Zheng Jiaxiang, Lee Jisu, Byun Jaemin, Yu Daeung, Ha Jung-Heun
Department of Food Science and Nutrition, Dankook University, Cheonan, Republic of Korea.
Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ, United States.
Front Nutr. 2023 Mar 16;10:1155436. doi: 10.3389/fnut.2023.1155436. eCollection 2023.
Metabolic syndrome (MetS) is considered as a complex, intertwined multiple risk factors that directly increase the risk of various metabolic diseases, especially cardiovascular atherosclerotic diseases and diabetes mellitus type 2. While lifestyle changes, including dietary intervention are effective in mitigating or preventing MetS, there are no specific therapies against MetS. Typical western diets comprise of high saturated fatty acid, cholesterol, and simple sugar; consequently their consumption may increase the potential pathological developmental risk of MetS. Partial replacement of dietary fatty acids with polyunsaturated fatty acids (PUFAs) is widely recommended measure to manage MetS-related disorders.
In the present study, we used rat model to investigate the role of -3 PUFA enriched beef tallows (BT) on MetS and tunicamycin (TM)-induced endoplasmic reticulum (ER) stress, by partially replacing dietary fat (lard) with equal amounts of two different BTs; regular BT or -3 PUFA-enriched BT. The experimental rats were randomly assigned to three different dietary groups ( = 16 per group): (1) high-fat and high-cholesterol diet (HFCD); (2) HFCD partially replaced with regular BT (HFCD + BT1); (3) HFCD partially replaced with -3 enhanced BT (w/w) (HFCD + BT2). After 10 weeks of dietary intervention, each experimental rodent was intraperitoneally injected with either phosphate-buffered saline or 1 mg/kg body weight of TM.
HFCD + BT2 showed improved dyslipidemia before TM injection, and increased serum high-density lipoprotein cholesterol (HDL-C) levels after TM injection. BT replacement groups had significantly reduced hepatic triglyceride (TG) levels, and decreased total cholesterol (TC) and TG levels in epididymal adipose tissue (EAT). Furthermore, BT replacement remarkably attenuated TM-induced unfolded protein responses (UPRs) in liver, showing reduced ER stress, with BT2 being more effective in the EAT.
Therefore, our findings suggest that partially replacing dietary fats with -3 PUFA to lower the ratio of -6/-3 PUFAs is beneficial in preventing pathological features of MetS by alleviating HFCD- and/or TM-induced dyslipidemia and ER stress.
代谢综合征（MetS）被认为是一种复杂的、相互交织的多种风险因素，直接增加了各种代谢性疾病的风险，尤其是心血管动脉粥样硬化疾病和2型糖尿病。虽然包括饮食干预在内的生活方式改变对减轻或预防代谢综合征有效，但目前尚无针对代谢综合征的特异性疗法。典型的西方饮食包含高饱和脂肪酸、胆固醇和单糖；因此，食用这些食物可能会增加代谢综合征潜在的病理发展风险。用多不饱和脂肪酸（PUFAs）部分替代膳食脂肪酸是广泛推荐的管理与代谢综合征相关疾病的措施。
在本研究中，我们使用大鼠模型，通过用等量的两种不同牛脂（BT）（普通BT或富含-3多不饱和脂肪酸的BT）部分替代膳食脂肪（猪油），研究富含-3多不饱和脂肪酸的牛脂对代谢综合征和衣霉素（TM）诱导的内质网（ER）应激的作用。将实验大鼠随机分为三个不同的饮食组（每组n = 16）：（1）高脂高胆固醇饮食（HFCD）；（2）用普通BT部分替代的HFCD（HFCD + BT1）；（3）用-3强化BT（重量/重量）部分替代的HFCD（HFCD + BT2）。经过10周的饮食干预后，给每只实验啮齿动物腹腔注射磷酸盐缓冲盐水或1 mg/kg体重的TM。
HFCD + BT2在注射TM前血脂异常得到改善，注射TM后血清高密度脂蛋白胆固醇（HDL-C）水平升高。BT替代组肝脏甘油三酯（TG）水平显著降低，附睾脂肪组织（EAT）中的总胆固醇（TC）和TG水平降低。此外，BT替代显著减轻了TM诱导的肝脏未折叠蛋白反应（UPR），显示内质网应激减轻，BT2在EAT中更有效。
因此，我们的研究结果表明，用-3多不饱和脂肪酸部分替代膳食脂肪以降低-6/-3多不饱和脂肪酸的比例，有利于通过减轻HFCD和/或TM诱导的血脂异常和内质网应激来预防代谢综合征的病理特征。
