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J Courty

Publications and source records attributed to J Courty.

49 records · Page 3Linked to original sources
PubMed1987

Biochemical comparative studies between eye- and brain-derived growth factors.

Two bovine brain-derived growth factors, BDGF I and BDGF II, were isolated using the same extraction procedure as previously described for eye-derived growth factors (EDGF). The hypothesis that these growth factors were identical to EDGF I and EDGF II, respectively, was supported by their similar molecular weights (16,000 and 15,000, respectively) and isoelectric points (9.0 and 5.0, respectively), their identical retention behavior on reverse-phase chromatography and their similar amino acid compositions. From studies on their binding properties to cell surfaces, competition between EDGF I and BDGF I as well as competition between EDGF II and BDGF II to the same receptor was observed. The amino terminal sequence of EDGF II (1-16) was shown to be identical to the amino acid residues (7-22) of the acidic FGF, strongly confirming our observations on the identity of the factors isolated from bovine brain and retina.

Amino Acid Sequence↗
PubMed1986

Evidence for FGF-like growth factor in adult bovine retina: analogies with EDGF I.

Eye Derived Growth Factor (EDGF) is the genus name for growth factor activities found in several ocular tissues. Purification from bovine retina by Cibacron blue affinity chromatography has previously given a fraction which can induce target cell proliferation at doses of 30 ng per ml of culture medium. Radioimmunoassay using a labelled synthetic decapeptide [Tyr 10]--FGF (1-10) including the 9 N terminal amino acids of brain Fibroblast Growth Factor (FGF) indicated that EDGF contained a FGF-like material. Further purification of Cibacron blue purified EDGF with heparin sepharose chromatography yielded two active fractions after elution with a sodium chloride gradient. One fraction named EDGF I eluted between 1.3 and 1.5 M NaCl and accounted for over 50% of the input biological activity and comigrated with purified FGF on SDS PAGE at a molecular weight of 16,000 d as a single band. FGF competed with EDGF I for binding to specific receptors on bovine epithelial lens cells. We conclude that retina contains a growth factor activity (EDGF I) similar if not identical to FGF.

Animals↗
PubMed1986

Eye-derived growth factor isolated from bovine retina and used for epidermal wound healing in vivo.

Eye-derived growth factor (EDGF) has been found in several ocular tissues and shown to be able to stimulate the in vitro proliferation of cells from various tissues and organisms. It had already been shown that EDGF differs biochemically and biologically from other growth factors such as epidermal growth factor (EGF) and fibroblast growth factor in that it is the only one that can stimulate the in vitro growth of human adult keratinocytes. Moreover EDGF stimulates reepithelialization and neovascularization. In this paper we report data concerning the effect on the rate of epidermal wound healing in guinea pigs of different extracts obtained from adult bovine retina. Our results show that EDGF can significantly increase the rate of reepithelialization when epidermis is detached from dermis and removed after induction of a blister. The doses used were comparable to the ones used to obtain maximal increase of cell proliferation in vitro. However no attempt was made to further investigate the mechanism accounting for the observed wound healing. At 24 h, control wounds maintained under occlusive dressing had only about 50% of their surface covered with cells as opposed to EDGF-treated wounds which were covered up to about 80% (p = 0.05). On the other hand, EGF does not increase the rate of wound healing in this model even at 1000-fold higher doses than those used in in vitro bioassays. Although EDGF is still not purified to homogeneity and another 10- to 100-fold purification might be necessary to achieve homogeneity, our results suggest that EDGF may find therapeutic applications as a potent in vivo epidermal wound healing agent.

Animals↗
PubMed1985

Bovine retina contains three growth factor activities with different affinity to heparin: eye derived growth factor I, II, III.

Several ocular tissues have been shown to contain growth factor activity designated under a generic name as Eye Derived Growth Factor. Purification from bovine retina was undertaken and a fraction which could induce target cells to proliferate at doses of 5 ng per ml of culture medium was obtained. Using heparin sepharose chromatography we now show that this mitogenic activity can be fractionated into three different activities. Crude extract of bovine retina used as starting material was separated into two major fractions, one with no affinity for heparin and which was named Eye Derived Growth Factor III, and one with a strong affinity for heparin and eluted from the column with 1.4 M NaCl named Eye Derived Growth Factor I. This fraction EDGF I induces cell proliferation at doses of 100 pg/ml of culture medium. A 10(5) fold purification was achieved by this single chromatography step. Cibacron Blue purified EDGF was also further fractionated by heparin sepharose. All biological activity was found to bind to heparin. One fraction eluted at 1 M NaCl named Eye Derived Growth Factor II had a biological activity at doses of 1 ng while the other growth factor was the EDGF I with biological activity at 25 pg. At this step of purification EDGF I runs as a single band on SDS polyacrylamide gel at a molecular weight of 17 000 d. These data strongly suggest that Eye Derived Growth Factors I and II are respectively similar to Brain Fibroblast Growth Factor and to Endothelial Cell Growth Factor from hypothalamus.

Animals↗
PubMed1985

A unique family of endothelial cell polypeptide mitogens: the antigenic and receptor cross-reactivity of bovine endothelial cell growth factor, brain-derived acidic fibroblast growth factor, and eye-derived growth factor-II.

Bovine brain, hypothalamus, pituitary, and retina contain potent anionic polypeptide mitogens for endothelial cells. Immunological assays using murine monoclonal antibodies against bovine endothelial cell growth factor (ECGF) and radioreceptor assays using [125I]ECGF were performed to determine the cross-reactivity of ECGF with bovine acidic pI brain-derived fibroblast growth factor (acidic FGF) and bovine eye-derived growth factor-II [EDGF-II). We observed that acidic FGF and EDGF-II are recognized by anti-ECGF monoclonal antibodies and compete with [125I] ECGF for receptor occupancy. Furthermore, the biological activity of ECGF, acidic FGF, and EDGF-II is potentiated by the glycosaminoglycan, heparin. These results argue that ECGF, acidic FGF, and EDGF-II belong to a common family of polypeptide growth factors.

Animals↗
PubMed1985

[Use of the eye-derived growth factor in the treatment of ulcer of the cornea. A veterinary medicine study in the dog].

A growth factor purified from adult bovine retina and named Eye Derived Growth Factor (EDGF) has been shown to stimulate proliferation of target cells in vitro and in vivo, and to increase the rate of wound healing of experimentally induced corneal ulcers in rabbits. In the present report, dogs (mainly boxers) with chronic recurrent ulcers resistant to various treatments, including chloramphenicol and reputed wound healing drugs, were treated by morning and evening instillations of drops containing 10 stimulation units of EDGF in phosphate buffer saline. Stable healing of the ulcer was obtained in all cases after 12 days of treatment, and no sign of relapse was detected after three months. During the healing period, as well as during the period of increase in cellular proliferation, transitory inflammation accompanied by neovascularization was observed. EDGF represents a new drug for treatment of ulcer.

Animals↗
PubMed1984

[In vitro properties of various growth factors and in vivo effects].

This article summarizes some of the data that have been accumulated on several growth factors. Biochemical and biological properties of the Epidermal, Fibroblast, Astrocytes and Tumor growth factors (EGF, FGF, AGF, TGF) and those of growth factors derived from Platelets (PDGF), Brain (BDGF, ECGF), Eye (EDGF) and Cartilage (CDGF) are reviewed, as well as the in vitro mechanism of action of EGF and PDGF. The in vivo effects of these growth factors, particularly the experiments achieved to understand the physiological or physiopathological significance are described. The potential interest of these molecules in pharmacology and their use as wound healing agents is discussed.

Animals↗
PubMed1984

Comparison of the effects of EGF, pFGF and EDGF on corneal epithelium wound healing.

EDGF, a growth factor purified from bovine retina is able to increase the rate of wound healing of rabbit corneal epithelium in a dose dependent way. Two applications a day are enough to obtain the maximum rate. The most purified preparation of EDGF is as effective as EGF or pFGF in promoting this phenomenon and allows the epithelium to reach its normal organization earlier. Excess addition of EDGF did not adversely affect the normal or healed epithelium.

Administration, Topical↗
PubMed1982

Purification, characterization, and biological properties of the eye-derived growth factor from retina: analogies with brain-derived growth factor.

Several ocular tissues contain a polypeptide growth factor(s) (eye-derived growth factor(s) or EDGF) that stimulates the proliferation of a large variety of cells from different tissues or species. Partial purification of EDGF from adult bovine retina was accomplished by acid precipitation, blue Ultrogel chromatography, and high-pressure liquid chromatography. EDGF has an isoelectrical point at pH 4.5 +/- 0.5 and an apparent molecular weight of 17,500 +/- 3,500 measured by high-pressure liquid chromatography. On the basis of these data as well as its biological properties EDGF is different from other known growth factors. The specific activity of highly purified EDGF is 1,000-fold greater than that of a 20,000g supernatant of a crude retinal extract. At this stage of purification, EDGF stimulates replicative DNA synthesis and cell proliferation of bovine epithelium lens cells at a concentration of 14 ng/ml of culture medium and for these cells is as efficient as purified brain fibroblast growth factor. The same purification steps were applied to crude bovine brain extracts. Growth factor activity was recovered exactly as for EDGF with slightly smaller apparent molecular weight 14,000 +/- 3,500, suggesting a great similarity between the two tissues as a source of growth factors. A purification of about 2,500-fold was obtained and cell proliferation stimulated at a concentration of 100 ng/ml. Interestingly an inhibitory activity not retained on blue Ultrogel was recovered from both preparations.

Acetates↗
PubMedDate not supplied

Effect of heparin affin regulatory peptide on the expression of vascular endothelial growth factor receptors in endothelial cells.

BACKGROUND: Heparin affin regulatory peptide (HARP) is an 18-kDa secreted protein that has been implicated in tumor growth and angiogenesis, although the mechanisms involved remain largely unknown. In the present work, the effect of human recombinant HARP on the expression of the vascular endothelial growth factor (VEGF) receptors KDR, Flt-1 and neuropilin-1 was studied in cultured human umbilical vein endothelial cells (HUVEC). MATERIALS AND METHODS: The mRNA and protein levels of VEGF receptors were estimated by semi-quantitative RT-PCR and Western blot, respectively. Cell proliferation and migration were measured by MTT, direct counting of the cells and modified Boyden chamber assays. RESULTS: HARP decreased the expression of KDR but increased the expression of Flt-1 and neuropilin-1 at both the mRNA and protein level. The effect reached a maximum 4 h after the addition of HARP into the cell culture medium and was reversed at later time-points. When HARP was added to the culture medium 4 h before the addition of VEGF165, it inhibited VEGF165-induced proliferation and migration of HUVEC. CONCLUSION: These data suggest that HARP affects the expression of VEGF receptors and inhibits VEGF165-induced activation of HUVEC.

Carrier Proteins↗