Arsenic (As) exposure is a significant worldwide environmental health concern. Low dose, chronic arsenic exposure has been associated with higher risk of skin, lung, and bladder cancer, as well as cardiovascular disease and diabetes. While arsenic-induced biological changes play a role in disease pathology, little is known about the dynamic cellular changes due to arsenic exposure and withdrawal. In these studies, we seek to understand the molecular mechanisms behind the biological changes induced by chronic low doses of arsenic exposure. We used a comprehensive approach involving chromatin structural studies and mRNA microarray analyses to determine how chromatin structure and gene expression patterns change in response to chronic low dose arsenic exposure and its subsequent withdrawal. Our results show that cells exposed to low doses of sodium arsenite have distinct temporal and coordinated chromatin, gene expression and miRNA changes that are consistent with differentiation and activation of multiple biochemical pathways. Most of these temporal patterns in gene expression are reversed when arsenic was withdrawn. However, some of the gene expression patterns remained altered, plausibly as a result of an adaptive response by these cells. Additionally, these gene expression patterns correlated with changes in chromatin structure, further solidifying the role of chromatin structure in gene regulatory changes due to arsenite exposure. Lastly, we show that arsenite exposure influences gene regulation both at the transcription initiation as well as at the splicing level. Thus our results suggest that general patterns of alternative splicing, as well as expression of particular gene regulators, can be indicative of arsenite-induced cell transformation.
Inorganic Arsenic-induced cellular transformation is coupled with genome wide changes in chromatin structure, transcriptome and splicing patterns.
Cell line
View SamplesNeuronal migration defects (NMDs) are among the most common and severe brain abnormalities in humans. Lack of disease models in mice or in human cells has hampered the identification of underlying mechanisms. From patients with severe NMDs we generated iPSCs then differentiated neural progenitor cells (NPCs). On artificial extracellular matrix, patient-derived neuronal cells showed defective migration and impaired neurite outgrowth. From a cohort of 107 families with NMDs, sequencing identified two homozygous C-terminal truncating mutations in CTNNA2, encoding aN-catenin, one of three paralogues of the a-catenin family, involved in epithelial integrity and cell polarity. Patient-derived or CRISPR-targeted CTNNA2- mutant neuronal cells showed defective migration and neurite stability. Recombinant aN-catenin was sufficient to bundle purified actin and to suppress the actin-branching activity of ARP2/3. Small molecule inhibitors of ARP2/3 rescued the CTNNA2 neurite defect. Thus, disease modeling in human cells could be used to understand NMD pathogenesis and develop treatments for associated disorders. Overall design: 2 biological replicates per individual (2 iPSC clone differentiations), excluding 1263A, which has one sample
Biallelic loss of human CTNNA2, encoding αN-catenin, leads to ARP2/3 complex overactivity and disordered cortical neuronal migration.
No sample metadata fields
View SamplesThe liver has inherent regenerative capacity via mitotic division of mature hepatocytes. However, if the hepatic loss is massive or mature hepatocyte proliferation is impaired by chronic liver injury, HSPC are activated to support liver regeneration. Access to liver tissue from 4 patients who underwent liver transplantation for hepatitis B virus (HBV)- associated acute liver failure (ALF) provided us with the opportunity to investigate the molecular mechanisms of liver regeneration in humans by means of gene expression profiling and immunohistochemistry (IHC). Gene expression profiling of 17 liver specimens from the 4 ALF cases and individual liver specimens from 10 liver donors documented a distinct gene signature for ALF. However, unsupervised multidimensional scaling and hierarchical clustering identified two-well defined clusters that segregated according to the histopathological severity, i.e. massive hepatic necrosis (MHN; 2 patients) and submassive hepatic necrosis (SHN; 2 patients). We found that ALF is characterized by a strong hepatic stem/progenitor cell (HSPC) gene signature, as also confirmed by IHC, along with ductular reaction, both of which are more prominent in MHN. Interestingly, no evidence of further lineage differentiation was seen in MHN, whereas in SHN we detected cells with hepatocyte-like morphology. Strikingly, ALF was associated with a strong tumorigenesis gene signature. MHN had the greatest upregulation of cancer stem cell genes (EpCAM, CK19 and CK7), whereas the most upregulated genes in SHN were related to cellular growth and proliferation (AKR1B10, NQO1, RRM2, SFN, TOP2A, CCNB1, CDC20, ANLN and KI67). The extent of liver necrosis correlated with an overriding fibrogenesis gene signature, reflecting the wound healing process. Conclusion: Our data provide evidence of marked HSPC cell activation and fibrogenesis in HBV-associated ALF, which positively correlate with the extent of liver necrosis. Moreover, we detected a strong tumorigenesis gene signature in ALF, which underlines the relationship between liver regeneration and liver cancer.
Liver regeneration signature in hepatitis B virus (HBV)-associated acute liver failure identified by gene expression profiling.
Specimen part, Disease, Disease stage, Subject
View SamplesInflammatory mediators play a role in the pathogenesis/progression of chronic heart failure (CHF). The aim of the present study was to identify diagnostic/prognostic markers and gene expression profiles of CHF vs control.
Gene expression profiles in peripheral blood mononuclear cells of chronic heart failure patients.
No sample metadata fields
View SamplesGene expression in intact and hypophysectomized adult mouse liver was assayed by RNA-seq analysis of total liver RNA, as part of a study of growth hormone regulation of hepatic lincRNAs. Overall design: Eight independent pools: two intact males, two intact females, two hypophysectomized males and two hypophysectomized females, comprised of total RNA isolated from 3-5 individual livers / pool, were prepared and used for unstranded RNA-seq.
Hepatic Long Intergenic Noncoding RNAs: High Promoter Conservation and Dynamic, Sex-Dependent Transcriptional Regulation by Growth Hormone.
No sample metadata fields
View SamplesGene expression in adult male mouse liver was assayed by nuclear RNA-seq, as part of a study of hepatic lincRNAs. Overall design: Three independent pools, comprised of nuclear RNA isolated from 4 individual male livers per pool, were prepared and used for RNA-seq.
Hepatic Long Intergenic Noncoding RNAs: High Promoter Conservation and Dynamic, Sex-Dependent Transcriptional Regulation by Growth Hormone.
No sample metadata fields
View SamplesGene expression in adult female mouse liver was assayed by nuclear RNA-seq, as part of a study of hepatic lincRNAs. Overall design: Three independent pools, comprised of nuclear RNA isolated from 4 individual livers per pool, were prepared and used for unstranded RNA-seq.
Hepatic Long Intergenic Noncoding RNAs: High Promoter Conservation and Dynamic, Sex-Dependent Transcriptional Regulation by Growth Hormone.
No sample metadata fields
View SamplesGene expression in adult male and female mouse liver was assayed by RNA-seq, as part of a study on hepatic lincRNAs. Overall design: Total liver RNA was prepared from 12 individual male and 12 individual female mice. Four independent pools, comprised of RNA isolated from 6 individual male or female livers (2 pooled biological replicates for each sex) were then prepared and used for RNA-seq.
Hepatic Long Intergenic Noncoding RNAs: High Promoter Conservation and Dynamic, Sex-Dependent Transcriptional Regulation by Growth Hormone.
No sample metadata fields
View SamplesGene expression in adult male and female mouse liver was assayed by RNA-seq, as part of a study on chromatin states in male and female mouse and their role in sex-biased liver gene expression (A Sugathan and DJ Waxman (2013) Mol Cell Biol. 33:3594-3610. doi: 10.1128/MCB.00280-13). Overall design: Total liver RNA was prepared from 12 individual male and 12 individual female mice. Four RNA pools, comprised of RNA isolated from 6 individual male or female livers (2 pooled biological replicates for each sex) were then prepared and used for RNA-seq.
Hepatic Long Intergenic Noncoding RNAs: High Promoter Conservation and Dynamic, Sex-Dependent Transcriptional Regulation by Growth Hormone.
Sex, Age, Cell line, Subject
View SamplesGene expression in adult male and female mouse liver was analyzed based on nuclear RNA-seq, as part of a study on hepatic lincRNAs. Overall design: Nuclear liver RNA was prepared from 6 individual male and 6 individual female mice. Pools comprised of RNA isolated from 6 individual male or female livers (1 pool of 6 biological replicates for each sex) were then prepared and used for strand-specific RNA-seq.
Hepatic Long Intergenic Noncoding RNAs: High Promoter Conservation and Dynamic, Sex-Dependent Transcriptional Regulation by Growth Hormone.
No sample metadata fields
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