Conclusion
High intakes of dietary SFAs and fructose might induce dysregulations in the cholesterol synthesis and blood lipoprotein levels via proposed nutrient-sensitive biomarkers PCSK9 and CD36 in liver and extrahepatic tissues involved in cholesterol homeostasis.
Methods
Forty male C57 BL/6 mice (8 wks of age) were divided into four groups and fed ad libitum with standard chow or three isocaloric diets containing high SFAs (SFA group), monounsaturated fatty acids (MUFA group, vehicle), or fructose for 15 wks. Subsequently, mice were sacrificed and blood, liver, and heart were collected for further analysis.
Results
Consequently, fructose or SFA intake resulted in higher plasma and liver total cholesterol (TC) levels, plasma low-density lipoprotein cholesterol (LDL-C), non-high-density lipoprotein cholesterol (HDL-C), apolipoprotein (Apo)-B levels, TC/HDL-C, and LDL-C/HDL-C ratios, and lower plasma levels of HDL-C and Apo-A1 (P < 0.05). Levels of 3-hydroxy-3-methylglutaryl-CoA reductase and acetyl-CoA acetyltransferase 1 enzymes in liver and CD36 levels in plasma were elevated by high SFAs and fructose intake (P < 0.05), whereas plasma PCSK9 levels were not significantly changed. Fructose and SFA intake increased PCSK9 and CD36 levels in the heart, along with increased CD36 levels in the liver (P < 0.05). Furthermore, plasma LDL-C was found to be positively correlated with liver PCSK9 (r = 0.85, P = 0.02), and CD36 (r = 0.70, P = 0.02) in the SFA and fructose groups.