生物基分子介导纳米金属材料的制备及其应用

纳米金属材料具有纳米晶强化效应、光吸收率大、较高的表面能和单磁畴性能等优点,因其在医药、化学催化、抗菌抑毒等方面发挥着越来越重要的作用而受到人们广泛关注。近年来,随着全球石化资源消耗与日俱增,环境污染加剧,基于可再生资源的生物基分子介导纳米材料的制备研究方兴未艾。生物基分子是指直接或间接来源于生物质的小分子或大分子物质,它们多数具有生物相容性好、低毒、可降解、来源广泛、价格低廉等优点。且由于生物基分子多数具有独特的理化性质,如具有生理活性的旋光性、酸碱两性、亲水亲油性以及易与金属离子络合等,其介导合成的纳米材料还兼具其独特功能性,比如消炎、抗癌、抗氧化、抗病毒以及降血糖血脂等,进一步拓宽了纳米金属材料的应用领域。文中对近年来基于生物基分子介导纳米金属材料的制备及应用进行全面综述,为开展相关研究提供参考。     

100%枸杞汁对递增负荷运动期间机体HPA轴及血糖调节的影响*

目的: 观察在递增负荷运动期间饮用100%枸杞汁对男大学生血清促肾上腺皮质激素(ACTH)、皮质醇(C)、胰岛素(INS)、胰高血糖素(PG)和血糖(Glu)变化,探讨100%枸杞汁在递增负荷运动期间对机体下丘脑-垂体-肾上腺(HPA)轴应激和血糖调节的作用。方法: 将28名健康男性大学生随机分为对照组(C组,16人)和实验组(E组,12人),所有受试者进行为期32 d、4个阶段的递增负荷运动,运动期间E组每人每天睡前饮用100 ml 100%枸杞汁。在实验前和每阶段结束后次日晨采用血糖仪测试受试者Glu及ELISA法测试血清ACTH、C、INS、PG。结果: ①与运动前相比,递增负荷运动期间两组受试者血清ACTH浓度均在第1、2阶段下降后,第3、4阶段持续升高(P＜0.01),且E组稍高于C组;②递增负荷运动期间受试者血清C呈持续下降趋势,E组第4阶段末显著低于对照组(P＜0.05);③递增负荷运动期间受试者血清INS水平先上升再下降,第4阶段末C组的浓度下降明显(P＜0.05);④实验末期E组血清PG显著降低(P＜0.05);⑤实验后期受试者Glu浓度下降,C组的Glu浓度下降趋势明显(P＜0.05)。结论: 100%枸杞汁可改善递增负荷期间机体HPA轴功能,提高机体对大负荷的应激能力,并调节机体血糖平衡。     

莱菔子乙醇提取物对ApoE-/-小鼠血脂血糖及肝脂肪变性的影响*

目的:探讨莱菔子乙醇提取物(AERS)对ApoE^-/-小鼠血脂血糖及肝脂肪变性的影响及其机制。方法:随机将60只ApoE^-/-小鼠分为对照组(CG)、生理盐水组(NG)、罗格列酮组(RG)、AERS治疗组,后者再分成AERS低、中、高剂量组(AERS-L/M/H),每组10只。除CG常规饲料外,其他动物均以高脂高糖高盐饲料饲养9周,CG和NG分别每天以等容量NS灌胃1次,RG每天灌胃罗格列酮(1.33 mg·kg^-1,NS稀释成等容量溶液,每次0.2 ml·10 g^-1),AERS组动物每天分别予AERS灌胃(100、300和900 mg·kg^-1)9周后。肝病理学观察,检测FPG、FIns,计算胰岛素抵抗指数(IRI)和肝系数(LC)。检测血清ALT、AST、瘦素(LEP)、TNF-α及血脂水平(TC、FFA等)。Western blot检测肝脂质代谢相关蛋白表达(HMG-R、LDL-R、LEP-R)。结果:与CG相比,NG和RG肝脏外观(色泽、肿胀情况等)和病理学(脂肪变性、肝细胞坏死等)改变明显,而AERS-M/H与CG相似;与CG相比,血清FPG、Fins、IRI、ALT、AST、TNF-α、LC、TG、LDL-C、FFA、LEP等指标明显升高(P＜0.05);与NG相比,AERS呈现剂量依赖性降低(P＜0.05);与RG相比,AERS-H的FPG、Fins明显升高(P＜0.05),而IRI明显降低(P＜0.05);与NG和RG相比,AERS组的HMG-R和LEP-R蛋白表达呈剂量依赖性减少,而LDL-R蛋白表达呈剂量依赖性增加(P＜0.05)。结论:AERS能阻止高脂高糖饲料诱导ApoE^-/^-小鼠血脂血糖升高及肝脂肪变性,其机制与减少FFA和LEP的生成,抑制TNF-α、HMG-R、LEP-R蛋白表达和促进LDL-R的蛋白表达有关。     

LncRNA Kcnq1ot1/miR-214-3p/caspase-1通路调控高糖处理的心脏成纤维细胞焦亡

摘要 目的：探讨长链非编码RNA Kcnq1ot1在高糖处理的心脏成纤维细胞中调控焦亡的作用及具体机制。方法：培养C57BL/6乳鼠原代心脏成纤维细胞,分别用5.5 mM和30 mM葡萄糖培养,用免疫荧光、qRT-PCR和western blot方法检测NLRP3、caspase-1和IL-1β的表达。高糖处理的成纤维细胞抑制Kcnq1ot1,检测caspase-1的表达。生物信息学和荧光素酶报告基因检测验证与Kcnq1ot1和caspase-1存在共同互补结合位点的microRNA。应用qRT-PCR和western blot方法检测高糖诱导的心脏成纤维细胞干扰Kcnq1ot1后miR-214-3p的表达,以及过表达或干扰miR-214-3p后caspase-1的表达水平。高糖诱导的细胞单独干扰Kcnq1ot1或同时抑制Kcnq1ot1和miR-214-3p,检测caspase-1、NLRP3和IL-1?茁的表达水平。结果：高糖诱导的成纤维细胞中焦亡激活,Kcnq1ot1表达明显升高;抑制Kcnq1ot1后caspase-1表达显著下调。生物信息学和荧光素酶报告基因检测发现miR-214-3p与Kcnq1ot1和caspase-1存在共同互补结合位点。高糖诱导的心脏成纤维细胞干扰Kcnq1ot1后miR-214-3p表达升高;过表达 miR-214-3p 后caspase-1表达降低,抑制miR-214-3p后caspase-1表达升高。同时抑制Kcnq1ot1和miR-214-3p可逆转干扰Kcnq1ot1对caspase-1的降低作用。结论：干扰Kcnq1ot1能够通过抑制miR-214-3p/caspase-1信号转导通路,抑制高糖诱导的心脏成纤维细胞焦亡。     

Understanding the binding interaction between phenyl boronic acid P1 and sugars: determination of association and dissociation constants using S–V plots,steady‐state spectroscopic methods and molecular docking

Continuous monitoring of glucose and sugar sensing plays a vital role in diabetes control. The drawbacks of the present enzyme‐based sugar sensors have encouraged the investigation into alternate approaches to design new sensors. The popularity of fluorescence sensors is due to their ability to bind reversibly to compounds containing diol. In this study we investigated the binding ability of phenyl boronic acid P1 for monosaccharides and disaccharides (sugars) in aqueous medium at physiological pH 7.4 using steady‐state fluorescence and absorbance. P1 fluorescence was quenched due to formation of esters with sugars. Absorbance and fluorescence measurements led to results that indicated that the sugars studied could be ordered in terms of their affinity to P1, as stated: sucrose > lactose > galactose > xylose > ribose > arabinose. In each case, the slope of modified Stern–Volmer plots was nearly 1, indicating the presence of only a single binding site in boronic acids for sugars. Docking studies were carried out using Schrodinger Maestro v.11.2 software. The binding affinity of phenyl boronic acid P1 with periplasmic protein (PDB ID 2IPM and 2IPL) was estimated using GlideScore.     

Thymoquinone attenuates doxorubicin‐cardiotoxicity in rats

Contrary to the fact that doxorubicin is a powerful chemotherapeutic agent for the treatment of neoplastic diseases, cardiotoxicity is too important to be ignored. Thymoquinone serves as a powerful free radical scavenger. In the study, the effects of thymoquinone against doxorubicin‐cardiotoxicity will be evaluated. Forty rats were divided into five groups. Group I: control group (n = 8); group II: olive oil group (n = 8); group III: thymoquinone group (n = 8); given 10 mg/kg thymoquinone intraperitoneally per day throughout the experiment; group IV: doxorubicin group (n = 8); injected with a single dose of 15 mg/kg ip doxorubicin on the 7th day of the experiment; group V: doxorubicin + thymoquinone group (n = 8); administered with 10 mg/kg thymoquinone per day during the experiment and 15 mg/kg doxorubicin ip on the 7th day. The experiment was planned for 14 days. Immunohistochemically, heat shock protein (HSP) 70 and HSP90, glucose‐regulated protein 78 (GRP78), caspase‐3 were stained. We made terminal deoxynucleotidyl transferase dUTP nick end labeling for apoptotic evaluation. Total oxidant status (TOS) levels and total antioxidant status (TAS) were measured in the heart tissue. Atrial natriuretic peptide (ANP) and pro‐B type natriuretic peptide (proBNP) were evaluated. In the study, HSP70, HSP90, GRP78, and caspase‐3 levels increased in group IV. TOS and TAS levels were significant compared to group I. Doxorubicin significantly increased ANP and NT‐proBNP levels. Thymoquinone revealed significant differences in these values. Thymoquinone can be an important cardioprotective agent against doxorubicin‐cardiotoxicity.