scholarly journals A blubber gene expression index for evaluating stress in marine mammals

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Laura Pujade Busqueta ◽  
Daniel E Crocker ◽  
Cory D Champagne ◽  
Molly C McCormley ◽  
Jared S Deyarmin ◽  
...  
Keyword(s):  
Gene Expression ◽  
Thyroid Hormone ◽  
Marine Mammal ◽  
Marine Mammals ◽  
Elephant Seals ◽  
Hormone Levels ◽  
Stress Markers ◽  
Thyroid Hormone Levels ◽  
Species Specific ◽  
Free Ranging

Abstract Evaluating the impacts of anthropogenic disturbance on free-ranging marine mammal populations, many of which are in decline, requires robust diagnostic markers of physiological stress and health. However, circulating levels of canonical ‘stress hormones’ such as glucocorticoids, which are commonly used to evaluate animal health, do not capture the complexity of species-specific responses and cannot be easily measured in large, fully aquatic marine mammals. Alternatively, expression of stress-responsive genes in hormone target tissues such as blubber, the specialized subcutaneous adipose tissue that can be manually or remotely sampled from many marine mammals, may be a more informative and sensitive indicator of recent (within 24 h) exposure to stressors. We previously identified genes that were upregulated in the inner blubber of juvenile northern elephant seals during experimental stimulation of the hypothalamic–pituitary–adrenal axis. In this study, we measured baseline expression levels of a subset of these genes in inner blubber of unmanipulated juvenile elephant seals of varying physiological states and correlated them with other stress markers (body condition index, corticosteroid and thyroid hormone levels). Expression of 10 genes, including those associated with lipid metabolism (ACSL1, HMGCS2, CDO1), redox homeostasis (GPX3), adipokine signaling (ADIPOQ), lipid droplet formation (PLIN1, CIDEA) and adipogenesis (DKK1, AZGP1, TGFBI), was described by three principal components and was associated with cortisol and thyroid hormone levels. Significantly, baseline gene expression levels were predictive of circulating hormone levels, suggesting that these markers may be potential indicators of exposure to stressors in marine mammal species that are inaccessible for blood sampling. A similar approach may be used to identify species-specific stress markers in other tissues that can be sampled by remote biopsy dart from free-ranging marine mammals, such as outer blubber and skin.

Seasonal thyroid hormone levels of free-ranging white-tailed deer (Odocoileus virginianus) in Ontario

1990 ◽  
Vol 68 (10) ◽  
pp. 2174-2180 ◽  
Author(s):  
J. Hamr ◽  
G. A. Bubenik
Keyword(s):  
Thyroid Hormone ◽  
Regional Differences ◽  
Latitudinal Gradient ◽  
Age Classes ◽  
Blood Samples ◽  
Male And Female ◽  
Hormone Levels ◽  
Thyroid Hormone Levels ◽  
Free Ranging

Blood samples from killed and livetrapped deer of southern and central Ontario were analyzed for thyroxine (T4) and triiodothyronine (T3). Mean seasonal levels for six sex-age classes of deer ranged from 150 to 400 ng/dL (T3) and from 6.0 to 18.0 μg/dL (T4). Seasonal variation of T4 was less pronounced than that of T3. Both hormones decreased in the fall as compared with spring and summer, especially in yearling and older bucks. T3 values were also low in the winter but increased in spring and summer for most tested categories of deer. Differences in seasonal T3 and T4 concentrations were found between male and female deer older than 1 year, and among sex-age classes of the same sex. Regional differences in thyroid hormone levels suggested a latitudinal gradient, with higher values in southern than in central Ontario. Hormone of artificially fed deer were elevated when compared with animals that consumed only natural browse. Hormone levels were also higher in deer provided with food supplements of higher protein content. Extremely low winter T3 and T4 concentrations were found in malnourished deer. It is concluded that thyroid hormones in deer blood are influenced by current food intake and quality of nutrition. The potential for T3 and T4 as indicators of range quality is discussed.

Hepatic deiodinase activity is dispensable for the maintenance of normal circulating thyroid hormone levels, but not for thyroid hormone-dependent gene expression

2005 ◽  
Vol 2005 (Fall) ◽  
Author(s):  
Ulrich Schweizer ◽  
Florian Streckfuß ◽  
Inka Hamann ◽  
Lutz Schomburg ◽  
Marten Michaelis ◽  
...  
Keyword(s):  
Gene Expression ◽  
Thyroid Hormone ◽  
Hormone Levels ◽  
Deiodinase Activity ◽  
Thyroid Hormone Levels

scholarly journals A thyroid hormone network exists in synovial fibroblasts of rheumatoid arthritis and osteoarthritis patients

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Anna-Sophia Pörings ◽  
Torsten Lowin ◽  
Bianca Dufner ◽  
Joachim Grifka ◽  
Rainer H. Straub
Keyword(s):  
Rheumatoid Arthritis ◽  
Gene Expression ◽  
Thyroid Hormone ◽  
Synovial Fluid ◽  
Thyroid Hormones ◽  
Synovial Tissue ◽  
Hormone Receptors ◽  
Synovial Fibroblasts ◽  
Hormone Levels ◽  
Thyroid Hormone Levels

Abstract While patients with rheumatoid arthritis (RA) sometimes demonstrate thyroidal illness, the role of thyroid hormones in inflamed synovial tissue is unknown. This is relevant because thyroid hormones stimulate immunity, and local cells can regulate thyroid hormone levels by deiodinases (DIO). The study followed the hypothesis that elements of a thyroid hormone network exist in synovial tissue. In 12 patients with RA and 32 with osteoarthritis (OA), we used serum, synovial fluid, synovial tissue, and synovial fibroblasts (SF) in order to characterize the local thyroid hormone network using ELISAs, immunohistochemistry, imaging methods, tissue superfusion studies, cell-based ELISAs, flow cytometry, and whole genome expression profiling. Serum/synovial fluid thyroid hormone levels were similar in RA and OA (inclusion criteria: no thyroidal illness). The degradation product termed reverse triiodothyronine (reverse T3) was much lower in serum compared to synovial fluid indicating biodegradation of thyroid hormones in the synovial environment. Superfusion experiments with synovial tissue also demonstrated biodegradation, particularly in RA. Cellular membrane transporters of thyroid hormones, DIOs, and thyroid hormone receptors were present in tissue and SF. Density of cells positive for degrading DIOs were higher in RA than OA. TNF increased protein expression of degrading DIOs in RASF and OASF. Gene expression studies of RASF revealed insignificant gene regulation by bioactive T3. RA and OA synovial tissue/SF show a local thyroid hormone network. Thyroid hormones undergo strong biodegradation in synovium. While bioactive T3 does not influence SF gene expression, SF seem to have a relay function for thyroid hormones.

Perinatal exposure to BDE-99 causes learning disorders and decreases serum thyroid hormone levels and BDNF gene expression in hippocampus in rat offspring

Toxicology ◽  
2013 ◽  
Vol 308 ◽  
pp. 122-128 ◽  
Author(s):  
Jordi Blanco ◽  
Miquel Mulero ◽  
Luis Heredia ◽  
Andreu Pujol ◽  
José L. Domingo ◽  
...  
Keyword(s):  
Gene Expression ◽  
Thyroid Hormone ◽  
Learning Disorders ◽  
Perinatal Exposure ◽  
Bdnf Gene ◽  
Hormone Levels ◽  
Rat Offspring ◽  
Serum Thyroid Hormone ◽  
Thyroid Hormone Levels
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