Histidine Deficiency Inhibits Intestinal Antioxidant Capacity and Induces Intestinal Endoplasmic-Reticulum Stress, Inflammatory Response, Apoptosis, and Necroptosis in Largemouth Bass (Micropterus salmoides)

Modulatory effects of necroptosis: A potential preventive approach to control diseases in fish

Necroptosis is a caspase-independent programmed cell death process characterized by morphological similarities to necrosis and the potential to cause significant inflammatory reactions. The initiation, execution, and inhibition of necroptosis involve a complex interplay of various signaling proteins. When death receptors bind to ligands, necroptosis is triggered through the receptor-interacting serine/threonine-protein kinase 1 (RIPK1)/RIPK3/Mixed Lineage Kinase Domain-Like (MLKL) axis, leading to inflammatory reactions in the surrounding tissues. This process encompasses numerous physiological regulatory mechanisms and contributes to the development and progression of certain diseases. The mechanisms of necroptosis were not well conserved across terrestrial and aquatic organisms, with differences in some components and functions. Given the significant challenges that aquatic animal diseases pose to aquaculture, research interest in necroptosis has surged recently, particularly in studies focusing on fish. Understanding necroptosis in fish can lead to interventions that offer potential breakthroughs in disease inhibition and fish health improvement.

The inverse associations of glycine and histidine in diet with hyperlipidemia and hypertension

BACKGROUND

Amino acids are crucial for nutrition and metabolism, regulating metabolic pathways and activities vital to organismal health and stability. Glycine and histidine act as potent antioxidants and anti-inflammatory agents; however, limited knowledge exists regarding the associations between these amino acids and hyperlipidemia and hypertension. The purpose of this study is to investigate the relationship between dietary glycine and histidine, and hyperlipidemia and hypertension.

METHODS

This population-based cross-sectional study evaluated the influence of dietary glycine and histidine, as well as their combined effect, on hyperlipidemia and hypertension in Chinese adults participating in the Nutrition Health Atlas Project (NHAP). General characteristics were acquired using a verified Internet-based Dietary Questionnaire for the Chinese. Binary logistic regression, along with gender, age groups, and median energy intake subgroup analyses, was employed to investigate the associations between dietary glycine and histidine and hyperlipidemia and hypertension. A sensitivity analysis was conducted to assess the impact of excluding individuals who smoke and consume alcohol on the results.

RESULTS

Based on the study's findings, 418 out of 1091 cases had hyperlipidemia, whereas 673 had hypertension. A significant inverse relationship was found between dietary glycine, histidine, and glycine + histidine and hyperlipidemia and hypertension. Compared with the 1st and 2nd tertiles, the multivariable-adjusted odd ratios (ORs) (95% confidence intervals) (CIs) of the 3rd tertile of dietary glycine for hyperlipidemia and hypertension were 0.64 (0.49-0.84) (p < 0.01) and 0.70 (0.56-0.88) (p < 0.001); histidine was 0.63 (0.49-0.82) (p < 0.01) and 0.80 (0.64-0.99) (p < 0.01); and glycine + histidine was 0.64 (0.49-0.83) (p < 0.01) and 0.74 (0.59-0.92) (p < 0.001), respectively. High glycine and high histidine (HGHH) intake were negatively associated with hyperlipidemia and hypertension OR (95% CIs) were: 0.71 (0.58-0.88) (p < 0.01) and 0.73 (0.61-0.87) (p < 0.01), respectively.

CONCLUSIONS

Dietary glycine and histidine, as well as their HGHH group, revealed an inverse relationship with hyperlipidemia and hypertension. Further investigations are needed to validate these findings.

Excessive Replacement of Fish Meal by Soy Protein Concentrate Resulted in Inhibition of Growth, Nutrient Metabolism, Antioxidant Capacity, Immune Capacity, and Intestinal Development in Juvenile Largemouth Bass (Micropterus salmoides)

This study investigated the effects of replacing 0% (SPC0), 25% (SPC25), 50% (SPC50), 75% (SPC75), and 100% (SPC100) of fish meal (FM) with soy protein concentrate (SPC) on the growth, nutritional metabolism, antioxidant capacity, and inflammatory factors in juvenile largemouth bass (Micropterus salmoides) (17.03 ± 0.01 g). After 56 days of culturing, various growth parameters including FW, WGR, and SGR were not significantly different among SPC0, SPC25, and SPC50 groups; however, they were significantly higher than those in SPC75 and SPC100 groups. Conversely, significantly lower FCR were determined for the SPC0, SPC25, and SPC50 groups compared with that for the SPC100 group; specifically, no significant difference among SPC0, SPC25, and SPC50 groups was found. Moreover, compared with SPC75 and SPC100 groups, a significantly higher FI was observed in the SPC0 group, whereas a significantly lower SR was observed in SPC100 compared with that in SPC0 and SPC25 groups. Compared with the SPC0 group, significantly lower mRNA levels of tor, rps6, 4ebp1, pparγ, and fas were found in SPC75 and SPC100. Additionally, the mRNA levels of cpt were significantly higher in SPC0, SPC25, and SPC50 groups than in SPC75 and SPC100 groups. Moreover, the mRNA levels of scd and acc remained unchanged for all the groups. Replacement of FM with SPC did not significantly affect the mRNA levels of gk, pk, and pepck. Compared with the SPC0 group, significantly decreased activities of CAT were observed in the SPC50, SPC75, and SPC100 groups, and significantly decreased activities of GSH-Px were observed in the SPC75 and SPC100 groups. In addition, significantly lower activity of SOD was observed in SPC100 compared with the other groups. Moreover, compared with the other groups, the SPC75 and SPC100 groups had significantly decreased and increased contents of GSH and MDA, respectively, while significantly lower mRNA levels of nrf2, cat, sod, and gsh-px were found in SPC50, SPC75, and SPC100; however, significantly higher mRNA levels of keap1 were observed in SPC75 and SPC100 groups. Additionally, significantly higher mRNA levels of il-8 and nf-κb were found in the SPC50, SPC75, and SPC100 groups compared with the SPC0 group. Conversely, significantly lower mRNA levels of il-10 and significantly higher mRNA levels of tnf-α were found in the SPC75 and SPC100 groups compared with the other groups. Compared with the SPC0 group, mucosal thickness and villus height were significantly decreased in the SPC75 and SPC100 groups. Collectively, SPC replacing 50% FM did not affect its growth of juvenile largemouth bass. However, SPC replacing 50% or more FM might inhibit antioxidant capacity and immune capacity to even threaten the SR, resulting in impaired intestinal development in replacing FM level of 75% or more.

An insight into role of amino acids as antioxidants via NRF2 activation

Oxidative stress can affect the protein, lipids, and DNA of the cells and thus, play a crucial role in several pathophysiological conditions. It has already been established that oxidative stress has a close association with inflammation via nuclear factor erythroid 2-related factor 2 (NRF2) signaling pathway. Amino acids are notably the building block of proteins and constitute the major class of nitrogen-containing natural products of medicinal importance. They exhibit a broad spectrum of biological activities, including the ability to activate NRF2, a transcription factor that regulates endogenous antioxidant responses. Moreover, amino acids may act as synergistic antioxidants as part of our dietary supplementations. This has aroused research interest in the NRF2-inducing activity of amino acids. Interestingly, amino acids' activation of NRF2-Kelch-like ECH-associated protein 1 (KEAP1) signaling pathway exerts therapeutic effects in several diseases. Therefore, the present review will discuss the relationship between different amino acids and activation of NRF2-KEAP1 signaling pathway pinning their anti-inflammatory and antioxidant properties. We also discussed amino acids formulations and their applications as therapeutics. This will broaden the prospect of the therapeutic applications of amino acids in a myriad of inflammation and oxidative stress-related diseases. This will provide an insight for designing and developing new chemical entities as NRF2 activators.

High-temperature stress response: Insights into the molecular regulation of American shad (Alosa sapidissima) using a multi-omics approach

High temperature is an important abiotic stressor that limits the survival and growth of aquatic organisms. American shad (Alosa sapidissima), a migratory fish suitable for culturing at low temperatures, is known for its delicious taste and thus has high economic value. Studies concerning changes in A. sapidissima under high temperature are limited, especially at the gene expression and protein levels. High-temperature stress significantly reduced the survival rates and increased vacuolar degeneration and inflammatory infiltration in the gills and liver. High temperature increased the activities of SOD, CAT, and cortisol, with a trend of initial increase followed by decreases in MDA, ALP, and LDH, and irregular changes in T-AOC and Na-K-ATPase. Comprehensive analysis of the transcriptome, proteome, and metabolome of gills from fish treated with different culture temperatures (24, 27, and 30 °C) revealed that differentially expressed genes, proteins, and metabolites were highly enriched in pathways involved in protein digestion and absorption, protein processing in endoplasmic reticulum, metabolic pathways, and purine metabolism. Gene expression and protein profiles indicated that genes coding for antioxidants (i.e., cat and alpl) and members of the heat shock protein (i.e., HSP70, HSP90AA1, and HSP5) were significantly upregulated. Additionally, a conjoint analysis revealed that several key enzymes, including nucleoside diphosphate kinase 2, adenosine deaminase, and ectonucleoside triphosphate diphosphohydrolase 5/6 were altered, thereby affecting the metabolism of guanosine, guanine, and inosine. An interaction network further confirmed that levels of the essential amino acids DL-arginine and L-histidine were significantly reduced, and corticosterone levels were significantly increased, suggesting that A. sapidissima may be more dependent on amino acids for energy in vivo. Overall, this work suggests that living in a high-temperature environment leads to differential defense responses in fishes. The results provide novel perspectives for studying the molecular basis of adaptation to climate change in A. sapidissima and for genetic selection.

Untargeted metabolomics analysis reveals spatial metabolic heterogeneity in different intestinal segments of type 1 diabetic mice

Type 1 diabetes (T1D) has been reported to cause systematic metabolic disorders, but metabolic changes in different intestinal segments of T1D remain unclear. In this study, we analyzed metabolic profiles in the jejunum, ileum, cecum and colon of streptozocin-induced T1D and age-matched control (CON) mice by an LC-MS-based metabolomics method. The results show that segment-specific metabolic disorders occurred in the gut of T1D mice. In the jejunum, we found that T1D mainly led to disordered amino acid metabolism and most amino acids were significantly lower relative to CON mice. Moreover, fatty acid metabolism was disrupted mainly in the ileum, cecum and colon of T1D mice, such as arachidonic acid, alpha-linolenic acid and linoleic acid metabolism. Thus, our study reveals spatial metabolic heterogeneity in the gut of T1D mice and provides a metabolic view on diabetes-associated intestinal diseases.

Enteral nutrition promotes the remission of colitis by gut bacteria-mediated histidine biosynthesis

BACKGROUND

Exclusive enteral nutrition (EEN) is an important alternative strategy for patients with Crohn's disease (CD), and during this process, microbiota alterations have been observed. However, the underlying mechanisms by which EEN reduces intestinal inflammation are currently unclear.

METHODS

The therapeutic potential of enteral nutrition (EN) was assessed using various mouse models. Fecal full-length 16S rDNA sequencing analysis and several CD metagenome datasets were used to identify the candidate therapeutic bacteria Faecalibaculum rodentium (F. rodentium). Whole genome sequencing of F. rodentium and widely-targeted metabolome analysis of the supernatant showed that EN-induced F. rodentium accumulation protected against colitis via histidine biosynthesis.

FINDINGS

The therapeutic potential of EN therapy was observed in both dextran sulfate sodium (DSS)-induced colitis and Il10-/- spontaneous colitis mouse models. Accumulation of F. rodentium after EN therapy was determined using full-length 16S rDNA sequencing and verified with several metagenome datasets from patients with CD. Colonization of an isolated F. rodentium could reduce colitis in Il10-/- mice. Significant histidine enrichment was observed in the F. rodentium culture supernatant, and a series of histidine biosynthesis genes were observed in the F. rodentium genome. Engineered Escherichia coli Nissle 1917 (EcN), encoding the heterologous hisG of F. rodentium (EcN-hisG), which was a key driver of histidine biosynthesis in F. rodentium, was found to protect against colitis.

INTERPRETATION

This study suggests that EN-induced F. rodentium accumulation protects against colitis in mice via gut bacteria-mediated histidine biosynthesis.

FUNDING

A full list of funding bodies can be found in the Acknowledgements section.

Environment-relevant concentrations of cadmium induces necroptosis and inflammation; baicalein maintains gill homeostasis through suppressing ROS/ER stress signaling in common carps (Cyprinus carpio L.)

Cadmium (Cd) is a major contaminant in natural environments and exerts adverse effects on aquatic biota at low concentrations. Gill is as vital respiratory organ and may cause pollutants to enter fish during gas exchange. Baicalein (BAI), as a kind of flavonoids, possess antioxidant properties through inactivating free radicals. To confirm the potential effects and approaches of BAI addition in maintaining the gill stability, 90 common carps (Cyprinus carpio L.) were selected and randomly divided into water environment exposure group (0.22 mg/L Cd) and/or feed added with 0.10 g/kg BAI for 30 days. The analysis of ion content in serum showed that Cd exposure disturbed ion homeostasis, and BAI could reduce serum Cd concentration. The histopathological results of gills showed that Cd exposure caused gill tissue lesions and structural damage, and BAI feeding effectively alleviated this damage. In addition, BAI could enhance antioxidant activity and activate Nrf2/HO-1 axis, thereby reducing oxidative stress and endoplasmic reticulum (ER) stress. Moreover, BAI lightened cytokine imbalance, inflammatory response, and necroptosis. Overall, the results indicated that BAI feeding could maintain gill homeostasis against Cd poisoning via the ROS/ER stress signaling. This trial revealed the properties of BAI resistance to metal Cd in aquaculture and partially elucidated its mechanism.

Sodium chloride alleviates oxidative stress and physiological responses induced by extreme winter cold in genetically improved farmed tilapia (GIFT; Oreochromis niloticus)

A 6-week trial was designed to investigate the effects of dietary sodium chloride supplementation on physiological, metabolic, and molecular stress response parameters. The findings showed that (1) there were no significant differences between sodium chloride supplementation groups (0.05S, 0.1S, and 0.15S) and the control group (P > 0.05), except for the 0.2S diet, which showed better final body weight, weight gain rate, specific growth rate, and feed conversion ratio than the control group (P < 0.05). (2) The hypothermic stress experiment results showed that the survival rates in the 0.1S and 0.15S diets were significantly higher than the control group (P < 0.05). (3) Transcription results showed that these enriched pathways in the gill were mainly energy metabolism and apoptosis pathways, while the major enrichment pathways in the liver were mainly amino acid metabolism and carbohydrate metabolism. (4) The plasma parameter results showed, compared to the control group, the 0.15S diet significantly increased the plasma GLU, TG contents, and Na+ and K+ concentrations and decreased the plasma ALT activity (P < 0.05). In addition, the 0.1S diet increased the plasma ALB content and Cl- concentration (P < 0.05). The gill Na+/K+-ATPase activity decreased markedly when the fish were fed the 0.1S and 0.15S diets (P < 0.05). The antioxidant enzyme activity results showed that the 0.1S and 0.15S diets significantly increased the T-SOD activities (P < 0.05). Gene expression results showed that compared to the control group, the 0.1S and 0.15S diets up-regulated the expression of gys, hsp70, mlcp, mlc, myosin, tnt mRNA, and down-regulated the akt, gk, and erk mRNA expression. Based on the regression analysis, the optimum dietary sodium chloride levels range from 0.10 % to 0.13 % of the diet, which could facilitate energy regulation, improve the immune response, and ultimately strengthen the cold resistance of GIFT.

XBP1 Modulates the Aging Cardiorenal System by Regulating Oxidative Stress

X-box binding protein 1 (XBP1) is a unique basic-region leucine zipper (bZIP) transcription factor. Over recent years, the powerful biological functions of XBP1 in oxidative stress have been gradually revealed. When the redox balance remains undisturbed, oxidative stress plays a role in physiological adaptations and signal transduction. However, during the aging process, increased cellular senescence and reduced levels of endogenous antioxidants cause an oxidative imbalance in the cardiorenal system. Recent studies from our laboratory and others have indicated that these age-related cardiorenal diseases caused by oxidative stress are guided and controlled by a versatile network composed of diversified XBP1 pathways. In this review, we describe the mechanisms that link XBP1 and oxidative stress in a range of cardiorenal disorders, including mitochondrial instability, inflammation, and alterations in neurohumoral drive. Furthermore, we propose that differing degrees of XBP1 activation may cause beneficial or harmful effects in the cardiorenal system. Gaining a comprehensive understanding of how XBP1 exerts influence on the aging cardiorenal system by regulating oxidative stress will enhance our ability to provide new directions and strategies for cardiovascular and renal safety outcomes.

Phenylalanine Plays Important Roles in Regulating the Capacity of Intestinal Immunity, Antioxidants and Apoptosis in Largemouth Bass (Micropterus salmoides)

This experiment was planned to explore the role of dietary phenylalanine levels in intestinal immunity, antioxidant activity and apoptosis in largemouth bass (Micropterus salmoides). Six iso-nitrogen and iso-energy diets with phenylalanine levels of 1.45% (DPHE1), 1.69% (DPHE2), 1.98% (DPHE3), 2.21% (DPHE4), 2.48% (DPHE5) and 2.76% (DPHE6) were designed. Juvenile largemouth bass were fed the experimental diet for 8 weeks. In this study, the DPHE5 group increased the expression of intestinal antioxidant genes in largemouth bass (p < 0.05), and the increase of antioxidant enzyme activities and content of related substances was most concentrated in the DPHE3 and DPHE4 groups (p < 0.05). The results of plasma biochemistry were similar to that of enzyme activity. The expression of genes related to the TOR signalling pathway mainly increased significantly in the DPHE5 group (p < 0.05). Similarly, the expression of inflammatory factors, as well as apoptotic factors, also showed significant increases in the DPHE5 group (p < 0.05). In conclusion, unbalanced phenylalanine in the diet could lead to a decrease in intestinal immune and antioxidant capacity and also cause a decline in the aggravation of intestinal cell apoptosis.

The Role of Algae Extract (Ulva lactuca and Solieria chordalis) in Fishmeal Substitution in Gibel Carp (Carrassius auratus gibeilo)

The function of algae extract (AE) in fishmeal (FM) substitution with plant proteins in the diets of Gibel carp (Carrassius auratus gibeilo) was investigated during a 56-day trial. Diets 1 and 2 contained 10% FM, Diets 3 and 4 contained 5% FM, and Diet 5 and 6 contained 0% FM. In contrast, Diets 2, 4, and 6 were supplemented with 0.2% AE. The results showed that FM reduction inhibited growth performance, while AE supplementation alleviated growth inhibition. FM reduction significantly decreased the crude protein levels of the whole body, while the contents of whole-body lipids were significantly decreased with AE supplementation. There were no significant changes in ALB, ALP, ALT, AST, TP, GLU, GLU, and TC in plasma. FM reduction with AE supplementation mitigated the decrease in antioxidant capacity by heightening the activity of antioxidant enzymes and related gene expressions, which mitigated the decrease in immune capacity by affecting the expression of inflammatory factors. In summary, AE supplementation could alleviate the negative effects of FM reduction in Gibel carp.