Bell Thomas A, Brown J Mark, Graham Mark J, Lemonidis Kristina M, Crooke Rosanne M, Rudel Lawrence L
Department of Pathology, Section on Lipid Sciences, Wake Forest University Health Sciences, Medical Center Blvd, Winston-Salem, NC 27157, USA.
Arterioscler Thromb Vasc Biol. 2006 Aug;26(8):1814-20. doi: 10.1161/01.ATV.0000225289.30767.06. Epub 2006 May 4.
The purpose of this study was to determine the effects of liver-specific inhibition of acyl-coenzyme A:cholesterol acyltransferase 2 (ACAT2) on the development of hypercholesterolemia and atherosclerosis in mice.
Apolipoprotein B100-only low-density lipoprotein (LDL) receptor-/- mice were given saline, a nontargeting control antisense oligonucleotide (ASO), or ASOs targeting ACAT2 biweekly for a period spanning 16 weeks. Mice treated with ACAT2 targeting ASOs had liver-specific reduction in ACAT2 mRNA, yet intestinal ACAT2 and cholesterol absorption was left undisturbed. ASO-mediated knockdown of ACAT2 resulted in reduction of total plasma cholesterol, increased levels of plasma triglyceride, and a shift in LDL cholesteryl ester (CE) fatty acid composition from mainly saturated and monounsaturated to polyunsaturated fatty acid enrichment. Furthermore, the liver-specific depletion of ACAT2 resulted in protection against diet-induced hypercholesterolemia and aortic CE deposition. This is the first demonstration that specific pharmacological inhibition of ACAT2, without affecting ACAT1, is atheroprotective.
Hepatic ACAT2 plays a critical role in driving the production of atherogenic lipoproteins, and therapeutic interventions, such as the ACAT2-specific ASOs used here, which reduce acyltransferase 2 (ACAT2) function in the liver without affecting ACAT1, may provide clinical benefit for cardiovascular disease prevention.
本研究旨在确定肝脏特异性抑制酰基辅酶A:胆固醇酰基转移酶2(ACAT2)对小鼠高胆固醇血症和动脉粥样硬化发展的影响。
仅载脂蛋白B100的低密度脂蛋白(LDL)受体基因敲除小鼠每两周接受一次生理盐水、非靶向对照反义寡核苷酸(ASO)或靶向ACAT2的ASO,持续16周。用靶向ACAT2的ASO处理的小鼠肝脏中ACAT2 mRNA特异性降低,但肠道ACAT2和胆固醇吸收未受影响。ASO介导的ACAT2敲低导致总血浆胆固醇降低、血浆甘油三酯水平升高,且LDL胆固醇酯(CE)脂肪酸组成从主要为饱和脂肪酸和单不饱和脂肪酸转变为多不饱和脂肪酸富集。此外,ACAT2的肝脏特异性缺失可预防饮食诱导的高胆固醇血症和主动脉CE沉积。这是首次证明在不影响ACAT1的情况下,对ACAT2进行特异性药理抑制具有抗动脉粥样硬化作用。
肝脏ACAT2在驱动致动脉粥样硬化脂蛋白的产生中起关键作用,像本文所用的ACAT2特异性ASO这样的治疗干预措施,可在不影响ACAT1的情况下降低肝脏中酰基转移酶2(ACAT2)的功能,可能为预防心血管疾病带来临床益处。