High plasma LDL cholesterol (LDL-c) concentration is a major risk factor for atherosclerosis. Hepatic LDL receptor (LDLR) regulates LDL metabolism, and thereby plasma LDL-c concentration. Recently, we have identified the (pro)renin receptor [(P)RR] as a novel regulator of LDL metabolism, which regulates LDLR degradation and hence its protein abundance and activity. In silico analysis suggests that the (P)RR is a target of miR-148a. In this study we determined whether miR-148a could regulate LDL metabolism by regulating (P)RR expression in HepG2 and Huh7 cells. We found that miR-148a suppressed (P)RR expression by binding to the 3’-untranslated regions (3’-UTR) of the (P)RR mRNA. Mutating the binding sites for miR-148a in the 3’-UTR of (P)RR mRNA completely abolished the inhibitory effects of miR-148a on (P)RR expression. In line with our recent findings, reduced (P)RR expression resulted in decreased cellular LDL uptake, likely as a consequence of decreased LDLR protein abundance. Overexpressing the (P)RR prevented miR-148a-induced reduction in LDLR abundance and cellular LDL uptake. Our study supports a new concept that miR-148a is a regulator of (P)RR expression. By reducing (P)RR abundance, miR-148a decreases LDLR protein abundance and consequently cellular LDL uptake.
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This work is supported by National Natural Science Foundation of China (grant no. 81870605, 81800383, 81500667) and Shenzhen Municipal Science and Technology Innovation Council (grant no. JCYJ20160307160819191).
Wang, Na; He, Lishu; Lin, Hui; Tan, Lunbo; Sun, Yuan; Zhang, Xiaoying; Danser, A. H. Jan; Lu, Hong S.; He, Yongcheng; and Lu, Xifeng, "MicroRNA-148a Regulates Low-Density Lipoprotein Metabolism by Repressing the (Pro)renin Receptor" (2020). Saha Cardiovascular Research Center Faculty Publications. 45.
S1 Fig. Small interfering RNA targeting 3’-UTR regions of human LDLR effectively reduces luciferase activity. https://doi.org/10.1371/journal.pone.0225356.s001
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S2 Fig. MiR-148a does not affect LDLR and ABCA1 expression under lipid-deficient condition. https://doi.org/10.1371/journal.pone.0225356.s002
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S3 Fig. MiR-148b regulates (P)RR expression by targeting its 3’-UTR sequences. https://doi.org/10.1371/journal.pone.0225356.s003
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S4 Fig. MiR-148a reduces SORT1 protein abundance but does not affect its transcript levels. https://doi.org/10.1371/journal.pone.0225356.s004
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S5 Fig. https://doi.org/10.1371/journal.pone.0225356.s005
pone.0225356.s006.docx (14 kB)
S1 Table. List of miRNA, siRNA and primers used in the current study. https://doi.org/10.1371/journal.pone.0225356.s006