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.

SARS-CoV-2 NSP5 antagonizes MHC II expression by subverting histone deacetylase 2.

SARS-CoV-2 interferes with antigen presentation by downregulating major histocompatibility complex (MHC) II on antigen-presenting cells, but the mechanism mediating this process is unelucidated. Herein, analysis of protein and gene expression in human antigen-presenting cells reveals that MHC II is downregulated by the SARS-CoV-2 main protease, NSP5. This suppression of MHC II expression occurs via decreased expression of the MHC II regulatory protein CIITA. CIITA downregulation is independent of the proteolytic activity of NSP5, and rather, NSP5 delivers HDAC2 to the transcription factor IRF3 at an IRF-binding site within the CIITA promoter. Here, HDAC2 deacetylates and inactivates the CIITA promoter. This loss of CIITA expression prevents further expression of MHC II, with this suppression alleviated by ectopic expression of CIITA or knockdown of HDAC2. These results identify a mechanism by which SARS-CoV-2 limits MHC II expression, thereby delaying or weakening the subsequent adaptive immune response.

Oxyresveratrol-ß-cyclodextrin mitigates streptozotocin-induced Alzheimer's model cognitive impairment, histone deacetylase activity in rats: in silico & in vivo studies.

Alzheimer's disease (AD) is associated with cognitive deficits and epigenetic deacetylation that can be modulated by natural products. The role of natural oxyresveratrol-ß-cyclodextrin (ORV) on cognition and histone deacetylase activity in AD is unclear. Herein, in-silico docking and molecular dynamics simulation analysis determined that oxyresveratrol potentially targets histone deacetylase-2 (HDAC2). We therefore evaluated the in vivo ameliorative effect of ORV against cognitive deficit, cerebral and hippocampal expression of HDAC in experimental AD rats. Intracerebroventricular injection of STZ (3 mg/kg) induced experimental AD and the rats were treated with low dose (200 mg/kg), high dose (400 mg/kg) of ORV and donepezil (10 mg/kg) for 21 days. The STZ-induced AD caused cognitive and behavioural deficits demonstrated by considerable increases in acetylcholinesterase activity and escape latency compared to sham control. The levels of malondialdehyde (MDA) and HDAC activity were significantly increased in AD disease group comparison to the sham. Interestingly, the ORV reversed the cognitive-behavioural deficit and prominently reduced the MDA and HDAC levels comparable to the effect of the standard drug, donepezil. The findings suggest anti-AD role of ORV via antioxidant effect and inhibition of HDAC in the hippocampal and frontal cortical area of rats for AD.

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.

HDAC2 counteracts vascular calcification by activating autophagy in chronic kidney disease.

Vascular calcification is a major risk factor for cardiovascular disease mortality, with a significant prevalence in chronic kidney disease (CKD). Pharmacological inhibition of histone acetyltransferase has been proven to protect against from vascular calcification. However, the role of Histone Deacetylase 2 (HDAC2) and molecular mechanisms in vascular calcification of CKD remains unknown. An in vivo model of CKD was established using mouse fed with a high adenine and phosphate diet, and an in vitro model was produced using human aortic vascular smooth muscle cells (VSMCs) stimulated with ß-glycerophosphate (ß-GP). HDAC2 expression was found to be reduced in medial artery of CKD mice and ß-GP-induced VSMCs. Overexpression of HDAC2 attenuated OPN and OCN upregulation, α-SMA and SM22α downregulation, and calcium deposition in aortas of CKD. The in vitro results also demonstrated that ß-GP-induced osteogenic differentiation was inhibited by HDAC2. Furthermore, we found that HDAC2 overexpression caused an increase in LC3II/I, a decrease in p62, and an induction of autophagic flux. Inhibition of autophagy using its specific inhibitor 3-MA blocked HDAC2's protective effect on osteogenic differentiation in ß-GP-treated VSMCs. Taken together, these results suggest that HDAC2 may protect against vascular calcification by the activation of autophagy, laying out a novel insight for the molecular mechanism in vascular calcification of CKD.

Epigenetic disruption of histone deacetylase-2 accelerated apoptotic signaling and retarded malignancy in gastric cells.

Background: The objective of this research was to determine whether HDAC2 function is associated with gastric cancer progression. Methods: HDAC2 was knocked out in EPG85.257 cells using CRISPR/Cas9 and tumorigenesis pathways were evaluated. Results: Cell proliferation, colony formation, wound healing and transwell invasion were inhibited in ΔHDAC2:EPG85.257 cells. Quantitative analyses revealed a significant downregulation of MMP1, p53, Bax, MAPK1, MAPK3, pro-Caspase3, ERK1/2, p-ERK1/2, AKT1/2/3, p-AKT1/2/3, p-NF-κB (p65), Twist, Snail and p-FAK transcripts/proteins, while SIRT1, PTEN, p21 and Caspase3 were upregulated in ΔHDAC2:EPG85.257 cells. Conclusion: These results indicated that HDAC2 enhanced migration, colony formation and transmigration ability. HDAC2 inhibition may improve gastric cancer chemotherapy pathways.

DNA changes are the main causes of cancer. Therefore, finding easy ways to manipulate and correct DNA changes has been the biggest medical concern in cancer treatment. Researchers have introduced CRISPR/Cas9 as the newest technology for gene editing that precisely and easily changes the genome of any cell. In our study, histone deacetylase-2 was disrupted in gastric cancer cells using CRISPR technology. This modification reduced growth kinetics and invasion of cancer cells. On the other hand, cell death (also called apoptosis) was induced. Sensitization of the cancer cells to chemotherapeutic agents is noticeable in this research. This study needs to uncover more signaling pathways in vitro and in vivo.

Hypoxia-activated XBP1s recruits HDAC2-EZH2 to engage epigenetic suppression of ΔNp63α expression and promote breast cancer metastasis independent of HIF1α.

Hypoxia is a hallmark of cancer development. However, the molecular mechanisms by which hypoxia promotes tumor metastasis are not fully understood. In this study, we demonstrate that hypoxia promotes breast cancer metastasis through suppression of ΔNp63α in a HIF1α-independent manner. We show that hypoxia-activated XBP1s forms a stable repressor protein complex with HDAC2 and EZH2 to suppress ΔNp63α transcription. Notably, H3K27ac is predominantly occupied on the ΔNp63 promoter under normoxia, while H3K27me3 on the promoter under hypoxia. We show that XBP1s binds to the ΔNp63 promoter to recruit HDAC2 and EZH2 in facilitating the switch of H3K27ac to H3K27me3. Pharmacological inhibition or the knockdown of either HDAC2 or EZH2 leads to increased H3K27ac, accompanied by the reduced H3K27me3 and restoration of ΔNp63α expression suppressed by hypoxia, resulting in inhibition of cell migration. Furthermore, the pharmacological inhibition of IRE1α, but not HIF1α, upregulates ΔNp63α expression in vitro and inhibits tumor metastasis in vivo. Clinical analyses reveal that reduced p63 expression is correlated with the elevated expression of XBP1, HDAC2, or EZH2, and is associated with poor overall survival in human breast cancer patients. Together, these results indicate that hypoxia-activated XBP1s modulates the epigenetic program in suppression of ΔNp63α to promote breast cancer metastasis independent of HIF1α and provides a molecular basis for targeting the XBP1s/HDAC2/EZH2-ΔNp63α axis as a putative strategy in the treatment of breast cancer metastasis.

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.

SOX4/HDAC2 Axis Enhances Cell Survivability and Reduces Apoptosis by Activating AKT/MAPK Signaling in Colorectal Cancer.

BACKGROUND: Increased SOX4 (SRY-related HMG-box) activity aids cellular transformation and metastasis. However, its specific functions and downstream targets remain to be completely elusive in colorectal cancer (CRC). AIMS: To investigate the role of SOX4 in CRC progression and the underlying mechanism. METHODS: In the current study, online available datasets of CRC patients were explored to check the expression status of SOX4. To investigate the further functions, SOX4 was overexpressed and knocked down in CRC cells. Colony formation assay, flowcytometry analysis, and MTT assay were used to check for proliferation and apoptosis. Acridine orange staining was done to check the role of SOX4 in autophagy induction. Furthermore, western blot, qRT-PCR, and bioinformatic analysis was done to elucidate the downstream molecular mechanism of SOX4. RESULTS: GEPIA database showed enhanced expression of SOX4 mRNA in CRC tumor, and the human protein atlas (HPA) showed strong staining of SOX4 protein in tumor when compared to the normal tissue. Ectopic expression of SOX4 enhanced colony formation ability as well as rescued cells from apoptosis. SOX4 overexpressed cells showed the formation of acidic vesicular organelles (AVOs) which indicated autophagy. Further results revealed the activation of p-AKT/MAPK molecules upon overexpression of SOX4. SOX4 expression was found to be positively correlated with histone deacetylase 2 (HDAC2). Knockdown of SOX4 or HDAC2 inhibition induced apoptosis, revealed by decrease in BCL2 and increase in BAX expression, and inactivated the p-AKT/MAPK signaling. CONCLUSION: The study uncovers that SOX4/HDAC2 axis improves cell survivability and reduces apoptosis via activation of the p-AKT/MAPK pathway.

Histone deacetylase-mediated silencing of PSTPIP2 expression contributes to aristolochic acid nephropathy-induced PANoptosis.

BACKGROUND AND PURPOSE: Aristolochic acid nephropathy (AAN) is a progressive kidney disease caused by using herbal medicines. Currently, no therapies are available to treat or prevent aristolochic acid nephropathy. Histone deacetylase (HDAC) plays a crucial role in the development and progression of renal disease. We tested whether HDAC inhibitors could prevent aristolochic acid nephropathy and determined the underlying mechanism. EXPERIMENTAL APPROACH: HDACs expression in the aristolochic acid nephropathy model was examined. The activation of PANoptosis of mouse kidney and renal tubular epithelial cell were assessed after exposure to HDAC1 and HDAC2 blockade. Kidney-specific knock-in of proline-serine-threonine-phosphatase-interacting protein 2 (PSTPIP2) mice were used to investigate whether PSTPIP2 affected the production of PANoptosome. KEY RESULTS: Aristolochic acid upregulated the expression of HDAC1 and HDAC2 in the kidneys. Notably, the HDAC1 and HDAC2 specific inhibitor, romidepsin (FK228, depsipeptide), suppressed aristolochic acid-induced kidney injury, epithelial cell pyroptosis, apoptosis and necroptosis (PANoptosis). Moreover, romidepsin upregulated PSTPIP2 in renal tubular epithelial cells, which was enhanced by aristolochic acid treatment. Conditional knock-in of PSTPIP2 in the kidney protected against aristolochic acid nephropathy. In contrast, the knockdown of PSTPIP2 expression in PSTPIP2-knock-in mice restored kidney damage and PANoptosis. PSTPIP2 function was determined in vitro using PSTPIP2 knockdown or overexpression in mouse renal tubular epithelial cells (mTECs). Additionally, PSTPIP2 was found to regulate caspase 8 in aristolochic acid nephropathy. CONCLUSION AND IMPLICATIONS: HDAC-mediated silencing of PSTPIP2 may contribute to aristolochic acid nephropathy. Hence, HDAC1 and HDAC2 specific inhibitors or PSTPIP2 could be valuable therapeutic agents for preventing aristolochic acid nephropathy.

USP43 impairs cisplatin sensitivity in epithelial ovarian cancer through HDAC2-dependent regulation of Wnt/ß-catenin signaling pathway.

Epithelial ovarian cancer (EOC) is the leading cause of cancer death all over the world. USP43 functions as a tumor promoter in various malignant cancers. Nevertheless, the biological roles and mechanisms of USP43 in EOC remain unknown. In this study, USP43 was highly expressed in EOC tissues and cells, and high expression of USP43 were associated with a poor prognosis of EOC. USP43 overexpression promoted EOC cell proliferation, enhanced the ability of migration and invasion, decreased cisplatin sensitivity and inhibited apoptosis. Knockdown of USP43 in vitro effectively retarded above malignant progression of EOC. In vivo xenograft tumors, silencing USP43 slowed tumor growth and enhanced cisplatin sensitivity. Mechanistically, USP43 inhibited HDAC2 degradation and enhanced HDAC2 protein stability through its deubiquitylation function. USP43 diminished the sensitivity of EOC cells to cisplatin through activation of the Wnt/ß-catenin signaling pathway mediated by HDAC2. Taken together, the data in this study revealed the functions of USP43 in proliferation, migration, invasion, chemoresistance of EOC cells, and the mechanism of HDAC2-mediated Wnt/ß-catenin signaling pathway. Thus, USP43 might serve as a potential target for the control of ovarian cancer progression.

Cardiac energy depletion in a rat model of polycystic ovarian syndrome is reversed by acetate and associated with inhibitory effect of HDAC2/mTOR.

In addition to the clinical manifestation of polycystic ovarian syndrome (PCOS), life-threatening diseases, especially hypertension and cardiovascular disease (CVD) are emerging critical complications of PCOS. Changes in cardiac energy remains an independent risk factor of CVD. Histone deacetylase (HDAC) inhibitors, including acetate has received attention for its beneficial role in energy regulation. Herein we hypothesized that acetate improves cardiac energy homeostasis in experimentally induced PCOS. Female Wistar rats (8-week-old) were divided into groups. To induce PCOS, 1 mg/kg of letrozole was given for 21 days. After confirmation of PCOS, acetate (200 mg/kg) was administered for 6 weeks. Rats with PCOS showed multiple ovarian cysts with androgen excess and decreased SHBG. The rats also manifested impaired glucose tolerance/hyperinsulinemia and hypertriglyceridemia. Increased systemic oxidative stress (malondialdehyde)/inflammatory (NF-kB/SDF-1) markers and nitric oxide deficiency (NO/eNOS) were observed. Though, the body weight was increased without affecting the cardiac mass index of PCOS rats. Nevertheless, there was an increase in cardiac triglyceride and oxidative stress/inflammatory markers with consequent cardiac injury, revealed by decreased levels of SIRT-1/HIF-1α and increased levels of CTGF/TGFß-1 and plasma troponin T. These led to cardiac ATP depletion with increased AMP and AMP/ATP ratio. These alterations were accompanied by elevated levels of mTOR and HDAC2, which were reversed when treated with acetate. The present results interestingly suggest that HDAC2 inhibition by acetate reversed cardiac energy depletion and attendant cardiomorbidities in experimental PCOS model. A beneficial effect that is accompanied by suppressed expression of mTOR.

USP17 regulates preeclampsia by modulating the NF-κB signaling pathway via deubiquitinating HDAC2.

INTRODUCTION: Ubiquitination is a significant post-translational modification engaged in diverse biological processes, such as cell differentiation, metastasis, and protein stability modulation. The dysregulation of ubiquitination and deubiquitination is inextricably linked to disease progression, including preeclampsia (PE). Ubiquitin-specific protease 17 (USP17), a prominent deubiquitinating enzyme that regulates ubiquitination modifications, performs multiple functions at the cellular level, whereas its role in PE remains elusive. In this study, we intended to probe the role of USP17 in PE and its underlying mechanisms. METHODS: The USP17 level in the plasma of PE patients was detected through Elisa. Western blot and qRT-PCR were performed to measure the mRNA and protein level of USP17 in placental tissues. CCK-8, EdU, and transwell assays were conducted to evaluate the proliferation, migration, and invasion of trophoblast cells. The interaction between HDAC2 and USP17 or STAT1 were determined by co-immunoprecipitation and Western blot assays. The expression of NF-κB pathway related proteins was examined using Western blot. RESULTS: USP17 was dramatically downregulated in PE patients. Overexpression of USP17 facilitated trophoblast proliferation, migration, and invasion. Moreover, histone deacetylase 2 (HDAC2) was validated as a substrate of USP17 deubiquitination, and USP17 upregulation enhanced HDAC2 protein level. Furthermore, HDAC2 could interact with and deacetylate Signal transducer and activator of transcription 1 (STAT1), resulting in the enhancement of STAT1 activity and inhibition of NF-κB signaling. DISCUSSION: Our findings disclosed that USP17 augmented the proliferation and invasion of trophoblast by deubiquitinating HDAC2, which will contribute to novel prospective targets for diagnosing and treating PE.

Hdac1 and Hdac2 positively regulate Notch1 gain-of-function pathogenic signaling in committed osteoblasts of male mice.

BACKGROUND: Skeletal development requires precise extrinsic and intrinsic signals to regulate processes that form and maintain bone and cartilage. Notch1 is a highly conserved signaling receptor that regulates cell fate decisions by controlling the duration of transcriptional bursts. Epigenetic molecular events reversibly modify DNA and histone tails by influencing the spatial organization of chromatin and can fine-tune the outcome of a Notch1 transcriptional response. Histone deacetylase 1 and 2 (HDAC1 and HDAC2) are chromatin modifying enzymes that mediate osteoblast differentiation. While an HDAC1-Notch interaction has been studied in vitro and in Drosophila, its role in mammalian skeletal development and disorders is unclear. Osteosclerosis is a bone disorder with an abnormal increase in the number of osteoblasts and excessive bone formation. METHODS: Here, we tested whether Hdac1/2 contribute to the pathogenesis of osteosclerosis in a murine model of the disease owing to conditionally cre-activated expression of the Notch1 intracellular domain in immature osteoblasts. RESULTS: Importantly, selective homozygous deletions of Hdac1/2 in osteoblasts partially alleviate osteosclerotic phenotypes (Col2.3kb-Cre; TGRosaN1ICD/+ ; Hdac1flox/flox ; Hdac2flox/flox ) with a 40% decrease in bone volume and a 22% decrease in trabecular thickness in 4 weeks old when compared to male mice with heterozygous deletions of Hdac1/2 (Col2.3 kb-Cre; TGRosaN1ICD/+ ; Hdac1flox/+ ; Hdac2flox/+ ). Osteoblast-specific deletion of Hdac1/2 in male and female mice results in no overt bone phenotype in the absence of the Notch1 gain-of-function (GOF) allele. CONCLUSIONS: These results provide evidence that Hdac1/2 contribute to Notch1 pathogenic signaling in the mammalian skeleton. Our study on epigenetic regulation of Notch1 GOF-induced osteosclerosis may facilitate further mechanistic studies of skeletal birth defects caused by Notch-related GOF mutations in human patients, such as Adams-Oliver disease, congenital heart disease, and lateral meningocele syndrome.

Valproic acid ameliorates cauda equina injury by suppressing HDAC2-mediated ferroptosis.

INTRODUCTION: Persistent neuroinflammatory response after cauda equina injury (CEI) lowers nociceptor firing thresholds, accompanied by pathological pain and decreasing extremity dysfunction. Histone deacetylation has been considered a key regulator of immunity, inflammation, and neurological dysfunction. Our previous study suggested that valproic acid (VPA), a histone deacetylase inhibitor, exhibited neuroprotective effects in rat models of CEI, although the underlying mechanism remains elusive. METHODS: The cauda equina compression surgery was performed to establish the CEI model. The Basso, Beattie, Bresnahan score, and the von Frey filament test were carried out to measure the animal behavior. Immunofluorescence staining of myelin basic protein and GPX4 was carried out. In addition, transmission electron microscope analysis was used to assess the effect of VPA on the morphological changes of mitochondria. RNA-sequencing was conducted to clarify the underlying mechanism of VPA on CEI protection. RESULTS: In this current study, we revealed that the expression level of HDAC1 and HDAC2 was elevated after cauda equina compression model but was reversed by VPA treatment. Meanwhile, HDAC2 knockdown resulted in the improvement of motor functions and pathologic pain, similar to treatment with VPA. Histology analysis also showed that knockdown of histone deacetylase (HDAC)-2, but not HDAC1, remarkably alleviated cauda equina injury and demyelinating lesions. The potential mechanism may be related to lowering oxidative stress and inflammatory response in the injured region. Notably, the transcriptome sequencing indicated that the therapeutic effect of VPA may depend on HDAC2-mediated ferroptosis. Ferroptosis-related genes were analyzed in vivo and DRG cells further validated the reliability of RNA-sequencing results, suggesting HDAC2-H4K12ac axis participated in epigenetic modulation of ferroptosis-related genes. CONCLUSION: HDAC2 is critically involved in the ferroptosis and neuroinflammation in cauda equina injury, and VPA ameliorated cauda equina injury by suppressing HDAC2-mediated ferroptosis.

Novel dual-targeting inhibitors of NSD2 and HDAC2 for the treatment of liver cancer: structure-based virtual screening, molecular dynamics simulation, and in vitro and in vivo biological activity evaluations.

Liver cancer exhibits a high degree of heterogeneity and involves intricate mechanisms. Recent research has revealed the significant role of histone lysine methylation and acetylation in the epigenetic regulation of liver cancer development. In this study, five inhibitors capable of targeting both histone lysine methyltransferase nuclear receptor-binding SET domain 2 (NSD2) and histone deacetylase 2 (HDAC2) were identified using a structure-based virtual screening approach. Notably, DT-NH-1 displayed a potent inhibition of NSD2 (IC50 = 0.08 ± 0.03 µM) and HDAC2 (IC50 = 5.24 ± 0.87 nM). DT-NH-1 also demonstrated a strong anti-proliferative activity against various liver cancer cell lines, particularly HepG2 cells, and exhibited a high level of biological safety. In an experimental xenograft model involving HepG2 cells, DT-NH-1 showed a significant reduction in tumour growth. Consequently, these findings indicate that DT-NH-1 will be a promising lead compound for the treatment of liver cancer with epigenetic dual-target inhibitors.

Differential expression of Hdac2 in male and female mice of differing social status.

Mice naturally form social hierarchies, and their experiences as subordinate or dominant mice inform future behavioural strategies. To better understand the neural bases of social dominance, we investigated hippocampal gene and protein expression of histone deacetylase 2 (HDAC2), an epigenetic regulator that decreases expression of synaptic plasticity genes and reduces excitatory synaptic function. Hdac2 in hippocampus was associated with social status. The gene for a closely related histone deacetylase (Hdac1), and HDAC2 protein expression, were not associated with social rank in hippocampus. These findings suggest that Hdac2 expression in hippocampus is distinctly linked with social status.

Discovery of novel and potent dual-targeting AXL/HDAC2 inhibitors for colorectal cancer treatment via structure-based pharmacophore modelling, virtual screening, and molecular docking, molecular dynamics simulation studies, and biological evaluation.

Colorectal cancer (CRC) is one of the most common cancers worldwide. Nowadays, owing to the complex mechanism of tumorigenesis, simultaneous inhibition of multiple targets is an important anticancer strategy. Recent studies have demonstrated receptor tyrosine kinase AXL (AXL) and histone deacetylase 2 (HDAC2) are closely associated with colorectal cancer. Herein, we identified five hit compounds concurrently targeting AXL and HDAC2 using virtual screening. Inhibitory experiments revealed these hit compounds potently inhibited AXL and HDAC2 in the nanomolar range. Among them, Hit-3 showed the strongest inhibitory effects which were better than that of the positive control groups. Additionally, MD assays showed that Hit-3 could bind stably to the AXL and HDAC2 active pockets. Further MTT assays demonstrated that Hit-3 showed potent anti-proliferative activity. Most importantly, Hit-3 exhibited significant in vivo antitumor efficacy in xenograft models. Collectively, this study is the first discovery of dual-targeting AXL/HDAC2 inhibitors for colorectal cancer treatment.

Single-cell RNA-seq and single-cell bisulfite-sequencing reveal insights into yak preimplantation embryogenesis.

Extensive epigenetic reprogramming occurs during preimplantation embryonic development. However, the impact of DNA methylation in plateau yak preimplantation embryos and how epigenetic reprogramming contributes to transcriptional regulatory networks are unclear. In this study, we quantified gene expression and DNA methylation in oocytes and a series of yak embryos at different developmental stages and at single-cell resolution using single-cell bisulfite-sequencing and RNA-seq. We characterized embryonic genome activation and maternal transcript degradation and mapped epigenetic reprogramming events critical for embryonic development. Through cross-species transcriptome analysis, we identified 31 conserved maternal hub genes and 39 conserved zygotic hub genes, including SIN3A, PRC1, HDAC1/2, and HSPD1. Notably, by combining single-cell DNA methylation and transcriptome analysis, we identified 43 candidate methylation driver genes, such as AURKA, NUSAP1, CENPF, and PLK1, that may be associated with embryonic development. Finally, using functional approaches, we further determined that the epigenetic modifications associated with the histone deacetylases HDAC1/2 are essential for embryonic development and that the deubiquitinating enzyme USP7 may affect embryonic development by regulating DNA methylation. Our data represent an extensive resource on the transcriptional dynamics of yak embryonic development and DNA methylation remodeling, and provide new insights into strategies for the conservation of germplasm resources, as well as a better understanding of mammalian early embryonic development that can be applied to investigate the causes of early developmental disorders.

Discovery of Selective Histone Deacetylase 1 and 2 Inhibitors: Screening of a Focused Library Constructed by Click Chemistry, Kinetic Binding Analysis, and Biological Evaluation.

Histone deacetylase 1 and 2 (HDAC1/2) inhibitors are potentially useful as tools for probing the biological functions of the isoforms and as therapeutic agents for cancer and neurodegenerative disorders. To discover potent and selective inhibitors, we screened a focused library synthesized by using click chemistry and obtained KPZ560 as an HDAC1/2-selective inhibitor. Kinetic binding analysis revealed that KPZ560 inhibits HDAC2 through a two-step slow-binding mechanism. In cellular assays, KPZ560 induced a dose- and time-dependent increase of histone acetylation and showed potent breast cancer cell growth-inhibitory activity. In addition, gene expression analyses suggested that the two-step slow-binding inhibition by KPZ560 regulated the expression of genes associated with cell proliferation and DNA damage. KPZ560 also induced neurite outgrowth of Neuro-2a cells and an increase in the spine density of granule neuron dendrites of mice. The unique two-step slow-binding character of o-aminoanilides such as KPZ560 makes them interesting candidates as therapeutic agents.