Small molecules enable cardiac reprogramming of mouse fibroblasts with a single factor, Oct4

Area of Science:

• * Regenerative Medicine
• * Molecular Biology
• * Cardiology

Background:

• * Fibroblast reprogramming to cardiac cells typically requires multiple genetic manipulations.
• * Reducing genetic interventions is crucial for therapeutic applications like cell-based therapy and in vivo cardiac regeneration.
• * Small molecules offer a promising alternative to genetic factors for cell fate conversion.

Purpose of the Study:

• * To identify a small-molecule cocktail for efficient cardiac reprogramming of fibroblasts.
• * To investigate if this reprogramming can be achieved with minimal genetic factors, specifically one transcription factor.
• * To assess the characteristics and developmental stage of the induced cardiac cells.

Main Methods:

• * Screening of small-molecule combinations to identify effective compounds for cardiac reprogramming.
• * Co-expression of a single transcription factor, Oct4, with the small-molecule cocktail in mouse fibroblasts.
• * Analysis of resulting cells for cardiac markers, spontaneous contraction, and phenotype.
• * Evaluation of the cells' developmental trajectory, including a cardiac progenitor stage.

Main Results:

• * A defined small-molecule cocktail was identified that efficiently converts mouse fibroblasts into cardiac cells.
• * Reprogramming was achieved using only one transcription factor (Oct4) without inducing pluripotency.
• * The induced cardiomyocytes exhibited spontaneous contraction and a ventricular phenotype.
• * The reprogrammed cells were observed to pass through a cardiac progenitor stage.

Conclusions:

• * Small molecules can significantly enhance cardiac reprogramming efficiency, reducing the need for multiple genetic factors.
• * This small-molecule-driven approach provides a foundation for pharmacological reprogramming strategies in regenerative medicine.
• * The findings offer a new method for generating cardiomyocytes for therapeutic use and mechanistic studies.