Fibulin-5 deposition in human skin: Decrease with aging and UVB exposure and increase in solar elastosis

Abstract

Skin aging is classified into two types, intrinsic aging and photoaging. Intrinsic aging is a basic biological process common to all living things, and can be characterized as age-dependent deterioration of skin functions and structures, such as epidermal atrophy and epidermal-dermal junction flattening [1]. Histologically, intrinsically aged skin has an atrophied extracellular matrix with a reduced amount of elastin [2]. On the other hand, photoaging is well known to be a consequence of chronic exposure to sunlight. Sun-exposed skin, such as the skin on the face or neck, is apparently prematurely aged compared with the relatively sun-protected skin of the trunk, and is characterized by various clinical features, including wrinkles, sagging, roughness, sallowness, pigmentary changes, telangiectasia, and neoplasia [3, 4], and histological features of sun-exposed skin including cellular atypia, loss of polarity, epidermal-dermal junction flattening, a decrease in collagen, and dermal elastosis, with abnormal deposition of elastotic material in the dermis [1, 5]. Damage to skin collagen and elastin (extracellular matrix) is the hallmark of long-term exposure to solar ultraviolet irradiation, and is believed to be responsible for the wrinkled appearance of sun-exposed skin [5]. © Springer-Verlag Berlin Heidelberg 2010.