老年缺血性心力衰竭的心脏DNA甲基化编码重编程与心肌细胞焦亡、铁死亡的关联

摘要 目的：探讨老年缺血性心力衰竭的心脏DNA甲基化编码重编程与心肌细胞焦亡、铁死亡的关联性。方法：2019年12月到2021月2月,选择在本院诊治的老年缺血性心力衰竭115例作为心衰组,同期选择在本院体检的非心血管疾病老年人群115例作为对照组。检测心脏DNA甲基化编码重编程、心肌细胞焦亡、铁死亡指标表达情况并进行相关性分析。结果：心衰组的心脏DNA甲基化编码重编程指标-miR-92a、miR-130a相对表达水平高于对照组（P<0.05）。心衰组的Caspase-1蛋白、Caspase-4蛋白相对表达水平高于对照组（P<0.05）。心衰组的铁调素含量高于对照组（P<0.05）。在两组230例入选者中,Spearsman相关分析显示：缺血性心力衰竭与miR-92a、miR-130a、半胱氨酸蛋白酶1（Caspase-1）、半胱氨酸蛋白酶4（Caspase-4）、铁调素存在正向相关性（P<0.05）。Logistic回归分析显示：miR-92a、miR-130a、Caspase-1、Caspase-4、铁调素为导致缺血性心力衰竭发生的重要因素（P<0.05）。结论：老年缺血性心力衰竭患者多伴随有心脏DNA甲基化编码重编程与心肌细胞焦亡、铁死亡,后三者与缺血性心力衰竭的发生存在关联性,也是导致缺血性心力衰竭发生的重要因素。     

Novel histone modifications in microglia derived from a mouse model of chronic pain

As the resident immune cells in the central nervous system, microglia play an important role in the maintenance of its homeostasis. Dysregulation of microglia has been associated with the development and maintenance of chronic pain. However, the relevant molecular pathways remain poorly defined. In this study, we used a mass spectrometry-based proteomic approach to screen potential changes of histone protein modifications in microglia isolated from the brain of control and cisplatin-induced neuropathic pain adult C57BL/6J male mice. We identified several novel microglial histone modifications associated with pain, including statistically significantly decreased histone H3.1 lysine 27 mono-methylation (H3.1K27me1, 54.8% of control) and H3 lysine 56 tri-methylation (7.5% of control), as well as a trend suggesting increased H3 tyrosine 41 nitration. We further investigated the functional role of H3.1K27me1 and found that treatment of cultured microglial cells for 4 consecutive days with 1–10 μM of NCDM-64, a potent and selective inhibitor of lysine demethylase 7A, an enzyme responsible for the demethylation of H3K27me1, dose-dependently elevated its levels with a greater than a two-fold increase observed at 10 μM compared to vehicle-treated control cells. Moreover, pretreatment of mice with NCDM-64 (10 or 25 mg/kg/day, i.p.) prior to cisplatin treatment prevented the development of neuropathic pain in mice. The identification of specific chromatin marks in microglia associated with chronic pain may yield critical insight into the contribution of microglia to the development and maintenance of pain, and opens new avenues for the development of novel nonopioid therapeutics for the effective management of chronic pain.     

Epigenetic-based therapy for colorectal cancer: Prospect and involved mechanisms

Epigenetic modifications are heritable variations in gene expression not encoded by the DNA sequence. According to reports, a large number of studies have been performed to characterize epigenetic modification during normal development and also in cancer. Epigenetics can be regarded more widely to contain all of the changes in expression of genes that make by adjusted interactions between the regulatory portions of DNA or messenger RNAs that lead to indirect variation in the DNA sequence. In the last decade, epigenetic modification importance in colorectal cancer (CRC) pathogenesis was demonstrated powerfully. Although developments in CRC therapy have been made in the last years, much work is required as it remains the second leading cause of cancer death. Nowadays, epigenetic programs and genetic change have pivotal roles in the CRC incidence as well as progression. While our knowledge about epigenetic mechanism in CRC is not comprehensive, selective histone modifications and resultant chromatin conformation together with DNA methylation most likely regulate CRC pathogenesis that involved genes expression. Undoubtedly, the advanced understanding of epigenetic-based gene expression regulation in the CRC is essential to make epigenetic drugs for CRC therapy. The major aim of this review is to deliver a summary of valuable results that represent evidence of principle for epigenetic-based therapeutic approaches employment in CRC with a focus on the advantages of epigenetic-based therapy in the inhibition of the CRC metastasis and proliferation.     

Diagnostic biomarker and therapeutic target applications of miR-326 in cancers: A systematic review

MicroRNAs (miRNAs) are endogenous mediators of RNA interference and have key roles in the modulation of gene expression under healthy, inflamed, stimulated, carcinogenic, or other cells, and tissues of a pathological state. Many studies have proved the association between miRNAs and cancer. The role of miR-326 as a tumor suppressor miRNA in much human cancer confirmed. We will explain the history and the role of miRNAs changes, especially miR-326 in cancers and other pathological conditions. Attuned with these facts, this review highlights recent preclinical and clinical research performed on miRNAs as novel promising diagnostic biomarkers of patients at early stages, prediction of prognosis, and monitoring of the patients in response to treatment. All related publications retrieved from the PubMed database, with keywords such as epigenetic, miRNA, microRNA, miR-326, cancer, diagnostic biomarker, and therapeutic target similar terms from 1899 to 2018 with limitations in the English language. Recently, researchers have focused on the impacts of miRNAs and their association in inflammatory, autoinflammatory, and cancerous conditions. Recent studies have suggested a major pathogenic role in cancers and autoinflammatory diseases. Investigations have explained the role of miRNAs in cancers, autoimmunity, and autoinflammatory diseases, and so on. The miRNA-326 expression has an important role in cancer conditions and other diseases.     

假单胞菌Pseudomonas fluorescens Pf0-1中转录调控因子SpfB负调控DNA磷硫酰化修饰

[目的]DNA磷硫酰化修饰是DNA骨架上非桥接的氧原子以序列选择性和R-构型被硫取代的一种新型DNA修饰。目前,磷硫酰化修饰在多种细菌、古生菌以及人类致病菌中多有发现,但其分子调控机制尚不清楚。为了全面解析磷硫酰化修饰的调控机制,本文选择荧光假单胞菌Pf0-1为研究对象,开展了其DNA磷硫酰化修饰的调控机制研究。[方法]首先,构建了spfB基因缺失和回补菌株,使用碘能特异性断裂磷硫酰化修饰DNA的方法,研究了该基因缺失对修饰表型的影响。利用cDNA在相邻同方向的基因间隔区进行PCR,确定了磷硫酰化修饰基因簇spfBCDE内的共转录单元。通过荧光定量RT-PCR,分析了spfB基因缺失突变株中磷硫酰化修饰基因的转录量。利用异源表达并纯化得到的重组蛋白SpfB进行了体外功能研究。通过EMSA实验,验证了SpfB蛋白具有与spfB启动子序列结合活性。通过DNase I footprinting实验,精确定位了SpfB蛋白与DNA结合序列。[结果]spfB基因的缺失加剧了磷硫酰化修饰DNA断裂所致电泳条带弥散的表型,spfB基因的回补能够恢复该表型,证明spfB基因负调控磷硫酰化修饰。鉴定了spf基因簇中只含有1个共转录单元,且该共转录单元在△spfB突变株中转录水平明显上升。通过EMSA和DNase I footprint实验,检测了SpfB蛋白与磷硫酰化修饰基因spfBCDE的启动子区域5''-TGTTTGT-3''相结合。[结论]SpfB作为转录调控因子负调控磷硫酰化修饰基因spfBCDE的表达,为解析磷硫酰化修饰的调控机制和全面理解基因组上的部分修饰特征奠定了基础。     

Precise recapitulation of methylation change in early cloned embryos

Change of DNA methylation during preimplantation development is very dynamic, which brings this term to the most attractive experimental target for measuring the capability of cloned embryo to reprogram its somatic genome. However, one weak point is that the preimplantation stage carries little information on genomic sequences showing a site-specific re-methylation after global demethylation; these sequences, if any, may serve as an advanced subject to test how exactly the reprogramming/programming process is recapitulated in early cloned embryos. Here, we report a unique DNA methylation change occurring at bovine neuropeptide galanin gene sequence. The galanin gene sequence in early bovine embryos derived by in vitro fertilization (IVF) maintained a undermethylated status till the morula stage. By the blastocyst, certain CpG sites became methylated specifically, which may be an epigenetic sign for the galanin gene to start a differentiation programme. The same sequence was moderately methylated in somatic donor cell and, after transplanted into an enucleated oocyte by nuclear transfer (NT), came rapidly demethylated to a completion, and then, at the blastocyst stage, re-methylated at exactly the same CpG sites, as observed so in normal blastocysts. The precise recapitulation of normal methylation reprogramming and programming at the galanin gene sequence in bovine cloned embryos gives a cue for the potential of cloned embryo to superintend the epigenetic states of foreign genome, even after global demethylation.