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Flashcards in Lipids 6 Deck (21):

What is an adaptive and reversible response to environmental challenges?

Browning of adipose tissue


What are the three types of adipocytes?

White adipocytes
Brown adipocytes
Beige adipocytes


Describe beige adipocytes?

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


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

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


What do mice lacking brown adipose tissue have?

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


What can a wild type moist do?

Rapidly increase heat generation


What is the hot and cold theory of reducing obesity?

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


What can promote beige adipocyte biogenesis?

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


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

Transmembrane receptor- provides a sensation of scalding heat and pain


How do capsinoids affect beige adipocyte biogenesis?

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


What is cancer-associated cachexia?

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


When is cachexia seen?

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


Cachexia is responsible for how many total deaths from cancer?



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

WAT browning


What induces WAT browning in cachexia?

Systemic inflammation and IL-6


What do cancer cachexia stain positive for?

UCP1 protein in WAT


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

Inhibition of WAT browning


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

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


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

Catecholaminergic surge


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

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


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

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