Nucleotide-binding oligomerization domain 1(NOD1) is an intracellular innate immune sensor for small molecules derived from bacterial cell components. NOD1 activation by its ligands leads to robust production of pro-i...Nucleotide-binding oligomerization domain 1(NOD1) is an intracellular innate immune sensor for small molecules derived from bacterial cell components. NOD1 activation by its ligands leads to robust production of pro-inflammatory cytokines and chemokines by innate immune cells, thereby mediating mucosal host defense systems against microbes. Chronic gastric infection due to Helicobacter pylori(H. pylori) causes various upper gastrointestinal diseases, including atrophic gastritis, peptic ulcers, and gastric cancer. It is now generally accepted that detection of H. pylori by NOD1 expressed in gastric epithelial cells plays an indispensable role in mucosal host defense systems against this organism. Recent studies have revealed the molecular mechanism by which NOD1 activation caused by H. pylori infection is involved in the development of chronic gastritis and gastric cancer. In this review, we have discussed and summarized how sensing of H. pylori by NOD1 mediates the prevention of chronic gastritis and gastric cancer.展开更多
Adenine is an essential building block of genetic material and a range of coenzymes.Chemical probes containing an adenine moiety have been used in kinase profiling studies in cell lysates.Here we report that adenine-d...Adenine is an essential building block of genetic material and a range of coenzymes.Chemical probes containing an adenine moiety have been used in kinase profiling studies in cell lysates.Here we report that adenine-derived small-molecule probes with an activated ester reactive group can covalently modify a conserved lysine residue of protein kinases and capture a number of nucleotide-binding proteins within living cells.展开更多
Bacterial wilt disease caused by several Ralstonia species is one of the most destructive diseases in Solanaceae crops.Only a few functional resistance genes against bacterial wilt have been cloned to date.Here,we sho...Bacterial wilt disease caused by several Ralstonia species is one of the most destructive diseases in Solanaceae crops.Only a few functional resistance genes against bacterial wilt have been cloned to date.Here,we showthat the broadly conserved typeⅢsecreted effector RipY is recognized by the Nicotiana benthamiana immune system,leading to cell death induction,induction of defense-related gene expression,and restriction of bacterial pathogen growth.Using a multiplexed virus-induced gene-silencing-based N.benthamiana nucleotide-binding and leucine-rich repeat receptor(NbNLR)library,we identified a coiled-coil(CC)nucleotide-binding and leucine-rich repeat receptor(CNL)required for recognition of RipY,which we named RESISTANCE TO RALSTONIA SOLANACEARUM RIPY(RRS-Y).Genetic complementation assays in RRS-Y-silenced plants and stable rrs-y knockout mutants demonstrated that RRS-Y is sufficient to activate RipY-induced cell death andRipY-induced immunity to Ralstonia pseudosolanacearum.RRS-Y function is dependent on the phosphate-binding loop motif of the nucleotide-binding domain but independent of the characterized signaling components ENHANCED DISEASE SUSCEPTIBILITY 1,ACTIVATED DISEASE RESISTANCE 1,and N REQUIREMENT GENE 1 and the NLR helpers NB-LRR REQUIRED FOR HR-ASSOCIATED CELL DEATH-2,-3,and-4 in N.benthamiana.We further show that RRS-Y localization at the plasma membrane is mediated by two cysteine residues in the CC domain and is required for RipY recognition.RRSY also broadly recognizes RipY homologs across Ralstonia species.Lastly,we show that the C-terminal region of RipY is indispensable for RRS-Y activation.Together,our findings provide an additional effector/receptor pair system to deepen our understanding of CNL activation in plants.展开更多
Objective The ATP responsive P2 purinergic receptors can be subdivided into metabotropic P2X family and ionotropic P2Y family.Among these,P2X3 is a type of P2X receptor which is specifically expressed on nerves,especi...Objective The ATP responsive P2 purinergic receptors can be subdivided into metabotropic P2X family and ionotropic P2Y family.Among these,P2X3 is a type of P2X receptor which is specifically expressed on nerves,especially on pre-ganglionic sensory fibers.This study investigates whether gefapixant possesses the potential of inhibiting cardiac sympathetic hypersensitivity to protect against cardiac remodeling in the context of myocardial infarction.Methods The Sprague-Dawley rats were divided randomly into three groups:sham group-myocardial infarction group,and myocardial infarction with gefapixant treatment group.Myocardial infarction was induced by left anterior descending branch ligation.The gefapixant solution was intraperitoneally injected each time per day for 7 days and the appropriate dosage of gefapixant was determined according to the results of hematoxylin-eosin(HE)staining and myocardial injury biomarkers.Conditions of cardiac function were assessed by echocardiograph and cardiac fibrosis was evaluated by Western blotting and immunofluorescence staining of collagen I and collagen III.The sympathetic innervation was detected by norepinephrine concentration(pg/mL),in-vivo electrophysiology,and typical sympathetic biomarkers.Inflammatory cell infiltration was shown from immunofluorescence staining and pro-inflammatory signaling pathway activation was checked by immunohistology,quantitative realtime PCR(qPCR)and Western blotting.Results It was found that gefapixant injection of 10 mg/kg per day had the highest dosage-efficacy ratio.Furthermore,gefapixant treatment improved cardiac pump function as shown by increased LVEF and LVFS,and decreased LVIDd and LVIDs.The expression levels of collagen I and collagen III,and TNF-αwere all decreased by P2X3 inhibition.Mechanistically,the decreased activation of nucleotide-binding and oligomerization domain-like receptors family pyrin-domain-containing 3(NLRP3)inflammasome and subsequent cleavage of caspase-1 which modulated interleukin-1β(IL-1β)and IL-18 level in heart after gefapixant treatment were associated with the suppressed cardiac inflammation.Conclusion It is suggested that P2X3 inhibition by gefapixant ameliorates post-infarct autonomic nervous imbalance,cardiac dysfunction,and remodeling possibly via inactivating NLRP3 inflammasome.展开更多
Spontaneous bacterial peritonitis(SBP) is a frequent, life-threatening bacterial infection in patients with liver cirrhosis and ascites. Portal hypertension leads to increased bacterial translocation from the intestin...Spontaneous bacterial peritonitis(SBP) is a frequent, life-threatening bacterial infection in patients with liver cirrhosis and ascites. Portal hypertension leads to increased bacterial translocation from the intestine. Failure to eliminate invading pathogens due to immune defects associated with advanced liver disease on the background of genetic predisposition may result in SBP. The efficacy of antibiotic treatment and prophylaxis has declined due to the spread of multi-resistant bacteria. Patients with nosocomial SBP and with prior antibiotictreatment are at a particularly high risk for infection with resistant bacteria. Therefore, it is important to adapt empirical treatment to these risk factors and to the local resistance profile. Rifaximin, an oral, nonabsorbable antibiotic, has been proposed to prevent SBP, but may be useful only in a subset of patients. Since novel antibiotic classes are lacking, we have to develop prophylactic strategies which do not induce bacterial resistance. Farnesoid X receptor agonists may be a candidate, but so far, clinical studies are not available. New diagnostic tests which can be carried out quickly at the patient's site and provide additional prognostic information would be helpful. Furthermore, we need tools to predict antibiotic resistance in order to tailor first-line antibiotic treatment of spontaneous bacterial peritonitis to the individual patient and to reduce mortality.展开更多
Background:The nucleotide-binding and oligomerization domain-like receptor protein 3 (NLRP3) inflammasome composed of NLRP3,apoptosis-associated speck-like protein containing CARD (ASC),and caspase-1 is engaged in the...Background:The nucleotide-binding and oligomerization domain-like receptor protein 3 (NLRP3) inflammasome composed of NLRP3,apoptosis-associated speck-like protein containing CARD (ASC),and caspase-1 is engaged in the inflammatory response of many kidney diseases and can be activated by purinergic 2X7 receptor (P2X7R).This study was conducted to explore whether P2X7R plays a pathogenic role in the podocyte damage of obesity-related glomerulopathy (ORG) and whether this role is mediated by the activation ofNLRP3 inflammasome.Methods:A mouse model of ORG was established by high-fat diet feeding.The conditionally immortalized mouse podocytes were cultured with leptin or with leptin and P2X7R antagonist (KN-62 or A438079).The mRNA and protein expression of the P2X7R and NLRP3 inflammasome components including NLRP3,ASC,and caspase-1,as well as the podocyte-associated molecules including nephrin,podocin,and desmin in mouse renal cortex or cultured mouse podocytes were tested by real-time-polymerase chain reaction and Westem blot analysis,respectively.Results:The significantly upregulated expression of P2X7R and NLRP3 inflammasome components and the NLRP3 inflammasome activation were observed in the renal cortex (in fact their location in podocytes was proved by confocal microscopy) of ORG mice in vivo,which were accompanied with the morphological changes of podocyte damage and the expression changes of podocyte-associated molecules.Similar changes in the expression of P2X7R and NLRP3 inflammasome components as well as in the expression ofpodocyte-associated molecules were also observed in the cultured podocyte studies treated by leptin in vitro,and all of the above changes were significantly attenuated by the P2X7R antagonist KN-62 or A438079.Conclusions:P2X7R could trigger the activation ofNLRP3 inflammasome,and the activated P2X7R/NLRP3 inflammasome in podocytes might be involved in the podocyte damage of ORG.展开更多
Obstructive sleep apnea can worsen the prognosis of subarachnoid hemorrhage.Howeve r,the underlying mechanism remains unclear.In this study,we established a mouse model of subarachnoid hemorrhage using the endovascula...Obstructive sleep apnea can worsen the prognosis of subarachnoid hemorrhage.Howeve r,the underlying mechanism remains unclear.In this study,we established a mouse model of subarachnoid hemorrhage using the endovascular perforation method and exposed the mice to intermittent hypoxia for 8 hours daily for 2 consecutive days to simulate sleep apnea.We found that sleep apnea aggravated brain edema,increased hippocampal neuron apoptosis,and worsened neurological function in this mouse model of subarachnoid hemorrhage.Then,we established an in vitro HT-22 cell model of hemin-induced subarachnoid hemorrhage/intermittent hypoxia and found that the cells died,and lactate dehydrogenase release increased,after 48 hours.We further investigated the underlying mechanism and found that sleep apnea increased the expression of hippocampal neuroinflammatory factors interleukin-1β,interleukin-18,inte rleukin-6,nuclear factorκB,pyro ptosis-related protein caspase-1,pro-caspase-1,and NLRP3,promoted the prolife ration of astrocytes,and increased the expression of hypoxia-inducible factor 1αand apoptosis-associated speck-like protein containing a CARD,which are the key proteins in the hypoxia-inducible factor 1α/apoptosis-associated speck-like protein containing a CARD signaling pathway.We also found that knockdown of hypoxia-inducible factor 1αexpression in vitro greatly reduced the damage to HY22 cells.These findings suggest that sleep apnea aggravates early brain injury after subarachnoid hemorrhage by aggravating neuroinflammation and pyroptosis,at least in part through the hypoxia-inducible factor 1α/apoptosis-associated speck-like protein containing a CARD signaling pathway.展开更多
Two sets of degenerate oligonucleotide primers were designed according to amino acid conserved regions of reported plant disease resistance genes which encode proteins that contain nucleotide-binding site and leucine-...Two sets of degenerate oligonucleotide primers were designed according to amino acid conserved regions of reported plant disease resistance genes which encode proteins that contain nucleotide-binding site and leucine-rich repeats(NBS-LRR), and the plant disease resistance genes which encode serine/threonine protein kinase(STK). By polymerase chain reaction(PCR), disease resistance gene analogues have been amplified from three wild rice species in Yunnan Province, China. The DIN A fragments from amplification have been cloned into the pGEM-T vector respectively. Sequencing of the DNA fragments indicated that 7 classes, 2 classes and 6 classes NBS-LRR disease resistance gene analogues from Oryza rufipogon Griff. , Oryza officinalis Wall. , and Oryza meyeriana Baill. were obtained respectively. The two representative fragments of TO12 from Oryza officinalis Wall, and TR19 from Oryza rufipogon Griff, belong to the same class and homology of their sequences are 100%. The result shows that the sequences of the same class disease resistance gene analogues have no difference among different species of wild rice. 5 classes STK disease resistance gene analogues were also obtained among which 4 classes from Oryza rufipogon Griff. , 1 class from Oryza officinalis Wall. By comparison analysis of amino acid sequences. we found that the obtained disease resistance gene analogues have very low identity(low to 25%) with the reported disease resistance gene L6, N, Bs2, Prf, Pto, Lr10 and Xa21 etc. The finding suggests that the obtained disease resistance gene analogues are analogues of putative disease resistance genes that have not been isolated so far.展开更多
Due to the overwhelming burden of colorectal cancer(CRC), great effort has been placed on identifying genetic mutations that contribute to disease development and progression. One of the most studied polymorphisms tha...Due to the overwhelming burden of colorectal cancer(CRC), great effort has been placed on identifying genetic mutations that contribute to disease development and progression. One of the most studied polymorphisms that could potentially increase susceptibility to CRC involves the nucleotide-binding and oligomerization-domain containing 2(NOD2) gene. There is growing evidence that the biological activity of NOD2 is far greater than previously thought and a link with intestinal microbiota and mucosal immunity is increasingly sought after. In fact, microbial composition may be an important contributor not only to inflammatory bowel diseases(IBD) but also to CRC. Recent studies have showed that deficient NOD2 function confers a communicable risk of colitis and CRC. Despite the evidence from experimental models, population-based studies that tried to link certain NOD2 polymorphisms and an increase in CRC risk have been described as conflicting. Significant geographic discrepancies in the frequency of such polymorphisms and different interpretations of the results may have limited the conclusions of those studies. Since being first associated to IBD and CRC, our understanding of the role of this gene has come a long way, and it is tempting to postulate that it may contribute to identify individuals with susceptible genetic background that may benefit from early CRC screening programs or in predicting response to current therapeutic tools. The aim of this review is to clarify the status quo of NOD2 mutations as genetic risk factors to chronic inflammation and ultimately to CRC. The use of NOD2 as a predictor of certain phenotypic characteristics of the disease will be analyzed as well.展开更多
Pattern recognition receptor(PRR)is a kind of sensor which is mainly expressed on the surface of innate immune cells.It can recognize pathogen related molecular patterns(PAMPs)or damage related molecular patterns(DAMP...Pattern recognition receptor(PRR)is a kind of sensor which is mainly expressed on the surface of innate immune cells.It can recognize pathogen related molecular patterns(PAMPs)or damage related molecular patterns(DAMPs).The innate immune system uses pattern recognition receptors to recognize pathogenic microorganisms in periodontal tissues and transmit signals to downstream pathways in time,thus triggering immune responses and then eliminating them.PRR has many family members,including toll like receptor family(TLRs),C-type lectin receptor family(CLRs),retinoic acid induced gene I(RIG-I)like receptor family(RLRs)and nucleotide binding oligomer domain(NOD)like receptor family(NLRs).Among them,RLRs are cytoplasmic receptors that recognize dsRNA from RNA viruses and have little association with chronic periodontitis.In this paper,the classification and structure of TLRs,CLRs,NLRs and the role of signal transduction pathway in chronic periodontitis are reviewed.In order to enrich the pathogenesis of periodontitis,provide new ideas for the treatment and prevention of chronic periodontitis.展开更多
Objective To explore the immune stimulation effect of recombinant E.coli LLO/OVA on mice bone marrow-derived dendritic cells (BMDCs) and T lymphocytes in vitro.Methods After BMDCs stimulated by E.coli LLO/OVA,their ...Objective To explore the immune stimulation effect of recombinant E.coli LLO/OVA on mice bone marrow-derived dendritic cells (BMDCs) and T lymphocytes in vitro.Methods After BMDCs stimulated by E.coli LLO/OVA,their Toll-like receptor (TLR) and nucleotide-binding oligomerization domain (NOD) receptor signalling pathway were examined by superarray hybridization;and the priming effect of the vaccine activated BMDCs on CD4+T and CD8+T was determined by [3H]thymidine uptake and ELISA,the tumor cytotoxic effect of activated CD8+T cells was determined by cytotoxic assay.Results After BMDCs were activated by E.coli LLO/OVA via TLR4,NOD1 receptor and NF-κB signalling pathway,the expression of their surface molecules including MHC class Ⅰ,MHC class Ⅱ,CD40,CD80 and CD86 significantly up-regulated;the secretion of IL-12 and IFN-? increased also.The mature BMDCs stimulated the allergic CD4+T and CD8+T cells proliferation and their IL-2 and IFN-γ secretion,and the activated CD8+T cells effectively killed B16-OVA melanoma cells and RMA-S/OVA lymphoma cells in vitro.Conclusion E.coli LLO/OVA is effective in inducing BMDCs maturation via activating TLR4 and NOD1 receptor signalling pathway and promoting specific anti-tumor T cell immunity in vitro.展开更多
Endoparasitoid wasps introduce venom into their host insects during the egglaying stage.Venom proteins play various roles in the host physiology,development,immunity,and behavior manipulation and regulation.In this st...Endoparasitoid wasps introduce venom into their host insects during the egglaying stage.Venom proteins play various roles in the host physiology,development,immunity,and behavior manipulation and regulation.In this study,we identified a venom protein,MmRhol,a small guanine nucleotide-binding protein derived from ovary in the endoparasitoid wasp Microplitis mediator and found that knockdown of its expression by RNA interference caused down-regulation of vitellogenin and juvenile hormone,egg production,and cocoons formation in the female wasps.We demonstrated that MmRho1 entered the cotton bollworm's(host)hemocytes and suppressed cellular immune responses after parasitism using immunofluorescence staining.Furthermore,wasp MmRhol interacted with the cotton bollworm's actin cytoskeleton rearrangement regulator diaphanous by yeast 2-hybrid and glutathione s-transferase pull-down.In conclusion,this study indicates that MmRho1 plays dual roles in wasp development and the suppression of the host insect cellular immune responses.展开更多
Plant genomes harbor dozens to hundreds of nucleotide-binding site-leucine-rich repeat (NBS-LRR) genes; however, the long-term evolutionary history of these resistance genes has not been fully understood, This study...Plant genomes harbor dozens to hundreds of nucleotide-binding site-leucine-rich repeat (NBS-LRR) genes; however, the long-term evolutionary history of these resistance genes has not been fully understood, This study focuses on five Brassicaceae genomes and the Carica papaya genome to explore changes in NBS-LRR genes that have taken place in this Rosid II lineage during the past 72 million years. Various numbers of NBS-LRR genes were identified from Arabidopsis lyrata (198), A. thaliana (165), Brassica rapa (204), Capsella rubella (127), Thellungiella salsuginea (88), and C. papaya (51). In each genome, the identified NBS-LRR genes were found to be unevenly distributed among chromosomes and most of them were clustered together. Phylogenetic analysis revealed that, before and after Brassicaceae speciation events, both toll/interleukin-1 receptor-NBS-LRR (TNL) genes and non-toll/interleukin-1 receptor-NBS-LRR (nTNL) genes exhibited a pattern of first expansion and then contraction, suggesting that both subclasses of NBS-LRR genes were responding to pathogen pressures synchronically. Further, by examining the gain/loss of TNL and nTNL genes at different evolutionary nodes, this study revealed that both events often occurred more drastically in TNL genes. Finally, the phylogeny of nTNL genes suggested that this NBS-LRR subclass is composed of two separate ancient gene types: RPW8-NBS-LRR and Coiled-coiI-N BS-LRR.展开更多
Plant nucleotide-binding leucine-rich repeat(NLR)receptors mediate immune responses by directly or indirectly sensing pathogen-derived effectors.Despite significant advances in the understanding of NLR-mediated immuni...Plant nucleotide-binding leucine-rich repeat(NLR)receptors mediate immune responses by directly or indirectly sensing pathogen-derived effectors.Despite significant advances in the understanding of NLR-mediated immunity,the mechanisms by which pathogens evolve to suppress NLR activation triggered by cognate effectors and gain virulence remain largely unknown.The agronomically important immune receptor RB recognizes the ubiquitous and highly conserved IPI-O RXLR family members(e.g.,IPI-O1)from Phytophthora infestans,and this process is suppressed by the rarely present and homologous effector IPIO4.Here,we report that self-association of RB via the coiled-coil(CC)domain is required for RB activation and is differentially affected by avirulence and virulence effectors.IPI-O1 moderately reduces the self-association of RB CC,potentially leading to changes in the conformation and equilibrium of RB,whereas IPIO4 dramatically impairs CC self-association to prevent RB activation.We also found that IPI-O1 associates with itself,whereas IPI-O4 does not.Notably,IPI-O4 interacts with IPI-O1 and disrupts its self-association,therefore probably blocking its avirulence function.Furthermore,IPI-O4 enhances the interaction between RB CC and IPI-O1,possibly sequestering RB and IPI-O1 and subsequently blocking their interactions with signaling components.Taken together,these findings considerably extend our understanding of the underlying mechanisms by which emerging virulent pathogens suppress the NLR-mediated recognition of cognate effectors.展开更多
BACKGROUND: P-glycoprotein (P-gp) is a 170-kDa membrane protein. It provides a barrier function and help to excrete toxins from the body as a transporter. Some bioflavonoids have been shown to block P-gp activity. ...BACKGROUND: P-glycoprotein (P-gp) is a 170-kDa membrane protein. It provides a barrier function and help to excrete toxins from the body as a transporter. Some bioflavonoids have been shown to block P-gp activity. OBJECTIVE: To evaluate the important amino acid residues within nucleotide binding domain 1 (NBD l) of P-gp that play a key role in molecular interactions with flavonoids using structure-based pharmacophore model. METHODS: In the molecular docking with NBD 1 models, a putative binding site of flavonoids was proposed and compared with the site for ATP. The binding modes for ligands were achieved using LigandScout to generate the P-gp-flavonoid pharmacophore models. RESULTS: The binding pocket for flavonoids was investigated and found these inhibitors compete with the ATP for binding site in NBD1 including the NBD1 amino acid residues identified by the in silico techniques to be involved in the hydrogen bonding and van der Waals (hydrophobic) interactions with flavonoids. CONCLUSION: These flavonoids occupy with the same binding site of ATP in NBD1 proffering that they may act as an ATP competitive inhibitor.展开更多
Objective: To determine whether Schisandrin B(Sch B) attenuates early brain injury(EBI) in rats with subarachnoid hemorrhage(SAH). Methods: Sprague-Dawley rats were divided into sham(sham operation), SAH, SAH+vehicle,...Objective: To determine whether Schisandrin B(Sch B) attenuates early brain injury(EBI) in rats with subarachnoid hemorrhage(SAH). Methods: Sprague-Dawley rats were divided into sham(sham operation), SAH, SAH+vehicle, and SAH+Sch B groups using a random number table. Rats underwent SAH by endovascular perforation and received Sch B(100 mg/kg) or normal saline after 2 and 12 h of SAH. SAH grading, neurological scores, brain water content, Evan’s blue extravasation, and terminal transferase-mediated dUTP nick end-labeling(TUNEL) staining were carried out 24 h after SAH. Immunofluorescent staining was performed to detect the expressions of ionized calcium binding adapter molecule 1(Iba-1) and myeloperoxidase(MPO) in the rat brain, while the expressions of B-cell lymphoma 2(Bcl-2), Bax, Caspase-3, nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3(NLRP3), apoptosis-associated specklike protein containing the caspase-1 activator domain(ASC), Caspase-1, interleukin(IL)-1β, and IL-18 in the rat brains were detected by Western blot. Results: Compared with the SAH group, Sch B significantly improved the neurological function, reduced brain water content, Evan’s blue content, and apoptotic cells number in the brain of rats(P<0.05 or P<0.01). Moreover, Sch B decreased SAH-induced expressions of Iba-1 and MPO(P<0.01). SAH caused the elevated expressions of Bax, Caspase-3, NLRP3, ASC, Caspase-1, IL-1β, and IL-18 in the rat brain(P<0.01), all of which were inhibited by Sch B(P<0.01). In addition, Sch B increased the Bcl-2 expression(P<0.01). Conclusion: Sch B attenuated SAH-induced EBI, which might be associated with the inhibition of neuroinflammation, neuronal apoptosis, and the NLRP3 inflammatory signaling pathway.展开更多
文摘Nucleotide-binding oligomerization domain 1(NOD1) is an intracellular innate immune sensor for small molecules derived from bacterial cell components. NOD1 activation by its ligands leads to robust production of pro-inflammatory cytokines and chemokines by innate immune cells, thereby mediating mucosal host defense systems against microbes. Chronic gastric infection due to Helicobacter pylori(H. pylori) causes various upper gastrointestinal diseases, including atrophic gastritis, peptic ulcers, and gastric cancer. It is now generally accepted that detection of H. pylori by NOD1 expressed in gastric epithelial cells plays an indispensable role in mucosal host defense systems against this organism. Recent studies have revealed the molecular mechanism by which NOD1 activation caused by H. pylori infection is involved in the development of chronic gastritis and gastric cancer. In this review, we have discussed and summarized how sensing of H. pylori by NOD1 mediates the prevention of chronic gastritis and gastric cancer.
基金funding support from the National Natural Science Foundation of China(No.81872749)Shenzhen Science and Technology Innovation Commission(Nos.20200815000631001 and JCYJ20200109120414564)Peking University。
文摘Adenine is an essential building block of genetic material and a range of coenzymes.Chemical probes containing an adenine moiety have been used in kinase profiling studies in cell lysates.Here we report that adenine-derived small-molecule probes with an activated ester reactive group can covalently modify a conserved lysine residue of protein kinases and capture a number of nucleotide-binding proteins within living cells.
基金supported by the National Research Foundation of Korea(NRF)funded by the Korean Ministry of Education(Global PhD Fellowship Program Project 500–20190213)by the Ministry of Sciences and ICT(Projects 2018R1A5A1023599,2020R1A2C1101419).
文摘Bacterial wilt disease caused by several Ralstonia species is one of the most destructive diseases in Solanaceae crops.Only a few functional resistance genes against bacterial wilt have been cloned to date.Here,we showthat the broadly conserved typeⅢsecreted effector RipY is recognized by the Nicotiana benthamiana immune system,leading to cell death induction,induction of defense-related gene expression,and restriction of bacterial pathogen growth.Using a multiplexed virus-induced gene-silencing-based N.benthamiana nucleotide-binding and leucine-rich repeat receptor(NbNLR)library,we identified a coiled-coil(CC)nucleotide-binding and leucine-rich repeat receptor(CNL)required for recognition of RipY,which we named RESISTANCE TO RALSTONIA SOLANACEARUM RIPY(RRS-Y).Genetic complementation assays in RRS-Y-silenced plants and stable rrs-y knockout mutants demonstrated that RRS-Y is sufficient to activate RipY-induced cell death andRipY-induced immunity to Ralstonia pseudosolanacearum.RRS-Y function is dependent on the phosphate-binding loop motif of the nucleotide-binding domain but independent of the characterized signaling components ENHANCED DISEASE SUSCEPTIBILITY 1,ACTIVATED DISEASE RESISTANCE 1,and N REQUIREMENT GENE 1 and the NLR helpers NB-LRR REQUIRED FOR HR-ASSOCIATED CELL DEATH-2,-3,and-4 in N.benthamiana.We further show that RRS-Y localization at the plasma membrane is mediated by two cysteine residues in the CC domain and is required for RipY recognition.RRSY also broadly recognizes RipY homologs across Ralstonia species.Lastly,we show that the C-terminal region of RipY is indispensable for RRS-Y activation.Together,our findings provide an additional effector/receptor pair system to deepen our understanding of CNL activation in plants.
基金supported by the National Natural Science Foundation of China(No.81370282).
文摘Objective The ATP responsive P2 purinergic receptors can be subdivided into metabotropic P2X family and ionotropic P2Y family.Among these,P2X3 is a type of P2X receptor which is specifically expressed on nerves,especially on pre-ganglionic sensory fibers.This study investigates whether gefapixant possesses the potential of inhibiting cardiac sympathetic hypersensitivity to protect against cardiac remodeling in the context of myocardial infarction.Methods The Sprague-Dawley rats were divided randomly into three groups:sham group-myocardial infarction group,and myocardial infarction with gefapixant treatment group.Myocardial infarction was induced by left anterior descending branch ligation.The gefapixant solution was intraperitoneally injected each time per day for 7 days and the appropriate dosage of gefapixant was determined according to the results of hematoxylin-eosin(HE)staining and myocardial injury biomarkers.Conditions of cardiac function were assessed by echocardiograph and cardiac fibrosis was evaluated by Western blotting and immunofluorescence staining of collagen I and collagen III.The sympathetic innervation was detected by norepinephrine concentration(pg/mL),in-vivo electrophysiology,and typical sympathetic biomarkers.Inflammatory cell infiltration was shown from immunofluorescence staining and pro-inflammatory signaling pathway activation was checked by immunohistology,quantitative realtime PCR(qPCR)and Western blotting.Results It was found that gefapixant injection of 10 mg/kg per day had the highest dosage-efficacy ratio.Furthermore,gefapixant treatment improved cardiac pump function as shown by increased LVEF and LVFS,and decreased LVIDd and LVIDs.The expression levels of collagen I and collagen III,and TNF-αwere all decreased by P2X3 inhibition.Mechanistically,the decreased activation of nucleotide-binding and oligomerization domain-like receptors family pyrin-domain-containing 3(NLRP3)inflammasome and subsequent cleavage of caspase-1 which modulated interleukin-1β(IL-1β)and IL-18 level in heart after gefapixant treatment were associated with the suppressed cardiac inflammation.Conclusion It is suggested that P2X3 inhibition by gefapixant ameliorates post-infarct autonomic nervous imbalance,cardiac dysfunction,and remodeling possibly via inactivating NLRP3 inflammasome.
文摘Spontaneous bacterial peritonitis(SBP) is a frequent, life-threatening bacterial infection in patients with liver cirrhosis and ascites. Portal hypertension leads to increased bacterial translocation from the intestine. Failure to eliminate invading pathogens due to immune defects associated with advanced liver disease on the background of genetic predisposition may result in SBP. The efficacy of antibiotic treatment and prophylaxis has declined due to the spread of multi-resistant bacteria. Patients with nosocomial SBP and with prior antibiotictreatment are at a particularly high risk for infection with resistant bacteria. Therefore, it is important to adapt empirical treatment to these risk factors and to the local resistance profile. Rifaximin, an oral, nonabsorbable antibiotic, has been proposed to prevent SBP, but may be useful only in a subset of patients. Since novel antibiotic classes are lacking, we have to develop prophylactic strategies which do not induce bacterial resistance. Farnesoid X receptor agonists may be a candidate, but so far, clinical studies are not available. New diagnostic tests which can be carried out quickly at the patient's site and provide additional prognostic information would be helpful. Furthermore, we need tools to predict antibiotic resistance in order to tailor first-line antibiotic treatment of spontaneous bacterial peritonitis to the individual patient and to reduce mortality.
基金grants from the National Natural Science Foundation of China (No.81573745and No.8160140274)Beijing Municipal Natural Science Foundation (No.7172066) Beijing Development Foundation of Traditional Chinese Medicine (QN2016-23).
文摘Background:The nucleotide-binding and oligomerization domain-like receptor protein 3 (NLRP3) inflammasome composed of NLRP3,apoptosis-associated speck-like protein containing CARD (ASC),and caspase-1 is engaged in the inflammatory response of many kidney diseases and can be activated by purinergic 2X7 receptor (P2X7R).This study was conducted to explore whether P2X7R plays a pathogenic role in the podocyte damage of obesity-related glomerulopathy (ORG) and whether this role is mediated by the activation ofNLRP3 inflammasome.Methods:A mouse model of ORG was established by high-fat diet feeding.The conditionally immortalized mouse podocytes were cultured with leptin or with leptin and P2X7R antagonist (KN-62 or A438079).The mRNA and protein expression of the P2X7R and NLRP3 inflammasome components including NLRP3,ASC,and caspase-1,as well as the podocyte-associated molecules including nephrin,podocin,and desmin in mouse renal cortex or cultured mouse podocytes were tested by real-time-polymerase chain reaction and Westem blot analysis,respectively.Results:The significantly upregulated expression of P2X7R and NLRP3 inflammasome components and the NLRP3 inflammasome activation were observed in the renal cortex (in fact their location in podocytes was proved by confocal microscopy) of ORG mice in vivo,which were accompanied with the morphological changes of podocyte damage and the expression changes of podocyte-associated molecules.Similar changes in the expression of P2X7R and NLRP3 inflammasome components as well as in the expression ofpodocyte-associated molecules were also observed in the cultured podocyte studies treated by leptin in vitro,and all of the above changes were significantly attenuated by the P2X7R antagonist KN-62 or A438079.Conclusions:P2X7R could trigger the activation ofNLRP3 inflammasome,and the activated P2X7R/NLRP3 inflammasome in podocytes might be involved in the podocyte damage of ORG.
基金the Natural Science Foundation of Jiangsu Province(Youth Program),No.BK20190129National Scientific Program of Jiangsu Colleges and Universities of China,No.19KJB320012(both to LY)。
文摘Obstructive sleep apnea can worsen the prognosis of subarachnoid hemorrhage.Howeve r,the underlying mechanism remains unclear.In this study,we established a mouse model of subarachnoid hemorrhage using the endovascular perforation method and exposed the mice to intermittent hypoxia for 8 hours daily for 2 consecutive days to simulate sleep apnea.We found that sleep apnea aggravated brain edema,increased hippocampal neuron apoptosis,and worsened neurological function in this mouse model of subarachnoid hemorrhage.Then,we established an in vitro HT-22 cell model of hemin-induced subarachnoid hemorrhage/intermittent hypoxia and found that the cells died,and lactate dehydrogenase release increased,after 48 hours.We further investigated the underlying mechanism and found that sleep apnea increased the expression of hippocampal neuroinflammatory factors interleukin-1β,interleukin-18,inte rleukin-6,nuclear factorκB,pyro ptosis-related protein caspase-1,pro-caspase-1,and NLRP3,promoted the prolife ration of astrocytes,and increased the expression of hypoxia-inducible factor 1αand apoptosis-associated speck-like protein containing a CARD,which are the key proteins in the hypoxia-inducible factor 1α/apoptosis-associated speck-like protein containing a CARD signaling pathway.We also found that knockdown of hypoxia-inducible factor 1αexpression in vitro greatly reduced the damage to HY22 cells.These findings suggest that sleep apnea aggravates early brain injury after subarachnoid hemorrhage by aggravating neuroinflammation and pyroptosis,at least in part through the hypoxia-inducible factor 1α/apoptosis-associated speck-like protein containing a CARD signaling pathway.
文摘Two sets of degenerate oligonucleotide primers were designed according to amino acid conserved regions of reported plant disease resistance genes which encode proteins that contain nucleotide-binding site and leucine-rich repeats(NBS-LRR), and the plant disease resistance genes which encode serine/threonine protein kinase(STK). By polymerase chain reaction(PCR), disease resistance gene analogues have been amplified from three wild rice species in Yunnan Province, China. The DIN A fragments from amplification have been cloned into the pGEM-T vector respectively. Sequencing of the DNA fragments indicated that 7 classes, 2 classes and 6 classes NBS-LRR disease resistance gene analogues from Oryza rufipogon Griff. , Oryza officinalis Wall. , and Oryza meyeriana Baill. were obtained respectively. The two representative fragments of TO12 from Oryza officinalis Wall, and TR19 from Oryza rufipogon Griff, belong to the same class and homology of their sequences are 100%. The result shows that the sequences of the same class disease resistance gene analogues have no difference among different species of wild rice. 5 classes STK disease resistance gene analogues were also obtained among which 4 classes from Oryza rufipogon Griff. , 1 class from Oryza officinalis Wall. By comparison analysis of amino acid sequences. we found that the obtained disease resistance gene analogues have very low identity(low to 25%) with the reported disease resistance gene L6, N, Bs2, Prf, Pto, Lr10 and Xa21 etc. The finding suggests that the obtained disease resistance gene analogues are analogues of putative disease resistance genes that have not been isolated so far.
文摘Due to the overwhelming burden of colorectal cancer(CRC), great effort has been placed on identifying genetic mutations that contribute to disease development and progression. One of the most studied polymorphisms that could potentially increase susceptibility to CRC involves the nucleotide-binding and oligomerization-domain containing 2(NOD2) gene. There is growing evidence that the biological activity of NOD2 is far greater than previously thought and a link with intestinal microbiota and mucosal immunity is increasingly sought after. In fact, microbial composition may be an important contributor not only to inflammatory bowel diseases(IBD) but also to CRC. Recent studies have showed that deficient NOD2 function confers a communicable risk of colitis and CRC. Despite the evidence from experimental models, population-based studies that tried to link certain NOD2 polymorphisms and an increase in CRC risk have been described as conflicting. Significant geographic discrepancies in the frequency of such polymorphisms and different interpretations of the results may have limited the conclusions of those studies. Since being first associated to IBD and CRC, our understanding of the role of this gene has come a long way, and it is tempting to postulate that it may contribute to identify individuals with susceptible genetic background that may benefit from early CRC screening programs or in predicting response to current therapeutic tools. The aim of this review is to clarify the status quo of NOD2 mutations as genetic risk factors to chronic inflammation and ultimately to CRC. The use of NOD2 as a predictor of certain phenotypic characteristics of the disease will be analyzed as well.
基金Scientific research project of Hainan Provincial Department of Education(No.hnky2018zd-7)。
文摘Pattern recognition receptor(PRR)is a kind of sensor which is mainly expressed on the surface of innate immune cells.It can recognize pathogen related molecular patterns(PAMPs)or damage related molecular patterns(DAMPs).The innate immune system uses pattern recognition receptors to recognize pathogenic microorganisms in periodontal tissues and transmit signals to downstream pathways in time,thus triggering immune responses and then eliminating them.PRR has many family members,including toll like receptor family(TLRs),C-type lectin receptor family(CLRs),retinoic acid induced gene I(RIG-I)like receptor family(RLRs)and nucleotide binding oligomer domain(NOD)like receptor family(NLRs).Among them,RLRs are cytoplasmic receptors that recognize dsRNA from RNA viruses and have little association with chronic periodontitis.In this paper,the classification and structure of TLRs,CLRs,NLRs and the role of signal transduction pathway in chronic periodontitis are reviewed.In order to enrich the pathogenesis of periodontitis,provide new ideas for the treatment and prevention of chronic periodontitis.
基金supported by a grant from the State Scholarship Fund under the China Scholarship Council (No.2003850064)the Chongqing Education Commission (KJ080319)
文摘Objective To explore the immune stimulation effect of recombinant E.coli LLO/OVA on mice bone marrow-derived dendritic cells (BMDCs) and T lymphocytes in vitro.Methods After BMDCs stimulated by E.coli LLO/OVA,their Toll-like receptor (TLR) and nucleotide-binding oligomerization domain (NOD) receptor signalling pathway were examined by superarray hybridization;and the priming effect of the vaccine activated BMDCs on CD4+T and CD8+T was determined by [3H]thymidine uptake and ELISA,the tumor cytotoxic effect of activated CD8+T cells was determined by cytotoxic assay.Results After BMDCs were activated by E.coli LLO/OVA via TLR4,NOD1 receptor and NF-κB signalling pathway,the expression of their surface molecules including MHC class Ⅰ,MHC class Ⅱ,CD40,CD80 and CD86 significantly up-regulated;the secretion of IL-12 and IFN-? increased also.The mature BMDCs stimulated the allergic CD4+T and CD8+T cells proliferation and their IL-2 and IFN-γ secretion,and the activated CD8+T cells effectively killed B16-OVA melanoma cells and RMA-S/OVA lymphoma cells in vitro.Conclusion E.coli LLO/OVA is effective in inducing BMDCs maturation via activating TLR4 and NOD1 receptor signalling pathway and promoting specific anti-tumor T cell immunity in vitro.
基金the National Natural Science Foundation of China(grants numbers 31772530,31970467 and 31872298)Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDPB16).
文摘Endoparasitoid wasps introduce venom into their host insects during the egglaying stage.Venom proteins play various roles in the host physiology,development,immunity,and behavior manipulation and regulation.In this study,we identified a venom protein,MmRhol,a small guanine nucleotide-binding protein derived from ovary in the endoparasitoid wasp Microplitis mediator and found that knockdown of its expression by RNA interference caused down-regulation of vitellogenin and juvenile hormone,egg production,and cocoons formation in the female wasps.We demonstrated that MmRho1 entered the cotton bollworm's(host)hemocytes and suppressed cellular immune responses after parasitism using immunofluorescence staining.Furthermore,wasp MmRhol interacted with the cotton bollworm's actin cytoskeleton rearrangement regulator diaphanous by yeast 2-hybrid and glutathione s-transferase pull-down.In conclusion,this study indicates that MmRho1 plays dual roles in wasp development and the suppression of the host insect cellular immune responses.
基金supported by the National Natural Science Foundation of China(30930008,31170210,31200177,91231102,31300190,31400201 and 31470327)China Postdoctoral Science Foundation(2013M540435 and 2014T70503)+3 种基金Postdoctoral Science Foundation of Jiangsu Province(1302131C)Fundamental Research Funds for the Central Universities(20620140546 and 20620140558)Natural Science Founding of Jiangsu Province(BK20130565)Qing Lan Project of Jiangsu Province
文摘Plant genomes harbor dozens to hundreds of nucleotide-binding site-leucine-rich repeat (NBS-LRR) genes; however, the long-term evolutionary history of these resistance genes has not been fully understood, This study focuses on five Brassicaceae genomes and the Carica papaya genome to explore changes in NBS-LRR genes that have taken place in this Rosid II lineage during the past 72 million years. Various numbers of NBS-LRR genes were identified from Arabidopsis lyrata (198), A. thaliana (165), Brassica rapa (204), Capsella rubella (127), Thellungiella salsuginea (88), and C. papaya (51). In each genome, the identified NBS-LRR genes were found to be unevenly distributed among chromosomes and most of them were clustered together. Phylogenetic analysis revealed that, before and after Brassicaceae speciation events, both toll/interleukin-1 receptor-NBS-LRR (TNL) genes and non-toll/interleukin-1 receptor-NBS-LRR (nTNL) genes exhibited a pattern of first expansion and then contraction, suggesting that both subclasses of NBS-LRR genes were responding to pathogen pressures synchronically. Further, by examining the gain/loss of TNL and nTNL genes at different evolutionary nodes, this study revealed that both events often occurred more drastically in TNL genes. Finally, the phylogeny of nTNL genes suggested that this NBS-LRR subclass is composed of two separate ancient gene types: RPW8-NBS-LRR and Coiled-coiI-N BS-LRR.
基金This work was supported by a start-up fund from Texas A&M AgriLife Research and a Hatch Project from the USDA National Institute of Food and Agriculture to J.S.(TEX0-1-9675).
文摘Plant nucleotide-binding leucine-rich repeat(NLR)receptors mediate immune responses by directly or indirectly sensing pathogen-derived effectors.Despite significant advances in the understanding of NLR-mediated immunity,the mechanisms by which pathogens evolve to suppress NLR activation triggered by cognate effectors and gain virulence remain largely unknown.The agronomically important immune receptor RB recognizes the ubiquitous and highly conserved IPI-O RXLR family members(e.g.,IPI-O1)from Phytophthora infestans,and this process is suppressed by the rarely present and homologous effector IPIO4.Here,we report that self-association of RB via the coiled-coil(CC)domain is required for RB activation and is differentially affected by avirulence and virulence effectors.IPI-O1 moderately reduces the self-association of RB CC,potentially leading to changes in the conformation and equilibrium of RB,whereas IPIO4 dramatically impairs CC self-association to prevent RB activation.We also found that IPI-O1 associates with itself,whereas IPI-O4 does not.Notably,IPI-O4 interacts with IPI-O1 and disrupts its self-association,therefore probably blocking its avirulence function.Furthermore,IPI-O4 enhances the interaction between RB CC and IPI-O1,possibly sequestering RB and IPI-O1 and subsequently blocking their interactions with signaling components.Taken together,these findings considerably extend our understanding of the underlying mechanisms by which emerging virulent pathogens suppress the NLR-mediated recognition of cognate effectors.
文摘BACKGROUND: P-glycoprotein (P-gp) is a 170-kDa membrane protein. It provides a barrier function and help to excrete toxins from the body as a transporter. Some bioflavonoids have been shown to block P-gp activity. OBJECTIVE: To evaluate the important amino acid residues within nucleotide binding domain 1 (NBD l) of P-gp that play a key role in molecular interactions with flavonoids using structure-based pharmacophore model. METHODS: In the molecular docking with NBD 1 models, a putative binding site of flavonoids was proposed and compared with the site for ATP. The binding modes for ligands were achieved using LigandScout to generate the P-gp-flavonoid pharmacophore models. RESULTS: The binding pocket for flavonoids was investigated and found these inhibitors compete with the ATP for binding site in NBD1 including the NBD1 amino acid residues identified by the in silico techniques to be involved in the hydrogen bonding and van der Waals (hydrophobic) interactions with flavonoids. CONCLUSION: These flavonoids occupy with the same binding site of ATP in NBD1 proffering that they may act as an ATP competitive inhibitor.
基金Supported by the Natural Science Foundation of Fujian Province of China (No. 2020J011016)the Joint Funds for the Innovation of Science and Technology of Fujian Province (No. 2018Y9004)the Startup Fund for Scientific Research of Fujian Medical University (No. 2019QH1055)。
文摘Objective: To determine whether Schisandrin B(Sch B) attenuates early brain injury(EBI) in rats with subarachnoid hemorrhage(SAH). Methods: Sprague-Dawley rats were divided into sham(sham operation), SAH, SAH+vehicle, and SAH+Sch B groups using a random number table. Rats underwent SAH by endovascular perforation and received Sch B(100 mg/kg) or normal saline after 2 and 12 h of SAH. SAH grading, neurological scores, brain water content, Evan’s blue extravasation, and terminal transferase-mediated dUTP nick end-labeling(TUNEL) staining were carried out 24 h after SAH. Immunofluorescent staining was performed to detect the expressions of ionized calcium binding adapter molecule 1(Iba-1) and myeloperoxidase(MPO) in the rat brain, while the expressions of B-cell lymphoma 2(Bcl-2), Bax, Caspase-3, nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3(NLRP3), apoptosis-associated specklike protein containing the caspase-1 activator domain(ASC), Caspase-1, interleukin(IL)-1β, and IL-18 in the rat brains were detected by Western blot. Results: Compared with the SAH group, Sch B significantly improved the neurological function, reduced brain water content, Evan’s blue content, and apoptotic cells number in the brain of rats(P<0.05 or P<0.01). Moreover, Sch B decreased SAH-induced expressions of Iba-1 and MPO(P<0.01). SAH caused the elevated expressions of Bax, Caspase-3, NLRP3, ASC, Caspase-1, IL-1β, and IL-18 in the rat brain(P<0.01), all of which were inhibited by Sch B(P<0.01). In addition, Sch B increased the Bcl-2 expression(P<0.01). Conclusion: Sch B attenuated SAH-induced EBI, which might be associated with the inhibition of neuroinflammation, neuronal apoptosis, and the NLRP3 inflammatory signaling pathway.