Publication Date:
2014-11-11
Description:
Autophagy is an evolutionarily conserved catabolic process that recycles nutrients upon starvation and maintains cellular energy homeostasis. Its acute regulation by nutrient-sensing signalling pathways is well described, but its longer-term transcriptional regulation is not. The nuclear receptors peroxisome proliferator-activated receptor-alpha (PPARalpha) and farnesoid X receptor (FXR) are activated in the fasted and fed liver, respectively. Here we show that both PPARalpha and FXR regulate hepatic autophagy in mice. Pharmacological activation of PPARalpha reverses the normal suppression of autophagy in the fed state, inducing autophagic lipid degradation, or lipophagy. This response is lost in PPARalpha knockout (Ppara(-/-), also known as Nr1c1(-/-)) mice, which are partially defective in the induction of autophagy by fasting. Pharmacological activation of the bile acid receptor FXR strongly suppresses the induction of autophagy in the fasting state, and this response is absent in FXR knockout (Fxr(-/-), also known as Nr1h4(-/-)) mice, which show a partial defect in suppression of hepatic autophagy in the fed state. PPARalpha and FXR compete for binding to shared sites in autophagic gene promoters, with opposite transcriptional outputs. These results reveal complementary, interlocking mechanisms for regulation of autophagy by nutrient status.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4267857/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉 〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4267857/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Lee, Jae Man -- Wagner, Martin -- Xiao, Rui -- Kim, Kang Ho -- Feng, Dan -- Lazar, Mitchell A -- Moore, David D -- DK43806/DK/NIDDK NIH HHS/ -- P30 DK019525/DK/NIDDK NIH HHS/ -- P30DX56338-05A2/PHS HHS/ -- P39CA125123-04/CA/NCI NIH HHS/ -- R01 DK049780/DK/NIDDK NIH HHS/ -- R01 DK49780/DK/NIDDK NIH HHS/ -- R37 DK043806/DK/NIDDK NIH HHS/ -- S10RR027783-01A1/RR/NCRR NIH HHS/ -- U54HD-07495-39/HD/NICHD NIH HHS/ -- England -- Nature. 2014 Dec 4;516(7529):112-5. doi: 10.1038/nature13961. Epub 2014 Nov 12.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA. ; Division of Endocrinology, Diabetes, and Metabolism and the Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania 19014, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25383539" target="_blank"〉PubMed〈/a〉
Keywords:
Animals
;
Autophagy/genetics/*physiology
;
Cell Line
;
Cells, Cultured
;
Fasting/physiology
;
Gene Expression Regulation
;
Hepatocytes/metabolism
;
Liver/cytology/*metabolism/ultrastructure
;
Male
;
Mice
;
Mice, Inbred C57BL
;
Mice, Knockout
;
Microtubule-Associated Proteins/genetics/metabolism
;
PPAR alpha
;
Receptors, Cytoplasmic and Nuclear/genetics/*metabolism
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
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