Enhancing Apolipoprotein A-I-dependent Cholesterol Efflux Elevates Cholesterol Export from Macrophages in Vivo
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Eight proteins potentially involved in cholesterol efflux [ABCA1, ABCG1, CYP27A1, phospholipid transfer protein (PLTP), scavenger receptor type BI (SR-BI), caveolin-1, cholesteryl ester transfer protein, and apolipoprotein A-I (apoA-I)] were overexpressed alone or in combination in RAW 264.7 macrophages. When apoA-I was used as an acceptor, overexpression of the combination of ABCA1, CYP27A1, PLTP, and SR-BI (Combination I) enhanced the efflux by 4.3-fold. It was established that the stimulation of efflux was due to increased abundance of ABCA1 and increased apoA-I binding to non-ABCA1 sites on macrophages. This combination caused only a small increase of the efflux to isolated HDL. When HDL was used as an acceptor, overexpression of caveolin-1 or a combination of caveolin-1 and SR-BI (Combination II) was the most active, doubling the efflux to HDL, without affecting the efflux to apoA-I. When tested in the in vivo mouse model of cholesterol efflux, overexpression of ABCA1 and Combination I elevated cholesterol export from macrophages to plasma, liver, and feces, whereas overexpression of caveolin-1 or Combination II did not have an effect. We conclude that pathways of cholesterol efflux using apoA-I as an acceptor make a predominant contribution to cholesterol export from macrophages in vivo.
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Hong B, Zheng J, Zivkovic A Int J Mol Sci. 2023; 24(20).
PMID: 37894984 PMC: 10607703. DOI: 10.3390/ijms242015305.
Zurkinden L, Sviridov D, Vogt B, Escher G Front Endocrinol (Lausanne). 2020; 11:586980.
PMID: 33193099 PMC: 7656987. DOI: 10.3389/fendo.2020.586980.
Low H, Mukhamedova N, Capettini L, Xia Y, Carmichael I, Cody S Arterioscler Thromb Vasc Biol. 2020; 40(10):2346-2359.
PMID: 32787522 PMC: 7530101. DOI: 10.1161/ATVBAHA.120.315037.
Mukhamedova N, Hoang A, Dragoljevic D, Dubrovsky L, Pushkarsky T, Low H PLoS Pathog. 2019; 15(7):e1007907.
PMID: 31344124 PMC: 6657916. DOI: 10.1371/journal.ppat.1007907.