Biomolecules 2015, 5, 545-589
Mark Rinnerthaler 1, Johannes Bischof 1, Maria Karolin Streubel 1, Andrea Trost 2 and Klaus Richter 1,*
1 Department of Cell Biology, Division of Genetics, University of Salzburg, Salzburg 5020, Austria; E-Mails: firstname.lastname@example.org (M.R.); email@example.com (J.B.); firstname.lastname@example.org (M.K.S.)
2 Department of Ophthalmology and Optometry, Paracelsus Medical University,
Muellner Hauptstrasse 48, 5020 Salzburg, Austria; E-Mail: A.Zurl@salk.at
* Authortowhomcorrespondenceshouldbeaddressed;E-Mail:email@example.com; Tel.: +43-0-662-8044-5763; Fax: +43-0-662-8044-144.
Academic Editors: Michael Breitenbach and Peter Eckl
Received: 12 January 2015 / Accepted: 9 April 2015 / Published: 21 April 2015
Abstract: Oxidative stress in skin plays a major role in the aging process. This is true for intrinsic aging and even more for extrinsic aging. Although the results are quite different in dermis and epidermis, extrinsic aging is driven to a large extent by oxidative stress caused by UV irradiation. In this review the overall effects of oxidative stress are discussed as well as the sources of ROS including the mitochondrial ETC, peroxisomal and ER localized proteins, the Fenton reaction, and such enzymes as cyclooxygenases, lipoxygenases, xanthine oxidases, and NADPH oxidases. Furthermore, the defense mechanisms against oxidative stress ranging from enzymes like superoxide dismutases, catalases, peroxiredoxins, and GSH peroxidases to organic compounds such as L-ascorbate, α-tocopherol, beta-carotene, uric acid, CoQ10, and glutathione are described in more detail. In addition the oxidative stress induced modifications caused to proteins, lipids and DNA are discussed. Finally age-related changes of the skin are also a topic of this review. They include a disruption of the epidermal calcium gradient in old skin with an accompanying change in the composition of the cornified envelope. This modified cornified envelope also leads to an altered anti-oxidative capacity and a reduced barrier function of the epidermis.
Keywords: lipofuscin; AGEs; cornified envelope; calcium gradient; extrinsic and intrinsic aging; DNA damage; lipid peroxidation; antioxidants; carbonylation