The Expression and Role of microRNA-133a in Plasma of Patients with Kawasaki Disease.

Kawasaki disease (KD)), also known as mucocutaneous lymph node syndrome (MCLS), is an autoimmune and systemic vasculitis syndrome. Its etiology and pathogenesis are still unclear. microRNAs (miRNA), a novel class of small non-coding RNAs, regulate the expression of multiple protein-encoding genes at the post-transcriptional level. We intend to study the change of miRNA-133a in the plasma of patients with KD, explore the role of miRNA-133a on HUVEC and define the pathogenesis of vascular dysfunction in KD. miRNA-133a expression and the mRNA and protein expression of protein phosphatase 2 catalytic subunit alpha (PPP2CA) were assessed by RT-qPCR and Western blot, respectively. The PPP2CA mRNA 3ʹUTR was predicted to be the potential target of miRNA-133a by using the miRNA databases and verified by the luciferase assay. The plasmids of miRNA-133a mimics and inhibitors were transfected into HUVEC cells. The plasma soluble vascular endothelial cadherin (sVE-cadherin, the excised extracellular part of VE-cadherin) levels were investigated by ELISA. The results suggested that miRNA-133a was increased by 3.8 times in the acute KD group and by 2.7 times in the convalescent KD group compared with the control group (both P =.000). PPP2CA is the target gene of miRNA-133a and its expression was inhibited by miRNA-133a acting on PPP2CA mRNA 3ʹUTR (P =.013). The plasma sVE-cadherin levels in the acute KD groups were increased compared with the control group (P =.024). The ROC curve analysis showed that the expression of miRNA-133a segregate acute KD patients from convalescent KD patients and healthy children. Our results suggest that miRNA-133a might be a new biomarker for KD. [ABSTRACT FROM AUTHOR]