Project description:Altitude acclimatization is the physiological process to restore oxygen delivery to the tissues and promote the oxygen application under high altitude hypoxia. High altitude illness could happen in individuals who did not get acclimatization. Unraveling the molecular underpinnings of altitude acclimatization would help people to understand the beneficial response of body to high altitude hypoxia and disturbed biological process in un-acclimatized individuals. Here, we measured physiological adjustments and circulating microRNAs (cmiRNAs) profiles of individuals exposed to high altitude to explore the altitude acclimatization in humans.
Project description:Hybridization and study was conducted to measure the impact of short-term sugar deprivation, on an acclimatization time-scale, imposed to plantlet transferred from in vitro to ex vitro culture conditions. We thus submitted in vitro tomato plantlets to sugar deprivation for 24-h in order to better understands the impact of sucrose retrieval upon ex vitro acclimatization.
Project description:Acclimatization to high altitude over 21 days, and upon re-ascent 7 and 21 days post-descent. See Subudhi et al. (2014) PLoS One 9(3):e92191, PMCID PMC3962396, PMID 24658407 for experiment details.
Project description:The malate shuttle is traditionally known to maintain the NAD+/NADH balance between the cytosol and mitochondria. Whether the malate shuttle has additional functions was unknown. Here we show that chronic viral infections induced the expression of GOT1, the key enzyme in the malate shuttle, in CD8+ T cells. Got1 deficiency indeed decreased the NAD+/NADH ratio and dampened antiviral CD8+ T cell responses to chronic infection; however, increasing the NAD+/NADH ratio did not restore antiviral T cell responses. Got1 deficiency reduced the production of the ammonia scavenger 2-ketoglutarate and led to toxic ammonia accumulation in CD8+ T cells. Supplementation with 2-ketoglutarate assimilated and detoxified ammonia in Got1-deficient T cells and restored antiviral responses. This study suggests that the major function of the malate shuttle in CD8+ T cells is not to maintain the NAD+/NADH ratio, but rather to detoxify ammonia and enable sustainable ammonia-neutral glutamine catabolism in CD8+ T cells during chronic infections.
Project description:The liver is the largest detoxification organ in the human body. RNA sequencing (RNA-seq) analyses of liver samples were performed to investigate the effects of high ammonia levels (ammonia exposure at 75 ± 5 ppm), a low ammonia level (ammonia exposure at 5 ± 5 ppm) was set as control group, on the metabolism and detoxification capabilities of laying ducks.
Project description:Investigation of the whole genome gene expression level changes relative to exponential phase growth in Nitrosomonas europaea ATCC19718 after 12 hours ammonia starvation, 144 hours ammonia starvation, and 20 minutes following ammonia addition to starved cells. The ammonia monooxygenase of chemolithotrophic ammonia oxidizing bacteria (AOB) catalyzes the first step in ammonia oxidation by converting ammonia to hydroxylamine. The monooxygenase of Nitrosomonas europaea is encoded by two nearly identical operon copies (amoCAB1,2). Several AOB, including N. europaea, also posess a divergent monocistronic copy of amoC (amoC3) of unknown function. Previous work suggested a possible functional role for amoC3 in N. europaea during recovery from extended ammonia starvation as part of the σE- stress response regulon during the recovery of N. europaea from extended ammonia starvation, thus indicating its importance during the exit of cells from starvation. We here used global transcription analysis to show that expression of amoC3 is part of a general post-starvation cellular response system in N. europaea. We also found that amoC3 is required for efficient exit from prolonged ammonia starvation, as deleting this gene impaired growth at elevated temperatures and recovery following starvation under high oxygen tensions. Deletion of the σ32 global stress response regulator demonstrated that the heat shock regulon also plays a significant role in mediating the recovery of N. europaea from starvation. These findings provide the first described phenotype associated with the divergent AmoC3 subunit which appears to function as a stress responsive subunit capable of maintaining ammonia oxidation activity under stress conditions.
Project description:Nitrogen fixation is a highly energy-demanding process and highly regulated at multiple levels. The two major signals that regulate nitrogen fixation in most diazotrophs are oxygen and ammonia. In order to study the complex regulated mechanism and to highlight the complete nitrogen fixing system in genome level, here we present the transcriptional profiles of the nitrogen fixation genes of P.stutzeri A1501 in different growth conditions with a genome-wide DNA microarray. In this study, the three samples of "P.stutzeri A1501 treated with 0.1mM ammonia and 0.5% Oxygen tension","P.stutzeri A1501 treated with 0.1mM ammonia and 0.5% Oxygen tension-2" and "P.stutzeri A1501 treated with 0.1mM ammonia and 0.5% Oxygen tension-3" were three repeat experiments, while, the other three samples of "P.stutzeri A1501 treated with 20mM ammonia and 0.5% Oxygen tension-1", "P.stutzeri A1501 treated with 20mM ammonia and 0.5% Oxygen tension-2" and "P.stutzeri A1501 treated with 20mM ammonia and 0.5% Oxygen tension-3" were three repeat experiments. The gene expressions under these two growth phases were compared to investigate which genes' expression were effected by different ammonia concentrations. Keywords: nitrogen fixation, nitrogen repression
Project description:Understanding molecular mechanism associated with high altitude exposure during acclimatization/adaptation/maladaptation. Data reveals specific components of the complex molecular circuitry underlying high altitude pulmonary edema.
2013-12-18 | GSE52209 | GEO
Project description:Microbial acclimatization in biomethane reactor