Differential expression of peroxisome proliferator-activated receptor subtypes during the differentiation of human keratinocytes.
The expression of mRNA encoding peroxisome proliferator-activated receptor (PPAR) subtypes in human keratinocytes was determined by semiquantitative reverse transcriptase-polymerase chain reaction. When normal human keratinocytes were induced to differentiate by shifting the culture medium to high Ca2+ concentration, the expression of PPAR-alpha and -gamma mRNA was increased, whereas that of PPAR-delta remained unchanged. At the protein level, the expression of PPAR in cultured human keratinocytes was demonstrated by a DNA mobility shift assay and the functionality of the receptor subtypes was assessed by transactivation experiments. In epidermis reconstructed in vitro, the level of PPAR-alpha and -gamma mRNA was also associated with keratinocyte differentiation. In lesional compared with nonlesional psoriatic epidermis, the expression of PPAR-alpha and -gamma mRNA was reduced, indicating that these two subtypes are tightly linked to the epidermal differentiation process.
Rivier
M
M
CIRD GALDERMA, Sophia Antipolis, Valbonne, France.
Safonova
I
I
Lebrun
P
P
Griffiths
C E
CE
Ailhaud
G
G
Michel
S
S
D002454:Cell Differentiation / Q000235:genetics; D015870:Gene Expression; D006801:Humans; D015603:Keratinocytes / Q000737:chemistry / Q000166:cytology*; D011565:Psoriasis / Q000235:genetics / Q000473:pathology*; D012333:RNA, Messenger / Q000378:metabolism; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors / Q000235:genetics*; D015533:Transcriptional Activation
D012333:RNA, Messenger; D018160:Receptors, Cytoplasmic and Nuclear; D014157:Transcription Factors