Glucocorticoids

Question 1

What are glucocorticoid receptors?

Answer 1

Type of nuclear receptor that binds cortisol and regulates gene transcription

Glucocorticoid receptors are involved in various physiological processes, including metabolism and immune response.

Question 2

What is the natural ligand for the glucocorticoid receptor?

Answer 2

Cortisol

Question 3

Name the four main types of receptors.

Answer 3

• G protein coupled receptors (GPCRs)
• Enzyme linked receptors
• Ligand-gated ion channels
• Nuclear receptors

Question 4

What happens to glucocorticoid receptors upon binding with agonists?

Answer 4

They dimerise and move to the nucleus

Question 5

What is the classification of nuclear receptors in humans?

Answer 5

48 NR genes in humans

Question 6

What physiological effects does cortisol have on metabolism?

Answer 6

• Increases plasma glucose
• Stimulates synthesis in the liver
• Breaks down proteins
• Breaks down fat

Question 7

True or False: Glucocorticoids have anti-inflammatory effects primarily through transactivation.

Answer 7

False

Question 8

What is the hypothalamic-pituitary-adrenal axis?

Answer 8

A system that regulates cortisol production in response to stress

Question 9

What is the role of corticotrophin releasing hormone (CRH)?

Answer 9

Stimulates the release of ACTH from the anterior pituitary

Question 10

What are some therapeutic uses of glucocorticoids?

Answer 10

• Joint inflammation
• Myasthenia gravis
• Crohn’s disease
• Asthma
• Severe allergies

Question 11

What condition is characterized by increased ACTH and cortisol due to a benign pituitary tumor?

Answer 11

Cushing’s disease

Question 12

Fill in the blank: Cortisol acts at _______ receptors in the kidney.

Answer 12

mineralocorticoid

Question 13

What is a side effect of inhaled glucocorticoids?

Answer 13

Local immunosuppression

Question 14

What is Addison’s disease?

Answer 14

Autoimmune destruction of the adrenal cortex leading to insufficient cortisol production

Question 15

What is a potential side effect of glucocorticoid treatment?

Answer 15

Adrenal suppression

Question 16

What is the significance of 11 beta-hydroxysteroid dehydrogenase type 2?

Answer 16

It protects mineralocorticoid receptors from cortisol

Question 17

What are selective glucocorticoid receptor agonists (SEGRAs)?

Answer 17

Drugs that favor transrepression effects of glucocorticoids

Question 18

What is a common effect of cortisol on electrolytes?

Answer 18

Increases calcium loss from bone

Question 19

What is the primary mechanism of action for glucocorticoids in reducing inflammation?

Answer 19

Transrepression of pro-inflammatory signals

Question 20

What are the time scales for nuclear receptors compared to GPCRs and ligand-gated ion channels?

Answer 20

Nuclear receptors: hours; GPCRs, LGICs: millisecond to second

Question 21

What happens during acute glucocorticoid withdrawal?

Answer 21

Adrenal crisis due to adrenal suppression

Question 22

What is the role of ACTH in the adrenal cortex?

Answer 22

Stimulates the release of cortisol

Question 23

What is the effect of cortisol on the central nervous system?

Answer 23

Modulates apoptosis of neurons and generation of new neurons

Question 24

What is adrenal crisis?

Answer 24

A severe and potentially life-threatening condition due to insufficient levels of cortisol

Requires immediate treatment with hydrocortisone

Question 25

What is aldosterone?

Answer 25

A steroid hormone produced by the adrenal glands Plays a central role in regulating blood pressure and electrolyte balance by increasing the reabsorption of sodium and the secretion of potassium in the kidneys

Question 26

What is biased agonism?

Answer 26

When a receptor has 2 potential signalling pathways and one of these pathways is favoured by a particular agonist

Question 27

What is a corticosteroid?

Answer 27

A steroid hormone produced by the adrenal cortex Includes cortisol and aldosterone

Question 28

Main glucocorticoid in rodents

Answer 28

Corticosterone

Question 29

What is cortisol crucial for in humans?

Answer 29

Glucose metabolism, immune response modulation and stress response

Question 30

What is Cushing’s syndrome?

Answer 30

A condition caused by excessive cortisol levels in the blood, typically due to long-term use of corticosteroid drugs or a tumour that increases ACTH production

Question 31

What is an inverted repeat?

Answer 31

A sequence of nucleotides that consists of 2 reverse complementary sequences separated by a spacer, often found in DNA response elements where receptors bind

Question 32

What is transactivation?

Answer 32

A mechanism where binding of a receptor to a DNA response element directly activates the transcription of target genes

Question 33

What is transrepression?

Answer 33

The process by which glucocorticoid receptors indirectly inhibit the expression of certain genes, typically by interfering with other transcription factors without binding directly to DNA