Patrick J.RochetteInvited by Serge Picaud, Prof. Patrick J Rochette (Ophthalmology research department at Laval University, Canada) will give a talk on Monday, March 4th at 11.30 AM, (Amphi Bailliart, 15-20 Hospital, 3rd floor)

This talk will be dealing with "Synergistic toxicity of blue light and pollution to the retina".

Cigarette smoking and high-energy visible blue (HEV; 400-500 nm) light exposure are environmental risk factors for age-related macular degeneration (AMD), the leading cause of blindness in industrialized countries. Individually, they have been shown to cause damage to the retina. We have investigated the photo-toxicity of organic combustion smoke (cigarette, wood burning) when combined to HEV light on retinal cells. We found that this toxicity is driven by photo-oxidation of different compounds. We have then identified a specific photo-sensitive compound, the indenopyrene (IcdP), an important organic combustion-derived polycyclic aromatic hydrocarbon (PAH), which can accumulate in the retina. HEV-light absorption by nanomolar concentrations of IcdP present in retinal cells promotes degenerative changes comparable to the ones observed in AMD. Using human retinal cells simultaneously exposed to individually low-toxic doses of IcdP and HEV light wavelengths, we found that, in spite of oxidative stress generation, IcdP-HEV light toxic impact on cells is not a direct consequence of photosensitized oxidation reactions. Instead, their interaction results in loss of the tight coupling between the two metabolic phases ensuring IcdP efficient detoxification. Our work raises the prospect that lifestyle and environmental pollution may be significant modulators of HEV light toxicity in the retina.

Prof. Patrick J Rochette is a full professor and the dean of ophthalmology research department at Laval University. He is also a senior researcher at the Research Centre of the CHU of Quebec, Canada. He is specialised in photobiology and, more precisely, on the molecular consequences of exposure to ultraviolet and blue light. Prof. Rochette’s laboratory is interested in two fields of study: ocular and cutaneous photobiology. At the cutaneous level, skin cells are used as a model to study the mechanisms of protection against the genotoxicity of UV. At the ocular level, his research aims to understand the molecular mechanisms involved in UV/blue light and atmospheric pollution on ocular health.