Effect of plasma exosomes on endothelial cell tight junction proteins in SLE patients with immune thrombocytopenia

Abstract

To study the expression of exosomes in peripheral blood of systemic lupus erythematosus (SLE) immune thrombocytopenia patients with and without hemorrhage symptoms, respectively, and the effect of exosomes on endothelial cell tight junction proteins (TJs) in vitro, so as to investigate the related mechanisms involved in the occurrence of hemorrhage symptoms. Patients diagnosed with SLE and immune thrombocytopenia (<50x109/L) were divided into 2 groups according to the presence or absence of hemorrhage symptoms. Plasma exosomes were isolated, and observed by transmission electron microscopy. The exosomes were co-cultured with endothelial cells in vitro. The permeability of umbilical vein endothelial cells (HUVECs) was measured by transendothelial electrical resistance (TEER). The mRNA and protein expression of tight junctions (occludin and claudin-5) were detected by RT-PCR and Western blot, respectively. Plasma exosomes were increased in the group without hemorrhage symptoms. The TEER value of HUVECs after adding plasma exosomes of hemorrhage group in vitro was not significantly changed compared to the control while increased after adding exosomes of non-hemorrhage group. Plasma exosomes of the non-hemorrhage group could increase both the mRNA and protein expression of TJs in vitro, while exosomes of the hemorrhage group could decrease the expression, the difference was statistically significant (p < 0.05). Plasma exosomes may influence the hemorrhage symptoms of SLE patients with immune thrombocytopenia by regulating the expression of endothelial tight junction proteins. Key Points • The role of exosomes in SLE immune thrombocytopenia is first reported in this study. • We have explored the mechanism that exosomes may participate in hemorrhage, which will facilitate individualized treatment of SLE immune thrombocytopenia. Key Points • The role of exosomes in SLE immune thrombocytopenia is first reported in this study. • We have explored the mechanism that exosomes may participate in hemorrhage, which will facilitate individualized treatment of SLE immune thrombocytopenia.