The atmosphere at the Palais des Congrès in Vichy was conductive to exchanges and discussions favourable to brainstorming on the conference’s key themes: aging, skin epithelium, disorders and rare diseases of the skin.
Epigenetics and mitochondria at the heart of aging
Epigenetics was at the centre of the presentation of Dr Eli Puterman, from the University of California in San Francisco. This researcher has highlighted the relation between the impact of lifestyle factors (physical activity, food, sleep quality, social relations, the level of psychological stress) with the telomerase activity and the length of telomeres, two known markers of cellular aging. "Psychological stress has an influence on the regulation system of the telomere/telomerase couple" he explained.
A study conducted by the team of Dr. Puterman during a year on 213 women with controlled life conditions has shown a decrease in telomere length and in the telomerase activity depending of the importance of perceived stress. According to Puterman, "in women with a good physical and health condition, the impact of stress on the length of telomeres, in connection with past events, is negligible, while it is significant for those whose health is fragile."
For its part, Prof. Andrew Dillin, of the Howard Hughes Institute in San Diego, took an interest in another approach to aging, by focusing on studies related to the mitochondria, in particular to the humoral control of the mitochondrial form and function in order to promote the longevity of a simple cell model, the C Elegans worm. His team sought to understand why, during aging, the organism starts losing control of the proteome and how this is transmitted to the whole organism.
Also from this angle, Dr. Johan Auwerx, from the Laboratory for Integrative and Systems Physiology from the Ecole Polytechnique Fédérale de Lausanne, studied how a decrease in mitochondrial functions - such as the one caused by caloric restriction - could have a positive impact on aging.
An epithelium at the origin of new studies and findings
Beyond aging a key focus was given to recent discoveries on the skin epithelium. For Prof. Jens Schroeder, from the Department of Dermatology at University of Kiel, the skin is considered as a microbial barrier where each skin layer contains antimicrobial peptides that protect the skin against infections. The presence of certain pro-inflammatory cytokines such as IL-17A, IL-1 beta, IL-22, IL-36 plays a role in the production of these peptides. The lipid layer is also important in the development of some skin diseases among which eczema.
Prof. Joke Bouwstra of the Leiden University, demonstrated for his part, that the lipid organization of the stratum corneum of skins affected by eczema was different from the one of healthy skins in terms of organization of lamellar structures and ceramides composition. ’We observed 28 patients, half of them with eczema. We took into account the composition and lipid organization of the skin, of the NMF and analysed the barrier function by measuring the transepidermal water loss. Although some mutations in the gene encoding the fillaggrine seem to be involved in eczema, we were unable to establish a correlation between the fillaggrine and the lipid properties, while on the other hand, the ceramide composition and the lipid organization appeared as factors correlated with the presence of eczema," he explained.
Dr Patricia Rousselle from the CNRS Lyon presented recent results on the role of the microenvironment in skin repair showing that the syndecan-1, a transmembrane protein capable of carrying heparan sulfate and chondroitin sulfate, was involved in important mechanisms at the skin repair level.
Skin disorders and rare diseases, a source of extensive research
Finally, several researchers shared their work on rare diseases: progeria or Hutchinson-Gilford syndrome by the Dr. Annachiara de Sandre-Giovannoli, the Kindler syndrome by Dr. Joey Lai-Cheong, the CMC (chronic mucocutaneous candidiasis) by Dr. Anne Puel.
For psoriasis, the study approach was done using the microRNA pathway which are short DNA segments playing an important role in gene regulation. "More than 2000 miRNAs were identified and each of them regulates hundreds of genes; it was demonstrated recently that these short DNA segments were involved in skin homeostasis and skin problems" exposed Andor Pivarcsi from the Unit of Dermatology and Venereology, Department of Medicine at the Karolinska Institutet in Stockholm, who uses the miR-203 that regulates keratinocyte differentiation or the miR-21 involved in psoriasis, as examples.
A springboard for young researchers
"We created SPIM to foster a spirit of open discussion, but also as a platform for young researchers," explains Jean-Yves Berthon CEO of Greentech. Three sessions are reserved to young researchers, a space for posters is available and they are awarded two prizes at the end of the two days.
"We retained 9 out of the 15 application files we had received. During a plenary session, the selected researchers present their work which will also published in the special edition of the SPIM III European Journal of Dermatology." detailed Berthon.
This year, Miss Manale El Kharbili was given the SPIM 2012 Junior Scientist Award for her work at the Centre for Molecular and Cellular Genetics and Physiology of Lyon on the involvement of tetraspanin 8 in the early invasion of cutaneous melanoma. The 2012 SPIM best poster was awarded to Miss Léa Moulin who identified a mechanism of epigenetic regulation specific to the aging of fibroblasts, by focusing on the Loxl1 gene repressed in aged fibroblasts.
The next appointment of the Spim will take place in 2014