Fibroblast rejuvenation by mechanical reprogramming and redifferentiation

Area of Science:

• Biomedical Engineering
• Cell Biology
• Regenerative Medicine

Background:

• Aging leads to fibroblast dysfunction, characterized by reduced contractility and connective tissue stiffness.
• Therapeutic strategies for connective tissue rejuvenation face challenges in restoring fibroblast function.
• Previous work showed that lateral confinement of fibroblasts induces stem-cell-like spheroids.

Purpose of the Study:

• To investigate the potential of partially reprogrammed fibroblast spheroids to restore connective tissue function within a three-dimensional (3D) matrix.
• To evaluate the impact of 3D matrix constraints on the redifferentiation and functional recovery of reprogrammed fibroblasts.

Main Methods:

• Fibroblast spheroids, generated via laterally confined growth on micropatterned substrates, were embedded in collagen-I matrices of varying densities.
• The resulting 3D connective tissue networks were analyzed for fibroblast redifferentiation, DNA damage, gene expression, cytoskeletal contractility, and matrix deposition.
• Chromatin compaction states of partially reprogrammed cells were assessed.

Main Results:

• Embedded spheroids regained fibroblastic properties and formed 3D networks in response to matrix constraints.
• Rejuvenated fibroblasts exhibited reduced DNA damage, enhanced cytoskeletal gene expression, and increased actomyosin contractility.
• These cells showed improved matrix protein deposition (fibronectin, laminin) and collagen remodeling compared to control networks.
• Partially reprogrammed cells displayed more open chromatin structures, suggesting a readiness for redifferentiation.

Conclusions:

• Laterally confined reprogramming can induce partially reprogrammed fibroblast spheroids with potential for rejuvenation.
• These spheroids can redifferentiate into functional fibroblasts within 3D collagen matrices, restoring connective tissue properties.
• This approach offers a promising strategy for fibroblast rejuvenation with significant implications for regenerative medicine and treating age-related tissue degeneration.