Glioma is the most common malignant brain tumor in the central nervous system with the poor prognosis of patients. The CNOT7 (CCR4-NOT Transcription Complex Subunit 7) is an important functional subunit of CCR4-NOT protein complex that has not been reported in glioma. In this study, we aimed to explore the function of CNOT7 in glioma. The TCGA (The Cancer Genome Atlas) and CGGA (Chinese Glioma Genome Atlas) databases were used for investigating the expression and survival condition of CNOT7 in glioma. The cellular function experiments of qRT-PCR, CCK-8 assays, wound healing assays, and Transwell assays were conducted to verify the function of knockdown CNOT7 in the glioma cell lines DBTRG and U251. Enrichment analysis was used to explore the molecular mechanism of CONT7 in glioma. What is more, the upstream regulation transcription factors of CNOT7 were analyzed based on the ChIP-Atlas and cBioportal (provisional) databases, and verified by the qRT-PCR and luciferase reporter assay. The CNOT7 was highly expressed in glioma and presented the poorer prognosis. The knockdown of CNOT7 inhibited the proliferation, migration, and invasion of glioma cell line, compared to control group. The enrichment analysis revealed that the CNOT7 participated in the development of glioma via G2M checkpoint, E2F targets, IL6-JAK-STAT3, and TNF-α signaling pathways via NF-κB. Besides, it was found that the HDAC2 (Human histone deacetylase-2) contributes to increased CNOT7 expression in glioma. The high-expressed CNOT7 is an oncogene with poor prognosis and participate the progression of glioma.

Epigenetics is the study of heritable changes to the genome and gene expression patterns that are not caused by direct changes to the DNA sequence. Examples of these changes include posttranslational modifications to DNA-bound histone proteins, DNA methylation, and remodeling of nuclear architecture. Collectively, epigenetic changes provide a layer of regulation that affects transcriptional activity of genes while leaving DNA sequences unaltered. Sequence variants or mutations affecting enzymes responsible for modifying or sensing epigenetic marks have been identified in patients with congenital heart disease (CHD), and small-molecule inhibitors of epigenetic complexes have shown promise as therapies for adult heart diseases. Additionally, transgenic mice harboring mutations or deletions of genes encoding epigenetic enzymes recapitulate aspects of human cardiac disease. Taken together, these findings suggest that the evolving field of epigenetics will inform our understanding of congenital and adult cardiac disease and offer new therapeutic opportunities.

The increasing prevalence and limited therapeutic options for liver fibrosis necessitates more medical attention. Our study aims to investigate the potential molecular targets by which Moringa oleifera Lam leaf extract (Mor) and/or telmisartan (Telm) alleviate carbon tetrachloride (CCl4)-induced liver fibrosis in rats. Liver fibrosis was induced in male Sprague-Dawley rats by intraperitoneal injection of 50% CCl4 (1 ml/kg) every 72 hours, for 8 weeks. Intoxicated rats with CCl4 were simultaneously orally administrated Mor (400 mg/kg/day for 8 weeks) and/or Telm (10 mg/kg/day for 8 weeks). Treatment of CCl4-intoxicated rats with Mor/Telm significantly reduced serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities compared to CCl4 intoxicated group (P < 0.001). Additionally, Mor/Telm treatment significantly reduced the level of hepatic inflammatory, profibrotic, and apoptotic markers including; nuclear factor-kappa B (NF-κB), tumor necrosis factor-alpha (TNF-α), transforming growth factor-βeta1 (TGF-β1), and caspase-3. Interestingly, co-treatment of CCl4-intoxicated rats with Mor/Telm downregulated m-RNA expression of histone deacetylase 2 (HDAC2) (71.8%), and reduced protein expression of mothers against decapentaplegic homolog 3 (p-SMAD3) (70.6%) compared to untreated animals. Mor/Telm regimen also elevated p-SMAD7 protein expression as well as m-RNA expression of peroxisome proliferator-activated receptor γ (PPARγ) (3.6 and 3.1 fold, respectively p < 0.05) compared to CCl4 intoxicated group. Histopathological picture of the liver tissue intoxicated with CCl4 revealed marked improvement by Mor/Telm co-treatment. Conclusively, this study substantiated the hepatoprotective effect of Mor/Telm regimen against CCl4-induced liver fibrosis through suppression of TGF-β1/SMAD3, and HDAC2/NF-κB signaling pathways and up-regulation of SMAD7 and PPARγ expression.

BACKGROUND: Metabolic-associated fatty liver disease (MAFLD) is a leading cause of chronic liver disease worldwide. Autophagy plays a pivotal role in lipid metabolism; however, the mechanism underlying the reduced autophagic activity in MAFLD remains elusive.
METHODS: Autophagy was monitored by TUNEL assay and immunofluorescence staining of LC3. The expression of autophagy-related proteins, PPARα, HDAC2, and HRD1 was detected by Western blot. The association between HDAC2 and PPARα promoter was assessed by chromatin immunoprecipitation (ChIP) and dual-luciferase assays, and the HRD1-mediated ubiquitin-proteasomal degradation of HDAC2 was detected by co-immunoprecipitation (co-IP). The in vitro findings were validated in a hypoxia-induced MAFLD mouse model. Histological changes, fibrosis, and apoptosis in liver tissues were detected by hematoxylin and eosin staining, Masson\'s trichrome staining, and TUNEL assay. The immunoreactivities of key molecules were examined by IHC analysis.
RESULTS: Hypoxia-suppressed autophagy in hepatocytes. Hypoxic exposure downregulated HRD1 and PPARα, while upregulating HDAC2 in hepatocytes. Overexpression of PPARα promoted hepatic autophagy, while knocking down HDAC2 or overexpressing HRD1 reduced hypoxia-suppressed autophagy in hepatocytes. Mechanistically, HDAC2 acted as a transcriptional repressor of PPARα, and HRD1 mediated the degradation of HDAC2 through the ubiquitin-proteasome pathway. Functional studies further showed that hypoxia-suppressed hepatic autophagy via the HRD1/HDAC2/PPARα axis in vitro and in vivo.
CONCLUSIONS: HRD1-mediated ubiquitination of HDAC2 regulates PPARα-mediated autophagy and ameliorates hypoxia-induced MAFLD.

BACKGROUND: Although numerous studies have indicated that activated pyroptosis can enhance the efficacy of antitumour therapy in several tumours, the precise mechanism of pyroptosis in colorectal cancer (CRC) remains unclear.
METHODS: Pyroptosis in CRC cells treated with antitumour agents was assessed using various techniques, including Western blotting, lactate dehydrogenase release assay and microscopy analysis. To uncover the epigenetic mechanisms that regulate NLRP3, chromatin changes and NLRP3 promoter histone modifications were assessed using Assay for Transposase-Accessible Chromatin using sequencing and RNA sequencing. Chromatin immunoprecipitation‒quantitative polymerase chain reaction was used to investigate the NLRP3 transcriptional regulatory mechanism. Additionally, xenograft and patient-derived xenograft models were constructed to validate the effects of the drug combinations.
RESULTS: As the core molecule of the inflammasome, NLRP3 expression was silenced in CRC, thereby limiting gasdermin D (GSDMD)-mediated pyroptosis. Supplementation with NLRP3 can rescue pyroptosis induced by antitumour therapy. Overexpression of HDAC2 in CRC silences NLRP3 via epigenetic regulation. Mechanistically, HDAC2 suppressed chromatin accessibility by eliminating H3K27 acetylation. HDAC2 knockout promotes H3K27ac-mediated recruitment of the BRD4-p-P65 complex to enhance NLRP3 transcription. Inhibiting HDAC2 by Santacruzamate A in combination with classic antitumour agents (5-fluorouracil or regorafenib) in CRC xenograft-bearing animals markedly activated pyroptosis and achieved a significant therapeutic effect. Clinically, HDAC2 is inversely correlated with H3K27ac/p-P65/NLRP3 and is a prognostic factor for CRC patients.
CONCLUSIONS: Collectively, our data revealed a crucial role for HDAC2 in inhibiting NLRP3/GSDMD-mediated pyroptosis in CRC cells and highlighted HDAC2 as a potential therapeutic target for antitumour therapy.
CONCLUSIONS: Silencing of NLRP3 limits the GSDMD-dependent pyroptosis in colorectal cancer. HDAC2-mediated histone deacetylation leads to epigenetic silencing of NLRP3. HDAC2 suppresses the NLRP3 transcription by inhibiting the formation of H3K27ac/BRD4/p-P65 complex. Targeting HDAC2 activates pyroptosis and enhances therapeutic effect.

Porcine reproductive and respiratory syndrome virus (PRRSV), a member of the Arteriviridae family, represents a persistent menace to the global pig industry, causing reproductive failure and respiratory disease in pigs. In this study, we delved into the role of histone deacetylases (HDAC2) during PRRSV infection. Our findings revealed that HDAC2 expression is downregulated upon PRRSV infection. Notably, suppressing HDAC2 activity through specific small interfering RNA led to an increase in virus production, whereas overexpressing HDAC2 effectively inhibited PRRSV replication by boosting the expression of IFN-regulated antiviral molecules. Furthermore, we identified the virus\'s nonstructural protein 11 (nsp11) as a key player in reducing HDAC2 levels. Mutagenic analyses of PRRSV nsp11 revealed that its antagonistic effect on the antiviral activity of HDAC2 is dependent on its endonuclease activity. In summary, our research uncovered a novel immune evasion mechanism employed by PRRSV, providing crucial insights into the pathogenesis of this virus and guiding the development of innovative prevention strategies against PRRSV infection.

OBJECTIVE: To investigate the roles of HDAC1/2 and HDAC3 in adult Meibomian gland (MG) homeostasis.
METHODS: HDAC1/2 or HDAC3 were inducibly deleted in MG epithelial cells of adult mice. The morphology of MG was examined. Proliferation, apoptosis, and expression of MG acinus and duct marker genes, meibocyte differentiation genes, and HDAC target genes, were analyzed via immunofluorescence, TUNEL assay, and RNA in situ hybridization.
RESULTS: Co-deletion of HDAC1/2 in MG epithelium caused gradual loss of acini and formation of cyst-like structures in the central duct. These phenotypes required homozygous deletion of both HDAC1 and HDAC2, indicating that they function redundantly in the adult MG. Short-term deletion of HDAC1/2 in MG epithelium had little effect on meibocyte maturation but caused decreased proliferation of acinar basal cells, excessive DNA damage, ectopic apoptosis, and increased p53 acetylation and p16 expression in the MG. By contrast, HDAC3 deletion in MG epithelium caused dilation of central duct, atrophy of acini, defective meibocyte maturation, increased acinar basal cell proliferation, and ectopic apoptosis and DNA damage. Levels of p53 acetylation and p21 expression were elevated in HDAC3-deficient MGs, while the expression of the differentiation regulator PPARγ and the differentiation markers PLIN2 and FASN was downregulated.
CONCLUSIONS: HDAC1 and HDAC2 function redundantly in adult Meibomian gland epithelial progenitor cells and are essential for their proliferation and survival, but not for acinar differentiation, while HDAC3 is required to limit acinar progenitor cell proliferation and permit differentiation. HDAC1/2 and HDAC3 have partially overlapping roles in maintaining survival of MG cells.

Androgen excess and metabolic abnormality largely contribute to the pathogenesis of polycystic ovarian syndrome (PCOS), which primarily precipitates ovarian dysfunction and infertility in reproductive-age women. Impaired mitochondrial function and epigenetic alteration have been linked to the development of PCOS. However, it is unknown whether acetate would exert a therapeutic effect on ovarian mitochondrial dysfunction in PCOS. Herein, the study hypothesized that acetate reverses ovarian mitochondrial dysfunction in experimental PCOS rat model, possibly through modulation of mitofusin-2 (MFn2). Eight-week-old female Wistar rats were randomized into four groups (n = 5). Induction of PCOS was performed by 1 mg/kg letrozole (p.o.), administered for 21 days. Thereafter, the rats were treated with acetate (200 mg/kg; p.o.) for 6 weeks. The PCOS rats demonstrated androgen excess, multiple ovarian cysts, elevated anti-mullerian hormone and leptin and decreased SHBG, adiponectin and 17-β estradiol with corresponding increase in ovarian transforming growth factor-β1. Additionally, inflammation (tumor growth factor and nuclear factor-kB), elevated caspase-6, decreased hypoxia-inducible factor-1α and elevated histone deacetylase-2 (HDAC2) were observed in the ovaries of PCOS rats, while mitochondrial abnormality with evidence of decreased adenosine triphosphate synthase and MFn2 was observed in rats with PCOS. Treatment with acetate reversed the alterations. The present results collectively suggest that acetate ameliorates ovarian mitochondrial abnormality, a beneficial effect that is accompanied by MFn2 with consequent normalization of reproductive-endocrine profile and ovarian function. Perhaps, the present data provide hope for PCOS individuals that suffer infertility.

Virtual screening of a library of 329 flavonoids obtained from the NPACT database was performed to find out potential novel HDAC2 inhibitors. Eleven out of 329 selected flavonoids were screened based on molecular docking studies, as they have higher binding affinities than the standard drugs vorinostat and panobinostat. All screened compounds occupying the catalytic site of HDAC2 showed important molecular interaction with Zn2+ and other important amino acids in the binding pocket. The screened compounds were validated using ADMET filtration and bioactivity prediction from which we obtained six compounds, NPACT00270, NPACT00676, NPACT00700, NPACT001008, NPACT001054, and NPACT001407, which were analyzed using DFT studies. DFT studies were performed for all six screened flavonoids. In DFT studies, three flavonoids, NPACT00700, NPACT001008, and NPACT001407, were found to be better based on HOMO-LUMO and molecular electrostatic potential (MEP) analyses. Furthermore, MD simulations were performed for 100 ns for the three compounds. In the MD analysis, NPACT001407 was found to be more stable in the active site of HDAC2 as zinc formed a coordination bond with ASP181, HIS183, ASP269, and GLY305, along with two hydroxyl groups of the ligand. Our findings reveal that these flavonoids can interact as ligands with the active site of HDAC2. Because of the absence of a hydroxamate group in flavonoids, there are no possibilities for the formation of isocyanate. This suggests that the major drawback of current HDACs inhibitors may be solved. Further experimental validation is needed to understand the selectivity of flavonoids as HDAC2 inhibitors.
UNASSIGNED: The online version contains supplementary material available at 10.1007/s13205-023-03912-5.

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 β-glycerophosphate (β-GP). HDAC2 expression was found to be reduced in medial artery of CKD mice and β-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 β-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 β-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.