine invertebrates that are among the most widespread benthic megafauna communities by both biomass and abundance in shallow‐water and deep‐sea ecosystems, their functions supporting important ecological services worldwide. Despite their simple appearance as sea cucumbers, holothurians show a wide range of feeding practices. However, information on what and how these animals eat is scattered and potentially confusing. We provide a comprehensive review of holothurian nutrition in coastal and deep‐sea ecosystems. First, we describe morphological aspects of holothurian feeding and the ultrastructure of tentacles. We discuss the two processes for food capture, concluding that mucus adhesion is likely the main method; two mucous cells, type‐1 and type‐2, possibly allow the adhesion and de‐adhesion, respectively, of food particles. Secondly, this review aims to clarify behavioural aspects of holothurian suspension‐ and deposit‐feeding. We discuss the daily feeding cycle, and selective feeding strategies. We conclude that there is selectivity for fine and organically rich particles, and that feeding through the cloaca is also a route for nutrient absorption. Third, we provide a wide description of the diet of holothurians, which can be split into two categories: living and non‐living material. We suggest that Synallactida, Molpadida, Persiculida, Holothuriida and Elasipodida, ingest the same fractions, and emphasise the importance of bacteria in the diet of holothurians.

Intermittent Fasting Inhibits High-Fat Diet-Induced Atherosclerosis by Ameliorating Hypercholesterolemia and Reducing Monocyte Chemoattraction.

Atherosclerosis is a major pathology for cardiovascular diseases (CVDs). Clinically, the intermittent fasting (IF) has been observed to reduce the risk of CVDs. However, the effect of IF on the development of atherosclerosis has not been fully elucidated. Herein, we determined the protection of IF against high-fat diet–induced atherosclerosis in pro-atherogenic low-density lipoprotein receptor deficient (LDLR-/-) mice and the potentially involved mechanisms. The LDLR-/- mice were scheduled intermittent fasting cycles of 3-day HFD feeding ad libitum and 1 day fasting, while the mice in the control group were continuously fed HFD. The treatment was lasted for 7 weeks (∼12 cycles) or 14 weeks (∼24 cycles). Associated with the reduced total HFD intake, IF substantially reduced lesions in the en face aorta and aortic root sinus. It also increased plaque stability by increasing the smooth muscle cell (SMC)/collagen content and fibrotic cap thickness while reducing macrophage accumulation and necrotic core areas. Mechanistically, IF reduced serum total and LDL cholesterol levels by inhibiting cholesterol synthesis in the liver. Meanwhile, HFD-induced hepatic lipid accumulation was attenuated by IF. Interestingly, circulating Ly6Chigh monocytes but not T cells and serum c-c motif chemokine ligand 2 levels were significantly reduced by IF. Functionally, adhesion of monocytes to the aortic endothelium was decreased by IF via inhibiting VCAM-1 and ICAM-1 expression. Taken together, our study indicates that IF reduces atherosclerosis in LDLR-/- mice by reducing monocyte chemoattraction/adhesion and ameliorating hypercholesterolemia and suggests its potential application for atherosclerosis treatment.

Towards Understanding the Direct and Indirect Actions of Growth Hormone in Controlling Hepatocyte Carbohydrate and Lipid Metabolism

Growth hormone (GH) is critical for achieving normal structural growth. In addition, GH plays an important role in regulating metabolic function. GH acts through its GH receptor (GHR) to modulate the production and function of insulin-like growth factor 1 (IGF1) and insulin. GH, IGF1, and insulin act on multiple tissues to coordinate metabolic control in a context-specific manner. This review will specifically focus on our current understanding of the direct and indirect actions of GH to control liver (hepatocyte) carbohydrate and lipid metabolism in the context of normal fasting (sleep) and feeding (wake) cycles and in response to prolonged nutrient deprivation and excess. Caveats and challenges related to the model systems used and areas that require further investigation towards a clearer understanding of the role GH plays in metabolic health and disease are discussed.

Effects of four different adjuvants separately combined with Aeromonas veronii inactivated vaccine on haematoimmunological state, enzymatic activity, inflammatory response and disease resistance in crucian carp

The purpose of the current study was to explore the immunomodulatory effects of different adjuvants combined with inactivated vaccines under Aeromonas veronii TH0426 infection in crucian carp. This study explored the best conditions for A. veronii as an inactivated vaccine, and included an animal safety test. Furthermore, we expressed the flagellin FlaA of the A. veronii TH0426 strain for use as an adjuvant supplemented in the diet. Crucian carp were fed 12 different experimental diets for 35 days, including the administration of 10 different adjuvants and inactivated vaccine combinations (50% aluminum hydroxide gel and inactivated vaccine combination, and inactivated vaccine with 20%, 30%, or 50% glucan, astragalus polysaccharide or flagellin), inactivated vaccine alone, and PBS control without adjuvant and inactivated vaccine. After the 42 day feeding trials, the fish were challenged with A. veronii TH0426, and the survival rate over 14 days was recorded. In addition, flagellin FlaA can be expressed normally in large amounts. All experimental groups produced higher levels of IgM serum titres than the control group in the different feeding cycles. Moreover, the activity of serum ACP, AKP, SOD, and LZM, and the expression of inflammatory factors were significantly increased in the experimental groups compared with the control group. The results of qRT-PCR analysis showed that the transcription levels of the IL-10, IL-1β, IFN-γ and TNF-α genes in heart, liver, spleen and kidney tissues were significantly enhanced by adjuvant treatment, indicating that the addition of adjuvants can significantly promote the body's inflammatory response. In addition, the phagocytic activity of leukocytes in each adjuvant treated group was significantly enhanced compared to that in the groups without adjuvant. After the A. veronii challenge, the survival rate of all adjuvant-treated groups was significantly higher than that of the control group, and the 50% flagellin adjuvant group had the highest rate of 78.37%. Overall, our findings strongly indicate that adjuvants not only significantly improve the body's immunity, but also exhibit a strong anti-infection ability. Importantly, this work provides a new perspective for the prevention and control of aquaculture diseases.