👤 Ulrike S Trampisch

Angiopoietin-like protein 8 (ANGPTL8) forms complexes with ANGPTL3 and ANGPTL4 to regulate lipoprotein lipase (LPL) activity, and decreased LPL activity is an established cardiovascular risk factor. Serum levels of ANGPTL4/8 and C-terminal domain-containing ANGPTL4 (CD-ANGPTL4) are positively associated with cardiovascular death, however, the underlying mechanisms remain incompletely understood. The present study investigated relationships of ANGPTL3, ANGPTL3/8, CD-ANGPTL4, and ANGPTL4/8 with coronary artery calcification (CAC) progression (using Agatston scores) and incident coronary events. ANGPTL3, ANGPTL3/8, CD-ANGPTL4, and ANGPTL4/8, were measured using dedicated immunoassays in participants of the Heinz Nixdorf Recall (HNR) study, an unselected, population-based cohort of subjects free from cardiovascular disease at baseline. CAC measurements were performed at baseline and after 5 years in 2887 participants, and there was follow-up for coronary events (median duration 18.8 years). Median Agatston scores increased over 5 years from 6.70 (t Associations of ANGPTL3 and ANGPTL3/8 with coronary atherosclerosis progression and incident coronary events were inconsistent, while CD-ANGPTL4 and ANGPTL4/8 were associated with both coronary atherosclerosis progression and incident coronary events. Associations of ANGPTL4/8 and CD-ANGPTL4 with cardiovascular events may reflect progression of coronary atherosclerosis conferred by diabetes, inflammation, or the potential intrinsic effects of CD-ANGPTL4 and ANGPTL4/8. Show less

ANGPTL3/4/8 (angiopoietin-like proteins 3, 4, and 8) are important regulators of LPL (lipoprotein lipase). ANGPTL8 forms complexes with ANGPTL3 and ANGPTL4. ANGPTL4/8 complex formation converts ANGPTL4 from a furin substrate to a plasmin substrate, and both cleavages generate similar C-terminal domain-containing (CD)-ANGPTL4 fragments. Whereas several studies have investigated associations of free ANGPTL proteins with cardiovascular risk, there are no data describing associations of the complexes and CD-ANGPTL4 with outcomes or describing the effects of the complexes on LPL bound to GPIHBP1 (glycosylphosphatidylinositol HDL-binding protein 1). Recombinant protein assays were used to study ANGPTL protein and complex effects on GPIHBP1-LPL activity. ANGPTL3/8, ANGPTL3, ANGPTL4/8, and CD-ANGPTL4 were measured with dedicated immunoassays in 2394 LURIC (Ludwigshafen Risk and Cardiovascular Health) study participants undergoing coronary angiography and 6188 getABI study (German Epidemiological Trial on Ankle Brachial Index) participants undergoing ankle brachial index measurement. There was a follow-up for cardiovascular death with a median (interquartile range) duration of 9.80 (8.75-10.40) years in the LURIC study and 7.06 (7.00-7.14) years in the getABI study. ANGPTL3/8 potently inhibited GPIHBP1-LPL activity and showed positive associations with LDL-C (low-density lipoprotein cholesterol) and triglycerides (both ANGPTL3/8 potently inhibited GPIHBP1-LPL enzymatic activity, consistent with its positive association with serum lipids. However, ANGPTL3/8, LDL-C, and triglyceride levels were not associated with cardiovascular death in the LURIC and getABI cohorts. In contrast, concentrations of ANGPTL4/8 and particularly CD-ANGPTL4 were positively associated with inflammation, the prevalence of diabetes, and cardiovascular mortality. Show less