Search results for "Secretion"
showing 10 items of 764 documents
Synthesis of honokiol analogues and evaluation of their modulating action on VEGF protein secretion and telomerase-related gene expressions
2017
A group of 36 biphenyl derivatives structurally related to honokiol were synthesized by means of Suzuki coupling reactions. Their cytotoxicities were evaluated and compared to that of honokiol. Some of the compounds were then evaluated for their ability to downregulate the secretion of the VEGF protein and the expression of the VEGF, hTERT, and c-Myc genes; the two latter involved in the activation of telomerase in tumoral cells. Some of the synthetized derivatives showed promising pharmacological features as they exhibited IC50 values in low micromolar range, good therapeutic margins, and a multiple mode of action on tumor cells based on the inhibition of VEGF and, at the same time, of the…
ASTROCYTES SHED EXTRACELLULAR VESICLES THAT CONTAIN FIBROBLAST GROWTH FACTOR-2 AND VASCULAR ENDOTHELIAL GROWTH FACTOR.
2007
An important component of the pathogenic process of multiple sclerosis (MS) is the blood-brain barrier (BBB) damage. We recently set an in vitro model of BBB, based on a three-cell-type co-culture system, in which rat neurons and astrocytes synergistically induce brain capillary endothelial cells to form a monolayer with permeability properties resembling those of the physiological BBB. Herein we report that the serum from patients with secondary progressive multiple sclerosis (SPMS) has a damaging effect on isolated neurons. This finding suggests that neuronal damaging in MS could be a primary event and not only secondary to myelin damage, as generally assumed. SPMS serum affects the perme…
NEURONS PRODUCE FGF-2 AND VEGF SECRETE THEM AT LEST IN PART BY SHEDDING EXTRACELLULAR VESCICLES
2007
Abstract We previously found that neurons are able to affect the ability of brain capillary endothelial cells to form in vitro a monolayer with properties resembling the blood-brain barrier. We then looked, by immunofluorescence and western analysis, for factors, produced by neurons, with the potential to influence growth and differentiation of endothelial cells. In the present paper, we report that neurons produce both vascular endothelial growth factor and fibroblast growth factor 2, two well-known angiogenic factors. More interestingly, we gained evidence that both factors are released by neurons, at least in part, by shedding of extracellular vesicles, that contain β1 integrin, a membra…
Extracellular HSP27 mediates angiogenesis through Toll-like receptor 3.
2013
The heat-shock protein 27 (HSP27) is up-regulated in tumor cells and released in their microenvironment. Here, we show that extracellular HSP27 has a proangiogenic effect evidenced on chick chorioallantoic membrane. To explore this effect, we test the recombinant human protein (rhHSP27) at physiopathological doses (0.1-10 μg/ml) onto human microvascular endothelial cells (HMECs) grown as monolayers or spheroids. When added onto HMECs, rhHSP27 dose-dependently accelerates cell migration (with a peak at 5 μg/ml) and favors spheroid sprouting within 12-24 h. rhHSP27 increases VEGF gene transcription and promotes secretion of VEGF-activating VEGF receptor type 2. Increased VEGF transcription is…
Effects of tetraethylammonium ions on frequency-dependent vasopressin release from the rat neurohypophysis.
1988
1. Isolated rat neurohypophyses were fixed by their stalks to a platinum wire electrode and superfused with oxygenated Krebs-HEPES solution. Vasopressin release into the medium was determined by radioimmunoassay. Vasopressin secretion was increased by electrical stimulation at different frequencies (3-30 Hz) and different train lengths (75-900 pulses). The effects of tetraethylammonium (TEA) ions and of enhanced calcium were tested. 2. Electrical stimulation at 7.5 or 15 Hz evoked a markedly larger release of vasopressin than stimulation at 3 Hz. During continuous stimulation at 7.5 and 15 Hz the evoked vasopressin release per pulse declined rapidly, but with similar time constants for both…
Variation in somatic cell count, California mastitis test, and electrical conductivity among various fractions of ewe's milk.
1991
Abstract Variation of three estimates of udder inflammation (SCC, California mastitis test, and electrical conductivity) among the foremilk, machine milk, and hand stripping samples were studied. Foremilk and hand stripping milks were taken from each individual teat; machine milk was taken from the entire udder. For this experiment a total of 30 Manchega ewes were subjected to machine milking during the 9th wk of lactation. Samples were taken in duplicate during two milkings on consecutive mornings. Significant differences were observed in the SCC and electrical conductivity, but not in California mastitis test, between foremilk and stripping milk The stripping fraction had higher SCC (70 ±…
Relative Frequencies and Significance of Faecal Coliforms as Indicators Related to Water Temperature
1983
Summary The faecal coliforms at different sites of a hypereutrophic lake near Valencia (Albufera) were identified and their relative amounts established along an annual cycle. Using lauryl tryptose broth at 35°C, followed by incubation at 44.4°C in 2% brilliant green bile, Escherichia coli and Klebsiella pneumoniae are practically the only coliforms present. A positive correlation was found between the water temperature and the relative amount of these two coliforms: K. pneumoniae predominates at high water temperatures, whereas E. coli shows preponderance during the cold period. The role of K. pneumoniae as the only faecal indicator under the circumstances described in the work is emphasiz…
Fat storing cells (FSC) of rat liver synthesize and secrete fibronectin
1987
Summary Fat storing cells (FSC) of rat liver were isolated and kept in culture for up to 2 weeks. Freshly isolated cells and cells in culture were characterized functionally (vitamin A content) and morphologically. Their synthetic capacity for fibronectin was studied quantitatively by ELISA-measurement and qualitatively by biosynthetic labeling, immunoprecipitation and SDS-PAGE analysis. The synthesis product and the kinetics of the synthesis and secretion were compared with those obtained from culture of hepatocytes. FSC were shown to synthesize and secrete fibronectin under the culture conditions used. No fibronectin synthesis was detected during the first 3 days of culture. Thereafter th…
Crystalloid lysozyme inclusions in Paneth cells of vitamin A-deficient rats.
1990
The effect of vitamin A-deficiency on jejunal Paneth cells in rats was investigated. Crystalloid particles were observed in secretion granules of Paneth cells from 6 out of 8 rats with vitamin A-deficiency. The particles were similar to those found in Paneth cells under other experimental conditions. Using an immuno-electron-microscopic technique we demonstrated a clear lysozyme immunoreactivity of these particles. In 2 vitamin A-deficient rats tubular structures have been detected in addition to the crystalloid particles. Crystalloid particles or tubular structures were not detectable in a control group of 8 vitamin A-supplemented rats. The morphological alterations of Paneth cells may be …
Antioxidant capacity of cow milk, whey and deproteinized milk
2009
The total antioxidant capacity (hydrophilic plus lipophilic) of sixteen different commercial samples of pasteurized and ultra high temperature (UHT) treated milk was determined using the oxygen radical absorbance capacity assay using fluorescein as a fluorescent probe. A significant correlation between the percentage of fat and the value of the total antioxidant capacity was found in milk samples obtained from the same batch of raw milk. Analyses of the whole milk, whey and deproteinized milk showed that the major contributor to the total antioxidant capacity of whole milk was the casein fractions, while albumin was the major contributor to the total antioxidant capacity of whey protein. Hy…