Characterization of Calcium Translocation across the Plasma Membrane of Primary Osteoblasts Using a Lipophilic Calcium-sensitive Fluorescent Dye, Calcium Green C18

Lloyd, Qin P.; Kuhn, Michael; Gay, Carol V.

doi:10.1074/jbc.270.38.22445

Cited by 49 publications

(31 citation statements)

References 37 publications

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“…Each oscillation consists of an abrupt fall in the Mag-fura-2 ratio followed by a (usually incomplete) recovery, then a pause or refractory period before the beginning of the next oscillation. (20). This indicator consists of a highly hydrophilic calcium-green molecule conjugated to a lipophilic alkyl chain that will insert into biological membranes.…”

Section: Resultsmentioning

confidence: 99%

Inositol 1,4,5-Trisphosphate-dependent Oscillations of Luminal [Ca2+] in Permeabilized HSY Cells

Tanimura

Turner

1996

Journal of Biological Chemistry

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In many cell types, stimulation of receptors linked to phosphoinositide signaling pathways results in oscillations of intracellular calcium concentration ([Ca 2ϩ ] i ) due to the periodic release and reuptake of Ca 2ϩ by intracellular stores (1-4). These oscillations often take the form of "base-line spikes" in which periodic spikes of [Ca 2ϩ ] i rise from a base-line [Ca 2ϩ ] i which is close to resting levels. It has been suggested that [Ca 2ϩ ] i oscillations provide a sort of digital encoding of the receptor-mediated signal that may have certain advantages, such as noise reduction and decreased exposure to high intra- ] i such that small increases in [Ca 2ϩ ] i above resting levels would be expected to activate the channel, but large increases would be inhibitory. Several detailed mathematical analyses (9 -11) have demonstrated that a single intracellular Ca 2ϩ pool possessing IP 3 receptors with properties derived from these (and other) empirical measurements can produce [Ca 2ϩ ] i oscillations that closely resemble experimental observations. Thus these calculations substantiate the interesting possibility that [Ca 2ϩ ] i oscillations may occur solely as a result of the intrinsic properties of the IP 3 -sensitive Ca 2ϩ channel. Briefly, the underlying operation of these models is the following. A small initial rise in [Ca 2ϩ ] i due to IP 3 -dependent Ca 2ϩ release results in a rapid Ca 2ϩ -dependent increase in IP 3 -sensitive channel activity. This feed forward effect of Ca 2ϩ on its own release generates the upstroke of a [Ca 2ϩ ] i spike. At this high [Ca 2ϩ ] i a somewhat slower process of Ca 2ϩ feedback inhibition then results in channel closure. Ca 2ϩ reuptake into intracellular stores via the SERCA pump subsequently returns [Ca 2ϩ ] i to near base-line levels where Ca 2ϩ feedback inhibition is slowly relieved, followed by reactivation of IP 3 -induced Ca 2ϩ release and a repetition of the [Ca 2ϩ ] i oscillation cycle. To date experimental studies of [Ca 2ϩ ] i oscillations have utilized intact cells, making it difficult to definitively confirm or exclude the involvement of many intracellular processes in this phenomenon, and consequently complicating tests of proposed mechanisms. In the work presented here we extend these studies to permeabilized cells. For our experiments we have employed the HSY cells, a human salivary epithelial cell line (12) that has been found to be a useful model system for investigations of intracellular Ca 2ϩ signaling events (13-15). We have previously shown (15) that the luminal calcium concentration ([Ca 2ϩ ] L ) within the IP 3 -sensitive intracellular Ca 2ϩ stores of saponin-permeabilized HSY cells can be monitored with the fluorescent Ca 2ϩ indicator Mag-fura-2. Using this permeabi-* The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

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Section: Resultsmentioning

confidence: 99%

Inositol 1,4,5-Trisphosphate-dependent Oscillations of Luminal [Ca2+] in Permeabilized HSY Cells

Tanimura

Turner

1996

Journal of Biological Chemistry

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“…They also locate in the plasma membrane and indicate the changes in [Ca 2ϩ ] near the plasma membrane (231). However, calcium green C 18 has a high negative charge, which aligns indicators in the plasma membrane in the outward orientation.…”

Section: Calcium Green C 18 and Fura-indoline-c 18mentioning

confidence: 99%

Measurement of Intracellular Calcium

Takahashi

Camacho

Lechleiter

et al. 1999

Physiological Reviews

674

511

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To a certain extent, all cellular, physiological, and pathological phenomena that occur in cells are accompanied by ionic changes. The development of techniques allowing the measurement of such ion activities has contributed substantially to our understanding of normal and abnormal cellular function. Digital video microscopy, confocal laser scanning microscopy, and more recently multiphoton microscopy have allowed the precise spatial analysis of intracellular ion activity at the subcellular level in addition to measurement of its concentration. It is well known that Ca2+ regulates numerous physiological cellular phenomena as a second messenger as well as triggering pathological events such as cell injury and death. A number of methods have been developed to measure intracellular Ca2+. In this review, we summarize the advantages and pitfalls of a variety of Ca2+ indicators used in both optical and nonoptical techniques employed for measuring intracellular Ca2+ concentration.

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“…Vanadate and quercetin have been reported to inhibit the parathyroid hormone-stimulated PM Ca 2C pump activity in osteoblasts (Lloyd et al 1995). We investigated the effect of sodium orthovanadate on MA-10 cell steroidogenesis.…”

Section: Effects Of Vanadate On Quercetin-stimulated Steroidogenesismentioning

confidence: 99%

“…The expression of the StAR gene is regulated by numerous factors (Manna & Stocco 2005) and have been shown to be suppressed by 17b-estradiol in MA-10 cells (Houk et al 2004). Apart from their estrogenic effects, genistein (Sargeant et al 1993) and quercetin (Lloyd et al 1995) are potent tyrosine kinase inhibitors and have effects in the alteration of cytoplasm Ca 2C level. Resveratrol has been characterized as a nonspecific cyclooxygenase (COX) inhibitor (Murias et al 2004).…”

Section: Introductionmentioning

confidence: 99%

Effects of genistein, resveratrol, and quercetin on steroidogenesis and proliferation of MA-10 mouse Leydig tumor cells

Chen

Nagpal

Stocco

et al. 2007

Journal of Endocrinology

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This study was performed to compare the effects of three well-known phytoestrogens such as genistein, resveratrol, and quercetin on steroidogenesis in MA-10 mouse tumor Leydig cells. Addition of genistein or resveratrol to MA-10 cells resulted in decreases in the cAMP-stimulated progesterone secretion, but quercetin had an opposite response. Steroidogenic acute regulatory (StAR) mRNA expression and StAR promoter activity in transiently transfected MA-10 cells were significantly reduced by genistein or resveratrol, but increased by quercetin. Genistein was found to inhibit MA-10 cell proliferation, while resveratrol and quercetin had no effect. Quercetin-induced increase in cAMP-stimulated progesterone secretion was reversed by ICI 182,780, an estrogen receptor (ER) antagonist. However, ICI 182,780 had no effect on cAMP plus quercetin-stimulated StAR promoter activity. To examine whether non-ER factors are associated with quercetin-stimulated progesterone production, we treated MA-10 cells with EGTA to deprive them of extracellular Ca 2C. We found that EGTA inhibited quercetin-plus cAMP-stimulated progesterone secretion and StAR promoter activity. Blocking of Ca 2C influx through L-or Ttype voltage-gated Ca 2C channels with verapamil or mibefradil respectively, attenuated quercetin-stimulated progesterone secretion, while they had no effect on quercetinplus cAMP-stimulated StAR promoter activity. Blocking of intracellular Ca 2C efflux by sodium orthovanadate, a Ca 2C -pump inhibitor, blocked quercetin-plus cAMP-stimulated progesterone secretion and StAR promoter activity in MA-10 cells. Finally, EGTA or vanadate reduced quercetin and cAMP-increased in StAR mRNA expression in MA-10 cells, while ICI 182,780 had no effect. Taken together, these results indicate that phytoestrogens have differential effects on steroidogenesis in MA-10 cells.

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Characterization of Calcium Translocation across the Plasma Membrane of Primary Osteoblasts Using a Lipophilic Calcium-sensitive Fluorescent Dye, Calcium Green C18

Cited by 49 publications

References 37 publications

Inositol 1,4,5-Trisphosphate-dependent Oscillations of Luminal [Ca2+] in Permeabilized HSY Cells

Inositol 1,4,5-Trisphosphate-dependent Oscillations of Luminal [Ca2+] in Permeabilized HSY Cells

Measurement of Intracellular Calcium

Effects of genistein, resveratrol, and quercetin on steroidogenesis and proliferation of MA-10 mouse Leydig tumor cells

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