Dermal connective tissue metabolism in photoageing

Ishikawa, Osamu

doi:10.1111/j.1440-0960.1998.tb01235.x

Cited by 13 publications

(8 citation statements)

References 26 publications

(22 reference statements)

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“…MMPs and their inhibitors regulate the degradative pathway of extracellular collagen. UV irradiation has been reported to stimulate collagenase (MMP-1) synthesis by human skin fibroblasts, an effect contributing to collagen degradation that leads to photoageing (Miyachi and Ishikawa, 1998).…”

Section: Discussionmentioning

confidence: 99%

Development of UV-Induced Squamous Cell Carcinomas Is Suppressed in the Absence of SPARC

Aycock

Bradshaw

Sage

et al. 2004

Journal of Investigative Dermatology

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SPARC (Secreted Protein Acidic and Rich in Cysteine) is a multifunctional glycoprotein belonging to a group of matrix-associated factors that mediate cell-extracellular matrix interactions but have no structural roles. In the present study we investigated the contribution of SPARC to factors that influence the development of skin tumors in response to UV irradiation. A hairless SPARC-null mouse was developed and compared to control SKH1 hairless mice in terms of skin tumor induction and extracellular matrix changes occurring in response to UV-irradiation. Following 23 weeks of exposure to UVB totaling 14.5 J per cm(2), tumor development in the wild-type mice was severe, with an average of over 20 tumors per mouse, many of which were squamous cell carcinomas. Conversely, the SPARC-null mice were strikingly tumor-resistant, developing no squamous cell carcinomas and averaging less than one small papilloma per mouse. SPARC was undetectable immunohistochemically in skin from the non-irradiated control group yet was present in relatively high quantities in the basal and superficial areas of the tumor mass. The SPARC-null mice also exhibited a limited contact hypersensitivity response and were refractory to UV induced immune suppression. In conclusion, SPARC appears to have a crucial role in mediating tumor formation in response to UV irradiation.

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Section: Discussionmentioning

confidence: 99%

Development of UV-Induced Squamous Cell Carcinomas Is Suppressed in the Absence of SPARC

Aycock

Bradshaw

Sage

et al. 2004

Journal of Investigative Dermatology

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“…Skin that ages chronologically, or enhanced by environmental effects such as UV irradiation (6), shows signs, such as wrinkles, that deepen and align in a parallel pattern, heterogenecity in pigmentation, and a dry, scaly aspect (7). When these phenomena are investigated by biopsy and histological sectioning and staining, dermal elastosis (8), a thin mean epidermal thickness and a flattened epidermal-dermal junction, can be seen (9). The corneocytes shed from the horny layer increase in size as a result of a lower proliferation rate and turn-over of the epidermis (10).…”

mentioning

confidence: 99%

Age related changes of human skin investigated with histometric measurements by confocal laser scanning microscopy in vivo

Sauermann

Clemann

Jaspers

et al. 2002

Skin Research and Technology

147

107

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Background/aims: The confocal laser scanning microscope Vivascope (Lucid, Henrietta) allows skin to be studied in real‐time with a resolution of 0.5 µm horizontal and 1.3 µm vertical in vivo. In this study, we present the results of a comparison between the skin of an older and a younger group of volunteers by in vivo histometric measurements. Methods: To investigate changes caused by age, 13 young (18–25 years) and 13 older (> 65 years) volunteers were examined. The following parameters were measured using the Vivascope at the volar forearm: minimal thickness of the epidermis (Emin), size of cells in the granular layer (Agran), thickness of the horny layer (DSC), thickness of the basal layer (DSB) and number of dermal papillae per area (PapI). The image analysis program image tool was used to measure the size of the cells and the thickness of the basal layer. Results: The older group of volunteers showed a significant increase in Emin, no significant change in DSC, a significant decrease in dermal papillae and in the thickness of the basal layer, and an increase in Agran compared to the younger group. Conclusions: Histometric measurements by in vivo confocal laser scanning microscopy are a sensitive and non‐invasive tool for characterizing and quantifying histological changes of the epidermis and papillary dermis due to ageing.

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“…[91] Together with decreased elastin, the skin becomes wrinkled, saggy, and inelastic, due to decreased collagen synthesis. Paradoxically, the photo-aged skin shows focally increased elastin owing to UV-induced transcriptional activation of the elastin gene[96] and lysozyme-induced reduction in leukocyte elastase activity. [97] Together with heliodermatitis,[91] photo-aged skin appears thick, dry, rough, deeply wrinkled, and inelastic owing to the disarrangement of collagen and elastic fibers.…”

Section: Paradoxes In Dermatopathologymentioning

confidence: 99%