An in vivo and in vitro assessment of autophagy-related gene expression in muscle of rainbow trout (Oncorhynchus mykiss).
In mammals, new evidence has demonstrated the important role of the autophagic/lysosomal pathway in regulating muscle mass and identified the transcription factor FoxO3 as a key factor of the control of this proteolytic system by inducing several autophagy-related genes. In contrast, the mechanisms responsible for the regulation of autophagy have not been investigated in teleosts, known to exhibit different muscle growth dynamics. The present work aimed to characterize both in vivo and in vitro the transcriptional regulation of several major genes involved in autophagy (LC3B, gabarapl1, atg12l, atg4b) in the white skeletal muscle of rainbow trout. We found that fasting fish for 14days or serum depletion of trout myocytes strongly induces the expression of all studied genes. Our in vitro study on trout myocytes indicated that IGF1 induces FoxO3 phosphorylation but has a low or no effect on autophagy-related gene expression, suggesting a moderate role for this transcription factor on the autophagic/lysosomal pathway in this species. Data reported here show for the first time in a lower vertebrate, the existence and the regulation of several major genes involved in the autophagy, opening a new area of research on the molecular bases of muscle protein degradation in teleosts.
Seiliez
Iban
I
INRA, UMR1067 Nutrition Aquaculture et Génomique, F-64310 Saint-Pée-sur-Nivelle, France. seiliez@st-pee.inra.fr
Gutierrez
Joaquim
J
Salmerón
Cristina
C
Skiba-Cassy
Sandrine
S
Chauvin
Charline
C
Dias
Karine
K
Kaushik
Sadasivam
S
Tesseraud
Sophie
S
Panserat
Stephane
S
D000595:Amino Acid Sequence; D000818:Animals; D001343:Autophagy / Q000235:genetics; D001483:Base Sequence; D002478:Cells, Cultured; D029941:Fish Proteins / Q000235:genetics / Q000378:metabolism*; D005508:Food Deprivation; D051858:Forkhead Transcription Factors / Q000378:metabolism; D005786:Gene Expression Regulation; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology; D008969:Molecular Sequence Data; D018482:Muscle, Skeletal / Q000187:drug effects / Q000378:metabolism*; D017686:Oncorhynchus mykiss / Q000235:genetics / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D015398:Signal Transduction
D029941:Fish Proteins; D051858:Forkhead Transcription Factors; D007334:Insulin-Like Growth Factor I; D051057:Proto-Oncogene Proteins c-akt