Hypoxia-preconditioned adipose-derived mesenchymal stem cells-derived exosomes transferring H19 obstruct neutrophil extracellular traps formation via HOXA5-mediated inactivation of TLR4/NF-κB/NLRP3 inflammatory signaling.

BACKGROUND

Hypoxia-stimulated adipose-derived mesenchymal stem cells (ADSCs)-derived exosomes (Hypo-Exo) have a positive impact on diabetic wound healing. Neutrophil extracellular traps (NETs) can delay wound healing under diabetic hyperglycemia. This study aimed to investigate the mechanisms by which Hypo-Exo influence NETs formation.

METHODS

The dorsal excisional wound model was performed using streptozotocin-induced diabetic mice. Neutrophils were treated with phorbol 12-myristate 13-acetate and Hypo-Exo or ADSCs overexpressing H19 Exo, which were prepared for subsequent exploration. NETs formation was analyzed employing Sytox Green staining and PicoGreen dsDNA assay. Human umbilical vein endothelial cells (HUVECs) were exposed to the culture medium of neutrophils with Hypo-Exo treatment. CD31 and Alpha-Smooth Muscle Actin protein expression were detected by immunofluorescence staining. Long non-coding RNA H19 (H19) expression was evaluated by RNA-FISH analysis. The luciferase reporter gene and RNA immunoprecipitation analysis verified the interactions between miRNA-130a/b-3p (miR-130a/b-3p) and H19 or Homeobox A5 (HOXA5).

RESULTS

Hypo-Exo promoted diabetic wound healing by repressing excessive NETs formation. Furthermore, Hypo-Exo inhibited Toll-like receptor 4 (TLR4)/Nuclear factor κB (NF-κB) pathway and inactivated NOD-like receptor pyrin domain-containing 3 (NLRP3) inflammasome. Moreover, Hypo-Exo-mediated inhibition of NETs formation promoted the proliferation, migration, and angiogenesis of HUVECs. H19 could interact with miR-130a/b-3p to generate a competing endogenous RNA regulatory network, thereby positively modulating HOXA5. Additionally, ADSCs overexpressing H19-derived exosomes promoted diabetic wound healing by regulating the miR-130a/b-3p/HOXA5 pathway in vivo.

CONCLUSION

Hypo-Exo transferring H19 promoted diabetic wound healing by repressing NETs formation via the miR-130a/b-3p/HOXA5 pathway.