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1.  Toll-like receptor and inflammasome signals converge to amplify the innate bactericidal capacity of T helper-1 cells 
Immunity  2014;40(2):213-224.
T cell effector functions can be elicited by non-cognate stimuli, but the mechanism and contribution of this pathway to the resolution of intracellular-macrophage infections has not been defined. Here we have shown that CD4+ T helper-1 (Th1) cells can be rapidly stimulated by microbe-associated molecular patterns (MAMPs) during active infection with Salmonella or Chlamydia. Further, maximal stimulation of Th1 cells by lipopolysaccharide (LPS) did not require T cell-intrinsic expression of toll-like receptor-4 (TLR4), interleukin-1 receptor (IL-1R), or interferon-γ receptor (IFN–γR), but instead required the adaptor protein Myd88, IL-18R, and IL-33R. Innate stimulation of Th1 cells also required host expression of TLR4 and inflammasome components that together increased serum concentrations of IL-18. Finally, the elimination of non-cognate Th1 cell stimulation hindered the resolution of primary Salmonella infection. Thus, the in vivo bactericidal capacity of Th1 cells is regulated by the response to non-cognate stimuli elicited by multiple innate immune receptors.
PMCID: PMC3960852  PMID: 24508233
2.  Parameters of Dynamic Contrast-Enhanced MRI as Imaging Markers for Angiogenesis and Proliferation in Human Breast Cancer 
Breast cancer is the most common malignancy and the leading cause of cancer death in women worldwide; however, early diagnosis has been difficult due to its complex pathological structure. This study evaluated the value of morphological examination in conjunction with dynamic contrast-enhanced MRI (DCE-MRI) for more precise diagnosis of breast cancer, as well as their correlation with angiogenesis and proliferation biomarkers.
DCE-MRI parameters (including Ktrans: volume transfer coefficient reflecting vascular permeability, Kep: flux rate constant, Ve: extracellular volume ratio reflecting vascular permeability, and ADC: apparent diffusion coefficient) were obtained from 124 patients with breast cancer (124 lesions). Microvessel density (MVD) was evaluated by the immunohistochemical analysis of tumor vessels for CD31 and CD105 expression. The proliferation was assessed by analyzing Ki67.
Ktrans values were in the order of: malignant lesions > benign lesions > normal glands. Similar results were observed for Kep. The opposite changes were seen with Ve. Ktrans and Kep values were significantly higher in invasive ductal carcinoma (IDC) and ductal carcinoma in situ (DCIS) than in mammary ductal dysplasia (MDD; ANOVA followed by Dunnett’s test). In sharp contrast, ADC values were lower in IDC and DCIS than in MDD, and Ve was not significantly different among the three groups. The data from MIP (maximum intensity projection) showed that benign breast lesions had no or only one blood vessel, whereas malignant lesions had two or more blood vessels. In addition, expression of CD105 and Ki67, the commonly recognized markers for angiogenesis and proliferation, respectively, were closely correlated with MRI parameters as revealed by Pearson analysis.
Determination of Ktrans, Kep and ADC values permits estimation of tumor angiogenesis and proliferation in breast cancer and DCE-MRI parameters can be used as imaging biomarkers to predict patient prognosis and the biologic aggressiveness of the tumor.
PMCID: PMC4324575  PMID: 25640082
Cell Proliferation; Magnetic Resonance Imaging; Neovascularization, Pathologic
3.  Sexual and Reproductive Health Knowledge, Contraception Uptake, and Factors Associated with Unmet Need for Modern Contraception among Adolescent Female Sex Workers in China 
PLoS ONE  2015;10(1):e0115435.
In China, policy and social taboo prevent unmarried adolescents from accessing sexual and reproductive health (SRH) services. Research is needed to determine the SRH needs of highly disadvantaged groups, such as adolescent female sex workers (FSWs). This study describes SRH knowledge, contraception use, pregnancy, and factors associated with unmet need for modern contraception among adolescent FSWs in Kunming, China.
A cross-sectional study using a one-stage cluster sampling method was employed to recruit adolescents aged 15 to 20 years, and who self-reported having received money or gifts in exchange for sex in the past 6 months. A semi-structured questionnaire was administered by trained peer educators or health workers. Multivariable logistic regression was conducted to determine correlates of low knowledge and unmet need for modern contraception.
SRH knowledge was poor among the 310 adolescents surveyed; only 39% had heard of any long-acting reversible contraception (implant, injection or IUD). Despite 98% reporting not wanting to get pregnant, just 43% reported consistent condom use and 28% currently used another form of modern contraception. Unmet need for modern contraception was found in 35% of adolescents, and was associated with having a current non-paying partner, regular alcohol use, and having poorer SRH knowledge. Past abortion was common (136, 44%). In the past year, 76% had reported a contraception consultation but only 27% reported ever receiving SRH information from a health service.
This study demonstrated a low level of SRH knowledge, a high unmet need for modern contraception and a high prevalence of unintended pregnancy among adolescent FSWs in Kunming. Most girls relied on condoms, emergency contraception, or traditional methods, putting them at risk of unwanted pregnancy. This study identifies an urgent need for Chinese adolescent FSWs to be able to access quality SRH information and effective modern contraception.
PMCID: PMC4307985  PMID: 25625194
4.  Absence of GJB2 gene mutations, the GJB6 deletion (GJB6-D13S1830) and four common mitochondrial mutations in nonsyndromic genetic hearing loss in a South African population 
The purpose of this study was to determine the prevalence of mutations in the GJB2 gene, the GJB6-D13S1830 deletion and the four common mitochondrial mutations (A1555G, A3243G, A7511C and A7445G) in a South African population.
Using single-strand conformation polymorphism and direct sequencing for screening GJB2 mutation; Multiplex PCR Amplification for GJB6-D13S1830 deletion and Restriction Fragment-Length Polymorphism (PCR-RFLP) analysis for the four common mtDNA mutations. We screened 182 hearing impaired students to determine the frequency of these mutations in the population.
None of the reported disease causing mutations in GJB2 nor any novel pathogenic mutations in the coding region were detected, in contrast to the findings among Caucasians. The GJB6-D13S1830 deletion and the mitochondrial mutations were not observed in this group.
These results suggest that GJB2 may not be a significant deafness gene among sub-Saharan Africans, pointing to other unidentified genes as responsible for nonsyndromic hearing loss in these populations.
PMCID: PMC4303037  PMID: 21392827
GJB2; GJB6-D13S1830; Molecular diagnosis; mtDNA mutations; Non-syndromic hearing loss; South African population
5.  Investment choice and perceived mating intentions regulated by external resource cues and internal fluctuation in blood glucose levels 
Frontiers in Psychology  2015;5:1523.
We examined resource allocation priorities in the framework of an updated Maslow hierarchy of fundamental human needs. In Experiment 1, the participants in the food abundance priming condition viewing photos of high-calorie food allocated more money to savings than to spending. However, the participants preferred spending to savings under the condition of mating availability priming with romantic photographs. In Experiment 2, before and after drinking either water or a sugary beverage, fasting participants rated photos of a conversation between a man and a woman. Water drinking lowered the rating scores of mating intentions as well as blood glucose (BG) levels. The sugary drink buffered this decline in sexual perceptivity. Overall, the change in BG levels was positively associated with changes in the ratings of mating intentions but was not associated with other likelihood ratings. These results suggest that both external cues of food and mating resources and internal BG fluctuation regulate the cognitive priority of physiological needs vs. mate acquisition and retention.
PMCID: PMC4284996  PMID: 25610412
resource allocation; blood glucose; hierarchy of needs; foraging; mating; life history
6.  Molecular Docking and Site-directed Mutagenesis of a Bacillus thuringiensis Chitinase to Improve Chitinolytic, Synergistic Lepidopteran-larvicidal and Nematicidal Activities 
Bacterial chitinases are useful in the biocontrol of agriculturally important pests and fungal pathogens. However, the utility of naturally occurring bacterial chitinases is often limited by their low enzyme activity. In this study, we constructed mutants of a Bacillus thuringiensis chitinase with enhanced activity based on homology modeling, molecular docking, and the site-directed mutagenesis of target residues to modify spatial positions, steric hindrances, or hydrophilicity/hydrophobicity. We first identified a gene from B. thuringiensis YBT-9602 that encodes a chitinase (Chi9602) belonging to glycosyl hydrolase family 18 with conserved substrate-binding and substrate-catalytic motifs. We constructed a structural model of a truncated version of Chi9602 (Chi960235-459) containing the substrate-binding domain using the homologous 1ITX protein of Bacillus circulans as the template. We performed molecular docking analysis of Chi960235-459 using di-N-acetyl-D-glucosamine as the ligand. We then selected 10 residues of interest from the docking area for the site-directed mutagenesis experiments and expression in Escherichia coli. Assays of the chitinolytic activity of the purified chitinases revealed that the three mutants exhibited increased chitinolytic activity. The ChiW50A mutant exhibited a greater than 60 % increase in chitinolytic activity, with similar pH, temperature and metal ion requirements, compared to wild-type Chi9602. Furthermore, ChiW50A exhibited pest-controlling activity and antifungal activity. Remarkable synergistic effects of this mutant with B. thuringiensis spore-crystal preparations against Helicoverpa armigera and Caenorhabditis elegans larvae and obvious activity against several plant-pathogenic fungi were observed.
PMCID: PMC4323370
Chitinase; Bacillus thuringiensis; Homology modeling; Molecular docking; Site-directed mutagenesis; Synergistic activity.
7.  Role of interleukin-22 in inflammatory bowel disease 
World Journal of Gastroenterology : WJG  2014;20(48):18177-18188.
Inflammatory bowel disease (IBD) is a chronic inflammatory disease thought to be mediated by the microbiota of the intestinal lumen and inappropriate immune responses. Aberrant immune responses can cause secretion of harmful cytokines that destroy the epithelium of the gastrointestinal tract, leading to further inflammation. Interleukin (IL)-22 is a member of the IL-10 family of cytokines that was recently discovered to be mainly produced by both adaptive and innate immune cells. Several cytokines and many of the transcriptional factors and T regulatory cells are known to regulate IL-22 expression through activation of signal transducer and activator of transcription 3 signaling cascades. This cytokine induces antimicrobial molecules and proliferative and antiapoptotic pathways, which help prevent tissue damage and aid in its repair. All of these processes play a beneficial role in IBD by enhancing intestinal barrier integrity and epithelial innate immunity. In this review, we discuss recent progress in the involvement of IL-22 in the pathogenesis of IBD, as well as its therapeutic potential.
PMCID: PMC4277955  PMID: 25561785
Inflammatory bowel disease; Interleukin-22; Signal transducer and activator of transcription 3
8.  Influenza Surveillance and Incidence in a Rural Area in China during the 2009/2010 Influenza Pandemic 
PLoS ONE  2014;9(12):e115347.
Most influenza surveillance is based on data from urban sentinel hospitals; little is known about influenza activity in rural communities. We conducted influenza surveillance in a rural region of China with the aim of detecting influenza activity in the 2009/2010 influenza season.
The study was conducted from October 2009 to March 2010. Real-time polymerase chain reaction was used to confirm influenza cases. Over-the-counter (OTC) drug sales were daily collected in drugstores and hospitals/clinics. Space-time scan statistics were used to identify clusters of ILI in community. The incidence rate of ILI/influenza was estimated on the basis of the number of ILI/influenza cases detected by the hospitals/clinics.
A total of 434 ILI cases (3.88% of all consultations) were reported; 64.71% of these cases were influenza A (H1N1) pdm09. The estimated incidence rate of ILI and influenza were 5.19/100 and 0.40/100, respectively. The numbers of ILI cases and OTC drug purchases in the previous 7 days were strongly correlated (Spearman rank correlation coefficient [r] = 0.620, P = 0.001). Four ILI outbreaks were detected by space-time permutation analysis.
This rural community surveillance detected influenza A (H1N1) pdm09 activity and outbreaks in the 2009/2010 influenza season and enabled estimation of the incidence rate of influenza. It also provides a scientific data for public health measures.
PMCID: PMC4277345  PMID: 25542003
9.  SC-III3, a novel scopoletin derivative, induces cytotoxicity in hepatocellular cancer cells through oxidative DNA damage and ataxia telangiectasia-mutated nuclear protein kinase activation 
BMC Cancer  2014;14:987.
Natural products from plants have been proven to be important resources of antitumor agents. In this study, we exploited the antitumor activity of (E)-3-(4-chlorophenyl)-N-(7-hydroxy-6-methoxy-2-oxo-2H-chromen-3-yl) acrylamide (SC-III3), a newly synthesized derivative of scopoletin, by in vitro and in vivo experiments.
Human hepatocellular carcinoma cell line HepG2 cells and xenograft of HepG2 cells in BALB/c nude mice were used to investigate the effects of SC-III3 on hepatocellular cancers. Cell cycle arrest and apoptosis were analyzed by flow cytometry. Cell cycle arrest, apoptosis and ATM-Chk pathway-related proteins were characterized by western blot.
SC-III3 selectively inhibited the viability of HepG2 cells without significant cytotoxicity against human normal liver cells LO2. In mouse xenograft model of HepG2 cells, SC-III3 showed a marked inhibition of tumor growth in a dose-dependent manner. Cell cycle analysis revealed that SC-III3 induced cells to accumulate in S phase, which was accompanied by a marked decrease of the expressions of cyclin A, cyclin B, cyclin E and Cdk2 proteins, the crucial regulators of S phase cell cycle. SC-III3 treatment resulted in DNA breaks in HepG2 cells, which might contribute to its S phase arrest. The S arrest and the activation of ATM-Chk1/Chk2-Cdc25A-Cdk2 pathways induced by SC-III3 in HepG2 cells could be efficiently abrogated by pretreatments of either Ku55933 (an inhibitor of ATM) or UCN-01 (an inhibitor of Chk1/Chk2). The activation of p53-p21 pathway by SC-III3 was also reversed by Ku55933 treatment. SC-III3 led to significant accumulation of intracellular reactive oxygen species (ROS), a breaker of DNA strand, in HepG2 cells but not LO2 cells. Pretreatment with N-acetyl-l-cysteine (NAC), a ROS scavenger, could reverse SC-III3-caused ROS accumulation, DNA damage, activation of signal pathways relevant to DNA damage, S phase arrest and cell viability decrease in HepG2 cells.
SC-III3 is able to efficiently inhibit the growth of hepatocellular carcinoma through inducing the generation of intracellular ROS, DNA damage and consequent S phase arrest, but lack of significant cytotoxicity against normal liver cells. This compound deserves further studies as a candidate of anticancer drugs.
PMCID: PMC4320555  PMID: 25527123
SC-III3; Hepatocellular cancer; ROS; DNA damage; Cell cycle arrest
11.  High-level SAE2 promotes malignant phenotype and predicts outcome in gastric cancer 
Background: The SUMO pathway has been shown to play an important role in tumorigenesis. This report analyzed the involvement of the sole SUMO-Activating Enzyme Subunit 2 (SAE2) in human gastric cancer (GC) progression and prognosis. Methods: Expression of SAE2 was examined by Quantigene Plex, western blotting and immunohistochemistry. The expression of SAE2 and c-MYC were detected in parallel in 276 cases. The molecular mechanisms of SAE2 expression and its effects on cell growth, colony formation, migration and invasion were also explored by CCK8 assay, colony formation experiment, transwell chamber assay with or without matrigel, immunoprecipitation and in vivo tumorigenesis and tumor metastasis. Results: SAE2 was markedly overexpressed in GC cell lines and primary tumor samples of GC, and significantly correlated with deeper tumor depth, distant metastasis, higher pathological stage and stratified survival in human GC. SAE2 positivity was independently associated with a worse outcome in multivariate analysis. Knockdown of SAE2 expression inhibited the proliferation, migration, and invasion of SAE2-overexpressing GC cells. Consistent with the in vitro results, down-regulation of SAE2 in human GC BGC823 cells significantly reduced the tumorigenic and metastatic potential of the cells in vivo. SAE2 protein was significantly associated with the higher expression of c-MYC in primary GC tissues. Moreover, FoxM1 was SUMOylated in GC and that inhibition of SAE2 resulted in a decrease in SUMO1-FoxM1 levels compared with those in the controls. Conclusions: These findings suggest that SAE2 has a pivotal role in the aggressiveness of GC, and highlight its usefulness as a prognostic factor in GC.
PMCID: PMC4300690  PMID: 25628926
SAE2; gastric cancer; prognosis; FoxM1; c-MYC
12.  The Basal Thermal Sensitivity of the TRPV1 Ion Channel Is Determined by PKCβII 
The Journal of Neuroscience  2014;34(24):8246-8258.
Peripheral nociceptors are excited by the activation of membrane receptors and ion channels. The heat-sensitive TRPV1 ion channel responds to various noxious chemical and thermal stimuli, causing pain and itch. Here, we show that TRPV1 is coexpressed with PKCβII in a subset of mouse sensory neurons and that, in these neurons, TRPV1 binds directly to PKCβII, leading to the activation and translocation of PKCβII. Activated PKCβII, in turn, significantly increases the responsiveness of TRPV1 by phosphorylating Thr705. The heat sensitivity of TRPV1 is almost eliminated by either knocking down PKCβII or mutating Thr705; however, neither of these manipulations affects the potentiation of TRPV1 caused by the activation of PKCε. PKCβII thus acts as an auxiliary subunit of TRPV1 by forming a population-dependent TRPV1 ion channel complex controlling the sensitivity of TRPV1 and setting the threshold for pain and itch.
PMCID: PMC4051976  PMID: 24920628
auxiliary subunit; pain; phosphorylation; PKC; TRP ion channels; TRPV1
13.  Understanding CELSRs - Cadherin EGF LAG seven-pass G-type receptors 
Journal of neurochemistry  2014;131(6):699-711.
The cadherin EGF LAG seven-pass G-type receptors (CELSRs) are a special subgroup of adhesion G protein-coupled receptors (GPCRs), which are pivotal regulators of many biological processes such as neuronal/endocrine cell differentiation, vessel valve formation and the control of planar cell polarity during embryonic development. All three members of the CELSR family (CELSR1-3) have large ecto-domains that form homophilic interactions and encompass more than 2,000 amino acids. Mutations in the ecto-domain or other gene locations of CELSRs are associated with neural tube defects (NTDs) and other diseases in humans. Celsr knockout (KO) animals have many developmental defects. Therefore, specific agonists or antagonists of CELSR members may have therapeutic potential. Although significant progress has been made regarding the functions and biochemical properties of CELSRs, our knowledge of these receptors is still lacking, especially considering that they are broadly distributed but have few characterized functions in a limited number of tissues. The dynamic activation and inactivation of CELSRs and the presence of endogenous ligands beyond homophilic interactions remain elusive, as do the regulatory mechanisms and downstream signaling of these receptors. Given this motivation, future studies with more advanced cell biology or biochemical tools, such as conditional KO mice, may provide further insights into the mechanisms underlying CELSR function, laying the foundation for the design of new CELSR-targeted therapeutic reagents.
PMCID: PMC4261025  PMID: 25280249
G Protein-Coupled Receptor (GPCR); Adhesion; CELSR; Development; Planar Cell Polarity (PCP)
14.  Genome-Wide Linkage Scan Identifies Two Novel Genetic Loci for Coronary Artery Disease: In GeneQuest Families 
PLoS ONE  2014;9(12):e113935.
Coronary artery disease (CAD) is the leading cause of death worldwide. Recent genome-wide association studies (GWAS) identified >50 common variants associated with CAD or its complication myocardial infarction (MI), but collectively they account for <20% of heritability, generating a phenomena of “missing heritability”. Rare variants with large effects may account for a large portion of missing heritability. Genome-wide linkage studies of large families and follow-up fine mapping and deep sequencing are particularly effective in identifying rare variants with large effects. Here we show results from a genome-wide linkage scan for CAD in multiplex GeneQuest families with early onset CAD and MI. Whole genome genotyping was carried out with 408 markers that span the human genome by every 10 cM and linkage analyses were performed using the affected relative pair analysis implemented in GENEHUNTER. Affected only nonparametric linkage (NPL) analysis identified two novel CAD loci with highly significant evidence of linkage on chromosome 3p25.1 (peak NPL  = 5.49) and 3q29 (NPL  = 6.84). We also identified four loci with suggestive linkage on 9q22.33, 9q34.11, 17p12, and 21q22.3 (NPL  = 3.18–4.07). These results identify novel loci for CAD and provide a framework for fine mapping and deep sequencing to identify new susceptibility genes and novel variants associated with risk of CAD.
PMCID: PMC4259362  PMID: 25485937
15.  Breast Cancer Redox Heterogeneity Detectable with Chemical Exchange Satruation Transfer (CEST) MRI 
Tissue redox state is an important mediator of various biological processes in health and diseases such as cancer. Previously, we discovered that the mitochondrial redox state of ex vivo tissues detected by redox scanning (an optical imaging method) revealed interesting tumor redox state heterogeneity that could differentiate tumor aggressiveness. Because the noninvasive chemical exchange saturation transfer (CEST) MRI can probe the proton transfer and generate contrasts from endogenous metabolites, we aim to investigate if the in vivo CEST contrast is sensitive to proton transfer of the redox reactions so as to reveal the tissue redox states in breast cancer animal models.
CEST MRI has been employed to characterize tumor metabolic heterogeneity and correlated with the redox states measured by the redox scanning in two human breast cancer mouse xenograft models, MDA-MB-231 and MCF-7. The possible biological mechanism on the correlation between the two imaging modalities was further investigated by phantom studies where the reductants and the oxidants of the representative redox reactions were measured.
The CEST contrast is found linearly correlated with NADH concentration and the NADH redox ratio with high statistical significance, where NADH is the reduced form of nicotinamide adenine dinucleotide. The phantom studies showed that the reductants of the redox reactions have more CEST contrast than the corresponding oxidants, indicating that higher CEST effect corresponds to the more reduced redox state.
This preliminary study suggests that CEST MRI, once calibrated, might provide a novel noninvasive imaging surrogate for the tissue redox state and a possible diagnostic biomarker for breast cancer in the clinic.
PMCID: PMC4251869  PMID: 24811957
Cancer metabolism; Redox state; Intratumor heterogeneity; CEST; NADH
16.  SUVR2 is involved in transcriptional gene silencing by associating with SNF2-related chromatin-remodeling proteins in Arabidopsis 
Cell Research  2014;24(12):1445-1465.
The SU(VAR)3-9-like histone methyltransferases usually catalyze repressive histone H3K9 methylation and are involved in transcriptional gene silencing in eukaryotic organisms. We identified a putative SU(VAR)3-9-like histone methyltransferase SUVR2 by a forward genetic screen and demonstrated that it is involved in transcriptional gene silencing at genomic loci targeted by RNA-directed DNA methylation (RdDM). We found that SUVR2 has no histone methyltransferase activity and the conserved catalytic sites of SUVR2 are dispensable for the function of SUVR2 in transcriptional silencing. SUVR2 forms a complex with its close homolog SUVR1 and associate with three previously uncharacterized SNF2-related chromatin-remodeling proteins CHR19, CHR27, and CHR28. SUVR2 was previously thought to be a component in the RdDM pathway. We demonstrated that SUVR2 contributes to transcriptional gene silencing not only at a subset of RdDM target loci but also at many RdDM-independent target loci. Our study suggests that the involvement of SUVR2 in transcriptional gene silencing is related to nucleosome positioning mediated by its associated chromatin-remodeling proteins.
PMCID: PMC4260354  PMID: 25420628
SUVR1; SUVR2; CHR19; DNA methylation; chromatin remodeling; transcriptional gene silencing
17.  Gypenosides Protected the Neural Stem Cells in the Subventricular Zone of Neonatal Rats that Were Prenatally Exposed to Ethanol 
Fetal alcohol spectrum disorder (FASD) can cause severe mental retardation in children who are prenatally exposed to ethanol. The effects of prenatal and early postnatal ethanol exposure on adult hippocampal neurogenesis have been investigated; however, the effects of prenatal ethanol exposure on the subventricular zone (SVZ) have not. Gypenosides (GPs) have been reported to have neuroprotective effects in addition to other bioactivities. The effects of GPs on neural stem cells (NSCs) in the FASD model are unknown. Here, we test the effect of prenatal ethanol exposure on the neonatal SVZ, and the protection potential of GPs on NSCs in FASD rats. Our results show that prenatal ethanol exposure can suppress the cell proliferation and differentiation of neural stem cells in the neonatal SVZ and that GPs (400 mg/kg/day) can significantly increase the cell proliferation and differentiation of neural stem cells inhibited by ethanol. Our data indicate that GPs have neuroprotective effects on the NSCs and can enhance the neurogenesis inhibited by ethanol within the SVZ of neonatal rats. These findings provide new evidence for a potential therapy involving GPs for the treatment of FASD.
PMCID: PMC4284688  PMID: 25464383
subventricular zone; cell proliferation; gypenosides; fetal alcohol spectrum disorder
18.  Regulation of spindle pole body assembly and cytokinesis by the centrin-binding protein Sfi1 in fission yeast 
Molecular Biology of the Cell  2014;25(18):2735-2749.
A previous model suggested doubling of Sfi1 as the first step of SPB assembly. Here it is shown that Sfi1 is gradually recruited to SPBs throughout the cell cycle. Conserved tryptophans in Sfi1 are required for its equal partitioning during mitosis, and unequal partitioning of Sfi1 underlies SPB assembly and mitotic defects in the next cell cycle.
Centrosomes play critical roles in the cell division cycle and ciliogenesis. Sfi1 is a centrin-binding protein conserved from yeast to humans. Budding yeast Sfi1 is essential for the initiation of spindle pole body (SPB; yeast centrosome) duplication. However, the recruitment and partitioning of Sfi1 to centrosomal structures have never been fully investigated in any organism, and the presumed importance of the conserved tryptophans in the internal repeats of Sfi1 remains untested. Here we report that in fission yeast, instead of doubling abruptly at the initiation of SPB duplication and remaining at a constant level thereafter, Sfi1 is gradually recruited to SPBs throughout the cell cycle. Like an sfi1Δ mutant, a Trp-to-Arg mutant (sfi1-M46) forms monopolar spindles and exhibits mitosis and cytokinesis defects. Sfi1-M46 protein associates preferentially with one of the two daughter SPBs during mitosis, resulting in a failure of new SPB assembly in the SPB receiving insufficient Sfi1. Although all five conserved tryptophans tested are involved in Sfi1 partitioning, the importance of the individual repeats in Sfi1 differs. In summary, our results reveal a link between the conserved tryptophans and Sfi1 partitioning and suggest a revision of the model for SPB assembly.
PMCID: PMC4161509  PMID: 25031431
19.  Gastric metastasis from sphenoid sinus melanoma: A case report 
Oncology Letters  2014;9(2):609-613.
Clinical reports of primary sphenoid sinus melanoma and isolated gastric metastatic melanoma are rare. Thus, to the best of our knowledge, the present study reports the first case of isolated gastric metastasis from a sphenoid sinus melanoma. The aim of the present study was to discuss the clinicopathological and radiographic characteristics, the treatment strategy and the prognosis of sphenoid sinus metastatic malignant melanoma of the stomach. Although almost 60% of patients who succumb to melanoma exhibit gastrointestinal metastases at autopsy, antemortem diagnosis is uncommon; this is predominantly due to gastric metastatic melanoma presenting with non-specific symptoms similar to other common gastrointestinal diseases. Gastrectomy may prolong overall survival and improve the quality of life for gastric metastatic melanoma patients, and the present case emphasizes the importance of palliative surgery in such cases.
PMCID: PMC4301530  PMID: 25624889
sphenoid sinus melanoma; gastric metastasis; gastrectomy
20.  Unusual synchronous skeletal muscle and lung metastasis in papillary thyroid cancer: A case report and review of the literature 
Oncology Letters  2014;9(2):727-730.
Papillary thyroid cancer (PTC) frequently metastasizes to the cervical lymph region and less often to the lung and bone. Metastasis to the skeletal muscles from PTC is extremely rare, especially concurrent lung and skeletal muscle metastases. The present study reports the case of a 31-year-old man with synchronous metastasis to the skeletal muscle and lung from PTC, six years following total thyroidectomy and consecutive 131Iodine treatments. Magnetic resonance imaging (MRI) revealed a 1.7×1.2×1.5 cm mass in the left gastrocnemius muscle, indicating a neurogenic tumor. The mass was subsequently resected and confirmed via histopathology to be metastatic PTC. We propose that, in the follow-up of patients with PTC, the measurable serum thyroglobulin level, whole body scan and other imaging modalities including MRI or positron emission tomography/computed tomography, must be closely monitored for potential distant metastases, particularly in cases of PTC with aggressive pathological behavior.
PMCID: PMC4301470  PMID: 25621043
papillary thyroid cancer; skeletal muscle metastasis; lung metastasis
21.  Structure and Specificity of the Bacterial Cysteine Methyltransferase Effector NleE Suggests a Novel Substrate in Human DNA Repair Pathway 
PLoS Pathogens  2014;10(11):e1004522.
Enteropathogenic E. coli (EPEC) and related enterobacteria rely on a type III secretion system (T3SS) effector NleE to block host NF-κB signaling. NleE is a first in class, novel S-adenosyl-L-methionine (SAM)-dependent methyltransferase that methylates a zinc-coordinating cysteine in the Npl4-like Zinc Finger (NZF) domains in TAB2/3 adaptors in the NF-κB pathway, but its mechanism of action and other human substrates are unknown. Here we solve crystal structure of NleE-SAM complex, which reveals a methyltransferase fold different from those of known ones. The SAM, cradled snugly at the bottom of a deep and narrow cavity, adopts a unique conformation ready for nucleophilic attack by the methyl acceptor. The substrate NZF domain can be well docked into the cavity, and molecular dynamic simulation indicates that Cys673 in TAB2-NZF is spatially and energetically favorable for attacking the SAM. We further identify a new NleE substrate, ZRANB3, that functions in PCNA binding and remodeling of stalled replication forks at the DNA damage sites. Specific inactivation of the NZF domain in ZRANB3 by NleE offers a unique opportunity to suggest that ZRANB3-NZF domain functions in DNA repair processes other than ZRANB3 recruitment to DNA damage sites. Our analyses suggest a novel and unexpected link between EPEC infection, virulence proteins and genome integrity.
Author Summary
Pathogens often manipulate host functions by posttranslational modifications such as ubiquitination and methylation. The NF-κB pathway is most critical for immune defense against infection, thereby frequently targeted by bacterial virulence factors. NleE, a virulence effector from EPEC, is a SAM-dependent methyltransferase that modifies a zinc-finger cysteine in TAB2/3 in the NF-κB pathway. NleE is not homologous to any known methyltransferases. We present the crystal structure of SAM-bound NleE that shows a novel methyltransferase fold with a unique SAM-binding mode. Computational docking and molecular dynamics simulation illustrate a structural and chemical mechanism underlying NleE recognition of the NZF and catalyzing site-specific cysteine methylation. Subsequent substrate specificity analyses identify an N-terminal region in TAB3 required for efficient NleE recognition as well as another NZF protein ZRANB3 being a new substrate of NleE. NleE-catalyzed cysteine methylation also disrupts the ubiquitin chain-binding of ZRANB3-NZF domain, providing new insights into ZRANB3-NZF functioning in DNA damage repair. These results reinforce the idea of harnessing bacterial effectors as a tool for dissecting eukaryotic functions.
PMCID: PMC4239114  PMID: 25412445
22.  Recurrent abdominal pain and fever as clinical manifestations: epiploic appendagitis 
Epiploic appendagitis is a relatively rare disease which includes primary and secondary types. Typical manifestations of Primary Epiploic Appendagitis (PEA) are similar to appendicitis except that it is not usually accompanied with fever or leucocytosis, thus misdiagnosis of diverticulitis or appendicitis in clinical settings is common. In this study, we presented a case study of a patient diagnosed with PEA and recurrent abdominal pain and fever for four months The patient experienced persistent dull abdominal pain since four months age and after tolerating a recent episode of pain for two days, and developed a fewer of up to 39°C accompanied with chills. Clinical analysis and computed tomography (CT) were conducted to better understand PEA.
PMCID: PMC4276238  PMID: 25550980
Epiploic appendagitis; computed tomography; clinical manifestations
23.  Probability expression for changeable and changeless uncertainties: an implicit test 
Frontiers in Psychology  2014;5:1313.
“Everything changes and nothing remains still.”We designed three implicit studies to understand how people react or adapt to a rapidly changing world by testing whether verbal probability is better in expressing changeable uncertainty while numerical probability is better in expressing unchangeable uncertainty. We found that the “verbal-changeable” combination in implicit tasks was more compatible than the “numerical-changeable” combination. Furthermore, the “numerical-changeless” combination was more compatible than the “verbal-changeless” combination. Thus, a novel feature called “changeability” was proposed to describe the changeable nature of verbal probability. However, numerical probability is a better carrier of changeless uncertainty than verbal probability. These results extend the domain of probability predictions and enrich our general understanding of communication with verbal and numerical probabilities. Given that the world around us is constantly changing, this “changeability” feature may play a major role in preparing for uncertainty.
PMCID: PMC4230050  PMID: 25431566
verbal probability; numerical probability; changeable uncertainty; unchangeable uncertainty; changeability feature
24.  Sexually dimorphic genetic architecture of complex traits in a large-scale F2 cross in pigs 
It is common for humans and model organisms to exhibit sexual dimorphism in a variety of complex traits. However, this phenomenon has rarely been explored in pigs.
To investigate the genetic contribution to sexual dimorphism in complex traits in pigs, we conducted a sex-stratified analysis on 213 traits measured in 921 individuals produced by a White Duroc × Erhualian F2 cross. Of the 213 traits examined, 102 differed significantly between the two sexes (q value <0.05), which indicates that sex is an important factor that influences a broad range of traits in pigs. We compared the estimated heritability of these 213 traits between males and females. In particular, we found that traits related to meat quality and fatty acid composition were significantly different between the two sexes, which shows that genetic factors contribute to variation in sexual dimorphic traits. Next, we performed a genome-wide association study (GWAS) in males and females separately; this approach allowed us to identify 13.6% more significant trait-SNP (single nucleotide polymorphism) associations compared to the number of associations identified in a GWAS that included both males and females. By comparing the allelic effects of SNPs in the two sexes, we identified 43 significant sexually dimorphic SNPs that were associated with 22 traits; 41 of these 43 loci were autosomal. The most significant sexually dimorphic loci were found to be associated with muscle hue angle and Minolta a* values (which are parameters that reflect the redness of meat) and were located between 9.3 and 10.7 Mb on chromosome 6. A nearby gene i.e. NUDT7 that plays an important role in heme synthesis is a strong candidate gene.
This study illustrates that sex is an important factor that influences phenotypic values and modifies the effects of the genetic variants that underlie complex traits in pigs; it also emphasizes the importance of stratifying by sex when performing GWAS.
Electronic supplementary material
The online version of this article (doi:10.1186/s12711-014-0076-2) contains supplementary material, which is available to authorized users.
PMCID: PMC4221709  PMID: 25374066
25.  G-Bean: an ontology-graph based web tool for biomedical literature retrieval 
BMC Bioinformatics  2014;15(Suppl 12):S1.
Currently, most people use NCBI's PubMed to search the MEDLINE database, an important bibliographical information source for life science and biomedical information. However, PubMed has some drawbacks that make it difficult to find relevant publications pertaining to users' individual intentions, especially for non-expert users. To ameliorate the disadvantages of PubMed, we developed G-Bean, a graph based biomedical search engine, to search biomedical articles in MEDLINE database more efficiently.
G-Bean addresses PubMed's limitations with three innovations: (1) Parallel document index creation: a multithreaded index creation strategy is employed to generate the document index for G-Bean in parallel; (2) Ontology-graph based query expansion: an ontology graph is constructed by merging four major UMLS (Version 2013AA) vocabularies, MeSH, SNOMEDCT, CSP and AOD, to cover all concepts in National Library of Medicine (NLM) database; a Personalized PageRank algorithm is used to compute concept relevance in this ontology graph and the Term Frequency - Inverse Document Frequency (TF-IDF) weighting scheme is used to re-rank the concepts. The top 500 ranked concepts are selected for expanding the initial query to retrieve more accurate and relevant information; (3) Retrieval and re-ranking of documents based on user's search intention: after the user selects any article from the existing search results, G-Bean analyzes user's selections to determine his/her true search intention and then uses more relevant and more specific terms to retrieve additional related articles. The new articles are presented to the user in the order of their relevance to the already selected articles.
Performance evaluation with 106 OHSUMED benchmark queries shows that G-Bean returns more relevant results than PubMed does when using these queries to search the MEDLINE database. PubMed could not even return any search result for some OHSUMED queries because it failed to form the appropriate Boolean query statement automatically from the natural language query strings. G-Bean is available at
G-Bean addresses PubMed's limitations with ontology-graph based query expansion, automatic document indexing, and user search intention discovery. It shows significant advantages in finding relevant articles from the MEDLINE database to meet the information need of the user.
PMCID: PMC4243180  PMID: 25474588

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