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The histone demethylase Jhdm1a regulates hepatic gluconeogenesis.

Pan D, Mao C, Zou T, Yao AY, Cooper MP, Boyartchuk V, Wang YX - PLoS Genet. (2012)

Bottom Line: In vivo, silencing of Jhdm1a promotes liver glucose synthesis, while its exogenous expression reduces blood glucose level.Importantly, the regulation of gluconeogenesis by Jhdm1a requires its demethylation activity.This is achieved, at least in part, by its USF1-dependent association with the C/EBPα promoter and its subsequent demethylation of dimethylated H3K36 on the C/EBPα locus.

View Article: PubMed Central - PubMed

Affiliation: Program in Gene Function and Expression and Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America.

ABSTRACT
Hepatic gluconeogenesis is required for maintaining blood glucose homeostasis; yet, in diabetes mellitus, this process is unrestrained and is a major contributor to fasting hyperglycemia. To date, the impacts of chromatin modifying enzymes and chromatin landscape on gluconeogenesis are poorly understood. Through catalyzing the removal of methyl groups from specific lysine residues in the histone tail, histone demethylases modulate chromatin structure and, hence, gene expression. Here we perform an RNA interference screen against the known histone demethylases and identify a histone H3 lysine 36 (H3K36) demethylase, Jhdm1a, as a key negative regulator of gluconeogenic gene expression. In vivo, silencing of Jhdm1a promotes liver glucose synthesis, while its exogenous expression reduces blood glucose level. Importantly, the regulation of gluconeogenesis by Jhdm1a requires its demethylation activity. Mechanistically, we find that Jhdm1a regulates the expression of a major gluconeogenic regulator, C/EBPα. This is achieved, at least in part, by its USF1-dependent association with the C/EBPα promoter and its subsequent demethylation of dimethylated H3K36 on the C/EBPα locus. Our work provides compelling evidence that links histone demethylation to transcriptional regulation of gluconeogenesis and has important implications for the treatment of diabetes.

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Knockdown of Jhdm1a specifically upregulates PEPCK and G6Pase expression in cultured hepatic cells.(A) HepG2 cells were treated with DMSO, NOG (1 mM), or DMOG (0.1 mM) for 12 hr. (B) shRNA-mediated screen. Each bar represents a single shRNA construct. Data were presented as fold relative to the scramble control. (C) Jhdm1a was knocked down in HepG2 cells with shRNA lentiviruses. Left, gene expression data were presented as fold relative to the scramble control from three experiments. Full names of individual genes are listed in Table S1. Right, levels of PEPCK and G6Pase protein were determined. (D) Jhdm1a knockdown or scramble HepG2 cells were treated with NOG (1 mM) for 12 hr. (E) Jhdm1a knockdown or scramble HepG2 cells were treated with a combination of dibutyryl cyclic-AMP (cAMP, 0.5 mM) and dexamethasone (Dex, 1 µM) in DMEM medium for 6 hr. Data were from two experiments. (F) Lentiviral knockdown of Jhdm1a in mouse hepatoma HepA1-6 cells. Data were from two experiments. (G) Adenoviral knockdown of Jhdm1a in mouse primary hepatocytes. Experiments were repeated three times with similar results.
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pgen-1002761-g001: Knockdown of Jhdm1a specifically upregulates PEPCK and G6Pase expression in cultured hepatic cells.(A) HepG2 cells were treated with DMSO, NOG (1 mM), or DMOG (0.1 mM) for 12 hr. (B) shRNA-mediated screen. Each bar represents a single shRNA construct. Data were presented as fold relative to the scramble control. (C) Jhdm1a was knocked down in HepG2 cells with shRNA lentiviruses. Left, gene expression data were presented as fold relative to the scramble control from three experiments. Full names of individual genes are listed in Table S1. Right, levels of PEPCK and G6Pase protein were determined. (D) Jhdm1a knockdown or scramble HepG2 cells were treated with NOG (1 mM) for 12 hr. (E) Jhdm1a knockdown or scramble HepG2 cells were treated with a combination of dibutyryl cyclic-AMP (cAMP, 0.5 mM) and dexamethasone (Dex, 1 µM) in DMEM medium for 6 hr. Data were from two experiments. (F) Lentiviral knockdown of Jhdm1a in mouse hepatoma HepA1-6 cells. Data were from two experiments. (G) Adenoviral knockdown of Jhdm1a in mouse primary hepatocytes. Experiments were repeated three times with similar results.

Mentions: To assess whether JmjC domain-containing histone demethylase(s) is involved in the regulation of gluconeogenesis, we treated human hepatoma HepG2 cells with N-oxalylglycine (NOG) or its derivative, dimethyloxalylglycine (DMOG), and examined the expression of the gluconeogenic enzymes. NOG and DMOG are analogues of α-ketoglutarate and are general enzymatic inhibitors of the JmjC domain-containing histone demethylases [22], [23]. Treatment with either compound led to an increase of PEPCK and G6Pase expression (Figure 1A), indicating a potential requirement of histone demethylation activity in the regulation of gluconeogenesis.


The histone demethylase Jhdm1a regulates hepatic gluconeogenesis.

Pan D, Mao C, Zou T, Yao AY, Cooper MP, Boyartchuk V, Wang YX - PLoS Genet. (2012)

Knockdown of Jhdm1a specifically upregulates PEPCK and G6Pase expression in cultured hepatic cells.(A) HepG2 cells were treated with DMSO, NOG (1 mM), or DMOG (0.1 mM) for 12 hr. (B) shRNA-mediated screen. Each bar represents a single shRNA construct. Data were presented as fold relative to the scramble control. (C) Jhdm1a was knocked down in HepG2 cells with shRNA lentiviruses. Left, gene expression data were presented as fold relative to the scramble control from three experiments. Full names of individual genes are listed in Table S1. Right, levels of PEPCK and G6Pase protein were determined. (D) Jhdm1a knockdown or scramble HepG2 cells were treated with NOG (1 mM) for 12 hr. (E) Jhdm1a knockdown or scramble HepG2 cells were treated with a combination of dibutyryl cyclic-AMP (cAMP, 0.5 mM) and dexamethasone (Dex, 1 µM) in DMEM medium for 6 hr. Data were from two experiments. (F) Lentiviral knockdown of Jhdm1a in mouse hepatoma HepA1-6 cells. Data were from two experiments. (G) Adenoviral knockdown of Jhdm1a in mouse primary hepatocytes. Experiments were repeated three times with similar results.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3375226&req=5

pgen-1002761-g001: Knockdown of Jhdm1a specifically upregulates PEPCK and G6Pase expression in cultured hepatic cells.(A) HepG2 cells were treated with DMSO, NOG (1 mM), or DMOG (0.1 mM) for 12 hr. (B) shRNA-mediated screen. Each bar represents a single shRNA construct. Data were presented as fold relative to the scramble control. (C) Jhdm1a was knocked down in HepG2 cells with shRNA lentiviruses. Left, gene expression data were presented as fold relative to the scramble control from three experiments. Full names of individual genes are listed in Table S1. Right, levels of PEPCK and G6Pase protein were determined. (D) Jhdm1a knockdown or scramble HepG2 cells were treated with NOG (1 mM) for 12 hr. (E) Jhdm1a knockdown or scramble HepG2 cells were treated with a combination of dibutyryl cyclic-AMP (cAMP, 0.5 mM) and dexamethasone (Dex, 1 µM) in DMEM medium for 6 hr. Data were from two experiments. (F) Lentiviral knockdown of Jhdm1a in mouse hepatoma HepA1-6 cells. Data were from two experiments. (G) Adenoviral knockdown of Jhdm1a in mouse primary hepatocytes. Experiments were repeated three times with similar results.
Mentions: To assess whether JmjC domain-containing histone demethylase(s) is involved in the regulation of gluconeogenesis, we treated human hepatoma HepG2 cells with N-oxalylglycine (NOG) or its derivative, dimethyloxalylglycine (DMOG), and examined the expression of the gluconeogenic enzymes. NOG and DMOG are analogues of α-ketoglutarate and are general enzymatic inhibitors of the JmjC domain-containing histone demethylases [22], [23]. Treatment with either compound led to an increase of PEPCK and G6Pase expression (Figure 1A), indicating a potential requirement of histone demethylation activity in the regulation of gluconeogenesis.

Bottom Line: In vivo, silencing of Jhdm1a promotes liver glucose synthesis, while its exogenous expression reduces blood glucose level.Importantly, the regulation of gluconeogenesis by Jhdm1a requires its demethylation activity.This is achieved, at least in part, by its USF1-dependent association with the C/EBPα promoter and its subsequent demethylation of dimethylated H3K36 on the C/EBPα locus.

View Article: PubMed Central - PubMed

Affiliation: Program in Gene Function and Expression and Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America.

ABSTRACT
Hepatic gluconeogenesis is required for maintaining blood glucose homeostasis; yet, in diabetes mellitus, this process is unrestrained and is a major contributor to fasting hyperglycemia. To date, the impacts of chromatin modifying enzymes and chromatin landscape on gluconeogenesis are poorly understood. Through catalyzing the removal of methyl groups from specific lysine residues in the histone tail, histone demethylases modulate chromatin structure and, hence, gene expression. Here we perform an RNA interference screen against the known histone demethylases and identify a histone H3 lysine 36 (H3K36) demethylase, Jhdm1a, as a key negative regulator of gluconeogenic gene expression. In vivo, silencing of Jhdm1a promotes liver glucose synthesis, while its exogenous expression reduces blood glucose level. Importantly, the regulation of gluconeogenesis by Jhdm1a requires its demethylation activity. Mechanistically, we find that Jhdm1a regulates the expression of a major gluconeogenic regulator, C/EBPα. This is achieved, at least in part, by its USF1-dependent association with the C/EBPα promoter and its subsequent demethylation of dimethylated H3K36 on the C/EBPα locus. Our work provides compelling evidence that links histone demethylation to transcriptional regulation of gluconeogenesis and has important implications for the treatment of diabetes.

Show MeSH
Related in: MedlinePlus