43 research outputs found
Atypical PKC and MAPK were involved in GSK-3 inactivation in EGF-promoted glioma invasion.
<p>(A) EGF-induced increase in pSer-GSK-3 levels was eliminated by inhibitors of aPKC and MAPK. <i>Left</i>: representative western blots of U251 lysates collected 3 hrs after wound recovery in the presence of EGF and indicated agents. <i>Right</i>: quantification of changes in pSer-GSK-3levels normalized to GSK-3 levels and then compared with the group without EGF treatment. (B) BothGSK-3Ī² and PKCĪ¶ were present in the same complexes. Western blot analysis of the complexes precipitated by the indicated antibodies (U251 lysates collected at 2 hrs after EGF stimulation). (C) Inhibition of aPKC and MAPK suppressed U87 cell invasion in the transwell assay. #<i>P</i><0.05 versus DMSO; * <i>P</i><0.05, ** <i>P</i><0.01 versus DMSO+EGF. Wortmannin, 1Ī¼M; LY294002, 5Ī¼M; Gƶ6976, 0.1Ī¼M; Gƶ6983, 10Ī¼M; U0126, 10Ī¼M, EGF, 40ng/ml. Data were mean Ā± SD of three independent experiments in triplicate.</p
Inhibiting GSK-3 blocked migration and invasion of human glioma cells.
<p>(A) Wound recovery of U251 and U87 cells in the presence of indicated agents. ** <i>P</i><0.01 versus DMSO. (B and C) Blockade of cell migration and invasion in the presence of GSK-3 inhibitors. (B) Representative images of U251 cells in the transwell invasion assay in different treatments. <i>Original magnification, 100Ć</i>. (C) Quantifications of transwell migration in invasion assays of U251 and U87 cells. ** <i>P</i><0.01 versus DMSO. (D) Western blot analysis of U87 cell lysates transfected with indicated constructs. The values indicated the amount of indicated proteins normalized to that of GAPDH and compared with non-sense (<i>si-ctl</i>) or pcDNA3 (<i>ctl</i>) control group. (E) GSK-3 down-regulation by small interfering RNA inhibited U87 cell migration and invasion in the transwell assay. * <i>P</i><0.05 versus non-sense control group (<i>si-ctl</i>). (F) Uniform up- or down-regulation of GSK-3Ī² activities inhibited U87 cell migration and invasion in the transwell assay. ** <i>P</i><0.01 versus pcDNA3 (<i>ctl</i>). si-3Ī±, siRNA against GSK-3Ī±; si-3Ī², siRNA against GSK-3Ī²; WT, wild-type form of GSK-3Ī²; S9A, constitutively active form of GSK-3Ī²; GID, inhibitory peptide of GSK-3Ī²; LP, mutant of GID without inhibitory effect. LiCl, 20mM, SB216763, 20Ī¼M, NaCl, 20mM. Data were mean Ā± SD of three independent experiments in triplicate. </p
Roles of GSK-3 in EGF-promoted glioma cell invasion.
<p>(A) EGF promoted U87 cell invasion in the transwell assay. ** <i>P</i><0.01 versus DMSO .(B) GSK-3 knock-down and uniform up-regulation of GSK-3Ī² activities inhibited U87 cell invasion. * <i>P</i><0.05, ** <i>P</i><0.01 versus pcDNA3 (<i>ctl</i>) or non-sense control (<i>si-ctl</i>). (C) Up-regulation of p-Ser-GSK-3 levels during EGF-induced wound recovery of U251 cells. <i>Left</i>: representative western blots of U251 cell lysates collected at indicated time points after scratching. <i>Right</i>: statistics of pSer-GSK-3 levels normalized to GSK-3 levels and then compared with the value at 0hr. *<i>P</i><0.05, ** <i>P</i><0.01 versus the value of pGSK-3/GSK-3 at 0hr. (D) Location of increased pGSK-3 staining in EGF-induced wound recovery of U251 cells 3 hrs after scratching. <i>Green</i>: anti-pSer21-GSK-3Ī±or anti-pSer9-GSK-3Ī²; <i>Red</i>: rhodamine phalloidin. <i>Original magnification, 400Ć</i>. si-3Ī±, siRNA against GSK-3Ī±; si-3Ī², siRNA against GSK-3Ī²; WT, wild-type form of GSK-3Ī²; S9A, constitutively active form of GSK-3Ī². Data were mean Ā± SD of three independent experiments. EGF, 40ng/ml.</p
Inhibition of GSK-3 influenced directional persistence and locomotion speed of human glioma cell migration.
<p>(A) Scheme to define the speed and relative step angles as described in <i>Materials and Method</i>. (B) Morphological changes of the U87 cells treated with LiCl. <i>Red</i>: rhodamine phalloidin. <i>Original magnification, 400Ć</i>. (C) Decreased locomotion speed of the U87 cells upon LiCl treatment. Data were mean Ā± SD of ten cells in each group ** <i>P</i><0.01 versus DMSO. (D) The representative migration traces of the cells in the presence or absence of LiCl, with the starting point of migration superimposed at the origin of the X-Y plot. (E) The relative step angle of representative four migrating cells in the presence or absence of LiCl. Relative step angle and direction change were defined as described in <i>Materials and Methods</i>. Negative or positive values in <i>y-axis</i> indicated angles in clockwise or counter-clockwise turn, respectively. Red line at 60Ā°or -60Ā° outlined time points when a direction change occurred (beyond the field of -60Ā°<āæĪ±<60Ā°). LiCl, 20mM.</p
Localized inactivation of GSK-3Ī² was associated with the formation of cell polarity.
<p>(A) Up-regulation of pSer-GSK-3 during the wound recovery of U251 cells. <i>Left</i>: representative western blot results of U251 cell lysates collected at indicated time points after scratching. <i>Right</i>: statistics of p-Ser-GSK-3 levels normalized to GSK-3 levels and compared with the value at 0hr. *<i>P</i><0.05, ** <i>P</i><0.01 versus the value of pGSK-3/GSK-3 at 0hr. (B) Location of increased pGSK-3 staining in the wound recovery of U251 cells at 0 hr or 3 hrs after scratching. Green: anti-pSer21-GSK-3Ī± or anti-pSer9-GSK-3Ī²; Red: rhodamine phalloidin. <i>Original magnification, 400Ć</i>.(C) MTOC mis-orientation in U251 caused by GSK-3 inhibitors. <i>Left</i>: representative images of MTOC in different treatments. Green: anti-Ī±-tubulin; Red: anti-pericentrin; Blue: Hoechst 33258. <i>Original magnification, 400Ć</i>. <i>Right</i>: quantification of centrosome polarization as described in <i>Materials and Methods</i> in U251 with or without GSK-3Ī² inhibitors. ** <i>P</i><0.01 versus DMSO. LiCl 20mM, SB216763, 20Ī¼M, NaCl, 20 mM. Data were mean Ā± SD of three independent experiments.</p
Stiffer but More Healable Exponential Layered Assemblies with Boron Nitride Nanoplatelets
Self-healing
ability and the elastic modulus of polymeric materials
may seem conflicting because of their opposite dependence on chain
mobility. Here, we show that boron nitride (BN) nanoplatelets can
simultaneously enhance these seemingly contradictory properties in
exponentially layer-by-layer-assembled nanocomposites as both surface
coatings and free-standing films. On one hand, embedding hard BN nanoplatelets
into a soft hydrogen bonding network can enhance the elastic modulus
and ultimate strength through effective load transfer strengthened
by the incorporation of interfacial covalent bonding; on the other
hand, during a water-enabled self-healing process, these two-dimensional
flakes induce an anisotropic diffusion, maintain the overall diffusion
ability of polymers at low loadings, and can be āsealingā
agents to retard the out-of-plane diffusion, thereby hampering polymer
release into the solution. A detailed mechanism study supported by
a theoretical model reveals the critical parameters for achieving
a complete self-healing process. The insights gained from this work
may be used for the design of high-performance smart materials based
on other two-dimensional fillers
Strong and Stiff Aramid Nanofiber/Carbon Nanotube Nanocomposites
Small but strong carbon nanotubes (CNTs) are fillers of choice for composite reinforcement owing to their extraordinary modulus and strength. However, the mechanical properties of the nanocomposites are still much below those for mechanical parameters of individual nanotubes. The gap between the expectation and experimental results arises not only from imperfect dispersion and poor load transfer but also from the unavailability of strong polymers that can be effectively utilized within the composites of nanotubes. Aramid nanofibers (ANFs) with analogous morphological features to nanotubes represent a potential choice to complement nanotubes given their intrinsic high mechanical performance and the dispersible nature, which enables solvent-based processing methods. In this work, we showed that composite films made from ANFs and multiwalled CNTs (MWCNTs) by vacuum-assisted flocculation and vacuum-assisted layer-by-layer assembly exhibited high ultimate strength of up to 383 MPa and Youngās modulus (stiffness) of up to 35 GPa, which represent the highest values among all the reported random CNT nanocomposites. Detailed studies using different imaging and spectroscopic characterizations suggested that the multiple interfacial interactions between nanotubes and ANFs including hydrogen bonding and ĻāĻ stacking are likely the key parameters responsible for the observed mechanical improvement. Importantly, our studies further revealed the attractive thermomechanical characteristics of these nanocomposites with high thermal stability (up to 520 Ā°C) and ultralow coefficients of thermal expansion (2ā6 ppmĀ·K<sup>ā1</sup>). Our results indicated that ANFs are promising nanoscale building blocks for functional ultrastrong and stiff materials potentially extendable to nanocomposites based on other nanoscale fillers
Four-phasic Doppler flow spectra of the MHV in the pulmonary hypertension (PH) group.
<p>Doppler spectra of MHV obtained from a patient with ventricular septal defect with the MPAP of 80 mmHg. The four-phasic waveform includes S wave, D wave, A wave and ventricular reversal (V wave) waves. Compared with the control group, the spectra had a higher value of the peak flow velocity and the velocity time integral (VTI) of A wave, and a lower value of peak flow velocity and VTI of S wave and D wave.</p
Bi-phasic Doppler flow spectra of the MHV in the PH group.
<p>Doppler spectra of MHV obtained from a patient with patent ductus arteriosus with the MPAP of 96 mmHg. The bi-phasic waveform of MHV includes S wave and A wave.</p
ROC curve of A/S, A/(S+D) and AVTI/(SVTI+DVTI) for predicting PH (MPAPā„ 25 mmHg).
<p>The diagnostic effect of the A/(S+D) radio is superior to the other three parameters. On the ROC curve of A/(S+D), the point that has the biggest Youden index is determined to be the cut-off point (0.30 with a sensitivity of 85.37% and specificity of 75.00%). (SVTI, systolic flow velocity time integral; DVTI, diastolic flow velocity time integral; AVTI, atrial reverse flow velocity time integral).</p