HDAC2 Expression Research Articles

High levels of histone acetylation modifications promote the formation of PGCs.

This study investigates the role of histone acetylation in the differentiation of chicken embryonic stem cells (ESCs) into primordial germ cells (PGCs). Transcriptomic sequencing was used to analyze differentially expressed genes during this differentiation process, with functional annotation identifying genes associated with histone acetylation. To explore the role of acetylation, acetate and an acetyltransferase inhibitor (ANAC) were added to the ESCs induction medium. Transcriptomic analysis revealed that during ESCs differentiation into PGCs, genes involved in histone acetyltransferase activity were upregulated, while those associated with histone deacetylase activity were downregulated. Functional enrichment analysis indicated these genes are involved in pathways critical for germ cell differentiation, underscoring their importance in avian reproductive biology. Quantitative real-time PCR (qRT-PCR) confirmed significant differential expression of HAT8 and HDAC10 between ESCs and PGCs (P < 0.01). The acetate treatment group exhibited a significantly higher number of embryoid bodies and elevated expression levels of CVH, C-KIT, and NANOS3 compared to the ANAC group (P < 0.01). Furthermore, indirect immunofluorescence and flow cytometry demonstrated a significantly higher proportion of DDX4-positive cells in the acetate group (P < 0.01). These findings provide preliminary evidence that histone acetylation regulates chicken PGCs formation, offering a theoretical framework for the epigenetic induction of PGCs in vitro. This study enhances our understanding of the molecular mechanisms underlying PGCs development in poultry and contributes to advancements in avian reproductive technologies and genetic conservation.

Structure similarity based screening coupled to integrated structural biochemistry approach for exploring the high affinity inhibitors against histone deacetylase (HDAC)-6.

Histone deacetylase (HDAC)-6 has overwhelming implications in multiple cancers and neurodegenerative disorders. Unusual HDAC6 expression modulates various signalling mechanisms which in turn forms the aetiology of the above-mentioned disorders. Thus, restoring the typical activity of HDAC6 through small molecules may prove as a promising approach to beat these disorders. Herein, we employed an integrated approach for exploring the high binding affinity manifesting molecules against HDAC6. We screened the entire PubChem database using Tubastatin A as the reference (query) molecule following which we carried out 110 molecular docking (XP-mode) and 110 MM-GBSA experiments. Thirty-three molecules demonstrated raised binding affinity than query in the HDAC6 active site. Further, the top 3 binders selected on logical grounds were subjected to interaction study, two hit molecules and tubastatin-A were subjected to convoluted molecular dynamics and three-dimensional e-Pharmacophores mapping was done to delineate the rationale behind the high binding tendency of hit molecules over control molecule. This work provides a solid foundation for additional research towards the development of lead molecules from the said hits for therapeutic intervention against HDAC6 overexpression-driven disorders.

Unraveling the mechanism of microRNA-134 in colon cancer progression: Targeting KRAS and PIK3CA for cell cycle control and histone deacetylase regulation.

Colon cancer is the leading cause of cancer-related deaths worldwide. MicroRNAs (miRNAs) are key regulators of gene expression, often dysregulated in colon cancer. This study aims to elucidate the therapeutic role of miR-134-5p as a tumor suppressor miRNA in colon cancer cells. We analyzed miRNA expression profiles in primary and metastatic colon cancer cells. The clinical significance of miR-134-5p was evaluated using the TCGA database. Bioinformatics tools (HADDOCK) predicted miRNA-mRNA interactions and the molecular docking of miRNA-mRNA-AGO2 complexes. Luciferase reporter assays, cell proliferation, immunofluorescence, colony forming unit assays, and qRT-PCR analysis assessed miR-134-5p effects on KRAS, PIK3CA, and downstream signaling pathways in primary and metastatic colon cancer cells. miR-134-5p was downregulated in colon cancer cells. Bioinformatics analysis suggested KRAS, PIK3CA, EGFR, and HDAC5 as potential targets. HADDOCK analysis revealed strong binding affinity and structural stability between KRAS, PIK3CA, miR-134-5p, and AGO2. Gene-reporter assays confirmed miR-134-5p-mediated degradation of KRAS and PIK3CA. miR-134-5p transfection reduced KRAS and PI3K protein levels, suppressed EGFR/RTK signaling and its downstream targets, and inhibited HDAC expression, ultimately reducing colon cancer cell proliferation. The results of this study confirm that miR-134-5p acts as a potential tumor suppressor miRNA in colon cancer cells by inhibiting KRAS and PI3K expression through AGO2-mediated gene silencing. It deregulates downstream EGFR signaling and HDACs, thereby reducing colon cancer cell proliferation. These findings highlight miR-134-5p as a promising therapeutic target for miRNA-mediated anticancer therapy.

HDAC3 inhibitors induce drug resistance by promoting IL-17 A production by T cells

HDAC3 has been demonstrated to play a crucial role in the progression of various tumors and the differentiation and development of T cells. However, its impact on peripheral T cells in the development of murine lung cancer remains unclear. In this experiment, a subcutaneous lung tumor model was established in C57BL/6 mice, and tumor-bearing mice were treated with the specific inhibitor of HDAC3, RGFP966, at different doses to observe changes in tumor size. Additionally, a lung tumor model was established using hdac3fl/flcd4cre+/+ mice to investigate its mechanism. Mice injected with 10 mg/kg RGFP966 had the smallest tumor volume, while those injected with 30 mg/kg RGFP966 had the largest tumors. Flow cytometry analysis revealed that the expression of HDAC3 in splenic T cells was reduced in all groups of mice, while IFN-γ and IL-17 A were increased. Moreover, the expression of granzyme B and perforin in splenic CD8+ T cells was increased in all groups of mice. Compared to the use of 30 mg/kg RGFP966 alone, the combination with anti-IL-17 A mAb reduced the infiltration of Neutrophils and exhausted T cells in mouse tumors, thereby impeding tumor development. These findings demonstrate that the use of RGFP966 or T cell-specific loss of hdac3 promotes the expression of IL-17 A in splenic T cells, leading to tumor resistance and providing insights for clinical treatment.

A pilot study on the efficacy of a telomerase activator in regulating the proliferation of A375 skin cancer cell line.

The changes in histone modifications are linked to the progression of benign and normal tissue to malignancy. Thus, numerous findings suggest that targeting epigenetic factors might be a focus for anti-cancer treatment. In this study, we tested the hypothesis that telomerase activator might be a potential epigenetic regulator in combatting skin cancer cell proliferation. Melanoma cell line A375 cells were treated with telomerase activator TA-65. Cell senescence assay was done to evaluate the senescence induction. Morphological changes and differences in expression of HDACs and hTERT genes were studied. Further, hyaluronidase and anti-oxidant assays were also performed. Additionally, telomerase enzyme and 20S proteasome activity was also studied. Morphological changes were observed in treated cells and it is evident that telomerase activator induced cellular senescence in high concentrations. From our results, it is evident that HDAC8 and HDAC10expression was upregulated, whereas hTERT gene expression was downregulated in treated groups. This suggests that the telomerase activator has a regulatory role in skin cancer cells proliferation by targeting the epigenetic factors. Targeting HDACs and hTERT in the treatment of melanoma is a prominent concern. In our current study, we highlight the most recent research, although in its initial stage, involving various epigenetic factors involved in melanoma cells proliferation.

An 8-Week Very Low-Calorie Ketogenic Diet (VLCKD) Alters the Landscape of Obese-Derived Small Extracellular Vesicles (sEVs), Redefining Hepatic Cell Phenotypes.

Background. Very low-calorie ketogenic diets (VLCKD) are an effective weight-loss strategy for obese individuals, reducing risks of liver conditions such as non-alcoholic steatohepatitis and fibrosis. Small extracellular vesicles (sEVs) are implicated in liver fibrosis by influencing hepatic cell phenotypes and contributing to liver damage. This study investigates sEVs derived from serum of 60 obese adults categorized into low fibrosis risk (LR) and intermediate/high fibrosis risk (IHR) groups based on FibroScan elastography (FIB E scores, limit value 8 kPa) and all participants underwent an 8-week VLCKD intervention. Methods. The study examines the impact of these sEVs on fibrosis markers, inflammation, and autophagy in a hepatocyte cell line (HEPA-RG) using bioinformatics, RNA sequencing, lipidomics, RT-PCR, and Western blotting before (T0) and after (T1) VLCKD. Results. sEVs from LR patients post-VLCKD reduced fibrosis related gene expression (e.g., ACTA2) and enhanced proteins associated with regeneration and inflammation (e.g., HDAC6). Conversely, sEVs from IHR patients increased fibrosis and inflammation related gene expression (PIK3CB, AKT1, ACTA2) in hepatocytes, raising concerns about VLCKD suitability for IHR patients. IHR sEVs also decreased expression of HDAC10, HDAC6, HDAC3, MMP19, and MMP2, while increasing modulation of p-AKT, α-SMA, and VIM. Conclusion. These findings underscore the critical role of sEVs in regulating inflammation, remodeling, and hepatic stress responses, particularly in IHR patients, and suggest sEVs could complement instrumental evaluations like FibroScan in fibrosis assessment.

Beta-hydroxybutyrate alters bovine preimplantation embryo development through transcriptional and epigenetic mechanisms†.

Developing embryos are susceptible to fluctuations in the nutrients and metabolites concentrations within the reproductive tract, which can lead to alterations in their developmental trajectory. Ketotic dairy cows have diminished fertility, and elevated levels of the ketone body beta-hydroxybutyrate (BHB) have been associated with poor embryonic development. We used an in vitro model based on either in vitro fertilization (IVF) or parthenogenesis to investigate the effects of BHB on the preimplantation bovine embryo development, epigenome, and transcriptome. Embryo culture medium was supplemented with BHB at a similar concentration to that present in the blood of cows suffering with severe ketosis, followed by analysis of blastocysts formation rate, diameter, total number of cells, levels of H3K9 beta-hydroxybutyrylation (H3K9bhb), apoptosis, and transcriptional alterations. As a result, we observed that BHB reduced the blastocysts rates, the diameter and the total number of cells in both parthenotes and IVF embryos. Exposure to BHB for either 3 or 7days greatly increased the H3K9bhb levels in parthenotes at the 8-cells and blastocyst stages, and affected the expression of HDAC1, TET1, DNMT1, KDM6B, NANOG, and MTHFD2 genes. Additionally, culture of IVF embryos with BHB for 7days dramatically increased H3K9bhb and reduced NANOG in blastocysts. RNA-seq analysis of IVF blastocysts revealed that BHB modulated the expression of 118 genes, which were involved with biological processes such as embryonic development, implantation, reproduction, proliferation, and metabolism. These findings provided valuable insights into the mechanisms through which BHB disrupts preimplantation embryonic development and affects the fertility in dairy cows.

MAP3K4 signaling regulates HDAC6 and TRAF4 coexpression and stabilization in trophoblast stem cells†.

Mitogen-activated protein kinase kinase kinase 4 (MAP3K4) promotes fetal and placental growth and development, with MAP3K4 kinase inactivation resulting in placental insufficiency and fetal growth restriction. MAP3K4 promotes key signaling pathways including JNK, p38, and PI3K/Akt, leading to activation of CREB-binding protein. MAP3K4 kinase inactivation results in loss of these pathways and gain of histone deacetylase 6 (HDAC6) expression and activity. Tumor necrosis factor receptor-associated factor 4 (TRAF4) binds MAP3K4 and promotes MAP3K4 activation of downstream pathways in the embryo; however, the role of TRAF4 and its association with MAP3K4 in the placenta is unknown. Our analyses of murine placenta single-cell RNA-Seq data showed that Traf4 is coexpressed with Map3k4 in trophoblast stem (TS) cells and labyrinth progenitors, whereas Hdac6 expression is higher in differentiated trophoblasts. We demonstrate that, like HDAC6, TRAF4 expression is increased in MAP3K4 kinase-inactive TS (TSKI) cells and upon inhibition of MAP3K4-dependent pathways in WT TS cells. Moreover, Hdac6 shRNA knockdown in TSKI cells reduces TRAF4 protein expression. We found that HDAC6 forms a protein complex with TRAF4 in TS cells and promotes TRAF4 expression in the absence of HDAC6 deacetylase activity. Finally, we examine the relationships among MAP3K4, TRAF4, and HDAC6 in the developing placenta, finding a previously unknown switch in coexpression of Traf4 with Map3k4 versus Traf4 with Hdac6 during differentiation of the placental labyrinth. Together, our findings identify previously unknown mechanisms of MAP3K4 and HDAC6 coregulation of TRAF4 in TS cells and highlight these MAP3K4, TRAF4, and HDAC6 associations during placental development.

Trichostatin A reverses rocuronium resistance in burn-injured rats.

This study aimed to investigate whether the histone deacetylase HDAC4 inhibitor, trichostatin A (TSA), could reverse resistance to non-depolarizing muscle relaxants (NDMRs) caused by burn injuries. A rat burn injury model was established, in which TSA was administered to inhibit HDAC4 expression. The potency of rocuronium was assessed through tension tests, and the levels of HDAC4 and myogenin proteins were determined using Western blot. Additionally, siRNA was utilized to explore the effects of HDAC4 knockdown on rocuronium potency and protein expression. The burn injuries increased the IC50 of rocuronium, which was reversed by TSA treatment. Furthermore, HDAC4 and myogenin protein expression levels were increased significantly in burned legs, a phenomenon that TSA effectively counteracted. HDAC4 knockdown decreased rocuronium IC50 and lowered HDAC4 and myogenin protein expression in the subsequent burn injuries. The HDAC4 inhibitor TSA has the ability to mitigate NDMR resistance in skeletal muscle via the HDAC4-myogenin pathway after burn injuries.

Intervention effects of Er Miao san on metabolic syndrome in Bama miniature pigs.

Metabolic syndrome (MS) refers to a cluster of metabolic disorders characterized by systemic chronic inflammation. Er Miao San (EMS) is a classic traditional Chinese medicine compound containing Phellodendron amurense and Atractylodis rhizome at a ratio of 1:1, proven to be effective against inflammatory diseases in clinical practice. Nevertheless, the precise functions of EMS in treating MS and its underlying mechanism have yet to be elucidated. This study focuses on the intervention effects of EMS on high humidity exposure and high sugar-fat diet (HHSF)-induced MS in pigs. Blood biochemical indices and metabolome analysis were employed to confirm the successful establishment of the MS model, and the preliminary evaluation of the intervention effect of EMS was conducted. Subsequently, a parallel microbiota analysis of the tongue and cecum was combined with metabolomic analysis, histopathologic examination, and other molecular biological detection to further assess the administration mechanism of EMS. The results demonstrated that EMS significantly reduced the excessive weight gain rate, fat accumulation, hyperlipidemia, hyperglycemia, and systemic inflammation while improving serum metabolic disorder in MS pigs. Moreover, microbiota analysis indicates that EMS restored the diversity and composition of oral-gut microbiota by increasing the proportions of Lactobacillus (gut), Roseburia (gut), Faecalibacterium (gut), CF231 (gut), Streptococcus (gut), Prevotella (gut), while decreasing those of Chryseobacterium (oral), Corynebacterium (oral), Clostridium (oral), Oscillospira (gut), and Turicibacter (oral, gut). Subsequently, EMS up-regulated the concentrations of acetic acid, butyric acid, propionic acid, while down-regulated isobutyric acid and isovaleric acid. This resulted in a suppression of HDAC3 expression and an increase of SCL16A1 expression in the colon. Notably, the changes in acetic acid and butyric acid showed a strong correlation with gut microbiota. Additionally, EMS reduced the serum level of lipopolysaccharide (LPS) and enhanced epithelial barrier integrity by inhibiting the LPS-TLR4/MyD88/NF-κB pathways. EMS was found to ameliorate MS by alleviating the dysbiosis of the oral-gut microbiota and serum metabolome, thereby improving gut barrier and reducing systemic inflammation. These findings suggest that EMS holds promise as a therapeutic agent for MS.

Zingerone Facilitates Apoptosis in Triple Negative Breast Cancer Cells by Inducing Autophagy

ABSTRACTTriple negative breast cancer (TNBC) is characterized by high heterogenicity and aggressiveness and autophagy plays a complicated role in cancer development. Zingerone is reported to possess multiple pharmacological activities, including antitumors. This study explored the biological role and the relevant mechanisms of zingerone in TNBC. Following zingerone treatment, the viability of normal breast cancer cells MCF‐10A and TNBC cells (MDA‐MB‐231 and MDA‐MB‐468) was detected with CCK‐8 assay. The proliferation, migration and invasion of TNBC cells were detected with colony formation, wound healing, and transwell assays. Western blot was used to detect the expressions of migration‐, apoptosis‐ and autophagy‐related proteins. Flow cytometry was used to detect the cell apoptotic level and immunofluorescence assay measured the autophagy. The experimental data revealed that zingerone with varying concentrations suppressed cell viability, proliferation, migration and invasion while promoting the apoptosis in TNBC, which might be mediated by autophagy activation. Besides, zingerone decreased HDAC1 expression in TNBC cells and regulated autophagy via HDAC1. Collectively, zingerone impeded the malignant progression of TNBC via inducing HDAC1‐mediated autophagy.

Adipose stem cell exosomes, stimulated by pro-inflammatory factors, enhance immune evasion in triple-negative breast cancer by modulating the HDAC6/STAT3/PD-L1 pathway through the transporter UCHL1

BackgroundTriple-negative breast cancer (TNBC) is characterized by high invasiveness and metastasis potential. Ubiquitin carboxy-terminal hydrolase L1 (UCHL1) is strongly associated with breast cancer progression, although the underlying mechanisms are largely unknown.MethodsThe gene expression profiles of TNBC samples were downloaded from the TCGA database, and ubiquitination enzymes related to immune regulation were screened. UCHL1 expression in the TNBC tissues and in adipose-derived mesenchymal stem cells (ADSCs) stimulated in vitro with pro-inflammatory cytokines were analyzed. Exosomes were isolated from these stimulated ADSCs and transfected with scrambled (si-NC) or UCHL1-specific (si-UCHL1) siRNA constructs. TNBC cells were treated with the ADSCs-derived exosomes (ADSCs-Exos) and then co-cultured with macrophages or T cells. Finally, the tumorigenic potential of the ADSCs-Exos was evaluated by injecting the exosomes into mice bearing TNBC xenografts.ResultsUCHL1 was highly expressed in TNBC tissues and the stimulated ADSCs. The exosomes derived from stimulated ADSCs increased the viability and migration capacity of TNBC cells in vitro, and significantly increased Ki-67 expression through UCHL1. Furthermore, ADSCs-Exos induced M2 polarization of THP-1 monocytes by upregulating CD206 and Arg-1, and downregulating TNF-α and iNOS, and also decreased the proportion of CD3+CD8+ T cells. Mechanistically, UCHL1 regulated the STAT3 and PD-L1 signaling pathways through HDAC6. Exosomes derived from the control and cytokine-stimulated ADSCs also promoted tumor growth in vivo, and increased the expression of UCHL1, CD206, HDAC6, STAT3, and PD-L1. However, UCHL1 knockdown reversed the pro-tumorigenic effects of the ADSCs-derived exosomes in vivo and in vitro.ConclusionPro-inflammatory factors (IFN-γ + TNF-α) stimulating ADSCs-Exos enhance immune evasion in triple-negative breast cancer by regulating the HDAC6/STAT3/PD-L1 pathway via UCHL1 transporter. Thus, UCHL1 inhibition may enhance the response of TNBC to immunotherapy.Graphical

N6-Methyladenosine Regulates Cilia Elongation in Cancer Cells by Modulating HDAC6 Expression.

Primary cilia are microtubule-based organelles that function as cellular antennae to address multiple metabolic and extracellular cues. The past decade has seen significant advances in understanding the pro-tumorigenic role of N6-methyladenosine (m6A) modification in tumorigenesis. Nevertheless, whether m6A modification modulates the cilia dynamics during cancer progression remains unclear. Here, the results show that m6A methyltransferase METTL3regulates cilia length in cancer cells via HDAC6-dependent deacetylation of axonemal α-tubulin, thereby controlling cancer development. Mechanically, METTL3 positively regulates the translation of HDAC6 in an m6A-dependent manner, while m6A methylation of A3678 in the coding sequence (CDS) of HDAC6 ameliorates its translation efficiency via facilitating the binding with YTHDF3. The upregulation of HDAC6 induced by METTL3 over-expression is capable of inhibitingcilia elongation and acetylation of α-tubulin, thereby shortening cilia length and accelerating the progression of cervical cancer both in vitro and in vivo. Collectively, depletion of METTL3-mediated m6A modification leads to abnormally elongated cilia via suppressing HDAC6-dependent deacetylation of axonemal α-tubulin, ultimately attenuating cell growth and cervical cancer development.

Abstract 4129974: Increased Expression of Histone Deacetylases-2 and -6 in Left Ventricular Myocardium of Dogs with Chronic Heart Failure

Background: Histone deacetylases (HDACs) -2 and -6 are localized in the nucleus and cytoplasm of cells and have been implicated in the development of left ventricular (LV) hypertrophy, cardiac interstitial fibrosis, inflammation and worsening of LV systolic and diastolic function thus contributing to progressive worsening of heart failure (HF) with reduced ejection fraction (HFrEF) as well as HF with preserved ejection fraction (HFpEF). There is considerable interest in the application of small molecules that inhibit the activity of HDAC proteins in HF in the hope of fostering clinical benefit. Purpose: In the present study we examined the expression of HDAC-2 and -6 in LV tissue from normal (NL) dogs and dogs with chronic HF (LVEF &lt;35%) produced by multiple sequential intracoronary microembolizations. Methods: Studies were performed in LV tissue from 7 NL dogs and 7 HF dogs. HDAC-2 and -6 protein levels were determined by Western blotting in the lysate of homogenate and 9000g supernatant (cytosolic) fractions prepared from powder of approximately 200 mg frozen LV tissue. After determining the protein by Lowry method, approximately 30 μg homogenate and 15 μg supernatant for HDAC-2 and 8 μg protein for both homogenate and supernatant for HDAC-6 were separated on 4%-20% SDS-PAGE and transferred on PVDF membrane. Band intensities were quantified in densitometric units (du). All data were normalized to glyceraldehyde-3-phosphate dehydrogenase (GAPDH). Results: HDAC-2 proteins levels normalized to GAPDH were higher in the cytosol (0.59 ± 0.10 vs. 0.17 ± 0.04, p&lt;0.05 vs. NL) and homogenate (0.75 ± 0.12 vs. 0.55 ± 0.10, not statistically significant) of LV tissue of dogs with HF compared to NL dogs. HDAC-6 protein levels were higher in the homogenate (2.54 ± 0.36 vs. 0.57 ± 0.19, p&lt;0.05 vs. NL) and the cytosol (0.96 ± 0.15 vs. 0.78 ± 0.13, not statistically significant) of LV tissue of dogs with HF compared to NL dogs. Conclusions: These findings indicate upregulation of protein levels of HDAC-2 and -6 isoforms in LV myocardium of dogs with chronic HF. These abnormalities are likely to contribute to worsening HF. Selective inhibition of HDAC-2 and -6 represents a potential therapeutic approach for the treatment of both HFrEF and HFpEF.

HDAC6 as a Prognostic Factor and Druggable Target in HER2-Positive Breast Cancer.

Adjuvant trastuzumab is the standard of care for HER2+ breast cancer (BC) patients. However, >50% of patients become resistant. This study aimed at the identification of the molecular factors associated with disease relapse and their further investigation as therapeutically exploitable targets. Analyses were conducted on formalin-fixed paraffin-embedded tissues of the primary tumors of relapsed (cases) and not relapsed (controls) HER2+ BC patients treated with adjuvant trastuzumab. The nCounter Human Breast Cancer Panel 360 was used. Logistic regression and partitioning around medoids were employed to identify the genes associated with disease recurrence. Cytotoxicity experiments using trastuzumab-resistant cell lines and a network pharmacology approach were carried out to investigate drug efficacy. A total of 52 patients (26 relapsed and 26 not relapsed) were analyzed. We found that a higher expression of HDAC6 was significantly associated with an increased risk of recurrence, with an adjusted OR of 3.20 (95% CI 1.38-9.91, p = 0.016). Then, we investigated the cytotoxic activity of the selective HDAC6 inhibitor Nexturastat A (NextA) on HER2+ cell lines, which were both sensitive and trastuzumab-resistant. A sub-cytotoxic concentration of NextA, combined with trastuzumab, showed a synergistic effect on BC cell lines. Finally, using a network pharmacology approach, we identified HSP90AA1 as the putative molecular candidate responsible for the synergism observed in vitro. Our findings encourage the exploration of the role of HDAC6 as a prognostic factor and the combinatorial use of HDAC6 selective inhibitors combined with trastuzumab in HER2+ BC, in particular for those patients experiencing drug resistance.

Inhibition of cytokine-like protein 1 transcription hinders wound-healing process in diabetic rats.

This study explored the function and mechanism of cytokine-like protein 1 (CYTL1) in regulating the wound-healing process of rats with diabetes mellitus (DM). A wound was made in diabetic rats, in which CYTL1 overexpression or HDAC1 expression-interfering adenovirus was injected. The wound area on day 0, 7, 14 and 21 was observed and photographed to calculate the wound-healing rate. The wound tissues were collected for H&E, Masson staining and CD31 immunohistochemistry. The HDAC1 and CYTL1 mRNA and protein expressions in wound tissues were detected by RT-qPCR and western blot. The regulation of HDAC1 on CYTL1 was predicted by hTFtarget and AnimalTFDB database. The H3K27Ac level in the CYTL1 promoter was detected by chromatin immunoprecipitation (ChIP). Diabetic rats with CYTL1 overexpression or interfered HDAC1 expression had accelerated the wound-healing rate, in which massive fibroblasts, attenuated inflammatory infiltration and increased collagen and microvessel density were observed. Further experiments found that HDAC1 can inhibit CYTL1 transcription and expression by inhibiting H3K27Ac expression in CYTL1 promoter. Collected evidence showed HDAC1 can inhibit CYTL1 transcription by down-regulating the H3K27Ac level in CYTL1 promoter to slow down the wound-healing process in diabetic ulcer rats.

Updated Survival Follow-Up for Phase Ib Trial of the Histone Deacetylase Inhibitor Abexinostat With Pazopanib in Patients With Solid Tumor Malignancies.

Histone deacetylase (HDAC) inhibition downregulates hypoxia-inducible factor-1α and modulates multiple metabolomic pathways relevant in cancer. Here we report a potential novel biomarker to predict exceptional responders (>3 years) in patients receiving HDAC and vascular endothelial growth factor (VEGF) inhibition. Patients with solid tumor malignancies were enrolled in this phase Ib trial of abexinostat (4/7 ×21 days) and pazopanib (28/28 days), with a dose expansion in renal cell carcinoma (RCC). Plasma was analyzed for metabolomics and peripheral blood mononuclear cells (PBMCs) for VEGF and HDAC2 expression levels. Fifty-one patients were enrolled: n = 36 patients in dose escalation and n = 15 in dose expansion. After the initial report in 2017, six patients had remained on study: four with RCC and one each with medullary thyroid and thymic neuroendocrine carcinoma. One patient with RCC remains on treatment for >11 years after progression on five systemic therapies. Overall, the median duration of therapy measured 5.6 (1-133) months. The median duration of therapy in exceptional responders measured 44.1 (39.8-133+) months. The median overall survival in patients with high PBMC HDAC2 expression versus low HDAC2 was 32.3 versus 9.2 months (P = .004) for all patients and 43.3 versus 25.1 months for patients with RCC (P = .09). Exceptional responders had lower kynurenine levels both pre- and post-treatment (P = .002, P < .001, respectively). HDAC2 and kynurenine expression levels were inversely correlated (P = .02). Abexinostat added to pazopanib shows extended tolerability and long-term responses and survival. PBMC HDAC2 levels, the abexinostat target, are relevant predictors of response. In addition, metabolomic assessment points to kynurenine as a predictor for exceptional response to combined VEGF plus HDAC inhibition.

Kaempferol alleviates myocardial ischemia injury by reducing oxidative stress via the HDAC3-mediated Nrf2 signaling pathway

IntroductionKaempferol (KAE) is a flavonoid found in various plants. Recent studies showed that high dietary intake of KAE was associated with a lower risk of myocardial infarction; however, the cardioprotective mechanism of KAE remains unknown. ObjectivesTo determine the effect of KAE on cardiac injury in isoproterenol (ISO)-induced rats and cobalt chloride (CoCl2)-treated cardiomyocytes, and the underlying mechanisms. MethodsMale rats were pretreated with different doses of KAE for 14 days, and then injected with ISO to induce myocardial ischemia injury. We also established a model of myocardial cell injury using rat H9c2 cardiomyocytes stimulated with CoCl2. ResultsWe found that KAE pretreatment significantly alleviated myocardial injury and improved cardiac function in ISO-injected rats. In addition, KAE reduced oxidative stress in rats with myocardial ischemia by decreasing malondialdehyde concentration and increasing superoxide dismutase activity, and protection of the myocardial mitochondrial structure. KAE also attenuated CoCl2-induced injuryof H9c2 cardiomyocytes via suppression ofoxidative stress. With regard to the mechanism, we found that KAE down-regulated HDAC3 expression and up-regulated Nrf2 expression in ISO-induced rats and CoCl2-stimulated cardiomyocytes. Incubation of cardiomyocytes with HDAC3-selective inhibitor RGFP966 augmented the protective effect of KAE and reduced oxidative stress. By contrast, HDAC3 overexpression by adenovirus attenuated the effect of KAE on oxidative stress compared with KAE treatment group. HDAC3 also regulated Nrf2 expression in the cardiomyocytes with RGFP966 or an adenovirus overexpressing HDAC3; but Nrf2 inhibition reduced the effect of KAE on ROS generation in CoCl2-induced cardiomyocytes. Immunoprecipitation assay showed that HDAC3 interacted with Nrf2 in cardiomyocytes. Further studies found that KAE increased the acetylation level of Nrf2, while HDAC3 overexpression decreased the acetylation of Nrf2 compared with KAE treatment group. ConclusionOur data show that KAE ameliorates cardiac injury by reducing oxidative stress via the HDAC3-mediated Nrf2 signaling pathway in cardiomyocytes.

Chidamide triggers pyroptosis in T-cell lymphoblastic lymphoma/leukemia via the FOXO1/GSDME axis.

T-cell lymphoblastic lymphoma/leukemia (T-LBL/ALL) is an aggressive form of hematological malignancy associated with poor prognosis in adult patients. Histone deacetylases (HDACs) are aberrantly expressed in T-LBL/ALL and are considered potential therapeutic targets. Here, we investigated the antitumor effect of a novel HDAC inhibitor, chidamide, on T-LBL/ALL. HDAC1, HDAC2 and HDAC3 levels in T-LBL/ALL cell lines and patient samples were compared with those in normal controls. Flow cytometry, transmission electron microscopy and lactate dehydrogenase release assays were conducted in Jurkat and MOLT-4 cells to assess apoptosis and pyroptosis. A specific forkhead box O1 (FOXO1) inhibitor was used to rescue pyroptosis and upregulated gasdermin E (GSDME) expression caused by chidamide treatment. The role of the FOXO1 transcription factor was evaluated by dual-luciferase reporter and chromatin immunoprecipitation assays. The efficacy of chidamide in vivo was evaluated in a xenograft mouse. The expression of HDAC1, HDAC2 and HDAC3 was significantly upregulated in T-LBL/ALL. Cell viability was obviously inhibited after chidamide treatment. Pyroptosis, characterized by cell swelling, pore formation on the plasma membrane and lactate dehydrogenase leakage, was identified as a new mechanism of chidamide treatment. Chidamide triggered pyroptosis through caspase 3 activation and GSDME transcriptional upregulation. Chromatin immunoprecipitation assays confirmed that chidamide led to the increased transcription of GSDME through a more relaxed chromatin structure at the promoter and the upregulation of FOXO1 expression. Moreover, we identified the therapeutic effect of chidamide in vivo. Our study suggested that chidamide exerts an antitumor effect on T-LBL/ALL and promotes a more inflammatory form of cell death via the FOXO1/GSDME axis, which provides a novel choice of targeted therapy for patients with T-LBL/ALL.

HDAC7 promotes ovarian cancer malignancy via AKT/mTOR signalling pathway.

Ovarian cancer is of the most lethal malignancy and causes serious threat to women health worldwide. A deep understanding of molecular mechanisms underlying ovarian cancer progression is critical for the development of promising therapeutic strategies. In this study, we aimed to employ immunohistochemistry to determine the protein level of HDAC7 in patient tissues, our data showed HDAC7 levels are upregulated in tumour tissues. In addition, we also performed Kaplan-Meier survival analysis to investigate the association between HDAC7 expression and clinical prognosis, and found that HDAC7 expression was associated with poor prognosis in ovarian cancer patients. Inhibition of HDAC7 cells resulted in lower cell proliferation, invasion and colony formation. Furthermore, we also found that HDAC7 inhibition suppressed PI3K/AKT/mTOR pathway. In contrast, exogenous HDAC7 expression activated the PI3K/AKT/mTOR pathway in HDAC7 knockout cells and rescued the cell proliferation, invasion and colony formation. However, inhibition of p-AKT induced lower cell proliferation, metastasis and colony formation abilities. In murine model, HDAC7 KO significantly decreased the tumour burden. These data indicate that HDAC7 is involved in regulation of PI3K/AKT/mTOR pathway and targeting of HDAC7 could be potential therapeutic strategy in the treatment of ovarian cancer.