Effect of short-term fasting and glucocorticoids on KLF15 expression and branched-chain amino acids metabolism in Chinese perch

Abstract

Skeletal muscle metabolism is highly adaptive in response to nutritional changes, as occur during food deprivation. Krüppel-like factor 15 (KLF15), as a critical regulator of branched-chain amino acids (BCAAs) metabolism, which plays an important role in energy metabolism. But the role for KLF15 in adaptation and physiology of fish skeletal muscle remains unclear. In this study, we obtained the complete cDNA of Chinese perch (Siniperca chuatsi) KLF15 and investigated its expression in different tissues as well as its expression characteristics during short-term (3 or 7 days) fasting and glucocorticoid (prednisolone) treatment in Chinese perch. Sequence analysis indicated that ScKLF15 showed a highly conservative Zinc finger C2H2 superfamily domain at its C terminal with those of other vertebrates. Tissue specificity analysis showed that ScKLF15 was highly expressed in fast muscle. During the short-term fasting, the expression of KLF15 was significantly increased after 3 days fasting and decreased after 7 days fasting as well as the expression of branched-chain aminotransferase 2 (BCAT2) and the activity of alanine aminotransferase (ALT). Under the prednisolone stimulation, the expression of KLF15 and BCAT2 were significantly increased at 5 days post injection. Furthermore, the activity of ALT and aspartate aminotransferase (AST) showed the same tendency after the injection. Thus, this work revealed that the catabolism of BCAAs was enhanced to maintain the physiological homeostasis in the fish when faced with food deprivation and glucocorticoids stress. More importantly, the study suggested that KLF15 plays a role in adaptive regulation of BCAAs metabolism in skeletal muscle of Chinese perch.