METTL5 promotes cell proliferation,invasion,and migration by up-regulating Toll-like receptor 8 expression in colorectal cancer

BACKGROUND N6-methyladenosine(m6A)modification represents the predominant alteration found in eukaryotic messenger RNA and plays a crucial role in the progression of various tumors.However,despite its significance,the comprehensive investigation of METTL5,a key m6A methyltransferase,in colorectal cancer(CRC)remains limited.AIM To investigate the role of METTL5 in CRC.METHODS We assessed METTL5 expression levels in clinical samples obtained from CRC patients as well as in CRC cell lines.To elucidate the downstream targets of METTL5,we performed RNA-sequencing analysis coupled with correlation analysis,leading us to identify Toll-like receptor 8(TLR8)as a potential downstream target.In vitro functional assessments of METTL5 and TLR8 were conducted using CCK-8 assays,scratch assays,as well as assays measuring cell migration and invasion.RESULTS Our findings reveal a pronounced upregulation of METTL5 expression in both CRC cells and tissues,which correlated significantly with an unfavorable prognosis.In vitro experiments unequivocally demonstrated the oncogenic role of METTL5,as evidenced by its promotion of CRC cell proliferation,invasion,and migration.Notably,we identified TLR8 as a downstream target of METTL5,and subsequent down-regulation of TLR8 led to a significant inhibition of CRC cell proliferation,invasion,and tumor growth.CONCLUSION The heightened expression of METTL5 in CRC is strongly associated with clinicopathological features and a poor prognosis,thereby underscoring its potential utility as a critical marker for facilitating early diagnosis and prognostication in CRC.

MicroRNA-630 alleviates inflammatory reactions in rats with diabetic kidney disease by targeting toll-like receptor 4

BACKGROUND Diabetic kidney disease(DKD)is a major complication of diabetes mellitus.Renal tubular epithelial cell(TEC)damage,which is strongly associated with the inflammatory response and mesenchymal trans-differentiation,plays a significant role in DKD;However,the precise molecular mechanism is unknown.The recently identified microRNA-630(miR-630)has been hypothesized to be closely associated with cell migration,apoptosis,and autophagy.However,the association between miR-630 and DKD and the underlying mechanism remain unknown.AIM To investigate how miR-630 affects TEC injury and the inflammatory response in DKD rats.METHODS Streptozotocin was administered to six-week-old male rats to create a hypergly cemic diabetic model.In the second week of modeling,the rats were divided into control,DKD,negative control of lentivirus,and miR-630 overexpression groups.After 8 wk,urine and blood samples were collected for the kidney injury assays,and renal tissues were removed for further molecular assays.The target gene for miR-630 was predicted using bioinformatics,and the association between miR-630 and toll-like receptor 4(TLR4)was confirmed using in vitro investigations and double luciferase reporter gene assays.Overexpression of miR-630 in DKD rats led to changes in body weight,renal weight index,basic blood parameters and histopathological changes.RESULTS The expression level of miR-630 was reduced in the kidney tissue of rats with DKD(P<0.05).The miR-630 and TLR4 expressions in rat renal TECs(NRK-52E)were measured using quantitative reverse transcription polymerase chain reaction.The mRNA expression level of miR-630 was significantly lower in the high-glucose(HG)and HG+mimic negative control(NC)groups than in the normal glucose(NG)group(P<0.05).In contrast,the mRNA expression level of TLR4 was significantly higher in these groups(P<0.05).However,miR-630 mRNA expression increased and TLR4 mRNA expression significantly decreased in the HG+miR-630 mimic group than in the HG+mimic NC group(P<0.05).Furthermore,the levels of tumor necrosis factor-alpha(TNF-α),interleukin-1β(IL-1β),and IL-6 were significantly higher in the HG and HG+mimic NC groups than in NG group(P<0.05).However,the levels of these cytokines were significantly lower in the HG+miR-630 mimic group than in the HG+mimic NC group(P<0.05).Notably,changes in protein expression were observed.The HG and HG+mimic NC groups showed a significant decrease in E-cadherin protein expression,whereas TLR4,α-smooth muscle actin(SMA),and collagen IV protein expression increased(P<0.05).Conversely,the HG+miR-630 mimic group exhibited a significant increase in E-cadherin protein expression and a notable decrease in TLR4,α-SMA,and collagen IV protein expression than in the HG+mimic NC group(P<0.05).The miR-630 targets TLR4 gene expression.In vivo experiments demonstrated that DKD rats treated with miR-630 agomir exhibited significantly higher miR-630 mRNA expression than DKD rats injected with agomir NC.Additionally,rats treated with miR-630 agomir showed significant reductions in urinary albumin,blood glucose,TLR4,and proinflammatory markers(TNF-α,IL-1β,and IL-6)expression levels(P<0.05).Moreover,these rats exhibited fewer kidney lesions and reduced infiltration of inflammatory cells.CONCLUSION MiR-630 may inhibit the inflammatory reaction of DKD by targeting TLR4,and has a protective effect on DKD.

Toll-like receptors 2 polymorphism is associated with psoriasis: A case-control study in the northern Chinese population

Background:Psoriasis is a disease caused by genetics and immune system dysfunction,affecting the skin and joints.Toll-like receptors(TLRs)play an important role in triggering the innate immune response and controlling adaptive immunity.The role of TLR2 in the progression of psoriasis is not well understood.Methods:A case-control study was conducted on a northern Chinese Han population,consisting of psoriasis patients and healthy control subjects.Genotyping was performed using the tetra-primer amplification refractory mutation system-polymerase chain reaction(ARMS-PCR),and allele and genotype frequencies of four SNPs in TLR2 were analyzed in 270 psoriasis patients and 246 healthy controls.Results:Four TLR2 SNPs(rs11938228,rs4696480,rs3804099,rs5743699)were genotyped and found to be in linkage disequilibrium.The genotype distributions of rs11938228 and rs4696480 in two groups were in Hardy-Weinberg equilibrium and statistically significant except for the overdominance model.The haplotypes ATTC and ATCC were found to be protective against psoriasis.Conclusion:Our study found a correlation between TLR2 genetic variations and the likelihood of psoriasis in northern China.

On the Impairment of Stress-Induced Changes in Triglyceride Levels via a Sub-Toxic Dose of Unmethylated Cytidine Phosphate Guanosine Oligodinucleotide (a Toll-Like Receptor 9 Ligand)

Changes in lipid metabolism have been implicated in protection against infectious diseases. In the first experiment of this study, we measured clinical lipid parameters in a murine model where the unmethylated cytidine phosphate guanosine (CpG) oligodinucleotide (ODN1826), a Toll-like receptor 9 (TLR9) agonist was administered in combination with D-galactosamine (GalN) that caused relatively liver-specific inflammation and toxicity. In the control mice group injected with phosphate-buffered saline (PBS) (acute psychological stress model associated with blood sampling), the serum triglyceride (TG) levels showed a rapid decrease followed by a rebound at 24 h as we have recently reported. However, such a TG rebound was impaired in the CpG/GalN- and solely CpG-treated groups of mice despite an absence of liver injury based on serum alanine aminotransferase levels in the latter group. Thus, the stress-associated serum TG rebound was abrogated by the injection of a sub-hepatotoxic CpG dose. In the second experiment, we simply measured the hepatic CD36 and SACRB1 (the gene for scavenger receptor B1 (SR-B1)) transcripts after the i.p. administration of PBS, CpG or CpG/GalN. There was a remarkable elevation of hepatic CD36 transcript expression in both the CpG- and CpG/GalN-treated mice at 8 h post-CpG injection whereas the increase in the PBS-treated mice was slower than the former two groups, suggesting that hepatic CD36 transcript expression is more pronounced in the combined stress models than under psychological stress alone. The individual mice data showed that the increase in CD36 expression was accompanied by a reduction in SCARB1 mRNA, showing reciprocal regulation between these two genes. Together with our previously reported findings, these data suggest that, in a murine model combining psychological stress with TLR-triggered hepatic inflammation, the psychological stress facilitates liver uptake of plasma TG (and its components fatty acids), but the subsequent re-esterification and/or release of TG-rich lipoproteins from the liver is impaired due to the concomitant TLR-signaling. We hypothesize that lipid metabolism during acute stress shifts toward an elevated hepatic uptake of lipids due to concomitant TLR signaling, facilitating the clearance of bacterial lipids by the liver.

Argon preconditioning protects neuronal cells with a Toll-like receptor-mediated effect

The noble gas argon has the potential to protect neuronal cells from cell death.So far,this effect has been studied in treatment after acute damage.Preconditioning using argon has not yet been investigated.In this study,human neuroblastoma SH-SY5Y cells were treated with different concentrations of argon(25%,50%,and 74%;21%O_(2),5%CO_(2),balance nitrogen)at different time intervals before inflicting damage with rotenone(20μM,4 hours).Apoptosis was determined by flow cytometry after annexin V and propidium iodide staining.Surface expressions of Toll-like receptors 2 and 4 were also examined.Cells were also processed for analysis by western blot and qPCR to determine the expression of apoptotic and inflammatory proteins,such as extracellular-signal regulated kinase(ERK1/2),nuclear transcription factor-κB(NF-κB),protein kinase B(Akt),caspase-3,Bax,Bcl-2,interleukin-8,and heat shock proteins.Immunohistochemical staining was performed for TLR2 and 4 and interleukin-8.Cells were also pretreated with OxPAPC,an antagonist of TLR2 and 4 to elucidate the molecular mechanism.Results showed that argon preconditioning before rotenone application caused a dose-dependent but not a time-dependent reduction in the number of apoptotic cells.Preconditioning with 74%argon for 2 hours was used for further experiments showing the most promising results.Argon decreased the surface expression of TLR2 and 4,whereas OxPAPC treatment partially abolished the protective effect of argon.Argon increased phosphorylation of ERK1/2 but decreased NF-κB and Akt.Preconditioning inhibited mitochondrial apoptosis and the heat shock response.Argon also suppressed the expression of the pro-inflammatory cytokine interleukin-8.Immunohistochemistry confirmed the alteration of TLRs and interleukin-8.OxPAPC reversed the argon effect on ERK1/2,Bax,Bcl-2,caspase-3,and interleukin-8 expression,but not on NF-κB and the heat shock proteins.Taken together,argon preconditioning protects against apoptosis of neuronal cells and mediates its action via Toll-like receptors.Argon may represent a promising therapeutic alternative in various clinical settings,such as the treatment of stroke.

Neuroprotective effects of G9a inhibition through modulation of peroxisome-proliferator activator receptor gamma-dependent pathways by miR-128

Dysregulation of G9a,a histone-lysine N-methyltransferase,has been observed in Alzheimer’s disease and has been correlated with increased levels of chronic inflammation and oxidative stress.Likewise,microRNAs are involved in many biological processes and diseases playing a key role in pathogenesis,especially in multifactorial diseases such as Alzheimer’s disease.Therefore,our aim has been to provide partial insights into the interconnection between G9a,microRNAs,oxidative stress,and neuroinflammation.To better understand the biology of G9a,we compared the global microRNA expression between senescence-accelerated mouse-prone 8(SAMP8)control mice and SAMP8 treated with G9a inhibitor UNC0642.We found a downregulation of miR-128 after a G9a inhibition treatment,which interestingly binds to the 3′untranslated region(3′-UTR)of peroxisome-proliferator activator receptor γ(PPARG)mRNA.Accordingly,Pparg gene expression levels were higher in the SAMP8 group treated with G9a inhibitor than in the SAMP8 control group.We also observed modulation of oxidative stress responses might be mainly driven Pparg after G9a inhibitor.To confirm these antioxidant effects,we treated primary neuron cell cultures with hydrogen peroxide as an oxidative insult.In this setting,treatment with G9a inhibitor increases both cell survival and antioxidant enzymes.Moreover,up-regulation of PPARγby G9a inhibitor could also increase the expression of genes involved in DNA damage responses and apoptosis.In addition,we also described that the PPARγ/AMPK axis partially explains the regulation of autophagy markers expression.Finally,PPARγ/GADD45αpotentially contributes to enhancing synaptic plasticity and neurogenesis after G9a inhibition.Altogether,we propose that pharmacological inhibition of G9a leads to a neuroprotective effect that could be due,at least in part,by the modulation of PPARγ-dependent pathways by miR-128.

Correlation between Toll-like Receptor Gene Polymorphisms and Idiopathic Nephrotic Syndrome in Chinese Children

Objective Idiopathic nephrotic syndrome(INS)is the most common glomerular disease in children.Toll-like receptors(TLRs)have been reported to be associated with response to steroid treatment in children with INS.Nevertheless,the correlation between TLR genes and the progression of INS has not yet been clarified.The present study aimed to investigate the association of single-nucleotide polymorphisms(SNPs)in TLR2,TLR4,and TLR9 with susceptibility to INS as well as the clinical phenotyping of steroid responsiveness in Chinese children with INS.Methods A total of 183 pediatric inpatients with INS were included and given standard steroid therapy.Based on their clinical response to steroids,the patients were classified into three groups:steroid-sensitive nephrotic syndrome(SSNS),steroid-dependent nephrotic syndrome(SDNS),and steroid-resistant nephrotic syndrome(SRNS).A total of 100 healthy children were employed as controls.The blood genome DNA was extracted from each participant.Six SNPs(rs11536889,rs1927914,rs7869402,rs11536891,rs352140,and rs3804099)in TLR2,TLR4,and TLR9 were selected and detected by multiplex polymerase chain reaction with next-generation sequencing to assess TLR gene polymorphisms.Results Among the 183 patients with INS,89(48.6%)had SSNS,73(39.9%)had SDNS,and 21(11.5%)had SRNS.No significant difference was found in the genotype distribution between healthy children and patients with INS.However,the genotype and allele frequencies of TLR4 rs7869402 were significantly different between SRNS and SSNS.Compared with patients with the C allele and CC genotype,patients with the T allele and CT genotype had an increased risk of SRNS.Conclusion TLR4 rs7869402 affected the steroid response in Chinese children with INS.It might be a predictor for the early detection of SRNS in this population.

Fecal microbiota transplantation alleviates experimental colitis through the Toll-like receptor 4 signaling pathway

BACKGROUND Fecal microbiota transplantation(FMT)has shown promising therapeutic effects on mice with experimental colitis and patients with ulcerative colitis(UC).FMT modulates the Toll-like receptor 4(TLR4)signaling pathway to treat some other diseases.However,it remains unknown whether this modulation is also involved in the treatment of UC.AIM To clarify the necessity of TLR4 signaling pathway in FMT on dextran sodium sulphate(DSS)-induced mice and explain the mechanism of FMT on UC,through association analysis of gut microbiota with colon transcriptome in mice.METHODS A mouse colitis model was constructed with wild-type(WT)and TLR4-knockout(KO)mice.Fecal microbiota was transplanted by gavage.Colon inflammation severity was measured by disease activity index(DAI)scoring and hematoxylin and eosin staining.Gut microbiota structure was analyzed through 16S ribosomal RNA sequencing.Gene expression in the mouse colon was obtained by transcriptome sequencing.RESULTS The KO(DSS+Water)and KO(DSS+FMT)groups displayed indistinguishable body weight loss,colon length,DAI score,and histology score,which showed that FMT could not inhibit the disease in KO mice.In mice treated with FMT,the relative abundance of Akkermansia decreased,and Lactobacillus became dominant.In particular,compared with those in WT mice,the scores of DAI and colon histology were clearly decreased in the KO-DSS group.Microbiota structure showed a significant difference between KO and WT mice.Akkermansia were the dominant genus in healthy KO mice.The ineffectiveness of FMT in KO mice was related to the decreased abundance of Akkermansia.Gene Ontology enrichment analysis showed that differentially expressed genes between each group were mainly involved in cytoplasmic translation and cellular response to DNA damage stimulus.The top nine genes correlating with Akkermansia included Aqp4,Clca4a,Dpm3,Fau,Mcrip1,Meis3,Nupr1 L,Pank3,and Rps13(|R|>0.9,P<0.01).CONCLUSION FMT may ameliorate DSS-induced colitis by regulating the TLR4 signaling pathway.TLR4 modulates the composition of gut microbiota and the expression of related genes to ameliorate colitis and maintain the stability of the intestinal environment.Akkermansia bear great therapeutic potential for colitis.

Relationship of Toll-Like Receptors 2 and 4 Gene Polymorphisms with Essential Hypertension in Chinese Han Population

Objective: There are numerous studies suggesting that genetic polymor-phisms of inflammation factors Toll-like receptors 2 and 4 (TLR2, TLR4) might play a role in the pathophysiological process of hypertension. In this study, we evaluated the association in a sample of members of the Chinese Han population. Method: We selected four single nucleotide polymor-phisms (SNP) of TLR2 (rs3804099, rs3804100, rs7656411) and TLR4 (rs1927906) genes, and measured the distributions of genotypic and allelic frequencies in 1063 participants, including 391 essential hypertension pa-tients and 672 controls. Result: No significant differences in the genotypic and allelic frequencies of the four SNPs were detected between cases and controls. However, three haplotypes, CCG, TTG and TTT of TLR2, were significantly associated with a decrease in the risk of essential hyperten-sion (OR: 0.512, 95% CI: 0.397 - 0.660, P P = 0.0038;OR: 0.797, 95% CI: 0.667 - 0.952, P = 0.0122, respectively). Inversely, the risk of essential hypertension increased sig-nificantly in patients with the CTG, TCG or TCT haplotypes (OR: 2.924, 95% CI: 2.157 - 3.963, P P P Conclusion: Our study suggested that haplotypes (CCG, TTG, TTT, CTG, TCG and TCT) of TLR2 might have profound effects on the development of essential hypertension in the Chinese Han population.

Lactobacilli inhibit interleukin-8 production induced by Helicobacter pylori lipopolysaccharide-activated Toll-like receptor 4

AIM： To investigate the effect of Lactobacillus bulgaricus （LBG） on the Toll-like receptor 4 （TLR4） pathway and interleukin-8 （IL-8） production in SGC-7901 cells treated with Helicobacter pyloriSydney strain 1 lipopolysaccharide （HpyloriSS1-LPS）. METHODS： SGC-7901 cells were treated with HpyloriSS1-LPS in the presence or absence of pretreatment for 1 h with viable LBG or supernatant recovered from LBG culture MRS broth （LBG-s）. Cellular lysates were prepared for Western blot with anti-TLR4, anti-transforming growth factor β-activated kinase 1 （TAK1）, anti-phospho-TAK1, anti-nuclear factor κB （NF-κB）, anti-p38 mitogen-activated protein kinase （p38MAPK）, and anti-phospho-p38MAPK antibodies. The amount of IL-8 in cell culture medium was measured by ELISA. RESULTS： H pyloriSS1-LPS up-regulated the expression of TLR4, stimulated the phosphorylation of TAKI, subsequently enhanced the activation of NF- κB and the phosphorylation of p38MAPK in a time- dependent manner, leading to augmentation of IL-8 production in SGC-7901 cells. Viable LBG or LBG-s pretreatment attenuated the expression of TLR4, inhibited the phosphorylation of TAK1 and p38MAPK, prevented the activation of NF-κB, and consequently blocked IL-8 production.CONCLUSION： H py/oriSS1-LPS induces IL-8 production through activating TLR4 signaling in SGC-7901 cells and viable LBG or LBG-s prevents H pyloriSS1-LPS-mediated IL-8 production via inhibition of the TLR4 pathway.

MyD88-independent activation of a novel actin-Cdc42/Rac pathway is required for Toll-like receptor-stimulated phagocytosis

Phagocytosis and subsequent degradation of pathogens by macrophages play a pivotal role in host innate immune responses to microbial infection. Recent studies have shown that Toll-like receptors （TLRs） play an important role in promoting the clearance of bacteria by up-regulating the phagocytic activity of macrophages. However, information regarding the signaling mechanism of TLR-mediated phagocytosis is still limited. Here, we provide evidence that the stimulation of TLR4 with LPS leads to activation of multiple signaling pathways including MAP kinases, phosphatidylinositide 3-kinase （PI3K）, and small GTPases in the murine macrophage-like cell line RAW264.7. Specific inhibition of Cdc42/Rac or p38 MAP kinase, but not PI3K, reduced TLR4-induced phagocytosis of bacteria. Moreover, we have found that either inhibition of actin polymerization by cytochalasin D or the knockdown of actin by RNAi markedly reduced the activation of Cdc42 and Rac by LPS. TLR4-induced activation of Cdc42 and Rac appears to be independent of MyD88. Taken together, our results described a novel actin-Cdc42/Rac pathway through which TLRs can specifically provoke phagocytosis.

The involvement of hypoxia-inducible factor 1 alpha in Toll-like receptor 7/8-mediated inflammatory response

Toll-like receptors （TLRs） 7 and 8 are crucial in host defence against single-stranded RNA （ssRNA） viruses. Such viruses cause severe illnesses, which remain a serious medical burden in both industrialised and developing countries. TLR7/8 downstream signaling leads tO a dramatic cellular stress associated with energy consumption. However, the molecular mechanisms of cell survival and adaptation to TLR7/8-induced stress, which give the cells an opportunity to initiate proper inflammatory reactions, are not clear at all. Here we report for the first time that ligand-induced activation of TLR7/8 leads to the accumulation of hypoxia-inducible factor 1 alpha （HIF-1α） protein in THP-1 human myeloid macrophages via redoxand reactive nitrogen species-dependent mechanisms. MAP kinases and phosphoinositol-3K are not involved in TLR7/8-mediated HIF-1α accumulation. Experiments with HIF-1α knockdown THP- 1 cells have clearly demonstrated that HIF-1α is important for the protection of these cells against TLR7/8-induced depletion of ATP. Thus, HIF-1α might support both cell survival and the production of pro-inflammatory cytokines upon TLR7/8 activation.

Innate Cytokine Responses and Toll-Like Receptor Induced by Recombinant Porcine Rotavirus VP6 and VP7 Proteins Expressing in <i>Lactobacillus plantarum</i>NC8 Strain Colonization in Mice

The significant function of Toll-like receptors (TLR) is the detection of microbes by host guard cells that guide to the innate immune responses and to the successive adaptive. The current study patterns of TLR2, TLR3 and TLR9 expressing antigen presenting cells (APCs) in blood of mice after colonization with L. plantarum NC8 strain were assessed. The power of L. plantarum on serum innate cytokine and TLR responses stimulated by recombinant NC8-pSIP409-pgsA-VP6-DCpep, NC8-pSIP409-pgsA-VP7-DCpep and NC8-pSIP409-pgsA were also assessed. We confirmed that L. plantarum NC8 stimulated powerful TLR2 expressing APC responses in blood Recombinant strain stimulated a TLR3 response in spleen, and TLR9 responses were stimulated in blood or in spleen. Recombinant NC8-pSIP409-pgsA-VP6-DCpep, NC8-pSIP409-pgsA-VP7-DCpep on TLR2 and TLR9 expressing APC responses has a preservative outcome, reliable with the DCpep adjuvant outcome. In serum the recombinant NC8-pSIP409-pgsA-VP6-DCpep, NC8-pSIP409-pgsA-VP7-DCpep has increased the IL-4 and IFN-γ responses, except that on the TLR3 and TLR9 expressing CD14 APC responses it had an oppressive consequence in spleen and the IFN-α response in serum-stimulated by PRV. Our results give details that following PRV infection after immunization with NC8-pSIP409-pgsA-VP6-DCpep, NC8-pSIP409-pgsA-VP7-DCpep, the systemic TLR2, TLR3, and TLR9 expressing cDC and macrophage/monocyte responses.

人Toll-like receptor 2胞外段的克隆和表达

目的 克隆、表达人Toll-like receptor2(TLR2)胞外段(A26-T588)基因,获得人TLR2胞外段蛋白。方法 RT-PCR扩增TLR2胞外段基因,以pcDNA3.1+质粒为载体在HEK293细胞中表达TLR2胞外段蛋白,同时以pcDNA3.1+/TLR2(A26-T588)重组质粒免疫昆明鼠,制备抗TLR2胞外段蛋白多抗。结果 PCR扩增及重组质粒测序结果表明成功地构建了pcDNA3.1+/TLR2(A26-T588)真核表达质粒,SDS-PAGE分析纯化产物在M_r为68000处出现明显蛋白条带。重组质粒DNA免疫小鼠3次后,血清抗体滴度可达1∶250。TLR2胞外段蛋白可与LPS结合,并在一定的质量浓度范围内呈剂量依赖性。结论 构建的pcDNA3.1+/TLR2(A26-T588)真核表达质粒可在哺乳动物细胞中表达TLR2胞外段蛋白,并与重组质粒DNA免疫小鼠抗血清及TLR2单克隆抗体TL2.1特异性反应,由此证明其表达正确。

广谱模式识别分子Toll-like receptor 2的研究进展

TLR-2（Toll-like receptor 2,TLR-2）是哺乳动物TLRs（Toll-like receptors,TLRs）家族的一员,作为细胞表面的天然受体蛋白,主要参与病原微生物产物的识别及炎症信号传导,介导天然抗感染兔疫;最近又发现其参与机体对非感染因子所致炎性组织损伤的识别。通过对TLR-2参与的识别和细胞内信号传导机制的研究,可为深入探讨抵御微生物感染的机制、对自身正常与非正常组织的识别提供新的思路。

Toll-like Receptor9在大鼠胰腺表达及与大鼠急性胰腺炎相关性的研究

目的 (1)建立急性胰腺炎大鼠模型,定性检测Toll-like Receptor 9(TLR 9)在大鼠胰腺的表达、分布情况;(2)定量测定TLR 9在大鼠急性胰腺炎不同时间点的表达变化情况;(3)结合TLR 9在大鼠胰腺的组织分布、表达情况及在雨蛙素诱导性胰腺炎(cerulein-induced pancreatitis,CIP)早期24 h的表达改变,探讨TLR9与CIP发生发展的相关性.方法(1)采用Wistar大鼠,并随机分配进入实验组或对照组;通过皮下注射雨蛙素建立急性胰腺炎模型;(2)采用免疫组化方法检测TLR 9在正常大鼠胰腺及CIP时大鼠胰腺的表达TLR 9在大鼠胰腺的组织分布情况;(3)提取总RNA,采用实时荧光定量逆转录-多聚酶链反应(Quantitative-Real-Time;QRT-PCR)法测定TLR9基因的表达.(4)分析TLR9的分布特征及可能的意义(5)统计分析TLR 9 mRNA的表达情况与CIP发生、发展的关系.结果 (1)TLR 9主要分布于胰管上皮、血管内皮和胰岛;(2)外分泌腺泡细胞没有明显的表达;(3)QRT-PCR结果显示TLR9 mRNA在正常大鼠胰腺组织呈现低水平表达;(4)CIP早期TLR9 mRNA表达出现快速上调并在1 h时达到最高值;TLR 9 mRNA表达在CIP前4 h内维持于高水平;其后下降缓慢,至到CIP的第24小时也未降至正常,保持相对较高的表达水平.结论 (1)TLR 9在大鼠胰腺有表达,且表达具有一定的组织特异性;(2)TLR9在CIP胰腺组织中的表达明显升高,提示TLR 9在胰腺炎早期炎症反应的发生、发展中具有重要作用,与之存在相关性.

NapA蛋白诱导巨噬细胞分泌趋化因子单核细胞趋化蛋白1和白细胞介素8的机制

目的:研究幽门螺杆菌NapA蛋白诱导巨噬细胞分泌趋化因子单核细胞趋化蛋白1(monocyte chemoattractant protein-1,MCP-1)和白细胞介素8(interleukin-8,IL-8)的机制。方法:利用NapA蛋白处理巨噬细胞,然后使用ELISA法检测上清中MCP-1和IL-8的表达量。使用C29、ST2825、SB203580、SP600125以及PDTC和巨噬细胞预先共孵育1 h,分别抑制Toll样受体2(toll-like receptors 2,TLR2)、髓样分化因子(myeloid differentiation factor 88,MyD88)、核糖核酸酶p蛋白亚基p38(ribonuclease p-protein subunit p38,p38)、应激活化蛋白激酶(c-Jun N-terminal kinase,c-Jun)和核因子κB(nuclear factor kappa B,NF-κB)的活性,然后再加入NapA蛋白孵育4 h,收集上清并检查其中MCP-1和IL-8的表达量。结果:NapA蛋白刺激巨噬细胞后,MCP-1和IL-8的表达量明显高于未处理组。利用抑制剂C29抑制TLR2的活性,NapA蛋白诱导的MCP-1和IL-8表达量降低。使用ST2825、PDTC以及SB203580分别抑制MyD88、NF-κB以及p38的活性,能够降低NapA蛋白诱导巨噬细胞分泌MCP-1和IL-8的能力,但是抑制c-Jun不影响NapA蛋白诱导巨噬细胞分泌MCP-1和IL-8。结论:幽门螺杆菌NapA蛋白通过TLR2/MyD88/NF-κB通路诱导巨噬细胞分泌MCP-1和IL-8。

Toll-like receptor 2及其信号传导通路在阿片类物质诱导细胞凋亡中的作用

目的:成瘾物质(Addictive drugs)导致的中毒性脑病的中枢神经系统损害以神经元凋亡为突出表现,具体机制仍有待进一步的研究探讨。方法:Toll-like receptor 2(TLR2)不仅是激活机体自身免疫防御和炎症反应的重要受体,而且广泛参与多种细胞功能,包括细胞凋亡。我们使用体外培养的HEK293和高表达TLR2的HEK2932种细胞,以及体外培养小鼠皮层原代神经元细胞,研究经过吗啡处理后细胞存活率和凋亡的变化,以探讨TLR2信号通路在吗啡诱导的细胞凋亡中的作用。结果:TLR2高表达导致吗啡诱导的细胞存活率下降和细胞凋亡的显著增加。使用MyD88抑制体竞争性抑制MyD88并阻断TLR2信号通路后,吗啡诱导的TLR2高表达细胞的凋亡也被明显抑制。长期的吗啡处理导致正常神经元的TLR2在信使RNA(mRNA)水平和蛋白水平表达明显增高,而且在TLR2功能缺失的原代神经元细胞中,吗啡诱导的caspase-3活性增高被阻断,吗啡诱导的神经元凋亡也被明显抑制。结论:TLR2信号通路参与吗啡诱导的神经元凋亡。

急性胆囊炎患者胆囊切除术后血清CCK-8、TREM1水平与发生感染的关系

目的分析急性胆囊炎(AC)患者胆囊切除术后血清胆囊收缩素-8(CCK-8)、髓系细胞触发受体1(TREM1)水平与发生感染的关系。方法将该院2020年12月至2022年12月收治的70例胆囊切除术后发生感染的AC患者纳入研究组,66例胆囊切除术后未发生感染的AC患者纳入对照组。采用酶联免疫吸附试验检测血清CCK-8、TREM1水平。采用Pearson相关分析胆囊切除术后发生感染AC患者血清中CCK-8、TREM1水平与炎症因子水平的相关性。采用受试者工作特征(ROC)曲线分析血清CCK-8、TREM1水平对AC患者胆囊切除术后发生感染的诊断价值。采用多因素Logistic回归分析AC患者胆囊切除术后感染的影响因素。结果研究组与对照组有胆囊结石、胆囊周边积液比例比较,差异均有统计学意义(P<0.05)。与对照组比较,研究组血清CCK-8水平明显降低,TREM1水平明显升高,差异均有统计学意义(P<0.05)。研究组C反应蛋白(CRP)、白细胞介素-8(IL-8)、肿瘤坏死因子-α(TNF-α)水平明显高于对照组,差异均有统计学意义(P<0.05)。胆囊切除术后发生感染的AC患者血清CCK-8水平与CRP、IL-8、TNF-α水平均呈负相关(P<0.05),TREM1水平与CRP、IL-8、TNF-α水平均呈正相关(P<0.05)。ROC曲线分析显示,血清CCK-8与TREM1联合检测诊断AC患者胆囊切除术后发生感染的曲线下面积(AUC)明显大于CCK-8、TREM1单独检测的AUC(Z=5.703,P<0.001;Z=4.584,P<0.001)。有胆囊结石、胆囊周边积液及血清CCK-8水平降低、血清TREM1水平升高均为AC患者胆囊切除术后发生感染的危险因素(P<0.05)。结论胆囊切除术后发生感染的AC患者血清CCK-8水平降低,TREM1水平升高,二者联合检测能够提高对AC患者胆囊切除术后发生感染的诊断价值。

炎性因子IL-8、PCT、IL-2R与严重细菌性颅内感染GCS评分的关系及预测预后的价值

目的分析严重细菌性颅内感染患者炎性因子白介素-8(IL-8)、降钙素原(PCT)、白介素-2受体(IL-2R)与格拉斯哥昏迷量表(GCS)评分的关系,并探讨其预测预后的价值。方法前瞻性选取2020年1月至2023年1月平顶山市第一人民医院收治的80例严重颅内感染患者作为研究对象,根据GCS评分分为轻中度组(9~14分)32例和重度组(≤8分)48例。比较两组患者的GCS评分和血清IL-8、PCT、IL-2R水平,采用Pearson相关系数分析血清IL-8、PCT、IL-2R水平与GCS评分的相关性,并以格拉斯哥预后量表(GOS)评估预后情况,比较预后良好、预后不良患者的临床资料和血清IL-8、PCT、IL-2R水平,通过Lasso回归筛选预后不良的预测因素,采用受试者工作特征(ROC)曲线分析血清IL-8、PCT、IL-2R预测预后不良的价值,并比较含与不含血清IL-8、PCT、IL-2R预测方案对预后不良的预测能力。结果重度组患者入院时血清IL-8、PCT、IL-2R水平分别为(35.12±4.26)pg/mL、(11.83±2.26)pg/mL、(912.35±105.83)U/m L,明显高于轻中度组的(26.74±3.81)pg/m L、(8.49±2.03)pg/m L、(749.21±92.56)U/m L,差异均有统计学意义(P<0.05);Pearson相关系数分析结果显示,严重细菌性颅内感染患者入院时的血清IL-8、PCT、IL-2R水平与GCS评分呈负相关(P<0.05);预后不良患者的年龄、机械通气占比、糖尿病占比、感染至入院时间、入院时血清IL-8、PCT、IL-2R水平分别为(65.13±7.26)岁、67.57%、27.03%、(38.05±4.17)h、(40.12±4.81)pg/m L、(12.67±2.59)pg/m L、(951.46±121.49)U/mL,明显高于预后良好患者的(56.39±6.41)岁、41.86%、9.30%、(26.92±3.46)h、(24.59±3.95)pg/mL、(8.61±2.24)pg/mL、(757.28±97.28)U/mL,入院时GCS评分为(6.72±0.39)分,明显低于预后良好患者的(10.81±0.82)分,差异均有统计学意义(P<0.05);经Lasso回归分析结果显示,年龄、感染至入院时间、GCS评分、血清IL-8、PCT、IL-2R水平均为预后不良的预测因素(P<0.05);经ROC分析结果显示,血清IL-8、PCT、IL-2R预测预后不良的曲线下面积(AUC)分别为0.729、0.717、0.719;含炎性因子预测方案的AUC为0.933,不含炎性因子预测方案的AUC为0.811;经DeLong检验结果显示,与不含炎性因子预测方案比较,含炎性因子预测方案的AUC明显增大(P<0.05),净重新分类指数(NRI)、综合判别改善指数(IDI)均>0(P<0.05)。结论严重细菌性颅内感染患者血清IL-8、PCT、IL-2R水平与GCS评分存在明显负相关,且与预后转归密切相关,可为临床预测预后提供参考。