OBJECTIVE: To explore the specific mechanism of histone deacetylase 2 (HDAC2) mediated histone H3 lysine 27 acetylation (H3K27ac) modification in promoting the proliferation and migration of hepatocellular carcinoma cells. METHODS: Samples of 40 cases of hepatocellular carcinoma and paracancerous tissues resected from January 2021 to January 2023 were collected. The expressions of HDAC2 and H3K27ac in hepatocellular carcinoma, paracancerous tissues and cell lines were detected by immunohistochemistry and Western blotting. The correlation between the expression levels of HDAC2 and H3K27ac and the relationship between HDAC2 expression and clinicopathological characteristics of patients with hepatocellular carcinoma were analyzed. The proliferation, migration and invasion of Hep3B and HepG2 cells were determined by MTS, clone formation, scratch and Transwell experiments. The acetylation of H3K27 mediated by HDAC2 was verified by Western blotting, real-time fluorescence quantitative PCR (qRT-PCR) and chromatin immunoprecipitation high-throughput sequencing (ChIP-seq). In vivo xenotransplantation experiment, the tumorigenicity of cells in each group was measured, and the expression of proteins related to phosphoinositide 3-kinases/phosphatase and tensin homolog deleted on chromosome ten/protein kinase B/mammalian target of rapamycin (PI3K/PTEN/AKT/mTOR) signal pathway was detected. RESULTS: High expression of HDAC2 and low expression of H3K27ac were found in hepatocellular carcinoma tissues and cell lines (P < 0.05), and there was a negative correlation between them (r=-0.477, P=0.002). The expression of HDAC2 was related to tumor size, hepatitis B virus infection, TNM stage and portal vein tumor thrombus (P < 0.05). Compared with the sh-NC group of Hep3B and HepG2 cells, the proliferation, clone formation, migration and invasion ability of sh-HDAC2 group were decreased (P < 0.05). Compared with the Empty group, the HDAC2 group exhibited increased expression levels and activity of HDAC2, as well as enhanced cell proliferation, clone formation, migration, invasion ability, tumor volume and mass in vivo, and elevated expression levels of p-PI3K, p-AKT, and p-mTOR (P < 0.05). Conversely, the enrichment and expression levels of H3K27ac, along with the expression level of PTEN, were decreased (P < 0.05). In the iHDAC2 group, the expression levels and activity of HDAC2, as well as the proliferation, clone formation, migration, invasion ability, tumor volume and mass in vivo, and expression levels of p-PI3K, p-AKT, and p-mTOR were reduced (P < 0.05). Additionally, the expression levels of H3K27ac and PTEN were increased (P < 0.05). To validate the involvement of the PI3K/PTEN/AKT/mTOR signaling pathway in HDAC2-mediated regulation of malignant behaviors in liver cancer cells through H3K27ac, the PI3K activator 740Y-P was introduced. Compared with the iHDAC2 group, the iHDAC2+740Y-P group exhibited increased proliferation, clone formation, migration, invasion ability, tumor volume and mass in vivo, and elevated expression levels of p-PI3K, p-AKT, and p-mTOR (P < 0.05). Conversely, the expression level of PTEN was decreased (P < 0.05). CONCLUSION HDAC2 initiates PI3K/PTEN/AKT/mTOR signal pathway by mediating H3K27 acetylation, which promotes the occurrence and development of hepatocellular carcinoma.
Humans ; Carcinoma, Hepatocellular/metabolism* ; Liver Neoplasms/metabolism* ; Histone Deacetylase 2/physiology* ; Cell Proliferation ; Acetylation ; Cell Movement ; Histones/metabolism* ; Animals ; Hep G2 Cells ; Male ; Female ; Mice ; Cell Line, Tumor ; Signal Transduction ; Mice, Nude ; PTEN Phosphohydrolase/metabolism* ; Lysine/metabolism* ; Middle Aged

OBJECTIVES: To explore the mechanism by which histone deacetylase 1 (HDAC1) regulates steroid-induced apoptosis of mouse osteocyte-like MLO-Y4 cells. METHODS: MLY-O4 cells were treated with 400 nmol/L trichostatin A (TSA) or 1 mmol/L dexamethasone for 24 h or transfected with a HDAC1-overexpressing vector prior to TSA or dexamethasone treatment. The changes in the expressions of HDAC1, SP1, cleaved caspase-3 and Bax, SP1 acetylation level, cell proliferation, and cell apoptosis were examined. The interaction between HDAC1 and SP1 was determined with immunoprecipitation assay and Western blotting. RESULTS: Treatment with dexamethasone significantly increased cell apoptosis, enhanced the expressions of cleaved caspase-3 and Bax, reduced HDAC1 expression, and suppressed proliferation of MLO-Y4 cells. Both TSA and dexamethasone obviously increased SP1 acetylation level and the expression of SP1 in MLO-Y4 cells. HDAC1 overexpression in the cells significantly attenuated the effect of TSA and dexamethasone, promoted cell proliferation, lowered the expressions of SP1, cleaved caspase-3 and Bax, and inhibited dexamethasone-induced cell apoptosis. Immunoprecipitation assay and Western blotting demonstrated the interaction between HDAC1 and SP1 in the cells. CONCLUSIONS HDAC1 inhibits dexamethasone-induced apoptosis and promotes proliferation of cultured mouse osteocytes by suppressing SP1 expression via promoting its deacetylation.
Animals ; Apoptosis/drug effects* ; Mice ; Histone Deacetylase 1/genetics* ; Osteocytes/drug effects* ; Sp1 Transcription Factor/metabolism* ; Acetylation ; Dexamethasone/pharmacology* ; Cell Proliferation/drug effects* ; Caspase 3/metabolism* ; Cell Line ; Hydroxamic Acids/pharmacology* ; bcl-2-Associated X Protein/metabolism*

Diffuse large B-cell lymphoma (DLBCL) is an aggressive type of non-Hodgkin's lymphoma. A total of 10%‒15% of DLBCL cases are associated with myelocytomatosis viral oncogene homolog(MYC) and/or B-cell lymphoma-2 (BCL2) translocation or amplification. BCL2 inhibitors have potent anti-tumor effects in DLBCL; however, resistance can be acquired through up-regulation of alternative anti-apoptotic proteins. The histone deacetylase (HDAC) inhibitor chidamide can induce BIM expression, leading to apoptosis of lymphoma cells with good efficacy in refractory recurrent DLBCL. In this study, the synergistic mechanism of chidamide and venetoclax in DLBCL was determined through in vitro and in vivo models. We found that combination therapy significantly reduced the protein levels of MYC, TP53, and BCL2 in activated apoptotic-related pathways in DLBCL cells by increasing BIM levels and inducing cell apoptosis. Moreover, combination therapy regulated expression of multiple transcriptomes in DLBCL cells, involving apoptosis, cell cycle, phosphorylation, and other biological processes, and significantly inhibited tumor growth in DLBCL-bearing xenograft mice. Taken together, these findings verify the in vivo therapeutic potential of chidamide and venetoclax combination therapy in DLBCL, warranting pre-clinical trials for patients with DLBCL.
Aminopyridines ; Animals ; Benzamides ; Biological Phenomena ; Bridged Bicyclo Compounds, Heterocyclic ; Down-Regulation ; Histone Deacetylase Inhibitors/therapeutic use* ; Humans ; Lymphoma, Large B-Cell, Diffuse/pathology* ; Mice ; Neoplasm Recurrence, Local ; Proto-Oncogene Proteins c-bcl-2/metabolism* ; Proto-Oncogene Proteins c-myc/therapeutic use* ; Sulfonamides ; Tumor Suppressor Protein p53/metabolism*

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

BACKGROUND: Glucocorticoids have been widely used to treat patients with chronic obstructive pulmonary disease (COPD). Nevertheless, corticosteroid insensitivity is a major barrier to the effective treatment of COPD and its mechanism remains unclear. This study aimed to evaluate the effect of cathelicidin LL-37 on corticosteroid insensitivity in COPD rat model, and to explore the involved mechanisms. METHODS: COPD model was established by exposing male Wistar rats to cigarette smoke combined with intratracheal instillation of lipopolysaccharide (LPS). Inhaled budesonide and LL-37 were consequently applied to COPD models separately or collectively to confirm the effects on inflammatory cytokines (tumor necrosis factor [TNF]-α and transforming growth factor [TGF]-β) by enzyme-linked immunosorbent assay (ELISA) and lung tissue histopathological morphology. Expression of histone deacetylase-2 (HDAC2) and phosphorylation of Akt (p-AKT) in lung were also measured. RESULTS: Briefly, COPD model rats showed an increased basal release of inflammatory cytokines (lung TNF-α: 45.7 ± 6.1 vs. 20.1 ± 3.8 pg/mL, P < 0.01; serum TNF-α: 8.9 ± 1.2 vs. 6.7 ± 0.5 pg/mL, P = 0.01; lung TGF-β: 122.4 ± 20.8 vs. 81.9 ± 10.8 pg/mL, P < 0.01; serum TGF-β: 38.9 ± 8.5 vs. 20.6 ± 2.3 pg/mL, P < 0.01) and COPD related lung tissue histopathological changes, as well as corticosteroid resistance molecular profile characterized by an increase in phosphoinositide 3-kinase (PI3K)/Akt (0.5 ± 0.1 fold of control vs. 0.2 ± 0.1 fold of control, P = 0.04) and a decrease in HDAC2 expression and activity (expression: 13.1 ± 0.4 μmol/μg vs. 17.4 ± 1.1 μmol/μg, P < 0.01; activity: 1.1 ± 0.1 unit vs. 1.4 ± 0.1 unit, P < 0.01), compared with control group. In addition, LL-37 enhanced the anti-inflammatory effect of budesonide in an additive manner. Treatment with combination of inhaled corticosteroids (ICS) and LL-37 led to a significant increase of HDAC2 expression and activity (expression: 15.7 ± 0.4 μmol/μg vs. 14.1 ± 0.9 μmol/μg, P < 0.01; activity: 1.3 ± 0.1 unit vs. 1.0 ± 0.1 unit, P < 0.01), along with decrease of p-AKT compared to budesonide monotherapy (0.1 ± 0.0 fold of control vs. 0.3 ± 0.1 fold of control, P < 0.01). CONCLUSIONS This study suggested that LL-37 could improve the anti-inflammatory activity of budesonide in cigarette smoke and LPS-induced COPD rat model by enhancing the expression and activity of HDAC2. The mechanism of this function of LL-37 might involve the inhibition of PI3K/Akt pathway.
Animals ; Antimicrobial Cationic Peptides ; pharmacology ; therapeutic use ; Glucocorticoids ; metabolism ; Histone Deacetylase 2 ; metabolism ; Humans ; Inflammation ; chemically induced ; drug therapy ; Lipopolysaccharides ; pharmacology ; Male ; Phosphatidylinositol 3-Kinases ; metabolism ; Proto-Oncogene Proteins c-akt ; metabolism ; Pulmonary Disease, Chronic Obstructive ; drug therapy ; metabolism ; Rats ; Rats, Wistar ; Smoking ; adverse effects ; Tumor Necrosis Factor-alpha ; metabolism

Interferon-γ (IFN-γ) has been used to control cancers in clinical treatment. However, an increasing number of reports have suggested that in some cases effectiveness declines after a long treatment period, the reason being unclear. We have reported previously that long-term IFN-γ treatment induces malignant transformation of healthy lactating bovine mammary epithelial cells (BMECs) in vitro. In this study, we investigated the mechanisms underlying the malignant proliferation of BMECs under IFN-γ treatment. The primary BMECs used in this study were stimulated by IFN-γ (10 ng/mL) for a long term to promote malignancy. We observed that IFN-γ could promote malignant cell proliferation, increase the expression of cyclin D1/cyclin-dependent kinase 4 (CDK4), decrease the expression of p21, and upregulate the expression of cellular-abelsongene (c-Abl) and histone deacetylase 2 (HDAC2). The HDAC2 inhibitor, valproate (VPA) and the c-Abl inhibitor, imatinib, lowered the expression level of cyclin D1/CDK4, and increased the expression level of p21, leading to an inhibitory effect on IFN-γ-induced malignant cell growth. When c-Abl was downregulated, the HDAC2 level was also decreased by promoted proteasome degradation. These data suggest that IFN-γ promotes the growth of malignant BMECs through the c-Abl/HDAC2 signaling pathway. Our findings suggest that long-term application of IFN-γ may be closely associated with the promotion of cell growth and even the carcinogenesis of breast cancer.
Animals ; Carcinogenesis/pathology* ; Cattle ; Cell Cycle Proteins/metabolism* ; Cell Proliferation/drug effects* ; Cell Transformation, Neoplastic/pathology* ; Cells, Cultured ; Epithelial Cells/pathology* ; Female ; Histone Deacetylase 2/metabolism* ; Imatinib Mesylate/pharmacology* ; Interferon-gamma/pharmacology* ; Mammary Glands, Animal/pathology* ; Mammary Neoplasms, Experimental/pathology* ; Proto-Oncogene Proteins c-abl/metabolism* ; Signal Transduction ; Valproic Acid/pharmacology*

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 effect of histone acetylation/deacetylation imbalances on embryonic hearts of mice and its effect on key genes of planar cell polarity (PCP) pathway-Vangl2, Scrib and Rac1 in H9C2 cells.

METHODSForty pregnant C57/B6 mice were randomly assigned into three groups: blank group (n=10), vehicle group (n=10), and valproic acid (VPA)-treated group (n=20). In the VPA-treated group, VPA, a histone deacetylase (HDAC) inhibitor, was administered to each individual dam intraperitoneally at a single dose of 700 mg/kg on embryonic day 10.5 (E10.5). The vehicle and blank groups received equivalent saline or no interventions, respectively. Dams were sacrificed on E15.5, and death rates of embryos were evaluated. Subsequently, embryonic hearts of survival fetus were removed to observe cardiac abnormalities by hematoxylin-eosin (HE) staining. H9C2 cells were cultured and allotted to the blank, vehicle, and VPA-treated groups: the VPA treated group received VPA exposure at concentrations of 2.0, 4.0 and 8.0 mmol/L; the vehicle and blank groups received equivalent saline or no interventions, respectively. HDAC1-3 as well as Vangl2, Scrib and Rac1 mRNA and protein expression levels were determined by quantitative real-time PCR and Western blot, respectively. The total HDAC activity was analyzed by colorimetric assay.

RESULTSThe fetus mortality rate after VPA treatment was 31.7%, with a significantly higher rate of cardiac abnormalities in comparison with the controls (P<0.05). In comparison with the blank and vehicle groups, HDAC1 mRNA was significantly increased at various concentrations of VPA treatment at all time points of exposure (P<0.05), together with a reduction of protein level after 48 and 72 hours of exposure (P<0.05). The inhibition of HDAC2 mRNA after various concentrations of VPA incubation was pronounced at 24 hours of exposure (P<0.05), while the protein levels were reduced at all time points (P<0.05). HDAC3 mRNA was prominently induced by VPA (4.0 and 8.0 mmol/L) at all time points of treatment (P<0.05). In contrast, the protein level was inhibited after VPA treatment (P<0.05). In comparison with the blank and vehicle groups, Vangl2 mRNA as well as Scrib mRNA/protein expression levels were markedly reduced after 48 and 72 hours of VPA treatment (P<0.05), together with a reduction of protein level in Vangl2 at 72 hours (P<0.05). Compared with the blank and vehicle groups, a significant repression in the total HDAC activity was observed in the VPA-treated group at concentrations of 4.0 and 8.0 mmol/L after 24 hours of treatment (P<0.05), and the effect persisted up to 48 and 72 hours, exhibiting pronounced inhibition at all concentrations (P<0.05).

CONCLUSIONSVPA might result in acetylation/deacetylation imbalances by inhibiting HDAC1-3 protein expression and total HDAC activity, leading to the down-regulation of mRNA and protein expression of Vangl2 and Scrib. This could be one of the mechanisms contributing to congenital heart disease.

Acetylation ; Animals ; Cell Polarity ; Cells, Cultured ; Fetal Heart ; drug effects ; metabolism ; Heart Defects, Congenital ; etiology ; Histone Deacetylase 1 ; genetics ; Histone Deacetylase 2 ; genetics ; Histones ; metabolism ; Mice ; Mice, Inbred C57BL ; Nerve Tissue Proteins ; genetics ; RNA, Messenger ; analysis ; Valproic Acid ; pharmacology

To confirm whether class I histone deacetylase inhibitors (HDACIs) are effective in relief of peripheral inflammatory pain, the effects of two selective inhibitors, MS-275 and MGCD0103, were studied in rats inflamed by subcutaneous (s.c.) injection of bee venom (BV). The BV test is characterized by displaying both persistent spontaneous nociception (PSN) and primary hypersensitivity. Intrathecal (i.t.) pre-treatment of either MS-275 or MGCD0103 with a single dose of 60 nmol/20 μL resulted in profound suppression of both PSN and primary thermal hypersensitivity but without significant influence upon the primary mechanical hypersensitivity and mirror-image thermal hypersensitivity. Moreover, the up-regulation of both HDAC1 and HDAC2 induced by s.c. BV injection was completely suppressed by i.t. pre-treatment of MS-275. The present results provide with another new line of evidence showing involvement of epigenetic regulation of chromatin structure by HDAC1/2-mediated histone hypoacetylation in the BV-induced PSN and thermal hypersensitivity and demonstrate the beneficial effects of class I HDACIs in prevention of peripheral inflammatory pain from occurring.
Animals ; Bee Venoms ; administration & dosage ; Benzamides ; pharmacology ; Epigenesis, Genetic ; Histone Deacetylase 1 ; genetics ; metabolism ; Histone Deacetylase 2 ; genetics ; metabolism ; Histone Deacetylase Inhibitors ; pharmacology ; Hot Temperature ; Hyperalgesia ; drug therapy ; Inflammation ; drug therapy ; Injections, Subcutaneous ; Nociception ; Pain ; chemically induced ; drug therapy ; Pain Measurement ; Pyridines ; pharmacology ; Pyrimidines ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Up-Regulation