590-P: Modulation of Adenine Phosphoribosyltransferase-Mediated Purine Salvage to Accelerate Diabetic Wound Healing

Abstract

Aim: Adenine phosphoribosyltransferase (APRT) is the key enzyme in purine salvage by the incorporation of adenine and phosphoribosyl pyrophosphate to provide adenylate nucleotide. Our aim was to evaluate the role of APRT in diabetic wound healing. Methods: The molecular mechanism of APRT-mediated cell survival was validated by the haploid HAP1 cell. The adenylate nucleotides in NIH-3T3 fibroblast response to adenine was monitoring by HPLC-MS/MS method. The effects of cell behaviors were evaluated by mice NIH-3T3 fibroblast and human epithelial keratinocytes. Genetically diabetic mice received surgery for full-thickness of the cutaneous wound and the adenine addition as the substrate for APRT on the wound. Results: In the wild type and APRT knockout HAP1 cell, our data revealed that APRT utilized adenine to rescue cellular ATP levels and proliferation against hydrogen peroxide-induced oxidative damage. The time-course of monitoring the total adenylate nucleotides in NIH-3T3 fibroblast showed that adenine addition enlarged the cellular adenylate pool, reduced the adenylate energy charge, and provided more AMP for the generation of ATP in further. In mice NIH-3T3 fibroblasts and human NHEK keratinocytes, adenine elevated cellular ATP levels in a dose-dependent manner and facilitated cell migration. The up-regulated APRT found in wound skin was correlated with the demands of wound repair in diabetic mice. Administration of adenine on the wound of diabetic mice exhibited elevated ATP levels in organismic skin and accelerated wound healing. Conclusions: Our data indicated the role of APRT during diabetic wound healing by regulating the nucleotide pool after injury and demonstrated the improvement by topical adenine, which highlights its value as a promising agent in therapeutic intervention. This study provided an explanation for the up-regulation of APRT in tissue repair and adenine supplement resulted in an enlargement of the adenylate pool for ATP generation. Disclosure G. Young: Employee; Self; Energenesis-Biomedical. J. Lin: Employee; Self; Energenesis-Biomedical. Y. Cheng: Employee; Self; Energenesis-Biomedical. H. Chen: Board Member; Self; Energenesis-Biomedical.