Predicting the potential global distribution of Ageratina adenophora under current and future climate change scenarios

AimInvasive alien species (IAS) threaten ecosystems and humans worldwide, and future climate change may accelerate the expansion of IAS. Predicting the suitable areas of IAS can prevent their further expansion. Ageratina adenophora is an invasive weed over 30 countries in tropical and subtropical regions. However, the potential suitable areas of A. adenophora remain unclear along with its response to climate change. This study explored and mapped the current and future potential suitable areas of Ageratina adenophora.LocationGlobal.TaxaAsteraceae A. adenophora (Spreng.) R.M.King & H.Rob. Commonly known as Crofton weed.MethodsBased on A. adenophora occurrence data and climate data, we predicted its suitable areas of this weed under current and future (four RCPs in 2050 and 2070) by MaxEnt model. We used ArcGIS 10.4 to explore the potential suitable area distribution characteristics of this weed and the “ecospat” package in R to analyze its altitudinal distribution changes.ResultsThe area under the curve (AUC) value (>0.9) and true skill statistics (TSS) value (>0.8) indicated excelled model performance. Among environment factors, mean temperature of coldest quarter contributed most to the model. Globally, the suitable areas for A. adenophora invasion decreased under climate change scenarios, although regional increases were observed, including in six biodiversity hotspot regions. The potential suitable areas of A. adenophora under climate change would expand in regions with higher elevation (3,000–3,500 m).Main conclusionsMean temperature of coldest quarter was the most important variable influencing the potential suitable area of A. Adenophora. Under the background of a warming climate, the potential suitable area of A. adenophora will shrink globally but increase in six biodiversity hotspot regions. The potential suitable area of A. adenophora would expand at higher elevation (3,000–3,500 m) under climate change. Mountain ecosystems are of special concern as they are rich in biodiversity and sensitive to climate change, and increasing human activities provide more opportunities for IAS invasion.     

Characterization and protection on acute liver injury of a polysaccharide MP-I from Mytilus coruscus

In this study, we analyzed a water-soluble polysaccharide MP-I isolated from Mytilus coruscus. MP-I was obtained by hot-water extraction, anion-exchange and gel-permeation chromatography. Complete hydrolysis, periodate oxidation, methylation analysis, as well as Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR) spectroscopy were conducted to elucidate its structure. MP-I was subjected to investigate the protective effect on carbon tetrachloride (CCl(4)) induced liver damage in male Kunming mice. Based on the data obtained, MP-I was found to be an alpha-(1-->4)-D-glucan, branched with a single alpha-D-glucose at the C-6 position every eight residue, on average, along the main chain. Based on the calibration with Dextran, the glucan had a molecular weight of about 1.35 x 10(6) Da. Pharmacological studies revealed that MP-I could decrease serum alanine aminotransferase (ALT), serum aspartate aminotransferase (AST), and hepatic malondialdehyde aldehydes (MDA) levels, increase the hepatic total superoxide dismutase (T-SOD) activity, and improve hepatic damage in the CCl(4) induced liver injury in mice in a dose-dependent manner. The results suggest that the possible mechanism is due to its antioxidant activity of MP-I.     

野生黄山短尾猴雄性睾酮的季节性变化

本文研究了黄山短尾猴野生群体雄性睾酮的变化规律.采用放射性免疫分析方法,对黄山短尾猴鱼鳞坑YA2群成年雄性个体在交配期(2005年10月至2006年1月;2006年7月至9月)与非交配期(2006年2月至6月)的粪便睾酮水平进行了测定,共采集到5只雄性个体的新鲜粪便样品426个.结果表明:在群体水平,黄山短尾猴成年雄性睾酮浓度交配季节(12.283±5.745 ng/ml)显著高于非交配季节(9.424±4.987 ng/ml),季节性变化显著(P<0.01);个体水平上,不同个体雄性睾酮均呈现显著的季节性变化(P<0.01);成年雄性睾酮分泌水平与生境温度变化呈显著正相关关系(P<0.05),且在交配季节初期雄性睾酮浓度最高,交配季节末期降到最低.研究结果支持短尾猴季节性繁殖的结论,且环境温度是影响短尾猴雄性睾酮浓度的可能因素.     

Inhibitors of Protein Tyrosine Phosphatase 1B from Marine Natural Products

The ocean is a capacious area with the most abundant biological resources on the earth. The particularity of the marine ecological environment (high pressure, high salt, and hypoxia) makes the marine species survival competition fiercely, forcing many marine organisms in the process of life to produce a great deal of secondary metabolites with special structures and biological activities. In this article, 118 natural products which were isolated from four kinds of marine organisms, sponges, algae, soft corals and fungus, showing PTP1B inhibitory activity were summarized from 2010 to 2016, which may become the leading compounds towards treating Diabetes mellitus (DM). What's more, we briefly summarized the structure–activity relationship of PTP1B inhibitors.     

Determination of scutellarin in rat plasma by high-performance liquid chromatography with ultraviolet detection

A validated high-performance liquid chromatography method is described for the determination of scutellarin in rat plasma using a liquid-liquid extraction and ultraviolet (UV) absorbance detection. The separation used a Diamonsil ODS column (250 mm x 4.6mm i.d., 5 microm particle size) with an isocratic mobile phase consisting of methanol-acetonitrile-50mM dihydrogen ammonium phosphate buffer (22:15:63 (v/v/v), adjusted to pH 2.5 with 1M phosphoric acid). The ultraviolet detector operated at 335 nm. Plasma samples were extracted with ethyl acetate after acidification. The extraction recovery of scutellarin ranged from 68.1 to 80.5%. High selectivity and a low quantitation limit (0.050 microg/ml) were achieved. The linear range was 0.050-12.5 microg/ml, correlation coefficient r=0.9981. The method has a good reproducibility, R.S.D. values were below 7.9% for within-day and between-day precision. The method is simple, rapid, and applicable to preliminary pharmacokinetic studies of scutellarin in rats.     

Cr(VI) increases tyrosine phosphorylation through reactive oxygen species-mediated reactions

While Cr (VI)containing compounds are well established carcinogens, the mechanisms of their action remain to be investigated. In this study we show that Cr (VI) causes increased tyrosine phosphorylation in human lung epithelial A549 cells in a timedependent manner. Nacetylcysteine (NAC), a general antioxidant, inhibited Cr (VI)induced tyrosine phosphorylation. Catalase, a scavenger of H₂O₂, sodium formate and aspirin, scavengers of hydroxyl radical (OH), also inhibited the increased tyrosine phosphorylation induced by Cr (VI). SOD, an inhibitor of superoxide radical (O₂ ^–), caused less inhibition. ESR study shows that incubation of Cr (VI) with the A549 cells generates OH radical. The generation of radical was decreased by addition of catalase and sodium formate, while SOD did not have any inhibitory effect. Oxygen consumption measurements show that addition of f Cr (VI) to A549 cells resulted in enhanced molecular oxygen consumption. These results indicate that Cr (VI) can induce an increase in tyrosine phosphorylation. H₂O₂ and OH radicals generated during the process are responsible for the increased tyrosine phosphorylation induced by Cr (VI).     

Exosomes from tendon stem cells promote injury tendon healing through balancing synthesis and degradation of the tendon extracellular matrix

Tendon injuries are common musculoskeletal system disorders in clinical, but the regeneration ability of tendon is limited. Tendon stem cells (TSCs) have shown promising effect on tissue engineering and been used for the treatment of tendon injury. Exosomes that serve as genetic information carriers have been implicated in many diseases and physiological processes, but effect of exosomes from TSCs on tendon injury repair is unclear. The aim of this study is to make clear that the effect of exosomes from TSCs on tendon injury healing. Exosomes were harvested from conditioned culture media of TSCs by a sequential centrifugation process. Rat Achilles tendon tendinopathy model was established by collagenase‐I injection. This was followed by intra‐Achilles‐tendon injection with TSCs or exosomes. Tendon healing and matrix degradation were evaluated by histology analysis and biomechanical test at the post‐injury 5 weeks. In vitro, TSCs treated with interleukin 1 beta were added by conditioned medium including exosomes or not, or by exosomes or not. Tendon matrix related markers and tenogenesis related markers were measured by immunostaining and western blot. We found that TSCs injection and exosomes injection significantly decreased matrix metalloproteinases (MMP)‐3 expression, increased expression of tissue inhibitor of metalloproteinase‐3 (TIMP‐3) and Col‐1a1, and increased biomechanical properties of the ultimate stress and maximum loading. In vitro, conditioned medium with exosomes and exosomes also significantly decreased MMP‐3, and increased expression of tenomodulin, Col‐1a1 and TIMP‐3. Exosomes from TSCs could be an ideal therapeutic strategy in tendon injury healing for its balancing tendon extracellular matrix and promoting the tenogenesis of TSCs.     

LncRNA FOXD2‐AS1 as a competitive endogenous RNA against miR‐150‐5p reverses resistance to sorafenib in hepatocellular carcinoma

The current study elucidated the role of a long non‐coding RNA (lncRNA), FOXD2‐AS1, in the pathogenesis of hepatocellular carcinoma (HCC) and the regulatory mechanism underlying FOXD2‐AS1/miR‐150‐5p/transmembrane protein 9 (TMEM9) signalling in HCC. Microarray analysis was used for preliminary screening of candidate lncRNAs in HCC tissues. qRT‐PCR and Western blot analyses were used to detect the expression of FOXD2‐AS1. Cell proliferation assays, luciferase assay and RNA immunoprecipitation were performed to examine the mechanism by which FOXD2‐AS1 mediates sorafenib resistance in HCC cells. FOXD2‐AS1 and TMEM9 were significantly decreased and miR‐150‐5p was increased in SR‐HepG2 and SR‐HUH7 cells compared with control parental cells. Overexpression of FOXD2‐AS1 increased TMEM9 expression and overcame the resistance of SR‐HepG2 and SR‐HUH7 cells. Conversely, knockdown of FOXD2‐AS1 decreased TMEM9 expression and increased the sensitivity of HepG2 and Huh7 cells to sorafenib. Our data also demonstrated that FOXD2‐AS1 functioned as a sponge for miR‐150‐5p to modulate TMEM9 expression. Taken together, our findings revealed that FOXD2‐AS1 is an important regulator of TMEM9 and contributed to sorafenib resistance. Thus, FOXD2‐AS1 may serve as a therapeutic target against sorafenib resistance in HCC.     

The arginine-facing amino acid residue of the rat aquaporin 1 constriction determines solute selectivity according to its size and lipophilicity

Aquaporins (AQP) are transmembrane channels for small, predominantly uncharged solutes. Their selectivity is partly determined by the aromatic/arginine constriction. Ammonia is similar in size and polarity to water, yet a subset of aquaporins distinguishes between the two. We mutated the constriction of water-selective rat AQP1 to mimic that of the ammonia-permeable human AQP8 by replacing Phenylalanine 56 with histidine, Histidine 180 with isoleucine, and Cysteine 189 with glycine, alone and in combination. Only AQP1 mutants including the H180I exchange increased the ammonia and methylamine tolerance of yeast. In a second set of mutations, we replaced Histidine 180 with alanine, leucine, methionine, phenylalanine, asparagine or glutamine. AQP1 H180A was equivalent to AQP1 H180I. AQP1 H180L increased ammonia but not methylamine tolerance of yeast. AQP1 mutants with methionine, phenylalanine, asparagine or glutamine in place of Histidine 180, increased neither ammonia nor methylamine tolerance of yeast. All mutants conducted water, as judged by osmotic assays with yeast sphaeroplasts. We propose that the arginine-facing amino acid residue is the most versatile selector of aquaporin constrictions, excluding Escherichia coli glycerol facilitator-type aquaporins.     

GLUT4在胰岛素调控葡萄糖转运中作用

机体的血糖平衡调节主要依赖于胰岛素,其中一个重要的机制是胰岛素通过调控GLUT4的囊泡运转来调节脂肪细胞和肌细胞对葡萄糖的摄取。由胰岛素受体介导的一系列磷酸化过程能调节一些关键的GLUT4转运相关蛋白质的活性,这些蛋白质包括小GTP酶、拴系复合体和囊泡融合体。而这些蛋白质又反过来通过内膜系统调节GLUT4储存囊泡的生成、滞留,并调控这些囊泡的靶向出胞方式。了解这些过程有助于解释2型糖尿病中胰岛素耐受的机制,并可能为糖尿病提供新的靶向治疗方法。