Transcriptional Profile of Aging in Healthy Human Skin

Gene expression changes were assessed from the non sun-exposed skin of the lower back of 98 healthy males aged 19-86. We show that contrary to previous thought, genome wide transcriptional activity does not display an exclusively linear correlation with ageing, but rather, in human skin, undergoes a period of significant transient change between 30 and 45 years of age. The identified transient transcriptional changes suggest a period of heightened metabolic activity and cellular damage mediated primarily through the actions of TP53 (tumour protein 53) and TNF (tumour necrosis factor). We also identified a subgroup of the population characterised by increased expression of a large group of hair follicle genes that correlates strongly with a younger age of onset and increasing severity of androgenetic alopecia. Skin was collected from the lower back at the level of the belt, aproximately 5cm lateral to midline from healthy males, (defined as; non-smoking, no hospital admissions in the previous 5 years, no significant medical conditions or medications). Each sample was individually hybridised to an exon 1.0 ST array.