Abnormal expression of autophagy-related proteins in immune thrombocytopenia.

ABSTRACT

Autophagy is a highly conserved protein degradation pathway that is essential for affecting some autoimmune diseases. Immune thrombocytopenia (ITP) is a common autoimmune disorder, and the complex dysregulation of cellular immunity has been observed; however, the relationship between autophagy-related proteins and immune responses in ITP remains unclear. Using real-time quantitative polymerase chain reaction (RT-PCR), the mRNA expression levels of Beclin-1, SQSTM1/p62 and LC3 were measured in the peripheral blood mononuclear cells (PBMCs) of 20 newly diagnosed patients with active ITP, 16 ITP patients in remission and 21 healthy volunteers. The stained Beclin-1 and SQSTM1/p62 proteins were also observed in the bone marrow of active ITP patients and normal controls by immunofluorescence. SQSTM1/p62 mRNA expression in PBMCs in newly diagnosed patients was significantly decreased. At the same time, Beclin-1 mRNA was increased significantly. During the remission stages, the levels of these autophagy-related proteins were comparable with those observed in healthy controls. Taken together, these results suggest that the aberrant expression of autophagy-related proteins might be involved in the pathogenesis of ITP. Further study of the autophagy pathway may provide a new strategy and direction for the treatment of ITP.