Q&A with Dr. Iuliana Popa, Faculty of Pharmacy, University of Paris XI

Q&A with Dr. Iuliana Popa, Faculty of Pharmacy, University of Paris XI

We caught up with one of our speakers, Dr. Iuliana Popa to find out how she plans to explore how skin biology is influenced by external and internal factors during her speaker session on environmental biological influences on sphingolipids metabolism in the epidermis at in-cosmetics 2015.

What are you speaking on at in-cosmetics 2015?

I am speaking about environmental biological influences on sphingolipids metabolism in epidermis at in-cosmetics 2015.

First of all we should know that the name “sphingolipid” came about because of novel chemical structures making the link between lipids and sugar, which was a mystery at that time as well as the signification of the enigmatic and mythological Sphinx. Sphingolipids were first discovered in the brain, but now specific structures which have been identified in different organs are found to be markers for sphingolipidoses (Fabry and Gaucher), and also markers for differentiation in cancer diseases or in skin, such as protein-bound ceramides in atopic dermatitis and dry skin.

I will provide an overview concerning biosynthesis pathway of shingolipids in skin, spotting out how the environment factors regulating the PPAR-gamma, beta-glucosidase, acid-sphingomyelinase, sphingomyelinase-2 activities or the sulfation of 25-hydroxycholesterol, the modification of the transporters, or beta-defensin production resulting in the alteration of lipid processing leading to aging in skin or to severe pathologies and barrier dysfunctions, such as atopy, with dry, scaly skin.

I will also explore psoriatic plates, an osteopontin (OPN) and the regulation of TLR3, the receptor for viruses in keratinocytes, that are related to repairing the barrier in the case of atopic dermatitis patients.

I will also look at the uptake of vitamins such as vitamin D, vitamin C, n-3 polyunsaturated fatty acids, dietary glucosyceramide, sea buckthorn, peptides, nicotinamide, polyphenols, that could increase ceramides and other lipids turnover in stratum corneum, preventing skin photoaging.

Why is it important for cosmetic manufacturers to understand the environmental biological influences on sphingolipids metabolism in epidermis?

It is important for manufacturers in order to help find a better adequation between the existing actives and the targets by possible new claims, finding new targets and developing a holistic approach concerning the skin shutting.

How can cosmetic manufacturers ensure they create products with active delivery?

The 3D skin models specific objectivation of enzymatic activity (ICH, WB, QPCR, Affix) and Franz diffusion cells experiments will help to answer this question at in-cosmetics.

How should sphingolipids metabolism affect formulations?

Knowing about sphingolipid metabolism will help when conceiving adapted formulation (live-on such as skincare/make-up, hair-care, or wash-off), in order to restore the integrity of the barrier and to maintain skin hydration. Some sphingolipids may be delivered into the live epidermis in order to increase aged or sensitive skin i.e. the level of the enzymes and their substrate and dowregulate inflammation, for example sphingosine.

How does environmental cellular stress affect sphingolipids metabolism?

In skin, the cellular stress is more complex because of the complexity of the cellular types and the diversity of the functional layers and this is the result of severe pathologies to dry or sensitive skin. Cellular stress may affect the intracellular accumulation of ceramides and fatty acids precursors (triglycerides, glucosylceramides, phospholids), leading to ROS accumulation, autophagy, tight junctions, paracrine/autocrine cytokines production, keratinocytes differentiation/proliferation ratio.

How can cosmetic manufacturers assess skin barrier integrity to implement optimum formulation requirements?

There are enough methods for the integrity and hydration of the skin barrier by conductometry, TEWL, Franz cell and others. Usually, the manufacturers are using the strips content measurements to assess the sebum, protein content and hydration. Experimentally, it is used to assess the protein-bound ceramides of the Stratum Corneum by taking strips of the skin barrier then assessing these by gas chromatography and mass spectrometry to give quantitative results.

Who should attend your seminar and what’s the single most important point you want delegates to take away?

I believe research and development teams and marketing teams will find the seminar useful. I want to uncover some of the mystery associated with sphingolipids and their enzymatic metabolism (de novo and recycling pathway, autophagy, catabolism). The sphingolipids issue changes the point of view from the structural “bricks” of the skin to the “active ingredient” defining the multifaceted target.

How will your discussion help formulators improve existing products? Will this knowledge help make formulation easier for attendees moving forward ?

Can a better understanding of how environmental biological influences on sphingolipids metabolism in epidermis reduce costs for formulators and NPD departments?

It is well known that some lipids active are already used in cosmetics in dry skin soothing and restoration of disturbed lipid barrier.

But I would like to show by this presentation on sphingolipids metabolism that almost all of the cosmetic actives could have an direct/indirect role in sphingolipids, improving metabolism in skin and thus leading to hydration, anti-aging or detoxification benefits.  This could change the way of approaching the sphingolipid metabolism and lead to a development of research in this specific field in relation with skin and repositioning/ discovering of some ingredients/ actives already marketed but for other benefits.

It could be at different levels, such as intracellular (ex: de novo synthesis of lipids, lamellar bodies formation) and extracellular (tight junctions, intercellular paracrine and autocrine signaling, extracellular matrix features and skin layers behavior.
On one hand, it was shown that sphingolipids signaling is involved in cell autophagy development by the contribution to the autophagosome formation (Yamagata M et al, 2011;   Li Y et al, 2014)  and “sphingolipids rheostat” role in regulating  mTOR pathway (Taniguchi M et al, 2012) and mitochondrial respiration by TORC2/Ypk1 association (Niles BJ and Powers T, 2014).

On the other hand, if we take only two examples- the Silab active CELLDETOX is claimed to be an autophagy activator and the Solabia active Celtonyl, that claims to be an energy booster, is a stimulator of mTOR pathway.

We may conclude that on the basis of the scientific articles both CELLDETOX or Celtonyl cases, sphingolipid metabolism is modulated by these actives at a certain level ofbiosynthesis and thus promote an implicit skin benefit even if that is not directly proven by the scientific file of the products and not stated in the claims.

Dr. Iuliana Popa is speaking at the Delivery systems for cosmetic actives: How to deliver your actives through the skin barrier to their site of action workshop at in-cosmetics on Wednesday 15 April 2015, 14:00 – 17:30 Workshop Room CC5.3

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