| Sjogren's syndrome SjS is a systemic autoimmune disorder characterized by exocrine dysfunction resulting from immune-mediated attack and associated with defective protein trafficking. Previous studies suggest cathepsins as proteases, function in MHC II-mediated antigen processing in antigen presenting cells (APCs) and thus play a complex role in initiation and progression of autoimmunity. Other work also suggests that these cathepsins may be missorted in animal model of SjS. Since, cathepsins are potentially pathogenic factors in the progression of SjS, we conducted enzymatic assays to quantify and characterize the activities of key cathepsins in NOD mice, - an animal model of SjS- relative to control BALB/c mice. Results suggest that cathepsin S (CATS) and cathepsin H (CATH) activities were significantly higher in lysates of NOD mouse lacrimal gland (LG) than lysates of BALB/c mouse lacrimal gland. CATS activity is significantly elevated in NOD mouse tears. These data suggest that CATS is a potential tear biomarker for diagnosis of dacryoadenitis in SjS. |
