Cataract treated by Lanosterol (a neighbouring molecule of cholesterol).
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An article published it there has a few days on the site of the prestigious magazine Nature reported the results of the use of a molecule called Lanosterol as track to explore for future medical treatment of cataract, leading cause of blindness in the world (Zhao et al. Lanosterol reverses protein aggregation in philadlephia. doi:10.1038 / nature14650).
The lens is a body whose apparent simplicity of the overall geometry and appearance (a simple transparent lens) conceals a physiological challenge: be flexible (for the update in near vision, the)accommodation), transparent (to let light and focus it to the retina)... and especially to keep these properties despite the ravages of time. The presbyopia is the result of a gradual reduction in the flexibility of the crystalline lens and cataract stems from the decline of its transparency: the Crystal is no longer enough clear. The ophthalmologist has means of direct examinations (slit lamp) and objectives to evaluate the transparency of the lens.
To be transparent and let the light without too much to absorb and diffuse, a biological tissue (cornea, lens, vitreous), must have some structural properties, which have in common the regularity of the layout of the cells and the extracellular matrix which make it up. Cristalliniennes say structures are transparent to a large part of the visible light because they are made up of molecules that are a regular, almost geometric layout. These structures are usually high rigidity (ex; quartz). The water is transparent to visible light, and some biological media (ex:vitre) are very watery.
In the case due Crystalline lens , which is made up of cells rich in so-called crystalline proteins, transparency is the result of a regular and orderly arrangement of these proteins and cellular bodies, which also possess elastic properties allowing the Crystalline lens to deform, at least in subjects not having reached the age of total presbyopia. Any phenomenon of protein aggregation results in a loss of the regularity of this matrix and a reduction of transparency, with an increase in the diffusion (dispersion) luminous, from which the Visual symptoms of cataract: veil, glare, etc.
The work of the Zhao team suggests that lanosterol may reduce the protein aggregation phenomena formed within the Crystalline lens , thus increasing the transparency of it,... which is tantamount to reducing the cataract phenomenon!
Lanosterol is a molecule manufactured by "lanosterol synthase", and is involved in the cycle of cholesterol synthesis. However, Lanonsterol is not a form of cholesterol, and this molecule is amphipatic: it has a hydrophobic pole, capable of adhering to protein Frings, and a hydrophilic pole. This peculiarity confers "detergent" properties, much like soaps, and could explain its physico-chemical action at the level of the protein aggregates of Crystalline lens that it could lead to re-solubiliser.
These encouraging results have been observed on in vitro animal models, but also in dogs in vivo, which helps to nourish the hope of a therapeutic efficacy in humans, which remains to be demonstrated today, but which can be expected to will be the subject of many research work to come. To date, the only effective treatment to treat a cataract remains the surgerywhich is to remove the lens and replace it with a implant.