Loss of SELENOW aggravates muscle loss with regulation of protein synthesis and the ubiquitin-proteasome system

Hepatoprotective effects of dandelion against AFB1-induced liver injury are associated with activation of bile acid-FXR signaling in chicks

This study aimed to investigate the protective effects of dandelion against AFB1-induced hepatotoxicity through the regulation of the FXR signaling pathway in chicks. A total of 144 one-day-old male broilers were randomly assigned to three groups and received a basal diet (BD), and BD supplemented with 0.5 mg/kg of AFB1 or 0.5 mg/kg AFB1 with 0.4 % dandelion for 3 weeks. The results showed that the AFB1 treatment caused liver injury and decreased the concentrations of albumin and alkaline phosphatase in serum and increased the total bile acid concentration in serum and liver. Dietary AFB1 supplementation also induced hepatocyte swelling, necrosis, neutrophils infiltration and lipid deposition in the liver. Notably, dietary dandelion supplementation alleviated these alterations induced by AFB1. Additionally, dietary dandelion supplementation alleviated AFB1-induced changes in ileum microbiota and decreased the abundance of Lactobacillus, L. vaginalis, and L. acidophilus compared to the AFB1 treatment. Furthermore, AFB1 downregulated Baat, Ntcp, Acc, FXR, SHP, and SREBP-1c expression, and upregulated Cyp8b1, Bacs, Fas, Pparα, Lxrα and CYP7A1 expression in liver. Meanwhile, AFB1 also downregulated Fgf19, Ostα, Ostβ and FXR expression and upregulated SHP expression in the ileum. Conclusively, dietary dandelion supplementation protected broilers from AFB1-induced hepatotoxicity, potentially due to the activation of bile acid-FXR signaling pathway.

Five glutathione S-transferase isozymes played crucial role in the detoxification of aflatoxin B1 in chicken liver

BACKGROUND

AFB1-8,9-exo-epoxide (AFBO) is the highly toxic product of Aflatoxin B1 (AFB1). Glutathione S-transferases (GSTs) play pivotal roles in detoxifying AFB1 by catalyzing the conjugation of AFBO with glutathione (GSH). Although there are over 20 GST isozymes that have been identified in chicken, GST isozymes involved in the detoxification process of AFB1 have not been identified yet. The objective of this study was to determine which GST isozymes played key role in detoxification of AFB1.

RESULTS

A total of 17 pcDNA3.1(+)-GST isozyme plasmids were constructed and the GST isozyme genes were overexpressed by 80-2,500,000 folds in the chicken Leghorn male hepatoma (LMH) cells. Compared to the AFB1 treatment, overexpression of GSTA2X, GSTA3, GSTT1L, GSTZ1-1, and GSTZ1-2 increased the cell viability by 6.5%-17.0% in LMH cells. Moreover, overexpression of five GST isozymes reduced the release of lactate dehydrogenase and reactive oxygen species by 8.8%-64.4%, and 57.2%-77.6%, respectively, as well as enhanced the production AFBO-GSH by 15.8%-19.6%, thus mitigating DNA damage induced by AFB1. After comprehensive evaluation of various indicators, GSTA2X displayed the best detoxification effects against AFB1. GSTA2X was expressed in Pichia pastoris X-33 and its enzymatic properties for catalyzing the conjugation of AFBO with GSH showed that the optimum temperature and pH were 20-25 °C and 7.6-8.6 as well as the enzymatic kinetic parameter Vmax was 0.23 nmol/min/mg and the Michaelis constant was 86.05 μmol/L with the AFB1 as substrate.

CONCLUSIONS

In conclusion, GSTA2X, GSTA3, GSTT1L, GSTZ1-1, and GSTZ1-2 played key roles in AFB1 detoxification, which will provide new remediation strategies to prevent aflatoxicosis in chickens.

T-2 toxin-induced splenic injury by disrupting the gut microbiota-spleen axis via promoting IL-6/JAK/STAT1 signaling-mediated inflammation and apoptosis and its mitigation by elemental nano-selenium

T-2 toxin is one of the most toxic A trichothecene mycotoxins prevalent in the environment and food chain, which brings severe health hazards to both animals and humans and it can significantly damage immune function. In this study, we comprehensively explained the impact of T-2 toxin on the spleen through gut microbiota-spleen axis by integrating the transcriptome and microbiome. Our results revealed that dietary T-2 toxin ≥ 1.0 mg/kg exposure significantly inhibited the growth performance and caused spleen injury in broilers chicks, accompanied by oxidative stress and histopathological damage. Cecal microbiome analysis suggested that T-2 toxin exposure caused gut microbial dysbiosis, especially leading to the decrease of some beneficial bacteria genera that enhanced gut barrier and reduced inflammation, including Blautia, Coprococcus, Lachnospira and Anaerostipes belonging to Lachnospiraceae family. Transcriptome analysis suggested that T-2 toxin exposure directly caused splenic inflammation and immune-related signaling, such as cytokine-cytokine receptor interaction, Toll-like receptor signaling pathway, NOD-like receptor signaling pathway and JAK-STAT signaling pathway. Furthermore, by integrating the transcriptome and microbiome analysis, we found that spleen damage induced by T-2 toxin was associated with the abnormal activation of IL-6/JAK/STAT1 signaling pathway-mediated inflammation and apoptosis, which was further verified by western bolt analysis. Notably, dietary selenium supplementation could protect chicks from T-2 toxin-induced adverse effects on growth performance and spleen injury by inhibiting the expression of the IL-6/JAK/STAT1 signaling-related genes. In summary, our findings provided new insights into the immunotoxicity mechanisms of T-2 toxin in the chickens' spleen and highlighted the potential of selenium to alleviate T-2 toxin-induced immunotoxicity.

A novel zearalenone lactonase can effectively mitigate zearalenone-induced reproductive toxicity in gilts

Zymdetox Z-2000 is a novel zearalenone (ZEN) lactonase produced by Bacillus subtilis that can biodegrade ZEN to hydrolyzed ZEN and decarboxylated hydrolyzed ZEN with much lower estrogenic activity. This study aims to evaluate the efficacy of Zymdetox Z-2000 in mitigating the adverse effects of ZEN on the growth performance and reproductive health of gilts. A total of 80 crossbred Landrace × Yorkshire gilts (9.82 ± 0.79 kg) were allocated into five groups and received a basal diet (BD; CON), BD supplemented with 0.4 mg/kg ZEN (ZEN), BD plus ZEN with 0.01% Zymdetox Z-2000 (ZEN-Zym), BD plus ZEN with 0.01% coated Zymdetox Z-2000 (ZEN-CoZym), and BD plus ZEN with 0.1% B. subtilis (ZEN-Bs), respectively, for 28 days. Compared to the CON group, ZEN treatment reduced the body weight gain of the gilts, increased vulva area and vaginal and uterus indices, and increased serum aspartate aminotransferase (AST) activity and estradiol (E2) concentration. ZEN treatment also induced ovaries histopathology changes, decreased the total antioxidant capacity (T-AOC) in uterus but increased T-AOC in ovaries, and increased ZEN concentration in stomach and duodenum than those of the CON group. Interestingly, dietary supplementation with the three products effectively alleviated these ZEN-induced adverse effects, as Zymdetox Z-2000 and coated Zymdetox Z-2000 showed better mitigating effects than B. subtilis. In conclusion, ZEN exposure impaired the growth and reproductive health of gilts, while dietary supplementation with Zymdetox Z-2000 and coated Zymdetox Z-2000 can effectively alleviate ZEN-induced reproductive toxicity in gilts.

Selenium and Selenoproteins: Mechanisms, Health Functions, and Emerging Applications

Selenium (Se) is an essential trace element crucial for human health that primarily functions as an immunonutrient. It is incorporated into polypeptides such as selenocysteine (SeC) and selenomethionine (SeMet), two key amino acids involved in various biochemical processes. All living organisms can convert inorganic Se into biologically active organic forms, with SeMet being the predominant form and a precursor for SeC production in humans and animals. The human genome encodes 25 selenoprotein genes, which incorporate low-molecular-weight Se compounds in the form of SeC. Organic Se, especially in the form of selenoproteins, is more efficiently absorbed than inorganic Se, driving the demand for selenoprotein-based health products, such as functional foods. Se-enriched functional foods offer a practical means of delivering bioavailable Se and are associated with enhanced antioxidant properties and various health benefits. Recent advancements in selenoprotein synthesis have improved our understanding of their roles in antioxidant defense, cancer prevention, immune regulation, anti-inflammation, hypoglycemia, cardiovascular health, Alzheimer's disease, fertility, and COVID-19. This review highlights key selenoproteins and their biological functions, biosynthetic pathways, and emerging applications while highlighting the need for further research.

The recent development, application, and future prospects of muscle atrophy animal models

Muscle atrophy, characterized by the loss of muscle mass and function, is a hallmark of sarcopenia and cachexia, frequently associated with aging, malignant tumors, chronic heart failure, and malnutrition. Moreover, it poses significant challenges to human health, leading to increased frailty, reduced quality of life, and heightened mortality risks. Despite extensive research on sarcopenia and cachexia, consensus in their assessment remains elusive, with inconsistent conclusions regarding their molecular mechanisms. Muscle atrophy models are crucial tools for advancing research in this field. Currently, animal models of muscle atrophy used for clinical and basic scientific studies are induced through various methods, including aging, genetic editing, nutritional modification, exercise, chronic wasting diseases, and drug administration. Muscle atrophy models also include in vitro and small organism models. Despite their value, each of these models has certain limitations. This review focuses on the limitations and diverse applications of muscle atrophy models to understand sarcopenia and cachexia, and encourage their rational use in future research, therefore deepening the understanding of underlying pathophysiological mechanisms, and ultimately advancing the exploration of therapeutic strategies for sarcopenia and cachexia.