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1.  Solution-processed small-molecule solar cells: breaking the 10% power conversion efficiency 
Scientific Reports  2013;3:3356.
A two-dimensional conjugated small molecule (SMPV1) was designed and synthesized for high performance solution-processed organic solar cells. This study explores the photovoltaic properties of this molecule as a donor, with a fullerene derivative as an acceptor, using solution processing in single junction and double junction tandem solar cells. The single junction solar cells based on SMPV1 exhibited a certified power conversion efficiency of 8.02% under AM 1.5 G irradiation (100 mW cm−2). A homo-tandem solar cell based on SMPV1 was constructed with a novel interlayer (or tunnel junction) consisting of bilayer conjugated polyelectrolyte, demonstrating an unprecedented PCE of 10.1%. These results strongly suggest solution-processed small molecular materials are excellent candidates for organic solar cells.
PMCID: PMC3842540  PMID: 24285006
2.  Engaging in an auditory task suppresses responses in auditory cortex 
Nature neuroscience  2009;12(5):646-654.
Although systems involved in attentional selection have been studied extensively, much less is known about non-selective systems. To study these preparatory mechanisms, we compared activity in auditory cortex elicited by sounds while rats performed an auditory task (“engaged”) with activity elicited by identical stimuli while subjects were awake but not performing a task (“passive”). Surprisingly, we found that engagement suppressed responses, an effect opposite in sign to that elicited by selective attention. In the auditory thalamus, however, engagement enhanced spontaneous firing rates but did not affect evoked responses. These results demonstrate that in auditory cortex, neural activity cannot be viewed simply as a limited resource allocated in greater measure as the state of the animal passes from somnolent to passively listening to engaged and attentive. Instead the engaged condition possesses a characteristic and distinct neural signature in which sound-evoked responses are paradoxically suppressed.
PMCID: PMC4084972  PMID: 19363491
3.  Clinical features and hypoxic marker expression of primary sinonasal and laryngeal small-cell neuroendocrine carcinoma: a small case series 
Small-cell neuroendocrine carcinoma (SCNEC) of the head and neck is rare. The prognosis of SCNEC in the nasal cavity and larynx is poor. The aim of this study was to investigate the clinicopathological features of nasal and laryngeal SCNEC and to determine the expression of HIF-1α, GLUT-1, PI3K, and p-Akt in SCNEC.
Between 2003 and 2012, 10 consecutive patients with histologically demonstrated nasal and laryngeal SCNEC were enrolled. Clinicopathological materials and follow-up data were analyzed retrospectively. Immunohistochemistry was used to detect GLUT-1, HIF-1α, PI3K, and p-Akt expression in paraffin wax-embedded tumor specimens.
The subjects were eight males and two females with a mean age of 60.8 (range: 53 to 71) years. Tumors were located in the maxillary sinus (n = 3) and larynx (n = 7). At last follow-up, four patients (40.0%) had local recurrence and five patients (50.0%) had developed distant metastases. Six patients died. The mean overall survival was 19.3 ± 2.1 months. Expression of GLUT-1, HIF-1α, PI3K, and p-Akt was seen in sinonasal and laryngeal SCNEC in 80 (8 out of 10), 50 (5 out of 10), 40 (4 out of 10), and 40% (4 out of 10) of cases, respectively. Expression of GLUT-1, HIF-1α, PI3K, and p-Akt was higher in sinonasal and laryngeal SCNEC than in precancerous lesions.
Primary sinonasal and laryngeal SCNEC is rare. This paper presents 10 cases of sinonasal and laryngeal SCNEC with more common local recurrence and distant metastasis. HIF-1α, GLUT-1, PI3K, and p-Akt expression was higher in sinonasal and laryngeal SCNEC than in precancerous lesions.
PMCID: PMC4083367  PMID: 24980293
Small-cell neuroendocrine carcinoma; Larynx; Nasal cavity and paranasal sinuses; Hypoxia-inducible factor-1α; Glucose transporter-1; PI3K/Akt pathway
4.  Protective effect of bone marrow mesenchymal stem cells in intestinal barrier permeability after heterotopic intestinal transplantation 
AIM: To explore the protective effect of bone marrow mesenchymal stem cells (BM MSCs) in the small intestinal mucosal barrier following heterotopic intestinal transplantation (HIT) in a rat model.
METHODS: BM MSCs were isolated from male Lewis rats by density gradient centrifugation, cultured, and analyzed by flow cytometry. The HIT models were divided into a non-rejection group, saline-treated rejection group (via penile vein), and BM MSC–treated group (via penile vein). Intestinal mucosal barrier injury was estimated by diamine oxidase (DAO) and D-lactic acid (D-LA) expression levels. Tumor necrosis factor-α (TNF-α), interferon-γ (INF-γ), interleukin-10 (IL-10), and transforming growth factor-β (TGF-β) were detected by enzyme-linked immunosorbent assay. Ultrastructural change of tight junctions (TJs) was observed under transmission electron microscope. Expression levels of the TJ proteins occludin and zona occludens (ZO)-1, affected by the inflammatory factors, were measured using real-time polymerase chain reaction and Western blotting.
RESULTS: The pathological score at each time point after surgery indicated significantly less serious injury in the BM MSCs-treated group than in the rejection group (P < 0.05). In the former, graft levels of DAO and D-LA were reduced, and TNF-α and INF-γ production was inhibited (at day 7: 10.6473 ± 0.0710 vs 17.2128 ± 0.4991, P < 0.05; 545.1506 ± 31.9416 vs 810.2637 ± 25.1175, P < 0.05). IL-10 and TGF-β production was increased greatly (at day 7: 125.7773 ± 4.7719 vs 80.3756 ± 2.5866, P < 0.05; 234.5273 ± 9.3980 vs 545.1506 ± 31.9416, P < 0.05). There was increased expression of occludin and ZO-1 protein (at day 7: 0.2674 ± 0.0128 vs 0.1352 ± 0.0142, P < 0.05; at day 5: 0.7189 ± 0.0289 vs 0.4556 ± 0.0242, P < 0.05) and mRNA (at day 7: 0.3860 ± 0.0254 vs 0.1673 ± 0.0369, P < 0.05; at day 5: 0.5727 ± 0.0419 vs 0.3598 ± 0.0242, P < 0.05).
CONCLUSION: BM MSCs can improve intestinal barrier permeability, repair TJs, and increase occludin and ZO-1 protein expression. With altered cytokine levels, they can protect the intestinal mucosa after transplantation.
PMCID: PMC4064089  PMID: 24966614
Bone marrow mesenchymal stem cells; Small intestinal transplantation; Intestinal mucosal barrier; Occludin; Zona occludens-1
5.  Social Network Ties and Inflammation in U.S. Adults with Cancer 
The growing evidence linking social connectedness and chronic diseases such as cancer calls for a better understanding of the underlying biophysiological mechanisms. This study assessed the associations between social network ties and multiple measures of inflammation in a nationally representative sample of adults with a history of cancer (N = 1,075) from the National Health and Nutrition Examination Survey III (1988–94). Individuals with lower social network index (SNI) scores showed significantly greater inflammation marked by C-reactive protein and fibrinogen, adjusting for age and sex. Compared to fully socially integrated individuals (SNI 4), those who were more socially isolated or had a SNI score of 3 or less exhibited = increasingly elevated inflammation burdens. Specifically, the age- and sex-adjusted odds ratios (95%CI) for SNIs of 3, 2, and 0–1 were 1.49 (1.08, 2.06), 1.69 (1.21, 2.36), and 2.35 (1.62, 3.40), respectively (p < .001). Adjusting for other covariates attenuated these associations. The SNI gradients in the risks of inflammation were particularly salient for the lower socioeconomic status groups and remained significant after adjusting for other social, health behavioral, and illness factors. This study provided initial insights into the immunological pathways by which social connections are related to morbidity and mortality outcomes of cancer in particular and aging-related diseases in general.
PMCID: PMC4064303  PMID: 24784985
6.  Millisecond-scale differences in neural activity in auditory cortex can drive decisions 
Nature neuroscience  2008;11(11):1262-1263.
Neurons in the auditory cortex can lock with millisecond precision to the fine timing of acoustic stimuli, but it is not known whether this precise spike timing can be used to guide decisions. We used chronically implanted microelectrode pairs to stimulate neurons in the rat auditory cortex directly. Here we demonstrate that rats can exploit differences in the timing of cortical activity as short as three milliseconds to guide decisions.
PMCID: PMC4062077  PMID: 18849984
7.  Positive Feedback of NDT80 Expression Ensures Irreversible Meiotic Commitment in Budding Yeast 
PLoS Genetics  2014;10(6):e1004398.
In budding yeast, meiotic commitment is the irreversible continuation of the developmental path of meiosis. After reaching meiotic commitment, cells finish meiosis and gametogenesis, even in the absence of the meiosis-inducing signal. In contrast, if the meiosis-inducing signal is removed and the mitosis-inducing signal is provided prior to reaching meiotic commitment, cells exit meiosis and return to mitosis. Previous work has shown that cells commit to meiosis after prophase I but before entering the meiotic divisions. Since the Ndt80 transcription factor induces expression of middle meiosis genes necessary for the meiotic divisions, we examined the role of the NDT80 transcriptional network in meiotic commitment. Using a microfluidic approach to analyze single cells, we found that cells commit to meiosis in prometaphase I, after the induction of the Ndt80-dependent genes. Our results showed that high-level expression of NDT80 is important for the timing and irreversibility of meiotic commitment. A modest reduction in NDT80 levels delayed meiotic commitment based on meiotic stages, although the timing of each meiotic stage was similar to that of wildtype cells. A further reduction of NDT80 resulted in the surprising finding of inappropriately uncommitted cells: withdrawal of the meiosis-inducing signal and addition of the mitosis-inducing signal to cells at stages beyond metaphase I caused return to mitosis, leading to multi-nucleate cells. Since Ndt80 enhances its own transcription through positive feedback, we tested whether positive feedback ensured the irreversibility of meiotic commitment. Ablating positive feedback in NDT80 expression resulted in a complete loss of meiotic commitment. These findings suggest that irreversibility of meiotic commitment is a consequence of the NDT80 transcriptional positive feedback loop, which provides the high-level of Ndt80 required for the developmental switch of meiotic commitment. These results also illustrate the importance of irreversible meiotic commitment for maintaining genome integrity by preventing formation of multi-nucleate cells.
Author Summary
There are two main types of cell division cycles, mitosis and meiosis. During mitosis, DNA is replicated and then chromosomes segregate, producing two daughter cells with the same ploidy as the progenitor cell. During meiosis, DNA is replicated and then chromosomes undergo two rounds of segregation, producing four gametes with half the ploidy of the progenitor cell. As the cell enters into the meiotic divisions, it irreversibly commits to finishing meiosis and cannot return to mitosis. The molecular mechanisms that define meiotic commitment are not well understood. In this study, we asked whether the regulatory network involved in the transcription of NDT80 has a role in meiotic commitment. Ndt80 is a transcription factor that induces the genes needed for the meiotic divisions. We found that a high-level of Ndt80 activity is required for meiotic commitment; in wildtype cells, this is achieved through a transcriptional positive feedback loop– a regulatory mechanism in which the Ndt80 protein increases the transcription of its own gene. In the absence of positive feedback, cells escape meiosis inappropriately, resulting in an aberrant cell cycle that causes an increase in genome copy number. This study shows the important role of positive feedback in meiotic commitment and in the maintenance of genome integrity.
PMCID: PMC4046916  PMID: 24901499
8.  Wnt pathway contributes to the protection by bone marrow stromal cells of acute lymphoblastic leukemia cells and is a potential therapeutic target 
Cancer letters  2013;333(1):10.1016/j.canlet.2012.11.056.
Leukemia cells are protected by various components of its microenvironment, including marrow stromal cells (MSCs). To understand the molecular mechanisms underlying this protection, we cultured acute lymphoblastic leukemia (ALL) cells with MSCs and studied the effect of the latter on the molecular profiling of ALL cells at the mRNA and protein levels. Our results indicated that activated Wnt signaling in ALL cells is involved in MSC-mediated drug resistance. Blocking the Wnt pathway sensitized the leukemia cells to chemotherapy and improved overall survival in a mouse model. Targeting the Wnt pathway may be an innovative approach to the treatment of ALL.
PMCID: PMC3880833  PMID: 23333798
Acute lymphoblastic leukemia; bone marrow stromal cells; Wnt pathway; Wnt pathway inhibitor; chemotherapy resistance
9.  Inherent Dynamics of Head Domain Correlates with ATP-Recognition of P2X4 Receptors: Insights Gained from Molecular Simulations 
PLoS ONE  2014;9(5):e97528.
P2X receptors are ATP-gated ion channels involved in many physiological functions, and determination of ATP-recognition (AR) of P2X receptors will promote the development of new therapeutic agents for pain, inflammation, bladder dysfunction and osteoporosis. Recent crystal structures of the zebrafish P2X4 (zfP2X4) receptor reveal a large ATP-binding pocket (ABP) located at the subunit interface of zfP2X4 receptors, which is occupied by a conspicuous cluster of basic residues to recognize triphosphate moiety of ATP. Using the engineered affinity labeling and molecular modeling, at least three sites (S1, S2 and S3) within ABP have been identified that are able to recognize the adenine ring of ATP, implying the existence of at least three distinct AR modes in ABP. The open crystal structure of zfP2X4 confirms one of three AR modes (named AR1), in which the adenine ring of ATP is buried into site S1 while the triphosphate moiety interacts with clustered basic residues. Why architecture of ABP favors AR1 not the other two AR modes still remains unexplored. Here, we examine the potential role of inherent dynamics of head domain, a domain involved in ABP formation, in AR determinant of P2X4 receptors. In silico docking and binding free energy calculation revealed comparable characters of three distinct AR modes. Inherent dynamics of head domain, especially the downward motion favors the preference of ABP for AR1 rather than AR2 and AR3. Along with the downward motion of head domain, the closing movement of loop139–146 and loop169–183, and structural rearrangements of K70, K72, R298 and R143 enabled ABP to discriminate AR1 from other AR modes. Our observations suggest the essential role of head domain dynamics in determining AR of P2X4 receptors, allowing evaluation of new strategies aimed at developing specific blockers/allosteric modulators by preventing the dynamics of head domain associated with both AR and channel activation of P2X4 receptors.
PMCID: PMC4039465  PMID: 24878662
10.  Mortality Increase in Late-Middle and Early-Old Age: Heterogeneity in Death Processes as a New Explanation 
Demography  2013;50(5):1563-1591.
Deviations from the Gompertz law of exponential mortality increases in late-middle and early-old age are commonly neglected in overall mortality analyses. In this study, we examined mortality increase patterns between ages 40 and 85 in 16 low-mortality countries and demonstrated sex differences in these patterns, which also changed across period and cohort. These results suggest that the interaction between aging and death is more complicated than what is usually assumed from the Gompertz law and also challenge existing biodemographic hypotheses about the origin and mechanisms of sex differences in mortality. We propose a two-mortality model that explains these patterns as the change in the composition of intrinsic and extrinsic death rates with age. We show that the age pattern of overall mortality and the population heterogeneity therein are possibly generated by multiple dynamics specified by a two-mortality model instead of a uniform process throughout most adult ages.
PMCID: PMC4028711  PMID: 23743628
Mortality acceleration; Sex differences; Two-mortality processes; Vitality
11.  The Surface Charge and Cellular Processing of Covalently Functionalized Multiwall Carbon Nanotubes Determine Pulmonary Toxicity 
ACS nano  2013;7(3):2352-2368.
Functionalized carbon nanotubes (f-CNTs) are being produced in increased volume because of the ease of dispersion and maintenance of the pristine material physicochemical properties when used in composite materials as well as for other commercial applications. However, the potential adverse effects of f-CNTs have not been quantitatively or systematically explored, and in this study we used a library of covalently functionalized multiwall carbon nanotubes (f-MWCNTs), established from the same starting material, to assess the impact of surface charge in a predictive toxicological model that relates the tubes’ pro-inflammatory and pro-fibrogenic effects at cellular level to the development of pulmonary fibrosis. Carboxylated (COOH), polyethylene glycol (PEG), amine (NH2), sidewall amine (sw-NH2) and polyetherimide (PEI) modified MWCNTs were successfully established from raw or as-prepared (AP-) MWCNTs, and comprehensively characterized by TEM, XPS, FTIR and DLS to obtain information about morphology, length, degree of functionalization, hydrodynamic size and surface charge. Cellular screening in BEAS-2B and THP-1 cells showed that, compared to AP-MWCNTs, anionic functionalization (COOH and PEG) decreased the production of pro-fibrogenic cytokines and growth factors (including IL-1β, TGF-β1 and PDGF-AA), while neutral and weak cationic functionalization (NH2 and sw-NH2) showed intermediary effects. In contrast, the strongly cationic PEI-functionalized tubes induced robust biological effects. These differences could be attributed to differences in cellular uptake and NLRP3 inflammasome activation, which depends on the propensity towards lysosomal damage and cathepsin B release in macrophages. Moreover, the in vitro hazard ranking was validated by the pro-fibrogenic potential of the tubes in vivo. Compared to pristine MWCNTs, strong cationic PEIMWCNTs induced significant lung fibrosis, while carboxylation significantly decreased the extent of pulmonary fibrosis. These results demonstrate that surface charge plays an important role in the structure-activity relationships that determine the pro-fibrogenic potential of f-CNTs in the lung.
PMCID: PMC4012619  PMID: 23414138
multiwall carbon nanotube (MWCNT); surface functionalization; charge; NLRP3 inflammasome; lung fibrosis
12.  Snapback Primer Mediated Clamping PCR for Detection of EGFR and KRAS Mutations in NSCLC Patients by High Resolution Melting Analysis 
BioMed Research International  2014;2014:407537.
Assays for detecting somatic mutations are requested with higher sensitivity and more convenience. Here, we describe snapback primer mediated allele clamping enrichment polymerase chain reaction (SPACE-PCR), a novel form of PCR that amplifies minority alleles selectively from mixtures. We replaced regular PCR with SPACE-PCR before sequencing or genotyping assays to improve mutation detection sensitivity by up to 100-fold in detecting EGFR and KRAS somatic mutations. Combined SPACE-PCR with analysis of snapback primer by high resolution melting (SPACE-HRM), the high sensitive system that enables a closed-tube detection of mutations after isolating mutants has been established, as low as 1/105–1/1000 mutant samples can be diagnosed. And finally, in a double-blind experiment of 150 cases of non-small-cell lung cancer (NSCLC) patients, compared with direct DNA sequencing and ADX-EGFR/KRAS mutation detection kit, up to 25% of the PCR-direct sequencing negative cases turned out to be positive in SPACE-HRM mutation tests; the specificity is 100%. Results demonstrated that the SPACE-HRM system we set up is a high sensitive assay that can be used for EGFR and KRAS allele enrichment and reliable detection. We anticipate that the method will be employed in multiple applications in the clinic, including diagnosis, scanner recurrence monitoring, and treatment management.
PMCID: PMC4026848  PMID: 24883309
13.  Study on Biopharmaceutics Classification and Oral Bioavailability of a Novel Multikinase Inhibitor NCE for Cancer Therapy 
Specific biopharmaceutics classification investigation and study on phamacokinetic profile of a novel drug candidate (2-methylcarbamoyl-4-{4-[3- (trifluoromethyl) benzamido] phenoxy} pyridinium 4-methylbenzenesulfonate monohydrate, NCE) were carried out. Equilibrium solubility and intrinsic dissolution rate (IDR) of NCE were estimated in different phosphate buffers. Effective intestinal permeability (Peff) of NCE was determined using single-pass intestinal perfusion technique in rat duodenum, jejunum and ileum at three concentrations. Theophylline (high permeability) and ranitidine (low permeability) were also applied to access the permeability of NCE as reference compounds. The bioavailability after intragastrical and intravenous administration was measured in beagle dogs. The solubility of NCE in tested phosphate buffers was quite low with the maximum solubility of 81.73 μg/mL at pH 1.0. The intrinsic dissolution ratio of NCE was 1 × 10−4 mg·min−1·cm−2. The Peff value of NCE in all intestinal segments was more proximate to the high-permeability reference theophylline. Therefore, NCE was classified as class II drug according to Biopharmaceutics Classification System due to its low solubility and high intestinal permeability. In addition, concentration-dependent permeability was not observed in all the segments, indicating that there might be passive transportation for NCE. The absolute oral bioavailability of NCE in beagle dogs was 26.75%. Therefore, dissolution promotion will be crucial for oral formulation development and intravenous administration route will also be suggested for further NCE formulation development. All the data would provide a reference for biopharmaceutics classification research of other novel drug candidates.
PMCID: PMC4057667  PMID: 24776763
biopharmaceutics classification system; intrinsic dissolution rate; permeability; bioavailability; multikinase inhibitor
14.  IGF-1R, a target of let-7b, mediates crosstalk between IRS-2/Akt and MAPK pathways to promote proliferation of oral squamous cell carcinoma 
Oncotarget  2014;5(9):2562-2574.
Insulin-like growth factor (IGF) signaling is involved in oral squamous cell carcinoma (OSCC), but IGF-1 receptor (IGF-1R)-mediated intricate regulatory networks among molecular interactions and signalling path ways in OSCC remain unclear. Here, we found that overexpression of IGF-1R and insulin receptor substrate-2 (IRS-2) was negatively associated with histological differentiation. IGF signaling stimulated OSCC cell growth. Conversely, overexpression of let-7b inhibited proliferation and colony formation and triggered S/G2 cell cycle arrest by targeting IGF-1R and IRS-2 through the Akt pathway. Also, the inverse relationship between expression of let-7b and IGF-1R/IRS-2 was confirmed in OSCC tumor xenografts and clinical specimens. Furthermore, by activating ERK1/2, IGF-1R transcriptionally upregulated IRS-2. Our results indicate that let-7b/IGF-1R-mediated crosstalk between IRS-2/Akt and MAPK is involved in OSCC and is a potential therapeutic target for therapy.
PMCID: PMC4058027  PMID: 24810113
oral squamous cell carcinoma; IGF-1R; IRS-2; let-7b; proliferation
15.  An Uncertainty-Based Distributed Fault Detection Mechanism for Wireless Sensor Networks 
Sensors (Basel, Switzerland)  2014;14(5):7655-7683.
Exchanging too many messages for fault detection will cause not only a degradation of the network quality of service, but also represents a huge burden on the limited energy of sensors. Therefore, we propose an uncertainty-based distributed fault detection through aided judgment of neighbors for wireless sensor networks. The algorithm considers the serious influence of sensing measurement loss and therefore uses Markov decision processes for filling in missing data. Most important of all, fault misjudgments caused by uncertainty conditions are the main drawbacks of traditional distributed fault detection mechanisms. We draw on the experience of evidence fusion rules based on information entropy theory and the degree of disagreement function to increase the accuracy of fault detection. Simulation results demonstrate our algorithm can effectively reduce communication energy overhead due to message exchanges and provide a higher detection accuracy ratio.
PMCID: PMC4063048  PMID: 24776937
fault detection; uncertainty; evidence fusion; data missing; information entropy
16.  MT1M and MT1G promoter methylation as biomarkers for hepatocellular carcinoma 
AIM: To investigate the potential of promoter methylation of two tumor suppressor genes (TSGs) as biomarkers for hepatocellular carcinoma (HCC).
METHODS: A total of 189 subjects were included in this retrospective cohort, which contained 121 HCC patients without any history of curative treatment, 37 patients with chronic hepatitis B (CHB), and 31 normal controls (NCs). DNA samples were extracted from 400 μL of serum of each subject and then modified using bisulfite treatment. Methylation of the promoters of the TSGs (metallothionein 1M, MT1M; and metallothionein 1G, MT1G) was determined using methylation-specific polymerase chain reaction. The diagnostic value of combined MT1M and MT1G promoter methylation was evaluated using the area under the receiver operating characteristic curves.
RESULTS: Our results indicated that the methylation status of serum MT1M (48.8%, 59/121) and MT1G (70.2%, 85/121) promoters in the HCC group was significantly higher than that in the CHB group (MT1M 5.4%, 2/37, P < 0.001; MT1G 16.2%, 6/37, P < 0.001) and NC group (MT1M 6.5%, 2/31, P < 0.001; MT1G 12.9%, 4/27, P < 0.001). Aberrant serum MT1M promoter methylation gave higher specificity to discriminate HCC from CHB (94.6%) and NCs (93.5%), whereas combined methylation of serum MT1M and MT1G promoters showed higher diagnostic sensitivity (90.9%), suggesting that they are potential markers for noninvasive detection of HCC. Furthermore, MT1M promoter methylation was positively correlated with tumor size (rs = 0.321, P < 0.001), and HCC patients with both MT1M and MT1G promoter methylation tended to show a higher incidence of vascular invasion or metastasis (P = 0.018).
CONCLUSION: MT1M and MT1G promoter methylation may be used as serum biomarkers for noninvasive detection of HCC.
PMCID: PMC4000509  PMID: 24782625
MT1M; MT1G; Methylation; Serum biomarker; Hepatocellular carcinoma
17.  Social Isolation and Adult Mortality: The Role of Chronic Inflammation and Sex Differences 
The health and survival benefits of social embeddedness have been widely documented across social species, but the underlying biophysiological mechanisms have not been elucidated in the general population. We assessed the process by which social isolation increases the risk for all-cause and chronic disease mortality through proinflammatory mechanisms. Using the 18-year mortality follow-up data (n = 6,729) from the National Health and Nutrition Examination Survey (1988–2006) on Social Network Index and multiple markers of chronic inflammation, we conducted survival analyses and found evidence that supports the mediation role of chronic inflammation in the link between social isolation and mortality. A high-risk fibrinogen level and cumulative inflammation burden may be particularly important in this link. There are notable sex differences in the mortality effects of social isolation in that they are greater for men and can be attributed in part to their heightened inflammatory responses.
PMCID: PMC3998519  PMID: 23653312
cancer; chronic inflammation; heart disease; mortality; sex differences
18.  Adenosine A2B receptor modulates intestinal barrier function under hypoxic and ischemia/reperfusion conditions 
Background: Intestinal barrier function failure from ischemia/reperfusion (I/R) and acute hypoxia has been implicated as a critical determinant in the predisposition to intestinal inflammation and a number of inflammatory disorders. Here, we identified the role of Adenosine A2B receptor (A2BAR) in the regulation of intestinal barrier function under I/R and acute hypoxic conditions. Methods: C57BL/6J mice were used, and were randomized into three groups: Sham, I/R, IR+PSB1115 (a specific A2BAR antagonist) groups. After surgery, the small bowel was harvested for immunohistochemical staining, RNA and protein content, and intestinal permeability analyses. Using an epithelial cell culture model, we investigated the influence of hypoxia on the epithelial function, and the role of A2BAR in the expressions of tight junction and epithelial permeability. The expressions of Claudin-1, occludin and ZO-1 were detected by RT-PCR and Western-Blot. Epithelial barrier function was assessed with transepithelial resistance (TER). Results and conclusions: The A2BAR antagonist, PSB1115, significantly increased tight junction protein expression after intestinal I/R or acute hypoxia conditions. PSB1115 also attenuated the disrupted distribution of TJ proteins. Furthermore, inhibition of A2BAR attenuated the decrease in TER induced by I/R or acute hypoxic conditions, and maintained intestinal barrier function. Antagonism of A2BAR activity improves intestinal epithelial structure and barrier function in a mouse model of intestinal I/R and a cell model of acute hypoxia. These findings support a potentially destructive role for A2BAR under intestinal I/R and acute hypoxic conditions.
PMCID: PMC4069946  PMID: 24966910
Ischemia/reperfusion; hypoxia; adenosine A2B receptor; tight junction; claudin-1; occludin; ZO-1; TER
19.  Integrating Gene Expression and Protein Interaction Data for Signaling Pathway Prediction of Alzheimer's Disease 
Discovering the signaling pathway and regulatory network would provide significant advance in genome-wide understanding of pathogenesis of human diseases. Despite the rich transcriptome data, the limitation for microarray data is unable to detect changes beyond transcriptional level and insufficient in reconstructing pathways and regulatory networks. In our study, protein-protein interaction (PPI) data is introduced to add molecular biological information for predicting signaling pathway of Alzheimer's disease (AD). Combining PPI with gene expression data, significant genes are selected by modified linear regression model firstly. Then, according to the biological researches that inflammation reaction plays an important role in the generation and deterioration of AD, NF-κB (nuclear factor-kappa B), as a significant inflammatory factor, has been selected as the beginning gene of the predicting signaling pathway. Based on that, integer linear programming (ILP) model is proposed to reconstruct the signaling pathway between NF-κB and AD virulence gene APP (amyloid precursor protein). The results identify 6 AD virulence genes included in the predicted inflammatory signaling pathway, and a large amount of molecular biological analysis shows the great understanding of the underlying biological process of AD.
PMCID: PMC4000644  PMID: 24812571
20.  Crystal Structure of the Receptor-Binding Domain from Newly Emerged Middle East Respiratory Syndrome Coronavirus 
Journal of Virology  2013;87(19):10777-10783.
The newly emerged Middle East respiratory syndrome coronavirus (MERS-CoV) has infected at least 77 people, with a fatality rate of more than 50%. Alarmingly, the virus demonstrates the capability of human-to-human transmission, raising the possibility of global spread and endangering world health and economy. Here we have identified the receptor-binding domain (RBD) from the MERS-CoV spike protein and determined its crystal structure. This study also presents a structural comparison of MERS-CoV RBD with other coronavirus RBDs, successfully positioning MERS-CoV on the landscape of coronavirus evolution and providing insights into receptor binding by MERS-CoV. Furthermore, we found that MERS-CoV RBD functions as an effective entry inhibitor of MERS-CoV. The identified MERS-CoV RBD may also serve as a potential candidate for MERS-CoV subunit vaccines. Overall, this study enhances our understanding of the evolution of coronavirus RBDs, provides insights into receptor recognition by MERS-CoV, and may help control the transmission of MERS-CoV in humans.
PMCID: PMC3807420  PMID: 23903833
21.  HIV-, HCV-, and Co-Infections and Associated Risk Factors among Drug Users in Southwestern China: A Township-Level Ecological Study Incorporating Spatial Regression 
PLoS ONE  2014;9(3):e93157.
The human immunodeficiency virus (HIV) and hepatitis C virus (HCV) are major public health problems. Many studies have been performed to investigate the association between demographic and behavioral factors and HIV or HCV infection. However, some of the results of these studies have been in conflict.
Methodology/Principal Findings
The data of all entrants in the 11 national methadone clinics in the Yi Autonomous Prefecture from March 2004 to December 2012 were collected from the national database. Several spatial regression models were used to analyze specific community characteristics associated with the prevalence of HIV and HCV infection at the township level. The study enrolled 6,417 adult patients. The prevalence of HIV infection, HCV infection and co-infection was 25.4%, 30.9%, and 11.0%, respectively. Prevalence exhibited stark geographical variations in the area studied. The four regression models showed Yi ethnicity to be associated with both the prevalence of HIV and of HIV/HCV co-infection. The male drug users in some northwestern counties had greater odds of being infected with HIV than female drug users, but the opposite was observed in some eastern counties. The ‘being in drug rehabilitation variable was found to be positively associated with prevalence of HCV infection in some southern townships, however, it was found to be negatively associated with it in some northern townships.
The spatial modeling creates better representations of data such that public health interventions must focus on areas with high frequency of HIV/HCV to prevent further transmission of both HIV and HCV.
PMCID: PMC3970964  PMID: 24687006
22.  Nanoparticle-assisted high photoconductive gain in polymer/fullerene matrix 
Nature nanotechnology  2008;3(9):543-547.
Polymer/inorganic nanocrystal composites1–10 offer an attractive means to combine the merits of organic and inorganic materials into novel electronic and photonic systems. However, many applications of these composites are limited by the solubility11 and distribution of nanocrystals (NCs) in polymer matrices. Here, a high photoconductive gain has been achieved by blending cadmium telluride (CdTe) nanoparticles (NPs) into a polymer/fullerene matrix followed by a solvent annealing12 process. The NP surface capping ligand, N-phenyl-N’-methyldithiocarbamate, renders the NPs highly soluble in the polymer blend thereby enabling high nanocrystal loadings. An external quantum efficiency (EQE) as high as ~8000% (at 350nm) is reached at −4.5V. Hole-dominant devices coupled with AFM images are studied to uncover the probable mechanism. We observe a higher concentration of CdTe NPs is located near the cathode/polymer interface. These NPs with trapped electrons assist hole injection into the polymer under reverse bias, which contributes to greater than 100% EQE.
PMCID: PMC3966304  PMID: 18772915
CdTe; nanoparticles; quantum dots; polymer photodetector; photoconductive gain; nanocrystal composites
23.  The Relationship between Seven Common Polymorphisms from Five DNA Repair Genes and the Risk for Breast Cancer in Northern Chinese Women 
PLoS ONE  2014;9(3):e92083.
Converging evidence supports the central role of DNA damage in progression to breast cancer. We therefore in this study aimed to assess the potential interactions of seven common polymorphisms from five DNA repair genes (XRCC1, XRCC2, XRCC3, XPA and APEX1) in association with breast cancer among Han Chinese women.
Methodology/Principal Findings
This was a case-control study involving 606 patients diagnosed with sporadic breast cancer and 633 age- and ethnicity-matched cancer-free controls. The polymerase chain reaction - ligase detection reaction method was used to determine genotypes. All seven polymorphisms were in accordance with Hardy-Weinberg equilibrium in controls. Differences in the genotypes and alleles of XRCC1 gene rs25487 and XPA gene rs1800975 were statistically significant between patients and controls, even after the Bonferroni correction (P<0.05/7). Accordingly, the risk for breast cancer was remarkably increased for rs25487 (OR = 1.28; 95% CI: 1.07–1.51; P = 0.006), but decreased for rs1800975 (OR = 0.77; 95% CI: 0.67–0.90; P = 0.001) under an additive model at a Bonferroni corrected alpha of 0.05/7. Allele combination analysis showed higher frequencies of the most common combination C-G-G-C-G-G-G (alleles in order of rs1799782, rs25487, rs3218536, rs861539, rs1800975, rs1760944 and rs1130409) in controls than in patients (PSim = 0.002). In further interaction analysis, two-locus model including rs1800975 and rs25487 was deemed as the overall best model with the maximal testing accuracy of 0.654 and the cross-validation consistency of 10 out of 10 (P = 0.001).
Our findings provide clear evidence that XRCC1 gene rs25487 and XPA gene rs1800975 might exert both independent and interactive effects on the development of breast cancer among northern Chinese women.
PMCID: PMC3958445  PMID: 24642895
24.  Effects of THAP11 on Erythroid Differentiation and Megakaryocytic Differentiation of K562 Cells 
PLoS ONE  2014;9(3):e91557.
Hematopoiesis is a complex process regulated by sets of transcription factors in a stage-specific and context-dependent manner. THAP11 is a transcription factor involved in cell growth, ES cell pluripotency, and embryogenesis. Here we showed that THAP11 was down-regulated during erythroid differentiation but up-regulated during megakaryocytic differentiation of cord blood CD34+ cells. Overexpression of THAP11 in K562 cells inhibited the erythroid differentiation induced by hemin with decreased numbers of benzidine-positive cells and decreased mRNA levels of α-globin (HBA) and glycophorin A (GPA), and knockdown of THAP11 enhanced the erythroid differentiation. Conversely, THAP11 overexpression accelerated the megakaryocytic differentiation induced by phorbol myristate acetate (PMA) with increased percentage of CD41+ cells, increased numbers of 4N cells, and elevated CD61 mRNA levels, and THAP11 knockdown attenuated the megakaryocytic differentiation. The expression levels of transcription factors such as c-Myc, c-Myb, GATA-2, and Fli1 were changed by THAP11 overexpression. In this way, our results suggested that THAP11 reversibly regulated erythroid and megakaryocytic differentiation.
PMCID: PMC3956667  PMID: 24637716
25.  Transcriptome profiling of the cold response and signaling pathways in Lilium lancifolium 
BMC Genomics  2014;15:203.
Lilium lancifolium, a very important cold-resistant wild flower for lily cold resistance breeding, is widely distributed in southwestern and northeastern China. To gain a better understanding of the cold signaling pathway and the molecular metabolic reactions involved in the cold response, we performed a genome-wide transcriptional analysis using RNA-Seq.
Approximately 104,703 million clean 90- bp paired-end reads were obtained from three libraries (CK 0 h, Cold-treated 2 h and 16 h at 4°C); 18,736 unigenes showed similarity to known proteins in the Swiss-Prot protein database, and 15,898, 13,705 and 1849 unigenes aligned to existing sequences in the KEGG and COG databases (comprising 25 COG categories) and formed 12 SOM clusters, respectively. Based on qRT-PCR results, we studied three signal regulation pathways —the Ca2+ and ABA independent/dependent pathways —that conduct cold signals to signal transduction genes such as LlICE and LlCDPK and transcription factor genes such as LlDREB1/CBF, LlAP2/EREBP, LlNAC1, LlR2R3-MYB and LlBZIP, which were expressed highly in bulb. LlFAD3, Llβ-amylase, LlP5CS and LlCLS responded to cold and enhanced adaptation processes that involve changes in the expression of transcripts related to cellular osmoprotectants and carbohydrate metabolism during cold stress.
Our study of differentially expressed genes involved in cold-related metabolic pathways and transcription factors facilitated the discovery of cold-resistance genes and the cold signal transcriptional networks, and identified potential key components in the regulation of the cold response in L lancifolium, which will be most beneficial for further research and in-depth exploration of cold-resistance breeding candidate genes in lily.
PMCID: PMC4003810  PMID: 24636716
Lilium lancifolium; RNA-Seq; Transcriptome; Cold response; Signaling pathway; Biochemical mechanism

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