Hypoxia preconditioned DPSC-derived exosomes regulate angiogenesis via transferring LOXL2.

Area of Science:

• Biomedical Engineering
• Stem Cell Biology
• Regenerative Medicine

Background:

• Hypoxia is known to enhance stem cell angiogenesis.
• The precise mechanisms behind hypoxia-enhanced angiogenic potential in dental pulp stem cells (DPSCs) remain unclear.
• Previous work indicated hypoxia upregulates lysyl oxidase-like 2 (LOXL2) in DPSC-derived exosomes, suggesting its role.

Purpose of the Study:

• To investigate if hypoxia-enhanced DPSC-derived exosomes promote angiogenesis through the transfer of lysyl oxidase-like 2 (LOXL2).
• To elucidate the specific contribution of LOXL2 to the angiogenic capabilities of exosomes derived from hypoxia-treated DPSCs.

Main Methods:

• Generated exosomes from hypoxia-pretreated DPSCs with stable LOXL2 silencing via lentiviral transfection.
• Characterized exosomes using transmission electron microscopy, nanosight, and Western blot.
• Assessed exosome effects on human umbilical vein endothelial cell (HUVEC) migration and angiogenesis (tube formation) and gene expression.

Main Results:

• Successful silencing of LOXL2 in DPSCs inhibited their proliferation and migration.
• LOXL2-silenced exosomes partially reduced the promotion of HUVEC migration and tube formation.
• The expression of angiogenesis-associated genes in HUVECs was inhibited by LOXL2-silenced exosomes.

Conclusions:

• Lysyl oxidase-like 2 (LOXL2) is identified as one of the factors mediating the angiogenic effects of exosomes derived from hypoxia-pretreated DPSCs.
• Exosome-mediated transfer of LOXL2 plays a partial role in enhancing endothelial cell angiogenesis.