Publications by authors named "Natascha Hennighausen"

2 Publications

  • Page 1 of 1

Targeted dry skin treatment using a multifunctional topical moisturizer.

Int J Cosmet Sci 2021 Apr 3;43(2):191-200. Epub 2021 Jan 3.

Bayer Healthcare SAS, Gaillard, France.

Objective: The development of dry skin is a complex process, with a wide variety of factors each playing different roles in its evolution. Given this, it is important when designing a formulation to tackle dry skin that these varied aspects of skin behaviour are addressed. Presented here are the results of a 3-week moisturization study carried out on dry legs. A wide range of traditional and more recently developed biophysical measurement methods have been combined with visual assessment of skin condition to enable multiple aspects of skin function to be determined. The observed changes in the skin are discussed in terms of the ingredients used in the moisturizing formulation.

Methods: A range of novel and traditional skin assessment methods and techniques were used to assess the effects of an oil in water-based moisturizing product compared to an untreated site during a 3-week in vivo study on dry lower leg skin.

Results: Statistically significant improvements were observed in a range of skin parameters as a result of product usage. Skin hydration assessed using Corneometer®, Epsilon® and visual dry skin grading all increased after 3 weeks of use. Skin barrier function measured using transepidermal water loss also improved. Levels of cholesterol, free fatty acids and Ceramide NH increased, as well as the average length of the stratum corneum (SC) lipid lamella bilayers, and the ratio of lipid to protein increased (measured using Lipbarvis® and in vivo Confocal Raman Spectroscopy). Increases in the levels of Ceramide EOS and NP were also observed, along with an improvement in corneocyte maturity, although these were not statistically significant.

Conclusions: Using a variety of traditional and novel skin assessment techniques, a wide range of factors associated with the evolution of dry skin have been assessed upon treatment with a new topical moisturizer. Product usage resulted in significant improvements to skin hydration and barrier function, the levels and morphology of SC barrier lipids, and overall epidermal differentiation. As a result there was a significant reduction in the characteristics associated with the development of dry skin after use of the test product.
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April 2021

αPIX Is a Trafficking Regulator that Balances Recycling and Degradation of the Epidermal Growth Factor Receptor.

PLoS One 2015 15;10(7):e0132737. Epub 2015 Jul 15.

Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.

Endosomal sorting is an essential control mechanism for signaling through the epidermal growth factor receptor (EGFR). We report here that the guanine nucleotide exchange factor αPIX, which modulates the activity of Rho-GTPases, is a potent bimodal regulator of EGFR trafficking. αPIX interacts with the E3 ubiquitin ligase c-Cbl, an enzyme that attaches ubiquitin to EGFR, thereby labelling this tyrosine kinase receptor for lysosomal degradation. We show that EGF stimulation induces αPIX::c-Cbl complex formation. Simultaneously, αPIX and c-Cbl protein levels decrease, which depends on both αPIX binding to c-Cbl and c-Cbl ubiquitin ligase activity. Through interaction αPIX sequesters c-Cbl from EGFR and this results in reduced EGFR ubiquitination and decreased EGFR degradation upon EGF treatment. However, quantitatively more decisive for cellular EGFR distribution than impaired EGFR degradation is a strong stimulating effect of αPIX on EGFR recycling to the cell surface. This function depends on the GIT binding domain of αPIX but not on interaction with c-Cbl or αPIX exchange activity. In summary, our data demonstrate a previously unappreciated function of αPIX as a strong promoter of EGFR recycling. We suggest that the novel recycling regulator αPIX and the degradation factor c-Cbl closely cooperate in the regulation of EGFR trafficking: uncomplexed αPIX and c-Cbl mediate a positive and a negative feedback on EGFR signaling, respectively; αPIX::c-Cbl complex formation, however, results in mutual inhibition, which may reflect a stable condition in the homeostasis of EGF-induced signal flow.
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April 2016