Branched-chain fatty acids from goat milk alleviate ulcerative colitis via the TLR4/NF-κB/NLRP3 pathway

Branched-chain fatty acids(BCFAs)are new bioactive fatty acids with anti-inflammatory properties.However,the role of BCFAs in alleviating ulcerative colitis has not been clarified.Herein,we evaluated the protective effect of BCFAs from goat milk in mice with colitis induced using dextran sodium sulfate(DSS)and explored the corresponding mechanism.These results show that BCFAs extracted from goat milk can significantly alleviate weight loss in mice,and reduce the disease activity index and the activity of myeloperoxidase while increasing the content of antioxidant enzymes in colon tissue and reducing the oxidation stress response.These data also show that BCFAs can down-regulate the gene and protein expression of the toll-like receptor 4(TLR4)/nuclear factorκB p65(NF-κB p65)/NOD-like receptor thermal protein domain associated protein 3(NLRP3)signaling pathway,and at the same time significantly reduce the expression of pro-inflammatory factors tumor necrosis factorα(TNF-α),interleukin 1β(IL-1β),and IL-18 in colon tissue,and significantly increase the expression of the anti-inflammatory factor IL-10.In conclusion,these results demonstrated that BCFAs in goat milk exerted effects on colitis-related inflammatory cytokines and inhibited inflammation by inducing the TLR4/NF-κB/NLRP3 pathway to alleviate DSS-induced ulcerative colitis.This study provides evidence for the potential of BCFAs as bioactive fatty acids in food products and to ameliorate ulcerative colitis development in mice.

Acacetin protects against cerebral ischemia-reperfusion injury via the NLRP3 signaling pathway

Acacetin(5,7-dihydroxy-4′-methoxyflavone), a potential neuroprotective agent, has an inhibitory effect on lipopolysaccharide-induced neuroinflammatory reactions. However, whether acacetin has an effect on inflammatory corpuscle 3(NLRP3) after cerebral ischemia-reperfusion injury has not been fully determined. This study used an improved suture method to establish a cerebral ischemia-reperfusion injury model in C57BL/6 mice. After ischemia with middle cerebral artery occlusion for 1 hour, reperfusion with intraperitoneal injection of 25 mg/kg of acacetin(acacetin group) or an equal volume of saline(0.1 mL/10 g, middle cerebral artery occlusion group) was used to investigate the effect of acacetin on cerebral ischemia-reperfusion injury. Infarct volume and neurological function scores were determined by 2,3,5-triphenyltetrazolium chloride staining and the Zea-Longa scoring method. Compared with the middle cerebral artery occlusion group, neurological function scores and cerebral infarction volumes were significantly reduced in the acacetin group. To understand the effect of acacetin on microglia-mediated inflammatory response after cerebral ischemia-reperfusion injury, immunohistochemistry for the microglia marker calcium adapter protein ionized calcium-binding adaptor molecule 1(Iba1) was examined in the hippocampus of ischemic brain tissue. In addition, tumor necrosis factor-α, interleukin-1β, and interleukin-6 expression in ischemic brain tissue of mice was quantified by enzyme-linked immunosorbent assay. Expression of Iba1, tumor necrosis factor-α, interleukin-1β and interleukin-6 was significantly lower in the acacetin group compared with the middle cerebral artery occlusion group. Western blot assay results showed that expression of Toll-like receptor 4, nuclear factor kappa B, NLRP3, procaspase-1, caspase-1, pro-interleukin-1β, and interleukin-1β were significantly lower in the acacetin group compared with the middle cerebral artery occlusion group. Our findings indicate that acacetin has a protective effect on cerebral ischemia-reperfusion injury, and its mechanism of action is associated with inhibition of microglia-mediated inflammation and the NLRP3 signaling pathway.

Chaihu Longgu Muli Decoction relieving temporal lobe epilepsy in rats by inhibiting TLR4 signaling pathway through miR-146a-3p and miR-146a-5p

Objective To explore the effect and mechanism of Chaihu Longgu Muli Decoction(柴胡龙骨牡蛎汤,CHLGMLD)in rats with temporal lobe epilepsy(TLE).Methods A total of 80 Sprague-Dawley(SD)male rats were randomized into control(CON),model(MOD),carbamazepine(CBZ,0.1 g/kg),CHLGMLD low dose(CHLGMLD-L,12.5 g/kg),and high dose(CHLGMLD-H,25 g/kg)groups,with 16 rats in each group.TLE rat models were established in the four groups with the use of lithium-pilocarpine except for the CON group.After the successful establishment of TLE models,all drugs were administered through gavage,and distilled water was given to rats in the CON and MOD groups for four weeks.The frequency and duration of seizures before and after treatment were recorded for the evaluation of the alleviation degree.Quantitative real-time polymerase chain reaction(qRT-PCR)was used to detect the expression levels of miR-146a-3p and miR-146a-5p.The expression levels of toll-like receptor 4(TLR4),interleukin-1 receptor-associated kinase 1(IRAK1),tumor necrosis factor(TNF)receptor-associated factor 6(TRAF6),TAK1-binding protein(TAB),nuclear factor-kappa B(NF-κB),and interleukin-1 beta(IL-1β)in hippocampus were tested by immunofluorescence assay.Correlation analysis between the above factors and expressions of miR-146a-3p and miR-146a-5p were performed separately.Results CHLGMLD decreased the frequency(P<0.05)and duration(P<0.01)of seizures in rats.CHLGMLD down-regulated the expression levels of miR-146a-5p and miR-146a-3p(P<0.05),and inhibited the expression levels of TLR4,IRAK1,TRAF6,TAB,NF-κB,and IL-1β(P<0.01).The correlation analysis revealed that the expression levels of TLR4,IRAK1,TRAF6,TAB,NF-κB,and IL-1β were positively correlated with the expression levels of miR-146a-3p and miR-146a-5p detected by qRT-PCR,respectively(P<0.01).Conclusion CHLGMLD can inhibite the TLR4 signaling pathway by lowering the expression levels of miR-146a-3p and miR-146a-5p to alleviate hippocampal dentate gyrus inflammation in TLE rats,thus relieving seizures.

To investigate the effect of Shenqi Tiaoshen Formula on CSE induced inflammatory response of MH-S cells based on TLR4/NF-kB/NLRP3 pathway

Objective:To study the effects of Shenqi Tiaoshen Formula(SQTS)on the inflammatory response of MH-S cells induced by cigarette smoking extract(CSE)and its mechanism based on TLR4/NF-kB/NLRP3 pathway.Methods:MH-S cells were used as subjects to evaluate cell viability by CCK-8 method.The levels of TNF-α,IL-1βand IL-6 in the supernatant were detected by ELISA.ROS were detected by DCFH-DA fluorescence probe.Western blotting was used to detect the expression of TLR4/NF-kB/NLRP3 pathway protein,and TAK-242,a TLR4 inhibitor,was used to verify the role of SQTS in the TLR4/NF-kB/NLRP3 pathway.Results:Compared with blank group,the cell survival rate of CSE group was decreased,and the contents of inflammatory cytokines TNF-α,IL-1βand IL-6 were increased(P<0.05),ROS fluorescence expression level was significantly increased(P<0.01),TLR4/NF-kB/NLRP3 pathway protein expression was significantly increased(P<0.05);Compared with CSE group,the survival rate of cells in SQTS groups was increased,and the expression levels of the above indexes were decreased(P<0.05),and TLR4/NF-kB/NLRP3 pathway protein decreased in TAK-242 groups(P<0.05).Conclusion:SQTS can reduce the inflammatory response of MH-S cells induced by CSE by inhibiting TLR4/NF-kB/NLRP3 pathway.

Effects of Liancao-Xieli capsule on intestinal mucosal inflammatory factors and TLR4/PI3K/Akt/mTOR signaling pathway in mice with ulcerative colitis

Objective:To observe the effect of Liancao-Xieli capsule on intestinal mucosal inflammatory factors and TLR4/PI3K/Akt/mTOR signaling pathway in mice with ulcerative colitis(UC);Methods:40 male C57BL/6 mice were randomly divided into the control group,model group,Liancao-Xieli group and mesalazine group,with 10 mice in each group.In addition to the control group,the remaining three groups of mice were induced by 3%dextran sulfate sodium(DSS)to induce acute UC model.During the modeling period,mice in each group were given corresponding drugs and normal saline by gavage.At the end of the experiment,HE staining was used to observe the pathological changes of colonic tissue in each group,and ELISA was used to detect the inflammatory factors(TNF-α,IL-6,IL-1β,IL-8,IL-17,and INF-γ)in serum and colonic tissue.The expression levels of TLR4/PI3K/Akt/mTOR signaling pathway related proteins were also detected by Western blot;Results:Compared with the model group,Liancao-Xieli capsule could significantly increase the colon length and decrease the score of colon histopathology in UC mice(P<0.01).In addition,the levels of TNF-α,IL-6,IL1β,IL-8,IL-17,and INF-γwere significantly reduced in serum and colon tissue,and the expressions of TLR4,PI3K,p-Akt and p-mTOR were significantly down-regulated in LiancaoXieyi group when compared with the model group(P<0.01).While the expressions of Akt and mTOR were not significantly affected in Liancao-Xieyi group(P>0.05);Conclusion:LiancaoXieli capsule can reduce the secretion of inflammatory factors,improve the intestinal mucosal damage and inflammatory response in UC by inhibiting the activation of TLR4/PI3K/Akt/mTOR signaling pathway。

Elaidic acid-induced intestinal barrier damage led to gut-liver axis derangement and triggered NLRP3 inflammasome in the liver of SD rats

Previous studies have shown that trans fatty acids(TFA) are associated with several chronic diseases,the gut microbiota is directly influenced by dietary components and linked to chronic diseases.Our research investigated the effects of elaidic acid(EA),a typical TFA,on the gut microbiota to understand the underlying mechanisms of TFA-related chronic diseases.16S rDNA gene sequencing on faecal samples from Sprague-Dawley rats were performed to explore the composition change of the gut microbiota by EA gavage for 4 weeks.The results showed that the intake of EA increased the abundance of well-documented harmful bacteria,such as Proteobacteria,Anaerotruncus,Oscillibacter and Desulfovibrionaceae.Plus,EA induced translocation of lipopolysaccharides(LPS) and the above pathogenic bacteria,disrupted the intestinal barrier,led to gut-liver axis derangement and TLR4 pathway activation in the liver.Overall,EA induced intestinal barrier damage and regulated TLR4-MyD88-NF-κB/MAPK pathways in the liver of SD rats,leading to the activation of NLRP3 inflammasome and inflammatory liver damage.

Mechanism of Sanshi decoction in the treatment of gouty arthritis by NLRP3 inflammasome

Objective:To observe the effect of Sanshi decoction on P2X7R/PKR pathway-mediated activation of macrophage NLRP3 inflammasome to elucidate the molecular mechanism of Sanshi decoction in the treatment of gouty arthritis.Methods:THP-1 macrophages were divided into control group,model group,low dose group,medium dose group,high dose group of Sanshi decoction and inhibitor group.The remaining groups were induced with monosodium urate crystals to establish a gouty arthritis cell model except the control group.Flow cytometry was used to detect macrophage ROS levels in each group,ELISA to detect MDA levels and SOD and GSH-PX activities in each group,and Western blot to detect P2X7R/PKR pathway and NLRP3 inflammasome-associated protein expression.We also used CCK-8 and flow cytometry to measure MH7A activity and apoptotic levels.Results:Compared with the control group,the ROS level,the content of MDA,the activities of SOD and GSH-PX were significantly increased,and the expression levels of NLRP3,full-length IL-1β,pro-IL-1β,full-length IL-18,pro-IL-18,full-length caspase-1,GSDMD-NT,P2X7R and p-PKR protein expression levels were significantly upregulated,and GSDMD-FL protein expression was significantly downregulated in the model group,and that the differences between them were statistically significant(P<0.05 and P<0.01).Compared with the model group,Sanshi decoction could reduce macrophage ROS levels,MDA content,SOD and GSHPX activities,and downregulate macrophage NLRP3,mature IL-1β,pro IL-1β,mature IL-18,pro IL-18,mature caspase-1,GSDMD-NT,P2X7R and p-PKR protein expression,and upregulate GSDMD-FL protein expression,with statistically significant differences(P<0.05 and P<0.01).In addition,MH7A activity was downregulated,and apoptosis level was upregulated in the model group in comparison with the control group,and differences were all significantly different(P<0.05).As compared to the model group,Sanshi decoction could significantly increase the activity of MH7A and inhibit the level of apoptosis,and that the differences between them were statistically significant(P<0.05 and P<0.01).Conclusion:Sanshi decoction can achieve the therapeutic effect of gouty arthritis by inhibiting P2X7R/PKR pathway activation,thus reducing the activation level of NLRP3.

Huoxin Pill Reduces Myocardial Ischemia Reperfusion Injury in Rats via TLR4/NFκB/NLRP3 Signaling Pathway

Objective:To explore the protective effect of Huoxin Pill(HXP)on acute myocardial ischemia-reperfusion(MIRI)injury in rats.Methods:Seventy-five adult SD rats were divided into the sham-operated group,model group,positive drug group(diltiazem hydrochloride,DH),high dose group(24 mg/kg,HXP-H)and low dose group(12 mg/kg,HXP-L)of Huoxin Pill(n=15 for every group)according to the complete randomization method.After 1 week of intragastric administration,the left anterior descending coronary artery of the rat's heart was ligated for 45 min and reperfused for 3 h.Serum was separated and the levels of creatine kinase(CK),creatine kinase isoenzyme(CK-MB)and lactate dehydrogenase(LDH),superoxide dismutase(SOD),and malondialdehyde(MDA),hypersensitive C-reactive protein(hs-CRP)and interleukin-1β(IL-1β)were measured.Myocardial ischemia rate,myocardial infarction rate and myocardial no-reflow rate were determined by staining with Evans blue and 2,3,5-triphenyltetrazolium chloride(TTC).Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform(TCMSP)and Bioinformatics Analysis Tool for Molecular mechANism of Traditional Chinese Medicine(BATMAN)databases were used to screen for possible active compounds of HXP and their potential therapeutic targets;the results of anti-inflammatory genes associated with MIRI were obtained from GeneC ards,Drugbank,Online Mendelian Inheritance in Man(OMIM),and Therapeutic Target Datebase(TTD)databases was performed;Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment were used to analyze the intersected targets;molecular docking was performed using AutoD ock Tools.Western blot was used to detect the protein expression of Toll-like receptor 4(TLR4)/nuclear factor kappa-B(NFκB)/NOD-like receptor protein 3(NLRP3).Results:Compared with the model group,all doses of HXP significantly reduced the levels of LDH,CK and CK-MB(P<0.05,P<0.01);HXP significantly increased serum activity of SOD(P<0.05,P<0.01);all doses of HXP significantly reduced the levels of hs-CRP and IL-1β(P<0.05,P<0.01)and the myocardial infarction rate and myocardial no-reflow rate(P<0.01).GO enrichment analysis mainly involved positive regulation of gene expression,extracellular space and identical protein binding,KEGG pathway enrichment mainly involved PI3K-Akt signaling pathway and lipid and atherosclerosis.Molecular docking results showed that kaempferol and luteolin had a better affinity with TLR4,NFκB and NLRP3 molecules.The protein expressions of TLR4,NFκB and NLRP3 were reduced in the HXP group(P<0.01).Conclusions:HXP has a significant protective effect on myocardial ischemia-reperfusion injury in rats,and its effect may be related to the inhibition of redox response and reduction of the inflammatory response by inhibiting the TLR4/NFκB/NLRP3 signaling pathway.

Hepatic protective effects of Shenling Baizhu powder, a herbal compound, against inflammatory damage via TLR4/NLRP3 signalling pathway in rats with nonalcoholic fatty liver disease

Objective: High-fat diet(HFD) and inflammation are two key contributors to nonalcoholic fatty liver disease(NAFLD). Shenling Baizhu powder(SLBZP), a classical herbal compound, has been successfully used to alleviate NAFLD. However, its specific mechanisms are not fully understood. In this study, we assessed the anti-NAFLD effect of SLBZP in vivo.Methods: Rats were fed an HFD with or without SLBZP or with probiotics. At the end of week 16, an echo magnetic resonance imaging(EchoMRI) body composition analyser was used to quantitatively analyse body composition;a micro-computed tomography(micro-CT) imaging system was used to evaluate whole body and liver fat;and the Moor full-field laser perfusion imager 2 was used to assess liver microcirculation, after which, all rats were sacrificed. Then, biochemical indicators in the blood and the ultrastructure of rat livers were evaluated. Protein expression related to the liver Toll-like receptor 4(TLR4)/Nod-like receptor family pyrin domain-containing 3(NLRP3) signalling pathway was assessed using Western blot analysis. Further, high-throughput screening of 29 related inflammatory factors in liver tissue was performed using a cytokine array.Results: SLBZP supplementation reduced body weight, serum free fatty acid, and insulin resistance index(P<0.05). It also ameliorated liver microcirculation and ultrastructural abnormalities. EchoMRI and micro-CT quantitative analyses showed that treatment with SLBZP reduced fat mass and visceral fat(P<0.05 and P<0.01, respectively). In addition, SLBZP decreased the expression of lipopolysaccharide(LPS)-activated TLR4/NLRP3 signalling pathway-related proteins and altered the expression levels of some inflammatory cytokines in liver tissues.Conclusion: SLBZP can inhibit NLRP3 inflammasome activation and interleukin-1 b release by suppressing LPS-induced TLR4 expression in rats with HFD-induced NAFLD. Thus, SLBZP may be beneficial for the prevention and treatment of inflammatory damage and associated diseases.

Role of GLCCI1 in inhibiting PI3K-induced NLRP3 inflammasome activation in asthma

Background:Glucocorticoid-induced transcript 1(GLCCI1)has been reported to be associated with the efficiency of inhaled glucocorticoids in patients with asthma.This study aimed to investigate the role of GLCCI1 in the regu-lation of nucleotide-binding oligomerization domain(NOD)-like receptor(NLR)family pyrin domain-containing 3(NLRP3)by the phosphatidylinositol 3-kinase(PI3K)pathway in the pathogenesis of allergic asthma.Methods:The expression levels of genes encoding GLCCI1,NLRP3 inflammasome components,and PI3K pathway-related indicators were detected in cells isolated from induced sputum from patients with asthma and healthy controls.Next,we induced asthma in wild-type C57BL/6 mice and Glcci1 knockout(Glcci1-/-)mice by injecting them with ovalbumin(OVA)and treated the asthmatic mice with a PI3K pathway inhibitor(LY294002)or left them untreated.We also performed adoptive transfer of macrophages into the mice and assessed lung inflam-mation,as well as GLCCI1,PI3K pathway component,and NLRP3 inflammasome component expression levels.Finally,primary bone marrow-derived macrophages(BMDMs)from wild-type and Glcci1-/-mice were treated with OVA,either in the presence or absence of LY294002 and the NLRP3 inhibitor(MCC950),to validate our findings.Results:The mRNA level of Glcci1 in induced sputum cells from asthmatic patients was lower compared to that of healthy controls.Additionally,Glcci1 mRNA expression correlated negatively with NLRP3 inflammasome in-dicators and the PI3K pathway components,as well as with IL-1𝛽expression in induced sputum macrophages.In vivo,Glcci1-/-asthmatic mice showed elevated levels of airway inflammation and NLRP3 inflammasome ac-tivation compared to wild-type asthmatic mice.Surprisingly,the efficacy of LY294002 in reducing lung tissue inflammation and NLRP3 inflammasome activity in wild-type asthmatic mice was attenuated by Glcci1 knockout.LY294002 enhanced GLCCI1 levels in macrophages within the lung tissue of wild-type asthmatic mice.Moreover,LY294002 did not inhibit lung inflammation in wild-type asthmatic mice depleted of macrophages that had re-ceived adoptive transfer of Glcci1-/-BMDMs.In vitro experiments further illustrated that LY294002 suppressed NLRP3 activation by upregulating GLCCI1 expression in BMDMs.The introduction of MCC950 led to a marked decrease in NLRP3 and apoptosis-associated speck-like protein containing a caspase recruitment domain(ASC)protein levels,but did not affect the expression levels of GLCCI1 or the phospho-protein kinase B(p-AKT)/AKT ratio.Conclusions:GLCCI1 deficiency promotes asthma inflammation through PI3K-induced NLRP3 inflammasome activation.

Study on the mechanism and active components of Radix et Rhizoma Rhei in the treatment of Alzheimer's disease based on molecular docking

Objective:To explore the mechanism and active components of Radix et Rhizoma Rhei in the treatment of Alzheimer's disease(AD)based on molecular docking.Methods:22 major components of Radix et Rhizoma Rhei were screened from TCMSP and related literatures,which docked with the key targets of NLRP3/Caspase-1/GSDMD signaling pathway.NLRP3,Caspase-1,GSDMD inhibitors MCC950,ML132 and LDC7559 were used as positive control to analyze the docking results.Results:The docking results showed that the main components of Radix et Rhizoma Rhei had different degrees of binding with NLRP3,Caspase-1 and GSDMD targets,and the potential active components were mutanochrome and physciondiglucoside.Conclusion:Molecular docking predicts that the main components of Radix et Rhizoma Rhei may act on NLRP3/Caspase-1/GSDMD signaling pathway,and the active components may be mutanochrome and physciondiglucoside,which provides theoretical basis for revealing the anti-inflammatory mechanism and active components of Radix et Rhizoma Rhei in the treatment of AD.

Mitochondrial DNA in the regulation of innate immune responses

Mitochondrion is known as the energy factory of the cell, which is also a unique mammalian organelle and con. sidered to be evolved from aerobic prokaryotes more than a billion years ago. Mitochondrial DNA, similar to that of its bacterial ancestor＇s, consists of a circular loop and contains significant number of unmethylated DNA as CpG islands. The innate immune system plays an important role in the mammalian immune response. Recent research has demonstrated that mitochondrial DNA （mtDNA） activates several innate immune path- ways involving TLR9, NLRP3 and STING signaling, which contributes to the signaling platforms and results in effector responses. In addition to facilitating antibac- terial immunity and regulating antiviral signaling, mounting evidence suggests that mtDNA contributes to inflammatory diseases following cellular damage and stress. Therefore, in addition to its well-appreciated roles in cellular metabolism and energy production, mtDNA appears to function as a key member in the innate immune system. Here, we highlight the emerging roles of mtDNA in innate immunity.

Whey protein peptide PEW attenuates hyperuricemia and associated renal inflammation in potassium oxonate and hypoxanthine-induced rat

Pro-Glu-Trp(PEW),a whey protein-derived peptide,has been previously shown in vitro to have antihyperuricemic potential.The current study further evaluated the roles and the underlying mechanism of PEW in the management of hyperuricemia(HUA)in rat induced by potassium oxonate(PO)and hypoxanthine.Results revealed that PEW significantly reduced the levels of uric acid(UA),creatinine(Cr),and blood urea nitrogen(BUN)in serum,and effectively suppressed the activities of xanthine oxidase(XOD)associated with UA synthesis and modulated the expression of organic ion transporters related to UA excretion.Moreover,PEW alleviated UAinduced renal inflammation by regulating oxidative stress,suppressing the level of pro-inflammatory cytokines,and inhibiting the activation of NOD-like receptor family pyrin domain-containing 3(NLRP3)inflammasome and Toll-like receptor 4/myeloid differentiation factor 88/NF-kappaB(TLR4/MyD88/NF-κB)signaling pathway.Taken together,these relults indicated that PEW improved HUA and renal inflammation by inhibiting UA synthesis,promoting renal UA excretion and suppressing NLRP3 inflammasome and TLR4/MyD88/NF-κB signaling pathways.