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.

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.

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 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。

Science Letters:A synthetic Toll-like receptor 2 ligand decreases allergic immune responses in a mouse rhinitis model sensitized to mite allergen

It has been proposed that activation of Toll-like receptors （TLRs） plays crucial roles in the polarization of adaptive immune responses. A synthetic Toll-like receptor 2 （TLR2） ligand, Pam3CSK4, has been reported to modulate the balance of Th1/Th2 responses. We evaluated the modulation effect of Pam3CSK4 on allergic immune response in a mouse rhinitis model sensitized to house dust mite allergen （HDM）. Mice were sensitized and challenged with Dermatophagoidesfarinae allergen （Der f）, and then the allergic mice were treated by Pam3CSK4. Nasal allergic symptoms and eosinophils were scored. Der f-specific cytokine responses were examined in the splenocytes and bronchoalveolar lavage fluid （BALF）. Serum level of total IgE was also detected. After establishing a mouse allergic rhinitis model with HDM, we have showed that Pam3CSK4 treatment not only ameliorated the nasal allergic symptoms remarkably but also decreased the eosinophils and total inflammation cells in BALF significantly. Analysis of cytokine profile found that IFN-7 released from either BALF or stimulated splenocytes increased markedly in Pam3CSK4-treated mice, while IL-13 decreased significantly. Moreover, serum level of total IgE was significantly lower in Pam3CSK4-treated mice than in the untreated. Thus, in an allergic rhinitis mouse model developed with HDM, Pam3CSK4 was shown to exhibit an antiallergic effect, indicating its potential application in allergic diseases.

Divergent expression of bacterial wall sensing toll-like receptors 2 and 4 in colorectal cancer

To characterize the expression of toll-like receptors (TLR) 2 and 4 in colorectal cancer (CRC) and in normal colorectal mucosa. METHODSWe analysed tissue samples from a prospective series of 118 unselected surgically treated patients with CRC. Sections from formalin fixed, paraffin embedded specimens were analysed for TLR2 and TLR4 expression by immunohistochemistry. Two independent assessors evaluated separately expression at the normal mucosa, at the invasive front and the bulk of the carcinoma, and in the lymph node metastases when present. Expression levels in different locations were compared and their associations with clinicopathological features including TNM-stage and the grade of the tumour and 5-year follow-up observations were analysed. RESULTSNormal colorectal epithelium showed a gradient of expression of both TLR2 and TLR4 with low levels in the crypt bases and high levels in the surface. In CRC, expression of both TLRs was present in all cases and in the major proportion of tumour cells. Compared to normal epithelium, TLR4 expression was significantly weaker but TLR2 expression stronger in carcinoma cells. Weak TLR4 expression in the invasive front was associated with distant metastases and worse cancer-specific survival at 5 years. In tumours of the proximal colon the cancer-specific survival at 5 years was 36.9% better with strong TLR4 expression as compared with those with weak expression (P = 0.044). In contrast, TLR2 expression levels were not associated with prognosis. Tumour cells in the lymph node metastases showed higher TLR4 expression and lower TLR2 expression than cells in primary tumours. CONCLUSIONTumour cells in CRC show downregulation of TLR4 and upregulation of TLR2. Low expression of TLR4 in the invasive front predicts poor prognosis and metastatic disease.

Protection against hepatic ischemia/reperfusion injury via downregulation of toll-like receptor 2 expression by inhibition of Kupffer cell function

AIM： To elucidate the mechanism of liver protection by inhibition of Kupffer cells （KCs） function.METHODS： All the animals were randomly divided into three groups. Blockade group （gadolinium chloride solution （GdCl3） injection plus ischemia/reperfusion （I/R） injury）：GdCl3 solution was injected once every 24 h for 2 d via the tail vein before I/R injury. Non-blockade group （saline solution injection plus I/R injury）： saline instead of GdCl3 as a control was injected as in the blockade group. Sham group： saline was injected without I/R injury. Liver samples were collected 4 h after blood inflow restoration. The blockade of the function of KCs was verified by immunostaining with an anti-CD68 mAb. Toll-like receptor2 （TLR2） was immunostained with a goat antimouse polydonal anti-TLR2 antibody. Membrane proteins were extracted from the liver samples and TLR2 protein was analyzed by Western blot. Portal vein serum and plasma were taken respectively at the same time point for further detection of the levels of tumor necrosis factor-α （TNF-α） and alanine aminotransferase （ALT）, an indicator of liver function.I/R injury via downregulation of theexpression of TLR2.RESULTS： Compared to non-blockade group, CD^68＋ cells significantly reduced in blockade group （OPTDI, optical density integral）： 32.97±10.55 vs 185.65±21.88, P〈0.01） and the liver function impairment was relieved partially （level of ALT： 435.89±178.37 U/L vs 890.21±272.91 U/L,P〈0.01）. The expression of TLR2 protein in blockade group significantly decreased compared to that in non- group（method of immunohistochemistry, OPDTI： 75.74±17.44 vs 170.58±25.14, P〈0.01; method of Western blot, A value： 125.89±15.49 vs 433.91±35.53, P〈0.02）. The latter correlated with the variation of CD68 staining （r = 0.745,P〈0.05）. Also the level of portal vein TNF-α decreased in blockade group compared to that in non-blockade group （84.45±14.73 ng/L vs 112.32±17.56 ng/L, P〈0.05）, butwas still higher than that in sham group （84.45±14.73 ng/L vs 6.07±5.33 ng/L, P〈0.01）.CONCLUSION： Inhibition of the function of KCs may protect liver against I/R injury via downregulation of the expression of TLR2.

Association between polymorphisms in the Toll-like receptor 4,CD14,and CARD15/NOD2and inflammatory bowel disease in the Greek population

AIM: Crohn's disease(CD)and ulcerative colitis(UC)are multifactorial diseases with a significant genetic background.Apart from CARD15/NOD2 gene, evidence is accumulating that molecules related to the innate immune response such as CD14 or Toll-like receptor 4 (TLR4), are involved in their pathogenesis. In further exploring the genetic background of these diseases, we investigated the variations in the CARD15/NOD2 gene (Arg702Trp,Gly908Arg and Leu1007fsinsC), and polymorphisms in the TLR4 gene (Asp299Gly and Thr399Ile) as well as in the promoter of the CD14 gene (T/C at position -159) in Greek patients with CD and UC.METHODS: DNA was obtained from 120 patients with CD,85 with UC and 100 healthy individuals. Genotyping was performed by allele specific PCR or by PCR-RFLP analysis.RESULTS: The 299Gly allele frequency of the TLR4 gene and the T allele and TT genotype frequendes of the CD14 promoter were significantly higher in CD patients only compared to healthy individuals (P = 0.026＜0.05; P = 0.0048＜0.01 and P= 0.047＜0.05 respectively). Concerning the NOD2/CARD15mutations the overall presence in CD patients was significantly higher than that in UC patients or in controls.Additionally, 51.67% of the CD patients were carriers of a TLR4 and/or CD14 polymorphic allele and at least one variant of the NOD2/CARD15, compared to 27% of the UC patients. It should be pointed out that both frequencies significantly increased as compared with the 10% frequency of multiple carriers found in healthy controls. A possible interaction of the NOD2/CARD15 with TLR4 and especially CD14, increased the risk of developing inflammatory bowel disease (IBD).CONCLUSION: Our results indicate that co-existence of a mutation in either the TLR4 or CD14 gene, and in NOD2/CARD15is associated with an increased susceptibility to developing CD compared to UC, and to developing either CD or UC compared to healthy individuals.

Clinical significance of NOD2/CARD15 and Toll-like receptor 4 gene single nucleotide polymorphisms in inflammatory bowel disease

AIM： To evaluate the role of genetic factors in the pathogenesis of Crohn＇s disease （CD） and ulcerative colitis （UC）, we investigated the single nucleotide polymorphisms （SNPs） of NOD2/CARD15 （R702W, Gg08R and L1007finsC）, and Toll-like receptor 4 （TLR4） genes （D299G and T399I） in a selected inflammatory bowel disease （IBD） population coming from Southern Italy. METHODS： Allele and genotype frequencies of NOD2/ CARD15 （R702W, Gg08R and L1007finsC） and TLR4 （D299G and T399I） SNPs were examined in 133 CD patients, in 45 UC patients, and in 103 healthy controls. A genotype-phenotype correlation was performed. RESULTS： NOD2/CARD15 R702W mutation was significantly more frequent in CD （9.8%） than in controls （2.4%, P = 0.001） and in UC （2.3%, P = 0.03）. No significant difference was found between UC patients and control group （P 〉 0.05）. In CD and UC patients, no significant association with G908R variant was found. L1007finsC SNP showed an association with CD （9.8%） compared with controls （2.9%, P = 0.002） and UC patients （2.3%, P = 0.01）. Moreover, in CD patients, G908R and L1007finsC mutations were significantly associated with different phenotypes compared to CD wild-type patients. No association of IBD with the TLR4 SNPs was found in either cohort （allele frequencies： D299G-controls 3.9%, CD 3.7%, UC 3.4%, P 〉 0.05; T399I-controls 2.9%, CD 3.0%, UC 3.4%, P 〉 0.05）. CONCLUSION： These findings confirm that, in our IBD patients selected from Southern Italy, the NOD2/ CARD15, but not TLR4 SNPs, are associated with increased risk of CD.

Over-expression of Toll-like receptor 2 up-regulates heme oxygenase-1 expression and decreases oxidative injury in dairy goats

Background： Mastitis, an infection caused by Gram-positive bacteria, produces udder inflammation and oxidative injury in milk-producing mammals. Toll-like receptor 2（TLR2） is important for host recognition of invading Grampositive microbes. Over-expression of TLR2 in transgenic dairy goats is a useful model for studying various aspects of infection with Gram-positive bacteria, in vivo.Methods： We over-expressed TLR2 in transgenic dairy goats. Pam3CSK4, a component of Gram-positive bacteria,triggered the TLR2 signal pathway by stimulating the monocytes-macrophages from the TLR2-positive transgenic goats, and induced over-expression of activator protein-1（AP-1）, phosphatidylinositol 3-kinase（PI3K） and transcription factor nuclear factor kappa B（NF-κB） and inflammation factors downstream of the signal pathway.Results： Compared with wild-type controls, measurements of various oxidative stress-related molecules showed that TLR2, when over-expressed in transgenic goat monocytes-macrophages, resulted in weak lipid damage, high level expression of anti-oxidative stress proteins, and significantly increased m RNA levels of transcription factor NF-E2-related factor-2（Nrf2） and the downstream gene, heme oxygenase-1（HO-1）. When Pam3CSK4 was used to stimulate ear tissue in vivo the HO-1 protein of the transgenic goats had a relatively high expression level.Conclusions： The results indicate that the oxidative injury in goats over-expressing TLR2 was reduced following Pam3CSK4 stimulation. The underlying mechanism for this reduction was increased expression of the anti-oxidation gene HO-1 by activation of the Nrf2 signal pathway.

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.

室旁核TLR4阻断改善2型糖尿病大鼠糖代谢及机制

目的 聚焦于下丘脑室旁核(PVN)区域,研究中枢Toll样受体(TLR)4阻断对2型糖尿病(T2DM)大鼠糖代谢的影响及探讨相应影响机制。方法 将SD大鼠随机分为:正常对照(NC+PVN vehicle)组、正常干预(NC+PVN TAK-242)组、糖尿病(DM+PVN vehicle)组、糖尿病干预(DM+PVN TAK-242)组。高糖高脂联合小剂量链脲佐菌素(STZ)方法建立T2DM大鼠模型,皮下植入室旁核微型渗透泵(28 d,输注速率0.11 L/h)给予TAK-242(一种TLR4特异性抑制剂)和人工脑脊液;各组大鼠监测体重、空腹血糖(FBG)、葡萄糖耐量试验(GTT)、胰岛素耐量试验(ITT)和丙酮酸耐量试验(PTT)评估体内糖代谢情况;肾交感神经放电检测交感神经活性;Western印迹检测还原型烟酰胺腺嘌呤二核苷酸磷酸(NADPH)氧化酶(NOX)4、Cu-Zn超氧化物歧化酶(SOD)、NF-κB通路激活标志物(TH)、谷氨酸脱羧酶(GAD)67蛋白表达;二氢乙淀(DHE)检测PVN中活性氧簇(ROS)水平;免疫荧光检测PVN中TLR4、TH阳性神经元表达数量;免疫组化检测PVN中神经元激活标志物(c-FOS)、NF-κB通路激活标志物(p-IKKβ)阳性神经元表达数量。结果 与正常组相比,T2DM组大鼠体重显著降低,FBG显著升高,体内存在胰岛素抵抗和糖异生紊乱,肾交感神经放电显著增加,PVN内TLR4、TH、ROS、c-FOS、p-IKKβ阳性神经元表达数量显著增多,PVN内NOX4、TH蛋白表达显著升高,Cu-Zn SOD、GAD67蛋白表达显著降低(P<0.05)。经TAK-242治疗的T2DM大鼠体重下降速度显著降低,FBG不断升高趋势被控制,体内胰岛素抵抗和糖异生紊乱显著改善,肾交感神经放电显著降低,PVN内TLR4、TH、ROS、c-FOS、p-IKKβ阳性神经元表达数量显著减少,PVN内NOX4、TH蛋白表达降低,Cu-Zn SOD、GAD67蛋白表达升高(P<0.05)。结论 PVN慢性输注TAK-242可有效阻断下丘脑PVN TLR4的表达,改善PVN内氧化应激和神经元凋亡,改善PVN内兴奋性神经递质和抑制性神经递质失平衡,进而降低交感神经活性,改善T2DM大鼠体内糖代谢。

TLR-2和TLR-5在弥漫大B细胞淋巴瘤组织中的表达及临床意义

目的探讨Toll样受体-2(TLR-2)和Toll样受体-5(TLR-5)在弥漫大B细胞淋巴瘤(DLBCL)组织中的表达及其临床意义。方法采用免疫组化法检测60例DLBCL组织标本中TLR-2和TLR-5的表达,以21例反应性淋巴结增生组织为对照组,并分析TLR-2和TLR-5表达与DLBCL临床病理特征的关系。结果 TLR-2在DLBCL组织中的阳性表达率为78.3%,在对照组中为28.5%,差异有统计学意义(P<0.05);TLR-2表达与年龄、性别和ECOG评分无关,与临床分期、乳酸脱氢酶水平、B症状、IPI、免疫亚型以及结外受累有关。TLR-5在DLBCL中的阳性表达率为26.6%,在对照组中为23.8%(P>0.05);TLR-5表达与各临床病理特征无关。结论 TLR-5与DLBCL临床特征无关;TLR-2可能参与了DLBCL的发生和发展,有望作为判断其预后的生物学指标。

Polymorphisms of the TLR2 and TLR4 genes are associated with risk of gastric cancer in a Brazilian population

AIM： TO investigate toll-like receptor 2 （TLR2） -196 to -274 del, and TLR4 （＋896A/G rs4986790 and ＋1196C/ T rs4986791） polymorphisms at risk of chronic gastritis and gastric cancer in a Brazilian population and associ-ation of gastric lesions with risk factors such as smoking, alcohol intake and Helicobacter pylori infection.METHODS： In this casecontrol study, polymorphism at TLR2 -96 to -174 del was investigated by using the allele-specific polymerase chain reaction （PCR） method, while the PCR-restriction fragment length polymorphism technique was carried out to identify the TLR4 （rs4986790 and rs4986791） genotypes in 607 Brazilian individuals （208 with chronic gastritis-CG, 174 with gastric cancer-GC and 225 controls -C）.RESULTS： The single nucleotide polymorphisms TLR4＋1196ClT was not associated with risk of chronic gastritis or gastric cancer and the homozygous genotypes TLR4＋896GG and TLR4＋1196TF were absent in the studied population. However, the frequency of TLR2 -196 to -174 ins/del ＋ del/del and TLR4＋896AGgenotypes was significantly higher （P 〈 0.01 and P = 0.01, respectively） in the cancer group （33.4% and 11.5%, respectively） than in the control group （16.9% and 4.5%, respectively）. It was also observed that the G-C haplotype of the TLR4＋896A/G＋1196C/T （P = 0.02） and the combination of variant alleles of the TLR21TLR4＋896G （P = 0.02） are associated with susceptibility to gastric cancer. In addition, the multiple logistic regression showed that male gender [odds ratio （OR） = 2.70; 95% CI： 1.66-4.41; P 〈 0.01], alcohol intake （OR = 2.93; 95% CI： 1.76-4.87, P 〈 0.01）, TLR2 -196 to -174 del （OR = 2.64; 95% CI： 1.56-4.44; P 〈 0.01） and TLR4＋896G （OR = 3.19; 95% CI： 1.34- 7.61; P 〈 0.01） polymorphisms were associated with a higher susceptibility to developing this neoplasm.CONCLUSION： Our data indicate that T/R2 -196 to -174 del and TLR4＋896G may increase the risk of gastric cancer in a Brazilian population.

TLR2 and TLR4 polymorphisms influence m RNA and protein expression in colorectal cancer

AIM: To evaluate the effect of promoter region polymorphisms of toll-like receptor(TLR)2-196 to-174 del and TLR4-1607T/C(rs10759932) on m RNA and protein expression in tumor tissue and of TLR4+896A/G(rs4986790) on colorectal cancer(CRC) risk.METHODS: The TLR2-196 to-174 del polymorphism was investigated using allele-specific polymerase chain reaction(PCR) and the TLR4-1607T/C and TLR4+896A/G by PCR-restriction fragment length p o l y m o r p h i s m( R F L P). W e g e n o t y p e d 4 3 4 D N A samples from 194 CRC patients and 240 healthy individuals. The m RNA relative quantification(RQ) was performed in 40 tumor tissue samples by quantitative PCR Taq Man assay, using specific probes for TLR2 and TLR4 genes, and ACTB and GAPDH reference geneswere used as endogenous controls. Protein expression was analyzed by immunohistochemistry with specific primary antibodies.RESULTS: No association was found for TLR4-1607T/C and TLR4+896A/G by three statistical models(logadditive, dominant and recessive). However, based on dominant and log-additive models, the polymorphic variant TLR2-196 to-174 del was associated with increased CRC risk [dominant: odds ratio(OR) = 1.72, 95%CI: 1.03-2.89; P = 0.038 and log-additive: OR =1.59, 95%CI: 1.02-2.48; P = 0.039]. TLR2 m RNA expression was increased in tumor tissue(RQ = 2.36) when compared to adjacent normal tissue(RQ = 1; P < 0.0001), whereas the TLR4 m RNA showed a basal expression(RQ = 0.74 vs RQ = 1, P = 0.452). Immunohistochemistry analysis of TLR2 and TLR4 protein expression was concordant with the findings of m RNA expression. In addition, the TLR2-196 to-174 del variant carriers showed m RNA relative expression 2.19 times higher than wild-genotype carriers. The TLR2 protein expression was also higher for the TLR2-196 to-174 del variant carriers [117 ± 10 arbitrary unit(a.u.) vs 95 ± 4 a.u., P = 0.03]. However, for the TLR4-1607T/C polymorphism no significant difference was found for both m RNA(P = 0.56) and protein expression(P = 0.26).CONCLUSION: Our findings suggest that TLR2-196 to-174 del polymorphism increases TLR2 m RNA expression and is associated with higher CRC risk, indicating an important role in CRC genetic susceptibility.

TLR2 mRNA Upregulation in Ischemic Lobes in Mouse Partial Hepatic Ischemia/Reperfusion Injury Model

To investigate TLR2 (Toll-like receptor 2) mRNA expression in ischemic hepatic lobes under the condition of partial hepatic ischemia/reperfusion injury in BALB/c mice and its relationship with liver function impairment. A partial ischemia/reperfusion injury model was established. The portal vein and hepatic artery supply to the median and left lobes of the liver were obstructed by an atraumatic artery micro-clip, with the obstruction lasting for about 60 min. Then reperfusion was fulfilled by removal of the clip. The liver samples were collected at the 4th h after the restoration of blood inflow. Total RNA was extracted from the liver samples and analyzed quantitatively by method of real-time PCR. At the same time, portal vein serum and plasma were taken respectively for further detection of the level of endotoxin, tumor necrosis factor alpha (TNF-alpha) and plasmic alanine aminotransferase (pALT). The results indicated that TLR2 mRNA in ischemic lobe was up-regulated markedly in mice partial liver ischemia/reperfusion injury model compared to that in sham operation group (ΔCt: 1.05±1.02 vs 5.08±1.36, P<0.001). The level of portal vein pALT and TNF-alpha increased significantly (112.32±17.56 pg/ml vs 6.07±5.33 pg/ml,P<0.01;890±127 μ/L vs 30±5 μ/L, P<0.001) . However, the level of portal vein endotoxin remained below the normal line, suggesting a state of non-endotoxemia. TLR2 mRNA expression in ischemic lobe, as well as portal vein pALT and TNF-alpha, was up-regulated in the model of mice partial ischemia/reperfusion injury, suggesting the involvement of TLR2 in ischemia/reperfusion pathological process.

Analysis of TLR4 and TLR2 polymorphisms in inflammatory bowel disease in a Guangxi Zhuang population

AIM: To study the polymorphisms of toll-like receptor 4 (TLR4) gene Asp299Gly, Thr399Ile and TLR2 gene Arg753Gln, Arg677Trp and susceptibility to inflammatory bowel disease (IBD) in the Zhuang population from Guangxi, China. METHODS: A case-control study was performed from February 2007 to October 2011 which included 146 Zhuang patients with IBD in the experimental group and 164 healthy Zhuang subjects who acted as the control group. All patients and healthy subjects were from the Guangxi Zhuang Autonomous Region of China. Genomic DNA was extracted from intestinal tissue by the phenol chloroform method. TLR4 gene Asp299Gly, Thr399Ile and TLR2 gene Arg753Gln, Arg677Trp were amplified by polymerase chain reaction (PCR), and then detected by PCR-restriction fragment length polymorphism (RFLP). RESULTS: The TLR4 gene Asp299Gly was digested using Nco Ⅰ restriction enzyme, and a single band of 249 bp was observed which showed that it was a wild type (AA). The TLR4 gene Thr399Ile was digested using Hinf Ⅰrestriction enzyme and only the wild type (CC) was detected. In addition, the TLR2 gene Arg-677Trp was digested using Aci Ⅰ restriction enzyme and only the wild type (CC) was detected. The TLR2 gene Arg753Gln was digested using Pst Ⅰ restriction enzyme. Only the wild type (GG) as a single band of 254 bp was observed during RFLP. Overall, no heterozygous or homozygous single nucleotide polymorphism mutations were found in patients with Crohn's disease and ulcerative colitis both in the TLR4 gene Asp299Gly, Thr399Ile and the TLR2 gene Arg677Trp, Arg753Gln in the Zhuang population from the Guangxi Zhuang Autonomous Region of China. CONCLUSION: The TLR4 gene Asp299Gly, Thr399Ile and TLR2 gene Arg753Gln, Arg677Trp polymorphisms may not be associated with IBD in the Zhuang population from the Guangxi Zhuang Autonomous Region of China.

Toll-like receptor expression and signaling in human diabetic wounds

AIM: To examine the contribution of toll-like receptors(TLRs) expression and activation to the prolonged inflammation often seen in human diabetic wounds.METHODS: Debridement wound tissue was collected from diabetic patients with informed consent. Total RNA and protein were isolated and subjected to real-time polymerase chain reaction and Western blot analyses. RESULTS: TLR1, 2, 4, and 6 mRNA expressions were increased significantly in wounds of diabetic patients compared with non-diabetic wounds(P 【 0.05). MyD88 protein expression was significantly increased in diabetic wounds compared to non-diabetic wounds. Interleukin-1beta, tumor necrosis factor-alpha concentration nuclear factor-kappa B activation, and thiobarbituric acid reactive substances were increased in diabetic wounds compared to non-diabetic wounds(P 【 0.01). CONCLUSION: Collectively, our novel findings show that increased TLR expression, signaling, and activation may contribute to the hyper inflammation in the human diabetic wounds.