斑马鱼急性无机砷暴露后肝脏差异表达基因的生物信息学分析

砷是一种致癌物,是心血管、外周血管疾病、神经疾病、糖尿病和各种癌症的致病因素。目的:利用GO数据库和KEGG数据库等生物信息学方法对GEO数据库数据中的差异表达基因进行评价。利用生物信息学分析软件对差异基因进行功能富集、功能注释分析和生存分析。利用Cytoscape上的蛋白-蛋白相互作用网络(Protein-protein interaction network, PPI)软件对179个差异基因进行筛选和分析。结果发现126个基因作用于蛋白靶点,其中有10个基因为关键基因分别为:PSMB3、HSP701、HSPE1、STIP1、HSPD1、HSP70、DNAJB1B、HSP90AA1.1、HSPA9H和TCP1。核心基因主要作用于内质网中的蛋白质加工通路。这可能会为砷对肝脏损伤的潜在生物标志物和生物学机制提供新的思路。     

Biological soil crusts in ecological restoration: emerging research and perspectives

Drylands encompass over 40% of terrestrial ecosystems and face significant anthropogenic degradation causing a loss of ecosystem integrity, services, and deterioration of social‐ecological systems. To combat this degradation, some dryland restoration efforts have focused on the use of biological soil crusts (biocrusts): complex communities of cyanobacteria, algae, lichens, bryophytes, and other organisms living in association with the top millimeters of soil. Biocrusts are common in many ecosystems and especially drylands. They perform a suite of ecosystem functions: stabilizing soil surfaces to prevent erosion, contributing carbon through photosynthesis, fixing nitrogen, and mediating the hydrological cycle in drylands. Biocrusts have emerged as a potential tool in restoration; developing methods to implement effective biocrust restoration has the potential to return many ecosystem functions and services. Although culture‐based approaches have allowed researchers to learn about the biology, physiology, and cultivation of biocrusts, transferring this knowledge to field implementation has been more challenging. A large amount of research has amassed to improve our understanding of biocrust restoration, leaving us at an opportune time to learn from one another and to join approaches for maximum efficacy. The articles in this special issue improve the state of our current knowledge in biocrust restoration, highlighting efforts to effectively restore biocrusts through a variety of different ecosystems, across scales and utilizing a variety of lab and field methods. This collective work provides a useful resource for the scientific community as well as land managers.     

Solid cultures of thrips-pathogenic fungi Isaria javanica strains for enhanced conidial productivity and thermotolerance

Entomopathogenic fungi have great potential to control agricultural and horticultural insect pests, however optimizing conidial production systems to demonstrate high productivity and stability still needs additional efforts for successful field application and industrialization. Although many virulent entomopathogenic fungal isolates have been viewed as potential candidates in a laboratory environment, very few of the isolates are being used in practice for application in agricultural fields as commercial products. I. javanicus is an entomopathogenic fungus that is parasitic to various diverse coleopteran and lepidopteran insects and thought good candidate as biopesticdes. In this work, the basic characteristics of two entomopathogenic fungi, I. javanica FG340 and Pf04, were investigated in morphological examinations, genetic identification, and virulence against Thrips palmi, and then the feasibility of various grains substrates for conidial production was assessed, particularly focusing on conidial productivity and thermotolerance. Isaria javanica FG340 and Pf04 conidia were solid-cultured on 12 grains for 14?days in a Petri dish. Of the tested Italian millet, perilla seed, millet and barley-based cultures showed high conidial production. The four-grain media yielded >1?×?10⁹ conidia/g of I. javanica FG340 and Pf04. Pf04 strain had enhanced thermotolerance up to 45?°C when cultured on Italian millet. In application, it was easy to make a conidial suspension using the cultured grains, and several surfactants were tested to release the conidia. This work suggests several possible inexpensive grain substrates by which to promote conidial production combined with enhanced stability against exposure to high temperature.     

Circadian variation of serum leptin in healthy and diabetic men

Leptin, from the Greek leptos, meaning thin (in reference to its ability to reduce body fat stores), is a hormone secreted primarily by adipocytes. At one time, leptin was portrayed as a potential means of combating obesity. Recently, leptin has been identified as a potent inhibitor of bone formation, acting through the central nervous system. Since numerous studies clearly show that bone remodeling is circadian rhythmic with peak activity during sleep, it is of interest to explore circadian variability in serum leptin. Accordingly, circadian characteristics of serum leptin were examined in 7 clinically healthy men and 4 obese men with type II diabetes. Blood samples were collected for 24 h at 3 h intervals beginning at 19:00. The dark (sleep) phase of the light-dark cycle extended from 22:30 to 06:30, with brief awakening for sampling at 01:00 and 04:00. Subjects consumed general hospital meals (2400 calories) at 16:30, 07:30, and 13:30. Serum leptin levels were determined by a R&D Systems enzyme immunoassay technique. Data were analyzed by linear least-squares estimation using the population multiple components method. A statistically significant (P < .018) circadian rhythm modeled by a single 24 h cosine curve characterized the data of each group. The 24 h mean leptin level was statistically greater (P < .001) in the obese diabetic men than in the healthy men (9.47 +/- 0.66 ng/mL vs. 24.07 +/- 1.71 ng/mL, respectively). Higher leptin levels occurred between midnight and roughly 02:30, and lowest leptin levels occurred between noon and the early afternoon. The phasing of this rhythm is similar to the circadian rhythm in bone remodeling previously described. Our results suggest the findings from a single morning blood sampling for leptin may be misleading since it may underestimate the mean 24 h and peak concentrations of the hormone.     

首次报道中国北方Fonsecaea monophora所致着色芽生菌病1例及其相关实验研究

目的首次报道中国北方1例由Fonsecaea monophora所致着色芽生菌病。方法患者男性,58岁,主因"右腕部皮损伴瘙痒8~9a"就诊。对皮损脓液直接镜检,皮损组织病理检查,真菌培养,并对培养获得菌株进行形态学,分子生物学鉴定等实验室研究。结果脓液直接镜检可见多个圆形、厚壁、棕色硬壳细胞,皮损组织病理表现为慢性肉芽肿样改变,并可见硬壳小体。真菌培养可见暗棕色,橄榄色至黑色菌落生长,生长速度较慢,镜下可见枝孢型和喙枝孢型产孢。ITS区序列分析鉴定为Fonsecaea monophora。依据临床及实验室检查确诊该例为Fonsecaea monophora所致的着色芽生菌病。口服伊曲康唑200mg,1次/d;特比萘芬250mg,1次/d。治疗3个月后,皮损消退痊愈。结论 Fonsecaea monophora感染也可见于我国北方地区的着色芽生菌病患者,而ITS区序列分析是该菌种鉴定的重要手段,伊曲康唑联合特比萘芬治疗本例患者显示较好疗效。     

Heparan sulfate proteoglycans regulate autophagy in Drosophila

Heparan sulfate-modified proteoglycans (HSPGs) are important regulators of signaling and molecular recognition at the cell surface and in the extracellular space. Disruption of HSPG core proteins, HS-synthesis, or HS-degradation can have profound effects on growth, patterning, and cell survival. The Drosophila neuromuscular junction provides a tractable model for understanding the activities of HSPGs at a synapse that displays developmental and activity-dependent plasticity. Muscle cell-specific knockdown of HS biosynthesis disrupted the organization of a specialized postsynaptic membrane, the subsynaptic reticulum (SSR), and affected the number and morphology of mitochondria. We provide evidence that these changes result from a dysregulation of macroautophagy (hereafter referred to as autophagy). Cellular and molecular markers of autophagy are all consistent with an increase in the levels of autophagy in the absence of normal HS-chain biosynthesis and modification. HS production is also required for normal levels of autophagy in the fat body, the central energy storage and nutritional sensing organ in Drosophila. Genetic mosaic analysis indicates that HS-dependent regulation of autophagy occurs non-cell autonomously, consistent with HSPGs influencing this cellular process via signaling in the extracellular space. These findings demonstrate that HS biosynthesis has important regulatory effects on autophagy and that autophagy is critical for normal assembly of postsynaptic membrane specializations.     

Biocidal activity in plant pathogenic Acidovorax, Burkholderia, Herbaspirillum, Ralstonia and Xanthomonas spp.

Antibacterial and antifungal activity was investigated for strains of Acidovorax spp., Burkholderia spp., Herbaspirillum rubrisubalbicans and Ralstonia solanacearum ; strains representing 118 species and pathovars of Xanthomonas were also tested for phytotoxic capacity. Antibacterial activity was present in all Burkholderia spp. except B. andropogonis , in biovars II and III of R. solanacearum but not in biovars I and IV, and in two strains of Xanthomonas. Little antibacterial activity was recorded for Acidovorax spp. Antifungal activity was expressed by most strains of A. avenae ssp. avenae and A. avenae ssp. cattleyae. Weak or variable antifungal reactions were given by strains of A. avenae ssp. citrulli and no activity was expressed by A. konjaci. Most strains of B. caryophylli, B. cepacia, B. gladioli pv. agaricicola, B. gladioli pv. alliicola, B. gladioli pv. gladioli , B. glumae and B. plantari produced extensive inhibition zones against Rhodotorula mucilaginosa. Strains of H. rubrisubalbicans and R. solanacearum gave negative, weak or variable reactions. Strains of Xanthomonas spp. exhibited no antifungal activity. In all cases antifungal activity was caused by a low molecular weight toxin. Three Xanthomonas strains exhibited phytotoxic activity. The ecological implications of these data are discussed.     

MCPIP1 ribonuclease antagonizes dicer and terminates microRNA biogenesis through precursor microRNA degradation

MicroRNAs (miRNAs) are versatile regulators of gene expression and undergo complex maturation processes. However, the mechanism(s) stabilizing or reducing these small RNAs remains poorly understood. Here we identify mammalian immune regulator MCPIP1 (Zc3h12a) ribonuclease as a broad suppressor of miRNA activity and biogenesis, which counteracts Dicer, a central ribonuclease in miRNA processing. MCPIP1 suppresses miRNA biosynthesis via cleavage of the terminal loops of precursor miRNAs (pre-miRNAs). MCPIP1 also carries a vertebrate-specific oligomerization domain important for pre-miRNA recognition, indicating its recent evolution. Furthermore, we observed potential antagonism between MCPIP1 and Dicer function in human cancer and found a regulatory role of MCPIP1 in the signaling axis comprising miR-155 and its target c-Maf. These results collectively suggest that the balance between processing and destroying ribonucleases modulates miRNA biogenesis and potentially affects pathological miRNA dysregulation. The presence of this abortive processing machinery and diversity of MCPIP1-related genes may imply a dynamic evolutional transition of the RNA silencing system.