Small EVs From Adipose-Derived MSCs Modulate Epidermal Barrier and Inflammation Via Sphingosine-1-Phosphate Signaling...

Area of Science:

• Dermatology
• Cell Biology
• Biochemistry

Background:

• Epidermal permeability barrier defects are hallmarks of skin diseases like atopic dermatitis (AD).
• Small extracellular vesicles (sEVs) derived from human adipose tissue mesenchymal stem cells (ASCs) have shown promise in ameliorating AD symptoms.
• The precise mechanisms by which ASC-sEVs normalize barrier function and reduce inflammation in AD remain to be fully elucidated.

Purpose of the Study:

• To investigate the lipid and ceramide metabolic enzyme content of ASC-sEVs compared to donor ASCs.
• To elucidate the molecular mechanisms by which ASC-sEVs alleviate skin inflammation and barrier defects in AD.
• To determine the role of sphingosine-1-phosphate signaling in ASC-sEV-mediated therapeutic effects.

Main Methods:

• Characterization of lipid profiles and key ceramide metabolic enzymes within ASC-sEVs and donor ASCs.
• Analysis of ASC-sEVs' impact on sphingosine-1-phosphate levels in AD-model human keratinocytes.
• Assessment of ASC-sEVs' effects on pro-inflammatory cytokine production and keratinocyte differentiation in vitro.

Main Results:

• ASC-sEVs are enriched in free fatty acids, ceramides, and sphingomyelin compared to donor ASCs.
• Key enzymes involved in ceramide synthesis and sphingosine-1-phosphate metabolism are upregulated in ASC-sEVs.
• ASC-sEV treatment increases sphingosine-1-phosphate levels in keratinocytes, suppressing inflammation and restoring differentiation.

Conclusions:

• ASC-sEVs possess a distinct lipid and enzyme profile that facilitates therapeutic effects in AD.
• The sphingosine-1-phosphate signaling pathway activated by ASC-sEVs is crucial for reducing inflammation and restoring skin barrier function.
• Cells internalizing ASC-sEVs can normalize epidermal barrier function and alleviate inflammation through this pathway.