Proteasome inhibition and oxidative biochemistry are synergistic triggers of metabolic heme toxicity
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ABSTRACT:
PROVIDER: PRJNA216509 | ENA |
REPOSITORIES: ENA
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Project description:Control of intracellular heme levels by extracellular scavenger proteins and intracellular heme oxygenases are essential functions during disease states with enhanced extracellular heme release. During severe hemolysis or rhabdomyolysis uncontrolled heme exposure can cause acute kidney injury and endothelial damage. The cytotoxic activity of heme has been primarily attributed to its pro-oxidative potential. However, the mechanisms of heme toxicity have never been systematically explored. Besides its redox reactivity, heme could also adversely alter cellular functions through its broad binding affinity to multiple non-hemoproteins. Such interactions may impair protein functions and support heme toxicity. In this study we mapped the gene expression profile of Hb triggered acute kidney injury in old blood transfused guinea pigs by serial analysis of gene expression (SAGE). Additionally, the toxic heme response of mouse embryo fibroblasts was systematically characterized on the gene and protein expression levels by gene array experiments and quantitative mass-spectrometry of stable isotope labeled cells. In all these studies, in addition to oxidative stress signals, the most significant signals were reproducibly found for biologic networks related to altered protein degradation, which ultimately triggers the response to unfolded proteins and apoptosis. These screening data could be mechanistically explained by heme-proteasome interactions and a proteasome inhibitor activity of heme. Proteasome inhibition drastically reduced the threshold of cellular toxicity during heme exposure. We therefore propose a novel model of heme toxicity whereby proteasome inhibition by the porphyrin fuels a vicious cycle of oxidative protein modification, accumulation of damaged proteins, cell damage and apoptosis. A two color common reference design was chosen with 2-4 independent biological replicates of each condition. Each experimental sample (Cy5 labeled) was hybridized against a non-treated reference sample (Cy3 labeled). To compensate for dye bias control arrays with competitively hybridized Cy3- and Cy5-labeled non-treated reference samples were used. The latter allowed for a very robust statistical analysis with pair-wise comparison of treatment array replicates versus the corresponding control array replicates.
2016-08-21 | E-GEOD-50145 | biostudies-arrayexpress
Project description:Control of intracellular heme levels by extracellular scavenger proteins and intracellular heme oxygenases are essential functions during disease states with enhanced extracellular heme release. During severe hemolysis or rhabdomyolysis uncontrolled heme exposure can cause acute kidney injury and endothelial damage. The cytotoxic activity of heme has been primarily attributed to its pro-oxidative potential. However, the mechanisms of heme toxicity have never been systematically explored. Besides its redox reactivity, heme could also adversely alter cellular functions through its broad binding affinity to multiple non-hemoproteins. Such interactions may impair protein functions and support heme toxicity. In this study we mapped the gene expression profile of Hb triggered acute kidney injury in old blood transfused guinea pigs by serial analysis of gene expression (SAGE). Additionally, the toxic heme response of mouse embryo fibroblasts was systematically characterized on the gene and protein expression levels by gene array experiments and quantitative mass-spectrometry of stable isotope labeled cells. In all these studies, in addition to oxidative stress signals, the most significant signals were reproducibly found for biologic networks related to altered protein degradation, which ultimately triggers the response to unfolded proteins and apoptosis. These screening data could be mechanistically explained by heme-proteasome interactions and a proteasome inhibitor activity of heme. Proteasome inhibition drastically reduced the threshold of cellular toxicity during heme exposure. We therefore propose a novel model of heme toxicity whereby proteasome inhibition by the porphyrin fuels a vicious cycle of oxidative protein modification, accumulation of damaged proteins, cell damage and apoptosis. A two color common reference design was chosen with 2-8 independent biological replicates of each condition. Each experimental sample (Cy5 labeled) was hybridized against a non-treated reference sample (Cy3 labeled). To compensate for dye bias control arrays with competitively hybridized Cy3- and Cy5-labeled non-treated reference samples were used. The latter allowed for a very robust statistical analysis with pair-wise comparison of treatment array replicates versus the corresponding control array replicates.
2016-08-21 | E-GEOD-50146 | biostudies-arrayexpress
Project description:Control of intracellular heme levels by extracellular scavenger proteins and intracellular heme oxygenases are essential functions during disease states with enhanced extracellular heme release. During severe hemolysis or rhabdomyolysis uncontrolled heme exposure can cause acute kidney injury and endothelial damage. The cytotoxic activity of heme has been primarily attributed to its pro-oxidative potential. However, the mechanisms of heme toxicity have never been systematically explored. Besides its redox reactivity, heme could also adversely alter cellular functions through its broad binding affinity to multiple non-hemoproteins. Such interactions may impair protein functions and support heme toxicity. In this study we mapped the gene expression profile of Hb triggered acute kidney injury in old blood transfused guinea pigs by serial analysis of gene expression (SAGE). Additionally, the toxic heme response of mouse embryo fibroblasts was systematically characterized on the gene and protein expression levels by gene array experiments and quantitative mass-spectrometry of stable isotope labeled cells. In all these studies, in addition to oxidative stress signals, the most significant signals were reproducibly found for biologic networks related to altered protein degradation, which ultimately triggers the response to unfolded proteins and apoptosis. These screening data could be mechanistically explained by heme-proteasome interactions and a proteasome inhibitor activity of heme. Proteasome inhibition drastically reduced the threshold of cellular toxicity during heme exposure. We therefore propose a novel model of heme toxicity whereby proteasome inhibition by the porphyrin fuels a vicious cycle of oxidative protein modification, accumulation of damaged proteins, cell damage and apoptosis.
2016-08-21 | GSE50146 | GEO
Project description:Control of intracellular heme levels by extracellular scavenger proteins and intracellular heme oxygenases are essential functions during disease states with enhanced extracellular heme release. During severe hemolysis or rhabdomyolysis uncontrolled heme exposure can cause acute kidney injury and endothelial damage. The cytotoxic activity of heme has been primarily attributed to its pro-oxidative potential. However, the mechanisms of heme toxicity have never been systematically explored. Besides its redox reactivity, heme could also adversely alter cellular functions through its broad binding affinity to multiple non-hemoproteins. Such interactions may impair protein functions and support heme toxicity. In this study we mapped the gene expression profile of Hb triggered acute kidney injury in old blood transfused guinea pigs by serial analysis of gene expression (SAGE). Additionally, the toxic heme response of mouse embryo fibroblasts was systematically characterized on the gene and protein expression levels by gene array experiments and quantitative mass-spectrometry of stable isotope labeled cells. In all these studies, in addition to oxidative stress signals, the most significant signals were reproducibly found for biologic networks related to altered protein degradation, which ultimately triggers the response to unfolded proteins and apoptosis. These screening data could be mechanistically explained by heme-proteasome interactions and a proteasome inhibitor activity of heme. Proteasome inhibition drastically reduced the threshold of cellular toxicity during heme exposure. We therefore propose a novel model of heme toxicity whereby proteasome inhibition by the porphyrin fuels a vicious cycle of oxidative protein modification, accumulation of damaged proteins, cell damage and apoptosis.
2016-08-21 | GSE50145 | GEO
Project description:This SuperSeries is composed of the SubSeries listed below. Refer to individual Series
2016-08-21 | E-GEOD-50147 | biostudies-arrayexpress
Project description:This SuperSeries is composed of the SubSeries listed below.
2016-08-21 | GSE50147 | GEO
Project description:Proteasome inhibition and oxidative biochemistry are synergistic triggers of metabolic heme toxicity (part 1)
| PRJNA216653 | ENA
Project description:Proteasome inhibition and oxidative biochemistry are synergistic triggers of metabolic heme toxicity (part 2)
| PRJNA216656 | ENA
Project description:Splenic red pulp macrophages (RPM) degrade senescent erythrocytes and recycle heme-associated iron. The transcription factor Spic is selectively expressed by RPM and is required for their development, but the physiologic stimulus inducing Spic is unknown. Here, we report that Spic also regulated the development of F4/80+VCAM+ bone marrow macrophages (BMM) and that Spic expression in BMM and RPM development was induced by heme, a metabolite of erythrocyte degradation. Pathologic hemolysis induced loss of RPM and BMM due to excess heme but induced Spic in monocytes to generate new RPM and BMM. Spic expression in monocytes was constitutively inhibited by the transcriptional repressor Bach1. Heme induced proteasome-dependent BACH1 degradation and rapid Spic derepression. Further, cysteine-proline dipeptide motifs in BACH1 that mediate heme-dependent degradation were necessary for Spic induction by heme. These findings are the first example of metabolite-driven differentiation of a tissue-resident macrophage subset and provide new insight into iron homeostasis. Global gene expression pattern of bone marrow-derived macrophages generated with GM-CSF in vitro and treated with heme were compared to those treated with vehicle at 6 hours, 24 hours, and 72 hours after treatment.
2014-03-14 | GSE46983 | GEO
Project description:Splenic red pulp macrophages (RPM) degrade senescent erythrocytes and recycle heme-associated iron. The transcription factor Spic is selectively expressed by RPM and is required for their development, but the physiologic stimulus inducing Spic is unknown. Here, we report that Spic also regulated the development of F4/80+VCAM+ bone marrow macrophages (BMM) and that Spic expression in BMM and RPM development was induced by heme, a metabolite of erythrocyte degradation. Pathologic hemolysis induced loss of RPM and BMM due to excess heme but induced Spic in monocytes to generate new RPM and BMM. Spic expression in monocytes was constitutively inhibited by the transcriptional repressor Bach1. Heme induced proteasome-dependent BACH1 degradation and rapid Spic derepression. Further, cysteine-proline dipeptide motifs in BACH1 that mediate heme-dependent degradation were necessary for Spic induction by heme. These findings are the first example of metabolite-driven differentiation of a tissue-resident macrophage subset and provide new insight into iron homeostasis. Global gene expression pattern of bone marrow-derived macrophages generated with GM-CSF in vitro and treated with heme were compared to those treated with vehicle at 6 hours, 24 hours, and 72 hours after treatment. GM-CSF cultures of Spic(igfp/igfp) BM cells were treated with heme (80 µm) or vehicle after 6 days in culture. Adherent fraction of cells were harvested 6 hours, 24 hours, and 72 hours after treatment and RNA was isolated using an RNeasy mini kit (Qiagen) and submitted for amplification, labeling and hybridization. Expression values were analyzed after RMA quantile normalization using ArrayStar software (DNASTAR).
2014-03-14 | E-GEOD-46983 | biostudies-arrayexpress