PURPOSE: Peroxisome proliferator-activated receptor α (PPARα) is an important transcriptional factor that regulates genes encoding endo/xenobiotic enzymes and lipid metabolizing enzymes. In this study, we investigated whether microRNAs (miRNAs) are involved in the regulation of PPARα in human liver. METHODS: Precursor or antisense oligonucleotide for miR-21 or miR-27b was transfected into HuH7 cells; expression of PPARα and acyl-CoA synthetase M2B was determined by Western blot and real-time RT-PCR. Luciferase assay was performed to identify the functional miRNA recognition element (MRE). Expression levels of PPARα, miR-21, and miR-27b in a panel of 24 human livers were determined. RESULTS: The overexpression and inhibition of miR-21 or miR-27b in HuH7 cells significantly decreased and increased the PPARα protein level, respectively, but not PPARα mRNA level. The miRNA-dependent regulation of PPARα affected the expression of its downstream gene. Luciferase assay identified a functional MRE for miR-21 in the 3'-untranslated region of PPARα. In human livers, the PPARα protein levels were not correlated with PPARα mRNA, but inversely correlated with the miR-21 levels, suggesting a substantial impact of miR-21, although the contribution of miR-27b could not be ruled out. CONCLUSIONS: We found that PPARα in human liver is regulated by miRNAs.
PURPOSE: Peroxisome proliferator-activated receptor α (PPARα) is an important transcriptional factor that regulates genes encoding endo/xenobiotic enzymes and lipid metabolizing enzymes. In this study, we investigated whether microRNAs (miRNAs) are involved in the regulation of PPARα in human liver. METHODS: Precursor or antisense oligonucleotide for miR-21 or miR-27b was transfected into HuH7 cells; expression of PPARα and acyl-CoA synthetase M2B was determined by Western blot and real-time RT-PCR. Luciferase assay was performed to identify the functional miRNA recognition element (MRE). Expression levels of PPARα, miR-21, and miR-27b in a panel of 24 human livers were determined. RESULTS: The overexpression and inhibition of miR-21 or miR-27b in HuH7 cells significantly decreased and increased the PPARα protein level, respectively, but not PPARα mRNA level. The miRNA-dependent regulation of PPARα affected the expression of its downstream gene. Luciferase assay identified a functional MRE for miR-21 in the 3'-untranslated region of PPARα. In human livers, the PPARα protein levels were not correlated with PPARα mRNA, but inversely correlated with the miR-21 levels, suggesting a substantial impact of miR-21, although the contribution of miR-27b could not be ruled out. CONCLUSIONS: We found that PPARα in human liver is regulated by miRNAs.
Authors: George Adrian Calin; Cinzia Sevignani; Calin Dan Dumitru; Terry Hyslop; Evan Noch; Sai Yendamuri; Masayoshi Shimizu; Sashi Rattan; Florencia Bullrich; Massimo Negrini; Carlo M Croce Journal: Proc Natl Acad Sci U S A Date: 2004-02-18 Impact factor: 11.205
Authors: Dennis Löffler; Katja Brocke-Heidrich; Gabriele Pfeifer; Claudia Stocsits; Jörg Hackermüller; Antje K Kretzschmar; Renate Burger; Martin Gramatzki; Conny Blumert; Kay Bauer; Helena Cvijic; A Kerstin Ullmann; Peter F Stadler; Friedemann Horn Journal: Blood Date: 2007-05-11 Impact factor: 22.113
Authors: Douglas F Dluzen; Dongxiao Sun; Anna C Salzberg; Nate Jones; Ryan T Bushey; Gavin P Robertson; Philip Lazarus Journal: J Pharmacol Exp Ther Date: 2014-01-07 Impact factor: 4.030