Project description:To determine hypoxia mediated changes in whole blood, normal C57Bl/10 mice were gradually exposed to a chronic hypoxic environment, equivalent to an altitude of 6500m, for 2 weeks in vivo. Control, age-matched mice were maintained under normoxic, normobaric conditions by exposing them to ambient air in Philadelphia (c. 50 mts above sea level).
Project description:High altitude environments are characterized by the unique and unavoidable stress of chronic hypoxia. While much is known about gene expression responses to acute or in vitro hypoxia, less is known about the gene expression profiles of animals exposed to systemic chronic hypoxia, such as that experienced at high elevations. Here we simulated the hypoxic environment of two high altitude elevations,and a third chamber recieved ambient Reno air. Mice were housed in the hypoxic chambers for 32 days. We used microarrays to characterize the differential gene expression in the livers of mice housed in hypoxic environment of 4500 m versus 3000 and 1400 m. We used this data to draw hypotheses related to novel physiological responses to chronic systemic hypoxia Experiment Overall Design: Mice were housed one of three chambers; the first received ambient Reno air (1400 m) and the other two received air mixed with nitrogen such that one chamber simulated the hypoxic environment of 3000 m and the third chamber simulated hypoxic environment of 4500 m. Twelve mice were housed in each chamber for 32 days. Liver were extracted, and RNA from livers of 4 mice were pooled such that each treatment was represented by 3 pooled samples. Eight of the nine arrays were used for data analysis; one array was excluded as several Affymetrix quality control metrics indicated data quality that was not reliable.
Project description:High altitude environments are characterized by the unique and unavoidable stress of chronic hypoxia. While much is known about gene expression responses to acute or in vitro hypoxia, less is known about the gene expression profiles of animals exposed to systemic chronic hypoxia, such as that experienced at high elevations. Here we simulated the hypoxic environment of two high altitude elevations,and a third chamber recieved ambient Reno air. Mice were housed in the hypoxic chambers for 32 days. We used microarrays to characterize the differential gene expression in the livers of mice housed in hypoxic environment of 4500 m versus 3000 and 1400 m. We used this data to draw hypotheses related to novel physiological responses to chronic systemic hypoxia
2009-04-30 | GSE15891 | GEO
Project description:Characteristics of dynamic changes of intestinal flora in rats under high altitude and low oxygen environment
Project description:High altitude exposes humans to hypobaric and hypoxic conditions, which induce various physiological and molecular changes. Recent evidence, mostly from animal models, points towards interaction between circadian rhythms and the hypoxic response, however their human relevance is largely unknown. To examine the interaction between elevated altitude-low oxygen and daily rhythms, we analyzed the effect of different high altitudes in conjunction with day-time on human whole blood transcriptome. We found that high altitude vastly affects the blood transcriptome and unexpectedly, does not necessarily follow a monotonic response to altitude elevation. We observed daily variance in gene expression, which was largely dependent on altitude. Moreover, using digital cytometry approach we estimated the relative changes in abundance of different cell types and found the several immune cell types were responding in a time- and altitude-dependent manner. Taken together, our data shed new light on the transcriptional response to high altitude and its interaction with daily rhythms.
Project description:In this study, we employed an integrated proteomic and metabolomic approach to systematically analyze the proteome and metabolome profiles of SHRs following prolonged exposure to a high-altitude hypoxic environment. Bioinformatics and enrichment analysis revealed that proteins with significant differential expression were predominantly involved in pathways such as oxidative phosphorylation, thermogenesis, TCA cycle, and carbon metabolism. Further analysis indicated that alterations in key metabolites, including thiamine, S-adenosylhomocysteine, pantothenic acid, fumaric acid, and homoserine, interact with differentially expressed proteins, collectively contributing to the modulation of blood pressure regulation in SHRs under hypoxic conditions. This research provides new molecular insights into understanding the impact of high-altitude hypoxia on the blood pressure regulatory mechanisms in spontaneously hypertensive rats.
2024-08-27 | PXD055443 |
Project description:High-Altitude Hypoxia Induced the Changes of Gut Microbiota
Project description:Background: The number of red blood cells (RBCs) increases significantly in response to high-altitude hypoxic environments, and the RBC microRNA (miRNA) expression pattern is similar to that in whole blood. Studies have shown that miRNA in plasma can act as a circulating hypoxia-associated marker, but the effect of a high-altitude hypoxic environment on RBC-derived miRNAs has not yet been reported. Methods: Blood samples were collected from 20 Han Chinese individuals residing at 500 m (Sichuan Han), 10 migrant Han Chinese citizens residing at 3658 m (Tibet Han) and 12 native Tibetans, and RBC indices measurements and miRNA sequencing analyses were performed for the three sample groups. The levels of some markedly altered miRNAs at high altitude were subsequently measured from 5 randomly selected samples of each group by real-time PCR. Bioinformatic analyses was performed to determine the potential target genes of selected hypoxia-associated miRNAs. Results: Marked changes of several RBC indices were observed among the Tibet Han population, the Tibetan population and the Sichuan Han population. A total of 516 miRNAs derived from RBCs were initially identified by miRNA sequencing in the three sample groups. Compared with the Sichuan Han population, 49 miRNAs were differentially expressed in the Tibet Han population (17 upregulated and 32 downregulated). 12 upregulated and 21 downregulated miRNAs were observed in the Tibetan population compared with the Sichuan Han population. A total of 40 RBC miRNAs were differentially expressed in the Tibetan population (15 upregulated and 25 downregulated) compared with the Tibet Han population. Two significantly altered miRNAs with the highest expression levels (miRNA-144-5p and miR-30b-5p) were selected for real-time PCR analysis, and the results were consistent with those of miRNA sequencing. Furthermore, bioinformatic analyses showed that some potential target genes of miR-144-5p and miR-30b-5p are involved in the erythroid- hypoxia-, and nitric oxide (NO)-related signaling pathways in response to hypoxia. Conclusion: Our findings provide clear evidence, for the first time, that a high-altitude hypoxic environment significantly affects human RBC miRNA profiles.