Oxygen and miRNAs in Cosmetology and Dermatology

A recent review by Nadim et al. casts some light on a Cosmetology and Dermatology, where circulating biomarkers, though studied to a certain extent so far, are yet unknown for many skin models. (1) A first element to have in mind when considering the skin-related experimental model is the “Oxygen level”. Oxygen levels may contribute to different findings, and the in vitro models used so far may not be so physiologically relevant as initially thought.

Hypoxia and miRNAs

Tissue oxygenation (which is a major part of the cell microenvironment) regulates the expression of the microRNAs called oxymiRs. OxymiRs may be categorized into three groups:

  1. microRNAs whose expression is directly modied by the Oxygen partial pressure,
  2. microRNAs whose expression is indirectly (pH, metabolites, etc.) modified by the Oxygen partial pressure, andpO2 percentage levels in various tissues
  3. microRNAs that target mediators of Oxygen sensing pathways to regulate biological networks for cell survival.

Examples of miRNAs important in skin physiology include miR-17, miR-21, miR-24, miR-27, miR-29b, miR-99 family, miR-125, miR-146a, miR-155, miR-203 and miR-205, among many other.

For example, in injured tissue, disruption of the vascular supply is associated with a low oxygen partial pressure, or hypoxia, which induces the expression of specic microRNAs referred to as HypoxamiRs (included in group (1) of the oxymiRs classification).

miR-210, known as the master HypoxamiR, is robustly induced under hypoxic conditions in nearly all kinds of cells. Under hypoxia, miR-21 also induces angiogenesis by targeting PTEN, leading to activation of AKT and ERK1/2 signaling pathways.

Transfection Factors and microRNAs

Other transcription factors such as p53 and NF-kB have been shown to affect the expression of microRNAs under hypoxia/anoxia conditions.

Numerous studies have demonstrated the modulation of microRNA expression and particularly that of the miR-200 family with oxidative stress due to excessive ROS levels.

Up to now, very few studies have shown the role of the intermediate Oxygen level (physioxia) in regulating microRNA expression in skin cells. Taken together, these results strongly support the idea that physioxia should be an important criterion in determining the microRNA expression level and consequently protein expression and skin functions.

Therefore, when trying to understand the role of microRNAs in skin models, it is important to choose a cell culture system that is as physiological as possible, and have the tools to analyse the different biomarkers (no only microRNA, but also signaling pathways, secretome, etc).

Should you like to have more information on this review, or know what we can do for you to support you with cell culture technologies with controlled oxygen levels or to support you for your biomarker discovery studies, do not hesitate to contact me by leaving a message below.


(1) Nadim M. et al. “Physioxia and MicroRNAs As Key Factors in the Skin Microenvironment” (2015) FSCC Magazine, Vol. 18 – #1, pp: 35-43

Innovative solutions in cosmetology: Cosmetic 360

The world’s leading perfumery cosmetics network, Cosmetic Valley, announces that its 2015 Cosmetic-360 Meeting will take place in Paris (October 15 – 16th, 2015).tebu-bio belong to the Cosmetic Valley Network.jpg

As a member of this network, tebu-bio will be participating in this trade show which is focussed on open innovations this year.

Recent advances in R&D in vitro cosmetic testings

Several innovative solutions have been designed by tebu-bio laboratories to better understand the mechanisms of action of ingredients, and also to further characterize efficient compounds.

These solutions cover cell-based and functional assays but also gene expression analysis.

Cell culture platform

Starting with cell culture, tebu-bio benefits from a huge bank of primary human cells (including keratinocytes, fibroblasts, adipocytes, sebocytes…) from various sources (donors with a large range of choice ex. gender, age, type, body zones) to develop tailored experimental projects.

Cosmetic-360, Paris 2015As an example, using keratinocytes from young vs. aged donors gives the opportunity to identify biomarkers involved in senescence and by comparison with those present in young donors, determine pathway and efficiency of active compounds. These projects do not need any artificial aging tools like UV irradiation which can generate pathway specific aging process and are not always representative of all natural mechanisms involved. Another approach uses adipocytes issued from normal or high BMI donors, which are helpful tools for testing all slimming mechanisms, including the adipokine pathway.

In combination with oxygen controlled cell culture devices, tebu-bio offers a wide variety of cell culture models including strict physioxic cell conditions for more predictive results and by modifying oxygen concentration they are able to create oxydative stress assays as well as hypoxic stress environment.

Profiling approaches

After cell culture treatment, tebu-bio’s labs offer unique access to a wide variety of biomarker identification tools (from cell culture supernatants for soluble released signaling biomarkers or intracellular biomarkers impacting cell behaviour). Approaches are multiple to allow high versatility such as :

  • Pathway specific gene profiling arrays (oxydative stress, senescence, innate immunity, inflammation, cell metabolism etc…)
  • Protein profiling arrays for qualitative (like multiple Western Blots with up to 1,350 markers per array) or quantitative (like multiple ELISAs with up to 360 markers at once) approaches. Markers available are soluble ones which will impact cell environment or intracellular ones wich will modify internal cell behaviour.
  • miRNA profiling – highly promising biomarkers are either secreted and found in cell culture supernatant or remain intracellular. miRNAs have the capacity to down regulate RNA translation and are thus powerful mediators of cell activity.


To further complete the analysis of active compounds, functional bioassays are ideal and available as ready-to-use kits or as fee-for-services. The most popular ones include:

Come and meet us at Cosmetic 360 – get your free invitation

I will be pleased to meet you at Cosmetic 360 and discuss the recent advances in cosmetology and in R&D. To receive an invitation to Cosmetic 360 free-of-charge offered by tebu-bio, get in contact via the form below. The number of complimentary inviations available is limited, early application is advised.

Anti cellulite compound evaluation with in vitro adipocyte-assays

Mechanisms leading to cellulite formation is complex. It involves lipid regulatory pathways and proinflammatory cross-talk that represent promising molecular targets in cosmetology. This post introduces a clever in vitro adipocyte-based assay targeting adipocytokines to better determine the anti cellulite effects of cosmetics compounds.

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Hyaluronic acid – size matters!

HA or Hyaluronan measurement | tebu-bio

Hyaluronan (HA) Competitive ELISA standard curve (cat. nr 117K-1200-1ea)

Hyaluronic acid (HA), or hyaluronan, is an ubiquitous, very high molecular mass polysaccharide that has applications in a variety of fields, including cosmetics, some types of surgery (e.g. opthalmic) and regenerative medicine. It can even be present as a contaminant in some bio-production processes. HA has also been suggested as a possible biomarker for Alzheimer’s disease (AD).

HA acts as a molecular shock-absorber and stabilizer for cells. Its visco-elastic properties, biologically speaking, are valuable for separating tissue and maintaining shape. It is a key in tissue lubrication, and it may play a role in wound repair. It is the ideal choice for some implants, as it does not usually cause an immune response (contrary to what may happen with some biomaterials). Size of the HA used in therapy has an impact on its success. Usually, higher weight forms usually render longer benefits. For bio-production, however, smaller HA forms are usually the main concern.

So, depending on the reason why you are studying this marker, keep size in mind in order to choose the best assay to measure the HA levels in your experimental model. It is of key importance that whatever product you use, analysis of the HA sizes detected with it are clearly mentioned in the technical documentation.

HA or Hyaluronan measurement | tebu-bio

Hyaluronic acid (HA) sandwich ELISA standard curve (direct assay cat. nr 117K-4800-1kit)

A post by my colleague Dr. Philippe Fixe is of great help for choosing the right assay!

It’s not that these assays will allow you to discriminate between high- and low-weight HA. What is intended here is that these assays will allow you to detect all or part of the HA forms depending on its weight. And that may be crucial, as you may be using the assay that does not detect the HA sizes relevant for your experiment.

It is also possible now to outsource HA measurements to an external lab performing regularly validated Hyaluronic acid-specific immuno-assays. As an example, Echelon’s Competitive or Sandwich HA ELISAs outsourcing by tebu-bio’s lab in cosmetology or drug discovery.

Any comments? Feel free to share them below!


MDR1 activity enhancement reduces senescence markers

During the last International Federation of Societies of Cosmetic Chemists (IFSCC) congress (Paris, Oct. 2014), Hajem N. et al (ALES Groupe) have shown that by enhancing MDR activity of fibroblasts grown in vitro, a positive effect on fibroblast cells was detected. In addition to directly testing MDR1 activity, the authors also used a genomic profiling approach to correlate the protective effect of their D-GlyOx complex with a reduction in senescence biomarkers on treated fibroblasts.

tebu-bio’s laboratories supported the Ales Groupe (LIERAC, PHYTO, CARON, Laboratoire DUCASTEL) by providing fibroblast cellular models and measuring the anti-ageing effect of their D-GlyOx complex by genomic profiling,

Source: Hajem N. et al “MultiDrug Resistance (MDR) proteins: active protective system, source of cell longevity” – International Federation of Societies of Cosmetic Chemists (IFSCC) congress – Oct. 27-30, 2014 – Paris) Poster # P-080.

Sircol for soluble and insoluble collagen assays!

Measuring soluble collagen in biological samples is a straightforward experiment which can be done with the Sircol soluble collagen assay using Sirius Red dye (Sircol dye) in a convenient manner (we explored this method in a recent post).  Nevertheless, up to now it has been a challenge to measure insoluble collagen.

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Primary cell sourcing: Cryopreserved Human Adult Sebocytes

Sebocytes are emerging cellular models to study skin biology but also to design new compounds to regulate acne, seborrhoea and other sebaceous gland-related diseases. Easy access to cryopreserved and well-qualified sources of Human Adult Sebocytes will boost skin research and compound testing projects.

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How to select Hyaluronic Acid (HA) quantitative tests?

Hyaluronic acid (also called HA or Hyaluronan) is a glycosaminoglycan with unique characteristics. HA possesses elevated viscosity, enabling tissues (eye, skin, joint and synovial fluid…) to resist to physical and mechanical constraints (torsion, flexion…). Over time, when HA production is declining, tissues progressively loss these tensile properties, leading to wrinkles and fold, weak reepithelization and age-related troubles. [Read more…]

1 simple way to rapidly quantify Collagen: Sircol Collagen Assay

Collagen is a structural protein expressed in mammalian tissues (ex. skin, muscles, tendons, ligaments, cartilages, blood vessels…).  Together with Elastin and Keratin, Collagen fibres give connective properties to mammalial tissues ensuring their physiological form but also firmness, strength and flexibilityNeedless to say, Collagen is trendy… a simple search in Google using the term “Collagen” clearly shows the economical dimension of this protein in well-being.

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