Researchers from the Vall d'Hebron Institute of Research and Bellvitge Biomedical Research Institute (IDIBELL) have shown that administration of genetically modified mesenchymal stem cells regenerates lung tissue and stops the inflammatory process in mice with acute lung injury. Study results were published in the "http://www.atsjournals.org/doi/abs/10.1165/rcmb.2012-0406OC?prevSearch=%3Cb%3EFull+Text%3C/b%3E%3A+human+mesenchymal+stem+cells+overexpressing+%22il+33%22+antagonist+sst2+attenuate+%22endotoxin+induced%22+acute+lung+injury&searchHistoryKey=" "http://www.atsjournals.org/doi/abs/10.1165/rcmb.2012-0406OC?prevSearch=%3Cb%3EFull+Text%3C/b%3E%3A+human+mesenchymal+stem+cells+overexpressing+%22il+33%22+antagonist+sst2+attenuate+%22endotoxin+induced%22+acute+lung+injury&searchHistoryKey=" American Journal of Respiratory Cell and Molecular Biology. Acute lung injury and its more severe manifestation, the acute respiratory distress syndrome, are characterized by very severe inflammatory processes that damage the lungs with a mortality of between 40% and 50%. Currently there is no effective treatment beyond palliative care and mechanical assistance to breath. "In the last years we have been working in the administration of human mesenchymal stem cells from adipose tissue obtained from liposuction in different pathologies," said the researcher of Human Molecular Genetics reserach group at IDIBELL Josep Maria Aran. "We have found that these stem cells are able to easily reach the lungs and there, secrete anti-inflammatory substances and growth factors."To demonstrate the effects of these stem cells, Dr. Maria Jesús Cruz, researcher of the Pneumology group at VHIR, and her colleagues tested them in two animal models: an animal model model with actue respiratory distress and another one with asthma designed and standardized by doctors Xavier Muñoz Gall, Oriol Roca and Joan Ramon Masclans". The studies conducted so far with these cells have shown a positive effect. IDIBELL and VHIR researchers have introduced a genetic modification in these cells that improves treatment. The cytokine IL33 is a protein that acts as an alarm signal in these patients. When the damage into the lungs begins, the cells secrete this highly proinflammatory substance and elicit a very strong immune system answer. "We believed," says Aran, "that if we modified genetically mesenchymal stem cells to secrete a molecule antagonist of IL-33, we could stop the inflammatory process and we found that, in mice, the effect was more positive than unmodified cells: regeneration of lung tissue and practically nullifies the inflammatory process in the lungs".