Antiviral Effect of Selenomethionine on Porcine Deltacoronavirus in Pig Kidney Epithelial Cells

Selenomethionine attenuates Klebsiella pneumoniae-induced jejunal injury in rabbits by inhibiting the TLR4/NF-κB pathway

Klebsiella pneumoniae (KP) infection often causes diarrhoea and intestinal barrier damage in young rabbits. The objective of this study was to explore whether selenomethionine (SeMet) can attenuate the jejunal injury caused by KP in rabbits. Therefore, we investigated the protective effect of SeMet by performing haematoxylin-eosin (HE), alcian blue periodic acid Schiff (AB-PAS), proliferating nuclear antigen (PCNA), TUNEL and immunofluorescence staining. In addition, the concentrations of Interleukin-1β (IL-1β), Interleukin-6 (IL-6), Tumor necrosisfactor-α (TNF-α) and Interleukin-10 (IL-10) in the jejunal tissue were detected by enzyme-linked immunosorbent assay (ELISA). The results showed that after KP infection, the productivity of rabbits decreased, and the mucosal barrier of the jejunum was damaged. Moreover, KP induced jejunal inflammation, activated the TLR4/NF-κB signalling pathway, and promoted the expression of the IL-1β, IL-6, and TNF-α. In addition, KP increased the apoptotic response of intestinal cells and upregulated the expression of caspase-3 and caspase-9. SeMet pretreatment significantly decreased the degree of intestinal epithelial cell apoptosis. Therefore, we showed that SeMet can reduce inflammation and enhance intestinal barrier function to improve the production performance of rabbits infected with KP.

Advances research in porcine enteric coronavirus therapies and antiviral drugs

The porcine enteric coronaviruses (PECs) currently reported include porcine epidemic diarrhea virus (PEDV), porcine deltacoronavirus (PDCoV), transmissible gastroenteritis virus (TGEV), and swine acute diarrhea syndrome coronavirus (SADS-CoV). In the absence of effective treatment, they can cause similar clinical characteristics including weight loss, sleepiness, vomiting, anorexia and fatal diarrhea in neonatal piglets, resulting in significant economic losses to the global pig industry. Although many studies on drugs for treating and combating PECs have been issued. There are still no specific drug targeting PECs and used in clinical production. Therefore, it is necessary to sort out and summarize the research on the treatment and anti PECs drugs, and further development of low toxicity and high efficiency drugs is needed. Here, we review the latest progress of anti PECs drugs, focus on the mechanism of anti PECs reaction of drug components, and try to clarify new strategies for effective control and elimination of PECs. These comprehensive and profound insights will help to further investigate, prevent and control the transmission of PECs infection.

Selenium nanoparticles alleviates cadmium induced hepatotoxicity by inhibiting ferroptosis and oxidative stress in vivo and in vitro

Cadmium (Cd) is an important environmental toxicant that could cause serious damage to various organs including severe hepatotoxicity in intoxicated animals. Selenium has been reported to possess the protective effects against Cd toxicity, but the specific mechanism is still unclear. The purpose of this study was to explore the effects and mechanism of chitosan coated selenium nanoparticles (CS-SeNPs) against Cd-induced hepatotoxicity in animal and cellular models. ICR mice and rat hepatocyte BRL-3A cells were exposed to cadmium chloride (CdCl2) to evaluate the therapeutic efficiency of CS-SeNPs. Analysis of histopathological images, mitochondrial membrane potential (MMP) and ultramicrostructure, serum liver enzyme activities, ferroptosis-related indicators contents, and further molecular biology experiments were performed to investigate the underlying mechanisms. In vivo experiment results showed that CdCl2 caused significant pathological damage involving significant increase of liver index, contents of tissue MDA and serum ALT and AST, and significant decrease of serum GSH-Px activity. Moreover, CdCl2 exposure upregulated ACSL4 and HO-1 protein levels, downregulated GPX4, TfR1, ferritin protein levels in the liver. Notably, CS-SeNPs increased the expression level of GPX4 and ameliorated CdCl2-induced changes in above-mentioned indicators. In vitro experimental results showed that treatment with CS-SeNPs significantly elevated GSH-Px activity and GPX4 protein level, reversed CdCl2-induced expression of several ferroptosis-related proteins TfR1, FTH1 and HO-1, and repressed ROS production and increased MMP of the cells exposed to CdCl2. Our research indicated that CdCl2 induced hepatocyte injury by inducing ferroptosis, while CS-SeNPs can inhibit ferroptosis and reduce the degree of hepatocyte injury. This study is of great significance for further revealing the mechanism of Cd hepatotoxicity and expanding the clinical application of SeNPs.

Selenomethionine Inhibited HADV-Induced Apoptosis Mediated by ROS through the JAK-STAT3 Signaling Pathway

Adenovirus (HAdV) can cause severe respiratory infections in children and immunocompromised patients. There is a lack of specific therapeutic drugs for HAdV infection, and the study of anti-adenoviral drugs has far-reaching clinical implications. Elemental selenium can play a specific role as an antioxidant in the human immune cycle by non-specifically binding to the amino acid methionine in body proteins. Methods: The antiviral mechanism of selenomethionine was explored by measuring cell membrane status, intracellular DNA status, cytokine secretion, mitochondrial membrane potential, and ROS production. Conclusions: Selenomethionine improved the regulation of ROS-mediated apoptosis by modulating the expression of Jak1/2, STAT3, and BCL-XL, which led to the inhibition of apoptosis. It is anticipated that selenomethionine will offer a new anti-adenoviral therapeutic alternative.

A novel host restriction factor MRPS6 mediates the inhibition of PDCoV infection in HIEC-6 cells

Introduction

Porcine deltacoronavirus (PDCoV) is a zoonotic pathogen with a global distribution, capable of infecting both pigs and humans. To mitigate the risk of cross-species transmission and potential outbreaks, it is crucial to characterize novel antiviral genes, particularly those from human hosts.

Methods

This research used HIEC-6 to investigate PDCoV infection. HIEC-6 cells were infected with PDCoV. Samples were collected 48 h postinfection for proteomic analysis.

Results

We discovered differential expression of MRPS6 gene at 48 h postinfection with PDCoV in HIEC-6 cells. The gene expression initially increased but then decreased. To further explore the role of MRPS6 in PDCoV infection, we conducted experiments involving the overexpression and knockdown of this gene in HIEC-6 and Caco2 cells, respectively. Our findings revealed that overexpression of MRPS6 significantly inhibited PDCoV infection in HIEC-6 cells, while knockdown of MRPS6 in Caco2 cells led to a significant increase of virus titer. Furthermore, we investigated the correlation between PDCoV infection and the expression of MRPS6. Subsequent investigations demonstrated that MRPS6 exerted an augmentative effect on the production of IFN-β through interferon pathway activation, consequently impeding the progression of PDCoV infection in cellular systems. In conclusion, this study utilized proteomic analysis to investigate the differential protein expression in PDCoV-infected HIEC-6 cells, providing evidence for the first time that the MRPS6 gene plays a restrictive role in PDCoV virus infection.

Discussion

Our findings initially provide the validation of MRPS6 as an upstream component of IFN-β pathway, in the promotion of IRF3, IRF7, STAT1, STAT2 and IFN-β production of HIEC-6 via dual-activation from interferon pathway.

Detoxification of Selenium Yeast on Mycotoxins and Heavy Metals: a Review

Mycotoxins are secondary metabolites produced by specific fungi. More than 400 different mycotoxins are known in the world, and the concentration of these toxins in food and feed often exceeds the acceptable limit, thus causing serious harm to animals and human body. At the same time, modern industrial agriculture will also bring a lot of environmental pollution in the development process, including the increase of heavy metal content, and often the clinical symptoms of low/medium level chronic heavy metal poisoning are not obvious, thus delaying the best treatment opportunity. However, the traditional ways of detoxification cannot completely eliminate the adverse effects of these toxins on the body, and sometimes bring some side effects, so it is essential to find a new type of safe antidote. Trace element selenium is among the essential mineral nutrient elements of human and animal bodies, which can effectively remove excessive free radicals and reactive oxygen species in the body, and has the effects of antioxidant, resisting stress, and improving body immunity. Selenium is common in nature in inorganic selenium and organic selenium. In previous studies, it was found that the use of inorganic selenium (sodium selenite) can play a certain protective role against mycotoxins and heavy metal poisoning. However, while it plays the role of antioxidant, it will also have adverse effects on the body. Therefore, it was found in the latest study that selenium yeast could not only replace the protective effect of sodium selenite on mycotoxins and heavy metal poisoning, but also improve the immunity of the body. Selenium yeast is an organic selenium source with high activity and low toxicity, which is produced by selenium relying on the cell protein structure of growing yeast. It not only has high absorption rate, but also can be stored in the body after meeting the physiological needs of the body for selenium, so as to avoid selenium deficiency again in the short term. However, few of these studies can clearly reveal the protective mechanism of yeast selenium. In this paper, the detoxification mechanism of selenium yeast on mycotoxins and heavy metal poisoning was reviewed, which provided some theoretical support for further understanding of the biological function of selenium yeast and its replacement for inorganic selenium. The conclusions suggest that selenium yeast can effectively alleviate the oxidative damage by regulating different signaling pathways, improving the activity of antioxidant enzymes, reversing the content of inflammatory factors, regulating the protein expression of apoptosis-related genes, and reducing the accumulation of mycotoxins and heavy metals in the body.

Evaluation of Selenomethionine Entrapped in Nanoparticles for Oral Supplementation Using In Vitro, Ex Vivo and In Vivo Models

Selenium methionine (SeMet) is an essential micronutrient required for normal body function and is associated with additional health benefits. However, oral administration of SeMet can be challenging due to its purported narrow therapeutic index, low oral bioavailability, and high susceptibility to oxidation. To address these issues, SeMet was entrapped in zein-coated nanoparticles made from chitosan using an ionic gelation formulation. The high stability of both the SeMet and selenomethionine nanoparticles (SeMet-NPs) was established using cultured human intestinal and liver epithelial cells, rat liver homogenates, and rat intestinal homogenates and lumen washes. Minimal cytotoxicity to Caco-2 and HepG2 cells was observed for SeMet and SeMet-NPs. Antioxidant properties of SeMet were revealed using a Reactive Oxygen Species (ROS) assay, based on the observation of a concentration-dependent reduction in the build-up of peroxides, hydroxides and hydroxyl radicals in Caco-2 cells exposed to SeMet (6.25–100 μM). The basal apparent permeability coefficient (Papp) of SeMet across isolated rat jejunal mucosae mounted in Ussing chambers was low, but the Papp was increased when presented in NP. SeMet had minimal effects on the electrogenic ion secretion of rat jejunal and colonic mucosae in Ussing chambers. Intra-jejunal injections of SeMet-NPs to rats yielded increased plasma levels of SeMet after 3 h for the SeMet-NPs compared to free SeMet. Overall, there is potential to further develop SeMet-NPs for oral supplementation due to the increased intestinal permeability, versus free SeMet, and the low potential for toxicity.

A Review of Bioactive Compounds against Porcine Enteric Coronaviruses

Pig diarrhea is a universal problem in the process of pig breeding, which seriously affects the development of the pig industry. Porcine enteric coronaviruses (PECoVs) are common pathogens causing diarrhea in pigs, currently including transmissible gastroenteritis virus (TGEV), porcine epidemic diarrhea virus (PEDV), porcine deltacoronavirus (PDCoV) and swine acute diarrhea syndrome coronavirus (SADS-CoV). With the prosperity of world transportation and trade, the spread of viruses is becoming wider and faster, making it even more necessary to prevent PECoVs. In this paper, the host factors required for the efficient replication of these CoVs and the compounds that exhibit inhibitory effects on them were summarized to promote the development of drugs against PECoVs. This study will be also helpful in discovering general host factors that affect the replication of CoVs and provide references for the prevention and treatment of other CoVs.

Seleno-Metabolites and Their Precursors: A New Dawn for Several Illnesses?

Selenium (Se) is an essential element for human health as it is involved in different physiological functions. Moreover, a great number of Se compounds can be considered potential agents in the prevention and treatment of some diseases. It is widely recognized that Se activity is related to multiple factors, such as its chemical form, dose, and its metabolism. The understanding of its complex biochemistry is necessary as it has been demonstrated that the metabolites of the Se molecules used to be the ones that exert the biological activity. Therefore, the aim of this review is to summarize the recent information about its most remarkable metabolites of acknowledged biological effects: hydrogen selenide (HSe-/H2Se) and methylselenol (CH3SeH). In addition, special attention is paid to the main seleno-containing precursors of these derivatives and their role in different pathologies.

Exploration of PDCoV-induced apoptosis through mitochondrial dynamics imbalance and the antagonistic effect of SeNPs

Porcine Deltacoronavirus (PDCoV), an enveloped positive-strand RNA virus that causes respiratory and gastrointestinal diseases, is widely spread worldwide, but there is no effective drug or vaccine against it. This study investigated the optimal Selenium Nano-Particles (SeNPs) addition concentration (2 - 10 μg/mL) and the mechanism of PDCoV effect on ST (Swine Testis) cell apoptosis, the antagonistic effect of SeNPs on PDCoV. The results indicated that 4 μg/mL SeNPs significantly decreased PDCoV replication on ST cells. SeNPs relieved PDCoV-induced mitochondrial division and antagonized PDCoV-induced apoptosis via decreasing Cyt C release and Caspase 9 and Caspase 3 activation. The above results provided an idea and experimental basis associated with anti-PDCoV drug development and clinical use.

Protective and detoxifying effects conferred by selenium against mycotoxins and livestock viruses: A review

Animal feed can easily be infected with molds during production and storage processes, and this can lead to the production of secondary metabolites, such as mycotoxins, which eventually threaten human and animal health. Furthermore, livestock production is also not free from viral infections. Under these conditions, the essential trace element, selenium (Se), can confer various biological benefits to humans and animals, especially due to its anticancer, antiviral, and antioxidant properties, as well as its ability to regulate immune responses. This article reviews the latest literature on the antagonistic effects of Se on mycotoxin toxicity and viral infections in animals. We outlined the systemic toxicity of mycotoxins and the primary mechanisms of mycotoxin-induced toxicity in this analysis. In addition, we pay close attention to how mycotoxins and viral infections in livestock interact. The use of Se supplementation against mycotoxin-induced toxicity and cattle viral infection was the topic of our final discussion. The coronavirus disease 2019 (COVID-19) pandemic, which is currently causing a health catastrophe, has altered our perspective on health concerns to one that is more holistic and increasingly embraces the One Health Concept, which acknowledges the interdependence of humans, animals, and the environment. In light of this, we have made an effort to present a thorough and wide-ranging background on the protective functions of selenium in successfully reducing mycotoxin toxicity and livestock viral infection. It concluded that mycotoxins could be systemically harmful and pose a severe risk to human and animal health. On the contrary, animal mycotoxins and viral illnesses have a close connection. Last but not least, these findings show that the interaction between Se status and host response to mycotoxins and cattle virus infection is crucial.