TY - JOUR
T1 - AMPK and ACCchange with fasting and physiological condition in euthermic and hibernating golden-mantled ground squirrels (Callospermophilus lateralis)
AU - Healy, Jessica E.
AU - Gearhart, Cassandra N.
AU - Bateman, Jenna L.
AU - Handa, Robert J.
AU - Florant, Gregory L.
N1 - Funding Information:
Thanks to Cara Ostrom, Kendra Burdett, Ashley Fenn, and Thomas Barnett for help with trapping and animal care, and Yvonne Diaz and Vanessa Selwyn for assistance with Western blots. We thank Denise Pearson of Fox Acres Country Club for allowing us to trap ground squirrels on their property. This work was supported by NIH R25DK067017 to GLF and NIH NS039951 grant to RJH.
PY - 2011/7
Y1 - 2011/7
N2 - AMP-activated protein kinase (AMPK) is a cellular energy sensor that responds to low endogenous energy by stimulating fatty acid oxidation (through inactivation of acetyl-CoA carboxylase (ACC)) and food intake. Fasting generally stimulates phosphorylation of AMPK (pAMPK) and ACC (pACC), but it is unclear how AMPK and ACC react to a long-term fast (i.e. hibernation). We performed Western blots for total and pAMPK and pACC on tissues from a species of hibernator (Callospermophilus lateralis) after short-term summer fasting (1-5days) and long-term winter fasting (3months). Winter animals were sacrificed during hibernation at low body temperature (torpid, Tb~5°C) or at normal high Tb(euthermic, Tb~37°C). We found a general increase in pAMPK in most tissues (liver, muscle, and white adipose tissue (WAT), but not hypothalamus) and pACC in all tissues after a short-term summer fast. Response of AMPK and ACC to a long-term winter fast differed by tissue-in liver, there was no difference in total or pAMPK or pACC between groups, but in muscle, WAT and BAT, euthermic GMGS had lower relative abundance of pAMPK and pACC than torpid animals. Therefore, AMPK may be an important energy sensor at all points in hibernator's circannual cycles of food intake and Tb.
AB - AMP-activated protein kinase (AMPK) is a cellular energy sensor that responds to low endogenous energy by stimulating fatty acid oxidation (through inactivation of acetyl-CoA carboxylase (ACC)) and food intake. Fasting generally stimulates phosphorylation of AMPK (pAMPK) and ACC (pACC), but it is unclear how AMPK and ACC react to a long-term fast (i.e. hibernation). We performed Western blots for total and pAMPK and pACC on tissues from a species of hibernator (Callospermophilus lateralis) after short-term summer fasting (1-5days) and long-term winter fasting (3months). Winter animals were sacrificed during hibernation at low body temperature (torpid, Tb~5°C) or at normal high Tb(euthermic, Tb~37°C). We found a general increase in pAMPK in most tissues (liver, muscle, and white adipose tissue (WAT), but not hypothalamus) and pACC in all tissues after a short-term summer fast. Response of AMPK and ACC to a long-term winter fast differed by tissue-in liver, there was no difference in total or pAMPK or pACC between groups, but in muscle, WAT and BAT, euthermic GMGS had lower relative abundance of pAMPK and pACC than torpid animals. Therefore, AMPK may be an important energy sensor at all points in hibernator's circannual cycles of food intake and Tb.
KW - ACC
KW - AMPK
KW - Fasting
KW - Hibernation
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U2 - 10.1016/j.cbpa.2011.03.026
DO - 10.1016/j.cbpa.2011.03.026
M3 - Article
C2 - 21473923
AN - SCOPUS:79955626531
VL - 159
SP - 322
EP - 331
JO - Comparative Biochemistry and Physiology - A Molecular and Integrative Physiology
JF - Comparative Biochemistry and Physiology - A Molecular and Integrative Physiology
SN - 1095-6433
IS - 3
ER -