Autophagy Modulates Cell Mineralization on Fluorapatite-Modified Scaffolds

Area of Science:

• Biomaterials Science
• Cell Biology
• Stem Cell Biology

Background:

• Autophagy maintains cellular homeostasis and remodeling.
• Fluorapatite (FA) crystal-coated polycaprolactone (PCL) scaffolds induce dental pulp stem cell differentiation and mineralization.
• The role of autophagy in this process remains unclear.

Purpose of the Study:

• To investigate the osteogenic inductive ability of FA crystals on adipose-derived stem cells (ASCs).
• To observe and elucidate the changes in autophagy during ASC osteogenic differentiation.
• To determine the role of autophagy in FA-induced ASC osteogenesis.

Main Methods:

• ASCs were seeded on PCL+FA and PCL scaffolds.
• Osteogenic differentiation was assessed using alkaline phosphatase activity, Alizarin red, and Von Kossa staining.
• Autophagy was analyzed using RT2 Profiler PCR array and Western blot for LC3-II.
• Autophagy inhibitors (3-MA, BAF A1, NH4Cl) were used to assess functional roles.

Main Results:

• PCL+FA scaffolds supported ASC growth and mineralization, unlike PCL scaffolds alone.
• Numerous autophagy-related genes and proteins, including LC3-II, showed dynamic changes during differentiation, peaking at day 7.
• Inhibition of autophagy before day 3 significantly attenuated osteogenic marker expression and mineralization.

Conclusions:

• Autophagy plays a critical role in the osteogenic differentiation of ASCs on PCL+FA scaffolds.
• Early-stage autophagy inhibition (before day 3) severely impairs osteogenic differentiation and mineralization.
• This study elucidates the mechanism of autophagy in mesenchymal stem cell osteogenic differentiation.