Reduced Type I and Type III Procollagens in Photodamaged Adult Human Skin

Abstract

We have quantitatively assessed the relation between type I and type III procollagen precursor levels and the severity of clinical photodamage in human skin. Levels of procollagen, pN collagen (collagen without the carbroxypropeptide), and/or pC collagen (collagen without the aminopropeptide) were determined by radioimmunoassay, Western blot, and immunohistology in punch biopsy specimens from mildly and severely photodamaged forearm skin and from sunprotected underarm and buttock skin of the same subjects. Collagen precursor levels in forearm and underarm skin were expressed relative to buttock levels for comparison. In the mildly photodamaged group, collagen precursors in the forearm did not differ from those in the underarm by any measurement, except for type I collagen precursors measured by radioimmunoassay, which were reduced 16%. In severely photodamaged forearm skin, both type I and type III collagen precursor levels, measured by radioimmunoassay, were significantly reduced (approximately 40%). Western analysis revealed similar significant reductions in type I and type III collagen precursor levels in severely photodamaged forearm skin compared with the sun-protected underarm. Immunohistology localized both type I and III pN collagens predominantly to the extracellular papillary dermis. Relative staining intensities of type I and type III pN collagen were also significantly reduced in severely photodamaged forearm skin. Multiple linear regression modeling of all data demonstrated that reductions in collagen precursor levels were significantly correlated (p < 0.03) with the severity of photodamage, but not with chronologic age. These data demonstrate, by three independent methods, coordinate reductions of both type I and type III collagen precursors in photodamaged human skin, and the degree of reduction correlated with the degree of photodamage. It is likely that such changes in collagen precursors lead to reduced levels and/or altered organization of fibrillar collagen, and thus may contribute to the wrinkled appearance of photodamaged human skin.

Inhibition of Type I Procollagen Synthesis by Damaged Collagen in Photoaged Skin and by Collagenase-Degraded Collagen in Vitro

“…38 Likewise, the ability of topical retinoid treatment to induce type I procollagen synthesis in photodamaged skin implies the existence of cells with potential for collagen synthesis in the tissue. 9,10 Finally, the present studies (see below) show that equivalent numbers of fibroblasts can be isolated from severely sun-damaged forearm skin and matched sun-protected hip skin. Based on these data, we favor the interpretation that interstitial fibroblasts are present in photodamaged skin but are producing little type I procollagen.…”

“…By focusing on collagenous components in the present study, we do not mean to rule out possible contributions of other components of the extracellular matrix. Regardless of the molecular mechanisms underlying reduced collagen synthesis in photodamaged skin, the beneficial effects of agents such as all-trans retinoic acid may derive not only from direct action on fibroblasts to stimulate collagen synthesis 9,10 and decrease collagenase expression, 7,8 but also from indirectly promoting (through the newly synthesized collagen) additional matrix-regenerative signals not present in untreated photodamaged skin.…”

“…In addition, previous studies have demonstrated decreased levels of type I and type III collagen precursors (procollagens and pN collagens) in photodamaged human skin, relative to sun-protected skin. 9,10 This suggests that failure to replace damaged collagen through new synthesis also occurs.…”

A split‐face study of intense pulsed light on photoaging skin in Chinese population

“…data, the mechanism of IPL photothermolysis of irregular pigmentation of photoaging skin consists of promoting a rapid differentiation of keratinocytes, accompanied by an upward transfer of melanosomes along with necrotic keratinocytes, which results in the elimination of melanin from the skin. With the cumulative exposure of ultraviolet irradiation, the level of extracellular matrix metalloproteinases (MMPs) in photoaging skin increases, resulting in the degeneration of collagen and elastin, reduction of type I and type III procollagens, and deposition of altered elastic tissue [14,15]. Zelickson and Kist [16,17] found IPL treatment can increase the type I collagen transcripts by 18%, and 85-100% of patients were documented recruitment of type I collagen, type III collagen, elastin, collagenase, as well as 50-70% of patients were documented an increase of procollagens.…”

Anti-aging Effects of Diospyros kaki Thunb. Extracts in UVA-irradiated Epidermal Keratinocytes

“…보습에 관여하 는 히알루론산을 생성하는 효소인 hyaluronan synthase 2 (HAS2) 역시 자외선 조사에 의해 감소된다는 보고가 있다 (Hašová et al, 2011 (Eckert et al, 2005). Results and Discussion (Talwar et al, 1995;Kim et al, 2011). …”