Protective effects of histone deacetylase 6 specific inhibitor tubastatin A on subarachnoid hemorrhage in rats and the underlying mechanisms / 中南大学学报(医学版)

OBJECTIVES@#Subarachnoid hemorrhage (SAH) is a serious cerebrovascular disease. Early brain injury (EBI) and cerebral vasospasm are the main reasons for poor prognosis of SAH patients. The specific inhibitor of histone deacetylase 6 (HDAC6), tubastatin A (TubA), has been proved to have a definite neuroprotective effect on a variety of animal models of acute and chronic central nervous system diseases. However, the neuroprotective effect of TubA on SAH remains unclear. This study aims to investigate the expression and localization of HDAC6 in the early stage of SAH, and to evaluate the protective effects of TubA on EBI and cerebral vasospasm after SAH and the underlying mechanisms.@*METHODS@#Adult male SD rats were treated with modified internal carotid artery puncture to establish SAH model. In the first part of the experiment, rats were randomly divided into 6 groups: a sham group, a SAH-3 h group, a SAH-6 h group, a SAH-12 h group, a SAH-24 h group, and a SAH-48 h group. At 3, 6, 12, and 24 h after SAH modeling, the injured cerebral cortex of rats in each group was taken for Western blotting to detect the expression of HDAC6. In addition, the distribution of HDAC6 in the cerebral cortex of the injured side was measured by immunofluorescence double staining in SAH-24 h group rats. In the second part, rats were randomly divided into 4 groups: a sham group, a SAH group, a SAH+TubAL group (giving 25 mg/kg TubA), and a SAH+TubAH group (giving 40 mg/kg TubA). At 24 h after modeling, the injured cerebral cortex tissue was taken for Western blotting to detect the expression levels of HDAC6, endothelial nitric oxide synthase (eNOS), and inducible nitric oxide synthase (iNOS), terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) staining to detect apoptosis, and hematoxylin and eosin (HE) staining to detect the diameter of middle cerebral artery.@*RESULTS@#The protein expression of HDAC6 began to increase at 6 h after SAH (P<0.05), peaked at 24 h (P<0.001), and decreased at 48 h, but there was still a difference compared with the sham group (P<0.05). HDAC6 is mainly expressed in the cytoplasm of the neurons. Compared with the sham group, the neurological score was decreased significantly and brain water content was increased significantly in the SAH group (both P<0.01). Compared with the SAH group, the neurological score was increased significantly and brain water content was decreased significantly in the SAH+TubAH group (both P<0.05), while the improvement of the above indexes was not significant in the SAH+TubAL group (both P>0.05). Compared with the sham group, the expression of eNOS was significantly decreased (P<0.01) and the expressions of iNOS and HDAC6 were significantly increased (P<0.05 and P<0.01, respectively) in the SAH group. Compared with the SAH group, the expression of eNOS was significantly increased, and iNOS and HDAC6 were significantly decreased in the SAH+TubA group (all P<0.05). Compared with the SAH group, the number of TUNEL positive cells was significantly decreased and the diameter of middle cerebral artery was significantly increased in the SAH+TubA group (both P<0.05) .@*CONCLUSIONS@#HDAC6 is mainly expressed in neurons and is up-regulated in the cerebral cortex at the early stage of SAH. TubA has protective effects on EBI and cerebral vasospasm in SAH rats by reducing brain edema and cell apoptosis in the early stage of SAH. In addition, its effect of reducing cerebral vasospasm may be related to regulating the expression of eNOS and iNOS.

CUDC-101 as a dual-target inhibitor of EGFR and HDAC enhances the anti-myeloma effects of bortezomib by regulating G2/M cell cycle arrest / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

CUDC-101, an effective and multi-target inhibitor of epidermal growth factor receptor (EGFR), histone deacetylase (HDAC), and human epidermal growth factor receptor 2 (HER2), has been reported to inhibit many kinds of cancers, such as acute promyelocytic leukemia and non-Hodgkin's lymphoma. However, no studies have yet investigated whether CUDC-101 is effective against myeloma. Herein, we proved that CUDC-101 effectively inhibits the proliferation of multiple myeloma (MM) cell lines and induces cell apoptosis in a time- and dose-dependent manner. Moreover, CUDC-101 markedly blocked the signaling pathway of EGFR/phosphoinositide-3-kinase (PI3K) and HDAC, and regulated the cell cycle G2/M arrest. Moreover, we revealed through in vivo experiment that CUDC-101 is a potent anti-myeloma drug. Bortezomib is one of the important drugs in MM treatment, and we investigated whether CUDC-101 has a synergistic or additive effect with bortezomib. The results showed that this drug combination had a synergistic anti-myeloma effect by inducing G2/M phase blockade. Collectively, our findings revealed that CUDC-101 could act on its own or in conjunction with bortezomib, which provides insights into exploring new strategies for MM treatment.

A novel second-generation platinum derivative and evaluation of its anti-cancer potential

Abstract Cisplatin is the primary anti-cancer agent for the treatment of most solid tumors. However, platinum-based anti-cancer chemotherapy produces severe side effects due to its poor specificity. There are a broad interest and literature base for a novel mechanism of action on platinum derivatives. Additionally, combining cisplatin with histone deacetylase inhibitors (HDACi) such as 4-hydroxybenzoic acid derivatives showed promising results in treating solid tumors. Here we aimed to conjugate 4-hydroxybenzoic acid with platinum to obtain a novel platinum derivative that can overcome cisplatin resistance. Cis-4-hydroxyphenylplatinum(II)diamine compound was synthesized under mild conditions and characterized. Cytotoxicity assay was performed on SKOV3-Luc and A549-Luc cells. Hemocompatibility and serum protein binding analysis were performed. Treatment potential was evaluated in xenograft tumor models. Biodistribution was tested on tumor-bearing mice via Pt analysis in organs with ICP-MS, ex vivo. In this study, cis-4-hydroxyphenylplatinum (II) diamine was synthesized with a yield of 62%. The MTT assay on A549-Luc and SKOV3-Luc cell lines resulted in IC50 values of 17.82 and 7.81 µM, respectively. While tumor growth was continued in the control group, the tumor volume decreased in the treatment group. All results point to the conclusion that the new compound has the potential to treat solid tumors

Desenvolvimento de inibidores duais de histona desacetilase 6 (HDAC6) e tirosina quinase (TQ) com vistas ao tratamento do câncer / Design of histone deacetylase 6 (HDAC6) and tyrosine kinase (TK) dual inhibitors for cancer treatment

Câncer é a denominação atribuída a um conjunto de doenças que são responsáveis pela segunda maior causa de morte no Brasil e no mundo. A quimioterapia figura entre uma das estratégias utilizadas para o tratamento e cura do câncer, sendo amplamente empregada em estratégias terapêuticas isoladas, ou em associação à radioterapia e cirurgia. A enzima histona desacetilase 6 (HDAC6) é responsável por desacetilar a cadeia lateral de N-acetillisinas em -tubulinas, desempanhando papel crítico na dinâmica do citoesqueleto celular, estando superexpressa em uma série de neoplasias. Neste sentido, na última década os receptores tirosina quinase (TQ) foram os principais alvos de fármacos aprovados para o tratamento do câncer e de doenças autoimunes e continuam atraindo a atenção de grupos de pesquisa dada a exorbitante diversidade do quinoma humano. É sabido que a monoterapia seja com inibidores de HDAC, seja com inibidores TQ, apresenta problemas de toxicidade, reações adversas, ineficácia, resistência e/ou recidiva. Diversos estudos relatam o desenvolvimento de inibidores duais de HDAC-TQ, almejando tanto a simplificação do tratamento, quanto sinergismo terapêutico e redução de efeitos adversos. Assim, o presente trabalho apresenta o planejamento, síntese e avaliação da citotoxicidade de inibidores duais, potencialmente seletivos para HDAC6 e receptores TQ. No total, 23 compostos foram sintetizados entre 2 a 4 etapas. Todos os compostos finais foram caracterizados por RMN (1H e 13C) e espectrometria de massas de alta resolução (HRMS). A citotoxicidade foi determinada pelo ensaio de MTT, em linhagens derivadas de tumores sólidos (HCT116 e MCF-7) e hematológicos (Jurkat e Namalwa). Os compostos apresentaram citotoxicidade em concentrações micro e nanomolares em todas as linhagens testadas, sendo que a linhagem MCF-7 foi a mais resistente à ação dos compostos, e as linhagens hematológicas foram as mais sensíveis. Os inibidores 4d-f foram os mais ativos na triagem por MTT, com IC50 iguais a 20, 30 e 50 nM, respectivamente, em células Jurkat. Estudos mecanísticos do efeito citotóxico indicaram que os compostos 4d-f exercem atividade de forma tempo-dependente, e majoritariamente por ação antiproliferativa, embora estímulos apoptóticos também tenham sido observados nos estudos. Simulações de ancoramento molecular (docking) e de relação entre as estruturas químicas dos compostos e suas respectivas atividades biológicas (REA) permitiram identificar padrões moleculares, propriedades físico-químicas e eletrônicas que potencialmente possuem relação com a atividade biológica dos compostos, permitindo futuras otimizações do arcabouço molecular desta série de compostos. Tomados em conjunto, os resultados deste trabalho revelam o potencial terapêutico de inibidores duais de HDAC6-TQ. Notadamente, os compostos apresentados aqui podem ser os primeiros potenciais inibidores duais de HDAC6-TQ a serem reportados na literatura

Cancer is the name of a series of diseases that are the second main cause of death in Brazil and worldwide. Chemotherapy is one of the main strategies to treat and cure cancer, and has been widely applied as a single therapeutic agent, and in association with radiotherapy and surgery. Histone deacetylase 6 (HDAC6) deacetylates N-acetyllysine side chains of tubulin, playing crucial role on cytoskeletal dynamics, and could be overexpressed in several cancers. Tyrosine kinase receptors (TK) have been the main targets of FDA-approved drugs through the last decade for both cancer and autoimmune diseases, and have been attracting special attention of research groups due to the exorbitant diversity of the human kinome. It is known that either HDAC or TK single therapy have toxicity issues, adverse effects, inefficacy, resistance and/or recidive. Therefore, many studies report the design of HDAC-TK dual inhibitors aiming simpler treatments, synergism of action and side effects reduction. Herein, the design, synthesis and cytotoxic evaluation of dual and selective HDAC6-TK inhibitors are presented. A total of 23 compounds were designed and synthesized through 2 to 4 steps. All final compounds were characterized by 1H/13C NMR and high-resolution mass spectrometry (HRMS). The cytotoxicity of compounds was determined by MTT assay for both solid (HCT116 and MCF-7 cells) and hematological cancers (Jurkat and Namalwa cells). Compounds exhibited micro and nanomolar ranges of cytotoxicity for all cell lines tested. MCF-7 cells were the most resistant against the treatment, and hematological cells were more susceptible to the cytotoxic effect of the compounds. Compounds 4d-f were the most actives in the MTT screening against Jurkat cells (IC50 = 20, 30 and 50 nM, respectively). Mechanistic studies regarding the cytotoxic effects of 4d-f indicated that the compounds induced cell death in a time-dependent manner mainly via cytostatic activity even though apoptotic stimuli were observed also. Molecular docking and structure-activity relationships (SARs) allowed the identification of molecular patterns, and physicochemical and electronic properties that potentially modulate the biological activity of these compounds, allowing further optimizations of the molecular scaffold for these series of compounds. Taken together, the results of this study reveal the therapeutic potential of HDAC6-TK dual inhibitors. Noteworthy, the compounds reported herein could be the first HDAC6-TK dual inhibitors ever reported in literature

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.

Planejamento, síntese, modelagem molecular e avaliação biológica de novos potenciais inibidores duais HDAC/ MMP não-hidroxamatos / Design, synthesis, molecular modeling and biological evaluation of novel potential non-hydroxamate dual HDAC/ MMP inhibitors

A inibição de alvos específicos como metaloproteinase de matriz (MMP) e histona desacetilase (HDAC) é amplamente estudada para impedir o progresso do câncer. Foi estabelecido que a inibição concomitante de MMP e HDAC é eficaz no combate de tumores sólidos e hematológicos. Ambos os alvos possuem um íon Zn2+ em seu sítio ativo, fundamental para a atividade destas enzimas. A alta afinidade dos inibidores conhecidos de MMP e de HDAC é conferida, principalmente, por um potente grupo ligante de zinco (ZBG). O ácido hidroxâmico é o ZBG mais potente conhecido atualmente, entretanto, este apresenta instabilidade farmacocinética, levando a ineficácia e genotoxicidade em testes clínicos. Frente a este contexto, o presente trabalho teve como objetivo o planejamento, síntese, modelagem molecular e avaliação biológica de novos inibidores duais MMP/HDAC não-hidroxamatos. Os compostos foram planejados utilizando estratégias de hibridação molecular, a partir de arcabouços provenientes inibidores de HDAC e MMP, gerando compostos arilsulfonamídicos com variações no tipo de ZBG inserido e na sua respectiva posição relativa na estrutura geral. Foram sintetizados sete análogos, em duas a três etapas reacionais, utilizando métodos de sulfonilação e acoplamento com agentes condensantes, partindo dos ésteres para e meta aminobenzoicos. Os rendimentos globais variaram de 25% a 55% e os produtos obtidos foram caracterizados por RMN 1H e 13C, LC/MS, CLAE e ponto de fusão. Os compostos tiveram sua atividade citotóxica avaliada em células HOG (oligodendroma) e T98G (glioblastoma), dentre os quais o 6a, que possui o ZBG 2-amino anilida, foi o mais promissor, apresentando atividade nas duas linhagens na casa de nM. Ensaios de coordenação com Fe2+ comprovaram a capacidade quelante dos análogos contendo ácido hidroxâmico e dos demais compostos citotóxicos, 4a e 4b (ZBG-2, salicilal-hidrazona), o que não foi observado para o composto 6a. Os estudos de ancoramento molecular permitiram sugerir um modo de interação para todos os ZBG propostos frente aos respectivos alvos (HDAC e MMP), sendo observado que o ZBG 4 (2-amino anilida) faria a interação de modo monodentado com a HDAC, enquanto não seria possível o encaixe no sítio catalítico da MMP. Conclui-se, portanto, que o planejamento proposto permitiu a obtenção de compostos promissores como antitumorais, e que a substituição do ácido hidroxâmico por outros ZBG fornece moléculas ativas frente a células tumorais. Entretanto, a avaliação biológica frente à MMP e HDAC é necessária para confirmar o mecanismo de ação proposto

Inhibition of specific targets such as matrix metalloproteinase (MMP) and histone deacetylase (HDAC) is extensively studied regarding arrest cancer growth. Particularly, concomitant inhibition of MMP and HDAC is effective against solid and hematologic tumors. Both targets have an ion Zn2+ at their catalytic site, which is essential for respective enzymatic activity. High affinity of known MMP and HDAC inhibitors is mainly provided by a potent zinc binding group (ZBG). Hydroxamic acid is the most potent ZBG currently known; however, it presents low pharmacokinetics stability, which results in its ineffectiveness and genotoxicity along clinical trial. So, the aim of this work comprised the design, synthesis, molecular modeling and biological evaluation of novel potential non-hydroxamate dual HDAC/ MMP inhibitors. Compounds were designed by molecular hybridation, employing scaffolds from HDAC and MMP inhibitors, which provided arylsulfonamides with variation about the ZBG type and its respective relative position in the general structure. Seven compounds were synthesized, in two to three reaction steps, through methods that comprise sulfonilation and coupling with condensing agents, using para and meta-aminobenzoic esters as starting material. Compounds showed global yields around 25-55 % and were characterized by 1H and 13C NMR, LC/MS, HPLC and melting point. Compounds were evaluated about their cytotoxicity against HOG (oligodendroma) and T98G (glioblastoma) cells, which 6a, with ZBG 2-aminobenzamide, was the most promising molecules, presenting activity against both cell lines at nM range. Coordination assays with Fe2+ proved the chelating capacity of hydroxamate analogues as well as the cytotoxic compounds, 4a and 4b (ZBG-2, salicylal-hydrazone), which was not observed about 6a. Molecular docking allowed to suggest an interaction model for all proposed ZBG with the respective targets (MMP and HDAC), showing that (ZBG-4) 2-aminobenzamide interacts with HDAC by monodentate way, but does not docks at MMP catalytic site. We conclude that the proposed design allowed obtaining promising compounds as antitumors agents, and the replacement of hydroxamic acid by other ZBG provide active molecules against tumor cells. However, biological evaluation against MMP and HDAC is necessary to confirm the proposed action mechanism

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.

RGFP966 inactivation of the YAP pathway attenuates cardiac dysfunction induced by prolonged hypothermic preservation / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Oxidative stress and apoptosis are the key factors that limit the hypothermic preservation time of donor hearts to within 4-6 h. The aim of this study was to investigate whether the histone deacetylase 3 (HDAC3) inhibitor RGFP966 could protect against cardiac injury induced by prolonged hypothermic preservation. Rat hearts were hypothermically preserved in Celsior solution with or without RGFP966 for 12 h followed by 60 min of reperfusion. Hemodynamic parameters during reperfusion were evaluated. The expression and phosphorylation levels of mammalian STE20-like kinase-1 (Mst1) and Yes-associated protein (YAP) were determined by western blotting. Cell apoptosis was measured by the terminal deoxynucleotidyl-transferase (TdT)-mediated dUTP nick-end labeling (TUNEL) method. Addition of RGFP966 in Celsior solution significantly inhibited cardiac dysfunction induced by hypothermic preservation. RGFP966 inhibited the hypothermic preservation-induced increase of the phosphorylated (p)-Mst1/Mst1 and p-YAP/YAP ratios, prevented a reduction in total YAP protein expression, and increased the nuclear YAP protein level. Verteporfin (VP), a small molecular inhibitor of YAP-transcriptional enhanced associate domain (TEAD) interaction, partially abolished the protective effect of RGFP966 on cardiac function, and reduced lactate dehydrogenase activity and malondialdehyde content. RGFP966 increased superoxide dismutase, catalase, and glutathione peroxidase gene and protein expression, which was abolished by VP. RGFP966 inhibited hypothermic preservation-induced overexpression of B-cell lymphoma protein 2 (Bcl-2)-associated X (Bax) and cleaved caspase-3, increased Bcl-2 mRNA and protein expression, and reduced cardiomyocyte apoptosis. The antioxidant and anti-apoptotic effects of RGFP966 were cancelled by VP. The results suggest that supplementation of Celsior solution with RGFP966 attenuated prolonged hypothermic preservation-induced cardiac dysfunction. The mechanism may involve inhibition of oxidative stress and apoptosis via inactivation of the YAP pathway.

Harnessing the HDAC-histone deacetylase enzymes, inhibitors and how these can be utilised in tissue engineering / 国际口腔科学杂志·英文版

There are large knowledge gaps regarding how to control stem cells growth and differentiation. The limitations of currently available technologies, such as growth factors and/or gene therapies has led to the search of alternatives. We explore here how a cell's epigenome influences determination of cell type, and potential applications in tissue engineering. A prevalent epigenetic modification is the acetylation of DNA core histone proteins. Acetylation levels heavily influence gene transcription. Histone deacetylase (HDAC) enzymes can remove these acetyl groups, leading to the formation of a condensed and more transcriptionally silenced chromatin. Histone deacetylase inhibitors (HDACis) can inhibit these enzymes, resulting in the increased acetylation of histones, thereby affecting gene expression. There is strong evidence to suggest that HDACis can be utilised in stem cell therapies and tissue engineering, potentially providing novel tools to control stem cell fate. This review introduces the structure/function of HDAC enzymes and their links to different tissue types (specifically bone, cardiac, neural tissues), including the history, current status and future perspectives of using HDACis for stem cell research and tissue engineering, with particular attention paid to how different HDAC isoforms may be integral to this field.

Traditional and Novel Mechanisms of Heat Shock Protein 90 (HSP90) Inhibition in Cancer Chemotherapy Including HSP90 Cleavage

HSP90 is a molecular chaperone that increases the stability of client proteins. Cancer cells show higher HSP90 expression than normal cells because many client proteins play an important role in the growth and survival of cancer cells. HSP90 inhibitors mainly bind to the ATP binding site of HSP90 and inhibit HSP90 activity, and these inhibitors can be distinguished as ansamycin and non-ansamycin depending on the structure. In addition, the histone deacetylase inhibitors inhibit the activity of HSP90 through acetylation of HSP90. These HSP90 inhibitors have undergone or are undergoing clinical trials for the treatment of cancer. On the other hand, recent studies have reported that various reagents induce cleavage of HSP90, resulting in reduced HSP90 client proteins and growth suppression in cancer cells. Cleavage of HSP90 can be divided into enzymatic cleavage and non-enzymatic cleavage. Therefore, reagents inducing cleavage of HSP90 can be classified as another class of HSP90 inhibitors. We discuss that the cleavage of HSP90 can be another mechanism in the cancer treatment by HSP90 inhibition.

Short-chain Fatty Acids Inhibit Staphylococcal Lipoprotein-induced Nitric Oxide Production in Murine Macrophages

Staphylococcus aureus, a Gram-positive pathogen, can cause severe inflammation in humans, leading to various life-threatening diseases. The lipoprotein is a major virulence factor in S. aureus-induced infectious diseases and is responsible for excessive inflammatory mediators such as nitric oxide (NO). Short-chain fatty acids (SCFAs) including butyrate, propionate, and acetate are microbial metabolites in the gut that are known to have anti-inflammatory effects in the host. In this study, we investigated the effects of SCFAs on S. aureus lipoprotein (Sa.LPP)-induced NO production in mouse macrophages. Butyrate and propionate, but not acetate, inhibited Sa.LPP-induced production of NO in RAW 264.7 cells and bone marrow-derived macrophages. Butyrate and propionate inhibited Sa.LPP-induced expression of inducible NO synthase (iNOS). However, acetate did not show such effects under the same conditions. Furthermore, butyrate and propionate, but not acetate, inhibited Sa.LPP-induced activation of NF-κB, expression of IFN-β, and phosphorylation of STAT1, which are essential for inducing transcription of iNOS in macrophages. In addition, butyrate and propionate induced histone acetylation at lysine residues in the presence of Sa.LPP in RAW 264.7 cells. Moreover, Sa.LPP-induced NO production was decreased by histone deacetylase (HDAC) inhibitors. Collectively, these results suggest that butyrate and propionate ameliorate the inflammatory responses caused by S. aureus through the inhibition of NF-κB, IFN-β/STAT1, and HDAC, resulting in attenuated NO production in macrophages.

Disruption of Planar Cell Polarity Pathway Attributable to Valproic Acid-Induced Congenital Heart Disease through Hdac3 Participation in Mice / 中华医学杂志(英文版)

Background@#Valproic acid (VPA) exposure during pregnancy has been proven to contribute to congenital heart disease (CHD). Our previous findings implied that disruption of planar cell polarity (PCP) signaling pathway in cardiomyocytes might be a factor for the cardiac teratogenesis of VPA. In addition, the teratogenic ability of VPA is positively correlated to its histone deacetylase (HDAC) inhibition activity. This study aimed to investigate the effect of the VPA on cardiac morphogenesis, HDAC1/2/3, and PCP key genes (Vangl2/Scrib/Rac1), subsequently screening out the specific HDACs regulating PCP pathway.@*Methods@#VPA was administered to pregnant C57BL mice at 700 mg/kg intraperitoneally on embryonic day 10.5. Dams were sacrificed on E15.5, and death/absorption rates of embryos were evaluated. Embryonic hearts were observed by hematoxylin-eosin staining to identify cardiac abnormalities. H9C2 cells (undifferentiated rat cardiomyoblasts) were transfected with Hdac1/2/3 specific small interfering RNA (siRNA). Based on the results of siRNA transfection, cells were transfected with Hdac3 expression plasmid and subsequently mock-treated or treated with 8.0 mmol/L VPA. Hdac1/2/3 as well as Vangl2/Scrib/Rac1 mRNA and protein levels were determined by real-time quantitative polymerase chain reaction and Western blotting, respectively. Total HDAC activity was detected by colorimetric assay.@*Results@#VPA could induce CHD (P 0.05); VPA exposure dramatically decreased the expression of Vanlg2/Scrib together with Hdac activity (P 0.05).@*Conclusion@#VPA could inhibit Hdac1/2/3, Vangl2/Scrib, or total Hdac activity both in vitro and in vivo and Hdac3 might participate in the process of VPA-induced cardiac developmental anomalies.

Inhibitory Effect of Histone Deacetylase Inhibitor SAHA on Proliferation of Mouse Multiple Myeloma Cell Line SP2/0 in vitro and in vivo / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To explore the anti-myeloma effect of suberoylanilide hydroxamic acid (SAHA) and on mouse myeloma cell line SP2/0 in vitro and in vivo and its mechanism.</p><p><b>METHODS</b>The inhibitory effect of SAHA on SP2/0 cells was measured by CCK-8 assay,and the apoptosis and cell cycle were analyzed by flow cytometry FACS. The protein expression of Caspase-3 and p53 of SP2/0 cells treated with SAHA were examined by Western blot. Annexin V/7-AAD double staining was performed to detect the apoptosis of SP2/0 induced by SAHA in vitro. SP2/0 cells (1×10) resuspended in 200 µl PBS were inoculated subcutaneously and intravenously into BALB/c mice, so as to establish aggressive or non-aggressive myeloma-bearing mouse models respectively. On day 3 after modeling, mice received SAHA or vehicle control treatment by intraperitoneal injection. The dose of SAHA was 60 mg/kg·d, 5 times a week for 3 weeks.</p><p><b>RESULTS</b>In SAHA-treated SP2/0 cells, the proliferation inhibition rate and apoptotic cells increased in a dose dependent manner. Also, SAHA significantly increased the ratio of cells in G phase and decreased in S phase. Molecular mechanisms of apoptosis and cell cycle arrest of SP2/0 induced by SAHA partly correlated with up-regulating the expression level of Caspase-3 and p53. In the non-aggressive myeloma-bearing mice, SP2/0 cells disappeared in peripheral blood after SAHA treatment. In the aggressive myeloma-bearing mice, inhibition of tumor growth and prolongation of the cell survival were observed after SAHA treatment.</p><p><b>CONCLUSION</b>SAHA inhibited SP2/0 cell proliferation, this effect associates with inducing apoptosis and cell cycle arrest, the mechanism of SAHA ralates partly with activating Caspase-3 and p53 pathway.</p>

Study on the immune functions of dendritic cells regulated by histone deacetylase inhibitor Belinostat / 中华血液学杂志

Objective: To explore effects of histone deacetylase inhibitor Belinostat on the immunologic function of dendritic cells (DC) and its possible mechanism. Methods: Cultured mouse bone marrow-derived DC from C57BL/6 mouse in vitro. The experiments were divided into 0, 50, 100 nmol/L Belinostat + immature DC (imDC) group, and 0, 50, 100 nmol/L Belinostat mature DC (mDC). The changes of the ultrastructure of DC were observed by transmission electron microscope (TEM). Immunophenotype and CCR7 expression rate were detected by FCM, and the migration rate was observed by chemotaxis assay. The proliferation of lymphocytes stimulated by different DC was detected by mixed lymphocyte culture reaction. The cytokines in the culture supernatant, including TNF-α, IL-12 and IL-10, were examined by ELISA. RQ-PCR was used to examine the relative expression of mRNA in RelB. Results: Successful cultured and identified the qualified imDC and mDC. Belinostat decreased the expression of CCR7 on imDC [(25.82±7.25)% vs (50.44±5.61)% and (18.71±2.00)% vs (50.44±5.61)%], meanwhile increased the rate on mDC [(71.14±1.96)% vs (64.90±1.47)%]. Chemotaxis assay showed that the migration rate of Belinostat+imDC and Belinostat+mDC group were both decreased, but the difference in imDC was not significant. T lymphocyte proliferation rate stimulated by 100 nmol/L Belinostat+imDC group was lower than imDC group in condition irritation cell∶reaction cell=1∶2 [(227.09±13.49)% vs (309.49±53.69)%]. Belinostat significantly suppressed the secretion of cytokines TNF-α, IL-12 and IL-10 (all P<0.01). The relative expression of mRNA in RelB was slightly decreased in Belinostat+imDC and Belinostat+mDC group (all P<0.05). Conclusion: Belinostat could effectly suppress DC maturation and regulate immune tolerance of DC, which may be due to the down-regulation of mRNA level of RelB in DC.

Effects of HDAC Inhibitor Scriptaid on IM9 Cell Line and Its Mechanism / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To study the effect of HDAC inhibitor Scriptaid on multiple myeloma IM9 cells and preliminarily clarify the mechanism of Scriptaid-induced cell apoptosis.</p><p><b>METHODS</b>The cell viability, cell cycle and cell apoptosis were measured by CCK8 assay and flow cytometry respectively, the relative target gene expression levels were detected by RT-PCR, the effect of Scriptaid on p21 promoter activity was detected by using luciferase reporter assay.</p><p><b>RESULTS</b>Scriptaid inhibited IM9 cell viability in a dose-dependent manner. Scriptaid induced IM9 cell cycle arrest at G/M phase in a dose-dependent manner. Scriptaid triggered IM9 cell apoptosis was obviously, the mRNA levels of apoptosis-related proteins Caspase 9, Caspase 3 and PARP1 were also activated. The apoptosis-associated factors BAD, PTEN and p21 increased following treatment with different dose of Scriptaid, meanwhile, p21 promoter activity was also activated significantly.</p><p><b>CONCLUSION</b>HDAC inhibitor Scriptaid can promote IM9 cell apoptosis by transcriptional activation of p21 promoter in concentration-dependent manner.</p>

Histone deacetylase inhibition attenuates hepatic steatosis in rats with experimental Cushing's syndrome

Cushing's syndrome (CS) is a collection of symptoms caused by prolonged exposure to excess cortisol. Chronically elevated glucocorticoid (GC) levels contribute to hepatic steatosis. We hypothesized that histone deacetylase inhibitors (HDACi) could attenuate hepatic steatosis through glucocorticoid receptor (GR) acetylation in experimental CS. To induce CS, we administered adrenocorticotropic hormone (ACTH; 40 ng/kg/day) to Sprague-Dawley rats by subcutaneous infusion with osmotic mini-pumps. We administered the HDACi, sodium valproate (VPA; 0.71% w/v), in the drinking water. Treatment with the HDACi decreased steatosis and the expression of lipogenic genes in the livers of CS rats. The enrichment of GR at the promoters of the lipogenic genes, such as acetyl-CoA carboxylase (Acc), fatty acid synthase (Fasn), and sterol regulatory element binding protein 1c (Srebp1c), was markedly decreased by VPA. Pan-HDACi and an HDAC class I-specific inhibitor, but not an HDAC class II a-specific inhibitor, attenuated dexamethasone (DEX)-induced lipogenesis in HepG2 cells. The transcriptional activity of Fasn was decreased by pretreatment with VPA. In addition, pretreatment with VPA decreased DEX-induced binding of GR to the glucocorticoid response element (GRE). Treatment with VPA increased the acetylation of GR in ACTH-infused rats and DEX-induced HepG2 cells. Taken together, these results indicate that HDAC inhibition attenuates hepatic steatosis hrough GR acetylation in experimental CS.

The Role of Histone Deacetylase Inhibitors in Regulation of Akt/GSK-3ß Signaling Pathway in Mice Following Transient Focal Cerebral Ischemia

Abstract Purpose: To investigate whether the neuroprotective effect of TSA on cerebral ischemia reperfusion injury is mediated by the activation of Akt/GSK-3β signaling pathway. Methods: Mice were randomly divided into four groups (n=15): sham group (S); ischemia reperfusion group (IR); ischemia reperfusion and pretreated with TSA group (IR+T); ischemia reperfusion and pretreated with TSA and LY294002 group (IR+T+L). The model of cerebral ischemia reperfusion was established by 1h of MCAO following 24h of reperfusion. TSA (5mg/kg) was intraperitoneally given for 3 days before MCAO, Akt inhibitor, LY294002 (15 nmol/kg) was injected by tail vein 30 min before the MCAO. Results: TSA significantly increased the expression of p-Akt, p-GSK-3β proteins and the levels of SOD, Bcl-2, reduced the infarct volume and the levels of MDA, ROS, TNF-α, IL-1β, Bax, Caspase-3, TUNEL and attenuated neurological deficit in mice with transient MCAO, LY294002 weakened such effect of TSA dramatically. Conclusions: TSA could significantly decrease the neurological deficit and reduce the cerebral infarct volume, oxidative stress, inflammation, as well as apoptosis during cerebral ischemia reperfusion injury, which was achieved by activation of the Akt/GSK-3β signaling pathway.

Induction of Apoptosis in Intestinal Toxicity to a Histone Deacetylase Inhibitor in a Phase I Study with Pelvic Radiotherapy / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: When integrating molecularly targeted compounds in radiotherapy, synergistic effects of the systemic agent and radiation may extend the limits of patient tolerance, increasing the demand for understanding the pathophysiological mechanisms of treatment toxicity. In this Pelvic Radiation and Vorinostat (PRAVO) study, we investigated mechanisms of adverse effects in response to the histone deacetylase (HDAC) inhibitor vorinostat (suberoylanilide hydroxamic acid, SAHA) when administered as a potential radiosensitiser. MATERIALS AND METHODS: This phase I study for advanced gastrointestinal carcinoma was conducted in sequential patient cohorts exposed to escalating doses of vorinostat combined with standard-fractionated palliative radiotherapy to pelvic target volumes. Gene expression microarray analysis of the study patient peripheral blood mononuclear cells (PBMC) was followed by functional validation in cultured cell lines and mice treated with SAHA. RESULTS: PBMC transcriptional responses to vorinostat, including induction of apoptosis, were confined to the patient cohort reporting dose-limiting intestinal toxicities. At relevant SAHA concentrations, apoptotic features (annexin V staining and caspase 3/7 activation, but not poly-(ADP-ribose)-polymerase cleavage) were observed in cultured intestinal epithelial cells. Moreover, SAHA-treated mice displayed significant weight loss. CONCLUSION: The PRAVO study design implemented a strategy to explore treatment toxicity caused by an HDAC inhibitor when combined with radiotherapy and enabled the identification of apoptosis as a potential mechanism responsible for the dose-limiting effects of vorinostat. To the best of our knowledge, this is the first report deciphering mechanisms of normal tissue adverse effects in response to an HDAC inhibitor within a combined-modality treatment regimen.

Valproic Acid Modulates the Multipotency in Periodontal Ligament Stem Cells via p53-Mediated Cell Cycle

Human periodontal ligament stem cells (PDLSCs), a type of mesenchymal stem cell, are a promising source for dental regeneration and are identified in human periodontal ligaments from extracted third molars. Valproic acid (VPA) is a histone deacetylase inhibitor that has been used as a wide-spectrum antiepileptic drug and a medication for mood disorders. VPA has shown several effects on increasing the pluripotency of embryonic stem cells and controlling osteogenic differentiation, besides the prevention of seizures. However, its effect on proliferation and osteogenesis depends on the cell type and concentration. The aim of this study was to investigate the effects of cyclic and constant VPA treatment on PDLSCs. Proliferation and apoptosis of PDLSCs were determined with cyclic and constant VPA treatment. In cemento/ osteogenic differentiation, osteogenic markers decreased significantly after cyclic treatment with 0.5 mM VPA. In contrast, VPA enhanced osteogenic differentiation after constant treatment. With cyclic VPA treatment, p53 levels related to apoptotic pathway decreased to induce proliferation. These findings indicated that VPA has different roles in proliferation and differentiation of PDLSCs in vitro and in vivo via p53-related pathway.

Effects of Trichostatin A on the Chondrogenesis from Human Mesenchymal Stem Cells

Histone deacetylase inhibitors (HDACi) are a class of compounds that suppress the function of histone deacetylases (HDACs). This study was performed to examine the effects of Trichostatin A (TSA), a typical HDACi, on chondrogenesis of human bone marrow mesenchymal stem cells (hBMMSCs) and related molecular pathways. After evaluating the concentration for cytotoxicity and HDAC activity, hBMMSCs underwent chondrogenic differentiation in pellet culture with or without TSA for 21 days. The weight of TSA-treated pellets was 25% lower than that of untreated pellets. DNA level was not significantly different, but glycosaminoglycan content per DNA level was lower in TSA-treated pellets than that of untreated pellets. Gene expression of the chondrogenic markers (SOX9, Aggrecan, and Col2A1) decreased by by 12.9-fold, 8.9-fold, and 7.6-fold respectively in TSA-treated pellets compared with that in TSA-untreated pellets. TSA-treated pellets had lower cell density and lower proteoglycan staining content compared with those of TSA-untreated pellets. A microarray analysis from TSA-treated pellets showed that 1,467 chondrogenic-related genes were downregulated and 1,524 were upregulated by more than 2-fold compared with TSA-untreated pellets. Col10A1, TGF-β3, and SOX9 decreased significantly by 10-fold, 2.1-fold, and 3.2-fold respectively in TSA-treated pellets compared with those in untreated pellets, whereas expression of BMP4 and FGFR3 increased significantly by 2.1-fold and 5.4-fold respectively. It is concluded that TSAinhibits chondrogenesis and does not seem to be useful for cartilage tissue engineering of hBMMSCs.