Expression and activity of the 5′-adenosine monophosphate-activated protein kinase pathway in selected tissues during chicken embryonic development

Abstract

The 5'-adenosine monophosphate-activated protein kinase (AMPK) is a highly conserved serine-threonine protein kinase and a key part of a kinase-signaling cascade that senses cellular energy status (adenosine monophosphate:adenosine triphosphate ratio) and acts to maintain energy homeostasis by coordinately regulating energy-consuming and energy-generating metabolic pathways. The objective of this study was to investigate aspects of the AMPK pathway in the liver, brain, breast muscle, and heart from d 12 of incubation through hatch in chickens. We first determined mRNA and protein expression profiles for a major upstream AMPK kinase, LKB1, which is known to activate (phosphorylate) AMPK in response to increases in the adenosine monophosphate:adenosine triphosphate ratio. Expression of LKB1 protein was greatest in the brain, which demonstrated tissue-specific patterns for phosphorylation. Next, AMPK subunit mRNA and protein expression profiles were determined. Significant changes in AMPK subunit mRNA expression occurred in all tissues from d 12 of incubation to hatch. Differences in the levels of active (phosphorylated) AMPK as well as alpha and beta subunit proteins were observed in all 4 tissues during embryonic development. Finally, we determined the protein level and phosphorylation status of an important downstream target for AMPK, acetyl-coenzyme A carboxylase. The expression of acetyl-co-enzyme A carboxylase and phosphorylated acetyl-coenzyme A was greater in the brain than the liver, but was undetectable by Western blotting in the breast muscle and heart throughout the period of study. Together, our results are the first to demonstrate the expression and activity of the AMPK pathway in key tissues during the transition from embryonic to posthatch development in chickens.

Glucocorticoids Increase NPY Gene Expression via Hypothalamic AMPK Signaling in Broiler Chicks

“…The membranes were blocked and immunoblotted with the following primary antibodies: phospho-AMPK␣ Thr172 antibody, AMPK␣ antibody, phospho-acetyl-coenzyme A carboxylase (ACC) Ser79 antibody, and ACC antibody. These antibodies were validated previously for use with chicken samples (28,29). Protein detection was performed using goat antirabbit IgG (heavy and light chains)-horseradish peroxidase-conjugated secondary antibody (Bio-Rad) or horseradish peroxidase-labeled goat antimouse IgG (heavy and light chains) secondary antibody by enhanced chemiluminescence using Western blotting detection reagents (Beyotime).…”

Skeletal muscle fatty acids shift from oxidation to storage upon dexamethasone treatment in chickens

“…Membranes were blocked for 1 h and immunoblotted overnight at 4°C with 1:1000 dilutions of phospho-AMPKa (Thr172) antibody and AMPKa antibody. The antibodies were purchased from Cell Signaling Technology (Beverly, MA) and previously validated for use with chicken samples [53,54]. b-Actin was used as an internal control (Beyotime, Jiangsu, PR China).…”

Effect of 24 h Fasting on Gene Expression of AMPK, Appetite Regulation Peptides and Lipometabolism Related Factors in the Hypothalamus of Broiler Chicks

“…Because feeding behavior and energy homeostasis are basic processes crucial to the survival of all animals (Richards and Proszkowiec-Weglarz, 2007), it is logical to assume that AMPK should be involved in poultry feed intake control. Gene expression of AMPK in chicken embryos has been explored (Proszkowiec-Weglarz and Richards, 2009), but information of its expression in chicks hypothalamus remains scarce. Previous studies in mammals showed that isoform composition of AMPK subunit changes during physiological and pathological conditions (Gregor et al, 2006; Kim et al, 2009).…”