Cyclometalated Platinum(II) Metallomesogens Based on Half-Disc-Shaped ß-Diketonate Ligands with Hexacatenar: Crystal Structures, Mesophase Properties, and Semiconductor Devices.

A series of new half-disc-shaped platinum(II) complexes [Pt(ppy)(ALn-6OCnH2n+1)] (Pt-An), [Pt(ppyF)(ALn-6OCnH2n+1)] (Pt-Bn), and [Pt(ppyCF3)(ALn-6OCnH2n+1)] (Pt-Cn) (ALn-6OCnH2n+1 = 1,3-bis(3,4,5-trialkoxyphenyl)propane-1,3-dionato; n = 1, 6, 12) with concise structures have been designed and synthesized, in which 2-phenylpyridine (ppy) derivatives were used as cyclometalated ligands and hexacatenar ß-diketonate derivatives ALn-6OCnH2n+1 as auxiliary ligands. The single-crystal data of the methoxy diketonate analogues Pt-A1, Pt-B1, and Pt-C1 indicate that they all display excellent square planarity. These platinum(II) complexes show a certain emission tunability (ranging from λ = 506-535 nm) by the introduction of fluorine or trifluoromethyl into ppy. Thermal studies reveal that the fluorine-substituted complexes are liquid crystals but the trifluoromethyl-substituted complexes are not. The platinum(II) complexes Pt-A12, Pt-B6, and Pt-B12 can form a hexagonal columnar mesophase via intermolecular π-π interactions. In addition, compared to the reported platinum(II) metallomesogens, Pt-A12 and Pt-B12 exhibit improved ambipolar carrier mobility behaviors in semiconductor devices at the liquid crystal states.

Characterization of Novel Bacteriophage AhyVDH1 and Its Lytic Activity Against Aeromonas hydrophila.

Phage therapy is an alternative approach to overcome the problem of multidrug-resistant bacteria. Here, a novel bacteriophage AhyVDH1, which infects Aeromonas hydrophila 4572, was isolated and its morphology, one-step growth curve, lytic activity, stability under various conditions, and genome were investigated. Transmission electron microscopy revealed that AhyVDH1 has an icosahedral head 49 nm in diameter and a contractile tail 127 nm in length, suggesting that it belongs to the family Myoviridae. AhyVDH1 showed strong adsorption to the surface of A. hydrophila 4572 (90% in 10 min). The latent period of AhyVDH1 was shown to be 50 min, and the burst size was 274 plaque-forming unit/infected cell. AhyVDH1 was stable at 30 °C for 1 h and lost infectivity after20 min of heating at 60 °C. Infectivity remained unaffected at pH 6-7 for 1 h, while the bacteriophage was inactivated at pH < 4 or > 11. AhyVDH1 has a 39,175-bp genome, with a 58% G + C content and 59 open reading frames. BLAST analysis indicated that the genome sequence of phage AhyVDH1 was related to that of Aeromonas phage Ahp2. Both time and MOI-dependent in vitro A. hydrophila growth inhibition were observed with AhyVDH1.Re-growth of the host bacteria appeared about 12 h after treatment, suggesting its potential therapeutic value in treating A. hydrophila infections, but phage cocktails should be developed.

Biased Symmetry Breaking and Chiral Control by Self-Replicating in Achiral Tetradentate Platinum (II) Complexes.

Obtaining homochirality from biased symmetry-breaking of self-assembly in achiral molecules remains a great challenge due to the lack of ingenious strategies and controlling their handedness. Here, we report the first case of biased symmetry breaking from achiral platinum (II) liquid crystals which self-organize into an enantiomerically enriched single domain without selection of handedness in twist grain boundary TGB [ *] phase. Most importantly, the chiral control of self-organization can be achieved by using above the homochiral liquid crystal films with determined handedness (P or M) as a template. Moreover, benefiting from self-assembled superhelix, these complexes exhibit prominent circularly polarized luminescence with high |glum | up to 3.4×10-3 in the TGB [ *] mesophase. This work paves a neoteric avenue for the development of chiral self-assemblies from achiral molecules.

Columnar Iridium(III) Metallomesogens Based on Polycatenar Pyridyltetrazolate with Ambipolar Carrier Mobility Behavior.

In this paper, we have designed and synthesized a series of neutral liquid-crystalline iridium(III) complexes based on polycatenar 2,5-diphenylpyridine and pyridyltetrazolate derivatives. Iridium(III) complexes all display highly emissive behavior with photoluminescence quantum yields in the range of 0.45-0.66 and a maximum emission wavelength at ∼563 nm. Hexagonal columnar mesophases of iridium(III) complexes can be obtained by changing the number and length of peripheral alkoxyl chains attached to a 2,5-diphenylpyridine ligand (main ligand) and a pyridyltetrazolate ligand (auxiliary ligand). Moreover, experimental results of the charge transport properties for these iridium(III) complexes, which were measured by the space charge limited-current method, exhibit ambipolar carrier mobility behavior. In particular, the liquid-crystalline iridium(III) complexes can self-organize into one-dimensional (1D) nanostructure after thermal annealing treatment in their liquid-crystalline phase. The devices based on liquid crystal film display improved charge transport behavior compared with that of the devices based on polycrystalline film, indicating 1D nanostructure is beneficial to charge carrier injection and transportation.

Spodoptera litura cyclophilin A is required for Microplitis bicoloratus bracovirus-induced apoptosis during insect cellular immune response.

Microplitis bicoloratus bracovirus (MbBV) is a polydnavirus found in the parasitic wasp M. bicoloratus. Although MbBV is a known inducer of apoptosis in host hemocytes, the mechanism by which this occurs remains elusive. In this study, we found that expression of cyclophilin A (CypA) was significantly upregulated in Spodoptera litura hemocytes at 6-day post-parasitization. Similar results were reported in High Five cells (Hi5 cells) infected by MbBV, suggesting that the upregulation of CypA is linked to MbBV infection in insect cells. cDNA encoding CypA was cloned from parasitized hemocytes of S. litura, and bioinformatic analyses showed that S. litura CypA belongs to the cyclophilin family of proteins. Overexpression of S. litura CypA in Hi5 cells revealed that the protein promotes MbBV-induced apoptosis in vitro. Conversely, suppression of the expression and activity of CypA protein significantly rescued the apoptotic phenotype observed in MbBV-infected Hi5 cells, suggesting that it plays a key role in this process. MbBV infection also promoted the cytoplasmic-nuclear translocation of CypA in Hi5 cells. Taken together, these results suggest that MbBV infection upregulates the expression of CypA, which is required for MbBV-mediated apoptosis. Our findings provide insight into the role that CypA plays in insect cellular immune response.

Cryo-EM structure reveals cylindrical nucleocapsids from two polydnaviruses.

Bracovirus is one of the two polydnavirus genera. Here, we used a cryo-EM analysis to reveal the near-native morphology of two nucleocapsid-containing model bracoviruses: Microplitis bicoloratus bracovirus (MbBV) and Microplitis mediator bracovirus (MmBV). MbBV and MmBV nucleocapsids have discernable cap structures in two distal regions with relatively high electron density. Adjacent to the end-cap structures are two electron-lucent rings. Some nucleocapsids were uniformly electron-dense and had a distinctive "helix-tail-like structure". Cryo-EM revealed inconsistent nucleocapsid diameters of 34-69.9 nm in MbBV and 46-69.9 nm in MmBV, and the largest observed cylindrical area length was expanded to 126 nm.

Unexpected link between insect innexins and apoptosis of HeLa cells.

Little is known about how mammalian cells respond to the expression of innexins (Inxs), which are known to mediate cell-to-cell communication that causes apoptosis in the cells of the insect Spodoptera litura. The mammalian expression system, p3xFLAG tag protein, containing the CMV promoter, allowed us to construct two C-terminally elongated innexins (Cte-Inxs), SpliInx2 (Inx2-FLAG), and SpliInx3 (Inx3-FLAG), which were predicted to have the same secondary topological structures as the native SpliInx2 and SpliInx3. Here, we found that only the mRNAs of the two Cte-Inxs were expressed under the control of the CMV promoter in HeLa cells. Unexpectedly, mRNA expression of the two Cte-Inxs enhanced apoptosis of HeLa cells. The two Cte-Inx mRNAs were associated with a significant decrease in Akt phosphorylation in HeLa cells undergoing apoptosis. Furthermore, Inx3-FLAG mRNA expression in nonapoptotic HCT116 cells was also associated with a significant decrease in the levels of phosphorylated Akt. Intriguingly, expression of the mRNAs of the two Cte-Inxs did not activate caspase 3, but it markedly reduced Bid levels in HeLa cells undergoing apoptosis. These results suggest that mRNA expression of the two Cte-Inxs may activate a Bid-dependent apoptotic pathway in HeLa cells. Our study demonstrates that invertebrate gap junction mRNAs can function in vertebrate cancer cells as tumor suppressors.

Inhibition of translation initiation factor eIF4A is required for apoptosis mediated by Microplitis bicoloratus bracovirus.

Apoptotic hemocytes induced by Microplitis bicoloratus parasitism have been reported, and M. bicoloratus bracovirus (MbBV) is known to be the apoptosis inducer. However, the mechanism how MbBV regulates apoptosis remains unclear. eIF4A, one of translation initiation factors, was found from a Spodoptera litura transcriptome, the expression of which in the parasitized hemocytes of S. litura was inhibited in RT-qPCR analysis. The western blot also illustrated eIF4A at 6-day post-parasitization was inhibited in hemocytes. For testing interaction of MbBV-eIF4A-apoptosis, a cDNA clone encoding 1,266 bp of eIF4A was obtained from S. litura hemocytes and sequenced. Then, a 48 kDa V5-fusion protein of the eIF4A was detected by using the anti-V5 antibody at 72-h post-transfection in the High Five cells, which is located in the cell cytoplasm. In vitro, overexpression of eIF4A rescued the apoptotic High Five cells induced by MbBV. Conversely, in vivo, loss of eIF4A proteins by dsRNA feeding increased apoptosis of hemocytes. Furthermore, RNAi and parasitism significantly increased apoptosis of hemocytes in S. litura. These findings suggested that MbBV inhibited the expression of eIF4A, which was required for apoptosis mediated by MbBV. This study will contribute to biological pest control and enhance our understanding of molecular mechanisms underlying polydnavirus-parasitoid-host interaction.

Identification of ß-chain of Fo F1 -ATPase in apoptotic cell population induced by Microplitis bicoloratus bracovirus and its role in the development of Spodoptera litura.

Two physiological changes of Spodoptera litura parasitized by Microplitis bicoloratus are hemocyte-apoptosis and retarded immature development. ß-Chain of Fo F1 -ATPase was found from a S. litura transcriptome. It belongs to a conserved P-loop NTPase superfamily, descending from a common ancestor of Lepidopteran clade. However, the characterization of ß-chain of ATPase in apoptotic cells and its involvement in development remain unknown. Here, the ectopic expression and endogenous Fo F1 -ATPase ß-chain occurred on S. litura cell membrane: in vivo, at the late stage of apoptotic hemocyte, endogenous Fo F1 -ATPase ß-chain was stably expressed during M. bicoloratus larva development from 4 to 7 days post-parasitization; in vitro, at an early stage of pre-apoptotic Spli221 cells by infecting with M. bicoloratus bracovirus particles, the proteins were speedily recover expression. Furthermore, endogenous Fo F1 -ATPase ß-chain was localized on the apoptotic cell membrane. RNA interference (RNAi) of Fo F1 -ATPase ß-chain led to significantly decreased head capsule width. This suggested that Fo F1 -ATPase ß-chain positively regulated the development of S. litura. The RNAi effect on the head capsule width was enhanced with parasitism. Our research found that Fo F1 -ATPase ß-chain was expressed and localized on the cell membrane in the apoptotic cells, and involved in the development of S. litura.

A polydnaviral genome of Microplitis bicoloratus bracovirus and molecular interactions between the host and virus involved in NF-κB signaling.

Polydnaviruses (PDVs) play a critical role in altering host gene expression to induce immunosuppression. However, it remains largely unclear how PDV genes affect host genes. Here, the complete genome sequence of Microplitis bicoloratus bracovirus (MbBV), which is known to be an apoptosis inducer, was determined. The MbBV genome consisted of 17 putative double-stranded DNA circles and 179 fragments with a total size of 336,336 bp and contained 116 open reading frames (ORFs). Based on conserved domains, nine gene families were identified, of which the IκB-like viral ankyrin (vank) family included 28 members and was one of the largest families. Among the 116 ORFs, 13 MbBV genes were expressed in hemocytes undergoing MbBV-induced apoptosis and further analyzed. Three vank genes (vank86, vank92, vank101) were expressed in hemocytes collected from Spodoptera litura larvae parasitized by M. bicoloratus, in which host NF-κB/IκBs, including relish, dorsal, and cactus, were also persistently expressed. When Spli221 cells were infected with MbBV viral particles, mRNA levels of host and viral NF-κB/IκB genes were persistent and also varied in Spli221 cells undergoing virus-induced pre-apoptosis cell from 1 to 5 hours postinfection. Both were then expressed in a time-dependent expression in virus-induced apoptotic cells. These data show that viral IκB-like transcription does not inhibit host NF-κB/IκB expression, suggesting that transcription of these genes might be regulated by different mechanisms.

N-TERMINALLY ELONGATED SpliInx2 AND SpliInx3 REDUCE BACULOVIRUS-TRIGGERED APOPTOSIS VIA HEMICHANNEL CLOSURE.

The hemichannel and gap junction channel are major portals for the release of factors responsible for the effects of apoptotic cells on the spread of apoptosis to neighboring cells and apoptotic corpse clearance, typically by phagocytes. The N-terminal cytoplasmic domain in the connexins, gap junction proteins in vertebrate, has been implicated in regulating channel closure. However, little is known about how the hemichannel close responds to apoptotic signaling transduction leading to the reduction of neighboring cellular apoptosis in an invertebrate. An insect Bac-to-Bac expression system, pFastBac(TM) HT A, allows us to construct an N-terminally elongated SpliInx2 (Nte-Inx2) and SpliInx3 (Nte-Inx3). Here, we demonstrated that recombinant baculovirus Bac-Nte-Inx2 (reBac-Net-Inx2) and Bac-Nte-Inx3 (reBac-Nte-Inx3) closed the endogenous hemichannel on the Sf9 cell surface. Importantly, primary baculovirus infections significantly caused early apoptosis, and this apoptosis was reduced by hemichannel-closed Sf9 cells at 24-h post-infection (PI). Although N-terminal-elongated residue led to the increase in the phosphorylated sites in both Nte-Inx2 and Nte-Inx3 and an additional transmembrane domain in Nte-Inx3, both the proteins localized on the cell surface, suggesting Nte-Inxs proteins could mediate hemichannel closure. Further supporting evidence showed that hemichannel closure was dependent on N-Inxs expressed by baculovirus polyhedrin promoter, which began to express at 18-24 h PI. These results identify an unconventional function of N-terminal-elongated innexins that could act as a plug to manipulate hemichannel closure and provide a mechanism connecting the effect of hemichannel closure directly to apoptotic signaling transduction from intracellular to extracellular compartment.

Phosphate ion targeted colorimetric and fluorescent probe and its use to monitor endogeneous phosphate ion in a hemichannel-closed cell.

Fluorescent probe 1, the first inorganic phosphate (Pi) targeted colorimetric and fluorescent probe to detect endogenous Pi in hemichannel-closed cells, has been developed. Probe 1 undergoes a unique Pi induced hydrolytic reaction in DMSO-HEPES (V/V = 9:1) buffered (0.02 M, pH 7.4) solutions that produces a colorimetric change associated with a 62 nm red-shift in the UV-vis absorption maximum and up to a 780-fold enhancement in the fluorescence intensity. The mechanistic proposal that these spectroscopic changes are associated with reaction Pi with 1 to form coumarin gains support from the results of theoretical calculations and mass spectrometry studies. Observations made in fluorescence imaging studies with HeLa cells and C. elegans show that 1 can be employed to monitor Pi production in vivo caused by apyrase-catalyzed ATP hydrolysis. Moreover, probe 1 was utilized to show that apoptosis of hemichannel-closed Sf9 cells is caused by Inx3 promoted dephosphorylation of Akt (RAC serine/threonine-protein kinase), leading to an elevation of the concentration of Pi. Overall, the study has produced the first fluorescent sensor 1 for endogenous inorganic phosphate. Moreover, the utility of 1 for measuring Pi release in vitro has been demonstrated and utilized to elucidate the mechanism of Inx3 action in hemichannel-closed Sf9 cells.

TWO INNEXINS OF Spodoptera litura INFLUENCES HEMICHANNEL AND GAP JUNCTION FUNCTIONS IN CELLULAR IMMUNE RESPONSES.

Insect cellular immune responses include encapsulation, nodule formation, and phagocytosis. Hemichannels and gap junctions are involved in these cellular actions. Innexins (Inxs: analogous to the vertebrate connexins) form hemichannels and gap junctions, but the molecular mechanisms underlying their biology is still unclear. In this article, we reported a steady-state level of Inxs (SpliInxs) in hemocytes of Spodoptera litura, which formed nonfunctional hemichannels on the cell surface to maintain normal metabolism. We also reported that two innnexins (SpliInx2 and SpliInx3) were expressed significantly higher in hemocytes compared to other tissues, suggesting that they play important roles in hemocytes. Amino acid analysis found that two cysteine residues in two extracellular loops provided the capability for SpliInx2 and SpliInx3 hemichannels to dock into gap junctions. Western blotting demonstrated that both extracellular and intracellular loops of SpliInx3 and the extracellular loops of SpliInx2 might undergo posttranslational modification during the formation of a steady-state hemichannel. During hemichannel formation, SpliInx2 presented as one isoform, while SpliInx3 presented as three isoforms. These results provide fundamental knowledge for further study of how steady-state levels of SpliInxs are dynamically adjusted to perform cellular immune responses under immune challenge.

Crystal structure of 6-eth-oxy-pyridin-1-ium-2-olate.

In the title compound, C7H9NO2, all non-H atoms are essentially coplanar [r.m.s. deviation = 0.032 Å]. The largest deviation from the plane of the pyridine ring is 0.105 (6) Šfor the terminal C atom of the eth-oxy group. In the crystal, mol-ecules are linked by pairs of N-H⋯O hydrogen bonds, forming inversion dimers. These dimers are further linked by C-H⋯π inter-actions and weak π-π inter-actions between pyridine rings [centroid-centroid distance = 4.023 (1) Å].

Crystal structure of (2-{3-[4-(4'-cyano-biphenyl-4-yl-oxy)but-oxy]pyridin-2-yl-κN}-5-(dodec-yloxy)phenyl-κC (1))(9-oxo-tetra-cos-7-en-7-olato-κ(2) O,O')platinum(II).

The central Pt(II) atom in the title compound, [Pt(C40H47N2O3)(C24H45O2)], has a slightly distorted square-planar coordination environment. The dihedral angle between the plane formed by Pt and the chelating C and N atoms and that formed by Pt and the chelating O atoms is 2.1 (3)°. The angle between the planes of the two rings in the biphenyl-4-carbo-nitrile unit is 35.1 (5)°. One lateral alkane chain is disordered over two sets of sites with site occupancy factors in a 0.595 (7):0.405 (7) ratio.

[Retracted] Inhibitory effect of Puerariae radix flavones on platelet­derived growth factor­BB­induced proliferation of vascular smooth muscle cells via PI3K and ERK pathways.

[This retracts the article DOI: 10.3892/etm.2014.2074.].

[Retracted] MicroRNA­29a inhibits cell migration and invasion by targeting Roundabout 1 in breast cancer cells.

Following the publication of this paper, it was drawn to the Editors' attention by a concerned reader that the Transwell migration and invasion assay data shown in Fig. 3A and B were strikingly similar to data appearing in different form in other articles written by different authors at different research institutes that had either already been published elsewhere prior to the submission of this paper to Molecular Medicine Reports, or were under consideration for publication at around the same time (a few of which have already been retracted). In view of the fact that certain of these data had already apparently been published previously, the Editor of Molecular Medicine Reports has decided that this paper should be retracted from the Journal. The authors were asked for an explanation to account for these concerns, but the Editorial Office did not receive a reply. The Editor apologizes to the readership for any inconvenience caused. [Molecular Medicine Reports 12: 3121-3126, 2015; DOI: 10.3892/mmr.2015.3749].

[2,6-Di-fluoro-3-(pyridin-2-yl-κN)pyridin-4-yl-κC (4)](penta-ne-2,4-dionato-κ(2) O,O')iridium(III).

The title compound, [Ir(C10H5F2N2)2(C5H7O2)], has a distorted octa-hedral coordination geometry around the Ir(III) atom, retaining the cis-C,C/trans-N,N chelate disposition in two 2,6-di-fluoro-3-(pyridin-2-yl-κN)pyridin-4-yl ligands which are nearly mutually perpendicular [dihedral angle = 82.75 (15)°]. The mol-ecular structure is stabilized by weak C-H⋯O and C-H⋯F hydrogen-bond inter-actions. The crystal structure is stabilized by π-π stacking inter-actions (centroid-centroid distance = 3.951 Å).

Simulating immunosuppressive mechanism of Microplitis bicoloratus bracovirus coordinately fights Spodoptera frugiperda.

Parasitoid wasps control pests via a precise attack leading to the death of the pest. However, parasitoid larvae exhibit self-protection strategies against bracovirus-induced reactive oxygen species impairment. This has a detrimental effect on pest control. Here, we report a strategy for simulating Microplitis bicoloratus bracovirus using Mix-T dsRNA targeting 14 genes associated with transcription, translation, cell-cell communication, and humoral signaling pathways in the host, and from wasp extracellular superoxide dismutases. We implemented either one-time feeding to the younger instar larvae or spraying once on the corn leaves, to effectively control the invading pest Spodoptera frugiperda. This highlights the conserved principle of "biological pest control," as elucidated by the triple interaction of parasitoid-bracovirus-host in a cooperation strategy of bracovirus against its pest host.

Envelope-Fusion-Syncytium Formation in Microplitis bicoloratus bracovirus Maturation.

The viral envelope is essential for virus maturation. Virus-mediated syncytium formations are induced by viral envelope proteins that cause membrane fusion of the infected cells. Polydnaviridae (Polydnavirus) are enveloped viruses with multiple nucleocapsids, and virions mature in symbiotic parasitoid wasp ovaries. However, the mechanism governing the envelope packaging of multiple nucleocapsids remains unclear. In this study, we used transmission electron microscopy to examine the process whereby multiple nucleocapsids of Microplitis bicoloratus bracovirus are packaged into an envelope and observed envelope-fusion-syncytium formation in symbiotic wasp calyx cells during virus maturation. The virus maturation process in calyx cells comprised four stages: pre-virogenic stroma, virogenic stroma, assembly, and fusion. Each virus contained a single envelope with one nucleocapsid in the assembly stage; multiple envelopes then fused to form a viral envelope with multiple nucleocapsids (i.e., the envelope-fusion-syncytium) around the envelope fusion core in the fusion stage. The envelope-fusion-syncytium then stabilized the virions that were released into the lumen of the ovary across the calyx epithelial layer. The phagocytic calyx epithelial cells on the border of the calyx and ovary lumen cleared the majority of non-enveloped nucleocapsids. In contrast, non-phagocytic calyx epithelial cells with microvilli and a cuticular line between the ovary wall and the lumen remained intact in the ovary lumen. These results indicate that envelope-fusion-syncytium formation is important for packaging multiple nucleocapsids in bracovirus maturation.