PMCC PMCC

Search tips
Search criteria

Advanced
Results 1-25 (28)
 

Clipboard (0)
None

Select a Filter Below

Journals
more »
Year of Publication
Document Types
1.  SAV742, a Novel AraC-Family Regulator from Streptomyces avermitilis, Controls Avermectin Biosynthesis, Cell Growth and Development 
Scientific Reports  2016;6:36915.
Avermectins are useful anthelmintic antibiotics produced by Streptomyces avermitilis. We demonstrated that a novel AraC-family transcriptional regulator in this species, SAV742, is a global regulator that negatively controls avermectin biosynthesis and cell growth, but positively controls morphological differentiation. Deletion of its gene, sav_742, increased avermectin production and dry cell weight, but caused delayed formation of aerial hyphae and spores. SAV742 directly inhibited avermectin production by repressing transcription of ave structural genes, and also directly regulated its own gene (sav_742) and adjacent gene sig8 (sav_741). The precise SAV742-binding site on its own promoter region was determined by DNase I footprinting assay coupled with site-directed DNA mutagenesis, and 5-nt inverted repeats (GCCGA-n10/n12-TCGGC) were found to be essential for SAV742 binding. Similar 5-nt inverted repeats separated by 3, 10 or 15 nt were found in the promoter regions of target ave genes and sig8. The SAV742 regulon was predicted based on bioinformatic analysis. Twenty-six new SAV742 targets were identified and experimentally confirmed, including genes involved in primary metabolism, secondary metabolism and development. Our findings indicate that SAV742 plays crucial roles in not only avermectin biosynthesis but also coordination of complex physiological processes in S. avermitilis.
doi:10.1038/srep36915
PMCID: PMC5107987  PMID: 27841302
2.  Effects of Di-(2-ethylhexyl) Phthalate on Lipid Metabolism by the JAK/STAT Pathway in Rats 
The most widely used plasticizer, di-(2-ethylhexyl) phthalate (DEHP), is known to affect lipid metabolism and adipogenesis. We studied the effects of dietary DEHP exposure on metabolism in rats as well as the role of the JAK/STAT pathway in this process. Eighty rats were exposed to DEHP (0, 5, 50 and 500 mg/kg/d) through dietary intake for 4 weeks. We then collected blood samples, liver, and adipose tissues to detect modifications in the levels of serum lipids, leptin, adiponectin and insulin. JAK3, STAT5a and PPARγ expression were detected at both the gene and protein levels. The activation of JAK3 and STAT5a was also detected. The DEHP-exposed rats had increased body weight, serum lipid, insulin, and leptin levels. Moreover, the JAK3/STAT5a pathway was activated in the adipose tissue; however, this pathway was not activated in the liver. The mRNA of SREBP-1c in the liver was increased significantly among each of the groups, in contrast to the levels found in the mature SREBP-1c protein form. Furthermore, the expression of FABP4, Acox and FASn was decreased in the liver, but increased in adipose tissue. Thus, we conclude that exposure to DEHP reduces the hydrolysis of lipid and promotes triglyceride accumulation by oppositely regulating the activation state of JAK/STAT pathway in the liver and adipose tissue, resulting in the disorder of body lipid metabolism and obesity.
doi:10.3390/ijerph13111085
PMCID: PMC5129295  PMID: 27827939
di-(2-ethylhexyl) phthalate; JAK/STAT; lipid metabolism; adipose tissue
3.  Effects of Di-(2-ethylhexyl) Phthalate on the Hypothalamus–Uterus in Pubertal Female Rats 
The pollution of endocrine disruptors and its impact on human reproductive system have attracted much attention. Di-(2-ethylhexyl) phthalate (DEHP), an environmental endocrine disruptor, is widely used in food packages, containers, medical supplies and children’s toys. It can cause diseases such as infertility, sexual precocity and uterine bleeding and thus arouse concerns from the society and scholars. The effect of DEHP on pubertal female reproductive system is still not well-studied. This study was to investigate the effects of DEHP on the hypothalamus–uterus in pubertal female rats, reveal the reproductive toxicity of DEHP on pubertal female rats and its mechanism, and provide scientific evidence for the evaluation of toxicity and toxic mechanism of DEHP on reproductive system. Forty-eight pubertal female rats were randomly divided into four groups and respectively administered via oral gavage 0, 250, 500, or 1000 mg/kg/d DEHP in 0.1 mL corn oil/20 g body weight for up to four weeks. Compared with control rats, the DEHP-treated rats showed: (1) higher gonadotropin-releasing hormone (GnRH) level in the hypothalamus; (2) higher protein levels of GnRH in the hypothalamus; and (3) higher mRNA and protein levels of GnRH receptor (GnRHR) in the uterus. Our data reveal that DEHP exposure may lead to a disruption in pubertal female rats and an imbalance of hypothalamus–uterus. Meanwhile, DEHP may, through the GnRH in the hypothalamus and its receptor on the uterus, lead to diseases of the uterus. DEHP may impose a negative influence on the development and functioning of the reproductive system in pubertal female rats.
doi:10.3390/ijerph13111130
PMCID: PMC5129340  PMID: 27845755
di-(2-ethylhcxyl) phthalate; hypothalamus; uterus; reproductive toxicity; pubertal
4.  Contrast-Enhanced Ultrasonography with Quantitative Analysis allows Differentiation of Renal Tumor Histotypes 
Scientific Reports  2016;6:35081.
Totally 85 patients with 93 renal lesions who underwent contrast-enhanced ultrasound (CEUS) were retrospectively studied with quantitative analysis to evaluate its value in the differential diagnosis of renal tumor histotypes. CEUS characteristics were analysed including the enhancement patterns, peak intensity, homogeneity of enhancement, and pseudocapsule. Quantitative parameters of peak intensity (P) and time to peak (TP) were measured with QontraXt software, and the index “relative enhancement percentage” ΔP% and “difference in TP between tumor and cortex” ΔTP were used to quantify the CEUS features of renal tumors. There are significant difference in CEUS features between the 46 clear cell renal cell carcinoma (CCRCC) and other types of renal tumors, including 17 low malignant lesions, 11 urothelial carcinoma of the renal pelvis, and 19 renal angiomyolipoma. The differences lie in the peak intensity, the homogeneity, the time of wash-in, peak, clearance and presence of pseudocapsule. The ΔTP and ΔP% of the CCRCC is significantly different from other tumors. With “fast to peak + high peak intensity” as the main criterion, assisted with “heterogeneous enhancement” and “fast wash-in” as the secondary criteria, the diagnostic accuracy of CCRCC is 91.4%, demonstrating quantitative CEUS imaging is highly valuable in differentiating CCRCC from other tumors.
doi:10.1038/srep35081
PMCID: PMC5057121  PMID: 27725761
5.  Genetic association of Toll-like receptor 4 gene and coronary artery disease in a Chinese Han population 
SpringerPlus  2016;5(1):1533.
Purpose
Toll-like receptor 4 (TLR4) is known to be involved in innate immunity and inflammatory responses that play important roles in the pathogenesis of coronary artery disease (CAD). But the relationship between TLR4 gene and CAD has yet to be investigated. The present study aimed to evaluate the association of TLR4 gene polymorphisms with CAD susceptibility in a Chinese Han population.
Methods
A total of 1094 subjects (577 unrelated patients with CAD and 517 controls) were recruited between 2008 and 2012. Three tag SNPs (rs1927907, rs1927911 and rs11536889) present in the TLR4 gene were genotyped using Sequenom Mass-ARRAY system.
Results
The genotypic distributions of the three SNPs were not deviate from Hardy–Weinberg equilibrium. There was no significant difference in distributions of allelic frequencies of each SNPs between healthy controls and CAD patients (P > 0.05). Genotype frequencies of TLR4 gene did not show any statistically significant difference between the two groups in co-dominant, dominant or recessive genetic models (P > 0.05). The frequency of haplotypes in the case group was similar to that in the control group (P > 0.05).
Conclusion
TLR4 gene do not relate to genetic susceptibility of CAD in the Chinese Han population.
doi:10.1186/s40064-016-3177-2
PMCID: PMC5019996  PMID: 27652106
Coronary artery disease; Gene polymorphism; Toll-like receptor 4
6.  Quantitative Study of Elasticity of Rabbit VX2 Liver Tumor with Alternated Cooling and Heating Treatment based on ARFI Ultrasound Imaging Technique 
Scientific Reports  2016;6:29303.
Acoustic radiation force impulse (ARFI) ultrasound imaging technique is used to quantitatively evaluate the elasticity of rabbit VX2 liver tumor with alternated cooling and heating treatment (ACHT). ACHT was performed on fifteen VX2 liver tumor models established in fifteen male New Zealand white rabbits with open tumor plant. ARFI was performed on day 0, 1, 7 and 14 after ACHT and shear wave velocity (SWV) in ARFI was recorded to evaluate the elasticity of the treated area. The SWV value of the lesion on day 0, 1, 7 and 14 was 2.33 ± 0.19 m/s, 3.09 ± 0.40 m/s, 2.64 ± 0.37 m/s and 2.26 ± 0.24 m/s, respectively, indicating the treated areas get stiffer on day 1 and then get softer gradually by day. All the difference between adjacent time points was statistically significant. The SWV value of different parts on day 7 approved that the hardness of the treated area is heterogenous: the treated area in the center >the peripheral strip-shaped area >normal liver tissues, consistent with pathological changes. Meanwhile, ARFI combined with conventional US imaging can qualitatively and quantitatively exam the healing process of rabbit VX2 liver tumor after ACHT, and corresponds well to the pathological results.
doi:10.1038/srep29303
PMCID: PMC4933955  PMID: 27381362
7.  Roles of the Picornaviral 3C Proteinase in the Viral Life Cycle and Host Cells 
Viruses  2016;8(3):82.
The Picornaviridae family comprises a large group of non-enveloped viruses that have a major impact on human and veterinary health. The viral genome contains one open reading frame encoding a single polyprotein that can be processed by viral proteinases. The crucial 3C proteinases (3Cpros) of picornaviruses share similar spatial structures and it is becoming apparent that 3Cpro plays a significant role in the viral life cycle and virus host interaction. Importantly, the proteinase and RNA-binding activity of 3Cpro are involved in viral polyprotein processing and the initiation of viral RNA synthesis. In addition, 3Cpro can induce the cleavage of certain cellular factors required for transcription, translation and nucleocytoplasmic trafficking to modulate cell physiology for viral replication. Due to interactions between 3Cpro and these essential factors, 3Cpro is also involved in viral pathogenesis to support efficient infection. Furthermore, based on the structural conservation, the development of irreversible inhibitors and discovery of non-covalent inhibitors for 3Cpro are ongoing and a better understanding of the roles played by 3Cpro may provide insights into the development of potential antiviral treatments. In this review, the current knowledge regarding the structural features, multiple functions in the viral life cycle, pathogen host interaction, and development of antiviral compounds for 3Cpro is summarized.
doi:10.3390/v8030082
PMCID: PMC4810272  PMID: 26999188
3Cpro; structure; viral replication; translation initiation; pathogenesis; protease inhibitor
8.  Efficiency of two nitrification inhibitors (dicyandiamide and 3, 4-dimethypyrazole phosphate) on soil nitrogen transformations and plant productivity: a meta-analysis 
Scientific Reports  2016;6:22075.
Dicyandiamide (DCD) and 3, 4-dimethypyrazole phosphate (DMPP) are often claimed to be efficient in regulating soil N transformations and influencing plant productivity, but the difference of their performances across field sites is less clear. Here we applied a meta-analysis approach to compare effectiveness of DCD and DMPP across field trials. Our results showed that DCD and DMPP were equally effective in altering soil inorganic N content, dissolve inorganic N (DIN) leaching and nitrous oxide (N2O) emissions. DCD was more effective than DMPP on increasing plant productivity. An increase of crop yield by DMPP was generally only observed in alkaline soil. The cost and benefit analysis (CBA) showed that applying fertilizer N with DCD produced additional revenues of $109.49 ha−1 yr−1 for maize farms, equivalent to 6.02% increase in grain revenues. In comparisons, DMPP application produced less monetary benefit of $15.67 ha−1 yr−1. Our findings showed that DCD had an advantage of bringing more net monetary benefit over DMPP. But this may be weakened by the higher toxicity of DCD than DMPP especially after continuous DCD application. Alternatively, an option related to net monetary benefit may be achieved through applying DMPP in alkaline soil and reducing the cost of purchasing DMPP products.
doi:10.1038/srep22075
PMCID: PMC4763264  PMID: 26902689
9.  A cotton miRNA is involved in regulation of plant response to salt stress 
Scientific Reports  2016;6:19736.
The present study functionally identified a new microRNA (microRNA ovual line 5, miRNVL5) with its target gene GhCHR from cotton (Gossypium hirsutum). The sequence of miRNVL5 precursor is 104 nt long, with a well developed secondary structure. GhCHR contains two DC1 and three PHD Cys/His-rich domains, suggesting that GhCHR encodes a zinc-finger domain-containing transcription factor. miRNVL5 and GhCHR express at various developmental stages of cotton. Under salt stress (50–400 mM NaCl), miRNVL5 expression was repressed, with concomitant high expression of GhCHR in cotton seedlings. Ectopic expression of GhCHR in Arabidopsis conferred salt stress tolerance by reducing Na+ accumulation in plants and improving primary root growth and biomass. Interestingly, Arabidopsis constitutively expressing miRNVL5 showed hypersensitivity to salt stress. A GhCHR orthorlous gene At2g44380 from Arabidopsis that can be cleaved by miRNVL5 was identified by degradome sequencing, but no confidential miRNVL5 homologs in Arabidopsis have been identified. Microarray analysis of miRNVL5 transgenic Arabidopsis showed six downstream genes (CBF1, CBF2, CBF3, ERF4, AT3G22920, and AT3G49200), which were induced by salt stress in wild-type but repressed in miRNVL5-expressing Arabidopsis. These results indicate that miRNVL5 is involved in regulation of plant response to salt stress.
doi:10.1038/srep19736
PMCID: PMC4728436  PMID: 26813144
10.  East Asian Monsoon Signals Reflected in Temperature and Precipitation Changes over the Past 300 Years in the Middle and Lower Reaches of the Yangtze River 
PLoS ONE  2015;10(6):e0131159.
Based on observational data and Asian monsoon intensity datasets from China, the relationships between the East Asian winter monsoon index and winter temperature, the East Asian summer monsoon index and Meiyu precipitation over the middle and lower reaches of the Yangtze River, were analyzed. We found that the monsoon signals were reflected in the temperature and Meiyu precipitation variations. Thus, we used the reconstructed Meiyu precipitation and winter temperature series for the past 300 years and detected the summer/winter monsoon intensity signals using multi-taper spectral estimation method and wavelet analysis. The main periodicities of Meiyu precipitation and winter temperature, such as interannual cycle with 2–7-year, interdecadal-centennial cycles with 30–40-year and 50–100-year, were found. The good relationships between the East Asian summer and winter monsoons suggested that they were in phase at 31-year cycle, while out of phase at 100-year cycle, but with 20-year phase difference. In addition, the winter monsoon intensity may be regulated by the North Atlantic Oscillation, the Arctic Oscillation and the Atlantic Multidecadal Oscillation, and the summer monsoon is closely related to the signal intensities of the Pacific Decadal Oscillation.
doi:10.1371/journal.pone.0131159
PMCID: PMC4479470  PMID: 26107375
11.  MicroRNA-26a inhibits proliferation by targeting high mobility group AT-hook 1 in breast cancer 
Objectives: To investigate the crucial role of miR-26a in breast cancer and to validate whether miR-26a could regulate proliferation of breast cancer cells by targeting high mobility group AT-hook 1 (HMGA1). Methods: Reverse transcription-polymerase chain reaction (RT-PCR) was used to quantify the expression levels of miR-26a in breast cancer and adjacent non-cancerous breast tissues. MTT, cell migration and invasion assay were carried out to characterize the miR-26a function. Finally, to validate the target gene of miR-26a, luciferase reporter assay was employed, followed by RT-PCR and Western blot confirmation. Results: Compared with normal tissues, a significant down-regulation of miR-26a expression was observed in breast cancer tissues (P=0.002). miR-26a suppresses MDA-MB-231 and Mcf-7 breast cancer cell lines proliferation and motility. The luciferase activity was significantly decreased after co-transfection with psiCHECK-2/HMGA1 3’-UTR and miR-26a mimics in comparison with control cells, and qRT-PCR and Western blotting analysis found that HMGA1 expression at the mRNA and protein levels decreased in the miR-26a mimic-treatment group relative to NC. MTT assay showed that down regulation of HMGA1 by siRNA could significantly enhance the tumor-suppressive effect of miR-26a (P < 0.05). Conclusions: The results of the present study indicate that miR-26a may be associated with human breast carcinogenesis, which inhibits tumor cell proliferation by targeting HMGA1.
PMCID: PMC4348937  PMID: 25755724
Breast cancer; HMGA1; miR-26a; proliferation
12.  The loss of taste genes in cetaceans 
Background
Five basic taste modalities, sour, sweet, bitter, salt and umami, can be distinguished by humans and are fundamental for physical and ecological adaptations in mammals. Molecular genetic studies of the receptor genes for these tastes have been conducted in terrestrial mammals; however, little is known about the evolution and adaptation of these genes in marine mammals.
Results
Here, all five basic taste modalities, sour, sweet, bitter, salt and umami, were investigated in cetaceans. The sequence characteristics and evolutionary analyses of taste receptor genes suggested that nearly all cetaceans may have lost all taste modalities except for that of salt.
Conclusions
This is the first study to comprehensively examine the five basic taste modalities in cetaceans with extensive taxa sampling. Our results suggest that cetaceans have lost four of the basic taste modalities including sour, sweet, umami, and most of the ability to sense bitter tastes. The integrity of the candidate salt taste receptor genes in all the cetaceans examined may be because of their function in Na+ reabsorption, which is key to osmoregulation and aquatic adaptation.
Electronic supplementary material
The online version of this article (doi:10.1186/s12862-014-0218-8) contains supplementary material, which is available to authorized users.
doi:10.1186/s12862-014-0218-8
PMCID: PMC4232718  PMID: 25305673
Cetacean; Taste genes; Pseudogenization; Molecular evolution
13.  Blood Lead Levels and Associated Factors among Children in Guiyu of China: A Population-Based Study 
PLoS ONE  2014;9(8):e105470.
Objectives
Children's health problems caused by the electronic waste (e-waste) lead exposure in China remains. To assess children's blood lead levels (BLLs) in Guiyu of China and investigate risk factors of children's elevated BLLs in Guiyu.
Material and Methods
842 children under 11 years of age from Guiyu and Haojiang were enrolled in this population-based study during 2011–2013. Participants completed a lifestyle and residential environment questionnaire and their physical growth indices were measured, and blood samples taken. Blood samples were tested to assess BLLs. Children's BLLs between the two groups were compared and factors associated with elevated BLLs among Guiyu children were analyzed by group Lasso logistic regression model.
Results
Children living in Guiyu had significant higher BLLs (7.06 µg/dL) than the quantity (5.89 µg/dL) of Haojiang children (P<0.05). Subgroup analyses of BLLs exceeding 10 µg/dL showed the proportion (24.80%) of high-level BLLs for Guiyu children was greater than that (12.84%) in Haojiang (P<0.05). Boys had greater BLLs than girls, irrespectively of areas (P<0.05). The number of e-waste piles or recycling workshops around the house (odds ratio, 2.28; 95% confidence interval [CI], 1.37 to 3.87) significantly contributed to the elevated BLLs of children in Guiyu, and girls had less risk (odds ratio, 0.51; 95% CI, 0.31 to 0.83) of e-waste lead exposure than boys.
Conclusions
This analysis reinforces the importance of shifting e-waste recycling piles or workshops to non-populated areas as part of a comprehensive response to e-waste lead exposure control in Guiyu. To correct the problem of lead poisoning in children in Guiyu should be a long-term mission.
doi:10.1371/journal.pone.0105470
PMCID: PMC4138148  PMID: 25136795
14.  Dynamic Transcription of Long Non-Coding RNA Genes during CD4+ T Cell Development and Activation 
PLoS ONE  2014;9(7):e101588.
Background
Recent evidence shows that long non-coding RNA (LncRNA) play important regulatory roles in many biology process, including cell development, activation and oncogenesis. However, the roles of these LncRNAs in the development and activation of CD4+ T cells, which is an important component of immune response, remain unknown.
Results
To predict the function of LncRNA in the development and activation of CD4+ T cells, first, we examined the expression profiles of LncRNAs and mRNAs in CD4−CD8− (DN), CD4+CD8+ (DP), CD4+CD8−, and activated CD4+CD8− T cells in a microarray analysis and verified these results by real time PCRs (qPCR). We found that the expression of hundreds of LncRNAs significantly changed in each process of developmental transition, including DN into DP, DP into CD4+CD8−, and CD4+CD8− into activated CD4+ T cells. A Kendall distance analysis suggested that the expression of LncRNAs in DN, DP, CD4+CD8− T cells and activated CD4+ T cells were correlated with the expression of mRNAs in these T cells. The Blat algorithm and GO analysis suggested that LncRNAs may exert important roles in the development and activation of CD4+ T cells. These roles included proliferation, homeostasis, maturation, activation, migration, apoptosis and calcium ion transportation.
Conclusion
The present study found that the expression profiles of LncRNAs in different stages of CD4+ T cells are distinguishable. LncRNAs are involved in the key biological process in CD4+ T cell development and activation.
doi:10.1371/journal.pone.0101588
PMCID: PMC4086894  PMID: 25003630
15.  Inhibitory effects of subcutaneous tumors in nude mice mediated by low-frequency ultrasound and microbubbles 
Oncology Letters  2014;7(5):1385-1390.
The aim of the present study was to investigate the sonication effects of 21-kHz ultrasound (US) with microbubbles (MBs) on the subcutaneous prostate tumors of nude mice. In total, 15 tumor-bearing nude mice were divided into three groups: The control group, the low-frequency US group and the US+MB group. The MBs used were from US contrast agent SonoVue. The parameters of the US were as follows: 21 kHz, 26 mW/cm2 and a 40% duty cycle (2 sec on, 3 sec off) for 3 min, once every other day for 2 weeks. Color Doppler flow imaging, hematoxylin and eosin (HE) staining, immunoblotting and transmission electron microscopy (TEM) were used to evaluate the results. Following 2 weeks of treatment, the blood flow signal disappeared in the US+MB group only, and the tumor size was smaller when compared with the control and US groups. For the immunoblotting, the intensity of cyclooxygenase-2 and vascular endothelial growth factor in the US+MB group was lower compared with the other two groups. Tumor necrosis was present and the nucleus disappeared upon HE staining in the US+MB group. Upon TEM analysis, increased cytoplasmic vacuolation and dilatation of the perinuclear cisternae of the tumor cells were found in the US+MB group. In the control and US groups, the tumors had intact vascular endothelia and vessel lumens. However, lumen occlusion of the vessels was observed in the US+MB group. In conclusion, 21-kHz low-intensity US with MBs may result in vessel occlusion and growth inhibitory effects in the subcutaneous tumors of nude mice.
doi:10.3892/ol.2014.1934
PMCID: PMC3997662  PMID: 24765142
ultrasound; low frequency; microbubbles; cavitation
16.  Cost-Utility of Lateral-Flow Urine Lipoarabinomannan for Tuberculosis Diagnosis in HIV-infected African Adults 
Setting
Inpatient hospitals in South Africa and Uganda
Objective
To evaluate the cost-effectiveness of a lateral flow urine lipoarabinomannan (LAM) test when added to existing strategies for tuberculosis (TB) diagnosis in HIV-infected adults (CD4+ T-cell counts<100 cells/μL) with symptoms of active TB.
Design
Decision-analytic cost-utility model with the primary outcome being the incremental cost-effectiveness ratio (ICER), expressed in 2010 US dollars per disability-adjusted life year (DALY) averted, from the perspective of a public-sector TB control program.
Results and Conclusion
For every 1000 patients tested, adding lateral-flow urine LAM generated 80 incremental appropriate TB treatments and averted 224 DALYs. Estimated cost-utility was $353 per DALY averted (95% uncertainty range: $192–$1161) in South Africa and $86 per DALY averted (95% uncertainty range: $49–$239) in Uganda, reflecting the lower treatment costs in Uganda. Cost-utility was most sensitive to assay specificity, cost of TB treatment, life expectancy after TB cure, and cohort TB prevalence but did not rise above $1500 per DALY averted in South Africa under any one-way sensitivity analysis. The probability of acceptability was >99.8% at a per-DALY willingness-to-pay threshold equal to the per-capita gross domestic product in South Africa ($7275) and Uganda ($509).
doi:10.5588/ijtld.12.0627
PMCID: PMC3918209  PMID: 23485389
17.  miR394 and LCR are involved in Arabidopsis salt and drought stress responses in an abscisic acid-dependent manner 
BMC Plant Biology  2013;13:210.
Background
MicroRNAs (miRNAs) are a class of short, endogenous non-coding small RNAs that have ability to base pair with their target mRNAs to induce their degradation in plants. miR394a/b are conserved small RNAs and its target gene LCR (LEAF CURLING RESPONSIVENESS) encodes an F-box protein (SKP1-Cullin/CDC53-F-box) but whether miR394a/b and its target gene LCR are involved in regulation of plant response to abscisic acid (ABA) and abiotic stresses is unknown.
Results
Mature miR394 and precursor miR394a/b are shown to be slightly induced by ABA. By contrast, LCR expression is depressed by ABA. Analysis of LCR and its promoter (pLCR::GUS) revealed that LCR is expressed at all development stages. MIR394a/b over-expression (35S::MIR394a/b) and lcr (LCR loss of function) mutant plants are hypersensitive to salt stress, but LCR over-expressing (35S::m5LCR) plants display the salt-tolerant phenotype. Both 35S::MIR394a/b and lcr plants are highly tolerant to severe drought stress compared with wild-type, but 35S::m5LCR plants are susceptible to water deficiency. Over-expression of MIR394a/b led to ABA hypersensitivity and ABA-associated phenotypes, whereas 35S::m5LCR plants show ABA resistance phenotypes. Moreover, 35S::MIR394a/b plants accumulated higher levels of ABA-induced hydrogen peroxide and superoxide anion radicals than wild-type and 35S::m5LCR plants. Expressions of ABA- and stress-responsive genes, ABI3, ABI4, ABI5, ABF3, and ABF4 are up-regulated in MIR394a/b over-expressing plants but down-regulated in 35S::m5LCR plants. Over-expression of MIR394a in abi4-1 or abi5-1 background resulted in loss of ABA-sensitivity in 35S::MIR394a plants.
Conclusions
The silencing of LCR mRNA by miR394 is essential to maintain a certain phenotype favorable for the adaptive response to abiotic stresses. The contrasting phenotypes of salt and drought responses may be mediated by a functional balance between miR394 and LCR. If the balance is perturbed in case of the abiotic stress, an identical phenotype related to the stress response occurs, resulting in either ABA sensitive or insensitive response. Thus, miR394-regulated LCR abundance may allow plants to fine-tune their responses to ABA and abiotic stress.
doi:10.1186/1471-2229-13-210
PMCID: PMC3870963  PMID: 24330668
miR394; LCR; Abscisic acid; Salinity; Drought; Arabidopsis
18.  Intervention Effects of Ganoderma Lucidum Spores on Epileptiform Discharge Hippocampal Neurons and Expression of Neurotrophin-4 and N-Cadherin 
PLoS ONE  2013;8(4):e61687.
Epilepsy can cause cerebral transient dysfunctions. Ganoderma lucidum spores (GLS), a traditional Chinese medicinal herb, has shown some antiepileptic effects in our previous studies. This was the first study of the effects of GLS on cultured primary hippocampal neurons, treated with Mg2+ free medium. This in vitro model of epileptiform discharge hippocampal neurons allowed us to investigate the anti-epileptic effects and mechanism of GLS activity. Primary hippocampal neurons from <1 day old rats were cultured and their morphologies observed under fluorescence microscope. Neurons were confirmed by immunofluorescent staining of neuron specific enolase (NSE). Sterile method for GLS generation was investigated and serial dilutions of GLS were used to test the maximum non-toxic concentration of GLS on hippocampal neurons. The optimized concentration of GLS of 0.122 mg/ml was identified and used for subsequent analysis. Using the in vitro model, hippocampal neurons were divided into 4 groups for subsequent treatment i) control, ii) model (incubated with Mg2+ free medium for 3 hours), iii) GLS group I (incubated with Mg2+ free medium containing GLS for 3 hours and replaced with normal medium and incubated for 6 hours) and iv) GLS group II (neurons incubated with Mg2+ free medium for 3 hours then replaced with a normal medium containing GLS for 6 hours). Neurotrophin-4 and N-Cadherin protein expression were detected using Western blot. The results showed that the number of normal hippocampal neurons increased and the morphologies of hippocampal neurons were well preserved after GLS treatment. Furthermore, the expression of neurotrophin-4 was significantly increased while the expression of N-Cadherin was decreased in the GLS treated group compared with the model group. This data indicates that GLS may protect hippocampal neurons by promoting neurotrophin-4 expression and inhibiting N-Cadherin expression.
doi:10.1371/journal.pone.0061687
PMCID: PMC3634853  PMID: 23637882
19.  Development of a Non-Invasive Method, Multiplex Methylation Specific PCR (MMSP), for Early Diagnosis of Nasopharyngeal Carcinoma 
PLoS ONE  2012;7(11):e45908.
Increasing evidence demonstrated that inactivation of tumor suppressor genes (TSGs) by aberrant promoter methylation is an early event during carcinogenesis. Aiming at developing early diagnostic or prognostic tools for various tumors, we took an EBV-associated tumor, nasopharyngeal carcinoma (NPC), as a model and developed a powerful assay based on “multiplex methylation specific-PCR (MMSP)”. The MMSP assay was designed to detect tumor-specific methylation status of several NPC-related genes and was capable of acquiring multiplex information simultaneously through a single PCR reaction with the tiny tumor DNA derived from the direct body fluid close to the primary tumor. In this study, we collected paired nasopharyngeal (NP) swabs and NPC biopsies from 49 NPC patients and twenty noncancerous controls. A panel of markers including two EBV, and two cellular TSG markers were applied in this NPC-specific-MMSP assay. We optimized the working condition of MMSP so that it provides information equal to that from the corresponding separate PCRs. The results showed that MMSP patterns of NPC swab were largely consistent with those of corresponding biopsies and significantly distinguished themselves from those of 20 noncancerous volunteers. Among the 69 samples (49 NPCs and 20 normal controls), the sensitivity of detecting NPC from NP swabs is 98%. The specificity is as high as 100%. In conclusion, being characterized by its noninvasiveness, high reproducibility and informativeness, MMSP assay is a reliable and potential diagnostic tool for NPC. It paves the way for the development of population screening and early diagnosis approaches for various tumor types.
doi:10.1371/journal.pone.0045908
PMCID: PMC3489875  PMID: 23144779
20.  Chronic Activation of the G Protein-Coupled Receptor 30 with Agonist G-1 Attenuates Heart Failure 
PLoS ONE  2012;7(10):e48185.
G protein-coupled receptor (GPR) 30 is a novel estrogen receptor. Recent studies suggest that activation of the GPR30 confers rapid cardioprotection in isolated rat heart. It is unknown whether chronic activation of GPR30 is beneficial or not for heart failure. In this study we investigated the cardiac effect of sustained activation or inhibition of GPR30. Female Sprague–Dawley rats were divided into 7 groups #2Q1: sham surgery (Sham), bilateral ovariectomy (OVX), OVX+estrogen (E2), OVX+isoproterenol (ISO), OVX+ISO+G-1, OVX+ISO+E2+G15, OVX+ISO+E2. ISO (85 mg/kg×17 day, sc) was given to make the heart failure models. G-1(120 µg/kg·d×14 day) was used to activate GPR30 and G15 (190 µg/kg·d×14 day) was used to inhibit GPR30. Concentration of brain natriuretic peptide in serum, masson staining in isolated heart, contractile function and the expression of β1 and β2- adrenergic receptor (AR) of ventricular myocytes were also determined. Our data showed that ISO treatment led to heart failure in OVX rats. G-1 or E2 treatment decreased concentration of brain natriuretic peptide, reduced cardiac fibrosis, and enhanced contraction of the heart. Combined treatment with β1 (CGP20712A) and β2-AR (ICI118551) antagonist abolished the improvement of myocardial function induced by G-1. We also found that chronic treatment with G-1 normalized the expression of β1-AR and increased the expression of β2-AR. Our results indicate that chronic activation of the GPR30 with its agonist G-1 attenuates heart failure by normalizing the expression of β1-AR and increasing the expression of β2-AR.
doi:10.1371/journal.pone.0048185
PMCID: PMC3482180  PMID: 23110207
21.  Ammine(2,2′-bipyridine-κ2 N,N′)silver(I) nitrate: a dimer formed by π–π stacking and ligand-unsupported Ag⋯Ag inter­actions 
Reaction of AgNO3 and 2,2′-bipyridine (bipy) under ultrasonic treatment gave the title compound, [Ag(C10H8N2)(NH3)]NO3. The crystal structure consists of dimers formed by two symmetry-related AgI–bipy monomers connected through intra-dimer π–π stacking and ligand-unsupported Ag⋯Ag inter­actions. A crystallographic C2 axis passes through the mid-point of and is perpendicular to the Ag⋯Agi(−x + 1, y, −z + ) axis. In addition, each AgI cation is coordinated by one chelating bipy ligand and one ammine ligand, giving a trigonal coordination environment capped by the symmetry-equivalent Ag atom. Mol­ecules are assembled by Ag⋯Ag, π–π, hydrogen-bond (N—H⋯O and C—H⋯O) and weak Ag⋯π inter­actions into a three-dimensional framework. Comparing the products synthesized under different mechanical treatments, we found that reaction conditions have a significant influence on the resulting structures. The luminescence properties of the title compound are also discussed.
doi:10.1107/S010827011000377X
PMCID: PMC2855567  PMID: 20203399
22.  Bis[diamminesilver(I)] 5-nitro­iso­phthalate monohydrate 
In the title compound, [Ag(NH3)2]2(C8H3NO6)·H2O, the cations have an almost linear coordination geometry with two ammine ligands and inter­act with the water mol­ecules [Ag⋯Owater = 2.725 (4) and 2.985 (4) Å]. In the crystal, N—H⋯O and O—H⋯O hydrogen bonds, combined with weak (lone pair)⋯π [O⋯centroid distance = 3.401 (4) Å] and π–π stacking [centroid–centroid distance = 3.975 (3) Å] inter­actions, stabilize the three-dimensional supra­molecular network.
doi:10.1107/S1600536810007725
PMCID: PMC2983872  PMID: 21580507
23.  Tetra­aqua­tetra­kis{μ3-3,3′-[(E,E)-ethane-1,2-diylbis(nitrilo­methyl­idyne)]benzene-1,2-diolato}octa­zinc(II) N,N-dimethyl­formamide hexa­solvate 
The asymmetric unit of the title compound [Zn8(C16H12N2O4)4(H2O)4]·6C3H7NO, consists of eight ZnII cations, four tetra­valent anionic ligands, L 4− (L 4− = 3,3′-(1E,1′E)-(ethane-1,2-diylbis(azan-1-yl-1-yl­idene))bis­(methan-1-yl-1-yl­idene)dibenzene-1,2-bis­(olate), four coordinated water mol­ecules and six N,N-dimethyl­formamide solvate mol­ecules. The coordination complex comprises an octa­nuclear ZnII unit with its ZnII centers coordinated in two discrete distorted square-pyramidal geometries. Four ZnII atoms each coordinate to two nitro­gen atoms and two phenolate oxygen atoms from an individual L 4− ligand and one coordinated water mol­ecule. The other four ZnII atoms each bind to five phenolate oxygen atoms from three different L 4− ligands. In the crystal structure, the ZnII complex unit, coordinated water mol­ecules and dimethyl­formamide solvate mol­ecules are linked via O—H⋯O and C—H⋯O hydrogen bonds. Mol­ecules are connected by additional inter­molecular O—H⋯O and C—H⋯O hydrogen bonds, forming an extensive three dimensional framework.
doi:10.1107/S1600536809046923
PMCID: PMC2972079  PMID: 21578596
24.  5-Bromo-2,3-dihydro-1H-cyclo­penta­[a]naphthalen-1-one 
The title compound, C13H9BrO, has been synthesized by the intra­molecular Friedel–Crafts reaction of 1-(1-bromo-4-naphth­yl)-3-chloro­propan-1-one. There are two approximately planar [maximum deviations of 0.8 (2) and 0.4 (2) Å in the two mol­ecules] molecules in the asymmetric unit. The dihedral angle between their mean planes is 19.72 (8)°. Weak inter­molecular C—H⋯O hydrogen bonding is present in the crystal structure.
doi:10.1107/S1600536809031547
PMCID: PMC2970092  PMID: 21577580
25.  Poly[(μ2-4,4′-bipyridine)bis­(μ4-5-tert-butyl­isophthalato)bis­(μ3-5-tert-butyl­isophthalato)di-μ3-hydroxido-penta­zinc(II)] 
The asymmetric unit of the title compound, [Zn5(C12H12O4)4(OH)2(C10H8N2)]n, consists of three ZnII ions (one of which is located on a twofold rotation axis), two 5-tert-butyl­isophthalate ligands, one 4,4′-bipyridine ligand and one hydroxide group. The five ZnII ions form a penta­nuclear zinc cluster, which is further bridged by ten organic ligands, forming two-dimensional sheets. The central zinc ion of the cluster has site symmetry 2 and is octahedrally coordinated in a N2O4 donor set, whereas the other four zinc atoms are tetrahedrally coordinated by four O atoms. The coordination modes for the 5-tert-butyl­isophthalates are bis­(bidentate) or bidentate-monodentate. Hydrogen bonds are formed between adjacent sheets through the hydroxide groups and the O atoms of the monodentate carboxyl­ate groups. The two tert-butyl groups are disordered over two positions with ratios of 0.64 (2):0.36 (2) and 0.85 (3):0.15 (3).
doi:10.1107/S1600536809031365
PMCID: PMC2969937  PMID: 21577432

Results 1-25 (28)