Translate this page to:
Portuguese
In JoVE (1)
Other Publications (5)
Automatic Translation
This translation into Portuguese was automatically generated.
English Version | Other Languages
Articles by Linxia Zhang in JoVE
JoVE General
Isolamento e Enriquecimento de células-tronco mesenquimais Rat (MSC) e Separação de-colônia Único Derivado MSCs
Department of Chemical Engineering and Materials Science, City of Hope Cancer Center
Rat CTMs foram isoladas do fémur ea tíbia e então enriquecida por separação de células magnéticas. Células classificadas foram confirmados para a expressão de marcadores de superfície por citometria de fluxo. Estas células também foram cultivadas na densidade clonal para formar colônias individuais e, em seguida essas colônias foram separados por cilindros de clonagem.
Other articles by Linxia Zhang on PubMed
A Novel Method Incorporating Gene Ontology Information for Unsupervised Clustering and Feature Selection
Among the primary goals of microarray analysis is the identification of genes that could distinguish between different phenotypes (feature selection). Previous studies indicate that incorporating prior information of the genes' function could help identify physiologically relevant features. However, current methods that incorporate prior functional information do not provide a relative estimate of the effect of different genes on the biological processes of interest.
The Effect of PEGylation of Mesoporous Silica Nanoparticles on Nonspecific Binding of Serum Proteins and Cellular Responses
Highly ordered MCM-41-type mesoporous silica nanoparticles (MSNs) with particle sizes of 150 +/- 20 nm were prepared and PEGylated by covalently grafting PEGxk chains of different molecular weights (x = 4, 6, 10, 20) and chain densities (0.05 wt%-3.75 wt%) on the outer surface. The influence of molecular weights and chain densities of PEGxk on the nonspecific binding of PEGylated MSNs to human serum protein (HSA) was investigated. The results revealed that the optimal molecular weights should be not less than 10k, and the corresponding optimal chain densities for PEG10k-MSNs and PEG20k-MSNs were 0.75 wt% and 0.075 wt%, respectively, and the resultant minimum HSA adsorbance (2.5%) on PEGxk-MSNs was far less than that on MSNs (18.7%) without PEGylation. Under the optimal conditions for the minimum HSA adsorbance, the phagocytosis of human THP-1 monocytic leukemia cell line-derived macrophages (THP-1 macrophages) and the hemolysis of human red blood cells (HRBCs) were investigated with MSNs and PEGylated MSNs. A minimum THP-1 phagocytosis percentage (0.1%) and a very low HRBCs hemolysis percentage (0.9%) of PEG10k-MSNs were obtained, which were much lower than those (8.6% and 14.2%, respectively) of MSNs.
Synergistic Effect of CAMP and Palmitate in Promoting Altered Mitochondrial Function and Cell Death in HepG2 Cells
Saturated free fatty acids (FFAs), e.g. palmitate, have long been shown to induce toxicity and cell death in various types of cells. In this study, we demonstrate that cAMP synergistically amplifies the effect of palmitate on the induction of cell death in human hepatocellular carcinoma cell line, HepG2 cells. Elevation of cAMP level in palmitate-treated cells led to enhanced mitochondrial fragmentation, mitochondrial reactive oxygen species (ROS) generation and mitochondrial biogenesis. Mitochondrial fragmentation precedes mitochondrial ROS generation and mitochondrial biogenesis, and may contribute to mitochondrial ROS overproduction and subsequent mitochondrial biogenesis. Fragmentation of mitochondria also facilitated the release of cytotoxic mitochondrial proteins, such as Smac, from the mitochondria and subsequent activation of caspases. However, cell death induced by palmitate and cAMP was caspase-independent and mainly necrotic.
Cell Adhesive Behavior on Thin Polyelectrolyte Multilayers: Cells Attempt to Achieve Homeostasis of Its Adhesion Energy
Linearly growing ultrathin polyelectrolyte multilayer (PEM) films of strong polyelectrolytes, poly(diallyldimethylammonium chloride) (PDAC), and sulfonated polystyrene, sodium salt (SPS) exhibit a gradual shift from cytophilic to cytophobic behavior, with increasing thickness for films of less than 100 nm. Previous explanations based on film hydration, swelling, and changes in the elastic modulus cannot account for the cytophobicity observed with these thin films as the number of bilayers increases. We implemented a finite element analysis to help elucidate the observed trends in cell spreading. The simulation results suggest that cells maintain a constant level of energy consumption (energy homeostasis) during active probing and thus respond to changes in the film stiffness as the film thickness increases by adjusting their morphology and the number of focal adhesions recruited and thereby their attachment to a substrate.
CAMP Initiates Early Phase Neuron-like Morphology Changes and Late Phase Neural Differentiation in Mesenchymal Stem Cells
The intracellular second messenger cAMP is frequently used in induction media to induce mesenchymal stem cells (MSCs) into neural lineage cells. To date, an understanding of the role cAMP exerts on MSCs and whether cAMP can induce MSCs into functional neurons is still lacking. We found cAMP initiated neuron-like morphology changes early and neural differentiation much later. The early phase changes in morphology were due to cell shrinkage, which subsequently rendered some cells apoptotic. While the morphology changes occurred prior to the expression of neural markers, it is not required for neural marker expression and the two processes are differentially regulated downstream of cAMP-activated protein kinase A. cAMP enabled MSCs to gain neural marker expressions with neuronal function, such as, calcium rise in response to neuronal activators, dopamine, glutamate, and potassium chloride. However, only some of the cells induced by cAMP responded to the three neuronal activators and further lack the neuronal morphology, suggesting that although cAMP is able to direct MSCs towards neural differentiation, they do not achieve terminal differentiation.
