Fifty-kDa Hyaluronic Acid Upregulates Some Epidermal Genes without Changing TNF-α Expression in Reconstituted Epidermis

Background: Due to its strong water binding potential, hyaluronic acid (HA) is a well-known active ingredient for cosmetic applications. However, based on its varying molecular size, skin penetration of HA may be limited. Recent studies have demonstrated that low-molecular-weight HA (LMW HA) may show a certain proinflammatory activity. We thus aimed to characterize an LMW-sized HA molecule that combines strong anti-aging abilities with efficient skin penetration but lacks potential proinflammatory effects. Methods: Total RNA and total protein were isolated from reconstituted human epidermis following incubation with HAs of various molecular weights (20, 50, 130, 300, 800 and 1,500 kDa). Tumor necrosis factor-alpha expression was determined using quantitative PCR. Genonnic and proteomic expression of various junctional proteins was determined using Affymetrix and common Western blotting techniques. Results: LMW HA of approximately 50 kDa did not significantly alter tumor necrosis factor-alpha expression compared to 20-kDa HA, but revealed significantly higher skin penetration rates than larger sized HA associated with increased expression of genes and proteins known to be involved in tight junction formation and keratinocyte cohesion. Conclusion: LMW HA of approximately 50 kDa shows better penetration abilities than larger-sized HA. In addition, LMW HA influences the expression of various genes including those contributing to keratinocyte differentiation and formation of intercellular tight junction complexes without showing proinflammatory activity. These observations contribute to current knowledge on the effects of LMW HA on keratinocyte biology and cutaneous physiology. Copyright (C) 2011 S. Karger AG, Base

A new method for the cytofluorometric analysis of mitochondrial membrane potential using the J-aggregate forming lipophilic cation 5,5’,6,6’-tetrachloro-1,1’,3,3’-tetraethylbenzim idazolcarbocyanine iodide (JC-1)

A new method for the cytofluorimetric analysis of mitochondrial membrane potential in intact cells has been developed by using the lipophilic cationic probe 5,5’,6,6’-tetrachloro-1,1’,3,3’-tetraethylbenzim idazolcarbocyanine iodide (JC-1), whose monomer emits at 527 nm after excitation at 490 nm. Depending on the membrane potential, JC-1 is able of forming J-aggregates that are associated with a large shift in emission (590 nm). The color of the dye changes reversibly from green to greenish orange as the mitochondrial membrane becomes more polarized. In two human cell lines (K562 and U937), we have studied by flow cytometry the changes in membrane potential provoked by the K+ ionophor valinomycin, a drug known to affect mitochondrial membrane potential, while the K+/H+ ionophor nigericin, known to affect intracellular pH but not mitochondrial membrane potential, was used as control. The incubation with valinomycin for 10 min. at 37°C in a low K+ medium provoked a marked and dose-dependent reduction in JC-1 greenish orange fluorescence, while nigericin had no effect. © 1993 Academic Press, Inc

Plasma lipoproteins in rats with experimental biliary obstruction. II. An ultrastructural study.

Acute biliary obstruction in the rat is associated with abnormalities of the ultrastructure of plasma lipoproteins. 1.1. The d < 1.006 g/ml fraction contains two types of particles: (a) vesicles having a mean diameter of 42.0 nm and (b) spheroidal particles which have a mean diameter of 80.0 nm. The latter show surface irregularities which make these particles appear as spherical bodies with holes.2.2. The d 1.019–1.063 g/ml fraction is heterogeneous. Gel filtration on 2% agarose allows the characterization of three components designated subfraction I, II and III respectively. Subfraction I is composed of large aggregates of spherical and vesicular particles. Subfraction II consists of 50.0–80.0 nm vesicles which show strong similarities to artificially prepared emulsions of phospholipids in water. Subfraction III contains particles which have a mean diameter of 20.0 nm and resemble low density lipoproteins of normal rats.3.3. The d 1.063–1.125 g/ml fraction contains 35.0 nm discoidal particles which tend to form ruleaux with a periodicity of 4.9 nm. This fraction also contains a few vesicles and 10.0 nm spherical particles similar to those found in the corresponding fraction of normal rat

The ultrastructure of rat plasma lipoproteins.

No abstract availabl

Effect of DL-penicillamine on the aorta of growing chickens. Ultrastructural and biochemical studies.

The effect of DL-penicillamine on the architecture of the aortic wall of growing chickens was studied, with particular attention to elastin and collagen. Penicillamine was added to the diet (0.2% and 0.4%, in the presence or not of 10 mg/kg CuSO4 and 100 mg/kg vitamin B6) from hatching, for periods from 7 days up to 2 months. The same regions of the thoracic aortas were examined and compared in all the different experimental conditions. The results showed that penicillamine induced relevant modifications in the process of elastin fibrogenesis. The alterations consisted of an increase of elastin in the extracellular space, associated with an increase in the number of elastin fibers per unit area, and a decrease of the mean profile area of the fibers. Interestingly, penicillamine induced the formation of numerous bundles of microfibrils associated or not with elastin fibers. After prolonged treatment, elastin tended to diminish and the fibers tended to fuse into polymorphic syncytia. Collagen fibrils were larger, showed more heterogeneous cross diameters, were less numerous, and were more spread out within the tissue. All the other components of the aortic wall appeared not to be altered by the chemical. Penicillamine did not modify the copper content of chick aortas, whereas it induced a 40-50% reduction of the activity of both salt and 4 M urea-soluble peptidyl lysyl oxidases in the same tissue. These data may help in understanding some of the pathologic manifestations in human beings during D-penicillamine treatment