Sexual dimorphism in miR-210 expression and mitochondrial dysfunction in the placenta with maternal obesity

BACKGROUND

Maternal obesity is a major problem in obstetrics, and the placenta is involved in obesity-related complications via its roles at the maternal-fetal interface. We have recently shown a causative role for micro(mi)RNA-210, a so called 'hypoxamir' regulated by HIF-1α, in mitochondrial dysfunction in placentas from women with preeclampsia. We also reported mitochondrial dysfunction in placentas with maternal obesity. Here we hypothesized that expression of miR-210 is dysregulated in the placentas with obesity.

METHODS

Placentas from uncomplicated pregnancies were collected at term from healthy weight or control (CTRL, pre-pregnancy body mass index (BMI)<25), overweight (OW, BMI=25-24.9) and obese (OB, BMI>30) women following C-section with no labor. Expression of miRNA-210 and its target genes was measured by reverse transcription-PCR and Western Blot, respectively. Mitochondrial respiration was assessed by Seahorse Analyzer in syncytiotrophoblast (ST) 72 h after cytotrophoblast isolation.

RESULTS

Expression of miR-210 was significantly increased in placentas of OB and OW women with female but not male fetuses compared with CTRL placentas of females. However, expression of HIF-1α in these placentas remained unchanged. Levels of tumor-necrosis factor-alpha (TNFα) were increased in OW and OB placentas of females but not males, and in silico analysis suggested that activation of miR-210 expression in these placentas might be activated by NFκB1 (p50) signaling. Indeed, chromatin Immunoprecipitation assay showed that NFkB1 binds to placental miR-210 promoter in a fetal sex-dependent manner. Female but not male STs treated with TNFα showed overexpression of miR-210, reduction of mitochondrial target genes and decreased mitochondrial respiration. Pre-treatment of these STs with small interfering RNA to NFkB1 or antagomiR-210 prevented the TNFα-mediated inhibition of mitochondrial respiration.

CONCLUSIONS

Our data suggest that the inflammatory intrauterine environment associated with maternal obesity induces an NFκB1-mediated increase in miR-210 in a fetal sex-dependent manner, leading to inhibition of mitochondrial respiration and placental dysfunction in the placentas of female fetuses.

Biodegradable poly-lactic acid based-composite reinforced unidirectionally with high-strength magnesium alloy wires

Biodegradable poly-lactic acid (PLA)--based composites reinforced unidirectionally with high-strength magnesium alloy wires (MAWs) are fabricated by a heat-compressing process and the mechanical properties and degradation behavior are studied experimentally and theoretically. The composites possess improved strengthening and toughening properties. The bending strength and impact strength of the composites with 40 vol% MAWs are 190 MPa and 150 kJ/m(2), respectively, although PLA has a low viscosity and an average molecular weight of 60,000 g/mol. The mechanical properties of the composites can be further improved by internal structure modification and interface strengthening and a numerical model incorporating the equivalent section method (ESM) is proposed for the bending strength. Micro arc oxidization (MAO) of the MAWs is an effective interfacial strengthening method. The composites exhibit high strength retention during degradation and the PLA in the composite shows a smaller degradation rate than pure PLA. The novel biodegradable composites have large potential in bone fracture fixation under load-bearing conditions.

Sex-dependent activity of de novo methyltransferase 3 (Tudnmt3) in the two-spotted mite, Tetranychus urticae Koch

DNA methylation is an epigenetic mechanism for regulating developmental and other important processes in eukaryotes. Several components of the DNA methylation machinery have been identified, such as DNA methyltransferases. However, little is known about DNA methyltransferases in chelicerates, which is the second largest arthropod group. Epigenetics are expected to have a crucial role in the metabolism and development of this group. Here, we investigated the role of DNA methyltransferase 3 in the development of Tetranychus urticae Koch. In silico analyses clearly showed that this enzyme possesses the necessary conserved motifs for the catalytic activity of de novo methylation of DNA. Real-time PCR revealed that T. urticae de novo methyltransferase 3 (Tudnmt3) is expressed ubiquitously and throughout the life cycle of the two-spotted spider mite. However, the pattern of Tudnmt3 expression was sex-dependent during the adult stage. Whole in situ hybridization provided supportive evidence that Tudnmt3 is linked to the differentiation of the gonads in adult females and males. Methylation-sensitive amplification polymorphism analyses of 119 loci showed that the status of DNA methylation is partially different between adult females and males, raising the possibility that this sex-dependent DNA methylation pattern is mediated by different methylation activity of Tudnmt3.

The effect of demonstrator age and number on duration of socially-induced food preferences in house mouse (Mus domesticus)

Present research was undertaken to investigate whether the transfer of food preference from a demonstrator mouse to an observer can be influenced by their relative age. In experiment 1 an adult female mouse, the observer, was allowed to interact with a recently-fed demonstrator which was a pup of her litter or an adult female mouse. The observer was then tested to assess whether it acquired a preference for the demonstrator's diet. The results showed that a pup demonstrator's influence on an adult's food preference is shorter-lasting than an adult demonstrator's influence. Experiment 2 was aimed to investigate whether many demonstrators have an additive effect in influencing their observer's choice. The results indicated that multiple pup demonstrations do not increase longevity of food preferences induced by pup demonstrators. Moreover, the longevity of an adult observer's preference for its demonstrator's food is reduced by the exposure to multiple adult demonstrators. Results are discussed in terms of demonstrator's reliability and of social constraints that could affect social transfer of food information in the house mouse.

An introduction to clinical practice guideline for Chinese undergraduates in stomatology

The Society of Dental Education, Chinese Stomatological Association has formulated the Standards of Clinical Practice for Chinese Undergraduate Students Majoring in Stomatology, on the basis of extensively soliciting the views of experts in various fields. The aim of this standard is to guide clinical teaching and improve teaching quality in schools of stomatology in China. The standards include eight parts: the standard of clinical practice for oral and maxillofacial surgery, for cariology and endodontics, for periodontics, for the oral mucosa diseases, for preventive dentistry, for pedodontology, for prosthodontics and for oral imageology. Each part includes introduction to subjects, the clinical practice time period, the purpose and requirements of practice, the disease types of practice and items of clinical operation, the index of the lowest workload of practice and the major methods of assessment. These standards are not only the basic requirements and guiding principles for clinical teaching, but also the major criteria for assessing the clinical teaching quality of stomatological colleges/schools of China.

The expression and significance of TIPE2 in peripheral blood mononuclear cells from asthmatic children

Tumour necrosis factor-α-induced protein-8 like-2 (TIPE2) is a newly identified immune negative regulator. The abnormal expression of TIPE2 has been found in several human inflammatory diseases. However, the expression level and clinical significance of TIPE2 in childhood asthma remain unclear. In this study, we detected TIPE2 expression in peripheral blood mononuclear cells (PBMC) from 42 children with asthma and 39 healthy controls by RT-PCR, qRT-PCR and Western blot. We also detected the levels of serum total immunoglobulin E (IgE), eosinophil (EO), interleukin-4 (IL-4) and interferon-γ (IFN-γ) and analysed the correlations of TIPE2 expression with IgE, EO, IL-4 and IFN-γ. The results showed that TIPE2 mRNA and protein expression were decreased in children with asthma compared with healthy controls. The levels of IgE, EO and IL-4 in the children with asthma were obviously higher than those in normal controls, while the level of IFN-γ in patients with asthma was significantly lower than that in healthy subjects. Furthermore, the expression level of TIPE2 mRNA was negatively correlated with IgE, EO and IL-4. However, no statistically significant correlation was found between TIPE2 mRNA expression and serum IFN-γ level. In conclusion, our data suggest that reduced TIPE2 expression may contribute to the pathogenesis of childhood asthma.

A statistical mechanics model for receptor clustering

We introduce and study a simple lattice statistical mechanics modelfor the clustering of tumor necrosis factor receptor I (TNFR1).Our model explains clustering under over-expression of the cytoplasmicsignal transducer as well as the clustering induced via extracellularligand binding; also we explain why the loss of transducer leads to arapid break-up of the clusters. The basic mechanism at work is a first-order(cooperative) phase transition caused by the multimeric binding capability ofthe receptor-transducer complex. Using cooperativity of this type, the cellsare found to have an enhanced sensitivity and robustness. In general, ourmethod can be applied to other receptor-clustering related signaling system.

Knock-down of USP22 by small interfering RNA interference inhibits HepG2 cell proliferation and induces cell cycle arrest

The Ubiquitin--specific protease 22 (USP22) is a new putative cancer stem cell marker, which plays a significant role in tumorigenesis and cell--cycle progression. However, little is known about the impact of USP22 knock--down on the growth of human hepatoma cell lines. In this study, elevated expression of USP22 was observed in the human HepG2 hepatic cancer cell line compared to the normal human hepatocyte Chang liver cell line. Subsequently, we used siRNA specifically suppressing expression of USP22 and observed that the knock--down of USP22 could effectively induce cell cycle arrest and inhibit HepG2 cell proliferation. Furthermore, our results showed that USP22 deletion caused down--regulation of cyclin D2 expression and up--regulation of p15 and p21 expression. Collectively, Our findings indicate that USP22 may be responsible for HepG2 cell growth and USP22 regulates the cell cycle via the c--Myc/cyclin D2 pathway and down--regulating p15 and p21 expression in HepG2 cell.

Cell type-specific translational profiling in the Xenopus laevis retina

BACKGROUND

Translating Ribosome Affinity Purification (TRAP), a method recently developed to generate cell type-specific translational profiles, relies on creating transgenic lines of animals in which a tagged ribosomal protein is placed under regulatory control of a cell type-specific promoter. An antibody is then used to affinity purify the tagged ribosomes so that cell type-specific mRNAs can be isolated from whole tissue lysates.

RESULTS

Here, cell type-specific transgenic lines were generated to enable TRAP studies for retinal ganglion cells and rod photoreceptors in the Xenopus laevis retina. Using real time quantitative PCR for assessing expression levels of cell type-specific mRNAs, the TRAP method was shown to selectively isolate mRNAs expressed in the targeted cell and was efficient at purifying mRNAs expressed at both high and low levels. Statistical measures used to distinguish cell type-specific RNAs from low level background and non-specific RNAs showed TRAP to be highly effective in Xenopus.

CONCLUSIONS

TRAP can be used to purify mRNAs expressed in rod photoreceptors and retinal ganglion cells in X. laevis. The generated transgenic lines will enable numerous studies into the development, disease, and injury of the X. laevis retina.

Binding mechanism of patulin to heat-treated yeast cell

AIMS

This study aims to assess the removal mechanism of patulin using heat-treated Saccharomyces cerevisiae cells and identify the role of different cell wall components in the binding process.

METHODS AND RESULTS

In order to understand the binding mechanism, viable cells, heat-treated cells, cell wall and intracellular extract were performed to assess their ability to remove patulin. Additionally, the effects of chemical and enzymatic treatments of yeast on the binding ability were tested. The results showed that there was no significant difference between viable (53·28%) and heat-treated yeast cells (51·71%) in patulin binding. In addition, the cell wall fraction decreased patulin by 35·05%, and the cell extract nearly failed to bind patulin. Treatments with protease E, methanol, formaldehyde, periodate or urea significantly decreased (P < 0·05) the ability of heat-treated cells to remove patulin. Fourier transform infrared (FTIR) analysis indicated that more functional groups were involved in the binding process of heat-treated cells.

CONCLUSIONS

Polysaccharides and protein are important components of yeast cell wall involved in patulin removal. In addition, hydrophobic interactions play a major role in binding processes.

SIGNIFICANCE AND IMPACT OF THE STUDY

Heat-treated S. cerevisiae cells could be used to control patulin contamination in the apple juice industry. Also, our results proof that the patulin removal process is based mainly on the adsorption not degradation.

MIR-210 modulates mitochondrial respiration in placenta with preeclampsia

Preeclampsia (PE) affects 5-8% of all pregnancies and is associated with significant maternal and fetal morbidity and mortality. Placental mitochondrial dysfunction has been reported in PE. MicroRNAs (miRNA) are small non-coding RNAs that regulate gene expression through mRNA degradation and translational repression. MiR-210 has been previously shown to be upregulated in placentas from pregnancies complicated by PE. We hypothesized that placental mitochondrial dysfunction during PE can be mediated by miR-210. Placentas were collected at term from normotensive pregnancies (CTRL) and those complicated by severe PE (n = 6 each) following c-section (no labor). Villous tissue from PE showed significantly increased levels of HIF-1α compared to CTRL with no change in corresponding mRNA expression but with reduced DNA-binding activity. Mitochondrial complex III was significantly decreased in PE along with significantly reduced protein expression in complex I and IV during PE. Among the four miRNAs tested, miR-210 showed significant up regulation in PE and significant downregulation of its target, ISCU mRNA. To understand the role of miR-210 in PE, loss- and gain-of-function studies were performed using primary trophoblasts. Trophoblasts were transfected with miR-210 inhibitor or pre-miR-210 and mitochondrial function was measured using Seahorse Extracellular Flux Analyzer. Cells transfected with pre-miR-210 showed significant reduction in oxygen consumption. In contrast, transfection of trophoblast with AntagomiR-210 was sufficient to prevent the DFO-mediated respiratory deficiency. These data collectively suggest that miR-210 overexpression during PE could be responsible for placental mitochondria dysfunction.

Comparison of clinical efficacy and safety between denosumab and alendronate in postmenopausal women with osteoporosis: a meta-analysis

The aim of this study was to perform a head-to-head comparison of efficacy and safety profile between 60 mg denosumab (Den) subcutaneously (SC) per 6 months (Q6M) and 70 mg alendronate (Aln) orally per week (QW) for postmenopausal women with low bone mineral density. We searched electronic databases comparing efficacy and safety of Den SC Q6M and Aln QW in postmenopausal women. The primary outcomes of efficacy evaluation in included trials were incidence of clinical fracture in both groups and bone mineral density (BMD) at different skeletal sites. And adverse events (AEs), including incidence of neoplasms and infections, were considered as secondary outcomes. Following the instructions of 'Cochrane Handbook for systematic Reviews of Interventions 5.0.2', we identified eligible studies, evaluated the methodological quality and abstracted relevant data. Four heterogeneous randomised controlled trials (RCTs) involving 1942 women were identified. The results of review showed low evidence quality that supported the hypothesis the denosumab vs. alendronate could reduce risk of fracture [OR (95% CI) 1.42 (0.84 to 2.40), 11 more women per 1000 (from 4 fewer to 36 more), p = 0.19] but the moderate to high quality evidence suggesting treatment with 60 mg Den SC Q6M was more effective for postmenopausal women in increasing BMD [at distal radius (DR), total hip (TH), lumbar spine (LS), and femoral neck (FN)]. Hazards of neoplasms [OR (95% CI) 1.10 (0.65 to 1.86), 3 more per 1000 (from 10 fewer to 24 more), p = 0.62] or infections [OR (95% CI) 0.95 (0.79 to 1.15), 12 fewer per 1000 (from 53 fewer to 33 more,), p = 0.62] were appeared to be similar.Our review suggested within 1 year 60 mg Den SC Q6M treatment was more effective in increasing bone mass but could not reduce the fracture risk to a greater extent than 70 mg Aln QW therapy. Also the Den SC Q6M therapy did not increase the risks of neoplasms and infections compared with Aln QW.

Protease activated receptor 4 status of mast cells in post infectious irritable bowel syndrome

BACKGROUND

Growing evidence suggests that protease activated receptors (PARs) are mediators of persistent neuropathic pain, but their possible function as mediators in patients with post infectious irritable bowel syndrome (PI-IBS) remains to be further explored. This article aims to investigate the expression of PAR(2) and PAR(4) in the colonic mucosa of patients with PI-IBS, focusing on correlation with mast cell activation status.

METHODS

A total of 17 normal controls and 23 patients with PI-IBS volunteered the study. The expression and localization of PAR(2) and PAR(4) were investigated by RT-PCR and immunohistochemistry, and the expression of PAR(2) and PAR(4) in the mast cells was examined using double-immunofluorescence staining.

KEY RESULTS

The immunohistochemical study revealed that epithelial and submucosal cells showed immunoreactivity for both PAR(2) and PAR(4). Protease activated receptor 4 mRNA expression and immunoreactivity were down-regulated in PI-IBS compared with the control group. Specifically, a reduced immunoreactivity for PAR(4) was observed in mast cells of PI-IBS compared with normal controls, whereas there are no significant differences shown in PAR(2) between the PI-IBS and the control group. It is also found that the PAR(4) immunoreactivity decreases, while the activity of mast cells increases in PI-IBS rather than normal controls.

CONCLUSIONS & INFERENCES

This study outlines the down-regulation of PAR(4) in the mast cells of PI-IBS. It could be of considerable interests in understanding the mechanisms involved in the persistent colonic hypersensitivity and their potential role as therapeutic targets for PI-IBS.

Removal of uracil by uracil DNA glycosylase limits pemetrexed cytotoxicity: overriding the limit with methoxyamine to inhibit base excision repair

Uracil DNA glycosylase (UDG) specifically removes uracil bases from DNA, and its repair activity determines the sensitivity of the cell to anticancer agents that are capable of introducing uracil into DNA. In the present study, the participation of UDG in the response to pemetrexed-induced incorporation of uracil into DNA was studied using isogenic human tumor cell lines with or without UDG (UDG(+/+)/UDG(-/-)). UDG(-/-) cells were very sensitive to pemetrexed. Cell killing by pemetrexed was associated with genomic uracil accumulation, stalled DNA replication, and catastrophic DNA strand breaks. By contrast, UDG(+/+) cells were >10 times more resistant to pemetrexed due to the rapid removal of uracil from DNA by UDG and subsequent repair of the resultant AP sites (abasic sites) via the base excision repair (BER). The resistance to pemetrexed in UDG(+/+) cells could be reversed by the addition of methoxyamine (MX), which binds to AP sites and interrupts BER pathway. Furthermore, MX-bound AP sites induced cell death was related to their cytotoxic effect of dual inactivation of UDG and topoisomerase IIα, two genes that are highly expressed in lung cancer cells in comparison with normal cells. Thus, targeting BER-based therapy exhibits more selective cytotoxicity on cancer cells through a synthetic lethal mechanism.

Surface nanomechanical behavior of ZrN and ZrCN films deposited on NiTi shape memory alloy by magnetron sputtering

Surface nanomechanical behavior under nanoindentation of ZrN and ZrCN film on NiTi substrate was studied. The surface hardness and modulus of the films increase initially with larger nanoindentation depths and then reach their maximum values. Afterwards, they diminish gradually and finally reaching plateau values which are the composite modulus and composite hardness derived from the ZrN/ZrCN film and NiTi substrate. They are higher than those of electropolished NiTi SMA due to the properties of ZrN and ZrCN. In comparison, the surface nanomechanical properties of electropolished NiTi exhibit a different change with depths.

Association of the ANTXR2 gene polymorphism and ankylosing spondylitis in Chinese Han

OBJECTIVE

Ankylosing spondylitis (AS) is an inflammatory disease of unknown origin. Both genetic and environmental factors are involved. A recent genome-wide association study (GWAS) found anthrax toxin receptor 2 (ANTXR2) to be associated with AS in Caucasians. We aimed to investigate whether the ANTXR2 polymorphism is also associated with AS in a Chinese Shandong Han population.

METHODS

From 2008 to 2009, we recruited 309 patients with AS and 384 age- and sex-matched controls of Han nationality. We selected six single nucleotide polymorphisms (SNPs) of ANTXR2 (rs4333130, rs6534708, rs6818557, rs12646132, rs12509658, and rs13140055) and genotyped them by polymerase chain reaction restriction fragment-length polymorphism (PCR-RFLP) and Taqman methods. We analysed linkage disequilibrium and constructed haplotypes.

RESULTS

Cases and controls did not differ in the frequency of ANTXR2 alleles, genotypes, or haplotypes. Thus, the six SNPs of ANTXR2 are not associated with AS in our Chinese Shandong Han population.

CONCLUSIONS

ANTXR2 might not be a susceptibility gene of AS in Chinese Han.

The FLOWERING LOCUS T orthologous gene of Platanus acerifolia is expressed as alternatively spliced forms with distinct spatial and temporal patterns

The FLOWERING LOCUS T (FT) protein is a likely component of the 'florigen' signal that plays a crucial role in regulating the transition from vegetative to reproductive growth. Here, we report the isolation of full-length cDNAs and the corresponding genomic clones encoding orthologous FT proteins (PaFT) of London plane (Platanus acerifolia Willd). Two genes with high sequence identity were isolated (PaFT1-2), but 34 different transcript products were identified, comprising 21 splice forms produced by alternative splicing of the PaFT pre-mRNAs. Expression of the alternative splicing forms of PaFT varied according to tissue type and developmental stage. PaFT transcripts were detected throughout adult trees, whereas in juvenile trees they were only detected in dormant sub-petiolar buds. In adult trees, levels of the various alternative splicing PaFT forms were related to flower development stage and tree dormancy. Ectopic expression of the archetypal splice form of PaFT-A in tobacco and Arabidopsis developed multiple altered phenotypes, notably early flowering and attenuation of apical dominance. The evidence in this study indicates that complex alternative processing of PaFT transcripts in P. acerifolia may be associated with multiple regulatory roles, including initiation of flowering, flower development, apical dominance, tree dormancy and dormancy release.

Perivascular visceral adipose tissue induces atherosclerosis in apolipoprotein E deficient mice

OBJECTIVE

Epicardial adipose tissue is associated with coronary artery disease, however the causal relationship between perivascular adipose tissue and local atherogenesis is unclear.

METHODS AND RESULTS

Apolipoprotein E deficient (ApoE(-/-)) mice underwent transplantation of visceral or subcutaneous adipose tissue immediately adjacent to the right common carotid artery. Carotid arteries with fat transplants were analyzed for atherosclerosis by surface oil-red-O staining and cross-sectional analysis. Vascular function of the carotid arteries was assessed using pressure myography. Visceral fat transplants were also performed to ApoE(-/-) mice with neutralization of P-selectin glycoprotein ligand-1 (Psgl-1). Atherosclerosis surface area and lesion thickness were greater in mice receiving the perivascular visceral fat compared to the subcutaneous fat. Mice with visceral fat transplants also displayed more complicated atherosclerotic lesions with evidence of atherothrombosis. Serum Mcp-1 was higher in mice receiving visceral fat transplants compared to subcutaneous transplants. Visceral fat transplantation also caused impaired endothelial-dependent relaxation of the carotid artery. Psgl-1 deficiency or neutralization of Psgl-1 with an anti-Psgl-1 antibody was protective against perivascular visceral adipose tissue-induced atherosclerosis and was associated with reduced Mcp-1 levels.

CONCLUSIONS

Perivascular visceral fat leads to endothelial dysfunction and accelerated atherosclerosis. This proatherogenic effect of perivascular adipose tissue is blocked by neutralization of Psgl-1.

Vitamin D insufficiency in Brazilian patients with SLE: prevalence, associated factors, and relationship with activity

The influence of vitamin D on the severity of systemic lupus erythematosus (SLE) has been studied. Our objectives were to determine the prevalence of vitamin D insufficiency in Brazilian lupus patients and its relationship with demographic, clinical, and laboratory variables and to study the relationship between vitamin D insufficiency and disease activity. This is a cross-sectional study of 159 SLE patients. Levels of serum 25-hydroxyvitamin D (25(OH)D) <30 ng/ml were defined as vitamin D insufficiency and <20 ng/ml as deficiency. Data collected included sex, age, ethnicity, postmenopausal status, disease duration, cumulative amount of oral glucocorticoids (GC) in the last six months, duration of GC usage, calcium and vitamin D supplements, photosensitivity, sunscreen usage, sun exposure, diabetes mellitus, creatinine clearance, lifestyle habits, and smoking. Disease activity was measured by the SLE Disease Activity Index 2000 (SLEDAI-2K). Bivariate statistical analysis was performed using the Mann-Whitney test, Spearman's correlation coefficient, Chi-square test, and Fisher's exact test. Multivariate analysis was performed with multiple linear regression. The prevalence of vitamin D insufficiency and deficiency were 37.7% and 8.2%, respectively. Levels of 25(OH) D were not associated with lupus activity score, disease duration, sun exposure, vitamin D supplementation, or use of corticosteroids.

Protective effects of bone morphogenetic protein 7 against amyloid-beta induced neurotoxicity in PC12 cells

Bone morphogenetic protein 7 (BMP7) has neuroprotective effects against ischemia, oxidation stress, and lipopolysaccharide, but its role on amyloid-beta (Aβ)-induced neurotoxicity in Alzheimer's disease (AD) and the underlying mechanisms remain unclear. In this study, we exposed PC12 cells to Aβ25-35 for 26 h to induce neurotoxicity, and added exogenous BMP7 at 2 h to observe the neuroprotective effects. The protective mechanisms involved, mostly related to inhibition of cell apoptosis and oxidation stress, were analyzed. In rat in vivo experiments, we bilaterally injected Aβ1-40 into the basal forebrain to simulate neuropathological processes in AD, performed the Morris water maze test to evaluate the effect of Aβ on spatial learning and memory, and explored the change of endogenous BMP7 expression in the brain. The present study demonstrated that BMP7 prevented neuronal injuries in PC12 cells induced by Aβ25-35, including cell apoptosis and morphological impairment of dendrites as well as oxidation stress. BMP7 treatment significantly protected PC12 cells against Aβ25-35-induced injury and inhibited the increasing content of the Bax gene and the decreasing activities of superoxide dismutase (SOD). Aβ1-40 bilaterally injected into the rat basal forebrain obviously inhibited the rat's spatial learning ability and memory, and significantly induced downregulation of endogenous BMP7 in the basal forebrain while upregulating it in the hippocampus. Our results suggest that BMP7 has neuroprotective effects against Aβ, which may be mediated through inhibition of Bax gene expression during cell apoptosis and elevation of SOD activities during the oxidative stress response. On the other hand, endogenous BMP7 may have a potential self-modulation capacity through negative feedback between the region of the basal forebrain and the hippocampus as a protective cytokine.

Deletion of the betaine-GABA transporter (BGT1; slc6a12) gene does not affect seizure thresholds of adult mice

Gamma-aminobutyric acid (GABA) is the major inhibitory neurotransmitter in the mammalian brain. Once released, it is removed from the extracellular space by cellular uptake catalyzed by GABA transporter proteins. Four GABA transporters (GAT1, GAT2, GAT3 and BGT1) have been identified. Inhibition of the GAT1 by the clinically available anti-epileptic drug tiagabine has been an effective strategy for the treatment of some patients with partial seizures. Recently, the investigational drug EF1502, which inhibits both GAT1 and BGT1, was found to exert an anti-convulsant action synergistic to that of tiagabine, supposedly due to inhibition of BGT1. The present study addresses the role of BGT1 in seizure control and the effect of EF1502 by developing and exploring a new mouse line lacking exons 3-5 of the BGT1 (slc6a12) gene. The deletion of this sequence abolishes the expression of BGT1 mRNA. However, homozygous BGT1-deficient mice have normal development and show seizure susceptibility indistinguishable from that in wild-type mice in a variety of seizure threshold models including: corneal kindling, the minimal clonic and minimal tonic extension seizure threshold tests, the 6Hz seizure threshold test, and the i.v. pentylenetetrazol threshold test. We confirm that BGT1 mRNA is present in the brain, but find that the levels are several hundred times lower than those of GAT1 mRNA; possibly explaining the apparent lack of phenotype. In conclusion, the present results do not support a role for BGT1 in the control of seizure susceptibility and cannot provide a mechanistic understanding of the synergism that has been previously reported with tiagabine and EF1502.

Contribution of the epithelial-mesenchymal (EMT) phenotype to the sensitivity of colorectal cancer cell lines to the p21-activated kinase inhibitor, PF-3758309

438

Background: Increased expression of p21–activated kinase (PAK) family proteins has been observed in a range of malignancies including those of breast, ovarian, colorectal (CRC), and pancreatic origin. PAK (PAK 1-6) proteins are critical mediators of cell proliferation, motility, transcription, and translation. In initial studies, we demonstrated that the PAK4 inhibitor, PF-3758309, exhibited robust single agent efficacy against selected CRC cell lines, with IC50s of less than 0.015 uM, whereas some cell lines were relatively resistant to the agent, with IC50s of greater than 1 uM. In subsequent gene array analyses, CRC cell lines sensitive or resistant to PF-3758309 exhibited overexpression of core genes associated with a mesenchymal or epithelial phenotype, respectively. Thus, the goal of this study was to assess the functional consequences of altering the expression of EMT-associated genes and to seek rational combination partners in CRC.

Methods: CRC cell lines that were sensitive to PF-3758309 (IC50=0.015 uM) were transfected with selected short hairpin- (sh)RNAs or micro-(mi)RNAs that are known to regulate EMT. Semi-quantitative RT-PCR and immunoblotting were performed to confirm target knockdown. The transfected cell lines were then exposed to increasing concentrations of PF-3758309 to determine the functional role of these genes in conferring responsiveness to PF-3758309.

Results: Sensitive CRC cell lines were transfected with shRNAs to Zeb1, vimentin, and caldesmon, genes that are associated with a mesenchymal phenotype. Interestingly, when the cell lines were exposed to increasing concentrations of PF- 3758309 they demonstrated a ′right shift′ towards a more resistant phenotype. Likewise, transfection with miRNA 200c, a known suppressor of Zeb1, resulted in a similar shift towards resistance.

Conclusions: These data suggest that the EMT phenotype may play a functional role in determining CRC sensitivity to the PAK4 inhibitor PF-3758309, and in addition, a rational combination targeting the epithelial phenotype with epidermal growth factor receptor inhibitors, may be warranted.

[Table: see text]

Diagnosis and microsurgery of symptomatic spontaneous spinal epidural hematoma

BACKGROUND

Symptomatic spontaneous spinal epidural hematoma (SSEH) is an uncommon cause of cord compression that needs emergent treatment. Without effective management of the symptomatic SSEH, irreversible severe spinal injury would be possible.

OBJECTIVES

We aimed to investigate the diagnosis and surgical management of symptomatic SSEH.

METHODS

Five cases of symptomatic SSEH with favorable neurological recovery after emergent microsurgery were prospectively analysed.

RESULTS

The main clinical presentations were root pain and palsy. The main manifestations of MRI were long-segment epidural lesions of high intensity on T1- and T2-weighted images without enhancement. Laminectomy via posterior approach and hematoma removal were undergone for all patients. All patients achieved full neurological recovery without complications.

CONCLUSIONS

MRI manifestation assisted with the main clinical symptoms may aid the preoperative diagnosis of SSEH, and the delay in obtaining preoperative Digital subtraction angiography is worthwhile, especially for those with progressive neurological deterioration.

Iron-Stimulated N(2) Fixation and Growth in Natural and Cultured Populations of the Planktonic Marine Cyanobacteria Trichodesmium spp

In light of recent proposals that iron (Fe) availability may play an important role in controlling oceanic primary production and nutrient flux, its regulatory impact on N(2) fixation and production dynamics was investigated in the widespread and biogeochemically important diazotrophic, planktonic cyanobacteria Trichodesmium spp. Fe additions, as FeCl(3) and EDTA-chelated FeCl(3), enhanced N(2) fixation (nitrogenase activity), photosynthesis (CO(2) fixation), and growth (chlorophyll a production) in both naturally occurring and cultured (on unenriched oligotrophic seawater) Trichodesmium populations. Maximum enhancement of these processes occurred under FeEDTA-amended conditions. On occasions, EDTA alone led to enhancement. No evidence for previously proposed molybdenum or phosphorus limitation was found. Our findings geographically extend support for Fe limitation of N(2) fixation and primary production to tropical and subtropical oligotrophic ocean waters often characterized by Trichodesmium blooms.

The Treg/Th17 imbalance in patients with idiopathic dilated cardiomyopathy

To assess whether Treg/Th17 balance was broken in patients with idiopathic dilated cardiomyopathy (DCM). We studied 25 patients who were diagnosed as idiopathic DCM (18 men and seven women, mean age 35.6 +/- 5.2) and 25 normal persons (18 men and seven women, mean age 33.8 +/- 4.9). Then, we detected Treg/Th17 functions on different levels including cell frequencies, related cytokine secretion and key transcription factors in patients with idiopathic DCM and controls. The results demonstrated that patients with idiopathic DCM revealed significant increase in peripheral Th17 number, Th17-related cytokines (IL-17, IL-6, IL-23) and transcription factor (RORgammat) levels and obvious decrease in Treg number, Treg-related cytokines (TGF-beta1 and IL-10) and transcription factor (Foxp3) levels when compared to normal persons. Results indicated that Treg/Th17 functional imbalance existed in patients with idiopathic DCM, suggesting a potential role for Treg/Th17 imbalance in the development of idiopathic DCM.