Autophagy Clears Cellular Debris to Accelerate Wound Healing in Fibroblasts

Wound healing requires precise coordination of cellular processes, and new research reveals autophagy—the cell's waste disposal system—as a critical regulator of this process. Scientists investigated how fibroblasts, the primary cells responsible for tissue repair, use autophagy to facilitate wound healing.

Using mice with fibroblast-specific deletion of the autophagy gene Atg7, researchers found that autophagy deficiency severely impaired wound healing. These mice showed delayed skin repair characterized by insufficient fibroblast proliferation, migration, and transformation into myofibroblasts—specialized repair cells that contract to close wounds.

The mechanism centers on SQSTM1 (also called p62), an autophagy receptor protein that normally gets degraded during the cleanup process. When autophagy is impaired, SQSTM1 accumulates and forms cellular aggregates that trap SMAD2 and SMAD3—key signaling proteins in the TGF-β pathway essential for wound repair. This sequestration prevents proper TGF-β signaling, disrupting the cellular responses needed for healing.

Strikingly, when researchers deleted the sqstm1 gene in autophagy-deficient mice, wound healing was restored to normal levels. This demonstrates that SQSTM1 degradation by autophagy is the critical mechanism enabling proper fibroblast function during repair.

The findings have therapeutic implications, as autophagy inducers promoted wound healing in an SQSTM1-dependent manner. This suggests that enhancing cellular cleanup mechanisms could accelerate healing in clinical settings, particularly for chronic wounds or delayed healing conditions.