OBJECTIVE: To study the role and mechanism of histone deacetylase 1 (HDAC1) and histone deacetylase 2 (HDAC2) in mouse neuronal development. METHODS: The mice with Synapsin1-Cre recombinase were bred with RESULTS: The mice with CONCLUSIONS Deletion of
Animals ; Blotting, Western ; Histone Deacetylase 1/genetics* ; Histone Deacetylase 2 ; Histone Deacetylases/genetics* ; Immunohistochemistry ; Mice ; Neurons/metabolism* ; Signal Transduction

Oogenesis is the basic reproductive process of female mammals and is essential for fertilization and embryo development. Recent studies have shown that epigenetic modifications play an important role in the regulation of mammalian reproductive processes (such as oogenesis, spermatogenesis, preimplantation embryo development and sex differentiation). Taking histone acetylation as an instance, the dynamic changes of histone acetyltransferases (HATs) and deacetylases (HDACs) are involved in the regulation of gene activation and inactivation when numerous key physiological events occur during reproduction. Thereinto, HDAC1 and HDAC2, which are highly homologous in terms of both structure and function, play a pivotal role in murine oogenesis. HDAC1 and 2 jointly regulate the global transcription and the incidence of apoptosis of growing oocytes and affect its subsequent growth and development, which reflects their compensatory function. In addition, HDAC1 and 2 also play a specific part in oogenesis respectively. It has shown that HDAC2 is more critical than HDAC1 for oocyte development, which regulates de novo DNA methylation and chromosome segregation. Reciprocally, HDAC1 is more critical than HDAC2 for preimplantation development. Deficiency of HDAC1 causes the decreased proliferation of embryonic stem cells and the smaller embryoid bodies with irregular shape. In this review, we summarized the role and the current research progress of HDAC1/2 in murine oogenesis, to provide a reference for further understanding the relationship between epigenetic modifications and reproductive regulation.
Acetylation ; Animals ; Embryonic Development ; Female ; Histone Deacetylase 1/metabolism* ; Histone Deacetylase 2/metabolism* ; Histone Deacetylases/metabolism* ; Male ; Mice ; Oocytes ; Oogenesis

BACKGROUNDPlacental multidrug resistance-associated protein 2 (MRP2), encoded by ABCC2 gene in human, plays a significant role in regulating drugs' transplacental transfer rates. Studies on placental MRP2 regulation could provide more therapeutic targets for individualized and safe pharmacotherapy during pregnancy. Currently, the roles of epigenetic mechanisms in regulating placental drug transporters are still unclear. This study aimed to investigate the effect of histone deacetylases (HDACs) inhibition on MRP2 expression in the placental trophoblast cell line and to explore whether HDAC1/2/3 are preliminarily involved in this process.

METHODSThe human choriocarcinoma-derived trophoblast cell line (Bewo cells) was treated with the HDAC inhibitors-trichostatin A (TSA) at different concentration gradients of 0.5, 1.0, 3.0, and 5.0 μmol/L. Cells were harvested after 24 and 48 h treatment. Small interfering RNA (siRNA) specific for HDAC1/HDAC2/HDAC3 or control siRNA was transfected into cells. Total HDAC activity was detected by colorimetric assay kits. HDAC1/2/3/ABCC2 messenger RNA (mRNA) and protein expressions were determined by real-time quantitative polymerase chain reaction and Western-blot analysis, respectively. Immunofluorescence for MRP2 protein expression was visualized and assessed using an immunofluorescence microscopy and ImageJ software, respectively.

RESULTSTSA could inhibit total HDAC activity and HDAC1/2/3 expression in company with increase of MRP2 expression in Bewo cells. Reduction of HDAC1 protein level was noted after 24 h of TSA incubation at 1.0, 3.0, and 5.0 μmol/L (vs. vehicle group, all P < 0.001), accompanied with dose-dependent induction of MRP2 expression (P = 0.045 for 1.0 μmol/L, P = 0.001 for 3.0 μmol/L, and P < 0.001 for 5.0 μmol/L), whereas no significant differences in MRP2 expression were noted after HDAC2/3 silencing. Fluorescent micrograph images of MRP2 protein were expressed on the cell membrane. The fluorescent intensities of MRP2 in the control, HDAC2, and HDAC3 siRNA-transfected cells were week, and no significant differences were noticed among these three groups (all P > 0.05). However, MRP2 expression was remarkably elevated in HDAC1 siRNA-transfected cells, which displayed an almost 3.19-fold changes in comparison with the control siRNA-transfected cells (P < 0.001).

CONCLUSIONSHDACs inhibition could up-regulate placental MRP2 expression in vitro, and HDAC1 was probably to be involved in this process.

Cell Line ; Histone Deacetylase 1 ; metabolism ; Histone Deacetylase 2 ; metabolism ; Histone Deacetylase Inhibitors ; pharmacology ; Histone Deacetylases ; metabolism ; Humans ; Hydroxamic Acids ; pharmacology ; Microscopy, Fluorescence ; Multidrug Resistance-Associated Proteins ; genetics ; metabolism ; RNA, Messenger ; Trophoblasts ; cytology ; metabolism

OBJECTIVETo investigate the inhibitory effect of trichostatin A (TSA) on the proliferation of HepG2 cells and explore the underlying mechanism.

METHODSHepG2 cells exposed to different concentrations of TSA for 24, 48, or 72 h were examined for cell growth inhibition using a cell counting kit, changes in cell cycle distribution with flow cytometry, cell apoptosis with annexin V-FTIC/PI double staining, and cell morphology changes under inverted microscope. The expressions of beta-catenin, HDAC1, HDAC3, H3K9, cyclinD1 and Bax proteins in the exposed cells were detected by Western blotting, and the expressions of HDAC1 and HDAC3 mRNAs by quantitative fluorescent PCR.

RESULTSExposure to TSA caused significant dose- and time-dependent inhibition of HepG2 cell proliferation (P<0.05) and resulted in increased cell percentage in G0/G1 and G2/M phases and decreased cell percentage in S phase. The apoptotic index in the control group was (6.22 ± 0.25)%, which increased to (7.17 ± 0.20)% and (18.14 ± 0.42)% after exposure to 250 and 500 nmol/L TSA, respectively. Exposure to 250 and 500 nmol/L TSA also caused cell morphology changes with numerous floating cells. The expressions of beta-catenin, H3K9 and Bax proteins were significantly increased and CyclinD1, HDAC1, and HDAC3 protein expressions decreased in TSA-treated cells, but the expressions of HDAC1 and HDAC3 mRNAs showed no significant changes.

CONCLUSIONSTSA can inhibit the proliferation of HepG2 cells and induce cell cycle arrest and apoptosis by inhibiting HDAC activity, promoting histone acetylation, and activating Wnt/beta-catenin signaling pathway.

Acetylation ; Apoptosis ; Cell Cycle Checkpoints ; Cell Proliferation ; drug effects ; Cyclin D1 ; metabolism ; Hep G2 Cells ; drug effects ; Histone Deacetylase 1 ; metabolism ; Histone Deacetylases ; metabolism ; Histones ; metabolism ; Humans ; Hydroxamic Acids ; pharmacology ; Wnt Signaling Pathway ; bcl-2-Associated X Protein ; metabolism ; beta Catenin ; metabolism

Sumoylation, the conjugation of a small ubiquitin-like modifier (SUMO) protein to a target, has diverse cellular effects. However, the functional roles of the SUMO modification during myogenesis have not been fully elucidated. Here, we report that basal sumoylation of histone deacetylase 1 (HDAC1) enhances the deacetylation of MyoD in undifferentiated myoblasts, whereas further sumoylation of HDAC1 contributes to switching its binding partners from MyoD to Rb to induce myocyte differentiation. Differentiation in C2C12 skeletal myoblasts induced new immunoblot bands above HDAC1 that were gradually enhanced during differentiation. Using SUMO inhibitors and sumoylation assays, we showed that the upper band was caused by sumoylation of HDAC1 during differentiation. Basal deacetylase activity was not altered in the SUMO modification-resistant mutant HDAC1 K444/476R (HDAC1 2R). Either differentiation or transfection of SUMO1 increased HDAC1 activity that was attenuated in HDAC1 2R. Furthermore, HDAC1 2R failed to deacetylate MyoD. Binding of HDAC1 to MyoD was attenuated by K444/476R. Binding of HDAC1 to MyoD was gradually reduced after 2 days of differentiation. Transfection of SUMO1 induced dissociation of HDAC1 from MyoD but potentiated its binding to Rb. SUMO1 transfection further attenuated HDAC1-induced inhibition of muscle creatine kinase luciferase activity that was reversed in HDAC1 2R. HDAC1 2R failed to inhibit myogenesis and muscle gene expression. In conclusion, HDAC1 sumoylation plays a dual role in MyoD signaling: enhancement of HDAC1 deacetylation of MyoD in the basally sumoylated state of undifferentiated myoblasts and dissociation of HDAC1 from MyoD during myogenesis.
Creatine Kinase, MM Form ; Gene Expression ; Histone Deacetylase 1 ; Histone Deacetylases ; Histones ; Luciferases ; Muscle Cells ; Muscle Development ; Myoblasts ; Myoblasts, Skeletal ; Sumoylation ; Transfection

Evidence for immunoregulatory roles of prostaglandins (PGs) is accumulating. Since our observation of PG production by human follicular dendritic cells (FDCs), we investigated the regulatory mechanism of PG production in FDC and attempted to understand the functions of released PGs in the responses of adjacent lymphocytes. Here, using FDC-like cells, HK cells, we analyzed protein expression alterations in cyclooxygenase-2 (COX-2) in the presence of IL-4 or histone deacetylase (HDAC) inhibitors. Both IL-4 and HDAC inhibitors suppressed COX-2 expression in dose-dependent manners. Their effect was specific to COX-2 and did not reach to COX-1 expression. Interestingly, HDAC inhibitors gave rise to an opposing effect on COX-2 expression in peripheral blood monocytes. Our results suggest that IL-4 may regulate COX-2 expression in FDCs by affecting chromatin remodeling and provide insight into the role of cellular interactions between T cells and FDC during the GC reaction. Given the growing interests in wide-spectrum HDAC inhibitors, the differential results on COX-2 expression in HK cells and monocytes raise cautions on their clinical use.
Chromatin Assembly and Disassembly ; Cyclooxygenase 2 ; Dendritic Cells, Follicular ; Histone Deacetylase Inhibitors ; Histone Deacetylases ; Histones ; Humans ; Interleukin-4 ; Lymphocytes ; Monocytes ; Prostaglandins ; Stromal Cells ; T-Lymphocytes

BACKGROUND: Many histone deacetylase (HDAC) inhibitors are well recognized as potential anti-cancer drugs. Inhibition of HDACs induces temporal transcription or epigenetic control, thus regulating many different biological responses. Here, we investigated the osteogenic effect of the HDAC inhibitor suberoylanilide hydroxamic acid (SAHA; vorinostat). METHODS: The effects of SAHA on osteoblast differentiation were examined in the 6XOSE-Luc reporter assay for determination of runt-related transcription factor 2 (Runx2) activity and alkaline phosphatase (ALP) activity and in an immunoprecipitation assay to determine the Runx2 acetylation state. The osteogenic activity of SAHA in vivo was studied in and receptor activator of nuclear factor-kappa B ligand (RANKL)-induced osteoporotic mouse model. RESULTS: SAHA increased the transcriptional activity of Runx2 in a dose-dependent manner in the 6XOSE-Luc reporter assay. SAHA by itself was unable to induce ALP activity; however, SAHA enhanced ALP activity induced by bone morphogenetic protein-2 (BMP-2). The degree of acetylation of Runx2 was increased with SAHA treatment, which suggests that the increase in Runx2 transcriptional activity might be dependent on stabilization by acetylation. Also, SAHA successfully reversed soluble RANKL-induced osteoporotic bone loss. CONCLUSIONS: Our study shows an intriguing osteogenic potential of SAHA in a BMP-2-dependent manner and suggests that SAHA could be used at lower doses along with BMP-2 to treat osteoporosis.
Acetylation ; Alkaline Phosphatase ; Animals ; Bone Morphogenetic Protein 2 ; Epigenomics ; Histone Deacetylase Inhibitors ; Histone Deacetylases ; Hydroxamic Acids* ; Immunoprecipitation ; Mice ; Osteoblasts ; Osteogenesis ; Osteoporosis ; RANK Ligand ; Transcription Factors

BACKGROUND: DNA methylation and histone modification are dynamically linked in the epigenetic control of gene silencing and they play an important role in tumorigenesis. METHODS: To evaluate the role of histone deacetylase 1 (HDAC1) in the development of lung cancer and the relationship between a HDAC1 overexpression and p16INK4a hypermethylation, we performed immunohistochemical staining for HDAC1 in 76 lung cancer specimens (39 squamous cell carcinomas and 37 adenocarcinomas) that had been previously evaluated for their p16INK4a methylation status by real-time quantitative polymerase chain reaction. RESULTS: A HDAC1 overexpression (>50% of HDAC1 immunoreactive cells) was detected in 65 (85.5%) out of the 76 cases and it was more frequently seen in the squamous cell carcinomas (97.4%) than in the adenocarcinomas (73.0%) (p=0.002). The incidence of HDAC1 overexpression tended to be higher in the heavy smokers with more than 20 pack-years (p=0.067). Although there was no statistical significance, the frequency of p16INK4a hypermethylation in the cases with a HDAC1 overexpression (27.7%) tended to be higher than that in the cases without a HDAC1 overexpression (9.0%) (p=0.175). CONCLUSIONS: A HDAC1 overexpression might be involved in lung carcinogenesis, and especially in a subgroup of smoking and squamous cell carcinoma patients, and a HDAC1 overexpression may be associated with p16INK4a hypermethylation.
Adenocarcinoma ; Carcinoma, Squamous Cell ; Cell Transformation, Neoplastic ; Cyclin-Dependent Kinase Inhibitor p16 ; DNA Methylation ; Epigenomics ; Gene Silencing ; Genes, p16 ; Histone Deacetylase 1 ; Histone Deacetylases ; Histones ; Humans ; Incidence ; Lung ; Lung Neoplasms ; Methylation ; Polymerase Chain Reaction ; Smoke ; Smoking

The prevalence of type 2 diabetes mellitus (T2DM) has been increasing worldwide. Therefore, a novel therapeutic strategy by which to prevent T2DM is urgently required. Calorie restriction (CR) can retard the aging processes, and delay the onset of numerous age-related diseases including diabetes. Metabolic CR mimetics may be therefore included as novel therapeutic targets for T2DM. Sirtuin 1 (SIRT1), a NAD+-dependent histone deacetylase that is induced by CR, is closely associated with lifespan elongation under CR. SIRT1 regulates glucose/lipid metabolism through its deacetylase activity on many substrates. SIRT1 in pancreatic beta-cells positively regulates insulin secretion and protects cells from oxidative stress and inflammation, and has positive roles in the metabolic pathway via the modulation in insulin signaling. SIRT1 also regulates adiponectin secretion, inflammation, glucose production, oxidative stress, mitochondrial function, and circadian rhythms. Several SIRT1 activators, including resveratrol have been demonstrated to have beneficial effects on glucose homeostasis and insulin sensitivity in animal models of insulin resistance. Therefore, SIRT1 may be a novel therapeutic target for the prevention of T2DM, implicating with CR. In this review, we summarize current understanding of the biological functions of SIRT1 and discuss its potential as a promising therapeutic target for T2DM.
Adiponectin ; Aging ; Caloric Restriction ; Circadian Rhythm ; Diabetes Mellitus, Type 2 ; Glucose ; Histone Deacetylases ; Homeostasis ; Inflammation ; Insulin ; Insulin Resistance ; Metabolic Networks and Pathways ; Models, Animal ; Oxidative Stress ; Prevalence ; Sirtuin 1 ; Stilbenes

The prevalence of type 2 diabetes mellitus (T2DM) has been increasing worldwide. Therefore, a novel therapeutic strategy by which to prevent T2DM is urgently required. Calorie restriction (CR) can retard the aging processes, and delay the onset of numerous age-related diseases including diabetes. Metabolic CR mimetics may be therefore included as novel therapeutic targets for T2DM. Sirtuin 1 (SIRT1), a NAD+-dependent histone deacetylase that is induced by CR, is closely associated with lifespan elongation under CR. SIRT1 regulates glucose/lipid metabolism through its deacetylase activity on many substrates. SIRT1 in pancreatic beta-cells positively regulates insulin secretion and protects cells from oxidative stress and inflammation, and has positive roles in the metabolic pathway via the modulation in insulin signaling. SIRT1 also regulates adiponectin secretion, inflammation, glucose production, oxidative stress, mitochondrial function, and circadian rhythms. Several SIRT1 activators, including resveratrol have been demonstrated to have beneficial effects on glucose homeostasis and insulin sensitivity in animal models of insulin resistance. Therefore, SIRT1 may be a novel therapeutic target for the prevention of T2DM, implicating with CR. In this review, we summarize current understanding of the biological functions of SIRT1 and discuss its potential as a promising therapeutic target for T2DM.
Adiponectin ; Aging ; Caloric Restriction ; Circadian Rhythm ; Diabetes Mellitus, Type 2 ; Glucose ; Histone Deacetylases ; Homeostasis ; Inflammation ; Insulin ; Insulin Resistance ; Metabolic Networks and Pathways ; Models, Animal ; Oxidative Stress ; Prevalence ; Sirtuin 1 ; Stilbenes