Sodium fluoride induces apoptosis and autophagy via the endoplasmic reticulum stress pathway in MC3T3-E1 osteoblastic cells

Molecular and Cellular Biochemistry - Fluorosis and bone pathologies can be caused by chronic and/or excessive fluoride intake. Despite this, few studies have been conducted on the cellular...     

Suberoylanilide Hydroxamic Acid Triggers Autophagy by Influencing the mTOR Pathway in the Spinal Dorsal Horn in a Rat Neuropathic Pain Model

Histone acetylation levels can be upregulated by treating cells with histone deacetylase inhibitors (HDACIs), which can induce autophagy. Autophagy flux in the spinal cord of rats following the left fifth lumber spinal nerve ligation (SNL) is involved in the progression of neuropathic pain. Suberoylanilide hydroxamic acid (SAHA), one of the HDACIs can interfere with the epigenetic process of histone acetylation, which has been shown to ease neuropathic pain. Recent research suggest that SAHA can stimulate autophagy via the mammalian target of rapamycin (mTOR) pathway in some types of cancer cells. However, little is known about the role of SAHA and autophagy in neuropathic pain after nerve injury. In the present study, we aim to investigate autophagy flux and the role of the mTOR pathway on spinal cells autophagy activation in neuropathic pain induced by SNL in rats that received SAHA treatment. Autophagy-related proteins and mTOR or its active form were assessed by using western blot, immunohistochemistry, double immunofluorescence staining and transmission electron microscopy (TEM). We found that SAHA decreased the paw mechanical withdrawal threshold (PMWT) of the lower compared with SNL. Autophagy flux was mainly disrupted in the astrocytes and neuronal cells of the spinal cord dorsal horn on postsurgical day 28 and was reversed by daily intrathecal injection of SAHA (n?=?100 nmol/day or n?=?200 nmol/day). SAHA also decreased mTOR and phosphorylated mTOR (p-mTOR) expression, especially p-mTOR expression in astrocytes and neuronal cells of the spinal dorsal horn. These results suggest that SAHA attenuates neuropathic pain and contributes to autophagy flux in astrocytes and neuronal cells of the spinal dorsal horn via the mTOR signaling pathway.

     

家蚕微孢子虫感染对家蚕海龟蛋白(Bmtutl)基因表达水平的影响

【目的】本研究旨在阐明家蚕微孢子虫Nosema bombycis感染不同时间对家蚕Bombyx mori幼虫不同组织中家蚕海龟蛋白(Bombyx Turtle, Bmtutl)基因表达水平的影响,为揭示家蚕微孢子虫的侵染机制奠定基础。【方法】利用生物信息学方法对家蚕海龟蛋白3种亚型Bmtutl-464, Bmtutl-519和Bmtutl-810的序列结构特征进行了分析;利用qPCR检测家蚕微孢子虫感染后12, 24, 48, 72, 96和120 h,家蚕幼虫中肠、血淋巴与脂肪体组织中Bmtutl-464, Bmtutl-519和Bmtutl-810基因表达水平的变化情况。【结果】家蚕海龟蛋白3种亚型的二级结构均主要由无规则卷曲、α螺旋、β转角和延伸链组成,其中无规则卷曲所占比例最高。但是PredictProtein分析发现,Bmtutl-464, Bmtutl-519和Bmtutl-810之间的蛋白/多核苷酸结合位点存在较大差异。qPCR结果表明,感染家蚕微孢子虫后,家蚕幼虫中肠、血淋巴与脂肪体组织中Bmtutl-464, Bmtutl-519和Bmtutl-810基因的整体表达处于被抑制状态,尤其在脂肪体中最为明显：Bmtutl-519和Bmtutl-810基因的表达在家蚕微孢子虫感染家蚕后的72 h开始受到显著抑制,特别是Bmtutl-519基因,其相对表达水平均不到对照的5.0%。【结论】家蚕海龟蛋白这3种亚型的序列结构特征存在较大差异,家蚕微孢子虫感染在一定程度抑制了家蚕幼虫中肠、血淋巴与脂肪体组织中Bmtutl-464, Bmtutl-519和Bmtutl-810基因尤其是Bmtutl-519的表达。结果说明,与其他两种家蚕海龟蛋白亚型相比,Bmtutl-519蛋白可能在家蚕微孢子虫侵染宿主的过程中起主要作用。     

Epstein–Barr virus noncoding RNAs from the extracellular vesicles of nasopharyngeal carcinoma (NPC) cells promote angiogenesis via TLR3/RIG-I-mediated VCAM-1 expression

Viral noncoding RNAs (Epstein–Barr virus-encoded RNAs, EBERs) are believed to play a critical role in the progression of lymphoma and nasopharyngeal carcinoma (NPC). However, the accurate mechanisms accounting for their oncogenic function have not been elucidated, especially in terms of interaction between tumor cells and mesenchymal cells. Here, we report that, in addition to NPC cells, EBERs are also found in endothelial cells in Epstein–Barr virus (EBV)-infected NPC parenchymal tissues, which implicates NPC-derived extracellular vesicles (EVs) in transmitting EBERs to endothelial cells. In support of this hypothesis, we first ascertained if EBERs could be transferred to endothelial cells via EVs isolated from NPC culture supernatant. Then, we clarified that EVs-derived EBERs could promote angiogenesis through stimulation of VCAM-1 expression. Finally, we explored the involvement of EBER recognition by TLR3 and RIG-I in NPC angiogenesis. Our observations collectively illustrate the significance and mechanism of EVs-derived EBERs in angiogenesis and underlie the interaction mechanisms between EBV-infected NPC cells and the tumor microenvironment.     

Repellent action and contact toxicity mechanisms of the essential oil extracted from Chinese chive against Plutella xylostella larvae

Botanical pesticides play increasingly important roles in the control of agricultural pests. In this study, the insecticidal effects, specifically the repellent action and contact toxicity, of the essential oil extracted from Chinese chive (EOC) against Plutella xylostella larvae were confirmed. The mechanisms of repellent’s action were studied using electroantennograms (EAGs), and the effects on glutathione S‐transferase (GST), carboxylesterase (CarE), and acetyl cholinesterase were investigated after EOC treatments. The EOC affected the EAG results and inhibited the activities of GST and CarE in treated P. xylostella larvae, which could explain its insecticidal effects. And, four pyrazines showed greater repellent activities than that of the EOC, which was confirmed as the main active compounds of EOC.     

An evaluation of transferability of ecological niche models

Ecological niche modeling (ENM) is used widely to study species’ geographic distributions. ENM applications frequently involve transferring models calibrated with environmental data from one region to other regions or times that may include novel environmental conditions. When novel conditions are present, transferability implies extrapolation, whereas, in absence of such conditions, transferability is an interpolation step only. We evaluated transferability of models produced using 11 ENM algorithms from the perspective of interpolation and extrapolation in a virtual species framework. We defined fundamental niches and potential distributions of 16 virtual species distributed across Eurasia. To simulate real situations of incomplete understanding of species’ distribution or existing fundamental niche (environmental conditions suitable for the species contained in the study area; N* _F ), we divided Eurasia into six regions and used 1–5 regions for model calibration and the rest for model evaluation. The models produced with the 11 ENM algorithms were evaluated in environmental space, to complement the traditional geographic evaluation of models. None of the algorithms accurately estimated the existing fundamental niche (N* _F ) given one region in calibration, and model evaluation scores decreased as the novelty of the environments in the evaluation regions increased. Thus, we recommend quantifying environmental similarity between calibration and transfer regions prior to model transfer, providing an avenue for assessing uncertainty of model transferability. Different algorithms had different sensitivity to completeness of knowledge of N* _F , with implications for algorithm selection. If the goal is to reconstruct fundamental niches, users should choose algorithms with limited extrapolation when N* _F is well known, or choose algorithms with increased extrapolation when N* _F is poorly known. Our assessment can inform applications of ecological niche modeling transference to anticipate species invasions into novel areas, disease emergence in new regions, and forecasts of species distributions under future climate conditions.     

Oleuropein induces apoptosis via abrogating NF-κB activation cascade in estrogen receptor–negative breast cancer cells

Oleuropein is one of the most abundant phenolic compounds found in olives. Epidemiological studies have indicated that an increasing intake of olive oil can significantly reduce the risk of breast cancer. However, the potential effect(s) of oleuropein on estrogen receptor (ER)-negative breast cancer is not fully understood. This study aims to understand the anticancer effects and underlying mechanism(s) of oleuropein on ER-negative breast cancer cells in vitro. The effect of oleuropein on the viability of breast cancer cell lines was examined by mitochondrial dye-uptake assay, apoptosis by flow cytometric analysis, nuclear factor-κB (NF-κB) activation by DNA binding/reporter assays and protein expression by Western blot analysis. In the present report, thiazolyl blue tetrazolium bromide assay results indicated that oleuropein inhibited the viability of breast cancer cells, and its effects were more pronounced on MDA-MB-231 as compared with MCF-7 cells. It was further found that oleuropein increased the level of reactive oxygen species and also significantly inhibited cellular migration and invasion. In addition, the activation of NF-κB was abrogated as demonstrated by Western blot analysis, NF-κB-DNA binding, and luciferase assays. Overall, the data indicates that oleuropein can induce substantial apoptosis via modulating NF-κB activation cascade in breast cancer cells.     

海藻糖酶基因TRE2-like和TRE2在异色瓢虫羽化过程中的表达与功能

【目的】异色瓢虫Harmonia axyridis是一种重要的捕食性天敌昆虫,海藻糖在异色瓢虫的变态发育、羽化等整个生命过程都起着重要的作用。本研究以前期获得的类似膜结合型海藻糖酶(TRE2-like)与膜结合型海藻糖酶(TRE2)基因为基础,探讨在异色瓢虫羽化阶段这两个海藻糖酶的潜在功能,为阐明异色瓢虫从蛹发育到成虫时海藻糖代谢机制提供参考。【方法】根据TRE2-like和TRE2基因序列设计双链RNA(dsRNA)区域片段并合成对应的dsRNA,通过RNAi将其注射到异色瓢虫2日龄蛹中。采用实时荧光定量PCR(RT-qPCR)检测RNAi处理后羽化第1天的异色瓢虫成虫糖代谢相关基因的表达;同时采用蒽酮比色法、酶标法等分别测定RNAi处理后羽化第1天的异色瓢虫成虫主要糖类物质含量及TRE活性变化,并观察异色瓢虫羽化后的表型变化。【结果】结果表明,与对照组(dsGFP注射组)相比,异色瓢虫2日龄蛹被注射TRE2-like或TRE2 dsRNA后,其新羽化成虫体内TRE2-like和TRE2表达量均极显著下调,且少数个体出现了蜕皮与翅形成困难等畸形表型。可溶性海藻糖酶活性在注射dsTRE2-like后显著降低,膜结合型海藻糖酶活性在注射dsTRE2后显著降低;注射dsTRE2后糖原含量显著下降,注射dsTRE2-like后糖原和海藻糖含量显著下降,注射dsTRE2-like+dsTRE2后糖原和葡萄糖含量显著下降,且海藻糖含量极显著下降。注射dsTRE2-like, dsTRE2和dsTRE2-like+dsTRE2后可溶性海藻糖酶基因TRE1-1和TRE1-2表达下降或显著下降,而TRE1-5表达上升或显著上升,海藻糖合成酶(trealose-6-phosphate synthase, TPS)、糖原磷酸化酶(glycogen phosphorylase, GP)、糖原合成酶(glycogen synthase, GS)基因的表达均显著下调。【结论】TRE2-like和TRE2基因表达被抑制后,异色瓢虫海藻糖等代谢受到影响。研究结果为探究异色瓢虫体内膜结合型海藻糖酶的潜在功能和调控机制奠定了基础。