Behavior of the two circulating androgens testosterone and DHEA and their main intracellular metabolites in an androgen-sensitive sebocyte cell line.

Androgens are known to strongly regulate the sebaceous gland. Relationships with testosterone have been reported and little is known about the role of DHEA. We showed that the most potent intracellular androgen metabolite, dihydrotestosterone (DHT), induced AR translocation, specific transcripts such as ras-related dexamethasone induced 1 (RASD1) and lipogenesis/lipid storage. We used these parameters to assess the behaviour and activity of the two main circulating androgens TESTO and DHEA, in comparison with DHT, in this model.

Behavior of the two circulating androgens testosterone and DHEA and their main intracellular metabolites in an androgen-sensitive sebocyte cell line.

Androgens are known to strongly regulate the sebaceous gland. Relationships with testosterone have been reported and little is known about the role of DHEA. We showed that the most potent intracellular androgen metabolite, dihydrotestosterone (DHT), induced AR translocation, specific transcripts such as ras-related dexamethasone induced 1 (RASD1) and lipogenesis/lipid storage. We used these parameters to assess the behaviour and activity of the two main circulating androgens TESTO and DHEA, in comparison with DHT, in this model.

Innate immunity activation of sebocyte cells by living bacteria. Evidence of a potential immunosuppressive effect of DHT.

Acne is a skin pathology targeting the pilosebaceous unit…sebum hypersecretion and bacterial infection. We studied the effects of living bacteria on the induction of an innate immune response in a sebocyte cell line.

Pharmacological effects of anti-androgens and other compounds in an androgen-sensitive sebocyte cell line.

We analysed the activity of reference anti-androgens (Finasteride, Dutasteride, Cyproterone acetate), at the level of their potential targets (5-alpha-reductase, AR translocation, induced transcripts) and in a functional lipid accumulation assay. We also evaluated this androgen-induced lipid accumulation assay as a potential pharmacological tool to detect potential inhibitors from both androgenic and non-androgenic origins.

Androgens activate lipogenesis through an AKT-independent mTOR pathway stimulation and a limitation of autophagy in an androgen-sensitive sebocyte cell line.

Androgens are key regulators of sebaceous function... A link between mTOR and androgen signaling has previously been reported...as well as a link between these processes and lipid synthesis...Here we aimed at confirming that DHT-induced lipid synthesis/accumulation is at least in part dependent on mTOR activation in the SEBO662AR cell line and that the autophagic process is consequently modified by the androgenic treatment.
in vitro and ex vivo assays: skin protection and immune defense system

Pollution and epigenetics: Histone H3 modifications in keratinocytes after exposure to urban dust and Benzo(a)pyrene

In this work, human epidermal keratinocytes were used to study the effects of urban dust and benzo(a)pyrene on the epigenetic pattern of the histone H3 protein. The assay was then used to screen a series of plant extracts in order to find cosmetic actives to protect the skin against air pollution.

Anti-inflammatory activity of CKC-containing cationic emulsion eye drop vehicles

Preservative-free cationic emulsion-based artificial tears (ATs) or drug vehicles are innovative eye drop formulations with tear film stabilization and drug delivery properties, and valuable in vivo anti-inflammatory and wound healing properties.

New Biological Activities of Lythrum salicaria L.

The perennial and widespread herb Lythrum salicaria L., also called purple loosestrife, is a plant that is traditionally used in European medicine.
lipid

Effects of different kinds of pollutants on the lipidic metabolism of human sebocytes and protective effects of a new macroalgae culture extract

Sebocytes lipid production are stimulated by pollutants. Ame acts by protecting epidermal cells, human sebocytes and skin from urban dust.

New biological effects of Aphloïol

In the present study, we identified new properties of Aphloïol (syn. mangiferin) in improving skin barrier function, especially by promoting keratinocyte differentiation, synthesis of transmembrane glycoprotein and lipid neosynthesis.
skin photoaging irradiations

in vitro modeling of skin photoaging: development of evaluation tools for cosmetics

Development of in vitro models skin for better understand the modifications during photo-aging induced by repetitive UV exposure.
skin photoaging irradiations

in vitro modeling of skin photoaging: development of evaluation tools for cosmetics

Development of in vitro models skin for better understand the modifications during photo-aging induced by repetitive UV exposure.
ageing reconstructed epidermis

Development of a new model of reconstructed aged skin useful to study antiageing effects of cosmetic compounds

The development of new anti-ageing products needs performant in vitro models mimicking morphological changes and physiological modifications appearing during skin ageing. In order to have access to a simple model mimicking the epidermis ageing but in relation with a normal dermis, we have developed a new in vitro model of reconstructed skin comprising an aged epidermis covering a reconstructed dermis built with collagen and normal (young) fibroblasts.

Androgens induce sebaceous differentiation in sebocyte cells expressing a stable functional androgen receptor

In order to study the impact of active androgens in sebocytes, we constructed a stable human sebocyte cell line derived from SEBO662 [17] constitutively expressing a fully functional AR. In these SEBO662 AR+ cells, dihydrotestosterone (DHT) induced AR nuclear translocation and the strong modulation of a set of transcripts (RASD1, GREB1...) known to be androgen-sensitive in other androgenic cells and tissues.

Atopic dermatitis: physio-pathology and clinical signs

Atopic dermatitis is the most common dermatosis affecting children: 65% of the patients are less than a year old and 85% are below 5 years. The prevalence of this pathology is constantly on the rise and currently affects 10 to 25% of the population.

Cystinosin is a melanosomal protein that regulates melanin synthesis

In vitro studies showed that cystinosin was located at melanosomes. CTNS silencing led to a 75% reduction of melanin synthesis that was caused by a degradation of tyrosinase by lysosomal proteases. Our results objectify the pigmentation defect in patients with cystinosis. We also identify the role of CTNS in melanogenesis and add a new gene to the list of the genes involved in the control of skin and hair pigmentation.

Immortalized sebocytes SEBO662 can spontaneously differentiate into a sebaceous-like phenotype when cultured as a 3D epithelium

SEBO662 multilayers spontaneously differentiate into a sebaceous-like structure as shown by the strong polarized expression of the late sebaceous marker EMA, the overexpression of some lipogenic markers and lipid production on the upper side of the epithelium.

Effect of C-xyloside on morphogenesis of the dermal epidermal junction in aged female skin. An ultrastuctural pilot study

These data suggest that topical C-xyloside application in vivo may be efficient in inducing a better dermal-epidermal cohesion when such a junction is deficient, as is the case in photo-aged or chronologically aged skin. Moreover, a statistically significant increase in CD44 expression was noted in the epidermis of C-xyloside-treated compared to the placebo treated skin areas.
Lipolytic

Lipolytic effect of a polyphenolic citrus dry extract of red orange, grapefruit, orange (Sinetrol) in human body fat adipocytes. Mechanism of action by inhibition of cAMP-Phosphodiesterase (PDE)

The present study investigated the lipolytic (break of fat stored) effect of a citrus-based polyphenolic dietary supplement (SINETROL) at human adipocytes (ex vivo), body fat (clinical) and biochemical levels (inhibition of phosphodiesterase).
tensin1

Reduced expression of the adhesion protein tensin1 in cultured human dermal fibroblasts affects collagen gel contraction

tensin1 plays an important role in cell-matrix interaction and that a reduced expression might contribute to the dermal alterations observed during skin ageing