FXR1P but not FMRP regulates the levels of mammalian brain-specific microRNA-9 and microRNA-124

Mammalian brain-specific miR-9 and miR-124 have been implicated in several aspects of neuronal development and function. However, it is not known how their expression levels are regulated in vivo. We found that the levels of miR-9 and miR-124 are regulated by FXR1P but not by the loss of FXR2P or FMRP in vivo, a mouse model of fragile X syndrome. Surprisingly, the levels of miR-9 and miR-124 are elevated in fmr1/fxr2 double-knock-out mice, in part reflecting posttranscriptional upregulation of FXR1P. Indeed, FXR1P is required for efficient processing of pre-miR-9 and pre-miR-124 in vitro and forms a complex with Dicer and pre-miRNAs. These findings reveal differential roles of FMRP family proteins in controlling the expression levels of brain-specific miRNAs

Boosting visible-light-driven photocatalytic performance of waxberry-like CeO<inf>2</inf> by samarium doping and silver QDs anchoring

In this work, waxberry-like CeO2 photocatalyst (denoted ASC) with prominent visible-light-driven photocatalytic performances for multi-model reactions was achieved by Sm doping and Ag quantum dots (QDs) anchoring. For instance, the as-fabricated ASC acquired 7.08-times and 6.83-times higher activities for CH3CHO removal and H2 production than those of pure CeO2 counterpart, respectively. The concentration of oxygen vacancies (Ov) in CeO2 is distinctly increased by Sm doping, resulting in a narrower bandgap of the Sm-doped CeO2 (SC). Under visible light irradiation, the Ov caused by doping can capture the photo-excited electrons and construct a doping-related transition state between the conduction band (CB) and the valence band (VB), which can effectively limit the recombination of photo-excited electrons and holes. These captured electrons further fleetly transfer to the co-catalytic sites of anchored Ag QDs, strengthening the absorption utilization for visible-light synchronously. The migration of charge carriers and proposed mechanisms were well elaborated by transient photovoltage (TPV), surface photovoltage (SPV) and density functional theory (DFT) calculation. It is hoped our work in this paper could provide potential and meaningful strategies for the design of noble metal quantum dots modified metal oxide semiconductors and facilitate their applications in other photocatalytic fields effectively

Preparation of stable magnetic nanofluids containing Fe3O4@PPy nanoparticles by a novel one-pot route

Stable magnetic nanofluids containing Fe3O4@Polypyrrole (PPy) nanoparticles (NPs) were prepared by using a facile and novel method, in which one-pot route was used. FeCl3·6H2O was applied as the iron source, and the oxidizing agent to produce PPy. Trisodium citrate (Na3cit) was used as the reducing reagent to form Fe3O4 NPs. The as-prepared nanofluid can keep long-term stability. The Fe3O4@PPy NPs can still keep dispersing well after the nanofluid has been standing for 1 month and no sedimentation is found. The polymerization reaction of the pyrrole monomers took place with Fe3+ ions as the initiator, in which these Fe3+ ions remained in the solution adsorbed on the surface of the Fe3O4 NPs. Thus, the core-shell NPs of Fe3O4@PPy were obtained. The particle size of the as-prepared Fe3O4@PPy can be easily controlled from 7 to 30 nm by the polymerization reaction of the pyrrole monomers. The steric stabilization and weight of the NPs affect the stability of the nanofluids. The as-prepared Fe3O4@PPy NPs exhibit superparamagnetic behavior

PwHAP5, a CCAAT-binding transcription factor, interacts with PwFKBP12 and plays a role in pollen tube growth orientation in Picea wilsonii

The HAP complex occurs in many eukaryotic organisms and is involved in multiple physiological processes. Here it was found that in Picea wilsonii, HAP5 (PwHAP5), a putative CCAAT-binding transcription factor gene, is involved in pollen tube development and control of tube orientation. Quantitative real-time reverse transcription-PCR showed that PwHAP5 transcripts were expressed strongly in germinating pollen and could be induced by Ca2+. Overexpression of PwHAP5 in pollen altered pollen tube orientation, whereas the tube with PwHAP5RNAi showed normal growth without diminishing pollen tube growth. Furthermore, PwFKBP12, which encodes an FK506-binding protein (FKBP) was screened and a bimolecular fluorescence complementation assay performed to confirm the interaction of PwHAP5 and PwFKBP12 in vivo. Transient expression of PwFKBP12 in pollen showed normal pollen tube growth, whereas the tube with PwFKBP12RNAi bent. The phenotype of overexpression of HAP5 on pollen tube was restored by FKBP12. Altogether, our study supported the role of HAP5 in pollen tube development and orientation regulation and identified FKBP12 as a novel partner to interact with HAP5 involved in the process

IGF-II Expression in Human Tumor Tissues and Human IGF-II Ribozyme Action

Insulin-like growth factors (IGFs) are potent mitogens for a variety of cancer cells in vitro. In breast, prostate and neuroblastoma cancer cells, it has been suggested that IGF-II plays a paracrine/autocrine role. However, information on cell-type -specific IGF-II expression in vivo is limited. In situ hybridization and immunohistochemistry were carried out to determine the cell type expressing IGF-II in different tumor tissues. Both IGF-II mRNA and protein were localized to malignant cells, and expression in the stroma was minimal in all the tumors. The data are consistent with the hypothesis that cancer cell growth is regulated by IGF-II, and therefore IGF-II is a potential target for cancer therapy. RNA enzymes (ribozymes) which selectively cleave RNA targets via base-pairing interactions can serve as therapeutic agents. We constructed IGF-II ribozymes and stably transfected them in prostate cancer PC-3 cells. Single- and double-hammerhead ribozymes were synthesized and cloned into the pTZU6+27 or pcDNA vectors. In vitro studies showed that both single- and double-ribozymes cleaved the ~ 140 bases and /or ~1 kilo bases IGF-II RNA substrates examined, while the mutant ribozymes did not. Kcat/Km for cleaving the shorter IGF-II substrate by double ribozyme and single ribozyme was 4772 and 1546 M-1S-1, respectively, suggesting that double ribozyme was ~3 fold more efficient in cleaving the IGF-II substrate than the single ribozyme in vitro. PC-3 stable transfectants expressing single ribozyme or double ribozyme, under control of U6 promoter, reduced the endogenous IGF-II mRNA and cell growth compared to mutant ribozyme transfectants. Similarly, PC-3 stable transfectants expressing single ribozyme, under control of CMV promoter, reduced the endogenous IGF-II mRNA and IGF-II protein secretion compared to vector-control cells. Furthermore, PC-3 cells expressing single ribozyme grew poorly under serum-free or 2% FCS conditions as judged by growth curves, supporting our hypothesis that IGF-II plays a critical role in prostate cancer cell growth, and thus provides a basis for developing a potential gene therapy for cancer