SAMHD1通过调控p27表达抑制肝细胞癌细胞增殖的研究

背景与目的：不育α基序结构域和组氨酸/天冬氨酸残基双联体结构域包涵蛋白1（sterile alpha motif and histidine/aspartic acid domain-containing protein 1，SAMHD1）具有抑制多种肿瘤细胞生长的作用，但其调节肝细胞癌（hepatocellular carcinoma，HCC）细胞增殖的作用及机制尚未见报道。探究SAMHD1调控p27的表达对HCC细胞Huh7的增殖、凋亡和细胞周期的影响。方法：首先通过蛋白质印迹法（Western blot）检测正常肝细胞和不同类型HCC细胞中SAMHD1的表达情况。利用基因修饰技术构建过表达SAMHD1、dNTP酶活性位点突变体（SAMHD1-D207N）和磷酸化位点突变体（SAMHD1-T592E）的重组质粒，然后利用四甲基偶氮唑蓝（methyl thiazolyl tetrazolium，MTT）法检测过表达SAMHD1及其突变体或siRNA干扰沉默SAMHD1对HCC细胞增殖的影响，采用流式细胞术检测细胞周期与细胞凋亡情况。在癌症基因组图谱（The Cancer Genome Atlas，TCGA）数据库中分析SAMHD1和p27表达的相关性。结果：HCC细胞中SAMHD1表达上调，过表达SAMHD1、SAMHD1-D207N和SAMHD1-T592E可以抑制Huh7细胞增殖，细胞周期停滞在G ₁ /G ₀ 期；相反，干扰SAMHD1后细胞增殖加快，细胞周期停滞在G ₂ /M期。机制研究表明，SAMHD1上调细胞周期蛋白激酶抑制因子p27的表达。在HCC组织中，p27的表达与SAMHD1表达呈正相关。结论：过表达SAMHD1可以上调p27的表达，导致细胞周期停滞在G ₁ /G ₀ 期，从而抑制HCC细胞增殖，这种抑制作用不依赖于其dNTP酶活性和磷酸化修饰。     

HPLC同时测定归芍疏肝散中芍药苷阿魏酸和甘草酸铵的含量

目的:建立同时测定归芍疏肝散中芍药苷、阿魏酸和甘草酸铵含量的高效液相色谱法。方法:采用Amethyst C18色谱柱(200 mm×4.6 mm,5μm),乙腈-0.1%磷酸为流动相,梯度洗脱,流速为1.0 mL·min-1,检测波长为237 nm,柱温为30℃。结果:在线性范围内3种成分线性良好(r≥0.9998),精密度RSD均<2%;重复性RSD均<3%;平均回收率98.81%~100.25%,RSD均<2%。结论:该方法快捷,操作简便,结果可靠,可用于归芍疏肝散的质量控制。     

小剂量丙戊酸联合拉莫三嗪治疗癫痫的疗效

目的探索小剂量的丙戊酸联合拉莫三嗪治疗癫痫的临床治疗效果。方法进行分组研究,对照组和观察组所选取的研究对象是本院在2018年2月-2019年2月收治的90例癫痫患者,每组患者各45例,观察组采用小剂量的丙戊酸联合拉莫三嗪进行治疗,对照组采用丙戊酸进行治疗,分析两组患者的癫痫发作次数、癫痫持续时间、临床症状好转时间及总有效率。结果观察组患者癫痫发作次数、癫痫持续时间和临床症状好转时间明显均优于对照组,观察组患者比对照组患者总有效率高,观察组总有效率为84.4%,对照组总有效率为62.2%,差异有统计学意义(P <0.05)。结论对癫痫患者的治疗,小剂量的丙戊酸联合拉莫三嗪提高了癫痫患者的治疗总有效率,具有显著疗效。     

同时分离纯化枇杷叶中熊果酸和科罗索酸工艺研究

目的采用大孔吸附树脂吸附法同时分离纯化枇杷叶中的熊果酸和科罗索酸,并确定分离纯化工艺。方法采用乙醇浸提法将枇杷叶中的熊果酸和科罗索酸进行提取分离纯化,对15种大孔吸附树脂进行筛选,利用大孔吸附树脂柱层析同时分离纯化枇杷叶中的熊果酸和科罗索酸。结果经过对15种大孔吸附树脂的筛选,HPD722的吸附量最好,因此选择HPD722大孔吸附树脂进行柱分离,并确立了最佳的分离纯化工艺。结论HPD722大孔吸附树脂能够使熊果酸和科罗索酸达到较好的分离纯化,工艺可行。     

Dietary fish oil,and to a lesser extent the fat-1 transgene,increases astrocyte activation in response to intracerebroventricular amyloid-β 1–40 in mice

Objectives: Increases in astrocytes and one of their markers, glial fibrillary acidic protein (GFAP) have been reported in the brains of patients with Alzheimer’s disease (AD). N-3 polyunsaturated fatty acids (PUFA) modulate neuroinflammation in animal models; however, their effect on astrocytes is unclear.

Methods: Fat-1 mice and their wildtype littermates were fed either a fish oil diet or a safflower oil diet deprived of n-3 PUFA. At 12 weeks, mice underwent intracerebroventricular infusion of amyloid-β 1-40. Astrocyte phenotype in the hippocampus was assessed at baseline and 10 days post-surgery using immunohistochemistry with various microscopy and image analysis techniques.

Results: GFAP increased in all groups in response to amyloid-β, with a greater increase in fish oil-fed mice than either fat-1 or wildtype safflower oil-fed mice. Astrocytes in this group were also more hypertrophic, suggesting increased activation. Both fat-1- and fish oil-fed mice had greater increases in branch number and length in response to amyloid-β infusion than wildtype safflower animals.

Conclusion: Fish oil feeding, and to a lesser extent the fat-1 transgene, enhances the astrocyte activation phenotype in response to amyloid-β 1-40. Astrocytes in mice fed fish oil were more activated in response to amyloid-β than in fat-1 mice despite similar levels of hippocampal n-3 PUFA, which suggests that other fatty acids or dietary factors contribute to this effect.     

A review on gentisic acid as a plant derived phenolic acid and metabolite of aspirin: Comprehensive pharmacology,toxicology, and some pharmaceutical aspects

Beneficial therapeutic effects of phenolic acids have been proven in various research projects including in vivo and in vitro studies. Gentisic acid (GA) is a phenolic acid that has been associated with useful effects on human health, such as antiinflammatory, antigenotoxic, hepatoprotective, neuroprotective, antimicrobial, and especially antioxidant activities. It is an important metabolite of aspirin and also widely distributed in plants as a secondary plant product such as Gentiana spp., Citrus spp., Vitis vinifera, Pterocarpus santalinus, Helianthus tuberosus, Hibiscus rosa‐sinensis, Olea europaea, and Sesamum indicum and in fruits such as avocados, batoko plum, kiwi fruits, apple, bitter melon, black berries, pears, and some mushrooms. This study was undertaken to review the pharmacological effects, pharmacokinetic properties as well as toxicity and pharmaceutical applications of GA.     

Nobiletin and its derivatives overcome multidrug resistance (MDR) in cancer: total synthesis and discovery of potent MDR reversal agents

Our recent studies demonstrated that the natural product nobiletin (NOB) served as a promising multidrug resistance (MDR) reversal agent and improved the effectiveness of cancer chemotherapy in vitro. However, low aqueous solubility and difficulty in total synthesis limited its application as a therapeutic agent. To tackle these challenges, NOB was synthesized in a high yield by a concise route of six steps and fourteen derivatives were synthesized with remarkable solubility and efficacy. All the compounds showed improved sensitivity to paclitaxel (PTX) in P-glycoprotein (P-gp) overexpressing MDR cancer cells. Among them, compound 29d exhibited water solubility 280-fold higher than NOB. A drug-resistance A549/T xenograft model showed that 29d, at a dose of 50 mg/kg co-administered with PTX (15 mg/kg), inhibited tumor growth more effective than NOB and remarkably increased PTX concentration in the tumors via P-gp inhibition. Moreover, Western blot experiments revealed that 29d inhibited expression of NRF2, phosphorylated ERK and AKT in MDR cancer cells, thus implying 29d of multiple mechanisms to reverse MDR in lung cancer.     

左旋肉碱修饰的壳聚糖-硬脂酸协载槲皮素口服紫杉醇纳米胶束的制备、表征及在体肠循环研究

目的 制备左旋肉碱修饰的壳聚糖-硬脂酸（LC-SA/CS-SA）纳米胶束，包载紫杉醇（PTX）且协载槲皮素，考察胶束特性，并以大鼠在体肠循环评估给药系统对PTX口服吸收的促进作用。方法 将硬脂酸（SA）通过酰胺化反应接枝于壳聚糖（CS），形成共聚物CS-SA；采用核磁共振H谱、红外光谱鉴定产物结构；以PTX为主药，槲皮素为辅药，采用激光粒径分析、Zeta电位分析和HPLC分析分别考察了胶束的粒径、Zeta电位、载药量、包封率；透射电子显微镜观察胶束形貌；芘荧光探针法测定LC-SA/CS-SA胶束的临界胶束浓度（critical micelle concentration，CMC）；透析袋法考察胶束的体外释放行为；大鼠在体肠吸收实验评估载药胶束的促吸收作用。结果 红外与核磁结果表明SA通过酰胺键接枝于CS；协载槲皮素的LC-SA/CS-SA载PTX胶束呈类球形，粒径为（148.3±1.7）nm，多分散系数（PDI）为0.16±0.07，Zeta电位为（24.600±0.167）mV，CMC为14.31 μg/mL；体外释放结果表明，与市售紫杉醇注射剂相比，协载槲皮素的LC-SA/CS-SA载PTX胶束、LC-SA/CS-SA载PTX胶束具有明显缓释效应；大鼠在体肠吸收实验表明，协载槲皮素的LC-SA/CS-SA胶束对载药PTX的胃肠吸收具有显著促进作用。结论 构建的协载槲皮素的LC-SA/CS-SA载PTX胶束性能优良，促进了PTX的大鼠肠吸收，具有增强药物口服吸收潜力。