title: Cytokeratin-related loss of cellular integrity is not a major driving force of human intrinsic skin aging.
abstract: The contribution of extracellular matrix components to intrinsic skin aging has been investigated thoroughly, however, there is little information as to the role of the cytoskeletal proteins in this process. Therefore, we compared the expression of the constituents of the cytoskeleton, keratins 1-23 (K1-K23) as well as junction-plakoglobin (JUP), alpha-tubulin (TUBA), and beta-actin (ACTB) in human foreskins of both young (mean 6.4 years) and aged (mean 54.3 years) individuals. By applying RNA expression analysis to intrinsically aged human skin, we demonstrated that the mRNA levels of the genes for K1, K3, K4, K9, K13, K15, K18, K19 and K20 are downregulated in aged skin, K5 and K14 are unchanged, and K2, K16 and K17 are upregulated in aged skin. The mRNA data were confirmed on the protein level. This diverse picture is in contrast to other cytoskeletal proteins including components of the desmosome (JUP), microtubuli (TUBA) and microfilaments (ACTB) - often regarded as house-keeping genes - that were all reduced in aged skin. These cytoskeletal features of intrinsic aging highlight the importance of the cellular compartment in this process and demonstrate that special attention has to be given to RNA as well as protein normalization in aging studies.
authors.affiliation: Department of Dermatology, Muellner Hauptstrasse 48, A-5020 Salzburg, Austria.
authors.forename: Kamil
authors.initials: K
authors.lastname: Oender
authors.forename: Andrea
authors.initials: A
authors.lastname: Trost
authors.forename: Christoph
authors.initials: C
authors.lastname: Lanschuetzer
authors.forename: Martin
authors.initials: M
authors.lastname: Laimer
authors.forename: Michael
authors.initials: M
authors.lastname: Emberger
authors.forename: Michael
authors.initials: M
authors.lastname: Breitenbach
authors.forename: Klaus
authors.initials: K
authors.lastname: Richter
authors.forename: Helmut
authors.initials: H
authors.lastname: Hintner
authors.forename: Johann W
authors.initials: JW
authors.lastname: Bauer
mesh_terms: D000199:Actins / Q000378:metabolism; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D051180:Desmoplakins / Q000096:biosynthesis; D052816:Foreskin / Q000378:metabolism*; D006801:Humans; D007223:Infant; D007633:Keratins / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000378:metabolism; D015595:Skin Aging; D014404:Tubulin / Q000378:metabolism; D051185:gamma Catenin
chemical_list: D000199:Actins; D051180:Desmoplakins; C495292:JUP protein, human; D012333:RNA, Messenger; D014404:Tubulin; D051185:gamma Catenin; D007633:Keratins