柑橘大实蝇精巢、精泵和精泵内骨骼的生长发育状况

【目的】柑橘大实蝇是一种严重为害柑橘类果实的经济害虫。研究其精巢、精泵以及精泵内骨骼生长发育状况,有助于提高柑橘大实蝇人工繁殖效率以及其田间防治效果,为柑橘大实蝇的预测预报及防治提供理论基础。【方法】基于光学显微镜测量恒温和室温条件下柑橘大实蝇雄虫的精巢、精泵以及精泵内骨骼的长度和宽度,并建立其长度、宽度和指数的函数模型,比较恒温和室温2种饲养条件下其雄虫器官发育状况差异。【结果】无论是在恒温还是室温条件下饲养,随着柑橘大实蝇雄成虫日龄的增加,其精巢、精泵以及精泵内骨骼的长度、宽度和指数变化趋势均符合幂函数增长模型。在恒温和室温条件下,其雄虫的精巢宽度、精泵的长度和宽度以及指数、精泵内骨骼宽度均无明显差异。在室温条件下饲养的雄虫的精巢长度[(4.00±0.14) mm]及指数(3.40±0.14)、精泵内骨骼长度[(1.65±0.03) mm]及指数(1.84±0.08)均分别显著高于在恒温条件下饲养的雄虫的精巢长度[(3.75±0.13) mm]及指数(3.19±0.14)、精泵内骨骼长度[(1.61±0.03) mm]及指数(1.77±0.08)。【结论】变温(室温)比恒温更有利于柑橘大实蝇雄虫的精巢和精泵内骨骼的发育,并推荐使用精泵长度推断其雄虫日龄的方法。     

含半胱氨酸的天冬氨酸蛋白水解酶(caspase-1)对猪伪狂犬病毒复制的影响

猪伪狂犬病是伪狂犬病毒(Pseudorabies virus,PRV)感染引起的一种烈性接触性传染病,其感染宿主会触发机体先天免疫应答,引起I型干扰素(Type I interferon,IFN-1)和炎性细胞因子等细胞因子的产生,为研究可诱导产生炎性细胞因子的含半胱氨酸的天冬氨酸蛋白水解酶(Cysteinyl aspartate specific proteinase 1,caspase-1)的基因敲除对PRV复制的影响,本试验利用近年来发展迅速的一项规律性短重复回文序列簇/Cas9核酸酶(Clustered regulatory interspaced short palindromic repeat/CRISPR associated system 9,CRISPR/Cas9)基因定点修饰技术构建猪肾上皮细胞(Porcine kidney epithelial cells,PK15)caspase-1基因稳定敲除细胞系,并通过T7核酸酶检测敲除效率;细胞毒性(Cell counting kit-8,CCK-8)试剂盒检测PK15敲除caspase-1增殖影响;采用流式细胞术检测PRV-GFP感染PK15以及PK15-caspase-1^-/-的增殖差异;实时荧光定量PCR(Real-time quantitative PCR,RT-PCR)检测PRV-gB、TK及白细胞介素1β(Interleukin-1β,IL-1β)、IFN-β、干扰素刺激基因(Interferon-stimulated genes 20,ISG20)mRNA的表达;Western Blot检测PRV-gB蛋白表达;滴度测定检测子代病毒滴度。结果表明,2对特异性单链引导RNA(Single guide RNA,sgRNA)均能对caspase-1进行基因编辑,但经T7核酸酶酶切进行基因编辑效率分析结果表明sgRNA2的基因编辑效率较高;CCK-8试剂盒检测细胞活力结果表明caspase-1基因敲除对PK15以及PK15-caspase-1^-/-细胞活力无影响(P>0.05);流式细胞仪检测结果表明PRV-GFP在PK15-caspase-1^-/-中的增殖显著低于PK15细胞(P<0.05);定量RT-PCR结果表明PRV-gB、TK基因在PK15-caspase-1^-/-的mRNA表达显著低于PK15细胞(gB:P<0.05,TK:P<0.05),而IFN-β、ISG20基因在PK15-caspase-1^-/-的mRNA表达显著高于PK15细胞(gB:P<0.05,TK:P<0.05);Western Blot结果表明,PRV的gB蛋白在PK15-caspase-1^-/-的表达显著低于PK15细胞(P<0.05);滴度测定结果表明,敲除caspase-1能够抑制PRV子代病毒的增殖。以上结果均表明caspase-1基因敲除可抑制PRV在PK15细胞中复制。     

Novel nonapeptide GLP (28–36) amide derivatives with improved hypoglycemic and body weight lowering effects

Glucagon-like peptide-1 (GLP-1) has emerged as a major therapeutic target for the treatment of type 2 diabetes. The nonapeptide GLP-1 (28–36) amide is one of the biological C-terminal products of GLP-1 modified by the neutral endopeptidase (NEP) 24.11 with limited hypoglycemic activity. In this study, we focused on the modification of GLP-1 (28–36) amide for the first time and synthesized a series of GLP-1 (28–36) amide analogues. Results of biological activity evaluation in INS-1 cell, STZ-induced diabetic and diet induced obesity (DIO) mice indicated that S3 as a promising candidate to treat type 2 diabetes and obesity.     

Genome-wide screen identifies signaling pathways that regulate autophagy during Caenorhabditis elegans development

The mechanisms that coordinate the regulation of autophagy with developmental signaling during multicellular organism development remain largely unknown. Here, we show that impaired function of ribosomal protein RPL-43 causes an accumulation of SQST-1 aggregates in the larval intestine, which are removed upon autophagy induction. Using this model to screen for autophagy regulators, we identify 139 genes that promote autophagy activity upon inactivation. Various signaling pathways, including Sma/Mab TGF-β signaling, lin-35/Rb signaling, the XBP-1-mediated ER stress response, and the ATFS-1-mediated mitochondrial stress response, regulate the expression of autophagy genes independently of the TFEB homolog HLH-30. Our study thus provides a framework for understanding the role of signaling pathways in regulating autophagy under physiological conditions.Subject Categories: Autophagy & Cell Death; Signal Transduction; Membrane & Intracellular Transport     

Doxycycline Inhibits Inflammation-Induced Lymphangiogenesis in Mouse Cornea by Multiple Mechanisms

Lymphangiogenesis is significantly involved in the pathogenesis of diseases, including graft rejection, cancer metastasis and various inflammatory conditions. The inhibition of lymphangiogenesis has become a new therapeutic target for the treatment of these diseases. Here, we explored the anti-lymphangiogenic effects of doxycycline in inflammation-induced lymphangiogenesis (ILA) in the cornea and the underlying mechanisms. In the present study, mice with ILA of the cornea were treated with topical doxycycline (0.1%) or vehicle control. Lymphangiogenesis was quantified using corneal immunostaining of lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1). Human dermal lymphatic endothelial cells (HDLECs) and a murine macrophage cell line (RAW264.7) were used to further explore the underlying mechanisms of doxycycline-mediated anti-lymphangiogenesis in vitro. Our results showed that doxycycline treatment dramatically inhibited ILA in the mouse cornea (p<0.001), with a significant decrease in vascular endothelial growth factor (VEGF)-C/VEGF receptor 3 signalling, macrophage infiltration and inflammatory cytokine expression. Doxycycline also significantly inhibited VEGF-C-induced HDLEC proliferation in vitro by modulating the PI3K/Akt/endothelial nitric oxide (NO) synthase (eNOS) pathway and significantly suppressed interleukin-1β (IL-1β), TNF-α and VEGF-C production in the RAW264.7 cell line by modulating the PI3K/Akt/nuclear factor-kappaB (NF-κB) pathway. Additionally, doxycycline treatment dramatically reduced the phosphorylation of NF-κBp65, Akt and eNOS in ILA and significantly inhibited matrix metalloproteinases (MMPs) activity in vitro and in ILA. In conclusion, doxycycline inhibited ILA, possibly through suppression of VEGF-C signalling, macrophage function and MMPs activity. This observation suggests that doxycycline is a potential therapeutic agent for lymphangiogenesis-related diseases.     

一株产细菌纤维素菌株的筛选鉴定及其产物分析

从红茶菌液中筛选获得一株产细菌纤维素的菌株BC-41,经生理生化分析和分子生物学鉴定,现证实该菌株为中间葡糖酸醋杆菌(Gluconacetobacter intermedius)。对该菌株所产生的细菌纤维素进行了物理特性的表征和分析,获得以下数据:BC-41所产的纤维素纯度达到91.32%,湿纤维素膜含水率达99.16%,每克干纤维素膜能吸水28.59 g;扫描电子显微镜观察,显示该纤维素具有网状结构,且纤维束宽度分布在40-100 nm之间;X射线衍射分析,证实该纤维素的晶型为纤维素I型,结晶指数为48.8%;通过黏度测定法,得出该纤维素的平均聚合度达2 100。     

生姜精油化学成分及其抗菌活性

【背景】随着耐药微生物种类的增多和耐药性增强,抗耐药微生物新药的发现已成为全球关注的问题。生姜精油是纯天然植物精油,是天然抗菌材料的优选。【目的】分析生姜精油的化学成分,研究生姜精油对常见条件致病菌抗菌活性的影响,并阐明其可能的抗菌机制。【方法】采用气相色谱/质谱技术(Gas Chromatography/Mass Spectrometry,GC/MS)对生姜精油的化学成分进行分析,利用牛津杯法、最小抑菌浓度法(Minimum Inhibitory Concentration,MIC)、最小杀菌浓度法(Minimum Bactericidal Concentration,MBC)和生长曲线绘制法研究生姜精油的抗菌活性和抗菌动力学特征,并通过透射电镜(Transmission Electron Microscopy,TEM)观察生姜精油对细菌超微结构的影响。【结果】生姜精油的化学成分主要为姜烯(22.014%)、β-倍半水芹烯(11.276%)、α-法呢烯(8.222%)、α-姜黄烯(6.854%)、姜酮(5.610%)、姜辣二酮(5.192%)、6-姜烯酚(4.670%)、桧烯(3.393%)和β-红没药烯(3.080%)等萜类物质。生姜精油对枯草芽孢杆菌的MIC和MBC分别为2.3μg/mL和4.6μg/mL;对表皮葡萄球菌及金黄色葡萄球菌的MIC均为9.2μg/mL,MBC均为18.4μg/mL;对肺炎克雷伯菌的MIC和MBC分别为18.4μg/m L和36.8μg/mL。生长曲线结果显示,生姜精油能延长细菌的生长停滞期、抑制细菌的生长速率。透射电镜结果表明,生姜精油能引起细菌细胞膜破损,致使胞内物质渗漏。【结论】生姜精油富含萜类化合物,具有中度的抗菌活性,能破坏细菌细胞膜的完整性,引起菌体损伤和死亡。本文有望更好地为有害微生物的防控提供新方法。