Anti-CENP-B and anti-TOPO-1-containing sera from systemic sclerosis-related diseases with Raynaud's phenomenon induce vascular endothelial cell senescence not via classical p53-p21 pathway

Raynaud's phenomenon (RP) is the earliest and most common clinical manifestation in patients with systemic sclerosis (SSc) and its related diseases containing anti-TOPO-1 and/or anti-CENP-B autoantibodies in the sera. However, the cause-effect relationship between the two autoantibodies and RP remains elucidation. Sera containing anti-CENP-B and anti-TOPO-1 autoantibodies were obtained from SSc-related diseases manifesting RP. The polyclonal auto-antibodies were purified from pooled sera by affinity chromatography. Mouse monoclonal anti-CENP-B and anti-TOPO-1 were purchased. Calf pulmonary arterial endothelial cells (CPAE) were incubated with 40% patient sera, purified polyclonal antibodies or mouse monoclonal antibodies for 1-6 days. The vascular endothelial biomarkers von Willebrand factor (vWF), thrombomodulin (CD141) and 6-keto-prostaglandin F1α (6-keto-PGF1α), cell viability marker ATP, and cell necrosis/lysis marker LDH in the culture supernatants were measured by ELISA. The cell senescence biomarker β-galactosidase and telomere content in the cells were stained by the respective kit. The classical p53-p21 senescence pathway was detected by Western blot. We found that 40% anti-CENP-B or anti-TOPO-1-containing sera without heat-inactivation and mouse monoclonal antibodies suppressed 6-keto-PGF1α production, increased β-galactosidase, and decreased relative telomere content. The cell senescence effects were proved not via p53-p21 pathway. The pathognomonic anti-CENP-B and anti-TOPO-1 autoantibodies in SSc-related diseases accelerate vascular endothelial cell senescence and functional impairment inducing RP. The real signaling pathway for autoantibody-induced cell senescence remains exploration.