Oxygen-glucose deprivation of neurons transfected with toll-like receptor 3-siRNA Determination of an optimal transfection sequence

Toll-like receptor 3 protein expression has been shown to be upregulated during cerebral ische- mia/reperfusion injury in rats. In this study, rat primary cortical neurons were subjected to oxy- gen-glucose deprivation to simulate cerebral ischemia/reperfusion injury. Chemically synthesized small interfedng RNA （siRNA）-1280, -1724 and -418 specific to toll-like receptor 3 were transfected into oxygen-glucose deprived cortical neurons to suppress the upregulation of toll-like receptor 3 protein expression. Western blotting demonstrated that after transfection with siRNA, toll-like re- ceptor 3 protein expression reduced, especially in the toll-like receptor 3-1724 group. These results suggested that siRNA-1724 is an optimal sequence for inhibiting toll-like receptor 3 expression in cortical neurons following oxygen-glucose deprivation.

Correlation analysis of Toll-like receptor 3 content in peripheral blood with electroencephalogram parameters and neurotransmitter content in children with intractable epilepsy

Objective:To detect the content of Toll-like receptor 3 (TLR3) in peripheral blood of children with intractable epilepsy, explore the correlation between TLR3 content and EEG parameters, neurotransmitter contents.Methods:37 cases of Intractable epilepsy children in our hospital during September 2016to June 2018 were chosen as Intractable epilepsy group, 30 cases of healthy volunteers who underwent physical examination in our hospital were treated as Normal control group. The levels of TLR3, neurotransmitter [5-hydroxytryptamine (5-HT), dopamine (DA), epinephrine (E), norepinephrine (NE)] and electroencephalogram parameters [alpha, beta, delta, theta] in peripheral blood of two groups were compared. Pearson test was used to evaluate the correlation of TLR3 content in peripheral blood with EEG parameters and neurotransmitter content in children with intractable epilepsy.Results: Content of TLR3 in peripheral blood of Intractable epilepsy group was significantly higher than that of Normal control group;the alpha power and theta power of EEG parameters were lower than those of Normal control group;contents of neurotransmitters such as 5-HT, DA, E and NE were significantly lower than those of Normal control group (P<0.05). The correlation analysis showed that content of TLR3 in peripheral blood of children with intractable epilepsy was negatively correlated with levels of alpha and theta power of EEG, positively correlated with content of neurotransmitters such as 5-HT, DA, E and NE (P<0.05), but had no significant correlation was found with level of beta and delta power (P>0.05).Conclusion: The abnormal increase of TLR3 in peripheral blood of children with intractable epilepsy may be one of the direct causes of neurological impairment in children with intractable epilepsy.

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 receptor 3(TLR3)regulation mechanisms and roles in antiviral innate immune responses

Toll-like receptor 3(TLR3)is a member of the TLR family,mediating the transcriptional induction of type I interferons(IFNs),proinflammatory cytokines,and chemokines,thereby collectively establishing an antiviral host response.Studies have shown that unlike other TLR family members,TLR3 is the only RNA sensor that is utterly dependent on the Tollinterleukin-1 receptor(TIR)-domain-containing adaptor-inducing IFN-β(TRIF).However,the details of how the TLR3-TRIF signaling pathway works in an antiviral response and how it is regulated are unclear.In this review,we focus on recent advances in understanding the antiviral mechanism of the TRIF pathway and describe the essential characteristics of TLR3 and its antiviral effects.Advancing our understanding of TLR3 may contribute to disease diagnosis and could foster the development of novel treatments for viral diseases.

Protective effect of Chushizi(Fructus Broussonetiae)on acetaminophen-induced rat hepatitis by inhibiting the Toll-like receptor 3/c-Jun N-terminal kinase/c-jun/c-fos/janus protein tyrosine kinase/activators of transcription 3 pathway

OBJECTIVE:To observe the intervention of Chushizi(Fructus Broussonetiae)(CSZ)on drug-induced liver injury(DILI)in rats,as well as indicators of liver function,serum levels of inflammatory cytokines,and expression of proteins and m RNA associated with toll-like receptor 3(TLR3)and the signal transducer and activator of transcription 3(STAT3)pathway in the liver[TLR3,janus protein tyrosine kinase 2(JAK2),c-jun,c-fos,c-Jun N-terminal kinase 2(JNK2),and STAT3].METHODS:Forty specified pathogen free grade Sprague-Dawley rats were randomly divided into the control group,the model group,the silybin group and the CSZ group.Rats were given acetaminophen(APAP)to trigger DILI.Histopathology of the liver was observed by hematoxylin-eosin staining.The levels of alanine aminotransferase(ALT),aspartate transaminase(AST),direct bilirubin(DBIL),and total bilirubin(TBIL)in serum were detected by a semi-automatic biochemical instrument.Content of tumor necrosis factor alpha(TNF-α),interleukin(IL)-6,IL-13,and IL-22 in serum were detected by the enzyme-linked immunosorbent assay,the expression of TLR3,phosphorylation of JAK2(p-JAK2),while c-jun and c-fos proteins in the liver were determined by immunohistochemistry;expression of JNK2,and STAT3 in the liver were assayed by Western blot and real-time quantitative polymerase chain reaction.P-JNK2 and p-STAT3 in the liver were assayed by Western blot.RESULTS:After treatment,the activity of ALT,AST,and concentrations of TBIL,DBIL,TNF-α,IL-6,as well as IL-13 in serum,were lower than those in the model group,and expression of p-JAK2,TLR3,c-jun,c-fos,p-STAT3,and p-JNK2 could be downregulated.CONCLUSION:Our findings suggest that CSZ is a valid medicine to alleviate APAP-induced DILI,while its partial mechanism may regulate the TLR3/JNK/c-jun/c-fos/JAK/STAT3 pathway.

Small molecule SMU-CX24 targeting toll-like receptor 3 counteracts inflammation:A novel approach to atherosclerosis therapy

Toll-like receptor 3(TLR3),as an important pattern recognition receptor(PRR),dominates the innate and adaptive immunity regulating many acute and chronic inflammatory diseases.Atherosclerosis is proved as an inflammatory disease,and inflammatory events involved in the entire process of initiation and deterioration.However,the contribution of TLR3 to atherosclerosis remains unclear.Herein,we identified the clinical relevance of TLR3 upregulation and disease processes in human atherosclerosis.Besides,activation of TLR3 also directly led to significant expression of atherogenic chemokines and adhesion molecules.Conversely,silencing TLR3 inhibited the uptake of oxLDL by macrophages and significantly reduced foam cell formation.Given the aberrance in TLR3 functions on atherosclerosis progression,we hypothesized that TLR3 could serve as novel target for clinical atherosclerosis therapy.Therefore,we developed the novel ellipticine derivative SMU-CX24,which specifically inhibited TLR3(IC_(50)=18.87±2.21 nmol/L).In vivo,atherosclerotic burden was alleviated in Western diet fed ApoE^(−/−)mice in response to SMU-CX24 treatment,accompanying notable reductions in TLR3 expression and inflammation infiltration within atherosclerotic lesion.Thus,for the first time,we revealed that pharmacological downregulation of TLR3 with specific inhibitor regenerated inflammatory environment to counteract atherosclerosis progression,thereby proposing a new strategy and probe for atherosclerosis therapy.

Polyinosine-polycytidylic acid promotes excessive iodine intake induced thyroiditis in non-obese diabetic mice via Toll-like receptor 3 mediated inflammation

Background Excessive iodine intake and viral infection are recognized as both critical factors associated with autoimmune thyroid diseases. Toll-like receptors （TLRs） have been reported to play an important role in autoimmune and inflammatory disorders. In this study, we aimed to clarify the possible mechanism of TLR3 involved in polyinosine- polycytidylic acid （poly（I：C）） promoting excessive iodine intake induced thyroiditis in non-obese diabetic （NOD） mice. Methods Both NOD and BALB/c mice were randomly assigned to four groups： control group （n=5）, high iodine intake （HI） group （n=7）, poly（I：C） group （n=7） and combination of excessive iodine and poly（l：C） injection （HIP） group （n=7）. After 8 weeks, mice were weighed and blood samples were collected. All the mice were sacrificed before dissection of spleen and thyroid gland. Then, thyroid histology, thyroid secreted hormone, expression of CD3＋ cells and TLR3 as well as inflammatory mRNA level were evaluated. Results Both NOD and BALB/c mice from HI and HIP group represented goiter and increasing thyroid relative weight. Thyroid histology evidence indicated that only HIP group of NOD mice showed severe thyroiditis with lymphocytes infiltration in majority of thyroid tissue, severe damage of follicles and general fibrosis. Immunofiuorescence staining results displayed a large number of CD3~ cells in HIP NOD mice. Real-time polymerase chain reaction （PCR） results suggested interferon （IFN）-a increased over 30 folds and IFN-y expression was doubled compared with control group, but interleukin （IL）-4 remained unchanged in HIP group of NOD mice thyroid. Meanwhile, over one third decrease of blood total thyroxine （TT4） and increased thyroid-stimulating hormone （TSH） was observed in HIP group of NOD mice. Only HIP group of NOD mice represented significantly elevation of TLR3 expression. Conclusion Poly（l：C） enhanced excessive dietary iodine induced thyroiditis in NOD mice through increasing TLR3 mediated inflammation.

Overexpression of low-density lipoprotein receptor prevents neurotoxic polarization of astrocytes via inhibiting NLRP3 inflammasome activation in experimental ischemic stroke

Neurotoxic astrocytes are a promising therapeutic target for the attenuation of cerebral ischemia/reperfusion injury.Low-density lipoprotein receptor,a classic cholesterol regulatory receptor,has been found to inhibit NLR family pyrin domain containing protein 3(NLRP3)inflammasome activation in neurons following ischemic stroke and to suppress the activation of microglia and astrocytes in individuals with Alzheimer’s disease.However,little is known about the effects of low-density lipoprotein receptor on astrocytic activation in ischemic stroke.To address this issue in the present study,we examined the mechanisms by which low-density lipoprotein receptor regulates astrocytic polarization in ischemic stroke models.First,we examined low-density lipoprotein receptor expression in astrocytes via immunofluorescence staining and western blotting analysis.We observed significant downregulation of low-density lipoprotein receptor following middle cerebral artery occlusion reperfusion and oxygen-glucose deprivation/reoxygenation.Second,we induced the astrocyte-specific overexpression of low-density lipoprotein receptor using astrocyte-specific adeno-associated virus.Low-density lipoprotein receptor overexpression in astrocytes improved neurological outcomes in middle cerebral artery occlusion mice and reversed neurotoxic astrocytes to create a neuroprotective phenotype.Finally,we found that the overexpression of low-density lipoprotein receptor inhibited NLRP3 inflammasome activation in oxygen-glucose deprivation/reoxygenation injured astrocytes and that the addition of nigericin,an NLRP3 agonist,restored the neurotoxic astrocyte phenotype.These findings suggest that low-density lipoprotein receptor could inhibit the NLRP3-meidiated neurotoxic polarization of astrocytes and that increasing low-density lipoprotein receptor in astrocytes might represent a novel strategy for treating cerebral ischemic stroke.

Cortico-striatal gamma oscillations are modulated by dopamine D3 receptors in dyskinetic rats

Long-term levodopa administration can lead to the development of levodopa-induced dyskinesia.Gamma oscillations are a widely recognized hallmark of abnormal neural electrical activity in levodopa-induced dyskinesia.Currently,studies have reported increased oscillation power in cases of levodopa-induced dyskinesia.However,little is known about how the other electrophysiological parameters of gamma oscillations are altered in levodopa-induced dyskinesia.Furthermore,the role of the dopamine D3 receptor,which is implicated in levodopa-induced dyskinesia,in movement disorder-related changes in neural oscillations is unclear.We found that the cortico-striatal functional connectivity of beta oscillations was enhanced in a model of Parkinson’s disease.Furthermore,levodopa application enhanced cortical gamma oscillations in cortico-striatal projections and cortical gamma aperiodic components,as well as bidirectional primary motor cortex(M1)↔dorsolateral striatum gamma flow.Administration of PD128907(a selective dopamine D3 receptor agonist)induced dyskinesia and excessive gamma oscillations with a bidirectional M1↔dorsolateral striatum flow.However,administration of PG01037(a selective dopamine D3 receptor antagonist)attenuated dyskinesia,suppressed gamma oscillations and cortical gamma aperiodic components,and decreased gamma causality in the M1→dorsolateral striatum direction.These findings suggest that the dopamine D3 receptor plays a role in dyskinesia-related oscillatory activity,and that it has potential as a therapeutic target for levodopa-induced dyskinesia.

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.

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.

The Role of Toll-Like Receptors and Nuclear Factor κB p65 Protein in the Pathogenesis of Otitis Media

The role of Toll-like receptor 4 (TLR4) and nuclear factor κB p65 (NF-κB p65) proteins in the pathogenesis of otitis media is explored. In recent years, the incidence of otitis media has been rising globally, becoming a significant threat to human health. More and more studies have found that Toll-like receptor 4 (TLR4), as a member of the Toll-like receptor family, can promote the generation of inflammatory factors and is closely related to the body’s immune response and inflammatory response. Nuclear factor-κB p65 (NF-κB p65) is a nuclear transcription factor that can interact with various cytokines, growth factors, and apoptotic factors, participating in processes such as oxidative stress, apoptosis, and inflammation in the body [1]. This article elaborates on the structure, function, and signaling pathways of TLR4 and NF-κB p65 proteins in the pathogenesis of otitis media, aiming to provide more precise targets and better therapeutic efficacy for the diagnosis and treatment of otitis media. The role of inflammation in disease.

Effects of ω-3 fatty acids on toll-like receptor 4 and nuclear factor-κB p56 in lungs of rats with severe acute pancreatitis

AIM To determine the effects of ω-3 fatty acids(ω-3FA) on the toll-like receptor 4(TLR4)/nuclear factor κB p56(NF-κBp56) signal pathway in the lungs of rats with severe acute pancreatitis(SAP).METHODS A total of 56 Sprague-Dawley rats were randomly divided into 4 groups: control group, SAP-saline group, SAP-soybean oil group and SAP-ω-3FA group. SAP was induced by the retrograde infusion of sodium taurocholate into the pancreatic duct. The expression of TLR4 and NF-κBp56 in the lungs was evaluated by immunohistochemistry and Western blot analysis. The levels of inflammatory cytokines interleukin-6 and tumor necrosis factor-alpha in the lungs were measured by enzyme-linked immunosorbent assay. RESULTS The expression of TLR4 and NF-κBp56 in lungs and of inflammatory cytokines in serum significantly increased in the SAP group compared with the control group(P < 0.05), but was significantly decreased in the ω-3FA group compared with the soybean oil group at 12 and 24 h(P < 0.05).CONCLUSION During the initial stage of SAP, ω-3FA can efficiently lower the inflammatory response and reduce lung injury by triggering the TLR4/NF-κBp56 signal pathway.

Effect of ω-3 Polyunsaturated Fatty Acid on Toll-like Receptors in Patients with Severe Multiple Trauma

This study examined the effects of ω-3 polyunsaturated fatty acid（ω-3PUFA） on the expression of toll-like receptor 2（TLR2）,toll-like receptor 4（TLR4） and some related inflammatory factors in peripheral blood mononuclear cells（PBMCs） of patients with early-stage severe multiple trauma.Thirty-two patients who were admitted to the Department of Traumatic Surgery,Tongji Hospital（Wuhan,China） between May 2010 and November 2010,and diagnosed as having severe multiple trauma with a injury severity score（ISS） no less than 16,were enrolled in the study and divided into two groups at random（n=16 in each）：ω-3PUFA group and control group in which routine parenteral nutrition supplemented with ω-3PUFA or not was administered to the patients in two groups for consecutive 7 days.Peripheral blood from these patients was collected within 2 h of admission（day 0）,and 1,3,5 and 7 days after the nutritional support.PBMCs were isolated and used for detection of the mRNA and protein expression of TLR2 and TLR4 by using real-time PCR and flow cytometry respectively,the levels of NF-κB by quantum dots-based immunofluorescence assay,the levels of TNF-α,IL-2,IL-6 and COX-2 by ELISA,respectively.The results showed that the mRNA and protein expression of TLR2 and TLR4 in PBMCs was significantly lower in ω-3PUFA group than in control group 5 and 7 days after nutrition support（both P0.05）.The levels of TNF-α,IL-2,IL-6 and COX-2 were found to be substantially decreased in PBMCs in ω-3PUFA group as compared with control group at 5th and 7th day（P0.05 for all）.It was concluded that ω-3PUFA can remarkably decrease the expression of TLR2,TLR4 and some related inflammatory factors in NF-κB signaling pathway in PBMCs of patients with severe multiple trauma,which suggests that ω-3PUFA may suppress the excessive inflammatory response meditated by the TLRs/NF-κB signaling pathway.

Effect of Ligands to Toll-Like Receptors (TLR) 3, 7 and 9 on Mice Infected with Mouse Hepatitis Virus A59

Mice infected with mouse hepatitis virus A59 (MHV-A59), an enveloped, positive-strand RNA Co-ronavirus, induce hepatitis, thymus involution, IgG2a-restricted hypergammaglobulinaemia, transaminase release and autoantibodies (autoAb) to liver and kidney fumarylacetoacetate hy-drolase (FAH). Since Toll-like receptors (TLR) play a central role in innate immunity, we explored the effects of TLR3, 7 and 9 stimulation on MHV mouse infection. Thus, the animals were treated with Poly (I:C), Loxoribine and CpG, the respective TLR ligands. MHV-infected mice inoculated with Poly (I:C) had significant lower levels of plasma transaminases and Ig, anti-MHV Ab, and uric acid than MHV-infected animals, whereas autoAb to kidney tissue were observed. Loxoribine only produced a slight decrease of uric acid levels and serum Ig. CpG showed deleterious effects on MHV-infected mice, since survival of animals dramatically dropped to about 10%. AutoAb to murine tissues and uric acid release were not affected, whereas transaminases and anti-MHV Ab were slightly elevated. Besides, CpG administration produced a decrease of the high levels of serum Ig induced by the virus. Therefore, results indicated that TLR3 stimulation appeared to protect the animals against the viral infection, whereas CpG aggravated its signs. Loxoribine, the TLR7 ligand, did not show major effects.

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.

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。