Dataset Information

Gene expression in a Drosophila model of mitochondrial disease.

ABSTRACT: BACKGROUND: A point mutation in the Drosophila gene technical knockout (tko), encoding mitoribosomal protein S12, was previously shown to cause a phenotype of respiratory chain deficiency, developmental delay, and neurological abnormalities similar to those presented in many human mitochondrial disorders, as well as defective courtship behavior. METHODOLOGY/PRINCIPAL FINDINGS: Here, we describe a transcriptome-wide analysis of gene expression in tko(25t) mutant flies that revealed systematic and compensatory changes in the expression of genes connected with metabolism, including up-regulation of lactate dehydrogenase and of many genes involved in the catabolism of fats and proteins, and various anaplerotic pathways. Gut-specific enzymes involved in the primary mobilization of dietary fats and proteins, as well as a number of transport functions, were also strongly up-regulated, consistent with the idea that oxidative phosphorylation OXPHOS dysfunction is perceived physiologically as a starvation for particular biomolecules. In addition, many stress-response genes were induced. Other changes may reflect a signature of developmental delay, notably a down-regulation of genes connected with reproduction, including gametogenesis, as well as courtship behavior in males; logically this represents a programmed response to a mitochondrially generated starvation signal. The underlying signalling pathway, if conserved, could influence many physiological processes in response to nutritional stress, although any such pathway involved remains unidentified. CONCLUSIONS/SIGNIFICANCE: These studies indicate that general and organ-specific metabolism is transformed in response to mitochondrial dysfunction, including digestive and absorptive functions, and give important clues as to how novel therapeutic strategies for mitochondrial disorders might be developed.

SUBMITTER: Fernandez-Ayala DJ

PROVIDER: S-EPMC2798955 | biostudies-literature | 2010

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Gene expression in a Drosophila model of mitochondrial disease.

Fernández-Ayala Daniel J M DJ Chen Shanjun S Kemppainen Esko E O'Dell Kevin M C KM Jacobs Howard T HT

PloS one 20100106 1

<h4>Background</h4>A point mutation in the Drosophila gene technical knockout (tko), encoding mitoribosomal protein S12, was previously shown to cause a phenotype of respiratory chain deficiency, developmental delay, and neurological abnormalities similar to those presented in many human mitochondrial disorders, as well as defective courtship behavior.<h4>Methodology/principal findings</h4>Here, we describe a transcriptome-wide analysis of gene expression in tko(25t) mutant flies that revealed s ...[more]

PMID: 20066047

Similar Datasets

Project description:Background: A point mutation in the Drosophila gene technical knockout (tko), encoding mitoribosomal protein S12, provokes a phenotype of respiratory chain deficiency, developmental delay and neurological abnormalities similar to those presented in many human mitochondrial disorders, as well as defective courtship behaviour. Results: Transcriptome-wide analysis of gene expression in tko25t mutant flies revealed systematic, compensatory changes in expression of genes connected with metabolism, including upregulation of lactate dehydrogenase and of many genes involved in the catabolism of fats and proteins, the TCA cycle and anaplerotic pathways feeding into it. Gut-specific enzymes involved in the primary mobilization of dietary fat and protein, as well as a number of transport functions, were strongly upregulated, consistent with the idea that OXPHOS dysfunction is perceived physiologically as a starvation for particular biomolecules. Many stress-response genes were also induced. Other changes may reflect a signature of developmental delay. There was also down-regulation of genes connected with reproduction, including gametogenesis, especially in females, and courtship behaviour in males. This might represent a programmed response to a mitochondrially generated starvation signal. Although human sexual behaviour is not known to respond to mitochondrial dysfunction, the underlying signaling pathway, if conserved, could influence many physiological processes in response to nutritional stress. Transcriptomic analysis suggested the possible involvement of the Akt1/sgg signaling pathway(s). Conclusions: The transformation of metabolism in response to mitochondrial dysfunction, including digestive and absorptive functions, gives important clues as to how novel therapeutic strategies for mitochondrial disorders might be developed. Experiment Overall Design: Crosses and maintenance: Inbreeding under stressful conditions inevitably results in the selection of compensatory alleles of many genes. In order to avoid such issues, and thus determine the global effects on gene expression of the tko25t mutation in a truly unselected and 'wild-type' background, we outbred tko25t over more than 10 generations by back-crossing to each of two commonly used wild-type strains, Canton S and Oregon R. Subsequent to this backcrossing, tko25t was maintained in each background using a balancer chromosome. These stocks were then used to generate a tko25t mutant F1 generation, by crossing virgin Canton S tko25t homozygous mutant females with Oregon R tko25t males. For comparison, we generated otherwise isogenic wild-type F1 progeny by crossing virgin Canton S wild-type females with Oregon R wild-type males. Experiment Overall Design: Samples: Both tko25t and wild-type Drosophila adult flies of both sexes were collected and aged to 1 day old prior to RNA extraction and hybridization on Affymetrix microarrays. We extracted RNA from 3 independent such crosses. Experiment Overall Design: Comparative analysis: Data analysis for each gene in the array compared each tko25t mutant RNA isolate with each wild-type RNA isolate from flies of the given sex, generating 9 comparative measurements, over which the statistical analysis was performed.

Project description:Neurodegeneration in Parkinson's disease (PD) affects mainly dopaminergic neurons in the substantia nigra, where age-related, increasing percentages of cells lose detectable respiratory activity associated with depletion of intact mitochondrial DNA (mtDNA). Replenishment of mtDNA might improve neuronal bioenergetic function and prevent further cell death. We developed a technology ("ProtoFection") that uses recombinant human mitochondrial transcription factor A (TFAM) engineered with an N-terminal protein transduction domain (PTD) followed by the SOD2 mitochondrial localization signal (MLS) to deliver mtDNA cargo to the mitochondria of living cells. MTD-TFAM (MTD = PTD + MLS = "mitochondrial transduction domain") binds mtDNA and rapidly transports it across plasma membranes to mitochondria. For therapeutic proof-of-principle we tested ProtoFection technology in Parkinson's disease cybrid cells, using mtDNA generated from commercially available human genomic DNA (gDNA; Roche). Nine to 11 weeks after single exposures to MTD-TFAM + mtDNA complex, PD cybrid cells with impaired respiration and reduced mtDNA genes increased their mtDNA gene copy numbers up to 24-fold, mtDNA-derived RNAs up to 35-fold, TFAM and ETC proteins, cell respiration, and mitochondrial movement velocities. Cybrid cells with no or minimal basal mitochondrial impairments showed reduced or no responses to treatment, suggesting the possibility of therapeutic selectivity. Exposure of PD but not control cybrid cells to MTD-TFAM protein alone or MTD-TFAM + mtDNA complex increased expression of PGC-1alpha, suggesting activation of mitochondrial biogenesis. ProtoFection technology for mitochondrial gene therapy holds promise for improving bioenergetic function in impaired PD neurons and needs additional development to define its pharmacodynamics and delineate its molecular mechanisms. It also is unclear whether single-donor gDNA for generating mtDNA would be a preferred therapeutic compared with the pooled gDNA used in this study.

Dataset Information

Gene expression in a Drosophila model of mitochondrial disease.

Publications

Gene expression in a Drosophila model of mitochondrial disease.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets