Abu-Farha Mohamed, Cherian Preethi, Al-Khairi Irina, Madhu Dhanya, Tiss Ali, Warsam Samia, Alhubail Asma, Sriraman Devarajan, Al-Refaei Faisal, Abubaker Jehad
Biochemistry and Molecular Biology Unit Dasman Diabetes Institute, Kuwait City, Kuwait.
Clinical Services Department; Dasman Diabetes Institute, Kuwait City, Kuwait.
PLoS One. 2017 Mar 6;12(3):e0173024. doi: 10.1371/journal.pone.0173024. eCollection 2017.
ANGPTL7 is a member of the Angiopoietin-like (ANGPTL) protein family that is composed of eight proteins (1-8). Increasing evidence is associating ANGPTL proteins to obesity and insulin resistance. The biological role of ANGPTL7 is yet to be understood except for a recently proposed role in the pathophysiology of glaucoma. This study was designed to shed light on the function of ANGPTL7 in obesity and its modulation by physical exercise as well as its potential association with lipid profile.
A total of 144 subjects were enrolled in this study and finished three months of physical exercise. The participants were classified based on their BMI, 82 subjects were non-obese and 62 obese. ANGPTL7 levels in plasma and adipose tissue were measured by ELISA, RT-PCR and immunohistochemistry.
In this study, we showed that ANGPTL7 level was increased in the plasma of obese subjects (1249.05± 130.39 pg/mL) as compared to non-obese (930.34 ± 87.27 pg/mL) (p-Value = 0.032). ANGPTL7 Gene and protein expression levels in adipose tissue also showed over two fold increase. Physical exercise reduced circulating level of ANGPTL7 in the obese subjects to 740.98± 127.18 pg/mL, (p-Value = 0.007). ANGPTL7 expression in adipose tissue was also reduced after exercise. Finally, ANGPTL7 circulating level showed significant association with TG level in the obese subjects (R2 = 0.183, p-Value = 0.03).
In conclusion, our data shows for the first time that obesity increases the level of ANGPTL7 in both plasma and adipose tissue. Increased expression of ANGPTL7 might play a minor role in the regulation of TG level in obese subjects either directly or through interaction with other ANGPTL protein members. Physical exercise reduced the level of ANGPTL7 highlighting the potential for targeting this protein as a therapeutic target for regulating dyslipidemia.
血管生成素样蛋白7（ANGPTL7）是血管生成素样（ANGPTL）蛋白家族的成员之一，该家族由8种蛋白质（1 - 8）组成。越来越多的证据表明ANGPTL蛋白与肥胖和胰岛素抵抗有关。除了最近提出的在青光眼病理生理学中的作用外，ANGPTL7的生物学作用尚不清楚。本研究旨在阐明ANGPTL7在肥胖中的功能、体育锻炼对其的调节作用以及它与血脂谱的潜在关联。
本研究共招募了144名受试者，并进行了为期三个月的体育锻炼。参与者根据体重指数（BMI）进行分类，82名受试者非肥胖，62名肥胖。采用酶联免疫吸附测定（ELISA）、逆转录聚合酶链反应（RT-PCR）和免疫组织化学方法检测血浆和脂肪组织中ANGPTL7的水平。
在本研究中，我们发现肥胖受试者血浆中ANGPTL7水平（1249.05±130.39 pg/mL）高于非肥胖受试者（930.34±87.27 pg/mL）（p值 = 0.032）。脂肪组织中ANGPTL7基因和蛋白表达水平也显示出两倍以上的增加。体育锻炼使肥胖受试者循环中的ANGPTL7水平降至740.98±127.18 pg/mL（p值 = 0.007）。运动后脂肪组织中ANGPTL7的表达也降低。最后，肥胖受试者中ANGPTL7循环水平与甘油三酯（TG）水平呈显著相关性（R2 = 0.183，p值 = 0.03）。
总之，我们的数据首次表明肥胖会增加血浆和脂肪组织中ANGPTL7的水平。ANGPTL7表达增加可能在肥胖受试者中甘油三酯水平的调节中直接或通过与其他ANGPTL蛋白成员相互作用发挥次要作用。体育锻炼降低了ANGPTL7水平，突出了将该蛋白作为调节血脂异常治疗靶点的潜力。
