Characterization of a Potent,Selective, and Safe Inhibitor,Ac15(Az8)2, in Reversing Multidrug Resistance Mediated by Breast Cancer Resistance Protein (BCRP/ABCG2)

Overexpression of breast cancer resistance transporter (BCRP/ABCG2) in cancers has been explained for the failure of chemotherapy in clinic. Inhibition of the transport activity of BCRP during chemotherapy should reverse multidrug resistance. In this study, a triazole-bridged flavonoid dimer Ac15(Az8)₂ was identified as a potent, nontoxic, and selective BCRP inhibitor. Using BCRP-overexpressing cell lines, its EC₅₀ for reversing BCRP-mediated topotecan resistance was 3 nM in MCF7/MX100 and 72 nM in S1M180 in vitro. Mechanistic studies revealed that Ac15(Az8)₂ restored intracellular drug accumulation by inhibiting BCRP-ATPase activity and drug efflux. It did not down-regulate the cell surface BCRP level to enhance drug retention. It was not a transport substrate of BCRP and showed a non-competitive relationship with DOX in binding to BCRP. A pharmacokinetic study revealed that I.P. administration of 45 mg/kg of Ac15(Az8)₂ resulted in plasma concentration above its EC₅₀ (72 nM) for longer than 24 h. It increased the AUC of topotecan by 2-fold. In an in vivo model of BCRP-overexpressing S1M180 xenograft in Balb/c nude mice, it significantly reversed BCRP-mediated topotecan resistance and inhibited tumor growth by 40% with no serious body weight loss or death incidence. Moreover, it also increased the topotecan level in the S1M180 xenograft by 2-fold. Our results suggest that Ac15(Az8)₂ is a promising candidate for further investigation into combination therapy for treating BCRP-overexpressing cancers.     

Contemporary Issues in Protein Requirements and Consumption for Resistance Trained Athletes

In recent years an explosion of research papers concerning protein consumption has been published. The need to consolidate this information has become critical from both practical and future research standpoints. For this reason, the following paper presents an in depth analysis of contemporary issues in protein requirements and consumption for resistance trained athletes. Specifically, the paper covers: 1.) protein requirements for resistance trained athletes; 2.) the effect of the digestion rate of protein on muscular protein balance; 3.) the optimal timing of protein intake relative to exercise; 4.) the optimal pattern of protein ingestion, relative to how an individual should consume their protein throughout a 24 hour period, and what sources are utilized during this time frame; 5.) protein composition and its interaction with measures of protein balance and strength performance; 6.) the combination of protein and carbohydrates on plasma insulin levels and protein balance; 7.) the efficacy of protein supplements and whole food protein sources. Our goal is to provide the reader with practical information in optimizing protein intake as well as for provision of sound advice to their clients. Finally, special care was taken to provide future research implications.     

ZmGLP1, a Germin-like Protein from Maize,Plays an Important Role in the Regulation of Pathogen Resistance

A gene encoding a protein similar to germin-like proteins (GLPs) was obtained from maize (Zea mays) and designated as ZmGLP1. Based on the ZmGLP1 conserved domain and phylogenetic status, ZmGLP1 was grouped into GLP subfamily b and has high similarity to OsGLP8-14 from Oryza sativa. ZmGLP1 is expressed in different maize tissues during different growth stages and is mainly expressed in the stems and leaves. The induced expression patterns confirmed that ZmGLP1 is differentially expressed under abiotic and hormone stress; it had an early response to jasmonic acid (JA) and ethephon (ET) but a late response to salicylic acid (SA) and was significantly upregulated under Bipolaris maydis infection. The overexpression of ZmGLP1 in Arabidopsis improved the resistance to biotrophic Pseudomonas syringae pv. tomato DC3000 (PstDC3000) and necrotrophic Sclerotinia sclerotiorum by inducing the expression of JA signaling-related genes. Moreover, the hydrogen peroxide (H₂O₂) content increased due to the overexpression of ZmGLP1 in Arabidopsis after pathogen infection. Compared to the wild-type control, the H₂O₂ content of ZmGLP1-overexpressing Arabidopsis infected by PstDC3000 increased significantly but was lower in transgenic plants infected with S. sclerotiorum. Furthermore, high-performance liquid chromatography–tandem mass (HPLC-MS/MS) spectrometry showed that the JA contents of ZmGLP1-overexpressing Arabidopsis markedly increased after pathogen infection. However, the improved resistance of ZmGLP1-overexpressing Arabidopsis pretreated with the JA biosynthetic inhibitor, sodium diethyldithiocarbamate trihydrate (DIECA), was suppressed. Based on these findings, we speculate that ZmGLP1 plays an important role in the regulation of Arabidopsis resistance to biotrophic PstDC3000 and necrotrophic S. sclerotiorum; the regulatory effects are achieved by inducing plant oxidative burst activity and activation of the JA signaling pathway.     

GsRSS3L,a Candidate Gene Underlying Soybean Resistance to Seedcoat Mottling Derived from Wild Soybean (Glycine soja Sieb. and Zucc)

Soybeans are a major crop that produce the best vegetable oil and protein for use in food and beverage products worldwide. However, one of the most well-known viral infections affecting soybeans is the Soybean Mosaic Virus (SMV), a member of the Potyviridae family. A crucial method for preventing SMV damage is the breeding of resistant soybean cultivars. Adult resistance and resistance of seedcoat mottling are two types of resistance to SMV. Most studies have focused on adult-plant resistance but not on the resistance to seedcoat mottling. In this study, chromosome segment-substituted lines derived from a cross between Suinong14 (cultivated soybean) and ZYD00006 (wild soybean) were used to identify the chromosome region and candidate genes underlying soybean resistance to seed coat mottling. Herein, two quantitative trait loci (QTLs) were found on chromosome 17, and eighteen genes were found in the QTL region. RNA-seq was used to evaluate the differentially expressed genes (DEGs) among the eighteen genes located in the QTLs. According to the obtained data, variations were observed in the expression of five genes following SMV infection. Furthermore, Nicotiana benthamiana was subjected to an Agrobacterium-mediated transient expression assay to investigate the role of the five candidate genes in SMV resistance. It has also been revealed that Glyma.17g238900 encoding a RICE SALT SENSITIVE 3-like protein (RSS3L) can inhibit the multiplication of SMV in N. benthamiana. Moreover, two nonsynonymous single-nucleotide polymorphisms (SNPs) were found in the coding sequence of Glyma.17g238900 derived from the wild soybean ZYD00006 (GsRSS3L), and the two amino acid mutants may be associated with SMV resistance. Hence, it has been suggested that GsRSS3L confers seedcoat mottling resistance, shedding light on the mechanism of soybean resistance to SMV.     

A Sprouty4 Mutation Identified in Kallmann Syndrome Increases the Inhibitory Potency of the Protein towards FGF and Connected Processes

Kallmann syndrome is the result of innate genetic defects in the fibroblast growth factor (FGF) regulated signaling network causing diminished signal transduction. One of the rare mutations associated with the syndrome alters the Sprouty (Spry)4 protein by converting the serine at position 241 into a tyrosine. In this study, we characterize the tyrosine Spry4 mutant protein in the primary human embryonic lung fibroblasts WI-38 and osteosarcoma-derived cell line U2OS. As demonstrated in a cell signaling assay, Spry4 gains the capability of inhibiting FGF, but not epithelial growth factor (EGF)-induced signaling as a consequence of the tyrosine substitution. Additionally, migration of normal embryonic lung fibroblasts and osteosarcoma-derived cells is potently inhibited by the tyrosine Spry4 variant, while an effect of the wildtype Spry4 protein is hardly measureable. Concerning cell proliferation, the unaltered Spry4 protein is ineffective to influence the WI-38 cells, while the mutated Spry4 protein decelerates the cell doubling. In summary, these data emphasize that like the other mutations associated with Kallmann syndrome the described Spry4 mutation creates a hyperactive version of a selective inhibitory molecule and can thereby contribute to a weakened FGF signaling. Additionally, the study pinpoints a Spry4 variation expanding the applicability of Spry4 in a potential cancer therapy.     

寡聚糖与多糖混合诱导蔬菜抗病性的研究

喷施人工合成的植物诱抗剂葡聚六糖与人工发酵的真菌多糖和果胶多糖的混合物,可诱导黄瓜、番茄抗病性的增加,且混合糖的防效要好于各单剂处理。葡聚六糖与多糖混合诱导间隔期为5d时的防效最好,防效达74.6%,7d时无增效作用。     

4,9-二[N-(2-二甲氨基)乙基]-9-吖啶胺-4-甲酰胺与蛋白质相互作用

应用水溶性4,9一二[N-(2一二甲氨基)乙基]-9-吖啶胺-4-甲酞胺(DNAF)探针,研究了DNAF与牛血清白蛋白(BSA)的相互结合作用机理.计算出相应的热力学参数△H,△G以及△S;通过荧光猝灭方法研究结合作用,测定出结合位点数n和表观结合常数KA;根据荧光共振能童转移理论求得供体BSA和受体DNAF的距离r;...     

Enhancing Animal Disease Resistance,Production Efficiency,and Welfare through Precise Genome Editing

The major goal of animal breeding is the genetic enhancement of economic traits. The CRISPR/Cas system, which includes nuclease-mediated and base editor mediated genome editing tools, provides an unprecedented approach to modify the mammalian genome. Thus, farm animal genetic engineering and genetic manipulation have been fundamentally revolutionized. Agricultural animals with traits of interest can be obtained in just one generation (and without long time selection). Here, we reviewed the advancements of the CRISPR (Clustered regularly interspaced short palindromic repeats)/Cas (CRISPR associated proteins) genome editing tools and their applications in animal breeding, especially in improving disease resistance, production performance, and animal welfare. Additionally, we covered the regulations on genome-edited animals (GEAs) and ways to accelerate their use. Recommendations for how to produce GEAs were also discussed. Despite the current challenges, we believe that genome editing breeding and GEAs will be available in the near future.     

CH_4-CO_2重整转化反应器热平衡和流体阻力特性的研究

基于炭催化剂特性、原料气组成和重整转化反应器的尺寸参数,建立了重整反应器体系的物料平衡和热平衡方程;并针对形状不规则炭催化剂粒度分布的特点,研究了重整转化反应器内流体阻力特性。研究结果表明:1)CO和H2O的生成热量是系统的主要放热源,占系统热量收入的71.03%,吸热的主要反应为CH4和CO2的转化反应,其吸热量占系统热量支出的33.54%,高温气体带走的大量热量占54.11%,散热量占13.51%;2)炭催化剂床层的流体阻力是重整转化反应器流体阻力的主要部分,炭催化剂粒度越大,炭催化剂床层的阻力越小,最适宜粒度组成是25～35mm的占80%,15～25 mm的占15%,5～15 mm的占5%,此时炭催化剂床层的流体阻力为313.5Pa/m。     

Escherichia coli Maltose-Binding Protein Induces M1 Polarity of RAW264.7 Macrophage Cells via a TLR2- and TLR4-Dependent Manner

Maltose-binding protein (MBP) is a critical player of the maltose/maltodextrin transport system in Escherichia coli. Our previous studies have revealed that MBP nonspecifically induces T helper type 1 (Th1) cell activation and activates peritoneal macrophages obtained from mouse. In the present study, we reported a direct stimulatory effect of MBP on RAW264.7 cells, a murine macrophage cell line. When stimulated with MBP, the production of nitric oxide (NO), IL-1β, IL-6 and IL-12p70, and the expressions of CD80, MHC class II and inducible nitric oxide synthase (iNOS) were all increased in RAW264.7 cells, indicating the activation and polarization of RAW264.7 cells into M1 macrophages induced by MBP. Further study showed that MBP stimulation upregulated the expression of TLR2 and TLR4 on RAW264.7 cells, which was accompanied by subsequent phosphorylation of IκB-α and p38 MAPK. Pretreatment with anti-TLR2 or anti-TLR4 antibodies largely inhibited the phosphorylation of IκB-α and p38 MAPK, and greatly reduced MBP-induced NO and IL-12p70 production, suggesting that the MBP-induced macrophage activation and polarization were mediated by TLR2 and TLR4 signaling pathways. The observed results were independent of lipopolysaccharide contamination. Our study provides a new insight into a mechanism by which MBP enhances immune responses and warrants the potential application of MBP as an immune adjuvant in immune therapies.     

Fatty-Acid-Binding Protein 4 as a Novel Contributor to Mononuclear Cell Activation and Endothelial Cell Dysfunction in Atherosclerosis

Background—Elevated circulating fatty-acid-binding protein 4 (FABP4) levels may be linked with cardiovascular events. This study aimed to investigate the mechanistic role of FABP4 in atherosclerosis. Methods—We recruited 22 patients with angiographically proven coronary artery disease (CAD) and 40 control subjects. Mononuclear cells (MNCs) and human coronary endothelial cells (HCAECs) were used for in vitro study. Results—Patients with CAD were predominantly male with an enhanced prevalence of hypertension, diabetes, and smoking history. FABP4 concentrations were up-regulated in culture supernatants of MNCs from CAD patients, which were positively correlated with the patients’ age, waist–hip ratio, body mass index, serum creatinine, type 2 diabetes, and the presence of hypertension. The adhesiveness of HCAECs to monocytic cells can be activated by FABP4, which was reversed by an FABP4 antibody. FABP4 blockade attenuated the oxidized low-density lipoprotein (oxLDL)-induced expression of ICAM-1, VCAM-1, and P-selectin. FABP4 impaired the tube formation and migration via the ERK/JNK/STAT-1 signaling pathway. FABP4 suppressed phosphorylation of eNOS and expression of SDF-1 protein, both of which can be reversed by treatment with VEGF. Blockade of FABP4 also improved the oxLDL-impaired cell function. Conclusion—We discovered a novel pathogenic role of FABP4 in MNC activation and endothelial dysfunction in atherosclerosis. FABP4 may be a therapeutic target for modulating atherosclerosis.     

Overexpression of Rice BSR2 Confers Disease Resistance and Induces Enlarged Flowers in Torenia fournieri Lind

Plant pathogens evade basal defense systems and attack different organs and tissues of plants. Genetic engineering of plants with genes that confer resistance against pathogens is very effective in pathogen control. Conventional breeding for disease resistance in ornamental crops is difficult and lagging relative to that in non-ornamental crops due to an inadequate number of disease-resistant genes. Therefore, genetic engineering of these plants with defense-conferring genes is a practical approach. We used rice BSR2 encoding CYP78A15 for developing transgenic Torenia fournieri Lind. lines. The overexpression of BSR2 conferred resistance against two devastating fungal pathogens, Rhizoctonia solani and Botrytis cinerea. In addition, BSR2 overexpression resulted in enlarged flowers with enlarged floral organs. Histological observation of the petal cells suggested that the enlargement in the floral organs could be due to the elongation and expansion of the cells. Therefore, the overexpression of BSR2 confers broad-spectrum disease resistance and induces the production of enlarged flowers simultaneously. Therefore, this could be an effective strategy for developing ornamental crops that are disease-resistant and economically more valuable.     

柯萨奇B4病毒非结构蛋白P_2C基因的克隆与表达

目的克隆并表达柯萨奇B4病毒(CVB4)非结构蛋白P2C基因。方法提取CVB4总RNA,RT-PCR扩增P2C基因,克隆入pUCm-T载体中,进行酶切和测序鉴定。双酶切重组质粒pUCm-T-P2C,将P2C基因片段定向亚克隆至原核表达载体pMAL-C2中,转化大肠杆菌JM109,IPTG诱导表达,SDS-PAGE和Western blot鉴定表达产物。结果RT-PCR扩增得到987bp的基因片段,测序结果与GenBank公布的P2C基因序列一致。pMAL-C2-P2C经双酶切鉴定,证明构建正确。表达的融合蛋白相对分子质量约78000,表达量约占菌体总蛋白的25%,且具有良好的反应原性。结论已成功克隆并表达了CVB4P2C基因,为进一步研究其生物学活性奠定了基础。     

Ligand-Dependent and Ligand-Independent Effects of Ephrin-B2–EphB4 Signaling in Melanoma Metastatic Spine Disease

Tumor–endothelial cell interactions represent an essential mechanism in spinal metastasis. Ephrin-B2–EphB4 communication induces tumor cell repulsion from the endothelium in metastatic melanoma, reducing spinal bone metastasis formation. To shed further light on the Ephrin-B2–EphB4 signaling mechanism, we researched the effects of pharmacological EphB4 receptor stimulation and inhibition in a ligand-dependent/independent context. We chose a preventative and a post-diagnostic therapeutic window. EphB4 stimulation during tumor cell seeding led to an increase in spinal metastatic loci and number of disseminated melanoma cells, as well as earlier locomotion deficits in the presence of endothelial Ephrin-B2. In the absence of endothelial Ephrin-B2, reduction of metastatic loci with a later manifestation of locomotion deficits occurred. Thus, EphB4 receptor stimulation affects metastatic dissemination depending on the presence/absence of endothelial Ephrin-B2. After the manifestation of solid metastasis, EphB4 kinase inhibition resulted in significantly earlier manifestation of locomotion deficits in the presence of the ligand. No post-diagnostic treatment effect was found in the absence of endothelial Ephrin-B2. For solid metastasis treatment, EphB4 kinase inhibition induced prometastatic effects in the presence of endothelial Ephrin-B2. In the absence of endothelial Ephrin-B2, both therapies showed no effect on the growth of solid metastasis.     

Reactions of 2-(4-morpholinothio)- and 2-(4-morpholinodithio)benzothiazole in the presence of polyisoprene

2-(4-Morpholinothio)benzothiazole (MOR) and 2-(4-morpholinodithio)-benzothiazole (MDB) were reacted, in combination with sulfur and ZnO, in the presence of polyisoprene (IR). Samples were heated in a DSC at 2.5°C/min and characterized by swelling experiments. The products formed at various temperatures were analyzed by HPLC. Crosslinking only occurred once all the benzothiazole sulfenamide had been consumed, the onset of vulcanization characterized by a considerable increase in 2-mercaptobenzothiazole (MBT) concentration. Crosslinking occurred earlier in all corresponding MDB formulations. Higher crosslink densities were recorded with addition of ZnO. The delayed action experienced in MOR systems was attributed to an exchange reaction between benzothiazole-terminated pendent groups and MOR and not due to the stability of the disulfide, MDB. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 1093–1099, 1997     

Disease Resistance and Molecular Variations in Irradiation Induced Mutants of Two Pea Cultivars

Induced mutation is useful for improving the disease resistance of various crops. Fusarium wilt and powdery mildew are two important diseases which severely influence pea production worldwide. In this study, we first evaluated Fusarium wilt and powdery mildew resistance of mutants derived from two elite vegetable pea cultivars, Shijiadacaiwan 1 (SJ1) and Chengwan 8 (CW8), respectively. Nine SJ1 and five CW8 M₃ mutants showed resistant variations in Fusarium wilt, and the same five CW8 mutants in powdery mildew. These resistant variations were confirmed in M₄ and M₅ mutants as well. Then, we investigated the genetic variations and relationships of mutant lines using simple sequence repeat (SSR) markers. Among the nine effective SSR markers, the genetic diversity index and polymorphism information content (PIC) values were averaged at 0.55 and 0.46, which revealed considerable genetic variations in the mutants. The phylogenetic tree and population structure analyses divided the M₃ mutants into two major groups at 0.62 genetic similarity (K = 2), which clearly separated the mutants of the two cultivars and indicated that a great genetic difference existed between the two mutant populations. Further, the two genetic groups were divided into five subgroups at 0.86 genetic similarity (K = 5) and each subgroup associated with resistant phenotypes of the mutants. Finally, the homologous PsMLO1 cDNA of five CW8 mutants that gained resistance to powdery mildew was amplified and cloned. A 129 bp fragment deletion was found in the PsMLO1 gene, which was in accord with er1-2. The findings provide important information on disease resistant and molecular variations of pea mutants, which is useful for pea production, new cultivar breeding, and the identification of resistance genes.     

3-N-乙酰基-2-芳基-5-(4-硝基苯基)-1,3,4-噁唑啉类化合物的合成与结构表征

首先以 4 硝基苯甲酸为原料,在w(H2SO4 ) =98%作用下,与无水乙醇反应制得 4 硝基苯甲酸乙酯 (Ⅰ ),收率 81 1%。再以无水乙醇为溶剂,于 105~110℃,与w(水合肼) =80%反应 8h,制得 4 硝基苯甲酰肼 (Ⅱ ),收率 78 3%。然后Ⅱ在乙醇作用下,回流温度 85~90℃分别与苯甲醛、2 氯苯甲醛、4 氯苯甲醛、2, 4 二氯苯甲醛、3 溴苯甲醛、4 甲氧基苯甲醛和苯乙酮反应,得到相应的酰腙 (Ⅲa~g),收率分别为 93 2%、91 8%、90 1%、91 4%、88 1%、85 7%和 82 8%。最后,Ⅲa~g分别与乙酸酐作用脱水环化成 3 N 乙酰基 2 芳基 5 (4 硝基苯基) 1, 3, 4 口恶唑啉类化合物 (Ⅳa~g),收率分别为 83 1%、85 6%、82 5%、79 5%、76 2%、73 1%和 70 8%。通过元素分析,IR,1HNMR和MS对化合物Ⅳa~e的结构进行了表征。