Abstract
Normal human keratinocytes are stimulated to proliferate in serum-free medium containing subphysiological concentrations of calcium (0.09 mM, low calcium). In this study, we examined the effect of increased levels of extracellular calcium (2.0 mM, normal calcium) on UVB-induced apoptosis. Apoptosis was assessed by changes in cellular morphology, annexind V-FITC flow cytometry, and the formation of internucleosomal DNA ladders. High doses of UVB induced keratinocytes grown in low calcium medium to undergo apoptosis. In contrast, keratinocytes grown for 72 h in normal calcium medium were completely resistant to UVB-induced apoptosis. No apoptosis was observed even at UVB doses as high as 1200 J/m2. However, despite the lack of UVB-induced cell death, keratinocytes grown in normal calcium medium lost the ability to proliferate following high levels of UVB irradiation. High doses of UVB also increased the expression of the differentiation-specific proteins involucrin and cytokeratin 10 in a dose-dependent manner. In addition, growth in normal calcium medium lowered the UVB-induced stimulation of the p53 protein and altered the normal subcellular localization pattern of p53. UVB irradiation of human keratinocytes grown in normal calcium medium may be inducing further cell differentiation in the absence of overt cell death.
| Original language | English |
|---|---|
| Pages (from-to) | 37-46 |
| Number of pages | 10 |
| Journal | Archives of Dermatological Research |
| Volume | 291 |
| Issue number | 1 |
| DOIs | |
| State | Published - 1999 |
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Keywords
- Apoptosis
- Calcium
- Keratinocyte
- p53
- UVB
ASJC Scopus subject areas
- Dermatology
Cite this
Subphysiological concentrations of extracellular calcium sensitize normal human keratinocytes to UVB-induced apoptosis. / Kumar, Manish G.; Hurwitz, Steven A.; Cotton, Jenny; Spandau, Dan.
In: Archives of Dermatological Research, Vol. 291, No. 1, 1999, p. 37-46.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Subphysiological concentrations of extracellular calcium sensitize normal human keratinocytes to UVB-induced apoptosis
AU - Kumar, Manish G.
AU - Hurwitz, Steven A.
AU - Cotton, Jenny
AU - Spandau, Dan
PY - 1999
Y1 - 1999
N2 - Normal human keratinocytes are stimulated to proliferate in serum-free medium containing subphysiological concentrations of calcium (0.09 mM, low calcium). In this study, we examined the effect of increased levels of extracellular calcium (2.0 mM, normal calcium) on UVB-induced apoptosis. Apoptosis was assessed by changes in cellular morphology, annexind V-FITC flow cytometry, and the formation of internucleosomal DNA ladders. High doses of UVB induced keratinocytes grown in low calcium medium to undergo apoptosis. In contrast, keratinocytes grown for 72 h in normal calcium medium were completely resistant to UVB-induced apoptosis. No apoptosis was observed even at UVB doses as high as 1200 J/m2. However, despite the lack of UVB-induced cell death, keratinocytes grown in normal calcium medium lost the ability to proliferate following high levels of UVB irradiation. High doses of UVB also increased the expression of the differentiation-specific proteins involucrin and cytokeratin 10 in a dose-dependent manner. In addition, growth in normal calcium medium lowered the UVB-induced stimulation of the p53 protein and altered the normal subcellular localization pattern of p53. UVB irradiation of human keratinocytes grown in normal calcium medium may be inducing further cell differentiation in the absence of overt cell death.
AB - Normal human keratinocytes are stimulated to proliferate in serum-free medium containing subphysiological concentrations of calcium (0.09 mM, low calcium). In this study, we examined the effect of increased levels of extracellular calcium (2.0 mM, normal calcium) on UVB-induced apoptosis. Apoptosis was assessed by changes in cellular morphology, annexind V-FITC flow cytometry, and the formation of internucleosomal DNA ladders. High doses of UVB induced keratinocytes grown in low calcium medium to undergo apoptosis. In contrast, keratinocytes grown for 72 h in normal calcium medium were completely resistant to UVB-induced apoptosis. No apoptosis was observed even at UVB doses as high as 1200 J/m2. However, despite the lack of UVB-induced cell death, keratinocytes grown in normal calcium medium lost the ability to proliferate following high levels of UVB irradiation. High doses of UVB also increased the expression of the differentiation-specific proteins involucrin and cytokeratin 10 in a dose-dependent manner. In addition, growth in normal calcium medium lowered the UVB-induced stimulation of the p53 protein and altered the normal subcellular localization pattern of p53. UVB irradiation of human keratinocytes grown in normal calcium medium may be inducing further cell differentiation in the absence of overt cell death.
KW - Apoptosis
KW - Calcium
KW - Keratinocyte
KW - p53
KW - UVB
UR - http://www.scopus.com/inward/record.url?scp=0033045639&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0033045639&partnerID=8YFLogxK
U2 - 10.1007/s004030050381
DO - 10.1007/s004030050381
M3 - Article
VL - 291
SP - 37
EP - 46
JO - Archives of Dermatological Research
JF - Archives of Dermatological Research
SN - 0340-3696
IS - 1
ER -