Hippocampal HMGB1/TLR4 Pathway Mediates Cognitive Dysfunction in Chronic Stress Mice

Objective Chronic stress can induce cognitive dysfunction,but the underlying mechanisms remain unknown.Studies have confirmed that the high mobility group box 1/Toll-like receptor 4(HMGB1/TLR4)pathway is closely associated with cognitive impairment.Therefore,this research aimed to explore whether the HMGB1/TLR4 pathway involves in chronic stress-induced cognitive dysfunction.Methods The chronic unpredictable mild stress(CUMS)mouse model was established by randomly giving different types of stress every day for four consecutive weeks.Cognitive function was detected by novel object recognition test,Y-maze test,and Morris water maze test.The protein expressions of HMGB1,TLR4,B-cell lymphoma 2(BCL2),and BCL2 associated X(BAX)were determined by Western blot.The damage of neurons in the hippocampal CA1 region was observed by hematoxylin-eosin(HE)staining.Results The protein expressions of HMGB1 and TLR4 were significantly increased in the hippocampus of chronic stress mice.Furthermore,inhibition of the HMGB1/TLR4 pathway induced by ethyl pyruvate(EP,a specific inhibitor of HMGB1)and TAK242(a selective inhibitor of TLR4)treatment attenuated cognitive impairment in chronic stress mice,according to the novel object recognition test,Y-maze test,and Morris water maze test.In addition,administration of EP and TAK242 also mitigated the increase of apoptosis in the hippocampus of chronic stress mice.Conclusion These results indicate that the hippocampal HMGB1/TLR4 pathway contributes to chronic stress-induced apoptosis and cognitive dysfunction.

The potential mechanism of Isodon suzhouensis against COVID-19 via EGFR/TLR4 pathways

Corona Virus Disease 2019(COVID-19)has brought the new challenges to scientific research.Isodon suzhouensis has good anti-inflammatory and antioxidant stress effects,which is considered as a potential treatment for COVID-19.The possibility for the treatment of COVID-19 with I.suzhouensis and its potential mechanism of action were explored by employing molecular docking and network pharmacology.Network pharmacology and molecular docking were used to screen drug targets,and lipopolysaccharide(LPS)induced RAW264.7 and NR8383 cells inflammation model was used for experimental verification.Collectively a total of 209 possible linkages against 18 chemical components from I.suzhouensis and 1194 COVID-19 related targets were selected.Among these,164 common targets were obtained from the intersection of I.suzhouensis and COVID-19.Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)enriched 582 function targets and 87 target proteins pathways,respectively.The results from molecular docking studies revealed that rutin,vitexin,isoquercitrin and quercetin had significant binding ability with 3 chymotrypsin like protease(3CLpro)and angiotensin converting enzyme 2(ACE2).In vitro studies showed that I.suzhouensis extract(ISE)may inhibit the activation of PI3K/Akt pathway and the expression level of downstream proinflammatory factors by inhibiting the activation of epidermal growth factor receptor(EGFR)in RAW264.7 cells induced by LPS.In addition,ISE was able to inhibit the activation of TLR4/NF-κB signaling pathway in NR8383 cells exposed to LPS.Overall,the network pharmacology and in vitro studies conclude that active components from I.suzhouensis have strong therapeutic potential against COVID-19 through multi-target,multi-pathway dimensions and can be a promising candidate against COVID-19.

TRDMT1 exhibited protective effects against LPS-induced inflammation in rats through TLR4-NF-κB/MAPK-TNF-αpathway

Background:Inflammation is a complex physiological and pathological process.Although many types of inflammation are well characterized,their physiological func-tions are largely unknown.tRNA aspartic acid methyltransferase 1(TRDMT1)has been implicated as a stress-related protein,but its intrinsic biological role is unclear.Methods:We constructed a Trdmt1 knockout rat and adopted the LPS-induced sepsis model.Survival curve,histopathological examination,expression of inflammatory fac-tors,and protein level of TLR4 pathway were analyzed.Results:Trdmt1 deletion had no obvious impact on development and growth.Trdmt1 de-letion slightly increased the mortality during aging.Our data showed that Trdmt1 strongly responded in LPS-treated rats,and Trdmt1 knockout rats were vulnerable to LPS treat-ment with declined survival rate.We also observed more aggravated tissue damage and more cumulative functional cell degeneration in LPS-treated knockout rats compared with control rats.Further studies showed upregulated TNF-αlevel in liver,spleen,lung,and serum tissues,which may be explained by enhanced p65 and p38 phosphorylation.Conclusions:Our data demonstrated that Trdmt1 plays a protective role in inflamma-tion by regulating the TLR4-NF-κB/MAPK-TNF-αpathway.This work provides useful information to understand the TRDMT1 function in inflammation.

Anti-inflammation Effects of Sinomenine on Macrophages through Suppressing Activated TLR4/NF-kB Signaling Pathway

Sinomenine(SN)has been used in the clinical treatment of systemic lupus erythematosus and rheumatoid arthritis for many years.Studies showed that SN held protective effects such as anti-inflammation,scavenging free radicals and suppressing immune response in many autoimmune diseases.The purpose of the present study is to explore the mechanism of anti-inflammation of SN on lipopolysaccharide(LPS)-induced macrophages activation and investigate whether the TLR4/NF-κB signaling pathway participated in.Macrophages isolated from mouse peritoneal cavity were stimulated by 1 pg/mL LPS for 24 h.And then the cells were treated with various concentrations of SN,TLR4 inhibitor respectively for additional 48 h.Drug toxicity was detected by MTT assay and Transwell experiment was used to assess chemotaxis.Furthermore,TLR4 and MyD88 mRNA levels were detected by real-time PCR.Western blotting was used to examine TLR4,MyD88 and phosphorylated IκB protein expression in macrophages.Immunofluorescence assay was applied to observe p65 NF-κB protein expression in macrophage nucleus.We extracted macrophages with high purity and activity from the abdominal cavity of mice.SN remarkably inhibited the chemotaxis and secretion function of LPS-stimulated macrophages.It also down-regulated both the protein levels of inflammatory cytokines(TNF-α,IL-β and IL-6)and the RNA and protein levels of the key factors(TLR4,MyD88,p-IkB)in TLR4 pathway.The expression of p65 NF-κB protein in nuclei was down-regulated,which was correlated with a similar decrease in p-IκB protein level.In conclusion,SN can inhibit the LPS induced immune responses in macrophages by blocking the activated TLR4/NF-κB signaling pathway.These results may provide a therapeutic approach to regulate inflammatory responses.

Milled flaxseed-added diets ameliorated hepatic inflammation by reducing gene expression of TLR4/NF-κB pathway and altered gut microbiota in STZ-induced type 1 diabetic mice

Flaxseed has displayed the potential beneficial as functional foods.However,most studies focused on effects of flaxseed extracts or ingredients in flaxseed.Besides,few studies showed that flaxseed extracts contributed to anti-type 1 diabetes(T1D),yet the underlying mechanism is still unknown.In the present study,16.7% of milled flaxseed(MF)-added diet was given to diabetic mice induced by streptozocin for 6 weeks.The results showed that MF feeding 1)slightly decreased blood glucose levels and improved the ability of glucose tolerance by oral glucose tolerance test,2)decreased liver tumor necrosis factor-αlevels and increased liver glycogen levels with significance via down-regulating TLR4/NF-κB pathways,3)and significantly altered some beneficial bacteria in gut microbiota.In conclusion,the present study showed that milled flaxseed showed the potential on anti-T1D through anti-inflammation via TLR4/NF-κB and altering the gut microbiota in STZ-induced diabetic mice.

Ramulus Cinnamomi extract attenuates neuroinflammatory responses via downregulating TLR4/MyD88 signaling pathway in BV2 cells

Ramulus Cinnamomi （RC）, a traditional Chinese herb, has been used to attenuate inflammatory responses. The purpose of this study was to investigate the effect of RC extract on lipopolysaccharide （LPS）-induced neuroinflammation in BV2 microglial cells and the underlying mechanisms involved. BV2 cells were incubated with normal medium （control group）, LPS, LPS plus 30 pg/mL RC extract, or LPS plus 100 pg/mL RC extract. The BV2 cell morphology was observed under an optical microscope and cell viability was detected by MTT assay. Nitric oxide level in BV2 cells was detected using Griess regents, and the levels of interleukin-6, interleukin-1 β, and tumor necrosis factor u in BV2 cells were determined by ELISA. The expression levels of cyclooxygenase-2, Toll-like receptor 4 and myeloid differentiation factor 88 proteins were detected by western blot assay. Compared with the LPS group, both 30 and 100 μg/mL RC extract had no significant effect on the viability of BV2 cells. The levels of nitric oxide, interleukin-6, interleukin-1β and tumor necrosis factor ct in BV2 cells were all significantly increased after LPS induction, and the levels were significantly reversed after treatment with 30 and 100 μg/mL RC extract. Furthermore, RC extract significantly inhibited the protein expression levels of cyclooxygenase-2, Toll-like receptor 4 and myeloid differentiation factor 88 in LPS-induced BV2 cells. Our findings suggest that RC extract alleviates neuroinflammation by downregulating the TLR4/MyD88 signaling pathway.

Research Progress and Research Ideas on Anti-hepatic Fibrosis and Promoting Blood Circulation and Removing Blood Stasis of the National Drug Plumbapin Based on TLR4 Signal Pathway

Hepatic fibrosis is a reversible pathological phenomenon in the early and middle stages,but but no satisfactory intervention drugs have been available so far.Recent studies have suggested that microcirculation disturbance of liver is one of the important pathogenesis of chronic liver disease,the improvement of microcirculation is beneficial to the recovery of liver function and the delay of liver fibrosis.Hepatic stellate cells are the core cells of hepatic fibrosis,and also the most critical cells that affect the microcirculation of the liver.While TLR4/MyD88/NF-κB and TLR4/MyD88/MAPKs which are based on the action of hepatic stellate cells are two pathways that have very important influence on the inflammatory response of liver,the proliferation and apoptosis of hepatic stellate cells,and the secretion of fibrogenic cytokines.It was found that Plumbapin,the active ingredient of Guangxi specialty ethnic medicine,has the definite effect of promoting blood circulation and removing blood stasis and anti-hepatic fibrosis,but its mechanism is not clear.In this study,the research progress of the above problems was reviewed,and further research ideas were derived as follows:the pharmacological effect of Plumbapin on anti-hepatic fibrosis,promoting blood circulation and removing stasis was based on the influence of TLR4/MyD88/NF-κB and MAPKs signal pathway.

Morroniside ameliorates lipopolysaccharide-induced inflammatory damage in iris pigment epithelial cells through inhibition of TLR4/JAK2/STAT3 pathway

AIM:To investigate the effect of morroniside(Mor)on lipopolysaccharide(LPS)-treated iris pigment epithelial cells(IPE).METHODS:IPE cells were induced by LPS and treated with Mor.Cell proliferation was detected by cell counting kit(CCK)-8,apoptosis was detected by flow cytometry,the levels of tumor necrosis factor-α(TNF-α),interleukin(IL)-6,and IL-8 were measured by enzyme-linked immunosorbent assay(ELISA)kits,and the protein expression of TLR4,JAK2,p-JAK2,STAT3,and p-STAT3 was analyzed by Western blotting.In addition,overexpression of TLR4 and Mor treatment of LPS-stimulated IPE cells were also tested for the above indices.RESULTS:Mor effectively promoted the proliferation and inhibited the apoptosis of LPS-treated IPE cells.In addition,Mor significantly reduced the levels of TNF-α,IL-6,and IL-8 and significantly inhibited the expression of TLR4,p-JAK2,and p-STAT3 in LPS-treated IPE cells.The effect of Mor on LPS-treated IPE cells was markedly attenuated after overexpression of TLR4.CONCLUSION:These findings suggest that Mor may ameliorate LPS-induced inflammatory damage and apoptosis in IPE through inhibition of TLR4/JAK2/STAT3 pathway.

Effects of Polysaccharides from Dicliptera chinensis(L.)Nees.on TLR4/NF-κB Signaling Pathway in Cell Model of Non-alcoholic Fatty Liver

[Objectives]To observe the effects of polysaccharides from Dicliptera chinensis(L.)Nees.on the expression of TLR/NF-κB pathway related proteins in HepG2 cells induced by oleic acid,and to explore the possible mechanism of polysaccharides from D.chinensis(L.)Nees.in the treatment of non-alcoholic fatty liver disease(NAFLD).[Methods]HepG2 cells were induced with oleic acid to establish a non-alcoholic fatty liver cell model.After intervention with 0.25 and 0.5 mg/mL of D.chinensis(L.)Nees.polysaccharides,the ALT and AST activity and TG and TC contents were detected with kits,and the changes in the expression of CDK5,TLR4,p-NF-κB and NF-κB were analyzed using Western-blotting.[Results]In the HepG2 cells induced with oleic acid,the ALT and AST activity increased significantly,the TG and TC contents increased significantly,and the expression levels of CDK5,TLR4 and p-NF-κB proteins up-regulated significantly.In the HepG2 cells intervened with D.chinensis(L.)Nees.polysaccharides,the activity of ALT and AST,the contents of TG and TC,and the expression levels of CDK5,TLR4 and p-NF-κB proteins all reduced significantly.[Conclusions]Polysaccharides from D.chinensis(L.)Nees.may interfere with NAFLD by inhibiting the TLR4/NF-κB pathway.

Quercetin regulates depression-like behavior in CUMS rat models via TLR4/NF-κB signaling

Background:Depression is becoming increasingly prevalent around the world,imposing a substantial burden on individuals,families,as well as society.Quercetin is known to be highly effective in treating depression.However,additional research is needed to dissect the mechanisms of its anti-depressive effects.Methods:For this study,Sprague-Dawley(SD)rats were randomized into the control,model,quercetin,or fluoxetine group.The latter three groups were exposed to chronic unpredictable mild stress(CUMS)for 42 d.The first two groups received saline solution daily via oral gavage.Meanwhile,the quercetin group was orally administered a quercetin suspension(52.08 mg/kg)every day,while the fluoxetine group was orally administered a fluoxetine solution(2.08 mg/kg).Here,fluoxetine served as the positive control drug to compare the therapeutic effects of quercetin.The experimental period was 6 weeks.Depressive behaviors in rats were assessed through various physiological and behavioral measures.Additionally,pathological changes in hippocampal tissues were examined using Nissl staining.Serum cytokines were detected using an enzymelinked immunosorbent assay(ELISA),and immunohistochemistry was employed to quantify the levels and integral optical density(IOD)values of ionized calcium binding adaptor molecule-1(Iba-1)expression in the brain.Real-time fluorescence quantitative PCR(RT-qPCR)was utilized to evaluate the mRNA levels of inflammatory indicators as well as toll-like receptor 4(TLR4),and nuclear factor-κappa B P65(NF-κB P65)in hippocampus.Western blot(WB)technique was employed to observe the protein levels of TLR4,NF-κB P65,and phospho-NF-κB P65(p-NF-κB P65).Results:After 42 d of exposure to CUMS,rats exhibited a slow increase in body weight,a reduction in food intake,an abnormal preference for sugar water,and aberrant open-field behaviors.Pathological analysis revealed the disintegration,rupture,interruption,and disorganization of hippocampal neuronal cells after CUMS exposure,along with a decrease in Nissl bodies in the CA1 region.This was accompanied by the elevated expression of interleukin-1β(IL-1β),tumor necrosis factor-α(TNF-α),and interleukin-6(IL-6)in the serum and the upregulation of IL-1β,IL-6,and TNF-αmRNA expression in the hippocampus.Increases in Iba-1-positive cells and the IOD values of Iba-1 were detected in hippocampal microglia.Furthermore,TLR4 and NF-κB P65 mRNA and protein levels were upregulated in hippocampal tissues.Quercetin,an antidepressant,could alleviate depression-like symptoms in rats and downregulate inflammatory factors associated with the TLR4/NF-κB signaling pathway in hippocampal microglia,and its therapeutic effect was comparable to fluoxetine.Conclusion:In rat models of CUMS,quercetin may act as an antidepressant by inhibiting inflammation in hippocampal microglia via TLR4/NF-κB signaling pathway.These results offer experimental and theoretical support for applying quercetin in the clinical management of depression.

Bioinformatic Analysis and Experimental Verification of QJHGD on Caerulein-induced Inflammatory Response in SAP Model Rats Based on TLR4/NF-κB/My D88 Pathway

[Objectives]To conduct bioinformatic analysis and experimental verification of Qingjie Huagong Decoction(QJHGD)on caerulein-induced inflammatory response in severe acute pancreatitis(SAP)model rats based on TLR4/NF-κB/MyD88 pathway.[Methods]The effective component groups and potential targets of QJHGD were collected by the network pharmacology method.A drug-component-target network was constructed.The GO and KEGG of targets were enriched and analyzed with the aid of Metascape database,and the target pathway related to SAP inflammation was screened.The SAP rat model was established by caerulein combined with lipopolysaccharide,and QJHGD was intragastrically administered.Pancreatic tissue was observed by HE staining.In addition,enzyme-linked immunosorbent assay and immunohistochemistry were used to verify the anti-inflammatory effect of QJHGD on SAP rats and its regulatory effect on TLR4/NF-κB/MyD88 target pathway.[Results]A total of 105 active components of QJHGD and 148 key targets of SAP were predicted and screened;KEGG was enriched in 320 different pathways including toll-like receptor and NF-κB classical pathways.Animal experiment verified that QJHGD reduced serum amylase,serum lipase activity,IL-6,TNF-αlevels in SAP rats;HE staining showed the effect of QJHGD on the pathological changes of pancreas,and QJHGD inhibited the positive expression of key proteins of TLR4,NF-κB and MyD88 in the inflammatory transduction pathway.[Conclusions]The mechanism of QJHGD improving pancreatic injury in SAP rats may be related to down-regulating the expression of key proteins in the TLR4/NF-κB/MyD88 pathway.

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.

Blautia producta displays potential probiotic properties against dextran sulfate sodium-induced colitis in mice

Blautia has attracted attention because of its potential efficacy in ameliorating host energy metabolism and inflammation.This study aims to investigate the influences of Blautia producta D4 on colitis induced by dextran sulfate sodium(DSS)and to reveal the underlying mechanisms.Results showed that B.producta D4 intervention significantly relieved body weight loss,and suppressed the elevation of pro-inflammatory cytokines(including interleukin-6(IL-6),tumor necrosis factor-α(TNF-α),and interleukin-1β(IL-1β))and excessive oxidative stress(myeloperoxidease(MPO)activity,superoxide dismutase(SOD)activity,glutathione peroxidase(GSH-Px)activity,and malondialdehyde(MDA)level)in colitis mice.Moreover,the concentrations of tight junction proteins(occludin,claudin-1,and ZO-1)related to the intestinal barrier were obviously elevated,and colitis-related TLR4/NF-κB pathway activation was remarkably inhibited after B.producta D4 intervention.The intestinal microbial disorder was evidently ameliorated by increasing the relative abundance of Clostridium sensu stricto 1,Bifidobacterium,GCA-900066225,Enterorhabdus,and reducing the relative abundance of Lachnospiraceae NK4A136 group.In conclusion,oral administration of B.producta D4 could ameliorate DSS-induced colitis by suppressing inflammatory responses,maintaining the intestinal barrier,inhibiting TLR4/NF-κB pathway,and regulating intestinal microbiota balance.These results are conducive to accelerate the development of B.producta D4 as a functional probiotic for colitis.

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.

Albiflorin attenuates inflammatory injury by regulating the TLR4 signaling pathway and its negative regulating factor Tollip in experimental models of ulcerative colitis

Albiflorin （AF） is the main active component extracted from Paeoniae Radix Alba. This study investigated the efficacy of AF in attenuating inflammatory injury by regulating the TLR4 signaling pathway and its negative regulating factor Tollip in an experimental ulcerative colitis （UC） model. We administrated trinitrobenzene sulfonic acid for 21 d to induce UC in rats. The efficacy of AF in attenuating UC was assessed using various biochemical markers, such as tumor necrosis factor-α （TNF-α）, interleukin- 1 （IL- 1）, interleukin- 10 （IL- 10）, 5-hydroxytryptamine （5-HT）, and tissue myeloperoxidase （MPO）, along with histopathological studies on toll-like receptor-4 （TLR-4） signaling pathway and its negative regulating factor Tollip. The results showed that AF can significantly downregulate the levels of TNF-α, IL-1, IL-10, and 5-HT. AF decreased the activation of TLR4, MyD88, and NF-κB p65 protein expression by increasing Tollip expression. AF can relieve symptoms of UC by suppressing the activation of the TLR4 signaling pathway and upregulating its negative regulating factor Tollip. Therefore, AF may be a potential natural product for treating UC.

Salvianolic Acid B Inhibits the TLR4-NFκ B-TNFα Pathway and Attenuates Neonatal Rat Cardiomyocyte Injury Induced by Lipopolysaccharide

Objective： To investigate the role of the TLR4-NF K B-TNFa inflammation pathway on lipopolysaccharide （LPS）-induced neonatal rat cardiomyocyte injury and the possible protective effects of salvianolic acid B （Sal B）. Methods： Wistar rat （1-2 days old） cardiomyocytes were isolated and cultured. Sal B 10-5mol/L, 10-6mol/L and 10-7mol/L were pro-treated for 6 h in the culture medium. LPS （1 μg/mL） was added to the culture medium and kept for 6 h to induce inflammation injury. The concentration of lactate dehydrogenase （LDH） in the supernatant was detected by spectrophotometry. The concentrations of tumor necrosis factor （TNF a） and heat shock protein 70 （HSP70） in the supernatant were detected by enzyme linked immunosorbent assay. The protein expressions of toll, such as receptor 4 （TLR4） and nuclear factor kappa B （NF K B） were detected by immunohistochemistry. The mRNA expressions of TLR4 and NF K B were detected by realtime reverse transcription polymerase chain reaction （RT-PCR）. Results： （1） The concentrations of LDH and TNF a in the LPS control group were significantly higher than those in the control group （561.41 ± 67,39 U/L and 77.94± 15.08 pg/mL, versus 292.13± 26.02 U/L and 25.39 ±16.53 pg/mL, respectively, P〈0.01, P〈0.05）. Compared with the LPS control group, the concentrations of LDH and TNF α were significantly decreased in the Sal B 10-5mol/L pro-treated group （451.76 ± 83.96 U/L and 34.00± 10.38 pg/mL, respectively, P〈0.05）. （2） The TLR4 and NF K B protein expression area in the LPS control group were significantly higher than those in the control group （1712.41 ± 410.12 μm2 and 2378.15 ± 175.29 μm2, versus 418.62 ± 24.42 μ m2 and 1721.74 ± 202.87μ m2, respectively, P〈0.01）. The TLR4 and NF K B protein expression internal optical density （IOD） values in the LPS control group were also significantly higher than those in the control group （3.06 ±0.33 and 7.20± 1.04, versus 0.91 ±0.21 and 4.24±0.48, respectively, P〈0.05 and P〈0.01）. Compared with the LPS control group, the TLR4 and NF K B protein expression areas were significantly decreased in the Sal B 10Smol/L pre-treated group （1251.54± 133.82 μ m2 and 1996.37 ± 256.67 μ m2, respectively, P〈0.05）, the TLR4 and NF K B protein expression IOD values were also significantly decreased in the Sal B 10-5mol/L pretreated group （1.92 ±0.28 and 5.17 ±0.77, respectively, P〈0.05）. （3） The TLR4 and NF K B mRNA expressions （2△△CT value） in the LPS control group were significantly higher than those in the control group （3.16 ± 0.38 and 5.03±0.43 versus 1.04±0.19 and 1.08±0.21, respectively, P〈0.01）. Compared with the LPS control group, the TLR4 and NF KB mRNA expressions （2△△CT value） were significantly decreased in the Sal B 10-5mol/L pre- treated group （1.34 ±0.22 and 1.74 ± 0.26, respectively, P〈0.05）. The concentration of HSP70 did not show any statistical differences in all groups （P〉0.05）. Conclusions： The TLR4-NF K B-TNF α pathway was quickly activated and was independent of HSP70 in the early phase of neonatal cardiomyocyte injury induced by LPS. The protective effects of Sal B may be through inhibiting the TLR4-NF K B-TNF a pathway and are dose-dependent.

Efficacy of herb-partitioned moxibustion at Qihai(CV 6) and bilateral Tianshu(ST 25) on colonic damage and the TLR4/NF-κB signaling pathway in rats with Crohn＇s disease

OBJECTIVE: To observe the effect of stimulating Qihai(CV 6) and bilateral Tianshu(ST 25) with herb-partitioned moxibustion(HPM) in rats with Crohn's disease(CD), and to investigate the possible anti-inflammatory mechanism of HPM.METHODS: Forty rats were randomly divided into four groups(n = 10 rats per group): normal control(NC), model control(MC), mesalamine(MES), and HPM. The CD rat model was established in the MC,MES, and HPM groups by administering a mixture of trinitrobenzenesulfonic acid and alcohol via enema. The HPM group received HPM on Qihai(CV 6)and bilateral Tianshu(ST 25), while the MES group received intragastric mesalamine. Colonic histomorphological scores, and serum concentrations of tumor necrosis factor α(TNF-α) and interleukin 1β(IL-1β) were assessed to evaluate the effects of HPM on colonic reparation and anti-inflammation.The expressions of Toll-like receptor 4(TLR-4), nuclear factor κB inhibitor α(IκB-α), IκB kinase α/β(IKKα/β), and NF-κB p65 were further analyzed to investigate the regulatory effects of the interventions on the TLR4/NF-κB pathway.RESULTS: CD rats showed inflammatory colonic damage and increased serum concentrations of TNF-α and IL-1β. The expressions of TLR4, IKKα/β,and NF-κB p65 in the colons of CD rats were significantly increased compared with the NC group,while the expression of IκBα(a key negative regulator of NF-κB p65) was decreased. HPM significantly mitigated colonic damage and reduced the serum concentrations of TNF-α and IL-1β. HPM downregulated the expressions of TLR4, IKKα/β, and NF-κB p65 in the colon, and upregulated the expression of IκBα. The effects of HPM in CD rats were similar to those of mesalamine.CONCLUSION: HPM alleviates colonic inflammation in CD rats. This may be achieved through regulation of TLR4, which induces NF-κB signal transduction.

Novel compound FLZ alleviates rotenoneinduced PD mouse model by suppressing TLR4/MyD88/NF-kB pathway through microbiotaegutebrain axis

Parkinson’s disease(PD)is the second most common neurodegenerative disease,but none of the current treatments for PD can halt the progress of the disease due to the limited understanding of the pathogenesis.In PD development,the communication between the brain and the gastrointestinal system influenced by gut microbiota is known as microbiota-gut-brain axis.However,the explicit mechanisms of microbiota dysbiosis in PD development have not been well elucidated yet.FLZ,a novel squamosamide derivative,has been proved to be effective in many PD models and is undergoing the phase I clinical trial to treat PD in China.Moreover,our previous pharmacokinetic study revealed that gut microbiota could regulate the absorption of FLZ in vivo.The aims of our study were to assess the protective effects of FLZ treatment on PD and to further explore the underlying microbiota-related mechanisms of PD by using FLZ as a tool.In the current study,chronic oral administration of rotenone was utilized to induce a mouse model to mimic the pathological process of PD.Here we revealed that FLZ treatment alleviated gastrointestinal dysfunctions,motor symptoms,and dopaminergic neuron death in rotenone-challenged mice.16 S rRNA sequencing found that PD-related microbiota alterations induced by rotenone were reversed by FLZ treatment.Remarkably,FLZ administration attenuated intestinal inflammation and gut barrier destruction,which subsequently inhibited systemic inflammation.Eventually,FLZ treatment restored blood-brain barrier structure and suppressed neuroinflammation by inhibiting the activation of astrocytes and microglia in the substantia nigra(SN).Further mechanistic research demonstrated that FLZ treatment suppressed the TLR4/MyD88/NF-κB pathway both in the SN and colon.Collectively,FLZ treatment ameliorates microbiota dysbiosis to protect the PD model via inhibiting TLR4 pathway,which contributes to one of the underlying mechanisms beneath its neuroprotective effects.Our research also supports the importance of microbiota-gut-brain axis in PD pathogenesis,suggesting its potential role as a novel therapeutic target for PD treatment.

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.

Modulating effects of Astragalus polysaccharide on immune disorders via gut microbiota and the TLR4/NF-κB pathway in rats with syndrome of dampness stagnancy due to spleen deficiency

The syndrome of dampness stagnancy due to spleen deficiency(DSSD)is relatively common globally.Although the pathogenesis of DSSD remains unclear,evidence has suggested that the gut microbiota might play a significant role.Radix Astragali,used as both medicine and food,exerts the effects of tonifying spleen and qi.Astragalus polysaccharide(APS)comprises a macromolecule substance extracted from the dried root of Radix Astragali,which has many pharmacological functions.However,whether APS mitigates the immune disorders underlying the DSSD syndrome via regulating gut microbiota and the relevant mechanism remains unknown.Here,we used DSSD rats induced by high-fat and low-protein(HFLP)diet plus exhaustive swimming,and found that APS of moderate molecular weight increased the body weight gain and immune organ indexes,decreased the levels of interleukin-1β(IL-1β),IL-6,and endotoxin,and suppressed the Toll-like receptor 4/nuclear factor-κB(TLR4/NF-κB)pathway.Moreover,a total of 27 critical genera were significantly enriched according to the linear discriminant analysis effect size(LEfSe).APS increased the diversity of the gut microbiota and changed its composition,such as reducing the relative abundance of Pseudoflavonifractor and Paraprevotella,and increasing that of Parasutterella,Parabacteroides,Clostridium XIVb,Oscillibacter,Butyricicoccus,and Dorea.APS also elevated the contents of short-chain fatty acids(SCFAs).Furthermore,the correlation analysis indicated that 12 critical bacteria were related to the body weight gain and immune organ indexes.In general,our study demonstrated that APS ameliorated the immune disorders in DSSD rats via modulating their gut microbiota,especially for some bacteria involving immune and inflammatory response and SCFA production,as well as the TLR4/NF-κB pathway.This study provides an insight into the function of APS as a unique potential prebiotic through exerting systemic activities in treating DSSD.