Document Detail


Expression of lysosome-associated membrane protein 1 (Lamp-1) and galectins in human keratinocytes is regulated by differentiation.
MedLine Citation:
PMID:  16710742     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Lysosomes and their components are suspected to be involved in epidermal differentiation. In this study, lysosomal enzyme activities, expression of the lysosome-associated membrane protein 1 (Lamp-1) and expression of the epidermal galectins-1, -3 and -7 were investigated in human keratinocytes cultured at different cell densities (subconfluence, confluence and postconfluence) in order to induce differentiation. Detected by Western blot and immunofluorescence, Lamp-1 expression is transiently upregulated at culture confluence, but reduced at postconfluence. Northern blot analyses performed on subconfluent, confluent and post-confluent cultures of keratinocytes show that Lamp-1 mRNA expression is also upregulated at culture confluence, but downregulated at postconfluence. Measurements of lysosomal enzyme activities indicate a transient upregulation at culture confluence, whereas cathepsins B, C and L are particularly downregulated at postconfluence. Cell density and differentiation of epidermal cells also differentially regulates galectin expression in autocrine cultures. As the expression of galectin-1 mRNA is high in subconfluent cells, it is assumed to be associated with their proliferative state. On the other hand, as the mRNA levels for galectins-3 and -7 are notably upregulated at culture confluence (galectin-7) or at postconfluence (galectin-3), their expression is thought to be related to the differentiated state of keratinocytes. However, we collected evidence by confocal microscopy that galectin-3 and Lamp-1 do not colocalize in vitro in keratinocytes. Altogether, our results suggest that the upregulated Lamp-1 expression at confluence could be involved in keratinocyte differentiation, but apparently not through interaction with galectin-3.
Authors:
Victoria Sarafian; Ralph Jans; Yves Poumay
Publication Detail:
Type:  Journal Article     Date:  2006-04-22
Journal Detail:
Title:  Archives of dermatological research     Volume:  298     ISSN:  0340-3696     ISO Abbreviation:  Arch. Dermatol. Res.     Publication Date:  2006 Jul 
Date Detail:
Created Date:  2006-05-19     Completed Date:  2007-08-06     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  8000462     Medline TA:  Arch Dermatol Res     Country:  Germany    
Other Details:
Languages:  eng     Pagination:  73-81     Citation Subset:  IM    
Affiliation:
Department of Histologie-Embryologie, Facultés Universitaires Notre-Dame de la Paix, 61, Rue de Bruxelles, 5000, Namur, Belgium.
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MeSH Terms
Descriptor/Qualifier:
Base Sequence
Cell Count
Cell Differentiation
Cells, Cultured
DNA Primers / genetics
Galectins / genetics*,  metabolism*
Gene Expression Regulation
Humans
Keratinocytes / cytology*,  metabolism*
Lysosome-Associated Membrane Glycoproteins / genetics*,  metabolism*
Lysosomes / metabolism
RNA, Messenger / genetics,  metabolism
Chemical
Reg. No./Substance:
0/DNA Primers; 0/Galectins; 0/LAMP1 protein, human; 0/Lysosome-Associated Membrane Glycoproteins; 0/RNA, Messenger

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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