Lipids/obesity Flashcards
critical enzyme mediating the transfer of triglyceride to Apo B48
MTP (microsomal triglyceride transfer protein)
defect in MTP leads to what clinical problem
abetalipoproteinemia
defect in Apo B48 leads to what clinical problem
hypobetalipoproteinemia
lipoprotein of chylomicrons
Apo B48
lipoprotein of HDL
Apo A
where are chylomicrons formed
brush border intestinal cells
which enzyme clears chylomicrons from the blood
lipoprotein lipase
where is LPL located
capillary walls
lipoprotein activators of LPL
Apo CII
Apo A
lipoprotein inhibitors of LPL
Apo CIII
ANGPTL3/4
chylomicron remnants are cleared by binding to which receptors in the liver
LDL receptor
ligand for chylomicron remnant binding
Apo E
Familial chylomicronemia syndrome defect
LPL mutation
clinical features of Familial chylomicronemia syndrome
lipemia retinalis
eruptive xanthomas
treatment of Familial chylomicronemia syndrome
dietary fat restriction
Lipoprotein deficiency syndromes with hypertriglyceridemia (similar to FCS)
Apo CII deficiency
Apo A
(both are activators of LPL)
dysbetalipoproteinemia defect
Chylomicron remnant problem Apo E (E2/E2 genotype)
lipid panel phenotype of dysbetalipoproteinemia
elevations in both serum TG and cholesterol (300-500)
which lipid disorder causes palmar xanthomas
dysbetalipoproteinemia
treatment of dysbetalipoproteinemia
statin, fibrate niacin, secondary causes
lipid panel disorder in Familial Lipodystrophy
elevated TG
which apolipoprotein is used in endogenous VLDL production
Apo B100
which enzyme converts VLDL to LDL in the liver
Hepatic lipase
what is the ligand for LDL -LDL receptor
Apo B100
which protein binds to LDL receptor and prevents it from recycling
PCSK9
defect in FH
LDL receptor
defect in Familial defective apolipoprotein B
Apo B (cannot bind to LDL receptor)
defect in sitosterolemia
ABCG5 receptor
absorbs plant cytosterols inappropriately
how to diagnose sitosterolemia
check sitosterol levels
where does HDL pick up excess peripheral cholesterol
peripheral macrophages (foam cells)
what does LCAT enzyme do
makes mature HDL from nascent HDL molecules
hepatic receptor for HDL
SR-B1 (not may of these receptors, so HDL transfers cholesterol to VLDL/LDL particles)
which enzyme allows HDL to transfer cholesterol to VLDL/LDL particles
CETP
deficiency that causes very low HDL
Apolipoprotein A1 deficiency
defect in Tangier disease
ABCA1 on peripheral macrophages
HDL can’t pick up cholesterol from “foam cell”
LCAT deficiency
can’t form mature HDL
fish eye disease
CETP deficiency
mostly Japanese
high HDL > 100
CETP role in insulin resistance
1) transfers TG from VLDL to HDL particles
HDL particles then take up
leads to LOW HDL levels
2) transfers TG from VLDL to LDL and cholesterol from LDL to VLDL
results in small, dense LDL
treatment of pt with DM and partial familial lipodystrophy
metformin
pioglitizone
monogenic causes of obesity
melanocortin 4 receptor (MC4R) fat mass and obesity-associated gene (FTO) proopiomelanocortin gene (POMC) leptin deficiency (LEP) Prader-willi
monogenic obesity that starts early in life (3)
MC4R
POMC deficiency
Leptin deficiency
obese child with red hair, adrenal insufficiency
POMC deficiency
avg age of weight gain in FTO mutation
7
underweight infant with hypotonia, wt gain starting around age 5
Prader-Willi
role of Coenzyme Q10 in preventing statin-induced myalgias
doesn’t work (recent meta-analyses)
