Project description:Jumonji D3 (JMJD3) histone demethylase epigenetically regulates development, differentiation, and immunity by demethylating a gene-repression histone mark, H3K27-me3, but a role for JMJD3 in metabolic regulation has not been described. SIRT1 deacetylase maintains energy balance during fasting by directly activating both hepatic gluconeogenic and mitochondrial fatty acid beta-oxidation genes, but the underlying epigenetic and gene-specific mechanisms remain unclear. To explore global hepatic functions of JMJD3, mRNA levels in control and JMJD3-downregulated hepatocytes were compared by RNA-seq analysis. Expression of 2,772 and 2,143 genes was significantly decreased and increased, respectively, over 1.5-fold, by downregulation of JMJD3. ). In gene ontology analysis, genes downregulated with the highest significance were those involved in mitochondrial functions, particularly oxidation/reduction, the respiratory chain, and fatty acid beta-oxidation, Overall, in this study, JMJD3 was shown unexpectedly to be a gene-specific transcriptional partner of SIRT1 and these epigenetic factors interact with the nuclear receptor PPARalpha to epigenetically activate mitochondrial beta-oxidation, but not gluconeogenic, genes during fasting.
Project description:Autophagy is essential for cellular survival and energy homeostasis under nutrient deprivation. Despite the emerging importance of nuclear events in autophagy regulation, epigenetic control of autophagy gene transcription remains unclear. Here, we identify Jumonji-D3 (JMJD3/KDM6B) histone demethylase as a key epigenetic activator of hepatic autophagy. Upon fasting-induced fibroblast growth factor-21 (FGF21) signaling, JMJD3 epigenetically upregulated global autophagy-network genes, including Tfeb, Atg7, Atgl, and Fgf21, through demethylation of histone H3K27-me3, resulting in autophagy-mediated lipid degradation. Mechanistically, phosphorylation of JMJD3 at Thr-1044 by FGF21 signal-activated PKA increased its nuclear localization and interaction with the nuclear receptor PPARa to transcriptionally activate autophagy. Chronic administration of FGF21 in obese mice improved defective autophagy and hepatosteatosis in a JMJD3-dependent manner. Remarkably, in non-alcoholic fatty liver disease patients, hepatic expression of JMJD3, ATG7, LC3, and bKL were substantially decreased. These findings demonstrate that FGF21-JMJD3 signaling epigenetically links nutrient deprivation with hepatic autophagy and lipid degradation in mammals.
Project description:Autophagy is essential for cellular survival and energy homeostasis under nutrient deprivation. Despite the emerging importance of nuclear events in autophagy regulation, epigenetic control of autophagy gene transcription remains unclear. Here, we identify Jumonji-D3 (JMJD3/KDM6B) histone demethylase as a key epigenetic activator of hepatic autophagy. Upon fasting-induced fibroblast growth factor-21 (FGF21) signaling, JMJD3 epigenetically upregulated global autophagy-network genes, including Tfeb, Atg7, Atgl, and Fgf21, through demethylation of histone H3K27-me3, resulting in autophagy-mediated lipid degradation. Mechanistically, phosphorylation of JMJD3 at Thr-1044 by FGF21 signal-activated PKA increased its nuclear localization and interaction with the nuclear receptor PPARto transcriptionally activate autophagy. Chronic administration of FGF21 in obese mice improved defective autophagy and hepatosteatosis in a JMJD3-dependent manner. Remarkably, in non-alcoholic fatty liver disease patients, hepatic expression of JMJD3, ATG7, LC3, and KL were substantially decreased. These findings demonstrate that FGF21-JMJD3 signaling epigenetically links nutrient deprivation with hepatic autophagy and lipid degradation in mammals
Project description:Jumonji D3 (JMJD3) histone demethylase epigenetically regulates development and differentiation, immunity, and tumorigenesis by demethylating a gene repression histone mark, H3K27-me3, but a role for JMJD3 in metabolic regulation has not been described. SIRT1 deacetylase maintains energy balance during fasting by directly activating both hepatic gluconeogenic and mitochondrial fatty acid β-oxidation genes, but the underlying epigenetic and gene-specific mechanisms remain unclear. In this study, JMJD3 was identified unexpectedly as a gene-specific transcriptional partner of SIRT1 and epigenetically activated mitochondrial β-oxidation, but not gluconeogenic, genes during fasting. Mechanistically, JMJD3, together with SIRT1 and the nuclear receptor PPARα, formed a positive autoregulatory loop upon fasting-activated PKA signaling and epigenetically activated β-oxidation-promoting genes, including Fgf21, Cpt1a, and Mcad. Liver-specific downregulation of JMJD3 resulted in intrinsic defects in β-oxidation, which contributed to hepatosteatosis as well as glucose and insulin intolerance. Remarkably, the lipid-lowering effects by JMJD3 or SIRT1 in diet-induced obese mice were mutually interdependent. JMJD3 histone demethylase may serve as an epigenetic drug target for obesity, hepatosteatosis, and type 2 diabetes that allows selective lowering of lipid levels without increasing glucose levels.
Project description:Autophagy is essential for cellular survival and energy homeostasis under nutrient deprivation. Despite the emerging importance of nuclear events in autophagy regulation, epigenetic control of autophagy gene transcription remains unclear. Here, we identify Jumonji-D3 (JMJD3/KDM6B) histone demethylase as a key epigenetic activator of hepatic autophagy. Upon fasting-induced fibroblast growth factor-21 (FGF21) signaling, JMJD3 epigenetically upregulated global autophagy-network genes, including Tfeb, Atg7, Atgl, and Fgf21, through demethylation of histone H3K27-me3, resulting in autophagy-mediated lipid degradation. Mechanistically, phosphorylation of JMJD3 at Thr-1044 by FGF21 signal-activated PKA increased its nuclear localization and interaction with the nuclear receptor PPARa to transcriptionally activate autophagy. Chronic administration of FGF21 in obese mice improved defective autophagy and hepatosteatosis in a JMJD3-dependent manner. Remarkably, in non-alcoholic fatty liver disease patients, hepatic expression of JMJD3, ATG7, LC3, and bKL were substantially decreased. These findings demonstrate that FGF21-JMJD3 signaling epigenetically links nutrient deprivation with hepatic autophagy and lipid degradation in mammals.
Project description:Autophagy is essential for cellular survival and energy homeostasis under nutrient deprivation. Despite the emerging importance of nuclear events in autophagy regulation, epigenetic control of autophagy gene transcription remains unclear. Here, we report fasting-induced Fibroblast Growth Factor-21 (FGF21) signaling activates hepatic autophagy and lipid degradation via Jumonji-D3 (JMJD3/KDM6B) histone demethylase. Upon FGF21 signaling, JMJD3 epigenetically upregulates global autophagy-network genes, including Tfeb, Atg7, Atgl, and Fgf21, through demethylation of histone H3K27-me3, resulting in autophagy-mediated lipid degradation. Mechanistically, phosphorylation of JMJD3 at Thr-1044 by FGF21 signal-activated PKA increases its nuclear localization and interaction with the nuclear receptor PPAR? to transcriptionally activate autophagy. Administration of FGF21 in obese mice improves defective autophagy and hepatosteatosis in a JMJD3-dependent manner. Remarkably, in non-alcoholic fatty liver disease patients, hepatic expression of JMJD3, ATG7, LC3, and ULK1 is substantially decreased. These findings demonstrate that FGF21-JMJD3 signaling epigenetically links nutrient deprivation with hepatic autophagy and lipid degradation in mammals.
Project description:Inflammatory responses triggered by either microbial or endogenous stimuli rely on a complex transcriptional program that involves the differential expression of hundreds of genes. Jmjd3, a JmjC family histone demethylase (HDM), is quickly induced by the transcription factor NF-kB in response to inflammatory stimuli. Jmjd3 erases a histone mark associated with transcriptional repression and silencing, trimethylated lysine 27 in histone H3 (H3K27me3). Thus, Jmjd3-mediated demethylation of H3K27me3 links inflammation to the control of a histone modification involved in lineage determination, differentiation and tissue homeostasis. However, the specific contribution of Jmjd3 induction to innate immunity and inflammation remains unknown. Here we combined genome-wide mapping and gene knockout studies to investigate this issue. Chromatin immunoprecipitation (ChIP) coupled to ultra high-throughput sequencing (ChIP-Seq) in LPS-stimulated primary mouse macrophages demonstrated that Jmid3 is recruited to a large number of genomic targets with a strong preference for active transcription start sites (TSS). Virtually all Jmjd3-bound TSSs were characterized by high levels of H3K4me3, a marker of gene activity, and high levels of RNA polymerase II (Pol_II). Inducible genes showing a strong increase in H3K4me3 and Pol_II recruitment after endotoxin treatment (including those encoding several cytokines, chemokines and antiviral proteins) were in most cases Jmjd3-associated. In Jmjd3-knockout macrophages, initial RNA_Pol II recruitment and activation of Jmjd3 target genes was unaffected, but RNA_Pol II was prematurely released, thus resulting in non-sustained responses. Importantly, most Jmjd3 target genes were not associated with detectable levels of H3K27me3, and transcriptional effects of Jmjd3 absence in the window of time analyzed here were uncoupled from measurable effects on this histone mark. Our data indicate that Jmjd3 is the effector of an NF-kB-controlled feed-forward transcriptional loop pervasively sustaining inflammatory transcriptional responses in a manner that is independent of H3K27me3 demethylation, and suggest the possible use of anti-Jmjd3 drugs to dampen pathologic inflammation. Keywords: Epigenetics Genome wide maps of histone demethylase jmjd3, the histone marks H3K4me3 and H3K27me3, and RNA-Polymerase II induction in mouse bone marrow-derived macrophages of two types: (a) untreated and (b) stimulated with lipopolysaccharide and interferon gamma to produce an inflammatory response.
Project description:Mutations in the JMJD3 (KDM6B) chromatin regulator are causally associated with autism spectrum disorder and syndromic intellectual disability, but the neurodevelopmental roles of this histone 3 lysine 27 (H3K27) demethylase are poorly understood. Neural stem cells (NSCs) in the hippocampal dentate gyrus (DG) generate new granule neurons throughout life, and deficits in DG neurogenesis are associated with cognitive and behavioral problems. Here we show that Jmjd3 is required for the establishment of adult neurogenesis in the mouse DG. Conditional deletion of Jmjd3 in embryonic DG precursors results in an adult hippocampus that is essentially devoid of NSCs. While early postnatal mice with Jmjd3-deletion have near normal numbers of DG NSCs, at later stages, Jmjd3-deleted NSCs fail to propagate normally. In addition to the loss of NSCs during postnatal development, neurogenesis from Jmjd3-deleted NSCs is impaired, corresponding to defective neurogenic gene expression. Without Jmjd3, NeuroD2 and Bcl11b(Ctip2) are not properly expressed and exhibit increased levels of H3K27me3, underscoring the role of Jmjd3 in the regulation of transcription for neuronal differentiation. Thus, these data indicate that Jmjd3 plays dual roles in postnatal DG neurogenesis, being critical for the establishment of the NSC pool as well as the differentiation of young DG granule neurons. More broadly, our results suggest a neurodevelopmental link between JMJD3 mutations and hippocampal dysfunction, providing new insights into how mutations in chromatin regulators may contribute to learning disorders.
Project description:Jmjd3 is trimethyl H3K27 specific demethylase required for M2 macrophage polarization. Genomic fragments obtained from wild-type and Jmjd3-/- mouse macrophages were immunoprecipitated with anti H3K27me3 Ab, and deep sequencing was performed. wild-type and Jmjd3-/- macrophages