Mucosal vaccination increases local chemokine production attracting immune cells to the stomach mucosa of Helicobacter pylori infected mice

Background

Vaccination is an attractive approach for the prevention of Helicobacter pylori infection and disease. In a mouse model, infection induces an accumulation of dendritic cells, macrophages, granulocytes, and B- and T cells to the stomach mucosa, which is further heightened when the infection is preceded by a mucosal immunization. We have studied the chemokines and chemokine receptors guiding infection- and vaccination-induced immune cells to the stomach and their relation to protection against H. pylori infection in mice.

Materials and methods

C57BL/6 mice were immunized sublingually with H. pylori lysate antigens and cholera toxin adjuvant or left unimmunized, and then challenged with live H. pylori bacteria. Stomach tissue was taken at 3, 7, 14 and 21 days after challenge and bacterial colonization, chemokine and chemokine receptor gene expression, and influx of cells into the stomach mucosa were evaluated.

Results

RT-PCR array screening revealed differential expression of a broad range of chemokine and chemokine receptor genes between immunized and unimmunized mice. A significant upregulation of chemokines known to attract, among other cells, eosinophils (CCL8), T cells (CXCL10, CXCL11) and neutrophils (CXCL2, CXCL5) and of their cognate receptors CCR3, CXCR3 and CXCR2, preceded or coincided with vaccine-induced protection, which was first evident 7 days after infection and was then sustained at the later time-points. Consistent with the increase in chemokines and chemokine receptors flow cytometric analysis indicated a sequential accumulation of CD4⁺ T cells, eosinophils, neutrophils and CD103⁺ dendritic cells in the gastric lamina propria of immunized mice.

Conclusions

This study provides insights into vaccination-induced chemokines that guide the influx of protective immune cells into the stomach of H. pylori infected mice.     

Regulation of the Intracellular ROS Level Is Critical for the Antiproliferative Effect of Quercetin in the Hepatocellular Carcinoma Cell Line HepG2

Quercetin, an antioxidant flavonoid, has been known that it can induce the cell cycle arrest and apoptosis of hepatocellular carcinoma (HCC) cells by the stabilization or induction of p53. Here, we found that quercetin reduced the proliferation of HepG2 cells significantly, but not Huh7 cells. Interestingly, quercetin down-regulated the intracellular ROS level in HepG2 cells, but not Huh7 cells. Functional study using siRNA showed that the proliferation of HepG2 cells was still regulated by quercetin in the absence of p53. Furthermore, we confirmed the effect of quercetin on HepG2 cells by H₂O₂ supplementation. This study demonstrates that the antiproliferative effect of quercetin on HCC cells can be mediated by reducing intracellular ROS, which is independent of p53 expression.     

Homing defects of B cells in HIV-1 infected children impair vaccination responses

Background

Successful vaccinations rely on antibody responses. Chemokine receptors play an important role in B cell homing to differentiation niches. We assessed CXCR4, CXCR5 and CCR6 expression on B cells during HIV-1 infection and relate it to antibody responses against a HBV vaccine.

趋化因子CXCL12对卵巢癌细胞侵袭和转移的作用及机制研究

目的 研究趋化因子CXCL12对卵巢癌细胞侵袭和转移的作用及机制.方法 采用RT-PCR检测20例上皮性卵巢癌组织、卵巢癌细胞株CAOV3、血管内皮细胞株HUVEC和20例正常卵巢组织中CXCL12的mRNA表达及卵巢癌腹膜后淋巴组织和输卵管平滑肌组织中CXCL12的表达,ELISA法检测20例卵巢癌患者腹水中趋化因子CXCL12表达水平,比较不同浓度CXCL12对CAOV3及HUVEC细胞迁移能力及其表面相关黏附分子表达水平的影响.结果 20例卵巢癌组织、卵巢细胞CAOV3、内皮细胞HUVEC、转移的淋巴组织中CXCL12mRNA相对表达量分别为2.41±1.05、1.92±1.17、1.73±1.12、1.68±1.13,而正常组未检出,各组比较有显著性差异(F=2.907,P=0.032).20例卵巢癌患者腹水中有19例检测到趋化因子CXCL12,检出率95.0%,CXCL12水平为(6 552.7±476.5)pg/mL.与对照组相比,CAOV3细胞经CXCL12处理后,与细胞外基质的粘附能力相对粘附率由(22.65±2.3)%上升至(51.47±2.7)%(t=4.696,P<0.05).卵巢癌细胞株CAOV3与内皮细胞HUVEC中,加入CXCL12处理后,经Tramswell法检测,结果显示细胞数显著增加(t值分别为3.326、3.897、3.215、3.168,均P<0.05),提示细胞的侵袭与迁移能力明显增强,其中浓度为100ng/mL的趋化活性最高,CAOV3 与HUVEC细胞趋化指数分别为4.0±1.5、4.3±1.7,对照组趋化指数分别为1.1±0.5、1.2±0.6,比较差异有统计学意义(t值分别为2.687、2.938,均P<0.05).结论 趋化因子CXCL12通过调控卵巢癌细胞的黏附、侵袭和转移能力,进而提高CAOV3、HUVEC细胞活性,参与卵巢癌细胞的侵袭和转移.     

Escin Suppresses Migration and Invasion Involving the Alteration of CXCL16/CXCR6 Axis in Human Gastric Adenocarcinoma AGS Cells

Escin, a natural mixture of triterpene saponins isolated from horse chestnut, has been reported to possess anticancer activity in many human cancer cells. However, the effect of escin on the metastasis has not been studied. The present study examined the effect of escin on the migration and invasion of AGS human gastric cancer cells. To examine the effects of escin on metastatic capacities of gastric cancer cells, AGS cells were cultured in the presence of 0–4 μmol/L escin. Escin inhibited cell migration and invasion in AGS cells. However, escin did not affect the viability of these cells at these concentrations. The chemokine receptor and its ligands play an important role in cancer metastasis. Escin decreased the production of soluble C-X-C motif chemokine (CXCL)16 but increased the expression of trans-membranous CXCL16. The expression of C-X-C chemokine receptor (CXCR)6 was not affected by escin treatment. Exogenous CXCL16 reversed escin-induced migration inhibition. In addition, escin inhibited the phosphorylation of focal adhesion kinase and Akt. These results demonstrate that escin inhibited the migration and invasion of AGS cells, which is associated with altered CXCL16/CXCR6 axis. These findings suggest that escin has potential as an antimetastatic agent in gastric cancer.     

Inflammation as well as angiogenesis may participate in the pathophysiology of brain radiation necrosis

Radiation necrosis (RN) after intensive radiation therapy is a serious problem. Using human RN specimens, we recently proved that leaky angiogenesis is a major cause of brain edema in RN. In the present study, we investigated the same specimens to speculate on inflammation''s effect on the pathophysiology of RN. Surgical specimens of symptomatic RN in the brain were retrospectively reviewed by histological and immunohistochemical analyses using hematoxylin and eosin (H&E) staining as well as immunohistochemical staining for VEGF, HIF-1α, CXCL12, CXCR4, GFAP, CD68, hGLUT5, CD45, IL-1α, IL-6 TNF-α and NF-kB. H&E staining demonstrated marked angiogenesis and cell infiltration in the perinecrotic area. The most prominent vasculature was identified as thin-walled leaky angiogenesis, i.e. telangiectasis surrounded by prominent interstitial edema. Two major cell phenotypes infiltrated the perinecrotic area: GFAP-positive reactive astrocytes and CD68/hGLUT5-positive cells (mainly microglias). Immunohistochemistry revealed that CD68/hGLUT5-positive cells and GFAP-positive cells expressed HIF-1α and VEGF, respectively. GFAP-positive cells expressed chemokine CXCL12, and CD68/hGLUT5-positive cells expressed receptor CXCR4. The CD68/hGLUT5-positive cells expressed pro-inflammatory cytokines IL-1α, IL-6 and TNF-α in the perinecrotic area. VEGF caused leaky angiogenesis followed by perilesional edema in RN. GFAP-positive cells expressing CXCL12 might attract CXCR4-expressing CD68/hGLUT5-positive cells into the perinecrotic area. These accumulated CD68/hGLUT5-positive cells expressing pro-inflammatory cytokines seemed to aggravate the RN edema. Both angiogenesis and inflammation might be caused by the regulation of HIF-1α, which is well known as a transactivator of VEGF and of the CXCL12/CXCR4 chemokine axis.     

Reducing CXCR4 Resulted in Impairing Proliferation and Promoting Aging

Background

Alzheimer’s disease (AD) is one of the most common and devastating aging related neurodegenerative diseases. Aging is a natural physiological process, a progressive deterioration of the overall homeostatic brain mechanisms, accompanied by cognitive decline. CXCL12/CXCR4 chemokine signaling plays a critical role in modulating various nervous system developmental processes and in regulating synaptic plasticity.

Results

In this article, we have firstly shown that CXCR4 is critical for cell proliferation and cytotoxicity in the SH-SY5Y cell model. Moreover, it has been firstly demonstrated that CXCR4 colocalized with AKT on the membrane and regulated the AKT activation to prevent aging and AD.

Discussion

In a word, we supply a novel pathway that CXCR4 pathway stimulated by CXCL12 regulated AKT activation, CREB phosphorylation and P53 level to affect the process of aging and AD. Therefore, CXCR4 may be a novel target and biomarker for the diagnosis and treatment of AD and aging.

     

CXC趋化因子配体3与相关疾病的研究进展

CXC趋化因子配体(CXCL)3是由多种细胞分泌的一种低相对分子质量的生物活性蛋白质，主要通过招募和活化多种表达CXC趋化因子受体(CXCR)1、2的细胞，参与细胞迁移、侵袭及血管新生等调控，在妊娠相关疾病、肿瘤、心血管疾病及肺部疾病发生、发展中具有重要作用。阻断CXCL3或CXCR1、2信号传导通路，可抑制细胞迁移、侵袭、血管生成、肿瘤发生及纤维化等病理生理过程，这可能成为多种疾病的潜在防治靶点。笔者拟就CXCL3与妊娠相关疾病、肿瘤、心血管疾病及肺部疾病关系的最新研究进展进行阐述，旨在发现CXCL3在上述疾病发病机制中的具体作用，为临床采取新策略诊断及分子靶向治疗上述疾病提供参考。     

HBV inhibits apoB production via the suppression of MTP expression

Background

Liver dominates the production and secretion of apolipoprotein B (apoB) and evidence shows that liver malfunction induced by hepatitis B virus (HBV) infection could lead to apolipoprotein metabolism disorders. The present study was undertaken to assess the effects of HBV on apoB expression.

Methods

Clinical examination: serum apoB levels in patients with chronic HBV infection and in healthy individuals were measured by immunoturbidimetry using biochemical analyzer Olympus 5400. Cell study: mRNA and protein expression levels of apoB in HepG2 and HepG2.2.15 cells were measured by RT-PCR and Western blot. Alternatively, HBV infectious clone pHBV1.3 or control plasmid pBlue-ks were tranfected into HepG2 cells, and mRNA and protein expression levels of apoB, as well as the microsomal triglyceride transfer protein (MTP) in tranfected HepG2 cells were also measured by RT-PCR and western blot.

Results

Serum apoB level was much lower in chronic HBV patients as compared to healthy individuals (P < 0.05). Expression of apoB mRNA and protein was lower in HepG2.2.15 cells than in HepG2 cells. Similarly, expression of apoB mRNA and protein was lower in pHBV1.3 transfected HepG2 cells than in pBlue-ks transfected HepG2 cells. Expression of MTP mRNA and protein in pHBV1.3 transfected HepG2 cells was reduced in a dose-dependent fashion.

Conclusion

HBV infection plays an inhibitory effect on apoB expression.

     

CXCL12/CXCR4在正常妊娠胎盘组织中的表达及意义

目的探讨CXCL12/CXCR4在正常妊娠不同孕期胎盘组织中的表达情况及其在滋养层细胞侵蚀及孕卵着床等正常妊娠过程中的作用。方法采用免疫组织化学SP法检测50例正常孕妇(早孕15例、中孕15例、晚孕20例)胎盘组织中CXCL12/CXCR4表达程度。结果CXCL12/CXCR4在早、中孕组滋养细胞、基质细胞、蜕膜组织中呈强阳性表达,晚孕组呈弱阳性或阴性表达,与早、中孕期组相比表达明显减弱,差异有极显著性(P<0.01)。结论CXCL12/CXCR4可能在胎盘形成、子宫-胎儿血管系统的建立等过程中发挥重要作用。     

CXCR7在骨肉瘤组织、细胞的表达及其意义

目的 研究CXCR7在骨肉瘤组织和骨肉瘤周围正常组织的表达差异,并构建CXCR7腺病毒表达载体,转染骨肉瘤细胞株MG63,观察CXCR7对MG63细胞增殖、炎症因子PGE2分泌的影响.方法 RT-qPCR检测CXCR7在骨肉瘤组织、细胞和骨肉瘤周围正常组织的表达差异;构建CXCR7腺病毒表达载体,感染MG63细胞后,采用RT-qPCR、MTT、ELISA分别检测其对MG63细胞CXCR7 mRNA表达、细胞增殖和PGE2分泌的影响.结果 （1）RT-qPCR结果显示,在骨肉瘤组织CXCR7 mRNA表达率93.80%和表达量（2.221±0.112）均显著高于骨肉瘤周围正常组织45.71%、（0.3448±0.098）;MG63细胞低表达CXCR7 mRNA.（2）CXCR7腺病毒表达载体转染MG63细胞48、72、96 h后,显著促进MG63细胞增殖（P〈0.05）和PGE2分泌（P〈0.05）.结论 骨肉瘤组织CX-CR7mRNA和蛋白表达显著高于骨肉瘤周围正常组织;CXCR7表达增高可以促进骨肉瘤细胞增值,促进炎症因子PGE2分泌,对骨肉瘤的进展将产生不利的影响.     

桦褐孔菌提取物体外抗肿瘤活性及对细胞周期的影响

目的 研究桦褐孔菌提取物的抗肿瘤活性及对人乳腺癌MCF-7 细胞周期的影响及其可能机制。方法 使用细胞计数试剂盒(cell counting kit-8,CCK-8)检测桦褐孔菌提取物对HepG2、A549、SGC-7901、HeLa和MCF-7细胞增殖的抑制作用并计算半数抑制浓度(half maximal inhibitory concentration,IC₅₀);选择抑制效果最好的MCF-7细胞株,观察其作用后细胞的形态学改变、细胞凋亡率和细胞周期的变化;并通过Western Blot实验检测细胞周期相关蛋白Cyclin D1、CDK4、PCNA和NUSAP1的表达。结果 桦褐孔菌提取物可有效抑制HepG2、A549、SGC-7901、HeLa和MCF-7细胞增殖,作用48 h后的IC₅₀分别为2.34、3.71、2.24、2.27、0.59 mg/ml;桦褐孔菌提取物可引起MCF-7细胞显著的形态学改变;可诱导MCF-7细胞凋亡,与对照组相比,差异有统计学意义(P<0.05或P<0.01);并明显影响MCF-7细胞的细胞周期分布,使细胞阻滞于S期(P＜0.01);桦褐孔菌提取物可抑制MCF-7细胞中Cyclin D1、CDK4、PCNA、NUSAP1蛋白的表达,与对照组比较,差异均有统计学意义(P<0.05)。结论 桦褐孔菌提取物可抑制多种组织来源的肿瘤细胞增殖,其中对MCF-7细胞抑制效果最好,可以诱导细胞凋亡,阻滞细胞周期达到抗肿瘤作用,可能是通过下调Cyclin D1、CDK4、PCNA和NUSAP1的蛋白表达来调控细胞周期,从而抑制肿瘤细胞过度增殖。本实验为桦褐孔菌提取物的药用开发提供新的方法和思路。     

趋化因子CXCL12在子宫腺肌病组织中的表达及意义

目的 探讨趋化因子CXCL12在子宫腺肌病发病中的作用.方法 选择2010年2月至2011年2月在济南军区总医院行全、次全子宫切除术或病灶切除术,经病理学确诊的36例子宫腺肌病患者术前、术中的取材标本为研究对象,并根据取材部位不同将其分为在位内膜组（n=36）、异位病灶组（n=36）和病灶周围组织组（n=36）.选择同期住院手术治疗的33例子宫肌瘤患者术中取材标本为对照,按照取材部位不同,将其分别纳入对照内膜组（n=33）和对照肌层组（n=33）（本研究遵循的程序符合济南军区总医院人体试验委员会所制定的伦理学标准,得到该委员会批准,分组征得受试对象本人的知情同意,与之签署临床研究知情同意书）.子宫腺肌病患者和子宫肌瘤患者年龄等一般资料比较,差异无统计学意义（P＞0.05）.对各组CXCL12蛋白表达和CXCL12 mRNA的含量进行比较及相关性分析.结果 ①异位病灶组CXCL12蛋白表达显著高于在位内膜组和对照内膜组,前者分别与后二者比较,差异有统计学意义（P＜0.05）,在位内膜组CXCL12蛋白表达与对照内膜组比较,差异亦有统计学意义（P＜0.05）.②在位内膜组、病灶周围组织组和异位病灶组CXCL12 mRNA含量均高于对照内膜组,前三者分别与后者比较,差异均有统计学意义（P＜0.05）;异位病灶组CXCL12 mRNA含量分别与在位内膜组和病灶周围组织组比较,差异也有统计学意义（P＜0.05）.③Pearson相关分析结果显示,在位内膜组CXCL12蛋白表达与异位病灶组具有相关关系（r=0.780,P=0.000）;在位内膜组CXCL12 mRNA含量与病灶周围组织组、异位病灶组均呈正相关关系（r=0.499和0.461;P=0.002和0.005）;病灶周围组织组CXCL12 mRNA含量与异位病灶组呈正相关关系（r=0.679,P=0.000）.结论 CXCL12在子宫腺肌病发生、发展过程中起一定作用,其可能通过诱导内膜细胞异位发挥致病作用.     

Asian plantain (Plantago asiatica) essential oils suppress 3-hydroxy-3-methyl-glutaryl-co-enzyme A reductase expression in vitro and in vivo and show hypocholesterolaemic properties in mice

Asian plantain (Plantago asiatica) essential oil (PAEO) contains multiple bioactive compounds, but its potential effects on lipid metabolism have not been examined. PAEO was found to be mostly composed of oxygenated monoterpenes, with linalool as the major component (82.5 %, w/w), measured using GC-MS. Incubation of 0-200 microg PAEO/ml with HepG2 cells for 24 h resulted in no significant toxicity. Incubation with 0.2 mg PAEO/ml altered the expression of LDL receptor (+83 %; P < 0.05) and 3-hydroxy-3-methyl-glutaryl-CoA (HMG-CoA) reductase ( - 37 %; P < 0.05), as assessed using RT-PCR. LDL oxidation was markedly inhibited by PAEO treatment due to the prevalence of linalool compounds in PAEO. Oral administration of PAEO for 3 weeks in C57BL/6 mice significantly reduced plasma total cholesterol and TAG concentrations by 29 and 46 %, respectively. The mRNA (+58 %; P < 0.05), but not protein, levels of the LDL receptor were significantly higher, whereas both mRNA and protein levels of HMG-CoA reductase were significantly lower ( - 46 and - 11 %, respectively; P < 0.05) in the liver of PAEO-fed than of control mice. The mRNA levels of CYP7A1 were marginally reduced in HepG2 cells, but not in mouse liver after PAEO treatment. Thus, PAEO may have hypocholesterolaemic effects by altering the expression of HMG-CoA reductase. Reduced TAG and oxidised LDL may provide additional cardiovascular protective benefits.     

Tetrahydro Iso-Alpha Acids and Hexahydro Iso-Alpha Acids from Hops Inhibit Proliferation of Human Hepatocarcinoma Cell Lines and Reduce Diethylnitrosamine Induced Liver Tumor Formation in Rats

Chronic inflammation plays important role in the pathogenesis of hepatocellular carcinoma (HCC). To date, no antiinflammatory approach has shown its efficacy in preventing HCC occurrence in humans. Because tetra- and hexahydro isoalpha acids (THIAA and HHIAA) from hops elicit antiinflammatory properties, we evaluated these compounds for antitumor effects in vitro in human HCC cell lines (HepG2, Hep3B, Huh7) and in vivo in diethylnitrosamine (DEN)-induced animal model of HCC. In human HCC cell lines, THIAA and HHIAA reduced cell proliferation and viability which was associated with the inhibition of the NF-κB-DNA binding and tumor necrosis factor α mRNA expression. Both compounds also inhibited phosphorylation of the mTOR effector p70S6 kinase without affecting ERK, AKT, JNK, and GSK3β phosphorylation or activator protein-1 activation. In DEN-treated rats, administration of THIAA and HHIAA in food reduced the tumor numbers and the expression of the cellular transformation marker glutathione-S-transferase in the liver. In conclusion, THIAA and HHIAA show antitumor properties in vitro in human HCC cell lines as well as in vivo in a chemically induced animal model of HCC.     

Vitamin C supplementation decreases oxidative DNA damage in mononuclear blood cells of smokers

Summary. Background: Antioxidants, in particular vitamin C, have been suggested to decrease oxidative DNA damage. Such effects have been shown in mononuclear blood cells in the first few hours after ingestion, whereas studies of longer-term effects in well-nourished humans have been mainly negative. Aim: To investigate the antioxidant effect of vitamin C in terms of oxidative DNA damage measured by the comet assay and DNA repair measured by expression of OGG1 mRNA in blood cells of male smokers given 2 × 250 mg vitamin C daily as plain or slow release tablets combined with plain release vitamin E 2 × 91mg, or placebo for 4 wk. Results: This study showed a difference in DNA protective effects between a slow release and a plain release vitamin C formulation. Ingestion of slow release vitamin C formulation was associated with fewer endonuclease III and formamidopyrimidine DNA glycosylase sensitive sites measured by the comet assay in mononuclear blood cells obtained 4 h and 8 h after a single tablet and 4 wk after two tablets a day. Ingestion of the vitamin formulation with plain release only indicated a damage-reducing effect 4 h after intake of a single tablet, and the effect was more apparent on endonuclease III than formamidopyrimidine DNA glycosylase sites. Overall the slow release tablets of vitamin C formulation had a more pronounced and a sustained protective effect on base damage compared with the plain release tablets. Plasma vitamin E was unaltered in the first 12 h after ingestion of a single tablet, suggesting that the antioxidant effect was mediated by vitamin C. Differences in plasma vitamin C levels at steady state could not explain the difference between the two vitamin C formulations, whereas wider amplitudes of plasma vitamin C were seen after ingestion of plain release formulation compared to slow release formulation. Assessment of OGG1 mRNA levels by RT-PCR did not indicate increased expression of this DNA repair gene after 4 wk of vitamin supplementation. Conclusion: This study suggests that long-term vitamin C supplementation at high dose, i. e. 500 mg together with vitamin E in moderate dose, 182mg, decreases the steady-state level of oxidative DNA damage in mononuclear blood cells of smokers.     

Intratumoral Concentrations and Effects of Orally Administered Micellar Curcuminoids in Glioblastoma Patients

Background: The oral bioavailability of curcuminoids is low, but can be enhanced by incorporation into micelles. The major curcuminoid curcumin has antitumor effects on glioblastoma cells in vitro and in vivo. We therefore aimed to determine intratumoral concentrations and the clinical tolerance of highly bioavailable micellar curcuminoids in glioblastoma patients. Methods: Thirteen glioblastoma patients ingested 70 mg micellar curcuminoids [57.4 mg curcumin, 11.2 mg demethoxycurcumin (DMC), and 1.4 mg bis-demethoxycurcumin (BDMC)] three times per day for 4 days (total amount of 689 mg curcumin, 134 mg DMC, and 17 mg BDMC) prior to planned resection of their respective brain tumors. Tumor and blood samples were taken during the surgery and analyzed for total curcuminoid concentrations. ³¹P magnetic resonance spectroscopic imaging was performed before and after curcuminoid consumption. Results: Ten patients completed the study. The mean intratumoral concentration of curcumin was 56 pg/mg of tissue (range 9–151), and the mean serum concentration was 253 ng/ml (range 129–364). Inorganic phosphate was significantly increased within the tumor (P = 0.034). The mean ratio of phosphocreatine to inorganic phosphate decreased, and the mean intratumoral pH increased (P = 0.08) after curcuminoid intervention. Conclusion: Oral treatment with micellar curcuminoids led to quantifiable concentrations of total curcuminoids in glioblastomas and may alter intratumoral energy metabolism.