Lipids 6

Question 1

What is an adaptive and reversible response to environmental challenges?

Answer 1

Browning of adipose tissue

Question 2

What are the three types of adipocytes?

Answer 2

White adipocytes
Brown adipocytes
Beige adipocytes

Question 3

Describe beige adipocytes?

Answer 3

Found in various white adipocyte tissue depots
Also known as brite adipocytes
Developed in response to cold and other stimuli

Question 4

What evidence is there that the browning of adipose tissue occurs?

Answer 4

Knockout most model (loss of gene for a receptor for a signalling molecule BMP (brown morphogenetic protein)
Involved in development of brown adipose tissue

Question 5

What do mice lacking brown adipose tissue have?

Answer 5

Reduced body temperature and exhibit increased browning of white adipose tissue for thermoregulation

Question 6

What can a wild type moist do?

Answer 6

Rapidly increase heat generation

Question 7

What is the hot and cold theory of reducing obesity?

Answer 7

Chilli peppers (capsinoids) supress body weight gain and increase energy expenditure on a high fat diet

Question 8

What can promote beige adipocyte biogenesis?

Answer 8

A synergistic antiobesity effect by a combination of capsinoids and cold temperature

Question 9

What type of receptor is a capsinoid receptor and what does it do?

Answer 9

Transmembrane receptor- provides a sensation of scalding heat and pain

Question 10

How do capsinoids affect beige adipocyte biogenesis?

Answer 10

They bind to capsinoid receptor, signal from receptor and cold sensation transmitted to WAT through b-adrenergic receptor. Stimulates BAT adipogenesis through increased b-adrenergic receptor expression and stabilisation of transcription factor PRDM16. PRDM16 is a dominant transcriptional regulator of BAT development

Question 11

What is cancer-associated cachexia?

Answer 11

A syndrome characterised by inflammation, body weight loss, atrophy of adipose tissue and skeletal muscle wasting

Question 12

When is cachexia seen?

Answer 12

Advancing stages of cancer, end stage of various diseases such as AIDS, congestive heart failure

Question 13

Cachexia is responsible for how many total deaths from cancer?

Answer 13

20%

Question 14

What contributes to high energy expenditure in cancer-associated cachexia?

Answer 14

WAT browning

Question 15

What induces WAT browning in cachexia?

Answer 15

Systemic inflammation and IL-6

Question 16

What do cancer cachexia stain positive for?

Answer 16

UCP1 protein in WAT

Question 17

What is a promising approach to ameliorating cachexia in cancer patients?

Answer 17

Inhibition of WAT browning

Question 18

What does burn trauma do to browning of white adipose tissue?

Answer 18

Causes prolonged revelation in circulating norepinephrine levels and there’s a found expression of UCP1 of white adipose tissue (indicating increased testing energy) - could be due to need for increased thermogenesis due to loss of insulating skin barrier

Question 19

What, caused by epinephrine, is associated with larger burns contributing to the browning of white adipose tissue?

Answer 19

Catecholaminergic surge

Question 20

Is it possible to stimulate an increase in beige adipose tissue in humans?

Answer 20

Yes (exposure to cold trials, and use of oral supplementation of bile acid in human)

Question 21

How can bile acid chendeoxycholic acid increase brown adipose tissue activity?

Answer 21

Can activate a G-protein coupled receptor= increased concentration of cAMP= activates deiodinase enzyme D2 responsible for producing active thyroid hormone