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.

LncRNA Airsci increases the inflammatory response after spinal cord injury in rats through the nuclear factor kappa B signaling pathway

Spinal cord injury(SCI)is a serious traumatic event to the central nervous system.Studies show that long non-coding RNAs(lncRNAs)play an important role in regulating the inflammatory response in the acute stage of SCI.Here,we investigated a new lncRNA related to spinal cord injury and acute inflammation.We analyzed the expression profile of lncRNAs after SCI,and explored the role of lncRNA Airsci(acute inflammatory response in SCI)on recovery following acute SCI.The rats were divided into the control group,SCI group,and SCI+lncRNA Airsci-siRNA group.The expression of inflammatory factors,including nuclear factor kappa B[NF-κB(p65)],NF-κB inhibitor IκBαand phosphorylated IκBα(p-IκBα),and the p-IκBα/IκBαratio were examined 1–28 days after SCI in rats by western blot assay.The differential lncRNA expression profile after SCI was assessed by RNA sequencing.The differentially expressed lncRNAs were analyzed by bioinformatics technology.The differentially expressed lncRNA Airsci,which is involved in NF-κB signaling and associated with the acute inflammatory response,was verified by quantitative real-time PCR.Interleukin(IL-1β),IL-6 and tumor necrosis factor(TNF-α)at 3 days after SCI were measured by western blot assay and quantitative real-time PCR.The histopathology of the spinal cord was evaluated by hematoxylin-eosin and Nissl staining.Motor function was assessed with the Basso,Beattie and Bresnahan Locomotor Rating Scale.Numerous differentially expressed lncRNAs were detected after SCI,including 151 that were upregulated and 186 that were downregulated in the SCI 3 d group compared with the control group.LncRNA Airsci was the most significantly expressed among the five lncRNAs involved in the NF-κB signaling pathway.LncRNA Airsci-siRNA reduced the inflammatory response by inhibiting the NF-κB signaling pathway,alleviated spinal cord tissue injury,and promoted the recovery of motor function in SCI rats.These findings show that numerous lncRNAs are differentially expressed following SCI,and that inhibiting lncRNA Airsci reduces the inflammatory response through the NF-κB signaling pathway,thereby promoting functional recovery.All experimental procedures and protocols were approved by the approved by the Animal Ethics Committee of Jining Medical University(approval No.JNMC-2020-DW-RM-003)on January 18,2020.

Study on the Hepatoprotective Effect of Oxalis coriniculata L. and Related Mechanism by Regulating Oxidative Stress and TLR-2/NF-κB Signaling Pathway

[Objectives]This study aimed to explore the protective effect of Oxalis coriniculata L.on rats with acute liver injury induced by carbon tetrachloride(CCl4)and related mechanism by regulating oxidative stress and the TLR-2 TLR-2/NF-κB signaling pathway.[Methods]A total of 48 female rats were randomly and evenly divided into normal group,model group,silymarin group(0.12 g/kg),and high(16 g/kg),middle(8 g/kg)and low-dose(4 g/kg)O.coriniculata L.groups.The rats in the groups were intragastrically administered with 5 mL/kg of corresponding drugs(equal-volume distilled water for normal group and control group),respectively.The administration was conducted twice a day,for 10 consecutive days.After 2 h of the last administration,the rats in all the groups except the normal group were intraperitoneally injected with 12%carbon tetrachloride(CCl4)olive oil solution(5 mL/kg),respectively to establish liver injury rat models.After 16 h,the eyeball blood of the rats was collected,and their liver tissues were collected for preparation of HE sections.The biochemical indicators detected included aspartate aminotransferase(AST),alanine aminotransferase(ALT),total superoxide dismutase(T-SOD)and glutathione peroxidase(GSH-Px)activity and malondialdehyde(MDA)content in the serum.The contents of tumor necrosis factor-α(TNF-α),interleukin-1β(IL-1β)and interleukin-6(IL-6)in the serum were detected by ELISA.The expression of Toll-like receptor-2(TLR-2)and nuclear factor-κB(NF-κB)in liver tissue was detected using Western blotting.The pathological changes of liver were observed under light microscope.[Results]Compared with the normal group,the ALT,AST activity and MDA,IL-1β,IL-6,TNF-αlevels in rat serum significantly increased(P<0.01),the GSH-Px,T-SOD activity in rat serum significantly decreased(P<0.01),and the expression of TLR-2 and NF-κB in liver tissue was up-regulated(P<0.01)in the model group.Compared with the model group,the ALT,AST activity and MDA,IL-1β,IL-6 and TNF-αlevels in rat serum reduced(P<0.05,P<0.01),the GSH-Px and T-SOD activity in rat serum increased(P<0.05,P<0.01),and the expression of TLR-2 and NF-κB in liver tissue was down-regulated(P<0.05,P<0.01)in the O.coriniculata L.administration groups.Pathological sections show that O.coriniculata L.had an improving effect on rats with acute liver injury induced by CCl4.[Conclusions]O.coriniculata L.has a good protective effect on rats with acute liver injury induced by CCl4.Its mechanism may be related to inhibition of oxidative stress,inhibition of inflammatory response and regulation of the TLR-2/NF-κB signaling pathway.

Inhibitory Effect of Bergenin on TLR-4/NF-κB Signal Pathway in Reducing Allergic Rhinitis in Mice

[Objectives]To explore the effect and possible mechanism of bergenin in relieving allergic rhinitis(AR)in mice.[Methods]50 C57/BL6 mice were randomly divided into blank group(n=10),model group(n=10)and high(100 mg/kg),medium(50 mg/kg)and low(25 mg/kg)dose bergenin groups with 10 mice in each group.Except for the blank group,the other mice were sensitized by basic ways combined with attack to replicate the AR model.From the 15th d of modeling(from the second d after the end of the basic modeling),the drug group was given bergenin orally for 15 d,and the blank group and model group were given the same volume of normal saline once a day.24 h after the last establishment of the model,the content of interleukin 4(IL-4),IL-6,TNF-αand IL-1βin nasal lavage fluid and serum of mice in each group was detected by ELISA.The expression of TLR-4,NF-κB and p-NF-κB in nasal mucosa of mice was detected by Western blot.[Results]Compared with the blank group,the content of inflammatory factors IL-4,IL-6,TNF-αand IL-1βin nasal lavage fluid and serum of model group was significantly increased,and the protein expression of TLR-4 and p-NF-κB was significantly increased.After the intervention of bergenin,the content of IL-4,IL-6,TNF-αand IL-1βin nasal lavage fluid and serum and TLR-4 and p-NF-κB protein in tissue was significantly inhibited in bergenin group.[Conclusions]Bergenin can effectively reduce allergic inflammation in AR model mice,and its mechanism may be related to inhibition of inflammation and down-regulation of TLR-4/NF-κB signal pathway.

Nucleolin Mediates LPS-induced Expression of Inflammatory Mediators and Activation of Signaling Pathways

Summary:In this study,we investigated the effects of nucleolin on lipopolysaccharide(LPS)-induced activation of MAPK and NF-KappaB(NF-kB)signaling pathways and secretion of TNF-a,IL-1βand HMGB1 in THP-1 monocytes.Immunofluorescence assay and Western blotting were used to identify the nucleolin expression in cell membrane,cytoplasm and nucleus of THP-1 monocytes.Inactivation of nucleolin was induced by neutralizing antibody against nucleolin.THP-1 monocytes were pretreated with anti-nucleolin antibody for 1 h prior to LPS challenge.The irrelevant IgG group was used as control.Secretion of inflammatory mediators(TNF-a,IL-1β and HMGB1)and activation of MAPK and NF-kB/I-kB signaling pathways were examined to assess the effects of nucleolin on LPS-mediated inflammatory response.Nucleolin existed in cell membrane,cytoplasm and nucleus of THP-1 monocytes.Pretreatment of anti-nucleolin antibody significantly inhibited the LPS-induced secretion of TNF-a,IL-1β and HMGB1.P38,JNK,ERK and NF-κB subunit p65 inhibitors could significantly inhibit the secretion of IL-1β,TNF-a and HMGB1 induced by LPS.Moreover,the phosphorylation of p38,JNK,ERK and p65(or nuclear translocation of p65)was significantly increased after LPS challenge.In contrast,pretreatment of anti-nucleolin antibody could significantly inhibit the LPS-induced phosphorylation of p38,JNK,ERK and p65(or nuclear translocation of p65).However,the irrelevant IgG,as a negative control,had no effect on LPS-induced secretion of TNF-a and IL-Iβ and phosphorylation of p38,JNK,ERK and p65(or nuclear translocation of p65).We demonstrated that nucleolin mediated the LPS-induced activation of MAPK and NF-κB signaling pathways,and regulated the secretion of inflammatory mediators(TNF-a,IL-1β and HMGB1).

Porcine enteric alphacoronavirus infection increases lipid droplet accumulation to facilitate the virus replication

Coronaviruses are widely transmissible between humans and animals, causing diseases of varying severity. Porcine enteric alphacoronavirus(PEAV) is a newly-discovered pathogenic porcine enteric coronavirus in recent years, which causes watery diarrhea in newborn piglets. The host inflammatory responses to PEAV and its metabolic regulation mechanisms remain unclear, and no antiviral studies have been reported. Therefore, we investigated the pathogenic mechanism and antiviral drugs of PEAV. The transcriptomic analysis of PEAV-infected host cells revealed that PEAV could upregulate lipid metabolism pathways. In lipid metabolism, steady-state energy processes, which can be mediated by lipid droplets(LDs), are the main functions of organelles. LDs are also important in viral infection and inflammation. In infected cells, PEAV increased LD accumulation, upregulated NF-κB signaling, promoted the production of the inflammatory cytokines IL-1β and IL-8, and induced cell death. Inhibiting LD accumulation with a DGAT-1 inhibitor significantly inhibited PEAV replication, downregulated the NF-κB signaling pathway, reduced the production of IL-1β and IL-8, and inhibited cell death. The NF-κB signaling pathway inhibitor BAY11-7082 significantly inhibited LD accumulation and PEAV replication. Metformin hydrochloride also exerted anti-PEAV effects and significantly inhibited LD accumulation, downregulated the NF-κB signaling pathway, reduced the production of IL-1β and IL-8, and inhibited cell death. LD accumulation in the lipid metabolism pathway therefore plays an important role in the replication and pathogenesis of PEAV, and metformin hydrochloride inhibits LD accumulation and the inflammatory response to exert anti-PEAV activity and reducing pathological injury. These findings contribute new targets for developing treatments for PEAV infections.

Taurolidine improved protection against highly pathogenetic avian influenza H5N1 virus lethal-infection in mouse model by regulating the NF-κB signaling pathway

Taurolidine(TRD),a derivative of taurine,has anti-bacterial and anti-tumor effects by chemically reacting with cell-walls,endotoxins and exotoxins to inhibit the adhesion of microorganisms.However,its application in antiviral therapy is seldom reported.Here,we reported that TRD significantly inhibited the replication of influenza virus H5N1 in MDCK cells with the half-maximal inhibitory concentration(EC_(50))of 34.45μg/mL.Furthermore,the drug inhibited the amplification of the cytokine storm effect and improved the survival rate of mice lethal challenged with H5N1(protection rate was 86%).Moreover,TRD attenuated virus-induced lung damage and reduced virus titers in mice lungs.Administration of TRD reduced the number of neutrophils and increased the number of lymphocytes in the blood of H5N1 virus-infected mice.Importantly,the drug regulated the NF-κB signaling pathway by inhibiting the separation of NF-κB and IκBa,thereby reducing the expression of inflammatory factors.In conclusion,our findings suggested that TRD could act as a potential anti-influenza drug candidate in further clinical studies.

Targeted and activatable nanosystem for fluorescent and optoacoustic imaging of immune-mediated inflammatory diseases and therapy via inhibiting NF-κB/NLRP3 pathways

Immune-mediated inflammatory diseases(IMIDs)represent a diverse group of diseases and challenges remain for the current medications.Herein,we present an activatable and targeted nanosystem for detecting and imaging IMIDs foci and treating them through blocking NF-κB/NLRP3 pathways.A ROS-activatable prodrug BH-EGCG is synthesized by coupling a near-infrared chromophore with the NF-κB/NLRP3 inhibitor epigallocatechin-3-gallate(EGCG)through boronate bond which serves as both the fluorescence quencher and ROS-responsive moiety.BH-EGCG molecules readily form stable nanoparticles in aqueous medium,which are then coated with macrophage membrane to ensure the actively-targeting capability toward inflammation sites.Additionally,an antioxidant precursor N-acetylcysteine is co-encapsulated into the coated nanoparticles to afford the nanosystem BH-EGCG&NAC@MM to further improve the anti-inflammatory efficacy.Benefiting from the inflammation-homing effect of the macrophage membrane,the nanosystem delivers payloads(diagnostic probe and therapeutic drugs)to inflammatory lesions more efficiently and releases a chromophore and two drugs upon being triggered by the overexpressed in-situ ROS,thus exhibiting better theranostic performance in the autoimmune hepatitis and hind paw edema mouse models,including more salient imaging signals and better therapeutic efficacy via inhibiting NF-κB pathway and suppressing NLRP3 inflammasome activation.This work may provide perceptions for designing other actively-targeting theranostic nanosystems for various inflammatory diseases.

Long non-coding RNA Coro Marker regulates oxidized LDL-induced inflammatory injury via NF-κB/NLRP3 signaling pathway

Background Long noncoding RNAs(lnc RNAs) are considered to be important for the development and progression of atherosclerosis. The lnc RNA AC100865.1(referred to as Coro Marker) has been recognized a novel and specific biomarker of coronary artery disease. However, its underlying molecular mechanisms remain unclear.Objective: The aim of this study was to investigate the implication of Coro Marker in oxidized low-density lipoprotein(ox-LDL)-induced apoptosis and inflammation in THP-1 cells. The regulatory relationship between Coro Marker and the nuclear factor kappa B(NF-κB)/NOD-like receptor protein 3(NLRP3) pathway was also explored.Methods: THP-1 cells were stimulated with ox-LDL to induce inflammatory injury. The expression of Coro Marker was silenced by small interfering RNA. Cell apoptosis were assessed by flow cytometry. Inflammatory response was determined by detecting levels of inflammatory cytokines using quantitative real-time polymerase chain reaction(q RT-PCR) and enzyme-linked immunosorbent assay(ELISA). Furthermore, western blot was used to assess the expression of NF-κB/NLRP3 signaling pathway-related proteins. Results: Ox-LDL markedly induced cell injury by promoting cell apoptosis, oxidative stress, and inflammation. Meanwhile, the expression of Coro Marker was also up-regulated in ox-LDL-injured THP-1 cells. The knockdown of Coro Marker reduced apoptosis rate and significantly changed the expression levels of apoptosis-related genes(Bax and BCL-2). In addition, knockdown of Coro Marker relieved oxidative stress by significant changes in the level of malondialdehyde, superoxide dismutase, and reactive oxygen species, and attenuated inflammatory injury by inhibit the production of interleukin-1β(IL-1β), IL-6 and tumor necrosis factor alpha(TNF-α). Importantly, the suppression of Coro Marker decreased the expression of NF-κB/NLRP3 signaling pathway-related proteins, including p-NF-κB, p-Ik Bα and NLRP3.Conclusion: This study demonstrated that downregulation of Coro Marker alleviated ox-LDL-induced oxidative stress and inflammatory injury in THP-1 cells, possibly by modulating the NF-κB/NLRP3 signaling pathway.

Effect of warming yang and supplementing kidney moxibustion therapy on the NF-κB signaling pathway of vascular dementia rats

Objective： To observe the effect of warming yang and supplementing kidney moxibustion therapy on the behavioristics and the expression levels of hippocampal IL-1β, TNF-α and NF-κB related genes and proteins of vascular dementia（VD） rats, and to explore the mechanism of warming yang and supplementing kidney moxibustion therapy in inhibiting VD inflammatory response. Methods Seventy-eight SD rats, except 10 rats as sham operation group（group A）, were established into VD models by applying the ischemia reperfusion method in bilateral common carotid arteries. 30 models were successful and were randomly divided into model group（group B）, moxibustion group（group C） and western medication group（group D）, with 10 rats in each group. After modeling, suspended moxibustion was conducted at ＂Dàzhuī（大椎GV 14）＂,＂Mìngmén（命门GV 4）＂ and ＂Guānyuán（关元CV 4）＂ of the rats in group C for15 min/time. The intervention was performed for once a day, and intervention for 4 consecutive weeks was needed. Intragastric administration with nimodipine（2 mgkg-1d-1） was carried out in the rats in group D for 4 consecutive weeks. Morris water maze test was adopted for behavioral test in the rats in each group. HE staining was conducted in order to observe the pathological changes. RT-qPCR method and Western blot method were used for detecting the expression levels of hippocampal IL-1β, TNF-αand NF-κB related genes and proteins.Results： After modeling, the Morris water maze escape latency of rats in operation groups was obviously longer than that in group A（P〈0.05）. According to HE staining results, the arrangement of neurons in group B was incompact, the cell membranes were undefined, the cytoplasm was heterogeneous, karyopyknosis was found, the amount of necrosis increased, and the number of inflammatory cells significantly increased. Compared with group B, the number of inflammatory cells significantly reduced in group C and group D, and the amount of neuron necrosis also reduced. After intervention, compared with group B, the expression levels of TNF-a, p-IκB and NF-κBp65 mRNA in the hippocampal of the rats in group C and group D significantly decreased（all P〈0.05）, compared with group B, the expression levels of IL-1β, TNF-α and NF-κBp65 mRNA in the hippocampal of rats in group C and group D also significantly decreased（all P〈0.05）.Conclusion： Warming yang and supplementing kidney moxibustion therapy may inhibit the NF-κB signaling pathway and reduce the inflammatory response through lowering the expression levels of IL-1β,TNF-α and NF-κB mRNA in the brain, thus achieving the purpose of treating VD.

Assessing the therapeutic impact of Qianjinba polysaccharide in a rheumatoid arthritis murine model

Qianjinba is primarily cultivated in the southern regions of China and finds extensive use in traditional Chinese medicine(TCM)for conditions such as rheumatism,arthralgia,and gynecological ailments.It has been officially recognized as a protected variety of TCM by the state.The aim of this study was to investigate the therapeutic potential of Qianjinba polysaccharide(QJBDT)in treating rheumatoid arthritis(RA)in mice,along with a preliminary exploration of its mechanisms for inhibiting RA in these animals.Kunming mice(KM)were randomly divided into several groups,including a normal group,a model group(LPS group),low-dose,medium-dose,and high-dose QJBDT groups,as well as a positive control group(TGP group),each consisting of 10 mice.To induce inflammation and create an RA model,type II collagen was injected into the right hind foot joint.Following a 7-day modeling period,various concentrations of QJBDT and the positive control drug total glycoside of peony were administered via gavage once a day for 21 consecutive days.Throughout the study,we monitored and recorded the mice's weight,measured foot swelling,and assessed the arthritis index on a weekly basis.We also conducted pathological examinations of joint tissues and analyzed the signal pathway of p38 mitogen-activated protein kinase(MAPK)as well as the protein expression of nuclear factor NF-κB in the mice’s right foot joint tissues.Additionally,we employed ELISA to detect the levels of interleukin-β(IL-β),IL-17,and tumor necrosis factor-α(TNF-α)in the mice’s serum.The results of this study revealed that QJBDT effectively reduced the degree of foot swelling and the arthritis index in collagen-induced arthritis mice while improving their weight loss(P<0.05).Furthermore,it alleviated the pathological damage observed in the mice’s joints.Notably,the expression of transcription factors p38 and NF-κB proteins was down-regulated(P<0.05),and the levels of inflammatory cytokines IL-β,IL-17,and TNF-αin the mice’s serum were decreased(P<0.05).In conclusion,this study demonstrated that polysaccharides could inhibit the expression of transcription factors p38 and NF-κB,reduce the production of inflammatory factors,and alleviate the progression of RA to a certain extent.

Discovery of novel aporphine alkaloid derivative as potent TLR2 antagonist reversing macrophage polarization and neutrophil infiltration against acute inflammation

Toll-like receptor 2(TLR2)mediated macrophages regulate the protective immune response to infectious microorganisms,but the aberrant activation of macrophages often leads to pathological inflammation,including tissue damage.In this study,we identified antagonists of TLR2 by screening2100 natural products and subsequently identified Taspine,an aporphine alkaloid,as an excellent candidate.Furthermore,analysis of the 10 steps chemical synthesis route and structural optimization yielded the Taspine derivative SMU-Y6,which has higher activity,better solubility,and improved drug-feasible property.Mechanistic studies and seq-RNA analysis revealed that SMU-Y6 inhibited TLR2 over other TLRs,hindered the formation of TLR2/MyD88 complex,and blocked the downstream NF-κB and MAPK signaling pathway,thus suppressing the release of inflammatory cytokines.SMU-Y6 could stabilize TLR2 and bind to TLR2 protein with a Kdof 0.18μmol/L.Additionally,SMU-Y6 could efficiently reverse the M1 phenotype macrophage polarization,reduce the production of cytokines as well as infiltration of neutrophiles and alleviate the local inflammation in mice with acute paw edema and colitis.Collectively,we reported the first aporphine alkaloid derivative that selectively inhibits TLR2 with high binding affinity and superior drug-feasible property,thus providing an urgently-needed molecular probe and potential drug candidate for inflammatory and autoimmune disease therapy.