Project description:An excess in thyroid hormone during rodent neonatal life causes abnormal prolifration and maturation of testicular cells, leading to reduced testis size and impairments in steroidogenesis, Sertoli cell function, spermatogenesis and fertility. The high expression of type 3 deiodinase in the neonatal testis protects this tissue from premature exposure to thyroid hormones, since this gene (Dio3) function is to degrade thyroid hormones. DIO3-deficient mice (Dio3KO) exhibit a marked reduction in Sertoli cell proliferation and testis size, abnormalities in the reproductive axis and impaired fertility (Martinez et al. 2016, Endocrinology157:1276). To identify genes that are untimely regulated by thyroid hormone in the developing testes, we have performed RNAseq in testis total RNA from wild type and DIO3KO mouse neonates.
Project description:We investigated the effects of thyroid hormone disruptions on gene expression in juvenile mice liver to develop a stronger understanding of the mechanisms by which thyroid disrupting chemicals impair development. Gene expression was examined by hybridization of hepatic RNA to Agilent mouse microarrays for hyper-, hypo-, hypo-replacement (hypo+) and euthyroid animals. Keywords: Toxicogenomics, biomarkers of thyroid disruptors
Project description:Using tadpoles mutant for thyroid hormone receptor alpha (thra), we show that TRa is required for thyroid hormone (T3) induction of cell proliferation in the brain. RNA-sequencing showed that the TRa is required for 95% of the gene regulation responses to T3.
Project description:Thyroid hormones are important for homeostatic control of energy metabolism and body temperature. Although skeletal muscle is considered an important site for thyroid action, the contribution of thyroid hormone receptor signaling, in muscle, to whole-body energy metabolism and body temperature has not been resolved. Here, we show that thyroid hormone-induced increase in energy expenditure requires thyroid hormone receptor alpha 1 (TRa1) in skeletal muscle, but that thyroid hormone induced elevation in body temperature is independent of muscle-TRa1. In slow-twitch soleus muscle, ablation of TRa1 leads to an altered fiber type composition toward a more oxidative phenotype, which, however, does not influence running capacity or motivation to voluntary running. RNA-sequencing of soleus muscle from WT mice and TRaHSACre mice revealed differentiated transcriptional regulation of genes associated with muscle thermogenesis, such as sarcolipin and UCP3, thus providing molecular clues pertaining to the mechanistic underpinnings of TRa1-linked control of whole-body metabolic rate. Together, this work establishes a fundamental role for skeletal muscle in thyroid hormone-stimulated increase in whole-body energy expenditure.
Project description:Cerebellar post-natal development is particularly sensitive to thyroid hormone and low levels of thyroid hormone (hypothyroidism) result in permanent defects in cerebellar architecture and function. All cell types of the cerebellum are affected, but the main sign of hypothyroidism in mice is the persistence of the external granular layer, composed of mitotic neuronal precursors at P21. To make the genetic link between thyroid hormone and cerebellar development, we sought to identify new thyroid hormone target genes, in particular in granule cells which represent the vast majority of cerebellar cells.
Project description:We investigated the effects of thyroid hormone disruptions on gene expression in juvenile mice liver to develop a stronger understanding of the mechanisms by which thyroid disrupting chemicals impair development. Gene expression was examined by hybridization of hepatic RNA to Agilent mouse microarrays for hyper-, hypo-, hypo-replacement (hypo+) and euthyroid animals. Keywords: Toxicogenomics, biomarkers of thyroid disruptors Hypothyroidism was induced from post natal day (PND) 13 to 15 by adding model thyroid toxicants methimazole and sodium perchlorate to drinking water of pregnant females. Hyperthyroidism was induced by intraperitoneal injections (i.p.) of THs at PND 15, 4 hours before decapitation and tissue collection. For the hypothyroid/replacement group; dams were provided with drinking water for 3 days (PND 13 to 15), containing a mixture of methimazole/sodium perchlorate. Pups then received intraperitoneal injections of thyoid hormones on PND 15, 4 hours before decapitation and tissue collection.
Project description:Cerebellar post-natal development is particularly sensitive to thyroid hormone and low levels of thyroid hormone (hypothyroidism) result in permanent defects in cerebellar architecture and function. All cell types of the cerebellum are affected, but the main sign of hypothyroidism in mice is the persistence of the external granular layer, composed of mitotic neuronal precursors at P21. To make the genetic link between thyroid hormone and cerebellar development, we sought to identify new thyroid hormone target genes, in particular in granule cells which represent the vast majority of cerebellar cells. Primary cultures of cerebellar neurons were made by dissociation of cerebella from newborn wild-type mice. These cells were plated 48 hours in serum-free medium to avoid invasion of the culture by glial cells. In order to include a kinetic and a maximum number of target genes, several cultures were either treated or left untreated as controls for 6 hours (T1), 16 hours (T2), 24 hours (T3) or 48 hours (T4) and results were pairwise compared for each time point.
Project description:This SuperSeries is composed of the following subset Series: GSE16017: Thyroid Hormone (TH) Controls The Remodeling Of The Pancreas And The Liver, Part B GSE16018: Thyroid Hormone (TH) Controls The Remodeling Of The Pancreas And The Liver, Part C GSE16074: Thyroid Hormone (TH) Controls The Remodeling Of The Pancreas And The Liver, Part A Refer to individual Series
Project description:Thyroid hormone (3,5,3'-triiodothyronine, T3) sensitively influences the pituitary gland, a source of hormones that control tissues throughout the body. The underlying transcriptional response is believed to hinge crucially on interaction of T3 receptors with enhancers in the genome but it remains unknown how T3 regulates pituitary chromatin and how this regulation adjusts to hypothyroid and hyperthyroid conditions.