MiR-339 attenuates LPS-induced intestinal epithelial cells inflammatory responses and apoptosis by targeting TLR4

Ethanol modulates astrocyte activation and neuroinflammation via miR-339/NLRP6 inflammasome signaling

Alcohol is the most abused substance among adolescents and has a profound impact on health, society, and the economy. Alcohol intoxication is linked to neuroinflammation and neuronal damage, which result in behavioral alterations such as motor dysfunction, neuronal injury, cognitive deficits, and inflammation. Alcohol-induced neuroinflammation is associated with the activation of central nervous system cells, including astrocytes, and the release of proinflammatory cytokines. In this study, we investigated the role of the NLRP6 inflammasome signaling pathway in inducing cellular activation and neuroinflammation in human primary astrocytes exposed to ethanol. Our results demonstrated that ethanol upregulates the expression of NLRP6 inflammasome signaling mediators, including NLRP6, caspase 1, and proinflammatory cytokines IL-1β and IL-18, in human primary astrocytes. Gene silencing studies using NLRP6 siRNA further validate ethanol-mediated activation of NLRP6, cleavage of caspase 1, IL-1β, and IL-18 in human primary astrocytes. miR array analysis of ethanol-exposed human primary astrocytes reveals decreased levels of miR-339, accompanied by an upregulation of NLRP6 inflammasome signaling and astrocyte activation. Through bioinformatics analyses, Argonaute immunoprecipitation assays, and miR-339 overexpression experiments, we identify NLRP6 as a novel 3'-UTR target of miR-339. Overall, our findings confirmed the involvement of miR-339 in NLRP6 inflammasome signaling and its association with cellular activation and neuroinflammation in human primary astrocytes exposed to ethanol and provide novel insights highlighting a previously unrecognized mechanism in alcohol-induced neuroinflammation.

Protective Effects of Tea Tree Oil on Inflammatory Injury of Porcine Intestinal Epithelial Cells Induced by Lipopolysaccharide In Vitro

Tea tree oil (TTO) improves the intestinal mucosal immunity of weaning piglets, but its underlying mechanism is not clear. We hypothesized that TTO may alleviate inflammatory injury by regulating the function of intestinal epithelial cells. Ileum epithelial cells (IPI-2I) were chosen and an inflammatory injury cell model was generated. The cell viability, cytokine secretion, and gene expression of TLR4 and NF-κB were measured to further evaluate the effects of TTO on the inflammatory injury in immune-stressed cells. The results showed that lipopolysaccharide (LPS; content: ≥30 μg/mL; time: 3 h, 6 h, or 9 h) decreased cell viability (p < 0.01), and 50 μg/mL LPS stimulated for 6 h resulted in an increased secretion of proinflammatory cytokines and a dramatically decreased secretion of anti-inflammatory cytokines (p < 0.05) in IPI-2I cells. Concentrations of 0-0.05% of TTO improved cell viability, while the 0.03% TTO treatment resulted in the highest cell viability and alleviated LPS-induced cell death (p < 0.01). In addition, 0.03% TTO alleviated the LPS-induced increase in the gene expression of IL-1β, TNFα, and IFNγ, as well as the decrease in the expression of IL-10 in IPI-2I cells (p < 0.05). LPS also upregulated the gene expression of TLR4 and NF-κB (p < 0.05); while TTO supplementation alleviated this effect (p < 0.05), 0.03% and 0.05% TTO supplementation had greater effects (p < 0.05). In conclusion, 50 μg/mL LPS stimulated for 6 h can be used to establish an immune-stressed cell model in IPI-2I cell lines, and 0.03% TTO treatment for 6 h alleviated inflammatory injury in the intestinal epithelial cells of pigs.

Effect of METTL3 Gene on Lipopolysaccharide Induced Damage to Primary Small Intestinal Epithelial Cells in Sheep

Newborn lambs are susceptible to pathogenic bacterial infections leading to enteritis, which affects their growth and development and causes losses in sheep production. It has been reported that N6-methyladenosine (m6A) is closely related to innate immunity, but the effect of m6A on sheep small intestinal epithelial cells (IECs) and the mechanism involved have not been elucidated. Here, we investigated the effects of m6A on lipopolysaccharide (LPS)-induced inflammatory responses, apoptosis and oxidative stress in primary sheep IECs. First, the extracted IECs were identified by immunofluorescence using the epithelial cell signature protein cytokeratin 18 (CK18), and the cellular activity of IECs induced by different concentrations of LPS was determined by the CCK8 assay. Meanwhile, LPS could induce the upregulation of mRNA and protein levels of IECs cytokines IL1β, IL6 and TNFα and the apoptosis marker genes caspase-3, caspase-9, Bax, and apoptosis rate, reactive oxygen species (ROS) levels and mRNA levels of CAT, Mn-SOD and CuZn-SOD, and METTL3 were found to be upregulated during induction. It was hypothesized that METTL3 may have a potential effect on the induction of IECs by LPS. Overexpression and knockdown of METTL3 in IECs revealed that a low-level expression of METTL3 could reduce the inflammatory response, apoptosis and ROS levels in LPS-induced IECs to some extent. The results suggest that METTL3 may be a genetic marker for potential resistance to cellular damage.

Expression profiles of miRNAs in the lung tissue of piglets infected with Glaesserella parasuis and the roles of ssc-miR-135 and ssc-miR-155-3p in the regulation of inflammation

MicroRNAs (miRNAs) have been shown to play an important regulatory role in the process of pathogenic infection. However, the miRNAs that regulate the pathogenic process of G. parasuis and their functions are still unknown. Here, high-throughput sequencing was used to quantify the expression of miRNA in piglet lung tissue after G. parasuis XX0306 strain infection. A total of 25 differentially expressed microRNAs (DEmiRNAs) were identified. GO and KEGG pathway enrichment analysis showed that many of the functions of genes that may be regulated by DEmiRNA are related to inflammatory response and immune regulation. Further studies found that ssc-miR-135 may promote the expression of inflammatory factors through NF-κB signaling pathway. Whereas, ssc-miR-155-3p inhibited the inflammatory response induced by G. parasuis, and its regulatory mechanism remains to be further investigated. This study provides a valuable reference for revealing the regulatory effects of miRNAs on the pathogenesis of G. parasuis. DATA AVAILABILITY: The datasets generated during the current study are not publicly available due to this study is currently in the ongoing research stage, and some of the data cannot be made public sooner yet, but are available from the corresponding author on reasonable request.

Repairing gut barrier by traditional Chinese medicine: roles of gut microbiota

Gut barrier is not only part of the digestive organ but also an important immunological organ for the hosts. The disruption of gut barrier can lead to various diseases such as obesity and colitis. In recent years, traditional Chinese medicine (TCM) has gained much attention for its rich clinical experiences enriched in thousands of years. After orally taken, TCM can interplay with gut microbiota. On one hand, TCM can modulate the composition and function of gut microbiota. On the other hand, gut microbiota can transform TCM compounds. The gut microbiota metabolites produced during the actions of these interplays exert noticeable pharmacological effects on the host especially gut barrier. Recently, a large number of studies have investigated the repairing and fortifying effects of TCM on gut barriers from the perspective of gut microbiota and its metabolites. However, no review has summarized the mechanism behand this beneficiary effects of TCM. In this review, we first briefly introduce the unique structure and specific function of gut barrier. Then, we summarize the interactions and relationship amidst gut microbiota, gut microbiota metabolites and TCM. Further, we summarize the regulative effects and mechanisms of TCM on gut barrier including physical barrier, chemical barrier, immunological barrier, and microbial barrier. At last, we discuss the effects of TCM on diseases that are associated gut barrier destruction such as ulcerative colitis and type 2 diabetes. Our review can provide insights into TCM, gut barrier and gut microbiota.

Isoquercitrin alleviates lipopolysaccharide-induced intestinal mucosal barrier damage in mice by regulating TLR4/MyD88/NF-κB signaling pathway and intestinal flora

Intestinal mucosal barrier damage is closely associated with the development of several intestinal inflammatory diseases. Isoquercitrin (IQ) is a natural flavonoid compound derived from plants, which exhibits high antioxidant and anti-inflammatory activity with minimal side effects in humans. Therefore, it shows great potential for preventing and treating intestinal mucosal barrier damage. This study aims to investigate the ameliorative effect and mechanism of IQ on lipopolysaccharide (LPS)-induced intestinal mucosal barrier damage in mice. The mice were treated with IQ for 7 days and then injected with LPS to induce intestinal mucosal barrier damage. The results revealed that IQ treatment alleviated LPS-induced intestinal mucosal barrier damage in mice, which can be evidenced by the improvements in intestinal morphology and the promotion of expression in intestinal tight junctions (ZO-1, Claudin-1, and Occludin), as well as MUC2 mucin. IQ also attenuated intestinal inflammatory responses by inhibiting the TLR4/MyD88/NF-κB signaling pathway and reducing the expression and plasma levels of IL-6, IL-1β, and TNF-α. Furthermore, IQ significantly increased the relative abundance of beneficial bacteria, including Dubosiella, Akkermansia muciniphila and Faecalibaculum rodentium, while suppressing the growth of harmful bacteria such as Mucispirillum schaedleri in the intestinal flora of mice. Consequently, IQ can alleviate the LPS-induced intestinal mucosal barrier damage in mice by inhibiting the TLR4/MyD88/NF-κB signaling pathway and modulating the intestinal flora.

The Immunomodulatory Role of Cell-Free Approaches in SARS-CoV-2-Induced Cytokine Storm-A Powerful Therapeutic Tool for COVID-19 Patients

Currently, there is still no effective and definitive cure for the coronavirus disease 2019 (COVID-19) caused by the infection of the novel highly contagious severe acute respiratory syndrome virus (SARS-CoV-2), whose sudden outbreak was recorded for the first time in China in late December 2019. Soon after, COVID-19 affected not only the vast majority of China's population but the whole world and caused a global health public crisis as a new pandemic. It is well known that viral infection can cause acute respiratory distress syndrome (ARDS) and, in severe cases, can even be lethal. Behind the inflammatory process lies the so-called cytokine storm (CS), which activates various inflammatory cytokines that damage numerous organ tissues. Since the first outbreak of SARS-CoV-2, various research groups have been intensively trying to investigate the best treatment options; however, only limited outcomes have been achieved. One of the most promising strategies represents using either stem cells, such as mesenchymal stem cells (MSCs)/induced pluripotent stem cells (iPSCs), or, more recently, using cell-free approaches involving conditioned media (CMs) and their content, such as extracellular vesicles (EVs) (e.g., exosomes or miRNAs) derived from stem cells. As key mediators of intracellular communication, exosomes carry a cocktail of different molecules with anti-inflammatory effects and immunomodulatory capacity. Our comprehensive review outlines the complex inflammatory process responsible for the CS, summarizes the present results of cell-free-based pre-clinical and clinical studies for COVID-19 treatment, and discusses their future perspectives for therapeutic applications.

Effect of inulin on small extracellular vesicles microRNAs in milk from dairy cows with subclinical mastitis

Milk contains microRNAs (miRNA) that are shielded by small extracellular vesicles (sEVs). Beyond variations among individuals, many factors including nutrition play a role in shaping miRNA expression profiles. This study is to explore milk-derived sEVs-miRNA variations induced by inulin supplementation in subclinical mastitis-suffering cows. Fourteen lactating cows diagnosed with subclinical mastitis were equally assigned to either an inulin or a control group. Apart from total mixed rations, cows in the inulin group were provided with 300 g/d inulin during the morning feeding, while the control group did not receive any supplement. Following 1 wk of adaptation and 5 wk of treatment, sEVs-miRNA were isolated from the milk of each cow. RNA is subjected to high-throughput sequencing and differentially expressed (DE) miRNA (P < 0.05 and ∣ log2FC∣> 1) were detected through bioinformatics analysis. Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were conducted to examine the target genes of DE miRNA. A sum of 350 miRNA was discovered, including 332 in the control group and 249 in the inulin group. Among these, 9 miRNA showed differential expression within the 2 groups, including 3 upregulated and 6 downregulated in the inulin group. The DE miRNA participates in regulating organismal systems, cellular processes, and signal transduction, which may affect inflammatory response and milk production. Overall, our study provides insight into the micromolecular-level mechanism of inulin in alleviating subclinical mastitis in dairy cows.

The Interplay of NEAT1 and miR-339-5p Influences on Mesangial Gene Expression and Function in Various Diabetic-Associated Injury Models

Mesangial cells (MCs), substantial cells for architecture and function of the glomerular tuft, take a key role in progression of diabetic kidney disease (DKD). Despite long standing researches and the need for novel therapies, the underlying regulatory mechanisms in MCs are elusive. This applies in particular to long non-coding RNAs (lncRNA) but also microRNAs (miRNAs). In this study, we investigated the expression of nuclear paraspeckle assembly transcript 1 (NEAT1), a highly conserved lncRNA, in several diabetes in-vitro models using human MCs. These cells were treated with high glucose, TGFβ, TNAα, thapsigargin, or tunicamycin. We analyzed the implication of NEAT1 silencing on mesangial cell migration, proliferation, and cell size as well as on mRNA and miRNA expression. Here, the miRNA hsa-miR-339-5p was not only identified as a potential interaction partner for NEAT1 but also for several coding genes. Furthermore, overexpression of hsa-miR-339-5p leads to a MC phenotype comparable to a NEAT1 knockdown. In-silico analyses also underline a relevant role of NEAT1 and hsa-miR-339-5p in mesangial physiology, especially in the context of DKD.

Role of omega-3 polyunsaturated fatty acids, citrus pectin, and milk-derived exosomes on intestinal barrier integrity and immunity in animals

The gastrointestinal tract of livestock and poultry is prone to challenge by feedborne antigens, pathogens, and other stress factors in the farm environment. Excessive physiological inflammation and oxidative stress that arises firstly disrupts the intestinal epithelial barrier followed by other components of the gastrointestinal tract. In the present review, the interrelationship between intestinal barrier inflammation and oxidative stress that contributes to the pathogenesis of inflammatory bowel disease was described. Further, the role of naturally existing immunomodulatory nutrients such as the omega-3 polyunsaturated fatty acids, citrus pectin, and milk-derived exosomes in preventing intestinal barrier inflammation was discussed. Based on the existing evidence, the possible molecular mechanism of these bioactive nutrients in the intestinal barrier was outlined for application in animal diets.

Functional miR-142a-3p Induces Apoptosis and Macrophage Polarization by Targeting tnfaip2 and glut3 in Grass Carp (Ctenopharyngodon idella)

In the process of microbial invasion, the inflammation reaction is induced to eliminate the pathogen. However, un-controlled or un-resolved inflammation can lead to tissue damage and death of the host. MicroRNAs (miRNAs) are the signaling regulators that prevent the uncontrolled progress of an inflammatory response. Our previous work strongly indicated that miR-142a-3p is related to the immune regulation in grass carp. In the present study, we found that the expression of miR-142a-3p was down-regulated after infection by Aeromonas hydrophila. tnfaip2 and glut3 were confirmed as be the target genes of miR-142a-3p, which were confirmed by expression correlation analysis, gene overexpression, and dual luciferase reporter assay. The miR-142a-3p can reduce cell viability and stimulate cell apoptosis by targeting tnfaip2 and glut3. In addition, miR-142a-3p also regulates macrophage polarization induced by A. hydrophila. Our results suggest that miR-142a-3p has multiple functions in host antibacterial immune response. Our research provides further understanding of the molecular mechanisms between miRNAs and their target genes, and provides a new insights for the development of pro-resolution strategies for the treatment of complex inflammatory diseases in fish.

Nontoxic-dose deoxynivalenol aggravates lipopolysaccharides-induced inflammation and tight junction disorder in IPEC-J2 cells through activation of NF-κB and LC3B

Lipopolysaccharide (LPS) is the key factor in various intestinal inflammation which could disrupt the epithelial barrier function. Deoxynivalenol (DON), a well-known mycotoxin, can induce intestinal injury. However, the combined enterotoxicity of LPS and DON has rarely been studied. In this study, IPEC-J2 cell monolayers were exposed to LPS and nontoxic-dose DON for 12 and 24 h to investigate the effects of DON on LPS-induced inflammatory response and tight junction variation, and specific inhibitor and CRISPR-Cas9 were used to explore the underlying mechanisms. Our results showed that nontoxic-dose DON aggravated LPS-induced cellular inflammatory response, reflecting on more significant changes of inflammatory cytokines mRNA expression, higher protein expression of NOD-like receptor protein 3 (NLRP3) and procaspase-1. Moreover, nontoxic-dose DON aggravated LPS-induced mRNA and protein expression decreased, and distribution confused of tight junction proteins. We found that DON further enhanced LPS-induced phosphorylation and nucleus translocation of p65, and expression of LC3B-Ⅱ. NF-κB inhibitor and CRISPR-Cas9-mediated knockout of LC3B attenuated the effects of combination which indicated nontoxic-dose DON aggravated LPS-induced intestinal inflammation and tight junction disorder through activating NF-κB signaling pathway and autophagy-related protein LC3B. It further warns that ingesting low doses of mycotoxins may exacerbate the effects of intestinal pathogens on the body.

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Nontoxic-dose DON aggravates LPS-induced cellular inflammatory response in IPEC-J2 cell monolayers.

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Nontoxic-dose DON aggravates LPS-induced decrease and distribution disorder of tight junction in IPEC-J2 cell monolayers.

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Nontoxic-dose DON aggravates LPS-induced inflammatory response and tight junction disorder by activating NF-κB and LC3B.