Project description:RNA sequencing and subsequent bioinformatics analyses were performed at early reoxygenation stages in HL-1 cardiomyocytes treated or not with BRL37344 Methods: HL-1 cardiomyocytes were subjected to Hypoxia/Reoxygenation (6h/1h) with/without a M-NM-23AR agonist (BRL37344 5M-BM-5mol/L). mRNA profiles were generated by deep sequencing, in triplicate, using Illumina GAIIx.The sequence reads that passed quality filters were quantified using BWA aligned reads using RSEM. qRTM-bM-^@M-^SPCR validation was performed using SYBR Green assay. Results: After 6h of hypoxia followed by 1h reoxygenation, 866 genes were differentially expressed upon M-NM-23AR stimulation by BRL37344. Among these, 177 were at least 2-fold up or downregulated. Conclusions: Our results show that Hsp70 plays a key role in the cardioprotection afforded by M-NM-23AR agonism in cardiomyocytes during the early window of H/R. mRNA profiles from cardiomyocyte subjected to H/R (6h/1h) with/without a M-NM-23AR agonist were generated by deep sequencing, in triplicate, using Illumina GAIIx.
Project description:RNA sequencing and subsequent bioinformatics analyses were performed at early reoxygenation stages in HL-1 cardiomyocytes treated or not with BRL37344 Methods: HL-1 cardiomyocytes were subjected to Hypoxia/Reoxygenation (6h/1h) with/without a β3AR agonist (BRL37344 5µmol/L). mRNA profiles were generated by deep sequencing, in triplicate, using Illumina GAIIx.The sequence reads that passed quality filters were quantified using BWA aligned reads using RSEM. qRT–PCR validation was performed using SYBR Green assay. Results: After 6h of hypoxia followed by 1h reoxygenation, 866 genes were differentially expressed upon β3AR stimulation by BRL37344. Among these, 177 were at least 2-fold up or downregulated. Conclusions: Our results show that Hsp70 plays a key role in the cardioprotection afforded by β3AR agonism in cardiomyocytes during the early window of H/R.
Project description:Hypoxia imposes a challenge upon most of the filamentous fungi that require oxygen for proliferation. Here, we used whole genome DNA microarrays to investigate global transcriptional changes in Aspergillus nidulans gene expression after exposure to hypoxia followed by normoxia. Aeration affected the expression of 2,864 genes (27% of the total number of genes in the fungus), of which 50% were either induced or repressed under hypoxic conditions. Up-regulated genes included those for glycolysis, ethanol production, the tricarboxylic acid (TCA) cycle, and for the γ-aminobutyrate (GABA) shunt that bypasses two steps of the TCA cycle. Ethanol and lactate production under hypoxic conditions indicated that glucose was fermented to these compounds via the glycolytic pathway. Since the GABA shunt bypasses the NADH-generating reaction of the TCA cycle catalyzed by oxoglutarate dehydrogenase, hypoxic A. nidulans cells eliminated excess NADH. Hypoxia down-regulated some genes involved in transcription initiation by RNA polymerase II, and lowered the cellular mRNA content. These functions were resumed by reoxygenation, indicating that A. nidulans controls global transcription to adapt to a hypoxic environment. This study is the first to show that hypoxia elicits systematic transcriptional responses in A. nidulans. We transferred A. nidulans cells from normoxic to hypoxic conditions for 6 h, and then back to normoxic conditions to examine the effect of hypoxia on gene expression. Total RNA was prepared for DNA microarray analysis from the cells after 3 and 6 h of exposure to hypoxia, followed by 3 and 6 h of reoxygenation.
Project description:High-altitude pulmonary hypertension (HAPH) is a severe and progressive disease caused by chronic hypoxia and subsequent pulmonary vascular remodeling. No cure is currently available owing to an incomplete understanding about vascular remodeling. It is believed that hypoxia-induced diseases can be prevented by treating hypoxia. Thus, this study aimed to determine whether daily short-duration reoxygenation at sea level attenuates pulmonary hypertension under high-altitude hypoxia. To this end, a simulated 5,000-m hypoxia rat model was used to evaluate the effect of short-duration reoxygenation. Results show that intermittent, not continuous, short-duration reoxygenation effectively attenuates hypoxia-induced pulmonary hypertension. The mechanisms underlining the protective effects involved that intermittent, short-duration reoxygenation prevented functional and structural remodeling of pulmonary arteries and proliferation, migration, and phenotypic conversion of pulmonary artery smooth muscle cells under hypoxia. The specific genes or potential molecular pathways responsible for mediating the protective effects were also characterised by RNA sequencing.This study is novel in revealing a new potential method in preventing high-altitude pulmonary hypertension. It gives insights into the selection and optimisation of oxygen supply schemes in high-altitude areas.
Project description:Purpose: Study hypoxia and reoxygenation induced changes in genome-wide H3K4me3 and H3K27me3 occupancy Methods: Using the MCF7 breast epithelial adenocarcinoma cell line as a model, we studied epigenomic reprogramming as a function of fluctuating oxygen tension. To this end, we combined chromatin-immunoprecipitation and deep-sequencing analysis to identify H3K4me3-marks and H3K27me3-marks in MCF7 cells subjected to changes in oxygenation (i.e. acute hypoxia, chronic hypoxia, reoxygenation). Results: H3K4me3 and H3K27me3-marks showed a rapid global increase at specific sites throughout the genome under hypoxia, both genic and inter-genic, that was partly restored upon reoxygenation. Conclusions: Our data show that oxygen availability dynamically regulates the epigenetic state of the genome.
Project description:Purpose: Study hypoxia and reoxygenation induced changes in genome-wide gene expression Methods: Using the MCF7 breast epithelial adenocarcinoma cell line as a model, we studied epigenomic reprogramming as a function of fluctuating oxygen tension. To this end, we performed a transcriptomics analysis in MCF7 cells subjected to changes in oxygenation (i.e. acute hypoxia, chronic hypoxia, reoxygenation). Results: Global downregulation upon hypoxia; partial restore on reoxygenation. Conclusions: Our data show that oxygen availability dynamically regulates gene transcription.
Project description:Gene expression analysis of 7d-old Arabidopsis seedlings exposed to short term (2 h) hypoxia, long term (9 h) hypoxia, and 1 h reoxygenation after long term (9 h) hypoxia to evaluate the regulation of gene expression at the level of translation. Keywords: Time Course, hypoxia recovery, polysomal mRNA, IP RNA, polysomes, hypoxia stress, reoxygenation, translational control.