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1.  Changes in Nitric Oxide, cGMP, and Nitrotyrosine Concentrations Over Skin Along the Meridians in Obese Subjects 
Obesity (Silver Spring, Md.)  2010;19(8):1560-1567.
The purposes of these studies were to quantify the concentrations of total nitrate and nitrite (NOx−) cyclic guanosine monophosphate (cGMP), and nitrotyrosine over skin surface in normal weight healthy volunteers (n = 64) compared to overweight/obese subjects (n = 54). A semicircular plastic tube was taped to the skin along acupuncture points (acupoints), meridian line without acupoint (MWOP), and nonmeridian control and filled with a 2-Phenyl-4,4,5,5-tetramethylimidazoline-3-oxide-1-oxyl solution for 20 min. The concentrations of NOx−, cGMP, and nitrotyrosine in the samples were quantified in a blinded fashion using chemiluminescence and enzyme-linked immunosorbent assay, respectively. In normal weight healthy volunteers, NOx− and cGMP concentrations were consistently increased over the pericardium meridian (PC) 4–7 compared with nonmeridian areas. NOx− concentration is enhanced over the bladder meridian (BL) 56–57, but cGMP level is similar between the regions. In overweight/obese subjects, NOx− contents were increased or tended to be elevated over PC and BL regions. cGMP is paradoxically decreased over PC acupoints and nonmeridian control on the forearm but the decreases were blunted along BL regions on the leg. Nitrotyrosine concentrations are markedly elevated (five- to sixfold) over both PC and BL in all areas of overweight/obese subjects. This is the first evidence showing that nitrotyrosine level is tremendously elevated over skin accompanied by paradoxical changes in nitric oxide (NO)-cGMP concentrations over PC skin region in overweight/obese subject. The results suggest that NO-related oxidant inflammation is systemically enhanced while cGMP generation is impaired over PC skin region but not over BL region in obesity.
doi:10.1038/oby.2010.294
PMCID: PMC3584154  PMID: 21151015
2.  Critical Role of Connexin 43 in Secondary Expansion of Traumatic Spinal Cord Injury 
Spinal cord injury (SCI) is often complicated by secondary injury as a result of the innate inflammatory response to tissue trauma and swelling. Previous studies have shown that excessive ATP release from peritraumatic regions contributes to the inflammatory response to SCI by activation of low-affinity P2X7 receptors. Because connexin hemichannels constitute an important route for astrocytic ATP release, we here evaluated the impact on post-traumatic ATP release of deletion of connexins (Cx30/Cx43) in astrocytes. In vivo bioluminescence imaging showed a significant reduction in ATP release after weight-drop injury in mice with deletion of Cx43 compared with Cx43-expressing littermates, both on a Cx30 knockout background. Moreover, astrogliosis and microglia activation were reduced in peritraumatic areas of those mice lacking Cx43; motor recovery was also significantly improved, and the traumatic lesion was smaller. Combined, these observations are consistent with a contribution by astrocytic hemichannels to post-traumatic ATP release that aggravates secondary injury and restrains functional recovery after experimental spinal cord injury. Connexins may thereby constitute a new therapeutic target in spinal cord injury.
doi:10.1523/JNEUROSCI.1216-11.2012
PMCID: PMC3569730  PMID: 22399755
3.  Expression of Inhibin-Alpha Is Regulated Synergistically by Wilms' Tumor Gene 1 (Wt1) and Steroidogenic Factor-1 (Sf1) in Sertoli Cells 
PLoS ONE  2013;8(1):e53140.
Wt1 encodes a zinc finger nuclear transcriptional factor, which is specifically expressed in testicular Sertoli cells and knockdown of Wt1 in Sertoli cells causes male mice subfertility. However, the underlying mechanism is still unclear. In this study, we found that expression of inhibin-α is significantly reduced in Wt1-deficient Sertoli cells. Luciferase assays using the inhibin-α promoter indicated that the inhibin-α promoter is transactivated by the Wt1 A, and B isoforms (−KTS), but not the C, and D isoforms (+KTS). Analysis of the Wt1 responsive element of the inhibin-α promoter region using site-directed mutagenesis showed that the nucleotides between −58 and −49 are essential for Wt1-dependent transactivation of the inhibin-α promoter. ChIP assays indicated that Wt1 directly interacts with the inhibin-α promoter. In addition, the inhibin-α promoter is activated synergistically by Wt1 and Sf1. Mutation of the ligand binding domain (LBD) of Sf1 (residues 235–238) completely abolished the synergistic action between Wt1 and Sf1, but did not affect the physical interaction between these two proteins, suggesting that other factor(s) may also be involved in the regulation of inhibin-α in Sertoli cells. Further studies demonstrated that β-catenin enhances the synergistic activation of Wt1 and Sf1 on the inhibin-α promoter. Given the fact that inhibin-α, a subunit of inhibin, is known to be involved in the regulation of spermatogenesis and testicular steroidogenesis, this study reveals a new regulatory mechanism of inhibin-α in Sertoli cells and also sheds light on the physiological functions of Wt1 in gonad development and spermatogenesis.
doi:10.1371/journal.pone.0053140
PMCID: PMC3543449  PMID: 23326390
4.  Variation in Dicer Gene Is Associated with Increased Survival in T-Cell Lymphoma 
PLoS ONE  2012;7(12):e51640.
Dicer, an endonuclease in RNase III family, is essential for the RNA interference (RNAi) pathway. Aberrant expression of Dicer has been shown in various cancers including some subtypes of T cell lymphoma (TCL), which influences patient prognosis. A single-nucleotide polymorphism (SNP) rs3742330A>G has been identified in the Dicer gene, located in the 3′ untranslated region (3′ UTR) that is important for mRNA transcript stability. We investigated whether rs3742330 is associated with the survival in 163 TCL patients. Significant association between Dicer rs3742330 and TCL survival were found. Patients carrying the GG genotype (n = 12) had a significantly increased overall survival (OS) compared with those carrying the GA and AA genotypes (n = 70 and n = 81, respectively; p = 0.031). Moreover, the significant association was maintained for patients with mature T type (n = 134; p = 0.026). In multivariate Cox-regression analysis, rs3742330 proved to be an independent predictor for OS, together with the commonly used International Prognostic Index (IPI) and BAFF rs9514828, another SNP we have previously reported to be associated with TCL survival, with hazard ratios (HRs) for patient death rate of 8.956 (95% CI, 1.210 to 66.318; p = 0.032) for the GA genotype and 10.145 (95% CI, 1.371 to 75.084; p = 0.023) for the AA genotype. Furthermore, we observed cumulative effects of Dicer rs3742330 and BAFF rs9514828 on TCL survival. Compared with patients carrying zero unfavorable genotype, those carrying one and two unfavorable genotypes had an increased risk of death with a HR of 7.104 (95% CI, 0.969–53.086; p = 0.054) and 14.932 (95% CI, 1.950–114.354; p = 0.009), respectively, with a significant dose-response trend (ptrend  = 0.004). In conclusion, Dicer rs3742330 is associated with TCL survival, suggesting that genetic variation might play a role in predicting prognosis of TCL patients.
doi:10.1371/journal.pone.0051640
PMCID: PMC3518478  PMID: 23251602
5.  Degradation and osteogenic potential of a novel poly(lactic acid)/nano-sized β-tricalcium phosphate scaffold 
The purpose of this study was to investigate the influence of nano-sized β-tricalcium phosphate (β-TCP) on the biological performance of poly (lactic acid) (PLA) composite scaffolds by using in vitro degradation and an in vivo model of heterotopic bone formation. Nano-sized β-TCP (nβ-TCP) was prepared with a wet grinding method from micro-sized β-TCP (mβ-TCP), and composite scaffolds containing 0, 10, 30, or 50 wt% nβ-TCP or 30 wt% mβ-TCP were generated using a freeze-drying method. Degradation was assessed by monitoring changes in microstructure, pH, weight, and compressive strength over a 26-week period of hydrolysis. Composite scaffolds were processed into blocks, and implanted into muscular pockets of rabbits after loading with recombinant human bone morphogenetic protein-2 (rhBMP-2). New bone formation was evaluated based on histological and immunohistochemical analysis 2, 4, and 8 weeks after implantation. The in vitro results indicated that the buffering effect of nβ-TCP was stronger than mβ-TCP, which was positively correlated with the content of nβ-TCP. The in vivo findings demonstrated that nβ-TCP enhanced the osteoconductivity of the scaffolds. Although composite scaffolds containing 30% nβ-TCP exhibited similar osteoconductivity to 50% nβ-TCP, they had better mechanical properties than the 50% nβ-TCP scaffolds. This study supports the potential application of a composite scaffold containing 30% nβ-TCP as a promising scaffold for bone regeneration.
doi:10.2147/IJN.S38127
PMCID: PMC3513910  PMID: 23226019
poly (lactic acid); β-tricalcium phosphate; biodegradation; porous scaffold; bone regeneration
6.  Biomechanical stability of a bioabsorbable self-retaining polylactic acid/nano-sized β-tricalcium phosphate cervical spine interbody fusion device in single-level anterior cervical discectomy and fusion sheep models 
Purpose
The aim of this study was to investigate the biomechanical stability provided by a novel, polylactic acid/nano-sized, β-tricalcium phosphate, bioabsorbable, self-retaining cervical fusion cage (BCFC).
Methods
Quasistatic nonconstraining torques (maximum 1.5 NM) induced flexion, extension, lateral bending (±1.5 NM), and axial rotation (±1.5 NM) on 32 sheep cervical spines (C2–C5). The motion segment C3–C4 was first tested intact; the following groups were tested after complete discectomy: autologous tricortical iliac crest bone graft, Medtronic–Wego polyetheretherketone (PEEK) cage, Solis PEEK cage, and BCFC. The autologous bone graft group was tested with an anterior plate. The mean range of motion (ROM) was calculated from the load-displacement curves.
Results
BCFC significantly decreased ROM in lateral bending and axial rotation compared to other implants, and no significant difference in ROM between two types of PEEK cages and BCFC could be observed in flexion and extension. Anterior cervical plate (ACP) significantly decreased ROM in flexion and extension, but no significant difference in ROM between BCFC and bone graft plus ACP could be determined in lateral bending and axial rotation.
Conclusion
The BCFC device showed better stability to autologous tricortical iliac crest bone graft and PEEK cages in single-level anterior cervical discectomy and fusion models and thus may be a potential alternative to the current PEEK cages.
doi:10.2147/IJN.S38288
PMCID: PMC3512541  PMID: 23226018
biomechanics; cervical spine; cages; bioabsorbable; sheep
7.  Differential Expression of Anthocyanin Biosynthetic Genes and Transcription Factor PcMYB10 in Pears (Pyrus communis L.) 
PLoS ONE  2012;7(9):e46070.
Anthocyanin biosynthesis in various plants is affected by environmental conditions and controlled by the transcription level of the corresponding genes. In pears (Pyrus communis cv. ‘Wujiuxiang’), anthocyanin biosynthesis is significantly induced during low temperature storage compared with that at room temperature. We further examined the transcriptional levels of anthocyanin biosynthetic genes in ‘Wujiuxiang’ pears during developmental ripening and temperature-induced storage. The expression of genes that encode flavanone 3-hydroxylase, dihydroflavonol 4-reductase, anthocyanidin synthase, UDP-glucose: flavonoid 3-O-glucosyltransferase, and R2R3 MYB transcription factor (PcMYB10) was strongly positively correlated with anthocyanin accumulation in ‘Wujiuxiang’ pears in response to both developmental and cold-temperature induction. Hierarchical clustering analysis revealed the expression patterns of the set of target genes, of which PcMYB10 and most anthocyanin biosynthetic genes were related to the same cluster. The present work may help explore the molecular mechanism that regulates anthocyanin biosynthesis and its response to abiotic stress at the transcriptional level in plants.
doi:10.1371/journal.pone.0046070
PMCID: PMC3460990  PMID: 23029391
8.  Enhanced Intestinal Absorption of Daidzein by Borneol/Menthol Eutectic Mixture and Microemulsion 
AAPS PharmSciTech  2011;12(4):1044-1049.
In the present study, the effect of a borneol/menthol eutectic mixture (25:75) and microemulsion on the absorption of daidzein in rat intestinal membrane was evaluated. The microemulsion formulation was composed of ethyl oleate (oil), Cremophor RH40 (surfactant), PEG400 (co-surfactant), and water. The borneol/menthol eutectic mixture and its microemulsion were found to enhance the intestinal absorption of daidzein in vitro. A diffusion chamber system with isolated rat intestinal membranes was used. In contrast, verapamil (0.3 mM), a typical P-glycoprotein inhibitor, showed no effect on the absorption of daidzein by this system. A pharmacokinetic study was conducted in rats. After oral administration of daidzein at a dose of 10 mg/kg in the form of either borneol/menthol eutectic mixtures or suspension, the relative bioavailability of borneol/menthol eutectic mixtures and microemulsion was enhanced by about 1.5- and 3.65-fold, respectively, compared with a daidzein suspension. In conclusion, a borneol/menthol eutectic mixture can enhance the absorption of daidzein, although the mechanism of absorption enhancement is still unclear.
doi:10.1208/s12249-011-9672-4
PMCID: PMC3225554  PMID: 21842308
absorption enhancer; bioavailability; borneol/menthol eutectic mixture; daidzein; microemulsion
9.  Decreased Expression of the ARID1A Gene Is Associated with Poor Prognosis in Primary Gastric Cancer 
PLoS ONE  2012;7(7):e40364.
Background
The ARID1A gene encodes adenine-thymine (AT)-rich interactive domain-containing protein 1A, which participates in chromatin remodeling. ARID1A has been showed to function as a tumor suppressor in various cancer types. In the current study, we investigated the expression and prognosis value of ARID1A in primary gastric cancer. Meanwhile, the biological role of ARID1A was further investigated using cell model in vitro.
Methodology/Principal Findings
To investigate the role of ARID1A gene in primary gastric cancer pathogenesis, real-time quantitative PCR and western blotting were used to examine the ARID1A expression in paired cancerous and noncancerous tissues. Results revealed decreased ARID1A mRNA (P = 0.0029) and protein (P = 0.0015) expression in most tumor-bearing tissues compared with the matched adjacent non-tumor tissues, and in gastric cancer cell lines. To further investigate the clinicopathological and prognostic roles of ARID1A expression, we performed immunohistochemical analyses of the 224 paraffin-embedded gastric cancer tissue blocks. Data revealed that the loss of ARID1A expression was significantly correlated with T stage (P = 0.001) and grade (P = 0.006). Consistent with these results, we found that loss of ARID1A expression was significantly correlated with poor survival in gastric cancer patients (P = 0.003). Cox regression analyses showed that ARID1A expression was an independent predictor of overall survival (P = 0.029). Furthermore, the functions of ARID1A in the proliferation and colony formation of gastric cell lines were analyzed by transfecting cells with full-length ARID1A expression vector or siRNA targeting ARID1A. Restoring ARID1A expression in gastric cancer cells significantly inhibited cell proliferation and colony formation. Silencing ARID1A expression in gastric epithelial cell line significantly enhanced cell growth rate.
Conclusions/Significance
Our data suggest that ARID1A may play an important role in gastric cancer and may serve as a valuable prognostic marker and potential target for gene therapy in the treatment of gastric cancer.
doi:10.1371/journal.pone.0040364
PMCID: PMC3396657  PMID: 22808142
10.  Endoscopic surgery versus conservative treatment for the moderate-volume hematoma in spontaneous basal ganglia hemorrhage (ECMOH): study protocol for a randomized controlled trial 
BMC Neurology  2012;12:34.
Background
Spontaneous intracerebral hemorrhage is a disease with high morbidity, high disability rate, high mortality, and high economic burden. Whether patients can benefit from surgical evacuation of hematomas is still controversial, especially for those with moderate-volume hematomas in the basal ganglia. This study is designed to compare the efficacy of endoscopic surgery and conservative treatment for the moderate-volume hematoma in spontaneous basal ganglia hemorrhage.
Methods
Patients meet the criteria will be randomized into the endoscopic surgery group (endoscopic surgery for hematoma evacuation and the best medical treatment) or the conservative treatment group (the best medical treatment). Patients will be followed up at 1, 3, and 6 months after initial treatment. The primary outcomes include the Extended Glasgow Outcome Scale and the Modified Rankin Scale. The secondary outcomes consist of the National Institutes of Health Stroke Scale and the mortality. The Barthel Index(BI) will also be evaluated. The sample size is 100 patients.
Discussion
The ECMOH trial is a randomized controlled trial designed to evaluate if endoscopic surgery is better than conservative treatment for patients with moderate-volume hematomas in the basal ganglia.
Trial registration
Chinese Clinical Trial Registry: ChiCTR-TRC-11001614
(http://www.chictr.org/en/proj/show.aspx?proj=1618)
doi:10.1186/1471-2377-12-34
PMCID: PMC3481459  PMID: 22676908
Endoscopic surgery; Conservative treatment; Moderate-volume hematoma; Spontaneous basal ganglia hemorrhage
11.  2009 Pandemic H1N1 Influenza Virus Causes Disease and Upregulation of Genes Related to Inflammatory and Immune Responses, Cell Death, and Lipid Metabolism in Pigs▿ 
Journal of Virology  2011;85(22):11626-11637.
There exists limited information about whether adaptation is needed for cross-species transmission of the 2009 pandemic H1N1 influenza virus (pH1N1). Here, we compare the pathogenesis of two pH1N1 viruses, one derived from a human patient (A/CA/04/09 [CA09]) and the other from swine (A/swine/Alberta/25/2009 [Alb09]), with that of the 1918-like classical swine influenza virus (A/swine/Iowa/1930 [IA30]) in the pig model. Both pH1N1 isolates induced clinical symptoms such as coughing, sneezing, decreased activity, fever, and labored breathing in challenged pigs, but IA30 virus did not cause any clinical symptoms except fever. Although both the pH1N1 viruses and the IA30 virus caused lung lesions, the pH1N1 viruses were shed from the nasal cavities of challenged pigs whereas the IA30 virus was not. Global gene expression analysis indicated that transcriptional responses of the viruses were distinct. pH1N1-infected pigs had an upregulation of genes related to inflammatory and immune responses at day 3 postinfection that was not seen in the IA30 infection, and expression levels of genes related to cell death and lipid metabolism at day 5 postinfection were markedly different from those of IA30 infection. These results indicate that both pH1N1 isolates are more virulent due in part to differences in the host transcriptional response during acute infection. Our study also indicates that pH1N1 does not need prior adaptation to infect pigs, has a high potential to be maintained in naïve swine populations, and might reassort with currently circulating swine influenza viruses.
doi:10.1128/JVI.05705-11
PMCID: PMC3209293  PMID: 21900171
12.  Enhancement of cell recognition in vitro by dual-ligand cancer targeting gold naoparticles 
Biomaterials  2011;32(10):2540-2545.
A dual-ligand gold nanoparticle (DLGNP) was designed and synthesized to explore the therapeutic benefits of multivalent interactions between gold nanoparticles (GNPs) and cancer cells. DLGNP was tested on human epidermal cancer cells (KB), which had high expression of folate receptor. The cellular uptake of DLGNP was increased by 3.9 and 12.7 folds compared with GNP-folate or GNP-glucose. The enhanced cell recognition was due to multivalent interactions between both ligands on GNPs and cancer cells as shown by the ligand competition experiments. Furthermore, the multivalent interactions increased contrast between cells with high and low expression of folate receptors. The enhanced cell recognition enabled DLGNP to kill KB cells under X-ray irradiation at a dose that was safe to folate receptor low-expression (such as normal) cells. Thus DLGP has the potential to be a cancer-specific nano-theranostic agent.
doi:10.1016/j.biomaterials.2010.12.031
PMCID: PMC3038783  PMID: 21232787
13.  Identification of the Immunogenic Outer Membrane Protein A Antigen of Haemophilus parasuis by a Proteomics Approach and Passive Immunization with Monoclonal Antibodies in Mice ▿ 
Clinical and Vaccine Immunology : CVI  2011;18(10):1695-1701.
Monoclonal antibodies (MAbs) against Haemophilus parasuis were generated by fusing spleen cells from BALB/c mice immunized with whole bacterial cells with SP2/0 murine myeloma cells. Desirable hybridomas were screened by enzyme-linked immunosorbent assay (ELISA). Neutralizing MAb 1D8 was selected in protection assays. ELISA results demonstrated that 1D8 can react with all 15 serotypes of H. parasuis and field isolate H. parasuis HLJ-018. Passive immunization studies showed that mice inoculated intraperitoneally with 1D8 had significantly reduced prevalence of H. parasuis colonization in the blood, lung, spleen, and liver and had prolonged survival time compared to that of the control group. Furthermore, the passive transfer experiment indicated that MAb 1D8 can protect mice from both homologous and heterologous challenges with H. parasuis. Using two-dimensional gel electrophoresis (2-DE), the immunoreactive protein target for MAb 1D8 was identified. The data presented confirm the protective role of MAb 1D8 and identify OmpA as the target of the protective monoclonal antibody. The data suggest that OmpA is a promising candidate for a subunit vaccine against H. parasuis.
doi:10.1128/CVI.05223-11
PMCID: PMC3187029  PMID: 21832103
14.  Reducing Personal Exposure to Particulate Air Pollution Improves Cardiovascular Health in Patients with Coronary Heart Disease 
Environmental Health Perspectives  2012;120(3):367-372.
Background: Air pollution exposure increases cardiovascular morbidity and mortality and is a major global public health concern.
Objectives: We investigated the benefits of reducing personal exposure to urban air pollution in patients with coronary heart disease.
Methods: In an open randomized crossover trial, 98 patients with coronary heart disease walked on a predefined route in central Beijing, China, under different conditions: once while using a highly efficient face mask, and once while not using the mask. Symptoms, exercise, personal air pollution exposure, blood pressure, heart rate, and 12-lead electrocardiography were monitored throughout the 24-hr study period.
Results: Ambient air pollutants were dominated by fine and ultrafine particulate matter (PM) that was present at high levels [74 μg/m3 for PM2.5 (PM with aerodynamic diamater <2.5 µm)]. Consistent with traffic-derived sources, this PM contained organic carbon and polycyclic aromatic hydrocarbons and was highly oxidizing, generating large amounts of free radicals. The face mask was well tolerated, and its use was associated with decreased self-reported symptoms and reduced maximal ST segment depression (–142 vs. –156 μV, p = 0.046) over the 24-hr period. When the face mask was used during the prescribed walk, mean arterial pressure was lower (93 ± 10 vs. 96 ± 10 mmHg, p = 0.025) and heart rate variability increased (high-frequency power: 54 vs. 40 msec2, p = 0.005; high-frequency normalized power: 23.5 vs. 20.5 msec, p = 0.001; root mean square successive differences: 16.7 vs. 14.8 msec, p = 0.007). However, mask use did not appear to influence heart rate or energy expenditure.
Conclusions: Reducing personal exposure to air pollution using a highly efficient face mask appeared to reduce symptoms and improve a range of cardiovascular health measures in patients with coronary heart disease. Such interventions to reduce personal exposure to PM air pollution have the potential to reduce the incidence of cardiovascular events in this highly susceptible population.
doi:10.1289/ehp.1103898
PMCID: PMC3295351  PMID: 22389220
air pollution; blood pressure; face mask; heart rate variability; myocardial ischemia
15.  Comparison of physiological and yield traits between purple- and white-pericarp rice using SLs 
Breeding Science  2012;62(1):71-77.
Five physiological and eleven yield traits of two pairs of sister lines generated from a high generation with similar genetic background (SLs) for purple pericarp were investigated to explore the reasons behind low-yield production of colored rice. Of the five physiological traits examined, except grain anthocyanin content, there were generally similar trends between the P (purple-pericarp) lines and the corresponding W (white-pericarp) lines over two seasons (in the year 2009 and 2010 separately). The results demonstrated that the chlorophyll content of flag leaves, the net photosynthetic rate of flag leaves, and the grain anthocyanin content could be easily influenced by the environment. The physiological functions of the traits for the P lines were more active than those of the corresponding W lines in the year 2010. The grain anthocyanin content of the P lines was much greater in the year 2010 than in the year 2009 during the growth period. The investigation of yield traits revealed that the P lines had reduced 1000-grain weight, yield per plot and grain/brown rice thickness compared to the W lines. A difference comparison of these traits and a source-sink and transportation relationship analysis for these SLs suggested that small sink size was a key reason behind yield reduction of purple pericarp rice.
doi:10.1270/jsbbs.62.71
PMCID: PMC3405958  PMID: 23136516
rice (Oryza sativa L.); purple pericarp; SLs (sister lines generated from a high generation with similar genetic background); 1000-grain weight; anthocyanin
16.  Pathogenicity of swine influenza viruses possessing an avian or swine-origin PB2 polymerase gene evaluated in mouse and pig models 
Virology  2010;410(1):1-6.
PB2 627K is a determinant of influenza host range and contributes to the pathogenicity of human-, avian-, and mouse-adapted influenza viruses in the mouse model. Here we used mouse and pig models to analyze the contribution of a swine-origin and avian-origin PB2 carrying either 627K or 627E in the background of the classical swine H1N1 (A/Swine/Iowa/15/30; 1930) virus. The results showed PB2 627K is crucial for virulence in the mouse model, independent of whether PB2 is derived from an avian or swine influenza virus (SIV). In the pig model, PB2 627E decreases pathogenicity of the classical 1930 SIV when it contains the swine-origin PB2, but not when it possesses the avian-origin PB2. Our study suggests the pathogenicity of SIVs with different PB2 genes and mutation of codon 627 in mice does not correlate with the pathogenicity of the same SIVs in the natural host, the pig.
doi:10.1016/j.virol.2010.10.027
PMCID: PMC3033585  PMID: 21074235
swine influenza virus; PB2; pathogenicity
17.  RGD peptide-mediated chitosan-based polymeric micelles targeting delivery for integrin-overexpressing tumor cells 
Background
Solid tumors need new blood vessels to feed and nourish them as well as to allow tumor cells to escape into the circulation and lodge in other organs, which is termed “angiogenesis.” Some tumor cells within solid tumors can overexpress integrins αvβ3 and αvβ5, which can specifically recognize the peptide motif Arg-Gly-Asp (RGD). Thus, the targeting of RGD-modified micelles to tumor vasculature is a promising strategy for tumor-targeting treatment.
Methods
RGD peptide (GSSSGRGDSPA) was coupled to poly(ethylene glycol)-modified stearic acid-grafted chitosan (PEG-CS-SA) micelles via chemical reaction in the presence of N,N′-Disuccinimidyl carbonate. The critical micelle concentration of the polymeric micelles was determined by measuring the fluorescence intensity of pyrene as a fluorescent probe. The micelle size, size distribution, and zeta potential were measured by light scattering and electrophoretic mobility. Doxorubicin (DOX) was chosen as a model anticancer drug to investigate the drug entrapment efficiency, in vitro drug-release profile, and in vitro antitumor activities of drug-loaded RGD-PEG-CS-SA micelles in cells that overexpress integrins (ανβ3 and ανβ5) and integrin-deficient cells.
Results
Using DOX as a model drug, the drug encapsulation efficiency could reach 90%, and the in vitro drug-release profiles suggested that the micelles could be used as a controlled-release carrier for the hydrophobic drug. Qualitative and quantitative analysis of cellular uptake indicated that RGD-modified micelles could significantly increase the DOX concentration in integrin-overexpressing human hepatocellular carcinoma cell line (BEL-7402), but not in human epithelial carcinoma cell line (Hela). The competitive cellular-uptake test showed that the cellular uptake of RGD-modified micelles in BEL-7402 cells was significantly inhibited in the presence of excess free RGD peptides. In vitro cytotoxicity tests demonstrated DOX-loaded RGD-modified micelles could specifically enhance the cytotoxicity against BEL-7402 compared with DOX-loaded PEG-CS-SA and doxorubicin hydrochlorate.
Conclusion
This study suggests that RGD-modified PEG-CS-SA micelles are promising drug carriers for integrin-overexpressing tumor active targeting therapy.
doi:10.2147/IJN.S26670
PMCID: PMC3265222  PMID: 22282676
cellular uptake; chitosan polymeric micelles; cytotoxicity; doxorubicin; integrin; RGD peptide
18.  Automatic Identification of Functional Clusters in fMRI Data using Spatial Information 
In independent component analysis (ICA) of functional magnetic resonance imaging (fMRI) data, extracting a large number of maximally independent components provides a more refined functional segmentation of brain. However, such segmentation does not per se establish the relationships among different brain networks, and also selecting and classifying components can be challenging. In this work, we present a multidimensional ICA (MICA) scheme to achieve automatic component clustering. In this MICA framework, stable components are hierarchically grouped into clusters based on spatial information and higher-order statistics, instead of typically used temporal information and second-order correlation. The final cluster membership is determined using a statistical hypothesis testing method. The experimental results from both simulated and real fMRI data sets show that the use of only spatial information with higher-order statistics leads to physiologically meaningful dependence structure of brain networks, which is consistently identified across various ICA model orders and algorithms. In addition, we observe that components related to artifacts, including cerebrospinal fluid (CSF), arteries, and large draining veins, demonstrate a higher degree of dependence among them and encouragingly distinguished from other components of interest using our MICA approach.
doi:10.1109/TBME.2011.2167149
PMCID: PMC3222740  PMID: 21900068
Independent component analysis; multidimensional ICA; spatial dependence; hierarchical clustering; fMRI
19.  Bis[N-(pyridin-2-ylcarbon­yl)pyridine-2-carboxamidato]iron(III) perchlorate monohydrate 
The structure of the title salt complex, [Fe(C12H8N3O2)2]ClO4·H2O, contains one FeIII cation, two N-(pyridin-2-ylcarbon­yl)pyridine-2-carboxamidate (bpca−) anions, one perchlorate anion and one water mol­ecule. The FeIII cation has an approximate octa­hedral geometry, defined by six N atoms from two bpca− anions. The nearly parallel [dihedral angle = 1.50 (1)°] bpca− anions form two-dimensional supermolecules along the a axis by the way of weak π–π stacking inteactirons [centroid–centroid distances = 3.948 (2), 4.000 (2), 3.948 (2), 3.911 (2), 3.897 (2), 3.984 (2) and 3.929 (2) Å]. Intra- and inter­molecular C—H⋯O hydrogen bonding occurs. The water mol­ecule [occupancies 0.520 (5) and 0.480 (5)], two carbonyl O atoms [occupancies 0.622 (7) and 0.378 (7)] and the four perchlorate O atoms [occupancies 0.887 (4) and 0.113 (4)] are each disordered over two positions.
doi:10.1107/S1600536811047684
PMCID: PMC3238670  PMID: 22199561
20.  Bivariate Genome-Wide Association Analyses of Femoral Neck Bone Geometry and Appendicular Lean Mass 
PLoS ONE  2011;6(11):e27325.
Objective
Femoral neck geometric parameters (FNGPs), such as periosteal diameter (W), cross-sectional area (CSA), cortical thickness (CT), buckling ratio (BR), and section modulus (Z), are highly genetically correlated with body lean mass. However, the specific SNPs/genes shared by these phenotypes are largely unknown.
Methods
To identify the specific SNPs/genes shared between FNGPs and appendicular lean mass (ALM), we performed an initial bivariate genome-wide association study (GWAS) by scanning ∼690,000 SNPs in 1,627 unrelated Han Chinese adults (802 males and 825 females) and a follow-up replicate study in 2,286 unrelated US Caucasians.
Results
We identified 13 interesting SNPs that may be important for both FNGPs and ALM. Two SNPs, rs681900 located in the HK2 (hexokinase 2) gene and rs11859916 in the UMOD (uromodulin) gene, were bivariately associated with FNGPs and ALM (p = 7.58×10−6 for ALM-BR and p = 2.93×10−6 for ALM-W, respectively). The associations were then replicated in Caucasians, with corresponding p values of 0.024 for rs681900 and 0.047 for rs11859916. Meta-analyses yielded combined p values of 3.05×10−6 and 2.31×10−6 for rs681900 and rs11859916, respectively. Our findings are consistent with previous biological studies that implicated HK2 and UMOD in both FNGPs and ALM. Our study also identified a group of 11 contiguous SNPs, which spanned a region of ∼130 kb, were bivariately associated with FNGPs and ALM, with p values ranging from 3.06×10−7 to 4.60×10−6 for ALM-BR. The region contained two neighboring miRNA coding genes, MIR873 (MicroRNA873) and MIR876 (MicroRNA876).
Conclusion
Our study implicated HK2, UMOD, MIR873 and MIR876, as pleiotropic genes underlying variation of both FNGPs and ALM, thus suggesting their important functional roles in co-regulating both FNGPs and ALM.
doi:10.1371/journal.pone.0027325
PMCID: PMC3210160  PMID: 22087292
21.  Transcriptional activation of histone H4 by C/EBPβ during the mitotic clonal expansion of 3T3-L1 adipocyte differentiation 
Molecular Biology of the Cell  2011;22(13):2165-2174.
Histone H4 is activated by C/EBPβ in mitotic clonal expansion during adipogenesis. C/EBP-binding sites are identified in histone H4 promoters, and H4 expression is suppressed when C/EBPβ is knocked down or its DNA-binding activity is inhibited by A-C/EBP. These results help in our understanding of how C/EBPβ plays important roles in the proliferation of other cells.
CCAAT enhancer binding protein β (C/EBPβ) is required for both mitotic clonal expansion (MCE) and terminal differentiation during the 3T3-L1 adipocyte differentiation program. Whereas the mechanism of C/EBPβ during terminal differentiation is well understood, the mechanism of C/EBPβ in MCE is not. We provide evidence that histone H4, the most conserved cell cycle–related histone, the change of which is strictly correlated with DNA content change during the cell cycle, is transcriptionally activated by C/EBPβ during MCE. Expression of histone H4 is increased at 16 h after induction when 3T3-L1 preadipocytes synchronously reenter S phase, which is correlated with the sequential phosphorylation and activation of C/EBPβ, and expression was partially suppressed when A-C/EBP (dominant negative for C/EBP protein) was overexpressed. One C/EBP-binding site was identified in one of the histone H4 gene promoters (hist4h4), confirmed by both electrophoretic mobility shift assay and chromatin immunoprecipitation assay. C/EBP-binding sites were also found in 9 of 11 other histone H4 promoters, which can also be transactivated by C/EBPβ. Knockdown of C/EBPβ by stealth small interfering RNA partially decreased H4 gene expression and arrested cells in G1 phase as indicated by bromodeoxyuridine incorporation and fluorescence-activated cell sorting analysis of DNA content. This study provides new insights into why C/EBPβ is required for MCE during 3T3-L1 adipocyte differentiation and why C/EBPβ plays important roles in the proliferation of other cell types.
doi:10.1091/mbc.E10-11-0912
PMCID: PMC3128520  PMID: 21562223
22.  Copy Number Variation in CNP267 Region May Be Associated with Hip Bone Size 
PLoS ONE  2011;6(7):e22035.
Osteoporotic hip fracture (HF) is a serious global public health problem associated with high morbidity and mortality. Hip bone size (BS) has been identified as one of key measurable risk factors for HF, independent of bone mineral density (BMD). Hip BS is highly genetically determined, but genetic factors underlying BS variation are still poorly defined. Here, we performed an initial genome-wide copy number variation (CNV) association analysis for hip BS in 1,627 Chinese Han subjects using Affymetrix GeneChip Human Mapping SNP 6.0 Array and a follow-up replicate study in 2,286 unrelated US Caucasians sample. We found that a copy number polymorphism (CNP267) located at chromosome 2q12.2 was significantly associated with hip BS in both initial Chinese and replicate Caucasian samples with p values of 4.73E-03 and 5.66E-03, respectively. An important candidate gene, four and a half LIM domains 2 (FHL2), was detected at the downstream of CNP267, which plays important roles in bone metabolism by binding to several bone formation regulator, such as insulin-like growth factor-binding protein 5 (IGFBP-5) and androgen receptor (AR). Our findings suggest that CNP267 region may be associated with hip BS which might influence the FHL2 gene downstream.
doi:10.1371/journal.pone.0022035
PMCID: PMC3137628  PMID: 21789208
23.  Exome Sequencing Identifies ZNF644 Mutations in High Myopia 
PLoS Genetics  2011;7(6):e1002084.
Myopia is the most common ocular disorder worldwide, and high myopia in particular is one of the leading causes of blindness. Genetic factors play a critical role in the development of myopia, especially high myopia. Recently, the exome sequencing approach has been successfully used for the disease gene identification of Mendelian disorders. Here we show a successful application of exome sequencing to identify a gene for an autosomal dominant disorder, and we have identified a gene potentially responsible for high myopia in a monogenic form. We captured exomes of two affected individuals from a Han Chinese family with high myopia and performed sequencing analysis by a second-generation sequencer with a mean coverage of 30× and sufficient depth to call variants at ∼97% of each targeted exome. The shared genetic variants of these two affected individuals in the family being studied were filtered against the 1000 Genomes Project and the dbSNP131 database. A mutation A672G in zinc finger protein 644 isoform 1 (ZNF644) was identified as being related to the phenotype of this family. After we performed sequencing analysis of the exons in the ZNF644 gene in 300 sporadic cases of high myopia, we identified an additional five mutations (I587V, R680G, C699Y, 3′UTR+12 C>G, and 3′UTR+592 G>A) in 11 different patients. All these mutations were absent in 600 normal controls. The ZNF644 gene was expressed in human retinal and retinal pigment epithelium (RPE). Given that ZNF644 is predicted to be a transcription factor that may regulate genes involved in eye development, mutation may cause the axial elongation of eyeball found in high myopia patients. Our results suggest that ZNF644 might be a causal gene for high myopia in a monogenic form.
Author Summary
People with myopia see near objects more clearly than objects far away. Myopia is the most common ocular disorder worldwide, with a high prevalence in Asian (40%–70%) and Caucasian (20%–30%) populations. Although the etiologies of myopia have not yet been established, previous studies have indicated the involvement of genetic and environmental factors (such as close working habits, higher education levels, and higher socioeconomic class). Genetic factors play a critical role in the development of myopia, especially high myopia. In this study, we use exome sequencing, a powerful tool for a disease gene identification, to identify a gene involved in high myopia in a monogenic form among Han Chinese. Mutations in zinc finger protein 644 isoform 1 (ZNF644) were identified as potentially responsible for the phenotype of high myopia. The main feature of high myopia is axial elongation of the eye globe. Given that ZNF644 is predicted to be a transcription factor that may regulate genes involved in eye development, a mutant ZNF644 protein may impact the normal eye development and therefore may underlie the axial elongation of the eye globe in high myopia patients. Further study of the biological function of ZNF644 will provide insight into the pathogenesis of myopia.
doi:10.1371/journal.pgen.1002084
PMCID: PMC3111487  PMID: 21695231
24.  Co-expression of Ubiquitin gene and capsid protein gene enhances the potency of DNA immunization of PCV2 in mice 
Virology Journal  2011;8:264.
A recombinant plasmid that co-expressed ubiquitin and porcine circovirus type 2 (PCV2) virus capsid protein (Cap), denoted as pc-Ub-Cap, and a plasmid encoding PCV2 virus Cap alone, denoted as pc-Cap, were transfected into 293T cells. Indirect immunofluorescence (IIF) and confocal microscopy were performed to measure the cellular expression of Cap. Three groups of mice were then vaccinated once every three weeks for a total of three doses with pc-Ub-Cap, pc-Cap or the empty vector pCAGGS, followed by challenging all mice intraperitoneally with 0.5 mL 106.5 TCID50/mL PCV2. To characterize the protective immune response against PCV2 infection in mice, assays of antibody titer (including different IgG isotypes), flow cytometric analysis (FCM), lymphocyte proliferation, cytokine production and viremia were evaluated. The results showed that pc-Ub-Cap and pc-Cap were efficiently expressed in 293T cells. However, pc-Ub-Cap-vaccinated animals had a significantly higher level of Cap-specific antibody and induced a stronger Th1 type cellular immune response than did pc-Cap-vaccinated animals, suggesting that ubiquitin conjugation improved both the cellular and humoral immune responses. Additionally, viral replication in blood was lower in the pc-Ub-Cap-vaccinated group than in the pc-Cap and empty vector groups, suggesting that the protective immunity induced by pc-Ub-Cap is superior to that induced by pc-Cap.
doi:10.1186/1743-422X-8-264
PMCID: PMC3135555  PMID: 21624113
PCV2; DNA immunization; Cap; Ubiquitin
25.  Poly[[tetra­kis­(μ-2-anilinobenzoato-κ2 O:O′)tetra-μ1,1,1-azido-tetra-μ1,1-azido-octa­methano­lhexa­nickel(II)] methanol hexa­solvate] 
The crystal structure of the title compound, [Ni6(C13H10NO2)4(N3)8(CH3OH)8]·6CH3OH, consists of a centrosymmetric hexa­nuclear [NiII 6(C13H10NO2)4(N3)8(CH3OH)8] mol­ecule and six methanol solvent mol­ecules. In the hexa­nuclear unit, the six octa­hedrally coordinated NiII atoms are linked by four μ1,1,1-azide and four μ1,1-azide bridges, forming a face-sharing Ni6N8 tetra­cubane-like unit with four missing corners. The NiII atoms are further bridged by four μ1,2-carboxalate groups. Neighbouring hexa­nuclear units are connected via N—H⋯O hydrogen-bonding inter­actions into a three-dimensional structure. Although the H atoms of the methanol OH groups could not be located, O⋯N/O contacts between 2.65 and 2.86 Å suggest that these mol­ecules participate in hydrogen bonding.
doi:10.1107/S1600536811003473
PMCID: PMC3051959  PMID: 21522244

Results 1-25 (51)