lncTIMP3 promotes osteogenic differentiation of bone marrow mesenchymal stem cells via miR-214/Smad4 axis to relieve postmenopausal osteoporosis

Apolipoprotein E as a Potential Regulator of Osteoclast-Osteoblast Coupling in Material-Induced Bone Formation

Osteoinductive materials which induce bone formation in non-osseous sites are promising bone substitutes to repair critical-sized bone defects. It appears that innate immune response (esp. osteoclastogenesis) to materials plays an important role in material-induced bone formation. In this study, the coupling between osteoclastogenesis and subsequent osteogenesis in material-induced bone formation was investigated. Osteoclastogenesis of mouse bone marrow-derived monocytes (BMMs) on osteoinductive tricalcium phosphate (TCPs) and non-osteoinductive tricalcium phosphate (TCPb) ceramics were evaluated with high-throughput RNA sequencing (RNA-seq) and RT-qPCR regarding secretory proteins. It turned out that osteoinductive TCPs supported osteoclastogenesis and enhanced Apolipoprotein E (ApoE) production. Meanwhile, ApoE enhanced osteogenic gene expression (Alp, Runx2, Col1a1, Osterix) and ALP staining and activity of CRL-12424 cells in vitro. Additionally, western blot assay revealed that ApoE played its role in osteogenesis of CRL-12424 by activating JAK-STAT pathway instead of PI3K-AKT pathway. The overall data indicated that ApoE was a potential coupling factor between osteoclastogenesis and osteogenesis in material-induced bone formation. By secreting ApoE, osteoclasts formed on osteoinductive materials stimulated osteogenic differentiation of osteo-progenitors via JAK-STAT pathway. STATEMENT OF SIGNIFICANCE: Osteoinductive materials can repair critical-sized bone defects, while the precise mechanism osteoinductive materials driving bone formation remains unclear. Recent research has highlighted the role of osteoclastogenesis in material-induced bone formation, how osteoclastogenesis playing its role in osteogenesis was subjected to investigation in the current study. Robust ApoE gene expression shown in osteoclastogenesis with the osteoinductive material and ApoE enhancing osteogenesis of mesenchymal stromal cells (CRL-12424) indicated ApoE as a potential regulator of osteoclast-osteoblast coupling, providing thus novel insights into the complex interplay of cellular responses and contributing to the development of more effective bone substitute materials.

LINC00968 accelerates osteogenic differentiation of bone marrow mesenchymal stem cells via the miR-17-5p/STAT3 axis

BACKGROUND

BMSCs with robust osteogenic differentiation capacity can participate in the repair of osteoporotic (OP) bone. Long non-coding RNAs (LncRNAs) serve as crucial regulators of osteogenic differentiation. This study aims to investigate the clinical implications of LINC00968 in OP and elucidate its molecular mechanisms.

METHODS

Patients with OP and controls without OP were enrolled. RT-qPCR was utilized the quantify the levels of LINC00968, miR-17-5p, STAT3, and osteogenic differentiation markers. ROC curve was conducted to evaluate the diagnostic significance. Osteogenic differentiation medium (OM) induced hBMSCs. Flow cytometry was used to examine apoptosis. DLR and RIP assay were performed to validate target binding.

RESULTS

LINC00968 was notably decreased in the serum and bone tissue of patients with OP, whereas it was markedly elevated during osteogenic differentiation of hBMSCs. LINC00968 has 78.65% sensitivity and 71.95% specificity in identifying OP patients from controls. Silencing of LINC00968 sharply diminished ALP activity and osteogenic differentiation markers levels while promoting apoptosis in hBMSCs under OM induction. However, this reduction was notably reversed by the administration of a miR-17-5p inhibitor. Molecularly, miR-17-5p directly targets LINC00968 and STAT3.

CONCLUSIONS

Our results indicate that LINC00968 downregulation is a diagnostic biomarker for OP, facilitating osteogenic differentiation and inhibiting apoptosis via miR-17-5p/STAT3 axis, suggesting a new therapeutic target for OP progression.