Several reports have focused on the identification of biological elements involved in the development of abnormal systemic biochemical alterations in chronic kidney disease, but this abundant literature results most of the time fragmented. To better define the cellular machinery associated to this condition, we employed an innovative high-throughput approach based on a whole transcriptomic analysis and classical biomolecular methodologies. The genomic screening of peripheral blood mononuclear cells revealed that 44 genes were up-regulated in both chronic kidney disease patients in conservative treatment (CKD, n=9) and hemodialysis (HD, n=17) compared to healthy subjects (NORM) (p<0.001, FDR=1%). Functional analysis demonstrated that 11/44 genes were involved in the oxidative phosphorylation system (OXPHOS). Western blotting for COXI and COXIV, key constituents of the complex IV of OXPHOS, performed on an independent testing-group (12 NORM, 10 CKD and 14 HD) confirmed the elevated synthesis of these subunits in CKD/HD patients. However, complex IV activity was significantly reduced in CKD/HD patients compared to NORM (p<0.01). Finally, CKD/HD patients presented higher reactive oxygen species and 8-hydroxydeoxyguanosine levels compared to NORM. Taken together these results suggest, for the first time, that CKD/HD patients may have an impaired mitochondrial respiratory system and this condition may be both the consequence and the cause of an enhanced oxidative stress.
Mitochondrial dysregulation and oxidative stress in patients with chronic kidney disease.
Disease, Treatment, Subject
View SamplesRNA-seq analysis of zebrafish foxc1a mutant Overall design: For RNA-seq, mRNA was extracted from 38-40 hpf old embryos. We isolated wild type and foxc1a mutant samples by dissecting the entire first 6 anterior somitic segments (AS) through which the fin nerves migrate, and the adjacent posterior segments (PS; segments 7 through ~12) devoid of fin innervating nerves. Heads and yolks were excluded from all samples. Tissues were stored in RNAlater solution (Life Technologies) for up to 2 days at 4 degree before RNA was extracted using the RNAeasy kit (Qiagen) according to the manufacture’s protocol. RNA was tested for integrity using a Bioanalyzer (Agilent technologies). RNA samples showing RIN value of 8 or higher were used for generating cDNA libraries as described in the TruSeq® Stranded mRNA sample preparation guide. At the final stage, 15 cycles of PCR amplifications was performed. Barcoded libraries representing duplicates of AS and PS samples of wild type and mutants were validated using Bionalyzer (Agilent Technology) and finally sequenced in Illumina HiSeq 2500 yielding paired end reads of 100bp. The RNA-seq Unified Mapper (RUM) (Grant et al., 2011) was used to align the reads to the Zv9/danRer7 reference genome and to assign each read uniquely to a transcript. We investigated transcripts that showed the highest fold changes of expression between the different groups. For Gene Ontology annotations, genes tagged by the GO term “axon guidance” were obtained from the gene ontology database (http://www.geneontology.org/). Next we filtered this list for the “Danio rerio” taxon (resulting in 116 unique genes) and used them to annotate our RNA-seq results.
Zebrafish foxc1a drives appendage-specific neural circuit development.
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View SamplesMitochondrial dysfunction causes biophysical, metabolic and signalling changes that alter homeostasis and reprogram cells. We used a Drosophila model in which TFAM is overexpressed in the nervous system with or without Ras/MAPK pathway inhibition, by knock-down of the ETS transcription factor pointed, to investigate the how mitochondrial dysfunction and Ras/MAPK signalling affect the transcriptome.
Ras-ERK-ETS inhibition alleviates neuronal mitochondrial dysfunction by reprogramming mitochondrial retrograde signaling.
Specimen part
View SamplesDrought tolerance is a key trait for increasing and stabilizing barley productivity in dry areas worldwide. Identification of the genes responsible for drought tolerance in barley (Hordeum vulgare L.) will facilitate understanding of the molecular mechanisms of drought tolerance, and also genetic improvement of barley through marker-assisted selection or gene transformation. To monitor the changes in gene expression at transcription levels in barley leaves during the reproductive stage under drought conditions, the 22K Affymetrix Barley 1 microarray was used to screen two drought-tolerant barley genotypes, Martin and Hordeum spontaneum 41-1 (HS41-1), and one drought-sensitive genotype Moroc9-75. Seventeen genes were expressed exclusively in the two drought-tolerant genotypes under drought stress, and their encoded proteins may play significant roles in enhancing drought tolerance through controlling stomatal closure via carbon metabolism (NADP malic enzyme (NADP-ME) and pyruvate dehydrogenase (PDH), synthesizing the osmoprotectant glycine-betaine (C-4 sterol methyl oxidase (CSMO), generating protectants against reactive-oxygen-species scavenging (aldehyde dehydrogenase (ALDH), ascorbate-dependant oxidoreductase (ADOR), and stabilizing membranes and proteins (heat-shock protein 17.8 (HSP17.8) and dehydrin 3 (DHN3). Moreover, 17 genes were abundantly expressed in Martin and HS41-1 compared with Moroc9-75 under both drought and control conditions. These genes were likely constitutively expressed in drought-tolerant genotypes. Among them, 7 known annotated genes might enhance drought tolerance through signaling (such as calcium-dependent protein kinase (CDPK) and membrane steroid binding protein (MSBP), anti-senescence (G2 pea dark accumulated protein GDA2) and detoxification (glutathione S-transferase (GST) pathways. In addition, 18 genes, including those encoding l-pyrroline-5-carboxylate synthetase (P5CS), protein phosphatase 2C-like protein (PP2C) and several chaperones, were differentially expressed in all genotypes under drought; thus, they were more likely general drought-responsive genes in barley. These results could provide new insights into further understanding of drought-tolerance mechanisms in barley.
Differentially expressed genes between drought-tolerant and drought-sensitive barley genotypes in response to drought stress during the reproductive stage.
Specimen part, Treatment
View SamplesAdaptive resistance to targeted therapy such as BRAF inhibitors represents in melanoma a major drawback to this otherwise powerful treatment. Some of the underlying molecular mechanisms have recently been described: hyperactivation of the BRAF-MAPK pathway, of the AKT pathway, of the TGF/EGFR/PDGFRB pathway, or the low MITF/AXL ratio. Nevertheless, the phenomenon of early resistance is still not clearly understood. In this report, we show that knockdown of neural crest-associated gene ID3 increases the melanoma sensitivity to vemurafenib short-term treatment. In addition, we observe an ID3-mediated regulation of cell migration and of the expression of resistance-associated genes such as SOX10 and MITF. In sum, these data suggest ID3 as a new key actor of melanoma adaptive resistance to vemurafenib and as a potential drug target. Molecular mechanisms that are responsible for the development of human skin epithelial cells are not completely understood so far. As a consequence, the efficiency to establish a pure skin epithelial cell population from human induced pluripotent stem cells (hiPSC) remains poor. Using an approach including RNA interference and high-throughput imaging of early epithelial cells, we could identify candidate kinases which are involved in skin epithelial differentiation. Among them, we found HIPK4 to be an important inhibitor of this process. Indeed, its silencing increased the amount of generated skin epithelial precursors, increased the amount of generated keratinocytes and improved growth and differentiation of organotypic cultures, allowing for the formation of a denser basal layer and stratification with the expression of several keratins. Our data bring substantial input in the regulation of human skin epithelial differentiation and for improving differentiation protocols from pluripotent stem cells.
New role of ID3 in melanoma adaptive drug-resistance.
Cell line, Treatment
View SamplesThe aim of this study was to compare the gene expression profile changes of DMBA-induced rat breast tumors after treatment with hydroxytyrosol (a natural compound from virgin olive oil). To this end, a cDNA microarray experiment was performed (Affymetrixs Rat Genome 230 2.0 array). This gene expression study was carried out on the tumor biopsy samples prior to hydroxytyrosol treatment, and compared with matched tumor biopsy samples after completion of the hydroxytyrosol treatment schedule. The result of this study was the identification of several genes related to apoptosis, cell cycle arrest, proliferation, differentiation, survival and transformation-related genes.
Hydroxytyrosol inhibits growth and cell proliferation and promotes high expression of sfrp4 in rat mammary tumours.
Sex, Age, Specimen part, Treatment
View SamplesThe aim of this study was to compare the gene expression profile changes of DMBA-induced rat breast tumors after treatment with adriamycin. To this end, a cDNA microarray was performed (Affymetrixs Rat Genome 230 2.0 array). This gene expression study was carried out on the tumor biopsy samples prior to adriamycin treatment, and compared with matched tumor biopsy samples after completion of the adriamycin treatment schedule.
Hydroxytyrosol inhibits growth and cell proliferation and promotes high expression of sfrp4 in rat mammary tumours.
Sex, Age, Specimen part, Treatment
View SamplesThe aim of this study was to compare the gene expression profile changes of DMBA-induced rat breast tumors from an initial stage to the moment of sacrifice. To this end, a cDNA microarray was performed (Affymetrixs Rat Genome 230 2.0 array). This gene expression study was carried out on the umor biopsy samples and compared with matched tumor biopsy samples once the study ended (7 weeks after initial biopsy).
Hydroxytyrosol inhibits growth and cell proliferation and promotes high expression of sfrp4 in rat mammary tumours.
Sex, Age, Specimen part, Treatment
View SamplesAlternative promoters (APs) occur in >30% protein-coding genes and contribute to proteome diversity. However, large-scale analyses of AP regulation are lacking, and little is known about their potential physiopathologic significance. To better understand the transcriptomic impact of estrogens, which play a major role in breast cancer, we analyzed gene and AP regulation by estradiol in MCF7 cells using pan-genomic exon arrays. We thereby identified novel estrogen-regulated genes, and determined the regulation of AP-encoded transcripts in 150 regulated genes. In <30% cases, APs were regulated in a similar manner by estradiol, while in >70% cases, they were regulated differentially. The patterns of AP regulation correlated with the patterns of estrogen receptor (ER) and CCCTC-binding factor (CTCF) binding sites at regulated gene loci. Interestingly, among genes with differentially regulated APs, we identified cases where estradiol regulated APs in an opposite manner, sometimes without affecting global gene expression levels. This promoter switch was mediated by the DDX5/DDX17 family of ER coregulators. Finally, genes with differentially regulated promoters were preferentially involved in specific processes (e.g., cell structure and motility, and cell cycle). We show in particular that isoforms encoded by the NET1 gene APs, which are inversely regulated by estradiol, play distinct roles in cell adhesion and cell cycle regulation, and that their expression is differentially associated with prognosis in ER+ breast cancer. Altogether, this study identifies the patterns of AP regulation in estrogen-regulated genes, demonstrates the contribution of AP-encoded isoforms to the estradiol-regulated transcriptome, as well as their physiopathologic significance in breast cancer.
Estrogen regulation and physiopathologic significance of alternative promoters in breast cancer.
Disease, Disease stage, Cell line, Time
View SamplesThis study was designed to identify candidate genes associated with iron efficiency in soybeans. Two genotypes, Clark (PI548553) and IsoClark (PI547430), were grown in both iron sufficient (100uM Fe(NO3)3) and iron deficient (50uM Fe(NO3)3) hydroponics conditions. The second trifoliate was harvested for RNA extraction for the microarray experiment. Candidate genes were identified by comparing gene expression profiles within genotypes between the two iron growth conditions.
Integrating microarray analysis and the soybean genome to understand the soybeans iron deficiency response.
No sample metadata fields
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