Hepatic carboxylesterase 1 is induced by glucose and regulates postprandial glucose levels.
Male; Animals; Mice; Blood Glucose/*metabolism; Histones/metabolism; Gene Expression Regulation; Acetylation/drug effects; Glucose/*pharmacology; Homeostasis; Carboxylic Ester Hydrolases/*metabolism; Nutritional Status; *Postprandial Period; ATP Citrate (pro-S)-Lyase/metabolism; Chromatin/metabolism; Liver/*enzymology; Inbred C57BL; Enzymologic/drug effects
Metabolic syndrome, characterized by obesity, hyperglycemia, dyslipidemia and hypertension, increases the risks for cardiovascular disease, diabetes and stroke. Carboxylesterase 1 (CES1) is an enzyme that hydrolyzes triglycerides and cholesterol esters, and is important for lipid metabolism. Our previous data show that over-expression of mouse hepatic CES1 lowers plasma glucose levels and improves insulin sensitivity in diabetic ob/ob mice. In the present study, we determined the physiological role of hepatic CES1 in glucose homeostasis. Hepatic CES1 expression was reduced by fasting but increased in diabetic mice. Treatment of mice with glucose induced hepatic CES1 expression. Consistent with the in vivo study, glucose stimulated CES1 promoter activity and increased acetylation of histone 3 and histone 4 in the CES1 chromatin. Knockdown of ATP-citrate lyase (ACL), an enzyme that regulates histone acetylation, abolished glucose-mediated histone acetylation in the CES1 chromatin and glucose-induced hepatic CES1 expression. Finally, knockdown of hepatic CES1 significantly increased postprandial blood glucose levels. In conclusion, the present study uncovers a novel glucose-CES1-glucose pathway which may play an important role in regulating postprandial blood glucose levels.
Xu Jiesi; Yin Liya; Xu Yang; Li Yuanyuan; Zalzala Munaf; Cheng Gang; Zhang Yanqiao
PloS one
2014
2014
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1371/journal.pone.0109663" target="_blank" rel="noreferrer noopener">10.1371/journal.pone.0109663</a>
Valproate increases dopamine transporter expression through histone acetylation and enhanced promoter binding of Nurr1.
Acetylation/drug effects; Animals; Butyrates/pharmacology; Cell Line; Cell Survival/drug effects; Dopamine Plasma Membrane Transport Proteins/*metabolism; Dopamine transporter; Dopaminergic Neurons/cytology/drug effects/metabolism; Dose-Response Relationship; Drug; Epigenesis; Epigenetics; Genetic; Genetic/drug effects; Group A; HDAC; Histone deacetylase; Histone Deacetylase Inhibitors/*pharmacology; Histone Deacetylases/metabolism; Histones/*drug effects/metabolism; Homeodomain Proteins/metabolism; Hydroxamic Acids/pharmacology; Member 2/*metabolism; Messenger/metabolism; Nuclear Receptor Subfamily 4; Nurr1; Pitx3; Promoter Regions; Rats; RNA; Transcription Factors/metabolism; Valproate; Valproic Acid/*pharmacology
The dopamine transporter (DAT) is the key regulator of dopaminergic transmission and is a target of several xenobiotics, including pesticides and pharmacological agents. Previously, we identified a prominent role for histone deacetylases in the regulation of DAT expression. Here, we utilized a rat dopaminergic cell line (N27) to probe the responsiveness of DAT mRNA expression to inhibitors of histone acetylation. Inhibition of histone deacetylases (HDACs) by valproate, butyrate and Trichostatin A led to a 3-10-fold increase in DAT mRNA expression, a 50% increase in protein levels, which were accompanied by increased H3 acetylation levels. To confirm the mechanism of valproate-mediated increase in DAT mRNA, chromatin immunoprecipitation (ChIP) assays were used and demonstrated a significant increase in enrichment of acetylation of histone 3 on lysines 9 and 14 (H3K9/K14ac) in the DAT promoter. Expression of Nurr1 and Pitx3, key regulators of DAT expression, were increased following valproate treatment and Nurr1 binding was enriched in the DAT promoter. Together, these results indicate that histone acetylation and subsequent enhancement of transcription factor binding are plausible mechanisms for DAT regulation by valproate and, perhaps, by other xenobiotics.
Green Ashley L; Zhan Le; Eid Aseel; Zarbl Helmut; Guo Grace L; Richardson Jason R
Neuropharmacology
2017
2017-10
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1016/j.neuropharm.2017.07.020" target="_blank" rel="noreferrer noopener">10.1016/j.neuropharm.2017.07.020</a>