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Flashcards in Lipids 6 Deck (21)
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1
Q

What is an adaptive and reversible response to environmental challenges?

A

Browning of adipose tissue

2
Q

What are the three types of adipocytes?

A

White adipocytes
Brown adipocytes
Beige adipocytes

3
Q

Describe beige adipocytes?

A

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

4
Q

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

A

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

5
Q

What do mice lacking brown adipose tissue have?

A

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

6
Q

What can a wild type moist do?

A

Rapidly increase heat generation

7
Q

What is the hot and cold theory of reducing obesity?

A

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

8
Q

What can promote beige adipocyte biogenesis?

A

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

9
Q

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

A

Transmembrane receptor- provides a sensation of scalding heat and pain

10
Q

How do capsinoids affect beige adipocyte biogenesis?

A

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

11
Q

What is cancer-associated cachexia?

A

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

12
Q

When is cachexia seen?

A

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

13
Q

Cachexia is responsible for how many total deaths from cancer?

A

20%

14
Q

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

A

WAT browning

15
Q

What induces WAT browning in cachexia?

A

Systemic inflammation and IL-6

16
Q

What do cancer cachexia stain positive for?

A

UCP1 protein in WAT

17
Q

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

A

Inhibition of WAT browning

18
Q

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

A

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

19
Q

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

A

Catecholaminergic surge

20
Q

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

A

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

21
Q

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

A

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