Abstract

In this study, our aim is to investigate the effect of dimer procyanidin B2 [epicatechin-(4β-8)-epicatechin] (PB2) on porcine skeletal myofiber gene expression in vitro. Our data showed PB2 promoted the protein expression of slow myosin heavy chain (MyHC) in porcine myotubes, concomitant with the increases in mRNA levels of MyHC I, MyHC IIa and Tnni1. We also found PB2 activated AMPK signaling in porcine myotubes. NRF1 and CaMKKβ that are two important upstream factors of AMPK, and Sirt1 and PGC-1α that are two major downstream factors of AMPK, were also up-regulated by PB2. The mechanism study showed the effect of PB2 on slow-twitch myofiber gene expression was abolished by AMPK inhibitor compound C or by AMPKα1 siRNA. Together, we found PB2 induced porcine skeletal slow-twitch myofiber gene expression by AMPK signaling pathway.

摘要

在这项研究中，我们的目的是研究二聚原花青素 B2 [表儿茶素-(4β-8)-表儿茶素] (PB2) 对猪骨骼肌纤维基因体外表达的影响。我们的数据显示 PB2 促进了猪肌管中慢肌球蛋白重链 (MyHC) 的蛋白质表达，伴随着MyHC I、MyHC IIa和Tnni1 mRNA 水平的增加. 我们还在猪肌管中发现了 PB2 激活的 AMPK 信号。AMPK的两个重要上游因子NRF1和CaMKKβ以及AMPK的两个主要下游因子Sirt1和PGC-1α也被PB2上调。机制研究表明，AMPK抑制剂化合物C或AMPKα1 siRNA消除了PB2对慢肌纤维基因表达的影响。总之，我们发现 PB2 通过 AMPK 信号通路诱导猪骨骼慢缩肌纤维基因表达。