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Fumonisin B1 (FB1), a water-soluble mycotoxin released by Fusarium moniliforme Sheld, is widely present in corn and its derivative products, and seriously endangers human life and health. Recent studies have reported that FB1 can lead to pyroptosis, however, the mechanisms by which FB1-induced pyroptosis remain indistinct. In the present study, we aim to investigate the mechanisms of pyroptosis in intestinal porcine epithelial cells (IPEC-J2) and the relationship between FB1-induced endoplasmic reticulum stress (ERS) and pyroptosis. Our experimental results showed that the pyroptosis protein indicators in IPEC-J2 were significantly increased after exposure to FB1. The ERS markers, including glucose-regulated Protein 78 (GRP78), PKR-like ER kinase protein (PERK), and preprotein translocation factor (Sec62) were also significantly increased. Using small interfering RNA silencing of PERK or Sec62, the results demonstrated that upregulation of Sec62 activates the PERK pathway, and activation of the PERK signaling pathway is upstream of FB1-induced pyroptosis. After using the ERS inhibitor 4-PBA reduced the FB1-triggered intestinal injury by the Sec62-PERK pathway. In conclusion, we found that FB1 induced pyroptosis by upregulating Sec62 to activate the PERK pathway, and mild ERS alleviates FB1-triggered damage. It all boils down to one fact, the study provides a new perspective for further, and improving the toxicological mechanism of FB1.
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Chaperona BiP do Retículo Endoplasmático , Estresse do Retículo Endoplasmático , Piroptose , Transdução de Sinais , eIF-2 Quinase , Piroptose/efeitos dos fármacos , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Animais , eIF-2 Quinase/metabolismo , eIF-2 Quinase/genética , Suínos , Transdução de Sinais/efeitos dos fármacos , Chaperona BiP do Retículo Endoplasmático/metabolismo , Linhagem Celular , Intestinos/efeitos dos fármacos , Intestinos/patologia , Células Epiteliais/metabolismo , Células Epiteliais/efeitos dos fármacos , Mucosa Intestinal/metabolismo , Mucosa Intestinal/efeitos dos fármacos , FumonisinasRESUMO
Deoxynivalenol (DON) as a mycotoxin was commonly found in food and cereals which can affect immune function and inflammatory response. The majority of foods contain DON at levels below the official limit. This study aimed to evaluate the effects of non-cytotoxic concentration of DON on inflammation and its mechanisms using the IL-10 gene-silenced RAW264.7 cell model. The results showed that a non-cytotoxic concentration of DON at 25 ng/ml aggravated IL-10 knockdown-induced inflammation, which was manifested by increasing IL-1ß and TNF-α mRNA expression, migration and phagocytosis, decreasing IL-10 mRNA expression, and enhancing JAK2/STAT3 phosphorylation. Adding JAK2 inhibitor AG490 attenuated the aggravating effect of DON on IL-10 knockdown-induced inflammation. In conclusion, a non-cytotoxic concentration of DON enhances the inflammatory response through the JAK2/STAT3 signaling pathway when inflammation occurs in the body. These results indicated that non-cytotoxic concentrations of DON could aggravate inflammation when inflammation was induced by IL-10 knockdown, which increases vigilance against DON contamination at low concentration especially when an animal's body has inflammation.
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Interleucina-10 , Transdução de Sinais , Camundongos , Animais , Interleucina-10/genética , Interleucina-10/metabolismo , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT3/metabolismo , Células RAW 264.7 , Inflamação/metabolismo , RNA Mensageiro/genéticaRESUMO
The Casparian strip (CS) is a ring-like lignin structure deposited between endodermal cells that forms an apoplastic barrier to control the selective uptake of nutrients in vascular plants. However, the molecular mechanism of CS formation in rice (Oryza sativa), which possesses one CS each in the endodermis and exodermis, is relatively unknown. Here, we functionally characterized CS INTEGRITY FACTOR1 (OsCIF1a, OsCIF1b), OsCIF2, and SCHENGEN3 (OsSGN3a, OsSGN3b) in rice. OsCIF1s and OsCIF2 were mainly expressed in the stele, while OsSGN3s localized around the CS at the endodermis. Knockout of all three OsCIFs or both OsSGN3s resulted in a discontinuous CS and a dramatic reduction in compensatory (less localized) lignification and suberization at the endodermis. By contrast, ectopic overexpression of OsCIF1 or OsCIF2 induced CS formation as well as overlignification and oversuberization at single or double cortical cell layers adjacent to the endodermis. Ectopic co-overexpression of OsCIF1 and SHORTROOT1 (OsSHR1) induced the formation of more CS-like structures at multiple cortical cell layers. Transcriptome analysis identified 112 downstream genes modulated by the OsCIF1/2-OsSGN3 signaling pathway, which is involved in CS formation and activation of the compensatory machinery in native endodermis and nonnative endodermis-like cell layers. Our results provide important insights into the molecular mechanism of CIF-mediated CS formation at the root endodermal and nonendodermal cell layers.
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Arabidopsis , Oryza , Arabidopsis/genética , Oryza/genética , Raízes de Plantas/metabolismo , Parede Celular/metabolismo , Peptídeos/metabolismo , Transdução de Sinais/genéticaRESUMO
Cholestatic liver disease is characterized by disturbances in the intestinal microbiota and excessive accumulation of toxic bile acids (BA) in the liver. Melatonin (MT) can improve liver diseases. However, the underlying mechanism remains unclear. This study aimed to explore the mechanism of MT on hepatic BA synthesis, liver injury, and fibrosis in 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC)-fed and Mdr2-/- mice. MT significantly improved hepatic injury and fibrosis with a significant decrease in hepatic BA accumulation in DDC-fed and Mdr2-/- mice. MT reprogramed gut microbiota and augmented fecal bile salt hydrolase activity, which was related to increasing intestinal BA deconjugation and fecal BA excretion in both DDC-fed and Mdr2-/- mice. MT significantly activated the intestinal farnesoid X receptor (FXR)/fibroblast growth factor 15 (FGF-15) axis and subsequently inhibited hepatic BA synthesis in DDC-fed and Mdr2-/- mice. MT failed to improve DDC-induced liver fibrosis and BA synthesis in antibiotic-treated mice. Furthermore, MT provided protection against DDC-induced liver injury and fibrosis in fecal microbiota transplantation mice. MT did not decrease liver injury and fibrosis in DDC-fed intestinal epithelial cell-specific FXR knockout mice, suggesting that the intestinal FXR mediated the anti-fibrosis effect of MT. In conclusion, MT ameliorates cholestatic liver diseases by remodeling gut microbiota and activating intestinal FXR/FGF-15 axis-mediated inhibition of hepatic BA synthesis and promotion of BA excretion in mice.
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Colestase , Hepatopatias , Melatonina , Camundongos , Animais , Melatonina/farmacologia , Melatonina/metabolismo , Fígado/metabolismo , Colestase/tratamento farmacológico , Colestase/metabolismo , Colestase/patologia , Hepatopatias/metabolismo , Hepatopatias/patologia , Ácidos e Sais Biliares/metabolismo , Ácidos e Sais Biliares/farmacologia , Camundongos Knockout , Cirrose Hepática/induzido quimicamente , Cirrose Hepática/tratamento farmacológico , Cirrose Hepática/metabolismo , Camundongos Endogâmicos C57BLRESUMO
Filopodia are slender cellular protrusions containing parallel actin bundles involved in environmental sensing and signaling, cell adhesion and migration, and growth cone guidance and extension. Myosin 10 (Myo10), an unconventional actin-based motor protein, was reported to induce filopodial initiation with its motor domain. However, the roles of the multifunctional tail domain of Myo10 in filopodial formation and elongation remain elusive. Herein, we generated several constructs of Myo10-full-length Myo10, Myo10 with a truncated tail (Myo10 HMM), and Myo10 containing four mutations to disrupt its coiled-coil domain (Myo10 CC mutant). We found that the truncation of the tail domain decreased filopodial formation and filopodial length, while four mutations in the coiled-coil domain disrupted the motion of Myo10 toward filopodial tips and the elongation of filopodia. Furthermore, we found that filopodia elongated through multiple elongation cycles, which was supported by the Myo10 tail. These findings suggest that Myo10 tail is crucial for promoting long filopodia.
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Miosinas , Pseudópodes , Actinas/metabolismo , Adesão Celular , Miosinas/química , Miosinas/genética , Miosinas/metabolismo , Domínios Proteicos , Pseudópodes/genética , Pseudópodes/metabolismo , Células COS , Animais , Chlorocebus aethiops , HumanosRESUMO
Rice (Oryza sativa) exhibits tremendous aluminum (Al)-tolerance. The C2H2-transcription factor (TF) ART1 critically regulates rice Al tolerance via modulation of specific gene expression. However, little is known about the posttranscriptional ART1 regulation. Here, we identified an ART1-interacted gene OsNAC016 via a yeast two-hybrid (Y2H) assay. OsNAC016 was primarily expressed in roots and weakly induced by Al. Immunostaining showed that OsNAC016 was a nuclear protein and localized in all root cells. Knockout of OsNAC016 did not alter Al sensitivity. Overexpression of OsNAC016 resulted in less Al aggregation within roots and enhanced Al tolerance in rice. Based on transcriptomic and qRT-PCR evaluations, certain cell-wall-related or ART-regulated gene expressions such as OsMYB30 and OsFRDL4 were altered in OsNAC016-overexpressing plants. These results indicated that OsNAC016 interacts with ART1 to cooperatively regulate some Al-tolerance genes and is a critical regulatory factor in rice Al tolerance.
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Oryza , Oryza/metabolismo , Alumínio/toxicidade , Alumínio/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Parede Celular/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Regulação da Expressão Gênica de Plantas , Raízes de Plantas/metabolismoRESUMO
Groundwater resources are often contaminated by arsenic, which poses a serious threat to human and animal's health. Some studies have demonstrated that acute arsenic exposure could induce kidney injury because the kidney is a key target organ for toxicity, but the exact mechanism remains unclear. Hence, we investigated the effect of SIRT1-/PINK1-mediated mitophagy on NaAsO2-induced kidney injury in vivo and in vitro. In our study, NaAsO2 exposure obviously induced renal tubule injury and mitochondrial dysfunction. Meanwhile, NaAsO2 exposure could inhibit the mRNA/protein level of SIRT1 and activate the mitophagy-related mRNA/protein levels in the kidney of mice. In HK-2 cells, we also confirmed that NaAsO2-induced nephrotoxicity depended on the activation of mitophagy. Moreover, the activation of SIRT1 by resveratrol alleviated NaAsO2-induced acute kidney injury via the activation of mitophagy in vivo and in vitro. Interestingly, the inhibition of mitophagy by cyclosporin A (CsA) further exacerbated NaAsO2-induced nephrotoxicity and inflammation in HK-2 cells. Taken together, our study found that SIRT1-regulated PINK1-/Parkin-dependent mitophagy was implicated in NaAsO2-induced acute kidney injury. In addition, we confirmed that PINK1-/Parkin-dependent mitophagy played a protective role against NaAsO2-induced acute kidney injury. Therefore, activation of SIRT1 and mitophagy may represent a novel therapeutic target for the prevention and treatment of NaAsO2-induced acute renal injury.
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Injúria Renal Aguda , Arsênio , Camundongos , Humanos , Animais , Mitofagia , Arsênio/toxicidade , Sirtuína 1/genética , Proteínas Quinases/genética , Injúria Renal Aguda/induzido quimicamente , Injúria Renal Aguda/genética , Ubiquitina-Proteína Ligases/genética , RNA MensageiroRESUMO
The mycotoxin ochratoxin A (OTA) causes nephrotoxicity, hepatotoxicity, and immunotoxicity in animals and humans. The farnesoid X receptor (FXR) is a member of the NR family and is highly expressed in the kidney, which has an antilipid production function. Ferroptosis is an iron-dependent form of regulated cell death involved in several pathophysiological cell death and kidney injury. The present study aims to evaluate the role of FXR and ferroptosis in OTA-induced nephrotoxicity in mice and HK-2 cells. Results showed that OTA induced nephrotoxicity as demonstrated by inducing the histopathological lesions and neutrophil infiltration of the kidney, increasing serum BUN, CRE, and UA levels, increasing Ntn-1, Kim-1, and pro-inflammatory cytokine expression, and decreasing IL-10 expression and the cell viability of HK-2 cells. OTA treatment also induced FXR deficiency, ROS release, MDA level increase, GSH content decrease, and 4-HNE production in the kidney and HK-2 cells. OTA treatment induced ferroptosis as demonstrated by increasing labile iron pool and lipid peroxidation levels as well as Acsl4, TFR1, and HO-1 mRNA and protein levels, decreasing GPX4 and FTH mRNA and protein expressions, and inducing mitochondrial injury. The FXR activator (GW4064) rescued the accumulation of lipid peroxides, intracellular ROS, and Fe2+, inhibited ferroptosis, and alleviated OTA-induced nephrotoxicity. The ferroptosis inhibitor (Fer-1) prevented ferroptosis and attenuated nephrotoxicity. Collectively, this study elucidates that FXR played a critical role in OTA-induced nephrotoxicity via regulation of ferroptosis, which provides a novel strategy against OTA-induced nephrotoxicity.
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Ferroptose , Humanos , Animais , Camundongos , Ferroptose/genética , Espécies Reativas de Oxigênio , Ferro , RNA MensageiroRESUMO
Huntington's disease (HD) is a progressive dominantly inherited neurodegenerative disease caused by the expansion of a cytosine-adenine-guanine (CAG) trinucleotide repeat in the huntingtin gene, which encodes the mutant huntingtin protein containing an expanded polyglutamine tract. One of neuropathologic hallmarks of HD is selective degeneration in the striatum. Mechanisms underlying selective neurodegeneration in the striatum of HD remain elusive. Neurodegeneration is suggested to be preceded by abnormal synaptic transmission at the early stage of HD. However, how mutant huntingtin protein affects synaptic vesicle exocytosis at single presynaptic terminals of HD striatal neurons is poorly understood. Here, we measured synaptic vesicle exocytosis at single presynaptic terminals of cultured striatal neurons (mainly inhibitory neurons) in a knock-in mouse model of HD (zQ175) during electrical field stimulation using real-time imaging of FM 1-43 (a lipophilic dye). We found a significant decrease in bouton density and exocytosis of synaptic vesicles at single presynaptic terminals in cultured striatal neurons. Real-time imaging of VGAT-CypHer5E (a pH sensitive dye conjugated to an antibody against vesicular GABA transporter (VGAT)) for inhibitory synaptic vesicles revealed a reduction in bouton density and exocytosis of inhibitory synaptic vesicles at single presynaptic terminals of HD striatal neurons. Thus, our results suggest that the mutant huntingtin protein decreases bouton density and exocytosis of inhibitory synaptic vesicles at single presynaptic terminals of striatal neurons, causing impaired inhibitory synaptic transmission, eventually leading to the neurodegeneration in the striatum of HD.
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BACKGROUND: The RING finger (RNF) proteins are a large group of ubiquitin ligases whose aberrant expression is often associated with disease progression. This study examines the function of RNF protein 182 (RNF182) in lung adenocarcinoma (LUAD) cells and its impact on p65 and programmed death ligand 1 (PDL1) regulation. METHODS: Expression of RNF182, p65, and PDL1 in LUAD tissues and cells was measured using immunohistochemistry, reverse transcription quantitative polymerase chain reaction (RT-qPCR), and/or western blot (WB) assays. LUAD cells were induced to overexpress RNF182 and p65, followed by cell counting kit-8, colony formation, Transwell, and flow cytometry assays to evaluate the cells' malignant phenotype. Coimmunoprecipitation and WB assays were used to verify RNF182's effect on p65 ubiquitination. Chromatin immunoprecipitation-qPCR and luciferase assays were used to analyze p65's transcriptional regulation of PDL1. Coculture of LUAD with CD8+ cytotoxic T cells was performed to detect lactate dehydrogenase release and interferon-γ and interleukin-2 concentrations. LUAD cells were implanted in mice to analyze tumorigenicity. RESULTS: RNF182 was poorly expressed, while p65 and PDL1 were highly expressed in LUAD tissues and cells. RNF182 overexpression suppressed the malignant properties of LUAD cells, and it promoted p65 ubiquitination and protein degradation. p65 activated PDL1 transcription. Overexpression of RNF182 suppressed the PDL1 expression, increased the cytotoxicity in LUAD cells cocultured with CD8+ T cells, and suppressed the tumorigenesis of cancer cells in vivo. However, these tumor-suppressive effects of RNF182 on LUAD cells were blocked by p65 restoration. CONCLUSION: This research demonstrates that RNF182 induces p65 ubiquitination to suppress PDL1 transcription and immunosuppression in LUAD.
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Adenocarcinoma de Pulmão , Neoplasias Pulmonares , Ubiquitina-Proteína Ligases , Animais , Camundongos , Adenocarcinoma de Pulmão/genética , Linfócitos T CD8-Positivos , Evasão da Resposta Imune , Neoplasias Pulmonares/genética , Ubiquitinação , Ubiquitina-Proteína Ligases/genética , HumanosRESUMO
To popularize the complete replacement of natural sand with manufactured sand, a study was performed to determine the effect of adding polypropylene fibres (PPFs) to increase the bending strength and carbonization resistance of manufactured sand concrete (MSC). A 2 × 3 factorial design with the content and length of PPF as variables was used to establish a carbonization depth prediction model and a response surface model (RSM). The phase composition and microstructure of polypropylene-fibre-reinforced manufactured sand concrete (PPF-MSC) were analysed using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show the addition of PPF with different contents and lengths increases the bending strength of PPF-MSC to varying degrees, while reducing the carbonization depth and increasing the dynamic elastic modulus after 28 days of carbonization. The highest bending strength (6.12 MPa) and carbonization resistance of PPF-MSC are obtained by the addition of 1 kg/m3 of 12 mm PPF, while the carbonization depth and an increase in the dynamic elastic modulus after 28 days of carbonization are maintained at a minimum of 2.26% and 1.94 mm, respectively. A prediction model was established to obtain a formula for the PPF-MSC carbonization depth in terms of the content and length of PPF and the carbonization time. The following results were obtained from the RSM: compared to the PPF length, the PPF content has a larger impact on the PPF-MSC bending strength and a smaller impact on the PPF-MSC carbonization resistance; there is no significant interaction between the content and length of PPF; and the predicted and measured values are close, indicating that the model is highly reliable. A comparison of the XRD patterns and SEM micrographs of PPF-MSC and MSC after 28 days of carbonization show a lower peak intensity of CaCO3 in the pattern for the carbonized area for PPF-MSC than for MSC and considerably fewer surface pores and cracks in PPF-MSC than in MSC. These results indicate that the addition of PPF increases the compactness of MSC and creates an effective resistance to the erosion by water molecules and carbon dioxide (CO2), thus enhancing the bending strength and carbonization resistance of MSC.
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Purpose: The study aimed to investigate the relationship between the expression of PD-1 and CTLA-4 on the surface of peripheral blood T lymphocyte subsets in patients with sepsis and the severity and prognosis of the disease. Patients and Methods: The study included patients with sepsis who were admitted to the intensive care unit. The expression of PD-1 and CTLA-4 on T lymphocyte subsets was detected by flow cytometry, and the severity of sepsis was assessed using the SOFA score. Results: The expression of PD-1 on CD4+T cells, PD-1 on Tregs, and CTLA-4 on Tregs increased with the severity of the disease (P<0.05). Multivariate logistic regression analysis showed that PD-1 expression on CD4+T cells, CTLA-4 expression on Tregs, and the SOFA score were independent risk factors for 28-day mortality in patients with sepsis (P<0.05). The area under the curve of the SOFA score combined with the expression of PD-1 on CD4+T cells and CTLA-4 on Treg cells was significantly higher than any single indicator (P<0.05). Patients with high expression of PD-1 on CD4+T cells (>31.25%) and CTLA-4 on Tregs (>12.64%) had a lower 28-day survival rate (P<0.05). Conclusion: The increased expression of PD-1 and CTLA-4 on CD4+T cells and Tregs is significantly associated with the severity and prognosis of sepsis patients. The combination of the SOFA score and the expression of PD-1 on CD4+T cells and CTLA-4 on Tregs can further improve the prognostic predictive value. These findings may be promising biomarkers for prognostic assessment, risk stratification, and identification of immunosuppression in patients with sepsis.
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Aflatoxin B1 (AFB1) is one of major pollutant in food and feed worldwide. The purpose of this study is to investigate the mechanism of AFB1-induced liver injury. Our results showed that AFB1 caused hepatic bile duct proliferation, oxidative stress, inflammation and liver injury in mice. AFB1 exposure induced gut microbiota dysbiosis and reduced fecal bile salt hydrolase (BSH) activity. AFB1 exposure promoted hepatic bile acid (BA) synthesis and changed intestinal BA metabolism, especially increased intestinal conjugated bile acids levels. AFB1 exposure inhibited intestinal farnesoid X receptor (FXR)/fibroblast growth factor 15 (FGF-15) signaling. Furthermore, the mice received fecal microbiota transplantation from AFB1-treated mice induced liver injury, reduced intestinal FXR signaling and increased hepatic BA synthesis. Finally, the intestine-restricted FXR agonist treatment decreased hepatic BA synthesis, ROS level, inflammation and liver injury in AFB1-treated mice. This study suggests that modifying the gut microbiota, altering intestinal BA metabolism and/or activating intestinal FXR/FGF-15 signaling may be of value for the treatment of AFB1-induced liver disease.
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Doença Hepática Crônica Induzida por Substâncias e Drogas , Microbioma Gastrointestinal , Camundongos , Animais , Aflatoxina B1/toxicidade , Aflatoxina B1/metabolismo , Ácidos e Sais Biliares/metabolismo , Doença Hepática Crônica Induzida por Substâncias e Drogas/metabolismo , Fígado/metabolismo , Inflamação/metabolismo , Camundongos Endogâmicos C57BLRESUMO
The etiology of inflammatory bowel diseases (IBDs) involves complex genetic and environmental factors such as mycotoxin contamination. Deoxynivalenol (DON), a well-known mycotoxin, contaminates food and feed and can induce intestinal injury and inflammatory response. The dose of DON in many foods is also below the limit, although the dose of DON exceeds the limit. The present study aims to evaluate the effects of the nontoxic dose of DON on colitis induced by dextran sodium sulfate (DSS) and the mechanism in mice. The results showed a nontoxic dose of DON at 50 µg/kg bw per day exacerbated DSS-induced colitis in mice as demonstrated by increased disease activity index, decreased colon length, increased morphological damage, decreased occludin and mucoprotein 2 expression, increased IL-1ß and TNF-α expression, and decreased IL-10 expression. DON at 50 µg/kg bw per day enhanced JAK2/STAT3 phosphorylation induced by DSS. Adding JAK2 inhibitor AG490 attenuated the aggravating effects of DON on DSS-induced colitis by reversing the morphological damage, occludin and mucoprotein 2 expression increased, IL-1ß and TNF-α expression increased, and IL-10 expression decreased. Taken together, a nontoxic dose of DON could aggravate DSS-induced colitis via the JAK2/STAT3 signaling pathway. This suggests that DON, below the standard limit dose, is also a risk for IBD and may be harmful to the health of humans and animals, which could provide the basis for establishing limits for DON.
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Colite , Micotoxinas , Humanos , Animais , Camundongos , Interleucina-10 , Ocludina/genética , Fator de Necrose Tumoral alfa , Colite/induzido quimicamente , Colite/genética , Mucoproteínas , Janus Quinase 2/genética , Fator de Transcrição STAT3/genéticaRESUMO
Ochratoxin A (OTA) is a potent mycotoxin found in foods and feeds, posing a health risk to animals and humans. Biological detoxification of OTA is considered a promising method, and some bacteria and fungi which can degrade OTA are isolated. However, research on safety and alleviating toxic effects are scarce. This study aims to isolate OTA-detoxification probiotics from natural samples and evaluate their safety and protective effects in mice. Here, a new OTA-detoxification strain named Pediococcus acidilactici NJB421 (P. acidilactici NJB421) was isolated from cow manure, which exhibited a removal rate of OTA at 48.53% for 48 h. P. acidilactici NJB421 exhibited high temperature resistance, acid tolerance, 0.3% bile salt and 1.4% trypsin resistance. The safety evaluation showed that P. acidilactici NJB421 at 2 × 108 CFU/per mouse had no abnormalities in body weight, organ indices, ALT, AST and ALP activities, BUN, CRE and TP contents. And P. acidilactici NJB421 alleviated the decreases in body weight, organ indices and small intestinal length, and alleviated intestinal injury, liver injury and kidney injury. These results suggest P. acidilactici NJB421 is safe and has protection against OTA poisoning, which provides a new OTA-detoxification strain for livestock and food industries.
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Ocratoxinas , Pediococcus acidilactici , Animais , Camundongos , Peso Corporal , Ocratoxinas/toxicidade , Ocratoxinas/metabolismo , Pediococcus/metabolismo , Pediococcus acidilactici/metabolismoRESUMO
Influenza A (H3N2) accounts for the majority of influenza worldwide and continues to challenge human health. Disturbance in the gut microbiota caused by many diseases leads to increased production of lipopolysaccharide (LPS), and LPS induces sepsis and conditions associated with local or systemic inflammation. However, to date, little attention has been paid to the potential impact of LPS on influenza A (H3N2) infection and the potential mechanism. Hence, in this study we used canine influenza A (H3N2) virus (CIV) as a model of influenza A virus to investigate the effect of low-dose of LPS on CIV replication and lung damage and explore the underlying mechanism in mice and A549 and HPAEpiC cells. The results showed that LPS (25 µg/kg) increased CIV infection and lung damage in mice, as indicated by pulmonary virus titer, viral NP levels, lung index, and pulmonary histopathology. LPS (1 µg/ml) also increased CIV replication in A549 cells as indicated by the above same parameters. Furthermore, low doses of LPS reduced CIV-induced p-mTOR protein expression and enhanced CIV-induced autophagy-related mRNA/protein expressions in vivo and in vitro. In addition, the use of the mTOR activator, MHY1485, reversed CIV-induced autophagy and CIV replication in A549 and HPAEpiC cells, respectively. siATG5 alleviated CIV replication exacerbated by LPS in the two lines. In conclusion, LPS aggravates CIV infection and lung damage via mTOR/autophagy.
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Vírus da Influenza A Subtipo H3N2 , Influenza Humana , Infecções por Orthomyxoviridae , Animais , Cães , Humanos , Camundongos , Autofagia , Lipopolissacarídeos/toxicidade , Pulmão/patologia , Infecções por Orthomyxoviridae/patologia , Serina-Treonina Quinases TOR/genéticaRESUMO
Mitophagy, the elimination of mitochondria via the autophagy-lysosome pathway, is essential for the maintenance of cellular homeostasis. The best characterised mitophagy pathway is mediated by stabilisation of the protein kinase PINK1 and recruitment of the ubiquitin ligase Parkin to damaged mitochondria. Ubiquitinated mitochondrial surface proteins are recognised by autophagy receptors including NDP52 which initiate the formation of an autophagic vesicle around the mitochondria. Damaged mitochondria also generate reactive oxygen species (ROS) which have been proposed to act as a signal for mitophagy, however the mechanism of ROS sensing is unknown. Here we found that oxidation of NDP52 is essential for the efficient PINK1/Parkin-dependent mitophagy. We identified redox-sensitive cysteine residues involved in disulphide bond formation and oligomerisation of NDP52 on damaged mitochondria. Oligomerisation of NDP52 facilitates the recruitment of autophagy machinery for rapid mitochondrial degradation. We propose that redox sensing by NDP52 allows mitophagy to function as a mechanism of oxidative stress response.
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Mitofagia , Proteínas Nucleares , Proteínas Quinases , Humanos , Autofagia , Células HeLa , Mitofagia/fisiologia , Oxirredução , Proteínas Quinases/genética , Proteínas Quinases/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Ubiquitina/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Proteínas Nucleares/metabolismoRESUMO
Currently, due to the actual contamination levels of multiple mycotoxins, the limits for a single mycotoxin may be no longer applicable. Deoxynivalenol (DON) and Fumonisin B1 (FB1) had high positive rate in grain and feed worldwide. The intestine is the first target of mycotoxins. NLRP3 plays a crucial role in the gut's defense against external stimuli, which contributes vitally to pyroptosis activation. However, whether pyroptosis is engaged in the regulation of intestinal toxicity induced by DON and FB1 remains unclear. In this study, we explored the combined toxicity of DON and FB1 on the intestine and its underlying mechanisms in vivo and in vitro. Our data demonstrated gavage with DON and FB1 led to intestinal damage and promoted the secretion of pro-inflammatory cytokines (IL-1ß, IL-18, IL-6) in mice, especially in the group exposed to both mycotoxins. Meanwhile, the expressions of pyroptosis related genes (NLRP3, ASC, caspase-1, GSDMD) were significantly increased after mycotoxins exposure. Same as in vivo, DON and FB1 promoted pyroptosis and cellular inflammatory response in IPEC-J2 cells, especially in the group exposed to both mycotoxins. In addition, the pretreatment with MCC950 and VX765, inhibitors for NLRP3 and caspase-1, abolished the expression of GSDMD and the release of pro-inflammatory factors (IL-1ß, IL-18) induced by DON and FB1 exposure in IPEC-J2 cells. Our data demonstrated that the combination of DON and FB1 exhibited a synergistic or additive effect in facilitating intestinal inflammation via pyroptosis. Our finding may contribute to improve mycotoxin limit standards in feed.
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Interleucina-18 , Micotoxinas , Camundongos , Animais , Piroptose , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Micotoxinas/toxicidade , Inflamação/induzido quimicamente , CaspasesRESUMO
Ochratoxin A (OTA) is one of the most harmful mycotoxins, which can cause multiple toxicological effects, especially nephrotoxicity in animals and humans. Taurine is an essential amino acid with various biological functions such as anti-inflammatory and anti-oxidation. However, the protective effect of taurine on OTA-induced nephrotoxicity and pyroptosis had not been reported. Our results showed that OTA exposure induced cytotoxicity and oxidative stress in PK-15 cells, including reactive oxygen species (ROS) accumulation, increased mRNA levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2), and decreased mRNA levels of catalase (CAT), glutathione peroxidase 1 (GPx1), and glutathione peroxidase 4 (GPx4). In addition, OTA treatment induced pyroptosis by increasing the expressions of pyroptosis-related proteins NLRP3, GSDMD, Caspase-1 P20, ASC, Pro-caspase-1, and IL-1ß. Meanwhile, taurine could alleviate OTA-induced pyroptosis and cytotoxicity, as well as reduce ROS level, COX-2, and iNOS mRNA levels, and increase the mRNA levels of the antioxidant enzyme in PK-15 cells. Taken together, taurine alleviated OTA-induced pyroptosis in PK-15 cells by inhibiting ROS generation and altering the activity of antioxidant enzymes, thereby attenuating its nephrotoxicity.
Assuntos
Antioxidantes , Piroptose , Animais , Humanos , Antioxidantes/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Taurina/farmacologia , Ciclo-Oxigenase 2/metabolismo , Estresse Oxidativo , Caspase 1/metabolismo , RNA Mensageiro/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismoRESUMO
In order to study the effect of polypropylene fibers on the frost resistance of natural sand and machine-made sand concrete, polypropylene fibers (PPF) of different volumes and lengths were mixed into natural sand and machine-made sand concrete, respectively. The freeze-thaw cycle test was carried out on polypropylene-fiber-impregnated natural sand concrete (PFNSC) and polypropylene-fiber-impregnated manufactured sand concrete (PFMSC), respectively, and the apparent structural changes before and after freezing and thawing were observed. Its strength damage was analyzed. A freeze-thaw damage model and a response surface model (RSM) were established used to analyze the antifreeze performance of PFMSC, and the effects of the fiber content, fiber length, and freeze-thaw times on the antifreeze performance of PFMSC were studied. The results show that with the increase in the number of freeze-thaw cycles, the apparent structures of the PFMSC gradually deteriorated, the strength decreased, and the degree of freeze-thaw damage increased. According to the strength damage model, the optimum volume of PPF for the PFNSC specimens is 1.2%, and the optimum volume of PPF for the PFMSC specimens is 1.0%. According to the prediction of RSM, PFNSC can maintain good antifreeze performance within 105 freeze-thaw cycles, and when the PPF length is 11.8 mm, the antifreeze performance of PFNSC reaches the maximum, its maximum compressive strength value is 33.8 MPa, and the split tensile strength value is 3.1 MPa; PFMSC can maintain a good antifreeze performance within 96 freeze-thaw cycles. When the length of PPF is 9.1 mm, the antifreeze performance of PFMSC reaches the maximum, its maximum compressive strength value is 45.8 MPa, and its split tensile strength value is 3.2 MPa. The predicted values are in good agreement with the measured values, and the model has high reliability.