Background: Transcription control of mitochondrial metabolism is essential for cellular function. A better understanding of this process will aid the elucidation of mitochondrial disorders, in particular of the many genetically unsolved cases of oxidative phosphorylation (OXPHOS) deficiency. Yet, to date only few studies have investigated nuclear gene regulation in the context of OXPHOS deficiency. In this study, we combined RNA sequencing of human complex I-deficient patient cells across 32 conditions of perturbed mitochondrial metabolism, with a comprehensive analysis of gene expression patterns, co-expression calculations and transcription factor binding sites. Results: Our analysis shows that OXPHOS genes have a significantly higher co-expression with each other than with other genes, including mitochondrial genes. We found no evidence for complex-specific mRNA expression regulation in the tested cell types and conditions: subunits of different OXPHOS complexes are similarly (co-)expressed and regulated by a common set of transcription factors. However, we did observe significant differences between the expression of OXPHOS complex subunits compared to assembly factors, suggesting divergent transcription programs. Furthermore, complex I co-expression calculations identified 684 genes with a likely role in OXPHOS biogenesis and function. Analysis of evolutionarily conserved transcription factor binding sites in the promoters of these genes revealed almost all known OXPHOS regulators (including GABP, NRF1/2, SP1, YY1, E-box factors) and a set of six yet uncharacterized candidate transcription factors (ELK1, KLF7, SP4, EHF, ZNF143, and EL2). Conclusions: OXPHOS genes share an expression program distinct from other mitochondrial genes, indicative of targeted regulation of this mitochondrial sub-process. Within the subset of OXPHOS genes we established a difference in expression between subunits and assembly factors. Most transcription regulators of genes that co-express with complex I are well-established factors for OXPHOS biogenesis. For the remaining six factors we here suggest for the first time a link with transcription regulation in OXPHOS deficiency. Overall design: RNA-SEQ of whole cell RNA in 2 control and 2 complex I deficient patient fibroblast cell lines treated with 4 compounds in duplicate, resulting in a total of 2x2x4x2=32 samples
Transcriptome analysis of complex I-deficient patients reveals distinct expression programs for subunits and assembly factors of the oxidative phosphorylation system.
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View SamplesDefective complex I (CI) is the most common type of oxidative phosphorylation (OXPHOS) disease in patients, with an incidence of 1 in 5,000 live births. Complex I deficiency can present in infancy or early adulthood and shows a wide variety of clinical manifestations, including Leigh syndrome, (cardio)myopathy, hypotonia, stroke, ataxia and lactic acidosis. A number of critical processes and factors, like superoxide production, calcium homeostasis, mitochondrial membrane potential and mitochondrial morphology, are known to be involved in clinical CI deficiency, but not all factors are yet known and a complete picture is lacking.
Transcriptional changes in OXPHOS complex I deficiency are related to anti-oxidant pathways and could explain the disturbed calcium homeostasis.
Sex, Age, Specimen part, Disease, Disease stage
View SamplesWe are investigating the response of human lymphoblastoid cells to low-dose exposure of environmental metals
Comparative genomic analyses identify common molecular pathways modulated upon exposure to low doses of arsenic and cadmium.
Cell line, Treatment
View SamplesTotal RNA samples from three replicate cultures of wild type and mutant yeast strains was isolated and expression profile done using Affymetrix arrays. Comparsion between the samples indicate how mutation in a single amino acid residue in histone H4 (H4R45H) affects gene expression in yeast. Such a mutation in histone H4 is known to generate a specific class of mutants called SWI/SNF independent (SIN) mutants, and the mutants were identified by their ability to carry out transcription in the absence of yeast chromatin remodeling complex SWI/SNF. SIN mutations are known to affect higher order chromatin structure and the comparative expression profile would help identification of genes which get affected by such altered chromatin landscape.
A single amino acid change in histone H4 enhances UV survival and DNA repair in yeast.
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View SamplesThis SuperSeries is composed of the SubSeries listed below.
Stable 5-Hydroxymethylcytosine (5hmC) Acquisition Marks Gene Activation During Chondrogenic Differentiation.
Specimen part
View SamplesTo understand the molecular control of development and regeneration in the mammalian cochlear sensory epithelia, we performed a comparative study of gene expression patterns between postnatal day-3 (P3) and adult stages using a microarrays approach.
Transcriptomic analysis of the developing and adult mouse cochlear sensory epithelia.
Specimen part
View SamplesRegulation of chondrogenic differentiation by DNA demethylation is little understood. The ten-eleven-translocation (TET) proteins oxidize methylated cytosines (5mC) to 5hmC, 5fC and 5caC eventually leading to DNA demethylation. However, 5hmC is stable and can potentially act as an epigenetic mark as well. In this study, we report that global changes in 5hmC mark chondrogenic differentiation.
Stable 5-Hydroxymethylcytosine (5hmC) Acquisition Marks Gene Activation During Chondrogenic Differentiation.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Epigenetics and Preeclampsia: Defining Functional Epimutations in the Preeclamptic Placenta Related to the TGF-β Pathway.
Specimen part, Disease, Race
View SamplesPlacental Tissue Samples from 36 women (17 normotensive women, denoted with a P, and 19 preeclamptic women, denoted with a Q) were analyzed for differenital methylation
Epigenetics and Preeclampsia: Defining Functional Epimutations in the Preeclamptic Placenta Related to the TGF-β Pathway.
Specimen part, Disease, Race
View SamplesWe are investigating the mRNA expression profiles of human lung cells to gaseous urban mixtures
A toxicogenomic comparison of primary and photochemically altered air pollutant mixtures.
Cell line, Treatment
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