Zhou, Jian-Ying | Dann, Geoffrey P. | Shi, Tujin | Wang, Lu | Gao, Xiaoli | Su, Dian | Nicora, Carrie D. | Shukla, Anil K. | Moore, Ronald J. | Liu, Tao | Camp, David G. | Smith, Richard D. | Qian, Wei-Jun
Sodium dodecyl sulfate (SDS) is one of the most popular laboratory reagents used for biological sample extraction; however, the presence of this reagent in samples challenges LC-MS-based proteomics analyses because it can interfer with reversed-phase LC separations and electrospray ionization. This study reports a simple SDS-assisted proteomics sample preparation method facilitated by a novel peptide-level SDS removal step. In an initial demonstration, SDS was effectively (>99.9%) removed from peptide samples through ion substitution-mediated DS- precipitation using potassium chloride (KCl), and excellent peptide recovery (>95%) was observed for <20 μg peptides. Further experiments demonstrated the compatibility of this protocol with LC-MS/MS analyses. The resulting proteome coverage obtained for both mammalian tissues and bacterial samples was comparable to or better than that obtained for the same sample types prepared using standard proteomics preparation methods and analyzed using LC-MS/MS. These results suggest the SDS-assisted protocol is a practical, simple, and broadly applicable proteomics sample processing method, which can be particularly useful when dealing with samples difficult to solubilize by other methods.
doi:10.1021/ac203394r
PMCID: PMC3310275
PMID: 22339560
SDS removal; KDS precipitation; proteomics; sample preparation; LC-MS
Background
Diabetes mellitus (DM) exacerbates coronary artery disease (CAD) morbidity and mortality. Mesenchymal stem cells (MSCs) play an important therapeutic role in myocardial ischemic injury. However, little is known about changes in the cardioprotective characteristics of MSCs from patients with DM.
Methods
Sternal bone marrow aspirates were taken at the time of coronary artery bypass graft surgery. The morphology and growth characteristics of hMSCs were observed in passage 3. Differences in gene expression profiling were measured by Affymetrix GeneChipHuman Genome U133 Plus 2.0 Arrays. Forty two adult male rats with experimentally CAD were randomized into three groups. MSCs from patients with CAD+DM or CAD were injected into the infarcted myocardium. Control animals received culture medium. Echocardiography, TUNEL, immunohistochemistry and Western-blot analysis were performed 4 weeks after transplantation.
Results
Growth curves showed that proliferation of hMSCs in the CAD+DM group was significantly lower than in the CAD group. Nine transcripts of genes related to apoptosis containing Bcl-2 were found to differentiate the two groups. Transplantation of hMSCs in the infarcted border zone improved cardiac function, but DM partly impaired this effect. Similar results were observed from TUNEL, immunohistochemistry and Western-blot analysis.
Conclusions
hMSCs from patients with CAD+DM and CAD alone both have proliferative properties. Transplantation of hMSCs ameliorate heart function, but proliferative ability and myocardial protection decrease significantly in MSCs obtained from patients with CAD+DM compared with cultures from patients with CAD alone, possibly as a result of differences in Bcl-2 protein expression and reduced anti-apoptosis.
doi:10.1186/1475-2840-12-40
PMCID: PMC3599413
PMID: 23452414
Mesenchymal stem cells; Coronary artery disease; Diabetes mellitus; Myocardial infarction; Bcl-2
Left supraclavicular lymph node metastasis is a rare presentation of hepatocellular carcinoma (HCC). This phenomenon is easily neglected in the clinic. A 56-year-old man presented with HCC. On examination, a 1cm long left supraclavicular lymph node was palpated. Auxiliary examination indicated a lesion located in the right lobe of the liver. Fine needle aspiration cytology (FNAC) of the enlarged lymph node was performed; however, only necrosis was found. Hepatectomy was performed and HCC was confirmed by Hematoxylin-Eosin staining. However, 14 d after surgery, significantly enlarged left supraclavicular lymph nodes, a new intrahepatic lesion, and pulmonary and mediastinal metastasis appeared. An excisional biopsy of the left supraclavicular lymph node was performed, and its findings confirmed metastatic HCC. The patient’s HCC rapidly progressed and he died one month later. It is possible for HCC to metastasize to the left supraclavicular lymph node. Surgeons should always consider an overall physical examination. When left supraclavicular lymphadenopathy of unknown origin is encountered, FNAC should be performed initially. If the results are negative, an excisional biopsy and subsequent Positron emission tomography - computed tomography scanning should be performed. These are very important for making the correct diagnosis and for selecting reasonable therapies.
doi:10.3748/wjg.v19.i6.960
PMCID: PMC3574897
PMID: 23429993
Left supraclavicular lymph node; Metastasis; Hepatocellular carcinoma; Fine needle aspiration cytology; Misdiagnosis
Luo, Yuan | Zhang, Yonghui | Liu, Tao | Rutherford, Shannon | Xu, Yanjun | Xu, Xiaojun | Wu, Wei | Xiao, Jianpeng | Zeng, Weilin | Chu, Cordia | Ma, Wenjun | Cameron, D. William
Background
Many studies have found extreme temperature can increase the risk of mortality. However, it is not clear whether extreme diurnal temperature range (DTR) is associated with daily disease-specific mortality, and how season might modify any association.
Objectives
To better understand the acute effect of DTR on mortality and identify whether season is a modifier of the DTR effect.
Methods
The distributed lag nonlinear model (DLNM) was applied to assess the non-linear and delayed effects of DTR on deaths (non-accidental mortality (NAD), cardiovascular disease (CVD), respiratory disease (RD) and cerebrovascular disease (CBD)) in the full year, the cold season and the warm season.
Results
A non-linear relationship was consistently found between extreme DTR and mortality. Immediate effects of extreme low DTR on all types of mortality were stronger than those of extreme high DTR in the full year. The cumulative effects of extreme DTRs increased with the increment of lag days for all types of mortality in cold season, and they were greater for extreme high DTRs than those of extreme low DTRs. In hot season, the cumulative effects for extreme low DTRs increased with the increment of lag days, but for extreme high DTR they reached maxima at a lag of 13 days for all types of mortality except for CBD(at lag6 days), and then decreased.
Conclusions
Our findings suggest that extreme DTR is an independent risk factor of daily mortality, and season is a modifier of the association of DTR with daily mortality.
doi:10.1371/journal.pone.0055280
PMCID: PMC3566202
PMID: 23405130
Xie, Huiyan | Yao, Zhibin | Zhang, Yonghui | Xu, Yanjun | Xu, Xiaojun | Liu, Tao | Lin, Hualiang | Lao, Xiangqian | Rutherford, Shannon | Chu, Cordia | Huang, Cunrui | Baum, Scott | Ma, Wenjun
Background: Few studies have been conducted to investigate the impact of extreme cold events on mortality in subtropical regions.
Objective: In the present study we aimed to investigate the effects of the 2008 cold spell on mortality and the possibility of mortality displacement in three subtropical cities in China.
Methods: Daily mortality, air pollution, and weather data were collected from 2006 to 2009 in Guangzhou, Nanxiong (no air pollutants), and Taishan. We used a polynomial distributed lag model (DLM) to analyze the relationship between the 2008 cold spell and mortality. To observe the mortality displacement of the cold spell, we estimated the cumulative effects at lag0, lag0–6, lag0–13, lag0–20, and lag0–27 separately.
Results: During the 2008 cold spell, the cumulative risk of nonaccidental mortality increased significantly in Guangzhou [relative risk (RR) = 1.60; 95% CI: 1.19, 2.14] and Taishan (RR = 1.60; 95% CI: 1.06, 2.40) when lagged up to 4 weeks after the cold spell ended. Estimated effects at lag0–27 were more pronounced for males than for females, for respiratory mortality than for cardiovascular mortality, and for the elderly (≥ 75 years of age) than for those 0–64 years of age. Most of the cumulative RRs increased with longer lag times in Guangzhou and Taishan. However, in Nanxiong, the trend with cumulative RRs was less consistent, and we observed no statistically significant associations at lag0–27.
Conclusion: We found associations between the 2008 cold spell and increased mortality in the three subtropical cities of China. The lag effect structure of the cold spell varied with location and the type of mortality, and evidence of short-term mortality displacement was inconsistent. These findings suggest that extreme cold is an important public health problem in subtropical regions.
doi:10.1289/ehp.1104541
PMCID: PMC3569675
PMID: 23128031
climate change; cold spell; mortality; subtropical cities; temperature
By using a fragment-assembly strategy and bioisosteric-replacement principle, a series of novel piperazine derivatives were designed, synthesized, and evaluated for their cellular target-effector fusion activities and in vitro antiviral activities against HIV-1. Preliminary structure-activity relationships (SARs) of target compounds were concluded in this study, and five compounds were found to exhibited medium to potent CCR5 fusion activities with IC50 values in low micromolar level. Among evaluated compounds, 23 h was found to be a CCR5 antagonist with an IC50 value of 6.29 µM and an anti-HIV-1 inhibitor with an IC50 value of 0.44 µM.
doi:10.1371/journal.pone.0053636
PMCID: PMC3538727
PMID: 23308267
Akt2 is considered as a potential target for cancer therapy. In order to find novel Akt2 inhibitors which have different scaffolds, structure-based pharmacophore model and 3D-QSAR pharmacophore model were built and validated by different methods. Then, they were used for chemical databases virtual screening. The selected compounds were further analyzed and refined using drug-like filters and ADMET analysis. Finally, seven hits with different scaffolds were picked out for docking studies. These seven hits were predicted to have high inhibitory activity and good ADMET properties, they may act as novel leads for Akt2 inhibitors designing.
doi:10.7150/ijms.5344
PMCID: PMC3558715
PMID: 23372433
Akt2; inhibitor; pharmacophore; docking; virtual screening.
AIM: To clarify the role of activated Notch2 in the invasiveness of gastric cancer.
METHODS: To investigate the invasiveness of silencing Notch2 gene expression, we established a Notch2 small interfering RNA (siRNA) transfected cell line using the MKN-45 gastric cancer cell line. After the successful transfection confirmed by real-time reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting, migration and invasion assays were employed to evaluate the aggressiveness of the gastric cancer. RT-PCR and Western blottings were employed to confirm the down-regulation of Notch2 and to evaluate the expression of epithelial mesenchymal transition-related gene matrix metallopeptidase 9 (MMP9), Akt, p-Akt. To confirm the relationship between PI3K-Akt and MMP9, the PI3K inhibitor LY294002 was used to treat MKN-45 cells.
RESULTS: Notch2 expression was dramatically decreased after Notch2 siRNA transfection (100.00% ± 9.74% vs 11.61% ± 3.85%, P < 0.01 by qRT-PCR). There was also a marked reduction of Notch target gene Hes1 (100.00% ± 4.74% vs 61.61% ± 3.58%, P < 0.05) at the mRNA, indicating an inhibition of Notch signaling. Inhibition of Notch signaling was also confirmed by the marked reduction of Notch2 intracellular domain at the protein levels (100.00% ± 9.74% vs 65.61% ± 7.58%, P < 0.05). Down-regulation of Notch2 by siRNA enhanced tumor cell invasion (100.00% ± 21.64% vs 162.22% ± 16.84%, P < 0.05) and expression of MMP9 (1.56 fold, P < 0.05), and activated the pro-MMP9 protein to its active form (1.48 fold, P < 0.05). There was no significant difference in the protein levels of Akt between the two groups (100.00% ± 10.87% vs 96.61% ± 7.33%, P > 0.05), while down-regulation of Notch2 elevated p-Akt expression (100.00% ± 9.87% vs 154.61% ± 13.10%, P < 0.05). Furthermore, p-Akt and MMP9 was down-regulated in response to the inhibitor LY294002 (p-Akt 100.00% ± 8.87% vs 58.27% ± 5.01%, P < 0.05; MMP9 100.00% ± 9.17% vs 50.03% ± 4.88%, P < 0.05).
CONCLUSION: Notch2 may negatively regulate cell invasion by inhibiting the PI3K-Akt signaling pathway in gastric cancer.
doi:10.3748/wjg.v18.i48.7262
PMCID: PMC3544028
PMID: 23326131
Notch2; Stomach; Cancer; Invasion; Epithelial mesenchymal transition; Matrix metallopeptidase 9; RNA interference
Traditional Chinese Medicine (TCM) has many unique features. Thequality-of-life (QoL) instrument for lung cancer based on Traditional Chinese Medicine (QLASTCM-Lu) was the first self-reported instrument specifically developed to assess the quality of life from the perspective of TCM. Structured group methods and theory in developmental rating scale were employed to establish a general and a specific module, respectively. Quantitative and qualitative data from 240 lung cancer patients were collected to assess the psychometric properties. The three identified scales of the QLASTCM-Lu (correspondence between man and universe, unity of the body and spirit, and lung cancer specific module) and the total score demonstrated excellent psychometric properties. Test-retest reliability of all domains ranged from 0.93 to 0.96, and internal consistency α ranged from 0.86 to 0.93. Correlation and factor analysis demonstrated good construct validity. Significant differences in the QLASTCM-Lu scales and total score were found among groups differing in TCM syndrome, supporting the clinical sensitivity of the QLASTCM-Lu. Statistically significant changes were found for each scale and the total score. Responsiveness of the QLASTCM-Lu was greater than that of QLQ-LC43. The QLASTCM-Lu is a psychometrically sound and clinically sensitive measure of quality of life for lung cancer patients, which can be applied to both TCM therapy and Western medicine therapy.
doi:10.1155/2012/945910
PMCID: PMC3530826
PMID: 23304229
Next generation sequencing (NGS) technologies have greatly changed the landscape of transcriptomic studies of non-model organisms. Since there is no reference genome available, de novo assembly methods play key roles in the analysis of these data sets. Because of the huge amount of data generated by NGS technologies for each run, many assemblers, e.g., ABySS, Velvet and Trinity, are developed based on a de Bruijn graph due to its time- and space-efficiency. However, most of these assemblers were developed initially for the Illumina/Solexa platform. The performance of these assemblers on 454 transcriptomic data is unknown. In this study, we evaluated and compared the relative performance of these de Bruijn graph based assemblers on both simulated and real 454 transcriptomic data. The results suggest that Trinity, the Illumina/Solexa-specialized transcriptomic assembler, performs the best among the multiple de Bruijn graph assemblers, comparable to or even outperforming the standard 454 assembler Newbler which is based on the overlap-layout-consensus algorithm. Our evaluation is expected to provide helpful guidance for researchers to choose assemblers when analyzing 454 transcriptomic data.
doi:10.1371/journal.pone.0051188
PMCID: PMC3517413
PMID: 23236450
Zhang, Haizhen | Burnum, Kristin E. | Luna, Maria L. | Petritis, Brianne O. | Kim, Jong-Seo | Qian, Wei-Jun | Moore, Ronald J. | Heredia-Langner, Alejandro | Webb-Robertson, Bobbie-Jo M. | Thrall, Brian D. | Camp, David G. | Smith, Richard D. | Pounds, Joel G. | Liu, Tao
Nanoparticle biological activity, biocompatibility and fate can be directly affected by layers of readily adsorbed host proteins in biofluids. Here, we report a study on the interactions between human blood plasma proteins and nanoparticles with a controlled systematic variation of properties using 18O-labeling and LC-MS-based quantitative proteomics. We developed a novel protocol to both simplify isolation of nanoparticle bound proteins and improve reproducibility. LC-MS analysis identified and quantified 88 human plasma proteins associated with polystyrene nanoparticles consisting of three different surface chemistries and two sizes, as well as, for four different exposure times (for a total of 24 different samples). Quantitative comparison of relative protein abundances was achieved by spiking an 18O-labeled “universal” reference into each individually processed unlabeled sample as an internal standard, enabling simultaneous application of both label-free and isotopic labeling quantification across the entire sample set. Clustering analysis of the quantitative proteomics data resulted in distinctive patterns that classified the nanoparticles based on their surface properties and size. In addition, temporal data indicated that the formation of the stable protein corona was at equilibrium within 5 min. The comprehensive quantitative proteomics results obtained in this study provide rich data for computational modeling and have potential implications towards predicting nanoparticle biocompatibility.
doi:10.1002/pmic.201100037
PMCID: PMC3252235
PMID: 21956884
Corona; Human plasma; LC-MS; Nanoparticle; Quantitative proteomics
Chen, Yiwen | Negre, Nicolas | Li, Qunhua | Mieczkowska, Joanna O. | Slattery, Matthew | Liu, Tao | Zhang, Yong | Kim, Tae-Kyung | He, Housheng Hansen | Zieba, Jennifer | Ruan, Yijun | Bickel, Peter J. | Myers, Richard M. | Wold, Barbara J. | White, Kevin P. | Lieb, Jason D. | Liu, X. Shirley
We performed a systematic evaluation of how variations in sequencing depth and other parameters influence interpretation of Chromatin immunoprecipitation (ChIP) followed by sequencing (ChIP-seq) experiments. Using Drosophila S2 cells, we generated ChIP-seq datasets for a site-specific transcription factor (Suppressor of Hairy-wing) and a histone modification (H3K36me3). We detected a chromatin state bias, open chromatin regions yielded higher coverage, which led to false positives if not corrected and had a greater effect on detection specificity than any base-composition bias. Paired-end sequencing revealed that single-end data underestimated ChIP library complexity at high coverage. The removal of reads originating at the same base reduced false-positives while having little effect on detection sensitivity. Even at a depth of ~1 read/bp coverage of mappable genome, ~1% of the narrow peaks detected on a tiling array were missed by ChIP-seq. Evaluation of widely-used ChIP-seq analysis tools suggests that adjustments or algorithm improvements are required to handle datasets with deep coverage.
doi:10.1038/nmeth.1985
PMCID: PMC3477507
PMID: 22522655
CyberKnife (CK), hypofractionated stereotactic radiosurgery, is a preferred option for the treatment of advanced refractory lung cancer which is usually inoperable. Cytokine-induced killer (CIK) cell immunotherapy has a marked radiosensitization effect which aids the elimination of residual tumor cells in distant areas. The main purpose of the present study was to evaluate the clinical efficacy of CK alone and combined with CIK cell therapy for advanced refractory lung cancer. In one year, 22 patients with advanced lung cancer underwent CK therapy at a CyberKnife Center. Of these patients, 11 received CIK cell therapy before or after the CK therapy course. The median prescribed dose in the combined CK and CIK group was 35 Gy (mean, 33.8±5.0 Gy) with a median number of fractions of 5. The median dose for patients who underwent CK alone was 35 Gy (mean, 35.2±6.0 Gy). CIK cell therapy was administered according to the condition of each patient, generally 2 continuous therapeutic sessions in 2 months. The median follow-up period was 3 months. The preliminary curative efficiency rate was 81.82% for patients who underwent CK/CIK and 72.73% for those who received CK alone, according to radiographic re-examination (P>0.05). The median improvement in the Karnofsky scores of the CK/CIK group was 20 (18±10.51) compared with 10 (8.6±11.85) for those who underwent CK alone (P<0.05). The median expression of carcinoembryonic antigen (CEA) before and after treatment was 40.81 and 12.21 ng/ml, respectively, for the CK/CIK group compared with 39.04 and 26.36 ng/ml for CK alone. The median percentage of phenotype expression of the CIK cells (CD3+/CD8+ and CD3+/CD56+) in the patients who underwent CK/CIK was recorded as 64.35% (57.08±16.94%) and 15.27% (18.80±7.00%), respectively, prior to transfusion. The preliminary results of the present study suggest that CK combined with CIK cell immunotherapy improved the short-term outcomes of patients for curative efficacy, Karnofsky scores, tumor marker levels and immune status compared with alternative CK treatments, although further studies are required.
doi:10.3892/etm.2012.818
PMCID: PMC3570163
PMID: 23403795
CyberKnife; stereotactic radiosurgery; cytokine-induced killer; immunotherapy; clinical efficacy
Luo, Yi-Juan | Wen, Xiao-Zhong | Ding, Peng | He, Yan-Hui | Xie, Chuan-Bo | Liu, Tao | Lin, Jian-miao | Yuan, Shi-Xin | Guo, Xiao-Ling | Jia, De-Qin | Chen, Li-Hua | Huang, Bao-Zhen | Chen, Wei-Qing | Szecsi, Pal Bela
Objective
The present study aimed to examine the association between maternal passive smoking during pregnancy and the risk of spontaneous PTD and to explore the potential interaction of the single or joint gene polymorphism of CYP1A1 and GSTs with maternal passive smoking on the risk of spontaneous PTD.
Method
We investigated whether the association between maternal passive smoking and PTD can be modified by 2 metabolic genes, i.e. cytochrome P4501A1 (CYP1A1) and glutathione S-transferases (GSTs), in a case-control study with 198 spontaneous preterm and 524 term deliveries in Shenzhen and Foshan, China. We used logistic regression to test gene-passive smoking interaction, adjusting for maternal socio-demographics and prepregnancy body mass index.
Results
Overall, maternal passive smoking during pregnancy was associated with higher risk of PTD (adjusted odds ratio = 2.20 [95% confidence interval: 1.56–3.12]). This association was modified by CYP1A1 and GSTs together, but not by any single genotype. For cross-categories of CYP1A1 Msp I and GSTs, maternal passive smoking was associated with higher risk of PTD among those women with CYP1A1 “TC/CC”+ GSTs “null”, but not among women with other genotypes; and this interaction was significant (OR = 2.66 [95% CI: 1.19–5.97]; P-value: 0.017). For cross-categories of CYP1A1 BsrD I and GSTs, maternal passive smoking was associated with higher risk of PTD only among those women with CYP1A1“AG/GG”+ GSTs “null”, but not among women with other genotypes; and this interaction was significant (OR = 3.00 [95% CI: 1.17–7.74]; P-value: 0.023).
Conclusions
Our findings suggest that the combined genotypes of CYP1A1 and GSTs can help to identify vulnerable pregnant women who are subject to high risk of spontaneous PTD due to passive smoking.
doi:10.1371/journal.pone.0049155
PMCID: PMC3496734
PMID: 23152866
Ventilator-associated pneumonia (VAP) is a common and sometimes fatal complication in pediatric intensive care units (PICU). The aim of our study was to characterize the distribution and drug susceptibility of the pathogens isolated from the sputum of patients with VAP in the PICU of our hospital and to provide support to the administration of antibiotics early and reasonably in the clinic. Our study was conducted between January 2007 and December 2011 at the PICU of the Children’s Hospital of Zhejiang University School of Medicine. The endotracheal aspirates were collected and transported to a microbiology laboratory within 15 min. The pathogens were routinely analyzed and identified with Vitek 60 and Kirby-Bauer disk diffusion methods. Among the 121 VAP patients, 127 pathogenic strains were isolated from sputum specimens. Gram-negative and gram-positive bacteria and fungi accounted for 64.57% (82/127), 29.92% (38/127) and 5.51% (7/127), respectively. Acinetobacter baumannii (25.61%), Escherichia coli (20.27%), Stenotrophomonas maltophilia (20.27%), Klebsiella pneumoniae (16.22%) and Pseudomonas aeruginosa (9.46%) were frequently identified isolates among gram-negative bacteria. Staphylococci were susceptible to vancomycin and linezolid. All fungi were sensitive to the antimicrobial agents. The gram-negative bacteria were more prevalent than gram-positive bacteria and fungi in VAP and demonstrated a higher drug resistance. It is important to administer antimicrobial agents early and reasonably for children with VAP. Knowledge of antibiotic resistance and the characteristics of drug resistance is important for VAP prophylaxis and treatment.
doi:10.3892/etm.2012.757
PMCID: PMC3524271
PMID: 23251300
pediatric intensive care unit; ventilator associated pneumonia; sputum; drug susceptibility
Objective: The purpose of this study was to measure the kinematics of the lower limbs of Chinese people during normal kneeling activity, as such data could be valuable in designing joint prosthesis and arthroplasty that meet the needs of Chinese citizens’ daily activities. Methods: Thirty young and twenty elderly Chinese participants with no personal history of joint diseases were recruited, and matched by age (average age: 23.8 years for the young group, 60.8 years for the elderly group). Each participant performed six trials during which three-dimensional (3D) kinematics data were collected and the means of the 3D angles of the ankle, knee, and hip joints of two groups were calculated. Results: There were no obvious differences between the two groups in the knee and ankle joints. The mean range of knee flexion was 139.6° for the young group and 140.9° for the elderly group. The mean range of ankle flexion was 35.7° for the young group and 37.6° for the elderly group. The maximal eccentric flexion at the hip joint was 67.5° for the young group compared to 100.5° for the elderly group. Conclusions: The elderly uses more hip flexion angles than the young when assuming the kneeling posture. The ranges of motion obtained during kneeling activity are greater than the reported mean ranges of motion achieved following joint arthroplasty. The data could be valuable in establishing criteria for lower limb prosthetics and rehabilitation protocol for the Chinese population.
doi:10.1631/jzus.B1100355
PMCID: PMC3468826
PMID: 23024050
Joint angle; Kneeling; Kinematics; Chinese people
Background
Embryonic stem cells (ESCs) are pluripotent stem cells and can form tumors containing cells from all three germ layers. Similarities between pluripotent stem cells and malignant tumor cells have been identified. The purpose of this study was to obtain ESCs-converted tumor cell lines and to investigate the mechanism of malignancy in pluripotent stem cells.
Methods
Mouse ESCs were subcutaneously injected into nude mice to obtain tumors from which a tumor-like cell line (ECCs1) was established by culturing the cells in chemical-defined N2B27 medium supplied with two small molecular inhibitors CHIR99021 and PD0325901 (2i). The ECCs1 were then subcutaneously injected into nude mice again to obtain tumors from which another tumor-like cells line (ECCs2) was established in the same 2i medium. The malignant degree of ESCs, ECCs1 and ECCs2 was compared and the underlying mechanism involved in the malignancy development of ESCs was examined.
Results
The three ESCs, ECCs1 and ECCs2 cell lines were cultured in the same 2i condition and showed some likeness such as Oct4-expression and long-term expansion ability. However, the morphology and the tumor-formation ability of the cell lines were different. We identified that ECCs1 and ECCs2 gradually acquired malignancy. Moreover, Wnt signaling-related genes such as CD133 and β-catenin expression were up-regulated and Frizzled related protein (FRP) was down-regulated during the tumor development of ESCs.
Conclusions
The two tumor-like cell lines ECCs1 and ECCs2 stand for early malignant development stage of ESCs and the ECCs2 was more malignant than the ECCs1. Moreover, we identified that Wnt/β-catenin signaling played an important role in the malignancy process of ESCs.
doi:10.1186/1479-5876-10-196
PMCID: PMC3515512
PMID: 22995718
Embryonic stem cell; Malignancy; Wnt/β-catenin signaling
One-bead-one-compound (OBOC) libraries provide a powerful tool for drug discovery as well as biomedical research. However, screening a large number of beads/compounds (>1 million) and rank ordering the initial hits (which are covalently attached to a solid support) according to their potencies still post significant technical challenges. In this work, we have integrated some of the latest technical advances from our own as well as other laboratories to develop a general methodology for rapidly screening large OBOC libraries. The methodology has been applied to synthesize and screen a cyclic peptide library that features: (1) spatially segregated beads containing cyclic peptides on the surface layer and linear encoding peptides in their interior; (2) rapid on-bead screening of the library (>1 million) by a multi-stage procedure (magnetic bead sorting, enzyme-linked assay, and fluorescence based screening); (3) selective release of cyclic peptides from single positive beads for solution-phase determination of their binding affinities; and (4) hit identification by partial Edman degradation/mass spectrometry (PED/MS). Screening of the library against protein phosphatase calcineurin (Cn) identified a series of cyclic peptides that bind to the substrate-docking site for nuclear factor of activated T cells (NFAT) with KD values of ~1 μM. Further improvement of the affinity and specificity of these compounds may lead to a new class of immunosuppressive agents that are more selective and therefore less toxic than cyclosporine A and FK506.
doi:10.1021/co200101w
PMCID: PMC3171643
PMID: 21848276
Calcineurin; combinatorial library; cyclic peptides; high-throughput screening; protein-protein interaction
Background
Previous studies showed that overexpression of sarco-endoplasmic reticulum calcium ATPase (SERCA2a) in a variety of heart failure (HF) models was associated with greatly enhanced cardiac performance. However, it still undefined the effect of SERCA2a overexpression on the systemic inflammatory response and neuro-hormonal factors.
Methods
A rapid right ventricular pacing model of experimental HF was used in beagles. Then the animals underwent recombinant adeno-associated virus 1 (rAAV1) mediated gene transfection by direct intra-myocardium injection. HF animals were randomized to receive the SERCA2a gene, enhanced green fluorescent protein (control) gene, or equivalent phosphate buffered saline. Thirty days after gene delivery, the cardiac function was evaluated by echocardiographic testing. The protein level of SERCA2a was measured by western blotting. The proteomic analysis of left ventricular (LV) sample was determined using two-dimensional (2-D) gel electrophoresis and MALDI-TOF-MS. The serum levels of the systemic inflammatory and neuro-hormonal factors were assayed using radioimmunoassay kits.
Results
The cardiac function improved after SERCA- 2a gene transfer due to the significantly increased SERCA2a protein level. Beagles treated with SERCA2a had significantly decreased serum levels of the inflammatory markers (interleukin-6 and tumor necrosis factor-α) and neuro-hormonal factors (brain natriuretic peptide, endothelin-1 and angiotensin II) compared with HF animals. The myocardial proteomic analysis showed that haptoglobin heavy chain, heat shock protein (alpha-crystallin-related, B6) were down-regulated, and galectin-1 was up-regulated in SERCA2a group compared with HF group, companied by up-regulated contractile proteins and NADH dehydrogenase.
Conclusions
These findings demonstrate that regional intramyocardial injections of rAAV1-SERCA2a vectors may improve global LV function, correlating with reverse activation of the systemic inflammatory, excessive neuroendocrine factors and the stress-associated myocardial proteins, suggesting that the beneficial effects of SERCA2a gene transfer may involve the attenuation of stress-associated reaction.
doi:10.3724/SP.J.1263.2012.05299
PMCID: PMC3470026
PMID: 23097657
Heart failure; Sarco-endoplasmic reticulum calcium ATPase; Gene transfer; Stress reaction; Neuro-hormonal factors
The sequential transplantation of embryonal carcinoma cells in vivo can accelerate the growth and malignancy of teratocarcinomas. However, the possible molecular mechanisms in this process that reflect cancer formation in the early stage are largely unknown and. To identify which genes are associated with the changes of malignancy of teratocarcinomas, we established a tumorigenesis model in which teratocarcinoma were induced via injecting embryonic stem cells into immuno-deficiency mice, isolating teratocarcinoma stem cell from a teratocarcinoma in serum-free culture medium and injecting teratocarcinoma stem cells into immune-deficient mice continuously. By using high-throughput deep sequence technology, we identified 26 differentially expressed genes related to the changes of characteristics of teratocarcinoma stem cell in which 18 out of 26 genes were down-regulated and 8 genes were up-regulated. Among these genes, several tumor-related genes such as Gata3, Arnt and Tdgf1, epigenetic associated genes such as PHC1 and Uty were identified. Pathway enrichment analysis result revealed that Wnt signaling pathway, primary immunodeficiency pathway, antigen processing and presentation pathway and allograft rejection pathway were involved in the teratocarcinoma tumorigenesis (corrected p value<0.05). In summary, our study established a tumorigenesis model and proposed some candidate genes and signaling pathways that may play a key role in the early stage of cancer occurrence.
doi:10.1371/journal.pone.0043955
PMCID: PMC3432059
PMID: 22952821
Protein arginine methyltransferase 5 (PRMT5) plays multiple roles in a large number of cellular processes, and its subcellular localization is dynamically regulated during mouse development and cellular differentiation. However, little is known of the functional differences between PRMT5 in the cytoplasm and PRMT5 in the nucleus. Here, we demonstrated that PRMT5 predominantly localized in the cytoplasm of prostate cancer cells. Subcellular localization assays designed to span the entire open-reading frame of the PRMT5 protein revealed the presence of three nuclear exclusion signals (NESs) in the PRMT5 protein. PRMT5 and p44/MED50/WD45/WDR77 co-localize in the cytoplasm, and both are required for the growth of prostate cancer cells in an PRMT5 methyltransferase activity-dependent manner. In contrast, PRMT5 in the nucleus inhibited cell growth in a methyltransferase activity-independent manner. Consistent with these observations, PRMT5 localized in the nucleus in benign prostate epithelium, whereas it localized in the cytoplasm in prostate premalignant and cancer tissues. We further found that PRMT5 alone methylated both histone H4 and SmD3 proteins but PRMT5 complexed with p44 and pICln methylated SmD3 but not histone H4. These results imply a novel mechanism by which PRMT5 controls cell growth and contributes to prostate tumorigenesis.
doi:10.1371/journal.pone.0044033
PMCID: PMC3428323
PMID: 22952863
Liu, Tao | Hossain, Mahmud | Schepmoes, Athena A. | Fillmore, Thomas L. | Sokoll, Lori J. | Kronewitter, Scott R. | Izmirlian, Grant | Shi, Tujin | Qian, Wei-Jun | Leach, Robin J. | Thompson, Ian M. | Chan, Daniel W. | Smith, Richard D. | Kagan, Jacob | Srivastava, Sudhir | Rodland, Karin D. | Camp, David G.
Recently, selected reaction monitoring mass spectrometry (SRM-MS) has been more frequently applied to measure low abundance biomarker candidates in tissues and biofluids, owing to its high sensitivity and specificity, simplicity of assay configuration, and exceptional multiplexing capability. In this study, we report for the first time the development of immunoaffinity depletion-based workflows and SRM-MS assays that enable sensitive and accurate quantification of total and free prostate-specific antigen (PSA) in serum without the requirement for specific PSA antibodies. Low ng/mL level detection of both total and free PSA was consistently achieved in both PSA-spiked female serum samples and actual patient serum samples. Moreover, comparison of the results obtained when SRM PSA assays and conventional immunoassays were applied to the same samples showed good correlation in several independent clinical serum sample sets. These results demonstrate that the workflows and SRM assays developed here provide an attractive alternative for reliably measuring candidate biomarkers in human blood, without the need to develop affinity reagents. Furthermore, the simultaneous measurement of multiple biomarkers, including the free and bound forms of PSA, can be performed in a single multiplexed analysis using high-resolution liquid chromatographic separation coupled with SRM-MS.
doi:10.1016/j.jprot.2012.01.035
PMCID: PMC3410652
PMID: 22846433
Selected reaction monitoring; immunoaffinity depletion; total PSA; free PSA; serum; immunoassay
Yang, Jun | Riella, Leonardo V. | Chock, Susanne | Liu, Tao | Zhao, Xiaozhi | Yuan, Xueli | Paterson, Alison M. | Watanabe, Toshihiko | Vanguri, Vijay | Yagita, Hideo | Azuma, Miyuki | Blazar, Bruce R. | Freeman, Gordon J. | Rodig, Scott J. | Sharpe, Arlene H. | Chandraker, Anil | Sayegh, Mohamed H.
The PDL1: PD1 costimulatory pathway plays an important role in the inhibition of alloimmune responses as well as in the induction and maintenance of peripheral tolerance. It has recently been demonstrated that PDL1 can also bind B7.1 to inhibit T cell responses in vitro. Using the bm12 into B6 heart transplant model, we investigated the functional significance of this interaction in alloimmune responses in vivo. PD1 blockade unlike PDL1 blockade failed to accelerate bm12 allograft rejection suggesting a role for an additional binding partner for PDL1 other than PD1 in transplant rejection. PDL1 blockade was able to accelerate allograft rejection in B7.2-deficient recipients but not B7.1-deficient recipients, indicating that PDL1 interaction with B7.1 was important in inhibiting rejection. Administration of the novel 2H11 anti-PDL1 mAb, which only blocks PDL1: B7.1 interaction, aggravated chronic injury of bm12 allografts in B6 recipients. Aggravated chronic injury was associated with an increased frequency of alloreactive IFN-γ-, IL-4-, and IL-6-producing splenocytes and a decreased percentage of regulatory T cells in the recipients. Using an in vitro cell culture assay, blockade of the interaction of PDL1 on dendritic cells with B7.1 on T cells increased IFN-γ production from alloreactive CD4+ T cells, whereas blockade of dendritic cell B7.1 interaction with T cell PDL1 did not. These data indicate that PDL1 interaction with B7.1 plays an important role in the inhibition of alloimmune responses in vivo and suggests a dominant direction for PDL1 and B7.1 interaction.
doi:10.4049/jimmunol.1100056
PMCID: PMC3140607
PMID: 21697455
Costimulation; Transplantation; MHC; Knockout mice
The NF-κB family member p65 is central to inflammation and immunity. The purpose of this study was to identify and characterize evolutionary conserved genes modulating p65 transcriptional activity. Using an RNAi screening approach, we identified chaperonin containing TCP1 subunit η (CCTη) as a regulator of Drosophila NF-κB proteins, Dorsal and Dorsal-related immunity factor (Dif). CCTη was also found to regulate NF-κB-driven transcription in mammalian cells, acting in a promoter-specific context, downstream of IκB kinase (IKK). CCTη knockdown repressed IκBα and CXCL2/MIP2 transcription during the early phase of NF-κB activation while impairing the termination of CCL5/RANTES and CXCL10/IP10 transcription. The latter effect was associated with increased DNA binding and reduced p65 acetylation, presumably by altering the activity of histone acetyltransferase CREB-binding protein (CBP). We identified p65 lysines (K) 122 and 123 as target residues mediating the CCTη-driven termination of NF-κB-dependent transcription. We propose that CCTη regulates NF-κB activity in a manner that resolves inflammation.
doi:10.1371/journal.pone.0042020
PMCID: PMC3409233
PMID: 22860050
Cheng, Ping | Liu, Tao | Zhou, Wei-Ying | Zhuang, Yuan | Peng, Liu-sheng | Zhang, Jin-yu | Yin, Zhi-Nan | Mao, Xu-hu | Guo, Gang | Shi, Yun | Zou, Quan-ming
Background
Staphylococcus aureus is the major cause of hospital-acquired and community-acquired pneumonia. Host defense to S.aureus infection is largely mediated by the innate immune system. γδ T cells play an important role in innate immunity to many infectious diseases. However, less is known about the role of these cells during S.aureus-induced pneumonia. In this study, we examined the response and the role of γδ T cells to pulmonary S.aureus infection.
Results
Mice infected with S. aureus intranasally showed rapid γδ T cells accumulation in the lung. Deficiency of γδ T cells led to attenuated bacterial clearance and less tissue damage in lung compared with WT mice. Moreover, TCR-δ−/− mice exhibited impaired neutrophil recruitment and reduced cytokine production at the site of infection. The γδ T cells in response to pulmonary S. aureus infection mainly secreted IL-17 and γδ T cells deficiency reduced IL-17 production, which might regulate the production of neutrophil-inducing cytokine/chemokine in the S. aureus-infected lungs.
Conclusions
Accumulation of γδ T cells in the lungs to S. aureus infection is beneficial for bacteria clearance and also contributes to the tissue damage. These cells were the primary source of IL-17, which might influence the recruitment of neutrophils at the early stage of infection.
doi:10.1186/1471-2172-13-38
PMCID: PMC3524664
PMID: 22776294