Joint-specific regulation of homeobox D10 expression in rheumatoid arthritis fibroblast-like synoviocytes.

Rheumatoid arthritis (RA) is a systemic immune-mediated disease characterized by joint inflammation and destruction. The disease typically affects small joints in the hands and feet, later progressing to involve larger joints such as the knees, shoulders, and hips. While the reasons for these joint-specific differences are unclear, distinct epigenetic patterns associated with joint location have been reported. In this study, we evaluated the unique epigenetic landscapes of fibroblast-like synoviocytes (FLS) from hip and knee synovium in RA patients, focusing on the expression and regulation of Homeobox (HOX) transcription factors. These highly conserved genes play a critical role in embryonic development and are known to maintain distinct expression patterns in various adult tissues. We found that several HOX genes, especially HOXD10, were differentially expressed in knee FLS compared with hip FLS. Epigenetic differences in chromatin accessibility and histone marks were observed in HOXD10 promoter between knee and hip FLS. Histone modification, particularly histone acetylation, was identified as an important regulator of HOXD10 expression. To understand the mechanism of differential HOXD10 expression, we inhibited histone deacetylases (HDACs) with small molecules and siRNA. We found that HDAC1 blockade or deficiency normalized the joint-specific HOXD10 expression patterns. These observations suggest that epigenetic differences, specifically histone acetylation related to increased HDAC1 expression, play a crucial role in joint-specific HOXD10 expression. Understanding these mechanisms could provide insights into the regional aspects of RA and potentially lead to therapeutic strategies targeting specific patterns of joint involvement during the course of disease.

HDAC1/2/3-mediated downregulation of neurogranin is involved in cognitive impairment in offspring exposed to maternal subclinical hypothyroidism.

Subclinical hypothyroidism (SCH) in pregnancy is the most common form of thyroid dysfunction in pregnancy, which can affect fetal nervous system development and increase the risk of neurodevelopmental disorders after birth. However, the mechanism of the effect of maternal subclinical hypothyroidism on fetal brain development and behavioral phenotypes is still unclear and requires further study. In this study, we constructed a mouse model of maternal subclinical hypothyroidism by exposing dams to drinking water containing 50 ppm propylthiouracil (PTU) during pregnancy and found that its offspring were accompanied by severe cognitive deficits by behavioral testing. Mechanistically, gestational SCH resulted in the upregulation of protein expression and activity of HDAC1/2/3 in the hippocampus of the offspring. ChIP analysis revealed that H3K9ac on the neurogranin (Ng) promoter was reduced in the hippocampus of the offspring of SCH, with a significant reduction in Ng protein, leading to reduced expression levels of synaptic plasticity markers PSD95 (a membrane-associated protein in the postsynaptic density) and SYN (synaptophysin, a specific marker for presynaptic terminals), and impaired synaptic plasticity. In addition, administration of MS-275 (an HDAC1/2/3-specific inhibitor) to SCH offspring alleviated impaired synaptic plasticity and cognitive dysfunction in offspring. Thus, our study suggests that maternal subclinical hypothyroidism may mediate offspring cognitive dysfunction through the HDAC1/2/3-H3K9ac-Ng pathway. Our study contributes to the understanding of the signaling mechanisms underlying maternal subclinical hypothyroidism-mediated cognitive impairment in the offspring.

A novel combinatorial approach using sulforaphane- and withaferin A-rich extracts for prevention of estrogen receptor-negative breast cancer through epigenetic and gut microbial mechanisms.

Estrogen receptor-negative [ER(-)] mammary cancer is the most aggressive type of breast cancer (BC) with higher rate of metastasis and recurrence. In recent years, dietary prevention of BC with epigenetically active phytochemicals has received increased attention due to its feasibility, effectiveness, and ease of implementation. In this regard, combinatorial phytochemical intervention enables more efficacious BC inhibition by simultaneously targeting multiple tumorigenic pathways. We, therefore, focused on investigation of the effect of sulforaphane (SFN)-rich broccoli sprouts (BSp) and withaferin A (WA)-rich Ashwagandha (Ash) combination on BC prevention in estrogen receptor-negative [ER(-)] mammary cancer using transgenic mice. Our results indicated that combinatorial BSp + Ash treatment significantly reduced tumor incidence and tumor growth (~ 75%) as well as delayed (~ 21%) tumor latency when compared to the control treatment and combinatorial BSp + Ash treatment was statistically more effective in suppressing BC compared to single BSp or Ash intervention. At the molecular level, the BSp and Ash combination upregulated tumor suppressors (p53, p57) along with apoptosis associated proteins (BAX, PUMA) and BAX:BCL-2 ratio. Furthermore, our result indicated an expressional decline of epigenetic machinery HDAC1 and DNMT3A in mammary tumor tissue because of combinatorial treatment. Interestingly, we have reported multiple synergistic interactions between BSp and Ash that have impacted both tumor phenotype and molecular expression due to combinatorial BSp and Ash treatment. Our RNA-seq analysis results also demonstrated a transcriptome-wide expressional reshuffling of genes associated with multiple cell-signaling pathways, transcription factor activity and epigenetic regulations due to combined BSp and Ash administration. In addition, we discovered an alteration of gut microbial composition change because of combinatorial treatment. Overall, combinatorial BSp and Ash supplementation can prevent ER(-) BC through enhanced tumor suppression, apoptosis induction and transcriptome-wide reshuffling of gene expression possibly influencing multiple cell signaling pathways, epigenetic regulation and reshaping gut microbiota.

Unveiling the role of HP1α-HDAC1-STAT1 axis as a therapeutic target for HP1α-positive intrahepatic cholangiocarcinoma.

BACKGROUND: Intrahepatic cholangiocarcinoma (ICCA) is a heterogeneous group of malignant tumors characterized by high recurrence rate and poor prognosis. Heterochromatin Protein 1α (HP1α) is one of the most important nonhistone chromosomal proteins involved in transcriptional silencing via heterochromatin formation and structural maintenance. The effect of HP1α on the progression of ICCA remained unclear. METHODS: The effect on the proliferation of ICCA was detected by experiments in two cell lines and two ICCA mouse models. The interaction between HP1α and Histone Deacetylase 1 (HDAC1) was determined using Electrospray Ionization Mass Spectrometry (ESI-MS) and the binding mechanism was studied using immunoprecipitation assays (co-IP). The target gene was screened out by RNA sequencing (RNA-seq). The occupation of DNA binding proteins and histone modifications were predicted by bioinformatic methods and evaluated by Cleavage Under Targets and Tagmentation (CUT & Tag) and Chromatin immunoprecipitation (ChIP). RESULTS: HP1α was upregulated in intrahepatic cholangiocarcinoma (ICCA) tissues and regulated the proliferation of ICCA cells by inhibiting the interferon pathway in a Signal Transducer and Activator of Transcription 1 (STAT1)-dependent manner. Mechanistically, STAT1 is transcriptionally regulated by the HP1α-HDAC1 complex directly and epigenetically via promoter binding and changes in different histone modifications, as validated by high-throughput sequencing. Broad-spectrum HDAC inhibitor (HDACi) activates the interferon pathway and inhibits the proliferation of ICCA cells by downregulating HP1α and targeting the heterodimer. Broad-spectrum HDACi plus interferon preparation regimen was found to improve the antiproliferative effects and delay ICCA development in vivo and in vitro, which took advantage of basal activation as well as direct activation of the interferon pathway. HP1α participates in mediating the cellular resistance to both agents. CONCLUSIONS: HP1α-HDAC1 complex influences interferon pathway activation by directly and epigenetically regulating STAT1 in transcriptional level. The broad-spectrum HDACi plus interferon preparation regimen inhibits ICCA development, providing feasible strategies for ICCA treatment. Targeting the HP1α-HDAC1-STAT1 axis is a possible strategy for treating ICCA, especially HP1α-positive cases.

PfHDAC1 is an essential regulator of P. falciparum asexual proliferation and host cell invasion genes with a dynamic genomic occupancy responsive to artemisinin stress.

Plasmodium falciparum, the deadly protozoan parasite responsible for malaria, has a tightly regulated gene expression profile closely linked to its intraerythrocytic development cycle. Epigenetic modifiers of the histone acetylation code have been identified as key regulators of the parasite's transcriptome but require further investigation. In this study, we map the genomic distribution of Plasmodium falciparum histone deacetylase 1 (PfHDAC1) across the erythrocytic asexual development cycle and find it has a dynamic occupancy over a wide array of developmentally relevant genes. Overexpression of PfHDAC1 results in a progressive increment in parasite load over consecutive rounds of the asexual infection cycle and is associated with enhanced gene expression of multiple families of host cell invasion factors (merozoite surface proteins, rhoptry proteins, etc.) and with increased merozoite invasion efficiency. With the use of class-specific inhibitors, we demonstrate that PfHDAC1 activity in parasites is crucial for timely intraerythrocytic development. Interestingly, overexpression of PfHDAC1 results in decreased sensitivity to frontline-drug dihydroartemisinin in parasites. Furthermore, we identify that artemisinin exposure can interfere with PfHDAC1 abundance and chromatin occupancy, resulting in enrichment over genes implicated in response/resistance to artemisinin. Finally, we identify that dihydroartemisinin exposure can interrupt the in vitro catalytic deacetylase activity and post-translational phosphorylation of PfHDAC1, aspects that are crucial for its genomic function. Collectively, our results demonstrate PfHDAC1 to be a regulator of critical functions in asexual parasite development and host invasion, which is responsive to artemisinin exposure stress and deterministic of resistance to it. IMPORTANCE: Malaria is a major public health problem, with the parasite Plasmodium falciparum causing most of the malaria-associated mortality. It is spread by the bite of infected mosquitoes and results in symptoms such as cyclic fever, chills, and headache. However, if left untreated, it can quickly progress to a more severe and life-threatening form. The World Health Organization currently recommends the use of artemisinin combination therapy, and it has worked as a gold standard for many years. Unfortunately, certain countries in southeast Asia and Africa, burdened with a high prevalence of malaria, have reported cases of drug-resistant infections. One of the major problems in controlling malaria is the emergence of artemisinin resistance. Population genomic studies have identified mutations in the Kelch13 gene as a molecular marker for artemisinin resistance. However, several reports thereafter indicated that Kelch13 is not the main mediator but rather hinted at transcriptional deregulation as a major determinant of drug resistance. Earlier, we identified PfGCN5 as a global regulator of stress-responsive genes, which are known to play a central role in artemisinin resistance generation. In this study, we have identified PfHDAC1, a histone deacetylase as a cell cycle regulator, playing an important role in artemisinin resistance generation. Taken together, our study identified key transcriptional regulators that play an important role in artemisinin resistance generation.

GATA4 regulates the transcription of MMP9 to suppress the invasion and migration of breast cancer cells via HDAC1-mediated p65 deacetylation.

GATA-binding protein 4 (GATA4) is recognized for its significant roles in embryogenesis and various cancers. Through bioinformatics and clinical data, it appears that GATA4 plays a role in breast cancer development. Yet, the specific roles and mechanisms of GATA4 in breast cancer progression remain elusive. In this study, we identify GATA4 as a tumor suppressor in the invasion and migration of breast cancer. Functionally, GATA4 significantly reduces the transcription of MMP9. On a mechanistic level, GATA4 diminishes MMP9 transcription by interacting with p65 at the NF-κB binding site on the MMP9 promoter. Additionally, GATA4 promotes the recruitment of HDAC1, amplifying the bond between p65 and HDAC1. This leads to decreased acetylation of p65, thus inhibiting p65's transcriptional activity on the MMP9 promoter. Moreover, GATA4 hampers the metastasis of breast cancer in vivo mouse model. In summary, our research unveils a novel mechanism wherein GATA4 curtails breast cancer cell metastasis by downregulating MMP9 expression, suggesting a potential therapeutic avenue for breast cancer metastasis.

Hydroxytyrosol ameliorates stress-induced liver injury through activating autophagy via HDAC1/2 inhibition.

Hydroxytyrosol (HT), a phenolic extra-virgin olive oil compound used as a food supplement, has been recognized to protect liver function and alleviate stress-induced depressive-like behaviors. However, its protective effects against stress-induced liver injury (SLI) remain unknown. Here, the anti-SLI effect of HT was evaluated in mice with chronic unpredictable mild stress-induced SLI. Network pharmacology combined with molecular docking was used to clarify the underlying mechanism of action of HT against SLI, followed by experimental verification. The results showed that accompanying with the alleviation of HT on stress-induced depressive-like behaviors, HT was confirmed to exert the protective effects against SLI, as represented by reduced serum corticosterone (CORT), aspartate aminotransferase and alanine aminotransferase activities, as well as repair of liver structure, inhibition of oxidative homeostasis collapse, and inflammation reaction in the liver. Furthermore, core genes including histone deacetylase 1 and 2 (HDAC1/2), were identified as potential targets of HT in SLI based on bioinformatic screening and simulation. Consistently, HT significantly inhibited HDAC1/2 expression to maintain mitochondrial dysfunction in an autophagy-dependent manner, which was confirmed in a CORT-induced AML-12 cell injury and SLI mice models combined with small molecule inhibitors. We provide the first evidence that HT inhibits HDAC1/2 to induce autophagy in hepatocytes for maintaining mitochondrial dysfunction, thus preventing inflammation and oxidative stress for exerting an anti-SLI effect. This constitutes a novel therapeutic modality to synchronously prevent stress-induced depression-like behaviors and liver injury, supporting the advantaged therapeutic potential of HT.

Zinc finger protein 36 like 2-histone deacetylase 1 axis is involved in the bone responses to mechanical stress.

The molecular mechanism underlying the promotion of fracture healing by mechanical stimuli remains unclear. The present study aimed to investigate the role of zinc finger protein 36 like 2 (ZFP36L2)-histone deacetylase 1 (HDAC1) axis on the osteogenic responses to moderate mechanical stimulation. Appropriate stimulation of fluid shear stress (FSS) was performed on MC3T3-E1 cells transduced with ZFP36L2 and HDAC1 recombinant adenoviruses, aiming to validate the influence of mechanical stress on the expression of ZFP36L2-HDAC1 and the osteogenic differentiation and mineralization. The results showed that moderate FSS stimulation significantly upregulated the expression of ZFP36L2 in MC3T3-E1 cells (p < 0.01). The overexpression of ZFP36L1 markedly enhanced the levels of osteogenic differentiation markers, including bone morphogenetic protein 2 (BMP2), runt-related transcription factor 2 (RUNX2), alkaline phosphatase (ALP), Osterix, and collagen type I alpha 1 (COL1A1) (p < 0.01). ZFP36L2 accelerated the degradation of HDAC1 by specifically binding to its 3' UTR region, thereby fulfilling its function at the post-transcriptional regulatory gene level and promoting the osteogenic differentiation and mineralization fate of cells. Mechanical unloading notably diminished/elevated the expression of ZFP36L2/HDAC1, decreased bone mineral density and bone volume fraction, hindered the release of osteogenic-related factors and vascular endothelial growth factor in callus tissue (p < 0.01), and was detrimental to fracture healing. Collectively, proper stress stimulation plays a crucial role in facilitating osteogenesis through the promotion of ZFP36L2 and subsequent degradation of HDAC1. Targeting ZFP36L2-HDAC1 axis may provide promising insights to enhance bone defect healing.

Exclusion of HDAC1/2 complexes by oncogenic nuclear condensates.

Nuclear condensates have been shown to regulate cell fate control, but its role in oncogenic transformation remains largely unknown. Here we show acquisition of oncogenic potential by nuclear condensate remodeling. The proto-oncogene SS18 and its oncogenic fusion SS18-SSX1 can both form condensates, but with drastically different properties and impact on 3D genome architecture. The oncogenic condensates, not wild type ones, readily exclude HDAC1 and 2 complexes, thus, allowing aberrant accumulation of H3K27ac on chromatin loci, leading to oncogenic expression of key target genes. These results provide the first case for condensate remodeling as a transforming event to generate oncogene and such condensates can be targeted for therapy. One sentence summary: Expulsion of HDACs complexes leads to oncogenic transformation.

Isobavachalcone alleviates ischemic stroke by suppressing HDAC1 expression and improving M2 polarization.

Ischemic stroke is a serious cerebrovascular condition. Isobavachalcone (ISO) has been documented to exhibit an anti-inflammatory effect across a variety of diseases; however, its protective impact on ischemic stroke remains unexplored. In this study, we evaluated the influence of ISO in both transient middle cerebral artery occlusion/reperfusion (tMCAO/R) rat models and oxygen-glucose deprivation/reperfusion (OGD/R) cell models. We observed that pretreatment with 50 mg/kg ISO diminished the volume of brain infarction, reduced brain edema, and ameliorated neurological deficits in rats. A reduction in Nissl bodies was noted in the tMCAO/R group, which was reversed following treatment with 50 mg/kg ISO. TUNEL/NeuN double staining revealed a decrease in TUNEL-positive cells in tMCAO/R rats treated with ISO. Furthermore, ISO treatment suppressed the expression of cleaved caspase-3 and BAX, while elevating the expression of BCL-2 in tMCAO/R rats. The levels of CD86 and iNOS were elevated in tMCAO/R rats; conversely, ISO treatment enhanced the expression of CD206 and Arg-1. Additionally, the expression of TNF-α, IL-6, and IL-1ß was elevated in tMCAO/R rats, whereas ISO treatment counteracted this effect. ISO treatment also increased the expression of TGF-ß and IL-10 in the ischemic penumbra of tMCAO/R rats. It was found that ISO treatment hindered microglial M1 polarization and favored M2 polarization. Histone Deacetylase 1 (HDAC1) is the downstream target protein of ISO, with ISO treatment resulting in decreased HDAC1 expression in both tMCAO/R rats and OGD/R-induced cells. Overexpression of HDAC1 was shown to promote microglial M1 polarization and inhibit M2 polarization in OGD/R+ISO cells. Overall, ISO treatment mitigated brain damage following ischemic stroke by promoting M2 polarization and attenuated ischemic injury by repressing HDAC1 expression.

Class I HDAC inhibitors enhance antitumor efficacy and persistence of CAR-T cells by activation of the Wnt pathway.

Epigenetic modification shapes differentiation trajectory and regulates the exhaustion state of chimeric antigen receptor T (CAR-T) cells. Limited efficacy induced by terminal exhaustion closely ties with intrinsic transcriptional regulation. However, the comprehensive regulatory mechanisms remain largely elusive. Here, we identify class I histone deacetylase inhibitors (HDACi) as boosters of CAR-T cell function by high-throughput screening of chromatin-modifying drugs, in which M344 and chidamide enhance memory maintenance and resistance to exhaustion of CAR-T cells that induce sustained antitumor efficacy both in vitro and in vivo. Mechanistically, HDACi decrease HDAC1 expression and enhance H3K27ac activity. Multi-omics analyses from RNA-seq, ATAC-seq, and H3K27ac CUT&Tag-seq show that HDACi upregulate expression of TCF4, LEF1, and CTNNB1, which subsequently activate the canonical Wnt/ß-catenin pathway. Collectively, our findings elucidate the functional roles of class I HDACi in enhancing CAR-T cell function, which provides the basis and therapeutic targets for synergic combination of CAR-T cell therapy and HDACi treatment.

A novel potent class I HDAC inhibitor reverses the STAT4/p66Shc apoptotic defect in B cells from chronic lymphocytic leukemia patients.

Chronic Lymphocytic Leukemia (CLL) patients have a defective expression of the proapoptotic protein p66Shc and of its transcriptional factor STAT4, which evoke molecular abnormalities, impairing apoptosis and worsening disease prognosis and severity. p66Shc expression is epigenetically controlled and transcriptionally modulated by STAT4; epigenetic modifiers are deregulated in CLL cells and specific histone deacetylases (HDACs) like HDAC1, are overexpressed. Reactivation of STAT4/p66Shc expression may represent an attractive and challenging strategy to reverse CLL apoptosis defects. New selective class I HDAC inhibitors (HDACis, 6a-g) were developed with increased potency over existing agents and preferentially interfering with the CLL-relevant isoform HDAC1, to unveil the role of class I HDACs in the upregulation of STAT4 expression, which upregulates p66Shc expression and hence normalizes CLL cell apoptosis. 6c (chlopynostat) was identified as a potent HDAC1i with a superior profile over entinostat. 6c induces marked apoptosis of CLL cells compared with SAHA, which was associated with an upregulation of STAT4/p66Shc protein expression. The role of HDAC1, but not HDAC3, in the epigenetic upregulation of STAT4/p66Shc was demonstrated for the first time in CLL cells and was validated in siRNA-induced HDAC1/HDAC3 knock-down EBV-B cells. To sum up, HDAC1 inhibition is necessary to reactivate STAT4/p66Shc expression in patients with CLL. 6c is one of the most potent HDAC1is known to date and represents a novel pharmacological tool for reversing the impairment of the STAT4/p66Shc apoptotic machinery.

ARID1A regulates DNA repair through chromatin organization and its deficiency triggers DNA damage-mediated anti-tumor immune response.

AT-rich interaction domain protein 1A (ARID1A), a SWI/SNF chromatin remodeling complex subunit, is frequently mutated across various cancer entities. Loss of ARID1A leads to DNA repair defects. Here, we show that ARID1A plays epigenetic roles to promote both DNA double-strand breaks (DSBs) repair pathways, non-homologous end-joining (NHEJ) and homologous recombination (HR). ARID1A is accumulated at DSBs after DNA damage and regulates chromatin loops formation by recruiting RAD21 and CTCF to DSBs. Simultaneously, ARID1A facilitates transcription silencing at DSBs in transcriptionally active chromatin by recruiting HDAC1 and RSF1 to control the distribution of activating histone marks, chromatin accessibility, and eviction of RNAPII. ARID1A depletion resulted in enhanced accumulation of micronuclei, activation of cGAS-STING pathway, and an increased expression of immunomodulatory cytokines upon ionizing radiation. Furthermore, low ARID1A expression in cancer patients receiving radiotherapy was associated with higher infiltration of several immune cells. The high mutation rate of ARID1A in various cancer types highlights its clinical relevance as a promising biomarker that correlates with the level of immune regulatory cytokines and estimates the levels of tumor-infiltrating immune cells, which can predict the response to the combination of radio- and immunotherapy.

Mechanisms of mesothelial cell response to viral infections: HDAC1-3 inhibition blocks poly(I:C)-induced type I interferon response and modulates the mesenchymal/inflammatory phenotype.

Infectious peritonitis is a leading cause of peritoneal functional impairment and a primary factor for therapy discontinuation in peritoneal dialysis (PD) patients. Although bacterial infections are a common cause of peritonitis episodes, emerging evidence suggests a role for viral pathogens. Toll-like receptors (TLRs) specifically recognize conserved pathogen-associated molecular patterns (PAMPs) from bacteria, viruses, and fungi, thereby orchestrating the ensuing inflammatory/immune responses. Among TLRs, TLR3 recognizes viral dsRNA and triggers antiviral response cascades upon activation. Epigenetic regulation, mediated by histone deacetylase (HDAC), has been demonstrated to control several cellular functions in response to various extracellular stimuli. Employing epigenetic target modulators, such as epidrugs, is a current therapeutic option in several cancers and holds promise in treating viral diseases. This study aims to elucidate the impact of TLR3 stimulation on the plasticity of human mesothelial cells (MCs) in PD patients and to investigate the effects of HDAC1-3 inhibition. Treatment of MCs from PD patients with the TLR3 agonist polyinosinic:polycytidylic acid (Poly(I:C)), led to the acquisition of a bona fide mesothelial-to-mesenchymal transition (MMT) characterized by the upregulation of mesenchymal genes and loss of epithelial-like features. Moreover, Poly(I:C) modulated the expression of several inflammatory cytokines and chemokines. A quantitative proteomic analysis of MCs treated with MS-275, an HDAC1-3 inhibitor, unveiled altered expression of several proteins, including inflammatory cytokines/chemokines and interferon-stimulated genes (ISGs). Treatment with MS-275 facilitated MMT reversal and inhibited the interferon signature, which was associated with reduced STAT1 phosphorylation. However, the modulation of inflammatory cytokine/chemokine production was not univocal, as IL-6 and CXCL8 were augmented while TNF-α and CXCL10 were decreased. Collectively, our findings underline the significance of viral infections in acquiring a mesenchymal-like phenotype by MCs and the potential consequences of virus-associated peritonitis episodes for PD patients. The observed promotion of MMT reversal and interferon response inhibition by an HDAC1-3 inhibitor, albeit without a general impact on inflammatory cytokine production, has translational implications deserving further analysis.

HDAC1-Mediated Downregulation of NEU1 Exacerbates the Aggressiveness of Cervical Cancer.

HDAC1 functions as an oncogene in multi-type cancers. This study aimed to investigate the roles of histone deacetylase 1 (HDAC1) in cervical cancer (CC). mRNA expression was determined using reverse transcription quantitative polymerase chain reaction. The protein-protein complexes was analyzed using co-immunoprecipitation assay. The binding sites between NRF2 and NEU1 were confirmed by chromatin immunoprecipitation assay. Cell viability was detected by CCK-8. Cell proliferation was measured using CCK-8 and colony formation assays. Cell migrative and invasive ability were determined using transwell assay. We found that HDAC1 was upregulated in CC patients and cells. Trichostatin A (TSA) treatment decreased the number of colonies and migrated and invaded cells. Moreover, HDAC1 interacted with NRF2 to downregulate NEU1 expression. NEU1 knockdown attenuated the effects of TSA and enhanced the aggressiveness of CC cells. In conclusion, HDAC1 functions as an oncogene in CC. Targeting HDAC1 may be an alternative strategy for CC.

Cisplatin-resistance induces lung squamous carcinoma cell growth by nicotine-mediated α7nAchR/HDAC1/Cyclin D1/pRb cell cycle activation.

The majority of adenocarcinoma lung cancer is found in nonsmokers. A history of tobacco use is more common in squamous cell carcinoma of the lung. The aim of this study is to identify the cisplatin (CDDP)-resistance that promotes lung squamous carcinoma cell growth through nicotine-mediated HDAC1/7nAchR/E2F/pRb cell cycle activation. Squamous cell carcinoma (NCI-H520 and NCI-H157) cells were examined after cisplatin and nicotine treatment by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assay, cell migration assay, immunofluorescence staining, western blot analysis, and immunoprecipitation analysis. Consequently, CDDP is released from DNA and Rb phosphorylated pRb as a result of nicotine-induced cancer cell proliferation through 7nAchR, which then triggers the opening of the HDAC1 cell cycle. The cell cycle is stopped when CDDP adducts are present. Nicotine exerts cancer cytoprotective effects by allowing HDAC1 repair mechanisms to re-establish E2F promoting DNA stimulation cell cycle integrity in the cytosol and preventing potential CDDP and HDAC1 suppressed in the nuclear. Concentration expression of nicotine causes squamous carcinoma cell carcinogens to emerge from inflammation. COX2, NF-KB, and NOS2 increase as a result of nicotine-induced squamous carcinoma cell inflammation. Nicotine enhanced the cell growth-related proteins such as α7nAchR, EGFR, HDAC1, Cyclin D, Cyclin E, E2F, Rb, and pRb by western blot analysis. It also induced cancer cell inflammation and growth. As a result, we suggest that nicotine will increase the therapeutic resistance effects of CDDP. This has the potential to interact with nicotine through α7nAchR receptors and HDAC1/Cyclin D/E2F/pRb potentially resulting in CDDP therapy resistance, as well as cell cycle-induced cancer cell growth.

PADI4 negatively regulates RIG-I-mediated antiviral response through deacetylation of IFN-ß promoter via HDAC1.

The production of type I interferon (IFN) is precisely modulated by host to protect against viral infection efficiently without obvious immune disorders. Elucidating the tight control towards type I IFN production would be helpful to get insight into natural immunity and inflammatory diseases. As yet, however, the mechanisms that regulate IFN-ß production, especially the epigenetic regulatory mechanisms, remain poorly explored. This study elucidated the potential function of Peptidylarginine deiminases (PADIs)-mediated citrullination in innate immunity. We identified PADI4, a PADIs family member that can act as an epigenetic coactivator, could repress IFN-ß production upon RNA virus infection. Detailed experiments showed that PADI4 deficiency increased IFN-ß production and promoted antiviral immune activities against RNA viruses. Mechanistically, the increased PADI4 following viral infection translocated to nucleus and recruited HDAC1 upon binding to Ifnb1 promoter, which then led to the deacetylation of histone H3 and histone H4 for repressing Ifnb1 transcription. Taken together, we identify a novel non-classical role for PADI4 in the regulation of IFN-ß production, suggesting its potential as treatment target in inflammatory or autoimmune diseases.

Re-exploration of tetrahydro-ß-carboline scaffold: Discovery of selective histone deacetylase 6 inhibitors with neurite outgrowth-promoting and neuroprotective activities.

Histone deacetylase 6 (HDAC6) has drawn more and more attention for its potential application in Alzheimer's disease (AD) therapy. A series of tetrahydro-ß-carboline (THßC) hydroxamic acids with aryl linker were synthesized. In enzymatic assay, all compounds exhibited nanomolar IC50 values. The most promising compound 11d preferentially inhibited HDAC6 (IC50, 8.64 nM) with approximately 149-fold selectivity over HDAC1. Molecular simulation revealed that the hydroxamic acid of 11d could bind to the zinc ion by a bidentate chelating manner. In vitro, 11d induced neurite outgrowth of PC12 cells without producing toxic effects and showed obvious neuroprotective activity in a model of H2O2-induced oxidative stress.

HDAC1/2 control mesothelium/ovarian cancer adhesive interactions impacting on Talin-1-α5ß1-integrin-mediated actin cytoskeleton and extracellular matrix protein remodeling.

BACKGROUND: Peritoneal metastasis, which accounts for 85% of all epithelial ovarian carcinoma (EOC) metastases, is a multistep process that requires the establishment of adhesive interactions between cancer cells and the peritoneal membrane. Interrelations between EOC and the mesothelial stroma are critical to facilitate the metastatic process. No data is available so far on the impact of histone acetylation/deacetylation, a potentially relevant mechanism governing EOC metastasis, on mesothelial cells (MCs)-mediated adhesion. METHODS: Static adhesion and peritoneal clearance experiments were performed pretreating mesenchymal-like MCs and platinum-sensitive/resistant EOC cell lines with MS-275-a Histone deacetylase (HDAC)1-3 pharmacological inhibitor currently used in combination trials. Results were acquired by confocal microscopy and were analyzed with an automated Opera software. The role of HDAC1/2 was validated by genetic silencing. The role of α4-, α5-α1 Integrins and Fibronectin-1 was validated using specific monoclonal antibodies. Quantitative proteomic analysis was performed on primary MCs pretreated with MS-275. Decellularized matrices were generated from either MS-275-exposed or untreated cells to study Fibronectin-1 extracellular secretion. The effect of MS-275 on ß1 integrin activity was assessed using specific monoclonal antibodies. The role of Talin-1 in MCs/EOC adhesion was analyzed by genetic silencing. Talin-1 ectopic expression was validated as a rescue tool from MS-275-induced phenotype. The in vivo effect of MS-275-induced MC remodeling was validated in a mouse model of peritoneal EOC dissemination. RESULTS: Treatment of MCs with non-cytotoxic concentrations of MS-275 caused a consistent reduction of EOC adhesion. Proteomic analysis revealed several pathways altered upon MC treatment with MS-275, including ECM deposition/remodeling, adhesion receptors and actin cytoskeleton regulators. HDAC1/2 inhibition hampered actin cytoskeleton polymerization by downregulating actin regulators including Talin-1, impairing ß1 integrin activation, and leading to abnormal extracellular secretion and distribution of Fibronectin-1. Talin-1 ectopic expression rescued EOC adhesion to MS-275-treated MCs. In an experimental mouse model of metastatic EOC, MS-275 limited tumor invasion, Fibronectin-1 secretion and the sub-mesothelial accumulation of MC-derived carcinoma-associated fibroblasts. CONCLUSION: Our study unveils a direct impact of HDAC-1/2 in the regulation of MC/EOC adhesion and highlights the regulation of MC plasticity by epigenetic inhibition as a potential target for therapeutic intervention in EOC peritoneal metastasis.

C/EBPα alleviates hepatic ischemia-reperfusion injury by inhibiting endoplasmic reticulum stress via HDAC1-mediated deacetylation of ATF4.

Hepatic ischemia-reperfusion (IR) injury is a complex systemic process causing a series clinical problem. C/EBPα is a key transcription factor for hepatocyte function, but its role and mechanism in regulating hepatic IR injury are largely unknown. Occluding portal vein and hepatic artery was used to establish a mouse model of hepatic IR injury. C/EBPα expression was decreased in IR-injured liver compared with the sham, accompanied by increased contents of serum alanine transaminase (ALT), aspartate transaminase (AST), high mobility group box-1, and proportion of hepatic cells. Oxygen and glucose deprivation/recovery (OGD/R) was used to establish a cellular hepatic IR model in WRL-68 hepatocytes in vitro, and C/EBPα was overexpressed in the hepatocytes to evaluate its effect on hepatic IR injury. OGD/R promoted oxidative stress, cell apoptosis and endoplasmic reticulum (ER) stress in hepatocytes, which was reversed by C/EBPα overexpression. Then, we found that C/EBPα promoted histone deacetylase 1 (HDAC1) transcription through binding to HDAC1 promoter. Moreover, HDAC1 deacetylated the activating transcription factor 4 (ATF4), a key positive regulator of ER stress. Trichostatin-A (an HDAC inhibitor) or ATF4 overexpression reversed the improvement of C/EBPα on OGD/R-induced ER stress and hepatocyte dysfunction. 4-Phenylbutyric acid (an endoplasmic reticulum stress inhibitor) also reversed the hepatic IR injury induced by ATF4 overexpression. Finally, lentivirus-mediated C/EBPα overexpression vector was applied to administrate hepatic IR mice, and the results showed that C/EBPα overexpression ameliorated IR-induced hepatic injury, manifesting with reduced ALT/AST, oxidative stress and ER stress. Altogether, our findings suggested that C/EBPα ameliorated hepatic IR injury by inhibiting ER stress via HDAC1-mediated deacetylation of ATF4 promoter.