Biomedical subjects

G Godeau

Publications and source records attributed to G Godeau.

At least 55 records · Page 3Linked to original sources

PubMed1997

Influence of successive and combined ultraviolet A and B irradiations on matrix metalloelastases produced by human dermal fibroblasts in culture.

To study the cumulative influence of UV irradiations on skin matrix alterations, human skin fibroblasts were irradiated successively three-fold, at 24 h intervals, with UVA (3x5J/cm2), UVB (3x8mJ/cm2), UVA plus UVB (3x5J/cm2 and 3x8mJ/cm2) and the levels of 92 kDa gelatinase (pro-MMP9), 72 kDa gelatinase (pro-MMP2) and plasma-membrane elastase type protease were determined, following subsequent 24-h culture in 10% serum-containing medium. UV irradiations had only minor influence (1.4-fold increase for UVB) on secreted levels of pro-MMP2 and decreased the amount of plasma membrane elastase produced by cells. It did however, for UVA and UVB alone, induce a significant increase of 66 kDa activated MMP2 production: 2.5- and 1.7-fold respectively. Such enhancement was not observed when combined irradiations were administered. UV exposure possessed a much higher influence on pro-MMP9 secretion by dermal fibroblast enhancing enzyme levels by 2.5-, 6.5- and 5-fold for UVA, UVB and UVA+UVB, respectively.

Adult↗

PubMed1997

Morphometric analysis of collagen and elastic fibers in normal skin and gingiva in relation to age.

The morphometric parameters of the human gingival elastic fiber network were determined by image analysis and compared with human skin elastic fibers in relation to age. Similarly, collagen fibers were also investigated in both tissues. In this study, 47 healthy patients, 10-75 years old were studied for gingiva and another 50 patients in the same age range were included for skin biopsies. Three groups were compared: group 1 from the age of 10-24 years, group 2 from 25 to 49 years, and group 3 from 50 to 75 years. The diameters of the oxytalan fibers were invariable in both tissues, whatever the age considered. On the other hand, the diameters of elastic fibers increased regularly with age in the gingiva (P < 0.01) and in the skin (P < 0.01) between each age group. The area fraction occupied by the oxytalan fibers decreased significantly in both tissues (P < 0.01) for the skin and (P < 0.001) for the gingiva. The area fraction occupied by the gingival elastic fibers remained constant with age while the skin elastic fibers increased significantly with age between groups 2 and 1 (P < 0.01) and between groups 3 and 2 (P < 0.001). In the mid-dermis and in the mid-gingiva, the diameters of the collagen fibers increased strongly with age, between groups 2 and 1 (P < 0.01) and between groups 3 and 2 (P < 0.001). The area fraction occupied by the collagen bundles increased regularly with age in the mid-gingival (P < 0.05 between each age group), while a significant decrease was observed in the mid-dermis from the age of 50-75 years (P < 0.05). The results obtained contribute to a better understanding of some modifications which dermis and gingiva undergo with aging and provide data to perfect diagnosis and therapy in odontology and dermatology.

Adolescent↗

PubMed1997

Increased expression of gelatinases A and B by skin explants from patients with anetoderma.

The extent of alterations to the elastic fibre network in lesional skin areas of three patients with anetoderma was assessed by quantitative image analysis of tissue sections and compared with morphometric parameters from unaffected sites of the same individuals. In the anetodermic skins pre-elastic fibres were undetectable or extremely rare: the volume fraction (Vv%) occupied by these pre-elastic fibres was 0-0.3%, while in unaffected skins the Vv% occupied by pre-elastic fibres was 0.5-0.8%. A nearly complete absence of dermal elastic fibres in lesional skins from the three patients was evidenced (Vv% = 0.2-0.3%). Organ cultures were performed using explants from skin with or without anetodermic lesions to quantify the expressions of elastase-type proteinases. All tissues from anetodermic lesions expressed proforms of gelatinases A and B and the activated form of gelatinase A; their levels increased with the culture time. In comparison, enzymatic activities on oligopeptide substrates specific for leucocyte elastase and fibroblast plasma membrane-associated metalloelastase were not detected in the conditioned media of any explants at any time of culture from 1 to 5 days. Increased production of progelatinases A and B and activation of progelatinase A could be mainly responsible for the degradation of skin elastic fibres demonstrated in anetodermic skins.

Adult↗

PubMed1997

Cyclosporin A-induced alterations of dentinogenesis in rat molars.

Cyclosporin A (CsA), a widely used immunosuppressive drug, induces gingival overgrowth and modifications of bone remodelling. The scope of this study was to investigate the possible effect of CsA on dentin. Thirty mg/kg/day of CsA were administered orally to male Sprague-Dawley rats for nineteen weeks. The same number of control rats received oil-based vehicle solution. Rats were anesthetized, and tissues were fixed by an intracardiac perfusion of fixative solution. Mandibles were dissected, demineralized, and processed for Epon embedding. Semi-thin sections of the first molars revealed alterations at the secondary dentin-pulp interface in four out of six experimental animals. The changes consisted of the formation of: 1) osteodentin spurs, in which the volume and interface with the secondary dentin varied from about 25,000 to 75,000 microns 3 and from 1400 to 3530 microns 2, respectively; 2) abnormally shaped and irregularly spaced incremental lines; and 3) numerous globular formations embedded in dentin or free in the pulp. These results indicate that CsA induces abnormal mineralized matrix formation in dentin and in the peripheral part of the pulp in rat molars.

Administration, Oral↗

PubMed1997

Active and alpha-1 proteinase inhibitor complexed leukocyte elastase levels in crevicular fluid from patients with periodontal diseases.

Human leukocyte elastase is present in large amounts in the crevicular fluid of patients with periodontal disease and was considered as a putative biological marker of the evolution of such diseases. The aim of this work was to measure spectrophotometrically amounts of active elastase (AE) and elastase complexed to alpha 1 proteinase inhibitor (E-alpha 1-PI) in gingival crevicular fluid obtained, from patients suffering from rapidly progressive periodontitis (RPP group) or adult periodontitis (AP group) with different probing depths (3 to 5 mm and > 6 mm). AE and E-alpha 1-PI concentrations were negligible in healthy individuals. AE, but not E-alpha 1-PI, concentration appears to vary significantly with the probing depth in patients suffering either from rapidly progressive or adult periodontitis. No correlations were found between levels of AE and E-alpha 1-PI in the different groups of patients. AE concentration seems to be a marker of periodontal diseases in relation with probing depth.

Adult↗

PubMed1995

Histomorphometric parameters and susceptibility to neutrophil elastase degradation of skin elastic fibres from healthy individuals and patients with Marfan syndrome, Ehlers-Danlos type IV, and pseudoxanthoma elasticum.

The morphometric parameters of mid-dermal elastic fibres from the skin of four patients with Marfan syndrome, four patients with Ehlers-Danlos syndrome type IV (EDS IV), and two patients with pseudoxanthoma elasticum (PXE) were determined, and compared with those of healthy individuals of a similar age range. The volume fraction occupied by elastic fibres was significantly reduced in Marfan patients compared with normal controls, and this was independent of age. In contrast, it was significantly increased in PXE patients, whereas the volume fraction occupied by skin elastic fibres varied within the EDS IV group. Dermal elastic fibres from patients with Marfan syndrome, EDS IV and PXE are hydrolysed by human neutrophil elastase in a qualitatively and quantitatively different fashion from those from healthy individuals. Marfan syndrome and EDS IV dermal elastic fibres were found to be more resistant to hydrolysis by human neutrophil elastase, but PXE elastic fibres were hydrolysed at a rate similar to elastic fibres from control skin.

Adolescent↗

PubMed1995

Elastin derived peptides protect elastic fibres degradation by human neutrophil elastase: in vitro and in vivo studies using a mechanically induced rat gingival inflammatory model.

An elastin peptide (kE57) obtained from organoalkaline hydrolysis of calf ligamentum nuchae insoluble elastin, was isolated by gel permeation on Sephadex G150 and high performance liquid chromatography on a TSK G 3000 SW column. It possessed an average Mr = 57,000 and similar amino acids composition as its insoluble counterpart. kE57 behave as a competitive inhibitor of human neutrophil elastase (HNE) with Ki = 1.4 microM; it also inhibited porcine pancreatic elastase (PPE) but less efficiently Ki = 180 microM. Identification of elastic fibres in rat gingiva was ascertained by light and electron microscopic studies. Morphometric studies indicated that rat gingiva contained similar levels of elastic fibres (= 2%) as human skin; elastic fibres networks from both tissues also displayed high structural analogy. Gingival chronic inflammation was induced in rats by mechanical impaction associated with an hyperglucidic diet. After 5 weeks, the levels of rat gingiva elastic fibres, decreased from Vv = 1.94 +/- 0.1% to Vv = 1.02 +/- 0.06%. Local injections of kE57: 100 micrograms per day, 5 days a week for 5 weeks did restore the integrity of the gingiva elastic fibres network: Vv = 1.84 +/- 0.1. Without influencing leucocyte infiltration, it is proposed that elastin-derived peptides, acting as potent competitive inhibitor of neutrophil elastase involved in periodontitis, might be of therapeutic value.

Animals↗

PubMed1995

Growth stimulation of human skin fibroblasts by elastin-derived peptides.

Elastin-derived peptides (kappa-elastin: kappa E, mean molecular mass: 75 kDa), either coated onto plastic dishes or added to culture media (0.26 to 1.33 nM) stimulated the growth of human skin fibroblasts (HSF) strains obtained from different donors and tested at different cell passages (4 to 12). Coated 44.4 micrograms/cm2 insoluble elastin (iE) exhibited the same action; coated iE or kappa E significantly modifies the HSF morphology: after 5-6 days of culture, HSF are more elongated, and at preconfluence state, formation of HSF clusters surrounding iE were observed. Increased 3H thymidine incorporation and proliferative effect of HSF by kappa E (1.3 to 2.2 fold as compared to control cells) was observed after a lag phase period which raised with initial HSF density. Optimal proliferative effect was obtained at kappa E 8.5 10(-10) M, a value close to the dissociation constant (kD = 2.7 10(-10) M) of kappa E to HSF. Valine-glycine-valine-alanine-proline-glycine (VGVAPG), but not valine-glycine-valine (VGV) or Valine-glycine-valine-valine-glycine-alanine (VGVVGA) also significantly stimulated, optimally at 7.0 10(-10) M, HSF proliferation. It was concluded that the stimulatory influence of elastin derived peptides on HSF proliferation was mediated through a binding to plasmalemmal receptor of HSF.

Adult↗

PubMed1994

Presence of gelatinase A and metalloelastase type protease at the plasma membrane of human skin fibroblasts. Influence of cytokines and growth factors on cell-associated metalloendopeptidase levels.

Gelatinase A and elastase type proteinase (Homsy, et al., 1988) present at plasma membranes of human skin fibroblasts (HSF) were separated by anion exchange chromatography on a DEAE Tris acryl M column. Elastase type proteinase (HSFE1) was able to convert 72 kDa progelatinase A to a lower 66 kDa M.W. active enzyme. Several cytokines (IL-1 beta, IL4, IL6), interferon gamma (IFN gamma) and tumor growth factor beta (TGF-beta) were studied for their ability to modify the levels of those plasma membrane associated proteinases. Among these mediators, only IL-1 beta was found to enhance the amounts of HSF membrane-bound HSFE1 and Gelatinase A.

Cell Membrane↗

PubMed1994

An animal model for the assessment of gingival lesions.

A model of gingival inflammation was performed in Sprague-Dawley rats weighing 180-200 g. Mechanical bamboo stick-induced injury was inflammatory when bacteria contaminated the sticks. Bacteria were first obtained from gingival fluid collected from a patient with adult periodontitis. Another strain from Institut Pasteur (IP 6444) induced similar inflammation. Inflammation was then quantified 10 days later by means of elastase assays performed in gingival extracts. In parallel, elastic structures were observed and elastic fibers were quantified by automated image analysis. This technique of "impaction" was able to induce a gingival inflammatory reaction characterized by a significant increase of gingival elastase content, infiltration of gingival tissues by elicited cells, and gingival elastic fiber breakdown. These parameters were correlated, and measurement of one of them might be useful for pharmacological studies applied to the treatment of periodontal lesions. An example of results obtained from animals treated by heparine was shown.

Animals↗

PubMed1993

Protective effect of oleoyl peptide conjugates against elastolysis by neutrophil elastase and kappa elastin-induced monocyte chemotaxis.

Elastin can impair the human neutrophil elastase (HNE) inhibitory capacity of elastase inhibitors. We synthesized oleoyl-alanyl-alanyl-prolyl-valine (Ol-Ala-Ala-Pro-Val-OH) (oleoyl peptide) and the amides (NH2 and NH-C3H7) of this peptide and studied their HNE-inhibitory potencies using succinyl-alanyl-alanyl-alanine-p-nitroanilide (Suc-Ala-Ala-Ala-pNA) or 3H-labeled elastin as substrates, as well as cryostat sections of rabbit skin as an ex vivo substrate. Using Suc-Ala-Ala-Ala-pNA, Ol-Ala-Ala-Pro-Val-OH had an IC50 of 3 microM. When the COOH terminal of the oleoyl peptide was derivatized to amide forms, the compound lost its ability to interact with HNE while keeping its elastin-protecting function: IC50 values for NH2 and NH-C3H7 derivatives were 22 and 17 microM, respectively. Also, the HNE-inhibitory capacity of Ol-Ala-Ala-Pro-Val-OH was only reduced 2-fold by using elastin as a substrate. This decrease was much lower than those determined with other HNE inhibitors of similar potency and could be accounted for by the ability of oleoyl peptide to bind to elastin. Cryostat sections of rabbit skin were also used as an ex vivo substrate for assessing the elastin-protecting property of Ol-Ala-Ala-Pro-Val-OH. Preincubating HNE and oleoyl peptide before application to tissue sections led to an IC50 of 8 microM, close to the value determined with elastin as a substrate. Treatment of sections with oleoyl peptide before adding HNE gave a lower IC50 (4 microM).(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗

PubMed1991

Recurrent ctb(7)(q31.3) and possible laminin involvement in a neonatal cutis laxa with a Marfan phenotype.

A 6-week-old girl presented with cutis laxa, emphysema, heart anomalies and a diaphragmatic hernia. She died at 22 weeks. A recurrent ctb(7)(q31.3) was found and the laminin gene was suspected to be involved in the disease. Anti-human laminin antiserum showed that this protein was absent from the skin. This case, together with 17 other similar cases, could represent a new type of connective tissue disease.

Cells, Cultured↗

PubMed1991

The elastolytic activity of cathepsin G: an ex vivo study with dermal elastin.

To determine whether human neutrophil cathepsin G can act by itself or in concert with human neutrophil elastase to destroy elastic fibers in vivo, we used cryostat sections of human skin as an ex vivo substrate for these leukoproteinases. Specifically stained dermal elastic fibers were quantitated using an accurate and almost entirely automatic morphometric procedure that included computerized threshold selection and elimination of non-elastic dark elements. AA, the area fraction occupied by the dermal elastic fibers, was found to be 0.100 +/- 0.014 (mean +/- SD) for 21 control skin sections originating from a single donor. Measurement of the fiber diameters in these control sections (2.4 +/- 0.8 microns [mean +/- SD]) allowed calculation of the Weibel factor used to convert AA into Vv, the volume fraction occupied by the elastic fibers: Vv was 0.028 +/- 0.004 (mean +/- SD). Incubation of skin sections with elastase, cathepsin G, or mixtures of the two enzymes resulted in an important decrease in AA accompanied by a slight increase in the average fiber diameter. The largest increase (14%) was noticed for cathepsin G and was due to a preferential attack of thin fibers and to fiber fragmentation. The AA of fibers remaining after elastolytic activity of cathepsin G was 20 to 30% that of elastase in this ex vivo assay. On the other hand, cathepsin G stimulated the elastolytic activity of elastase. For instance, the activity of a mixture of 1.1 microM elastase and 1.5 microM cathepsin G was 1.9-fold higher than the sum of the activities of the individual proteinases. The stimulation increased with the cathepsin G concentration.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1991

The consequences of aortic calcium overload following vitamin D3 plus nicotine treatment in young rats.

Treatment of young rats with vitamin D3 plus nicotine has been proposed as a model of cardiovascular calcium overload. This treatment produced a 20-35-fold increase in the calcium content of the aorta, a compliance vessel, and this increase was accompanied by a 1.6-fold elevation of pulse pressure. In aortic rings, the maximal inhibition by the endothelium-dependent vasodilator, carbachol, of vasoconstriction induced by noradrenaline decreased from 90% in controls to 61% in treated animals. There were significant correlations between aortic calcium content and pulse pressure and aortic calcium content and carbachol-induced relaxation. In conclusion, the vitamin D3 plus nicotine model may be useful for the study of the role of calcium overload in decreased arterial compliance coupled with endothelial injury.

Animals↗

PubMed1990

Early modifications of outgrowth and metallo-endopeptidase activity in fibroblasts from rat cutaneous explants after local gamma-irradiation: dermis cellularity and collagen fibre alterations.

The initial response to local gamma-irradiation of skin was investigated in fibroblasts from cutaneous explants after doses of 4, 8, 12, 16 or 20 Gy. On the day of irradiation, fibroblast outgrowth was inhibited in a dose-dependent manner, but by day 7 post-irradiation, cell restoration occurred especially in explants exposed to 4 or 8 Gy. The dose-dependent inhibition of fibroblast outgrowth correlated with the decrease in cellular metallo-endopeptidase (MEP) activity against succinyl trialanine paranitroanilide. However, the secretion of this MEP activity was 10-fold higher in the culture medium after the lowest irradiation dose (4 Gy). Its inhibition profile was not modified after local irradiation, whatever the dose. In vivo, the cell density of mastocytes, pericytes and endothelial cells decreased after irradiation. Moreover, damaged collagen was observed in the superficial dermis after local irradiation. These results strongly suggest that this MEP may be involved in the alterations occurring in dermal connective tissue components after skin irradiation. The rapid decrease with the dose in fibroblast outgrowth and MEP activity also suggests that these two parameters may provide useful tools for dosimetric assay of the heterogeneity and extent of irradiated areas.

Aminopeptidases↗

PubMed1990

[The effect of procyanidolic oligomers on vascular permeability. A study using quantitative morphology].

In normal conditions vascular permeability is precisely regulated by mechanisms which involve among others the macromolecules of extracellular matrix of the vascular wall. Permeability for a given substance will vary according to the anatomical localisation of the vessel determining also its structure and composition. In some pathological conditions, such as inflammation or diabetes, permeability can be abnormally increased. Increased permeability can be reproduced by i.v. collagenase injection. This permeability increase can be quantified by image analysis using appropriate tracers such as FITC-dextrans or horse-radish peroxidase, on histological sections from control and collagenase treated rats, pretreated or not with procyanidolic oligomers (PCO). We studied cerebral capillaries, aorta and cardiac muscle capillaries. It could be shown that previous treatment of animals with procyanidolic oligomers prevented the permeability increase produced by collagenase injection.

Animals↗

PubMed1989

Immunolocalisation of extracellular matrix macromolecules in the rat spinal cord.

Extracellular matrix macromolecules are involved in many aspects of cell biology. The knowledge concerning the presence, the distribution and the role of these macromolecules in the central nervous system has not yet received sufficient attention. In the present work we studied by indirect immunohistochemical methods the localisation of five extracellular matrix macromolecules in the spinal cord of rats: three collagens: type I, type III, and type IV, and two structural glycoproteins: laminin and fibronectin. We found that all five macromolecules are present in the spinal cord of normal animals. They are localised exclusively in the connective type tissues: the meningeal sheets and the vascular walls. Only type I and type III collagens and fibronectin could be demonstrated around the epithelial cells of the ependyma.

Animals↗

PubMed1989

[Effect of procyanidolic oligomers on cultured mesenchymal cells. I. Effect on attachment, proliferation and detachment of cells].

The effect of procyanidolic oligomers (OPC) was studied on mesenchymal cells in culture: human skin fibroblasts (FB) and porcine aorta smooth muscle cells (CML). In presence of OPC part of the freshly seeded FB did not attach. There was no significant effect on the attachment of CML. Proliferation of FB was also slowed down in a dose-dependent manner. Proliferation of CML-s was also decreased, but much less than for FB-s. The detachment of the cells was also studied by adding trypsin to previously attached cells. Detachment of FB-s was strongly inhibited in presence of OPC in a dose-dependent manner. Much less effect was seen on CML. It appears therefore that OPC may interact with some components of the FB cell membrane and modify the attachment, proliferation and detachment of these cells. The only cell kinetic parameter significantly influenced by OPC for CML was their rate of proliferation. This may be due to the different constitution of the CML cell surface as compared to the FB cell surface.

Adult↗