Proportions of myosin heavy chain mRNAs, protein isoforms and fiber types in the slow and fast skeletal muscles are maintained after alterations of thyroid status in rats

0443224 - FGÚ 2016 RIV CZ eng J - Journal Article
Soukup, Tomáš - Diallo, Michael
Proportions of myosin heavy chain mRNAs, protein isoforms and fiber types in the slow and fast skeletal muscles are maintained after alterations of thyroid status in rats.
Physiological Research. Roč. 64, č. 1 (2015), s. 111-118. ISSN 0862-8408. E-ISSN 1802-9973
R&D Projects: GA ČR(CZ) GA304/08/0256; GA MŠMT(CZ) 7AMB12SK158; GA MŠMT(CZ) 7AMB14SK123; GA MŠMT(CZ) EE2.3.30.0025
Grant - others:EC(XE) LSH-CT-2004-511978
Institutional support: RVO:67985823
Keywords : thyroid hormones * muscle gene expression * MyHC isoforms and muscle fiber types * quantitative real time RT-PCR * SDS-PAGE and 2-D Stereological analysis
Subject RIV: EA - Cell Biology
Impact factor: 1.643, year: 2015

Recently we have established that slow soleus (SOL) and fast extensor digitorum longus (EDL) muscles of euthyroid (EU) Lewis rats possess the same proportions between their four myosin heavy chain (MyHC) mRNAs, protein isoforms and fiber types as determined by real time RT-PCR, SDS-PAGE and 2-D stereological fiber type analysis, respectively. In the present paper we investigated if these proportions are maintained in adult Lewis rats with hyperthyroid (HT) and hypothyroid (HY) status. Although HT and HY states change MyHC isoform expression, results from all three methods showed that proportion between MyHC mRNA-1, -2a, -2x/d, -2b, protein isoforms MyHC-1, -2a, -2x/d, -2b and to lesser extent also fiber types 1, 2A, 2X/D, 2B were preserved in both SOL and EDL muscles. Furthermore, in the SOL muscle mRNA expression of slow MyHC-1 remained up to three orders higher compared to fast MyHC transcripts, which explains the predominance of MyHC-1 isoform and fiber type 1 even in HT rats. Although HT status led in the SOL to increased expression of MyHC-2a mRNA, MyHC-2a isoform and 2A fibers, it preserved extremely low expression of MyHC-2x and -2b mRNA and protein isoforms, which explains the absence of pure 2X/D and 2B fibers. HY status, on the other hand, almost completely abolished expression of all three fast MyHC mRNAs, MyHC protein isoforms and fast fiber types in the SOL muscle. Our data present evidence that a correlation between mRNA, protein content and fiber type composition found in EU status is also preserved in HT and HY rats
Permanent Link: http://hdl.handle.net/11104/0245969