Arthritis first healed in the mouse model

For the first time, the complete cure of arthritis in the mouse model has been achieved

08/07/2014

For the first time, the complete cure of arthritis in the mouse model has been achieved with the help of a new active substance, reports ETH Zurich in a recent press release. So far it was only possible, „to slow down or stabilize the course of the disease with medication“, However, the ETH scientists were able to achieve a comprehensive therapeutic success with a drug developed by them.

In a mouse model for chronic polyarthritis, the animals were cured after administration of the medication, reports ETH Zurich. First, it is with the help of the drug „managed to cure arthritis in mice.“ In a further step, the effectiveness of the drug will now be tested in humans. The results of the study were published in the journal „Proceedings of the National Academy of Sciences“ (PNAS).

So far no cure possible
The „Chronic polyarthritis (also: rheumatoid arthritis) is a painful inflammation of multiple joints of the body“, in which the joint capsules swell and with the progression of the disease also cartilage and bone can be destroyed, write the ETH scientists. Worldwide, 0.5 to 1 percent of all people are affected by the disease. For years, researchers worldwide have been looking for possible drug therapies, but so far a cure is not possible. Only the course of the disease can be slowed down. However, at ETH Zurich, the researchers have now achieved a complete cure of diseased mice with the combination of two drugs.

Targeted use of the active ingredient IL-4
„The drug is a bioengineered drug consisting of two contiguous parts“, reports ETH Zurich. On the one hand the body's own immune messenger Interleukin-4 (IL-4) and on the other hand an antibody coupled to it, „which binds to a protein-form according to the key-lock principle, which occurs only in certain diseases in inflamed tissue (as well as in tumor tissue)“, so the message of the researchers. About the IL-4 had already been known from previous studies, „that this messenger protects mice suffering from chronic polyarthritis from cartilage and bone damage.“ The special antibody now allows a more targeted use of IL-4.

Armed antibody
„Thanks to the coupling with the antibody, IL-4 gets in place of the disease when the fusion molecule is injected into the body“, the study author Teresa Hemmerle reports. This makes it possible to concentrate the active ingredient at the site of the disease, while in the rest of the body the concentration is minimal and the side effects can thus be reduced. That as well „armed antibody“ designated new fusion molecule tested the researchers „with a mouse model in which the animals developed swollen toes and paws due to the inflammation within a few days.“ They investigated both the new drug and the already known cortisone-like, anti-inflammatory drug dexamethasone, which is used to treat chronic polyarthritis in humans.

Long-term cure achieved
The researchers began treatment as soon as the first swelling of the extremities occurred in the animals. They investigated both the separate effects of the two drugs, as well as a combination therapy with dexamethasone and the new fusion molecule. In each case, the active ingredients could only slow down the disease process in the diseased animals. „On the other hand, the arthritis-typical signs such as swollen toes and paws completely disappeared within a few days, when both drugs were administered simultaneously“, reports ETH Zurich. In addition, the levels of a range of immune messengers in the blood and disease tissues, which are altered in polyarthritis, have returned to normal levels. „In our mouse model, this combined therapy leads to long-term healing“, so the conclusion of Teresa Hemmerle. (Fp)