TY - JOUR
T1 - Intracellular calcium oscillations in cell populations of ras- transfected I-7 subline of human HaAaT keratinocytes
AU - Shi, B.
AU - Isseroff, Roslyn Rivkah
PY - 1997
Y1 - 1997
N2 - We have observed oscillations of intracellular Ca2+ (Ca(i)) concentration in populations of ras-transfected HaCaT keratinocytes of I-7 subline. In postconfluent monolayers of I-7 keratinocytes, an increase in extracellular Ca2+ (Ca(o)) concentration to 0.25-0.5 mM induced sinusoidal Ca(i) oscillations, which persisted longer than 1 h with amplitudes of 50- 150 nM and periods of 5-10 min. Thapsigargin, which depletes internal Ca2+ stores, did not prevent Cat-induced Ca(i) oscillations, and it also induced Ca(i) oscillations in the ras-transfected I-7 line. Removal of extracellular Ca2+ or addition of Ca2+-entry blocker La3+ or SKandF 96365 inhibited Ca(i) oscillations, suggesting that Ca(i) oscillations in ras-transfected HaCaT keratinocytes were dependent on Ca2+ influx across the plasma membrane. Because the Ca(o)-induced Ca(i) oscillations have been observed only in ras-transfected I-7 subline and not in its nontransfected parental HaCaT line, this may provide a partial explanation for the divergent responses of ras-transfected and nontransfected keratinocytes to Ca(o) signal for control of growth and differentiation.
AB - We have observed oscillations of intracellular Ca2+ (Ca(i)) concentration in populations of ras-transfected HaCaT keratinocytes of I-7 subline. In postconfluent monolayers of I-7 keratinocytes, an increase in extracellular Ca2+ (Ca(o)) concentration to 0.25-0.5 mM induced sinusoidal Ca(i) oscillations, which persisted longer than 1 h with amplitudes of 50- 150 nM and periods of 5-10 min. Thapsigargin, which depletes internal Ca2+ stores, did not prevent Cat-induced Ca(i) oscillations, and it also induced Ca(i) oscillations in the ras-transfected I-7 line. Removal of extracellular Ca2+ or addition of Ca2+-entry blocker La3+ or SKandF 96365 inhibited Ca(i) oscillations, suggesting that Ca(i) oscillations in ras-transfected HaCaT keratinocytes were dependent on Ca2+ influx across the plasma membrane. Because the Ca(o)-induced Ca(i) oscillations have been observed only in ras-transfected I-7 subline and not in its nontransfected parental HaCaT line, this may provide a partial explanation for the divergent responses of ras-transfected and nontransfected keratinocytes to Ca(o) signal for control of growth and differentiation.
KW - Ca(i) homeostasis
KW - Ca signal
KW - Cell growth and differentiation
KW - Thapsigargin
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M3 - Article
C2 - 9406818
AN - SCOPUS:0031450867
VL - 109
SP - 765
EP - 769
JO - Journal of Investigative Dermatology
JF - Journal of Investigative Dermatology
SN - 0022-202X
IS - 6
ER -