Diabetes and dyslipidemia: characterizing lipoprotein metabolism

Figures

• 

  Figure 1. Lipoprotein cascade. Notes: In the circulation, VLDL is gradually delipidated, resulting in increasingly smaller lipoprotein particles, ie, IDL, LDL, and small dense LDL. The intestinally derived chylomicron, characterized by presence of apoB48, is delipidated to form the chylomicron remnant, which is taken up by the liver. Abbreviations: HDL, high-density lipoprotein; IDL, intermediate-density lipoprotein; LDL, low-density lipoprotein; VLDL, very-low-density lipoprotein.

• 

  Figure 2. Metformin stimulates AMPK, which downregulates gluconeogenesis both directly and through downregulation of FoxO. Abbreviation: AMPK, adenosine monophosphate-activated protein kinase.

• 

  Figure 3. FGF 15/19 and FGF 21 have opposing effects on bile acid synthesis through their effect on Cyp7A1. Note: Glucagon, leptin, and insulin increase FGF 21, which increases adipose tissue UCP1. Cyp7A1 is also termed cholesterol 7a-hydroxylase. Abbreviation: FGF, fibroblast growth factor.

• 

  Figure 4. Effect of FoxO1 on adipocyte differentiation and mitochondrial function. Notes: FoxO is a regulator of glucose metabolism, lipid accumulation, and adipocyte differentiation. It also increases adipocyte browning and interacts with Tfeb to regulate UCPs 1, 2, and 3. Abbreviation: Tfeb, transcription factor EB.

• 

  Figure 5. Cholesterol absorption and chylomicron assembly and breakdown. Notes: Diacylglycerol is formed from free fatty acids under the influence of DGAT-1. Dietary cholesterol uptake from the intestine into the lymph is regulated by NPC1L1. ApoB48 is synthesized in the intestine. Triglyceride, cholesterol, and apoB48 are combined under the influence of MTP to form the chylomicron. In the circulation, the chylomicron is delipidated by LPL and cleared by the liver. Abbreviations: DGAT, diglyceride acyltransferase; LPL, lipoprotein lipase.