Proximity association in polygynous western black crested gibbons (Nomascus concolor jingdongensis): network structure and seasonality

We investigated the structure and seasonality of the proximity network in a group of polygynous western black crested gibbons (Nomascus concolor) using social network analysis. The spatial proximity changed seasonally and was affected by temperature and rainfall. Preferred proximity association was not distributed randomly among individuals. Kinship was one explanation for the social structure, as offspring preferred to maintain close proximity with their mothers. The proximity of infants to mothers decreased with age, and independent offspring had lower proximity to mothers than dependent ones. We found that the adult male had different proximity relationships with two different adult females. The frequency of proximity between the male and the infant-carrying female was significantly higher than that between the male and the female who had immigrated carrying one offspring of uncertain paternity into the group. Infanticide avoidance and/or predation protection for dependent infants might explain the proximity relationship differences. Temperature influenced group proximity association, with individual proximity increasing in the cold months and decreasing in the hot months. Group proximity decreased in months with higher anthropogenic disturbance.     

Rotenone-induced oxidative stress and apoptosis in human liver HepG2 cells

Rotenone, a commonly used pesticide, is well documented to induce selective degeneration in dopaminergic neurons and motor dysfunction. Such rotenone-induced neurodegenration has been primarily suggested through mitochondria-mediated apoptosis and reactive oxygen species (ROS) generation. But the status of rotenone induced changes in liver, the major metabolic site is poorly investigated. Thus, the present investigation was aimed to study the oxidative stress-induced cytotoxicity and apoptotic cell death in human liver cells-HepG2 receiving experimental exposure of rotenone (12.5–250 μM) for 24 h. Rotenone depicted a dose-dependent cytotoxic response in HepG2 cells. These cytotoxic responses were in concurrence with the markers associated with oxidative stress such as an increase in ROS generation and lipid peroxidation as well as a decrease in the glutathione, catalase, and superoxide dismutase levels. The decrease in mitochondrial membrane potential also confirms the impaired mitochondrial activity. The events of cytotoxicity and oxidative stress were found to be associated with up-regulation in the expressions (mRNA and protein) of pro-apoptotic markers viz., p53, Bax, and caspase-3, and down-regulation of anti-apoptotic marker Bcl-2. The data obtain in this study indicate that rotenone-induced cytotoxicity in HepG2 cells via ROS-induced oxidative stress and mitochondria-mediated apoptosis involving p53, Bax/Bcl-2, and caspase-3.     

Leprosy Reactions Show Increased Th17 Cell Activity and Reduced FOXP3+ Tregs with Concomitant Decrease in TGF-β and Increase in IL-6

Background

50% of leprosy patients suffer from episodes of Type 1/ reversal reactions (RR) and Type 2/ Erythema Nodosum Leprosum (ENL) reactions which lead to morbidity and nerve damage. CD4⁺ subsets of Th17 cells and CD25⁺FOXP3⁺ regulatory T cells (Tregs) have been shown to play a major role in disease associated immunopathology and in stable leprosy as reported by us and others. The aim of our study was to analyze their role in leprosy reactions.

Methodology and Principle Findings

Quantitative reverse transcribed PCR (qPCR), flowcytometry and ELISA were used to respectively investigate gene expression, cell phenotypes and supernatant levels of cytokines in antigen stimulated PBMC cultures in patients with stable disease and those undergoing leprosy reactions. Both types of reactions are associated with significant increase of Th17 cells and associated cytokines IL-17A, IL-17F, IL-21, IL-23 and chemokines CCL20, CCL22 as compared to matching stable forms of leprosy. Concurrently patients in reactions show reduction in FOXP3⁺ Treg cells as well as reduction in TGF-β and increase in IL-6. Moreover, expression of many T cell markers, cytokines, chemokines and signaling factors were observed to be increased in RR as compared to ENL reaction patients.

Conclusions

Patients with leprosy reactions show an imbalance in Th17 and Treg populations. The reduction in Treg suppressor activity is associated withhigherTh17cell activity. The combined effect of reduced TGF-β and enhanced IL-6, IL-21 cytokines influence the balance between Th17 or Treg cells in leprosy reactions as reported in the murine models and autoimmune diseases. The increase in Th17 cell associated cytokines may contribute to lesional inflammation.     

Ultrasonic synthesis of tyramine derivatives as novel inhibitors of α-glucosidase in vitro

Tyramine derivatives 3–27 were synthesized by using conventional and environmental friendly ultrasonic techniques. These derivatives were then evaluated for the first time for their α-glucosidase (Sources: Saccharomyces cerevisiae and mammalian rat-intestinal acetone powder) inhibitory activity by using in vitro mechanism-based biochemical assays. Compounds 7, 14, 20, 21 and 26 were found to be more active (IC₅₀?=?49.7?±?0.4, 318.8?±?3.7, 23.5?±?0.9, 302.0?±?7.3 and 230.7?±?4.0?μM, respectively) than the standard drug, acarbose (IC₅₀?=?840.0?±?1.73?μM (observed) and 780?±?0.028?μM (reported)) against α-glucosidase obtained from Saccharomyces cerevisiae. Kinetic studies were carried out on the most active members of the series in order to determine their mode of inhibition and dissociation constants. Compounds 7, 20 and 26 were found to be the competitive inhibitors of α-glucosidase. These compounds were also screened for their protein antiglycation, and dipeptidyl peptidase-IV (DPP-IV) inhibitory activities. Only compounds 20, 22 and 27 showed weak antiglycation activity with IC₅₀ values 505.27?±?5.95, 581.87?±?5.50 and 440.58?±?2.74?μM, respectively. All the compounds were found to be inactive against DDP-IV enzyme. Inhibition of α-glucosidase, DPP-IV enzymes and glycation of proteins are valid targets for the discovery of antidiabetic drugs. Cytotoxicity of compounds 3–27 was also evaluated by using mouse fibroblast 3T3 cell lines. All the compounds were found to be noncytotoxic. The current study describes the synthesis α-glucosidase inhibitory activity of derivatives, based on a natural product tyramine template. The compounds reported here may serve as the starting point for the design and development of novel α-glucosidase inhibitors as antidiabetic agents.     

大胡蜂蜂毒中多肽和蛋白质结构和功能的多样性

为证明大胡蜂Vespa magnifica(Smith)蜂毒具有较大的药用开发价值,本研究采用超高效液相色谱-质谱和电泳技术对其多肽和蛋白质的分布进行分析,发现其蛋白质的相对分子质量主要分布在17~45kDa范围内。蜂毒多肽类物质的相对分子质量呈"单峰"式分布,61%在500~3000Da范围内,为大胡蜂蜂毒中多肽含量最为丰富的部分。通过牛津杯法对蜂毒的抑菌活性进行研究,且以HepG2人肝癌细胞及B16黑色素瘤细胞为研究对象,用MTT法检测蜂毒的细胞毒性活性,证明其具有良好的抑菌作用和细胞毒活性,其结果与已报道的其他蜂类既有相似性又存在具体差异,展示了大胡蜂蜂毒的分子多样性,为后续该毒素的物质基础研究及药用价值开发提供参考。     

模拟氮沉降对北京东灵山辽东栎林树木生长的影响

传统的元素限制模型认为氮是温带森林生长的限制元素, 不过该结论更多是从地上生物量以及群落水平进行阐述, 忽视了不同物种以及不同径级树木对外源氮的响应差异。辽东栎(Quercus wutaishanica)林是华北地区常见的森林类型, 该研究以北京东灵山辽东栎林为研究对象, 通过设置3个氮添加水平的实验, 即对照CK (0 kg·hm ^-2·a ^-1), N50 (50 kg·hm ^-2·a ^-1)和N100 (100 kg·hm ^-2·a ^-1), 模拟氮沉降对群落和物种水平以及不同径级树木生长的影响。经过7年氮添加, 实验结果显示: 物种水平上, 氮添加明显促进了优势树种辽东栎的生长; 群落水平上, 树木生长随氮浓度增加有不断上升趋势, 但统计学差异不显著; 氮添加显著抑制了辽东栎以及群落内小径级(3-10 cm)树木生长, 中(10-20 cm)、大径级(>20 cm)树木生长随氮沉降水平增加呈上升趋势, 但统计学差异不显著。表明氮是辽东栎以及温带森林树木生长的限制元素; 不同径级的辽东栎和群落内其他植物对氮添加响应不一致, 氮添加抑制了小径级树木生长, 中、大径级树木生长对氮添加响应不明显。     

小鼠休眠胚胎与正常胚胎冻融后体内外发育潜力的比较

目的检验小鼠休眠胚胎冻融后的质量及体内外发育潜力,为胚胎休眠技术的生产应用提供必要的参考。方法采用常规冷冻方法将正常孵化期胚胎和休眠胚胎进行冷冻,之后分别进行体外复苏培养实验和胚胎移植实验。随后利用双重荧光染色的方法分别对冻融前后的小鼠休眠胚胎与正常孵化期胚胎进行细胞计数,观察两种胚胎冻融前后的质量变化。结果休眠胚胎的冷冻解冻回收率、发育率均极显著高于孵化期胚胎(72.1%vs 50.2%,P<0.01;94.2%vs 73.9%,P<0.01)。休眠胚胎的移植妊娠率显著高于孵化期胚胎(40.8%vs 30.1%,P<0.05)。休眠胚胎的内细胞团细胞数显著高于孵化期胚胎(27.83 vs 19.53,P<0.05),滋养层细胞数差异不显著。冻融培养后休眠胚胎的内细胞团数,滋养层细胞数均显著高于孵化期胚胎(25.18 vs 14.68,P<0.05;114.09 vs 73.88,P<0.05)。结论小鼠休眠胚胎冻融后胚胎质量及体内外发育潜力均优于小鼠正常孵化期胚胎。     

硫化氢与自噬:一把双刃剑

硫化氢(hydrogen sulfide, H_2S)被认为是第三种气体信号分子,在许多生理及病理生理情况下发挥重要的调节作用。然而,在硫化氢对自噬的作用这一方面仍有一些争论。许多信号通路参与硫化氢的促自噬作用,例如AMPK/mTOR、LKB1/STRAD/MO25以及MiR-30c信号通路。同时,也有许多信号通路在硫化氢的抗自噬作用中发挥重要作用,例如SR-A、PI3K/SGK1/GSK3β、PI3K/AKT/mTOR、Nrf2-ROS-AMPK、AMPK/mTOR以及JNK1信号通路。在治疗人类疾病时,可以设计研发新型硫化氢相关药物,通过调节自噬增加疗效。本文主要讨论硫化氢在其介导的自噬信号通路中的作用。     

基于地理探测器的宁夏贺兰山植被覆盖度时空分异及驱动因子

监测区域植被覆盖变化并分析其驱动因子,有利于实现生态环境的可持续发展。本研究以1989—2021年Landsat 5/8遥感影像为数据源,利用像元二分模型获取宁夏贺兰山植被覆盖度,基于地理探测器量化了环境和人为等10个因子对其时空分布的影响。结果表明: 1989—2021年间,宁夏贺兰山平均植被覆盖度为35.8%,时间尺度上总体呈增加趋势,平均增幅为0.043·(10 a)^-1,空间尺度上呈现从西南向东北递减的分布特征;研究区58.1%的区域植被覆盖度未来将持续性改善,但仍有30.7%的植被存在退化的潜在风险。降水是影响植被分布的主要环境因子,与单因子相比,环境因子和人为因子的交互作用对植被覆盖度的解释力更强,降水与其他因子的交互作用处于主导作用。