Search results for "Culture media"
showing 10 items of 272 documents
Swelling and death of neuronal cells by lactic acid.
1993
Lactacidosis occurring in cerebral ischemia or trauma is a major mechanism of cytotoxic brain edema and brain damage. Respective effects of lactacidosis were currently analyzed in vitro by employment of the murine neuronal cell line, Neuro-2A, in order to obtain a better understanding of specific mechanisms underlying cell swelling and cell death in comparison with glial cells. The cells were suspended in a physiological medium in the presence of lactic acid at increasing concentrations. Levels of acidosis reaching from pH 6.8-5.6 were obtained while other parameters, such as osmolarity and electrolyte concentrations, were maintained in the physiological range. Assessment of cell swelling a…
Secretion of haemolysins and proteases by Aeromonas hydrophila EO63: separation and characterization of the serine protease (caseinase) and the metal…
2004
C . E S T E V E A N D T . H . B I R K B E C K . 2004. Aims: To determine the haemolysins and proteases excreted by the virulent strain EO63 of Aeromonas hydrophila grown in complex media and to then fractionate and characterize them, in particular those with elastolytic activity. Methods and Results: The amount of haemolytic and proteolytic activity in EO63 culture supernatants was dependent on the culture media used. In all media, haemolysins appeared during the phase of active growth and haemolytic activity decreased quickly thereafter, as previously described for aerolysin. In contrast, proteases were mainly released during the stationary phase. Serine protease activity in EO63 culture s…
Characterization of EprA, a major extracellular protein of Oenococcus oeni with protease activity
2008
International audience; Extracellular proteins from Oenococcus oeni. a wine-making bacterium, were isolated during growth on media differing by their nitrogen content. Analysis by two-dimensional electrophoresis revealed a low number of protein signals. Among the main spots, one signal corresponded to a single protein, which contained a lysine repeat domain characteristic of cell-wall hydrolases. We demonstrated that this major protein, named EprA, was able to hydrolyse several proteins. The heterologous production of this protein in Escherichia coli confirmed the protease activity of EprA. With a MW of 21.3 kDa and a pl of 5.3, EprA presents optimal activity at pH 7.0 and 45 degrees C. Thi…
Meprins process matrix metalloproteinase-9 (MMP-9)/gelatinase B and enhance the activation kinetics by MMP-3
2012
Abstract Meprin α and β, members of the astacin family of zinc metalloproteinases, are unique plasma membrane and secreted proteases known to cleave a wide range of biological substrates involved in inflammation, cancer and fibrosis. In this study, we identified proMMP-9 as a novel substrate and show that aminoterminal meprin-mediated clipping improves the activation kinetics of proMMP-9 by MMP-3, an efficient activator of proMMP-9. Interestingly, the NH2-terminus LVLFPGDL, generated by incubation with meprin α, is identical to the form produced in conditioned media from human neutrophils and monocytes. Hence, this meprin-mediated processing and enhancement of MMP-9 activation kinetics may …
Cell Susceptibility to Baculovirus Transduction and Echovirus Infection Is Modified by Protein Kinase C Phosphorylation and Vimentin Organization
2013
ABSTRACT Some cell types are more susceptible to viral gene transfer or virus infection than others, irrespective of the number of viral receptors or virus binding efficacy on their surfaces. In order to characterize the cell-line-specific features contributing to efficient virus entry, we studied two cell lines (Ea.hy926 and MG-63) that are nearly nonpermissive to insect-specific baculovirus (BV) and the human enterovirus echovirus 1 (EV1) and compared their characteristics with those of a highly permissive (HepG2) cell line. All the cell lines contained high levels of viral receptors on their surfaces, and virus binding was shown to be efficient. However, in nonpermissive cells, BV and it…
Proteomic analysis of exosome-like vesicles derived from breast cancer cells.
2012
Background/Aim: The phenomenon of membrane vesicle-release by neoplastic cells is a growing field of interest in cancer research, due to their potential role in carrying a large array of tumor antigens when secreted into the extracellular medium. In particular, experimental evidence show that at least some of the tumor markers detected in the blood circulation of mammary carcinoma patients are carried by membrane-bound vesicles. Thus, biomarker research in breast cancer can gain great benefits from vesicle characterization. Materials and Methods: Conditioned medium was collected from serum starved MDA-MB-231 sub-confluent cell cultures and exosome-like vesicles (ELVs) were isolated by ultra…
Differential proteomic analysis of an engineered Streptomyces coelicolor strain reveals metabolic pathways supporting growth on n-hexadecane
2012
The alkB gene, encoding an alkane monooxygenase in the actinomycete Gordonia sp. SoCg, was expressed in the non-alkane-degrading actinomycete Streptomyces coelicolor M145. The resulting engineered strain, M145-AH, can grow on n-hexadecane as sole carbon source. To unravel proteins associated with growth on n-alkanes, proteome of M145-AH after 6, 24, and 48 h of incubation in the Bushnell-Haas (BH) mineral medium containing n-hexadecane as sole carbon source (H condition) and in BH without any carbon source (0 condition) were compared using 2D-differential gel electrophoresis. Proteome analysis revealed significant changes only at 48 h, showing 48 differentially abundant proteins identified …
Multiple changes induced by fibroblasts on breast cancer cells.
2010
It is now widely recognised that the cross-talk between cancer and stromal cells may play a crucial role in cancer progression. However little is known about the complex underlying molecular mechanisms that occur within the tumor microenvironment. Fibroblasts are the major stromal cells with multiple roles, especially towards both the extracellular matrix and the neighbouring cell population, including neoplastic cells. Consequently, proteomic analyses would provide a wider resource for a better understanding of the potential modulating effects exerted by fibroblasts on cancer cells. In this report we describe the effects of fibroblast stimulation on the breast cancer cell line (8701-BC) pr…
Cigarette smoke exposure inhibits extracellular MMP-2 (gelatinase A) activity in human lung fibroblasts
2007
Abstract Background Exposure to cigarette smoke is considered a major risk factor for the development of lung diseases, since its causative role has been assessed in the induction and maintenance of an inflamed state in the airways. Lung fibroblasts can contribute to these processes, due to their ability to produce proinflammatory chemotactic molecules and extracellular matrix remodelling proteinases. Among proteolytic enzymes, gelatinases A and B have been studied for their role in tissue breakdown and mobilisation of matrix-derived signalling molecules. Multiple reports linked gelatinase deregulation and overexpression to the development of inflammatory chronic lung diseases such as COPD.…
Pyruvate fermentation by Oenococcus oeni and Leuconostoc mesenteroides and role of pyruvate dehydrogenase in anaerobic fermentation.
2005
ABSTRACT The heterofermentative lactic acid bacteria Oenococcus oeni and Leuconostoc mesenteroides are able to grow by fermentation of pyruvate as the carbon source (2 pyruvate → 1 lactate + 1 acetate + 1 CO 2 ). The growth yields amount to 4.0 and 5.3 g (dry weight)/mol of pyruvate, respectively, suggesting formation of 0.5 mol ATP/mol pyruvate. Pyruvate is oxidatively decarboxylated by pyruvate dehydrogenase to acetyl coenzyme A, which is then converted to acetate, yielding 1 mol of ATP. For NADH reoxidation, one further pyruvate molecule is reduced to lactate. The enzymes of the pathway were present after growth on pyruvate, and genome analysis showed the presence of the corresponding st…