Sodium butyrate alleviates deoxynivalenol-induced porcine intestinal barrier disruption by promoting mitochondrial homeostasis via PCK2 signaling

Necroptosis contributes to the intestinal toxicity of deoxynivalenol and is mediated by methyltransferase SETDB1

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 4 mg/kg DON for 3 weeks or given a gavage of 2 mg/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.

Deoxynivalenol induces cell senescence in RAW264.7 macrophages via HIF-1α-mediated activation of the p53/p21 pathway

Deoxynivalenol (DON), a potent mycotoxin, exhibits strong immunotoxicity and poses a significant threat to human and animal health. Cell senescence has been implicated in the immunomodulatory effects of DON; however, the potential of DON to induce cell senescence remains inadequately explored. Emerging evidence suggests that hypoxia-inducible factor-1α (HIF-1α) serves as a crucial target of mycotoxins and is closely involved in cell senescence. To investigate this potential, we employed the RAW264.7 macrophage model and treated the cells with varying concentrations of DON (2-8 μM) for 24 h. Transcriptome analysis revealed that 2365 genes were significantly upregulation while 2405 genes were significantly decreased after exposure to DON. KEGG pathway enrichment analysis demonstrated substantial enrichment in pathways associated with cellular senescence and hypoxia. Remarkably, we observed a rapid and sustained increase in HIF-1α expression following DON treatment. DON induced cell senescence through the activation of the p53/p21WAF1/CIP1 (p21) and p16INK4A (p16) pathways, while also upregulating the expression of nuclear factor-κB, leading to the secretion of senescence-associated secretory phenotype (SASP) factors, including IL-6, IL-8, and CCL2. Crucially, HIF-1α positively regulated the expression of p53, p21, and p16, as well as the secretion of SASP factors. Additionally, DON induced cell cycle arrest at the S phase, enhanced the activity of the senescence biomarker senescence-associated β-galactosidase, and disrupted cell morphology, characterized by mitochondrial damage. Our study elucidates that DON induces cell senescence in RAW264.7 macrophages by modulating the HIF-1α/p53/p21 pathway. These findings provide valuable insights for the accurate prevention of DON-induced immunotoxicity and associated diseases.

Effects of hesperidin on mitochondrial function, mitochondria-associated endoplasmic reticulum membranes and IP3R-MCU calcium axis in the intestine of piglets exposed to deoxynivalenol

Deoxynivalenol (DON) pollution is prevalent in crops, and can induce oxidative stress and intestinal injury. Hesperidin is one of the major flavonoids in citrus fruits that has various biological activities such as antioxidant and anti-inflammatory activities. However, whether hesperidin could alleviate DON-induced intestinal injury and the mechanism remain unclear. Mitochondria-associated endoplasmic reticulum (ER) membranes (MAMs) have attracted attention for their crucial signaling points to regulate ER-mitochondria calcium transfer. This study aims to evaluate the effects of hesperidin on the intestinal barrier, mitochondrial function, MAMs, and inositol 1,4,5-triphosphate receptor (IP3R)-mitochondrial calcium uniporter (MCU) calcium axis in the intestine of piglets exposed to DON. Twenty-four piglets were randomly divided into four groups in a 2 × 2 factorial arrangement for a 21-d experiment: Control: basal diet; hesperidin group: basal diet + 300 mg kg-1 hesperidin; DON: basal diet + 1.5 mg kg-1 DON; DON + hesperidin group: basal diet + 1.5 mg kg-1 DON + 300 mg kg-1 hesperidin. The data showed that when compared with the DON group, hesperidin improved growth performance and the intestinal barrier, alleviated intestinal oxidative stress and ER stress, and decreased the serum alanine aminotransferase (ALT) level (P < 0.05). Hesperidin also alleviated mitochondrial dysfunction and ferroptosis in the intestine of piglets exposed to DON (P < 0.05). Importantly, hesperidin prevented excessive MAM formation by downregulating the protein levels of Mitofusin 2 (Mfn2) and glucose-regulated protein 75 (GRP75), decreasing the ratio of the mitochondria with MAMs/total mitochondria and the ratio of MAM length/mitochondrial perimeter and lengthening the mitochondria-ER distance in MAMs (P < 0.05). Furthermore, hesperidin regulated the IP3R-glucose-regulated protein 75 (GRP75)-voltage-dependent anion channel 1 (VDAC1)-MCU calcium axis by decreasing the protein levels of GRP75 and MCU and the calcium level of the mitochondria compared with the DON group (P < 0.05). An in vitro experiment was conducted to further explore whether IP3R-mediated ER-mitochondria calcium transfer was involved in the protective effects of hesperidin on the intestinal epithelium barrier and mitochondria. Data showed that hesperidin may exert protective effects on the intestinal epithelium barrier and mitochondria via inhibiting ER-mitochondrial calcium transfer mediated by IP3Rs. These data suggested that hesperidin could alleviate MAM-mediated mitochondrial calcium overload, thereby improving mitochondrial function and alleviating oxidative stress and intestinal injury in DON-challenged piglets.

Microbial metabolite sodium butyrate enhances the anti-tumor efficacy of 5-fluorouracil against colorectal cancer by modulating PINK1/Parkin signaling and intestinal flora

Colorectal cancer (CRC) is a prevalent global health issue, with 5-fluorouracil (5-FU) being a commonly used chemotherapeutic agent for its treatment. However, the efficacy of 5-FU is often hindered by drug tolerance. Sodium butyrate (NaB), a derivative of intestinal flora, has demonstrated anti-cancer properties both in vitro and in vivo through pro-apoptotic effects and has shown promise in improving outcomes when used in conjunction with traditional chemotherapy agents. This study seeks to evaluate the impact and potential mechanisms of NaB in combination with 5-FU on CRC. We employed a comprehensive set of assays, including CCK-8, EdU staining, Hoechst 33258 staining, flow cytometry, ROS assay, MMP assay, immunofluorescence, and mitophagy assay, to detect the effect of NaB on the biological function of CRC cells in vitro. Western blotting and immunohistochemistry were used to verify the above experimental results. The xenograft tumor model was established to evaluate the in vivo anti-CRC activity of NaB. Subsequently, 16S rRNA gene sequencing was used to analyze the intestinal flora. The findings of our study demonstrate that sodium butyrate (NaB) exerts inhibitory effects on tumor cell proliferation and promotes tumor cell apoptosis in vitro, while also impeding tumor progression in vivo through the enhancement of the mitophagy pathway. Furthermore, the combined treatment of NaB and 5-fluorouracil (5-FU) yielded superior therapeutic outcomes compared to monotherapy with either agent. Moreover, this combination therapy resulted in the specific enrichment of Bacteroides, LigiLactobacillus, butyric acid-producing bacteria, and acetic acid-producing bacteria in the intestinal microbiota. The improvement in the intestinal microbiota contributed to enhanced therapeutic outcomes and reduced the adverse effects of 5-FU. Taken together, these findings indicate that NaB, a histone acetylation inhibitor synthesized through intestinal flora fermentation, has the potential to significantly enhance the therapeutic efficacy of 5-FU in CRC treatment and improve the prognosis of CRC patients.

Gut microbiota and metabolites as predictors of biologics response in inflammatory bowel disease: A comprehensive systematic review

Nonresponse to biologic agents in patients with inflammatory bowel disease (IBD) poses a significant public health burden, and the prediction of response to biologics offers valuable insights for IBD management. Given the pivotal role of gut microbiota and their endogenous metabolites in IBD, we conducted a systematic review to investigate the potential of fecal microbiota and mucosal microbiota and endogenous metabolomic markers as predictors for biotherapy response in IBD patients. A total of 38 studies were included in the review. Following anti-TNF-α treatment, the bacterial community characteristics of IBD patients exhibited a tendency to resemble those observed in healthy controls, indicating an improved clinical response. The levels of endogenous metabolites butyrate and deoxycholic acid were significantly associated with clinical remission following anti-TNF-α therapy. IBD patients who responded well to vedolizumab treatment had higher levels of specific bacteria that produce butyrate, along with increased levels of metabolites such as butyrate, branched-chain amino acids and acetamide following vedolizumab treatment. Crohn's disease patients who responded positively to ustekinumab treatment showed higher levels of Faecalibacterium and lower levels of Escherichia/Shigella. In conclusion, fecal microbiota and mucosal microbiota as well as their endogenous metabolites could provide a predictive tool for assessing the response of IBD patients to various biological agents and serve as a valuable reference for precise drug selection in clinical IBD patients.

Electrospun Poly-l-Lactic Acid Membranes Promote M2 Macrophage Polarization by Regulating the PCK2/AMPK/mTOR Signaling Pathway

Electrospun membranes are widely used in tissue engineering. Regretfully, there is limited research on how its morphological characteristics precisely regulate macrophage activation and immune response. Therefore, electrospun poly-l-lactic acid (PLLA) membranes with different alignments (align and random) and diameters (nanoscale and microscale) are prepared to investigate the effects of different surface morphologies on M2 macrophage polarization. Additionally, transcriptome, proteome, and phosphoproteome sequencings are combined to examine the underlying regulatory mechanisms. The results show that the electrospun PLLA membranes with different surface morphologies have good biocompatibility and can regulate the phenotype and function of macrophages by changing the micromorphology of the matrix surface. Especially, macrophages cultured on the electrospun membranes of the A600 group exhibit higher M2 macrophage polarization than the other three groups. Furthermore, the findings demonstrate that electrospun PLLA membranes enhance AMP-activated protein kinase (AMPK)/ mammalian target of rapamycin (mTOR) signaling activation by upregulating the expression of integrin phosphoenolpyruvate carboxykinase 2 (PCK2), which is critical for M2 macrophage polarization. Taken together, electrospun PLLA membranes promote M2 macrophage polarization by regulating the PCK2/AMPK/mTOR signaling pathway. This research can provide further theoretical bases for scaffold design, immunoregulatory mechanisms, and clinical application based on electrospinning technology in the future.

Enhanced glutathione production protects against zearalenone-induced oxidative stress and ferroptosis in female reproductive system

Zearalenone (ZEN, a widespread fusarium mycotoxin) causes evoked oxidative stress in reproductive system, but little is known about whether this is involved in ferroptosis. Melatonin, a well-known antioxidant, has demonstrated unique anti-antioxidant properties in several studies. Here, this study was aimed to investigate whether ZEN-induced oxidative stress in female pig's reproductive system was involved in ferroptosis, and melatonin was then supplemented to protect against ZEN-induced abnormalities in vitro cell models [human granulosa cell (KGN) and mouse endometrial stromal cell (mEC)] and in vivo mouse model. According to the results from female pig's reproductive organs, ZEN-induced abnormalities in vulvar swelling, inflammatory invasion and pathological mitochondria, were closely linked with evoked oxidative stress. Using RNA-seq analysis, we further revealed that ZEN-induced reproductive toxicity was due to activated ferroptosis. Mechanistically, by using in vitro cell models (KGN and mEC) and in vivo mouse model, we observed that ZEN exposure resulted in oxidative stress and ferroptosis in a glutathione-dependent manner. Notably, these ZEN-induced abnormalities above were alleviated by melatonin supplementation through enhanced productions of glutathione peroxidase 4 and glutathione. Herein, the present results suggest that potential strategies to improve glutathione production protect against ZEN-induced reproductive toxicity, including oxidative stress and ferroptosis.

Complementary transcriptomic and proteomic analyses elucidate the toxicological molecular mechanisms of deoxynivalenol-induced contractile dysfunction in enteric smooth muscle cells

Deoxynivalenol (DON) is one of the frequent Fusarium mycotoxins and poses a serious threat to public health worldwide. DON-induced weight loss is tightly connected with its ability to decrease feed intake by influencing gastrointestinal tract (GIT) motility. Our previous reports indicated that DON interfered with intestinal motility by injuring the contractility of enteric smooth muscle cells (SMC). Here, we further explored the potential mechanisms by employing a complementary method of transcriptomics and proteomics using the porcine enteric smooth muscle cell line (PISMC) as an experimental model. The transcriptomic and proteomic data uncover that the expression of numerous extracellular matrix (ECM) proteins and multiple integrin subunits were downregulated in PISMC under DON exposure, suppressing the ECM-integrin receptor interaction and its mediated signaling. Furthermore, DON treatment could depress actin polymerization, as reflected by the upregulated expression of Rho GTPase-activating proteins and cofilin in PISMC. Meanwhile, the expression levels of downstream contractile apparatus genes were significantly inhibited after challenge with DON. Taken together, the current results suggest that DON inhibits enteric SMC contractility by regulating the ECM-integrin-actin polymerization signaling pathway. Our findings provide novel insights into the potential mechanisms behind the DON toxicological effects in the GIT of humans and animals.

Living, Heat-Killed Limosilactobacillus mucosae and Its Cell-Free Supernatant Differentially Regulate Colonic Serotonin Receptors and Immune Response in Experimental Colitis

Lactobacillus species have been shown to alleviate gut inflammation and oxidative stress. However, the effect of different lactobacilli components on gut inflammation has not been well studied. This study aims to identify the differences in the effect and mechanisms of different forms and components of Limosilactobacillus mucosae (LM) treatment in the alleviation of gut inflammation using a colitis mouse model that is induced by dextran sodium sulfate (DSS). Seventy-two C57BL/6 mice were divided into six groups: control, DSS, live LM+DSS (LM+DSS), heat-killed LM+DSS (HKLM+DSS), LM cell-free supernatant + DSS (LMCS+DSS), and MRS medium + DSS (MRS+DSS). The mice were treated with different forms and components of LM for two weeks before DSS treatment. After that, the mice were sacrificed for an assessment of their levels of inflammatory cytokines, serotonin (5-HT) receptors (HTRs), and tryptophan metabolites. The results showed that, compared to other treatments, LMCS was more effective (p < 0.05) in the alleviation of DSS-induced body weight loss and led to an increase in the disease activity index score. All three forms and components of LM increased (p < 0.05) the levels of indole-3-acetic acid but reduced (p < 0.05) the levels of 5-HT in the colon. HKLM or LMCS reduced (p < 0.05) the percentages of CD3+CD8+ cytotoxic T cells but increased (p < 0.05) the percentages of CD3+CD4+ T helper cells in the spleen. LM or HKLM increased (p < 0.05) abundances of CD4+Foxp3+ regulatory T cells in the spleen. The LM and LMCS treatments reduced (p < 0.05) the expression of the pro-inflammatory cytokines Il6 and Il17a. The mice in the HKLM+DSS group had higher (p < 0.05) mRNA levels of the anti-inflammatory cytokine Il10, the cell differentiation and proliferation markers Lgr5 and Ki67, the 5-HT degradation enzyme Maoa, and HTRs (Htr1a, Htr2a, and Htr2b) in the colon. All three forms and components of LM reduced the phosphorylation of STAT3. The above findings can help to optimize the functionality of probiotics and develop new dietary strategies that aid in the maintenance of a healthy gut.

Maintaining the Mitochondrial Quality Control System Was a Key Event of Tanshinone IIA against Deoxynivalenol-Induced Intestinal Toxicity

Deoxynivalenol (DON) is the one of the most common mycotoxins, widely detected in various original foods and processed foods. Tanshinone IIA (Tan IIA) is a fat-soluble diterpene quinone extracted from Salvia miltiorrhiza Bunge, which has multi-biological functions and pharmacological effects. However, whether Tan IIA has a protective effect against DON-induced intestinal toxicity is unknown. In this study, the results showed Tan IIA treatment could attenuate DON-induced IPEC-J2 cell death. DON increased oxidation product accumulation, decreased antioxidant ability and disrupted barrier function, while Tan IIA reversed DON-induced barrier function impairment and oxidative stress. Furthermore, Tan IIA dramatically improved mitochondrial function via mitochondrial quality control. Tan IIA could upregulate mitochondrial biogenesis and mitochondrial fusion as well as downregulate mitochondrial fission and mitochondrial unfolded protein response. In addition, Tan IIA significantly attenuated mitophagy caused by DON. Collectively, Tan IIA presented a potential protective effect against DON toxicity and the underlying mechanisms were involved in mitochondrial quality control-mediated mitophagy.

Selenomethionine protects the liver from dietary deoxynivalenol exposure via Nrf2/PPARγ-GPX4-ferroptosis pathway in mice

Deoxynivalenol (DON) is a significant Fusarium toxin that has gained global attention due to its high frequency of contamination in food and feed. It was reported to have hepatotoxicity, immunotoxicity, and reproduction toxicity in organs. On the other hand, Selenomethionine (SeMet) was proven to have anti-oxidation, tissue repairing, immunity improvement, and antifungal mycotoxin infection functions. However, the molecular mechanism by which SeMet alleviates DON damage is not yet clear. C57BL/6 mice were randomly divided into three groups, Se-A and Se-A+DON were fed with a diet containing 0.2 mg/kg Se whereas Se-S+DON were fed with a diet of 1.0 mg/kg Se. After feeding for four weeks, the mice were gavaged for 21 days with DON (2.0 mg/kg BW) or ultrapure water once per day. In the present study, we showed that SeMet significantly decreased the lipid peroxidation product malondialdehyde, and increased activities of antioxidant enzymes superoxide dismutase and total antioxidant capacity after DON exposure. In addition, our investigation revealed that SeMet regulated pathways related to lipid synthesis and metabolisms, and effectively mitigated DON-induced liver damage. Moreover, we have discovered that SeMet downregulation of N-acylethanolamine and HexCer accumulation induced hepatic lipotoxicity. Further study showed that SeMet supplementation increased protein levels of glutathione peroxidase 4 (GPX4), peroxisome proliferator-activated receptor γ (PPARγ), nuclear erythroid 2-related factor 2 (Nrf2), and upregulated target proteins, indicating suppression of oxidative stress in the liver. Meanwhile, we found that SeMet significantly reduced the DON-induced protein abundances of Bcl2, Beclin1, LC3B and proteins related to ferroptosis (Lpcat3, and Slc3a2), and downregulation of Slc7a11. In conclusion, SeMet protected the liver from damage by enhancing the Nrf2/PPARγ-GPX4-ferroptosis pathway, inhibiting lipid accumulation and hepatic lipotoxicity. The findings of this study indicated that SeMet has a positive impact on liver health by improving antioxidant capacity and relieving lipotoxicity in toxin pollution.

Effective protective agents against organ toxicity of deoxynivalenol and their detoxification mechanisms: A review

Deoxynivalenol (DON) is one of the most prevalent mycotoxins in feed, which causes organ toxicity in animals. Therefore, reducing DON-induced organ toxicity can now be accomplished effectively using protective agents. This review provides an overview of multiple studies on a wide range of protective agents and their molecular mechanisms against DON organ toxicity. Protective agents include plant extracts, yeast products, bacteria, peptides, enzymes, H2, oligosaccharides, amino acids, adsorbents, vitamins and selenium. Among these, biological detoxification of DON using microorganisms to reduce the toxicity of DON without affecting the growth performance of pigs may be the most promising detoxification strategy. This paper also evaluates future developments related to DON detoxification and discusses the detoxification role and application potential of protective agents. This paper provides new perspectives for future research and development of safe and effective feed additives.