| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland 21201; and 2 Division of Pulmonary and Critical Care Medicine, Department of Medicine, School of Medicine, University of California, San Diego, California 92103
 |
ABSTRACT |
|---|
 TOP
 ABSTRACT
 INTRODUCTION
MATERIALS AND METHODS
RESULTS
DISCUSSION
REFERENCES
|
|---|
A rise in cytosolic Ca2+ concentration ([Ca2+]cyt) due to Ca2+ release from intracellular Ca2+ stores and Ca2+ influx through plasmalemmal Ca2+ channels plays a critical role in mitogen-mediated cell growth. Depletion of intracellular Ca2+ stores triggers capacitative Ca2+ entry (CCE), a mechanism involved in maintaining Ca2+ influx and refilling intracellular Ca2+ stores. Transient receptor potential (TRP) genes have been demonstrated to encode the store-operated Ca2+ channels that are activated by Ca2+ store depletion. In this study, we examined whether CCE, activity of store-operated Ca2+ channels, and human TRP1 (hTRP1) expression are essential in human pulmonary arterial smooth muscle cell (PASMC) proliferation. Chelation of extracellular Ca2+ and depletion of intracellularly stored Ca2+ inhibited PASMC growth in media containing serum and growth factors. Resting [Ca2+]cyt as well as the increases in [Ca2+]cyt due to Ca2+ release and CCE were all significantly greater in proliferating PASMC than in growth-arrested cells. Consistently, whole cell inward currents activated by depletion of intracellular Ca2+ stores and the mRNA level of hTRP1 were much greater in proliferating PASMC than in growth-arrested cells. These results suggest that elevated [Ca2+]cyt and intracellularly stored [Ca2+] play an important role in pulmonary vascular smooth muscle cell growth. CCE, potentially via hTRP1-encoded Ca2+-permeable channels, may be an important mechanism required to maintain the elevated [Ca2+]cyt and stored [Ca2+] in human PASMC during proliferation.
transient receptor potential gene; pulmonary hypertension; pulmonary artery smooth muscle cells
| |
INTRODUCTION |
|---|
|
TOP
ABSTRACT
INTRODUCTION
MATERIALS AND METHODS
RESULTS
DISCUSSION
REFERENCES
|
|---|
PULMONARY ARTERIAL PRESSURE is the function of cardiac
output and pulmonary vascular resistance. Pulmonary vasoconstriction and vascular medial hypertrophy (due to smooth muscle cell
proliferation) greatly contribute to the increased pulmonary vascular
resistance in patients with primary pulmonary hypertension (PPH), a
fatal disease with an unknown cause (31, 38). Studies from
patients with essential hypertension demonstrate that, at the cellular level, blood pressure (BP) is directly proportional to cytosolic free
Ca2+ concentration ([Ca2+]cyt),
which is determined primarily by extracellular Ca2+
concentration ([Ca2+]o) and intracellularly
stored Ca2+ ([Ca2+]SR) in the
sarcoplasmic reticulum (SR): BP 
k[Ca2+]cyt = k(f [Ca2+]o + g[Ca2+]SR), where k,
f, and g are proportionality factors
(30). Hypertension is then a progressive disease
manifested clinically by elevated blood pressure and cellularly
by, at least in part, an excessive [Ca2+]cyt in vascular smooth muscle cells and
an improper balance of extracellular [Ca2+] and
[Ca2+]SR (30). A common
hypothesis is that vasoconstriction and cell proliferation, two linked
phenomena in the etiology of PPH (31), use overlapping
signaling processes that result in parallel intracellular events
(35, 38).
Intracellular Ca2+ is a critical signal transduction element in regulating muscle contraction (34), gene expression (8, 19), and cell proliferation (6, 16, 28). Because Ca2+ diffuses rapidly between the cytosol and nucleus (1), an increase in [Ca2+]cyt activates Ca2+-dependent events occurring in both the cytosol and nucleus. A variety of mitogenic agents stimulate cell growth by increasing [Ca2+]cyt (6, 16, 23, 28, 32). The mitogen-mediated changes in [Ca2+]cyt usually consist of initial Ca2+ release from the SR followed by sustained Ca2+ entry through sarcolemmal Ca2+ channels. Depletion of Ca2+ from the SR due to the agonist-induced Ca2+ release triggers Ca2+ influx through store-operated Ca2+ channels (SOCs) in the plasma membrane, namely capacitative Ca2+ entry (CCE) (29). Therefore, CCE is a mechanism that links [Ca2+]SR to membrane Ca2+ permeability (4, 27) and serves as an important pathway to refill intracellular Ca2+ stores and maintain sustained Ca2+ influx (27). A novel gene family, transient receptor potential (TRP) genes, which are essential for agonist-activated CCE, have recently been cloned in mammals and humans (hTRP) (4, 39, 44, 45). Expression of TRP genes has been demonstrated to form the Ca2+-permeable cation channels that are activated by Ca2+ store depletion. This suggests that the TRP-encoded proteins may be the putative channels responsible for CCE (4, 5, 37, 40, 44, 45).
In vascular smooth muscle cells, sustained Ca2+ influx and maintaining sufficient Ca2+ in the SR are both required for cell growth (15, 33). Indeed, removal of extracellular Ca2+ and depletion of the SR Ca2+ significantly inhibited cell growth (33). This study was designed to test the hypothesis that CCE, potentially through TRP-encoded Ca2+-permeable channels, is an important mechanism to maintain the elevated [Ca2+]cyt and [Ca2+]SR that are necessary for human pulmonary arterial smooth muscle cell (PASMC) proliferation.
| |
MATERIALS AND METHODS |
|---|
|
TOP
ABSTRACT
INTRODUCTION
MATERIALS AND METHODS
RESULTS
DISCUSSION
REFERENCES
|
|---|
Cell preparation and culture. Patients undergoing lobectomy for bronchogenic carcinoma and lung/heart transplantation for cardiopulmonary diseases, who had no evidence of pulmonary hypertension, were the source of control lung tissues for preparing primary cultured PASMC. In some cases, patients undergoing lung transplantation with PPH or secondary pulmonary hypertension (SPH; e.g., patients with congenital heart disease and pulmonary thromboembolic disease) were the source of diseased lung tissues. Lung tissues were removed from patients in the operating room and immediately placed in cold (4°C) saline and taken to the laboratory for dissection (41).
Small muscular intrapulmonary arteries were isolated and incubated for 20 min in Hank's balanced salt solution containing 2 mg/ml collagenase (Worthington). After the incubation, the adventitia was carefully stripped off, and the endothelium was removed. Remaining smooth muscle was digested with 2.0 mg/ml collagenase (Worthington), 0.5 mg/ml elastase, and 1 mg/ml bovine albumin (Sigma) at 37°C. Single PASMC were resuspended, plated onto 25-mm cover slips (for fluorescence microscopy and electrophysiological experiments) or 10-cm Petri dishes (for molecular biological experiments), and incubated in a humidified atmosphere of 5% CO2 in air at 37°C (41). The cells were cultured in smooth muscle growth medium (Clonetics), which consisted of smooth muscle basal medium, 5% fetal bovine serum, 5 µg/ml insulin, 2 ng/ml human fibroblast growth factor, and 0.5 ng/ml human endothelial growth factor (Clonetics), for 5-7 days before each experiment. In some experiments, normal human PASMC (Clonetics) were used at passages 4-6. The cells were stained with the membrane-permeable nucleic acid stain 4',6'-diamidino-2-phenylindole (5 µM, Molecular Probes). All the 4',6'-diamidino-2-phenylindole-stained cells in the cultures cross-reacted with the smooth muscle cell
-actin antibody,
indicating that the cultures consisted only of smooth muscle cells.
There were no significant morphological differences between the cells
cultured in media with or without serum and growth factors. Cell counts
were determined using a hemocytometer. The viable cell number
normalized by size of the Petri dishes (in cells/cm2) was
used to compare cell growth rate.
Measurement of [Ca2+]cyt. The cells were loaded in culture medium containing the acetoxymethyl ester form of fura 2 (fura 2-AM; 3 µM, Molecular Probes) for 30 min at room temperature under an atmosphere of 5% CO2 in air (10). The fura 2-loaded cells were then superfused with standard bath solution for 30 min at 32-34°C to wash away extracellular dye and permit intracellular esterases to cleave cytosolic fura 2-AM into active fura 2. Fura 2 fluorescence (510-nm emission; 380- and 360-nm excitation) from the cells and background fluorescence were imaged using a GEN III charge-coupled device camera (Stanford Photonics) coupled to a Carl Zeiss microscope. Fluorescent images were obtained using a microchannel plate image intensifier (Amperex XX1381) coupled by fiber optics to the charged-coupled device camera. Image acquisition and analysis were performed with a MetaMorph imaging system (Universal Imaging). Video frames containing images of fura 2 fluorescence from cells, as well as the corresponding background images (fluorescence from fields devoid of cells), were digitized at a resolution of 512 horizontal × 480 vertical pixels and an 8-bit grey scale using a Matrix LC imaging board operating in an IBM-compatible PC. To improve the signal-to-noise ratio, four to eight consecutive video frames were usually averaged at a video frame rate of 30 frames/s. Images were acquired at a rate of one averaged image every 3 s when [Ca2+]cyt was changing and every 60 s when [Ca2+]cyt was stable. [Ca2+]cyt was calculated from fura 2 fluorescent emission excited at 380 and 360 nm using the ratio method (11). In most experiments, multiple (6-10) cells were imaged in single field, and one arbitrarily chosen peripheral cytosolic area (4-6 × 4-6 pixels) from each cell was spatially averaged.
Measurement of Ca2+ release-activated
Ca2+ currents.
Whole cell and single-channel Ca2+ release-activated
Ca2+ currents (ICRAC) were recorded
with an Axopatch-1D amplifier and a DigiData 1200 interface (Axonpatch)
using patch-clamp techniques (12). Patch pipettes
(2-4 M
) were fabricated on a Sutter electrode puller using
borosilicate glass tubes and fire polished on a microforge (Narishige).
For whole cell current recordings, voltage stimuli lasting 300 ms were
delivered from a holding potential of 0 mV (to inactivate voltage-gated
Ca2+ and Na+ channels) using voltage steps from
+80 mV to 
80 mV. Traces recorded before the activation of SOCs were
used as a template to subtract leak currents. All experiments were
performed at room temperature (22-24°C). In both whole cell and
single-channel configurations, SOCs were activated by passive depletion
of the SR using 10 µM cyclopiazonic acid (CPA; Sigma) dissolved in
the Ca2+-free solution.
Solution and reagents.
For [Ca2+]cyt measurement experiments, the
cells were superfused (2-3 ml/min) with physiological salt
solution (PSS). The PSS contained (in mM) 141 NaCl, 4.7 KCl, 1.8 CaCl2, 1.2 MgCl2, 10 HEPES, and 10 glucose (pH
7.4 with 5 M NaOH). The bath solution for recording whole cell
ICRAC contained (in mM) 120 sodium methane sulfonate, 20 calcium aspartate, 0.5 3,4-diaminopyridine, 10 glucose, and 10 HEPES (pH 7.4 with methane sulfonic acid). The pipette (intracellular) solution contained (in mM) 138 cesium aspartate, 1.15 EGTA, 1 Ca(OH)2, 2 Na2ATP, and 10 HEPES (pH
7.2). These ionic conditions eliminated the currents through
K+ or Cl
channels. In Ca2+-free
PSS, CaCl2 was replaced by equimolar MgCl2, and
1 mM EGTA was added to chelate residual Ca2+. In the
high-K+ (40 mM) solution, NaCl was replaced, mole-for-mole,
by KCl to maintain the osmolarity of the solution. For cell-attached
recording of single-channel ICRAC, the pipette
(extracellular) solution contained (in mM) 120 sodium methane
sulfonate, 20 calcium aspartate, 0.5 3,4-diaminopyridine, and 10 HEPES
(pH 7.4 with methane sulfonic acid). The bath (extracellular) solution
contained (in mM) 141 NaCl, 4.7 KCl, 1.2 MgCl2, 1.8 CaCl2, 10 glucose, and 10 HEPES (pH 7.4).
RT-PCR assay.
Total RNA (2-3 µg) prepared from the cells by the acid
guanidinium thiocyanate-phenol-chloroform
extraction method, was reverse-transcribed using the
First-Strand cDNA synthesis kit (Pharmacia Biotech). The
sense/antisense primers were designed from coding regions of
hTRP1 [5'-CAAGATTTTGGAAAATTTCTTG-3' (nt.
2,338-2,359)/5'-TTTGTCTTCATGATTTGCTAT-3' (nt. 2,689-2,709);
U31110]; hTRP3 [5'-TGACTTCCGTTGTGCTCAAATATG-3' (nt.
2,316-2339)/5'-TCTGAAGCCTTCTCCTTCTGC-3' (nt. 2,610-2,633); Y13758], and the human voltage-dependent Ca2+ channel
(VDCC) 
2-subunit [5'-TGGTGGATAGGGCGATTGGT-3' (nt.
808-827)/5'-TGCGTGCTTACTGGGATTGTT-3' (nt. 1336-1356);
U95019], respectively. The first-strand cDNA reaction mixture (2 µl)
was used in a 50-µl PCR reaction consisting of 0.1 µM of each
primer, 10 mM Tris · HCl (pH 8.3), 50 mM KCl, 2 mM
MgCl2, 200 µN of each dNTP, and 2 units of Taq DNA
polymerase (Perkin-Elmer). The cDNA samples were amplified in a DNA
thermal cycler (Perkin-Elmer) under the following conditions: the
mixture was annealed at 50-61°C (for 1 min), extended at 72°C
(for 2 min), and denatured at 94°C (for 1 min) for 25 cycles. This
was followed by a final extension at 72°C (for 10 min) to ensure
complete product extension. The PCR products were electrophoresed
through a 1% agarose gel, and amplified cDNA bands were visualized by
ethidium bromide staining. The PCR product was sequenced, and the
result indicated that the sequence of our PCR product using the sense and antisense primers designed for hTRP1 matched exactly
with the hTRP1 sequence (U31110) in GenBank. To quantify the
PCR products, an invariant mRNA of human -actin was used as an
internal control. The OD value for each band on the gel was measured by a Gel Documentation System (UVP). The OD values in the channel signals
were normalized to the OD values in the -actin signals; the ratios
are expressed as arbitrary units for quantitative comparison.
Statistical analysis. The composite data are expressed as means ± SE. Statistical analyses were performed using unpaired Student's t-test or ANOVA and post hoc tests (Student Newman-Keuls) where appropriate. Differences were considered to be significant when P < 0.05.
| |
RESULTS |
|---|
|
TOP
ABSTRACT
INTRODUCTION
MATERIALS AND METHODS
RESULTS
DISCUSSION
REFERENCES
|
|---|
Requirement of extracellular Ca2+ and intracellularly
stored Ca2+ for PASMC growth.
A rise in [Ca2+]cyt can activate cytoplasmic
mitogen-activated protein kinase (6) (which is part of the
phosphorylation cascade that leads to activation of DNA
synthesis-promoting factor), rapidly increase nuclear
[Ca2+] (1), and promote cell proliferation
(22). The addition of 2 mM EDTA, a Ca2+
chelator, to the culture medium (which contains 1.6 mM
Ca2+) decreases the free [Ca2+] to 59 µM
(9) and significantly inhibited human PASMC growth in
media containing 5% fetal bovine serum and growth factors (Fig. 1). Depletion of intracellular
Ca2+ stores (mainly the SR) with 1 µM thapsigargin
further inhibited proliferation of human PASMC cultured in media
containing 2 mM EDTA (Fig. 1). These results demonstrate that a
sustained Ca2+ influx through sarcolemmal Ca2+
channels and sufficient [Ca2+] maintained within the SR
(33) are both required for PASMC growth.
|
Increased resting [Ca2+]cyt and CCE in proliferating PASMC. Withdrawal of serum and growth factors from culture media abolished cell growth (Fig. 1). This indicates that the cells cultured in smooth muscle basal medium (without serum and growth factors) are growth-arrested cells, whereas the cells cultured in smooth muscle growth medium (smooth muscle basal medium supplemented with 5% fetal bovine serum and growth factors) are proliferating cells.
In the absence of extracellular Ca2+, CPA, by blocking Ca2+ sequestration into the SR, induced a transient [Ca2+]cyt rise due to leakage of Ca2+ from the SR to the cytosol. The CPA-induced [Ca2+]cyt transient declined back to the original baseline level after 5-7 min as the SR Ca2+ was depleted. Under these conditions, restoration of extracellular Ca2+ induced a rise in [Ca2+]cyt, which was obviously due to CCE (Fig. 2A)
|
Inhibitory effects of Ni2+ on CCE and PASMC growth.
Blockade of L-type VDCC with nifedipine (1 µM) abolished the 40 mM
K+-induced increase in [Ca2+]cyt
but had little effect on the CCE-mediated increase in
[Ca2+]cyt (Fig.
3A, top). CCE is
largely determined by the conductance of SOCs when the transmembrane
Ca2+ electrochemical gradient is constant. Ni2+
has been demonstrated to block SOCs (46). Indeed,
Ni2+ (0.5 mM) or SKF-96365 (10 µM) (7)
significantly attenuated CCE in proliferating PASMC in the presence of
nifedipine (Fig. 3A). Accordingly, treatment of the cells
with 0.5 mM Ni2+ for 2 days significantly diminished human
PASMC growth in media containing serum and growth factors (Fig.
3B).
|
Increased SOC activity in proliferating PASMC.
The flux of Ca2+ ions through SOCs has been defined
electrophysiologically as ICRAC (14, 17,
18, 20, 27). Whole cell ICRAC were
recorded in cells superfused with solutions containing 120 mM
Na+ and 20 mM Ca2+ and dialyzed with solutions
containing 138 mM Cs+ and ~100 nM free Ca2+.
Holding potential was set at 0 mV to inactivate voltage-gated Na+ and Ca2+ channels. Whole cell
ICRAC were elicited by 300-ms voltage steps from
80 to +80 mV before and after application of 10 µM CPA (Fig. 4A). Subtracting the currents
recorded under control conditions from the currents recorded after
10-15 min application of CPA revealed ICRAC
that were activated by CPA-induced depletion of the SR Ca2+
(Fig. 4A, right). The inward current was
apparently carried by Ca2+ (and Na+), and the
outward current was carried by Cs+ (Cs permeability = Na
permeability for SOCs) (2, 17, 18).
|
80 mV, were 252 ± 69 pA in proliferating cells and 33 ± 12 pA in growth-arrested cells (Fig. 4B, right). Extracellular application
of Mg2+ (2 mM), which has been demonstrated to inhibit CCE
in vascular smooth muscle cells (2, 10), significantly
reduced whole cell ICRAC in both growth-arrested
(by 16 ± 2% at +80 mV, P < 0.01) and
proliferating (by 22 ± 2%, P < 0.01) PASMC.
Single-channel ICRAC were recorded in
cell-attached patches from proliferating PASMC using the ionic
conditions under which inward Ca2+ (or Na+)
currents could be displayed at negative holding potentials for the
patches. While the cell was held at 45 mV, application of 10 µM CPA
(for 4-8 min) gradually induced a small amplitude inward current
that was apparently carried by Ca2+ (or Na+)
through SOCs (Fig. 5A). The
slope conductance of this current, calculated from the current-voltage
relationship curve, is 5.34 pS (Fig. 5B).
|
Enhanced hTRP1 expression in proliferating PASMC.
It has been demonstrated that TRP-encoded proteins may be
responsible for CCE (4, 5, 37, 44, 45). Human PASMC from
nonpulmonary hypertension patients expressed hTRP1 but not hTRP3 (Fig. 6A).
The mRNA level of hTRP1 was significantly higher in
proliferating cells than in growth-arrested cells (Fig. 6). The
enhanced mRNA expression was selective to hTRP1 because the mRNA level of the hVDCC 2-subunit was unaltered in
proliferating PASMC (Fig. 6B). These results are consistent
with the electrophysiological and fluorescence microscopy experiments
showing that ICRAC and CCE were enhanced in
human PASMC during proliferation.
|
Temporal relationship between hTRP1 expression and PASMC
proliferation.
Whether the mRNA expression of hTRP1 was temporally
related to the cell proliferation was examined by comparing the time
courses of the change of hTRP1 mRNA levels and the cell
growth rate. The cells were first growth arrested by incubation
in smooth muscle basal medium (the basal medium without serum and
growth factors) for 24-36 h and then cultured in smooth muscle
growth medium (smooth muscle basal muscle supplemented with 5% fetal
bovine serum and growth factors) for up to 4 days. As shown in Fig.
7, the cell number in culture dishes
(A) and the mRNA level of hTRP1 (B)
were both increased after incubating the cells in media containing serum (5% fetal bovine serum) and growth factors (smooth muscle growth
medium). However, the time courses are quite different (Fig.
7C): the mRNA expression of hTRP1 was
significantly increased after 6 h of incubation (by 10.1 ± 3.4%, P < 0.05) in the smooth muscle growth medium
(5% fetal bovine serum and growth factors), whereas the cell growth
was not significantly increased until 24 h (by 15.4 ± 2.4%,
P < 0.001) (Fig. 7C). The calculated times for the 50% increase in the hTRP1 mRNA expression and the
cell growth are 18.36 and 46.56 h, respectively (Fig. 7C).
These results suggest that enhancement of hTRP1 mRNA
expression precedes the onset of cell proliferation in the presence of
fetal bovine serum and growth factors. The precise temporal
relationship between hTRP1 expression and actual
proliferating process (e.g., different cell cycle phases) needs further
study.
|
Elevated resting [Ca2+]cyt and
[Ca2+]SR in growth-arrested PASMC from
patients with PPH.
Patients with SPH (n = 18) and PPH (n = 7), from whom PASMC were isolated, had similar mean pulmonary arterial
pressure (48 ± 4 vs. 53 ± 4 mmHg, P = 0.30)
and total vascular resistance (13.6 ± 3 vs. 11.2 ± 1.7 mmHg · l1 · min1,
P = 0.48) (41). However, the resting
[Ca2+]cyt in quiescent (growth arrested)
PASMC (n = 16) from PPH patients was significantly
higher than in cells (n = 19) from SPH patients (Fig.
8, A and
C).
|
| |
DISCUSSION |
|---|
|
TOP
ABSTRACT
INTRODUCTION
MATERIALS AND METHODS
RESULTS
DISCUSSION
REFERENCES
|
|---|
In human PASMC, chelation of extracellular Ca2+ and depletion of intracellularly stored Ca2+ markedly inhibited cell growth in media containing serum and growth factors, whereas resting [Ca2+]cyt was much higher in proliferating cells than in growth-arrested cells. These results imply that elevated [Ca2+]cyt and [Ca2+]SR, due to a constant Ca2+ influx, are necessary for human PASMC proliferation. CCE is a critical mechanism involved in maintaining sustained Ca2+ influx and refilling Ca2+ into the SR (4, 27, 36). Indeed, the CCE-mediated increase in [Ca2+]cyt, whole cell ICRAC, and hTRP1 mRNA expression were all significantly enhanced in PASMC during proliferation. Inhibition of SOCs with Ni2+ reduced CCE and significantly attenuated human PASMC growth. These results suggest that CCE, potentially through the upregulated hTRP1 expression and the resultant increase in ICRAC, is a critical mechanism required to maintain the elevated [Ca2+]cyt and [Ca2+]SR in PASMC during proliferation.
Regulation of cytosolic free [Ca2+].
In vascular smooth muscle cells, including PASMC,
[Ca2+]cyt is regulated by Ca2+
influx through Ca2+-permeable channels in the plasma
membrane and Ca2+ release from intracellular
Ca2+ stores, such as the sarco(endo)plasmic reticulum
(34, 36). Many vasoactive agonists stimulate smooth muscle
proliferation by increasing [Ca2+]cyt
(6, 16, 23, 28, 32). The mitogen-induced changes in
[Ca2+]cyt usually consist of an initial
release of Ca2+ from the SR followed by a sustained
Ca2+ influx through sarcolemmal Ca2+ channels.
In human PASMC, resting membrane potential is approximately 45 mV,
and resting [Ca2+]cyt is 50-150 nM. Thus
the observations that extracellular Ca2+ chelation
inhibited human PASMC growth imply that continuous Ca2+
influx is essential for human PASMC.
Molecular identification of CCE. Electrophysiological studies on the store depletion-activated ICRAC suggest that SOCs are complex and heterogeneous in molecular composition and in their cellular regulation (4). There are at least seven members (TRP1-TRP7) in the mouse TRP gene family, of which at least four (TRP1, TRP3, TRP4, and TRP6) have been identified in human tissues (4, 26, 44, 45). Expression of TRP genes results in the formation of the Ca2+-permeable cation channels that are activated by Ca2+ store depletion, suggesting that SOCs may be composed of subunits encoded in TRP genes (3-5, 25, 37, 44, 45). SOCs are hypothesized to be heterotetramers and/or homotetramers made of different TRPs (3, 4, 27). In mammalian tissues, it has been recently demonstrated that TRP1, TRP2, TRP4, and TRP5 may encode the endogenous SOCs that are activated by store depletion, whereas TRP3, TRP6, and TRP7 may encode the channels that are activated by inositol 1,4,5-trisphosphate (3, 4, 21, 26) and store depletion.
Patch-clamp studies on the store depletion-activated ICRAC indicate that there are multiple SOCs based on the single-channel conductance (0.2-110 pS) (14, 17, 18, 20, 27). In human PASMC, only the hTRP1 transcript (but not hTRP3 transcript) was identified using RT-PCR, suggesting that hTRP1 is a critical TRP gene that encodes SOCs in human PASMC. In proliferating PASMC, we observed a 5.34-pS channel that was activated by CPA-induced depletion of the SR Ca2+. These observations suggest that the 5.34-pS channel may be an important SOC that participates in regulating human PASMC growth.Role of Ca2+ in PASMC Proliferation. Cytosolic Ca2+ stimulates cell proliferation (22, 23, 28, 32), whereas [Ca2+]SR may regulate cell proliferation by modulating the amplitude and frequency of Ca2+ signals in the cytosol and nucleus (6, 8, 19, 33). Maintaining a sufficient level of Ca2+ in the SR is also critical for cell growth; indeed, depletion of the SR Ca2+ stores induces growth arrest (15, 33). In the cell cycle, there are four Ca2+-sensitive steps: transitions 1) from the G0 (resting state) to the G1 phase (the beginning of DNA synthesis); 2) from the G1 to the S phase (an interphase during which replication of the nuclear DNA occurs); 3) from the G2 to the M phase (mitosis); and 4) through the M phase (22). Thus a rise in [Ca2+]cyt plays a critical role in stimulating PASMC proliferation.
A critical signal transduction pathway upon activation of membrane receptors by mitogenic agonists is the increase in [Ca2+]cyt due to 1) Ca2+ release from the SR and 2) Ca2+ influx through sarcolemmal Ca2+ channels (4, 13, 32, 36). In human PASMC, CCE, potentially through hTRP1-encoded SOCs, is an important mechanism involved in 1) maintaining the sustained increase in [Ca2+]cyt and 2) refilling Ca2+ into the SR. Thus the expression of TRPs and the function of SOCs may play an important role in regulating PASMC growth via modulation of [Ca2+]cyt and [Ca2+]SR (10).Mechanisms involved in elevated [Ca2+]cyt
in PASMC from PPH patients.
Pulmonary vasoconstriction and vascular smooth muscle proliferation
greatly contribute to the increased pulmonary vascular resistance in
patients with PPH (31, 35, 38). Elevated pulmonary arterial pressure in patients with SPH is often caused by primary diseases, such as left to right shunt in congenital heart diseases and
vascular embolism in pulmonary thromboembolic disease. The results from
this study demonstrate that resting [Ca2+]cyt
and [Ca2+]SR are higher, and CCE is greater,
in PASMC from PPH patients than in the cells from SPH patients. These
data suggest that increases in [Ca2+]cyt and
[Ca2+]SR due to enhanced CCE may also play a
role in the development of pulmonary vascular smooth muscle
proliferation in patients with PPH (Fig.
9).
|
| |
ACKNOWLEDGEMENTS |
|---|
We thank S. S. McDaniel, Dr. Ying Yu, and S. Krick for excellent technical assistance.
| |
FOOTNOTES |
|---|
* Authors contributed equally to this work.
This work was supported by National Heart, Lung, and Blood Institute Grants HL-54043 and HL-64945 (to J. X.-J. Yuan) and by the American Heart Association, Mid-Atlantic Affiliate (to V. Golovina). J. X.-J. Yuan is an Established Investigator of the American Heart Association.
Present address of J. Wang: Div. of Gastroenterology, St. Joseph's Health Center, London, Ontario N6A 4V2, Canada.
Address for reprint requests and other correspondence: J. X.-J. Yuan, Dept. of Medicine, Univ. of California at San Diego, 200 West Arbor Dr., San Diego, California 92103-8382 (E-mail: xiyuan{at}ucsd.edu).
The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
Received 5 July 2000; accepted in final form 14 September 2000.
| |
REFERENCES |
|---|
|
TOP
ABSTRACT
INTRODUCTION
MATERIALS AND METHODS
RESULTS
DISCUSSION
REFERENCES
|
|---|
1.
Allbritton, NL,
Oancea E,
Kuhn MA,
and
Meyer T.
Source of nuclear calcium signals.
Proc Natl Acad Sci USA
91:
12458-12462,
1995
2.
Arnon, A,
Hamlyn JM,
and
Blaustein MP.
Na+ entry via store-operated channels modulates Ca2+ signaling in arterial myocytes.
Am J Physiol Cell Physiol
278:
C163-C173,
2000
3.
Berridge, MJ,
Lipp P,
and
Bootman MD.
The calcium entry pas de deux.
Science
287:
1604-1605,
2000
4.
Birnbaumer, L,
Zhu X,
Jiang M,
Boulay G,
Peyton M,
Vannier B,
Brown D,
Platano D,
Sadeghi H,
Stefani E,
and
Birnbaumer M.
On the molecular basis and regulation of cellular capacitative calcium entry: roles for Trp proteins.
Proc Natl Acad Sci USA
93:
15195-15202,
1996
5.
Boulay, G,
Brown DM,
Qing N,
Jiang M,
Dietrich A,
Zhu MX,
Chen Z,
Birnbaumer M,
Mikoshiba K,
and
Birnbaumer L.
Modulation of Ca2+ entry by polypeptides of the inositol 1,4,5-trisphosphate receptor (IP3R) that bind transient receptor potential (TRP): evidence for roles of TRP and IP3R in store depletion-activated Ca2+ entry.
Proc Natl Acad Sci USA
96:
14955-14960,
1999
6.
Chao, T-S,
Byron KL,
Lee KM,
Villereal M,
and
Rosner MR.
Activation of MAP kinase by calcium-dependent and calcium-independent pathways: Stimulation by thapsigargin and epidermal growth factor.
J Biol Chem
267:
19876-19883,
1992
7.
Doi, S,
Damron DS,
Horibe M,
and
Murray PA.
Capacitative Ca2+ entry and tyrosine kinase activation in canine pulmonary arterial smooth muscle cells.
Am J Physiol Lung Cell Mol Physiol
278:
L118-L130,
2000
8.
Dolmetsch, RE,
Lewis RS,
Goodnow CC,
and
Healy JI.
Differential activation of transcription factors induced by Ca2+ response amplitude and duration.
Nature
386:
855-858,
1997[Medline].
9.
Fabiato, A,
and
Fabiato F.
Calculator programs for computing the composition of the solutions containing multiple metals and ligands used for experiments in skinned muscle cells.
J Physiol (Paris)
75:
463-505,
1979[Medline].
10.
Golovina, VA.
Cell proliferation is associated with enhanced capacitative Ca2+ entry in human arterial myocytes.
Am J Physiol Cell Physiol
277:
C343-C349,
1999
11.
Grynkiewicz, G,
Poenie M,
and
Tsien RY.
A new generation of Ca2+ indicators with greatly improved fluorescence properties.
J Biol Chem
260:
3440-3450,
1985
12.
Hamill, OP,
Marty A,
Neher E,
Sakmann B,
and
Sigworth FJ.
Improved patch-clamp techniques for high-resolution current recording from cells and cell-free membrane patches.
Pfluegers Arch
391:
85-100,
1981[Web of Science][Medline].
13.
Hardingham, GE,
Chawla S,
Cruzalegui FH,
and
Bading H.
Control of recruitment and transcription-activating function of CBP determines gene regulation by NMDA receptors and L-type calcium channels.
Neuron
22:
789-798,
1999[Web of Science][Medline].
14.
Hoth, M,
and
Penner R.
Calcium release-activated calcium current in rat mast cells.
J Physiol (Lond)
465:
359-386,
1993
15.
Husain, M,
Bein K,
Jiang L,
Alper SL,
Simons M,
and
Rosenberg RD.
c-Myb-dependent cell cycle progression and Ca2+ storage in cultured vascular smooth muscle cells.
Circ Res
80:
617-626,
1997
16.
Kao, JPY,
Alderton JM,
Tsien RY,
and
Steinhardt RA.
Active involvement of Ca2+ in mitotic progression of Swiss 3T3 fibroblasts.
J Cell Biol
111:
183-196,
1990
17.
Kerschbaum, HH,
and
Cahalan MD.
Monovalent permeability, rectification, and ionic block of store-operated calcium channels in Jurkat T lymphocytes.
J Gen Physiol
111:
521-537,
1998
18.
Kerschbaum, HH,
and
Cahalan MD.
Single-channel recording of a store-operated Ca2+ channel in Jurkat T lymphocytes.
Science
283:
836-839,
1999
19.
Li, W-H,
Llopis J,
Whitney M,
Zlokarnic G,
and
Tsien RY.
Cell-permeant caged InsP3 ester shows that Ca2+ spike frequency can optimize gene expression.
Nature
392:
936-941,
1998[Medline].
20.
Luckhoff, A,
and
Clapham DE.
Calcium channels activated by depletion of internal calcium stores in A431 cells.
Biophys J
67:
177-182,
1994[Web of Science][Medline].
21.
Ma, H-T,
Patterson RL,
van Rossum DB,
Birnbaumer L,
Mikoshiba K,
and
Gill DL.
Requirement of the inositol trisphosphate receptor for activation of store-operated Ca2+ channels.
Science
287:
1647-1651,
2000
22.
Means, AR.
Calcium, calmodulin and cell cycle regulation.
FEBS Lett
347:
1-4,
1994[Web of Science][Medline].
23.
Negulescu, PAN,
Shastri N,
and
Cahalan MD.
Intracellular calcium dependence of gene expression in single T lymphocytes.
Proc Natl Acad Sci USA
91:
2873-2877,
1994
24.
Nelson, MT,
Patlak JB,
Worley JF,
and
Standen NB.
Calcium channels, potassium channels, and voltage dependence of arterial smooth muscle tone.
Am J Physiol Cell Physiol
259:
C3-C18,
1990
25.
Niemeyer, B,
Suzuki E,
Scott K,
Jalinik K,
and
Zuker CS.
The Drosophila light-activated conductance is composed of the two channels TRP and TRPL.
Cell
83:
651-659,
1996.
26.
Okada, T,
Inoue R,
Yamazaki K,
Maeda A,
Kurosaki T,
Yamakuni T,
Tanaka I,
Shimizu S,
Ikenaka K,
Imoto K,
and
Mori Y.
Molecular and functional characterization of a novel mouse transient receptor potential protein homologue TRP7: Ca2+ permeable cation channel that is constitutively activated and enhanced by stimulation of G protein-coupled receptor.
J Biol Chem
274:
27359-27370,
1999
27.
Parekh, AB,
and
Penner R.
Store depletion and calcium influx.
Physiol Rev
77:
901-930,
1997
28.
Pitt, BR,
Weng W,
Steve AR,
Blakely RD,
Reynolds I,
and
Davies P.
Serotonin increases DNA synthesis in rat proximal and distal pulmonary vascular smooth muscle cells in culture.
Am J Physiol Lung Cell Mol Physiol
266:
L178-L186,
1994
29.
Putney, JW, Jr.
A model for receptor-regulated calcium entry.
Cell Calcium
7:
1-12,
1986[Web of Science][Medline].
30.
Resnick, LM.
Divalent cations in essential hypertension.
In: Hypertension Primer: the Essentials of High Blood Pressure (2nd ed.), edited by Izzo JL, Jr,
and Black HR.. Dallas, TX: American Heart Association, 1999, p. 125-127.
31.
Rubin, LJ.
Primary pulmonary hypertension.
N Engl J Med
336:
111-117,
1997
32.
Sheng, M,
McFadden G,
and
Greenberg ME.
Membrane depolarization and calcium induce c-fos transcription via phosphorylation of transcription factor CREB.
Neuron
4:
571-582,
1990[Web of Science][Medline].
33.
Short, AD,
Bian J,
Ghosh TK,
Waldron RT,
Rybak SL,
and
Gill DL.
Intracellular Ca2+ pool content is linked to control of cell growth.
Proc Natl Acad Sci USA
90:
4986-4990,
1993
34.
Somlyo, AP,
and
Somlyo AV.
Signal transduction and regulation in smooth muscle.
Nature
372:
231-236,
1994[Medline].
35.
Stenmark, KR,
and
Mecham RP.
Cellular and molecular mechanisms of pulmonary vascular remodeling.
Annu Rev Physiol
59:
89-144,
1997[Web of Science][Medline].
36.
Tsien, RW,
and
Tsien RY.
Calcium channels, stores, and oscillations.
Annu Rev Cell Biol
6:
715-760,
1990[Web of Science].
37.
Vannier, B,
Peyton M,
Boulay G,
Brown D,
Qin N,
Jiang M,
Zhu X,
and
Birnbaumer L.
Mouse trp2, the homologue of the human trpc2 pseudogene, encodes mTrp2, a store depletion-activated capacitative Ca2+ entry channel.
Proc Natl Acad Sci USA
96:
2060-2064,
1999
38.
Wagenvoort, CA.
Vasoconstriction and medial hypertrophy in pulmonary hypertension.
Circulation
22:
535-546,
1960
39.
Wes, PD,
Chevesich J,
Jeromin A,
Rosenberg C,
Stetten G,
and
Montell C.
TRPC1, a human homolog of a Drosophila store-operated channel.
Proc Natl Acad Sci USA
92:
9652-9656,
1995
40.
Xu, X-Z S,
Li H-S,
Guggino WB,
and
Montell C.
Coassembly of TRP and TRPL produces a distinct store-operated conductance.
Cell
89:
1155-1164,
1997[Web of Science][Medline].
41.
Yuan, J X-J,
Aldinger AM,
Juhaszova M,
Wang J,
Conte JV,
Gaine SP,
Orens JB,
and
Rubin LJ.
Dysfunctional voltage-gated K+ channels in pulmonary artery smooth muscle cells of patients with primary pulmonary hypertension.
Circulation
98:
1400-1406,
1998
42.
Yuan, X-J.
Voltage-gated K+ currents regulate resting membrane potential and [Ca2+]i in pulmonary arterial myocytes.
Circ Res
77:
370-378,
1995
43.
Yuan, X-J,
Wang J,
Juhaszova M,
Gaine SP,
and
Rubin LJ.
Attenuated K+ channel gene transcription in primary pulmonary hypertension.
Lancet
351:
726-727,
1998[Web of Science][Medline].
44.
Zhu, X,
Jiang M,
Peyton M,
Boulay G,
Hurst R,
Stefani E,
and
Birnbaumer L.
Trp, a novel mammalian gene family essential for agonist-activated capacitative Ca2+ entry.
Cell
85:
661-671,
1996[Web of Science][Medline].
45.
Zitt, C,
Zobel A,
Obukhov AG,
Harteneck C,
Kalkbrenner F,
Luckhoff A,
and
Schultz G.
Cloning and functional expression of a human Ca2+-permeable cation channel activated by calcium store depletion.
Neuron
16:
1189-1196,
1996[Web of Science][Medline].
46.
Zweifach, A,
and
Lewis RS.
Calcium-dependent potentiation of store-operated calcium channels in T lymphocytes.
J Gen Physiol
107:
597-610,
1996
This article has been cited by other articles:
|
|
 |
|
  S. G. Baryshnikov, M. V. Pulina, A. Zulian, C. I. Linde, and V. A. Golovina Orai1, a critical component of store-operated Ca2+ entry, is functionally associated with Na+/Ca2+ exchanger and plasma membrane Ca2+ pump in proliferating human arterial myocytes Am J Physiol Cell Physiol, November 1, 2009; 297(5): C1103 - C1112. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Ogawa, A. L. Firth, W. Yao, M. M. Madani, K. M. Kerr, W. R. Auger, S. W. Jamieson, P. A. Thistlethwaite, and J. X.-J. Yuan Inhibition of mTOR attenuates store-operated Ca2+ entry in cells from endarterectomized tissues of patients with chronic thromboembolic pulmonary hypertension Am J Physiol Lung Cell Mol Physiol, October 1, 2009; 297(4): L666 - L676. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. G. Chicoine, J. A. Stewart Jr, and P. A. Lucchesi Is Resveratrol the Magic Bullet for Pulmonary Hypertension? Hypertension, September 1, 2009; 54(3): 473 - 474. [Full Text] [PDF]
|
|
|
|
 |
|
 S. Wang, Y. Zhang, W. G. Wier, X. Yu, M. Zhao, H. Hu, L. Sun, X. He, Y. Wang, B. Wang, et al. Role of store-operated Ca2+ entry in adenosine-induced vasodilatation of rat small mesenteric artery Am J Physiol Heart Circ Physiol, July 1, 2009; 297(1): H347 - H354. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 N. W. Morrell, S. Adnot, S. L. Archer, J. Dupuis, P. Lloyd Jones, M. R. MacLean, I. F. McMurtry, K. R. Stenmark, P. A. Thistlethwaite, N. Weissmann, et al. Cellular and molecular basis of pulmonary arterial hypertension. J. Am. Coll. Cardiol., June 30, 2009; 54(1 Suppl): S20 - S31. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Y. Yu, S. H. Keller, C. V. Remillard, O. Safrina, A. Nicholson, S. L. Zhang, W. Jiang, N. Vangala, J. W. Landsberg, J.-Y. Wang, et al. A Functional Single-Nucleotide Polymorphism in the TRPC6 Gene Promoter Associated With Idiopathic Pulmonary Arterial Hypertension Circulation, May 5, 2009; 119(17): 2313 - 2322. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Abramowitz and L. Birnbaumer Physiology and pathophysiology of canonical transient receptor potential channels FASEB J, February 1, 2009; 23(2): 297 - 328. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. B. Helli and L. J. Janssen Properties of a store-operated nonselective cation channel in airway smooth muscle Eur. Respir. J., December 1, 2008; 32(6): 1529 - 1538. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Ogawa, A. L. Firth, W. Yao, L. J. Rubin, and J. X.-J. Yuan Prednisolone inhibits PDGF-induced nuclear translocation of NF-{kappa}B in human pulmonary artery smooth muscle cells Am J Physiol Lung Cell Mol Physiol, October 1, 2008; 295(4): L648 - L657. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Berra-Romani, A. Mazzocco-Spezzia, M. V. Pulina, and V. A. Golovina Ca2+ handling is altered when arterial myocytes progress from a contractile to a proliferative phenotype in culture Am J Physiol Cell Physiol, September 1, 2008; 295(3): C779 - C790. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
W. Lu, J. Wang, L. A. Shimoda, and J. T. Sylvester Differences in STIM1 and TRPC expression in proximal and distal pulmonary arterial smooth muscle are associated with differences in Ca2+ responses to hypoxia Am J Physiol Lung Cell Mol Physiol, July 1, 2008; 295(1): L104 - L113. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. M. Lounsbury Preventing Stenosis by Local Inhibition of KCa3.1: A Finger on the Phenotypic Switch Arterioscler Thromb Vasc Biol, June 1, 2008; 28(6): 1036 - 1038. [Full Text] [PDF]
|
|
|
|
|
|
M. Yang, X. Ding, and P. A. Murray Differential effects of intravenous anesthetics on capacitative calcium entry in human pulmonary artery smooth muscle cells Am J Physiol Lung Cell Mol Physiol, May 1, 2008; 294(5): L1007 - L1012. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. R. Kovac, T. Chrones, and S. M. Sims Temporal and spatial dynamics underlying capacitative calcium entry in human colonic smooth muscle Am J Physiol Gastrointest Liver Physiol, January 1, 2008; 294(1): G88 - G98. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. C. Ng, B. D. Kyle, A. R. Lennox, X.-M. Shen, W. J. Hatton, and J. R. Hume Cell culture alters Ca2+ entry pathways activated by store-depletion or hypoxia in canine pulmonary arterial smooth muscle cells Am J Physiol Cell Physiol, January 1, 2008; 294(1): C313 - C323. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. P. Albert, S. N. Saleh, C. M. Peppiatt-Wildman, and W. A. Large Multiple activation mechanisms of store-operated TRPC channels in smooth muscle cells J. Physiol., August 15, 2007; 583(1): 25 - 36. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
O. Platoshyn, Y. Yu, E. A Ko, C. V. Remillard, and J. X.-J. Yuan Heterogeneity of hypoxia-mediated decrease in IK(V) and increase in [Ca2+]cyt in pulmonary artery smooth muscle cells Am J Physiol Lung Cell Mol Physiol, August 1, 2007; 293(2): L402 - L416. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Hirota, P. Helli, and L. J. Janssen Ionic mechanisms and Ca2+ handling in airway smooth muscle Eur. Respir. J., July 1, 2007; 30(1): 114 - 133. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Zhang, H. Dong, L. J. Rubin, and J. X.-J. Yuan Upregulation of Na+/Ca2+ exchanger contributes to the enhanced Ca2+ entry in pulmonary artery smooth muscle cells from patients with idiopathic pulmonary arterial hypertension Am J Physiol Cell Physiol, June 1, 2007; 292(6): C2297 - C2305. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Zhang, H. H. Patel, F. Murray, C. V. Remillard, C. Schach, P. A. Thistlethwaite, Paul. A. Insel, and J. X.-J. Yuan Pulmonary artery smooth muscle cells from normal subjects and IPAH patients show divergent cAMP-mediated effects on TRPC expression and capacitative Ca2+ entry Am J Physiol Lung Cell Mol Physiol, May 1, 2007; 292(5): L1202 - L1210. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Lorin-Nebel, J. Xing, X. Yan, and K. Strange CRAC channel activity in C. elegans is mediated by Orai1 and STIM1 homologues and is essential for ovulation and fertility J. Physiol., April 1, 2007; 580(1): 67 - 85. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. R. Resnik, M. Keck, D. J. Sukovich, J. M. Herron, and D. N. Cornfield Chronic intrauterine pulmonary hypertension increases capacitative calcium entry in fetal pulmonary artery smooth muscle cells Am J Physiol Lung Cell Mol Physiol, April 1, 2007; 292(4): L953 - L959. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Kapur, G. A. Mignery, and K. Banach Cell cycle-dependent calcium oscillations in mouse embryonic stem cells Am J Physiol Cell Physiol, April 1, 2007; 292(4): C1510 - C1518. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Dalrymple, K. Mahn, L. Poston, E. Songu-Mize, and R.M. Tribe Mechanical stretch regulates TRPC expression and calcium entry in human myometrial smooth muscle cells Mol. Hum. Reprod., March 1, 2007; 13(3): 171 - 179*. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Morales, A. Diez, A. Puyet, P. J. Camello, C. Camello-Almaraz, J. M. Bautista, and M. J. Pozo Calcium controls smooth muscle TRPC gene transcription via the CaMK/calcineurin-dependent pathways Am J Physiol Cell Physiol, January 1, 2007; 292(1): C553 - C563. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S.-Z. Xu, G. Boulay, R. Flemming, and D. J. Beech E3-targeted anti-TRPC5 antibody inhibits store-operated calcium entry in freshly isolated pial arterioles Am J Physiol Heart Circ Physiol, December 1, 2006; 291(6): H2653 - H2659. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
W. F. Jackson Vascular smooth muscle store-operated Ca2+ channels: what a TRP! Am J Physiol Heart Circ Physiol, December 1, 2006; 291(6): H2592 - H2594. [Full Text] [PDF]
|
|
|
|
|
|
D. L. Tharp, B. R. Wamhoff, J. R. Turk, and D. K. Bowles Upregulation of intermediate-conductance Ca2+-activated K+ channel (IKCa1) mediates phenotypic modulation of coronary smooth muscle Am J Physiol Heart Circ Physiol, November 1, 2006; 291(5): H2493 - H2503. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 X. Yan, J. Xing, C. Lorin-Nebel, A. Y. Estevez, K. Nehrke, T. Lamitina, and K. Strange Function of a STIM1 Homologue in C. elegans: Evidence that Store-operated Ca2+ Entry Is Not Essential for Oscillatory Ca2+ Signaling and ER Ca2+ Homeostasis J. Gen. Physiol., October 1, 2006; 128(4): 443 - 459. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. R. Stenmark, K. A. Fagan, and M. G. Frid Hypoxia-Induced Pulmonary Vascular Remodeling: Cellular and Molecular Mechanisms Circ. Res., September 29, 2006; 99(7): 675 - 691. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Inoue, L. J. Jensen, J. Shi, H. Morita, M. Nishida, A. Honda, and Y. Ito Transient Receptor Potential Channels in Cardiovascular Function and Disease Circ. Res., July 21, 2006; 99(2): 119 - 131. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. A. Pulver-Kaste, C. A. Barlow, J. Bond, A. Watson, P. L. Penar, B. Tranmer, and K. M. Lounsbury Ca2+ source-dependent transcription of CRE-containing genes in vascular smooth muscle Am J Physiol Heart Circ Physiol, July 1, 2006; 291(1): H97 - H105. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. I. Aaronson TRPC Channel Upregulation in Chronically Hypoxic Pulmonary Arteries: The HIF-1 Bandwagon Gathers Steam Circ. Res., June 23, 2006; 98(12): 1465 - 1467. [Full Text] [PDF]
|
|
|
|
|
|
J. Wang, L. Weigand, W. Lu, J.T. Sylvester, G. L. Semenza, and L. A. Shimoda Hypoxia Inducible Factor 1 Mediates Hypoxia-Induced TRPC Expression and Elevated Intracellular Ca2+ in Pulmonary Arterial Smooth Muscle Cells Circ. Res., June 23, 2006; 98(12): 1528 - 1537. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
X.-R. Yang, M.-J. Lin, L. S. McIntosh, and J. S. K. Sham Functional expression of transient receptor potential melastatin- and vanilloid-related channels in pulmonary arterial and aortic smooth muscle Am J Physiol Lung Cell Mol Physiol, June 1, 2006; 290(6): L1267 - L1276. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. N. Rao, O. Platoshyn, V. A. Golovina, L. Liu, T. Zou, B. S. Marasa, D. J. Turner, J. X.-J. Yuan, and J.-Y. Wang TRPC1 functions as a store-operated Ca2+ channel in intestinal epithelial cells and regulates early mucosal restitution after wounding Am J Physiol Gastrointest Liver Physiol, April 1, 2006; 290(4): G782 - G792. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. Kumar, K. Dreja, S.S. Shah, A. Cheong, S.-Z. Xu, P. Sukumar, J. Naylor, A. Forte, M. Cipollaro, D. McHugh, et al. Upregulated TRPC1 Channel in Vascular Injury In Vivo and Its Role in Human Neointimal Hyperplasia Circ. Res., March 3, 2006; 98(4): 557 - 563. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. L. Jernigan, B. R. S. Broughton, B. R. Walker, and T. C. Resta Impaired NO-dependent inhibition of store- and receptor-operated calcium entry in pulmonary vascular smooth muscle after chronic hypoxia Am J Physiol Lung Cell Mol Physiol, March 1, 2006; 290(3): L517 - L525. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Thebault, M. Flourakis, K. Vanoverberghe, F. Vandermoere, M. Roudbaraki, V. Lehen'kyi, C. Slomianny, B. Beck, P. Mariot, J.-L. Bonnal, et al. Differential Role of Transient Receptor Potential Channels in Ca2+ Entry and Proliferation of Prostate Cancer Epithelial Cells Cancer Res., February 15, 2006; 66(4): 2038 - 2047. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. Nunez, R. A. Valero, L. Senovilla, S. Sanz-Blasco, J. Garcia-Sancho, and C. Villalobos Cell proliferation depends on mitochondrial Ca2+ uptake: inhibition by salicylate J. Physiol., February 15, 2006; 571(1): 57 - 73. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. R. H. Mauban, K. Wilkinson, C. Schach, and J. X.-J. Yuan Histamine-mediated increases in cytosolic [Ca2+] involve different mechanisms in human pulmonary artery smooth muscle and endothelial cells Am J Physiol Cell Physiol, February 1, 2006; 290(2): C325 - C336. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 O. Mignen, C. Brink, A. Enfissi, A. Nadkarni, T. J. Shuttleworth, D. R. Giovannucci, and T. Capiod Carboxyamidotriazole-induced inhibition of mitochondrial calcium import blocks capacitative calcium entry and cell proliferation in HEK-293 cells J. Cell Sci., December 1, 2005; 118(23): 5615 - 5623. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. B. Helli, E. Pertens, and L. J. Janssen Cyclopiazonic acid activates a Ca2+-permeable, nonselective cation conductance in porcine and bovine tracheal smooth muscle J Appl Physiol, November 1, 2005; 99(5): 1759 - 1768. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. G. Kovacs, A. Zsembery, S. J. Anderson, P. Komlosi, G. Y. Gillespie, P. D. Bell, D. J. Benos, and C. M. Fuller Changes in intracellular Ca2+ and pH in response to thapsigargin in human glioblastoma cells and normal astrocytes Am J Physiol Cell Physiol, August 1, 2005; 289(2): C361 - C371. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. Weigand, J. Foxson, J. Wang, L. A. Shimoda, and J. T. Sylvester Inhibition of hypoxic pulmonary vasoconstriction by antagonists of store-operated Ca2+ and nonselective cation channels Am J Physiol Lung Cell Mol Physiol, July 1, 2005; 289(1): L5 - L13. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Wang, L. A. Shimoda, L. Weigand, W. Wang, D. Sun, and J. T. Sylvester Acute hypoxia increases intracellular [Ca2+] in pulmonary arterial smooth muscle by enhancing capacitative Ca2+ entry Am J Physiol Lung Cell Mol Physiol, June 1, 2005; 288(6): L1059 - L1069. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. M. Rodman, K. Reese, J. Harral, B. Fouty, S. Wu, J. West, M. Hoedt-Miller, Y. Tada, K.-X. Li, C. Cool, et al. Low-Voltage-Activated (T-Type) Calcium Channels Control Proliferation of Human Pulmonary Artery Myocytes Circ. Res., April 29, 2005; 96(8): 864 - 872. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. B. Parekh and J. W. Putney Jr. Store-Operated Calcium Channels Physiol Rev, April 1, 2005; 85(2): 757 - 810. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Bergdahl, M. F. Gomez, A.-K. Wihlborg, D. Erlinge, A. Eyjolfson, S.-Z. Xu, D. J. Beech, K. Dreja, and P. Hellstrand Plasticity of TRPC expression in arterial smooth muscle: correlation with store-operated Ca2+ entry Am J Physiol Cell Physiol, April 1, 2005; 288(4): C872 - C880. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. F. Pla, D. Maric, S.-C. Brazer, P. Giacobini, X. Liu, Y. H. Chang, I. S. Ambudkar, and J. L. Barker Canonical Transient Receptor Potential 1 Plays a Role in Basic Fibroblast Growth Factor (bFGF)/FGF Receptor-1-Induced Ca2+ Entry and Embryonic Rat Neural Stem Cell Proliferation J. Neurosci., March 9, 2005; 25(10): 2687 - 2701. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. C. Ng, S. M Wilson, and J. R Hume Mobilization of sarcoplasmic reticulum stores by hypoxia leads to consequent activation of capacitative Ca2+ entry in isolated canine pulmonary arterial smooth muscle cells J. Physiol., March 1, 2005; 563(2): 409 - 419. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Zhang, J. X.-J. Yuan, K. E. Barrett, and H. Dong Role of Na+/Ca2+ exchange in regulating cytosolic Ca2+ in cultured human pulmonary artery smooth muscle cells Am J Physiol Cell Physiol, February 1, 2005; 288(2): C245 - C252. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. R. H. Mauban, C. V. Remillard, and J. X.-J. Yuan Hypoxic pulmonary vasoconstriction: role of ion channels J Appl Physiol, January 1, 2005; 98(1): 415 - 420. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 N. Kunichika, J. W. Landsberg, Y. Yu, H. Kunichika, P. A. Thistlethwaite, L. J. Rubin, and J. X.-J. Yuan Bosentan Inhibits Transient Receptor Potential Channel Expression in Pulmonary Vascular Myocytes Am. J. Respir. Crit. Care Med., November 15, 2004; 170(10): 1101 - 1107. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Kunichika, Y. Yu, C. V. Remillard, O. Platoshyn, S. Zhang, and J. X.-J. Yuan Overexpression of TRPC1 enhances pulmonary vasoconstriction induced by capacitative Ca2+ entry Am J Physiol Lung Cell Mol Physiol, November 1, 2004; 287(5): L962 - L969. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Zhang, C. V. Remillard, I. Fantozzi, and J. X.-J. Yuan ATP-induced mitogenesis is mediated by cyclic AMP response element-binding protein-enhanced TRPC4 expression and activity in human pulmonary artery smooth muscle cells Am J Physiol Cell Physiol, November 1, 2004; 287(5): C1192 - C1201. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. J. Beech, K. Muraki, and R. Flemming Non-selective cationic channels of smooth muscle and the mammalian homologues of Drosophila TRP J. Physiol., September 15, 2004; 559(3): 685 - 706. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Takai, R. Sugawara, H. Ohinata, and A. Takai Two types of non-selective cation channel opened by muscarinic stimulation with carbachol in bovine ciliary muscle cells J. Physiol., September 15, 2004; 559(3): 899 - 922. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M.-J. Lin, G. P.H. Leung, W.-M. Zhang, X.-R. Yang, K.-P. Yip, C.-M. Tse, and J. S.K. Sham Chronic Hypoxia-Induced Upregulation of Store-Operated and Receptor-Operated Ca2+ Channels in Pulmonary Arterial Smooth Muscle Cells: A Novel Mechanism of Hypoxic Pulmonary Hypertension Circ. Res., September 3, 2004; 95(5): 496 - 505. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. Lemonnier, Y. Shuba, A. Crepin, M. Roudbaraki, C. Slomianny, B. Mauroy, B. Nilius, N. Prevarskaya, and R. Skryma Bcl-2-Dependent Modulation of Swelling-Activated Cl- Current and ClC-3 Expression in Human Prostate Cancer Epithelial Cells Cancer Res., July 15, 2004; 64(14): 4841 - 4848. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. F. Cantiello Regulation of calcium signaling by polycystin-2 Am J Physiol Renal Physiol, June 1, 2004; 286(6): F1012 - F1029. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. A. Pulver, P. Rose-Curtis, M. W. Roe, G. C. Wellman, and K. M. Lounsbury Store-Operated Ca2+ Entry Activates the CREB Transcription Factor in Vascular Smooth Muscle Circ. Res., May 28, 2004; 94(10): 1351 - 1358. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. W. Landsberg and J. X.-J. Yuan Calcium and TRP Channels in Pulmonary Vascular Smooth Muscle Cell Proliferation Physiology, April 1, 2004; 19(2): 44 - 50. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Wang, L. A. Shimoda, and J. T. Sylvester Capacitative calcium entry and TRPC channel proteins are expressed in rat distal pulmonary arterial smooth muscle Am J Physiol Lung Cell Mol Physiol, April 1, 2004; 286(4): L848 - L858. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
I. Fantozzi, S. Zhang, O. Platoshyn, C. V. Remillard, R. T. Cowling, and J. X.-J. Yuan Hypoxia increases AP-1 binding activity by enhancing capacitative Ca2+ entry in human pulmonary artery endothelial cells Am J Physiol Lung Cell Mol Physiol, December 1, 2003; 285(6): L1233 - L1245. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Wang, L. G. Laurier, S. M. Sims, and H. G. Preiksaitis Enhanced capacitative calcium entry and TRPC channel gene expression in human LES smooth muscle Am J Physiol Gastrointest Liver Physiol, June 1, 2003; 284(6): G1074 - G1083. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. Lipskaia, M.-L. Pourci, C. Delomenie, L. Combettes, D. Goudouneche, J.-L. Paul, T. Capiod, and A.-M. Lompre Phosphatidylinositol 3-Kinase and Calcium-Activated Transcription Pathways Are Required for VLDL-Induced Smooth Muscle Cell Proliferation Circ. Res., May 30, 2003; 92(10): 1115 - 1122. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. M. Tribe, P. Moriarty, A. Dalrymple, A. A. Hassoni, and L. Poston Interleukin-1{beta} Induces Calcium Transients and Enhances Basal and Store Operated Calcium Entry in Human Myometrial Smooth Muscle Biol Reprod, May 1, 2003; 68(5): 1842 - 1849. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. M. Lee, B. J. Kim, H. J. Kim, D. K. Yang, M. H. Zhu, K. P. Lee, I. So, and K. W. Kim TRPC5 as a candidate for the nonselective cation channel activated by muscarinic stimulation in murine stomach Am J Physiol Gastrointest Liver Physiol, April 1, 2003; 284(4): G604 - G616. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Yu, M. Sweeney, S. Zhang, O. Platoshyn, J. Landsberg, A. Rothman, and J. X.-J. Yuan PDGF stimulates pulmonary vascular smooth muscle cell proliferation by upregulating TRPC6 expression Am J Physiol Cell Physiol, February 1, 2003; 284(2): C316 - C330. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G.-L. Wang, X.-R. Wang, M.-J. Lin, H. He, X.-J. Lan, and Y.-Y. Guan Deficiency in ClC-3 Chloride Channels Prevents Rat Aortic Smooth Muscle Cell Proliferation Circ. Res., November 15, 2002; 91 (10): e28 - e32. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Ma, P. E. Kudlacek, and S. C. Sansom Protein kinase Calpha participates in activation of store-operated Ca2+ channels in human glomerular mesangial cells Am J Physiol Cell Physiol, November 1, 2002; 283(5): C1390 - C1398. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Dalrymple, D.M. Slater, D. Beech, L. Poston, and R.M. Tribe Molecular identification and localization of Trp homologues, putative calcium channels, in pregnant human uterus Mol. Hum. Reprod., October 1, 2002; 8(10): 946 - 951. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A P Albert and W A Large Activation of store-operated channels by noradrenaline via protein kinase C in rabbit portal vein myocytes J. Physiol., October 1, 2002; 544(1): 113 - 125. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Sweeney, Y. Yu, O. Platoshyn, S. Zhang, S. S. McDaniel, and J. X.-J. Yuan Inhibition of endogenous TRP1 decreases capacitative Ca2+ entry and attenuates pulmonary artery smooth muscle cell proliferation Am J Physiol Lung Cell Mol Physiol, July 1, 2002; 283(1): L144 - L155. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Sweeney, S. S. McDaniel, O. Platoshyn, S. Zhang, Y. Yu, B. R. Lapp, Y. Zhao, P. A. Thistlethwaite, and J. X.-J. Yuan Role of capacitative Ca2+ entry in bronchial contraction and remodeling J Appl Physiol, April 1, 2002; 92(4): 1594 - 1602. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. S. McDaniel, O. Platoshyn, Y. Yu, M. Sweeney, V. A. Miriel, V. A. Golovina, S. Krick, B. R. Lapp, J.-Y. Wang, and J. X.-J. Yuan Anorexic effect of K+ channel blockade in mesenteric arterial smooth muscle and intestinal epithelial cells J Appl Physiol, November 1, 2001; 91(5): 2322 - 2333. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. S. McDaniel, O. Platoshyn, J. Wang, Y. Yu, M. Sweeney, S. Krick, L. J. Rubin, and J. X.-J. Yuan Capacitative Ca2+ entry in agonist-induced pulmonary vasoconstriction Am J Physiol Lung Cell Mol Physiol, May 1, 2001; 280(5): L870 - L880. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Jung, R. Strotmann, G. Schultz, and T. D. Plant TRPC6 is a candidate channel involved in receptor-stimulated cation currents in A7r5 smooth muscle cells Am J Physiol Cell Physiol, February 1, 2002; 282(2): C347 - C359. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
) and hTRP1 mRNA levels (
)
in human PASMC cultured with SMBM (day 0) and SMGM
(day 0.25-4). The vertical broken lines indicate the
time required for a 50% increase in cell growth or hTRP1
mRNA expression. The time-course curve for the increase in
hTRP1 expression is significantly different from the curve
for the cell growth (P < 0.001, by
Student-Newman-Keuls test).
