Clinical value of miR-551b-5p in children with primary nephrotic syndrome and its regulatory role in disease progression

BACKGROUND: Primary nephrotic syndrome (PNS) is a common glomerular disorder in children. Despite significant advances in glucocorticoid therapy, considerable challenges remain in the early diagnosis and prognostic management of PNS. Elevated miR-551b-5p expression has been detected in the PNS. This study aims to further explore the role of miR-551b-5p in the onset and progression of PNS and its potential mechanisms. METHODS: A total of 107 patients with primary nephrotic syndrome (PNS) and 99 healthy volunteers (HV) were included in this study. And the PNS group was further divided into subgroups with favorable (n = 76) and poor (n = 31) prognosis. The expression of miR-551b-5p in the PNS and the poor prognosis group was quantified using qRT-PCR. The predictive capability of miR-551b-5p for the occurrence and poor prognosis of PNS was evaluated. The effects of miR-551b-5p knockdown on podocyte growth and inflammatory injury were examined. The interaction between miR-551b-5p and CD2AP was verified via database and luciferase assay. RESULTS: miR-551b-5p is obviously elevated in PNS and the poor prognosis group. miR-551b-5p exhibits strong diagnostic capability for both the onset and poor prognosis of pediatric PNS. High miR-551b-5p expression is an independent risk factor for poor prognosis in pediatric PNS patients. miR-551b-5p downregulation potently promotes podocyte proliferation and reduces apoptosis, and improves intracellular inflammatory responses and oxidative stress levels. Furthermore, CD2AP is a direct target of miR-551b-5p, and this regulatory axis synergistically contributes to the pathogenesis and progression of PNS. CONCLUSION: miR-551b-5p is a potential biomarker for predicting the occurrence and poor prognosis of PNS. miR-551b-5p promotes the onset and progression of PNS by targeting CD2AP.