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

Primers used for constructing plasmids and strand-specific reverse transcription-polymerase chain reactions.

Primers used for constructing plasmids and strand-specific reverse transcription-polymerase chain reactions.</p

The TLS element is essential for viral RNAs to enhance satRNA replication in <i>trans</i>-replication assays.

(A) Schematic diagrams of L3, ncL3 and their derivatives. The 3′ UTR of CMV RNAs is divided into three regions: a variable region (VR) at the 5′ end, a conserved TLS at the 3′ end, and a highly conserved region (CR) separating them. Deleted sequences in the constructed mutants were indicated by dashed lines. The TLS in ncL3 was substituted with the TLS of BMV, PSV, TAV, TMV, or TYMV, to generate six chimeric ncL3 mutants. (B-D, F) Northern blotting analyses of the accumulation of sat-T1, L3 and its mutants in the 5th true leaves of Nicotiana benthamiana transiently expressing LS replication proteins (L1a+L2a) and the RNA silencing suppressor P19. The mutants of L3 or ncL3 tested in these experiments are shown above. (E) Northern blotting analyses of TLS, RNA4 (L4) and its noncoding version (ncL4) of L3, as well as both polarities of sat-T1 in the trans-replication assays. In this replication assay, the TLS, L4 and ncL4 were provided separately in trans via agroinfiltration. It is worth mentioning that the probe used to detect RNA3 and its subgenomic RNA4 in (C) & (D) is the digoxin-labeled oligonucleotide complementary to the sequence spanning from nt 1200 to 1333 of L3. The digoxin-labeled oligonucleotide probe used to detect these RNAs in (E) is complementary to the sequence positioning at nt 2128–2167 of L3. Mock plants were treated by infiltration solution alone. The relative accumulation levels of RNA3, and positive-sense or negative-sense RNA of sat-T1 in (B-D, F) are shown below. Ethidium bromide-stained ribosomal RNAs served as the loading control.</p

The flowchart depicting exposure protocols and time duration of exposure.

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

The replication proteins of Fny-CMV and LS-CMV exhibit significant differences in their ability to recruit positive-sense RNA of sat-T1.

(A) The hairpin structures containing the Box-B sequence in blue and the mutated Box-B (mBox-B) in red. mF3 denotes the F3 mutant, in which the Box-B was substituted with mBox-B. mF3-T1(+) and mF3-T1(-) are mF3 derivatives with positive-sense or negative-sense RNA of sat-T1 inserted between the CP and 3′ UTR in mF3, respectively. A fragment of the GUS gene (337 nt), equivalent in size of sat-T1, was introduced into F3 or mF3, resulting to the creation of F3-gus or mF3-gus, respectively. (B) The accumulation levels of F3 and mF3 in the trans-replication assay. Either F3 or mF3 was co-expressed with LS replication proteins and P19 in the 5th true leaves of N. benthamiana plants. Mock plants were treated with infiltration solution. At 3 days post-infiltration, total RNAs were extracted separately from three infiltrated leaves for each treatment and subjected to northern blotting analyses. The relative accumulation levels of F3 and mF3 are shown below as the mean values with standard errors from three independent biological samples. (C) Determination of the replication activities of mF3-T1(+), mF3-T1(-), and the controls F3-gus and mF3-gus. These four F3 derivatives was co-expressed with the P19 suppressor and the replication proteins of LS-CMV (upper panel) or Fny-CMV (the lower panel) in the 5th true leaves of Nicotiana benthamiana plants. Mock plants were treated with infiltration solution. At 3 days post-infiltration, total RNAs were extracted separately from three infiltrated leaves for each treatment, and analyzed by northern blot hybridization. The relative accumulation levels with standard errors shown below were calculated from three independent biological samples. “UD” denotes the undetectable level. Ethidium bromide-stained ribosomal RNAs were used as a loading control for normalization of the relative accumulation levels.</p

Subcellular distribution of F1a-mCherry when co-expressed with 6×MS2-satT1 in the leaf tissues of <i>Nicotiana benthamiana</i>.

The lower epidermis of the leaves was infiltrated with Agrobacterium cells harboring the binary plasmids to express F1a-mCherry, 6×MS2-satT1, and p19. At 2 days post-agroinfiltration, the infiltrated leaves were subjected to Laser confocal microscopy for visualizing red fluorescence omitted from F1a-mCherry. (TIF)</p