Starvation-induced NEDD4-mediated autophagy in BMSCs

Area of Science:

• Cell Biology
• Stem Cell Biology
• Molecular Biology

Background:

• Autophagy is critical for bone marrow mesenchymal stem cell (BMSC) osteogenic differentiation and bone remodeling.
• Pathological conditions like osteoporosis involve dysregulated BMSC function.
• Mechanisms controlling autophagy in BMSCs are not fully understood.

Purpose of the Study:

• To investigate the role of Neural precursor cell-expressed developmentally down-regulated protein 4 (NEDD4) in regulating autophagy in BMSCs.
• To elucidate the molecular mechanisms underlying NEDD4-mediated autophagy in BMSCs.

Main Methods:

• Autophagy was induced in BMSCs via serum starvation.
• NEDD4 expression was silenced using lentiviral short hairpin RNA.
• Quantitative real-time polymerase chain reaction, western blotting, and immunofluorescence were used to analyze autophagy markers (LC3, Beclin-1) and signaling pathways (mTOR).

Main Results:

• Serum starvation significantly activated autophagy in BMSCs, increasing NEDD4, LC3, and Beclin-1 expression.
• NEDD4 knockdown attenuated the starvation-induced upregulation of LC3 and Beclin-1.
• NEDD4 knockdown prevented the decrease in phosphorylated mTOR, suggesting involvement of the mTOR signaling pathway.

Conclusions:

• NEDD4 positively regulates autophagy in BMSCs, likely via the mTOR signaling pathway.
• NEDD4 is essential for BMSC autophagy.
• NEDD4 represents a potential therapeutic target for modulating BMSC function in bone-related diseases.