Cell-Based Double-Screening Method to Identify a Reliable Candidate for Osteogenesis-Targeting Compounds.

Area of Science:

• Biomedical Engineering
• Pharmacology
• Regenerative Medicine

Background:

• Small molecules influencing osteogenesis are key for bone regenerative medicine.
• Current cell-based screening methods for osteogenic compounds have limitations in accurately reflecting osteogenic phenotype activation.

Purpose of the Study:

• To develop and evaluate a double-screening system combining a reporter assay and alkaline phosphatase (ALP) activity detection.
• To identify novel osteogenic inducible compounds for therapeutic applications in bone regeneration.

Main Methods:

• Utilized MC3T3-E1 cells stably transfected with a green fluorescent protein (GFP) reporter gene under the type I collagen promoter (Col-1a1GFP-MC3T3-E1).
• Screened 1280 pharmacologically active compounds (Lopack1280) using the Col-1a1/GFP reporter assay and ALP staining.
• Assessed GFP fluorescence after 7 days and ALP activity after 14 days of osteogenic induction.

Main Results:

• The double-screening method identified three candidate compounds with significant osteogenic induction ability.
• Leflunomide, one of the identified candidates, demonstrated a significant promotion of new bone formation in vivo.
• The combined reporter and ALP assay proved more reliable than conventional screening methods.

Conclusions:

• The developed double-screening system enhances the reliability of identifying osteogenesis-targeting compounds.
• This method offers a powerful tool for discovering therapeutic agents in bone regenerative medicine.
• Leflunomide emerges as a promising candidate for promoting bone formation.