The lysine methyltransferase SMYD2 facilitates neointimal hyperplasia by regulating the HDAC3-SRF axis

Coronary restenosis is an important cause of poor long-term prognosis in patients with coronary heart disease. Here, we show that lysine methyltransferase SMYD2 expression in the nucleus is significantly elevated in serum- and PDGF-BB-induced vascular smooth muscle cells (VSMCs), and in tissues of carotid artery injury-induced neointimal hyperplasia. Smyd2 overexpression in VSMCs (Smyd2-vTg) facilitates, but treatment with its specific inhibitor LLY-507 or SMYD2 knockdown significantly inhibits VSMC phenotypic switching and carotid artery injury-induced neointima formation in mice. Transcriptome sequencing revealed that SMYD2 knockdown represses the expression of serum response factor (SRF) target genes and that SRF overexpression largely reverses the inhibitory effect of SMYD2 knockdown on VSMC proliferation. HDAC3 directly interacts with and deacetylates SRF, which enhances SRF transcriptional activity in VSMCs. Moreover, SMYD2 promotes HDAC3 expression via tri-methylation of H3K36 at its promoter. RGFP966, a specific inhibitor of HDAC3, not only counteracts the pro-proliferation effect of SMYD2 overexpression on VSMCs, but also inhibits carotid artery injury-induced neointima formation in mice. HDAC3 partially abolishes the inhibitory effect of SMYD2 knockdown on VSMC proliferation in a deacetylase activity-dependent manner. Our results reveal that the SMYD2-HDAC3-SRF axis constitutes a novel and critical epigenetic mechanism that regulates VSMC phenotypic switching and neointimal hyperplasia.

Role of epigenetic regulation of biological clock genes in tumors / 中国药理学通报

The circadian clock is regulated at the molecular level by transcriptional-translational feedback loop of clock genes, which ensures that a variety of physiological processes have a-round 24 h circadian rhythms, including cell metabolism, cell proliferation, cell apoptosis and tumorigenesis, to maintain the homeostasis. Thus, the disturbance of circadian clock will disrupt homeostasis, causing various diseases, including neoplasm, metabolic syndrome, Parkinson's disease, COPD and cardiovascular diseases. Disturbance of circadian clock is closely related with tumorigenesis, and acts on various molecules and pathways leading to tumorigenesis, including oncogene and tumor suppressor gene, cell cycle, metabolic reprogramming, immune escape, endocrine disruption, alteration of gastrointestinal microbiome. This review focuses on changes in clock genes expression which disrupt cell cycle and may play a role in tumorigenesis, and epi-geneties, an important way to regulate gene expression, which can alter clock gene expression, thus playing an important role in the process of " the alternation of clock gene expression-disruption of cell cycle-tumorigenesis".

Research progress of histone acetylation in prevention and treatment of heart failure and new ideas based on traditional Chinese medicine / 中国中药杂志

Chronic heart failure(CHF) has become a worldwide public health problem due to its high morbidity and mortality, which seriously endangers people's lifespan and quality of life. In recent years, the treatment strategy of CHF has shifted its emphasis on short-term improvement and transformation of hemodynamics to long-term repair as well as improvement of the biological properties of heart failure. At present, with the continuous deepening of medical research, it has been found that histone acetylation is closely related to the occurrence and development of CHF. Traditional Chinese medicine, via regulating histone acetylation, delays ventricular remodeling, improves energy metabolism, inhibits fibrosis and cardiomyocyte hypertrophy, and intervenes in the development process of heart failure, thus reducing the mortality and the readmission rate and ultimately improving long-term prognosis. Therefore, this study reviewed the mechanism of histone acetylation in the treatment of heart failure as well as its prevention and treatment with traditional Chinese medicine, to provide reference for clinical treatment of CHF.

Knockdown of ACC1 promotes migration of esophageal cancer cell / 中华肿瘤杂志

Objective: To investigate the effect of acetyl-CoA carboxylase 1 (ACC1) knockdown on the migration of esophageal squamous cell carcinoma (ESCC) KYSE-450 cell and underlying mechanism. Methods: Lentiviral transfection was conducted to establish sh-NC control cell and ACC1 knocking down cell (sh-ACC1). Human siRNA HSP27 and control were transfected by Lipo2000 to get si-HSP27 and si-NC. The selective acetyltransferase P300/CBP inhibitor C646 was used to inhibit histone acetylation and DMSO was used as vehicle control. Transwell assay was performed to detect cell migration. The expression of HSP27 mRNA was examined by reverse transcription-quantitative real-time polymerase chain reaction (RT-qPCR) and the expressions of ACC1, H3K9ac, HSP27 and epithelial-mesenchymal transition-related proteins E-cadherin and Vimentin were detected by western blot. Results: The expression level of ACC1 in sh-NC group was higher than that in sh-ACC1 group (P<0.01). The number of cell migration in sh-NC group was (159.00±24.38), lower than (361.80±26.81) in sh-ACC1 group (P<0.01). The protein expression levels of E-cadherin and Vimentin in sh-NC group were statistically significant compared with sh-AAC1 group (P<0.05). The migrated cell number in sh-NC+ si-NC group was (189.20±16.02), lower than (371.60±38.40) in sh-ACC1+ si-NC group (P<0.01). The migrated cell number in sh-NC+ si-NC group was higher than that in sh-NC+ si-HSP27 group (152.40±24.30, P<0.01), and the migrated cell number in sh-ACC1+ si-NC group was higher than that in sh-ACC1+ si-HSP27 group (P<0.01). The protein expression levels of E-cadherin and Vimentin in sh-NC+ si-NC group were significantly different from those in sh-ACC1+ si-NC and sh-NC+ si-HSP27 groups (P<0.01). The protein expression levels of E-cadherin and Vimentin in sh-ACC1+ si-NC group were significantly different from those in sh-ACC1+ si-HSP27 group (P<0.01). After 24 h treatment with C646 at 20 μmmo/L, the migrated cell number in sh-NC+ DMSO group was (190.80±11.95), lower than (395.80±17.10) in sh-ACC1+ DMSO group (P<0.01). The migrated cell number in sh-NC+ DMSO group was lower than that in sh-NC+ C646 group (256.20±23.32, P<0.01). The migrated cell number in sh-ACC1+ DMSO group was higher than that in sh-ACC1+ C646 group (87.80±11.23, P<0.01). The protein expressions of H3K9ac, HSP27, E-cadherin and Vimentin in sh-NC+ DMSO group were significantly different from those in sh-ACC1+ DMSO group and sh-NC+ C646 group (P<0.01). The protein expression levels of H3K9ac, HSP27, E-cadherin and Vimentin in sh-ACC1+ DMSO group were significantly different from those in sh-ACC1+ C646 group (P<0.01). Conclusion: Knockdown of ACC1 promotes the migration of KYSE-450 cell by up-regulating HSP27 and increasing histone acetylation.

Hedgehog pathway orchestrates the interplay of histone modifications and tailors combination epigenetic therapies in breast cancer

Epigenetic therapies that cause genome-wide epigenetic alterations, could trigger local interplay between different histone marks, leading to a switch of transcriptional outcome and therapeutic responses of epigenetic treatment. However, in human cancers with diverse oncogenic activation, how oncogenic pathways cooperate with epigenetic modifiers to regulate the histone mark interplay is poorly understood. We herein discover that the hedgehog (Hh) pathway reprograms the histone methylation landscape in breast cancer, especially in triple-negative breast cancer (TNBC). This facilitates the histone acetylation caused by histone deacetylase (HDAC) inhibitors and gives rise to new therapeutic vulnerability of combination therapies. Specifically, overexpression of zinc finger protein of the cerebellum 1 (ZIC1) in breast cancer promotes Hh activation, facilitating the switch of H3K27 methylation (H3K27me) to acetylation (H3K27ac). The mutually exclusive relationship of H3K27me and H3K27ac allows their functional interplay at oncogenic gene locus and switches therapeutic outcomes. Using multiple in vivo breast cancer models including patient-derived TNBC xenograft, we show that Hh signaling-orchestrated H3K27me and H3K27ac interplay tailors combination epigenetic drugs in treating breast cancer. Together, this study reveals the new role of Hh signaling-regulated histone modifications interplay in responding to HDAC inhibitors and suggests new epigenetically-targeted therapeutic solutions for treating TNBC.

Epigenetic regulation and retinal degenerative diseases / 中华实验眼科杂志

Epigenetics pertains to heritable alterations in gene expression when the nucleotide sequence remains unchanged.Epigenetic regulation mechanisms are diverse, among which DNA methylation, histone modification and non-coding RNA (ncRNA) regulation have been studied in depth.Epigenetic regulation is associated with a variety of human diseases.In the occurrence and development of retinal degenerative diseases, many epigenetic regulation processes such as DNA methylation, histone acetylation and ncRNA regulation have changed.DNA methylation is one of the important regulation processes in retinal degeneration.Aberrant DNA methylation patterns are associated with retinitis pigmentosa (RP), age-related macular degeneration (AMD), inflammation and oxidative stress.Histone acetylation is associated with RP, diabetic retinopathy (DR), glaucoma and retinal nerve ischemic injury.NcRNA is associated with RP, AMD, pathological angiogenesis, and DR.In this article, the application of epigenetic regulation in retinal degeneration was reviewed.

Changes and significance of granulocyte-like myeloid-derived suppressor cells during acute phase of Kawasaki disease / 中华微生物学和免疫学杂志

Objective:To investigate the changes and significance of granulocyte-like myeloid-derived suppressor cells (G-MDSC) in the acute phage of Kawasaki disease (KD).Methods:Forty-two children with acute KD were enrolled in the present study and 32 age-matched healthy children were selected as control group. The proportion of HLA-DR -CD11b + CD33 + CD14 -CD15 + G-MDSC, the concentration of reactive oxygen species (ROS) and the expression of arginase-1 (Arg-1), programmed death-ligand 1 (PD-L1), cytotoxic T lymphocyte associated protein 4 (CTLA4), glycoprotein 130 (gp130) and phosphorylated signal transducer and activator of transcription 3 (pSTAT3) at protein level were detected by flow cytometry. Quantitative real-time PCR was used to measure the expression of inducible nitric oxide synthase (iNOS), interferon regulatory factor 8 (IRF-8), IL-6 receptor α subunit (IL-6Rα), granulocyte colony-stimulating factor receptor (G-CSFR), CCAAT/enhancer binding protein β (C/EBPβ), suppressor of cytokine signaling 1 (SOCS1) and SOCS3 at mRNA level in G-MDSC. Chromatin immunoprecipitation was performed to detect the acetylation of histone H3 at the promoters of SOCS1 and SOCS3 genes. Plasma concentrations of IL-6 and granulocyte colony-stimulating factor (G-CSF) and protein levels of IL-10, transforming growth factor-β (TGF-β) and nitric oxide (NO) in the culture supernatant of G-MDSC stimulated with LPS were measured by ELISA. Results:(1) Compared with the control group, the proportion of HLA-DR -CD11b + CD33 + CD14 -CD15 + G-MDSC as well as the concentration of ROS and the expression of inhibitory molecules (Arg-1, PD-L1 and CTLA4) in G-MDSC increased significantly in patients with acute KD ( P<0.05). Moreover, the concentrations of IL-10 and TGF-β in culture supernatant of G-MDSC were also higher than those of the control group after stimulation with lipopolysaccharide for 48 h ( P<0.05). All of the seven afore-mentioned indexes in KD patients with coronary artery lesion (CAL group ) were lower than those in patients without coronary artery lesion (NCAL group) ( P<0.05), and restored to some extent after IVIG therapy ( P<0.05). There were no statistical differences in iNOS expression or NO concentration in culture supernatant of G-MDSC among different groups ( P<0.05). (2) Plasma concentrations of IL-6 and G-CSF, and the expression of IL-6Rα, gp130, G-CSFR, pSTAT3 and C/EBPβ increased remarkably during acute phase of KD ( P<0.05). The expression of IRF-8 at transcription level in patients with acute KD was found to be lower than that of healthy controls ( P<0.05), and restored significantly after IVIG therapy ( P<0.05). Moreover, the plasma concentrations of IL-6 and G-CSF and the expression of IL-6Rα, gp130, G-CSFR and IRF-8 in the CAL group were higher than those in the NCAL group ( P<0.05), while the expression of pSTAT3 and C/EBPβ was lower in the CAL group ( P<0.05), which were restored by IVIG therapy ( P<0.05). (3) In patients with acute KD, the expression of SOCS1 and SOCS3 at mRNA level and histone acetylation at the promoters of SOCS1 and SOCS3 genes were reduced significantly in comparison with those in healthy controls ( P<0.05) , but were increased remarkably after IVIG treatment( P<0.05). The four indexes were higher in the CAL group than in the NCAL group ( P<0.05). Pearson correlation analysis showed the expression of SOCS1 and SOCS3 was negatively correlated with the protein level of pSTAT3 in G-MDSC of patients with acute KD ( r=-0.46 and -0.32, P<0.05). Conclusions:Changes in the number and function of G-MDSC caused by aberrant histone acetylation at SOCS1 and SOCS3 genes might contribute to the immune dysfunction and vascular damage in patients with KD.

Romidepsin (FK228) improves the survival of allogeneic skin grafts through downregulating the production of donor-specific antibody via suppressing the IRE1α-XBP1 pathway / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Antibody-mediated rejection (AMR) is one of the major causes of graft loss after transplantation. Recently, the regulation of B cell differentiation and the prevention of donor-specific antibody (DSA) production have gained increased attention in transplant research. Herein, we established a secondary allogeneic in vivo skin transplant model to study the effects of romidepsin (FK228) on DSA. The survival of grafted skins was monitored daily. The serum levels of DSA and the number of relevant immunocytes in the recipient spleens were evaluated by flow cytometry. Then, we isolated and purified B cells from B6 mouse spleens in vitro by magnetic bead sorting. The B cells were cultured with interleukin-4 (IL-4) and anti-clusters of differentiation 40 (CD40) antibody with or without FK228 treatment. The immunoglobulin G1 (IgG1) and IgM levels in the supernatant were evaluated by enzyme-linked immunosorbent assay (ELISA). Quantitative reverse transcription-polymerase chain reaction (RT-qPCR) and western blotting were conducted to determine the corresponding levels of messenger RNA (mRNA) and protein expression in cultured cells and the recipient spleens. The results showed that FK228 significantly improved the survival of allogeneic skin grafts. Moreover, FK228 inhibited DSA production in the serum along with the suppression of histone deacetylase 1 (HADC1) and HDAC2 and the upregulation of the acetylation of histones H2A and H3. It also inhibited the differentiation of B cells to plasma cells, decreased the transcription of positive regulatory domain-containing 1 (Prdm1) and X-box-binding protein 1 (Xbp1), and decreased the expression of phosphorylated inositol-requiring enzyme 1 α (p-IRE1α), XBP1, and B lymphocyte-induced maturation protein-1 (Blimp-1). In conclusion, FK228 could decrease the production of antibodies by B cells via inhibition of the IRE1α-XBP1 signaling pathway. Thus, FK228 is considered as a promising therapeutic agent for the clinical treatment of AMR.

Effects of brain-specific knockout of Sirt6 gene on cerebral cortex in aged mice / 中华行为医学与脑科学杂志

Objective:To study the effect of senescence gene silent information regulator 6 (Sirt6) knockout on the brain of aged mice.Methods:Sirt6-flox transgenic mice were constructed, and the mouse brain tissue was specifically knocked out by Emx1-Cre tool mice.According to genotyping, 11 wild-type mice were selected as control group(WT group) and 10 Sirt6 gene konckout mice were selected as conditional knockout group(cKO group). Body size and body weight of the aged mice were measured and cerebral cortex thickness was measured by HE staining.Brain neurogenesis was analyzed with EdU markers.The expression of RNA-binding protein HuR and apoptosis-related protein Caspase-3 were detected by Western blot.Meanwhile, histone acetylation levels in the cortex were detected.Results:Sirt6 brain tissue-specific knocked out mice were successfully constructed.Compared with the brain tissue area((2.07±0.22) cm 2)and cortical thickness ((970.56±80.91) μm) of WT mice in the 12-month-old group, the brain tissue area ((1.61±0.14)cm 2) and cortical thickness ((822.88±53.94) μm) in Sirt6 cKO group were smaller, and the differences were statistically significant (both P<0.05). EdU incorporation into nerve cells showed that the number of EdU incorporation into periventricular nerve cells in cKO group was lower ((4.75±1.48)) than that in WT group ((10.29±1.93)). The difference was statistically significant ( P<0.001). In the experiment of 17 months age group, mice in cKO group were smaller in body size, lower in body weight ((29.00±1.08) g) and smaller in brain area ((1.54±0.55)cm 2)compared with WT group in body size, body weight ((35.25±4.17) g) and brain tissue area ((1.98±0.18) cm 2)(both P<0.05). The expression of Caspase-3 and HuR in cortical proteins of these two age groups decreased( t=2.95, 5.38, both P<0.05), and the expression of H3K9ac and H3K56ac increased( t=3.53, 2.78, both P<0.05), but the expression of Sirt1 homologous gene remained unchanged( t=1.26, P>0.05). Conclusion:The specific deletion of Sirt6 in brain tissue can lead to the decrease of brain neurogenesis in aged mice, and the aggravation of aging and the increase of apoptosis, which may be the reason for the thinning of cerebral cortex and brain tissue atrophy.The molecular mechanism is speculated to be related to the increase of acetylation level after Sirt6 knockout

Histone Deacetylase Inhibitors in the in Vitro Expansion of Hematopoietic Stem Cells / 中国医学科学院学报

The self-renewal and differentiation of hematopoietic stem cells(HSCs)are highly regulated by epigenetic modification,in which histone acetylation can activate or silence gene transcription.Histone deacetylase inhibitors(HDACIs)can inhibit the activity of histone deacetylase in HSCs to increase histone acetylation.A variety of HDACIs,such as trichostatin A and valproic acid,are used to expand HSCs in vitro,especially cord blood HSCs,combined with cytokines in serum-free culture to obtain more long-term repopulating cells.HDACIs promote the transcription of pluripotent genes related to stem cell self-renewal and inhibit the expression of genes related to differentiation,so as to promote the expansion and inhibit differentiation of HSCs.The expansion of cord blood HSCs by small molecular HDACIs in vitro is expected to improve the quantity of cord blood HSCs.The further research will focus on high-throughput screening for the most powerful HDACIs and the highly selective HDACIs,exploring the combination of epigenetic modifiers of different pathways.

Cellular environment controls the dynamics of histone H3 lysine 56 acetylation in response to DNA damage in mammalian cells

Epigenetic changes play a crucial role in sensing signals and responding to fluctuations in the extracellularenvironment. How the cellular micro-environment affects DNA damage response signalling in chromatincontext is not extensively studied. Histone acetylation is dynamic and very sensitive to changes in theextracellular environment. Existing literature on H3 lysine 56 acetylation (H3K56ac) levels upon DNA damagein mammals presents a conflicting picture. The occurrence of both increased and decreased H3K56ac uponDNA damage in our experiments led us to investigate the role of the micro-environment on H3K56ac. Here,we show that the global levels of H3K56ac increase as cells grow from low density to high density whileSIRT1 and SIRT6 expression decrease. Additionally, rising lactic acid levels increase H3K56ac. Our resultsshow that cell density and accumulation of metabolites affect dynamics of H3K56ac in response to DNAdamage. Upon DNA damage, H3K56ac increases in low density cells with low initial acetylation, whileacetylation decreases in high cell density cells. These results highlight that H3K56ac levels upon DNA damageare dependent on the metabolites in the extracellular milieu which impact chromatin structure by regulatingchromatin modifying enzymes. Accumulation of lactic acid at high cell density reflects conditions similar to thetumour micro-environment. As H3K56ac increases in tumours, lactic acid and low pH might alter H3K56ac intumours, leading to deregulated gene expression, contributing to tumour progression.

Enriched environment improves sevoflurane-induced cognitive impairment during late-pregnancy via hippocampal histone acetylation

Fetal exposure to sevoflurane induces long-term cognitive impairment. Histone acetylation regulates the transcription of genes involved in memory formation. We investigated whether sevoflurane exposure during late-pregnancy induces neurocognitive impairment in offspring, and if this is related to histone acetylation dysfunction. We determined whether the effects could be reversed by an enriched environment (EE). Pregnant rats were exposed to 2.5% sevoflurane or control for 1, 3, or 6 h on gestational day 18 (G18). Sevoflurane reduced brain-derived neurotrophic factor (BDNF), acetyl histone H3 (Ac-H3), and Ac-H4 levels and increased histone deacetylases-2 (HDAC2) and HDAC3 levels in the hippocampus of the offspring on postnatal day 1 (P1) and P35. Long-term potentiation was inhibited, and spatial learning and memory were impaired in the 6-h sevoflurane group at P35. EE alleviated sevoflurane-induced cognitive dysfunction and increased hippocampal BDNF, Ac-H3, and Ac-H4. Exposure to 2.5% sevoflurane for 3 h during late-pregnancy decreased hippocampal BDNF, Ac-H3, and Ac-H4 in the offspring but had no effect on cognitive function. However, when the exposure time was 6 h, impaired spatial learning and memory were linked to reduced BDNF, Ac-H3, and Ac-H4, which could be reversed by EE.

Role of histone acetylation in the pathogenesis of IgA nephropathy / 上海交通大学学报（医学版）

Objective: To study the role of abnormal histone acetylation modification in the pathogenesis of IgA nephropathy (IgAN), and explore the pathogenesis of IgAN from the perspective of epigenetics. Methods: 30 patients with primary IgAN and 19 healthy controls were included. Of the 19 controls, 16 cases were used to collect blood samples and 3 cases were used to collect normal renal tissues. Peripheral venous blood was collected to extract mononuclear cells (PBMC) for detection. The levels of histone H3 and H4 acetylation in PBMC of IgAN group and healthy control group were detected by ELISA. Real-time PCR was used to detect the mRNA expressions of P300, CREBBP, HDAC1-3, HDAC7, HDAC8, C1GALT1 and ST6GALNAC2. The acetylation levels of histone H3 and H4 in promoter regions of C1GALT1 and ST6GALNAC2 were detected by chromatin immuneprecipitation (CHIP). The protein expression of HDAC1 and H3Ac was detected by immunofluorescence. T-test was used for statistical analysis. Results: Compared with the healthy control group, the acetylation levels of H3 and H4 in IgAN group were significantly higher than those in healthy control group (P=0.035, P=0.012);the mRNA expressions of P300, CREBBP, HDAC1, HDAC8 and ST6GALNAC2 were significantly increased in IgAN group (P=0.002, P=0.001, P=0.001, P=0.045 P=0.012); the mRNA expressions of HDAC2 and C1GALT1 were decreased significantly (P=0.035, P=0.008); the acetylation degree of H3 and H4 in C1GALT1 promoter region was significantly decreased (P=0.043, P=0.005), the degree of H3 and H4 acetylation in the promoter region of ST6GALNAC2 gene was increased significantly in IgAN group (P=0.038, P=0.021);immune fluorescent results of renal tissue indicated that the HDAC1 protein expression was increased obviously, and H3Ac protein expression was significantly reduced in the renal tissue of IgAN patiegts. Conclusion: Abnormal acetylation modification exists in IgAN patients. Histone acetylation modification may participate in the pathogenesis of IgAN by regulating the expression of glycosylase gene.

Molecular cloning and subcellular localization of six HDACs and their roles in response to salt and drought stress in kenaf (Hibiscus cannabinus L)

BACKGROUND: Histone acetylation is an important epigenetic modification that regulates gene activity in response to stress. Histone acetylation levels are reversibly regulated by histone acetyltransferases (HATs) and histone deacetylases (HDACs). The imperative roles of HDACs in gene transcription, transcriptional regulation, growth and responses to stressful environment have been widely investigated in Arabidopsis. However, data regarding HDACs in kenaf crop has not been disclosed yet. RESULTS: In this study, six HDACs genes (HcHDA2, HcHDA6, HcHDA8, HcHDA9, HcHDA19, and HcSRT2) were isolated and characterized. Phylogenetic tree revealed that these HcHDACs shared high degree of sequence homology with those of Gossypium arboreum. Subcellular localization analysis showed that GFP-tagged HcHDA2 and HcHDA8 were predominantly localized in the nucleus, HcHDA6 and HcHDA19 in nucleus and cytosol. The HcHDA9 was found in both nucleus and plasma membranes. Real-time quantitative PCR showed that the six HcHDACs genes were expressed with distinct expression patterns across plant tissues. Furthermore, we determined differential accumulation of HcHDACs transcripts under salt and drought treatments, indicating that these enzymes may participate in the biological process under stress in kenaf. Finally, we showed that the levels of histone H3 and H4 acetylation were modulated by salt and drought stress in kenaf. CONCLUSIONS: We have isolated and characterized six HDACs genes from kenaf. These data showed that HDACs are imperative players for growth and development as well abiotic stress responses in kenaf.

Effect of histone acetylation on osteogenic differentiation of periodontal ligament stem cells derived from periodontitis tissue / 华西口腔医学杂志

Epigenetics is defined as a change in gene expression without the alteration of the genetic sequence. Such a change would be inherited by offspring. Histone acetylation is a type of epigenetics. Existing studies proposed that chronic periodontitis is related to epigenetic modification. In this review, we summarised the influence of chronic periodontitis on periodontal ligament stem cells by histone acetylation.

Regulation on brain-derived neurotrophic factor and relevant mechanism of anemarrhena saponin in H2O2-induced SH-SY5Y cells / 上海交通大学学报（医学版）

Objective • To investigate the effect of anemarrhena saponin (ZMS) on mRNA level of brain-derived neurotrophic factor (BDNF) and relevant mechanism in oxidative stress damage of SH-SY5Y cells. Methods • SH-SY5Y cells treated with H2O2 were chosen as cell models of oxidative stress. Cell viability was determined using cell counting kit-8 (CCK-8). The mRNA levels of BDNF and its important transcripts were detected by quantitative real-time PCR (qPCR). The histone deacetylases (HDACs) activity fluorescence quantification assay kit was used to measure the effect of ZMS on HDACs activity. Western blotting was used to detect the protein expression levels of acetylated histone H3, acetylated histone H4, specific acetylation site-related proteins, and HDAC1/2/3. Results • qPCR showed that ZMS could increase the mRNA levels of BDNF and its transcript in the cell models. Western blotting showed that ZMS pretreatment could increase the protein levels of acetylated histone H3, acetylated histone H4 and acetylated histone H3K14, and there was no significant effect on protein levels of HDAC1/2/3. In addition, HDACs activity fluorescence quantification assay kit showed that ZMS could inhibit HDACs activity significantly. Conclusion • ZMS can increase the mRNA levels of BDNF and its transcript in oxidative stress damage cell models, which may be related to the regulation of histone acetylation level

Effect of Long-time Slow-frozen Storage on Epigenetic Changes of Histone in Cleavage-stage Embryos / 中山大学学报(医学科学版)

@#【Objective】To investigate the impact of long- term storage time on epigenetic modification of histone in human cleavage stage embryos.【Methods】According to the length of storage time，donated embryos after slow-freezing were divided into 3 groups ：6-year group ，9-year group ，and 12-year group ，while the control group consisted of donated fresh embryos. Immunocytochemistry was performed to compare the expression levels of HDAC1， H3K9ac， H3K4me3 ，and H3K9me3 among 4 groups. Transcription levels of HDAC1 ，SUV39H1 ，SETDB1 ，and KDM5A were analyzed through Single-Cell qRT-PCR.【Results】The relative abundances of HDAC1 and SUV39H1 mRNA showed no significant differences among 4 groups（P > 0.05）. SETDB1 exhibited a climbing pattern as storage time increased，but no significant difference was observed（P > 0.05）. There were no differences in H3K9 trimethylation and H3K9 methylation among 4 groups. However ，the expression level of KDM5A increased with the increasing storage time（P < 0.05）.【Conclusions】 Storage time did not affect the expression of deacetylase HDAC1，methylase SUV39H1 and SETDB1. H3K9ac/me3 and H3K4me3 also exhibited no significant difference as the storage time increases. However ，the increasing storage length might induce the elevating expression of demethylase KDM5A，which may be associated with inhibition of embryonic transcription.

Insights on the epigenetic mechanisms underlying pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH), characterized by localized increased arterial blood pressure in the lungs, is a slow developing long-term disease that can be fatal. PAH is characterized by inflammation, vascular tone imbalance, pathological pulmonary vascular remodeling, and right-sided heart failure. Current treatments for PAH are palliative and development of new therapies is necessary. Recent and relevant studies have demonstrated that epigenetic processes may exert key influences on the pathogenesis of PAH and may be promising therapeutic targets in the prevention and/or cure of this condition. The aim of the present mini-review is to summarize the occurrence of epigenetic-based mechanisms in the context of PAH physiopathology, focusing on the roles of DNA methylation, histone post-translational modifications and non-coding RNAs. We also discuss the potential of epigenetic-based therapies for PAH.

Aberrant histone modification in peripheral blood CD4+ T lymphocytes in oral lichen planus / 口腔疾病防治

Objective@#To investigate the histone acetylation level and histone deacetylase (HDAC) activity of peripheral blood CD4+ T lymphocytes in patients with oral lichen planus (OLP). @*Methods @#Twenty-three OLP patients were selected from August 2016 to January 2017 from the Stomatological Hospital, Southern Medical University. The diagnosis was confirmed by pathology, and the lesions were divided into a nonerosive OLP group (11 cases) and an erosive OLP group (12 cases). Ten healthy sex- and age-matched volunteers served as controls. Immunomagnetic beads were used to separate CD4+ T lymphocytes, and histones and nucleoproteins were extracted. The global histone H3/H4 acetylation levels and HDAC activity of CD4+ T lymphocytes from all subjects were detected by ELISA. The differences between the OLP and control groups were statistically analyzed. @*Results@#Global histone H3 hypoacetylation was observed in the OLP group compared with the control group (u = -2.410, P = 0.012). However, there was no significant difference in the serum CD4+ T lymphocyte histone H4 acetylation level between the OLP and control group (u = -1.412, P = 0.158). HDAC activity was significantly higher in the OLP group than in the healthy control group (F = 5.749, P = 0.023), and much higher HDAC activity was observed in the erosive group than in the nonerosive (P = 0.014) and healthy control groups (P = 0.001). The degree of histone H3 acetylation correlated negatively with increased HDAC activity in the OLP group (rs = -0.771, P < 0.001). There was no correlation between the level of histone H3 acetylation and HDAC activity in the healthy control group (rs = 0.382,P = 0.276). The histone H4 acetylation level in the OLP group showed no correlation with HDAC activity (rs = 0.149, P = 0.498), and the histone H4 acetylation level in the control group also showed no correlation with HDAC activity (rs = 0.527, P = 0.117).@*Conclusion @#Abnormal histone acetylation of CD4+ T lymphocytes in the peripheral blood of patients with OLP was identified and could be related to HDAC activity, suggesting that the epigenetic modification of histone acetylation may play a role in the pathogenesis of OLP.

Regulatory mechanism of ginsenoside Rd on histone H3 acetylation / 中草药

Objective Based on quantitative proteomics analysis and molecular biology experimental verification, the regulatory mechanism of ginsenoside Rd on histone H3 acetylation levels was elucidated. Methods The effects of ginsenoside Rd on the dynamic changes of proteome of HEK293T cells were detected by.stable isotope labeling with amino acid (SILAC) technique and LC-MS/MS; Quantitative proteomics database analysis was used to monitor the changes in histone acetyltransferase HATs and histone deacetylase HDACs expression levels. Western blotting and qRT-PCR were used to verify the changes of related protein expression and transcriptional level. Gene knockdown experiments were performed using siRNAs to determine the role of ginsenoside Rd in regulating the level of acetyl modifications at histone H3K9 and K18 sites. Results The histone H3K9ac, H3K18ac expression levels in HEK293T cells decreased after ginsenoside Rd treatment, but the P300 catalytic modification of these two sites did not change significantly; At the same time, ginsenoside Rd up-regulated the transcription and expression of HDAC2, and siHDAC2 treatment reversed the down-regulation effects of ginsenoside Rd on H3K9ac and H3K18ac in HEK293T cells. Conclusion Ginsenoside Rd down-regulates the acetylation level of lysine at histone H3K9 and K18 sites by up-regulating HDAC2, thereby affecting transcriptional activation of downstream genes.