Biomedical subjects

C Chaudagne

Publications and source records attributed to C Chaudagne.

5 recordsLinked to original sources

PubMed1998

Age-related functional and structural changes in human dermo-epidermal junction components.

Cultured normal human keratinocytes obtained from 14 facial skin biopsies of donors aged 9-79 y were used to study the influence of donor age on the integrin receptors, cell adhesive properties in vitro, and type VII collagen synthesis. Immuno-spectrofluorimetric quantitation of integrins showed a decrease in the beta1- and beta4-subunits in low (0.08 mM) and high (1.8 mM) calcium conditions with aging. Calcium ions decreased the fluorescence intensity by relocating integrins at cell boundaries. Measurements of adhering cells showed that adhesion to bovine serum albumin-, type IV collagen- or laminin 1-coated plastic surfaces initially increased until donor age reached 30 y and then decreased. Specific adhesion to type IV collagen and laminin 1 did not vary with age, but the increase in adhesion to type IV collagen produced by manganese ions increased with age, suggesting an age-dependent feature of beta1 integrin. Synthesis of type VII collagen, increased or not by TGFbeta1 (10 ng per ml), did not vary with the donor age. Global normalized principal component analysis showed that variables related to integrins were strongly correlated, as were those of adhesion. Pre-embedding immunoelectron microscopy of freshly isolated keratinocytes showed that certain hemidesmosomes from aged cells had little or no reaction with anti-beta4-chain antibody. Post-embedding type IV collagen immunostaining and image analysis showed less type IV collagen in adult dermo-epidermal junctions. These findings indicate that there are structural and functional changes in the dermo-epidermal junction components with aging, probably giving a less effective epidermal anchoring system.

Adolescent↗

PubMed1996

Age-related response of human dermal fibroblasts to L-ascorbic acid: study of type I and III collagen synthesis.

Stimulation of the synthesis of type I and III collagens by 0.15 mM L-ascorbic acid (AA) was investigated in primary cultures of dermal fibroblasts form 30 females aged between 19 and 70 years. At this concentration allowing maximal stimulation, fibroblast cultures responded to this agent by an increase in collagen secretion, but to a lower extent for type III compared to type I, leading to an increase in the type I/III collagen ratio. We showed that AA stimulation of type I and III collagen secretion decreased in a statistically significant linear manner with donor age (slope = 1.9; p = 0.0014 and slope = -0.5; p = 0.0164, respectively). We also observed an age-related AA stimulation of the cell-associated collagen pool for type I collagen but not for type III (slope = 0.29; p = 0.015). This might indicate that a reduced ability of fibroblasts to secrete the newly synthesized type I collagen is involved in loss of the cellular response to AA stimulation. Analysis of AA stimulation as a function of body site showed that during aging, the loss of AA stimulation of type I and III collagen synthesis was more for periauricular (slope = 2.7; p = 0.0280 and slope = -0.8; p = 0.0309, respectively) than for mammary skin (slope = 2.1; p = 0.0071 and slope = 0.1; p = 0.7337, respectively). This led us to consider that UV-exposed cutaneous sites may accelerate cellular dermal aging in terms of response to AA, making this parameter a quantitative indicator of human dermal cell aging.

Adult↗

PubMed1995

[Comparative activity of asiaticoside and madecassoside on type I and III collagen synthesis by cultured human fibroblasts].

Type I and III collagens are the major components of skin dermis. Skin aging is related mainly to a decrease in type I collagen levels. Collagen I also plays an important role in wound healing. An enzyme-linked immunosorbent assay (ELISA) was used to determine the levels of secretion of type I and III collagen in human fibroblast cultures with or without asiaticoside and madecassoside. Normal adult dermal fibroblast cultures were established using the explant method from a skin (lifting) sample obtained from a 50 year-old woman. Fibroblasts were grown to confluence in supplemented E 199 medium and after 24 hours of growth, products were added in serum free medium containing 0.15 mM sodium ascorbate. The media were then collected and type I and III collagen secretion levels determined. Kinetics of type I and III collagen secretion led to determine the effects to asiaticoside and madecassoside after 48 hours for collagen I secretion and 72 hours for collagen III. Two triterpenes with an ursenoic skeleton, asiaticoside and madecassoside, were shown to stimulate collagen secretion. Type I secreted collagen (for 10(4) fibroblasts per 48 hours) was increased for 25-30% with asiaticoside and madecassoside. Interestingly, only Madecassoside was able to increase significantly collagen III secretion.

Anti-Infective Agents↗

PubMed1994

In vitro biosynthesis of type I and III collagens by human dermal fibroblasts from donors of increasing age.

A quantitative study of type I and type III collagen production was carried out on primary cultures of human dermal fibroblasts. Cultures were initiated from facial and mammary skin of 29 women aged between 19 and 68 years. Secreted and cell-associated collagen levels were determined by an enzyme linked immunosorbent assay (ELISA). We found that the secretion of type I and type III collagen decreased linearly with age (r = 0.432; P = 0.0193 and r = 0.502; P = 0.0147, respectively). There was a 29% loss in secretion ability for type I and type III collagen over the 49-year period studied. Furthermore, no significant linear age-related decrease was observed for type I and type III collagen associated with the cellular fraction. The influence of body site was also analysed. We observed a significant linear age-related decrease in type I collagen secretion by mammary skin cells (P = 0.0183 and r = 0.618) as well as facial skin cells (P = 0.0037 and r = 0.699). Furthermore, only mammary skin fibroblasts showed a significant linear age-related decrease in secreted type III collagen (P = 0.106 and r = 0.513). No age-related variations in cell-associated collagen were found.

Adult↗

PubMed1994

Influence of asiatic acid, madecassic acid, and asiaticoside on human collagen I synthesis.

Asiatic acid, madecassic acid, and asiaticoside, terpenoids with an ursane skeleton, were tested separately and in combination on skin human fibroblast collagen I synthesis in vitro. In the absence of ascorbic acid, the mixture as well as each individual component stimulated collagen I synthesis to a similar extent. In the presence of ascorbic acid, the level of collagen I secretion was higher for each individual component and for the mixture. A comparison of asiaticoside and asiatic acid shows that the sugar moiety of the molecule does not seem to be necessary for this biological activity.

Adult↗