New giant cell arteritis genetics study results reported from University of Barcelona, Department of Internal Medicine
2007 NOV 12 -- Fresh data on giant cell arteritis are presented in the report 'Gelatinase expression and proteolytic activity in giant-cell arteritis.' "Gelatinases (MMP2 and MMP9) are expressed in giant-cell arteritis (GCA) and are thought to play a role in vessel disruption. However, their activation status and enzymatic activity have not been evaluated," scientists in Barcelona, Spain report. "Our aim was to investigate the distribution and proteolytic activity of gelatinases in GCA lesions at different stages Expression of MMP2, MMP9, MMP2-activator MMP14 and their natural inhibitors TIMP1 and TIMP2 was determined by real-time PCR and immunohistochemistry in temporal artery sections from 46 patients and 12 controls. MMP activation status and enzymatic activity were assessed by gelatin and film in situ zymography Vascular smooth muscle cells from normal specimens constitutively expressed pro-MMP2 and its inhibitor TIMP2 with no resulting proteolytic activity. In GCA MMP2, MMP9 and MMP14 were strongly expressed in their active form by infiltrating leucocytes. Inflamed arteries also expressed TIMP1 and TIMP2. However, the MMP9/TIMP1 and MMP2/TIMP2 ratios were higher in patients compared with controls, indicating an increased proteolytic balance in GCA which was confirmed by in situ zymography. Maximal gelatinase expression and activity occurred at the granulomatous areas surrounding the internal elastic lamina (IEL). Myointimal cells also expressed MMPs and exhibited proteolytic activity, suggesting a role for gelatinases in vascular remodelling and repair GCA lesions show intense expression of gelatinases. Activators and inhibitors are regulated to yield enhanced gelatinase activation and proteolytic activity," wrote M. Segarra and colleagues, University of Barcelona, Department of Internal Medicine. The researchers concluded: "Distribution of expression and proteolytic activity suggests that gelatinases have a major role not only in the progression of inflammatory infiltrates and vessel destruction but also in vessel repair." Segarra and colleagues published their study in Annals of the Rheumatic Diseases (Gelatinase expression and proteolytic activity in giant-cell arteritis. Annals of the Rheumatic Diseases, 2007;66(11):1429-35). For more information, contact M. Segarra, University of Barcelona, Hospital Clinic, Dept. of Internal Medicine, Hospital Clinic, Institut d'Investigacions Biomediques August Pi I Sunyer, Barcelona, Spain. Publisher contact information for the journal Annals of the Rheumatic Diseases is: B M J Publishing Group, British Med Association House, Tavistock Square, London WC1H 9JR, England. Keywords: Spain, Barcelona, Giant Cell Arteritis Genetics, Cardiology, Enzyme Research, Enzymology, Gelatinase, Giant Cell Arteritis, Rheumatic Disease, Temporal Arteritis. This article was prepared by Proteomics Weekly editors from staff and other reports. Copyright 2007, Proteomics Weekly via NewsRx.com.
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