Publication details for Dr Arto MaattaDuit, Rebecca, Hawkins, Tim J. & Määttä, Arto (2019). Depilatory chemical thioglycolate affects hair cuticle and cortex, degrades epidermal cornified envelopes and induces proliferation and differentiation responses in keratinocytes. Experimental Dermatology 28(1): 76-79.
- Publication type: Journal Article
- ISSN/ISBN: 0906-6705, 1600-0625
- DOI: 10.1111/exd.13838
- Further publication details on publisher web site
- Durham Research Online (DRO) - may include full text
Author(s) from Durham
Thioglycolate is a potent depilatory agent. In addition, it has been proposed to be useful as a penetration enhancer for transepidermal drug delivery. However, the effects on hair structure and stress responses it elicits in epidermal keratinocytes have not been fully characterized. We have used label‐free confocal and fluorescence lifetime imaging supported by electron microscopy to demonstrate how thioglycolate damages hair cuticle cells by generating breakages along the endocuticle and leading to swelling of cortex cells. Maleimide staining of free SH‐groups and a decrease in the average fluorescence lifetime of endogenous fluorophores demonstrate a specific change in protein structure in both hair cuticle and cortex. We found that the thioglycolate damages cornified envelopes isolated from the stratum corneum of the epidermis. However, thioglycolate‐treated epidermal equivalent cultures recover within 48 hours, which highlights the reversibility of the damage. HaCaT keratinocytes respond to thioglycolate by increased proliferation, onset of differentiation and expression of the chaperone protein Hsp 70, but not Hsp 27. Up‐regulation of involucrin can be blocked by an application of c‐Jun N–terminal kinase (JNK) inhibitor, but the up‐regulation of Hsp 70 takes place regardless of the presence of the JNK inhibitor.