Inhibition of Nrf2 promotes the antitumor effect of Pinelliae rhizome in papillary thyroid cancer

We previously reported that Xiaotan Sanjie (XTSJ) decoction can prevent the progression of gastric cancer in vitro and in vivo. Pinelliae rhizome (PR), one component of XTSJ decoction, has an inhibitory effect on the growth and proliferation of tumor cells. The present study investigated the underlying mechanisms of action of PR. Using the human papillary thyroid cancer cell lines, TPC-1 and BCPAP, we found that XTSJ decoction and PR alone decreased cell viability to a similar extent in both cell lines, whereas treatment with XTJS decoction without PR [PR (−)] had a lesser effect. PR treatment inhibited the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) in a dose-dependent manner. To investigate the role of Nrf2 in the PR-mediated effects of XTSJ, knockdown of Nrf2 in the tumor cell lines using Nrf2 siRNA (siNrf2) was performed and transfected cells were treated with PR. Silencing of Nrf2 amplified the effects on autophagy, cell viability, apoptosis, and colony formation. Similar results were obtained following treatment with the autophagy inhibitor 3-methyladenine (3-MA). Furthermore, treatment with PR, siNrf2, and/or 3-MA inhibited the MAPK pathway, and analysis of the MAPK pathway components confirmed the role of this pathway in the PR-mediated cellular effects. In mice implanted with siNrf2-transfected cells, the effects of PR were amplified. Taken together, these findings indicate that PR is critical for the inhibitory effects of XTSJ decoction on tumor cell viability and that downregulation of Nrf2 promotes the antitumor effects of PR on papillary thyroid cancer cells.     

Pre-colonization of PGPR triggers rhizosphere microbiota succession associated with crop yield enhancement

Plant and Soil - Plant growth-promoting rhizobacteria (PGPR) substantially improve plant growth and health, but their effects on the succession of rhizosphere microbiota throughout the growth...     

Tomato stigma exsertion induced by high temperature is associated with the jasmonate signalling pathway

High temperature (HT) is becoming an increasingly serious factor in limiting crop production with global climate change. During hot seasons, owing to prevailing HT, cultivated tomatoes are prone to exhibiting stigma exsertion, which hampers pollination and causes fruit set failure. However, the underlying regulatory mechanisms of the HT‐induced stigma exsertion remain largely unknown. Here, we demonstrate that stigma exsertion induced by HT in cultivated tomato is caused by more seriously shortened stamens than pistils, which is different from the stigma exsertion observed in wild tomato species. Under the HT condition, the different responses of pectin, sugar, expansin, and cyclin cause cell wall remodelling and differentially localized cell division and selective cell enlargement, which further determine the lengths of stamens and pistils. In addition, auxin and jasmonate (JA) are implicated in regulating cell division and cell expansion in stamens and pistils, and exogenous JA instead of auxin treatment can effectively rescue tomato stigma exsertion through regulating the JA/COI1 signalling pathway. Our findings provide a better understanding of stigma exsertions under the HT condition in tomato and uncover a new function of JA in improving plant abiotic stress tolerance.     

Expression Changes of NMDA and AMPA Receptor Subunits in the Hippocampus in rats with Diabetes Induced by Streptozotocin Coupled with Memory Impairment

Neurochemical Research - Cognitive impairment in diabetes (CID) is a severe chronic complication of diabetes mellitus (DM). It has been hypothesized that diabetes can lead to cognitive dysfunction...     

昆虫病原线虫Heterorhabditis beicherriana LF品系与Bt HBF-18菌株混用对华北大黑鳃金龟幼虫的防治效果

【目的】明确昆虫病原线虫 Heterorhabditis beicherriana LF品系(LF)与苏云金芽孢杆菌 Bacillus thuringiensis HBF-18菌株(Bt HBF-18)混用后对华北大黑鳃金龟 Holotrichia oblita 幼虫的致病力的协同增效作用,为该害虫的防治提供新的技术措施。【方法】在室内测定了LF在不同使用剂量、不同环境温度及不同土壤湿度条件下对华北大黑鳃金龟7-10日龄幼虫的致病力;通过室内生测测定了Bt HBF-18对LF存活的影响,以及Bt HBF-18与LF两者混用后对7-10日龄华北大黑鳃金龟幼虫的防治效果;同时通过室外盆栽试验测定了两者混用对华北大黑鳃金龟幼虫的防治效果。【结果】华北大黑鳃金龟幼虫死亡率随LF施用剂量和处理时间的增加而升高,其中,侵染期线虫(infective juveniles, IJs)800 IJs/100 μL及以上剂量处理7 d后幼虫死亡率达到了100%;25℃为该线虫侵染的最适宜环境温度;适宜土壤湿度范围为14%~20%,湿度过低或过高都会显著影响其侵染效率。室内生测结果表明, Bt HBF-18处理9 d对华北大黑鳃金龟幼虫的致死中浓度(LC 50 )为 1.44× 10^8 CFU/g土,此浓度对LF的存活基本没有影响。另外,室内生测和室外盆栽试验结果均表明,将LF与Bt HBF-18混用能显著提高对华北大黑鳃金龟幼虫的防治效果,混用后具有不同程度的加成或协同增效作用。室内生测试验中LC 50 Bt+200 IJs/100 μL LF混用处理3 d后,较单独LF和Bt HBF-18处理幼虫死亡率分别提高了约43.07%和36.05%,具有显著的协同增效作用;室外盆栽试验中1/2 LC 50 Bt+1 000 IJs/mL LF, LC 50 Bt+1 000 IJs/mL LF和1/2 LC 50 Bt+1 500 IJs/mL LF均具有协同增效作用,其中1/2 LC 50 Bt+1 500 IJs/mL LF增效作用最佳,较单独LF和Bt HBF-18处理幼虫死亡率分别提高了约38.89%和80.55%。【结论】将昆虫病原线虫LF与Bt HBF-18混用对华北大黑鳃金龟幼虫的防治具有加成或协同增效作用。     

The function of extrafloral nectaries in the pollination and reproduction of Sambucus javanica

Sambucus javanica is a perennial herb with extrafloral nectaries (EFNs) on its inflorescences. To explore the ecological functions of EFNs, a factorial combination experiment of ant (access or exclusion) and EFNs (with or without) at the plant level was created in two populations. The role of EFNs in the attraction of ants and flying pollinators, the defensive role of ants against foliar herbivores, the effects of ants on pollinator visitation and the effects of ant–pollinator interactions on fruit production in one or both populations were assessed. Ants were common on the ant-access plants with EFNs, but absent from the ant-access plants without EFNs. Foliar herbivory was independent of ant and EFN treatments and their interactions. The visitation frequency of flying pollinators (honeybees and syrphid flies) and fruit set were significantly higher for plants with EFNs than plants without EFNs, but were not affected by ant treatments or their interactions with EFN treatments. These results suggest that EFNs in S. javanica attracted both ants and flying pollinators, but ants did not present a defensive role against herbivores, did not deter flying pollinators from visiting inflorescences and had no effects on fruit production. In addition, ants were not significant pollen vectors.     

Investigation of the molecular interactions of triclocarban with human serum albumin using multispectroscopies and molecular modeling

Triclocarban (TCC), as a broad spectrum antibacterial agent widely used in personal care products, has recently been recognized as environmental pollutant with the potential of adversely affecting wildlife and human health. However, the behavior of TCC in blood circulatory system and the potential toxicity of TCC at the molecular level have been poorly investigated. In this study, the effect of TCC on human serum albumin (HSA) and the binding mechanism of TCC to HSA were examined using spectroscopic techniques and molecular modeling methods. The fluorescence results suggested that the fluorescence of HSA was quenched by TCC through a static quenching mechanism and nonradiation energy transfer, and TCC was bound to HSA with moderately strong binding affinity via hydrophobic interaction based on the analysis of the thermodynamic parameters. The site marker competitive experiments revealed that TCC bound into subdomain IIA (site I) of HSA. In addition, the results obtained from the circular dichroism, Fourier transform infrared (FT-IR), 8-anilino-1-naphthalenesulfonic acid fluorescence, synchronous fluorescence, three-dimensional fluorescence spectra and dynamic light scattering suggested the change in the microenvironment and conformation of HSA during the binding reaction. Finally, the best binding mode of TCC and specific interaction of TCC with amino acid residues were determined using molecular docking and molecular dynamics simulations. In a word, the present studies can provide a way to help us well understand the transport, distribution and toxicity effect of TCC when it diffused in the human body.

Communicated by Ramaswamy H. Sarma     

小地老虎食诱剂糖醋酒液配方筛选及发酵增效作用

【目的】为筛选和规范诱集小地老虎Agrotis ipsilon成虫的最佳糖醋酒液配方及最佳发酵时间,确定发酵液中的挥发物成分。【方法】优选以单一纯物质糖、醋、酒和水进行混配的配方A, B, C和D, 其配比分别为蔗糖(g)∶乙酸(mL)∶无水乙醇(mL)∶纯水(mL)(m/v/v/v)=3∶1∶3∶80, 3∶1∶3∶160, 3∶1∶6∶80和1∶1∶3∶80及常见配方E［白糖(g)∶白醋(mL)∶白酒(mL)∶自来水(mL)= 6∶3∶1∶10(m/v/v/v)］,分别并采用Y型嗅觉仪及GC-MS测试和分析小地老虎成虫对发酵1~15 d后的糖醋酒液的趋性及发酵液中的挥发物成分。【结果】趋性试验结果表明,糖醋酒液B配方对小地老虎诱集效果显著优于A, C, D和E配方,C配方次之。小地老虎成虫对B和C这两种配方发酵8 d发酵液的选择反应率均显著高于对未发酵及发酵5 d和7 d外的其他发酵时间发酵液的选择反应率。挥发物成分组成分析结果显示,糖醋酒液B配方发酵8 d发酵液的挥发物共有41种化合物,主要包括17种烃类化合物、8种醛类化合物、2种酮类化合物、4种醇类化合物、5种酯类化合物和5种醚类化合物。而且发酵8 d的糖醋酒液B配方与其未发酵以及发酵4 d和发酵12 d的糖醋酒液B配方之间的挥发物成分差异较大。【结论】优选并明确单一物质糖、醋、酒和水进行混配的小地老虎食诱剂配方(3∶1∶3∶160, m/v/v/v),其糖醋酒液通过发酵可以产生增效作用,最佳发酵时间为8 d。     

Conformational analysis of β-methyl-para-nitrophenylalanine stereoisomers of cyclo[D-Pen2, D-Pen5]enkephalin by NMR spectroscopy and conformational energy calculations

Solution conformations of β-methyl-para-nitrophenylalanine⁴ analogues of the potent δ-opioid peptide cyclo[D-Pen², D-Pen⁵]enkephalin (DPDPE) were studied by combined use of nmr and conformational energy calculations. Nuclear Overhauser effect connectivities and ³J_HNC^α_H coupling constants measured for the (2S, 3S)-, (2S, 3R)-, and (2R, 3R)-stereoisomers of[β-Me-p-NO₂Phe⁴]DPDPE in DMSO were compared with low energy conformers obtained by energy minimization in the Empirical Conformational Energy Program for Peptides #2 force field. The conformers that satisfied all available nmr data were selected as probable solution conformations of these peptides. Side-chain rotamer populations, established using homonuclear (³J_H^α_H^β) and heteronuclear (³J_H^αC^γ) coupling constants and ¹³C chemical shifts, show that the β-methyl substituent eliminates one of the three staggered rotamers of the torsion angle x¹ for each stereoisomer of the β-Me-p-NO₂Phe⁴. Similar solution conformations were suggested for the L-Phe⁴-containing (2S, 3S)- and (2S, 3R)-stereoisomers. Despite some local differences, solution conformations of L- and D-Phe⁴-containing analogues have a common shape of the peptide backbone and allow similar orientations of the main δ-opioid pharmacophores. This type of structure differs from several models of the solution conformations of DPDPE, and from the model of biologically active conformations of DPDPE suggested earlier. The latter model is allowed for the potent (2S, 3S)- and (2S, 3R)-stereoisomers of [β-Me-p-NO₂Phe⁴] DPDPE, but it is forbidden for the less active (2R, 3R)- and (2R, 3S)-stereoisomers. It was concluded that the biologically active stereoisomers of [β-Me-p-No₂Phe⁴] DPDPE in the δ-receptor-bound state may assume a conformation different from their favorable conformations in DMSO. © 1996 John Wiley & Sons, Inc.