Plasma and adipose tissue level of angiopoietin-like 7 (ANGPTL7) are increased in obesity and reduced after physical exercise

Abstract

ObjectiveANGPTL7 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.MethodsA 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.ResultsIn 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).ConclusionIn 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.

Rare protein-altering variants in ANGPTL7 lower intraocular pressure and protect against glaucoma

“…Recent studies have associated ANGPTL proteins with cardiometabolic phenotypes [26][27][28][29][30]. Although it has been proposed that ANGPTL7 levels are increased in obesity (and reduced after physical exercise), we do not observe any evidence of genetic association in either UK Biobank or FinnGen to support this hypothesis [31].…”

Increased Plasma Levels of Adenylate Cyclase 8 and cAMP Are Associated with Obesity and Type 2 Diabetes: Results from a Cross-Sectional Study

“…Glycated hemoglobin (HbA1c) was measured using the Variant TM device (Bio-Rad, Hercules, CA, USA). Insulin resistance was assessed using the homeostatic model assessment of insulin resistance (HOMA-IR) formula(FPG [mmol/L] × fasting insulin [mU/L]/22.5), as previously described [ 46 ].…”

Tissue-Specific Epigenetics of Atherosclerosis-Related ANGPT and ANGPTL Genes

“…Their encoded proteins have roles in lipid deposition in the aorta, vascular growth, vessel permeability and remodeling, vascular inflammation, neovascularization and plaque destabilization during disease progression [6,7,9,10]. Two of the ANGPT/ANGPTL genes, ANGPTL6 and ANGPTL7 [6], are associated with obesity, a risk factor for atherosclerosis [11,12].…”