摘　要：动脉粥样硬化是一种慢性炎症疾病，是由于机体内脂质代谢异常从而导致富含胆固醇的脂蛋白在动脉壁中大量积累，进而造成动脉壁增厚、变硬、弹性减退和管腔狭窄的病理改变。据报道，低剂量弱激光疗法（LDLT）具有保护心血管的作用，但其发挥作用的机制尚未明确。本研究旨在探索LDLT是否可以延缓动脉粥样硬化疾病的发展。用高脂饮食（HFD）诱导载脂蛋白E缺失（ApoE–/–）的小鼠18周，以形成血管动脉粥样硬化斑块病变，在HFD诱导的后10周里每日对小鼠进行LDLT处理。处理结束后，取小鼠的主动脉、心脏和肝脏等组织进行组织学染色和聚合酶链式反应（PCR）试验，以判断小鼠动脉粥样硬化病情的发展变化。试验结果显示：相比对照组小鼠，LDLT处理后的小鼠主动脉斑块面积更小，同时肝脏内脂质沉积也更少；另外，实时荧光定量PCR（RT-qPCR）试验结果显示，LDLT处理显著下调肝脏中参与胆固醇合成的甾醇调节元件结合转录因子2（Srebp2）和3-羟基-3-甲基戊二酰辅酶A还原酶（Hmgcr）的基因的表达。这些试验结果说明LDLT可以改善机体脂质代谢从而对动脉粥样硬化疾病具有改善作用。
关键字：低剂量弱激光疗法；动脉粥样硬化；斑块；脂质代谢；小鼠模型
中图分类号：Q631　　　　　　文献标志码：ADOI：10.3969/j.issn.1007-7146.2022.01.003

Abstract: Atherosclerosis is a chronic inflammatory disease, which is due to abnormal lipid metabolism in the body that causes excessive cholesterol-rich lipoproteins to accumulate in the arterial wall, resulting in thickening and hardening of arterial wall, decreasing its elasticity and lumen stenosis. Low-dose laser therapy (LDLT) has been reported to possess cardioprotective effects whereas there is no consensus on the underlying mechanisms. This study aimed to explore whether LDLT could ameliorate atherosclerosis and explore the potential molecular mechanisms. ApoE-/- mice were fed with a high-fat diet (HFD) for 18 weeks to develop atherosclerotic lesions, and were treated with LDLT daily in the last 10 weeks. After the treatment, the aorta, heart, liver and other tissues of the mice were taken for histological staining and polymerase chain reaction (PCR) to determine the development of atherosclerosis in the mice. The experimental results showed that the LDLT-treated mice had a smaller aortic plaque area and less lipid deposits in liver than the control mice did. In addition, the results of real time quantitative PCR (RT-qPCR) showed that LDLT treatment significantly downregulated the expression of sterol regulatory element-binding protein 2 (Srebp2) and 3-hydroxy-3-methylglutaryl CoA reductase (Hmgcr), which were involved in liver cholesterol synthesis. These results indicated that LDLT could improve the body’s lipid metabolism and has a protective effect on cardiovascular diseases.
Key words: low-dose laser therapy; atherosclerosis; plaque; lipid metabolisim; mouse model
（Acta Laser Biology Sinica, 2022, 31(1): 012-018）