Laurent Barnes

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The main limitation of using topical corticosteroids in dermatology is their atrophic effects on the skin. We have previously proposed a molecular platform composed of CD44, EGFR, and hyaluronate synthase (HAS) that is functionally defective in dermatoporosis, a chronic cutaneous insufficiency/fragility syndrome. In this study, we explored the molecular(More)
Exposure to bile induces curing of the virulence plasmid in Salmonella enterica serovar Typhimurium (pSLT). Disruption of the ccdB gene increases pSLT curing, both spontaneous and induced by bile, suggesting that the pSLT ccdAB genes may encode a homolog of the CcdAB addiction module previously described in the F sex factor. Unlike the F sex factor,(More)
BACKGROUND CD44 is a polymorphic proteoglycan and functions as the principal cell-surface receptor for hyaluronate (HA). Heparin-binding epidermal growth factor (HB-EGF) activation of keratinocyte erbB receptors has been proposed to mediate retinoid-induced epidermal hyperplasia. We have recently shown that intermediate size HA fragments (HAFi) reverse skin(More)
Cytosolic Ca(2+) signals are performed by Ca(2+) releases from the endoplasmic reticulum and Ca(2+) influx from the extracellular medium. Releases rely on the refilling of the intracellular Ca(2+) stores by the Ca(2+) influx "Store-Operated Calcium Entry" (SOCE) via the channel Orai1. Here we show that Orai1 expression, SOCE amplitude, and epidermal(More)
Skin atrophy is an adverse effect of topical corticosteroids (TCs) which, as an established non-life-threatening effect, has been poorly reported by trials involving these drugs. Atopic dermatitis and psoriasis are example of disorders that require repeated therapies with TCs; however, assessing the atrophogenic activity of TCs is still an issue. This study(More)
Lrig1 is known to repress the epidermal growth through its inhibitory activity on EGFR, while CD44 promotes it. We analyzed the expression of these molecules in senescent atrophic human epidermis and in the epidermis of CD44KO mice. In normal human epidermis, Lrig1+ cells form clusters located in the basal layer in which CD44 expression is downregulated and(More)
BACKGROUND Sebaceous glands contribute significantly to the barrier functions of the skin. However, little is known about their homeostasis and tumorigenesis. Recently, increased expression of stem cell marker Lrig1 has been reported in sebaceous carcinoma-like tumors of K14ΔNLef1 transgenic mice. In this study, we analyzed the Lrig1 expression in human(More)
We have previously shown that CYP1A1 was highly induced for a long period of time in a patient who had been poisoned by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a compound known to activate the aryl hydrocarbon receptor (AhR). During that period of time no sebaceous glands could be observed in the skin of this patient. In the present study, starting from(More)
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