Zinc is a common metal in most ambient particulate matter (PM), and has been proposed to be a causative component in PM-induced adverse cardiovascular health effects. Zinc is also an essential metal and has the potential to induce many physiological and nonphysiological changes. Most toxicological studies employ high levels of zinc. We hypothesized that subchronic inhalation of environmentally relevant levels of zinc would cause cardiac changes in healthy rats. To address this question, healthy male WKY rats (12 wks age) were exposed via nose only inhalation to filtered air or 10, 30 or 100 ug/m3 of aerosolized Zn in sulfate form, 5 h/d, 3 d/wk for 16 wks. Necropsies occurred 48 h after the last exposure to ensure effects were due to chronic exposure rather than the last exposure. No significant changes were observed in neutrophil or macrophage count, total lavageable cells, or enzyme activity levels (lactate dehydrogenase, n-acetyl ?-D-glucosaminidase, ?-glutamyl transferase) in bronchoalveolar lavage fluid, indicating minimal pulmonary effect. In the heart, cytosolic glutathione peroxidase activity decreased, while mitochondrial ferritin levels increased and succinate dehydrogenase activity decreased, suggesting a mitochondria-specific effect. Although no cardiac pathology was seen, cardiac gene array analysis indicated changes in genes involved in cell signaling, a pattern concordant with known zinc effects. These data indicate that inhalation of zinc at environmentally relevant levels may induce cardiac effects. While changes are small in healthy rats, these may be especially relevant in individuals with pre-existent cardiovascular disease.
Subchronic inhalation of zinc sulfate induces cardiac changes in healthy rats.
No sample metadata fields
View SamplesLow back pain (LBP) is one of the most prevalent conditions which need medical advice and result in chronic disabilities. Degenerative disc disease (DDD) is a common reason for LBP. A lot of researchers think that CEP degeneration play critical roles in the initiation and development of DDD. In recent years, researchers have put interests on cell-based therapies for regenerating disc structure and function. Our research team has isolated cartilage endplate-derived stem cells (CESCs) and validated their chondrogenic and osteogenic differentiation ability. Enhanced chondrogenic differentiation and inhibited osteogenic differentiation of CESCs may retard CEP calcification and restore the nutrition supply, possibly regenerating the degenerated discs.
Global Gene Expression Profiling and Alternative Splicing Events during the Chondrogenic Differentiation of Human Cartilage Endplate-Derived Stem Cells.
Specimen part
View SamplesWe have developed a method for mapping unmethylated sites in human genome based on the resistant of TspR1 digested ends to exoIII nuclease degradation. Digestion with TspR1 and methylation-sensitive restriction endonuclease, HpaII, followed by exoIII and single strand DNA nuclease allows the removal of DNA fragments containing unmethylated HpaII sites. We then use array CGH to map the sequences depleted by this procedures in human genomes derived from five human tissues, a primary breast tumor and two breast tumor cell lines. Analysis of methylation patterns of the normal tissue genomes indicates that the hypomethylated sites are enriched in the 5 end of widely expressed genes including promoter, first exon and first intron. In contrast, genomes of the MCF-7 and MDA-MB-231 cell lines show extensive hypomethylation in the intragenic and intergenic regions whereas primary tumor exhibits intermediate pattern between normal tissue and cell lines. A striking characteristic of tumor genomes is the presence of megabase-sized hypomethylated zones. These hypomethylated zones are associated with large genes, fragile sites, evolutionary breakpoints, chromosomal rearrangement breakpoints, tumor supperessor genes, and with regions containing tissue-specific gene clusters or with gene poor region containing novel tissue-specific genes. Bisulfite sequencing analysis shows a novel mosaic methylation pattern with alternative methylated and unmethylated zones was found in human histone gene clusters in chromosome 6. Correlation with microarray analysis show that genes with hypomethylated sequence 2kb up- or down-stream of transcription start site are highly expressed whereas genes with extensive intragenic and 3 UTR hypomethylation are silenced. The method described herein can be used for large scale screening of changes in methylation pattern in the genome of interest.
Genome-wide mapping and characterization of hypomethylated sites in human tissues and breast cancer cell lines.
Sex, Age, Specimen part, Cell line
View SamplesPre-leukemic mutations are thought to promote clonal expansion of hematopoietic stem cells (HSCs) by increasing self-renewal and competitiveness. However, mutations that increase HSC proliferation tend to reduce competitiveness and self-renewal potential, raising the question of how a mutant HSC can sustainably outcompete wild-type HSCs. Activating mutations in NRAS are prevalent in human myeloproliferative disease and leukemia. Here we show that a single allele of oncogenic NrasG12D increases HSC proliferation but also increases reconstituting and self-renewal potential upon serial transplantation in irradiated mice, all without immortalizing HSCs or causing leukemia in our experiments. NrasG12D also confers long-term self-renewal potential upon multipotent progenitors. To explore the mechanism by which NrasG12D promotes HSC proliferation and self-renewal we assessed HSC cell cycle kinetics using H2B-GFP label retention. We found that NrasG12D had a bimodal effect on HSCs, increasing the proliferation of some HSCs while increasing the quiescence and competitiveness of other HSCs. One signal can therefore increase HSC proliferation, competitiveness, and self-renewal through a bimodal effect that promotes proliferation in some HSCs and quiescence in others.
Oncogenic Nras has bimodal effects on stem cells that sustainably increase competitiveness.
Specimen part
View SamplesExpression microarrays were employed to identify genes induced by phorbol ester and ionomycin stimulation of EL4 cells. EL4 is a murine T cell line. To identify induced genes that were independent of new protein synthesis cells were pre-treated with cycloheximide. This expression study was used in conjunction with histone acetylation ChIP-chip to determine if inducible genes had a specific histone acetylation profile and whether the acetylation profile differed for genes with different kinetics of induction.
Defining the chromatin signature of inducible genes in T cells.
Cell line, Treatment
View SamplesHere we show that biotin-labelled miR-34a can be loaded to AGO2, and AGO2 immunoprecipitation can pulldown biotinylated miR-34a (Bio-miR pulldown). RNA-sequencing (RNA-seq) of the Bio-miR pulldown RNAs efficiently identified miR-34a mRNA targets, which could be verified with luciferase assays. In contrast to the approach of Bio-miR pulldown, RNA-seq of miR-34a overexpression samples had limited value in identifying direct targets of miR-34a. It seems that pulldown of 30 -Biotin-tagged miRNA can identify bona fide microRNA targets at least for miR34a. Overall design: biotin-labelled miR-34a pulldown and RNA sequencing of miR-34a overexpression samples
Comparing two approaches of miR-34a target identification, biotinylated-miRNA pulldown vs miRNA overexpression.
Cell line, Subject
View SamplesMultidrug resistance (MDR) frequently develops in cancer patients exposed to chemotherapeutic agents and is usually brought about by over-expression of P-glycoprotein (P-gp) which acts as a drug efflux pump. MiRNAome profiling using next-generation sequencing identified differentially expressed microRNAs (miRs) between parental K562 cells and MDR K562 cells (K562/ADM) induced by chronic adriamycin treatment. Overall design: MiRNAome profiling in untreated K562 cells and K562 cells exposed to long-term adriamycin treatment
Changes in the expression of miR-381 and miR-495 are inversely associated with the expression of the MDR1 gene and development of multi-drug resistance.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
PrtT-regulated proteins secreted by Aspergillus fumigatus activate MAPK signaling in exposed A549 lung cells leading to necrotic cell death.
Specimen part, Cell line, Treatment
View SamplesGene expression was evaluated in 9 appendix samples removed from patients who went to the operating room with the diagnosis of acute appendicitis and 4 samples removed for non-inflammatory reasons.
Acute appendicitis is characterized by a uniform and highly selective pattern of inflammatory gene expression.
No sample metadata fields
View SamplesResponse of A549 cells treated with Aspergillus fumigatus wild type germinating conidia (WT_GC) or PrtT protease deficient mutant conidia (PrtT-GC) or inert acrylic 2-4 micron beads (Beads) for 8h
PrtT-regulated proteins secreted by Aspergillus fumigatus activate MAPK signaling in exposed A549 lung cells leading to necrotic cell death.
Specimen part, Cell line, Treatment
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