ABSTRACT
Many scholars have suggested that exosomes (Exos) can carry active molecules to induce angiogenesis and thus accelerate diabetic wound healing. Heme oxygenase-1 (HO-1) encoded by the gene HMOX1 promotes wound healing in DM by enhancing angiogenesis. Nevertheless, whether HMOX1 regulates wound healing in DM through mesenchymal stem cell-derived exosomes (MSC-Exos) remains to be further explored. The primary isolated- and cultured-cells expressed MSC-specific marker proteins, and had low immunogenicity and multi-differentiation potential, which means that MSCs were successfully isolated in this study. Notably, HO-1 protein expression was significantly higher in Exo-HMOX1 than in Exos, indicating that HMOX1 could be delivered to Exos as an MSCs-secreted protein. After verifying the -Exo structure, fibroblasts, keratinocytes, and human umbilical vein endothelial cells (HUVECs) were incubated with Exo-HMOX1 or Exo, and the findings displayed that Exo-HMOX1 introduction promoted the proliferation and migration of fibroblasts, keratinocytes and the angiogenic ability of HUVECs in vitro study. After establishing diabetic wound model mice, PBS, Exo, and Exo-HMOX1 were subcutaneously injected into multiple sites on the 1st, 3rd, 7th, and 14th day, DM injected with Exo-HMOX1 showed faster wound healing, re-epithelialization, collagen deposition, and angiogenesis than those in PBS and Exo groups in vitro study. In summary, Exo-HMOX1 could enhance the activity of fibroblasts, keratinocytes, and HUVEC, and accelerate wound healing by promoting angiogenesis in DM.
