温室白粉虱取食行为的刺探电位(EPG)研究

该文揭示了温室白粉虱Trialeurodes vaporariorum Westwood成虫及幼虫的刺探电位波形与其刺探、取食、产卵行为之间的对应关系,并讨论了这项技术在研究植物抗虫机理方面的应用价值。在成虫,A波、C波分别代表刺探的开始和进行过程;F波代表刺探过程中遇到机械障碍;G波表示吸食木质部导管汁液;E(pd)的(1)和(2)分别表示与取食韧皮部筛管汁液有关的两种行为;粉虱的产卵波形分为两种亚波,分别由Ovi-I和Ovi-II表示,各自代表产卵时的两种行为：产卵器接触并划破叶表皮及卵柄插入叶组织。在幼虫,H波代表吸食筛管液,而L波则表示在筛管细胞内的一种非吸食行为。幼虫蜕皮时先拔出口针,新龄期的幼虫将其口针重新刺入叶组织。     

Gene Expression of Neuropilin-1 and Its Receptors,VEGF/Semaphorin 3a,in Normal and Cancer Cells

Extracellular domains of the transmembrane glycoprotein, neuropilin-1 (Np1), specifically bind an array of factors and co-receptors including class-3 semaphorins (Sema3a), vascular endothelial growth factor (VEGF), hepatocyte growth factor, platelet-derived growth factor BB, transforming growth factor-β 1 (TGF-β1), and fibroblast growth factor2 (FGF2). Np1 may have a role in immune response, tumor cell growth, and angiogenesis, but its relative expression in comparison to its co-primary receptors, VEGF and Sema3a, is not known. In this study we determined the mRNA expression of Np1 and its co-receptors, VEGF and Sema3a, and the ratio of VEGF/Sema3a in different human and rodent cell lines. Expression of Np1, VEGF and Sema3a is very low in cells derived from normal tissues, but these proteins are highly expressed in tumor-derived cells. Furthermore, the ratio of VEGF/Sema3a is highly variable in different tumor cells. The elevated mRNA expression of Np1 and its putative receptors in tumor cells suggests a role for these proteins in tumor cell migration and angiogenesis. As different tumor cells exhibit varying VEGF/Sema3a ratios, it appears that cancer cells show differential response to angiogenic factors. These results bring to light the individual variation among the cancer-related genes, Np1, VEGF, and Sema3a, and provide an important impetus for the possible personalized therapeutic approaches for cancer patients.     

鞘内联合给予米诺环素和IL-6的中和抗体对脊神经结扎模型所引起的热痛敏的镇痛作用

目的:研究鞘内联合给予米诺环素和IL-6的中和抗体在大鼠脊神经结扎(spinal nerve ligation,SNL)模型所引起的神经病理性痛中的镇痛作用.方法:建立大鼠SNL模型,分别在手术前和手术后鞘内给予米诺环素100 μg、在手术后鞘内给予IL-6的中和抗体0.03 μg、手术后鞘内联合给予两种药物,观察给药3天各组大鼠热刺激的缩足反应潜伏期(paw withdrawal latencies,PWL).结果:①SNL手术前后给予米诺环素都可以提高大鼠的PWL(P＜0.05),但SNL手术前给药对大鼠PWL的提升明显高于手术后给药(P＜0.05).②手术后给予IL-6的中和抗体可以有效提升SNL组的PWL(P＜0.05),但是还是比给予生理盐水的假手术组大鼠的PWL明显减少(P＜0.05).③手术后联合给予两种药物可以明显逆转SNL组的PWL(P＜0.05).④联合给药对大鼠PWL的提高明显高于SNL手术后给予米诺环素组和给予IL-6的中和抗体组(P＜0.05),但与手术前给予米诺环素组的PWL相比无明显差异(P＞0.05).结论:鞘内联合给予米诺环素和IL-6的中和抗体对SNL引起的神经病理性痛有明显的镇痛作用.     

Structure-based design and structure-activity relationships of 1,2,3,4-tetrahydroisoquinoline derivatives as potential PDE4 inhibitors

This paper describes our medicinal chemistry efforts on 7-(cyclopentyloxy)-6-methoxy1,2,3,4-tetrahydroisoquinoline scaffold: design, synthesis and biological evaluation using conformational restriction approach and bioisosteric replacement strategy. Biological data revealed that the majority of the synthesized compounds of this series displayed moderate to potent inhibitory activity against PDE4B and strong inhibition of LPS-induced TNFα release. Among them, compound 19 exhibited the strongest inhibition against PDE4B with an IC₅₀ of 0.88?µM and 21 times more potent selectivity toward PDE4B over PDE4D when compared to rolipram. A primary structure-activity relationship study showed that the attachment of CH₃O group or CF₃O group to the phenyl ring at the para-position was helpful to enhance the inhibitory activity against PDE4B. Moreover, sulfonamide group played a key role in improving the inhibitory activity against PDE4B and subtype selectivity. In addition, the attachment of the additional rigid substituents at the C-3 position of 1,2,3,4-tetrahydroisoquinoline ring was favored to subtype selectivity, which was consistent well with the observed docking simulation.     

Antibody responses to SARS-CoV-2 in patients with COVID-19

This paper aimed to analyze antibody responses to SARS-CoV-2 in various populations. Two hundred and six COVID-19 patients, 46 convalescent patients, and 270 healthy population were enrolled. Antibodies against nucleocapsid protein (N) and spike protein's receptor-binding domain (RBD), and neutralizing antibody were detected. The results demonstrated both anti-N and anti-RBD antibodies could be detected in about 80% of COVID-19 patients and 90% of convalescent patients, while no antibodies could be detected in some convalescents and patients even after 14 days post-onset of symptoms. The level of anti-RBD antibody strongly correlated with the neutralizing activity of sera from these two cohorts. The titer of neutralizing antibody was lower in convalescents than that in active COVID-19 patients. In addition, the titer of neutralizing antibody was less than 1:80 in none of the severe COVID-19 patients, 18.8% in non-severe COVID-19 patients, and 32.6% in convalescents. The study suggests that the level of anti-RBD antibody is closely related to neutralization activity in COVID-19 patients and convalescents. Some SARS-CoV-2-infected cases trigger a weak antiviral immune response, and the level of neutralizing antibody may have a faster decay rate.     

Characterization of zebrafish mutants with defects in bone calcification during development

Using the fluorescent dyes calcein and alcian blue, we stained the F3 generation of chemically (ENU) mutagenized zebrafish embryos and larvae, and screened for mutants with defects in bone development. We identified a mutant line, bone calcification slow (bcs), which showed delayed axial vertebra calcification during development. Before 4–5 days post-fertilization (dpf), the bcs embryos did not display obvious abnormalities in bone development (i.e., normal number, size and shape of cartilage and vertebrae). At 5–6 dpf, when vertebrae calcification starts, bcs embryos began to show defects. At 7 dpf, for example, in most of the bcs embryos examined, calcein staining revealed no signals of vertebrae mineralization, whereas during the same developmental stages, 2–14 mineralized vertebrae were observed in wild-type animals. Decreases in the number of calcified vertebrae were also observed in bcs mutants when examined at 9 and 11 dpf, respectively. Interestingly, by 13 dpf the defects in bcs mutants were no longer evident. There were no significant differences in the number of calcified vertebrae between wild-type and mutant animals. We examined the expression of bone development marker genes (e.g., Sox9b, Bmp2b, and Cyp26b1, which play important roles in bone formation and calcification). In mutant fish, we observed slight increases in Sox9b expression, no alterations in Bmp2b expression, but significant increases in Cyp26b1 expression. Together, the data suggest that bcs delays axial skeletal calcification, but does not affect bone formation and maturation.     

Inhibition of MAPK by prolactin signaling through the short form of its receptor in the ovary and decidua: involvement of a novel phosphatase

Prolactin (PRL) is essential for normal reproduction and signals through two types of receptors, the short (PRL-RS) and long (PRL-RL) form. We have previously shown that transgenic mice expressing only PRL-RS (PRLR(-/-)RS) display abnormal follicular development and premature ovarian failure. Here, we report that MAPK, essential for normal follicular development, is critically inhibited by PRL in reproductive tissues of PRLR(-/-)RS mice. Consequently, the phosphorylation of MAPK downstream targets are also markedly inhibited by PRL without affecting immediate upstream kinases, suggesting involvement of MAPK specific phosphatase(s) in this inhibition. Similar results are obtained in a PRL-responsive ovary-derived cell line (GG-CL) that expresses only PRL-RS. However, we found the expression/activation of several known MAPK phosphatases not to be affected by PRL, suggesting a role of unidentified phosphatase(s). We detected a 27-kDa protein that binds to the intracellular domain of PRL-RS and identified it as dual specific phosphatase DUPD1. PRL does not induce expression of DUDP1 but represses its phosphorylation on Thr-155. We also show a physical association of this phosphatase with ERK1/2 and p38 MAPK. Using an in vitro phosphatase assay and overexpression studies, we established that DUPD1 is a MAPK phosphatase. Dual specific phosphatase inhibitors as well as siRNA to DUPD1, completely prevent PRL-mediated MAPK inhibition in ovarian cells. Our results strongly suggest that deactivation of MAPK by PRL/PRL-RS contributes to the severe ovarian defect in PRLR(-/-)RS mice and demonstrate the novel association of PRL-RS with DUPD1 and a role for this phosphatase in MAPK deactivation.     

LncRNA882 regulates leukemia inhibitory factor (LIF) by sponging miR-15b in the endometrial epithelium cells of dairy goat

Despite the fact that long noncoding RNAs (lncRNAs) play roles in almost all biological processes, little is known about their biological function in the endometrium during the formation of endometrial receptivity. In this study, a comprehensive analysis of lncRNAs in goat endometrial tissues on Day 5 (prereceptive endometrium, PE) and Day 15 (receptive endometrium, RE) of pregnancy was performed by using RNA-Seq. As a result, 668 differentially expressed lncRNAs (DELs) were found between the PE and RE. Further study showed that lncRNA882, regulated by estrogen (E2) and progestin (P4), could act as competing endogenous RNAs (ceRNAs) for miR-15b, which inhibited the expression of transforming growth factor-b-activated kinase 1 binding protein 3 (TAB3) and then indirectly regulated the level of leukemia inhibitory factor (LIF). This was helpful for the formation of endometrial receptivity in dairy goats. In conclusion, we elucidated the endometrium lncRNA profiles of PE and RE in dairy goats; lncRNA882 acted as a ceRNA for miR-15b and then indirectly regulated the level of LIF in goat endometrial epithelium cells. Thus, this study helped us to better understand the molecular regulation of endometrial receptivity in dairy goats.     

Effect of Methamphetamine on Spectral Binding,Ligand Docking and Metabolism of Anti-HIV Drugs with CYP3A4

Cytochrome P450 3A4 (CYP3A4) is the major drug metabolic enzyme, and is involved in the metabolism of antiretroviral drugs, especially protease inhibitors (PIs). This study was undertaken to examine the effect of methamphetamine on the binding and metabolism of PIs with CYP3A4. We showed that methamphetamine exhibits a type I spectral change upon binding to CYP3A4 with δA_max and K_D of 0.016±0.001 and 204±18 μM, respectively. Methamphetamine-CYP3A4 docking showed that methamphetamine binds to the heme of CYP3A4 in two modes, both leading to N-demethylation. We then studied the effect of methamphetamine binding on PIs with CYP3A4. Our results showed that methamphetamine alters spectral binding of nelfinavir but not the other type I PIs (lopinavir, atazanavir, tipranavir). The change in spectral binding for nelfinavir was observed at both δA_max (0.004±0.0003 vs. 0.0068±0.0001) and K_D (1.42±0.36 vs.2.93±0.08 μM) levels. We further tested effect of methamphetamine on binding of 2 type II PIs; ritonavir and indinavir. Our results showed that methamphetamine alters the ritonavir binding to CYP3A4 by decreasing both the δA_max (0.0038±0.0003 vs. 0.0055±0.0003) and K_D (0.043±0.0001 vs. 0.065±0.001 nM), while indinavir showed only reduced K_D in presence of methamphetamine (0.086±0.01 vs. 0.174±0.03 nM). Furthermore, LC-MS/MS studies in high CYP3A4 human liver microsomes showed a decrease in the formation of hydroxy ritonavir in the presence of methamphetamine. Finally, CYP3A4 docking with lopinavir and ritonavir in the absence and presence of methamphetamine showed that methamphetamine alters the docking of ritonavir, which is consistent with the results obtained from spectral binding and metabolism studies. Overall, our results demonstrated differential effects of methamphetamine on the binding and metabolism of PIs with CYP3A4. These findings have clinical implication in terms of drug dose adjustment of antiretroviral medication, especially with ritonavir-boosted antiretroviral therapy, in HIV-1-infected individuals who abuse methamphetamine.     

ITMSQ: A software tool for N‐ and C‐terminal fragment ion pairs based isobaric tandem mass spectrometry quantification

Tandem MS (MS2) quantification using the series of N‐ and C‐terminal fragment ion pairs generated from isobaric‐labelled peptides was recently considered an accurate strategy in quantitative proteomics. However, the presence of multiplexed terminal fragment ion in MS2 spectra may reduce the efficiency of peptide identification, resulting in lower identification scores or even incorrect assignments. To address this issue, we developed a quantitative software tool, denoted isobaric tandem MS quantification (ITMSQ), to improve N‐ and C‐terminal fragment ion pairs based isobaric MS2 quantification. A spectrum splitting module was designed to separate the MS2 spectra from different samples, increasing the accuracy of both identification and quantification. ITMSQ offers a convenient interface through which parameters can be changed along with the labelling method, and the result files and all of the intermediate files can be exported. We performed an analysis of in vivo terminal amino acid labelling labelled HeLa samples and found that the numbers of quantified proteins and peptides increased by 13.64 and 27.52% after spectrum splitting, respectively. In conclusion, ITMSQ provides an accurate and reliable quantitative solutionfor N‐ and C‐terminal fragment ion pairs based isobaric MS2 quantitative methods.