Thioredoxin-1 augments wound healing and promote angiogenesis in a murine ischemic full-thickness wound model

Nonhealing wounds are a continuing health problem in the United States. Overproduction of reactive oxygen species is a major causative factor behind delayed wound healing. Previously we reported that thioredoxin-1 treatment could alleviate oxidative stress under ischemic conditions, such as myocardial infarction and hindlimb ischemia. In this study, we explored the potential for thioredoxin-1 gene therapy to effectively aid wound healing through improved angiogenesis in a murine ischemic wound model.

Full-thickness, cutaneous, ischemic wounds were created in the dorsum skin flap of 8- to 12-week-old CD1 mice. Nonischemic wounds created lateral to the ischemic skin flap served as internal controls. Mice with both ischemic wounds and nonischemic wounds were treated with Adeno-LacZ (1 × 10⁹ pfu) or Adeno-thioredoxin-1 (1 × 10⁹ pfu), injected intradermally around the wound. Digital imaging was performed on days 0, 3, 6, and 9 to assess the rate of wound closure. Tissue samples collected at predetermined time intervals were processed for immunohistochemical analysis.

No significant differences in wound closure were identified among the nonischemic wounds control, nonischemic wounds-LacZ, and nonischemic wounds-thioredoxin-1 groups. Hence, only mice with ischemic wounds were further analyzed. The ischemic wounds-thioredoxin-1 group had significant improvement in wound closure on days 6 and 9 after surgery compared with the ischemic wounds control and ischemic wounds-LacZ groups. Immunohistochemical analysis indicated increased thioredoxin-1, vascular endothelial cell growth factor, and β-catenin levels in the ischemic wounds-thioredoxin-1 group compared with the ischemic wounds control and ischemic wounds-LacZ groups, as well as increased capillary density and cell proliferation, as represented by Ki-67 staining.

Taken together, thioredoxin-1 gene therapy promotes vascular endothelial cell growth factor signaling and re-epithelialization and activates wound closure in mice with ischemic wounds.