Project description:We have shown that intravenous injection of HDAC3 floxed mice with adeno-associated virus (AAV) expressing Cre depletes hepatic HDAC3, upregulates lipogenic gene expression, and causes fatty liver. When AAV-Flag-HDAC3 wild-type (WT) is co-injected along with AAV-Cre, the exogenous HDAC3 is expressed at endogenous levels and can completely rescue fatty liver phenotype. Here we profile transcriptome of the rescued WT livers in comparison with HDAC3-depleted (KO) livers. 4-months old C57BL/6 male mice were co-injected with AAV-Cre or AAV-Cre plus AAV-Flag-HDAC3. Mice were fed ad libitum and harvested at 5 pm (ZT10) at 2-weeks post-injection. Liver total RNA was extracted and hybridized to Affymetrix Mouse Gene 1.0ST array.
Project description:Gene expression changes in the heart of MCH3-KO mouse (HDAC3 f/f, Muscle Creatine Kinase-Cre) versus control WT mouse (HDAC3 f/f). Histone deacetylases (HDACs) play important roles in cardiac development and function. We show here that mice deficient of HDAC3 in heart and skeletabl muscle are relatively normal on normal chow, but develop hypertrophic cardiomyopathy and heart failure that leads to death on high-fat diet. This microarray experiment is to explore the underlying molecular mechanism. Hearts from 6-weeks old WT and MCH3-KO C57BL/6 mice (n=4 in each group, male) on normal chow were subjected to RNA extraction and Affymetrix Mouse Gene 1.0ST analysis.
Project description:We profiled gene expression in livers depleted of NCOR (nuclear receptor corepressor) along with wild-type livers as control. NCOR floxed mice were intravenously injected with adeno-associated virus (AAV) expressing Cre or GFP. Livers were harvested at 2-weeks post-injection at 5pm (ZT10). Total RNA was extracted and hybridized to Affymetrx Mouse Gene 2.0 array.
Project description:Liver-specific depletion of HDAC3 leads to liver steatosis (fatty liver), suggesting disregulation of lipid metabolism. This is correlated with changes in lipid metabolic gene expression. Livers depleted of HDAC3 were removed from 12 week old male HDAC3 fl/fl mice (loxP sites flanking exon 4 to 7 of the HDAC3 gene encoding the catalytic domain of HDAC3) one week after the injection of AAV2/8-Tbg-Cre virus. Livers from the HDAC3 fl/fl mice injected with AAV2/8-Tbg-GFP were used as normal controls. mRNA was extracted from 100mg mouse liver samples and hybridized to Affymetrix microarrays. For each group (HDAC3 depleted liver and normal liver), we have 5 samples from different mice.
Project description:We report the hepatic gene expression changes in NCOR and SMRT DADm-mutated mice. 10-12 wk male mouse liver for RNA extraction and hybridization on Affymetrix microarrays. We sought to find differential gene changes between wt and NS-DADm mice.
Project description:Histone deacetylase 3 (HDAC3) is an epigenome-modifying enzyme that is required for normal mouse development and tissue-specific functions. In vitro, HDAC3 protein itself has minimal enzyme activity, but gains its histone deacetylation function from stable association with the conserved deacetylase activation domain (DAD) contained in nuclear receptor corepressors NCOR1 and SMRT. Here we show that HDAC3 enzyme activity is undetectable in mice bearing point mutations in the DAD of both NCOR1 and SMRT (NS-DADm), despite normal levels of HDAC3 protein. Local histone acetylation is increased, and genomic HDAC3 recruitment is reduced though not abrogated. Remarkably, the NS-DADm mice are born and live to adulthood, whereas genetic deletion of HDAC3 is embryonic lethal. These findings demonstrate that nuclear receptor corepressors are required for HDAC3 enzyme activity in vivo, and suggest that a deacetylase-independent function of HDAC3 may be required for life. This SuperSeries is composed of the SubSeries listed below. Refer to individual Series.
Project description:Rett syndrome (RTT; OMIM 312750), a progressive neurological disorder, is caused by mutations in methyl-CpG-binding protein 2 (MECP2; OMIM 300005), a ubiquitously expressed factor. A genetic suppressor screen designed to identify therapeutic targets surprisingly revealed that downregulation of the cholesterol biosynthesis pathway improves neurological phenotypes in Mecp2 mutant mice. Here, we show that MeCP2 plays a direct role in regulating lipid metabolism. Mecp2 deletion in mice results in a host of severe metabolic defects caused by lipid accumulation, including insulin resistance, fatty liver, perturbed energy utilization, and adipose inflammation by macrophage infiltration. We show that MeCP2 regulates lipid homeostasis by anchoring the repressor complex containing NCoR1 and HDAC3 to its lipogenesis targets in hepatocytes. Consistently, we find that liver targeted deletion of Mecp2 causes fatty liver disease and dyslipidemia similar to HDAC3 liver-specific deletion. These findings position MeCP2 as a novel component in metabolic homeostasis. Rett syndrome patients also show signs of peripheral dyslipidemia; thus, together these data suggest that RTT should be classified as a neurological disorder with systemic metabolic components. We previously showed that treatment of Mecp2 mice with statin drugs alleviated motor symptoms and improved health and longevity. Lipid metabolism is a highly treatable target; therefore, our results shed light on new metabolic pathways for treatment of Rett syndrome.
Project description:The oncogene DEK is found fused with the NUP214 gene creating oncoprotein DEK-NUP214 that induces acute myeloid leukemia (AML) in patients, and secreted DEK protein functions as a hematopoietic cytokine to regulate hematopoiesis; however, the intrinsic role of nuclear DEK in hematopoietic stem cells (HSCs) remains largely unknown. Here, we show that HSCs lacking DEK display defects in long-term self-renew capacity, eventually resulting in impaired hematopoiesis. DEK deficiency reduces quiescence and accelerates mitochondrial metabolism in HSCs, in part, dependent upon activating mTOR signaling. At the molecular level, DEK recruits the corepressor NCoR1 to repress acetylation of histone 3 at lysine 27 (H3K27ac) and restricts the chromatin accessibility of HSCs, governing the expression of quiescence-associated genes (e.g., Akt1/2, Ccnb2, and p21). Inhibition of mTOR activity largely restores the maintenance and potential of Dek-cKO HSCs. These findings highlight the crucial role of nuclear DEK in preserving HSC potential, uncovering a new link between chromatin remodelers and HSC homeostasis, and have clinical implications.
Project description:Histone deacetylase 3 (HDAC3) and nuclear receptor co-repressor (NCoR1/2) are epigenetic regulators that play a key role in gene expression and metabolism. HDAC3 is a class I histone deacetylase that functions as a transcriptional co-repressor, modulating gene expression by removing acetyl groups from histones and non-histone proteins. NCoR1, on the other hand, is a transcriptional co-repressor that interacts with nuclear hormone receptors, including peroxisome proliferator-activated receptor gamma (PPARγ) and liver X receptor (LXR), to regulate metabolic gene expression. Recent research has revealed a functional link between HDAC3 and NCoR1 in the regulation of metabolic gene expression. Genetic deletion of HDAC3 in mouse models has been shown to improve glucose intolerance and insulin sensitivity in the liver, skeletal muscle, and adipose tissue. Similarly, genetic deletion of NCoR1 has improved insulin resistance and reduced adiposity in mouse models. Dysregulation of this interaction has been associated with the development of cardio-metabolic diseases such as cardiovascular diseases, obesity and type 2 diabetes, suggesting that targeting this pathway may hold promise for the development of novel therapeutic interventions. In this review, we summarize the current understanding of individual functions of HDAC3 and NCoR1/2 and the co-repressor complex formation (HDAC3/NCoR1/2) in different metabolic tissues. Further studies are needed to thoroughly understand the mechanisms through which HDAC3, and NCoR1/2 govern metabolic processes and the implications for treating metabolic diseases.