Studies in mice
Immune cells also have a role in the development of type 2 diabetes
■ Several studies relate obesity to immunological alterations
■ Obcessious mice tissue barely has T cells, in front of a healthy animal
One of the obese mice of the study (Photo: Sara Becerril)
Updated Sunday 07/26/2009 19:16 (CET) María Valerio
Madrid.- It is increasingly clear than obesity, in addition to being a metabolic disorder, it is accompanied by a chronic inflammation of fatty tissues, which ends up triggering the resistance of the cells to insulin and the appearance of type 2 diabetes.Citches of cell signals that occurs in fat and that escape control of the body's defensive system is one of the new fields of research in this field and four independent studies in the magazine 'Nature Medicine' show that immunology could be more relatedwith diabetes of what was believed so far.
The four studies (one of them with Spanish participation), carried out with mice, open the door to the possibility of treating metabolic disease with treatments aimed at acting on the organism's defensive cells.However, researchers are still cautious about the possible application of their results in humans.
In fact, although so far immunotherapy has been crucial in the field of type 1 diabetes (which is 10% of cases and is, after all, an autoimmune disease), this is a terrain practically in diapers in diapers in diapers inThe case of diabetes linked to obesity, as Dr. Rafael Simó.
"If until now it was thought that type 2 diabetes was a strictly metabolic disorder, these works demonstrate the participation of the immune system," says Elmundo.es Laura Herrero, a biologist at the University of Barcelona and signer in one of theResearch, directed by the professors of Harvard University Diane Mathis and Steven E. Shoelson.
Antiallergic for diabetes
In another of the studies, headed by Guo-Ping Shi, biochemist at Harvard University and the Brigham and Women's Boston Hospital (both in the US), two antiallergic medications were used (the smootifen of fumarate that is used for allergic conjunctivitis, and the sodium chromoglycate that some patients with respiratory difficulties use) to treat a group of rodents that suffer diabetes and obesity for two months.
In previous works, Shi had already observed that these two drugs are able to regulate the action of mast cells, a type of cells that participates in the immunological and inflammatory reactions of the organism.Under normal conditions, mast cells facilitate tissue healing;However, in some situations (and diabetes could be one of them), mast cellIn a press release.
Immunometabolism
In fact, Shi and his partner Jian Liu, knew that mast cell levels are more abundant in the fatty tissue of mice and obese individuals;So they wondered if these medications would also have some kind of action at this level.To do this, they compared for two months the evolution of a group of rodents: some of them subjected to a normal diet, others combining healthy diet and medication or, only, administering low -fat and sugar foods.
Although the diet fulfilled its function of improving metabolic control, it was with antiallergic as a practically 100% recovery was observed in all parameters related to obesity and diabetes.
To confirm this observation, they tried to gain weight with a dietrich in fat and sugar to a group of genetically modified animals so that they could not manufacture mast cells.After three months, the animals had not become obese or developed diabetes.
But the only elements of the immune system that seem to play an important role in this disease are not the mast cells.In the other three works, attention focuses on the so -called T cells, which could somehow regulate the inflammation suffered by fatty tissues in the subjects with obesity.In fact, in the composition of fat they can not only find fat cells themselves (adipocytes), but also other immunological varieties.
Again from Harvard, another team led by Markus Feuerer (in which Laura Herrero, of the University of Barcelona has also collaborated) has discovered that obese rodents had a surprisingly low number of regulatory T cells in their adipose tissue compared to thehealthy specimens.If until now it was believed that these white blood cells only regulated other immune cells (they are known as the guardians of the immune system), these works suggest that they are actually a link between the metabolic and immune system.
As Herrero explains, while the adipose tissue of obese and diabetic rodents is full of inflammatory macrophages, but barely has T cells;The fat of a healthy individual with a normal weight has the reverse composition: few macrophages and more T cells. "Now we are seeing that enhancing anti -inflammatory properties of these cells can have a therapeutic application against metabolic diseases such as type 2 diabetes or resistanceto insulin. "