title: 3,5,3'-Triiodo-L-Thyronine- and 3,5-Diiodo-L-Thyronine- Affected Metabolic Pathways in Liver of LDL Receptor Deficient Mice.
abstract: 3,5,3'-triiodo-L-thyronine (T3) and 3,5-diiodo-L-thyronine (T2), when administered to a model of familial hypercholesterolemia, i.e., low density lipoprotein receptor (LDLr)-knockout (Ldlr-/-)mice fed with a Western type diet (WTD), dramatically reduce circulating total and very low-density lipoprotein/LDL cholesterol with decreased liver apolipoprotein B (ApoB) production. The aim of the study was to highlight putative molecular mechanisms to manage cholesterol levels in the absence of LDLr. A comprehensive comparative profiling of changes in expression of soluble proteins in livers fromLdlr-/-mice treated with either T3 or T2 was performed. From a total proteome of 450 liver proteins, 25 identified proteins were affected by both T2 and T3, 18 only by T3 and 9 only by T2. Usingin silicoanalyses, an overlap was observed with 11/14 pathways common to both iodothyronines, with T2 and T3 preferentially altering sub-networks centered around hepatocyte nuclear factor 4 α (HNF4α) and peroxisome proliferator-activated receptor α (PPARα), respectively. Both T2 and T3 administration significantly reduced nuclear HNF4α protein content, while T2, but not T3, decreased the expression levels of the HNFα transcriptional coactivator PGC-1α. Lower PPARα levels were found only following T3 treatment while both T3 and T2 lowered liver X receptor α (LXRα) nuclear content. Overall, this study, although it was not meant to investigate the use of T2 and T3 as a therapeutic agent, provides novel insights into the regulation of hepatic metabolic pathways involved in T3- and T2-driven cholesterol reduction inLdlr-/-mice.
authors.affiliation: Department of Science and Technologies, University of Sannio Benevento, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Moreno
authors.affiliation: Department of Science and Technologies, University of Sannio Benevento, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Silvestri
authors.affiliation: Department of Science and Technologies, University of Sannio Benevento, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Coppola
authors.affiliation: Department of Medicine, Columbia University New York, NY, USA.
authors.forename: Ira J
authors.initials: IJ
authors.lastname: Goldberg
authors.affiliation: Department of Medicine, Columbia University New York, NY, USA.
authors.forename: Li-Shin
authors.initials: LS
authors.lastname: Huang
authors.affiliation: Proteomics and Mass Spectrometry Laboratory, Instituto per Il Sistema Produzione Animale in Ambiente Mediterraneo, National Research Council Napoli, Italy.
authors.forename: Anna M
authors.initials: AM
authors.lastname: Salzano
authors.affiliation: Biogem s.c.a r.l., Ariano Irpino (AV) Italy.
authors.forename: Fulvio
authors.initials: F
authors.lastname: D'Angelo
authors.affiliation: Department of Medicine, Intermountain Healthcare Salt Lake City, UT, USA.
authors.forename: Joel R
authors.initials: JR
authors.lastname: Ehrenkranz
authors.affiliation: Department of Science and Technologies, University of Sannio Benevento, Italy.
authors.forename: Fernando
authors.initials: F
authors.lastname: Goglia
keywords: LDL receptor; cholesterol; iodothyronines; liver; proteomics