Aging Alters Functionally Human Dermal Papillary Fibroblasts but Not Reticular Fibroblasts: A New View of Skin Morphogenesis and Aging

Understanding the contribution of the dermis in skin aging is a key question, since this tissue is particularly important for skin integrity, and because its properties can affect the epidermis. Characteristics of matched pairs of dermal papillary and reticular fibroblasts (Fp and Fr) were investigated throughout aging, comparing morphology, secretion of cytokines, MMPs/TIMPs, growth potential, and interaction with epidermal keratinocytes. We observed that Fp populations were characterized by a higher proportion of small cells with low granularity and a higher growth potential than Fr populations. However, these differences became less marked with increasing age of donors. Aging was also associated with changes in the secretion activity of both Fp and Fr. Using a reconstructed skin model, we evidenced that Fp and Fr cells do not possess equivalent capacities to sustain keratinopoiesis. Comparing Fp and Fr from young donors, we noticed that dermal equivalents containing Fp were more potent to promote epidermal morphogenesis than those containing Fr. These data emphasize the complexity of dermal fibroblast biology and document the specific functional properties of Fp and Fr. Our results suggest a new model of skin aging in which marked alterations of Fp may affect the histological characteristics of skin

Biology of human hair: Know your hair to control it

Hair can be engineered at different levels—its structure and surface—through modification of its constituent molecules, in particular proteins, but also the hair follicle (HF) can be genetically altered, in particular with the advent of siRNA-based applications. General aspects of hair biology are reviewed, as well as the most recent contributions to understanding hair pigmentation and the regulation of hair development. Focus will also be placed on the techniques developed specifically for delivering compounds of varying chemical nature to the HF, indicating methods for genetic/biochemical modulation of HF components for the treatment of hair diseases. Finally, hair fiber structure and chemical characteristics will be discussed as targets for keratin surface functionalization

The perceived well-being and health costs of exiting self-employment

We explore how involuntary and voluntary exits from self-employment affect life and health satisfaction. To that end, we use rich longitudinal data from the German Socio-Economic Panel from 1985 to 2017 and a difference-in-differences estimator. We find that while transitioning from self-employment to salaried employment brings small improvements in health and life satisfaction, the negative psychological costs of business failure (i.e., switching from self-employment to unemployment) are substantial and exceed the costs of involuntarily losing a salaried job. Meanwhile, leaving self-employment has no consequences for self-reported physical health and behaviors such as smoking and drinking, implying that the costs of losing self-employment are mainly psychological. Moreover, former business owners fail to adapt to an involuntary self-employment exit even 2 or more years after this traumatic event. Our findings imply that policies encouraging entrepreneurship should also carefully consider the nonmonetary implications of business failure

Das Sozio-oekonomische Panel (SOEP): Multidisziplinäres Haushaltspanel und Kohortenstudie für Deutschland – Eine Einführung (für neue Datennutzer) mit einem Ausblick (für erfahrene Anwender)

SOEP, Biographische Erhebung, Haushaltspanel, Paneldesign, Kohortenstudie, Lebensverlauf, Stichprobenziehung, Hochrechnung, Datenstruktur, Service, SOEP, Biographical survey, Household panel, Panel design, Cohort study, Life course, Life span, Sampling procedure, Weighting, Data structure, Service,