Histone Deacetylase 1 Knockdown Research Articles

The Potential Mechanism of HDAC1-Catalyzed Histone Crotonylation of Caspase-1 in Nonsmall Cell Lung Cancer.

Nonsmall cell lung cancer (NSCLC) is a predominant subtype of lung cancer and accounts for over 80% of all lung cancer cases. The resistance to pemetrexed (PEM) is frequently occurred and severely affects the NSCLC therapy. Proteomic analysis of histones indicated that the histone deacetylase 1 (HDAC1) complex could hydrolyze lysine crotonylation on histone3 (H3K18cr), affecting epigenetic regulation in cancers. However, the effect of HDAC1-mediated H3K18cr on the PEM resistance of NSCLC is still unclear. Here, we aimed to explore the function of HDAC1-mediated H3K18cr in NSCLC PEM resistance. The expression of HDAC1 was upregulated in clinical NSCLC tissues and cell lines and correlated with the poor prognosis of NSCLC samples. We constructed the PEM-resistant NSCLC cell lines, and the depletion of HDAC1 remarkably reduced the viability of the cells. The proliferation of PEM-resistant NSCLC cells was decreased by HDAC1 knockdown, and the IC50 of PEM was repressed by the silencing of HDAC1 in the cells. Mechanically, we identified the enrichment of HDAC1 on the promoter of caspase-1 in PEM-resistant NSCLC cells. The depletion of HDAC1 inhibited the enrichment of histone H3K18cr and RNA polymerase II (RNA pol II) on the caspase-1 promoter in the cells. The expression of caspase-1 was suppressed by HDAC1 knockdown. The knockdown of HDAC1 reduced proliferation of PEM-resistant NSCLC cells, in which caspase-1 or GSDMD depletion reversed the effect. Clinically, the HDAC1 expression was negatively associated with caspase-1 and GSDMD in clinical NSCLC tissues, while caspase-1 and GSDMD expression was positively correlated in the samples. Therefore, we concluded that HDAC1-catalyzed histone crotonylation of caspase-1 modulates PEM sensitivity of NSCLC by targeting GSDMD.

Exosomal lncRNA HOTAIR Promotes the Progression and Angiogenesis of Endometriosis via the miR-761/HDAC1 Axis and Activation of STAT3-Mediated Inflammation.

BackgroundLong non-coding RNA (lncRNA) and exosomes are implicated in endometriosis development. We measured the expression of an exosomal lncRNA, homeobox transcript antisense RNA (HOTAIR), and explored its molecular mechanism in endometriosis progression.MethodsExpression of HOTAIR and microRNA (miR)-761 in different endometrial tissues was measured. Exosomes were isolated from a culture medium of endometrial stromal cells (ESCs). RT-qPCR was used to measure HOTAIR expression in different exosome types. CCK-8, Edu, wound healing, transwell assays, flow cytometry and tube formation were used to detect the role of exosomal HOTAIR on ESCs and human umbilical vein endothelial cells (HUVECs). The relationship among miR-761, HOTAIR, and histone deacetylase 1 (HDAC1) was verified by dual-luciferase reporter assay. ESCs were transfected with miR-761 mimics or HDAC1 small interfering RNA (si-RNA) to ascertain if alterations in expression of miR-761 or HDAC1 could reverse the effect of exosomal HOTAIR. Then, we detected the effect of the HOTAIR/miR-761/HDAC1 axis on signal transducer and activator of transcription 3 (STAT3)-mediated inflammation. In vivo experiments were conducted to verify in vitro results.ResultsHOTAIR expression was upregulated and miR-761 expression was downregulated in ectopic endometrium tissues. HOTAIR was packaged into exosomes and transported from ESCs to surrounding cells. Exosomal HOTAIR promoted the proliferation, migration, and invasion, and inhibited the apoptosis of ESCs. Angiogenesis of HUVECs was enhanced after cultured with exosomal HOTAIR. HOTAIR acted as a competing endogenous RNA to downregulate miR-761 and increase HDAC1 expression. miR-761 overexpression or HDAC1 knockdown reversed the role of exosomal HOTAIR on ESCs and HUVECs. The HOTAIR/miR-761/HDAC1 axis could activate STAT3-related proinflammatory cytokines and stattic (inhibitor of phosphorylated-STAT3) could reverse the effect of HOTAIR on ESCs and HUVECs. In vivo experiments suggested that exosomal HOTAIR promoted the growth of endometrial lesions in vivo.ConclusionExosomal HOTAIR promoted the progression and angiogenesis of endometriosis by regulating the miR-761/HDAC1 axis and activating STAT3-mediated inflammation in vitro and in vivo, which may provide promising treatment for endometriosis.

Histone deacetylase 1 interacts with HIV-1 Integrase and modulates viral replication

BackgroundHIV-1 hijacks the cellular machinery for its own replication through protein-protein interactions between viral and host cell factors. One strategy against HIV-1 infection is thus to target these key protein complexes. As the integration of reverse transcribed viral cDNA into a host cell chromosome is an essential step in the HIV-1 life cycle, catalyzed by the viral integrase and other important host factors, we aimed at identifying new integrase binding partners through a novel approach.MethodsA LTR-derived biotinylated DNA fragment complexed with the integrase on magnetic beads was incubated with extracts from integrase-expressing 293 T cells. Liquid chromatography-mass spectrometry/mass spectrometry and co-immunoprecipitation/pull-down experiments were used for the identification of binding partners. Transfections of histone deacetylase 1 (HDAC1) expression vectors and/or specific siRNA were conducted in HeLa-CD4 and 293 T cells followed by infection with fully infectious NL4–3 and luciferase-expressing pseudotyped viruses or by proviral DNA transfection. Fully infectious and pseudotyped viruses produced from HDAC1-silenced 293 T cells were tested for their infectivity toward HeLa-CD4 cells, T cell lines and primary CD4+ T cells. Late RT species and integrated viral DNA were quantified by qPCR and infectivity was measured by luciferase activity and p24 ELISA assay. Results were analyzed by the Student’s t-test.ResultsUsing our integrase-LTR bait approach, we successfully identified new potential integrase-binding partners, including HDAC1. We further confirmed that HDAC1 interacted with the HIV-1 integrase in co-immunoprecipitation and pull-down experiments. HDAC1 knockdown in infected HeLa cells was shown to interfere with an early preintegration step of the HIV-1 replication cycle, which possibly involves reverse transcription. We also observed that, while HDAC1 overexpression inhibited HIV-1 expression after integration, HDAC1 knockdown had no effect on this step. In virus producer cells, HDAC1 knockdown had a limited impact on virus infectivity in either cell lines or primary CD4+ T cells.ConclusionsOur results show that HDAC1 interacts with the HIV-1 integrase and affects virus replication before and after integration. Overall, HDAC1 appears to facilitate HIV-1 replication with a major effect on a preintegration step, which likely occurs at the reverse transcription step.

Histone deacetylase-1 as a prognostic factor and mediator of gastric cancer progression by enhancing glycolysis

Histone deacetylase 1 (HDAC1) has been shown to be closely associated with tumor development. We investigated its effects on survival and biological behavior in gastric cancer (GC). HDAC1 expression and glycolysis activity were analyzed in a cohort of 252 samples of primary GC tumors and in vitro study. High HDAC1 (HDAC1High) staining was seen in 60.7% patients with GCs, which was significantly greater than was seen in normal epithelial cells (19.4%; P < .005). HDAC1High expression was associated with larger tumor size (P = .001), advanced T stage (P = .001), lymph node metastases (N stage; P < .001), and lymphovascular invasion (P = .005). Univariate and multivariate survival analyses showed HDAC1 expression to be an independent prognostic factor for both disease-free survival and overall survival (P < .05). In vitro studies showed a notably decreased glycolysis rate in HDAC1 knockdown cells. In patients' samples, HDAC1High expression was always accompanied with high Maximal standardized uptake value (SUVmax) value (P < .05). A hypoxia-inducible factor (HIF)-1α response element-luciferase reporter system showed HDAC1 to affect HIF1α activity in a dose-dependent manner. In conclusion, HDAC1 promotes glycolysis in GC and affects HIF-1α activity in tumor progression and metastasis. HDAC1High expression was also an independent adverse prognostic factor for overall survival and disease-free survival.

Acetylation of PGC1α by Histone Deacetylase 1 Downregulation Is Implicated in Radiation-Induced Senescence of Brain Endothelial Cells.

Peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC1α) is a potent transcription factor for mitochondrial function, lipid metabolism, and detoxification in a variety of tissues. PGC1α also promotes brain cell proliferation and memory. However, how PGC1α is involved in aging is not well known. In brain endothelial cells, we found that PGC1α knockdown accelerated DNA damage-induced senescence, evidenced by an increase in senescence-associated β-galactosidase-positive cells and a decrease in cell proliferation and adenosine triphosphate production. PGC1α knockdown delayed DNA damage repair mechanisms compared with the wild-type condition as shown by γ-H2AX foci staining assay. Overexpression of PGC1α reduced senescence-associated β-galactosidase-positive cells and increased the proliferation of senescent cells. Although PGC1α protein levels were not decreased, PGC1 acetylation was increased by ionizing radiation treatment and aging. Histone deacetylase 1 (HDAC1) expression was decreased by ionizing radiation treatment and aging, and downregulation of HDAC1 induced acetylation of PGC1α. HDAC1 knockdown affected sirtuin 1 expression and decreased its deacetylation of PGC1α. In the mouse brain cortex, acetylation of PGC1α was increased by ionizing radiation treatment. These results suggest that acetylation of PGC1α is induced by DNA damage agents such as ionizing radiation, which deregulates mitochondrial mechanisms and metabolism, resulting in acceleration of radiation-induced senescence. Therefore, acetylation of PGC1α may be a cause of brain disorders and has the potential to serve as a therapeutic target for radiation-induced senescence after radiation cancer therapy.

Histone deacetylase 1 promotes glioblastoma cell proliferation and invasion via activation of PI3K/AKT and MEK/ERK signaling pathways

Histone deacetylase 1 (HDAC1) plays a crucial role in cancer progression and development. This enzyme has been confirmed to be a key regulator of tumor biology functions, such as tumor cell proliferation, migration and invasion. However, HDAC1 expression in glioma remains controversial, and its specific function and molecular mechanism in glioblastoma is poorly understood. In this study, our findings demonstrated that protein and mRNA levels of HDAC1 were increased in glioma cell lines and glioma tissues compared to normal glial cell lines and non-neoplastic brain tissues, respectively. Furthermore, HDAC1 knockdown cells displayed decreased proliferation and invasion capabilities, whereas HDAC1 overexpressing glioblastoma cells displayed more proliferation and invasion capabilities in vitro. These novel outcomes suggested that knockdown of HDAC1 possibly suppressed the expression of phosphorylated AKT (p-AKT) and phosphorylated ERK (p-ERK) proteins, while overexpression of HDAC1 significantly increased p-AKT and p-ERK protein in glioblastoma cells. In addition, knockdown of HDAC1 repressed subcutaneous tumor growth in vivo, and led to down-regulation of p-AKT and p-ERK protein in U87 MG xenograft tumors. For the first time, we have demonstrated that HDAC1 promotes proliferation and invasion in glioblastoma cells by activating PI3K/AKT and MEK/ERK signaling pathways in vitro and in vivo. These results suggest that HDAC1 may be a novel biomarker and potential therapeutic target in glioblastoma.

HDAC1 knockdown inhibits invasion and induces apoptosis in non-small cell lung cancer cells.

Non-small cell lung cancer (NSCLC) is a common malignant tumor. Although the abnormal expression and potential clinical prognostic value of histone deacetylase 1 (HDAC1) were recently discovered in many kinds of cancer, the roles and molecular mechanisms of HDAC1 in NSCLC is still limited. The CCK-8 assay is used to evaluate the viability of NSCLC cells. Downregulation of HDAC1 by shRNA. The TUNEL assay was used to evaluate the role of HDAC1 in NSCLC apoptosis. To evaluate the role of HDAC1 in NSCLC cells migration, the Boyden chamber transwell assay and wound healing assay were used. To evaluate the cells invasion, the matrigel precoated Transwell assay was used. Enzyme-linked immunosorbent assays (ELISAs) were used to detect the level of vascular endothelial growth factor (VEGF) and IL-8 in NSCLC. To investigate the role of HDAC1 in angiogenesis, the tube formation assay was investigated. In this study, we showed that HDAC1 expression was elevated in NSCLC lines compared to that in normal liver cells LO2. Furthermore, downregulation of HDAC1 inhibited cell proliferation, prevented cell migration, decreased cell invasion, reduced tumor angiogenesis and induced cell apoptosis. In summary, HDAC1 may be regarded as a potential indicator for NSCLC patient treatment.

Knockdown of HDAC1 expression suppresses invasion and induces apoptosis in glioma cells.

Glioma is the most common malignant tumor of the central nervous system, with a low survival rate of five years worldwide. Although high expression and prognostic value of histone deacetylase 1 (HDAC1) have been recently reported in various types of human tumors, the molecular mechanism underlying the biological function of HDAC1 in glioma is still unclear. We found that HDAC1 was elevated in glioma tissues and cell lines. HDAC1 expression was closely related with pathological grade and overall survival of patients with gliomas. Downregulation of HDAC1 inhibited cell proliferation, prevented invasion of glioma cell lines, and induced cell apoptosis. The expression of apoptosis and metastasis related molecules were detected by RT-PCR and Western blot, respectively, in U251 and T98G cells with HDAC1 knockdown. We found that HDAC1 knockdown upregulated expression of BIM, BAX, cleaved CASPASE3 and E-CADHERIN, and decreased expression of TWIST1, SNAIL and MMP9 in U251 and T98G cells with HDAC1 knockdown. In vivo data showed that knockdown of HDAC1 inhibited tumor growth in nude mice. In summary, HDAC1 may therefore be considered an unfavorable progression indicator for glioma patients, and may also serve as a potential therapeutic target.

Visual experience dependent regulation of neuronal structure and function by histone deacetylase 1 in developing Xenopus tectum in vivo.

Histone deacetylase 1 (HDAC1) is thought to play pivotal roles in neurogenesis and neurodegeneration. However, the role of HDAC1 in neuronal growth and structural plasticity in the developing brain in vivo remains unclear. Here, we show that in the optic tectum of Xenopus laevis, HDAC1 knockdown dramatically decreased the frequency of AMPAR-mediated synaptic currents and increased the frequency of GABAAR-mediated currents, whereas HDAC1 overexpression significantly decreased the frequency of GABAAR-mediated synaptic currents. Both HDAC1 knockdown and overexpression adversely affected dendritic arbor growth and visual experience-dependent structural plasticity. Furthermore, HDAC1 knockdown decreased BDNF expression via a mechanism that involves acetylation of specific histone H4 residues at lysine K5. In particular, the deficits in dendritic growth and visually guided avoidance behavior in HDAC1-knockdown tadpoles could be rescued by acute tectal infusion of BDNF. These results establish a relationship between HDAC1 expression, histone H4 modification and BDNF signaling in the visual-experience dependent regulation of dendritic growth, structural plasticity and function in intact animals in vivo. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 77: 947-962, 2017.

TAp73 Protein Stability Is Controlled by Histone Deacetylase 1 via Regulation of Hsp90 Chaperone Function

Histone deacetylases (HDACs) play important roles in fundamental cellular processes, and HDAC inhibitors are emerging as promising cancer therapeutics. p73, a member of the p53 family, plays a critical role in tumor suppression and neural development. Interestingly, p73 produces two classes of proteins with opposing functions: the full-length TAp73 and the N-terminally truncated ΔNp73. In the current study, we sought to characterize the potential regulation of p73 by HDACs and found that histone deacetylase 1 (HDAC1) is a key regulator of TAp73 protein stability. Specifically, we showed that HDAC1 inhibition by HDAC inhibitors or by siRNA shortened the half-life of TAp73 protein and subsequently decreased TAp73 expression under normal and DNA damage-induced conditions. Mechanistically, we found that HDAC1 knockdown resulted in hyperacetylation and inactivation of heat shock protein 90, which disrupted the interaction between heat shock protein 90 and TAp73 and thus promoted the proteasomal degradation of TAp73. Functionally, we found that down-regulation of TAp73 was required for the enhanced cell migration mediated by HDAC1 knockdown. Together, we uncover a novel regulation of TAp73 protein stability by HDAC1-heat shock protein 90 chaperone complex, and our data suggest that TAp73 is a critical downstream mediator of HDAC1-regulated cell migration.

Abstract 340: From Stem Cells to Cardiomyocytes: HDAC1 Induces Cardiovascular Differentiation by Regulating SOX17-BMP2 Expression in Early Development.

Cardiomyocytes derived from embryonic and induced pluripotent stem cells (ES/iPS) provide an excellent source for cell replacement therapies following myocardial ischemia. However, some of the obstacles in the realization of the full potential of iPS/ES cells arise from incomplete and poorly understood molecular mechanisms and epigenetic modifications that govern their cardiovascular specific differentiation. We identified Histone Deacetylase 1 (HDAC1) as a crucial regulator in early differentiation of mES and iPS cells. We propose a novel pathway in which HDAC1 regulates cardiovascular differentiation by regulating SOX17 which in turn regulates BMP2 signaling in differentiating pluripotent cells. Utilizing stable HDAC1 knock-down (HDAC1-KD) cell lines, we report an essential role for HDAC1 in deacetylating regulatory regions of pluripotency-associated genes during early cardiovascular differentiation. HDAC1-KD cells show severely repressed cardiomyocyte differentiation potential. We propose a novel HDAC1-BMP2-SOX17 dependent pathway through which deacetylation of pluripotency associated genes leads to their suppression and allows for early cardiovascular-associated genes to be expressed and differentiation to occur. Furthermore, we show that HDAC1 affects DNA methylation both during pluripotency and differentiation and plays a crucial, non-redundant role in cardiovascular specific differentiation and cardiomyocyte maturation. Our data elucidates important differences between ES and iPS HDAC1-KD cells that affect their ability to differentiate into cardiovascular lineages. As varying levels of chromatin modifying enzymes are likely to exist in patient derived iPS cells, understanding the molecular circuitry of these enzymes in ES and iPS cells is critical for their potential therapeutic applications in regenerative medicine. Further research in the molecular mechanisms involved in this process will greatly aid our understanding of the epigenetic circuitry of pluripotency and differentiation in pluripotent cells.

Sirt2 is a novel in vivo downstream target of Nkx2.2 and enhances oligodendroglial cell differentiation

Although Sirt2 is primarily expressed in oligodendrocytes of the central nervous system, its role in oligodendroglial lineage differentiation is not fully understood. Our findings demonstrate that the transcription factor Nkx2.2 binds to the Sirt2 promoter via histone deacetylase 1 (HDAC-1), the binding site for Nkx2.2 maps close to the start codon of the Sirt2 gene, and Nkx2.2 negatively regulates Sirt2 expression in CG4 cells, an oligodendroglial precursor cell line. HDAC-1 knock-down not only significantly attenuates the binding capacity of Nkx2.2 to the Sirt2 promoter but also releases repression of Sirt2 expression by Nkx2.2. Nkx2.2 over-expression down-regulates Sirt2 expression and delays differentiation of CG4 cells; in contrast, up-regulation of Sirt2 does not impact Nkx2.2 expression level. Sirt2 knock-down via RNAi or inhibition of Sirt2 by sirtinol, a Sirt2 activity inhibitor, blocks CG4 cell differentiation. Over-expression of Sirt2 facilitates CG4 cell differentiation at both molecular and cellular levels, enhancing expression of myelin basic protein and facilitating the growth of cell processes. We have conclusively demonstrated that Sirt2 enhances CG4 oligodendroglial differentiation and report a novel mechanism through which Nkx2.2 represses CG4 oligodendroglial differentiation via Sirt2.

Histone Deacetylase 1 Down-Regulation on Developmental Capability and Histone Acetylation in Bovine Oocytes and Parthenogenetic Embryos

Histone deacetylase 1 (HDAC1) is one of the most conserved enzymes present in the nuclei of cells, including bovine oocytes and pre-implantation embryos. However, the biological functions of HDAC1 in supporting the growth and development of bovine oocytes and embryos are still not fully elucidates. In this study, three siRNAs (si299, si672, and si1272) targeting to HDAC1 mRNA sequence were designed. After transfection into bovine fibroblast cells, si299, the most effective one in HDAC1 knock-down, was selected. The selected siRNA was microinjected into bovine germinal vesicle (GV) stage oocytes to determine the functions of HDAC1 in the maturation of bovine oocytes. Finally, the siRNA was microinjected into mature oocytes, which were then parthenogenetically activated and cultured in vitro until the blastocyst stage. The rates of cleavage, blastocyst development and acetylation of lysine 14 of H3 (H3K14) state were checked. The results suggest that HDAC1 knock-down in oocytes did not influence the rates of maturation or cleavage of parthenogenetic embryos. However, the rates of blastocyst decreased after siRNA microinjection. Furthermore, histone H3K14 acetylation level increased after siRNA microinjection into parthenogenetic embryos.

Requirement of histone deacetylase1 (HDAC1) in signal transducer and activator of transcription 3 (STAT3) nucleocytoplasmic distribution

Signal Transducer and Activator of Transcription 3 (STAT3) is a transcription factor that plays a crucial role in interleukin-6 (IL-6) signaling, mediating the acute-phase induction of the human Angiotensinogen (hAGT) gene in hepatocytes. We showed earlier that IL-6 induces acetylation of the STAT3 NH2-terminus by the recruitment of the p300 coactivator. We had also observed a physical interaction of STAT3 and Histone Deacetylase1 (HDAC1) in an IL-6-dependent manner that leads to transcriptional repression. In this study, we sought to elucidate the mechanism by which HDAC1 controls STAT3 transcriptional activity. Here, we mapped the interacting domains of both STAT3 and HDAC1 and found that the COOH-terminal domain of HDAC1 is necessary for IL-6-induced STAT3 transcriptional repression, whereas the NH2-terminal acetylation domain of STAT3 is required for HDAC1 binding. Interestingly, over expression of HDAC1 in HepG2 cells leads to significantly reduced amounts of nuclear STAT3 after IL-6 induction, whereas silencing of HDAC1 resulted in accumulation of total and acetylated STAT3 in the nucleus. We have found that HDAC1 knockdown also interferes with the responsiveness of the STAT3-dependent MCP1 target gene expression to IL-6, as confirmed by real-time RT–PCR analysis. Together, our study reveals the novel functional consequences of IL-6-induced STAT3-HDAC1 interaction on nucleocytoplasmic distribution of STAT3.

Histone deacetylase 1 (HDAC1) regulates histone acetylation, development, and gene expression in preimplantation mouse embryos

Superimposed on activation of the embryonic genome in preimplantation mouse embryos is the formation of a chromatin-mediated transcriptionally repressive state that arises in the late two-cell embryo and becomes more pronounced with development. In this study, we investigated expression and function of Class I histone deacetylases (HDAC) HDAC1, HDAC2, and HDAC3 during preimplantation development. HDAC1 is likely a major deacetylase in preimplantation embryos and its expression inversely correlates with changes in the acetylation state of histone H4K5 during preimplantation development. RNAi-mediated reduction of HDAC1 leads to hyperacetylation of histone H4 and a developmental delay even though expression of HDAC2 and HDAC3 is significantly induced in Hdac1-suppresssed embryos; increased expression of p21 Cip1 / Waf may contribute to the observed developmental delay. RNAi-mediated reduction of HDAC2 has no noticeable effect on preimplantation development, suggesting that individual HDACs have distinct functions during preimplantation development. Although RNAi-mediated targeting of Hdac3 mRNA was very efficient, maternal HDAC3 protein was stable during preimplantation development, thereby preventing an examination of its role. HDAC1 knockdown does not increase the rate of global transcription in late 2-cell embryos, but does result in elevated levels of expression of a subset of genes; this increased expression correlates with hyperacetylation of histone H4. Results of these experiments suggest that HDAC1 is involved in the development of a transcriptionally repressive state that initiates in 2-cell embryos.