Since photoaging of skin is caused by chronic sun exposure, it is well-recognized that regular sunscreen use can help prevent photoaging of skin in fair-skinned people. Therefore, application of sunscreen is recommended for the prevention of photoaging in many countries. However, the relationship between UV exposure and photoaging has rarely been investigated in clinical studies in Japan. In ad...

Exposure to ultraviolet (UV) light reduces levels of type I collagen in the dermis and results in human skin damage and premature skin aging (photoaging). This leads to a wrinkled appearance through the inhibition of transforming growth factor‑β (TGF‑β)/Smad signaling. UV irradiation increases type I collagen degradation through upregulating matrix metalloproteinase (MMP) expression. Astragalos...

Photoaging mainly occurs due to ultraviolet (UV) radiation, and is accompanied by increased secretion of matrix metalloproteinases (MMPs) degradation collagen. UV radiation induces cell senescence in the skin; however, role senescent cells photoaging remains unclear. Therefore, elucidate photoaging, we evaluated effect senolytics a mouse model investigated underlying mechanism their antiaging e...

Pigment blemishes, wrinkles, and flaccid skin are not just the natural consequence of the passage of time, but the result of excessive time in the sun. Photodamage also develops into actinic keratoses and skin cancer, and because we live in an era of ‘ozone holes’, we can expect the incidence of photoaging and skin cancer to increase dramatically. People are simultaneously living longer than ev...

BACKGROUND Photoaging is cumulative damage to skin, caused by chronic, repeated solar radiation exposure. Its molecular mechanisms are poorly understood at the level of global gene expression. OBJECTIVE This study set out to uncover genes and functional modules involved in photoaging at the level of transcription, with the use of skin samples from Chinese women. METHODS Using the Illumina m...

Ultraviolet (UV) radiation plays an important role in the pathogenesis of skin photoaging. Depending on the wavelength of UV, the epidermis is affected primarily by UVB. One major characteristic of photoaging is the dehydration of the skin. Membrane-inserted water channels (aquaporins) are involved in this process. In this study we demonstrated th...

BACKGROUND AND AIMS Excessive exposure to the sun can cause severe photoaging as early as the second decade of life resulting in a loss of physiological elastic fiber functions. We designed a first study to assess differences in facial skin pH, sebum, elasticity, hydration and tonicity and serum levels of fibronectin, elastin, neutrophil elastase 2, hyaluronic acid and carbonylated proteins bet...

Epigenetic repressor polycomb group (PcG) proteins are thought to serve a role in a number of cellular processes, including carcinogenesis, senescence, apoptosis and DNA repair. In the present study, long-wave ultraviolet A (UVA) was used to irradiate human skin fibroblasts (HSFs) and embryonic skin fibroblasts (ESFs) in order to simulate photoaging of the skin. The results of cell proliferatio...

Liver X receptors (LXRalpha and -beta) are liposensors that exert their metabolic effects by orchestrating the expression of macrophage genes involved in lipid metabolism and inflammation. LXRs are also expressed in other tissues, including skin, where their natural oxysterol ligands induce keratinocyte differentiation and improve epidermal barrier function. To extend the potential use of LXR l...

The photoaging process of facial skin is investigated by use of multiphoton fluorescence and second-harmonic generation (SHG) microscopy. We obtain the autofluorescence (AF) and SHG images of the superficial dermis from the facial skin of three patients aged 20, 40, and 70 years. The results show that areas of AF increase with age, whereas areas of SHG decrease with age. The results are consist...