Oral Progenitor Cell Line-Derived Small Extracellular Vesicles as a Treatment for Preferential Wound Healing Outcome

Abstract

Scar formation during wound repair can be devastating for affected individuals. Our group previously documented the therapeutic potential of novel progenitor cell populations from the non-scarring buccal mucosa. These Oral Mucosa Lamina Propria-Progenitor Cells (OMLP-PCs) are multipotent, immunosuppressive, and antibacterial. Small extracellular vesicles (sEVs) may play important roles in stem cell–mediated repair in varied settings; hence, we investigated sEVs from this source for wound repair. We created an hTERT immortalized OMLP-PC line (OMLP-PCL) and confirmed retention of morphology, lineage plasticity, surface markers, and functional properties. sEVs isolated from OMLP-PCL were analyzed by nanoparticle tracking analysis, Cryo-EM and flow cytometry. Compared to bone marrow–derived mesenchymal stromal cells (BM-MSC) sEVs, OMLP-PCL sEVs were more potent at driving wound healing functions, including cell proliferation and wound repopulation and downregulated myofibroblast formation. A reduced scarring potential was further demonstrated in a preclinical in vivo model. Manipulation of OMLP-PCL sEVs may provide novel options for non-scarring wound healing in clinical settings.

Generation of Functional Immortalized Human Corneal Stromal Stem Cells

“…Overexpression of hTERT was not sufficient in extending CSSCs’ expansion beyond 12 passages [ 34 , 35 ]. Similar to our findings, others observed that hTERT alone was not sufficient to immortalize adipose and bone marrow derived-MSCs [ 36 , 37 ] but has been demonstrated to extend the lifespan of other cells such as oral progenitor cells [ 17 ]. The addition of other viral genes such as p53 [ 38 ], BMI-1 [ 39 ], or HPV E6/E7 [ 40 ] to hTERT overexpression has demonstrated to improve the efficacy of hTERT overexpression to produce immortalized cells.…”

“…All newly generated cell lines, hTERT-imCSSC, c-MYC-imCSSC, and SV40T-imCSSC, extended the pCSSC lifespan. Moreover, hTERT overexpression bypasses replicative cellular senescence and prolongs cellular lifespan in vitro while retaining their progenitor/stem cells properties [ 17 , 30 , 31 , 32 , 33 ]. Overexpression of hTERT was not sufficient in extending CSSCs’ expansion beyond 12 passages [ 34 , 35 ].…”

“…While the idea of immortalizing primary cells is not new, there have been several reports outlining the difficulty in producing a cell line that maintains the phenotype of the primary MSCs [ 14 , 15 , 16 , 17 ]. What is novel here is the successful immortalization of CSSCs that maintain the function of the primary cells while also demonstrating the desired ability for continued cell culture without senescence beyond 10 passages.…”

Oncostatin M-Enriched Small Extracellular Vesicles Derived from Mesenchymal Stem Cells Prevent Isoproterenol-Induced Fibrosis and Enhance Angiogenesis

“…Previous work by our group and others demonstrated the feasibility of immortalizing MSCs from different tissues to obtain a stable parental source of MSC-SEVs [ 44 , 45 ]. In particular, the overexpression of human TERT in MSCs and other progenitors does not alter their therapeutic features or the properties of SEVs [ 46 , 47 ]. These cells can be further modified to bolster their therapeutic potential, as performed with wild-type MSCs [ 48 , 49 , 50 ].…”

Stem cell-derived exosomes: emerging therapeutic opportunities for wound healing

“…Oral mucosa lamina propria-progenitor cells (OMLP-PCs) possess unique properties, such as easy isolation, immunosuppression, and multipotency. OMLP-PC line (OMLP-PCL) exosomes were capable of decreasing myofibroblast formation and enhancing wound repopulation [ 79 ]. OMLP-PCL exosomes also achieved scar-free healing in a preclinical wound mouse model.…”