DEC1 directly interacts with estrogen receptor (ER) α to suppress proliferation of ER-positive breast cancer cells.

Aberrant ERα signaling and altered circadian rhythms are both features of ER-positive breast cancer, however, the molecular interaction between them is still not fully understood. Herein, we analyzed the interplay between the circadian rhythm molecule DEC1 and ERα and its effect on the proliferation of ER-positive breast cancer cells, providing a new clue for clarifying the pathogenesis of breast cancer. In this study, we revealed that DEC1 negatively regulates the proliferation of ER-positive breast cancer MCF-7 cells through interaction with ERα protein. DEC1 co-localized with ERα in the nucleus of MCF7 cells, stabilized ERα protein independently of its transcriptional activity and without affecting by estrogen stimulation and inhibited the degradation of ERα mediated by CHX in a time-dependent manner. Moreover, results from luciferase reporter assay showed that overexpression of DEC1 significantly inhibits ERα-mediated transcriptional activity in a dose-dependent manner. These results together suggested that DEC1 may serve as a co-repressor of ERα in ER-positive breast cancer. Although DEC1 improved the stability of ERα and alleviated protein degradation, DEC1 inhibited the proliferation of MCF7 cells by decreasing ERα-mediated signal transduction.

Strong Association of Lipid Metabolism Related MicroRNA Binding Sites Polymorphisms with the Risk of Late Onset Alzheimer's Disease.

Although altered lipid metabolism has been extensively implicated in the pathogenesis of late onset Alzheimer's disease (LOAD) through cell biological and epidemiological studies, genetic studies linking lipid metabolism and LOAD are still not well understood. MicroRNAs (miRNAs) exert posttranscriptional down-regulation and their target sequence on the 3' untranslated regions (3'UTR) may be altered by single nucleotide polymorphisms (SNPs). We therefore explore whether the six loci in Clusterin gene (CLU) (rs9331949), Lipoprotein lipase gene (LPL) (rs1059507, rs3200218, rs3208305, rs3735964) and Low-density lipoprotein receptor related protein 6 (LRP6) (rs2160525) could modulate LOAD risk through the alteration of miRNA binding sites. We performed a case-control study of 2338 unrelated subjects (984 cases and 1354 age- and gender-matched controls) in the Northern Han Chinese. We found that the minor C allele in rs9331949 significantly increased the risk of LOAD (P<0.001, OR=1.31, 95% CI=1.14-1.51), even after adjusting for multiple testing. Logistic analysis identified the rs9331949 polymorphism was still strongly associated with LOAD, even in Apolipoprotein E (APOE) ε4 allele noncarrier subgroups. However, the other five loci were not significantly associated with LOAD after Bonferroni adjustment. In conclusion, we have identified that the locus (rs9331949) located in the binding site of 3' UTR of CLU has a strong association with LOAD rather than loci in LPL and LRP6. However, additional independent replication is required for further validation.

A promoter polymorphism in APJ gene is significantly associated with blood pressure changes and hypertension risk in Chinese women.

The aim of this study was to interrogate the gender-specific association of 5 well-defined polymorphisms in apelin/APJ system with both blood pressure changes and hypertension risk in a northeastern Chinese population. This is a population-based case-control study, including 650 hypertensive patients and 645 normotensive controls. Data were analyzed by STATA and Haplo.Stats. The genotype distributions of 5 study polymorphisms were in Hardy-Weinberg equilibrium in both genders. The rs7119375 and rs10501367 were completely linked. The genotypes (P = 0.001) and alleles (P < 0.001) of rs7119375 differed significantly between patients and controls in women. Carriers of rs7119375-AA genotype had significant higher systolic blood pressure (SBP) than carriers of rs7119375-GG genotype in both patients and controls of female gender (P < 0.01). Moreover, carriers of rs7119375-A allele were 1.80 times more likely to develop hypertension relative to carriers of rs7119375-GG genotype after adjusting for age, body mass index and glucose (odds ratio: 1.80; 95% confidence interval: 1.03-3.16; P= 0.040). Further allele combination analysis supported the leading contribution of rs7119375 to hypertension risk. Our findings demonstrated that the mutation of promoter polymorphism rs7119375 in APJ gene was significantly associated with elevated SBP and increased hypertension risk in Chinese women.

Genetic predisposition of six well-defined polymorphisms in HMGB1/RAGE pathway to breast cancer in a large Han Chinese population.

Breast cancer constitutes an enormous burden in China. A strong familial clustering of breast cancer suggests a genetic component in its carcinogenesis. To examine the genetic predisposition of high mobility group box-1/receptor for advanced glycation end products (HMGB1/RAGE) pathway to breast cancer, we genotyped six well-defined polymorphisms in this pathway among 524 breast cancer patients and 518 cancer-free controls from Heilongjiang province, China. There were no deviations from Hardy-Weinberg equilibrium for all polymorphisms. In single-locus analysis, the frequency of rs1800624 polymorphism mutant A allele in RAGE gene was significantly higher in patients than in controls (24.52% versus 19.50%, P = 0.006), with the carriers of rs1800624-A allele being 1.51 times more likely to develop breast cancer relative to those with rs1800624-GG genotype after adjustment (95% confidence interval or CI: 1.17-1.94, P = 0.001). In HMGB1 gene, haplotype analysis did not reveal any significance, while in RAGE gene, haplotypes C-T-A and C-A-G (alleles in order of rs1800625, rs18006024, rs2070600) were significantly associated with an increased risk of breast cancer (adjusted OR = 2.72 and 10.35; 95% CI: 1.20-6.18 and 1.58-67.80; P = 0.017 and 0.015 respectively). In further genetic score analysis, per unit and quartile increments of unfavourable alleles were significantly associated with an increased risk of breast cancer after adjustment (odds ratio or OR = 1.20 and 1.26; 95% CI: 1.09-1.32 and 1.12-1.42; P < 0.001 and <0.001 respectively). Our findings altogether demonstrate a significant association between RAGE gene rs1800624 polymorphism and breast cancer risk, and more importantly a cumulative impact of multiple risk associated polymorphisms in HMGB1/RAGE pathway on breast carcinogenesis.

Genetically-reduced serum ACE activity might be a causal risk factor for obstructive sleep apnea syndrome: A meta-analysis.

We meta-analytically summarized the associations of angiotensin converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism with ACE activity and obstructive sleep apnea syndrome (OSAS) to see whether ACE activity is causally associated with OSAS. Literature search and data abstraction were done in duplicate. Sixteen articles including 2060 OSAS patients and 1878 controls were summarized. Overall, no significance was observed for the association of I/D polymorphism with OSAS, whereas carriers of II genotype (weighted mean difference or WMD, 95% confidence interval or CI, P: -11.976, -17.168 to -6.783, <0.001) or I allele (-9.842, -14.766 to -4.918, <0.001) had a lower level of serum ACE activity compared with DD genotype carriers, respectively. In subgroup analyses, carriers of II genotype were 3.806 times more likely to develop OSAS (95% CI, P: 1.865 to 7.765, <0.001) in OSAS patients with hypertension, without heterogeneity. Mendelian randomization analysis indicated there was 37.4% (95% CI: 1.115 to 3.142) and 32.4% (1.106 to 2.845) increased risk of OSAS by a reduction of 1 U/L in ACE activity for the II genotype and I allele carriers versus DD genotype carriers, respectively. There was no observable publication bias. Collectively, genetically-reduced serum ACE activity might be a causal risk factor for OSAS.

Designing piezoelectric films for micro electromechanical systems.

Piezoelectric thin films are of increasing interest in low-voltage micro electromechanical systems for sensing, actuation, and energy harvesting. They also serve as model systems to study fundamental behavior in piezoelectrics. Next-generation technologies such as ultrasound pill cameras, flexible ultrasound arrays, and energy harvesting systems for unattended wireless sensors will all benefit from improvements in the piezoelectric properties of the films. This paper describes tailoring the composition, microstructure, orientation of thin films, and substrate choice to optimize the response. It is shown that increases in the grain size of lead-based perovskite films from 75 to 300 nm results in 40 and 20% increases in the permittivity and piezoelectric coefficients, respectively. This is accompanied by an increase in the nonlinearity in the response. Band excitation piezoresponse force microscopy was used to interrogate the nonlinearity locally. It was found that chemical solution-derived PbZr(0.52)Ti(0.48)O(3) thin films show clusters of larger nonlinear response embedded in a more weakly nonlinear matrix. The scale of the clusters significantly exceeds that of the grain size, suggesting that collective motion of many domain walls contributes to the observed Rayleigh behavior in these films. Finally, it is shown that it is possible to increase the energy-harvesting figure of merit through appropriate materials choice, strong imprint, and composite connectivity patterns.

[Hydroxysafflor yellow A up-regulates HIF-1alpha via inhibition of VHL and p53 in Eahy 926 cell line exposed to hypoxia].

In present study, we investigated the mechanism of regulating HIF-1alpha expression by hydroxysafflor yellow A (HSYA) in Eahy 926 cell line under 1% O2 hypoxia. Eahy 926 cells were incubated with HSYA (100, 10 and 1 micromol x L(-1)) under hypoxia for the indicated time after treatment. Cell proliferation rate was detected using MTT assays. VHL and p53 location and protein expression were analyzed by immunocytochemical stain. HIF-1alpha, VHL and p53 mRNA expression were detected by RT-PCR. Protein expression of HIF-1alpha, VHL and p53 were assayed by Western blotting method. HSYA at 100 micromol x L(-1) increased Eahy 926 cells proliferation rate under hypoxia. HIF-1alpha mRNA and protein expression were up-regulated in the presence of HSYA. VHL, p53 mRNA and protein expression decreased significantly after 8 hours of treatment under hypoxia. HSYA protected Eahy 926 cells from hypoxia, and up-regulated HIF-1alpha expression partially via its inhibition of VHL and p53 expression.

6,7-di-O-glucopyranosyl-esculetin protects SH-SY5Y cells from dopamine-induced cytotoxicity.

Dopamine, as a neurotoxin, can elicit severe Parkinson's disease-like syndrome by elevating intracellular reactive oxygen species levels and apoptotic activity. In this study, we examined the effect of 6,7-di-O-glucopyranosyl-esculetin, which was extracted from Fraxinus sieboldiana bloom, on dopamine-induced cytotoxicity and the underlying mechanism in human neuroblastoma SH-SY5Y cells. Our results suggest that the protective effects of 6,7-di-O-glucopyranosyl-esculetin (0.1, 1 and 10 microM) on dopamine-induced cytotoxicity may be ascribed to its anti-oxidative properties by reducing reactive oxygen species levels, and its anti-apoptotic effect via protecting mitochondrion membrane potential (Delta Psi m), enhancing superoxide dismutaese (SOD) activity and reduced glutathione (GSH) levels, and regulating p53, Bax and Bcl-2 expression. In addition, 6,7-di-O-glucopyranosyl-esculetin inhibited the release of cytochrome c and apoptosis-inducing factor (AIF), and the protein expression of activated caspase 3. These data indicate that 6,7-di-O-glucopyranosyl-esculetin may provide a useful therapeutic strategy for the treatment of progressive neurodegenerative diseases such as Parkinson's disease.

Anti-apoptotic effect of esculin on dopamine-induced cytotoxicity in the human neuroblastoma SH-SY5Y cell line.

Dopamine (DA), as a neurotoxin, can elicit severe Parkinson's disease-like syndrome by elevating intracellular reactive oxygen species (ROS) levels and apoptotic activity. In this study, we examined the effect of esculin, which was extracted from Fraxinus sielboldiana blume, on DA-induced cytotoxicity and the underlying mechanism in human neuroblastoma SH-SY5Y cells. Our results suggest that the protective effects of esculin (10(-7), 10(-6) and 10(-5) M) on DA-induced cytotoxicity may be ascribed to its anti-oxidative properties by reducing ROS level, and its anti-apoptotic effect via protecting mitochondrion membrane potential (DeltaPsim), enhancing superoxide dismutaese (SOD) activity and reduced glutathione (GSH) levels, and regulating P53, Bax and Bcl-2 expression. In addition, esculin inhibited the release of cytochrome c and apoptosis-inducing factor (AIF), and the protein expression of activated caspase 3. These data indicate that esculin may provide a useful therapeutic strategy for the treatment of progressive neurodegenerative diseases such as Parkinson's disease (PD).

A cell-based model of alpha-synucleinopathy for screening compounds with therapeutic potential of Parkinson's disease.

AIM: To develop a cell-based model by stable transfection of SH-SY5Y with mutant A53T human alpha-synuclein, recapitulating neurotoxicity of alpha -synuclein overexpression. METHODS: The overexpression of mutant alpha -synuclein was analyzed by Western blotting, immunocytochemistry, and RT-PCR. Cell viability was processed when treated with different concentrations of 1-methyl-4-phenylpyridinium (MPP+) and exogenous dopamine (DA) for 24, 48, and 72 h by 3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Early apoptosis and late apoptosis/necrosis were analyzed by flow cytometry using Annexin V and propidium iodide double staining, respectively. DNA was isolated and applied to agarose gel for electrophoresis; the typical DNA "ladder"represented severe apoptosis. We also used this model to screen 99 compounds with therapeutic potential by MTT assay. RESULTS: One of the stably-transfected clones overexpressed exogenous genes on both the protein level and the transcriptive level. Significant differences in cytotoxicity were found between the pcDNA3.1(+) group and the pcDNA3.1(+)-hm alpha-synuclein group in the presence of the same concentration of MPP+ and DA within the same incubation time. The level of either early apoptosis or late apoptosis/necrosis was remarkably increased in transfected cells compared with the control after treatment with 100 micromol/L MPP+ for 24 h. In addition, the presence of the typical DNA "ladder" was observed in the pcDNA3.1(+)-hm alpha-synuclein group when treated with 200 micromol/L MPP+ for 48 h. After the screening experiment, 12 of the 99 compounds were found to decrease DA-induced cytotoxicity on cell viability. CONCLUSION: We established a cell-based model which is useful for studying the function of alpha-synuclein and screening compounds with therapeutic potential. In addition, it was identified that cells overexpressing A53T mutant alpha-synuclein were significantly vulnerable against MPP+ or dopamine exposures.