Ageing processes influence keratin and KAP expression in human hair follicles

Abstract

In many cultures, a youthful look is strictly linked to strong and healthy hair. Source of the hair fibre is the hair follicle, a highly specialized skin appendage. Biological alterations because of intrinsic or extrinsic stimuli can destabilize this perfectly organized system, thus effecting hair growth or metabolism. Also, ageing could be characterized as a disturbance in this wellbalanced machinery. Albeit the predominant symptom of hair ageing, greying, is addressed in a plurality of research activities, further age-related changes, e.g. related to hair structure, remain obscure. Therefore, we characterized hair follicles of two volunteer panels (below 25 years, above 50 years) on the molecular level, especially focussing on alterations influencing gene expression of keratins and keratin-associated proteins. We showed that concordantly to other biological systems the hair follicle undergoes several modifications during the ageing process associated among others with a significant decline in these structural proteins. Providing strategies to fight against these agerelated changes is a challenge for hair science.

Resolving the insertion sites of polymorphic duplications reveals aHERC2haplotype under selection

“…This whole gene duplication is common in African populations, but not observed in Eurasian populations ( Table 1). Gene expression of KRT34 in human hair follicles is higher in young individuals than that in old individuals (Giesen et al 2011). Based on GTEx data (Lonsdale et al 2013), we demonstrate that the haplotype harboring the duplication led to an increase in the dosage of the KRT34 expression.…”

Human hair shaft proteomic profiling: individual differences, site specificity and cuticle analysis

“…This likely reflects variation in transcription factor binding affinity for chromatin that can even have epigenetic consequences (Kasowski et al, 2013; Kilpinen et al, 2013; McVicker et al, 2013). However, indications that the profile in humans could depend on age (Giesen et al, 2011) and the possible influence of other factors including environment and diet (Almeida et al, 2014) merit further study. In addition, how well cuticle cells remain attached to the shaft could influence the profile.…”

Dexpanthenol Modulates Gene Expression in Skin Wound Healing in vivo

“…Hair keratin-associated proteins are a major component of the hair fiber, and play crucial roles in forming a strong hair shaft through a cross-linked network with keratin intermediate filaments, which are produced from hair keratins [24]. Recently, it has been show that aging processes influence the gene expression of KAP4 family members in human hair follicles which are expressed predominantly in the highly differentiated portions of the middle and upper cortex [25]. Previously, changes in epithelial keratin expression during healing of rabbit corneal wounds and delayed wound healing in keratin 6a knockout mice have been reported [26,27].…”