title: Modulators of hepatic lipoprotein metabolism identified in a search for small-molecule inducers of tribbles pseudokinase 1 expression.
abstract: Recent genome wide association studies have linked tribbles pseudokinase 1 (TRIB1) to the risk of coronary artery disease (CAD). Based on the observations that increased expression of TRIB1 reduces secretion of VLDL and is associated with lower plasma levels of LDL cholesterol and triglycerides, higher plasma levels of HDL cholesterol and reduced risk for myocardial infarction, we carried out a high throughput phenotypic screen based on quantitative RT-PCR assay to identify compounds that induce TRIB1 expression in human HepG2 hepatoma cells. In a screen of a collection of diversity-oriented synthesis (DOS)-derived compounds, we identified a series of benzofuran-based compounds that upregulate TRIB1 expression and phenocopy the effects of TRIB1 cDNA overexpression, as they inhibit triglyceride synthesis and apoB secretion in cells. In addition, the compounds downregulate expression of MTTP and APOC3, key components of the lipoprotein assembly pathway. However, CRISPR-Cas9 induced chromosomal disruption of the TRIB1 locus in HepG2 cells, while confirming its regulatory role in lipoprotein metabolism, demonstrated that the effects of benzofurans persist in TRIB1-null cells indicating that TRIB1 is sufficient but not necessary to transmit the effects of the drug. Remarkably, active benzofurans, as well as natural products capable of TRIB1 upregulation, also modulate hepatic cell cholesterol metabolism by elevating the expression of LDLR transcript and LDL receptor protein, while reducing the levels of PCSK9 transcript and secreted PCSK9 protein and stimulating LDL uptake. The effects of benzofurans are not masked by cholesterol depletion and are independent of the SREBP-2 regulatory circuit, indicating that these compounds represent a novel class of chemically tractable small-molecule modulators that shift cellular lipoprotein metabolism in HepG2 cells from lipogenesis to scavenging.
authors: Therapeutics Platform, Center for the Science of Therapeutics, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America.
authors: Marek M
authors: MM
authors: Nagiec
authors: Therapeutics Platform, Center for the Science of Therapeutics, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America.
authors: Adam P
authors: AP
authors: Skepner
authors: Therapeutics Platform, Center for the Science of Therapeutics, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America.
authors: Joseph
authors: J
authors: Negri
authors: Therapeutics Platform, Center for the Science of Therapeutics, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America.
authors: Michelle
authors: M
authors: Eichhorn
authors: Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts, United States of America.
authors: Nicolas
authors: N
authors: Kuperwasser
authors: Therapeutics Platform, Center for the Science of Therapeutics, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America.
authors: Eamon
authors: E
authors: Comer
authors: Therapeutics Platform, Center for the Science of Therapeutics, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America.
authors: Giovanni
authors: G
authors: Muncipinto
authors: Cancer Program, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America.
authors: Aravind
authors: A
authors: Subramanian
authors: Metabolite Profiling Platform, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America.
authors: Clary
authors: C
authors: Clish
authors: Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts, United States of America.
authors: Kiran
authors: K
authors: Musunuru
authors: Therapeutics Platform, Center for the Science of Therapeutics, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America.
authors: Jeremy R
authors: JR
authors: Duvall
authors: Therapeutics Platform, Center for the Science of Therapeutics, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America.
authors: Michael
authors: M
authors: Foley
authors: Therapeutics Platform, Center for the Science of Therapeutics, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America.
authors: Jose R
authors: JR
authors: Perez
authors: Therapeutics Platform, Center for the Science of Therapeutics, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America.
authors: Michelle A J
authors: MA
authors: Palmer
mesh_terms: D016000:Cluster Analysis; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000187:drug effects*; D056945:Hep G2 Cells; D022781:Hepatocytes / Q000187:drug effects* / Q000378:metabolism*; D057166:High-Throughput Screening Assays; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics* / Q000378:metabolism*; D050356:Lipid Metabolism / Q000187:drug effects / Q000235:genetics; D008074:Lipoproteins / Q000378:metabolism*; D008077:Lipoproteins, LDL / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D053683:Oncostatin M / Q000494:pharmacology; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D054852:Small Molecule Libraries
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D008074:Lipoproteins; D008077:Lipoproteins, LDL; D054852:Small Molecule Libraries; C493170:TRIB1 protein, human; D053683:Oncostatin M; D017346:Protein Serine-Threonine Kinases; D020928:Mitogen-Activated Protein Kinases