MicroRNA and cholesterol homeostasis

Question 1

Why is LDL bad

Answer 1

It can become oxidized, leading to T-cell attack. This bloated T cell gets stuck under the endothelial lining of blood vessels, leading to blockage

Question 2

What is the substance that removes LDL?

Answer 2

HDL

Question 3

What is ABCA1?

Answer 3

Responsible for manufacturing HDL and reverse-cholesterol transport to the liver and bile ducts

Question 4

Define miR-33

Answer 4

• a negative regulator of cholesterol efflux and HDL
• targets proteins of reverse cholesterol transport
• srebf2 contains miR-33 in one of its introns

Question 5

What are the results of miR-33 downregulation

Answer 5

o Decreased lipids
o Decreased macrophage activity
o STABLE PLAQUE (more isn’t made)

Question 6

Define SREBF2 and its relation to miR-33

Answer 6

• SREBF2 is a regulator and sensor for cholesterol, and is involved in the metabolism of cholesterol
• An intron of this protein contains miR-33, a negative regualtor of cholesterol efflux
• thus, they are co-regulated