J Y Beranger

French National Centre for Scientific Research, Lutetia Parisorum, Île-de-France, France

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Publications (4)3.59 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: The control of human hair follicle growth and differentiation is dependent upon several well-identified factors, including androgens, cytokines, and growth factors. In humans, alopecia androgenetica is a common aging process thought to be regulated through complex genetic imbalances, which also involve several of these crucial identified factors (and probably others not yet characterized), alone or in combination. Among these factors, epidermal growth factor (EGF), as well as pro-inflammatory cytokines, play a pivotal role, as evidenced by their direct inhibitory effects on hair growth both in vitro and in vivo. Following such treatments, the in vitro growth of hair follicles was rapidly arrested and deleterious modifications of hair morphology were also observed. Because these cytokines act, at least partly, through the induction of matrix metalloproteinases (MMP), and because tissue remodeling occurs during the hair cycle, we attempted to identify and localize MMP in the human pilosebaceous unit. We used zymography to observe human hair follicles in culture in vitro. We observed that human hair follicles in culture in vitro mainly and almost exclusively produce MMP-2 and MMP-9 gelatinolytic activities. Furthermore, after stimulation with EGF, tumor necrosis factor-alpha (TNF-alpha), or interleukin-1alpha (IL-1alpha), MMP-9 production was strongly increased. Using immunohistochemistry, we then precisely localized MMP-9 in the lower part of the inner root sheath (Henle's layer) of control human anagen hair follicles. Cytokine- and EGF-induced upregulation of MMP-9 in the lower epithelial compartment of the human hair bulb is a major mechanism through which hair follicle involution, observed in alopecia, may occur.
    International Journal of Dermatology 07/2001; 40(6):385-92. · 1.34 Impact Factor
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    ABSTRACT: The purpose of this investigation is to examine the possible biochemical and topographic cytokeratin alterations in lichen planus of oral mucosa. Biopsy samples of clinically normal buccal mucosa (n = 5), normal gingiva (n = 5), lichen planus from buccal mucosa (n = 5), and lichen planus from gingiva (n = 5) were obtained from patients of both sexes. Cytokeratin expression was determined by means of immunohistochemical labeling with use of a battery of monoclonal antibodies against cytokeratins and filaggrin and two-dimensional gel electrophoresis. In buccal mucosa, which is not keratinized cytokeratins 4 and 13 are expressed in the majority. In buccal mucosa lichen planus, the appearance of cytokeratins 1, 2, 10, and 11 coincides with a decrease in cytokeratins 4 and 13 and a moderate increase in cytokeratins 6, 16, 17, and 19. In normal gingiva, which is normally keratinized, the main cytokeratins are 1, 2, 10, and 11. In gingival lichen planus, a slight decrease in these cytokeratins and in cytokeratin 13 expression was noted. Finally, alterations in cytokeratins 5 and 14, explained by marked alterations of basal cells, were observed. The battery of antibodies used in this study, in correlation with two-dimensional gel electrophoresis, could represent useful diagnostic tools that enable the distinction between inflammatory keratosis and so-called quiescent lichen planus. Moreover, this work showed that cytokeratins 1, 2, 10, and 11 and filaggrin are sensitive tools that may help detect early relapse before clinical exacerbation. Finally, these biochemical techniques may be useful to follow the evolution of lichen planus under treatment.
    Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology 03/1995; 79(2):207-15.
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    ABSTRACT: 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 Biology International 08/1994; 18(7):715-22. · 1.64 Impact Factor
  • Annales de Dermatologie et de Vénéréologie 02/1993; 120(11):853-5. · 0.60 Impact Factor