OBJECTIVE: Our recent studies identified berberine (BBR) as a novel cholesterol-lowering drug that upregulates low-density lipoprotein (LDL) receptor expression through mRNA stabilization. Here, we investigated mechanisms underlying regulatory effects of BBR on LDL receptor (LDLR) messenger. METHODS AND RESULTS: We show that the extracellular signal-regulated kinase (ERK) signaling pathway is used primarily by BBR to attenuate the decay of LDLR mRNA in HepG2 cells. Using different reporter constructs, we demonstrate that BBR affects LDLR mRNA stability entirely through 3' untranslated region (UTR) in an ERK-dependent manner, and this stabilizing effect is more prominent in liver-derived cells than nonhepatic cell lines. In contrast to BBR, the mRNA stabilizing effect of bile acid chenodeoxycholic acid is mediated through the LDLR coding sequence, whereas the 5'UTR, 3'UTR, and the coding sequence of LDLR mRNA are all implicated in the action of phorbol 12-myristate 13-acetate. By performing UV cross-linking and SDS-PAGE, we identify 2 cytoplasmic proteins of 52 and 42 kDa that specifically bind to the LDLR 3'UTR in BBR-inducible and ERK-dependent manners. CONCLUSIONS: These new findings demonstrate that the BBR-induced stabilization of LDLR mRNA is mediated by the ERK signaling pathway through interactions of cis-regulatory sequences of 3'UTR and mRNA binding proteins that are downstream effectors of this signaling cascade.
OBJECTIVE: Our recent studies identified berberine (BBR) as a novel cholesterol-lowering drug that upregulates low-density lipoprotein (LDL) receptor expression through mRNA stabilization. Here, we investigated mechanisms underlying regulatory effects of BBR on LDL receptor (LDLR) messenger. METHODS AND RESULTS: We show that the extracellular signal-regulated kinase (ERK) signaling pathway is used primarily by BBR to attenuate the decay of LDLR mRNA in HepG2 cells. Using different reporter constructs, we demonstrate that BBR affects LDLR mRNA stability entirely through 3' untranslated region (UTR) in an ERK-dependent manner, and this stabilizing effect is more prominent in liver-derived cells than nonhepatic cell lines. In contrast to BBR, the mRNA stabilizing effect of bile acid chenodeoxycholic acid is mediated through the LDLR coding sequence, whereas the 5'UTR, 3'UTR, and the coding sequence of LDLR mRNA are all implicated in the action of phorbol 12-myristate 13-acetate. By performing UV cross-linking and SDS-PAGE, we identify 2 cytoplasmic proteins of 52 and 42 kDa that specifically bind to the LDLR 3'UTR in BBR-inducible and ERK-dependent manners. CONCLUSIONS: These new findings demonstrate that the BBR-induced stabilization of LDLR mRNA is mediated by the ERK signaling pathway through interactions of cis-regulatory sequences of 3'UTR and mRNA binding proteins that are downstream effectors of this signaling cascade.
Authors: Steve Poirier; Samaneh Samami; Maya Mamarbachi; Annie Demers; Ta Yuan Chang; Dennis E Vance; Grant M Hatch; Gaétan Mayer Journal: J Biol Chem Date: 2014-05-22 Impact factor: 5.157
Authors: Bin Dong; Minhao Wu; Hai Li; Fredric B Kraemer; Khosrow Adeli; Nabil G Seidah; Sahng Wook Park; Jingwen Liu Journal: J Lipid Res Date: 2010-01-04 Impact factor: 5.922
Authors: Arrigo F G Cicero; Alessandro Colletti; Gani Bajraktari; Olivier Descamps; Dragan M Djuric; Marat Ezhov; Zlatko Fras; Niki Katsiki; Michel Langlois; Gustavs Latkovskis; Demosthenes B Panagiotakos; Gyorgy Paragh; Dimitri P Mikhailidis; Olena Mitchenko; Bernhard Paulweber; Daniel Pella; Christos Pitsavos; Željko Reiner; Kausik K Ray; Manfredi Rizzo; Amirhossein Sahebkar; Maria-Corina Serban; Laurence S Sperling; Peter P Toth; Dragos Vinereanu; Michal Vrablík; Nathan D Wong; Maciej Banach Journal: Arch Med Sci Date: 2017-08-04 Impact factor: 3.318
Authors: Hai Li; Wei Chen; Yue Zhou; Parveen Abidi; Orr Sharpe; William H Robinson; Fredric B Kraemer; Jingwen Liu Journal: J Lipid Res Date: 2009-01-13 Impact factor: 5.922