| 1. |
- Tang, Zhongshu, et al.
(författare)
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Survival effect of PDGF-CC rescues neurons from apoptosis in both brain and retina by regulating GSK3β phosphorylation
- 2010
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Ingår i: Journal of Experimental Medicine. - : The Rockefeller University Press. - 0022-1007 .- 1540-9538. ; 207:4, s. 867-880
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Tidskriftsartikel (refereegranskat)abstract
- Platelet-derived growth factor CC (PDGF-CC) is the third member of the PDGF family discovered after more than two decades of studies on the original members of the family, PDGF-AA and PDGF-BB. The biological function of PDGF-CC remains largely to be explored. We report a novel finding that PDGF-CC is a potent neuroprotective factor that acts by modulating glycogen synthase kinase 3beta (GSK3beta) activity. In several different animal models of neuronal injury, such as axotomy-induced neuronal death, neurotoxin-induced neuronal injury, 6-hydroxydopamine-induced Parkinson's dopaminergic neuronal death, and ischemia-induced stroke, PDGF-CC protein or gene delivery protected different types of neurons from apoptosis in both the retina and brain. On the other hand, loss-of-function assays using PDGF-C null mice, neutralizing antibody, or short hairpin RNA showed that PDGF-CC deficiency/inhibition exacerbated neuronal death in different neuronal tissues in vivo. Mechanistically, we revealed that the neuroprotective effect of PDGF-CC was achieved by regulating GSK3beta phosphorylation and expression. Our data demonstrate that PDGF-CC is critically required for neuronal survival and may potentially be used to treat neurodegenerative diseases. Inhibition of the PDGF-CC-PDGF receptor pathway for different clinical purposes should be conducted with caution to preserve normal neuronal functions.
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| 2. |
- Zhang, Fan, et al.
(författare)
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VEGF-B is dispensable for blood vessel growth but critical for their survival, and VEGF-B targeting inhibits pathological angiogenesis
- 2009
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 106:15, s. 6152-6157
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Tidskriftsartikel (refereegranskat)abstract
- VEGF-B, a homolog of VEGF discovered a long time ago, has not been considered an important target in antiangiogenic therapy. Instead, it has received little attention from the field. In this study, using different animal models and multiple types of vascular cells, we revealed that although VEGF-B is dispensable for blood vessel growth, it is critical for their survival. Importantly, the survival effect of VEGF-B is not only on vascular endothelial cells, but also on pericytes, smooth muscle cells, and vascular stem/progenitor cells. In vivo, VEGF-B targeting inhibited both choroidal and retinal neovascularization. Mechanistically, we found that the vascular survival effect of VEGF-B is achieved by regulating the expression of many vascular prosurvival genes via both NP-1 and VEGFR-1. Our work thus indicates that the function of VEGF-B in the vascular system is to act as a "survival," rather than an "angiogenic" factor and that VEGF-B inhibition may offer new therapeutic opportunities to treat neovascular diseases.
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| 3. |
- Cai, Yongqing, et al.
(författare)
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Impact of wave breaking on upper-ocean turbulence
- 2017
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Ingår i: Journal of Geophysical Research - Oceans. - 2169-9275 .- 2169-9291. ; 122:2, s. 1513-1528
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Tidskriftsartikel (refereegranskat)abstract
- Previous studies have demonstrated that surface wave breaking can impact upper-ocean turbulence through wave-breaking-induced turbulence kinetic energy (TKE) flux and momentum flux. Wave-breaking-induced momentum flux decays approximately exponentially with depth, and the decay exponent depends on both the wind speed and wave age. With increasing wave age, the decay speed of wave-breaking-induced momentum flux first decreases, reaching a minimum around a wave age of 16, and then increases. In this study, a wave-breaking-induced momentum flux parameterization was proposed based on wave age and wind-speed dependence. The new proposed parameterization was introduced into a one-dimensional (1-D) ocean model along with a wave-age-dependent wave-breaking-induced TKE flux parameterization. The simulation results showed that the wave-breaking impact on the ocean mainly affected the upper-ocean layer. Adding the wave-age impact to the wave-breaking-induced TKE flux and momentum flux improved the 1-D model performance concerning the sea temperature. Moreover, the wave-breaking-induced momentum flux had a larger impact on the simulation results than the wave-breaking-induced TKE flux.
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| 4. |
- Tao, Yongqing, et al.
(författare)
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The application potential of self-glazed zirconia crowns confirmed by easy grinding and polishing of the enamel-like surface
- 2020
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Ingår i: Advances in Applied Ceramics. - : Informa UK Limited. - 1743-6753 .- 1743-6761. ; 119:5-6, s. 297-304
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Tidskriftsartikel (refereegranskat)abstract
- The surface profile roughness (Ra), surface area roughness (Sa), and surface topography of newly developed as-prepared, ground, and polished self-glazed zirconia (SGZ) were evaluated using a profilometer, 3D optical surface profiler, and SEM, with conventional dry-milled zirconia (CZ) as a reference. A statistical analysis was conducted using repeated measures analysis of variance (ANOVA) and the Bonferroni test (alpha = .05). Results revealed that the material (p = .005), clinical adjustment procedure (p < .001), and interaction between factors (p < .001) had statistically significant effects on the Ra values. SGZ showed lower Sa values than CZ during the same period. Ten patient cases involving the restoration of the monolithic anatomic contour SGZ crowns were investigated. All crowns remained functional until the latest clinical follow-up and no further antagonist wear was observed. Thus, SGZ had relatively lower surface roughness, which was also more easily altered than that of CZ.
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| 5. |
- Vazin, Tandis, et al.
(författare)
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A Novel Combination of Factors, Termed SPIE, which Promotes Dopaminergic Neuron Differentiation from Human Embryonic Stem Cells
- 2009
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Ingår i: PLOS ONE. - : Public Library Science. - 1932-6203. ; 4:8, s. e6606-
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Tidskriftsartikel (refereegranskat)abstract
- Background: Stromal-Derived Inducing Activity (SDIA) is one of the most efficient methods of generating dopaminergic (DA) neurons from embryonic stem cells (ESC). DA neuron induction can be achieved by co-culturing ESC with the mouse stromal cell lines PA6 or MS5. The molecular nature of this effect, which has been termed "SDIA" is so far unknown. Recently, we found that factors secreted by PA6 cells provided lineage-specific instructions to induce DA differentiation of human ESC (hESC). Methodology/Principal Findings: In the present study, we compared PA6 cells to various cell lines lacking the SDIA effect, and employed genome expression analysis to identify differentially-expressed signaling molecules. Among the factors highly expressed by PA6 cells, and known to be associated with CNS development, were stromal cell-derived factor 1 (SDF1/CXCL12), pleiotrophin (PTN), insulin-like growth factor 2 (IGF2), and ephrin B1 (EFNB1). When these four factors, the combination of which was termed SPIE, were applied to hESC, they induced differentiation to TH-positive neurons in vitro. RT-PCR and western blot analysis confirmed the expression of midbrain specific markers, including engrailed 1, Nurr1, Pitx3, and dopamine transporter (DAT) in cultures influenced by these four molecules. Electrophysiological recordings showed that treatment of hESC with SPIE induced differentiation of neurons that were capable of generating action potentials and forming functional synaptic connections. Conclusions/Significance: The combination of SDF-1, PTN, IGF2, and EFNB1 mimics the DA phenotype-inducing property of SDIA and was sufficient to promote differentiation of hESC to functional midbrain DA neurons. These findings provide a method for differentiating hESC to form DA neurons, without a requirement for the use of animal-derived cell lines or products.
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| 6. |
- Vazin, Tandis, et al.
(författare)
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The Molecular Nature of Stromal-Derived Inducing Activity in Dopaminergic Differentiation of Human Embryonic Stem Cells
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The utilization of Stromal-Derived Inducing Activity (SDIA) is one of the most efficientmethods in generating dopaminergic (DA) neurons from embryonic stem cells (ESC).Neuronal and dopaminergic induction can be achieved by co-culturing ESC with mousestromal cell lines, PA6 or MS5. Although it is clear that SDIA has neural inducing andmidbrain patterning activity, the molecular nature of SDIA is so far unknown. There arecontrary reports that either cell surface activity or factors secreted by PA6 cells areresponsible for SDIA. Recently, we found that PA6 cell surface and extracellular matrixmolecules primarily promoted cell survival and general neurogenesis of hESC. Incontrast, factors secreted by PA6 cells provided lineage-specific instructions in thepresence of a stabilizing factor, heparin. In the present study, in an attempt to identify thefactors responsible for dopaminergic induction of hESC, we performed cell wholegenome expression analysis to search for soluble factors produced by PA6 cells bycomparing them to various cell lines lacking the SDIA effect. Among the soluble secretedfactors differentially expressed by PA6 cells were stromal cell-derived factor 1 (SDF-1/CXCL12), pleiotrophin (PTN), insulin-like growth factor 2 (IGF2), and ephrin B1(EFNB1). The combination of these factors, which we termed SPIE, was sufficient toproduce dopaminergic neuronal differentiation of the hESC line BG01V2 and otherkaryotypically normal hESC lines in vitro.
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| 7. |
- Xueyan, Zhang, et al.
(författare)
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NDVI spatial pattern and its differentiation on the Mongolian Plateau
- 2009
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Ingår i: JOURNAL OF GEOGRAPHICAL SCIENCES. - : Springer Science and Business Media LLC. - 1009-637X .- 1861-9568. ; 19:4, s. 403-415
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Tidskriftsartikel (refereegranskat)abstract
- GIMMS NDVI database and geo-statistics were used to depict the spatial distribution and temporal stability of NDVI on the Mongolian Plateau. The results demonstrated that: (1) Regions of interest with high NDVI indices were distributed primarily in forested mountainous regions of the east and the north, areas with low NDVI indices were primarily distributed in the Gobi desert regions of the west and the southwest, and areas with moderate NDVI values were mainly distributed in a middle steppe strap from northwest to southeast. (2) The maximum NDVI values maintained for the past 22 years showed little variation. The average NDVI variance coefficient for the 22-year period was 15.2%. (3) NDVI distribution and vegetation cover showed spatial autocorrelations on a global scale. NDVI patterns from the vegetation cover also demonstrated anisotropy; a higher positive spatial correlation was indicated in a NW-SE direction, which suggested that vegetation cover in a NW-SE direction maintained increased integrity, and vegetation assemblage was mainly distributed in the same specific direction. (4) The NDVI spatial distribution was mainly controlled by structural factors, 88.7% of the total spatial variation was influenced by structural and 11.3% by random factors. And the global autocorrelation distance was 1178 km, and the average vegetation patch length (NW-SE) to width (NE-SW) ratio was approximately 2.4:1.0.
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