Changes In Stratum Corneum Lipids Research Articles

Changes in skin barrier during treatment with systemic alitretinoin: focus on skin susceptibility and stratum corneum ceramides

Alitretinoin is a new drug for systemic treatment of chronic hand eczema. Previous functional tests of skin topically treated with retinoids have indicated impaired skin barrier function, but no data are available on barrier parameters after systemic alitretinoin treatment. To investigate the effect of systemic alitretinoin on skin barrier function and response to irritants, a secondary objective was to determine if changes occur in the lipid profile of stratum corneum after treatment with systemic alitretinoin. We conducted an open clinical intervention study on eight people ascribed to systemic alitretinoin treatment. The criteria for being ascribed to alitretinoin were chronic hand eczema and insufficient therapeutic response to potent topical corticosteroids. Before initiation and after 2 months of systemic treatment with 30 mg alitretinoin, a challenge with sodium lauryl sulphate (SLS) was performed on the volar forearm and evaluated by trans-epidermal water loss (TEWL), erythema, and a cyanoacrylate skin sample was obtained for lipid analysis. We found no significant changes in response to SLS irritation as evaluated by TEWL and erythema, after treatment with alitretinoin for 2 months. No significant changes in stratum corneum lipids were found after 2 months of treatment. In conclusion, systemic alitretinoin does not influence skin susceptibility to irritants or the ceramide profile of stratum corneum.

Conformational Changes in Stratum Corneum Lipids by Effect of Bicellar Systems

Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy was applied to study the effects of the bicelles formed by dimyristoyl-glycero-phosphocholine (DMPC) and dihexanoyl-glycero-phosphocholine (DHPC) in porcine stratum corneum (SC) in vitro. A comparison of skin samples treated and untreated with bicelles at different temperatures was carried out. The analysis of variations after treatment in the position of the symmetric CH2 stretching, CH2 scissoring, and CH2 rocking vibrations reported important information about the effect of bicelles on the skin. Bicellar systems caused a phase transition from the gel or solid state to the liquid crystalline state in the lipid conformation of SC, reflecting the major order-disorder transition from hexagonally packed to disordered chains. Grazing incidence small and wide X-ray scattering (GISAXS and GIWAXS) techniques confirmed this effect of bicelles on the SC. These results are probably related to with the permeabilizing effect previously described for the DMPC/DHPC bicelles.

Stratum corneum lipids in skin xerosis.

Lipids of the stratum corneum are implicated in cohesion and desquamation of the stratum corneum as well as in the maintenance of normal barrier function. Evidence linking the intercellular lipids to such processes has mainly been derived from studies on acquired or inherited diseases of lipid metabolism manifesting abnormalities in the structure and the function of the stratum corneum. We have studied the composition of stratum corneum lipids in clinically normal individuals with typical xerosis or 'winter dry skin' in order to establish if the lipid composition differs from that of normal individuals, showing no signs of xerosis. The amount of total stratum corneum lipids was not related to xerosis (22.0 +/- 1.8 micrograms/cm2 for normal skin, and 26.3 +/- 2.9 micrograms/cm2 for severe xerosis), and no correlation was evident between polar lipids, cholesterol sulfate (2.8 +/- 0.5% for normal skin, and 1.6 +/- 0.2% for severe xerosis), or ceramides types I-VI, and dry skin. It therefore appears that dramatic changes in stratum corneum lipids are not detectable in normal 'winter dry' skin. However, a decreased proportion of neutral lipids (sterol esters, triglycerides), coupled to increased amounts of free fatty acids, were found associated to the severity of dry skin. Apart from a decline in the sebaceous function and in esterases activity, winter dry skin does not appear to be associated to dramatic changes in polar stratum corneum lipids.

Age-associated changes in stratum corneum lipids and their relation to dryness.

Stratum corneum lipids (SCL) were collected on the right and left legs of 50 subjects of varying ages and skin dryness. The level of dryness and composition of the lipid was the same on both sides. While skin dryness continuously increased with age, the composition of SCL showed a constant profile from the 50s. Aging was mostly associated with a decrease in sterol esters and triglycerides. On the legs, the SCL do not seem to primarily govern the increased desquamative process which features xerosis.