TY - JOUR
T1 - Phosphatidylserine efflux and intercellular fusion in a BeWo model of human villous cytotrophoblast
AU - Das, M.
AU - Xu, B.
AU - Lin, L.
AU - Chakrabarti, S.
AU - Shivaswamy, V.
AU - Rote, N. S.
N1 - Funding Information:
The authors would like to thank Ms Patricia Glazebrook and Dr Diana Kunze for assistance in confocal microscopy. This work was supported by a US Public Health Services Award HD23697 from the National Institute of Child Health and Human Development and a grant from the MetroHealth Foundation.
PY - 2004/5
Y1 - 2004/5
N2 - Phosphatidylserine (PS) efflux characterizes cytotrophoblast apoptosis and differentiation. To evaluate whether PS externalization and intercellular fusion were secondary to apoptosis, BeWo cells were induced to differentiate by forskolin or undergo apoptosis by staurosporine. PS externalization was measured by FITC-annexin V binding, and intercellular fusion was quantified by counting nuclei in syncytial cells. During forskolin treatment, vanadate decreased PS efflux by 78.0 per cent from 68.0 [5.3] (mean [SD] to 15.0 [8.8] Lum ( × 103) (P< 0.001), whereas Z-VAD-fmk had no effect (66.5 [7.3]). Vanadate decreased intercellular fusion from 78.1 per cent [4.1] fusion in uninhibited cultures to 23.4 per cent [2.5], compared with 10.0 per cent [1.7] in media alone. Z-VAD-fmk did not affect fusion (80.4 per cent [6.8]). Staurosporine induced PS efflux was not affected by vanadate (69.6 [5.5] Lum × 103), but was inhibited 87.8 per cent by Z-VAD-fmk; from 71.5 [6.2] to 8.7 [3.6] Lum ( × 103) (P<0.001). Apoptosis was measured by the TUNEL and COMET assays, lamin B fragmentation, activation of procaspase 3, mitochondrial membrane potential, and release of mitochondrial cytochrome c and apoptosis inducing factor. There was no indication of apoptosis associated with differentiation. Thus, PS efflux and intercellular fusion occurred through a vanadate-sensitive mechanism that was independent of apoptosis.
AB - Phosphatidylserine (PS) efflux characterizes cytotrophoblast apoptosis and differentiation. To evaluate whether PS externalization and intercellular fusion were secondary to apoptosis, BeWo cells were induced to differentiate by forskolin or undergo apoptosis by staurosporine. PS externalization was measured by FITC-annexin V binding, and intercellular fusion was quantified by counting nuclei in syncytial cells. During forskolin treatment, vanadate decreased PS efflux by 78.0 per cent from 68.0 [5.3] (mean [SD] to 15.0 [8.8] Lum ( × 103) (P< 0.001), whereas Z-VAD-fmk had no effect (66.5 [7.3]). Vanadate decreased intercellular fusion from 78.1 per cent [4.1] fusion in uninhibited cultures to 23.4 per cent [2.5], compared with 10.0 per cent [1.7] in media alone. Z-VAD-fmk did not affect fusion (80.4 per cent [6.8]). Staurosporine induced PS efflux was not affected by vanadate (69.6 [5.5] Lum × 103), but was inhibited 87.8 per cent by Z-VAD-fmk; from 71.5 [6.2] to 8.7 [3.6] Lum ( × 103) (P<0.001). Apoptosis was measured by the TUNEL and COMET assays, lamin B fragmentation, activation of procaspase 3, mitochondrial membrane potential, and release of mitochondrial cytochrome c and apoptosis inducing factor. There was no indication of apoptosis associated with differentiation. Thus, PS efflux and intercellular fusion occurred through a vanadate-sensitive mechanism that was independent of apoptosis.
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U2 - 10.1016/j.placenta.2003.11.004
DO - 10.1016/j.placenta.2003.11.004
M3 - Article
C2 - 15081634
AN - SCOPUS:1942539923
SN - 0143-4004
VL - 25
SP - 396
EP - 407
JO - Placenta
JF - Placenta
IS - 5
ER -