Project description:As part of a comprehensive post-genomic investigation of the model archaeon Halobacterium sp. NRC-1, we used whole genome DNA microarrays to compare transcriptional profiles of cells grown anaerobically via arginine fermentation versus cells either respiring aerobically in the presence of oxygen or anaerobically using trimethylamine N-oxide (TMAO) as a terminal electron acceptor. In the study presented here, a consecutively performed series of experiments were performed to examine the effects of regulator deletions (dmsR, bat) and oxygen limitations of Haloarchaeal cells. Microarrays were used to acquire expression profiles of a total of 2484 genes, leading to the successful identification of affected genes.
Project description:As part of a comprehensive post-genomic investigation of the model archaeon Halobacterium sp. NRC-1, we used whole genome DNA microarrays to compare transcriptional profiles of cells grown anaerobically via arginine fermentation versus cells either respiring aerobically in the presence of oxygen or anaerobically using trimethylamine N-oxide (TMAO) as a terminal electron acceptor.
Project description:High-throughput sequencing of murine retina of the oxygen induced retinopathy (OIR) model compared to control mice at 5 consecutive days (P12-P16)
Project description:Retinal neovascularization poses heightened risks of vision loss and blindness. Despite its clinical significance, the molecular mechanisms underlying the pathogenesis of retinal neovascularization remain elusive. This study utilized single-cell multiomics profiling in an oxygen-induced retinopathy (OIR) model to comprehensively investigate the intricate molecular landscape of retinal neovascularization.
Project description:Oxygen is toxic across all three domains of life. Yet, the underlying molecular mechanisms remain largely unknown. Here, we systematically investigate the major cellular pathways affected by excess molecular oxygen. We find that hyperoxia destabilizes a specific subset of Fe-S cluster (ISC)-containing proteins, resulting in impaired diphthamide synthesis, purine metabolism, nucleotide excision repair, and electron transport chain (ETC) function. Our findings translate to primary human lung cells and a mouse model of pulmonary oxygen toxicity. We demonstrate that the ETC is the most vulnerable to damage, resulting in decreased mitochondrial oxygen consumption. This leads to further tissue hyperoxia and cyclic damage of the additional ISC-containing pathways. In support of this model, primary ETC dysfunction in the Ndufs4 KO mouse model causes lung tissue hyperoxia and dramatically increases sensitivity to hyperoxia-mediated ISC damage. This work has important implications for hyperoxia pathologies, including bronchopulmonary dysplasia, ischemia-reperfusion injury, aging, and mitochondrial disorders.
Project description:Senescent is an irreversible form of cell cycle arrest initiated by damaged cell constituents and subsequent pro-oncogenic signaling. Replicative senescence in vitro can be considered a model for human aging. When fibroblasts are cultured under atmospheric oxygen conditions of 20%, typical of normal tissue culture procedure, fibroblasts generally reach their replicative capacity at 50-60 population doublings (PDs). When fibroblasts are cultured under normal physiological oxygen conditions of 3%, PDs increase about 30% relative to atmospheric levels. Hence while oxygen is a requirement for normal aerobic respiration, it can contribute to the total amount of oxidative stress to which cells are exposed to, leading to a long-term adverse effect in vitro. Inasmuch, cultures maintained under hyperoxic and hypoxic conditions provide a convenient model system for assessing the relationship between oxygen/oxidative stress and senescence. We used microarrays to profile the changes in global gene expression during aging and senescence of Imr90 cells under growth oxygen conditions of 3% and 20%. Imr90 cells at various population doubling timepoints (young, old, and senescent) grown separately under 3 and 20% oxygen growth conditions were selected for RNA extraction and hybridization on Affymetrix microarrays. Timepoints from cells grown under 3% and 20% oxygen conditions were age matched via population doublings to ensure accurate cross sample comparison.