Adipose tissue and adipogenesis Flashcards
What is the most widely used mammalian model
mouse
What are knock out mice
Mice with a disrupted gene in order to study the effects
Is there a change in fat cell number or size?
Both fat cell number and size increase in response to store excess energy as TG
What are stem cells
Undifferentiated cells that can become specialized cell types
Stage of adipogenesis
Stem cell gets signal to become adipoblasts, then gets signal to become a pre-adipocyte.
Once PPARy is released and incresases, the pre-adipocyte will begin the slow accumulation of lipid to differentiate into a mature adipocyte. PPARy is a switch to start the differentiation
What is PPARy
Master regulator of adipogenesis
What do peroxisomes have to do with adipocytes
PPAR controls peroxisomal proliferation
Mechanism of PPARy
PPARy becomes a heterodimer with RxR (RxR is bound to retinoic acid). it then binds to PPRE
What does the binding of PPRE activate
Glucose uptake, lipid metabolism, and adipocyte differentiation
What is rosiglitazone
Lowers blood glucose
insulin sensitizer
PPARy agonist
WHat happens in mice without PPARy
No white adipose tissue, have a fatty liver
what is the other role of adipose tissue besides energy storage
It is also an endocrine organ regulating many bodily functions.
Creates Leptin
What is Leptin
Obesity gene
suppresses appetite
if two mice were joined so they share blood circulation and specific regions of the hypothalamus were destroyed in the lesioned obese mouse. Explain why the un-lesioned mouse died of starvation
A satiety factor was produced by the lesioned mouse as body fat accumulated.
The lesioned mouse was insensitive to the factor due to the destroyed hypothalamus. The other mouse would not eat and died.
What is Leptin
Hormone produced by adipose tissue.
suppresses appetite and inceases energy expenditure
