Alterations of lipid metabolism, blood pressure and fatty liver in spontaneously hypertensive rats transgenic for human cholesteryl ester transfer protein

Cholesteryl ester transfer protein (CETP) mediates a step in reverse cholesterol transport, which channels cholesterol from peripheral tissues back to the liver. Mice and rats are CETP-deficient species, which assumedly contribute to rodent atherosclerosis resistance. Both pro- and anti-atherogenic effects have been shown in studies of CETP-transgenic rodent models thus far. As the results of pharmacological studies of CETP modification are largely controversial in humans, further knowledge about the impact of CETP on atherogenic phenotypes is required to evaluate its clinical utility for the prevention of cardiovascular and other organ damage associated with metabolic syndrome. Therefore, we newly generated a human CETP-transgenic (Tg[hCETP]) strain on the genetic background of spontaneously hypertensive rats (SHRs), which are characterized by the spontaneous occurrence of hypertension and insulin resistance. This allowed us to assess the in vivo role of CETP on cardiometabolic phenotypes in combination with hypertension. In Tg[hCETP] SHRs fed normal rat chow, systolic blood pressure was markedly elevated by 20–37 mmHg throughout the study period, and the development of fatty liver was accelerated with appreciable changes in the plasma lipid profile (HDL cholesterol reduction and triglyceride elevation). These phenotypic changes are in accordance with the assumption of proatherogenic effects inducible by the overexpression of CETP. However, with plasma LDL cholesterol levels concomitantly reduced, no apparent progression of atherosclerosis was detected in either the aorta or coronary arteries of Tg[hCETP] SHRs fed a high-fat, high-cholesterol diet. Our data provide new insight into the multifaceted regulation of cardiometabolic phenotypes via the modification of CETP.