Histone deacetylase 9 deficiency exaggerates uterine M2 macrophage polarization

The maternal-foetal interface is an immune-privileged site where the semi-allogeneic embryo is protected from attacks by the maternal immune system. Uterine macrophages are key players in establishing and maintaining pregnancy, and the dysregulation of the M1-M2 subpopulation balance causes abortion. We separated two distinct mouse uterine macrophage subpopulations during early pregnancy, CD45⁺F4/80⁺CD206⁻ M1-like (M1) and CD45⁺F4/80⁺CD206⁺ M2-like (M2) cells. The M1 preponderance was significantly exaggerated at 6 hours after lipopolysaccharide (LPS) treatment, and adoptive transfer of M2 macrophages partially rescued LPS-induced abortion. RNA sequencing analysis of mouse uterine M2 versus M1 revealed 1837 differentially expressed genes (DEGs), among which 629 was up-regulated and 1208 was down-regulated. Histone deacetylase 9 (Hdac9) was one of the DEGs and validated to be significantly up-regulated in uterine M2 as compared with M1. Remarkably, this differential expression profile between M1 and M2 was also evident in primary splenic macrophages and in vitro polarized murine peritoneal, bone marrow–derived and RAW 264.7 macrophages. In Hdac9/HDAC9 knockout RAW 264.7 and human THP-1–derived macrophages, the expression of M1 differentiation markers was unchanged or decreased whereas M2 markers were increased compared with the wild-type cells, and these effects were unrelated to compromised proliferation. Furthermore, Hdac9/HDAC9 ablation significantly enhanced the phagocytosis of fluorescent microspheres in M2 Raw 264.7 cells yet decreased the capacity of THP-1-derived M1 macrophages. The above results demonstrate that Hdac9/HDAC9 deficiency exaggerates M2 macrophage polarization in mouse and human macrophages, which may provide clues for our understanding of the epigenetic regulation on macrophage M1/M2 polarization in maternal-foetal tolerance.     

Siblings with opposite chromosome constitutions,dup(2q)/del(7q) and del(2q)/dup(7q)

Chromosome 7q36 microdeletion syndrome is a rare genomic disorder characterized by underdevelopment of the brain, microcephaly, anomalies of the sex organs, and language problems. Developmental delay, intellectual disability, autistic spectrum disorders, BDMR syndrome, and unusual facial morphology are the key features of the chromosome 2q37 microdeletion syndrome. A genetic screening for two brothers with global developmental delay using high-resolution chromosomal analysis and subtelomeric multiplex ligation-dependent probe amplification revealed subtelomeric rearrangements on the same sites of 2q37.2 and 7q35, with reversed deletion and duplication. Both of them showed dysmorphic facial features, severe disability of physical and intellectual development, and abnormal genitalia with differential abnormalities in their phenotypes. The family did not have abnormal genetic phenotypes. According to the genetic analysis of their parents, adjacent-1 segregation from their mother's was suggested as a mechanism of their gene mutation. By comparing the phenotypes of our patients with previous reports on similar patients, we tried to obtain the information of related genes and their chromosomal locations.     

Metabolite induction via microorganism co-culture: A potential way to enhance chemical diversity for drug discovery

Microorganisms have a long track record as important sources of novel bioactive natural products, particularly in the field of drug discovery. While microbes have been shown to biosynthesize a wide array of molecules, recent advances in genome sequencing have revealed that such organisms have the potential to yield even more structurally diverse secondary metabolites. Thus, many microbial gene clusters may be silent under standard laboratory growth conditions. In the last ten years, several methods have been developed to aid in the activation of these cryptic biosynthetic pathways. In addition to the techniques that demand prior knowledge of the genome sequences of the studied microorganisms, several genome sequence-independent tools have been developed. One of these approaches is microorganism co-culture, involving the cultivation of two or more microorganisms in the same confined environment. Microorganism co-culture is inspired by the natural microbe communities that are omnipresent in nature. Within these communities, microbes interact through signaling or defense molecules. Such compounds, produced dynamically, are of potential interest as new leads for drug discovery. Microorganism co-culture can be achieved in either solid or liquid media and has recently been used increasingly extensively to study natural interactions and discover new bioactive metabolites. Because of the complexity of microbial extracts, advanced analytical methods (e.g., mass spectrometry methods and metabolomics) are key for the successful detection and identification of co-culture-induced metabolites.     

Characterization of the divalent metal binding site of bacterial polysaccharide deacetylase using crystallography and quantum chemical calculations

Peptidoglycan deacetlyase (HP0310, HpPgdA) from the gram‐negative pathogen Helicobacter pylori, is the enzyme responsible for a peptidoglycan modification that counteracts the host immune response. In a recent study, we determined the crystallographic structure of the enzyme, which is a homo‐tetramer (Shaik et al., PloS One 2011;6:e19207). The metal‐binding site, which is essential for the enzyme's catalytic activity, is visible within the structure, but we were unable to identify the nature of the metal itself. In this study, we have obtained a higher‐resolution crystal structure of the enzyme, which shows that the ion bound is, in fact, zinc. Analysis of the structure of the four sites, one per monomer, and quantum chemical calculations of models of the site in the presence of different divalent metal ions show an intrinsic preference for zinc, but also significant flexibility of the site so that binding of other ions can eventually occur. Proteins 2014; 82:1311–1318. © 2013 Wiley Periodicals, Inc.     

Effects of Ethylene Glycol Monomethyl Ether and Its Metabolite, 2‐Methoxyacetic Acid,on Organogenesis Stage Mouse Limbs In Vitro

Exposure to ethylene glycol monomethyl ether (EGME), a glycol ether compound found in numerous industrial products, or to its active metabolite, 2‐methoxyacetic acid (2‐MAA), increases the incidence of developmental defects. Using an in vitro limb bud culture system, we tested the hypothesis that the effects of EGME on limb development are mediated by 2‐MAA‐induced alterations in acetylation programming. Murine gestation day 12 embryonic forelimbs were exposed to 3, 10, or 30 mM EGME or 2‐MAA in culture for 6 days to examine effects on limb morphology; limbs were cultured for 1 to 24 hr to monitor effects on the acetylation of histones (H3K9 and H4K12), a nonhistone protein, p53 (p53K379), and markers for cell cycle arrest (p21) and apoptosis (cleaved caspase‐3). EGME had little effect on limb morphology and no significant effects on the acetylation of histones or p53 or on biomarkers for cell cycle arrest or apoptosis. In contrast, 2‐MAA exposure resulted in a significant concentration‐dependent increase in limb abnormalities. 2‐MAA induced the hyperacetylation of histones H3K9Ac and H4K12Ac at all concentrations tested (3, 10, and 30 mM). Exposure to 10 or 30 mM 2‐MAA significantly increased acetylation of p53 at K379, p21 expression, and caspase‐3 cleavage. Thus, 2‐MAA, the proximate metabolite of EGME, disrupts limb development in vitro, modifies acetylation programming, and induces biomarkers of cell cycle arrest and apoptosis     

Synergistic action by multi-targeting compounds produces a potent compound combination for human NSCLC both in vitro and in vivo

By screening a collection of one hundred combinations of thiazolidinone compounds, we identified one combination (M4) that synergistically inhibited the growth of H460 and H460/TaxR cells and tumor growth in H460/TaxR xenograft mice. A whole genome microarray assay showed that genes involved in negative regulation of microtubule polymerization or depolymerization, intracellular protein kinase cascade, positive regulation of histone acetylation, cell cycle arrest and apoptosis were upregulated. Further analysis proved that the four compounds act as either microtubule polymerization inhibitors or histone deacetylase inhibitors. They act synergistically targeting multiple proteins and leading to the regulation of cell cycle checkpoint proteins, including p53, p21, cdc25C and cdc2, the activation of caspases, JNK, p38 cascades and the inactivation of Akt. These events resulted in the G2/M cell cycle arrest and cell apoptosis. These data provide a new strategy for discovering anticancer drugs and drug combinations for drug-resistant cancers.     

水稻组蛋白脱乙酰化酶基因HDA705启动子的克隆与表达特性分析

为探讨水稻(Oryza sativa)组蛋白脱乙酰化酶基因HDA705的功能和表达特性,根据NCBI上登录的水稻HDA705基因(GenBank登录号:AK111861)的序列,克隆了5′端2 kb的启动子片段proHDA705,并构建了proHDA705:GUS表达载体。通过农杆菌介导法转化水稻,并获得了转基因株系。GUS检测结果表明,proHDA705仅在水稻的根、茎、叶及部分颖壳的表皮毛等器官中表达,而在花器官中不表达,这表明HDA705具有组织表达特异性。     

Epigenetic modulators for brain cancer stem cells: Implications for anticancer treatment

Primary malignant brain tumors are a major cause of morbidity and mortality in both adults and children, with a dismal prognosis despite multimodal therapeutic approaches. In the last years, a specific subpopulation of cells within the tumor bulk, named cancer stem cells(CSCs) or tumor-initiating cells, have been identified in brain tumors as responsible for cancer growth and disease progression. Stemness features of tumor cells strongly affect treatment response, leading to the escape from conventional therapeutic approaches and subsequently causing tumor relapse. Recent research efforts have focused at identifying new therapeutic strategies capable of specifically targeting CSCs in cancers by taking into consideration their complex nature. Aberrant epigenetic machinery plays a key role in the genesis and progression of brain tumors as well as inducing CSC reprogramming and preserving CSC characteristics. Thus, reverting the cancer epigenome can be considered a promising therapeutic strategy. Three main epigenetic mechanisms have been described: DNA methylation, histone modifications, and non-coding RNA, particularly micro RNAs. Each of these mechanisms has been proven to be targetable by chemical compounds, known as epigeneticbased drugs or epidrugs, that specifically target epigenetic marks. We review here recent advances in the study of epigenetic modulators promoting and sustaining brain tumor stem-like cells. We focus on their potential role in cancer therapy.     

组蛋白去乙酰化酶 6 及其选择性抑制剂的研究进展

组蛋白去乙酰化酶 6(HDAC6)是组蛋白去乙酰化酶(HDACs)IIb 家族中的一员,主要催化 α- 微管蛋白、热休克蛋白 Hsp90、皮质肌动蛋白及过氧化物还原酶等的去乙酰化。HDAC6 与肿瘤、神经退行性疾病、炎症、自身免疫应答、细菌感染及心脏病等 诸多疾病的病理生理进程密切相关,是一个极具应用前景的药物靶标。选择性 HDAC6 抑制剂是目前该领域的研究热点,有望克服广谱 HDAC 抑制剂存在的选择性差、副作用大等缺点。综述 HDAC6 的结构、生化功能、与疾病的关系及其选择性抑制剂的研究进展,为开发 新型选择性 HDAC6 抑制剂提供参考。