LAL (Lysosomal Acid Lipase) Promotes Reverse Cholesterol Transport In Vitro and In Vivo

Autor: Kristin Bowden, Teddy Chan, Hong Du, Gregory A. Grabowski, Gordon A. Francis, You-Hai Xu, Joshua A. Dubland
Rok vydání: 2018
Předmět:
Zdroj: Arteriosclerosis, Thrombosis, and Vascular Biology. 38:1191-1201
ISSN: 1524-4636
1079-5642
DOI: 10.1161/atvbaha.117.310507
Popis: Objective— To explore the role of LAL (lysosomal acid lipase) in macrophage cholesterol efflux and whole-body reverse cholesterol transport. Approach and Results— Immortalized peritoneal macrophages from lal −/− mice showed reduced expression of ABCA1 (ATP-binding cassette transporter A1) and ABCG1 (ATP-binding cassette transporter G1), reduced production of the regulatory oxysterol 27-hydroxycholesterol, and impaired suppression of cholesterol synthesis on exposure to acetylated low-density lipoprotein when compared with lal +/+ macrophages. LAL-deficient mice also showed reduced hepatic ABCG5 (ATP-binding cassette transporter G5) and ABCG8 (ATP-binding cassette transporter G8) expression compared with lal +/+ mice. LAL-deficient macrophages loaded with [ 3 H]-cholesteryl oleate-labeled acetylated low-density lipoprotein showed impaired efflux of released [ 3 H]-cholesterol to apoA-I (apolipoprotein A-I), with normalization of [ 3 H]-cholesteryl ester levels and partial correction of ABCA1 expression and cholesterol efflux to apoA-I when treated with exogenous rhLAL (recombinant human LAL protein). LAL-deficient mice injected intraperitoneally with lal −/− macrophages cholesterol loaded and labeled in the same way exhibited only 1.55±0.35% total injected [ 3 H]-cholesterol counts appearing in the feces for 48 h (n=30), compared with 5.38±0.92% in lal +/+ mice injected with labeled lal +/+ macrophages (n=27), P −/− macrophages into lal +/+ mice resulted in a significant increase in reverse cholesterol transport (2.60±0.46% of 3 H-cholesterol counts in feces at 48 hours [n=19]; P −/− mice). Conclusions— These results indicate a critical role for LAL in promoting both macrophage and whole-body reverse cholesterol transport and the ability of supplemental LAL to be taken up and correct reverse cholesterol transport in vivo.
Databáze: OpenAIRE