Glutathione enhances fibroblast collagen contraction and protects keratinocytes from apoptosis in hyperglycaemic culture

Background Cutaneous wound healing is relatively slow in patients with diabetes. Objectives To test the hypothesis that this defect in healing of wounds in patients with diabetes results from dysfunction of skin fibroblasts and epidermal keratinocytes and that this dysfunction is related to disrupted intracellular glutathione (GSH) homeostasis. Methods We investigated the effects of esterified GSH on the contraction of fibroblasts in a fibroblast-populated collagen lattice and on keratinocyte apoptosis. Results High glucose medium (hyperglycaemia) reduced the contraction ability of fibroblasts (P < 0.05). The normalization of glucose medium concentrations for hyperglycaemic fibroblasts did not restore the contraction capacity. The percentage of apoptotic keratinocytes was statistically higher in hyperglycaemic cells (P < 0.05). GSH media concentrations ranging from 0.1 to 100 mu mol L-1 restored the ability of hyperglycaemic fibroblasts to contract the gels in a concentration-dependent manner. Primary human keratinocytes grown in hyperglycaemic medium were more susceptible to apoptosis, and treatment with esterified GSH rescued the keratinocytes from apoptosis. Conclusions These data suggest that intracellular GSH can normalize skin cell functions disrupted by in vitro cell growth under hyperglycaemic conditions.