内侧前额叶皮质DNA甲基化调控大鼠酒精相关行为

酒精滥用不仅导致组织器官损伤,还易诱发神经精神疾病。研究表明,DNA甲基化在酒精诱导基因表达和行为改变中发挥重要作用,但具体的神经生物学机制尚未被阐明。为了探索DNA甲基化在酒精滥用中的作用机制,本研究选取健康成年雄性SD大鼠(Rattus norvegicus)32只,随机分为饮水对照组(n=16)和慢性酒精暴露组(n=16),运用双瓶选择实验(two bottle choice test,TBCT)评估大鼠酒精偏爱率(alcohol preference),通过旷场行为(open field test,OFT)评估活动状态并检测血酒精浓度。分离两组大鼠内侧前额叶皮质(medial prefrontal cortex,mPFC),提取总DNA,利用简化代表性重亚硫酸盐测序技术(reduced representation bisulfite sequencing,RRBS)构建mPFC甲基化谱,对差异基因进行功能富集和通路分析,筛选与酒精滥用密切相关的甲基化差异基因,运用qRT-PCR技术检测差异基因的表达,验证DNA甲基化对基因的表达调控;利用qRT-PCR和Western blot检测甲基转移酶(DNA methyltransferases,DNMTs)和甲基化CpG位点结合蛋白2(methyl CpG binding protein 2,MeCP2)的表达;同时,还检测了短期酒精暴露(7 d)对大鼠mPFC内DNMTs和MeCP2的影响(n=8/组)。结果表明,慢性酒精暴露大鼠mPFC内基因启动子区甲基化水平显著升高。与酒精滥用密切相关的差异基因中,慢性酒精暴露组Ntf3和Ppm1G启动子区甲基化水平升高,mRNA表达降低;Hap1和DUSP1启动子区甲基化水平降低,mRNA表达升高。慢性酒精暴露使DNMT3B和MeCP2 mRNA和蛋白表达升高,而短期内酒精暴露不影响它们的表达。本研究初步证实DNA甲基化与酒精滥用的发展相关,可能受DNMT3B和MeCP2分子的调控,并发现了与酒精滥用相关的靶基因Ntf3、Ppm1G、Hap1和DUSP1,为研究酒精滥用的神经生物学机制提供了新见解,同时为酒精滥用治疗提供了可能的药理学靶点。     

The Brain Activity in Brodmann Area 17: A Potential Bio-Marker to Predict Patient Responses to Antiepileptic Drugs

In this study, we aimed to predict newly diagnosed patient responses to antiepileptic drugs (AEDs) using resting-state functional magnetic resonance imaging tools to explore changes in spontaneous brain activity. We recruited 21 newly diagnosed epileptic patients, 8 drug-resistant (DR) patients, 11 well-healed (WH) patients, and 13 healthy controls. After a 12-month follow-up, 11 newly diagnosed epileptic patients who showed a poor response to AEDs were placed into the seizures uncontrolled (SUC) group, while 10 patients were enrolled in the seizure-controlled (SC) group. By calculating the amplitude of fractional low-frequency fluctuations (fALFF) of blood oxygen level-dependent signals to measure brain activity during rest, we found that the SUC patients showed increased activity in the bilateral occipital lobe, particularly in the cuneus and lingual gyrus compared with the SC group and healthy controls. Interestingly, DR patients also showed increased activity in the identical cuneus and lingual gyrus regions, which comprise Brodmann’s area 17 (BA17), compared with the SUC patients; however, these abnormalities were not observed in SC and WH patients. The receiver operating characteristic (ROC) curves indicated that the fALFF value of BA17 could differentiate SUC patients from SC patients and healthy controls with sufficient sensitivity and specificity prior to the administration of medication. Functional connectivity analysis was subsequently performed to evaluate the difference in connectivity between BA17 and other brain regions in the SUC, SC and control groups. Regions nearby the cuneus and lingual gyrus were found positive connectivity increased changes or positive connectivity changes with BA17 in the SUC patients, while remarkably negative connectivity increased changes or positive connectivity decreased changes were found in the SC patients. Additionally, default mode network (DMN) regions showed negative connectivity increased changes or negative changes with BA17 in the SUC patients. The abnormal increased in BA17 activity may be a key point that plays a substantial role in facilitating seizure onset.     

NME2 Reduces Proliferation,Migration and Invasion of Gastric Cancer Cells to Limit Metastasis

Gastric cancer is one of the most common malignancies and has a high rate of metastasis. We hypothesize that NME2 (Nucleoside Diphosphate Kinase 2), which has previously been considered as an anti-metastatic gene, plays a role in the invasiveness of gastric cancer cells. Using a tissue chip technology and immunohistochemistry, we demonstrated that NME2 expression was associated with levels of differentiation of gastric cancer cells and their metastasis into the lymph nodes. When the NME2 gene product was over-expressed by ;in vitro stable transfection, cells from BGC823 and MKN45 gastric cancer cell lines had reduced rates of proliferation, migration, and invasion through the collagen matrix, suggesting an inhibitory activity of NME2 in the propagation and invasion of gastric cancer. NME2 could, therefore, severe as a risk marker for gastric cancer invasiveness and a potential new target for gene therapy to enhance or induce NME2 expression.     

Chiral amorphous metal–organic polyhedra used as the stationary phase for high-resolution gas chromatography separations

Herein, we describe a new chiral amorphous metal–organic polyhedra used as the stationary phase for high-resolution gas chromatography (GC). The chiral stationary phase was coated onto a capillary column via a dynamic coating process and investigated for a variety of compounds. The experimental results showed that the chiral stationary phase exhibits good selectivity for linear alkanes, linear alcohols, polycyclic aromatic hydrocarbons, isomers, and chiral compounds. In addition, the column has the advantages of high column efficiency and short analysis time. The present work indicated that amorphous metal–organic polyhedra have great potential for application as a new type of stationary phase for GC.     

Betulinic acid inhibits pyroptosis in spinal cord injury by augmenting autophagy via the AMPK-mTOR-TFEB signaling pathway

Spinal cord injury (SCI) results in a wide range of disabilities. Its complex pathophysiological process limits the effectiveness of many clinical treatments. Betulinic acid (BA) has been shown to be an effective treatment for some neurological diseases, but it has not been studied in SCI. In this study, we assessed the role of BA in SCI and investigated its underlying mechanism. We used a mouse model of SCI, and functional outcomes following injury were assessed. Western blotting, ELISA, and immunofluorescence techniques were employed to analyze levels of autophagy, mitophagy, pyroptosis, and AMPK-related signaling pathways were also examined. Our results showed that BA significantly improved functional recovery following SCI. Furthermore, autophagy, mitophagy, ROS level and pyroptosis were implicated in the mechanism of BA in the treatment of SCI. Specifically, our results suggest that BA restored autophagy flux following injury, which induced mitophagy to eliminate the accumulation of ROS and inhibits pyroptosis. Further mechanistic studies revealed that BA likely regulates autophagy and mitophagy via the AMPK-mTOR-TFEB signaling pathway. Those results showed that BA can significantly promote the recovery following SCI and that it may be a promising therapy for SCI.     

In vitro selections with RNAs of variable length converge on a robust catalytic core

In vitro selection is a powerful tool that can be used to understand basic principles of molecular evolution. We used in vitro selection to understand how changes in length and the accumulation of point mutations enable the evolution of functional RNAs. Using RNA populations of various lengths, we performed a series of in vitro experiments to select for ribozymes with RNA ligase activity. We identified a core ribozyme structure that was robust to changes in RNA length, high levels of mutagenesis, and increased selection pressure. Elaboration on this core structure resulted in improved activity which we show is consistent with a larger trend among functional RNAs in which increasing motif size can lead to an exponential improvement in fitness. We conclude that elaboration on conserved core structures is a preferred mechanism in RNA evolution. This conclusion, drawn from selections of RNAs from random sequences, is consistent with proposed evolutionary histories of specific biological RNAs. More generally, our results indicate that modern RNA structures can be used to infer ancestral structures. Our observations also suggest a mechanism by which structural outcomes of early RNA evolution would be largely reproducible even though RNA fitness landscapes consist of disconnected clusters of functional sequences.     

Integrating multiple references for single-cell assignment

Efficient single-cell assignment is essential for single-cell sequencing data analysis. With the explosive growth of single-cell sequencing data, multiple single-cell sequencing data sources are available for the same kind of tissue, which can be integrated to further improve single-cell assignment; however, an efficient integration strategy is still lacking due to the great challenges of data heterogeneity existing in multiple references. To this end, we present mtSC, a flexible single-cell assignment framework that integrates multiple references based on multitask deep metric learning designed specifically for cell type identification within tissues with multiple single-cell sequencing data as references. We evaluated mtSC on a comprehensive set of publicly available benchmark datasets and demonstrated its state-of-the-art effectiveness for integrative single-cell assignment with multiple references.     

Bioimaging nitric oxide in activated macrophages in vitro and hepatic inflammation in vivo based on a copper–naphthoimidazol coordination compound

Nitric oxide (NO) serves as a messenger for cellular signaling and physiological reactions such as inflammatory responses in vivo. Fluorescent bioimaging of nitric oxide is a very useful tool in NO functional research. Although many encouraging results have been achieved in the field of NO fluorescent detection, there is rarely satisfying result in inflammatory NO imaging in vivo. Here we report that fluorescent 5′-chloro-2-(2′-hydroxyphenyl)-1H-naphtho[2,3-d]imidazol can coordinate with Cu(II) to form a non-fluorescent coordination compound, which is able to directly and quickly image NO in cellular system or in vivo inflammation system with a turn-on fluorescence, based on a redox action of Cu(II). It was used to image NO produced by inducible nitric oxide synthase (iNOS) in lipopolysaccharide (LPS) activated murine macrophages. More importantly, it could image the NO production in an acute severe hepatic injury (ASHI) model of BALB/c mice induced by integrative LPS and d-galactosamine (GalN) treatment. The results prove that the 5′-chloro-2-(2′-hydroxyphenyl)-1H-naphtho[2,3-d]imidazol coordinated with cupric ions can serve as an excellent NO bioimaging agent in different biological systems especially in inflammation related systems, and it may be valuable for diagnostic and pathological studies of NO related diseases.