Search

Deletions and reciprocal triplications of the human chromosomal 15q11-13 region cause two distinct neurodevelopmental disorders. Maternally-derived deletions or inactivating mutations of UBE3A , a 15q11-13 gene expressed exclusively from the maternal allele in neurons, cause Angelman syndrome, characterized by intellectual disability, motor deficits, seizures, and a characteristic increased social smiling, laughing, and eye contact. Conversely, maternally-derived triplications of 15q11-13 cause a behavioral disorder on the autism spectrum with clinical features that include decreased sociability that we recently reconstituted in mice with Ube3a alone. Based on the unique sociability features reported in Angelman syndrome and the repressed sociability observed when Ube3a gene dosage is increased, we hypothesized that mice with neuronal UBE3A loss that models Angelman syndrome would display evidence of hypersocial behavior. We report that mice with maternally-inherited Ube3a gene deletion (Ube3a mKO ) have a prolonged preference for, and interaction with, social stimuli in the three chamber social approach task. By contrast, interactions with a novel object are reduced. Further, ultrasonic vocalizations and physical contacts are increased in male and female Ube3a mKO mice paired with an unfamiliar genotype-matched female. Single housing wild type mice increased these same social behavior parameters to levels observed in Ube3a mKO mice where this effect was partially occluded. These results indicate sociability is repressed by social experience and the endogenous levels of UBE3A protein and suggest some social behavioral features observed in Angelman syndrome may reflect an increased social motivation. [ABSTRACT FROM AUTHOR]

Organizer activity, once thought to be restricted to vertebrates, has ancient origins. However, among non-bilaterians, it has only been subjected to detailed investigation during embryonic development of the sea anemone, Nematostella vectensis . As a step toward establishing the extent to which findings in Nematostella can be generalized across the large and diverse phylum Cnidaria, we examined the expression of some key organizer and gastrulation genes during the embryonic development of the coral Acropora millepora. Although anemones and corals both belong to the cnidarian class Anthozoa, the two lineages diverged during the Cambrian and the morphological development of Acropora differs in several important respects from that of Nematostella . While the expression patterns of the key genes brachyury , bmp2/4 , chordin , goosecoid and forkhead are broadly similar, developmental differences between the two species enable novel observations, and new interpretations of their significance. Specifically, brachyury expression during the flattened prawnchip stage before gastrulation, a developmental peculiarity of Acropora , leads us to suggest that it is the key gene demarcating ectoderm from endoderm in Acropora , and by implication in other cnidarians, whereas previous studies in Nematostella proposed that forkhead plays this role. Other novel observations include the transient expression of Acropora forkhead in scattered ectodermal cells shortly after gastrulation, and in the developing mesenterial filaments, with no corresponding expression reported in Nematostella . In addition, the expression patterns of goosecoid and bmp2/4 confirm the fundamental bilaterality of the Anthozoa. [ABSTRACT FROM AUTHOR]

Highlights: [•] Developed a Quantigene multiplex panel for eight endocrine growth genes in salmon. [•] Provides the first validation of the panel in fishes by comparison to RT-qPCR. [•] Differences between results of the panel and RT-qPCR are discussed. [ABSTRACT FROM AUTHOR]

Abstract: The field of in vivo gene therapy has matured to the point where there are numerous clinical trials underway including late-stage clinical trials. Several viral vectors are especially efficient and support lifetime protein expression in the brain and a number of clinical trials are underway for various progressive or chronic neurological disorders including Parkinson''s disease, Alzheimer''s disease, and Batten''s disease. To date, however, none of the vectors in clinical use have any direct way to reverse or control their transgene product in the event continued protein expression should become problematic. Several schemes that use elements within the vector design have been developed that allow an external drug or pro-drug to alter ongoing protein expression after in vivo gene transfer. The most promising and most studied regulated protein expression methods for in vivo gene transfer are reviewed. In addition, potential scientific and clinical advantages of transgene regulation for gene therapy are discussed. [Copyright &y& Elsevier]

Abstract: Hsp40-like co-chaperones are ubiquitous enzymes that stimulate the protein refolding activity of Hsp70 family chaperones. They are widespread in prokaryotic and eukaryotic systems. In bacteria, the best characterized co-chaperone is the Escherichia coli DnaJ protein. Many γ-proteobacteria encode a functional homologue of DnaJ, known as CbpA, which is expressed in response to starvation and environmental stress. The activity of CbpA is regulated by the “modulator” protein CbpM. Here, we have used a combination of genetics and biochemistry to identify the co-chaperone contact determinant of CbpM. We show that the nature of the interaction is conserved in enterobacteria. [Copyright &y& Elsevier]

Abstract: Adipose tissue inflammation in obesity is a major factor leading to cardiovascular disease and type 2 diabetes.12/15 lipoxygenases (ALOX) play an important role in the generation of inflammatory mediators, insulin resistance and downstream immune activation in animal models of obesity. However, the expression and roles of 12/15ALOX isoforms, and their cellular sources in human subcutaneous (sc) and omental (om) fat in obesity is unknown. The objective of this study was to examine the gene expression and localization of ALOX isoforms and relevant downstream cytokines in subcutaneous (sc) and omental (om) adipose tissue in obese humans. Paired biopsies of sc and om fat were obtained during bariatric surgeries from 24 morbidly obese patients. Gene and protein expression for ALOX15a, ALOX15b and ALOX 12 were measured by real-time PCR and western blotting in adipocytes and stromal vascular fractions (SVF) from om and sc adipose tissue along with the mRNA expression of the downstream cytokines IL-12a, IL-12b, IL-6, IFNγ and the chemokine CXCL10. In a paired analysis, all ALOX isoforms, IL-6, IL-12a and CXCL10 were significantly higher in om vs. sc fat. ALOX15a mRNA and protein expression was found exclusively in om fat. All of the ALOX isoforms were expressed solely in the SVF. Further fractionation of the SVF in CD34+ and CD34− cells indicated that ALOX15a is predominantly expressed in the CD34+ fraction including vascular and progenitor cells, while ALOX15B is mostly expressed in the CD34− cells containing various leucocytes and myeloid cells. This result was confirmed by immunohistochemistry showing exclusive localization of ALOX15a in the om fat and predominantly in the vasculature and non-adipocyte cells. Our finding is identifying selective expression of ALOX15a in human om but not sc fat. This is a study showing a major inflammatory gene exclusively expressed in visceral fat in humans. [Copyright &y& Elsevier]

Abstract: Ecdysis in arthropods is a complex process, regulated by many neurohormones, which must be released in a precisely coordinated manner. In insects, the ultimate hormone involved in this process is the cuticle tanning hormone, bursicon. Recently, this hormone has been identified in crustaceans. To further define the distribution of bursicon in crustacean nervous systems, and to compare hormone structures within the sub-phylum, cDNAs encoding both bursicon subunits were cloned and sequenced from the nervous system of the European lobster, Homarus gammarus, and expression patterns including those for CCAP determined using in-situ hybridisation, quantitative RT-PCR and immunohistochemistry. Full-length cDNAs encoded bursicon subunits of 121 amino acids (Average M r: 13365.48) for Burs α, 115 amino acids (Average M r: 12928.54) for Burs β. Amino acid sequences were most closely related to those of crabs, and for Burs β the sequence was identical to that of the American lobster, Homarus americanus. Complete co-localisation with CCAP in the VNC was seen. Copy numbers burs α, burs β and CCAP mRNAs were between 0.5 and 1.5×105 for both bursicon subunits, 0.5–6×105 per cdn neurone for CCAP. The terminal abdominal ganglia (AG 6–8) contained about 52 cdn-type neurons, making it the largest bursicon producing region in the CNS. Double labelling IHC using recombinant Carcinus Burs α and CCAP antisera demonstrated complete co-localisation in the VNC. On the basis of the results obtained, it is proposed that CCAP and bursicon release occur simultaneously during ecdysis in crustaceans. [Copyright &y& Elsevier]

Abstract: Prenatal inflammation prevents normal lung morphogenesis and leads to bronchopulmonary dysplasia (BPD), a common complication of preterm birth. We previously demonstrated in a bacterial endotoxin mouse model of BPD that disrupting fibronectin localization in the fetal lung mesenchyme causes arrested saccular airway branching. In this study we show that expression of the fibronectin receptor, integrin α8β1 is decreased in the lung mesenchyme in the same inflammation model suggesting it is required for normal lung development. We verified a role for integrin α8β1 in lung development using integrin α8-null mice, which develop fusion of the medial and caudal lobes as well as abnormalities in airway division. We further show in vivo and in vitro that α8-null fetal lung mesenchymal cells fail to form stable adhesions and have increased migration. Thus we propose that integrin α8β1 plays a critical role in lung morphogenesis by regulating mesenchymal cell adhesion and migration. Furthermore, our data suggest that disruption of the interactions between extracellular matrix and integrin α8β1 may contribute to the pathogenesis of BPD. [Copyright &y& Elsevier]

Abstract: Transcription is a sophisticated multi-step process in which RNA polymerase II (Pol II) transcribes a DNA template into RNA in concert with a broad array of transcription initiation, elongation, capping, termination, and histone modifying factors. Recent global analyses of Pol II distribution have indicated that many genes are regulated during the elongation phase, shedding light on a previously underappreciated mechanism for controlling gene expression. Understanding how various factors regulate transcription elongation in living cells has been greatly aided by chromatin immunoprecipitation (ChIP) studies, which can provide spatial and temporal resolution of protein–DNA binding events. The coupling of ChIP with DNA microarray and high-throughput sequencing technologies (ChIP-chip and ChIP-seq) has significantly increased the scope of ChIP studies and genome-wide maps of Pol II or elongation factor binding sites can now be readily produced. However, while ChIP-chip/ChIP-seq data allow for high-resolution localization of protein–DNA binding sites, they are not sufficient to dissect protein function. Here we describe techniques for coupling ChIP-chip/ChIP-seq with genetic, chemical, and experimental manipulation to obtain mechanistic insight from genome-wide protein–DNA binding studies. We have employed these techniques to discern immature promoter-proximal Pol II from productively elongating Pol II, and infer a critical role for the transition between initiation and full elongation competence in regulating development and gene induction in response to environmental signals. [Copyright &y& Elsevier]

Abstract: The virulence-associated alpha C protein (ACP) of Group B Streptococcus (GBS) facilitates the bacterial interaction with host epithelial cells. We previously demonstrated that phase-variable expression of ACP is controlled by variation in short-sequence repeat sequences present upstream of the promoter of bca, the gene encoding ACP. To determine if trans-acting transcriptional control also influences ACP expression, we developed an in silico prediction algorithm that identified a potential transcription-factor binding motif (TTT-N6-ATAT) in the bca upstream region. In vitro reporter gene expression studies confirmed that this motif is required for full ACP expression, and DNA-binding assays with a GBS protein extract demonstrated that the predicted site is bound by a protein. This approach demonstrates the utility of in silico genomic predictive methods in the study of GBS regulatory mechanisms. [Copyright &y& Elsevier]

Abstract: ragged seedling2 (rgd2) is a novel, recessive mutation affecting lateral organ development in maize. The mutant phenotype of homozygous rgd2-R leaves is variable. Mild leaf phenotypes have a reduced midrib and may be moderately narrow and furcated; severe Rgd2-R− leaves are filamentous or even radial. Despite their radial morphology, severe Rgd2-R− mutant leaves develop distinct adaxial and abaxial anatomical features. Although Rgd2-R− mutants exhibit no reduction in adaxial or abaxial cell types, areas of epidermal cell swapping may occur that are associated with misaligned vascular bundles and outgrowths of ectopic margins. Scanning electron microscopy of young primordia and analyses of leaf developmental-marker gene expression in mutant apices reveal that RGD2 functions during recruitment of leaf founder cells and during expansive growth of leaf primordia. Overall, these phenotypes suggest that development is uncoordinated in Rgd2-R− mutant leaves, so that leaf components and tissues may develop quasi-independently. Models whereby RGD2 is required for developmental signaling during the initiation, anatomical patterning, and lateral expansion of maize leaves are discussed. [Copyright &y& Elsevier]

The caspase family of cell death proteases has been implicated in the mechanism of neuronal death following seizures. We investigated the expression and processing of caspases 6 and 7, putative executioner caspases. Brief limbic seizures were evoked by intraamygdala kainic acid to elicit unilateral death of target hippocampal CA3 neurons in the rat. Seizures rapidly induced cleavage of constitutively expressed caspase-6, followed by elevated VEIDase activity and the proteolysis of lamin A. Neuronal caspase-6 immunoreactivity was markedly upregulated within cortex and hippocampus in relation to bursts of polyspike paroxysmal discharges. In contrast, while caspase-7 expression also increased within cortical and hippocampal neuronal populations in response to the same seizure patterns, caspase-7 was not proteolytically activated. These data highlight differences in expression and activation of caspases 6 and 7 in response to identifiable seizure patterns, focusing potential therapeutic targets for neuroprotection in epilepsy. [Copyright &y& Elsevier]

Epilepsy is a network disorder driven by fundamental changes in the function of the cells which compose these networks. Driving this aberrant cellular function are large scale changes in gene expression and gene expression regulation. Recent studies have revealed rapid and persistent changes in epigenetic control of gene expression as a critical regulator of the epileptic transcriptome. Epigenetic-mediated gene output regulates many aspects of cellular physiology including neuronal structure, neurotransmitter assembly and abundance, protein abundance of ion channels and other critical neuronal processes. Thus, understanding the contribution of epigenetic-mediated gene regulation could illuminate novel regulatory mechanisms which may form the basis of novel therapeutic approaches to treat epilepsy. In this review we discuss the effects of epileptogenic brain insults on epigenetic regulation of gene expression, recent efforts to target epigenetic processes to block epileptogenesis and the prospects of an epigenetic-based therapy for epilepsy, and finally we discuss technological advancements which have facilitated the interrogation of the epigenome. [ABSTRACT FROM AUTHOR]

Highlight: [•] Moderate swim exercise modestly enhanced the antimicrobial peptide expression, and attenuated chronic stress-induced intestinal barrier dysfunction. [ABSTRACT FROM AUTHOR]

Abstract: Cfr is a radical-SAM (S-adenosyl-l-methionine) enzyme that methylates the 8 position of 23S rRNA residue A2503 to confer resistance to multiple antibiotic classes acting upon the large subunit of the bacterial ribosome. Radical-SAM enzymes use an Fe–S cluster to generate the 5′-deoxyadenosyl (DOA) radical from SAM, enabling them to modify intrinsically unreactive centres such as adenosine C8. However, despite its mechanistic interest and clinical relevance, until recently Cfr remained little characterised. Accordingly we have used co-expression with the Azotobacter vinelandii isc operon, encoding genes responsible for Fe–S cluster biosynthesis, to express hexahistidine-tagged Cfr in Escherichia coli BL21Star, and purified the recombinant protein in a yield more than 20times greater than has been previously reported. As aerobically purified, Cfr contains secondary structure, is monomeric in solution and has an absorbance spectrum suggestive of a 2Fe–2S cluster. After anaerobic purification a 4Fe–4S cluster is indicated, while on reconstitution with excess iron and sulphide a further increase in metal content suggests that an additional, most likely 4Fe–4S, cluster is formed. Acquisition of additional secondary structure under these conditions indicates that Fe–S clusters are of structural, as well as functional, importance to Cfr. In the presence of sodium dithionite reconstituted Cfr is both reducible and able to cleave SAM to 5′-deoxyadeonsine (DOA), demonstrating that the purified reconstituted enzyme has radical-SAM activity. Co-expression with isc proteins thus enables recombinant active Cfr to be obtained in yields that facilitate its future spectroscopic and structural characterisation. [ABSTRACT FROM AUTHOR]

Abstract: Mutations in the sdn-1/syndecan gene act as genetic enhancers of the ventral-to-dorsal distal tip cell (DTC) migration defects caused by a weak allele of the netrin receptor gene unc-5. The sdn-1(ev697) allele was identified in a genetic screen for enhancers of unc-5 DTC migration defects, and carried a nonsense mutation predicted to truncate the SDN-1 protein prior to the transmembrane domain. The enhancement of unc-5 caused by an sdn-1 mutation was rescued by expression of wild-type sdn-1 in the hypodermis or nervous system rather than the DTCs, indicating a cell non-autonomous function of sdn-1. The enhancement was also partially reversed by mutations in the egl-17/FGF or egl-20/Wnt genes, suggesting that sdn-1 affects UNC-5 function through a mis-regulation of signaling in growth factor pathways. egl-20 reporter constructs exhibited increased and mis-localized EGL-20 distribution in sdn-1 mutants compared to wild-type animals. Finally, using loss of function mutations, we show that egl-17/Fgf and egl-20/Wnt are partially redundant in regulating the migration pattern of the posterior DTC, as double mutants exhibit significant frequencies of defects in migration phases along both the anteroposterior and dorsoventral axes. Together these results suggest that SDN-1 affects UNC-5 function by regulating the proper extracellular distribution of growth factors. [Copyright &y& Elsevier]

Symbionts (e.g., endoparasites and commensals) play an integral role in their host's ecology, yet in many cases their diversity is likely underestimated. Although endoparasites are traditionally characterized using morphology, sequences of conserved genes, and shotgun metagenomics, host transcriptomes constitute an underused resource to identify these organisms’ diversity. By isolating non-host transcripts from host transcriptomes, individual host tissues can now simultaneously reveal their endoparasite species richness (i.e., number of different taxa) and provide insights into parasite gene expression. These approaches can be used in host taxa whose endoparasites are mostly unknown, such as those of tropical amphibians. Here, we focus on the poison frogs (Dendrobatidae) as hosts, which are a Neotropical clade known for their bright coloration and defensive alkaloids. These toxins are an effective protection against vertebrate predators (e.g., snakes and birds), bacteria, and skin-biting ectoparasites (e.g., mosquitoes); however, little is known about their deterrence against eukaryotic endoparasites. With de novo transcriptomes of dendrobatids, we developed a bioinformatics pipeline for endoparasite identification that uses host annotated RNA-seq data and set of a priori parasite taxonomic terms, which are used to mine for specific endoparasites. We found a large community of helminths and protozoans that were mostly restricted to the digestive tract and a few systemic parasites (e.g., Trypanosoma ). Contrary to our expectations, all dendrobatid frogs regardless of the presence of alkaloid defenses have endoparasites, with their highest species richness located in the frog digestive tract. Some of these organisms (e.g., roundworms) might prove to be generalists, as they were not found to be co-diversifying with their frog hosts. We propose that endoparasites may escape poison frogs’ chemical defenses by colonizing tissues with fewer alkaloids than the frog’s skin, where most toxins are stored. [ABSTRACT FROM AUTHOR]

Intraneuronal aggregates of the microtubule binding protein Tau are a hallmark of different neurodegenerative diseases including Alzheimer's disease (AD). In these aggregates, Tau is modified by posttranslational modifications such as phosphorylation as well as by proteolytic cleavage. Here we identify a novel Tau cleavage site at aspartate 65 (D65) that is specific for caspase-2. In addition, we show that the previously described cleavage site at D421 is also efficiently processed by caspase-2, and both sites are cleaved in human brain samples. Caspase-2-generated Tau fragments show increased aggregation potential in vitro , but do not accumulate in vivo after AAV-mediated overexpression in mouse hippocampus. Interestingly, we observe that steady-state protein levels of caspase-2 generated Tau fragments are low in our in vivo model despite strong RNA expression, suggesting efficient clearance. Consistent with this hypothesis, we find that caspase-2 cleavage significantly improves the recognition of Tau by the ubiquitin E3 ligase CHIP, leading to increased ubiquitination and faster degradation of Tau fragments. Taken together our data thus suggest that CHIP-induced ubiquitination is of particular importance for the clearance of caspase-2 generated Tau fragments in vitro and in vivo. • Caspase-2 cleaves Tau at D65 and D421. • In vivo overexpression leads to low steady-state protein levels for caspase-2 generated Tau fragments. • CHIP specifically co-immunoprecipitates with Tau fragments in vivo. • Caspase-2 generated Tau fragments are preferentially ubiquitinated by CHIP. • CHIP is linked to accelerated degradation of caspase-2 generated Tau fragments in vitro. [ABSTRACT FROM AUTHOR]

The Rett-syndrome-associated methyl-CpG-binding protein 2 (MeCP2) selectively binds methylated DNA to regulate transcription during the development of mature neurons. Like other members of the methyl-CpG-binding domain (MBD) family, MeCP2 functions through the recognition of symmetrical 5-methylcytosines in CpG (mCG) dinucleotides. Advances in base-level resolution epigenetic mapping techniques have revealed, however, that MeCP2 can bind asymmetrically methylated and hydroxymethylated CpA dinucleotides and that this alternative binding selectivity modifies gene expression in the developing mammalian brain. The structural determinants of binding to methylated CpA (mCA) and hydroxymethylated DNA have not been previously investigated. Here, we employ isothermal titration calorimetry and NMR spectroscopy to characterize MeCP2 binding to methylated and hydroxymethylated mCG and mCA DNA, examine the effects of Rett-syndrome-associated missense mutations, and make comparisons to the related and evolutionarily most ancient protein, MBD2. These analyses reveal that MeCP2 binds mCA with high affinity in a strand-specific and orientation-dependent manner. In contrast, MBD2 does not show high affinity or methyl-specific binding to mCA. The Rett-associated missense mutations (T158M, R106W, and P101S) destabilize the MeCP2 MBD and disrupt the recognition of mCG and mCA equally. Finally, hydroxymethylation of a high-affinity mCA site does not alter the binding properties, whereas hemi-hydroxylation of the equivalent cytosine in an mCG site decreases affinity and specificity. Based on these findings, we suggest that MeCP2 recognition of methylated/hydroxymethylated CpA dinucleotides functions as an epigenetic switch redistributing MeCP2 among mCG and mCA loci. [ABSTRACT FROM AUTHOR]

There is a growing need for models of human diseases that utilise native, donated human tissue in order to model disease processes and develop novel therapeutic strategies. In this paper we assessed the suitability of adult human retinal explants as a potential model of chronic retinal ganglion cell (RGC) degeneration. Our results confirmed that RGC markers commonly used in rodent studies (NeuN, βIII Tubulin and Thy-1) were appropriate for labelling human RGCs and followed the expected differential expression patterns across, as well as throughout, the macular and para-macular regions of the retina. Furthermore, we showed that neither donor age nor post-mortem time (within 24 h) significantly affected the initial expression levels of RGC markers. In addition, the feasibility of using human post mortem donor tissue as a long-term model of RGC degeneration was determined with RGC protein being detectable up to 4 weeks in culture with an associated decline in RGC mRNA and significant, progressive, apoptotic labelling of NeuN + cells. Differences in RGC apoptosis might have been influenced by medium compositions indicating that media constituents could play a role in supporting axotomised RGCs. We propose that using ex vivo human explants may prove to be a useful model for testing the effectiveness of neuroprotective strategies. [ABSTRACT FROM AUTHOR]

The discovery of cytosolic RNA granule (RG) component proteins associated with human cataract has initiated investigations on post-transcriptional mechanisms of gene expression control in the lens. Application of established mouse lens epithelial cell lines (LECs) can provide rapid insights on RG function in lens cells, especially because mouse mutants in several RG components are not available. However, although these LECs represent potential reagents for such analyses, they are uncharacterized for lens gene expression or RG formation. Therefore, a detailed molecular and cellular characterization of three permanent mouse LECs 17EM15, 21EM15 and αTN4 is performed in this study. Comparative analysis between microarray gene expression datasets on LEC 21EM15 and iSyTE lens tissue demonstrates that 30% of top 200 iSyTE identified lens-enriched genes are expressed in these cells. Majority of these candidates are independently validated to either have lens expression, function or linkage to cataract. Moreover, analysis of microarray data with genes described in Cat-Map, an online database of cataract associated genes and loci, demonstrates that 131 genes linked to cataract loci are expressed in 21EM15 cells. Furthermore, gene expression in LECs is compared to isolated lens epithelium or fiber cells by qRT-PCR and by comparative analyses with publically available epithelium or fiber-specific microarray and RNA-seq (sequencing) datasets. Expression of select candidate genes was validated by regular and real-time quantitative RT-PCR. Expression of lens epithelium-enriched genes Foxe3 , Pax6 , Anxa4 and Mcm4 is up-regulated in LEC lines, compared to isolated lens fiber cells. Moreover, similar to isolated lens epithelium, all three LECs exhibit down-regulation of fiber cell-expressed genes Crybb1 , Mip and Prox1 when compared to fiber cells. These data indicate that the LEC lines exhibit greater similarity to lens epithelium than to fiber cells. Compared to non-lens cell line NIH3T3, LECs exhibit significantly enriched expression of transcription factors with important function in the lens, namely Pax6 , Foxe3 and Prox1 . In addition to these genes, all three LECs also express key lens- and cataract-associated genes, namely Dkk3 , Epha2 , Hsf4 , Jag1 , Mab21l1 , Meis1 , Pknox1 , Pou2f1 , Sfrp1 , Sparc , Tdrd7 and Trpm3 . Additionally, 21EM15 microarrays indicate expression of Chmp4b , Cryab and Tcfap2a among others important genes. Immunostaining with makers for Processing bodies (P-bodies) and Stress granules (SGs) demonstrates that these classes of RGs are robustly expressed in all three LECs. Moreover, under conditions of stress, 17EM15 and αTN4 exhibit significantly higher numbers of P-bodies and SGs compared to NIH3T3 cells. In sum, these data indicate that mouse LECs 21EM15, 17EM15 and αTN4 express key lens or cataract genes, are similar to lens epithelium than fiber cells, and exhibit high levels of P-bodies and SGs, indicating their suitability for investigating gene expression control and RG function in lens-derived cells. [ABSTRACT FROM AUTHOR]

Abstract: Identifying genes that contribute to white matter microstructure should provide insights into the neurobiological processes that regulate white matter development, plasticity and pathology. We detected five significant SNPs using genome-wide association analysis on a global measure of fractional anisotropy in 776 individuals from large extended pedigrees. Genetic correlations and genome-wide association results indicated that the genetic signal was largely homogeneous across white matter regions. Using RNA transcripts derived from lymphocytes in the same individuals, we identified two genes (GNA13 and CCDC91) that are likely to be cis-regulated by top SNPs, and whose expression levels were also genetically correlated with fractional anisotropy. A transcript of HTR7 was phenotypically associated with FA, and was associated with an intronic genome-wide significant SNP. These results encourage further research in the mechanisms by which GNA13, HTR7 and CCDC91 influence brain structure, and emphasize a role for g-protein signaling in the development and maintenance of white matter microstructure in health and disease. [Copyright &y& Elsevier]

Abstract: Brief seizures (epileptic/seizure preconditioning) are capable of activating endogenous protective pathways in the brain which can temporarily generate a damage-refractory state against subsequent and otherwise harmful episodes of prolonged seizures (tolerance). Altered expression of microRNAs, a class of non-coding RNAs that function post-transcriptionally to regulate mRNA translation has recently been implicated in the molecular mechanism of epileptic tolerance. Here we characterized the effect of seizure preconditioning induced by low-dose systemic kainic acid on microRNA expression in the hippocampus of mice. Seizure preconditioning resulted in up-regulation of 25 mature microRNAs in the CA3 subfield of the mouse hippocampus, with the highest levels detected for miR-184. This finding was supported by real time PCR and in situ hybridization showing increased neuronal miR-184 levels and a reduction in protein levels of a miR-184 target. Inhibiting miR-184 expression in vivo resulted in the emergence of neuronal death after preconditioning seizures and increased seizure-induced neuronal death following status epilepticus in previously preconditioned animals, without altered electrographic seizure durations. The present study suggests miRNA up-regulation after preconditioning may contribute to development of epileptic tolerance and identifies miR-184 as a novel contributor to neuronal survival following both mild and severe seizures. [Copyright &y& Elsevier]

Abstract: Previous studies suggested that FGF signaling is important for lens formation. However, the times at which FGFs act to promote lens formation, the FGFs that are involved, the cells that secrete them and the mechanisms by which FGF signaling may promote lens formation are not known. We found that transcripts encoding several FGF ligands and the four classical FGF receptors are detectable in the lens-forming ectoderm at the time of lens induction. Conditional deletion of Fgfr1 and Fgfr2 from this tissue resulted in the formation of small lens rudiments that soon degenerated. Lens placodes lacking Fgfr1 and 2 were thinner than in wild-type embryos. Deletion of Fgfr2 increased cell death from the initiation of placode formation and concurrent deletion of Fgfr1 enhanced this phenotype. Fgfr1/2 conditional knockout placode cells expressed lower levels of proteins known to be regulated by FGF receptor signaling, but proteins known to be important for lens formation were present at normal levels in the remaining placode cells, including the transcription factors Pax6, Sox2 and FoxE3 and the lens-preferred protein αA-crystallin. Previous studies identified a genetic interaction between BMP and FGF signaling in lens formation and conditional deletion of Bmpr1a caused increased cell death in the lens placode, resulting in the formation of smaller lenses. In the present study, conditional deletion of both Bmpr1a and Fgfr2 increased cell death beyond that seen in Fgfr2 CKO placodes and prevented lens formation. These results suggest that the primary role of autocrine or paracrine FGF signaling is to provide essential survival signals to lens placode cells. Because apoptosis was already increased at the onset of placode formation in Fgfr1/2 conditional knockout placode cells, FGF signaling was functionally absent during the period of lens induction by the optic vesicle. Since the expression of proteins required for lens formation was not altered in the knockout placode cells, we can conclude that FGF signaling from the optic vesicle is not required for lens induction. [Copyright &y& Elsevier]

Abstract: BspQI is a thermostable Type IIS restriction endonuclease (REase) with the recognition sequence 5′GCTCTTC N1/N4 3′. Here we report the cloning and expression of the bspQIR gene for the BspQI restriction enzyme in Escherichia coli. Alanine scanning of the BspQI charged residues identified a number of DNA nicking variants. After sampling combinations of different amino acid substitutions, an Nt.BspQI triple mutant (E172A/E248A/E255K) was constructed with predominantly top-strand DNA nicking activity. Furthermore, a triple mutant of BspQI (Nb.BspQI, N235A/K331A/R428A) was engineered to create a bottom-strand nicking enzyme. In addition, we demonstrated the application of Nt.BspQI in optical mapping of single DNA molecules. Nt or Nb.BspQI-nicked dsDNA can be further digested by E. coli exonuclease III to create ssDNA for downstream applications. BspQI contains two potential catalytic sites: a top-strand catalytic site (Ct) with a D-H-N-K motif found in the HNH endonuclease family and a bottom-strand catalytic site (Cb) with three scattered Glu residues. BlastP analysis of proteins in GenBank indicated a putative restriction enzyme with significant amino acid sequence identity to BspQI from the sequenced bacterial genome Croceibacter atlanticus HTCC2559. This restriction gene was amplified by PCR and cloned into a T7 expression vector. Restriction mapping and run-off DNA sequencing of digested products from the partially purified enzyme indicated that it is an EarI isoschizomer with 6-bp recognition, which we named CatHI (CTCTTC N1/N4). [Copyright &y& Elsevier]

Abstract: The cumulative exposure to estrogens is an important determinant in the risk of breast cancer, yet the full range of mechanisms involving estrogens in the genesis and progression of breast cancer remains a subject of debate. Interactions of estrogens and environmental toxicants have received attention as putative factors contributing to carcinogenesis. Mechanistic studies have demonstrated interactions between estrogen receptor α (ERα) and the aryl hydrocarbon receptor (AhR), with consequences on the genes that they regulate. Many studies of ERα and AhR-mediated effects and crosstalk between them have focused on the initial molecular events. In this study, we investigated ERα- and AhR-mediated effects in long-term estrogen exposed (LTEE) MCF-7 human breast cancer cells, which were obtained by continuous culturing for at least 12 weeks in medium supplemented with 1 nM of 17β-estradiol (E2). With these LTEE cells and with parallel control cells cultured without E2 supplementation, we performed an extensive study of cytochrome P450 (CYP) induction, carcinogen bioactivation, global gene expression, and tumorigenicity in immunocompromised mice. We found that LTEE cells, in comparison with control cells, had higher levels of AhR mRNA and protein, greater responsiveness for AhR-regulated CYP1A1 and CYP1B1 induction, a 6-fold higher initial level of benzo(a)pyrene-DNA adducts as determined by liquid chromatography tandem mass spectrometry, marked differences in the expression of numerous genes, and a higher rate of E2-dependent tumor growth as xenografts. These studies indicate that LTEE causes adaptive responses in MCF-7 cells, which may reflect processes that contribute to the overall carcinogenic effect of E2. [Copyright &y& Elsevier]

Abstract: Preconditioning brain with a sub-lethal stressor can temporarily generate a damage-refractory state. Microarray analyses have defined the changes in hippocampal gene expression that follow brief preconditioning seizures, but not the transcriptome after a prolonged and otherwise injurious seizure in previously preconditioned brain. Presently, microarray analysis was performed 24 h after status epilepticus in mice that had received previously either seizure preconditioning (tolerance) or sham-preconditioning (injury). Transcriptional changes in the hippocampal CA3 subfield of ≥2 fold were detected for 1357 genes in the tolerance group compared to a non-seizure control group, with 54% up-regulated. Of these regulated genes, 792 were also regulated in the injury group. Among the remaining 565 genes regulated only in tolerance, 73% were down-regulated. Analysis of the genes differentially suppressed in tolerance identified calcium signaling, ion channels and excitatory neurotransmitter receptors, and the synapse as over-represented among pathways, functions and compartments. Finally, 12 days continuous EEG recordings determined mice with induced tolerance had fewer spontaneous electrographic seizures compared to the injury group. Our data suggest the transcriptional phenotype of neuroprotection in tolerance may be dictated by the biology of the preconditioning stressor, functions by transcriptional reduction of vulnerability to excitotoxicity, and has anti-epileptogenic effects. [Copyright &y& Elsevier]

Background: Postmenopausal women receiving hormone replacement therapy have more adverse outcomes after vascular reconstructions. Estrogen-binding receptors have been identified on vascular smooth muscle cells (VSMCs), indicating that vascular function may be under direct hormonal control. A key group of enzymes involved in vascular remodeling are matrix metalloproteinases (MMPs). Here we studied the effect of estrogen (Est) and progesterone (Prog) on MMP gene expression in human VSMCs. Methods and results: VSMCs were incubated with Est (5 ng/mL), Prog (50 ng/mL), Est+Prog combination (Est/Prog), and interleukin-1β (100 U/mL; IL-1β). Gene array analysis indicated Est+IL-1β increased the expression of MMP-3. Reverse transcriptase-polymer chain reaction (RT-PCR) analyses revealed MMP-3 mRNA levels were significantly increased by Est/Prog+IL-1β treatment. However, Western blot and further RT-PCR analyses indicated no change in MMP-3 in response to hormones alone. RT-PCR analyses revealed membrane type 1 (MT1)-MMP mRNA levels, not MMP-2 or tissue inhibitor of MMP (TIMP), were significantly increased by Est/Prog+IL-1β, and Western blot analyses confirmed a significant increase in MT1-MMP protein in response to Est alone. Conclusion: Estrogen and progesterone affect the MMP pathway of VSMCs via isoform specific mechanisms and may lead to unbalanced MMP regulation. Estrogen up-regulates MT1-MMP without a corresponding increase in TIMP-2, known activator and inhibitor of MMP-2, respectively. Additionally, estrogen up-regulates MMP-3 only in the presence of IL-1β. This differential regulation, combined with case-specific variations in degree of inflammatory response, may explain why some women receiving exogenous hormone therapy at the time of vascular interventions are more susceptible to complications. [Copyright &y& Elsevier]

Abstract: Chagas disease, characterized by acute myocarditis and chronic cardiomyopathy, is caused by infection with the protozoan parasite Trypanosoma cruzi. We sought to identify genes altered during the development of parasite-induced cardiomyopathy. Microarrays containing 27,400 sequence-verified mouse cDNAs were used to analyze global gene expression changes in the myocardium of a murine model of chagasic cardiomyopathy. Changes in gene expression were determined as the acute stage of infection developed into the chronic stage. This analysis was performed on the hearts of male CD-1 mice infected with trypomastigotes of T. cruzi (Brazil strain). At each interval we compared infected and uninfected mice and confirmed the microarray data with dye reversal. We identified eight distinct categories of mRNAs that were differentially regulated during infection and identified dysregulation of several key genes. These data may provide insight into the pathogenesis of chagasic cardiomyopathy and provide new targets for intervention. [Copyright &y& Elsevier]

Abstract: cDNA arrays compared gene expression in kidneys of neonatal mice subjected to 1, 2, and 4 weeks of chronic constant (CCH) or intermittent (CIH) hypoxia with normoxic littermates. Five to twenty percent of genes were regulated in each condition, with greater changes in CCH. Up-regulation of 42% of the solute carriers after 1 week of CCH suggests a strong activation of pH controlling pathways. Significant reduction in expression change of genes important in growth, development, and aging as a function of time indicates reduced maturation rate in CIH and CCH treatments. Regulated genes showed gender dependence in CCH, being higher in females than males at 1 week and higher in males than females thereafter. Transcriptional control was enhanced in CCH but not in CIH. Thus, CCH and CIH both alter gene expression and retard maturation with the more profound changes occurring in CCH than in CIH. [Copyright &y& Elsevier]

Abstract: The purpose of this study was to evaluate gene expression profiles in the liver and blood for prediction of infection severity from Listeria monocytogenes (LM). Mice were injected with medium broth (control) or a nonlethal or lethal dose of LM and sacrificed 6 h later. Gene expression changes were determined using Affymetrix MGU74Av2 GeneChips and confirmed by real-time polymerase chain reaction analysis. We identified discernable genes whose gene expression profiles can be used in pattern recognition to predict and classify samples in differently treated groups, with ≥90% accuracy in liver samples and 80% accuracy in blood at prediction; however, different genes were predictive in each tissue. Our results suggest that gene expression profiling in response to LM in mice may be able to distinguish samples in groups with varying severity of infection and provide information in finding molecular mechanisms and early biomarkers for subsequent conventional clinical endpoints. [Copyright &y& Elsevier]