Regulation of parathyroid hormone-related protein gene expression by epidermal growth factor-family ligands in primary human keratinocytes

Autor: Thomas J. Rosol, Todd Gocken, Yong-Mee Cho, Dan F. Spandau, Raymond L. Konger, Virgile Richard, Peter F Koltz, John Foley, Davina A. Lewis
Rok vydání: 2004
Předmět:
Adult
Keratinocytes
MAPK/ERK pathway
EGF Family of Proteins
medicine.medical_specialty
Endocrinology
Diabetes and Metabolism
Biology
Amphiregulin
Endocrinology
Bacterial Proteins
Epidermal growth factor
Internal medicine
Gene expression
medicine
Humans
RNA
Messenger
Cells
Cultured
Glycoproteins
Messenger RNA
Reporter gene
Expression vector
Epidermal Growth Factor
Parathyroid hormone-related protein
Reverse Transcriptase Polymerase Chain Reaction
Infant
Newborn
Parathyroid Hormone-Related Protein
Antibodies
Monoclonal
Genes
erbB-1
Transforming Growth Factor alpha
Molecular biology
ErbB Receptors
Gene Expression Regulation
Dactinomycin
Quinazolines
Intercellular Signaling Peptides and Proteins
Epidermis
Cell Division
hormones
hormone substitutes
and hormone antagonists
Heparin-binding EGF-like Growth Factor
Signal Transduction
Zdroj: Journal of Endocrinology. 181:179-190
ISSN: 1479-6805
0022-0795
DOI: 10.1677/joe.0.1810179
Popis: Cultured primary human keratinocytes were the first non-cancer-derived cell type reported to produce the humoral hypercalcemia factor, parathyroid hormone-related protein (PTHrP). Emerging evidence suggests that only a subset of keratinocytes produce high levels of PTHrP in vivo. We found that the PTHrP mRNA content of intact human skin was minimal, whereas transcripts were easily detectable in primary keratinocytes derived from those skin samples. We hypothesized that conditions associated with growth in culture activated PTHrP gene expression in primary keratinocytes. In culture, keratinocytes produce a number of epidermal growth factor (EGF)-like ligands (transforming growth factor-alpha, heparin binding-EGF and amphiregulin) and their receptor, ErbB1. Treatment of keratinocytes with a specific erbB1 inhibitor (PD153035) reduced PTHrP mRNA levels by >80% in rapidly growing keratinocytes. Treatment of keratinocytes with reagents that neutralize amphiregulin reduced PTHrP mRNA levels by approximately 60%. Blockade of erbB1 signaling reduces transcription from the endogenous PTHrP P3-TATA promoter. The Ets transcription factor-binding site, 40 bases upstream of the P3 promoter, is required for baseline expression of PTHrP reporter gene constructs in keratinocytes; in addition, cotransfection of Ets-1 and Ets-2 expression vectors activate the reporter gene constructs. Finally, disruption of both ras and raf signaling reduce reporter gene expression by 80%, suggesting that ErbB1 signaling is mediated by the classic ras/MAP kinase pathway. These findings suggest that acquisition of EGF-like ligand expression has the potential to substantially activate PTHrP gene expression in the epidermis.
Databáze: OpenAIRE
Externí odkaz: