Project description:Adaptation to environmental stresses is crucial for survival. Transgenerational epigenetic inheritance allows organisms to respond to irregular conditions, alert their naïve descendants that stresses could still be present, and for distant descendants to eventually return to a basal state after several generations without the stress. However, it is still unclear whether organisms adapt on a transgenerational scale after repeated generational exposures to the same environmental stress. We recently found that C. elegans exposed to hypoxia in the parental (P0) generation: increased longevity in the P0 generation, caused an intergenerational reduction in lipids, and elicited a transgenerational reduction in fertility (P0-F2) that was dependent on small RNAs that were transmitted from parents to their naïve children. Here, we find that exposure of subsequent generations of C. elegans to hypoxia caused a transgenerational adaptation such that C. elegans that had repeated generational exposure to hypoxia failed to display hypoxia induced phenotypes. We show that upon two repeated generational exposures to hypoxia, C. elegans no longer display an increase in lifespan, and after four repeated generational exposures to hypoxia, C. elegans no longer display a decrease in reproduction. Transgenerational adaptation of the reproduction phenotype is dependent on the putative H3K27 trimethytransferase PRC2 complex and we identified critical genes that adapted on a transgenerational timeframe to repeated hypoxia exposure. Our findings reveal that transgenerational adaptation occurs and suggest that H3K27me3 is a critical modification for adapting to repeated generational stresses.
Project description:<p>Although it has long been proposed that genetic factors contribute to adaptation to high altitude, such factors remain largely unverified. Recent advances in high-throughput sequencing have made it feasible to analyze genome-wide patterns of genetic variation in human populations. Since traditionally such studies surveyed only a small fraction of the genome (either exons or a subset of SNPs) or a group of candidate genes, interpretation of the results was limited.</p> <p>We focused our study on Ethiopian highlander populations, which have been found to be well adapted to high altitudes (~3500m). We sequenced and analyze the genomes of 13 high altitude native Ethiopians: 6 individuals of Oromo heritage living on Bale Plateau (labeled "Oromos"), and 7 individuals residing on the Chennek field in the Simien Mountains (labeled "Amhara").</p> <p>Our study revealed evolutionarily conserved genes that modulate hypoxia tolerance.</p>
Project description:This study explores the long-term adaptation mechanisms of lymphoma cells subjected to hypoxic conditions, with an emphasis on the HBL2 and Ramos cell lines under normoxia and 1% O2 environments. The research methodology encompassed lysing cells using a buffer containing sodium deoxycholate and TEAB, followed by protein quantification via a BCA assay. Subsequent steps involved protein digestion with trypsin, labelling with TMTpro™ 16plex Label Reagent Set for quantitative analysis, peptide fractionation, and LC-MS/MS analysis. The analytical process was supported by Proteome Discoverer 2.4 for protein identification and quantification. Experimental groups were categorized into "HBL2 normoxia," "HBL2 1% O2 adaptation," "Ramos normoxia," and "Ramos 1% O2 adaptation," conducted in triplicates to ensure reliability. This meticulous approach facilitated the delineation of unique proteomic landscapes indicative of hypoxia adaptation, unveiling cellular strategies employed by lymphoma cells to navigate low oxygen conditions. The findings advance our comprehension of how hypoxia influences cancer progression and potentially opens new avenues for targeting hypoxic niches within tumors.
Project description:Hypoxic stress is a feature of rapidly growing thyroid tumors. Cancer progression is thought to be driven by reactive oxygen species (ROS) induced hypoxia adaptation. NADPH oxidases (NOXs), which produce ROS as their primary and sole function, has become of particular interest in thyroid malignancy. NOX4 was demonstrated to be upregulated in papillary thyroid cancers, functioning as a mitochondrial energetic sensor to modulate ATP levels, mediating overproduction of ROS induced by IL-δ, inversely correlating to thyroid differentiation. In this study, we analyzed hypoxia-treated BCPAP cells transfected with siRNA against NOX4. Results provides insight into the role of NOX4 in hypoxia adaptation.
Project description:The response to insufficient oxygen, termed hypoxia, is orchestrated by the conserved master regulator Hypoxia-Inducible Factor-1 (HIF-1), which is hyperactive in many cancers. Here, we describe a HIF-1 independent hypoxia response pathway controlled by Caenorhabditis elegans Nuclear Hormone Receptor NHR-49, an orthologue of mammalian lipid metabolism regulator Peroxisome Proliferator-Activated Receptor alpha (PPARα). nhr-49 is required for worm survival in hypoxia and is synthetically lethal with hif-1 in this context, demonstrating independent activity. RNA-seq data show that nhr-49 regulates a set of hif-1 independent hypoxia responsive genes, including autophagy genes that promote hypoxia survival. We further identified the Nuclear Hormone Receptor nhr-67 as a negative regulator and the Homeodomain-interacting Protein Kinase hpk-1 as a positive regulator in the NHR-49 pathway. Together, our experiments describe an essential hypoxia response pathway controlled by nhr-49 that includes new upstream and downstream components and is as important as hif-1 dependent hypoxia adaptation.
Project description:Hypoxia is amongst the most widespread and pressing problems in aquatic environments. Here we demonstrate that fish (Oryzias melastigma) exposed to hypoxia show reproductive impairments (retarded gonad development, decrease in sperm count and sperm motility) in F1 and F2 generations despite these progenies (and their germ cells) having never been exposed to hypoxia. We further show that the observed transgenerational reproductive impairments are associated with a differential methylation pattern of specific genes in sperm of both F0 and F2 coupled with relevant transcriptomic and proteomic alterations, which may impair spermatogenesis.
Project description:Hypoxia is amongst the most widespread and pressing problems in aquatic environments. Here we demonstrate that fish (Oryzias melastigma) exposed to hypoxia show reproductive impairments (retarded gonad development, decrease in sperm count and sperm motility) in F1 and F2 generations despite these progenies (and their germ cells) having never been exposed to hypoxia. We further show that the observed transgenerational reproductive impairments are associated with a differential methylation pattern of specific genes in sperm of both F0 and F2 coupled with relevant transcriptomic and proteomic alterations, which may impair spermatogenesis.
Project description:Hypoxia is amongst the most widespread and pressing problems in aquatic environments. Here we demonstrate that fish (Oryzias melastigma) exposed to hypoxia show reproductive impairments (retarded gonad development, decrease in sperm count and sperm motility) in F1 and F2 generations despite these progenies (and their germ cells) having never been exposed to hypoxia. We further show that the observed transgenerational reproductive impairments are associated with a differential methylation pattern of specific genes in sperm of both F0 and F2 coupled with relevant transcriptomic and proteomic alterations, which may impair spermatogenesis.
Project description:Oxygen (O2) is a double-edged sword to cells for while it is vital for energy production in all aerobic animals and insufficient O2 (hypoxia) can lead to cell death, the reoxygenation of hypoxic tissues may trigger the generation of reactive oxygen species (ROS) that can destroy any biological molecule. Indeed, both hypoxia and hypoxia-reoxygenation (H/R) stress are harmful, and may play a critical role in the pathophysiology of many human diseases such as myocardial ischemia and stroke. Therefore, understanding how animals adapt to hypoxia and H/R stress is critical for developing better treatments for these diseases. Previous studies showed that the neuroglobin GLB-5(Haw) is essential for the fast recovery of the nematode Caenorhabditis elegans (C. elegans) from H/R stress. Here, we characterize the changes in neuronal gene expression during the adaptation of worms to hypoxia and recovery from H/R stress. Our analysis show that innate immunity genes are differentially expressed during both adaptation to hypoxia and recovery from H/R stress.
Project description:Using Caenorhabditis elegans to investigate environmental cues-induced mitochondrial dysfunction, we found that exposure to electron transport chain (ETC) inhibitors at the parental generation initiates the transmission of heritable information to descendants and make descendants stress-adaptive. This mitochondrial stress adaptation phenotype can persist for at least three generations. Animals lacking histone H3K4me3 chromatin modifiers, or the methyltransferase of N6-methyldeoxyadenosine (6mA), lose the ability to initiate stress adaptation in progeny. H3K4me3 plays a role upstream of 6mA, while both mark promoter regions of mitochondrial unfolded protein response (UPR mt ) genes and activate the UPR mt pathway to alleviate mitochondrial damage.