Cytosolic epoxide hydrolase in fetal and adult human liver

The epoxide hydrolase and glutathione S-transferase activity towards styrene oxide as substrate were investigated and compared in fetal and adult human liver cytosols. The rate of formation of styrene glycol from styrene oxide (nmole/min/mg protein) was 0.23±0.02 (¯x±SE;n=10) in fetal and 0.83±0.05 (¯x±SE;n=14) in adult liver specimens. The enzyme followed Michealis-Menten kinetics in the fetal liver. In adult liver specimens the enzyme showed biphasic kinetics.For comparative purposes, the cytosolic glutathione S-transferase activity was investigated in the cytosolic fractions from the same liver specimens. The fetal activity was 40% of the adult activity 3.9±0.50 (¯x±SE;n=10) versus 9.94±1.75 (¯x±SE;n=14) nmoles/min/mg protein.     

基于网络药理学及分子对接探讨香连片对新型冠状病毒肺炎(COVID-19)的机制研究

目的:基于网络药理学及分子对接技术探讨香连片对新型冠状病毒肺炎(Corona Virus Disease 2019,COVID-19)的作用机制.方法:通过中药系统药理学数据库与分析平台(Traditional Chinese Medicine Systems Pharmacology Database andAnal...     

基于网络药理学与分子对接技术的补肺活血胶囊用于新型冠状病毒肺炎（COVID-19）恢复期治疗的分子机制研究

目的探索补肺活血胶囊用于新型冠状病毒肺炎(COVID-19)恢复期治疗的潜在作用机制,为其临床用药提供理论指导。方法通过中药系统药理学分析平台(TCMSP)、BATMAN-TCM、中国知网(CNKI)和Pubmed数据库获得补肺活血胶囊的活性成分及作用靶点;通过GeneCards数据库获取COVID-19相关靶点,并采用交集法筛选出与补肺活血胶囊活性组分作用的共同靶点,运用Cytoscape 3.7.2构建"中药-化合物-靶点"网络,并通过String数据库构建蛋白-蛋白相互作用(PPI)网络;通过DAVID数据库进行KEGG通路和GO功能富集分析,并运用R version 3.6.3软件将结果进行可视化;采用AutoDock Tools 1.5.6、AutoDock vina 1.1.2进行分子对接研究。结果从补肺活血胶囊中共筛选出潜在活性成分32个,对应靶点203个,核心化合物11个,核心靶点52个;PPI网络分析获得补肺活血胶囊干预COVID-19关键作用靶点25个;GO及KEGG富集分析得出与补肺活血胶囊治疗COVID-19作用相关的生物过程251个(P<0.05),相关...     

Blockade of deubiquitinase YOD1 degrades oncogenic PML/RARα and eradicates acute promyelocytic leukemia cells

In most acute promyelocytic leukemia (APL) cells, promyelocytic leukemia (PML) fuses to retinoic acid receptor α (RARα) due to chromosomal translocation, thus generating PML/RARα oncoprotein, which is a relatively stable oncoprotein for degradation in APL. Elucidating the mechanism regulating the stability of PML/RARα may help to degrade PML/RARα and eradicate APL cells. Here, we describe a deubiquitinase (DUB)-involved regulatory mechanism for the maintenance of PML/RARα stability and develop a novel pharmacological approach to degrading PML/RARα by inhibiting DUB. We utilized a DUB siRNA library to identify the ovarian tumor protease (OTU) family member deubiquitinase YOD1 as a critical DUB of PML/RARα. Suppression of YOD1 promoted the degradation of PML/RARα, thus inhibiting APL cells and prolonging the survival time of APL cell-bearing mice. Subsequent phenotypic screening of small molecules allowed us to identify ubiquitin isopeptidase inhibitor I (G5) as the first YOD1 pharmacological inhibitor. As expected, G5 notably degraded PML/RARα protein and eradicated APL, particularly drug-resistant APL cells. Importantly, G5 also showed a strong killing effect on primary patient-derived APL blasts. Overall, our study not only reveals the DUB-involved regulatory mechanism on PML/RARα stability and validates YOD1 as a potential therapeutic target for APL, but also identifies G5 as a YOD1 inhibitor and a promising candidate for APL, particularly drug-resistant APL treatment.     

In Situ Kinetics Reveal the Influence of Solvents and Monomer Structure on the Anionic Ring-Opening Copolymerization of Epoxides

In-depth understanding of copolymerization kinetics and the resulting polymer microstructure is crucial for the design of materials with well-defined properties. Further, insights regarding the impact of solvents on copolymerization kinetics allows for precisely tuned materials. In this regard, in situ ¹H NMR spectroscopy enables precise monitoring of the living anionic ring-opening copolymerization (AROP) of ethylene oxide (EO) with the glycidyl ethers allyl glycidyl ether (AGE) and ethoxy vinyl glycidyl ether (EVGE), respectively. Determination of reactivity ratios reveals slightly higher reactivity of both glycidyl ethers compared to EO, emphasizing a pronounced counterion chelation effect by glycidyl ethers in AROP. Implementation of density functional theory (DFT) calculations further illustrates the complexation capability of ether-containing side groups in glycidyl ethers, in analogy to crown ethers (“crown ether effect”). Investigation of the copolymerization in i) THF-d₈ and ii) DMSO-d₆ shows an increasing disparity of reactivity ratios for both glycidyl ethers compared to EO, clearly related to decreasing solvent polarity.     

ADMA/DDAH系统与脑白质疏松症的关系

脑白质疏松症(LA)是深部脑小血管病变(SVD)引起的弥漫性脑缺血,可导致脑白质区神经传导纤维脱髓鞘疾病,是脑损害的一个早期标志。一氧化氮(NO)是血管内皮舒张因子,由体内的一氧化氮合酶(NOS)催化产生。非对称性二甲基精氨酸(ADMA)是NOS的内源性竞争抑制物。ADMA增加使NO生成减少,导致血管内皮功能障碍。二甲基精氨酸二甲胺水解酶(DDAH)是内源性ADMA的主要代谢酶,是决定血浆ADMA浓度的关键因素。ADMA/DDAH通路可能通过血管内皮损伤机制影响LA。