Project description:Hypothyroidism is commonly detected in patients with medulloblastoma (MB), a pediatric brain tumor, which is generally considered as a treatment-related complication. Although reduced levels of thyroid hormone (TH) significantly correlate with poor survival of patients with MB, the possible link between TH signaling and MB pathogenicity is unknown. Here, we found that TH regulating terminal differentiation of tumor cells. Reduction in the levels of TH frees the unliganded TH receptor, TRα, to bind to EZH2 and repress expression of NeuroD1, a transcription factor that drives terminal differentiation of neuronal progenitors as well as MB cells. Moreover, TH promotes extensive differentiation and reduced proliferation of tumor cells from multiple molecular subtypes of MB including the hedgehog (HH) group as well as group 3 (G3) MB. Consequently, TH treatment significantly inhibits the in vivo growth of SHH- and G3-MB by promoting tumor cell differentiation, with no obvious increase in tumor cell death, indicating that TH signaling represents a novel therapeutic entry-point for broad treatment of MB.
Project description:We have found that thyroid hormones (THs), acting as soluble integrin αvβ3 ligands, activate growth-related signaling pathways in T-cell lymphomas (TCL). Specifically, TH-activated αvβ3 integrin signaling promotes TCL proliferation and angiogenesis, in part, via the up-regulation of VEGF.
Project description:We have found that thyroid hormones (THs), acting as soluble integrin αvβ3 ligands, activate growth-related signaling pathways in T-cell lymphomas (TCL). Specifically, TH-activated αvβ3 integrin signaling promotes TCL proliferation and angiogenesis, in part, via the up-regulation of VEGF. CUTLL1 cells were treated with T3- and T4-bound agarose or agarose alone for 24hrs. Total RNA was harvested from cells and used for expression profiling via RNA-seq.
Project description:An inverse correlation between circulating thyroid hormone levels and longevity has been reported in several species and reduced thyroid hormone levels have been proposed as a biomarker for healthy aging and metabolic fitness in humans. However, hypothyroidism is a serious medical condition associated with reduced health and life expectancy. In this report, we show that severe and even subtle modulations on thyroid hormone levels leading to different forms of hyperthyroidism and hypothyroidism produce an overall unhealthy status and reduced lifespan in mice. A mild reduction in circulating T4 levels (~10%) resulted in hepatic mitochondrial dysfunction, increased ROS production and oxidative damage accumulation. These actions may contribute to the development of metabolic disorders, increased prevalence of hepatocellular carcinomas and early mortality in mice. Our findings raise concerns regarding the development of interventions aiming to modulate thyroid hormones to promote healthy aging or lifespan extension in mammals.
Project description:The thyroid gland is responsible for supplying the thyroid hormones to the body. The gland is an endocrine organ with an intricate structure enabling production, storage and release of the thyroid hormones. The gland is composed of numerous spherical follicles of varying sizes, surrounded by thyroid follicular epithelial cells, or thyrocytes. The thyrocytes surrounding the follicles generate the thyroid hormones in a multi-step process. Though the machinery responsible for the production of thyroid hormones by thyrocytes is well established, it remains unknown if all the thyrocytes resident in the thyroid gland are equally capable of generating thyroid hormones. In other words, the extent of molecular homogeneity between individual thyrocytes has not yet been investigated. To obtain an unbiased picture into the molecular heterogeneity present in zebrafish thyrocytes, we performed droplet based next-generation sequencing of individual thyrod gland cells. Using unsupervised clustering, we could identify all the major cell types present in the thyroid gland. Moreover, we could define sub-populations within the major cell-types, demonstrating the presence of molecular heterogeneity within nominally homogenous cell-populations.
Project description:Origins of the brain tumor, medulloblastoma, from stem cells or restricted pro-genitor cells are unclear. To investigate this, we activated oncogenic Hedgehog signaling in multipotent and lineage-restricted CNS progenitors. We observed that normal unipo-tent cerebellar granule neuron precursors (CGNP) derive from hGFAP+ and Olig2+ rhombic lip progenitors. Hedgehog activation in a spectrum of early and late stage CNS progenitors generated similar medulloblastomas, but not other brain cancers, indicating that acquisition of CGNP identity is essential for tumorigenesis. We show in human and mouse medulloblastoma that cells expressing the glia-associated markers Gfap and Olig2 are neoplastic and that they retain features of embryonic-type granule lineage progenitors. Thus, oncogenic Hedgehog signaling promotes medulloblastoma from lineage-restricted granule cell progenitors. Gene expression profiling of cerebellar tumors generated from various early and late stage CNS progenitor cells. Experiment Overall Design: Group comparisons with biological replicates
Project description:The function of the thyroid gland is to metabolize iodide to synthesize hormones that act on almost all tissues and are essential for normal growth and metabolism. Low plasma levels of thyroid hormones lead to hypothyroidism, which is one of the most common diseases in the general population and cannot be always satisfactorily treated by lifelong hormone replacement. Therefore, in addition to the lack of in vitro tractable models to study human thyroid development, differentiation and maturation, there is a need for new therapeutic approaches that involve replacement of thyroid tissue to better control hormone balance. Here we report the first model of thyroid organoids derived from human embryonic stem cells that produce thyroid hormones in vitro and are capable of restoring plasma thyroid hormone levels when transplanted into athyreotic mice.
Project description:The function of the thyroid gland is to metabolize iodide to synthesize hormones that act on almost all tissues and are essential for normal growth and metabolism. Low plasma levels of thyroid hormones lead to hypothyroidism, which is one of the most common diseases in the general population and cannot be always satisfactorily treated by lifelong hormone replacement. Therefore, in addition to the lack of in vitro tractable models to study human thyroid development, differentiation and maturation, there is a need for new therapeutic approaches that involve replacement of thyroid tissue to better control hormone balance. Here we report the first model of thyroid organoids derived from human embryonic stem cells that produce thyroid hormones in vitro and are capable of restoring plasma thyroid hormone levels when transplanted into athyreotic mice.
Project description:The function of the thyroid gland is to metabolize iodide to synthesize hormones that act on almost all tissues and are essential for normal growth and metabolism. Low plasma levels of thyroid hormones lead to hypothyroidism, which is one of the most common diseases in the general population and cannot be always satisfactorily treated by lifelong hormone replacement. Therefore, in addition to the lack of in vitro tractable models to study human thyroid development, differentiation and maturation, there is a need for new therapeutic approaches that involve replacement of thyroid tissue to better control hormone balance. Here we report the first model of thyroid organoids derived from human embryonic stem cells that produce thyroid hormones in vitro and are capable of restoring plasma thyroid hormone levels when transplanted into athyreotic mice.
Project description:The function of the thyroid gland is to metabolize iodide to synthesize hormones that act on almost all tissues and are essential for normal growth and metabolism. Low plasma levels of thyroid hormones lead to hypothyroidism, which is one of the most common diseases in the general population and cannot be always satisfactorily treated by lifelong hormone replacement. Therefore, in addition to the lack of in vitro tractable models to study human thyroid development, differentiation and maturation, there is a need for new therapeutic approaches that involve replacement of thyroid tissue to better control hormone balance. Here we report the first model of thyroid organoids derived from human embryonic stem cells that produce thyroid hormones in vitro and are capable of restoring plasma thyroid hormone levels when transplanted into athyreotic mice.