CCBE1 promotes wound healing in diabetic rats by improving the functional impairment of AD-MSCs induced by AGEs

The etiology of chronic and non-healing diabetic wounds is manifold; the progression of the non-healing phenotype is strongly associated with poor vascular networks. Mesenchymal stem cells (MSCs) are reckoned as a promising therapy for wound healing, especially in angiogenesis. Here, we explored the role of CCBE1 in diabetic wound healing using human adipose-derived MSCs (hAD-MSCs).

Human adipose-derived hAD-MSCs were isolated and expanded through serial in vitro passaging. Cell proliferation and migration were evaluated using Cell Counting Kit-8 (CCK8) and scratch wound assays, respectively. collagen, and calcium-binding EGF domain-containing protein 1 (CCBE1) and vascular endothelial growth factor (VEGF) expression were analyzed via western blotting. Functional studies of CCBE1 were conducted using siRNA-mediated knockdown and plasmid-driven overexpression approaches. Type 2 diabetes mellitus was induced in Sprague-Dawley rats through a high-fat/high-glucose diet combined with streptozotocin administration. Full-thickness excisional wounds were generated on the dorsal skin, and the effects of CCBE1 modulation in hAD-MSCs on wound closure were examined. Reepithelialization and angiogenesis were analyzed using histological and immunohistochemical methods. Protein levels of CCBE1 and vascular endothelial growth factor (VEGF) were quantified by western blotting.

hAD-MSCs showed a gradual decrease in cell proliferation, migrationand increased apoptosis, during advanced glycation end products (AGEs) conditions; meanwhile, CCBE1 and VEGF expression decreased The downregulation of CCBE1 inhibited cell proliferation and migration, and enhanced apoptosis, while CCBE1 overexpression enhanced proliferation and migration, and reduced apoptosis. Compared with untransduced hAD-MSCs, local subcutaneous injection of CCBE1-overexpressing hAD-MSCs accelerated wound closure, enhanced angiogenesis and reepithelialization at the wound bed, and increased VEGF levels in wound tissues.

CCBE1 overexpression promoted hAD-MSC proliferation and migration and reduced cell apoptosis in vitro and accelerated diabetic wound closure, reepithelialization, and angiogenesis by improving hAD-MSCs in vivo. These beneficial effects of CCBE1 overexpression in diabetic wound healing by hAD-MSCs were at least partially mediated by increased VEGF levels in wound tissues.