Miércoles 09 Enero 2008; 09:30 hrs.

Celiac Disease: Discovery Of Enzyme's Structure May Lead To New Treatments

ScienceDaily (Jan. 9, 2008) — Researchers have discovered a new structure for a key enzyme associated with celiac disease, a finding that could lead to the design of new medications for the common digestive disorder, according to an article scheduled for the Jan. 7 issue of Chemical & Engineering News. Celiac disease is a condition in which the stomach cannot properly digest wheat and other gluten-containing foods. The disease afflicts an estimated 2 million people in the United States alone.

In the article, C&EN Deputy Assistant Managing Editor Stu Borman notes that the disease is believed to occur when the protein gluten interacts with an enzyme called transglutaminase 2 (TG2), triggering an autoimmune reaction that damages the small intestine and causes diarrhea, abdominal pain and other symptoms. As a result, people with the disease are urged to follow a strict gluten-free diet.

Although scientists have previously obtained the X-ray crystal structure of human TG2, they have only revealed its "closed" or inactive form, the article points out. Now, Chaitan Khosla and colleagues at Stanford University report the first-ever determination of the "open" structure of the enzyme, in which its active site is accessible to substrates.

The finding that could help scientists design inhibitors of the enzyme that could serve as medications for celiac disease and other related conditions, according to the article.

Journal article: "Enzyme opens for business"

Adapted from materials provided by American Chemical Society.

Martes 08 Enero 2008; 09:56 hrs.

Genetic Background of Celiac Disease and Its Clinical Implications

Victorien M. Wolters, M.D.  and Cisca Wijmenga, Ph.D. Am J Gastroenterol 2007;102:1–6 Celiac disease (CD) is a complex genetic disorder with multiple contributing genes. Linkage studies have identified several genomic regions that probably contain CD susceptibility genes. The most important genetic factors identified are HLA-DQ2 and HLA-DQ8, which are necessary but not sufficient to predispose to CD. The associations found in non-HLA genomewide linkage and association studies are much weaker. This might be because a large number of non-HLA genes contributes to the pathogenesis of CD. Hence, the contribution of a single predisposing non-HLA gene might be quite modest. Practically all CD patients carry HLA-DQ2 or HLA-DQ8, while the absence of these molecules has a negative predictive value for CD close to 100%. Genetic risk profiles for CD would be helpful in clinical practice for predicting disease susceptibility and progression.Más.