Tratamento promissor para Psoríase pode passar por terapia com microRNA

Tratamento promissor para Psoríase pode passar por terapias com microRNA Com o avanço da investigação científica é atualmente possível silenciar uma pequena porção de material genético que influencia a produção de proteínas a nível celular - microRNA. No caso concreto da Psoríase, uma doença inflamatória crónica da pele, verificou-se que em alguns casos os níveis de microRNA miR-21 se encontrava elevado nas lesões cutâneas dos pacientes. Este estudo realizado em Madrid no Nacional Cancer Research recorreu a um inibidor do miR-21, o anti-miR-21 para estudar a relação deste microRNA com a patologia. A terapia com anti-miR-21 funcionou aumentando a enzima TIMP-3, que reduz a atividade da enzima responsável pela produção de citocinas inflamatórias associadas ao crescimento anormal de células da pele, culminando em Psoríase, tratando-se de uma terapia promissora.

NATURE MEDICINE | SPOONFUL OF MEDICINE

Promising psoriasis treatment signals hope for microRNA therapies

26 Feb 2014 | 17:06 EST | Posted by Nicholette Zeliadt | Category: Drugs, drugs and more drugs

Nearly 2% of people worldwide chronically suffer from itchy and painful patches on their bodies, the manifestation of psoriasis, an incurable inflammatory disease in which immune cells infiltrate the skin and release molecules called cytokines that stimulate the skin cells to grow too rapidly. Treatments such as corticosteroids and immunosuppressants can help alleviate mild forms of the disease, and newer antibody-based therapies provide some relief for some of the most severe cases, but some patients fail to respond to these treatments or experience harmful side effects. Now, a new study shows that inhibiting a specific microRNA—a short bit of genetic material that influences the production of proteins in cells—appears to be an effective psoriasis treatment in mice, leaving researchers hopeful that this therapeutic approach will one day be tested in clinical trials.

Psoriasis researchers have known for some time that the levels of a microRNA called miR-21 are elevated in the skin lesions of patients with psoriasis. To determine whether miR-21 plays a crucial role in the disease, a team of scientists led by Erwin Wagner at the Spanish National Cancer Research Centre in Madrid inhibited these genetic elements using an anti-miR-21 treatment. The anti-miR-21 molecules are tiny strands of nucleotides that specifically glom onto miR-21 and prevent it from functioning. Wagner and his colleagues injected this treatment into the skin of mice bearing grafts of diseased tissue from human patients with psoriasis. The anti-miR-21 reduced the thickness of the human skin lesions by about half, a response similar to that obtained using the antibody-based psoriasis therapy etanercept (commercially available from California-based Amgen as Enbrel).

The anti-miR-21therapy appears to work by increasing the levels of an enzyme called tissue inhibitor of matrix metalloproteinase 3 (TIMP-3), which reduces the activity of the enzyme responsible for producing the inflammatory cytokine that triggers the abnormal growth of skin cells in psoriasis. The researchers report their findings online today in Science Translational Medicine.

“This is a completely new way of dealing with the disease,” says Andor Pivarsci, an immunologist at the Karolinska Institutet in Stockholm who studies psoriasis and was not involved in the study. He adds that the small size of the inhibitor might allow it to be applied topically to the skin, which is a formidable barrier to most substances unless they are small, uncharged, and relatively fat-soluble. For patients who don’t respond to the available psoriasis therapies, “this could be a new hope,” he says. 

Continue a ler a notícia original: http://blogs.nature.com/spoonful/2014/02/promising-psoriasis-treatment-signals-hope-for-mircorna-therapies.html

Por: Patrícia Lindeza m5945