In one of the largest studies of its kind ever conducted, an international team of scientists has thrown new light on the genetic basis of the inflammatory bowel diseases (IBD). Crohn's disease and ulcerative colitis, the two most common forms of IBD, are chronic inflammatory digestive disorders affecting 230,000 Canadians.
Dr. John Rioux, researcher at the Montreal Heart Institute and Associate Professor of Medicine at the Université de Montréal, is one of the researchers who have identified 71 genetic regions newly associated with inflammatory bowel disease (IBD), increasing the total number discovered to date to 163, in one of the largest studies of its kind.
Also, the study points out that these regions showed a striking overlap with those implicated in autoimmune diseases and in immune deficiencies. Even more surprising was the observation of a significant overlap with genetic regions controlling our response to microbial infections such as in the case of tuberculosis. These highlights were published in the prestigious scientific journal Nature today.
Moreover, these findings suggest that IBD results from overactive immune defence systems that evolved to fight off serious bacterial infections. In IBD, the body's immune system produces an ongoing inflammatory reaction in the intestinal tract that injures the intestinal wall, leading to diarrhea and abdominal pain. IBD patients typically require lifelong treatment with drug therapy, and often need surgery to repair tissue damage caused by the disease.Common research
In the first step of the study, the researchers conducted a "meta-analysis" of 15 previous genomic studies of either Crohn's disease (CD) or ulcerative colitis (UC), the two most common forms of IBD, creating a large dataset that combined genetic information from some 34,000 individuals who took part in those studies. The results then formed part of a second meta-analysis that included data from new genome-wide scans of more than 41,000 DNA samples from CD/UC patients and healthy comparison subjects collected at 11 centers around the world by the International IBD Genetics Consortium.
"We have greatly expanded the map of genetic regions that are associated with IBD", agreed Dr. John Rioux, co-lead author of this study and chair of the Consortium, with Jeffrey Barrett of the Wellcome Trust Sanger Institute in Cambridge, England, lead author of the study. "Each of these regions only increases a person's chance of developing IBD by a fraction of a per cent and even taken together they cannot tell us who will or will not develop the disease. But they each tell a small story about the biology of this disorder, and by combining them we find biological pathways that, if disrupted, can lead to IBD."Immune system: a major factor
"We see a genetic balancing act between defending against bacterial infection and attacking the body's own cells," said Dr. Barrett. "Many of the regions we found are involved in sending out signals and responses to defend against bad bacteria. If these responses are over-activated, we found it can contribute to the inflammation that leads to IBD."
Nearly 100 scientists in 15 countries contributed to the new work, which "highlights the incredible power that working together in a large team can have," said Barrett. "This would not have been possible without the thousands of DNA samples from patients with these conditions assembled by the International IBD Genetics Consortium. Collectively, our findings have begun to uncover the biological mechanisms behind this disease."About inflammatory bowel diseases
About the Montreal Heart Institute: www.icm-mhi.org.
About the Université de Montréal: www.umontreal.caNotes to Editors:
Published in Nature online November 1st, 2012
William Raillant-Clark | EurekAlert!
Scientists uncover the role of a protein in production & survival of myelin-forming cells
19.07.2018 | Advanced Science Research Center, GC/CUNY
NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
19.07.2018 | Earth Sciences
19.07.2018 | Power and Electrical Engineering
19.07.2018 | Materials Sciences