FP01 Cortisol modulation of dermal fibroblast migration and early fibrotic markers in diabetic wounds
Carol-Ann Lao, Begonya Alcacer-Pitarch, Keith Hussey, Steven Patterson, Ana Tiganescu, Catherine WrightAbstract
Introduction and aims
Delayed wound healing in diabetes is driven, in part, by impaired dermal fibroblast migration and increased fibrosis. Local cortisol regeneration via 11β-hydroxysteroid dehydrogenase (11β-HSD1) is elevated in diabetic skin, but the direct effects of cortisol on dermal fibroblast behaviour under diabetic conditions remain unclear. The aim of this study was to investigate how cortisol influences dermal fibroblast migration and early fibrotic markers in an in vitro diabetic wound model.
Methods
Adult human dermal fibroblasts were cultured in low-glucose insulin (LGI) (5.5 mmol L–1 glucose, 1 nmol L–1 insulin) or high-glucose insulin (HG); 25 mmol L–1 glucose, 10 nmol L–1 insulin) and subjected to scratch-wound assays. Cells were treated with 100 nmol L–1 cortisol or cortisone, with or without the 11β-HSD1 inhibitor carbenoxolone (CBX). Transforming growth factor (TGF)-β1 (10 ng mL–1) treatment was used as a control for fibrosis. Wound closure was measured at 0, 24 and 48 h. Cell proliferation was assessed using WST-1, and preliminary immunocytochemistry [α-smooth muscle actin (α-SMA), vimentin] was performed to examine early fibrotic changes. Initial dose–response experiments (1 nmol L–1 to 1 µmol L–1 cortisol) were conducted in healthy fibroblasts and fibroblasts isolated from diabetic foot ulcers.
Results
Fibroblasts in LGI closed ∼47% of the wound area at 48 h vs. ∼27% in HGI, confirming impaired migration under hyperglycaemia. In HGI, 100 nmol L–1 cortisol or cortisone treatment improved wound closure by ∼18% compared with the untreated control, whereas effects in LGI were minimal. The effect of cortisone was reduced in the presence of CBX, indicating partial dependence on 11β-HSD1. Cortisol reduced proliferation relative to untreated controls, while transforming growth factor (TGF)-β1 increased proliferation. Preliminary immunocytochemistry suggested increased α-SMA expression following cortisol and TGF-β1 treatment, indicating increased fibrosis. Early dose–response experiments showed context-dependent effects of cortisol, with diabetic wound-edge fibroblasts appearing more responsive than healthy fibroblasts.
Conclusions
Cortisol influences dermal fibroblast migration in diabetic wound models in a context-dependent manner. Further work using diabetic donor cells and chronic exposure models is needed to determine how altered glucocorticoid signalling contributes to impaired healing.