Free cadmium ions released from CdTe-based nanoparticles and their cytotoxicity on Phaeodactylum tricornutum

The risk of nanoparticles (NPs) to organisms and the environment has become more noticeable alongside their rapid applications in many fields. The release of Cd2+ from CdTe-based NPs (CdTe-NPs), an important class of engineered nanomaterials, is one of the possible factors responsible for the cytotoxicity of these NPs. Based on the same CdTe core, CdTe/CdS, CdTe/ZnS and CdTe/SiO2 NPs were synthesized and their Cd2+ release rates were carefully studied based on dialysis using inductively coupled plasma mass spectrometry (ICPMS). Results obtained indicated that the Cd2+ release rates of the CdTe-NPs decreased in the order CdTe (8.78 ng mL(-1) mg(-1) h(-1)) > CdTe/CdS (2.63) > CdTe/SiO2 (0.89) > CdTe/ZnS (0.72). Phaeodactylum tricornutum was used as a model diatom for evaluating the cytotoxicity of the CdTe-NPs. Results obtained from the CdTe-NPs exposure experiments together with ICPMS and fluorescence microscopy studies suggested that the cytotoxicity of the CdTe-NPs increased along with the increase in their Cd2+ release rates. Effective coating materials such as ZnS and SiO2 for the CdTe core significantly reduced the cytotoxicity of CdTe.National Natural Science Foundation of China [20775062]; National Basic Research Program of China [2009CB421605

Platelet factor-4 and its p17-70 peptide inhibit myeloma proliferation and angiogenesis in vivo

<p>Abstract</p> <p>Background</p> <p>Angiogenesis plays an important role in the development of multiple myeloma (MM). The interaction between MM cells and the bone marrow microenvironment stimulates the proliferation and migration of endothelial progenitor cells (EPCs). Vascular endothelial growth factor (VEGF) contributes to the formation of new blood vessels by actively recruiting circulating EPCs. The production of proangiogenic and antiangiogenic factors is also dysregulated in MM. Platelet factor 4 (PF4) is a potent angiostatic cytokine that inhibits angiogenesis and tumor growth in several animal models.</p> <p>Methods</p> <p>In this study, we stably transfected human myeloma cell lines with the PF4 gene or the sequence encoding its more potent p17-70 peptide and investigated the effects of PF4 and p17-70 on angiogenesis and tumor growth <it>in vitro </it>and in a SCID-rab myeloma model.</p> <p>Results</p> <p>PF4 and p17-70 significantly attenuated VEGF production, both <it>in vitro </it>and <it>in vivo</it>. In a migration study using a Transwell system, PF4 or p17-70 markedly suppressed the migration of co-cultured human endothelial progenitor cells. PF4 or p17-70 also caused a significant reduction in microvessel densities in myeloma xenografts and markedly reduced the tumor volume in the SCID mice. Kaplan-Meier analysis demonstrated that PF4 and p17-70 significantly extended the overall survival of SCID mice bearing human myeloma xenografts.</p> <p>Conclusions</p> <p>Our findings indicate that PF4 or p17-70 could be valuable in combating multiple myeloma by disrupting tumor angiogenesis.</p

Effect of the pollen of transgenic rice line, TT9-3 with a fused cry1Ab/cry1Ac gene from Bacillus thuringiensis Berliner on non-target domestic silkworm, Bombyx mori Linnaeus (Lepidoptera: Bombyxidae)

Some cry genes from Bacillus thuringiensis Berliner (Bt) have been transferred into rice plants for resistance to lepidopterans. The ecological risks of Bt rice, especially the non-target effects of Bt rice pollen on the domestic silkworm, Bombyx mori Linnaeus in mulberry-rice mixed cropping area should be clarified cautiously. In light of B. mori fully domesticated and not surviving independently in the field, a series of laboratory bioassays were conducted to evaluate the effect of the pollen from an indica transgenic rice line, TT9-3 with a fused cry1Ab/cry1Ac gene on B. mori based on the investigation of rice pollen deposition under normal field conditions and the quantitation of the fused insecticidal protein expression in the pollen. No significant adverse effects were observed on the survival, growth and development of B. mori young larvae, even after the neonates had been exposed to Bt pollen at the highest density of 3,395.0 grains/cm2 for 48 h which the pollen density is far higher than the highest pollen density on mulberry leaf, 1,635.9 grains/cm2, naturally occurred in the field. According to these results and considering the extensive biotic and non-biotic factors such as the type of Bt genes used and expressed in Bt rice line TT9-3 which are safe to B. mori, the relatively low exposure amount of insecticidal protein in the Bt pollen, and other conditions which influence the silkworm's exposure to Bt pollens, it suggests that the pollen from Bt rice line, TT9-3 poses little effect on silkworm rearing in natural settings

Comparative whole-genome analysis reveals artificial selection effects on Ustilago esculenta genome

Ustilago esculenta, infects Zizania latifolia, and induced host stem swollen to be a popular vegetable called Jiaobai in China. It is the long-standing artificial selection that maximizes the occurrence of favourable Jiaobai, and thus maintaining the plant-fungi interaction and modulating the fungus evolving from plant pathogen to entophyte. In this study, whole genome of U. esculenta was sequenced and transcriptomes of the fungi and its host were analysed. The 20.2Mb U. esculenta draft genome of 6,654 predicted genes including mating, primary metabolism, secreted proteins, shared a high similarity to related Smut fungi. But U. esculenta prefers RNA silencing not repeat-induced point in defence and has more introns per gene, indicating relatively slow evolution rate. The fungus also lacks some genes in amino acid biosynthesis pathway which were filled by up-regulated host genes and developed distinct amino acid response mechanism to balance the infection-resistance interaction. Besides, U. esculenta lost some surface sensors, important virulence factors and host range-related effectors to maintain the economic endophytic life. The elucidation of the U. esculenta genomic information as well as expression profiles can not only contribute to more comprehensive insights into the molecular mechanism underlying artificial selection but also into smut fungi-host interactions

Analysis of global ionospheric scintillation and GPS positioning interference triggered by full-halo CME-driven geomagnetic storm: A case study

Currently, the 25th solar activity peak has commenced, driving frequent geomagnetic storms and causing irregular disturbances in the global ionosphere, leading to the scintillation of Global Positioning System (GPS) signals, consequently decreasing the accuracy of GPS positioning. Analyzing the patterns of global ionospheric scintillation and changes in GPS positioning accuracy caused by geomagnetic storms is crucial to mitigate the adverse effects of GPS positioning. Current research has primarily concentrated on analyzing the effects of geomagnetic storms on ionospheric scintillation disturbances and GPS positioning interference. However, there is a notable gap in studying the holistic impact of coronal mass ejections (CMEs)-driven geomagnetic storms on GPS performance as an integrated event complex. This study investigates the conditions under which a CME drives a severe geomagnetic storm to elucidate the space weather phenomena associated with CME-driven geomagnetic storms. The ionospheric scintillation induced by the geomagnetic storm is analyzed, while we also examine the accuracy variability in kinematic precision point positioning (PPP) and its possible leading reasons. The research findings suggest that factors such as a high-speed full-halo CME, a southward interplanetary magnetic field (IMF) Bz, and high-speed solar wind contribute to the onset of this geomagnetic storm. Ionospheric scintillation and the decrease in positioning accuracy in low-latitude regions are less pronounced compared to mid- and high-latitude areas. Geomagnetic-storm-induced scintillation increases cycle slips, leading to a decrease in PPP accuracy. Even in the cases where geomagnetic storms do not induce ionospheric scintillation, positioning accuracy can still be affected by cycle slips, deterioration of the precision of the GPS measurements, data outages, and the decrease in the number of available satellites. </p

Genome-wide association study of hippocampal blood-oxygen-level-dependent-cerebral blood flow correlation in Chinese Han population

Correlation between blood-oxygen-level-dependent (BOLD) and cerebral blood flow (CBF) has been used as an index of neurovascular coupling. Hippocampal BOLD-CBF correlation is associated with neurocognition, and the reduced correlation is associated with neuropsychiatric disorders. We conducted the first genome-wide association study of the hippocampal BOLD-CBF correlation in 4,832 Chinese Han subjects. The hippocampal BOLD-CBF correlation had an estimated heritability of 16.2-23.9% and showed reliable genome-wide significant association with a locus at 3q28, in which many variants have been linked to neuroimaging and cerebrospinal fluid markers of Alzheimer&#39;s disease. Gene-based association analyses showed four significant genes (GMNC, CRTC2, DENND4B, and GATAD2B) and revealed enrichment for mast cell calcium mobilization, microglial cell proliferation, and ubiquitin-related proteolysis pathways that regulate different cellular components of the neurovascular unit. This is the first unbiased identification of the association of hippocampal BOLD-CBF correlation, providing fresh insights into the genetic architecture of hippocampal neurovascular coupling.</p

A host plant genome (Zizania latifolia) after a century-long endophyte infection

Despite the importance of host-microbe interactions in natural ecosystems, agriculture and medicine, the impact of long-term (especially decades or longer) microbial colonization on the dynamics of host genomes is not well understood. The vegetable crop Jiaobai' with enlarged edible stems was domesticated from wild Zizania latifolia (Oryzeae) approximately 2000years ago as a result of persistent infection by a fungal endophyte, Ustilago esculenta. Asexual propagation via infected rhizomes is the only means of Jiaobai production, and the Z.latifolia-endophyte complex has been maintained continuously for two centuries. Here, genomic analysis revealed that cultivated Z.latifolia has a significantly smaller repertoire of immune receptors compared with wild Z.latifolia. There are widespread gene losses/mutations and expression changes in the plant-pathogen interaction pathway in Jiaobai. These results show that continuous long-standing endophyte association can have a major effect on the evolution of the structural and transcriptomic components of the host genome. Significance Statement This study reports the genome of Jiaobai, a unique crop species domesticated from wild Zizania latifolia (Oryzeae) as a consequence of persistent infection by a fungal endophyte. Cultivated Z.latifolia (Jiaobai') has a significantly smaller repertoire of immune receptors compared with wild Z.latifolia, showing that continuous long-standing endophyte association can have a major effect on the evolution of the host genome