The effect of ST2 gene product on anchorage-independent growth of a glioblastoma cell line, T98G.

The ST2 gene, which is specifically induced by growth stimulation in fibroblasts, encodes interleukin-1 receptor-related proteins and is widely expressed in hematopoietic, helper T, and various cancer cells. However, the physiological as well as pathological functions of the ST2 gene products are not yet fully understood. In this study, we analyzed the expression of the ST2 gene in human glioma cell lines and human brain tumor samples with real-time polymerase chain reaction method, the results of which revealed that the expression level of the ST2 gene in glioma cell lines and glioblastoma samples is significantly lower than that in a fibroblastic cell line, TM12, and benign brain tumors, suggesting the reverse relationship between malignancy and ST2 expression. As we could not detect the soluble ST2 protein in the culture fluid of the T98G glioblastic cell line by ELISA, we established stable transformants of T98G that continuously produce and secrete the ST2 protein, in order to study the effect of the ST2 protein on malignancy. Although we could not detect a remarkable difference in proliferation between transformants and control cells in conventional tissue culture dishes, the efficiency of colony formation in soft agar was significantly decreased in the case of cells that continuously produce the ST2 protein. Furthermore, inhibition of colony formation in soft agar was observed in wild-type T98G cells when purified soluble ST2 protein was added to the culture, in a dose-dependent manner. Taken together, the results suggest that the expression of ST2 suppressed the anchorage-independent growth and malignancy.     

Secretion rates and levels of vascular endothelial growth factor in clone A or HCT-8 human colon tumour cells as a function of oxygen concentration

Molecular and in situ hybridization studies have shown, in a number of cell types, that under hypoxic conditions, vascular endothelial growth factor (VEGF) mRNA expression is up-regulated and VEGF protein is concomitantly increased. To establish a quantitative relationship between VEGF protein levels and oxygenation, we exposed exponentially growing clone A or HCT-8 human colon tumour cells in vitro (22 h at 37°C) to oxygen concentrations from 21% (air mixture) to 0.01%. Protein levels in cells and medium were then assayed using an enzyme-linked immunoabsorbent assay (ELISA). Intracellular levels of VEGF in clone A or HCT-8 cells exposed to either air (21% O₂) or the 0.01% O₂ mixture respectively increased from about 73 to 1270, and 1.5 to 1180 pg/10⁶ cells (about 17- and 80-fold increases). The shapes of the response curves (log of the intracellular VEGF concentrations v. log oxygen concentration) for both cell types were sigmoidal. However, intracellular VEGF levels in HCT-8 cells were always less than that of clone A cells until levels of about 0.3 to 0.1% O₂ were reached. Levels of VEGF in the supernatant were also increased after the 22 h hypoxic exposures. Because cell proliferation and clonogenicity were also measured, it was possible to estimate the secretion rates of VEGF for both cell lines as a function of oxygen percentage. For clone A cells, the secretion rate (pg/10⁶ cells/h) in 21% O₂ was 62.5. This rate increased to 428.8 pg/10⁶ cells/h at 0.01% O₂, a 7-fold increase. For HCT-8 cells, levels in the medium at 21% O₂ were too low to be measured by ELISA. However, between 10% and 0.01% O₂, secretion rates increased from 5.0 to 376.0 pg/10⁶ cells/h, a 75-fold increase. Therefore, at very low O₂ levels, VEGF secretion rates were similar in the two cell lines. We propose that the different VEGF responses of clone A and HCT-8 colon tumour cells to hypoxic stress in vitro are related to the in vivo observation that the respective hypoxic percentages of solid neoplasms originating from these cell lines are markedly different (i.e. about 3 versus 80%) at equivalent volumes of 750 mm³.     

冷应激条件下猪睾丸细胞中RNA结合基序蛋白3过表达对Caspase 3表达的影响

目的：探讨冷应激（32℃）条件下,猪睾丸（ST）细胞系中RNA结合基序蛋白3（RBM3）过表达时凋亡蛋白半胱天冬酶3（Caspase 3）表达量变化情况。方法：利用本实验室成功构建的携带绿色荧光蛋白（GFP）的RBM3过表达慢病毒载体pLenti6/V5-GW/EmGFP-RBM3和空病毒载体pLenti6/V5-GW/EmGFP-DEST分别感染ST细胞,作为过表达病毒（OEV）组和空载体病毒（EVV）组,此外还设立野生型细胞（WTC）组作对照,利用实时荧光定量RCR（qPCR）法和Western blot分析法检测各组中RBM3 mRNA和蛋白的表达情况。然后对各组细胞进行37℃以及32℃（2 h、4 h,8 h）的冷应激处理,利用酶联免疫吸附实验（ELISA）法检测各组Caspase 3表达量的变化。结果：OEV组RBM3基因和蛋白相对表达量高于EVV组和WTC组。在37℃以及32℃冷应激实验（2 h、4 h,8 h）中,OEV组Caspase 3表达量显著低于EVV组和WTC组。结论：冷应激ST细胞中RBM3过表达能够显著地降低Caspase 3的表达程度,为RBM3基因具有抵抗低温诱导ST细胞凋亡作用提供实验依据。     

机械牵拉诱导人RPE细胞IL-8分泌及其对PI3K/AKT 通路的影响

目的:视网膜脱离发生机制尚不明确,本文旨在研究机械应力牵拉后视网膜色素上皮细胞上清中IL-8分泌量的变化以及人其对RPE细胞PI3K/AKT通路变化影响。方法:培养人RPE细胞,应用Flex-cell细胞应力加载系统牵拉人RPE细胞不同时间(0h、1 h、3 h、6 h、9 h)建立不同牵拉时间的模型。分别标记为对照组、牵拉1 h组、牵拉3 h组、牵拉6 h组、牵拉9 h组。随后用ELISA方法检测人RPE细胞不同实验组上清中IL-8分泌量的变化。细胞免疫荧光和Western blot方法观察PI3K、PPI3K、T-AKT、P-AKT的表达。结果:随着牵拉时间的延长,ELISA方法检测人RPE细胞不同实验组上清中IL-8分泌量逐渐增加[924.79±5.92 pg/m L、947.73±5.34 pg/m L、974.53±5.74 pg/m L、979.57±1.12 pg/m L、1019.22±4.25 pg/m L],差异有统计学意义(F=166,p0.01),各牵拉组与对照组分别对比,差异有统计学意义(P0.05)。细胞中P-AKT蛋白表达增加[0.61±0.02、0.97±0.05、0.99±0.04、1.21±0.11、1.20±0.07],差异有统计学意义(F=41.24,p0.01),各牵拉组与对照组分别对比,差异有统计学意义(P0.05),AKT表达未见明显变化。结论:机械应力牵拉人RPE细胞时,细胞上清中IL-8分泌量逐渐增加同时RPE细胞内PI3K/AKT通路明显激活,并与牵拉时间有关,为探究EMT原因和对防治PVR提供了理论基础。     

羧甲司坦通过巯基上调HDAC2 抑制气道炎症

目的:探究羧甲司坦(carbocysteine,S-CMC)在气道炎症中对组蛋白去乙酰化酶2(histone deacetylase2,HDAC2)表达的调控作用和机制。方法:建立脂多糖(lipopolysaccharide,LPS)诱导大鼠肺泡巨噬细胞(NR8383)炎症模型、短期烟熏Sprague Dawely(SD)大鼠气道炎症模型,采用酶联免疫吸附测定法(enzyme-linked immunosorbent assay,ELISA)检测炎症因子白细胞介素6(interleukin-6,IL-6)和白细胞介素8(interleukin-8,IL-8)的水平,蛋白免疫印迹(Western blotting)及免疫组化染色检测HDAC2的表达。结果:与对照组相比,模型组NR8383细胞中HDAC2的表达明显降低至对照组的0.47±0.11倍,细胞上清IL-6、IL-8水平明显升高,分别为157.6±15.0 pg/m L、378.0±17.9 pg/m L;模型组SD大鼠肺组织中HDAC2的表达明显降低到对照组的0.42±0.12倍,气道灌洗液(bronchoalveolar lavage fluid,BALF)中IL-6、IL-8分别为162.2±51.4 pg/m L、331.4±62.7 pg/m L,炎症因子水平明显升高。而与模型组比较,经S-CMC处理后细胞中HDAC2表达明显上调至对照组的1.23±0.05倍,细胞上清中IL-6为92.3±4.3 pg/m L,IL-8为300.7±17.7 pg/m L,炎症因子水平降低;肺组织中HDAC2为对照组的0.78±0.10倍,表达水平明显升高,BALF中IL-6、IL-8水平分别为100.6±32.7 pg/m L,185.0±50.4 pg/m L(P0.05)炎症因子明显降低。组蛋白去乙酰化酶抑制剂曲古抑霉素A(trichostatin,TSA)能够抑制NR8383细胞中HDAC2的表达至对照组的0.19±0.06倍,增加IL-6(197.0±42.6 pg/m L)、IL-8(567.0±97.4 pg/m L)水平,该作用可以被S-CMC所逆转(P0.05)。另外,加入巯基供体二硫苏糖醇(dithiothreitol,DTT)可增强S-CMC上调HDAC2表达,降低IL-6、IL-8的作用,而巯基耗竭剂丁硫氨酸亚砜亚胺(buthionine-sulfoximine,BSO)可减弱S-CMC的作用(P0.05)。进一步表明S-CMC调控HDAC2的过程与巯基相关。结论:S-CMC可通过巯基上调HDAC2的表达抑制气道炎症。     

Immuno-PCR--a new tool for paleomicrobiology: the plague paradigm

Background

The cause of past plague pandemics was controversial but several research teams used PCR techniques and dental pulp as the primary material to reveal that they were caused by Yersinia pestis. However, the degradation of DNA limits the ability to detect ancient infections.

Methods

We used for the first time immuno-PCR to detect Yersinia pestis antigens; it can detect protein concentrations 70 times lower than the standard ELISA. After determining the cut-off value, we tested 34 teeth that were obtained from mass graves of plague, and compared previous PCR results with ELISA and immuno-PCR results.

Results

The immuno-PCR technique was the most sensitive (14 out of 34) followed by the PCR technique (10 out of 34) and ELISA (3 out of 34). The combination of these three methods identified 18 out of 34 (53%) teeth as presumably being from people with the plague.

Conclusion

Immuno-PCR is specific (no false-positive samples were found) and more sensitive than the currently used method to detect antigens of ancient infections in dental pulp. The combination of three methods, ELISA, PCR and immuno-PCR, increased the capacity to identify ancient pathogens in dental pulp.     

Determination of human serum 8-hydroxy-2′-deoxyguanosine (8-OHdG) by HPLC-ECD combined with solid phase extraction (SPE)

Human serum 8-hydroxy-2′-deoxyguanosine (8-OHdG) was measured by HPLC-ECD method combined with solid phase extraction (SPE) developed by our group: (our proprietary kit, named 8-OHdG Pre-treatment Kit (TANITA Corporation)). The major interfering substances and proteins in serum were removed by 8-OHdG Pre-treatment Kit. This measurement method was highly reproducible (CV = 2.2–7.1%) and demonstrated the lower detection limit for control serum sample of less than 10 pg/ml without the sample evaporation. The other hand 8-OHdG concentration in serum for healthy people was in the range of 0–70 pg/ml (25.5 ± 13.8 pg/ml, n = 37). Secondary a relationship between the HPLC-ECD and ELISA methods was investigated. ELISA method could not detect 8-OHdG concentration in serum for healthy people, because the detection limit of 130 pg/ml was higher than the normal range for healthy people. These results show our SPE method has high sensitivity and quantitative accuracy for 8-OHdG analysis.     

HPV16 Seropositivity and Subsequent HPV16 Infection Risk in a Naturally Infected Population: Comparison of Serological Assays

Background

Several serological assays have been developed to detect antibodies elicited against infections with oncogenic human papillomavirus (HPV) type 16. The association between antibody levels measured by various assays and subsequent HPV infection risk may differ. We compared HPV16-specific antibody levels previously measured by a virus-like particle (VLP)-based direct enzyme-linked immunoassay (ELISA) with levels measured by additional assays and evaluated the protection against HPV16 infection conferred at different levels of the assays.

Methodology/Principal Findings

Replicate enrollment serum aliquots from 388 unvaccinated women in the control arm of the Costa Rica HPV vaccine trial were measured for HPV16 seropositivity using three serological assays: a VLP-based direct ELISA; a VLP-based competitive Luminex immunoassay (cLIA); and a secreted alkaline phosphatase protein neutralization assay (SEAP-NA). We assessed the association of assay seropositivity and risk of subsequent HPV16 infection over four years of follow-up by calculating sampling-adjusted odds ratios (OR) and HPV16 seropositivity based on standard cutoff from the cLIA was significantly associated with protection from subsequent HPV16 infection (OR = 0.48, CI = 0.27–0.86, compared with seronegatives). Compared with seronegatives, the highest seropositive tertile antibody levels from the direct ELISA (OR = 0.53, CI = 0.28–0.90) as well as the SEAP-NA (OR = 0.20, CI = 0.06, 0.64) were also significantly associated with protection from HPV16 infection.

Conclusions/Significance

Enrollment HPV16 seropositivity by any of the three serological assays evaluated was associated with protection from subsequent infection, although cutoffs for immune protection were different. We defined the assays and seropositivity levels after natural infection that better measure and translate to protective immunity.     

Utility of survival motor neuron ELISA for spinal muscular atrophy clinical and preclinical analyses

Objectives

Genetic defects leading to the reduction of the survival motor neuron protein (SMN) are a causal factor for Spinal Muscular Atrophy (SMA). While there are a number of therapies under evaluation as potential treatments for SMA, there is a critical lack of a biomarker method for assessing efficacy of therapeutic interventions, particularly those targeting upregulation of SMN protein levels. Towards this end we have engaged in developing an immunoassay capable of accurately measuring SMN protein levels in blood, specifically in peripheral blood mononuclear cells (PBMCs), as a tool for validating SMN protein as a biomarker in SMA.

Methods

A sandwich enzyme-linked immunosorbent assay (ELISA) was developed and validated for measuring SMN protein in human PBMCs and other cell lysates. Protocols for detection and extraction of SMN from transgenic SMA mouse tissues were also developed.

Results

The assay sensitivity for human SMN is 50 pg/mL. Initial analysis reveals that PBMCs yield enough SMN to analyze from blood volumes of less than 1 mL, and SMA Type I patients'' PBMCs show ∼90% reduction of SMN protein compared to normal adults. The ELISA can reliably quantify SMN protein in human and mouse PBMCs and muscle, as well as brain, and spinal cord from a mouse model of severe SMA.

Conclusions

This SMN ELISA assay enables the reliable, quantitative and rapid measurement of SMN in healthy human and SMA patient PBMCs, muscle and fibroblasts. SMN was also detected in several tissues in a mouse model of SMA, as well as in wildtype mouse tissues. This SMN ELISA has general translational applicability to both preclinical and clinical research efforts.     

长链非编码RNA Hotair通过调控巨噬细胞表型转换促进胃癌细胞增殖与侵袭

目的探讨胃癌细胞是否通过长链非编码RNA Hotair作用于巨噬细胞,将其转化为癌症支持细胞,进而促进胃癌的增殖与侵袭。 方法实验分为对照组与AGS细胞共培养组,转染实验分为对照组、Hotair过表达组和RNA干扰组胃癌细胞与巨噬细胞共培养实验检测巨噬细胞表型转换。进行原位杂交实验对M2型巨噬细胞与lncRNA Hotair共定位。通过RT-?PCR实验检测并筛选出促进巨噬细胞表型转换的关键lncRNA。通过RNA干扰技术敲低胃癌细胞lncRNA水平并进行共培养实验。随后通过CCK-8实验与Transwell实验检测转型后的癌症相关巨噬细胞对胃癌细胞增殖与侵袭能力的影响。两组间均数比较采用t检验,多组均数间比较采用单因素方差分析,组间多重比较采用SNK-q检验。 结果共培养实验结果表明,相比于对照组（5.63±1.97）个,AGS细胞组中含有更多的CD206阳性M2型癌症相关巨噬细胞（32.51±5.44）个,两者比较差异有统计学意义（t =25.742,P = 0.001）;ELISA实验也证明AGS细胞组的巨噬细胞分泌更多的抑炎因子[TGF-β：（163.45±54.91）pg/ml,对照组：（87.32±19.24）?pg/ml;IL-4：（156.83±69.25）pg/ml,对照组：（49.94±17.55）pg/ml;IL-10：（385.65±24.75）pg/ml,对照组：（98.82±46.26）pg/ml],两组间比较差异有统计学意义（t?= 7.167,8.203,29.991,P均< 0.05）。GEO数据库鉴定并使用RT-PCR筛选出Hotair为关键lncRNA,随后的RNA干扰实验表明,Hotair敲低会抑制巨噬细胞的转变（CD206阳性细胞数量由41.12±6.91变为21.45±2.19）,进而降低胃癌细胞的增殖与侵袭能力。 结论胃癌细胞的lncRNA Hotair会被巨噬细胞摄取,将其转化为癌症相关巨噬细胞,进而促进胃癌细胞的增殖与侵袭能力,这为胃癌的治疗提供了新的可能的靶点。     

miR-27a-3p通过靶向Sema7A调控病毒性心肌炎心肌细胞损伤的机制研究

目的 探讨微小RNA-27a-3p(miR-27a-3p)过表达对病毒性心肌炎(VMC)细胞损伤的影响及其可能的作用机制.方法 原代培养大鼠心肌细胞,柯萨奇B3病毒(CVB3)感染心肌细胞建立VMC模型(CVB3组).正常心肌细胞作为对照组,分别将miR-NC、miR-27a-3pmimics、si-NC、si-Sem...     

Highly sensitive SERS detection of cancer proteins in low sample volume using hollow core photonic crystal fiber

Enzyme-linked immunosorbent assays (ELISA) are commonly used for detecting cancer proteins at concentration in the range of about ng-μg/mL. Hence it often fails to detect tumor markers at the early stages of cancer and other diseases where the amount of protein is extremely low. Herein, we report a novel photonic crystal fiber (PCF) based surface enhanced Raman scattering (SERS) sensing platform for the ultrasensitive detection of cancer proteins in an extremely low sample volume. As a proof of concept, epidermal growth factor receptors (EGFRs) in a lysate solution from human epithelial carcinoma cells were immobilized into the hollow core PCF. Highly sensitive detection of protein was achieved using anti-EGFR antibody conjugated SERS nanotag. This SERS nanotag probe was realized by anchoring highly active Raman molecules onto the gold nanoparticles followed by bioconjugation. The proposed sensing method can detect low amount of proteins at ～100 pg in a sample volume of ～10 nL. Our approach may lead to the highly sensitive protein sensing methodology for the early detection of diseases.     

妊娠高血压外周血中促Th2的细胞因子水平及IL-2／IL-10平衡的临床意义

目的：检测妊娠高血压患者外周血中促Th2的分子IL-4、IL-2与IL-10的水平,探讨IL-2／IL-10在妊高症中的临床意义。方法：选择40例未妊娠妇女为对照组,30例正常妊娠妇女为妊娠组,28例妊娠高血压患者为妊娠高血压组,ELISA检测血清中IL-4、IL-2和IL-10的水平。结果：与对照组外周血中IL-4水平（0．53±0．04）pg／ml相比：正常妊娠组IL-4水平升高至（0．91±0．03）pg／ml（P〈0．05）,妊娠高血压组IL-4水平（0．67±0．35）pg／ml升高但明显低于正常妊娠组（P〈0．01）。与对照组外周血中IL-2水平（0．41±0．05）pg／ml相比：正常妊娠组IL-2水平升高至（0．82±0．11）pg／ml（P〈0．01）;妊娠高血压组IL-2水平高达1．57±0．22（pg／m1）明显高于其它两组（P〈0．01）。妊娠高血压组外周血中IL-10水平明显低于正常妊娠组IL-10水平（P〈0．01）;妊娠高血压组外周血中IL-2／IL-10比值明显高于于对照组及正常妊娠组的比值。结论：妊娠高血压患者外周血中细胞因子IL-2和IL-10分泌异常且诱导Th2细胞产生的IL-4降低,打破Th1／Th2平衡,致使Th1型免疫反应增强,使早孕期滋养细胞受到免疫损伤以致侵入能力下降,导致妊娠期高血压疾病的发生。     

Multiple regulation of constitutive and induced interleukin 8 secretion in human myelomonocytic cell lines

Secretion of interleukin 8 (IL-8) and its regulation was investigated in myelomonocytic leukaemia cell lines. Quantification by ELISA revealed a constitutive production in the cell lines HL-60, ML-2, MONO-MAC-6 and MUTZ-3 ranging between 1500 and ca. 5000 pg/ml IL-8 per million cells. No measurable IL-8 was detected in the culture medium of MONO-MAC-1 and THP-1. Stimulation with lipopolysaccharide (LPS) or tetradecanoyl phorbol acetate (TPA) significantly increased the IL-8 level secreted by all cell lines; the best producers were TPA-treated MONO-MAC-6 and MUTZ-3 cultures, generating more than 50 000 pg/ml IL-8. Also the calcium ionophore A-23187, IL-13, macrophage colony-stimulating factor (M-CSF), thapsigargin, an inhibitor of the Ca(2+)-ATPase, and tumour necrosis factor-alpha (TNF-alpha) strongly enhanced the IL-8 production in MONO-MAC-6 cells. The glucocorticoid dexamethasone and the protein kinase inhibitor staurosporine distinctively inhibited the IL-8 production of MONO-MAC-6 cells. Thus, our results demonstrate a strong constitutive IL-8 secretion in human myelomonocytic leukaemia cell lines; the variety of different modulators affecting IL-8 production leads to the suggestion of a multiple regulation of IL-8 expression and secretion.