MiR-33 contributes to the regulation of cholesterol homeostasis

KJ Rayner, Y Suárez, A Dávalos, S Parathath… - science, 2010 - science.org
KJ Rayner, Y Suárez, A Dávalos, S Parathath, ML Fitzgerald, N Tamehiro, EA Fisher
science, 2010science.org
Cholesterol metabolism is tightly regulated at the cellular level. Here we show that miR-33,
an intronic microRNA (miRNA) located within the gene encoding sterol-regulatory element–
binding factor–2 (SREBF-2), a transcriptional regulator of cholesterol synthesis, modulates
the expression of genes involved in cellular cholesterol transport. In mouse and human
cells, miR-33 inhibits the expression of the adenosine triphosphate–binding cassette (ABC)
transporter, ABCA1, thereby attenuating cholesterol efflux to apolipoprotein A1. In mouse …
Cholesterol metabolism is tightly regulated at the cellular level. Here we show that miR-33, an intronic microRNA (miRNA) located within the gene encoding sterol-regulatory element–binding factor–2 (SREBF-2), a transcriptional regulator of cholesterol synthesis, modulates the expression of genes involved in cellular cholesterol transport. In mouse and human cells, miR-33 inhibits the expression of the adenosine triphosphate–binding cassette (ABC) transporter, ABCA1, thereby attenuating cholesterol efflux to apolipoprotein A1. In mouse macrophages, miR-33 also targets ABCG1, reducing cholesterol efflux to nascent high-density lipoprotein (HDL). Lentiviral delivery of miR-33 to mice represses ABCA1 expression in the liver, reducing circulating HDL levels. Conversely, silencing of miR-33 in vivo increases hepatic expression of ABCA1 and plasma HDL levels. Thus, miR-33 appears to regulate both HDL biogenesis in the liver and cellular cholesterol efflux.
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