Extraction and translation of collagen mRNA from fetal calf skin

peer reviewedRNA was extracted from fetal calf skin by two different procedures, using phenol or guanidine hydrochloride. Poly(A)-rich RNA was separated by oligo(dT)-cellulose affinity chromatography and was further fractionated by sucrose density gradient centrifugation. When translated in an optimized wheat germ extract cell-free system, unfractionated guanidine-hydrochloride-extracted poly(A)-rich RNA directed the synthesis of two collagenase-sensitive protein bands, while phenol-extracted poly(A)-rich RNA with a sedimentation coefficient higher than 25 S was the only fraction to direct the same synthesis. On the basis of their electrophoretic mobility on a sodium dodecylsulfate/urea/polyacrylamide gel, these proteins were identified with procollagen alpha 1(I) and procollagen alpha 2. Inhibition of translation by phenol-extracted poly(A)-rich RNA with a sedimentation coefficient lower than 25 S was also observed. Guanidine-hydrochloride-extracted poly(A)-rich RNA from fetal skin directed the synthesis of three distinct collagenase-sensitive proteins in the micrococcal-nuclease-digested rabbit reticulocyte cell-free system; these seemed to correspond to procollagen alpha 1(I), procollagen alpha 2 and procollagen alpha 1 (III)

What are subcutaneous adipocytes really good for…?

Our acute awareness of the cosmetic, psychosocial and sexual importance of subcutaneous adipose tissue contrasts dramatically with how poorly we have understood the biology of this massive, enigmatic, often ignored and much‐abused skin compartment. Therefore, it is timely to recall the exciting, steadily growing, yet underappreciated body of evidence that subcutaneous adipocytes are so much more than just ‘fat guys’, hanging around passively to conspire, at most, against your desperate attempts to maintain ideal weight. Although the subcutis, quantitatively, tends to represent the dominant architectural component of human skin, conventional wisdom confines its biological key functions to those of energy storage, physical buffer, thermoregulation and thermoinsulation. However, already the distribution of human superficial adipose tissue, by itself, questions how justified the popular belief is that ‘skin fat’ (which actually may be more diverse than often assumed) serves primarily thermoinsulatory purposes. And although the metabolic complications of obesity are well appreciated, our understanding of how exactly subcutaneous adipocytes contribute to extracutaneous disease – and even influence important immune and brain functions! – is far from complete. The increasing insights recently won into subcutaneous adipose tissue as a cytokine depot that regulates innate immunity and cell growth exemplarily serve to illustrate the vast open research expanses that remain to be fully explored in the subcutis. The following public debate carries you from the evolutionary origins and the key functional purposes of adipose tissue, via adipose‐derived stem cells and adipokines straight to the neuroendocrine, immunomodulatory and central nervous effects of signals that originate in the subcutis – perhaps, the most underestimated tissue of the human body. The editors are confident that, at the end, you shall agree: No basic scientist and no doctor with a serious interest in skin, and hardly anyone else in the life sciences, can afford to ignore the subcutaneous adipocyte – beyond its ample impact on beauty, benessence and body mass