Oxygen-sensitive genetic responses in rat vascular tissue after simulated diving
Ontology highlight
ABSTRACT: To identify genetic factors potentially involved in the etiology of DCS, using rats exposed to hyperoxic air in a pressure chamber to simulate diving
Project description:Characterization of gene expression in blood after single and repetitive SCUBA diving to 18 meters while breathing compressed air or a mixture of 36 percent oxygen and 64 percent nitrogen.
Project description:In order to better understand physiological mechanisms and neurological symptoms involved in the development of decompression sickness we determined effects in rats on the brain proteome of fast decompression (1 bar/20 s) compared to controls (1 bar/10 min) after heliox saturation diving. The orbitrap LC-MS/MS data files presented here resulted in 1062 proteins quantified using label-free proteomics. Based on the 128 significantly regulated proteins in the orbitrap dataset and 56 in an iontrap dataset (967 quantified proteins), the networks “synaptic vesicle fusion and recycling in nerve terminals” and “translation initiation” were significantly enriched in a system biological database analysis (Metacore). Ribosomal proteins (RLA2, RS10) and the proteins hippocalcin-like protein 4 and proteasome subunit beta type-7 were significantly upregulated in both datasets. The heat shock protein 105 kDa, Rho-associated protein kinase 2 and Dynamin-1 were significantly downregulated in both datasets.
Project description:Dahl salt-sensitive (DS) rats were obtained from Harlan Sprague Dawley Laboratory at 5 weeks of age. At 6 weeks of age, physiologic cardiac hypertrophy was generated by a; vigorous daily exercise regimen for 6 weeks (e group). The exercise protocol is based on those described previously with modifications (Wisloff U et al., 2001; Jin H et al., 1994). Rats were exercised daily for 6 weeks on a rodent treadmill (Exer-6M; Columbus Instruments). The exercise program consisted of three weeks of progressively strenuous exercise regimens; followed by three weeks of maintenance period, during which the rats were exercised at 16 m/min at a 5o incline for 90 minutes/day. All rats completed the exercise protocol. Pathological cardiac hypertrophy was generated by feeding a 6% NaCl diet to DS rats at 6 weeks of age (h group) (Inoko M et al., 1994). Control rats (c group) were age matched and sedentary DS rats fed normal rat chow. Read more at http://cardiogenomics.med.harvard.edu/groups/proj1/pages/rat_home.html<br><br>Note that files GSM11886.txt and GSM12308.txt, and files GSM11887.txt and GSM12309.txt as downloaded from GEO contain identical data.
Project description:substantial number of people at risk to develop type 2 diabetes could not improve insulin sensitivity by physical training intervention. We studied the mechanisms of this impaired exercise response in 20 middle-aged individuals who performed a controlled eight weeks cycling and walking training at 80 % individual VO2max. Participants identified as non-responders in insulin sensitivity (based on Matsuda index) did not differ in pre-intervention parameters compared to high responders. The failure to increase insulin sensitivity after training correlates with impaired up-regulation of mitochondrial fuel oxidation genes in skeletal muscle, and with the suppression of the upstream regulators PGC1α and AMPKα2. The muscle transcriptome of the non-responders is further characterized by an activation of TGFβ and TGFβ target genes, which is associated with increases in inflammatory and macrophage markers. TGFβ1 as inhibitor of mitochondrial regulators and insulin signaling is validated in human skeletal muscle cells. Activated TGFβ1 signaling down-regulates the abundance of PGC1α, AMPKα2, mitochondrial transcription factor TFAM, and of mitochondrial enzymes. Thus, increased TGFβ activity in skeletal muscle can attenuate the improvement of mitochondrial fuel oxidation after training and contribute to the failure to increase insulin sensitivity. We performed gene expression microarray analysis on muscle biopsies from humans before and after an eight weeks endurance training intervention
Project description:Here we used microarrays to characterize changes in global gene expression in the hepatopancreas of Pacific white shrimp, Litopenaeus vannamei, exposed to short term (4 h) hypoxia (H) or hypercapnic hypoxia (HH) or long term (24 h) H or HH, compared to animals in air-saturated water (normoxia). The transcriptomes of crustaceans exposed to low O2 and high CO2 contained both shared and treatment-specific signature genes (q M-bM-^IM-$ 0.01, FC M-bM-^IM-% 1.5), with shifts characteristic of metabolic depression rather than anaerobic metabolism. Down-regulated signature genes dominated the transcript profile in three of the four treatments (H 4 h, H 24 h, 4 h HH); many of these genes were involved in amino acid or RNA metabolism or in translation, including several tRNA synthetases. Unique patterns of gene expression such as increased lipid metabolism and hemocyanin synthesis (H 24 h) and initiation of apoptosis (24 h HH) were tied to specific treatments. This work contributes insight to the effects that human perturbations might have on estuarine organisms, and the importance of examining the impacts of environmentally relevant combinations of hypoxia and hypercapnia on estuarine populations. L. vannamei were exposed for 4 or 24 hours to one of the following conditions: normoxia, hypoxia or hypercapnic hypoxia. Hepatopancreas tissue from individual animals was dissected, total RNA extracted, labelled and hybridized to oligonucleotide microarrays with probes for 21,864 L. vannamei unigenes. Treatments were repeated until a total of 7 biological replicates was obtained for each time:treatment combination, except for the 24 h normoxia group, represented by 6 replicates.
Project description:Adverse effects of statins include skeletal muscle toxicity; Type II glycolytic fibers are more senstive to statin damage; exercise exacerbates statin muscle degeneration. We used a well-characterized rat model of statin-induced muscle degeneration, at which 1.0 mg/kg/day (high dose) cerivastatin produces mild to moderate histological degeneration. We used microarrays to detail the global programme of gene expression underlying cerivastatin effects on rat gastrocnemius and soleus muscles, as well as the effect of cerivastatin combined with treadmill exercise. We identified distinct classes of up- and down-regulated genes during this process. Experiment Overall Design: We treated female SD rats with vehicle or 3 doses of cerivastatin (0.1, 0.5, 1.0 mg/kg/day) for 14 days, plus or minus 5 days/week of exercise on treadmills (20 min/day at 20 m/min). Gastrocnemius and soleus muscle samples were harvested for RNA extraction and hybridization on Affymetrix microarrays. A total of 12 samples were analyzed with 3-4 biological replicates per sample. Our goals were to determine 1) the effect of cerivastatin; 2) the effect of exercise combined with cerivastatin; 3) an explanation for the muscle fiber type sensitivity to statins. Since all doses of cerivastatin had no effect on soleus muscle (PubMed ID: 16141437), we analysed samples from soleus from control and high dose groups only.
Project description:Six rats (treatment group) underwent a 13-week downhill treadmill running exercise programme and six rats (control group) were studied in this experiments. The RNAs were extracted from rat Achille's tendon tissue and sequenced using Illumina Hiseq platform.
Project description:Exercise is a fundamental component of human health that is associated with greater life expectancy and reduced risk of chronic diseases. While the beneficial effects of endurance exercise on human health are well established, the molecular mechanisms responsible for these observations remain unclear. Endurance exercise reduces the accumulation of mitochondrial DNA (mtDNA) mutations, alleviates multisystem pathology, and increases the lifespan of the mtDNA mutator mouse model of aging, in which the proof-reading capacity of mitochondrial polymerase gamma (POLG1) is deficient. Clearly, exercise recruited a POLG1-independent mtDNA repair pathway to induce these adaptations, a novel finding as POLG1 is canonically considered to be the sole mtDNA repair enzyme. Here we investigate the identity of this pathway, and show that endurance exercise prevents mitochondrial oxidative damage, attenuates telomere erosion, and mitigates cellular senescence and apoptosis in mtDNA mutator mice. Unexpectedly, we observe translocation of tumour suppressor protein p53 to mitochondria in response to endurance exercise that facilitates mtDNA mutation repair. Indeed, endurance exercise failed to prevent mtDNA mutations, induce mitochondrial biogenesis, preserve mitochondrial morphology, reverse sarcopenia, and mitigate premature mortality in mtDNA mutator mice with muscle-specific deletion of p53. Our data establish an exciting new role for p53 in exercise-mediated maintenance of the mtDNA genome, and presents mitochondrially-targeted p53 as a novel therapeutic modality for aging-associated diseases of mitochondrial etiology. Microarray analysis of gene expression from skeletal muscle (quadriceps femoris) from Mus musculus. N=23 samples per treatment were analysed for whole transcriptiome gene expression profile using NimbleGen Arrays. The treatment groups included wild-type C57Bl/6J mice as the control group, then two treatment groups which both contained homozygous knock-in mtDNA mutator mice (PolG; PolgAD257A/D257A). Once group of these heterozygous knock out mice received regular endurance exercise sessions while the other group remained sedentraty for 6 months. The control group specimens were wild-type litter mates to the transgenic knockout mice.
Project description:Although skeletal muscle metabolism is a well-studied physiological process, little is known about how it is regulated at the transcriptional level. The myogenic transcription factor myogenin is required for skeletal muscle development during embryonic and fetal life, but myogeninâs role in adult skeletal muscle is unclear. We sought to determine myogeninâs function in adult muscle metabolism. A Myog conditional allele and Cre-ER transgene were used to delete Myog in adult mice. Mice were analyzed for exercise capacity by involuntary treadmill running. To assess oxidative and glycolytic metabolism, we monitored blood glucose and lactate levels and performed histochemical analysis on muscle fibers. Surprisingly, we found that Myog-deleted mice performed significantly better than controls in high- and low-intensity treadmill running. This enhanced exercise capacity was due to more efficient oxidative metabolism during low-intensity exercise and more efficient glycolytic metabolism during high-intensity exercise. Furthermore, Myog-deleted mice had an enhanced response to long-term voluntary exercise training on running wheels. We identified several candidate genes whose expression was altered in exercise-stressed muscle of mice lacking myogenin. The results suggest that myogenin plays a critical role as a high-level transcriptional regulator to control the energy balance between aerobic and anaerobic metabolism in adult skeletal muscle. We used microarrays to detail the global program of gene expression underlying enhanced exercise endurance associated with myog-deletion and long-term exercise training. Mouse gastrocnemius muscles were selected after 6 months of myog-deletion and exercise training for RNA extraction and hybridization on Affymetrix microarrays. We chose 3 wild type and 3 myog-deleted mice that best represented the average of each larger group that was tested during our mouse exercise studies.
Project description:Purpose: Aerobic capacity is a strong predictor of cardiovascular mortality. To determine the relationship between inborn aerobic capacity and soleus gene expression we examined genome-wide gene expression in soleus muscle of rats artificially selected for high and low running capacity (HCR and LCR, respectively) over 16 generations. The artificial selection of LCR caused accumulation of risk factors of cardiovascular disease similar to the metabolic syndrome seen in man, whereas HCR had markedly better cardiac function. We also studied alterations in gene expression in response to exercise training in the two groups, since accumulating evidence indicates that exercise has profound beneficial effects on the metabolic syndrome. Methods:; Soleus gene expression of both sedentary and exercise trained HCR and LCR was characterized by microarray- and gene ontology analysis. Results: Although HCR and LCR had an inborn 347% difference in running capacity, only three genes were found differentially expressed in the soleus muscle between the two groups. Up-regulation of the mitochondrial enzyme leucyl-transferRNA synthetase (LARS2) was found in the sedentary LCR. Increased expression of LARS2 has been associated with a mitochondrial DNA mutation linked to maternally inherited diabetes and mitochondrial dysfunction. In line with our findings, a growing body of evidence suggests that LCR have compromised mitochondrial function. After exercise training, 58 genes were altered in the soleus muscle of HCR, in contrast to only one in the LCR group. This suggests that animals born with different levels of fitness respond different to the same type of exercise training. Adaptations to exercise in HCR seemed to be associated with increased lipid metabolism and fatty acid elongation in the mitochondria. Also, genes associated with the peroxisomes, seemed to be central in the adaptation to exercise. Conclusion: The results indicate that (i) LCR might have mitochondrial dysfunction, which may be a contributing factor of the low inborn aerobic capacity, (ii) animals born with different levels of fitness respond different to the same exercise program. Experiment Overall Design: There are 16 samples in this study.