Acute Stretch-shortening Cycle Contractions Affecting Gene Expression Levels In Old And Young Rat Skeletal Muscle

2005 ◽  
Vol 37 (Supplement) ◽  
pp. S319
Author(s):  
Stacey Sylvester
2009 ◽  
Vol 161 (2) ◽  
pp. 243-250 ◽  
Author(s):  
Liese Mebis ◽  
Deborah Paletta ◽  
Yves Debaveye ◽  
Björn Ellger ◽  
Lies Langouche ◽  
...  

ObjectiveProlonged critically ill patients have low circulating thyroid hormone (TH) levels without a rise in TSH, a condition labeled ‘the low tri-iodothyronine (T3) syndrome’. Currently, it is not clear whether this represents an adaptive response. We examined the role of TH transporters monocarboxylate transporter 8 (MCT8, also known as SLC16A2) and MCT10 in the pathogenesis of the low T3 syndrome in prolonged critical illness.MethodsA clinical observational study in critically ill patients and an intervention study in an in vivo animal model of critical illness. Gene expression levels of MCT8 and MCT10 were measured by real-time PCR.ResultsIn prolonged critically ill patients, we measured increased MCT8 but not MCT10 gene expression levels in liver and skeletal muscle as compared with patients undergoing acute surgical stress. In a rabbit model of prolonged critical illness, gene expression levels of MCT8 in liver and of MCT10 in skeletal muscle were increased as compared with healthy controls. Treatment of prolonged critically ill rabbits with TH (thyroxine+T3) resulted in a downregulation of gene expression levels of MCT8 in liver and of MCT10 in muscle. Transporter expression levels correlated inversely with circulating TH parameters.ConclusionsThese data suggest that alterations in the expression of TH transporters do not play a major role in the pathogenesis of the ‘low T3 syndrome’ but rather reflect a compensatory effort in response to hypothyroidism.


Medicina ◽  
2021 ◽  
Vol 57 (10) ◽  
pp. 1028
Author(s):  
Cong Wu ◽  
Siyi Zhou ◽  
Sihui Ma ◽  
Katsuhiko Suzuki

The purpose of this study was to investigate the influences of oral high-dose genistein (GE) administration on exercise-induced oxidative stress, inflammatory response, tissue damage, and physical performance. Plasma aspartate aminotransferase (AST), alanine aminotransferase (ALT) levels, liver interleukin (IL)-6, IL-1β, superoxide dismutase 1 (SOD1), catalase (CAT), hemeoxygenase-1 (HO-1) gene expression levels and skeletal muscle IL-6, nuclear factor erythroid 2-related factor (Nrf2), and increased immediately after exhaustive exercise. Thiobarbituric acid reactive substance (TBARS) and protein carbonyl (PC) concentrations in plasma and skeletal muscles were not altered by exercise or GE supplementation. Contrary to our expectations, GE supplementation increased liver protein carbonyl concentrations. On the other hand, GE supplementation significantly decreased SOD1, CAT gene expression levels in the liver and Nrf2, and HO-1 gene expression levels in the skeletal muscles. In conclusion, acute exercise was able to induce organ damage, inflammation, and oxidative stress in skeletal muscles and the liver. However, a single dose of GE supplementation before exercise did not lead to favorable antioxidant and anti-inflammatory effects in this study. Moreover, the oxidative stress in the liver was actually aggravated by GE supplementation, slightly, along with the suppression of antioxidant enzyme expression. According to our findings, further studies are needed to use relatively low-dose and long-term GE supplementation to elicit its health-promoting effects.


Genes ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 854
Author(s):  
Yishu Wang ◽  
Lingyun Xu ◽  
Dongmei Ai

DNA methylation is an important regulator of gene expression that can influence tumor heterogeneity and shows weak and varying expression levels among different genes. Gastric cancer (GC) is a highly heterogeneous cancer of the digestive system with a high mortality rate worldwide. The heterogeneous subtypes of GC lead to different prognoses. In this study, we explored the relationships between DNA methylation and gene expression levels by introducing a sparse low-rank regression model based on a GC dataset with 375 tumor samples and 32 normal samples from The Cancer Genome Atlas database. Differences in the DNA methylation levels and sites were found to be associated with differences in the expressed genes related to GC development. Overall, 29 methylation-driven genes were found to be related to the GC subtypes, and in the prognostic model, we explored five prognoses related to the methylation sites. Finally, based on a low-rank matrix, seven subgroups were identified with different methylation statuses. These specific classifications based on DNA methylation levels may help to account for heterogeneity and aid in personalized treatments.


2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Weitong Cui ◽  
Huaru Xue ◽  
Lei Wei ◽  
Jinghua Jin ◽  
Xuewen Tian ◽  
...  

Abstract Background RNA sequencing (RNA-Seq) has been widely applied in oncology for monitoring transcriptome changes. However, the emerging problem that high variation of gene expression levels caused by tumor heterogeneity may affect the reproducibility of differential expression (DE) results has rarely been studied. Here, we investigated the reproducibility of DE results for any given number of biological replicates between 3 and 24 and explored why a great many differentially expressed genes (DEGs) were not reproducible. Results Our findings demonstrate that poor reproducibility of DE results exists not only for small sample sizes, but also for relatively large sample sizes. Quite a few of the DEGs detected are specific to the samples in use, rather than genuinely differentially expressed under different conditions. Poor reproducibility of DE results is mainly caused by high variation of gene expression levels for the same gene in different samples. Even though biological variation may account for much of the high variation of gene expression levels, the effect of outlier count data also needs to be treated seriously, as outlier data severely interfere with DE analysis. Conclusions High heterogeneity exists not only in tumor tissue samples of each cancer type studied, but also in normal samples. High heterogeneity leads to poor reproducibility of DEGs, undermining generalization of differential expression results. Therefore, it is necessary to use large sample sizes (at least 10 if possible) in RNA-Seq experimental designs to reduce the impact of biological variability and DE results should be interpreted cautiously unless soundly validated.


Agronomy ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 92
Author(s):  
Joon Seon Lee ◽  
Lexuan Gao ◽  
Laura Melissa Guzman ◽  
Loren H. Rieseberg

Approximately 10% of agricultural land is subject to periodic flooding, which reduces the growth, survivorship, and yield of most crops, reinforcing the need to understand and enhance flooding resistance in our crops. Here, we generated RNA-Seq data from leaf and root tissue of domesticated sunflower to explore differences in gene expression and alternative splicing (AS) between a resistant and susceptible cultivar under both flooding and control conditions and at three time points. Using a combination of mixed model and gene co-expression analyses, we were able to separate general responses of sunflower to flooding stress from those that contribute to the greater tolerance of the resistant line. Both cultivars responded to flooding stress by upregulating expression levels of known submergence responsive genes, such as alcohol dehydrogenases, and slowing metabolism-related activities. Differential AS reinforced expression differences, with reduced AS frequencies typically observed for genes with upregulated expression. Significant differences were found between the genotypes, including earlier and stronger upregulation of the alcohol fermentation pathway and a more rapid return to pre-flooding gene expression levels in the resistant genotype. Our results show how changes in the timing of gene expression following both the induction of flooding and release from flooding stress contribute to increased flooding tolerance.


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