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Downregulation of Pgc‐1α expression by tea leaves and their by‐products
Author(s) -
Shibuya Erika,
Murakami Masaru,
Kondo Makoto,
Kamei Yasutomi,
Tomonaga Shozo,
Matsui Tohru,
Funaba Masayuki
Publication year - 2014
Publication title -
cell biochemistry and function
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.933
H-Index - 61
eISSN - 1099-0844
pISSN - 0263-6484
DOI - 10.1002/cbf.3006
Subject(s) - silage , luciferase , myogenesis , downregulation and upregulation , c2c12 , green tea , transcription (linguistics) , chemistry , food science , myocyte , transcription factor , biochemistry , biology , gene , microbiology and biotechnology , transfection , linguistics , philosophy
Previous studies indicate that muscle Pgc‐1α expression governs the proportion of muscle fibre types. As a first step in using diet to manipulate the proportion of muscle fibre types by using Pgc‐1α expression, the present study investigates the modulation of Pgc‐1α expression by feedstuffs. A luciferase‐based Pgc‐1α reporter construct (Pgc‐1α(‐2553)‐luc) that contains the mouse Pgc‐1α promoter (−2553 to +78 bp) was prepared. A screen of ethanol extracts from 33 feedstuffs indicated that oolong tea and roasted green tea extracts decreased Pgc‐1α(‐2553)‐luc expression in C2C12 myoblasts. The transcriptional repression of Pgc‐1α by tea leaf extracts was reproduced in hepatic HepG2 cells. We further examined the effects of the alcohol extracts of tea waste and its silage on Pgc‐1α transcription; the tea waste silage extract inhibited Pgc‐1α transcription. Treatment with the extracts of raw tea leaves, tea waste and tea waste silage effectively decreased Pgc‐1α mRNA levels during myogenesis of myosatellite cells. The present results suggest that tea leaves and their by‐products could be used to modulate proportions of muscle fibre types. Copyright © 2013 John Wiley & Sons, Ltd.