Week 4 Flashcards
What are nuclear receptors?
A family of ligand-regulated transcription factors that are activated by steroid hormones, such as estrogen and progesterone, and various other lipid-soluble signals, including retinoic acid, oxysterols, and thyroid hormone
How does endocrine signalling operate?
The signaling molecules (hormones) are secreted by specialized endocrine cells and carried through the circulation to act on target cells at distant body sites
What is the hormonal system?
A network of glands and organs in the body that produces hormones
How does the hormonal system work?
When a hormone is released from a gland, it travels in the bloodstream through the body. It passes by most cells, but eventually reaches its target.
What medical conditions relate to the hormonal system?
Some common hormonal problems are:
- Diabetes
- Thyroid problems, such as hypothyroidism and hyperthyroidism
- Cushing’s syndrome
- Some fertility problems
- Congenital adrenal hyperplasia
Examples of polypeptide/protein hormones?
- Growth hormone
- Vasopressin
- Insulin
- Glucagon
- Parathyroid hormone
What’s the difference between peptide hormones and protein hormones?
Peptide hormones consist of short chains of amino acids, whereas protein hormones are longer polypeptides.
What are lipophilic hormones?
Lipid-soluble hormones
What is a hormone receptor?
A receptor molecule that binds to a specific chemical messenger.
What is meant by nuclear receptors?
Nuclear receptors are a family of ligand-regulated transcription factors that are activated by steroid hormones, such as estrogen and progesterone, and various other lipid-soluble signals, including retinoic acid, oxysterols, and thyroid hormone
What do nuclear receptors sense?
Changes in lipid metabolite levels to drive differential gene expression, producing distinct physiologic effects
What does the allosteric binding of nuclear receptors?
Drives the recruitment of diverse transcriptional co‐regulators at chromatin and ultimately transactivation or transrepression of target genes
What does the dysregulation of nuclear receptors lead to?
Various malignances, metabolic disorders, and inflammatory disease
What ligands bind to nuclear receptors?
lipophilic substances such as endogenous hormones, vitamins A and D, and xenobiotic hormones
What is cortisol?
A steroid hormone, in the glucocorticoid class of hormones.