Scientists in Scotland, Ireland and Japan have found a genetic defect in mice that mimics inflammation seen in allergic diseases such as eczema. The defect in the filaggrin gene could be used in research to further understand these diseases.
Eczema is inflammation of the skin, which causes itching and irritation, and often leads to other allergic conditions such as asthma. Eczema affects one in five children in the UK and other western nations, but the incidence of these allergic conditions has risen sharply over the last decade, most likely due to unknown environmental factors.
The fillagrin gene produces a protein in the outer layers of the skin that helps it produce a protective barrier. This barrier stops allergens entering the body and causing eczema and asthma, as well as hay fever and other allergies, and also prevents water loss to keep the skin hydrated. A mutation in the filaggrin gene affects the integrity of the barrier, thereby making the skin more permeable to allergens and causing allergic reactions.
Previous work has suggested that about half of severe cases of eczema in children were caused by defects in the filaggrin gene. The gene defect is carried by 10 per cent of the population.
This new research, published online in the journal Nature Genetics, shows that mice with the gene defect had allergic inflammation comparable to the human conditions. Professor Irwin McLean from the University of Dundee, who lead the research, says that 'the filaggrin-deficient mice will allow us to identify key substances in the environment responsible for the huge increase in allergic disease. These mice also represent a key to unlock new and improved therapies for eczema, asthma and allergies by targeting or supplementing the defective filaggrin gene'.
The hope that the findings can be used to develop treatments for the diseases, however, remains a long way off, warn the researchers: 'drugs or other treatments aimed at the filaggrin gene are still some years away but this work is a major step in the right direction and should give hope to those with these distressing conditions'.
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'Major step' in allergic work