Giant panda umbilical cord mesenchymal stem cell-derived exosomes promote dermal fibroblast proliferation and wound healing.

Abstract

UC‑MSC‑Exos (umbilical cord mesenchymal stem cell‑derived exosomes) offer a potential therapy for captive giant pandas. This study aimed to clarify their proteomic and miRNA profiles and functions to understand therapeutic mechanisms and optimize their application. UC‑MSC‑Exos were isolated from giant panda UC‑MSC culture supernatant by ultracentrifugation. Proteomic and miRNA profiles were identified by mass spectrometry and high‑throughput small RNA sequencing, respectively. Dual‑luciferase gene reporter assays were used to evaluate the impact of miR‑21‑5p on DF proliferation. Giant panda UC‑MSC‑Exos are rich in proteins and miRNAs. They significantly boosted DF proliferation and migration, mediated by growth factors like PDGF, TGF‑β1, b‑FGF, and miR‑21‑5p. We found that miR‑21‑5p contributes to fibroblast proliferation by targeting the programmed cell death 4 (PDCD4) and reversion inducing cysteine rich protein with Kazal motifs (RECK) genes, attenuating the expression of α‑smooth muscle actin (α‑SMA) induced by TGF‑β1, and impeding the differentiation of fibroblasts into myoblasts. This study comprehensively reveals the functional properties of giant panda UC‑MSC‑Exos as well as their therapeutic potential in wound healing, providing insights for improving tissue regeneration and health in giant pandas.