TGF-alpha and TGF-beta expression during sodium-N-butyrate-induced differentiation of human keratinocytes: evidence for subpopulation-specific up-regulation of TGF-beta mRNA in suprabasal cells.
Sodium-N-butyrate (NaB) induces terminal differentiation and cornified envelope formation in cultured human keratinocytes. In the present study we explored the question of whether NaB-induced maturation could be mediated through changes in TGF-alpha and TGF-beta expression in normal keratinocytes. NaB induced a four-fold increase in TGF-beta mRNA transcript levels. This increase in TGF-beta mRNA abundance occurred only within the nonbasal keratinocyte subpopulation which maximally responds to NaB treatment by progression to cornified envelopes. Basal keratinocytes, which are relatively refractive to cornified envelope formation, did not show any increase in TGF-beta mRNA abundance after NaB treatment. By comparison, TGF-alpha mRNA transcript and extracellular TGF-alpha protein levels were unaffected by NaB treatment. A 50% decrease in EGF receptor binding was observed in NaB-treated keratinocyte cultures, rendering the cells less responsive to proliferation induction.
Staiano-Coico
L
L
Department of Surgery, New York Hospital-Cornell Medical Center, New York 10021.
Khandke
L
L
Krane
J F
JF
Sharif
S
S
Gottlieb
A B
AB
Krueger
J G
JG
Heim
L
L
Rigas
B
B
Higgins
P J
PJ
D002087:Butyrates / Q000494:pharmacology*; D020148:Butyric Acid; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D066246:ErbB Receptors / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D015870:Gene Expression / Q000187:drug effects / Q000502:physiology; D006801:Humans; D007150:Immunohistochemistry; D015603:Keratinocytes / Q000166:cytology* / Q000378:metabolism / Q000648:ultrastructure; D008233:Lymphotoxin-alpha / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D012333:RNA, Messenger / Q000187:drug effects / Q000235:genetics; D014158:Transcription, Genetic / Q000187:drug effects / Q000502:physiology; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D015854:Up-Regulation / Q000187:drug effects / Q000235:genetics / Q000502:physiology
D002087:Butyrates; D008233:Lymphotoxin-alpha; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D020148:Butyric Acid; D066246:ErbB Receptors