Detection of cleaved alpha-fodrin autoantigen in Sjögren's syndrome: apoptosis and co-localisation of cleaved alpha-fodrin with activated caspase-3 and cleaved poly(ADP-ribose) polymerase (PARP) in labial salivary glands.

UNLABELLED: Sjögren's syndrome (SS) is a systemic autoimmune disease which targets the exocrine glands and is associated with autoantibodies. The mechanism of salivary gland destruction or autoantibody production is poorly understood but it is increasingly accepted that apoptosis plays a role. OBJECTIVE: The objective of this study is to demonstrate the presence of cleaved alpha-fodrin autoantigen and apoptosis in the salivary glands of patients with primary Sjögren's syndrome. METHODS: 18 patients with primary Sjögren's syndrome provided tissues from a labial salivary gland biopsy. Using terminal deoxynucleotidyl transferase mediated dUTP nick end labelling (TUNEL) assays to detect DNA fragmentation followed by sequential immunoperoxidase assays in the same patient biopsy to detect cleaved alpha-fodrin, Poly(ADP-ribose) polymerase (PARP), and caspase-3, we show a co-localisation between apoptotic markers and disease. RESULTS: Co-localisation of cleaved alpha-fodrin, PARP and caspase-3 expression was demonstrated primarily in the ducts along with DNA fragmentation in 16/18 salivary gland biopsies from Sjögren's syndrome patients. None of these apoptotic markers was strongly expressed in healthy tissues. CONCLUSION: Apoptotic signals may provide useful therapeutic targets and cleaved alpha-fodrin may prove to be a marker of disease in primary Sjögren's syndrome. Further studies are required to ascertain the specific association of cleaved alpha-fodrin with primary and secondary Sjögren's syndrome.

Can application of exogenous fibronectin enhance periodontal regeneration?

BACKGROUND: Although fibronectin (FN) is an important extracellular glycoprotein involved in periodontal wound healing, it is not clear whether the application of exogenous fibronectin (ExoFN) offers any clinical benefit. The purpose of this preliminary in vitro study was to determine the binding of FN from three different sources, viz. endogenous EDTA-plasma, endogenous serum and exogenous commercial purified human fibronectin in PBS buffer, to demineralized and non-demineralized root powder. METHOD: The binding of FN to a known quantity of mineralized and non-demineralized root powder by overnight incubation at 15 degrees C was studied by enzyme immunoassay (EIA) technique. The criteria for optimal performance of EIA procedure for the determination of FN was established. Particle size of powdered root structure was standardized using a Vibratory Sieve Shaker. RESULTS: The EDTA-plasma and the serum FN exhibited binding of (17.8 +/- 2.1 microg) and (6.5 +/- 4.5 microg), respectively, to the non-demineralized root powder. However, the binding was only significant for the EDTA-plasma FN (p < 0.01) when compared to controls. In the demineralized group there was no ascertainable binding of FN from either endogenous or exogenous sources. ExoFN in buffer exhibited no binding at all to the non-demineralized or demineralized root powder. CONCLUSION: The preliminary data suggest that additional plasma and serum factors may facilitate the binding of FN to root powder. High levels of FN in blood do not necessarily indicate that FN is available for binding to the root surface during periodontal surgery.