Fourteen novel compounds were prepared and their antagonistic activities against liver X receptors (LXR) α/β were tested in vitro. Compound 26 had an IC50 value of 6.4 µM against LXRα and an IC50 valu Show more
Fourteen novel compounds were prepared and their antagonistic activities against liver X receptors (LXR) α/β were tested in vitro. Compound 26 had an IC50 value of 6.4 µM against LXRα and an IC50 value of 5.6 µM against LXRβ. Docking studies and the results of structure-activity relationships support the further development of this chemical series as LXRα/β antagonists. Show less
The additional mutational complexity associated with copy number variation (CNV) can provide important clues as to the underlying mechanisms of CNV formation. Correct annotation of the additional muta Show more
The additional mutational complexity associated with copy number variation (CNV) can provide important clues as to the underlying mechanisms of CNV formation. Correct annotation of the additional mutational complexity is, however, a prerequisite for establishing the mutational mechanism. We illustrate this point through the characterization of a novel ∼230 kb EXT1 duplication CNV causing autosomal dominant hereditary multiple osteochondromas. Whole-genome sequencing initially identified the CNV as having a 22-bp insertion at the breakpoint junction and, unprecedentedly, multiple breakpoint-flanking micromutations on both sides of the duplication. Further investigation revealed that this genomic rearrangement had a duplication-inverted triplication-duplication structure, the inverted triplication being a 41-bp sequence synthesized from a nearby template. This permitted the identification of the sequence determinants of both the initiation (an inverted Alu repeat) and termination (a triplex-forming sequence) of break-induced replication and suggested a possible model for the repair of replication-associated double-strand breaks. Show less
Mengyang Liu, Yuanli Chen, Ling Zhang+10 more · 2015 · The Journal of biological chemistry · American Society for Biochemistry and Molecular Biology · added 2026-04-24
Cholesteryl ester transfer protein (CETP) transfers cholesteryl esters from high density lipoprotein to triglyceride-rich lipoproteins. CETP expression can be transcriptionally activated by liver X re Show more
Cholesteryl ester transfer protein (CETP) transfers cholesteryl esters from high density lipoprotein to triglyceride-rich lipoproteins. CETP expression can be transcriptionally activated by liver X receptor (LXR). Etoposide and teniposide are DNA topoisomerase II (Topo II) inhibitors. Etoposide has been reported to inhibit atherosclerosis in rabbits with un-fully elucidated mechanisms. In this study we determined if Topo II activity can influence cholesterol metabolism by regulating hepatic CETP expression. Inhibition of Topo II by etoposide, teniposide, or Topo II siRNA increased CETP expression in human hepatic cell line, HepG2 cells, which was associated with increased CETP secretion and mRNA expression. Meanwhile, inhibition of LXR expression by LXR siRNA attenuated induction of CETP expression by etoposide and teniposide. Etoposide and teniposide induced LXRα expression and LXRα/β nuclear translocation while inhibiting expression of receptor interacting protein 140 (RIP140), an LXR co-repressor. In vivo, administration of teniposide moderately reduced serum lipid profiles, induced CETP expression in the liver, and activated reverse cholesterol transport in CETP transgenic mice. Our study demonstrates a novel function of Topo II inhibitors in cholesterol metabolism by activating hepatic CETP expression and reverse cholesterol transport. Show less
Circulating trans fatty acids (TFAs), which cannot be synthesized by humans, are linked to adverse health outcomes. Although TFAs are obtained from diet, little is known about subsequent influences (e Show more
Circulating trans fatty acids (TFAs), which cannot be synthesized by humans, are linked to adverse health outcomes. Although TFAs are obtained from diet, little is known about subsequent influences (e.g., relating to incorporation, metabolism, or intercompetition with other fatty acids) that could alter circulating concentrations and possibly modulate or mediate impacts on health. The objective was to elucidate novel biologic pathways that may influence circulating TFAs by evaluating associations between common genetic variation and TFA biomarkers. We performed meta-analyses using 7 cohorts of European-ancestry participants (n = 8013) having measured genome-wide variation in single-nucleotide polymorphisms (SNPs) and circulating TFA biomarkers (erythrocyte or plasma phospholipids), including trans-16:1n-7, total trans-18:1, trans/cis-18:2, cis/trans-18:2, and trans/trans-18:2. We further evaluated SNPs with genome-wide significant associations among African Americans (n = 1082), Chinese Americans (n = 669), and Hispanic Americans (n = 657) from 2 of these cohorts. Among European-ancestry participants, 31 SNPs in or near the fatty acid desaturase (FADS) 1 and 2 cluster were associated with cis/trans-18:2; a top hit was rs174548 (β = 0.0035, P = 4.90 × 10(-15)), an SNP previously associated with circulating n-3 and n-6 polyunsaturated fatty acid concentrations. No significant association was identified for other TFAs. rs174548 in FADS1/2 was also associated with cis/trans-18:2 in Hispanic Americans (β = 0.0053, P = 1.05 × 10(-6)) and Chinese Americans (β = 0.0028, P = 0.002) but not African Americans (β = 0.0009, P = 0.34); however, in African Americans, fine mapping identified a top hit in FADS2 associated with cis/trans-18:2 (rs174579: β = 0.0118, P = 4.05 × 10(-5)). The association between rs174548 and cis/trans-18:2 remained significant after further adjustment for individual circulating n-3 and n-6 fatty acids, except arachidonic acid. After adjustment for arachidonic acid concentrations, the association between rs174548 and cis/trans-18:2 was nearly eliminated in European-ancestry participants (β-coefficient reduced by 86%), with similar reductions in Hispanic Americans and Chinese Americans. Our findings provide novel evidence for genetic regulation of cis/trans-18:2 by the FADS1/2 cluster and suggest that this regulation may be influenced/mediated by concentrations of arachidonic acid, an n-6 polyunsaturated fat. Show less
Cyclosporine A (CsA) increases β-catenin messenger RNA (mRNA) and protein expression. The present study demonstrates that Wnt/β-catenin signaling inhibits β-catenin degradation in the gingiva. Forty 5 Show more
Cyclosporine A (CsA) increases β-catenin messenger RNA (mRNA) and protein expression. The present study demonstrates that Wnt/β-catenin signaling inhibits β-catenin degradation in the gingiva. Forty 5-week-old male Sprague-Dawley rats were assigned to two study groups after healing from right maxillary molar extractions. The rats in the experimental group were fed 30 mg/kg CsA daily for 4 weeks, whereas the control rats were fed mineral oil. At the end of the study, all rats were sacrificed, and the gingivae were obtained. The gingival morphology after CsA treatment was evaluated by histology, and the genes related to Wnt/β-catenin signaling were initially screened by microarray. Polymerase chain reaction, Western blotting, and immunohistochemistry were used to examine the mRNA and protein expression of proliferating cell nuclear antigen, cyclin D1, E-cadherin, β-catenin, Dvl-1, glycogen synthase kinase-3β, axin-1, and adenomatous polyposis coli (APC). Phosphoserine and ubiquitinylated β-catenin were detected after immunoprecipitation. In rats treated with CsA, overgrowth of gingivae was observed, and altered expression of genes related to Wnt/β-catenin signaling was detected by the microarray. The gingival mRNA and protein expression profiles for genes associated with Wnt/β-catenin signaling further confirmed the effect of CsA: β-catenin and Dvl-1 expression increased, but APC and axin-1 expression decreased. Western blotting and immunohistochemistry showed decreases in β-catenin serine phosphorylation (33/37) and ubiquitinylation in the gingivae of CsA-treated rats. CsA-enhanced gingival β-catenin stability may be involved in gene upregulation or β-catenin degradation via the Wnt/β-catenin pathway. Show less
Overexpression of 5-hydroxytryptamine (5-HT) in human cancer contributes to tumor metastasis, but the role of 5-HT receptor family in cancer has not been thoroughly explored. Here, we report overexpre Show more
Overexpression of 5-hydroxytryptamine (5-HT) in human cancer contributes to tumor metastasis, but the role of 5-HT receptor family in cancer has not been thoroughly explored. Here, we report overexpression of 5-HT(1D) receptor (5-HT(1D)R) was associated with Wnt signaling pathway and advanced tumor stage. The underlying mechanism of 5-HT(1D)R-promoted tumor invasion was through its activation on the Axin1/β-catenin/MMP-7 pathway. In an orthotopic colorectal cancer mouse model, we demonstrated that a 5-HT(1D)R antagonist (GR127935) effectively inhibited tumor metastasis through targeting Axin1. Furthermore, in intestinal epithelium cells, we observed that 5-HT(1D)R played an important role in cell invasion via Axin1/β-catenin/MMP-7 pathway. Together, our findings reveal an essential role of the physiologic level of 5-HT(1D)R in pulmonary metastasis of colorectal cancer. Show less
The cell cycle is composed of bistable molecular switches that govern the transitions between gap phases (G1 and G2) and the phases in which DNA is replicated (S) and partitioned between daughter cell Show more
The cell cycle is composed of bistable molecular switches that govern the transitions between gap phases (G1 and G2) and the phases in which DNA is replicated (S) and partitioned between daughter cells (M). Many molecular details of the budding yeast G1-S transition (Start) have been elucidated in recent years, especially with regard to its switch-like behavior due to positive feedback mechanisms. These results led us to reevaluate and expand a previous mathematical model of the yeast cell cycle. The new model incorporates Whi3 inhibition of Cln3 activity, Whi5 inhibition of SBF and MBF transcription factors, and feedback inhibition of Whi5 by G1-S cyclins. We tested the accuracy of the model by simulating various mutants not described in the literature. We then constructed these novel mutant strains and compared their observed phenotypes to the model's simulations. The experimental results reported here led to further changes of the model, which will be fully described in a later article. Our study demonstrates the advantages of combining model design, simulation, and testing in a coordinated effort to better understand a complex biological network. Show less
Sesame seed is rich in sesamin. The present study was to (i) investigate the plasma cholesterol-lowering activity of dietary sesamin and (ii) examine the interaction of dietary sesamin with the gene e Show more
Sesame seed is rich in sesamin. The present study was to (i) investigate the plasma cholesterol-lowering activity of dietary sesamin and (ii) examine the interaction of dietary sesamin with the gene expression of sterol transporters, enzymes, receptors, and proteins involved in cholesterol metabolism. Thirty hamsters were divided into three groups fed the control diet (CON) or one of two experimental diets containing 0.2% (SL) and 0.5% (SH) sesamin, respectively, for 6 weeks. Plasma total cholesterol (TC) levels in hamsters given the CON, SL, and SH diets were 6.62 ± 0.40, 5.32 ± 0.40, and 5.00 ± 0.44 mmol/L, respectively, indicating dietary sesamin could reduce plasma TC in a dose-dependent manner. Similarly, the excretion of total fecal neutral sterols was dose-dependently increased with the amounts of sesamin in diets (CON, 2.65 ± 0.57; SL, 4.30 ± 0.65; and SH, 5.84 ± 1.27 μmol/day). Addition of sesamin into diets was associated with down-regulation of mRNA of intestinal Niemann-Pick C1 like 1 protein (NPC1L1), acyl-CoA:cholesterol acyltransferase 2 (ACAT2), microsomal triacylglycerol transport protein (MTP), and ATP-binding cassette transporters subfamily G members 5 and 8 (ABCG5 and ABCG8). Results also showed that dietary sesamin could up-regulate hepatic cholesterol-7α-hydroxylase (CYP7A1), whereas it down-regulated hepatic 3-hydroxy-3-methyl-glutaryl-CoA (HMG-CoA) reductase and liver X receptor alpha (LXRα). It was concluded that the cholesterol-lowering activity of sesamin was mediated by promoting the fecal excretion of sterols and modulating the genes involved in cholesterol absorption and metabolism. Show less
Dickkopf1 (DKK1), a canonical Wnt/β-catenin pathway antagonist, is closely associated with cardiovascular disease and adipogenesis. We performed an in vitro study to determine whether oxidized low-den Show more
Dickkopf1 (DKK1), a canonical Wnt/β-catenin pathway antagonist, is closely associated with cardiovascular disease and adipogenesis. We performed an in vitro study to determine whether oxidized low-density lipoprotein (ox-LDL) increased the expression of DKK1 in macrophages and whether β-catenin and liver X receptor α (LXRα) were involved in this regulation. Induction of DKK1 expression by ox-LDL decreased the level of lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) via a Wnt/β-catenin pathway and increased ATP-binding cassette transporter A/G1 (ABCA/G1) levels via a signal transducer and activator of transcription 3 (STAT3) pathway. Lower LOX-1 and higher ABCA/G1 levels inhibited cholesterol loading in macrophages. In conclusion, ox-LDL may induce DKK1 expression in macrophages to inhibit the accumulation of lipids through a mechanism that involves downregulation of LOX-1-mediated lipid uptake and upregulation of ABCA/G1-dependent cholesterol efflux. Show less
The objective of this study was to investigate the multiple relations between the preliminary molecular structural characteristics and antioxidant activities of polysaccharides from Canarium album (Lo Show more
The objective of this study was to investigate the multiple relations between the preliminary molecular structural characteristics and antioxidant activities of polysaccharides from Canarium album (Lour.) Raeusch (CPS). Three polysaccharide fractions, CPS1, CPS2, and CPS3, were isolated from CPS by column chromatography. CPS1 and CPS3 were mainly composed of neutral polysaccharides linked by α- and β-glycosidic linkages while CPS2 was pectin polysaccharides mainly linked by β-glycosidic linkages. According to the SEC-MALLS-RI system, the molecular weight of CPS1 was greater compared to CPS2 and CPS3, and the molecular weight and radius of CPS did not display positive correlation. The chain conformation analysis indicated CPS1 and CPS2 were typical highly branched polysaccharides while CPS3 existed as a globular shape in aqueous. Furthermore, the antioxidant activity of CPS2 was better than that of CPS3, while that of CPS1 was the weakest. The antioxidant activities of polysaccharide fractions were affected by their monosaccharide composition, glycosidic linkage, molecular weight, and chain conformation. This functional property was a result of a combination of multiple molecular structural factors. CPS2 was the major antioxidant component of CPS and it could be exploited as a valued antioxidant product. The molecular structural characteristics, antioxidant activities, and structure-function relationships of polysaccharide fractions from Canarium album were first investigated in this study. The results provided background and practical knowledge for the deep-processed products of C. album with high added value. CPS2 was the major antioxidant component of CPS, which could be exploited as a valued antioxidant ingredient in food and pharmaceutical industries. Show less
MYBPC3 dysfunctions have been proven to induce dilated cardiomyopathy, hypertrophic cardiomyopathy, and/or left ventricular noncompaction; however, the genotype-phenotype correlation between MYBPC3 an Show more
MYBPC3 dysfunctions have been proven to induce dilated cardiomyopathy, hypertrophic cardiomyopathy, and/or left ventricular noncompaction; however, the genotype-phenotype correlation between MYBPC3 and restrictive cardiomyopathy (RCM) has not been established. The newly developed next-generation sequencing method is capable of broad genomic DNA sequencing with high throughput and can help explore novel correlations between genetic variants and cardiomyopathies. A proband from a multigenerational family with 3 live patients and 1 unrelated patient with clinical diagnoses of RCM underwent a next-generation sequencing workflow based on a custom AmpliSeq panel, including 64 candidate pathogenic genes for cardiomyopathies, on the Ion Personal Genome Machine high-throughput sequencing benchtop instrument. The selected panel contained a total of 64 genes that were reportedly associated with inherited cardiomyopathies. All patients fulfilled strict criteria for RCM with clinical characteristics, echocardiography, and/or cardiac magnetic resonance findings. The multigenerational family with 3 adult RCM patients carried an identical nonsense MYBPC3 mutation, and the unrelated patient carried a missense mutation in the MYBPC3 gene. All of these results were confirmed by the Sanger sequencing method. This study demonstrated that MYBPC3 gene mutations, revealed by next-generation sequencing, were associated with familial and sporadic RCM patients. It is suggested that the next-generation sequencing platform with a selected panel provides a highly efficient approach for molecular diagnosis of hereditary and idiopathic RCM and helps build new genotype-phenotype correlations. Show less
FADS1 (fatty acid desaturase 1) plays a crucial role in fatty acid metabolism, and it was recently reported to be involved in tumorigenesis. However, the role of FADS1 expression in esophageal squamou Show more
FADS1 (fatty acid desaturase 1) plays a crucial role in fatty acid metabolism, and it was recently reported to be involved in tumorigenesis. However, the role of FADS1 expression in esophageal squamous cell carcinoma (ESCC) remains unknown. In the current study, we investigated the expression and clinical pathologic and prognostic significance of FADS1 in ESCC. Immunohistochemical analyses revealed that 58.2% (146/251) of the ESCC tissues had low levels of FADS1 expression, whereas 41.8% (105/251) exhibited high levels of FADS1 expression. In positive cases, FADS1 expression was detected in the cytoplasm of cells. Correlation analyses demonstrated that FADS1 expression was significantly correlated with tumor location (p=0.025) but not with age, gender, histological grade, tumor status, nodal status or TNM staging. Furthermore, patients with tumors expressing high levels of FADS1had a longer disease-free survival time (p<0.001) and overall survival time (p<0.001). Univariate and multivariate analyses revealed that, along with nodal status, FADS1 expression was an independent and significant predictive factor (p<0.001). In conclusion, our study suggested that FADS1 might be a valuable biomarker and potential therapeutic target for ESCC. Show less
Recent genome-wide association studies have identified several loci influencing lipid levels. The present study focused on the triglycerides (TG)-associated locus, the APOA4-APOA5-ZNF259-BUD13 gene cl Show more
Recent genome-wide association studies have identified several loci influencing lipid levels. The present study focused on the triglycerides (TG)-associated locus, the APOA4-APOA5-ZNF259-BUD13 gene cluster on chromosome 11, to explore the role of genetic variants in this gene cluster in the development of increasing TG levels and coronary heart disease (CHD). Six single nucleotide polymorphisms (SNPs), rs4417316, rs651821, rs6589566, rs7396835, rs964184 and rs17119975, in the APOA4-APOA5-ZNF259-BUD13 gene cluster were selected and genotyped in 5374 healthy Chinese subjects. There were strong significant associations between the six SNPs and TG levels (P < 1.0 × 10(-8)). Moreover, a weighted genotype score was found to be associated with TG levels (P = 3.28 × 10(-13)). The frequencies of three common haplotypes were observed to be significantly different between the high TG group and the low TG group (P < 0.05). However, no significant effects were found for the SNPs regarding susceptibility to CHD in the Chinese case-control populations. This study highlights the genotypes, genotype scores and haplotypes of the APOA4-APOA5-ZNF259-BUD13 gene cluster that were associated with TG levels in a Chinese population; however, the genetic variants in this gene cluster did not increase the risk of CHD in the Chinese population. Show less
Cell reprogramming mediated by histone methylation and demethylation is crucial for the activation of the embryonic genome in early embryonic development. In this study, we employed quantitative real- Show more
Cell reprogramming mediated by histone methylation and demethylation is crucial for the activation of the embryonic genome in early embryonic development. In this study, we employed quantitative real-time polymerase chain reaction (qRT-PCR) to detect mRNA levels and expression patterns of all known histone demethylases in early germinal vesicle stage and in vitro-matured metaphase II (MII) oocytes (which are commonly used as donor cells for nuclear transfer). On screening, the Jumonji domain containing 1C (JMJD1C) gene had the highest level of expression and hence was used for subsequent experiments. We also found that JMJD1C was primarily expressed in the nucleus and showed relatively high levels of expression at the 2-cell, 4-cell, 8-cell, 16-cell, morula, and blastocyst stages of embryos developed from MII oocytes fertilized in vitro. Further, we knocked down the JMJD1C gene in MII oocytes using siRNA and monitored the cleavage of zygotes and development of early embryos after in vitro fertilization. The results showed that the zygote cleavage and blastocyst rates of the transfection group were reduced by 57.1 ± 0.07 and 50 ± 0.01% respectively, which were significantly lower than those of the negative control group (P < 0.05). These data suggest that JMJD1C plays a key role in the normal development of early bovine embryos. Our results also provide a theoretical basis for the investigation of the role and molecular mechanism of histone demethylation in the early development of bovine embryos. Show less
To investigate whether activation of liver X receptors (LXRs) protects N-methyl-D-aspartic (NMDA)-induced retinal neurotoxicity in mice and to explore the underlying mechanism. Inner retinal damage wa Show more
To investigate whether activation of liver X receptors (LXRs) protects N-methyl-D-aspartic (NMDA)-induced retinal neurotoxicity in mice and to explore the underlying mechanism. Inner retinal damage was induced by intravitreal injection of NMDA. A synthetic LXR ligand TO901317 (TO90, 50 mg/kg/d) or vehicle was intragastrically administrated from 3 days before to 1 day or 7 days after NMDA injection. The severity of retinal damage was evaluated with histological analysis and TUNEL staining, and retinal functions were evaluated by ERG. The expressions of caspase-3, bax, bcl-2, TNF-α, and BACE1, the rate-limiting enzyme in the formation of amyloid β (Aβ), in the retina were examined by real-time PCR and ELISA. The levels of LXRs, NF-κB subunit p65, p-p38 mitogen-activated protein kinase (MAPK), and an LXR target gene ABCA1 were detected with real-time PCR and Western blotting. The localization and protein expression of Aβ in the retina was assessed by immunohistochemistry and Western blotting. The NMDA enhanced the expression of LXRβ but not LXRα and ABCA1 in mouse retina. Nevertheless, administration of TO90 after NMDA injection not only enhanced the expression of LXRβ but also upregulated the level of ABCA1, suggesting retinal LXRs were activated in a ligand-dependent manner. The LXRα expression was unchanged in the vehicle and the TO90-treated groups. Activation of LXRβ with TO90 inhibited cell death in the ganglion cell layer (GCL) and inner nuclear layer (INL), preserved ERG b- and a-wave amplitudes, and the b/a ratio in the NMDA-treated mice. Meanwhile, TO90 suppressed the elevation of apoptosis factors caspase-3 and bax induced by NMDA and upregulated the level of an antiapoptotic factor bcl-2. The TO90 also inhibited the increase of p-p38 MAPK and proinflammatory cytokine TNF-α after NMDA injection. Furthermore, activation of LXR attenuated the activation of NF-κB, and reduced gene expression of BACE1 and accumulation of Aβ induced by NMDA. Activation of LXRβ with a synthetic LXR ligand TO90 protects the inner retinal damage induced by NMDA in mice. We speculate the protective effect is associated with inhibition of the NF-κB signaling pathway and reduction of Aβ formation in retina. The LXR agonists may become a new class of neuroprotective agent for retinal diseases associated with glutamate-induced excitotoxicity. Show less
To evaluate whether the Chinese Han population harbors genetic markers associated with risk of acute myocardial infarction (MI), which have previously been identified in other ethnic populations. Acco Show more
To evaluate whether the Chinese Han population harbors genetic markers associated with risk of acute myocardial infarction (MI), which have previously been identified in other ethnic populations. According to predefined criteria, 549 Chinese patients with acute MI and 551 Chinese subjects (controls) without a history of coronary artery disease (CAD) were selected for the study. Three prevalent single nucleotide polymorphisms (SNPs; rs1412444(LIPA), rs662799(APOA5) and rs964184(ZNF259)) associated with CAD and MI in other ethnic populations, were selected for sequence and association analyses within blood DNA of the Chinese Han population. Only two SNPs, rs662799 (APOA5) and rs964184 (ZNF259) found at two independent loci, were associated with risk of MI in the Chinese Han population. Using Bonferroni correction methods, significant differences in the association of these two SNPs (rs662799 (p = 0.0228) and rs964184 (p = 0.0060)) between Chinese patients with MI versus controls were revealed. We identified a significant association between two SNPs (rs964184 and rs662799) on chromosome 11q23.3 and MI risk in the Chinese Han population, which extends their clinical relevance to predicting the risk of MI in diverse ethnic populations. Show less
During development, scaffold proteins serve as important platforms for orchestrating signaling complexes to transduce extracellular stimuli into intracellular responses that regulate dendritic spine m Show more
During development, scaffold proteins serve as important platforms for orchestrating signaling complexes to transduce extracellular stimuli into intracellular responses that regulate dendritic spine morphology and function. Axin ("axis inhibitor") is a key scaffold protein in canonical Wnt signaling that interacts with specific synaptic proteins. However, the cellular functions of these protein-protein interactions in dendritic spine morphology and synaptic regulation are unclear. Here, we report that Axin protein is enriched in synaptic fractions, colocalizes with the postsynaptic marker PSD-95 in cultured hippocampal neurons, and interacts with a signaling protein Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) in synaptosomal fractions. Axin depletion by shRNA in cultured neurons or intact hippocampal CA1 regions significantly reduced dendritic spine density. Intriguingly, the defective dendritic spine morphogenesis in Axin-knockdown neurons could be restored by overexpression of the small Rho-GTPase Cdc42, whose activity is regulated by CaMKII. Moreover, pharmacological stabilization of Axin resulted in increased dendritic spine number and spontaneous neurotransmission, while Axin stabilization in hippocampal neurons reduced the elimination of dendritic spines. Taken together, our findings suggest that Axin promotes dendritic spine stabilization through Cdc42-dependent cytoskeletal reorganization. Show less
Dual-specificity phosphatase 6 (DUSP6) is a negative feedback mechanism of the mitogen-activated protein (MAP) kinase superfamily (MAPK/ERK, SAPK/JNK, p38), that is associated with cellular proliferat Show more
Dual-specificity phosphatase 6 (DUSP6) is a negative feedback mechanism of the mitogen-activated protein (MAP) kinase superfamily (MAPK/ERK, SAPK/JNK, p38), that is associated with cellular proliferation and differentiation. It has been reported that the expression of DUSP6 in different types of breast cancer is diverse and therefore it has altered functions in various types of breast cancer. Our aim was to explore the exact function of DUSP6 in triple-negative breast cancer cells (MDA-MB-231 cell) and to determine whether the suppression of DUSP6 by small interfering RNA (siRNA) and mircroRNA (miRNA) inhibits the growth of human MDA-MB-231 breast cancer cells. DUSP6-siRNA was used to inhibit the expression of DUSP6 directly and miR-145 to inhibit the expression of DUSP6 either in MDA-MB-231 breast cancer cells and successful transfection being confirmed by Real-time PCR and Western Blotting. Down regulation of DUSP6 in MDA-MB-231 cells suppressed the cell proliferation as investigated by MTT assay and colony form assay. Transwell test and Scratch assay were conducted to investigate the migration and invasion of MDA-MB-231 cells. T-test (two-tailed) was used to compare differences between groups, and the significance level was set at P<0.05. DUSP6 mRNA expression and protein expression were reduced after transfection with DUSP6-siRNA directly and similar trend with transfection with miR-145. The treated group with DUSP6-siRNA or miR-145 suppressed MDA-MB-231 cells proliferation, migration and invasion, and meanwhile the cells were arrested at G0/G1 phase. DUSP6 plays a role in triple-negative breast cancer cells that might promote growth in MDA-MB-231 triple-negative breast cancer cells. Show less
Cryptococcus demonstrates predilection for invasion of the brain, but the mechanism by which Cryptococcus crosses the blood-brain barrier (BBB) to cause brain invasion is largely unknown. In order for Show more
Cryptococcus demonstrates predilection for invasion of the brain, but the mechanism by which Cryptococcus crosses the blood-brain barrier (BBB) to cause brain invasion is largely unknown. In order for Cryptococcus to cross the BBB, there must be a way to either cross human brain microvascular endothelial cells, which are the main constitute of the BBB, or go in between tight junctions. Recent evidence of human brain microvascular endothelial cell responses to transcellular brain invasions includes membrane rearrangements, intracellular signaling pathways and cytoskeletal activations. Several Cryptococcal genes related to the traversal of BBB have been identified, including CPS1, ITR1a, ITR3c, PLB1, MPR1, FNX1 and RUB1. In addition, Cryptococcus neoformans-derived microvesicles may contribute to cryptococcal brain invasion. Paracellularly, Cryptococcus may traverse across BBB using either routes utilizing plasmin, ammonia or macrophages in a Trojan horse mechanism. Show less
Rapsyn, a scaffold protein, is required for the clustering of acetylcholine receptors (AChRs) at contacts between motor neurons and differentiating muscle cells. Rapsyn is also expressed in cells that Show more
Rapsyn, a scaffold protein, is required for the clustering of acetylcholine receptors (AChRs) at contacts between motor neurons and differentiating muscle cells. Rapsyn is also expressed in cells that do not express AChRs. However, its function in these cells remains unknown. Here, we show that rapsyn plays an AChR-independent role in organizing the distribution and mobility of lysosomes. In cells devoid of AChRs, rapsyn selectively induces the clustering of lysosomes at high density in the juxtanuclear region without affecting the distribution of other intracellular organelles. However, when the same cells overexpress AChRs, rapsyn is recruited away from lysosomes to colocalize with AChR clusters on the cell surface. In rapsyn-deficient (Rapsn(-/-)) myoblasts or cells overexpressing rapsyn mutants, lysosomes are scattered within the cell and highly dynamic. The increased mobility of lysosomes in Rapsn(-/-) cells is associated with a significant increase in lysosomal exocytosis, as evidenced by increased release of lysosomal enzymes and plasma membrane damage when cells were challenged with the bacterial pore-forming toxin streptolysin-O. These findings uncover a new link between rapsyn, lysosome positioning, exocytosis and plasma membrane integrity. Show less
To comprehensively understand the underlying molecular events accounting for aberrant Wnt signaling activation in hepatocellular carcinoma (HCC). This study was retrospective. The HCC tissue specimens Show more
To comprehensively understand the underlying molecular events accounting for aberrant Wnt signaling activation in hepatocellular carcinoma (HCC). This study was retrospective. The HCC tissue specimens used in this research were obtained from patients who underwent liver surgery. The Catalogue of Somatic Mutations in Cancer (COSMIC) database was searched for the mutation statuses of CTNNB1, TP53, and protein degradation regulator genes of CTNNB1. Dual-luciferase reporter assay was performed with TOP/FOP reporters to detect whether TP53 gain-of-function (GOF) mutations could enhance the transcriptional activity of Wnt signaling. Methylation sensitive restriction enzyme-quantitative PCR was used to explore the methylation status of CpG islands located in the promoters of APC, SFRP1, and SFRP5 in HCCs with different risk factors. Finally, nested-reverse transcription PCR was performed to examine the integration of HBx in front of LINE1 element and the existence of HBx-LINE1 chimeric transcript in Hepatitis B virus-related HCC. All results in this article were analyzed with the software SPSS version 19.0 for Windows, and different groups were compared by χ(2) test as appropriate. Based on the data from COSMIC database, compared with other solid tumors, mutation frequency of CTNNB1 was significantly higher in HCC (P < 0.01). The rate of CTNNB1 mutation was significantly less frequent in Hepatitis B virus-related HCC than in other etiologies (P < 0.01). Dual-luciferase reporter system and TOP/FOP reporter assays confirmed that TP53 GOF mutants were able to enhance the transcriptional ability of Wnt signaling. An exclusive relationship between the status of TP53 and CTNNB1 mutations was observed. However, according to the COSMIC database, TP53 GOF mutation is rare in HCC, which indicates that TP53 GOF mutation is not a reason for the aberrant activation of Wnt signaling in HCC. APC and AXIN1 were mutated in HCC. By using methylation sensitive restriction enzyme-quantitative PCR, hypermethylation of APC was detected in HCC with different risk factors, whereas SFRP1 and SFRP5 were not hypermethylated in any of the HCC etiologies, which indicates that the mutation of APC and AXIN1, together with the methylation of APC could take part in the overactivation of Wnt signaling. Nested-reverse transcription PCR failed to detect the integration of HBx before the LINE1 element, or the existence of an HBx-LINE1 chimeric transcript, suggesting that integration could not play a role in the aberrant activation of Wnt signaling in HCC. In HCC, genetic/epigenetic aberration of CTNNB1 and its protein degradation regulators are the major cause of Wnt signaling overactivation. Show less
Exome sequencing is a successful option for diagnosing individuals with previously uncharacterized genetic conditions, however little has been reported regarding its utility in a prenatal setting. The Show more
Exome sequencing is a successful option for diagnosing individuals with previously uncharacterized genetic conditions, however little has been reported regarding its utility in a prenatal setting. The goal of this study is to describe the results from a cohort of fetuses for which exome sequencing was performed. We performed a retrospective analysis of the first seven cases referred to our laboratory for exome sequencing following fetal demise or termination of pregnancy. All seven pregnancies had multiple congenital anomalies identified by level II ultrasound. Exome sequencing was performed on trios using cultured amniocytes or products of conception from the affected fetuses. Relevant alterations were identified in more than half of the cases (4/7). Three of the four were categorized as 'positive' results, and one of the four was categorized as a 'likely positive' result. The provided diagnoses included osteogenesis imperfecta II (COL1A2), glycogen storage disease IV (GBE1), oral-facial-digital syndrome 1 (OFD1), and RAPSN-associated fetal akinesia deformation sequence. This data suggests that exome sequencing is likely to be a valuable diagnostic testing option for pregnancies with multiple congenital anomalies detected by prenatal ultrasound; however, additional studies with larger cohorts of affected pregnancies are necessary to confirm these findings. Show less
To explore the potential molecular mechanisms involved in migratory glioma cells. The gene expression profiles of GSE28167, employing human malignant glioma U251MG cells cultured on strictly aligned v Show more
To explore the potential molecular mechanisms involved in migratory glioma cells. The gene expression profiles of GSE28167, employing human malignant glioma U251MG cells cultured on strictly aligned versus randomly oriented electrospun nanofibers of polycaprolactone, were downloaded from the Gene Expression Omnibus database. Gene differential expression analysis was carried out by the package of Gene Expression Omnibus query and limma in R language. The Gene Set Analysis Toolkit V2 was used for pathway analysis. Gene set enrichment analysis was used to screen for target sites of transcription factors, miRNA and small drug molecules. Totally 586 differentially expressed genes were identified and the differentially expressed genes were mainly enriched in the pathway of muscle cell TarBase, MAPK cascade, adipogenesis and epithelium TarBase. Thirty-two significant target sites of transcription factors, such as hsa_RTAAACA_V$FREAC2₀₁, were screened. The top 20 potential miRNAs including MIR-124A, MIR-34A and MIR-34C were screened for a constructing gene-miRNA interaction network. Small molecules that can inhibit the motility of glioma cells such as diclofenamide and valinomycin were mined. By integrating the regulatory relationships among transcription factors, miRNAs and differentially expressed genes, we found that 7 differentially expressed genes, including SOX4, ANKRD28 and CCND1, might play crucial roles in the migration of glioma cells. The screened migration-associated genes, significant pathways, and small molecules give us new insight for the mechanism of migratory glioma cells. Interest in such genes as potential target genes in the treatment of glioblastoma justifies functional validation studies. Show less
Smooth muscle 22α (SM22α) is involved in stress fiber formation and enhances contractility in vascular smooth muscle cells (VSMCs). In many cases, SM22α acts as an adapter protein to assemble signalin Show more
Smooth muscle 22α (SM22α) is involved in stress fiber formation and enhances contractility in vascular smooth muscle cells (VSMCs). In many cases, SM22α acts as an adapter protein to assemble signaling complexes and regulate signaling, but whether SM22α regulates contractile signaling induced by angiotensin II (AngII) remains unclear. To address this issue, we established a hypertension model of Sm22α(-/-) mice, and demonstrated that hypertension induced by AngII was attenuated in Sm22α(-/-) mice. A decreased vasoconstriction was observed in aortic rings from Sm22α(-/-) mice. Furthermore, loss of SM22α resulted in a reduced contractile response to AngII in VSMCs in vitro. The phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) induced by AngII was impaired following depletion of SM22α, in parallel with a reduced contractility. The decay of ERK1/2 activity was associated with increased expression of mitogen-activated protein kinase phosphatase 3 (MKP3). Inhibition of MKP3 activity rescued ERK1/2 activity. SM22α depletion caused an enhanced interaction of MKP3 with ERK1/2, and a reduced ubiquitination and degradation of MKP3. Knockdown of SM22α extended the half-life of MKP3. In conclusion, SM22α promotes AngII-induced contraction by maintenance of ERK1/2 signaling cascades through facilitating ubiquitination and degradation of MKP3. The vasoconstriction is attenuated in aortic rings from Sm22α(-/-) mice. MKP3 mediates dephosphorylation of ERK1/2 in AngII-induced VSMC contraction. SM22α inhibits the interaction of ERK1/2 with MKP3. SM22α promotes ubiquitination and degradation of MKP3. SM22α facilitates AngII-induced contraction by maintenance of ERK1/2 signaling. Show less
Genome-wide association studies (GWAS) of chronic obstructive pulmonary disease (COPD) have identified disease-susceptibility loci, mostly in subjects of European descent. We hypothesized that by stud Show more
Genome-wide association studies (GWAS) of chronic obstructive pulmonary disease (COPD) have identified disease-susceptibility loci, mostly in subjects of European descent. We hypothesized that by studying Hispanic populations we would be able to identify unique loci that contribute to COPD pathogenesis in Hispanics but remain undetected in GWAS of non-Hispanic populations. We conducted a metaanalysis of two GWAS of COPD in independent cohorts of Hispanics in Costa Rica and the United States (Multi-Ethnic Study of Atherosclerosis [MESA]). We performed a replication study of the top single-nucleotide polymorphisms in an independent Hispanic cohort in New Mexico (the Lovelace Smokers Cohort). We also attempted to replicate prior findings from genome-wide studies in non-Hispanic populations in Hispanic cohorts. We found no genome-wide significant association with COPD in our metaanalysis of Costa Rica and MESA. After combining the top results from this metaanalysis with those from our replication study in the Lovelace Smokers Cohort, we identified two single-nucleotide polymorphisms approaching genome-wide significance for an association with COPD. The first (rs858249, combined P value = 6.1 × 10(-8)) is near the genes KLHL7 and NUPL2 on chromosome 7. The second (rs286499, combined P value = 8.4 × 10(-8)) is located in an intron of DLG2. The two most significant single-nucleotide polymorphisms in FAM13A from a previous genome-wide study in non-Hispanics were associated with COPD in Hispanics. We have identified two novel loci (in or near the genes KLHL7/NUPL2 and DLG2) that may play a role in COPD pathogenesis in Hispanic populations. Show less
Ammonia detoxification is essential for physiological well-being, and the urea cycle in liver plays a predominant role in ammonia disposal. Nobiletin (NOB), a natural dietary flavonoid, is known to ex Show more
Ammonia detoxification is essential for physiological well-being, and the urea cycle in liver plays a predominant role in ammonia disposal. Nobiletin (NOB), a natural dietary flavonoid, is known to exhibit various physiological efficacies. In the current study, we investigated a potential role of NOB in ammonia control and the underlying cellular mechanism. C57BL/6 mice were fed with regular chow (RC), high-fat (HFD) or high-protein diet (HPD) and treated with either vehicle or NOB. Serum and/or urine levels of ammonia and urea were measured. Liver expression of genes encoding urea cycle enzymes and C/EBP transcription factors was determined over the circadian cycle. Luciferase reporter assays were carried out to investigate function of CCAAT consensus elements on the carbamoyl phosphate synthetase (Cps1) gene promoter. A circadian clock-deficient mouse mutant, Clock (Δ19/Δ19) , was utilized to examine a requisite role of the circadian clock in mediating NOB induction of Cps1. NOB was able to lower serum ammonia levels in mice fed with RC, HFD or HPD. Compared with RC, HFD repressed the mRNA and protein expression of Cps1, encoding the rate-limiting enzyme of the urea cycle. Interestingly, NOB rescued CPS1 protein levels under the HFD condition via induction of the transcription factors C/EBPα and C/EBPβ. Expression of other urea cycle genes was also decreased by HFD relative to RC and again restored by NOB to varying degrees, which, in conjunction with Cps1 promoter reporter analysis, suggested a C/EBP-dependent mechanism for the co-induction of urea cycle genes by NOB. In comparison, HPD markedly increased CPS1 levels relative to RC, yet NOB did not further enrich CPS1 to a significant extent. Using the circadian mouse mutant Clock (Δ19/Δ19) , we also showed that a functional circadian clock, known to modulate C/EBP and CPS1 expression, was required for NOB induction of CPS1 under the HFD condition. NOB, a dietary flavonoid, exhibits a broad activity in ammonia control across varying diets, and regulates urea cycle function via C/EBP-and clock-dependent regulatory mechanisms. Show less
Mammalian milk is a key source of lipids, providing not only important calories but also essential fatty acids. Veterinary medicine and omics systems sciences intersection, termed as "veterinomics" he Show more
Mammalian milk is a key source of lipids, providing not only important calories but also essential fatty acids. Veterinary medicine and omics systems sciences intersection, termed as "veterinomics" here, has received little attention to date but stands to offer much promise for building bridges between human and animal health. We determined the changes in porcine mammary genes and proteomics expression associated with milk triacylglycerol (TAG) synthesis and secretion from late pregnancy to lactation. TAG content and fatty acid (FA) composition were determined in porcine colostrum (the 1st day of lactation) and milk (the 17th day of lactation). The mammary transcriptome for 70 genes and 13 proteins involved in TAG synthesis and secretion from six sows, each at d -17(late pregnancy), d 1(early lactation), and d 17 (peak lactation) relative to parturition were analyzed using quantitative real-time PCR and Western blot analyses. The TAG content and the concentrations of de novo synthesized FAs, saturated FAs, and monounsaturated FAs were higher in milk than in colostrum (p<0.05). Robust upregulation with high relative mRNA abundance was evident during lactation for genes associated with FA uptake (VLDLR, LPL, CD36), FA activation (ACSS2, ACSL3), and intracellar transport (FABP3), de novo FA synthesis (ACACA, FASN), FA elongation (ELOVL1), FA desaturation (SCD, FADS1), TAG synthesis (GPAM, AGPAT1, LPIN1, DGAT1), lipid droplet formation (BTN2A1, XDH, PLIN2), and transcription factors and nuclear receptors (SREBP1, SCAP, INSIG1/2). In conclusion, a wide variety of lipogenic genes and proteins regulate the channeling of FAs towards milk TAG synthesis and secretion in porcine mammary gland tissue. These findings inform future omics strategies to increase milk fat production and lipid profile and attest to the rise of both veterinomics and lipidomics in postgenomics life sciences. Show less
RUNX1-RUNX1T1 (formerly AML1-ETO), a transcription factor generated by the t(8;21) translocation in acute myeloid leukemia (AML), dictates a leukemic program by increasing self-renewal and inhibiting Show more
RUNX1-RUNX1T1 (formerly AML1-ETO), a transcription factor generated by the t(8;21) translocation in acute myeloid leukemia (AML), dictates a leukemic program by increasing self-renewal and inhibiting differentiation. Here we demonstrate that the histone demethylase JMJD1C functions as a coactivator for RUNX1-RUNX1T1 and is required for its transcriptional program. JMJD1C is directly recruited by RUNX1-RUNX1T1 to its target genes and regulates their expression by maintaining low H3K9 dimethyl (H3K9me2) levels. Analyses in JMJD1C knockout mice also establish a JMJD1C requirement for RUNX1-RUNX1T1's ability to increase proliferation. We also show a critical role for JMJD1C in the survival of multiple human AML cell lines, suggesting that it is required for leukemic programs in different AML cell types through its association with key transcription factors. Show less
In the present study, we demonstrate that prolonged treatment by trastuzumab induced resistance of NCI-N87 gastric cancer cells to trastuzumab. The resistant cells possessed typical characteristics of Show more
In the present study, we demonstrate that prolonged treatment by trastuzumab induced resistance of NCI-N87 gastric cancer cells to trastuzumab. The resistant cells possessed typical characteristics of epithelial to mesenchymal transition (EMT)/cancer stem cells and acquired more invasive and metastatic potentials both in vitro and in vivo. Long term treatment with trastuzumab dramatically inhibited the phosphorylation of Akt, but triggered the activation of STAT3. The level of IL-6 was remarkably increased, implicating that the release of IL-6 that drives the STAT3 activation initiates the survival signaling transition. Furthermore, the Notch activities were significantly enhanced in the resistant cells, companied by upregulation of the Notch ligand Jagged-1 and the Notch responsive genes Hey1 and Hey2. Inhibiting the endogenous Notch pathway reduced the IL-6 expression and restored the sensitivities of the resistant cells to trastuzumab. Blocking of the STAT3 signaling abrogated IL-6-induced Jagged-1 expression, effectively inhibited the growth of the trastuzumab resistant cells, and enhanced the anti-tumor activities of trastuzumab in the resistant cells. These findings implicate that the IL-6/STAT3/Jagged-1/Notch axis may be a useful target and that combination of the Notch or STAT3 inhibitors with trastuzumab may prevent or delay clinical resistance and improve the efficacy of trastuzumab in gastric cancer. Show less