Abstract
The effect of angiotensin II (Ang II) on Ca2+ signalling in human primary cultured breast epithelial cells was investigated by using fura-2 as the Ca2+ probe. Ang II (0.1-1000 nM) induced an intracellular free calcium ([Ca2+]i) transient peak which was unchanged by external Ca2+ removal. In Ca2+-free medium pretreatment with thapsigargin abolished Ang II-induced Ca2+ release. Suppression of 1,4,5-inositol trisphosphate formation by U73122, a phospholipase C inhibitor, blocked the Ang II-induced Ca2+ response. Losartan (DuP753), an inhibitor of Ang II type I receptor (AT1), decreased the [Ca2+]i increase evoked by Ang II, while CGP4221A, an inhibitor of Ang II type II receptor (AT2) did not. AT1 desensitisation was demonstrated with respect to the Ca2+ response after subsequent exposure of cells to Ang II and also after pretreatment for 25 min with 1000 nM phorbol 12-myristate 13-acetate. Staurosporine, an inhibitor of protein kinases C (PKC), inhibited the AT1 desensitisation. Epithelial breast cells expressed PKC-α, -β1, -δ and -ζ isozymes, and Ang II provoked translocation from the cytosol to the membranes of PKC-α, -β1, and -δ (but not -ζ). Ang II was also able to stimulate cell proliferation in a dose-dependent manner; this effect was blocked by Gö 6976, a specific inhibitor of PKC-α and -β1, the Ca2+-dependent isozymes. The main conclusion of this study is that the the Ang II signalling mechanism in breast epithelial cells is based on the elevation of [Ca2+]i released from intracellular stores through AT1 activation. In addition, Ang II stimulates cell proliferation by the activation of PKC isozymes.
| Original language | English |
|---|---|
| Pages (from-to) | 205-214 |
| Number of pages | 10 |
| Journal | Journal of Endocrinology |
| Volume | 174 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - Aug 2002 |
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ASJC Scopus subject areas
- Endocrinology
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Activation of angiotensin II type I receptor promotes protein kinase C translocation and cell proliferation in human cultured breast epithelial cells. / Greco, S.; Muscella, A.; Elia, M. G.; Salvatore, P.; Storelli, C.; Marsigliante, S.
In: Journal of Endocrinology, Vol. 174, No. 2, 08.2002, p. 205-214.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Activation of angiotensin II type I receptor promotes protein kinase C translocation and cell proliferation in human cultured breast epithelial cells
AU - Greco, S.
AU - Muscella, A.
AU - Elia, M. G.
AU - Salvatore, P.
AU - Storelli, C.
AU - Marsigliante, S.
PY - 2002/8
Y1 - 2002/8
N2 - The effect of angiotensin II (Ang II) on Ca2+ signalling in human primary cultured breast epithelial cells was investigated by using fura-2 as the Ca2+ probe. Ang II (0.1-1000 nM) induced an intracellular free calcium ([Ca2+]i) transient peak which was unchanged by external Ca2+ removal. In Ca2+-free medium pretreatment with thapsigargin abolished Ang II-induced Ca2+ release. Suppression of 1,4,5-inositol trisphosphate formation by U73122, a phospholipase C inhibitor, blocked the Ang II-induced Ca2+ response. Losartan (DuP753), an inhibitor of Ang II type I receptor (AT1), decreased the [Ca2+]i increase evoked by Ang II, while CGP4221A, an inhibitor of Ang II type II receptor (AT2) did not. AT1 desensitisation was demonstrated with respect to the Ca2+ response after subsequent exposure of cells to Ang II and also after pretreatment for 25 min with 1000 nM phorbol 12-myristate 13-acetate. Staurosporine, an inhibitor of protein kinases C (PKC), inhibited the AT1 desensitisation. Epithelial breast cells expressed PKC-α, -β1, -δ and -ζ isozymes, and Ang II provoked translocation from the cytosol to the membranes of PKC-α, -β1, and -δ (but not -ζ). Ang II was also able to stimulate cell proliferation in a dose-dependent manner; this effect was blocked by Gö 6976, a specific inhibitor of PKC-α and -β1, the Ca2+-dependent isozymes. The main conclusion of this study is that the the Ang II signalling mechanism in breast epithelial cells is based on the elevation of [Ca2+]i released from intracellular stores through AT1 activation. In addition, Ang II stimulates cell proliferation by the activation of PKC isozymes.
AB - The effect of angiotensin II (Ang II) on Ca2+ signalling in human primary cultured breast epithelial cells was investigated by using fura-2 as the Ca2+ probe. Ang II (0.1-1000 nM) induced an intracellular free calcium ([Ca2+]i) transient peak which was unchanged by external Ca2+ removal. In Ca2+-free medium pretreatment with thapsigargin abolished Ang II-induced Ca2+ release. Suppression of 1,4,5-inositol trisphosphate formation by U73122, a phospholipase C inhibitor, blocked the Ang II-induced Ca2+ response. Losartan (DuP753), an inhibitor of Ang II type I receptor (AT1), decreased the [Ca2+]i increase evoked by Ang II, while CGP4221A, an inhibitor of Ang II type II receptor (AT2) did not. AT1 desensitisation was demonstrated with respect to the Ca2+ response after subsequent exposure of cells to Ang II and also after pretreatment for 25 min with 1000 nM phorbol 12-myristate 13-acetate. Staurosporine, an inhibitor of protein kinases C (PKC), inhibited the AT1 desensitisation. Epithelial breast cells expressed PKC-α, -β1, -δ and -ζ isozymes, and Ang II provoked translocation from the cytosol to the membranes of PKC-α, -β1, and -δ (but not -ζ). Ang II was also able to stimulate cell proliferation in a dose-dependent manner; this effect was blocked by Gö 6976, a specific inhibitor of PKC-α and -β1, the Ca2+-dependent isozymes. The main conclusion of this study is that the the Ang II signalling mechanism in breast epithelial cells is based on the elevation of [Ca2+]i released from intracellular stores through AT1 activation. In addition, Ang II stimulates cell proliferation by the activation of PKC isozymes.
UR - http://www.scopus.com/inward/record.url?scp=0036686836&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0036686836&partnerID=8YFLogxK
U2 - 10.1677/joe.0.1740205
DO - 10.1677/joe.0.1740205
M3 - Article
C2 - 12176659
AN - SCOPUS:0036686836
VL - 174
SP - 205
EP - 214
JO - Journal of Endocrinology
JF - Journal of Endocrinology
SN - 0022-0795
IS - 2
ER -