FGF21 (fibroblast growth factor 21) reverses senescence in aged human adipose-derived mesenchymal stem cells (ASCs) by restoring impaired autophagy flux through nuclear translocation of transcription factor TFE3, operating via the FGFR1-SIRT1-mTOR signaling axis. Beyond reversing the senescence phenotype and improving cell viability, FGF21-treated ASCs showed enhanced differentiation capacity toward neural stem cells. In acute intracerebral hemorrhage (ICH) rat models, FGF21-primed ASC transplantation demonstrably outperformed unprimed aged ASCs therapeutically.
This finding lands at a compelling intersection of cellular aging biology and regenerative medicine. The autophagy-senescence connection is well-established — declining lysosomal flux accelerates cellular aging — but identifying FGF21 as a pharmacological lever capable of rescuing this deficit in clinically relevant human stem cells is meaningful. The SIRT1-mTOR node is particularly noteworthy: SIRT1 activation suppressing mTOR to permit TFE3 nuclear entry mirrors mechanisms seen in caloric restriction and rapamycin longevity research, suggesting FGF21 may partially mimic metabolic anti-aging signals.
Practically, the translational gap between aged donor cells and therapeutic efficacy has been a genuine obstacle for stem cell medicine. A pre-conditioning protocol using FGF21 before transplantation could address this directly. However, critical limitations apply: the in vivo work is rodent-only, ICH-specific findings may not generalize to other stem cell therapies, and causality within the proposed signaling pathway relies partly on pharmacological inhibitors rather than clean genetic knockouts. Still, for the stem cell therapy and longevity fields, this represents a mechanistically grounded, incrementally important advance.
