Abstract
Impaired wound healing in critical limb ischemia (CLI) results from multiple factors that affect many cell types and their behavior. Epidermal keratinocytes and dermal fibroblasts play crucial roles in wound healing. However, it remains unclear whether these cell types irreversibly convert into a non-proliferative phenotype and are involved in impaired wound healing in CLI. Here, we demonstrate that skin keratinocytes and fibroblasts isolated from CLI patients maintain their proliferative potentials. Epidermal keratinocytes and dermal fibroblasts were isolated from the surrounding skin of foot wounds in CLI patients with diabetic nephropathy on hemodialysis, and their growth potentials were evaluated. It was found that keratinocytes from lower limbs and trunk of patients can give rise to proliferative growing colonies and can be serially passaged. Fibroblasts can also form colonies with a proliferative phenotype. These results indicate that skin keratinocytes and fibroblasts maintain their proliferative capacity even in diabetic and ischemic microenvironments and can be reactivated under appropriate conditions. This study provides strong evidence that the improvement of the cellular microenvironments is a promising therapeutic approach for CLI and these cells can also be used for potential sources of skin reconstruction.