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Neoseiulus californicus (Acari: Phytoseiidae) is a commercialized predatory mite that is used as a biological control agent against Tetranychus urticae (Acari: Tetranychidae). Long-term feeding on alternative prey could impact the predatory capacity of N. californicus. Although most studies on the learning behavior of predatory mites have indicated that learning behavior could help them adapt from feeding on thrips (alternative prey) to spider mites (target prey), the role of learning behavior in adapting from feeding on astigmatid mites to spider mites has not been studied thus far. Therefore, this study explored the learning behavior of N. californicus in adapting from feeding on alternative prey (Oulenziella bakeri [Acari: Winterschmidtiidae]) to target mites (T. urticae). The attack latencies, prey preferences, and functional responses of female N. californicus were compared between two strains, N. californicus fed on T. urticae (TU) or O. bakeri (OB), and a learning behavior (LB) treatment. The results showed that the attack latency of OB strain was significantly longer than those of TU strain and LB treatment; OB strain did not show obvious prey preference between protonymphs of T. urticae and O. bakeri; and the functional response among TU, OB, and LB-treated strains were not significantly different. Our results demonstrated that long-term feeding on alternative prey had little effect on the predatory ability of N. californicus. To a certain extent, learning behavior can help N. californicus shift from feeding on alternative prey to target prey. Therefore, in the long run, it is reasonable to rear N. californicus on O. bakeri.

Pardosa pseudoannulata is the main predatory natural enemy of crop pests in a paddy ecosystem. When P. pseudoannulata is exposed to unfavorable temperature conditions, the response of heat shock proteins could resist the damage, and is therefore, conducive to the organism’s rapid adaptation to the surrounding stress environment. In this study, we explored the roles of hsp70 and hsp90 genes in response to heat stress, using the rapid amplification of cDNA ends technique and cloned full-length cDNAs of Pphsp70, Pphsp83, and Pphsp90. The mRNA expression levels of the three genes under different temperature stresses (25, 28, 31, 34, 37, 40, and 43 °C) and with different duration stresses (4, 8, 12, 16, and 20 h) were analyzed by quantitative real-time polymerase chain reaction. The full-length cDNA of Pphsp70, Pphsp83, and Pphsp90 was 2331 base pair (bp), 2466 bp, and 2663 bp, respectively. Phylogenetic analysis of amino acid sequences of Pphsp70, Pphsp83, and Pphsp90 showed that the sequences had high homology with that of other spiders. The mRNA expression of all three genes was extremely significantly up-regulated at 43 °C. Moreover at 43 °C, the expression of all three genes in both female and male spiders at the duration of 4 h was the highest compared to that of other stress duration groups. Therefore, it can be inferred that the three genes of P. pseudoannulata play a crucial protective role in resistance in a high-temperature environment.

Oulenziella bakeri is often used as an alternative prey for the mass rearing of Neoseiulus californicus in China. Long-term alternative prey feeding experience may cause a decline in the predatory capacity of phytoseiid mites toward their target prey. Learning behavior of predatory mites can help them adapt to the changes from preying on thrips to preying on spider mites (Rahmani et al., 2010), but there are few studies on the learning behavior of predatory mites from astigmatid mites to spider mites. Here, we compared the attack latency, prey preference, and functional response of N. californicus toward Tetranychus urticae among the “natural prey strains” (feeding only on T. urticae), “alternative prey strains” (feeding only on O. bakeri), and “learning behavior treatment” (alternative prey strains experienced in attacking but not feeding on T. urticae). The results showed that the attack latency of “alternative prey strain” of N. californicus on T. urticae was significantly longer than that of “natural prey strain” and “learning behavior treatment”. The “alternative prey strain” showed no obvious predatory preference between the protonymphs of T. urticae and O. baker. There were no significant differences in the capture rate and handling time among the three treatments. Our results indicated that the long-term rearing on alternative prey mainly prolonged the attack latency of N. californicus to the target prey and changed its prey preference, while learning behavior could help alternative prey strain of N. californicus to shorten the attack latency and restore its prey preference toward target prey (Zhu et al., 2022).

A solution-processed hole-transporting layer for planar perovskite solar cells (PSCs) is developed by simply incorporating the CrO3 aqueous solution into the ploy(3,4-ethylene-dioxythiophene):ploystyrenesulfonate (PEDOT:PSS) aqueous dispersion. Besides the merits of high conductivity and interface modification, PEDOT:PSS-CrO3 composite films can act as a good underlayer for the growth of the crystal perovskite films. The CH3NH3PbI3−xClx film deposited on the PEDOT:PSS-CrO3 underlayer demonstrates high quality with large-scale domains and good film uniformity, which results in obvious improvement of the absorption in almost whole visible-light range. The resulting PSC device shows a power conversion efficiency (PCE) as high as 16.90%.

Cancer stem cells or cancer initiating cells are believed to contribute to cancer recurrence after therapy. MicroRNAs (miRNAs) are short RNA molecules with fundamental roles in gene regulation. The role of miRNAs in cancer stem cells is only poorly understood. Here, we report miRNA expression profiles of glioblastoma stem cell-containing CD133+ cell populations. We find that miR-9, miR-9* (referred to as miR-9/9*), miR-17 and miR-106b are highly abundant in CD133+ cells. Furthermore, inhibition of miR-9/9* or miR-17 leads to reduced neurosphere formation and stimulates cell differentiation. Calmodulin-binding transcription activator 1 (CAMTA1) is a putative transcription factor, which induces the expression of the anti-proliferative cardiac hormone natriuretic peptide A (NPPA). We identify CAMTA1 as an miR-9/9* and miR-17 target. CAMTA1 expression leads to reduced neurosphere formation and tumour growth in nude mice, suggesting that CAMTA1 can function as tumour suppressor. Consistently, CAMTA1 and NPPA expression correlate with patient survival. Our findings could provide a basis for novel strategies of glioblastoma therapy.

MicroRNAs (miRNAs) represent a conserved class of small noncoding RNAs that are found in all higher eukaryotes as well as some DNA viruses. miRNAs are 20 to 25 nucleotides in length and have important regulatory functions in biological processes such as embryonic development, cell differentiation, hormone secretion, and metabolism. Furthermore, miRNAs have been implicated in the pathology of various diseases, including cancer. miRNA expression profiles not only classify different types of cancer but also may even help to characterize distinct tumor stages, therefore constituting a valuable tool for prognosis. Here we report the miRNA profile of Epstein-Barr virus (EBV)-positive nasopharyngeal carcinoma (NPC) tissue samples characterized by cloning and sequencing. We found that all EBV miRNAs from the BART region are expressed in NPC tissues, whereas EBV miRNAs from the BHRF1 region are not found. Moreover, we identified two novel EBV miRNA genes originating from the BART region that have not been found in other tissues or cell lines before. We also identified three new human miRNAs which might be specific for nasopharyngeal tissues. We further show that a number of different cellular miRNAs, including miR-15a and miR-16, are upor downregulated in NPC tissues compared to control tissues. We found that the tumor suppressor BRCA-1 is a target of miR-15a as well as miR-16, suggesting a miRNA role in NPC pathogenesis. Copyright © 2009, American Society for Microbiology., link_to_OA_fulltext

MicroRNAs (miRNAs) constitute a class of small non-coding RNAs that regulate gene expression on the level of translation and/or mRNA stability. Mammalian miRNAs associate with members of the Argonaute (Ago) protein family and bind to partially complementary sequences in the 3' untranslated region (UTR) of specific target mRNAs. Computer algorithms based on factors such as free binding energy or sequence conservation have been used to predict miRNA target mRNAs. Based on such predictions, up to one third of all mammalian mRNAs seem to be under miRNA regulation. However, due to the low degree of complementarity between the miRNA and its target, such computer programs are often imprecise and therefore not very reliable. Here we report the first biochemical identification approach of miRNA targets from human cells. Using highly specific monoclonal antibodies against members of the Ago protein family, weco-immunoprecipitate Ago-bound mRNAs and identify them by cloning. Interestingly, most of the identified targets are also predicted by different computer programs. Moreover, we randomly analyzed six different target candidates and were able to experimentally validate five as miRNA targets. Our data clearly indicate that miRNA targets can be experimentally identified from Ago complexes and therefore provide a new tool to directly analyze miRNA function.

TNFα has previously been used in anticancer therapy. However, the therapeutic application of TNFα was largely limited due to its general toxicity and the fact that it activates the NF-κB–family transcription factors, which are proinflammatory and antiapoptotic. To overcome this problem in vitro, specific NF-κB inhibitors or transcription or protein synthesis inhibitors such as actinomycin D and cycloheximide are usually used in combination to increase TNFα killing of tumor cells. However, these agents also cause harmful side effects in vivo. We show here that wogonin, derived from the popular Chinese herb Huang-Qin, attenuates NF-κB activity by shifting TNFα-induced free radical ·O2– to a more reduced nonradical product, H2O2, and thereby sensitizes TNFα-resistant leukemia cells to TNFα-induced apoptosis. Importantly, wogonin does not affect the viability of normal peripheral blood T cells. Wogonin also sensitizes TRAIL-induced apoptosis. Our data suggest a potential use of wogonin as a TNFα or TRAIL adjuvant for cancer treatment. Our data also demonstrate how a herbal compound enhances killing of tumor cells with reduced side effects compared with other treatments.

The Epstein–Barr virus (EBV) is an oncogenic human Herpes virus found in ∼15% of diffuse large B-cell lymphoma (DLBCL). EBV encodes miRNAs and induces changes in the cellular miRNA profile of infected cells. MiRNAs are small, non-coding RNAs of ∼19–26 nt which suppress protein synthesis by inducing translational arrest or mRNA degradation. Here, we report a comprehensive miRNA-profiling study and show that hsa-miR-424, -223, -199a-3p, -199a-5p, -27b, -378, -26b, -23a, -23b were upregulated and hsa-miR-155, -20b, -221, -151-3p, -222, -29b/c, -106a were downregulated more than 2-fold due to EBV-infection of DLBCL. All known EBV miRNAs with the exception of the BHRF1 cluster as well as EBV-miR-BART15 and -20 were present. A computational analysis indicated potential targets such as c-MYB, LATS2, c-SKI and SIAH1. We show that c-MYB is targeted by miR-155 and miR-424, that the tumor suppressor SIAH1 is targeted by miR-424, and that c-SKI is potentially regulated by miR-155. Downregulation of SIAH1 protein in DLBCL was demonstrated by immunohistochemistry. The inhibition of SIAH1 is in line with the notion that EBV impedes various pro-apoptotic pathways during tumorigenesis. The down-modulation of the oncogenic c-MYB protein, although counter-intuitive, might be explained by its tight regulation in developmental processes. ISSN:1362-4962 ISSN:0301-5610

Murine gammaherpesvirus 68 (MHV-68) is closely related to Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV) and provides a small-animal model with which to study the pathogenesis of gammaherpesvirus (γHV) infections. To completely explore the potential of the MHV-68 system for the investigation of γHV microRNAs (miRNAs), it would be desirable to know the number and expression patterns of all miRNAs encoded by MHV-68. By deep sequencing of small RNAs, we systematically investigated the expression profiles of MHV-68 miRNAs in both lytically and persistently infected cells. In addition to the nine known MHV-68 miRNAs, we identified six novel MHV-68 miRNA genes and analyzed the expression levels of all MHV-68 miRNAs. Furthermore, we also characterized the cellular miRNA expression signatures in MHV-68-infected versus noninfected NIH 3T3 fibroblasts and in 12- O -tetradecanoyl-phorbol-13-acetate (TPA)-treated versus nontreated S11 cells. We found that mmu-mir-15b and mmu-mir-16 are highly upregulated upon MHV-68 infection of NIH 3T3 cells, indicating a potential role for cellular miRNAs during MHV-68 infection. Our data will aid in the full exploration of the functions of γHV miRNAs.

microRNAs (miRNAs) are small non-coding RNAs with fundamental roles in the regulation of gene expression. miRNAs assemble with Argonaute (Ago) proteins to miRNA-protein complexes (miRNPs), which interact with distinct binding sites on mRNAs and regulate gene expression. Specific miRNAs are key regulators of tissue and organ development and it has been shown in mammals that miRNAs are also involved in the pathogenesis of many diseases including cancer. Here, we have characterized the miRNA expression profile of the developing murine genitourinary system. Using a computational approach, we have identified several miRNAs that are specific for the analyzed tissues or the developmental stage. Our comprehensive miRNA expression atlas of the developing genitourinary system forms an invaluable basis for further functional in vivo studies.