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Functional Consequences of a Neutral pH in Neonatal Rat Stratum Corneum.

Authors :
Fluhr, Joachim W.
Mao-Qiang, Man
Brown, Barbara E.
Hachem, Jean-Pierre
Moskowitz, David G.
Demerjian, Marianne
Haftek, Marek
Serre, Guy
Crumrine, Debra
Mauro, Theodora M.
Elias, Peter M.
Feingold, Kenneth R.
Source :
Journal of Investigative Dermatology. Jul2004, Vol. 123 Issue 1, p140-151. 12p.
Publication Year :
2004

Abstract

At birth, neonatal stratum corneum (SC) pH is close to neutral but acidifies with maturation, which can be ascribed, in part, to secretory phospholipase A2 and sodium/hydrogen antiporter 1 (NHE1) activities. Here we assessed the functional consequences of a neutral SC pH in a newborn rat model. While basal transepidermal water loss rates are near normal, barrier recovery (BR) rates after acute barrier disruption were delayed in newborn animals. The abnormality in barrier homeostasis could be improved by topical applications of an acidic buffer, indicating that barrier abnormality is primarily due to high SC pH. The delay in BR correlated with incompletely processed lamellar membranes and decreased activity of beta-glucocerebrosidase. Inhibition of NHE1 delayed BR after acute barrier perturbation. SC integrity was abnormal in newborn animals. Electron microscopy demonstrated decreased corneodesmosomes (CD) in newborn animals with decreased expression of desmoglein 1 and corneodesmosin. Serine protease activation appears to be responsible for CD degradation in newborn animals, because serine protease activity is increased in the SC and it can be reduced by acidification of the SC. The delay in acidification of neonatal SC results in abnormalities in permeability barrier homeostasis and SC integrity and are likely due to pH-induced modulations in enzyme activity. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
0022202X
Volume :
123
Issue :
1
Database :
Academic Search Index
Journal :
Journal of Investigative Dermatology
Publication Type :
Academic Journal
Accession number :
13416680
Full Text :
https://doi.org/10.1111/j.0022-202X.2004.22726.x