The effects of interactions between genetic materials and polycyclic aromatic hydrocarbons (PAHs) on gene expression in the extracellular environment remain to be elucidated and little information is currently available on the effect of ionic strength on the transformation of plasmid DNA exposed to PAHs. Phenanthrene and pyrene were used as representative PAHs to evaluate the transformation of plasmid DNA after PAH exposure and to determine the role of Ca2+ during the transformation. Plasmid DNA exposed to the test PAHs demonstrated low transformation efficiency. In the absence of PAHs, the transformation efficiency was 4.7 log units; however, the efficiency decreased to 3.72–3.14 log units with phenanthrene/pyrene exposures of 50 µg·L–1. The addition of Ca2+ enhanced the low transformation efficiency of DNA exposed to PAHs. Based on the co-sorption of Ca2+ and phenanthrene/pyrene by DNA, we employed Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and mass spectrometry (MS) to determine the mechanisms involved in PAH-induced DNA transformation. The observed low transformation efficiency of DNA exposed to either phenanthrene or pyrene can be attributed to a broken hydrogen bond in the double helix caused by planar PAHs. Added Ca2+ formed strong electrovalent bonds with “–POO––” groups in the DNA, weakening the interaction between PAHs and DNA based on weak molecular forces. This decreased the damage of PAHs to hydrogen bonds in double-stranded DNA by isolating DNA molecules from PAHs and consequently enhanced the transformation efficiency of DNA exposed to PAH contaminants. The findings provide insight into the effects of anthropogenic trace PAHs on DNA transfer in natural environments.
Microbial lipid production by using lignocellulosic biomass as the feedstock holds a great promise for biodiesel production and biorefinery. This usually involves hydrolysis of biomass into sugar-rich hydrolysates, which are then used by oleaginous microorganisms as the carbon and energy sources to produce lipids. However, the costs of microbial lipids remain prohibitively high for commercialization. More efficient and integrated processes are pivotal for better techno-economics of microbial lipid technology.
Here we describe the simultaneous saccharification and enhanced lipid production (SSELP) process that is highly advantageous in terms of converting cellulosic materials into lipids, as it integrates cellulose biomass hydrolysis and lipid biosynthesis. Specifically, Cryptococcus curvatus cells prepared in a nutrient-rich medium were inoculated at high dosage for lipid production in biomass suspension in the presence of hydrolytic enzymes without auxiliary nutrients. When cellulose was loaded at 32.3 g/L, cellulose conversion, cell mass, lipid content and lipid coefficient reached 98.5%, 12.4 g/L, 59.9% and 204 mg/g, respectively. Lipid yields of the SSELP process were higher than those obtained by using the conventional process where cellulose was hydrolyzed separately. When ionic liquid pretreated corn stover was used, both cellulose and hemicellulose were consumed simultaneously. No xylose was accumulated over time, indicating that glucose effect was circumvented. The lipid yield reached 112 mg/g regenerated corn stover. This process could be performed without sterilization because of the absence of auxiliary nutrients for bacterial contamination.
The SSELP process facilitates direct conversion of both cellulose and hemicellulose of lignocellulosic materials into microbial lipids. It greatly reduces time and capital costs while improves lipid coefficient. Optimization of the SSELP process at different levels should further improve the efficiency of microbial lipid technology, which in turn, promote the biotechnological production of fatty acid-derived products from lignocellulosic biomass.
Microbial lipids; Cryptococcus curvatus; Biodiesel; Corn stover; Simultaneous saccharification and enhanced lipid production
In this paper, a novel image registration method is proposed to achieve accurate registration between images having large shape differences with the help of a set of appropriate intermediate templates. We first demonstrate that directionality is a key factor in both pairwise image registration and groupwise registration, which is defined in this paper to describe the influence of the registration direction and paths on the registration performance. In our solution, the intermediate template selection and intermediate template guided registration are two coherent steps with directionality being considered. To take advantage of the directionality, a directed graph is built based on the asymmetric distance defined on all ordered image pairs in the image population, which is fundamentally different from the undirected graph with symmetric distance metrics in all previous methods, and the shortest distance between template and subject on the directed graph is calculated. The allocated directed path can be thus utilized to better guide the registration by successively registering the subject through the intermediate templates one by one on the path towards the template. The proposed directed graph based solution can also be used in groupwise registration. Specifically, by building a minimum spanning arborescence (MSA) on the directed graph, the population center, i.e., a selected template, as well as the directed registration paths from all the rest of images to the population center, is determined simultaneously. The performance of directed graph based registration algorithm is demonstrated by the spatial normalization on both synthetic dataset and real brain MR images. It is shown that our method can achieve more accurate registration results than both the undirected graph based solution and the direct pairwise registration.
Image registration; directionality; directed graph; minimum spanning arborescence (MSA); intermediate templates; groupwise registration
The growth factor myostatin (MSTN) negatively regulates skeletal muscle mass. Mstn gene deletion in mice causes increased muscle mass, reduced adiposity and resistance to genetic or diet-induced obesity. Pharmacologic MSTN inhibition in mice also causes increased muscle mass and resistance to diet-induced obesity. To test whether MSTN inhibition causes weight loss in mice that are already obese, we inhibited MSTN in mice fed a high-fat diet. Mice were fed a diet containing 60% kcal from fat for 12 weeks followed by treatment with a soluble MSTN receptor derived from the activin receptor type IIB extracellular domain. During the next 12 weeks of soluble receptor treatment and high-fat diet feeding, lean mass increased without a loss of adipose mass. Glucose metabolism was also similar between groups. Our results suggest that MSTN inhibition may be ineffective at inducing weight loss in obese patients.
Celery is an increasing popular vegetable species, but limited transcriptome and genomic data hinder the research to it. In addition, a lack of celery molecular markers limits the process of molecular genetic breeding. High-throughput transcriptome sequencing is an efficient method to generate a large transcriptome sequence dataset for gene discovery, molecular marker development and marker-assisted selection breeding.
Celery transcriptomes from four tissues were sequenced using Illumina paired-end sequencing technology. De novo assembling was performed to generate a collection of 42,280 unigenes (average length of 502.6 bp) that represent the first transcriptome of the species. 78.43% and 48.93% of the unigenes had significant similarity with proteins in the National Center for Biotechnology Information (NCBI) non-redundant protein database (Nr) and Swiss-Prot database respectively, and 10,473 (24.77%) unigenes were assigned to Clusters of Orthologous Groups (COG). 21,126 (49.97%) unigenes harboring Interpro domains were annotated, in which 15,409 (36.45%) were assigned to Gene Ontology(GO) categories. Additionally, 7,478 unigenes were mapped onto 228 pathways using the Kyoto Encyclopedia of Genes and Genomes Pathway database (KEGG). Large numbers of simple sequence repeats (SSRs) were indentified, and then the rate of successful amplication and polymorphism were investigated among 31 celery accessions.
This study demonstrates the feasibility of generating a large scale of sequence information by Illumina paired-end sequencing and efficient assembling. Our results provide a valuable resource for celery research. The developed molecular markers are the foundation of further genetic linkage analysis and gene localization, and they will be essential to accelerate the process of breeding.
Radiotherapy is the primary treatment modality used for patients with head-and-neck cancers, but inevitably causes microorganism-related oral complications. This study aims to explore the dynamic core microbiome of oral microbiota in supragingival plaque during the course of head-and-neck radiotherapy. Eight subjects aged 26 to 70 were recruited. Dental plaque samples were collected (over seven sampling time points for each patient) before and during radiotherapy. The V1–V3 hypervariable regions of bacterial 16S rRNA genes were amplified, and the high-throughput pyrosequencing was performed. A total of 140 genera belonging to 13 phyla were found. Four phyla (Actinobacteria, Bacteroidetes, Firmicutes, and Proteobacteria) and 11 genera (Streptococcus, Actinomyces, Veillonella, Capnocytophaga, Derxia, Neisseria, Rothia, Prevotella, Granulicatella, Luteococcus, and Gemella) were found in all subjects, supporting the concept of a core microbiome. Temporal variation of these major cores in relative abundance were observed, as well as a negative correlation between the number of OTUs and radiation dose. Moreover, an optimized conceptual framework was proposed for defining a dynamic core microbiome in extreme conditions such as radiotherapy. This study presents a theoretical foundation for exploring a core microbiome of communities from time series data, and may help predict community responses to perturbation as caused by exposure to ionizing radiation.
To identify the function of ST2 and explore the role of IL-33/ST2 signaling in regulating the pro-allergic cytokine production in human corneal epithelial cells (HCECs).
Human corneal tissues and cultured primary HCECs were treated with IL-33 in different concentrations without or with different inhibitors to evaluate the expression, location and signaling pathways of ST2 in regulating production of pro-allergic cytokine and chemokine. The expression of mRNA was determined by reverse transcription and real time PCR, and protein production was measured by enzyme-linked immunosorbent assay (ELISA), immunohistochemical and immunofluorescent staining. ST2 protein was detected in donor corneal epithelium, and ST2 signal was enhanced by exposure to IL-33.
IL-33 significantly stimulated production of pro-allergic cytokines thymic stromal lymphopoietin (TSLP) and chemokine (CCL2, CCL20, CCL22) in HCECs at both mRNA and protein levels. These stimulated productions of pro-allergic mediators by IL-33 were blocked by ST2 antibody or soluble ST2 protein (P<0.05). Interestingly, the IκB-α inhibitor BAY11-7082 or NF-κB activation inhibitor quinazoline blocked NF-κB p65 protein nuclear translocation, and also suppressed the productions of these pro-allergic cytokines and chemokine induced by IL-33.
These findings demonstrate that IL-33/ST2 signaling plays an important role in regulating IL-33 induced pro-allergic responses. IL-33 and ST2 could become novel molecular targets for the intervention of allergic diseases in ocular surface.
ST2; interleukin 33; human; cornea; epithelium; allergic diseases; NF-κB
To investigate the expression of dendritic cell-associated C-type lectin-1(dectin-1) at the early period of Aspergillus fumigatus infection in rat's corneal epithelium.
A total of 72 Wistar rats were randomly divided into three groups: A, B and C. The right eyes were chosen as experimental eyes. Group A was control group. Rats in group B were not inoculated with Aspergillus fumigatus. Group C was taken as Aspergillus fumigatus keratitis model. Rats in group B and C (six from each group) were executed randomly at 4, 8, 16 and 24 hours after experimental model being established to assess the expression of dectin-1 mRNA through real-time PCR. Another six rats in group B and C were executed randomly at 24 hours to assess the expression of dectin-1 protein through immunohistochemistry.
The results of real-time PCR indicated that dectin-1 mRNA expression was low in corneal epithelium of normal rats'. There was no significantly difference of dectin-1 mRNA expression in group A and B (P>0.05). The expression of Aspergillus fumigatus infected corneal epithelium increased gradually after 8 hours in group C. The synchronous expression of group A and C had significant difference (P<0.01). Immunohistochemisty discovered that dectin-1 receptor existed in normal rat's corneal epithelium. Dectin-1 protein increased after 24 hours in group C. There was a significant difference of synchronous expression in group B and C (P<0.01).
Dectin-1 exists in rat's corneal epithelium and its expression significantly increases at the early period of Aspergillus fumigatus infection. Dectin-1 is a pattern recognition receptor that expresses in corneal epithelium and involves in immune response to Aspergillus fungal keratitis.
keratitis; Aspergillus fumigatus; dectin-1; rat
This study is aimed to investigate the effect of human resistin on myocyte differentiation and insulin resistance. The human resistin eukaryotic expression vector was stable transfected into C2C12 myocyte cells and was transiently transfected into COS7 cells. The effects of human resistin on cell proliferation, cell cycle, and myogenic differentiation of C2C12 cells were examined. Glucose uptake assays was performed on C2C12 myotubes by using [3H] 2-deoxy-D-glucose. The mRNA levels of insulin receptor (IR) and glucose transporter 4 (GLUT4) were evaluated by semiquantitative RT-PCR. Results showed by the C2C12 cells transfected with human resistin gene compared with that without transfecting gene are as follows: (1) cell proliferation was significantly promoted, (2) after inducing differentiation, the myotube's diameters and expression of desmin and myoglobin decreased, and (3) glucose uptake ratio was lowered and expression of IR and GLUT4 decreased. However, there was no significant difference in the glucose uptake ratio between C2C12 myotubes treated with a human resistin conditioned medium of COS7 cells and treated with control medium. These results suggest that maybe human resistin has not a direct role on insulin sensitivity of myocytes. However, maybe it impaired the insulin sensitivity of myocytes through suppressing myogenesis and stimulating proliferation of myoblasts.
Sexually transmitted infections (STIs) have become a major public health problem among female sex workers (FSWs) in China. There have been many studies on prevalences of HIV and syphilis but the data about Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) infections are limited in this population in China.
A cross-sectional study was performed among FSWs recruited from different types of venues in 8 cities in China. An interview with questionnaire was conducted, followed by collection of a blood and cervical swab specimens for tests of HIV, syphilis, NG and CT infections.
A total of 3,099 FSWs were included in the study. The overall prevalence rates of HIV, syphilis, NG and CT were 0.26%, 6.45%, 5.91% and 17.30%, respectively. Being a FSW from low-tier venue (adjusted odds ratios [AOR]=1.39) had higher risk and being age of ≥ 21 years (AOR=0.60 for 21–25 years; AOR=0.29 for 26–30 years; AOR=0.35 for 31 years or above) had lower risk for CT infection; and having CT infection was significantly associated with NG infection.
The high STI prevalence rates found among FSWs, especially among FSWs in low-tier sex work venues, suggest that the comprehensive prevention and control programs including not only behavioral interventions but also screening and medical care are needed to meet the needs of this population.
Sexually transmitted infections; Prevalence; Female sex worker; China
Ara h 2 and Ara h 6, co-purified together in a 13-25 kD fraction (Ara h 2/6; 20 kD fraction) on gel filtration chromatography, account for the majority of effector activity in a crude peanut extract (CPE) when assayed with RBL SX-38 cells sensitized with IgE from human peanut allergic sera.
To determine if Ara h 2/6 are the primary peanut allergens responsible for allergic reactions in vivo and to determine if Ara h 2/6 would be sufficient to prevent allergic reactions to a complete CPE.
An oral sensitization mouse model of peanut allergy was used to assess the activity of Ara h 2/6 (20 kD) and CPE without the 20 kD fraction (CPE w/o 20 kD) for allergic provocation challenge and immunotherapy. The activity of these preparations was also tested in an assay of histamine release from human basophils in whole blood.
Compared to mice challenged with control CPE, mice challenged with CPE w/o 20 kD experienced reduced symptoms (p<0.05) and a smaller decrease in body temperature (p<0.01). Results with the basophil histamine release assay corroborated these findings (p<0.01). The mouse model was also used to administer Ara h 2/6 (20 kD) in an immunotherapy protocol, in which peanut-allergic mice treated with the 20 kD fraction experienced significantly reduced symptoms, changes in body temperature, and mast cell protease (MMCP-1) release compared to placebo (p<0.01 for all parameters). Importantly, immunotherapy with the 20 kD fraction was just as effective as treatment with CPE, whereas CPE w/o 20 kD was significantly less effective for higher dose peanut challenges.
Conclusions and Clinical Relevance
Ara h 2/6 are the most potent peanut allergens in vivo and can be used to desensitize peanut-allergic mice. These results have potential implications for clinical research in the areas of diagnosis and immunotherapy for peanut allergy.
Food allergy; peanut allergy; Ara h 2; Ara h 6; desensitization; immunotherapy; human basophil assay; mouse model
The global biomechanical impact of cranial sutures on the face and cranium during dynamic conditions is not well understood. It is hypothesized that sutures act as energy absorbers protecting skulls subjected to dynamic loads. This hypothesis predicts that sutures have a significant impact on global patterns of strain and cranial structural stiffness when analyzed using dynamic simulations; and that this global impact is influenced by suture material properties. In a finite element model developed from a juvenile Rhesus macaque cranium, five different sets of suture material properties for the zygomaticotemporal sutures were tested. The static and dynamic analyses produced similar results in terms of strain patterns and reaction forces, indicating that the zygomaticotemporal sutures have limited impact on global skull mechanics regardless of loading design. Contrary to the functional hypothesis tested here, the zygomaticotemporal sutures did not absorb significant amounts of energy during dynamic simulations regardless of loading speed. It is alternatively hypothesized that sutures are mechanically significant only insofar as they are weak points on the cranium that must be shielded from unduly high stresses so as not to disrupt vitally important growth processes. Thus, sutural and overall cranial form in some vertebrates may be optimized to minimize or otherwise modulate sutural stress and strain.
vertebrate skulls; elastic properties; loading speed
Hemoglobinopathies are the most common inherited diseases in southern China. However, there have been only a few epidemiological studies of hemoglobinopathies in Guangdong province.
Materials and Methods
Peripheral blood samples were collected from 15299 “healthy” unrelated subjects of dominantly ethnic Hakka in the Meizhou region, on which hemoglobin electrophoresis and routine blood tests were performed. Suspected cases with hemoglobin variants and hereditary persistence of fetal hemoglobin (HPFH) were further characterized by PCR, DNA sequencing, reverse dot blot (RDB) or multiplex ligation-dependent probe amplification (MLPA). In addition, 1743 samples were randomly selected from the 15299 subjects for thalassemia screening, and suspected thalassemia carriers were identified by PCR and RDB.
The gene frequency of hemoglobin variants was 0.477% (73/15299). The five main subgroups of the ten hemoglobin variants were Hb E, Hb G-Chinese, Hb Q-Tahiland, Hb New York and Hb J-Bangkok. 277 cases (15.89%, 277/1743) of suspected thalassemia carriers with microcytosis (MCV<82 fl) were found by thalassemia screening, and were tested by a RDB gene chip to reveal a total of 196 mutant chromosomes: including 124 α-thalassemia mutant chromosomes and 72 β-thalassemia mutant chromosomes. These results give a heterozygote frequency of 11.24% for common α and β thalassemia in the Hakka population in the Meizhou region. 3 cases of HPFH/δβ-thalassemia were found, including 2 cases of Vietnamese HPFH (FPFH-7) and a rare Belgian Gγ(Aγδβ)0–thalassemia identified in Chinese.
Our results provide a detailed prevalence and molecular characterization of hemoglobinopathies in Hakka people of the Meizhou region. The estimated numbers of pregnancies each year in the Meizhou region, in which the fetus would be at risk for β thalassemia major or intermedia, Bart’s hydrops fetalis, and Hb H disease, are 25 (95% CI, 15 to 38), 40 (95% CI, 26 to 57), and 15 (95% CI, 8 to 23), respectively.
In this work we created electrospun fibrous scaffolds with random and aligned fiber orientations in order to mimic the 3D structure of the natural extracellular matrix (ECM). The rigidity and topography of the ECM environment have been reported to alter cancer cell behavior. But the complexity of the in vivo system makes it difficult to isolate and study such extracellular topographical cues that trigger cancer cells’ response. Breast cancer cells were cultured on these fibrous scaffolds for 3–5 days. The cells showed elongated spindle-like morphology in the aligned fibers whereas kept mostly flat stellar shape in the random fibers. Gene expression profiling of these cells post seeding, showed up-regulation of transforming growth factor β-1 (TGFβ-1) along with other mesenchymal biomarkers, suggesting that these cells are undergoing epithelial-mesenchymal transitions in response to the polymer scaffold. The results of this study indicate that the topographical cue may play a significant role in tumor progression.
Associations between transcription factor 7-like 2 (TCF7L2) polymorphisms and type 2 diabetes mellitus (T2DM) have been evaluated extensively in multiple ethnic groups. TCF7L2 has emerged as the strongest T2DM susceptibility gene in Europeans, but the findings have been inconsistent in the Chinese population. The purpose of this meta-analysis was to evaluate the associations between TCF7L2 single nucleotide polymorphisms (SNPs) and T2DM risk in the Chinese population.
We performed searches in the PubMed, EMBASE, Cochrane, and Chinese databases (CNKI, CQVIP and Wanfang databases) for literature published from January 2007 to February 2012. We reviewed all relevant articles on TCF7L2 polymorphisms and susceptibility to T2DM in the Chinese population written in English and Chinese. Two reviewers extracted data independently using a standardized protocol, and any discrepancies were adjudicated by a third reviewer. Fixed-effects and random-effects meta-analyses were performed to pool the odds ratios (ORs). Publication bias and heterogeneity were examined.
A total of 21 articles were confirmed to be eligible for and included in this meta-analysis: 7 (with 3942 cases and 3502 controls) concerning rs11196218 (IVS−/+4G>A), 8 (with 3377 cases and 2975 controls) concerning rs290487 (IVS3−/+C>T), and 14 (with 7902 cases and 7436 controls) concerning rs7903146 (IVS3−/+C>T). Overall, the results showed a significant association between rs7903146 and T2DM risk. The pooled ORs were 1.54 for the comparison of T and C alleles (95% CI [confidence interval]: 1.37–1.74, p = 1.47 × 10-12, I2 = 25.20%) and 1.56 for TC heterozygotes and CC homozygotes (95% CI : 1.38–1.76, p = 8.25 × 10-9, I2 = 21.00%). The rs11196218(IVS4G>A) and rs290487 (IVS3C>T) SNPs were not associated with T2DM risk.
The rs7903146 SNP of the TCF7L2 gene is associated with increased susceptibility to T2DM in the Chinese population as a whole as well as northern Chinese and southern Chinese as subgroups.
Type 2 diabetes; T2DM; TCF7L2; SNPs; Meta-analysis
Accurate measurement of longitudinal changes of brain structures and functions is very important but challenging in many clinical studies. Also, across-subject comparison of longitudinal changes is critical in identifying disease-related changes. In this paper, we propose a novel method to meet these two requirements by simultaneously registering sets of longitudinal image sequences of different subjects to the common space, without assuming any explicit template. Specifically, our goal is to 1) consistently measure the longitudinal changes from a longitudinal image sequence of each subject, and 2) jointly align all image sequences of different subjects to a hidden common space. To achieve these two goals, we first introduce a set of temporal fiber bundles to explore the spatial-temporal behavior of anatomical changes in each longitudinal image sequence. Then, a probabilistic model is built upon the temporal fibers to characterize both spatial smoothness and temporal continuity. Finally, the transformation fields that connect each time-point image of each subject to the common space are simultaneously estimated by the expectation maximization (EM) approach, via the maximum a posterior (MAP) estimation of the probabilistic models. Promising results have been obtained in quantitative measurement of longitudinal brain changes, i.e., hippocampus volume changes, showing better performance than those obtained by either the pairwise or the groupwise only registration methods.
Longitudinal registration; groupwise registration; fiber bundles; spatial-temporal consistency; implicit template
Tetraology of Fallot (TOF) is the most common form of cyanotic congenital heart disease and is a major cause of significant morbidity and mortality. Emerging evidence demonstrates that genetic risk factors are involved in the pathogenesis of TOF. However, TOF is genetically heterogeneous and the genetic defects responsible for TOF remain largely unclear. In the present study, the whole coding region of the GATA5 gene, which encodes a zinc-finger transcription factor essential for cardiogenesis, was sequenced in 130 unrelated patients with TOF. The relatives of the index patients harboring the identified mutations and 200 unrelated control individuals were subsequently genotyped. The functional characteristics of the mutations were analyzed using a luciferase reporter assay system. As a result, 2 novel heterozygous GATA5 mutations, p.R187G and p.H207R, were identified in 2 families with autosomal dominantly inherited TOF, respectively. The variations were absent in 400 control alleles and the altered amino acids were completely conserved evolutionarily. Functional analysis showed that the GATA5 mutants were associated with significantly decreased transcriptional activation compared with their wild-type counterpart. To our knowledge, this is the first report on the association of GATA5 loss-of-function mutations with TOF, suggesting potential implications for the early prophylaxis and allele-specific therapy of human TOF.
Congenital heart disease; Tetralogy of Fallot; Genetics; Transcription factor; GATA5.
This study was performed to explore other potential mechanisms underlying hemolysis in addition to pore-formation of tentacle extract (TE) from the jellyfish Cyanea capillata. A dose-dependent increase of hemolysis was observed in rat erythrocyte suspensions and the hemolytic activity of TE was enhanced in the presence of Ca2+, which was attenuated by Ca2+ channel blockers (Diltiazem, Verapamil and Nifedipine). Direct intracellular Ca2+ increase was observed after TE treatment by confocal laser scanning microscopy, and the Ca2+ increase could be depressed by Diltiazem. The osmotic protectant polyethylenglycol (PEG) significantly blocked hemolysis with a molecular mass exceeding 4000 Da. These results support a pore-forming mechanism of TE in the erythrocyte membrane, which is consistent with previous studies by us and other groups. The concentration of malondialdehyde (MDA), an important marker of lipid peroxidation, increased dose-dependently in rat erythrocytes after TE treatment, while in vitro hemolysis of TE was inhibited by the antioxidants ascorbic acid—Vitamin C (Vc)—and reduced glutathione (GSH). Furthermore, in vivo hemolysis and electrolyte change after TE administration could be partly recovered by Vc. These results indicate that lipid peroxidation is another potential mechanism besides pore-formation underlying the hemolysis of TE, and both Ca2+ channel blockers and antioxidants could be useful candidates against the hemolytic activity of jellyfish venoms.
jellyfish; Cyanea capillata; hemolysis; pore-formation; lipid peroxidation
Transient potential receptor melastatin-2 (TRPM2) is a non-selective Ca2+-permeable cation channel of the TRPM channel subfamily and is mainly activated by intracellular adenosine diphosphate ribose (ADPR). Here we synthesized a 1-(2-nitrophenyl)ethyl caged ADPR (NPE-ADPR) and found that uncaging of NPE-ADPR efficiently stimulated Ca2+, Mg2+, and Zn2+ influx in a concentration-dependent manner in intact human Jurkat T-lymphocytes. The cation influx was inhibited by inhibitors or knockdown of TRPM2. Likewise, uncaging of NPE-ADPR markedly induced cation entry in HEK 293 cells that overexpress TRPM2. As expected, high temperature increased the ability of the photolyzed NPE-ADPR to induce cation entry, whereas acidic pH inhibited. Moreover, the absence of extracellular Ca2+ significantly inhibited Mg2+ and Zn2+ influx after uncaging NPE-ADPR. On the other hand, the absence of extracellular Na+ or Mg2+ had no effect on photolyzed NPE-ADPR induced Ca2+ entry. Taken together, our results indicated that NPE-ADPR is a cell permeable ADPR analogue that is useful for studying TRPM2-mediated cation entry in intact cells.
Infection with human papillomavirus type 16 (HPV-16) can lead to low- or high-grade squamous intraepithelial lesions (LSIL or HSIL). Here we show that these in vivo disease states can be replicated in raft cultures of early-pass HPV-16 episomal cell lines, at both the level of pathology and the level of viral gene expression. A reduced responsiveness to cell-cell contact inhibition and an increase in E6/E7 activity correlated closely with phenotype. Similar deregulation is likely to underlie the appearance of LSIL or HSIL soon after infection.
ChIP-seq provides new opportunities to study allele-specific protein-DNA binding (ASB). However, detecting allelic imbalance from a single ChIP-seq dataset often has low statistical power since only sequence reads mapped to heterozygote SNPs are informative for discriminating two alleles.
We develop a new method iASeq to address this issue by jointly analyzing multiple ChIP-seq datasets. iASeq uses a Bayesian hierarchical mixture model to learn correlation patterns of allele-specificity among multiple proteins. Using the discovered correlation patterns, the model allows one to borrow information across datasets to improve detection of allelic imbalance. Application of iASeq to 77 ChIP-seq samples from 40 ENCODE datasets and 1 genomic DNA sample in GM12878 cells reveals that allele-specificity of multiple proteins are highly correlated, and demonstrates the ability of iASeq to improve allelic inference compared to analyzing each individual dataset separately.
iASeq illustrates the value of integrating multiple datasets in the allele-specificity inference and offers a new tool to better analyze ASB.
Allele-specific binding; Transcription factor; Histone modification; Data integration; Next-generation sequencing; Statistical model
HER2/Neu is overexpressed in 20-30% of breast cancers and associated with aggressive phenotypes and poor prognosis. For deciphering the role of HER2/Neu in breast cancer, mouse mammary tumor virus (MMTV)-Her2/neu transgenic mice that develop mammary tumors resembling human HER2-subtype breast cancer have been established. Several recent studies have revealed that HER2/Neu is overexpressed in and regulates self renewal of breast tumor initiating cells (TICs). However, in the MMTV-Her2/neu transgenic mouse model, the identity of TICs remains elusive, despite previous studies showing supportive evidence for existence of TICs in Her2/neu-induced mammary tumors. Through systematic screening and characterization, we identified surface markers CD49f, CD61 and ESA were aberrantly overexpressed in Her2-overexpressing mammary tumor cells. Analysis of these markers as well as CD24 detected anomalous expansion of the luminal progenitor population in preneoplastic mammary glands of Her2/neu-transgenic mice, indicating that aberrant luminal progenitors originated Her2-induced mammary tumors. The combined markers, CD49f and CD61, further delineated the CD49fhighCD61high-sorted fraction as a TIC-enriched population, which displayed increased tumorsphere formation ability, enhanced tumorigenicity both in vitro and in vivo and drug resistance to pacitaxel and doxorubicin. Moreover, the TIC-enriched population manifested increased TGFβ signaling and exhibited gene expression signatures of stemness, TGFβ signaling and Epithelial-to-Mesenchymal Transition. Our findings that self-renewal and clonogenicity of TICs were suppressed by pharmacologically inhibiting the TGFβ signaling further indicate that the TGFβ pathway is vital for maintenance of the TIC population. Finally, we showed that the integrin β3 (CD61) signaling pathway was required for sustaining active TGFβ signaling and self-renewal of TICs. We for the first time developed a technique to highly enrich TICs from mammary tumors of Her2/neu-transgenic mice, unraveled their properties and identified the cooperative integrin β3-TGFβ signaling axis as a potential therapeutic target for HER2-induced TICs.
Tumor Initiating Cells; Her2/neu; mammary tumor; CD49f; CD61; ESA
The contraction phase of antigen-specific immune responses involves the apoptotic loss of numerous activated lymphocytes. While apoptotic cells are known to induce immune suppression, the mechanisms involved therein are still ambiguous. Some reports have speculated that macrophages can induce regulatory T cells (Tregs) after engulfing apoptotic cells. In this study, we showed that dendritic cells (DCs) that phagocytose apoptotic T cells acquire inhibitory function (named DCapos) toward CD4+ and CD8+ T cells. These inhibitory DCs could not induce the generation of Tregs, but they were found to directly inhibit mDCs that initiate CD4+ and CD8+ T cell proliferation both in vitro and in vivo. Soluble factors including NO play a role in the DCapos-induced suppression of CD4+ and CD8+ T cell proliferation. Further results showed that STAT3 phosphorylation and inducible nitric oxide synthase (iNOS) generation were enhanced when DCs were co-cultured with apoptotic cells. Both iNOS transcription and NO secretion were inhibited in the presence of the specific p-STAT3 inhibitor JSI-124. All the data indicated that apoptotic cells could turn DCs to inhibitory DCs, which might play important roles in the suppression of immune responses. STAT3 activation and the consequent release of NO are responsible for the inhibitory functions of DCapos.
Neonatal hypoxic-ischemic encephalopathy (HIE) is a leading cause of severe and permanent neurologic disability after birth. The inducible cyclooxygenase COX-2, which along with COX-1 catalyzes the first committed step in prostaglandin (PG) synthesis, elicits significant brain injury in models of cerebral ischemia, however its downstream PG receptor pathways trigger both toxic and paradoxically protective effects. Here, we investigated the function of PGE2 E-prostanoid (EP) receptors in the acute outcome of hypoxic-ischemic (HI) injury in the neonatal rat. We determined the temporal and cellular expression patterns of the EP1-4 receptors before and after HIE and tested whether modulation of EP1-4 receptor function could protect against cerebral injury acutely after HIE. All four EP receptors were expressed in forebrain neurons and were induced in endothelial cells after HIE. Inhibition of EP1 signaling with the selective antagonist SC-51089 or co-activation of EP2-4 receptors with the agonist misoprostol significantly reduced HIE cerebral injury 24h after injury. These receptor ligands also protected brain endothelial cells subjected to oxygen glucose deprivation, suggesting that activation of EP receptor signaling is directly cytoprotective. These data indicate that the G-protein coupled EP receptors may be amenable to pharmacologic targeting in the acute setting of neonatal HIE.
PGE2; EP1-4 receptors; G-protein coupled receptors; misoprostol; hypoxic ischemic encephalopathy
YY1 is a zinc-finger transcription factor involved in regulation of cell growth, development, and differentiation. Although YY1 can regulate human papillomavirus type (HPV) viral oncogene E6 and E7, it remains unknown if YY1 plays a key role in carcinoma progression of HPV infected cells. Here we sought to determine whether YY1 is up-regulated in the cervical cancer tissues and YY1 inhibition contributes to apoptosis of cervical cancer cells which is at least partly p53 dependent. Therefore, YY1 can be a potential therapeutic target for cervical cancer treatment by arsenic trioxide (As2O3).
YY1 expression level was examined and analyzed by Western blot in pathologically confirmed primary cervical cancer samples, the adjacent normal samples as well as normal cervix samples. The effects of YY1 inhibition by specific siRNA in HeLa cells were determined by Western blot analysis of p53 level, cell growth curve, colony formation assay, and apoptosis. The contribution of YY1 to As2O3-induced p53 activation and apoptosis were also examined by Western blot and cell cycle analysis.
Here we report that the YY1 expression level is significantly elevated in the primary cancer tissues. In HPV-positive HeLa cells, siRNA-mediated YY1 inhibition induced apoptosis and increased the expression of p53. Treatment of HeLa cells with As2O3, a known anti-cervical cancer agent, reduced both protein and mRNA levels of YY1 in Hela cells. YY1 knockdown significantly further enhanced As2O3-induced apoptosis.
These results demonstrated that YY1 expression is up-regulated in cervical carcinomas and YY1 plays a critical role in the progression of HPV-positive cervical cancer. In addition, YY1 inhibition induces p53 activation and apoptosis in HPV-infected HeLa cells. Thus, YY1 is an As2O3 target and could serve as a potential drug sensitizer for anti-cervical cancer therapy.
YY1; therapeutic target; cervical cancer; arsenic trioxide