The life in a gradient: calcium, the lncRNA SPRR2C and mir542/mir196a meet in the epidermis to regulate the aging process.

The turnover of the epidermis beginning with the progenitor cells in the basal layer to the fully differentiated corneocytes is tightly regulated by calcium. Calcium more than anything else promotes the differentiation of keratinocytes which implies the need for a calcium gradient with low concentrations in the stratum basale and high concentrations in the stratum granulosum. One of the hallmarks of skin aging is a collapse of this gradient that has a direct impact on the epidermal fitness.

Slow Growth and Increased Spontaneous Mutation Frequency in Respiratory Deficient Yeast Suppressed by a Dominant Mutation in .

A yeast deletion mutation in the nuclear-encoded gene, , which codes for a mitochondrial ribosomal protein, led to slow growth on glucose, the inability to grow on glycerol or ethanol, and loss of mitochondrial DNA and respiration. We noticed that yeast readily obtains secondary mutations that suppress aspects of this phenotype, including its growth defect. We characterized and identified a dominant missense suppressor mutation in the gene.

Behead and live long or the tale of cathepsin L.

In recent decades Saccharomyces cerevisiae has proven to be one of the most valuable model organisms of aging research. Pathways such as autophagy or the effect of substances like resveratrol and spermidine that prolong the replicative as well as chronological lifespan of cells were described for the first time in S. cerevisiae.

The Human NADPH Oxidase, Nox4, Regulates Cytoskeletal Organization in Two Cancer Cell Lines, HepG2 and SH-SY5Y.

NADPH oxidases of human cells are not only functional in defense against invading microorganisms and for oxidative reactions needed for specialized biosynthetic pathways but also during the past few years have been established as signaling modules. It has been shown that human Nox4 is expressed in most somatic cell types and produces hydrogen peroxide, which signals to remodel the actin cytoskeleton. This correlates well with the function of Yno1, the only NADPH oxidase of yeast cells.

Clearing the outer mitochondrial membrane from harmful proteins via lipid droplets.

In recent years it turned out that there is not only extensive communication between the nucleus and mitochondria but also between mitochondria and lipid droplets (LDs) as well. We were able to demonstrate that a number of proteins shuttle between LDs and mitochondria and it depends on the metabolic state of the cell on which organelle these proteins are predominantly localized. Responsible for the localization of the particular proteins is a protein domain consisting of two -helices, which we termed V-domain according to the predicted structure.

Oxidative stress in aging human skin.

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.

Skin aging, gene expression and calcium.

The human epidermis provides a very effective barrier function against chemical, physical and microbial insults from the environment. This is only possible as the epidermis renews itself constantly. Stem cells located at the basal lamina which forms the dermoepidermal junction provide an almost inexhaustible source of keratinocytes which differentiate and die during their journey to the surface where they are shed off as scales.