Clinical review on triglycerides

Figure 1. Overview of triglyceride-rich lipoprotein metabolism focused on disease genes and drug targets. Triglyceride-rich lipoprotein assembly begins with triglyceride synthesis, which derive from fatty acids in the intestine from the diet or in the liver taken up from plasma, fatty acids released from lysosomes after breakdown of endocytosed triglyceride-rich lipoproteins, and fatty acids generated from glucose by de novo lipogenesis. A series of enzymes, culminating in tissue-specific isoforms of diacylglycerol acyltransferase in intestine and liver, produce triglyceride. Microsomal triglyceride transfer protein unites triglyceride, cholesterol, and phospholipids, with tissue-specific isoforms of apolipoprotein (apo) B, i.e. small B-48, shortened as a result of RNA editing in enterocytes and full-length B-100 in hepatocytes, forming chylomicrons and very-low-density lipoprotein, respectively. Chylomicrons formation also requires Sar1 homolog B GTPase (SAR1B gene product, not shown). Chylomicrons enter plasma indirectly through lymphatics while very-low-density lipoprotein is secreted directly into the circulation. Hydrolysis of circulating chylomicrons and very-low-density lipoprotein…