Search results for "Acellular"
showing 10 items of 1986 documents
Differential vesicular targeting and time course of synaptic secretion of the mammalian neurotrophins.
2005
Neurotrophins are a family of secreted neuronal survival and plasticity factors comprising NGF, BDNF, neurotrophin-3 (NT-3), and NT-4. Whereas synaptic secretion of BDNF has been described, the routes of intracellular targeting and secretion of NGF, NT-3, and NT-4 in neurons are poorly understood.To allow for a direct comparison of intracellular targeting and release properties, all four mammalian neurotrophins were expressed as green fluorescent protein fusion proteins in cultured rat hippocampal neurons. We show that BDNF and NT-3 are targeted more efficiently to dendritic secretory granules of the regulated pathway of secretion (BDNF, in 98% of cells; NT-3, 85%) than NGF (46%) and NT-4 (…
Neurons and ECM regulate occludin localization in brain endothelial cells
2000
We report that extracellular matrix and neurons modulate the expression of occludin, one of the main components of tight junctions, by rat brain endothelial cells (RBE4.B). Of the three extracellular matrix proteins which we tested (collagen I, collagen IV, and laminin), collagen IV stimulated at the best the expression of occludin mRNA. The corresponding protein, however, was not synthesized. Significant amounts of occludin accumulated only when RBE4.B cells were cultured on collagen IV-coated inserts, in the presence of cortical neurons, plated on laminin-coated companion wells. Finally, occludin segregated at the cell periphery, only when endothelial cells were co- cultured with neurons …
Impact of oral contraceptive use and menstrual phases on patellar tendon morphology, biochemical composition, and biomechanical properties in female …
2013
Sex differences exist with regards to ligament and tendon injuries. Lower collagen synthesis has been observed in exercising women vs. men, and in users of oral contraceptives (OC) vs. nonusers, but it is unknown if OC will influence tendon biomechanics of women undergoing regular training. Thirty female athletes (handball players, 18–30 yr) were recruited: 15 long-term users of OC (7.0 ± 0.6 yr) and 15 nonusers (>5 yr). Synchronized values of patellar tendon elongation (obtained by ultrasonography) and tendon force were sampled during ramped isometric knee extensor maximum voluntary contraction to estimate mechanical tendon properties. Furthermore, tendon cross-sectional area and lengt…
The Effect of Long-Term Storage on the Biological and Histological Properties of Cryopreserved Amniotic Membrane
2011
Cryopreserved amniotic membrane (AM) is widely used in ophthalmology because of its anti-angiogenic, anti-inflammatory, and wound healing promoting capabilities. A common method to conserve the tissue is the storage in cryo-medium containing 50% glycerol at -80°C. The aim of this study was to examine the influence of storage time on the sterility as well as the histological and biological properties of cryopreserved AM.Amniotic membrane from different donors was stored in cell culture media containing 50% glycerol for different time periods, on average 4 months (group 1), 15 months (group 2), and 24 months (group 3), at -80°C. Samples of the tissue and cryo-medium were examined for bacteria…
Factor VIIa-induced interaction with integrin controls the release of tissue factor on extracellular vesicles from endothelial cells.
2019
Essentials Prothrombotic extracellular vesicles (EV) carry agonist pathway-specific proteomes Agonists for protease activated receptor (PAR) 2 signaling have distinct effects on EV composition PAR2 signaling rapidly generates prothrombotic EV and slowly EV with inactive tissue factor (TF) FVIIa integrin ligation restricts TF incorporation into EV from endothelial cells SUMMARY: Background Cell injury signal-induced activation and release of tissue factor (TF) on extracellular vesicles (EVs) from immune and vessel wall cells propagate local and systemic coagulation initiation. TF trafficking and release on EVs occurs in concert with the release of cell adhesion receptors, including integrin …
Signalling molecules and growth factors for tissue engineering of cartilage-what can we learn from the growth plate?
2009
Modern tissue engineering concepts integrate cells, scaffolds, signalling molecules and growth factors. For the purposes of regenerative medicine, fetal development is of great interest because it is widely accepted that regeneration recapitulates in part developmental processes. In tissue engineering of cartilage the growth plate of the long bone represents an interesting, well-organized developmental structure with a spatial distribution of chondrocytes in different proliferation and differentiation stages, embedded in a scaffold of extracellular matrix components. The proliferation and differentiation of these chondrocytes is regulated by various hormonal and paracrine factors. Thus, mem…
From attachment to damage: defined genes of Candida albicans mediate adhesion, invasion and damage during interaction with oral epithelial cells.
2010
Candida albicans frequently causes superficial infections by invading and damaging epithelial cells, but may also cause systemic infections by penetrating through epithelial barriers. C. albicans is an unusual pathogen because it can invade epithelial cells via two distinct mechanisms: induced endocytosis, analogous to facultative intracellular enteropathogenic bacteria, and active penetration, similar to plant pathogenic fungi. Here we investigated the molecular basis of C. albicans epithelial interactions. By systematically assessing the contributions of defined fungal pathways and factors to different stages of epithelial interactions, we provide an expansive portrait of the processes an…
Urokinase activates macrophage PON2 gene transcription via the PI3K/ROS/MEK/SREBP-2 signalling cascade mediated by the PDGFR-β
2009
Aims We have recently shown that urokinase plasminogen activator (uPA) increases oxidative stress (OS), cholesterol biosynthesis, and paraoxonase 2 (PON2) expression in macrophages via binding to its receptor, the uPAR. Since PON2 is regulated by both OS and cholesterol content, we hypothesized that uPA elicits a cascade of signal transduction events shared by NADPH oxidase and cholesterol biosynthesis that culminates in PON2 gene expression. Here, we investigated the signalling pathway that leads to the expression of PON2 in macrophages in response to uPA. Methods and results The increase in macrophage PON2 mRNA levels in response to uPA was shown to depend on PON2 gene promoter activation…
Cadmium effects on p38/MAPK isoforms in MDA-MB231 breast cancer cells
2009
Emerging evidence seems to indicate that the heavy metal cadmium (Cd) is able to regulate gene expression, drastically affecting the pattern of transcriptional activity in normal and pathological eukaryotic cells, also affecting intracellular signalization events. Human p38 is a family of mitogen-activated protein kinases consisting of four isoforms (alpha, beta, gamma and delta) which mediate signal transduction cascades controlling several aspects of cell physiology. In this study we examined whether exposure of MDA-MB231 tumor cells from the human breast to Cd may exert some effect on p38 isoform expression and accumulation, as well as on p38 activation. Employing a combination of prolif…
Impairing Otp homeodomain function in oral ectoderm cells affects skeletogenesis in sea urchin embryos
2003
AbstractIn the sea urchin embryo skeletogenesis is the result of a complex series of molecular and cellular events that coordinate the morphogenetic process. Past and recent evidence strongly indicate that skeletal initiation and growth are strictly dependent on signals emanating from the oral ectodermal wall. As previously suggested, Orthopedia (Otp), a homeodomain-containing transcription factor specifically expressed in a small subset of oral ectoderm cells, might be implicated in this signalling pathway. In this study, we utilize three different strategies to address the issue of whether Otp is an upstream regulator of sketelogenesis. We describe the effects of microinjection of Otp mor…