Sex and sex hormones mediate wound healing

Abstract

In healthy individuals cutaneous wound repair occurs through a combination of overlapping, tightly regulated phases to ensure the skin heals effectively. Disruption to these processes results in impaired healing and development of nonhealing chronic wounds. The incidence of chronic wounds is escalating as those populations most susceptible, the diabetic and elderly, continue to rise. One of the major complications associated with chronic wounds is infection. The amount and type of bacteria within a wound is linked to healing outcome. Current therapies to promote healing of chronic wounds are surprisingly limited and generally ineffective. Furthermore, the development of antibiotic-resistant bacteria and prevalence of wounds infected with recalcitrant biofilm renders current antimicrobial therapies ineffective. Treating this ever-growing problem puts financial strain on the world's health services. Thus, there is an urgent need to understand the mechanisms which result in impaired healing and to understand the differences in wound infections between males and females. Sex steroid hormones, in particular estrogens, play a pivotal role in skin maintenance of homeostasis, and research has shown that our ability to heal cutaneous wounds is modulated by host sex. A plethora of data now indicate estrogens as a primary regulator of cutaneous healing and systemic or topical oestradiol treatment promotes impaired healing. However, it is still not understood what effects estrogen treatment has on microbial profiles within a wound and how this differs between males and females. Future studies are therefore required to determine sex and gender differences in wound infections and whether hormone treatment to promote healing alters microbial profiles.