Netrin1-Enriched Exosomes From Genetically Modified ADSCs as a Novel Treatment for Diabetic Limb Ischemia.

Diabetic limb ischemia (DLI) is a frequent complication of diabetes and the leading cause of non-traumatic amputation. Traditional treatments like stent placement and bypass surgery may not suit all patients. Exosome transplantation has emerged as a promising therapy. Netrin1, a protective cardiovascular factor, has an unclear role in DLI. This study investigates the role of Netrin1 in DLI patients and evaluates the therapeutic potential of exosomes derived from Netrin1-overexpressing adipose-derived stem cells (N-ADSCs). The expression of Netrin1 is significantly decreased in both endothelial cells and serum of DLI patients, highlighting its potential as a biomarker or therapeutic target. In vitro, Netrin1-enriched exosomes (N-Exos) promoted human umbilical vein endothelial cell (HUVEC) proliferation, migration, tube formation, and increased resistance to apoptosis under high glucose conditions. These protective effects are mediated through PI3K/AKT/eNOS and MEK/ERK pathways, and N-Exos further facilitated macrophage polarization from M1 to M2. In vivo, N-Exos demonstrates superior therapeutic effects over ADSC exosomes (Exos), including enhanced angiogenesis, improved collateral artery remodeling, reduced inflammation, and muscle protection. Collectively, these findings identify Netrin1 as a critical factor in DLI and underscore its significance in disease progression and therapeutic strategies. N-Exos offers a promising non-cellular therapeutic approach for the treatment of DLI.