Both the sera of patients with Behçet's disease and Streptococcus sanguis stimulate membrane expression of hnRNP A2/B1 in endothelial cells. (May 2013)

• Record Type: Journal Article
• Authors: Cho, SB; Zheng, Z; Cho, S; Ahn, KJ; Choi, MJ; Kim, D-Y; Lee, KH; Bang, D
• Is Part Of: Scandinavian journal of rheumatology. Volume 42:Number 3(2013)
• Page Start: 241
• Page End: 246
• Publication Date: 2013-05
• Subjects: Rheumatology -- Periodicals; Arthritis; Rheumatic Diseases; 616.72005
• DOI: 10.3109/03009742.2012.733728
• Languages: English
• ISSNs: 0300-9742

Abstract

<abstract> <title> <x xml:space="preserve">Abstract</x> </title> <p> <bold>Objectives:</bold> Heterogeneous nuclear ribonucleoprotein (hnRNP) A2/B1 has been identified as a target antigen of anti-endothelial cell immunglobulin (Ig)A antibodies in patients with Behçet's disease (BD). The aim was to investigate the effects of the sera from BD patients and <italic>Streptococcus sanguis</italic> on the subcellular expression of hnRNP A2/B1 in human dermal microvascular endothelial cells (HDMECs).</p> <p> <bold>Method:</bold> The sera of BD patients and healthy controls (HC) as well as cultured <italic>S. sanguis</italic> were used to stimulate HDMECs. Subcellular fractions were obtained from stimulated HDMECs and were subjected to immunoblot analyses. The distribution of hnRNP A2/B1 was investigated by immunocytochemistry and direct immunofluorescence study was performed in biopsy specimens of mucosal ulcers from BD patients.</p> <p> <bold>Results:</bold> BD patients' sera increased the membrane expression of hnRNP A2/B1 in HDMECs after 12 and 24 h of incubation compared with HDMECs incubated with endothelial cell culture media and HC sera. <italic>S. sanguis</italic> also increased hnRNP A2/B1 in the cellular membrane. hnRNP A2/B1 mRNA level was also significantly upregulated in HDMECs incubated with BD patients' sera and <italic>S. sanguis</italic>. Immunocytochemistry demonstrated marked expression of hnRNP A2/B1 in the cytoplasm and cellular membrane of HDMECs incubated with BD patients' sera or <italic>S. sanguis</italic>. In addition, direct immunofluorescence experiments revealed the co-localization of serum IgA antibodies and monoclonal antibodies (mAbs) against hnRNP A2/B1 in tissue sections from ulcers of BD patients.</p> <p> <bold>Conclusions:</bold> Our data indicate that both the sera of BD patients with active disease and <italic>S. sanguis</italic> infection are inflammatory stimuli that can induce membranous hnRNP A2/B1 expression in HDMECs.</p> </abstract>