Functional Characterizations of Port Wine Birthmark IPSC-Derived Extracellular Vesicles in Laser-Resistant Endothelial Phenotypes

Vascular malformations (VMs) are a group of congenital vascular anomalies characterized by abnormal development of the vascular system. Capillary malformation (CM), also known as Port-wine Birthmark or Stain (PWB, or PWS), is a cutaneous capillary disorder with an estimated prevalence of 0.3% to 0.5% in newborns. PWB with brain neurocutaneous disorder involvement is known as Sturge-Weber syndrome (SWS). Pathologically, PWB is manifested by progressively dilated vasculature, hypertrophic collagens, proliferating endothelial cells (ECs) and increased exocytosis. Pulsed dye laser (PDL) is the gold standard therapy for PWB. Increased Collagen V was found in PWB lesions. In order to investigate the effects of upregulated Collagen V in ECM, a 3D-toroids assay was applied to examine the human dermal microvascular endothelial cell (hDMVECs) migration. An increase in Collagen V in the ECM results in a smaller size of hDMVECs-formed toroids, demonstrating an increased cell migration rate. Our results show that upregulation of Collagen V can impair capillary ECM compositions in PWB lesions, thus promoting hDMVECs migration through activation of the ERK signaling pathway. Extracellular vesicles (EVs) are intercellular signaling mediators, facilitating the transfer of bioactive molecules and promoting intercellular communications. PWB lesional ECs exhibit increased EVs secretion and exocytosis. We treated the hDMVEC or induced pluripotent stem cells (iPSCs)-derived ECs with PWB iPSC-derived EVs for 7 days, followed by ICG-PDT (Indocyanine Green Photodynamic Therapy). The hDMVECs and control iPSC-derived ECs acquired a “laser-resistant” tendency induced by laser-resistant iPSC-derived EVs. In addition, PWB iPSC-derived EVs incubated hDMVECs formed enlarged and perfused capillaries in a Xenograft Mouse Model, resulting in PWB-like xenografted vasculatures. A PWB clinical related literature mining was conducted to compare clinical efficacies between PDL and PDT. PubMed records were searched for all relevant studies of PWB and HMME-PDT. The overall CI (C0) was used to evaluate the final efficacy. The clearance rates in PDL is nearly achieved statistical significance compared with HMME-PDT, in young children (< 3 years old). The outcomes revealed that evidence still supports PDL as the first choice of treatment for PWBs, especially for young children less than three years old.