Association of angiopoietin-like protein 3 ( ANGPTL 3 ) with HTGL and LPL activities in human plasma

Background: The relationship between plasma angiopoietin-like protein 3 (ANGPTL3), and lipoprotein lipase (LPL) activity and hepatic triglyceride lipase (HTGL) activity has not been investigated in the metabolism of remnant lipoproteins and HDL. Methods: Angiopoietin-like protein-3 (ANGPTL3), LPL activity, HTGL activity, remnant lipoproteins (RLP-C & RLP-TG), small dense LDL-Cholesterol (sd LDL-C) were measured in 20 overweight and obese subjects in the fasting and postprandial state. Results: Plasma TG, RLP-C, RLP-TG and sd LDL-C were inversely correlated with LPL activity both in the fasting and postprandial state, but not correlated with HTGL activity and ANGPTL3. However, plasma HDL-C was positively correlated with LPL activity both in the fasting and postprandial state, while inversely correlated with HTGL activity. ANGPTL3 was inversely correlated with HTGL activity both in the fasting and postprandial state, but not correlated with LPL activity. .Conclusion: Plasma remnant lipoproteins and sdLDL-C were inversely correlated with LPL activity but not correlated with HTGL activity and ANGPTL3, indicating that LPL, but not HTGL, plays a major role in the metabolism of remnant lipoproteins including small dense LDL. However, HDL-C was inversely correlated with HTGL activity and positively correlated with ANGPTL3, indicating that HTGL plays a major role in HDL metabolism but not remnant lipoprotein metabolism. These findings suggest that ANGPTL3 is strongly associated with the inhibition of HTGL activity and regulates HDL metabolism, but not associated with the inhibition of LPL activity for the metabolism of remnant lipoproteins in human plasma..