ABSTRACT
BACKGROUND: Extracellular matrix protein 1 (ECM1) is a secreted protein expressed in skin. Its dermatological relevance has been highlighted by the discovery of loss-of-function mutations in ECM1 in patients with lipoid proteinosis (LiP). OBJECTIVES: To determine the role of ECM1 in epidermal differentiation by examining gene and protein expression of epidermal differentiation markers in individuals with LiP and histological assessment of transgenic mouse skin that overexpresses Ecm1a in basal or suprabasal epidermis. METHODS: Subconfluent, confluent and postconfluent LiP and control keratinocyte cultures were analysed by Northern and Western blotting for differences in expression of differentiation markers. Expression of these markers was analysed in skin of patients with LiP by immunohistochemistry. To study effects of Ecm1 overexpression on epidermal differentiation, transgenic mice were generated under control of either a keratin 14 or an involucrin promoter. RESULTS: No differential expression of the different markers analysed was observed in LiP keratinocytes compared with controls. No histological differences were found in Ecm1-overexpressing mouse skin compared with wild-type. CONCLUSIONS: Absence of ECM1 does not lead to differences in epidermal differentiation. Moreover, overexpression of Ecm1a in vivo does not exert dramatic effects on epidermal structure. Collectively, these findings suggest no role of ECM1 in epidermal differentiation.
Subject(s)
Epidermis/pathology , Extracellular Matrix Proteins/physiology , Lipoid Proteinosis of Urbach and Wiethe/pathology , Adult , Animals , Cell Differentiation , Cells, Cultured , Extracellular Matrix Proteins/genetics , Extracellular Matrix Proteins/metabolism , Humans , Keratinocytes/metabolism , Lipoid Proteinosis of Urbach and Wiethe/metabolism , Mice , Mice, Transgenic , Mutation , Skin/metabolism , Skin/pathologyABSTRACT
The simplified Hb A2 determination based on microchromatography in Pasteur pipets filled with DEAE-cellulose with glycine-KCN-NaCl as developers [14] is compared with a reference Hb A2 determination procedure based on starch-block electrophoresis. The utility of microchromatography as a routine Hb A2 assay and as a screening method to detect beta-thalassemia trait carriers and patients with iron deficiency anemia was investigated. Day-to-day variation of a control hemolysate and the correlation between the values obtained with the two methods and between determinations in duplicate on the same sample are given. The mean values obtained with both methods for the different groups do not differ significantly but the standard deviations and the coefficients of variation observed by the microchromatography are generally higher. Microchromatography in Pasteur pipets tends to overestimate low and normal Hb A2 concentrations and to underestimate high Hb A2 concentrations. The results of microchromatography are more significant for the diagnosis when Hb A2 concentrations are expressed in weight hemoglobin per volume of blood and not in percentages. The microchromatographic procedure was recently marketed. The results obtained with the commercial columns were in good correlation with those obtained with starch-block electrophoresis, but commercial columns give a 18% overestimation of the Hb A2 concentrations.