LncRNA EPB41L4A-AS1 regulates osteogenic differentiation and bone microenvironment-associated functions in ADSCs by targeting miR-302d-3p

Abstract

Postmenopausal osteoporosis (PMOP) is a prevalent female bone disease. It can progress to fractures at advanced stages and raise disability risks. This study evaluated the value of EPB41L4A-AS1 in PMOP diagnostic and fracture risk prediction, and explored its mechanism of regulating osteogenic differentiation in an in vitro ADSC model. A total of 118 healthy controls and 146 PMOP patients (75 non-fracture and 71 fracture) were enrolled. Serum levels of EPB41L4A-AS1, miR-302d-3p, and CUL3 were detected. ROC curves and logistic regression were performed to assess its clinic value. The regulatory mechanisms of EPB41L4A-AS1, miR-302d-3p and CUL3 were investigated using adipose-derived mesenchymal stem cells (ADSCs) models and a series of cellular experiments. Serum EPB41L4A-AS1 were downregulated in PMOP patients and further decreased in the fracture subgroup ( P  < 0.001). EPB41L4A-AS1 exhibited high diagnostic performance for PMOP (AUC = 0.818). Its expression was strongly correlated with key bone metabolism indicators. Low EPB41L4A-AS1 expression was an independent risk factor for PMOP (OR = 0.164) and fractures occurrence (OR = 0.208). During osteogenic induction of ADSCs, silencing EPB41L4A-AS1 significantly reduced osteogenic markers expression and mineralized nodule formation, and disrupted cellular function and bone microenvironment homeostasis. Mechanically, EPB41L4A-AS1 targeted miR-302d-3p, which further regulated CUL3. Rescue experiments confirmed that the EPB41L4A-AS1/miR-302d-3p/CUL3 axis modulated ADSC osteogenic differentiation and bone microenvironment homeostasis. EPB41L4A-AS1 serves as a marker for diagnosis and fracture risk prediction in PMOP patients, and in vitro evidence suggests it regulates ADSC osteogenic differentiation via miR-302d-3p/CUL3, providing an in vitro mechanistic proof-of-concept.