Search results for "CELLULAR"
showing 10 items of 6449 documents
Reprogrammed induced pluripotent stem cells: how suitable could they be in reproductive medicine?
2008
Human embryonic stem cells have the greatest potential for regenerative and reproductive medicine; unfortunately, their full application is limited by ethical and technical problems. In order to overcome these problems and get patient specific pluripotent cells from somatic cells, the field of reprogramming has moved to the generation of induced pluripotent stem cells by overexpression of four transcription factors after viral infection of the patient's somatic cells. In the present paper we review the limitations and milestones of this technique in both regenerative and reproductive medicine.
TBBPA causes neurotoxic and the apoptotic responses in cultured mouse hippocampal neurons in vitro
2015
Abstract Background Tetrabromobisphenol A (TBBPA) is a brominated flame retardant widely used in a variety of commercial and household products. TBBPA can become bioaccumulated in human body fluids, and also in different brain regions. The aim of the present study was to determine the viability and apoptosis of cultured mouse hippocampal neurons in vitro after exposure to TBBPA. Additionally, we examined the involvement of ROS generation in the effect of TBBPA. Methods Primary hippocampal neuron cultures were prepared from Swiss mouse embryos on day 17/18 of gestation. The cultures were treated with TBBPA at concentrations ranging from 1 nM to 100 μM for 30 min or 3, 6 or 24 h. To study apo…
Oligodendrocytes in mouse corpus callosum are coupled via gap junction channels formed by connexin47 and connexin32.
2010
According to previously published ultrastructural studies, oligodendrocytes in white matter exhibit gap junctions with astrocytes, but not among each other, while in vitro oligodendrocytes form functional gap junctions. We have studied functional coupling among oligodendrocytes in acute slices of postnatal mouse corpus callosum. By whole-cell patch clamp we dialyzed oligodendrocytes with biocytin, a gap junction-permeable tracer. On average 61 cells were positive for biocytin detected by labeling with streptavidin-Cy3. About 77% of the coupled cells stained positively for the oligodendrocyte marker protein CNPase, 9% for the astrocyte marker GFAP and 14% were negative for both CNPase and GF…
Differentiation-regulated loss of the polysialylated embryonic form and expression of the different polypeptides of the neural cell adhesion molecule…
1989
The expression of the neural cell adhesion molecule (N-CAM) on cultured murine oligodendrocytes, their precursors, and myelin was examined by indirect immunofluorescence, biosynthetic radiolabeling followed by immunoprecipitation and Western blot analysis, using antibodies specific for various forms of the molecule. In all culture systems studied, whether the oligodendrocytes were cultured as an enriched fraction containing precursor cells or in the presence of astrocytes and neurons, a similar differentiation-stage-related expression of N-CAM was seen. At early developmental stages many tetanus toxin receptor- and A2B5 antigen-positive putative oligodendrocyte precursors with bipolar morph…
Partially Quarternized Amino Functional Poly(methacrylate) Terpolymers: Versatile Drug Permeability Modifiers
2011
Partially quarternized poly(methacrylate) terpolymers (Q-BBMCs) have been synthesized, based on the basic butylated methacrylate copolymer (BBMC/EUDRAGIT E), an excipient approved by the Food and Drug Administration (FDA) and to date mainly applied for tablet coatings. Via straightforward polymer modification reactions, a series of Q-BBMCs with quarternization degrees of 22%, 42%, and 65% has been prepared. Apical to basolateral transport across Caco-2 cell monolayers was investigated, employing the paracellular transported compounds trospium and mannitol. At pH 6.5 quarternization resulted in increased permeation enhancement up to 2.8-fold compared to BBMC, that is, up to 7.3-fold compared…
Structure of Polymer Brushes in Cylindrical Tubes: A Molecular Dynamics Simulation
2006
Molecular Dynamics simulations of a coarse-grained bead-spring model of flexible macromolecules tethered with one end to the surface of a cylindrical pore are presented. Chain length $N$ and grafting density $\sigma$ are varied over a wide range and the crossover from ``mushroom'' to ``brush'' behavior is studied for three pore diameters. The monomer density profile and the distribution of the free chain ends are computed and compared to the corresponding model of polymer brushes at flat substrates. It is found that there exists a regime of $N$ and $\sigma$ for large enough pore diameter where the brush height in the pore exceeds the brush height on the flat substrate, while for large enoug…
Cellular Uptake of DNA Block Copolymer Micelles with Different Shapes
2008
The cellular uptake of DNA block copolymer micelles composed of DNA-b-PPO in Caco-2 cells was studied. In particular it was investigated if the shape of micelle aggregates influences the internalization. Rod-like polymeric particles were taken up 12 times more efficiently than their spherical counter parts although they were composed of the same constituents. Furthermore, it was observed that internalization of all the micelle systems was more efficient than the pristine DNA controls. A cytotoxicity assay proved the non-toxic nature of DNA-b-PPO micelle aggregates.
Core Cross-Linked Polymeric Micelles for Specific Iron Delivery: Inducing Sterile Inflammation in Macrophages.
2021
Iron is an essential co-factor for cellular processes. In the immune system, it can activate macrophages and represents a potential therapeutic for various diseases. To specifically deliver iron to macrophages, iron oxide nanoparticles are embedded in polymeric micelles of reactive polysarcosine-block-poly(S-ethylsulfonyl-l-cysteine). Upon surface functionalization via dihydrolipoic acid, iron oxide cores act as crosslinker themselves and undergo chemoselective disulfide bond formation with the surrounding poly(S-ethylsulfonyl-l-cysteine) block, yielding glutathione-responsive core cross-linked polymeric micelles (CCPMs). When applied to primary murine and human macrophages, these nanoparti…
Therapeutic potential of dietary polyphenols against brain ageing and neurodegenerative disorders
2010
In recent years there has been a growing interest, supported by a large number of experimental and epidemiological studies, in the beneficial effects of some commonly used food-derived products in preventing various age-related pathologic conditions, ranging from cancer to neurodegenerative diseases. Spices and herbs often contain active phenolic substances endowed with potent antioxidative and chemopreventive properties. Curcumin is a phytochemical compound extracted from the rhizome of Curcuma Longa. It is the pigment responsible for the characteristic yellow color of Indian curry. Data from our and other laboratories demonstrated that curcumin, as well as some other polyphenols, strongly…
Amorphous Ca2+ polyphosphate nanoparticles regulate the ATP level in bone-like SaOS-2 cells
2015
ABSTRACT Polyphosphate (polyP) is a physiologically occurring polyanion that is synthesized especially in bone-forming osteoblast cells and blood platelets. We used amorphous polyP nanoparticles, complexed with Ca2+, that have a globular size of ∼100 nm. Because polyP comprises inorganic orthophosphate units that are linked together through high-energy phosphoanhydride bonds, we questioned whether the observed morphogenetic effect, elicited by polyP, is correlated with the energy-generating machinery within the cells. We show that exposure of SaOS-2 osteoblast-like cells to polyP results in a strong accumulation of mitochondria and a parallel translocation of the polyP-degrading enzyme alka…