摘要:
ScopeFerroptosis has been demonstrated to play an important role in various tissue injuries and diseases. Flaxseed oil (FO) has been proven to have benefits for intestinal health. This study aims to explore whether FO relieved lipopolysaccharide (LPS)-induced intestinal injury through modulating ferroptosis signaling pathway.Methods and resultsA total of 120 weaned piglets are fed diets with 3% soybean oil (SO) or 3% FO for 4 weeks. At the end of the trial, 24 piglets selected from two dietary treatment groups are used in a 2 x 2 factorial design with oil treatment (3% SO versus 3% FO) and LPS challenge (saline versus LPS). At 4 h postinjection with LPS, 24 piglets are slaughtered and intestinal samples are collected. FO improves growth performance of pigs. After LPS treatment, FO mitigates intestinal morphological damage and functional damage. Notably, FO reverses the typical ultra-morphology and biochemical indexes of ferroptosis involving glutathione, malondialdehyde, and 4-hydroxynonenal contents. Mechanistically, FO ameliorates the changes on mRNA or protein abundance of key ferroptosis signals including transferrin receptor protein 1 (TFR1), recombinant iron responsive element binding protein 2 (IREB2), FTL, HSPB1, ferritin heavy chain 1 (FTH1), ferroportin 1 (FPN1), SLC7A11, solute carrier family 3 member 2 (SLC3A2), glutathione peroxidase 4 (GPX4), and arachidonate-15-lipoxygenase (ALOX15).ConclusionsFO improves growth performance and mitigates intestinal structural and functional damage, which is involved in regulating ferroptosis signaling pathway. Structural and functional damage occurred in the intestines of piglets after injection of LPS. Mechanistically, LPS induced ferroptosis in intestinal epithelial cells and activated this signaling pathway. However, Flaxseed oil (FO) improved growth performance of pigs. After LPS treatment, FO mitigated intestinal morphological and functional damage. FO ameliorated the changes on mRNA or protein abundance of key ferroptosis signals including TFR1, IREB2, FTL, HSPB1, FTH1, ferroportin 1, SLC7A11, SLC3A2, GPX4, and ALOX15. image
摘要:
Deoxynivalenol (DON) is a secondary metabolite produced by fungi, which causes serious health issues worldwide due to its widespread presence in human and animal diets. Necroptosis is a newly proposed cell death mode and has been proposed as a potential mechanism of intestinal disease. This study aimed to investigate the role of necroptosis in intestinal damage caused by DON exposure. Piglets were fed diets with or without 4mg/kg DON for 3 weeks or given a gavage of 2mg/kg BW DON or sterile saline to investigate the effects of chronic or acute DON exposure on the gut, respectively. IPEC-1 cells were challenged with different concentrations of DON to investigate the effect of DON exposure on the intestinal epithelial cells (IECs) in vitro. Subsequently, the inhibitors of necroptosis were used to treat cells or piglets prior to DON challenge. Chronic and acute DON exposure both caused morphological damage, reduction of disaccharidase activity, decrease of tight junction protein expression, inflammation of the small intestine, and necroptosis of intestinal epithelial cells in piglets. Necroptosis was also detected when IPEC-1 cell damage was induced by DON in vitro. The suppression of necroptosis in IPEC-1 cells by inhibitors (necrostatin-1 (Nec-1), GSK'872, or GW806742X) alleviated cell death, the decrease of tight junction protein expression, oxidative stress, and the inflammatory response induced by DON. Furthermore, pre-treatment with Nec-1 in piglets was also observed to protect the intestine against DON-induced enterotoxicity. Additionally, the expression of histone methyltransferase SETDB1 was abnormally downregulated upon chronic and acute DON exposure in piglets, and necroptosis was activated in IPEC-1 cells due to knockout of SETDB1. Collectively, these results demonstrate that necroptosis of IECs is a mechanism of DON-induced enterotoxicity and SETDB1 mediates necroptosis upon DON exposure in IECs, suggesting the potential for targeted inhibition of necroptosis to alleviate mycotoxin-induced enterotoxicity and intestinal disease.
通讯机构:
[Yulan Liu] H;Hubei Key Laboratory of Animal Nutrition and Feed Science, Hubei Collaborative Innovation Center for Animal Nutrition and Feed Safety, Wuhan Polytechnic University, Wuhan 430023, China<&wdkj&>Author to whom correspondence should be addressed.
摘要:
Stressors cause activation of the hypothalamic-pituitary-adrenal (HPA) axis and a systemic inflammatory response. As a newly proposed cell death manner in recent years, necroptosis occurs in a variety of tissue damage and inflammation. However, the role of necroptosis in HPA axis activation remains to be elucidated. The aim of this study was to investigate the occurrence of necroptosis and its role in HPA activation in a porcine stress model induced by Escherichia coli lipopolysaccharide (LPS). Several typical stress behaviors like fever, anorexia, shivering and vomiting were observed in piglets after LPS injection. HPA axis was activated as shown by increased plasma cortisol concentration and mRNA expression of pituitary corticotropin-releasing hormone receptor 1 (CRHR1) and adrenal steroidogenic acute regulatory protein (StAR). The mRNA expression of tumor necrosis factor alpha (TNF-alpha), interleukin-1 beta (IL-1 beta) and IL-6 in the hypothalamus, pituitary gland and adrenal gland was elevated by LPS, accompanied by the activation of necroptosis indicated by higher mRNA expression of necroptosis signals including receptor-interacting protein kinase (RIP) 1, RIP3, and phosphorylated mixed-lineage kinase domain-like protein (MLKL). Furthermore, necrostatin-1 (Nec-1), an inhibitor of necroptosis, inhibited necroptosis indicated by decreased mRNA levels of RIP1, RIP3, MLKL, and phosphoglycerate mutase family member 5 (PGAM5) in the hypothalamus, pituitary gland and adrenal gland. Nec-1 also decreased the mRNA expression of TNF-alpha and IL-beta and inhibited the activation of the HPA axis indicated by lower plasma cortisol concentration and mRNA expression of adrenal type 2 melanocortin receptor (MC2R) and StAR. These findings suggest that necroptosis is present and contributes to HPA axis activation induced by LPS. These findings provide a potential possibility for necroptosis as an intervention target for alleviating HPA axis activation and stress responses.
通讯机构:
[Yulan Liu; Yulan Liu Yulan Liu Yulan Liu] H;Hubei Key Laboratory of Animal Nutrition and Feed Science, Wuhan Polytechnic University, Wuhan, 430023 P. R. China
摘要:
DSS‐induced colitis is associated with intestinal stem cell (ISC) damage and perturbations of mitochondrial fission and fusion. Aspartate enhances ISC proliferation and differentiation to maintain the integrity of colonic epithelium against DSS through the regulation of mitochondrial fusion. Therefore, dietary aspartate supplementation may be a good nutritional strategy in the prevention of inflammatory bowel diseases. Scope Proliferation and differentiation of intestinal stem cells (ISCs) are crucial for functional restoration after injury, which can be regulated by nutritional molecules. Aspartate is implicated in maintaining intestinal barrier after injury, but underlying mechanisms remain elusive. Here, this study seeks to investigate if aspartate alleviates colonic epithelial damage by regulating ISC function, and to elucidate its mechanisms. Methods and results Eight‐week‐old male C57BL/6 mice supplement with or without 1% L‐aspartate are subjected to drinking water or 2.5% DSS to induce colitis. In this study, aspartate administration alleviates the severity of colitis, as indicated by reduced body weight loss, colon shortening, and inhibited pro‐inflammatory cytokine expression in DSS‐challenged mice. Additionally, aspartate promotes colonic epithelial cell proliferation and differentiation after DSS‐induced damage in mice. Pretreatment with aspartate not only enhances ISC proliferation but also induces ISC differentiation toward enterocytes and goblet cells, which prevent TNF‐α‐induced colonoid damage. Mechanistically, aspartate ameliorates DSS/TNF‐α‐induced perturbation of mitochondrial metabolism and maintains mitochondrial dynamics in colonic epithelium and colonoids. Moreover, aspartate‐mediated ISC proliferation and differentiation are primarily dependent on mitochondrial fusion rather than fission. Conclusions The findings indicate that aspartate promotes ISC proliferation and differentiation to alleviate colonic epithelial damage by regulation of mitochondrial metabolism and dynamics.
摘要:
<jats:p><jats:bold>Background:</jats:bold> Holly (<jats:italic>Ilex latifolia</jats:italic> Thunb.) polyphenols extracts (HPE) contain high amounts of polyphenols, including phenolic acids, triterpenoids, tannic acids, and so on, which have strong antioxidant function. This experiment was aimed to explore the protective effect and mechanism of HPE against hepatic injury induced by diquat.</jats:p><jats:p><jats:bold>Methods:</jats:bold> Thirty-two weaned piglets were allotted by a 2 × 2 factorial experiment design with diet type (basal diet vs. HPE diet) and diquat challenge (saline vs. diquat). On the 21st day, piglets were injected with diquat or saline. One week later, blood samples were collected. Then all piglets were slaughtered and hepatic samples were collected.</jats:p><jats:p><jats:bold>Results:</jats:bold> Dietary HPE supplementation improves hepatic morphology, the activities of plasma aspartate aminotransferase, alanine aminotransferase, and glutamyl transpeptidase, and enhances hepatic anti-oxidative capacity, while it regulates the expression of ferroptosis mediators (transferrin receptor protein 1, heat shock protein beta 1, solute carrier family 7 member 11, and glutathione peroxidase 4) in diquat-challenged piglets.</jats:p><jats:p><jats:bold>Conclusion:</jats:bold> These results indicate that dietary HPE supplementation enhances hepatic morphology and function, which is involved in modulating antioxidant capacity and ferroptosis.</jats:p>
关键词:
Long non-coding RNA;lipopolysaccharide;intestinal inflammation;cam signalling pathway;mTOR signalling pathway
摘要:
LPS can induce an inflammatory immune response in the intestine, and long non-coding RNA (lncRNA) is involved in the process of inflammatory disease. However, the biological role of lncRNA in the intestinal inflammation of piglets remains unclear. In this study, the lncRNA expression profile of the ileal mucosa of piglets challenged by LPS was analysed using lncRNA sequencing. In total, 112 novel lncRNAs were predicted, of which 58 were up-regulated and 54 down-regulated following LPS challenge. Expression of 15 selected lncRNAs was validated by quantitative PCR. We further investigated the target genes of lncRNA that were enriched in the signalling pathways involved in the inflammatory immune response by utilising Gene Ontology and Kyoto Encyclopaedia of Genes and Genomes analysis, with cell adhesion molecules and mTOR signalling pathway identified. In addition, the co-expression networks between the differentially expressed lncRNAs and the target mRNAs were constructed, with seven core lncRNAs identified, which also demonstrated that the relationship between lncRNAs and the target genes was highly correlated. Our study offers important information about the lncRNAs of the mucosal immune system in piglets and provides new insights into the inflammatory mechanism of LPS challenge, which might serve as a novel target to control intestinal inflammation.
摘要:
Scope Flaxseed oil is a rich source of α‐linolenic acid (ALA), which is the precursor of the long‐chain n‐3 polyunsaturated fatty acids (PUFAs), including docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). This study investigates the protective effect of flaxseed oil against intestinal injury induced by lipopolysaccharide (LPS). Materials and results Twenty‐four weaned pigs were used in a 2 × 2 factorial experiment with dietary treatment (5% corn oil vs 5% flaxseed oil) and LPS challenge (saline vs LPS). On day 21 of the experiment, pigs were administrated with LPS or saline. At 2 h and 4 h post‐administration, blood samples were collected. After the blood harvest at 4 h, all piglets were slaughtered and intestinal samples were collected. Flaxseed oil supplementation led to the enrichment of ALA, EPA, and total n‐3 PUFAs in intestine. Flaxseed oil improved intestinal morphology, jejunal lactase activity, and claudin‐1 protein expression. Flaxseed oil downregulated the mRNA expression of intestinal necroptotic signals. Flaxseed oil also downregulated the mRNA expression of intestinal toll‐like receptors 4 (TLR4) and its downstream signals myeloid differentiation factor 88 (MyD88), nuclear factor kappa B (NF−κB), and nucleotide‐binding oligomerization domain proteins 1, 2 (NOD1, NOD2) and its adapter molecule, receptor‐interacting protein kinase 2 (RIPK2). Conclusion These results suggest that dietary addition of flaxseed oil enhances intestinal integrity and barrier function, which is involved in modulating necroptosis and TLR4/NOD signaling pathways. The protective effect of flaxseed oil against intestinal injury induced by lipopolysaccharide (LPS) is investigated. The results indicate that flaxseed oil supplementation improves intestinal integrity and barrier function, which is involved in modulating the necroptosis and TLR4/NOD signaling pathway.