To determine the effects of primary antiphospholipid syndrome (PAPS)‐derived anti‐β2GPI antibodies on gene expression in human umbilical vein endothelial cells (HUVEC) by gene profiling using microarrays.
Anti‐β2GPI antibodies purified from sera of patients with PAPS or control IgG isolated from normal subjects were incubated with HUVEC for 4 h before isolation of RNA and processing for hybridisation to Affymetrix Human Genome U133A‐2.0 arrays. Data were analysed using a combination of the MAS 5.0 (Affymetrix) and GeneSpring (Agilent) software programmes. For selected genes microarray data were confirmed by real‐time PCR analysis or at the protein level by ELISA.
A total of 101 genes were found to be upregulated and 14 genes were downregulated twofold or more in response to anti‐β2GPI antibodies. A number of novel genes not previously associated with APS were induced, including chemokines CCL20, CXCL3, CX3CL1, CXCL5, CXCL2 and CXCL1, the receptors Tenascin C, OLR1, IL‐18 receptor 1, and growth factors CSF2, CSF3 IL‐6, IL1β and FGF18. The majority of downregulated genes were transcription factors/signalling molecules including ID2. Quantitative real‐time RT‐PCR analysis confirmed the microarray results for selected genes (CSF3, CX3CL1, FGF18, ID2, SOD2, Tenascin C).
This study reveals a complex gene expression response in HUVEC to anti‐β2GPI antibodies with multiple chemokines, pro‐inflammatory cytokines, pro‐thrombotic and pro‐adhesive genes regulated by these antibodies in vitro. Some of these newly identified anti‐β2GPI antibody‐regulated genes could contribute to the vasculopathy associated with this disease.