The Proliferation and Migration-Enhancing Effects of Vitronectin in SMMC 7721 Cells: A Pilot Study

To understand the effects of Vitronectin on cell proliferation and migration in the cell line of hepatocellular carcinoma, SMMC 7721, the effects of Vitronectin on cell proliferation rate or on the prevention of the cells from the apoptotic stimuli were appraised with WST-1 assay; and the morphology of b-Tubulin was observed with con-focal microscope. The effect on migration was detected with transwell chamber. The results show that Vitronectin helps the cells adhere to Petri dish as well as the sustaining of the morphology of b-Tubulin. Vitronectin could enhance the proliferation rate of SMMC 7721 with the concentration-effect mode, and could protect the cells from the stimuli of apoptosis inducer. As to cell migration, the results show that Vitronectin enhance cell migration across the membrane of transwell chamber. According the results, the conclusion could be made that Vitronectin might play important roles in the following biological effects, such as sustaining the morphology of the tumor cells, enhancing the proliferation as well as the migration

Role of synaptic structural plasticity in impairments of spatial learning and memory induced by developmental lead exposure in Wistar rats.

Lead (Pb) is found to impair cognitive function. Synaptic structural plasticity is considered to be the physiological basis of synaptic functional plasticity and has been recently found to play important roles in learning and memory. To study the effect of Pb on spatial learning and memory at different developmental stages, and its relationship with alterations of synaptic structural plasticity, postnatal rats were randomly divided into three groups: Control; Pre-weaning Pb (Parents were exposed to 2 mM PbCl2 3 weeks before mating until weaning of pups); Post-weaning Pb (Weaned pups were exposed to 2 mM PbCl2 for 9 weeks). The spatial learning and memory of rats was measured by Morris water maze (MWM) on PND 85-90. Rat pups in Pre-weaning Pb and Post-weaning Pb groups performed significantly worse than those in Control group (p<0.05). However, there was no significant difference in the performance of MWM between the two Pb-exposure groups. Before MWM (PND 84), the number of neurons and synapses significantly decreased in Pre-weaning Pb group, but not in Post-weaning Pb group. After MWM (PND 91), the number of synapses in Pre-weaning Pb group increased significantly, but it was still less than that of Control group (p<0.05); the number of synapses in Post-weaning Pb group was also less than that of Control group (p<0.05), although the number of synapses has no differences between Post-weaning Pb and Control groups before MWM. In both Pre-weaning Pb and Post-weaning Pb groups, synaptic structural parameters such as thickness of postsynaptic density (PSD), length of synaptic active zone and synaptic curvature increased significantly while width of synaptic cleft decreased significantly compared to Control group (p<0.05). Our data demonstrated that both early and late developmental Pb exposure impaired spatial learning and memory as well as synaptic structural plasticity in Wistar rats

Effects of low-level organic selenium on lead-induced alterations in neural cell adhesion molecules.

Low-level lead (Pb) exposure has been reported to impair the formation and consolidation of learning and memory by inhibiting the expression of neural cell adhesion molecules (NCAMs) and altering the temporal profile of its polysialylation state. In this study, we investigated whether administration of low-level organic selenium (selenomethionine, Se) at different time points could affect Pb-induced changes of NCAMs in female Wistar rats. Here we reported that the exposure of Se (60μg/kg body weight/day) at different time points significantly alleviated Pb-induced reductions in the mRNA and protein levels of NCAMs, and increases in the mRNA levels of two polysialyltransferases (St8sia II, Stx; St8sia IV, Pst) as well as the sialyltransferase activity (p\u3c0.05). The concentrations of Pb in blood and hippocampi of Wistar rats treated with the combination of Se and Pb were significantly lower than those treated with Pb alone (p\u3c0.05). Our results suggest that low-level organic Se can not only prevent but also reverse Pb-induced alterations in the expression and polysialylated state of NCAMs as well as the concentration of Pb in rat blood and hippocampus. Brain Res 2013 Sep 12; 1530:76-81

The effect of developmental lead exposure on the synaptic structure parameters in the CA1 region of rat hippocampus on PND91.

<p>Values are expressed as the means ± S.D. of 10 samples in each group; <b>*</b><i>p</i><0. 05, <i>versus</i> Control (one-way ANOVA and the Bonferroni test).</p><p>The effect of developmental lead exposure on the synaptic structure parameters in the CA1 region of rat hippocampus on PND91.</p

The effect of developmental lead exposure on the number of neurons in the rat hippocampus on PND 84.

<p>Values are expressed as the means ± S.D. of 10 samples in each group; <b>*</b><i>p</i><0. 05 and <b>**</b><i>p</i><0. 01, <i>versus</i> Control (one-way ANOVA and the Bonferroni test).</p><p>The effect of developmental lead exposure on the number of neurons in the rat hippocampus on PND 84.</p

The flowchart depicting exposure protocols and time duration of exposure.

<p>The flowchart depicting exposure protocols and time duration of exposure.</p

Effect of developmental lead exposure on the performance of rat pups in the probe trial of MWM test on PND85–90.

<p>Values are expressed as the means ± S.D. of 10 samples in each group; <b>**</b><i>p</i><0. 01, <b>***</b><i>p</i><0.0 01, <i>versus</i> Control (one-way ANOVA and the Bonferroni test).</p><p>Effect of developmental lead exposure on the performance of rat pups in the probe trial of MWM test on PND85–90.</p

Infection of <i>Nigrospora nonsegmented RNA Virus 1</i> Has Important Biological Impacts on a Fungal Host

Nigrospora nonsegmented RNA virus 1 (NoNRV1) has been reported previously in the fungus Nigrospora oryzae, but its biological effects on its host are unknown. In this work, we isolated a strain 9-1 of N. oryzae from a chrysanthemum leaf and identified NoNRV1 infection in the isolated strain. The genome sequence of NoNRV1 identified here is highly homologous to that of the isolate HN-21 of NoNRV1 previously reported; thus, we tentatively designated the newly identified NoNRV1 as NoNRV1-ZJ. Drug treatment with Ribavirin successfully removed NoNRV1-ZJ from the strain 9-1, which provided us with an ideal control to determine the biological impacts of NoNRV1 infection on host fungi. By comparing the virus-carrying (9-1) and virus-cured (9-1C) strains, our results indicated that infection with NoNRV1 promoted the pigmentation of the host cells, while it had no discernable effects on host growth on potato dextrose agar plates when subjected to osmotic or oxidative stress. Interestingly, we observed inhibitory impacts of virus infection on the thermotolerance of N. oryzae and the pathogenicity of the host fungus in cotton leaves. Collectively, our work provides clear evidence of the biological relevance of NoNRV1 infection in N. oryzae, including pigmentation, hypovirulence, and thermotolerance