Though loss of function in CBP/p300, a family of CREB-binding proteins, has been causally associated with a variety of human neurological disorders, such as Rubinstein-Taybi syndrome, Huntington’s disease and drug addiction, the role of EP300 interacting inhibitor of differentiation 1 (EID1), a CBP/p300 inhibitory protein, in modulating neurological functions remains completely unknown. Through the examination of EID1 expression and cellular distribution, we discovered that there is a significant increase of EID1 nuclear translocation in the cortical neurons of Alzheimer’s disease (AD) patient brains compared to that of control brains. To study the potential effects of EID1 on neurological functions associated with learning and memory, we generated a transgenic mouse model with a neuron-specific expression of human EID1 gene in the brain. Overexpression of EID1 led to an increase in its nuclear localization in neurons mimicking that seen in human AD brains. The transgenic mice had a disrupted neurofilament organization and increase of astrogliosis in the cortex and hippocampus. Furthermore, we demonstrated that overexpression of EID1 reduced hippocampal long-term potentiation and impaired spatial learning and memory function in the transgenic mice. Our results indicated that the negative effects of extra nuclear EID1 in transgenic mouse brains are likely due to its inhibitory function on CBP/p300 mediated histone and p53 acetylation, thus affecting the expression of downstream genes involved in the maintenance of neuronal structure and function. Together, our data raise the possibility that alteration of EID1 expression, particularly the increase of EID1 nuclear localization that inhibits CBP/p300 activity in neuronal cells, may play an important role in AD pathogenesis.
doi:10.1016/j.nbd.2011.12.007
PMCID: PMC3276739
PMID: 22186421
EP300 interacting inhibitor of differentiation 1; CBP/p300; histone; p53; Acetylation; Alzheimer’s disease
Lipid A is a key component of the outer membrane of Gram-negative bacteria and stimulates proinflammatory responses via the Toll-like receptor 4 (TLR4)-MD2-CD14 pathway. Its endotoxic activity depends on the number and length of acyl chains and its phosphorylation state. In Salmonella enterica serovar Typhimurium, removal of the secondary laurate or myristate chain in lipid A results in bacterial attenuation and growth defects in vitro. However, the roles of the two lipid A phosphate groups in bacterial virulence and immunogenicity remain unknown. Here, we used an S. Typhimurium msbB pagL pagP lpxR mutant, carrying penta-acylated lipid A, as the parent strain to construct a series of mutants synthesizing 1-dephosphorylated, 4′-dephosphorylated, or nonphosphorylated penta-acylated lipid A. Dephosphorylated mutants exhibited increased sensitivity to deoxycholate and showed increased resistance to polymyxin B. Removal of both phosphate groups severely attenuated the mutants when administered orally to BALB/c mice, but the mutants colonized the lymphatic tissues and were sufficiently immunogenic to protect the host from challenge with wild-type S. Typhimurium. Mice receiving S. Typhimurium with 1-dephosphorylated or nonphosphorylated penta-acylated lipid A exhibited reduced levels of cytokines. Attenuated and dephosphorylated Salmonella vaccines were able to induce adaptive immunity against heterologous (PspA of Streptococcus pneumoniae) and homologous antigens (lipopolysaccharide [LPS] and outer membrane proteins [OMPs]).
doi:10.1128/IAI.00123-12
PMCID: PMC3418755
PMID: 22753374
Hu, Zhenhua | Gao, Jian | Zhang, Danye | Liu, Qing | Yan, Limei | Gao, Lili | Liu, Juanjuan | Liu, Dawo | Zhang, Shulan | Lin, Bei | Hawkins, Shannon M.
Objectives
To measure Lewis y antigen and CD44 antigen expression in epithelial ovarian carcinoma and to correlate the levels of these antigens with clinical response to chemotherapy.
Methods
The study cases included 34 cases of ovarian carcinoma with resistance to chemotherapeutic drugs, 6 partially drug-sensitive cases, and 52 drug-sensitive cases (92 total).
Results
The rates of expression of Lewis y antigen and CD44 antigen were significantly greater in the drug-resistant group than that in the partially-sensitive or sensitive groups. Surgical stage, residual tumor size and expression of CD44 and Lewis y antigen in ovarian carcinoma tissues were independent risk factors for chemotherapeutic drug resistance.
Conclusions
Over-expression of Lewis y and CD44 antigen are strong risk factors for chemotherapeutic drug resistance in ovarian carcinoma patients.
doi:10.1371/journal.pone.0057250
PMCID: PMC3585297
PMID: 23468946
Humans can use hand tools smoothly and effectively in varying circumstances; in other words, skillfully. A few other species of primates crack encased foods using hammer tools and anvils. Are they skilled? Positioning the food on the anvil so that it does not fall off when struck is a component of skilled cracking. We discovered that bearded capuchin monkeys deliberately place palm nuts in a relatively stable position on the anvil before striking them. In the first experiment, we marked the meridians of palm nuts where they stopped when rolled on a flat surface (“Stop meridian”). We videotaped monkeys as they cracked these nuts on an anvil. In playback we coded the position of the Stop meridian prior to each strike. Monkeys typically knocked the nuts on the anvil a few times before releasing them in a pit. They positioned the nuts so that the Stop meridian was within 30 degrees of vertical with respect to gravity more often than expected, and the nuts rarely moved after the monkeys released them. In the second experiment, 14 blindfolded people (7 men) asked to position marked nuts on an anvil as if to crack them reliably placed them with the Stop meridian in the same position as the monkeys did. In the third experiment, two people judged that palm nuts are most bilaterally symmetric along a meridian on, or close to, the Stop meridian. Thus the monkeys reliably placed the more symmetrical side of the nuts against the side of the pit, and the nuts reliably remained stationary when released. Monkeys apparently used information gained from knocking the nut to achieve this position. Thus, monkeys place the nuts skillfully, strategically managing the fit between the variable nuts and pits in the anvil, and skilled placement depends upon information generated by manual action.
doi:10.1371/journal.pone.0056182
PMCID: PMC3584076
PMID: 23460793
Background
In 2011, World Health Organization revised its recommendation for microbiological monitoring during treatment for multidrug-resistant tuberculosis (MDR-TB) by increasing the frequency of culture examination from quarterly to monthly after culture conversion. Implementing the recommendation requires substantial additional investment in laboratory infrastructure. The objective of this review is to provide cost evidence that is needed for national TB programs to budget for optimal monitoring strategies.
Methods and Findings
We conducted the first systematic literature review on unit cost estimates of three monitoring strategies: 1) smear only; 2) culture only; 3) combined smear and culture. 26 peer-reviewed studies were selected by searching 10 databases in English and Chinese for literature published between 1995 and 2012. Cost estimates were converted into 2010 constant USD and international dollars. We assessed the quality of the estimates using a matrix with five essential elements and provided a cost projection for the combined smear and culture tests where the data were available. The 26 studies reported the cost estimates in 16 predominantly high- or middle-income countries from 1993 to 2009. The estimated unit cost for smear, culture, and combined tests ranges from $0.26 to $10.50, $1.63 to $62.01, and $26.73 to $39.57, respectively. The ratio of culture to smear costs varies from 1.35 to 11.98. The wide range of estimates is likely attributable to using different laboratory methods in different regions and years and differing practices in collecting and reporting cost data. Most studies did not report information critical for generalizing their conclusions.
Conclusion
The paucity and low quality of unit cost estimates for TB monitoring in resource-poor settings impose technical challenges in predicting the resources needed for strengthening microbiological monitoring. To improve the validity and comparability of the cost data, we strongly advocate the data collection, estimation, and reporting follow protocols proposed by WHO.
doi:10.1371/journal.pone.0056074
PMCID: PMC3574085
PMID: 23457502
Background
The application and nutritional value of vegetable oil is highly dependent on its fatty acid composition, especially the relative proportion of its two major fatty acids, i.e oleic acid and linoleic acid. Microsomal oleoyl phosphatidylcholine desaturase encoded by FAD2 gene is known to introduce a double bond at the Δ12 position of an oleic acid on phosphatidylcholine and convert it to linoleic acid. The known plant FAD2 enzymes are encoded by small gene families consisting of 1-4 members. In addition to the classic oleate Δ12-desaturation activity, functional variants of FAD2 that are capable of undertaking additional or alternative acyl modifications have also been reported in a limited number of plant species. In this study, our objective was to identify FAD2 genes from safflower and analyse their differential expression profile and potentially diversified functionality.
Results
We report here the characterization and functional expression of an exceptionally large FAD2 gene family from safflower, and the temporal and spatial expression profiles of these genes as revealed through Real-Time quantitative PCR. The diversified functionalities of some of the safflower FAD2 gene family members were demonstrated by ectopic expression in yeast and transient expression in Nicotiana benthamiana leaves. CtFAD2-1 and CtFAD2-10 were demonstrated to be oleate desaturases specifically expressed in developing seeds and flower head, respectively, while CtFAD2-2 appears to have relatively low oleate desaturation activity throughout the plant. CtFAD2-5 and CtFAD2-8 are specifically expressed in root tissues, while CtFAD2-3, 4, 6, 7 are mostly expressed in the cotyledons and hypocotyls in young safflower seedlings. CtFAD2-9 was found to encode a novel desaturase operating on C16:1 substrate. CtFAD2-11 is a tri-functional enzyme able to introduce a carbon double bond in either cis or trans configuration, or a carbon triple (acetylenic) bond at the Δ12 position.
Conclusions
In this study, we isolated an unusually large FAD2 gene family with 11 members from safflower. The seed expressed FAD2 oleate Δ12 desaturase genes identified in this study will provide candidate targets to manipulate the oleic acid level in safflower seed oil. Further, the divergent FAD2 enzymes with novel functionality could be used to produce rare fatty acids, such as crepenynic acid, in genetically engineered crop plants that are precursors for economically important phytoalexins and oleochemical products.
doi:10.1186/1471-2229-13-5
PMCID: PMC3554562
PMID: 23289946
Fan, Nai-Jun | Gao, Chun-Fang | Wang, Chang-Song | Lv, Jing-Jing | Zhao, Guang | Sheng, Xin-Hua | Wang, Xiu-Li | Li, Dong-Hui | Liu, Qing-Yin | Yin, Jian
Despite the wide range of available colorectal cancer (CRC) screening tests, less than 50% of cases are detected at early stages. However, the identification of differentially expressed proteins or novel protein biomarkers in CRC may have some utility and, ultimately, improve patient care and survival. Proteomics combined with mass spectroscopy and liquid chromatography are emerging as powerful tools that have led to the discovery of potential markers in cancer biomarker discovery in several types of cancers. This article describes a novel technology that uses isotopic reagents to tag selected proteins that show a consistent pattern of differential expression in CRC.
OBJECTIVE:
To identify and validate potential biomarkers of colorectal adenocarcinoma using a proteomic approach.
METHODS:
Multidimensional liquid chromatography/mass spectrometry was used to analyze biological samples labelled with isobaric mass tags for relative and absolute quantitation to identify differentially expressed proteins in human colorectal adenocarcinoma and paired normal mucosa for the discovery of cancerous biomarkers. Cancerous and noncancerous samples were compared using online and offline separation. Protein identification was performed using mass spectrometry. The downregulation of gelsolin protein in colorectal adenocarcinoma samples was confirmed by Western blot analysis and validated using immunohistochemistry.
RESULTS:
A total of 802 nonredundant proteins were identified in colorectal adenocarcinoma samples, 82 of which fell outside the expression range of 0.8 to 1.2, and were considered to be potential cancer-specific proteins. Immunohistochemistry revealed a complete absence of gelsolin expression in 86.89% of samples and a reduction of expression in 13.11% of samples, yielding a sensitivity of 86.89% and a specificity of 100% for distinguishing colorectal adenocarcinoma from normal tissue.
CONCLUSIONS:
These findings suggest that decreased expression of gelsolin is a potential biomarker of colorectal adenocarcinoma.
PMCID: PMC3275404
PMID: 22288069
Biomarker; Colorectal cancer; Gelsolin; Proteomic
MicroRNAs (miRNAs) are key regulators of gene expression at the post-transcription level. The present study specifically explored and compared the miRNA expression profiles of F. gigantica and F. hepatica using an integrated sequencing and bioinformatics platform and quantitative real-time PCR. Nineteen and 16 miRNA candidates were identified from F. gigantica and F. hepatica, respectively. The two parasites shared 11 miRNAs, with 8 also showing similarity to miRNAs of Schistosoma japonicum. Another 8 miRNAs were identified as F. gigantica-specific and 5 as F. hepatica-specific, most of which were novel. Predicted target analysis with 11465 mRNA and EST sequences of F. hepatica and F. gigantica revealed that all of the miRNAs had more than one target, ranging from 2 to 398 with an average of 51 targets. Some functions of the predicted targets were only found in F. gigantica, such as “transcription regulator”, while some others were only found in F. hepatica, such as “reproduction” and “response to stimulus”, indicating the different metabolism and gene regulation patterns of the two parasites. The present study represents the first global comparative characterization of miRNA expression profiles of F. gigantica and F. hepatica, which has provided novel valuable resources for a better understanding of the two zoonotic trematodes.
doi:10.1371/journal.pone.0053387
PMCID: PMC3534066
PMID: 23300925
AIM: To retrospectively analyze the imaging features of hepatic focal nodular hyperplasia (FNH) in children on dynamic contrast-enhanced multi-slice computed tomography (MSCT) and computed tomography angiography (CTA) images.
METHODS: From September 1999 to April 2012, a total of 218 cases of hepatic FNH were confirmed by either surgical resection or biopsy in the Sun Yat-sen Memorial Hospital of Sun Yat-sen University and the Cancer center of Sun Yat-sen University, including 12 cases (5.5%) of FNH in children (age ≤ 18 years old). All the 12 pediatric patients underwent MSCT. We retrospectively analyzed the imaging features of FNH lesions, including the number, location, size, margin, density of FNH demonstrated on pre-contrast and contrast-enhanced computed tomography (CT) scanning, central scar, fibrous septa, pseudocapsule, the morphology of the feeding arteries and the presence of draining vessels (portal vein or hepatic vein).
RESULTS: All the 12 pediatric cases of FNH had solitary lesion. The maximum diameter of the lesions was 4.0-12.9 cm, with an average diameter of 5.5 ± 2.5 cm. The majority of the FNH lesions (10/12, 83.3%) had well-defined margins. Central scar (10/12, 83.3%) and fibrous septa (11/12, 91.7%) were commonly found in children with FNH. Central scar was either isodense (n = 7) or hypodense (n = 3) on pre-contrast CT images and showed progressive enhancement in 8 cases in the equilibrium phase. Fibrous septa were linear hypodense areas in the arterial phase and isodense in the portal and equilibrium phases. Pseudocapsule was very rare (1/12, 8.3%) in pediatric FNH. With the exception of central scars and fibrous septa within the lesions, all 12 cases of pediatric FNH were homogenously enhanced on the contrast-enhanced CT images, significantly hyperdense in the arterial phase (12/12, 100.0%), and isodense in the portal venous phase (7/12, 58.3%) and equilibrium phase (11/12, 91.7%). Central feeding arteries inside the tumors were observed on CTA images for all 12 cases of FNH, whereas no neovascularization of malignant tumors was noted. In 9 cases (75.0%), there was a spoke-wheel shaped centrifugal blood supply inside the tumors. The draining hepatic vein was detected in 8 cases of pediatric FNH. However, the draining vessels in the other 4 cases could not be detected. No associated hepatic adenoma or hemangioma was observed in the livers of the 12 pediatric cases.
CONCLUSION: The characteristic imaging appearances of MSCT and CTA may reflect the pathological and hemodynamic features of pediatric FNH. Dynamic multi-phase MSCT and CTA imaging is an effective method for diagnosing FNH in children.
doi:10.3748/wjg.v18.i47.7048
PMCID: PMC3531693
PMID: 23323007
Focal nodular hyperplasia; Liver; Children; Benign hepatic lesions; X-ray; Computed tomography
Cifani, Carlo | Koya, Eisuke | Navarre, Brittany M. | Calu, Donna J. | Baumann, Michael H. | Marchant, Nathan J. | Liu, Qing-Rong | Khuc, Thi | Pickel, James | Lupica, Carl R. | Shaham, Yavin | Hope, Bruce T.
Relapse to maladaptive eating habits during dieting is often provoked by stress and there is evidence for a role of ovarian hormones in stress responses and feeding. We studied the role of these hormones in stress-induced reinstatement of food seeking and medial prefrontal cortex (mPFC) neuronal activation in c-fos-GFP transgenic female rats, which express green fluorescent protein (GFP) in strongly activated neurons. Food-restricted ovariectomized or sham-operated c-fos-GFP rats were trained to lever-press for palatable food pellets. Subsequently, lever-pressing was extinguished and reinstatement of food seeking and mPFC neuronal activation was assessed after injections of the pharmacological stressor yohimbine (0.5–2 mg/kg) or pellet priming (1–4 non-contingent pellets). Estrous cycle effects on reinstatement were also assessed in wild-type rats. Yohimbine- and pellet-priming-induced reinstatement was associated with Fos and GFP induction in mPFC; both reinstatement and neuronal activation were minimally affected by ovarian hormones in both c-fos-GFP and wild-type rats. c-fos-GFP transgenic rats were then used to assess glutamatergic synaptic alterations within activated GFP-positive and non-activated GFP-negative mPFC neurons following yohimbine-induced reinstatement of food seeking. This reinstatement was associated with reduced AMPAR/NMDAR current ratios and increased paired-pulse facilitation in activated GFP-positive but not GFP-negative neurons. Together, while ovarian hormones do not appear to play a role in stress-induced relapse of food seeking in our rat model, this reinstatement was associated with unique synaptic alterations in strongly activated mPFC neurons. Our paper introduces the c-fos-GFP transgenic rat as a new tool to study unique synaptic changes in activated neurons during behavior.
doi:10.1523/JNEUROSCI.5895-11.2012
PMCID: PMC3389493
PMID: 22723688
Diet; c-fos-GFP transgenic rats; Medial prefrontal cortex; Ovarian hormones; Reinstatement; Relapse; Stress; Yohimbine
Prolonged bed rest may cause changes in the autonomic nervous system that are related to cognition and emotion. This study adopted an emotional flanker task to evaluate the effect of 45 days -6° head-down bed rest (HDBR) on executive functioning in 16 healthy young men at each of six time points: the second-to-last day before the bed rest period, the eleventh, twentieth, thirty-second and fortieth day during the bed rest period, and the eighth day after the bed rest period. In addition, self-report inventories (Beck Anxiety Inventory, BAI; Beck Depression Inventory, BDI; Positive Affect and Negative Affect Scale, PANAS) were conducted to record emotional changes, and the participants’ galvanic skin response (GSR), heart rate (HR) and heart rate variability (HRV) were assessed as measures of physiological activity. The results showed that the participants’ reaction time on the flanker task increased significantly relative to their responses on the second-to-last day before the period of bed rest, their galvanic skin response weakened and their degrees of positive affect declined during the bed rest period. Our results provide some evidence for a detrimental effect of prolonged bed rest on executive functioning and positive affect. Whether this stems from a lack of aerobic physical activity and/or the effect of HDBR itself remains to be determined.
doi:10.1371/journal.pone.0052160
PMCID: PMC3524097
PMID: 23284916
Liu, Qing | Davit, Barbara M. | Cherstniakova, Svetlana A. | Dandamudi, Suman | Walters, Johnetta F. | Lee, Christina H. | Raines, Kimberly W. | Ren, Ke | Williamson, Leeh N. | Conner, Dale P.
ABSTRACT
Purpose
A generic product must meet the standards established by the Food and Drug Administration (FDA) to be approved for marketing in the USA. FDA approves a generic product for marketing if it is proved to be therapeutically equivalent to the reference product. Bioequivalence (BE) between a proposed generic product and its corresponding reference product is one of the major components of therapeutic equivalence. These approvals may be delayed if the BE portion of the submission is determined to be deficient. Many of these BE deficiencies recur commonly and can be avoided.
Method
We conducted a survey of the BE submissions to abbreviated new drug applications (ANDAs) over years 2001 to 2008 to identify the most commonly occurring BE deficiencies.
Results
Recurring deficiencies are found in a majority of the ANDAs reviewed by FDA’s Division of Bioequivalence. The most common deficiencies were the two deficiencies related to dissolution (method and specifications) found in 23.3% of the applications and analytical method validation and/or report found in 16.5% of the applications. The approval of generic drugs would be greatly accelerated if these deficiencies could be avoided.
doi:10.1208/s12248-011-9312-7
PMCID: PMC3291193
PMID: 22130775
ANDA; bioequivalence; common deficiency; FDA; Biomedicine; Biotechnology; Pharmacy; Pharmacology/Toxicology; Biochemistry, general
Tarkkonen, Kati M. | Nilsson, Emeli M. | Kähkönen, Tiina E. | Dey, Julien H. | Heikkilä, Jari E. | Tuomela, Johanna M. | Liu, Qing | Hynes, Nancy E. | Härkönen, Pirkko L. | Agoulnik, Irina
Fibroblast growth factors (FGFs) regulate the growth and progression of breast cancer. FGF signaling is transduced through FGF receptors 1–4, which have oncogenic or anti-oncogenic roles depending on the ligand and the cellular context. Our aim was to clarify the roles of FGFR1–3 in breast cancer cell growth in vitro and in vivo. Pools of S115 mouse breast cancer cells expressing shRNA against FGFR1, 2 and 3 were created by lentiviral gene transfer, resulting in cells with downregulated expression of FGFR1, FGFR2 or FGFR3 (shR1, shR2 and shR3 cells, respectively) and shLacZ controls. FGFR1-silenced shR1 cells formed small, poorly vascularized tumors in nude mice. Silencing of FGFR2 in shR2 cells was associated with strong upregulation of FGFR1 expression and the formation of large, highly vascularized tumors compared to the control tumors. Silencing FGFR3 did not affect cell survival or tumor growth. Overexpressing FGFR2 in control cells did not affect FGFR1 expression, suggesting that high FGFR1 expression in shR2 cells and tumors was associated with FGFR2 silencing by indirect mechanisms. The expression of FGFR1 was, however, increased by the addition of FGF-8 to starved shLacZ or MCF-7 cells and decreased by the FGFR inhibitor PD173074 in shR2 cells with an elevated FGFR1 level. In conclusion, our results demonstrate that FGFR1 is crucial for S115 breast cancer cell proliferation and tumor growth and angiogenesis, whereas FGFR2 and FGFR3 are less critical for the growth of these cells. The results also suggest that the expression of FGFR1 itself is regulated by FGF-8 and FGF signaling, which may be of importance in breast tumors expressing FGFs at a high level.
doi:10.1371/journal.pone.0049970
PMCID: PMC3503871
PMID: 23185502
Background
Chinese fir (Cunninghamia lanceolata) is an important timber species that accounts for 20–30% of the total commercial timber production in China. However, the available genomic information of Chinese fir is limited, and this severely encumbers functional genomic analysis and molecular breeding in Chinese fir. Recently, major advances in transcriptome sequencing have provided fast and cost-effective approaches to generate large expression datasets that have proven to be powerful tools to profile the transcriptomes of non-model organisms with undetermined genomes.
Results
In this study, the transcriptomes of nine tissues from Chinese fir were analyzed using the Illumina HiSeq™ 2000 sequencing platform. Approximately 40 million paired-end reads were obtained, generating 3.62 gigabase pairs of sequencing data. These reads were assembled into 83,248 unique sequences (i.e. Unigenes) with an average length of 449 bp, amounting to 37.40 Mb. A total of 73,779 Unigenes were supported by more than 5 reads, 42,663 (57.83%) had homologs in the NCBI non-redundant and Swiss-Prot protein databases, corresponding to 27,224 unique protein entries. Of these Unigenes, 16,750 were assigned to Gene Ontology classes, and 14,877 were clustered into orthologous groups. A total of 21,689 (29.40%) were mapped to 119 pathways by BLAST comparison against the Kyoto Encyclopedia of Genes and Genomes (KEGG) database. The majority of the genes encoding the enzymes in the biosynthetic pathways of cellulose and lignin were identified in the Unigene dataset by targeted searches of their annotations. And a number of candidate Chinese fir genes in the two metabolic pathways were discovered firstly. Eighteen genes related to cellulose and lignin biosynthesis were cloned for experimental validating of transcriptome data. Overall 49 Unigenes, covering different regions of these selected genes, were found by alignment. Their expression patterns in different tissues were analyzed by qRT-PCR to explore their putative functions.
Conclusions
A substantial fraction of transcript sequences was obtained from the deep sequencing of Chinese fir. The assembled Unigene dataset was used to discover candidate genes of cellulose and lignin biosynthesis. This transcriptome dataset will provide a comprehensive sequence resource for molecular genetics research of C. lanceolata.
doi:10.1186/1471-2164-13-648
PMCID: PMC3561127
PMID: 23171398
Chinese fir; De novo assembly; RNA-Seq; Transcriptome; Cellulose and lignin biosynthesis; Gene expression
Kupzig, Sabine | Deaconescu, Delia | Bouyoucef, Dalila | Walker, Simon A. | Liu, Qing | Polte, Christian L. | Daumke, Oliver | Ishizaki, Toshimasa | Lockyer, Peter J. | Wittinghofer, Alfred | Cullen, Peter J.
GAP1IP4BP is a member of the GAP1 family of Ras GTPase-activating proteins (Ras GAPs) that includes GAP1m, CAPRI, and RASAL. Composed of a central Ras GAP domain, surrounded by amino-terminal C2 domains and a carboxyl-terminal pleckstrin homology/Bruton’s tyrosine kinase domain, GAP1IP4BP has previously been shown to possess an unexpected GAP activity on the Ras-related protein Rap, besides the predicted Ras GAP activity (Cullen, P. J., Hsuan, J. J., Truong, O., Letcher, A. J., Jackson, T. R., Dawson, A. P., and Irvine, R. F. (1995) Nature 376, 527–530). Here we have shown that GAP1IP4BP is indeed an efficient Ras/Rap GAP, having Kms of 213 and 42 μM and estimated kcats of 48 and 16 s−1 for Ras and Rap, respectively. For this dual activity, regions outside the Ras GAP domain are required, as the isolated domain (residues 291–569) retains a pronounced Ras GAP activity yet has very low activity toward Rap. Interestingly, mutagenesis of the Ras GAP argi-nine finger, and surrounding residues important in Ras binding, inhibit both Ras and Rap GAP activity of GAP1IP4BP. Although the precise details by which GAP1IP4BP can function as a Rap GAP remain to be determined, these data are consistent with Rap associating with GAP1IP4BP through the Ras-binding site within the Ras GAP domain. Finally, we have established that such dual Ras/Rap GAP activity is not restricted to GAP1IP4BP. Although GAP1m appears to constitute a specific Ras GAP, CAPRI and RASAL display dual activity. For CAPRI, its Rap GAP activity is modulated upon its Ca2+-induced association with the plasma membrane.
doi:10.1074/jbc.M512802200
PMCID: PMC1904491
PMID: 16431904
Background
Omega-3 long-chain (≥C20) polyunsaturated fatty acids (ω3 LC-PUFA) have critical roles in human health and development with studies indicating that deficiencies in these fatty acids can increase the risk or severity of cardiovascular and inflammatory diseases in particular. These fatty acids are predominantly sourced from fish and algal oils, but it is widely recognised that there is an urgent need for an alternative and sustainable source of EPA and DHA. Since the earliest demonstrations of ω3 LC-PUFA engineering there has been good progress in engineering the C20 EPA with seed fatty acid levels similar to that observed in bulk fish oil (∼18%), although undesirable ω6 PUFA levels have also remained high.
Methodology/Principal Findings
The transgenic seed production of the particularly important C22 DHA has been problematic with many attempts resulting in the accumulation of EPA/DPA, but only a few percent of DHA. This study describes the production of up to 15% of the C22 fatty acid DHA in Arabidopsis thaliana seed oil with a high ω3/ω6 ratio. This was achieved using a transgenic pathway to increase the C18 ALA which was then converted to DHA by a microalgal Δ6-desaturase pathway.
Conclusions/Significance
The amount of DHA described in this study exceeds the 12% level at which DHA is generally found in bulk fish oil. This is a breakthrough in the development of sustainable alternative sources of DHA as this technology should be applicable in oilseed crops. One hectare of a Brassica napus crop containing 12% DHA in seed oil would produce as much DHA as approximately 10,000 fish.
doi:10.1371/journal.pone.0049165
PMCID: PMC3492320
PMID: 23145108
Background and Aims Eleusine
(Poaceae) is a small genus of the subfamily Chloridoideae exhibiting considerable morphological and ecological diversity in East Africa and the Americas. The interspecific phylogenetic relationships of Eleusine are investigated in order to identify its allotetraploid origin, and a chronogram is estimated to infer temporal relationships between palaeoenvironment changes and divergence of Eleusine in East Africa.
Methods
Two low-copy nuclear (LCN) markers, Pepc4 and EF-1α, were analysed using parsimony, likelihood and Bayesian approaches. A chronogram of Eleusine was inferred from a combined data set of six plastid DNA markers (ndhA intron, ndhF, rps16-trnK, rps16 intron, rps3, and rpl32-trnL) using the Bayesian dating method.
Key Results
The monophyly of Eleusine is strongly supported by sequence data from two LCN markers. In the cpDNA phylogeny, three tetraploid species (E. africana, E. coracana and E. kigeziensis) share a common ancestor with the E. indica–E. tristachya clade, which is considered a source of maternal parents for allotetraploids. Two homoeologous loci are isolated from three tetraploid species in the Pepc4 phylogeny, and the maternal parents receive further support. The A-type EF-1α sequences possess three characters, i.e. a large number of variations of intron 2; clade E-A distantly diverged from clade E-B and other diploid species; and seven deletions in intron 2, implying a possible derivation through a gene duplication event. The crown age of Eleusine and the allotetraploid lineage are 3·89 million years ago (mya) and 1·40 mya, respectively.
Conclusions
The molecular data support independent allotetraploid origins for E. kigeziensis and the E. africana–E. coracana clade. Both events may have involved diploids E. indica and E. tristachya as the maternal parents, but the paternal parents remain unidentified. The habitat-specific hypothesis is proposed to explain the divergence of Eleusine and its allotetraploid lineage.
doi:10.1093/aob/mcr231
PMCID: PMC3197458
PMID: 21880659
Allotetraploid origin; chloroplast markers; East Africa; Eleusine; low-copy nuclear markers; phylogeny; Poaceae
Qiu, Jie | Lv, Ling | Lin, Xiaojuan | Long, Lixia | Zhu, Daling | Xu, Ruifeng | Deng, Xiaohui | Li, Zhiyuan | Zhu, Lan | Kim, Christopher | Liu, Qing | Zhang, Yawei
Objective
To elucidate the influence of recreational physical activity, body mass index (BMI), and waist circumference on the risk of specific types of urinary incontinence.
Study design
We conducted a population-based cross-sectional survey in Gansu, China among 2603 women aged 20 years or older.
Results
The study found that BMI was positively associated with urinary incontinence (P for trend = 0.008) and the association was mainly observed for stress urinary incontinence (OR = 1.4, 95% CI: 1.1, 1.9 for BMI = 24.0–27.9 kg/m2; OR = 2.3, 95% CI: 1.5, 3.6 for BMI ≥ 28.0 kg/m2; P for trend = 0.0005). A positive association between stress incontinence (OR = 1.7, 95% CI: 1.2, 2.5) and waist circumference was observed for women who had waist circumference between 70 cm and 75 cm compared to waist circumference less than 70 cm. Recreational physical activity was inversely associated with overall and mixed urinary incontinence (P for trend <0.0001 for both). A significant interaction between physical activity and waist circumference was found for overall (P = 0.0007) and stress incontinence (P = 0.001).
Conclusions
The findings that physical activity inversely associated with urinary incontinence and its interaction with waist circumference warrant further investigation, particularly in prospective studies.
doi:10.1016/j.ejogrb.2011.07.016
PMCID: PMC3229870
PMID: 21821342
Recreational physical activity; Body mass index; Waist circumference; Female urinary incontinence
AIM
To investigate whether 15-Lipoxygenase-1 (15-LOX-1) plays an important role in the regulation of angiogenesis, inhibiting hypoxia-induced proliferation of retinal microvascular endothelial cells (RMVECs) and the underlying mechanism.
METHODS
Primary RMVECs were isolated from the retinas of C57/BL6J mice and identified by an evaluation for FITC-marked CD31. The hypoxia models were established with the Bio-bag and evaluated with a blood-gas analyzer. Experiments were performed using RMVECs treated with and without transfer Ad-15-LOX-1 or Ad-vector both under hypoxia and normoxia condition at 12, 24, 48, 72 hours. The efficacy of the gene transfer was assessed by immunofluorescence staining. Cells proliferation was evaluated by the CCK-8 method. RNA and protein expressions of 15-LOX-1, VEGF-A, VEGFR-2, eNOs and PPAR-r were analyzed by real-time reverse transcription polymerase chain reaction (RT-PCR) and Western blot.
RESULTS
Routine evaluation for FITC-marked CD31 showed that cells were pure. The results of blood-gas analysis showed that when the cultures were exposed to hypoxia for more than 2 hours, the Po2 was 4.5 to 5.4 Kpa. We verified RMVECs could be infected with Ad-15-LOX-1 or Ad-vector via Fluorescence microscopy. CCK-8 analysis revealed that the proliferative capacities of RMVECs in hypoxic group were significantly higher at each time point than they were in normoxic group (P<0.05). In a hypoxic condition, the proliferative capacities of RMVECs in 15-LOX-1 group were significantly inhibited (P<0.05). Real-time RT-PCR analysis revealed that the expressions of VEGF-A, VEGF-R2 and eNOs mRNA increased in hypoxia group compared with normoxia group (P<0.01). However, the expressions of 15-LOX-1, PPAR-r mRNA decreased in hypoxia group compared with normoxia group (P<0.01). It also showed that in a hypoxic condition, the expressions of VEGF-A, VEGF-R2 and eNOs mRNA decreased significantly in 15-LOX-1 group compared with hypoxia group (P<0.01). However, 15-LOX-1 and PPAR-r mRNA increased significantly in 15-LOX-1 group compared with hypoxia group (P<0.01). There was no significant difference of the mRNA expressions between vector group and hypoxia group (P>0.05). Western blot analysis revealed that the expressions of relative proteins were also ranked in that order.
CONCLUSION
Our results suggested that 15-LOX-1 and PPAR-r might act as a negative regulator of retinal angiogenesis. And the effect of 15-LOX-1 overexpression is an anti-angiogenic factor in hypoxia-induced retinal neovascularization (RNV). Overexpression 15-LOX-1 on RMVECs of hypoxia-induced RNV blocked signaling cascades by inhibiting hypoxia-induced increases in VEGF family. PPAR-r effect on VEGFR2 could be an additional mechanism whereby 15-LOX-1 inhibited the hypoxia-induced RNV.
doi:10.3980/j.issn.2222-3959.2012.05.04
PMCID: PMC3484709
PMID: 23166865
15-Lipoxygenase-1; hypoxia; retinal microvascular endothelial cells; retinal neovascularization
Background. Colorectal cancer (CRC) is one of the most common cancers in the world, identification of biomarkers for early detection of CRC represents a relevant target. The present study aims to determine serum peptidome patterns for CRC diagnosis.
Methods. The present work focused on serum proteomic analysis of 32 health volunteers and 38 CRC by ClinProt Kit combined with mass spectrometry. This approach allowed the construction of a peptide patterns able to differentiate the studied populations. An independent group of serum (including 33 health volunteers, 34 CRC, 16 colorectal adenoma, 36 esophageal carcinoma, and 31 gastric carcinoma samples) was used to verify the diagnostic and differential diagnostic capability of the peptidome patterns blindly. An immunoassay method was used to determine serum CEA of CRC and controls. Results. A quick classifier algorithm was used to construct the peptidome patterns for identification of CRC from controls. Two of the identified peaks at m/z 741 and 7772 were used to construct peptidome patterns, achieving an accuracy close to 100% (>CEA, P < 0.05). Furthermore, the peptidome patterns could differentiate validation group with high accuracy.
Conclusions. These results suggest that the ClinProt Kit combined with mass spectrometry yields significantly higher accuracy for the diagnosis and differential diagnosis of CRC.
doi:10.1155/2012/985020
PMCID: PMC3469310
PMID: 23091368
Postoperative radiotherapy has shown positive efficacy in lowering the recurrence rate and improving the survival rate in cases involving lymph node (LN) metastasis. However, the radiotherapy target volume remains controversial. Certain published studies have paid more attention to LNs found to be affected during surgery, while little effort has been made to study the LN metastatic pattern following surgery and its influence on the determination of the target volume of postoperative radiotherapy. In this study, the locoregional recurrence of esophageal squamous cell cancer was examined in 134 patients receiving radical surgery with two-field lymph node dissection from 2004 to 2009. In the 134 cases of recurrence, LN metastasis occurred in 126 patients (94.0%) while 13 patients (9.7%) developed anastomotic recurrence and 5 patients (3.7%) experienced tumor bed recurrence. The difference among the groups was statistically significant (P= 0.000). In the 126 cases with lymph node metastasis, the mediastinal metastasis rate (80.2%) was significantly higher compared with the rate of supraclavicular metastasis and abdominal metastasis (P= 0.000). A significant difference was identified between right and left supraclavicular LN metastasis (31.7% vs 16.7%, P= 0.005). Furthermore, the difference between the metastatic rates in the upper (73.8%), middle (39.7%) and lower mediastinum (1.6%) was statistically significant (P=0.000). Nevertheless, no significant correlation between the rate of LN metastasis was observed in the supraclavicular, mediastinal and abdominal regions for upper, middle and lower thoracic carcinomas (P= 0.404, P= 0.718 and P= 0.169, respectively). Based on our data, LN metastasis is the major locoregional recurrence pattern for esophageal squamous cell cancer following radical surgery. The high-risk lymphatic drainage areas include the supraclavicular nodes, recurrent laryngeal nerve nodes, azygos nodes and subcarinal nodes.
doi:10.3892/ol.2012.946
PMCID: PMC3525472
PMID: 23255948
esophageal squamous cell carcinoma; lymph node metastasis; postoperative recurrence; two-field esophagectomy
doi:10.1128/IAI.06258-11
PMCID: PMC3294674
As with other elements of the peripheral auditory system, spiral ganglion neurons display specializations that vary as a function of location along the tonotopic axis. Previous work has shown that voltage-gated K+ channels and synaptic proteins show graded changes in their density that confers rapid responsiveness to neurons in the high frequency, basal region of the cochlea and slower, more maintained responsiveness to neurons in the low frequency, apical region of the cochlea. In order to understand how voltage-gated calcium channels (VGCCs) may contribute to these diverse phenotypes, we identified the VGCC α-subunits expressed in the ganglion, investigated aspects of Ca2+-dependent neuronal firing patterns, and mapped the intracellular and intercellular distributions of seven VGCC α-subunits in the spiral ganglion in vitro.
Initial experiments with qRT-PCR showed that eight of the ten known VGCC α-subunits were expressed in the ganglion and electrophysiological analysis revealed firing patterns that were consistent with the presence of both LVA and HVA Ca2+ channels. Moreover, we were able to study seven of the α-subunits with immunocytochemistry, and we found that all were present in spiral ganglion neurons, and that three of them were neuron-specific (CaV1.3, CaV2.2, and CaV3.3). Further characterization of neuron-specific α-subunits showed that CaV1.3 and CaV3.3 were tonotopically-distributed, whereas CaV2.2 was uniformly distributed in apical and basal neurons. Multiple VGCC α-subunits were also immunolocalized to Schwann cells, having distinct intracellular localizations, and, significantly, appearing to distinguish putative compact0 (CaV2.3, CaV3.1) from loose (CaV1.2) myelin.
Electrophysiological evaluation of spiral ganglion neurons in the presence of TEA revealed Ca2+ plateau potentials with slopes that varied proportionately with the cochlear region from which neurons were isolated. Because afterhyperpolarizations were minimal or absent under these conditions, we hypothesize that differential density and/or kinetics of one or more of the VGCC α-subunits could account for observed tonotopic differences. These experiments have set the stage for defining the clear multiplicity of functional control in neurons and Schwann cells of the spiral ganglion.
doi:10.1016/j.heares.2011.01.016
PMCID: PMC3223918
PMID: 21281707
Spiral ganglion neurons; primary afferents; firing patterns; ion channels; calcium channels; VGCC; myelin; Schwann cells
Background
Identification of essential proteins plays a significant role in understanding minimal requirements for the cellular survival and development. Many computational methods have been proposed for predicting essential proteins by using the topological features of protein-protein interaction (PPI) networks. However, most of these methods ignored intrinsic biological meaning of proteins. Moreover, PPI data contains many false positives and false negatives. To overcome these limitations, recently many research groups have started to focus on identification of essential proteins by integrating PPI networks with other biological information. However, none of their methods has widely been acknowledged.
Results
By considering the facts that essential proteins are more evolutionarily conserved than nonessential proteins and essential proteins frequently bind each other, we propose an iteration method for predicting essential proteins by integrating the orthology with PPI networks, named by ION. Differently from other methods, ION identifies essential proteins depending on not only the connections between proteins but also their orthologous properties and features of their neighbors. ION is implemented to predict essential proteins in S. cerevisiae. Experimental results show that ION can achieve higher identification accuracy than eight other existing centrality methods in terms of area under the curve (AUC). Moreover, ION identifies a large amount of essential proteins which have been ignored by eight other existing centrality methods because of their low-connectivity. Many proteins ranked in top 100 by ION are both essential and belong to the complexes with certain biological functions. Furthermore, no matter how many reference organisms were selected, ION outperforms all eight other existing centrality methods. While using as many as possible reference organisms can improve the performance of ION. Additionally, ION also shows good prediction performance in E. coli K-12.
Conclusions
The accuracy of predicting essential proteins can be improved by integrating the orthology with PPI networks.
doi:10.1186/1752-0509-6-87
PMCID: PMC3472210
PMID: 22808943
Petrie, James R. | Vanhercke, Thomas | Shrestha, Pushkar | El Tahchy, Anna | White, Adam | Zhou, Xue-Rong | Liu, Qing | Mansour, Maged P. | Nichols, Peter D. | Singh, Surinder P.
PLoS ONE
2012;7(7):10.1371/annotation/f0547e8e-5cec-4ae4-8348-07f5aa3b8f34.
doi:10.1371/annotation/f0547e8e-5cec-4ae4-8348-07f5aa3b8f34
PMCID: PMC3393633