(Circulation. 2000;101:2431.)
© 2000 American Heart Association, Inc.
Basic Science Reports |
From the Department of Pediatrics, Childrens Hospital Medical Center, University of Cincinnati (Ohio).
Correspondence to Jeffery D. Molkentin, Division of Molecular Cardiovascular Biology, Childrens Hospital Medical Center, 3333 Burnet Ave, Cincinnati, OH 45229-3039. E-mail molkj0{at}chmcc.org
| Abstract |
|---|
|
|
|---|
Methods and ResultsWe showed that calcineurin enzymatic activity is increased 3.2-fold in the heart in response to pressure-overload hypertrophy induced by abdominal aortic banding in the rat. Western blot analysis further demonstrates that calcineurin A (catalytic subunit) protein content and association with calmodulin are increased in response to pressure-overload hypertrophy. This increase in calcineurin protein content was prevented by administration of the calcineurin inhibitor cyclosporine A (CsA). CsA administration attenuated load-induced cardiac hypertrophy in a dose-dependent manner over a 14-day treatment protocol. CsA administration also partially reversed pressure-overload hypertrophy in aortic-banded rats after 14 days. CsA also attenuated the histological and molecular indexes of pressure-overload hypertrophy.
ConclusionsThese data suggest that calcineurin is an important upstream regulator of load-induced hypertrophy.
Key Words: aorta hypertrophy pressure
| Introduction |
|---|
|
|
|---|
Cardiac hypertrophy can be induced by hemodynamic overload, ischemic disease, neurohumoral factors, or intrinsic defects in cardiac structural protein genes.3 4 Studies in cultured cardiomyocytes and in animal models of heart disease have implicated the mitogen-activated protein kinase cascade in cardiac hypertrophy. Hypertrophic agonists such as angiotensin II, endothelin-1, cardiotrophin-1, and catecholamines were shown to activate the mitogen-activated protein kinase cascade in cultured cardiomyocytes.5 6 7 8 9 10 11 Recent investigation suggests that both a JNK-dependent and a p38-dependent pathway are capable of initiating hypertrophy of cultured neonatal cardiomyocytes.12 13 14
Another intracellular regulatory pathway implicated in cardiac hypertrophy involves the calcium-regulated phosphatase calcineurin and the transcription factor NF-AT3.15 This calcineurin-dependent pathway was first identified in T cells as an early response pathway to T-cell receptor activation mediated through increases in intracellular calcium.16 Activated calcineurin directly dephosphorylates cytosolic NF-AT transcription factors, resulting in their nuclear translocation and activation of immune response genes. The immunosuppressive drugs cyclosporine A (CsA) and FK506 prevent T-cellmediated responses through inhibition of calcineurin activity.17
Cardiac overexpression by transgenesis of either activated calcineurin or a constitutively nuclear NF-AT3 mutant produced substantial hypertrophy that rapidly progressed to heart failure. These studies were extended to demonstrate prevention of phenotypic hypertrophy with cyclosporine or FK506 in genetically altered mouse models of cardiomyopathy and in a pathophysiological model of pressure-overload hypertrophy in the rat.18 In contrast, a number of recent studies have reported that calcineurin inhibitors are ineffective in preventing pressure-overload hypertrophy in aortic-banded rodent models.19 20 21 22 23
We showed that calcineurin is activated early in the time course of load-induced hypertrophy and that activation is maintained long term. Treatment of aortic-banded rats with CsA at 2 different doses significantly attenuated calcineurin activation and load-induced hypertrophy after 14 days. CsA administration also partially reversed load-induced hypertrophy once established.
| Methods |
|---|
|
|
|---|
200 to 225 g, all female) were anesthetized with
isoflurane, and their abdominal aortas were exposed. The aorta was
constricted below the celiac trunk and above the superior mesentric
artery using 1-0 silk and 21-gauge wire, which is removed to generate a
defined construction. CsA (Sandimmune, Novartis) was administered
subcutaneously into the nape of the neck 1 day before aortic banding
and continued for 14 additional days. For the prevention studies, 19
and 13 rats were initially banded and placed on 2 dosages of CsA (10
mg/kg twice daily or 4 mg/kg twice daily), of which 14 and 11 survived
the treatment protocol, respectively. In addition, 13 untreated, banded
rats were generated, of which 10 survived the 14-day protocol. Six sham
animals were analyzed in 2 separate groups (with or without
CsA) without deaths. For weight loss studies, a VLCD consisting of 16.7% of normal rodent chow formula 5008 (a 200-g rat consumes 70 kcal/d ad libitum24 ) was instituted.25 Eight sham rats and 13 banded rats were placed on the VLCD, of which 7 and 10 survived 14 days, respectively.
For the reversal study, CsA administration (10 mg/kg twice daily) was begun on day 14 after banding and continued through day 28 (14 rats began the study, with 2 deaths). Twelve rats began the 28-day banding study, of which 10 survived.
Western Blots and Assay for Calcineurin
To demonstrate activated calcineurin, protein extracts
were made from either the left ventricle or atria in
immunoprecipitation buffer (20 mmol/L NaPO4,
150 mmol/L NaCl, 2 mmol/L MgCl2, 0.1%
NP40, 10% glycerol, 10 mmol/L NaF, 0.1 mmol/L sodium
orthovanadate, 10 mmol/L sodium pyrophosphate, 1 mmol/L DTT,
10 µg/mL leupeptin, 10 µg/mL aprotinin, 10 µg/mL pepstatin, 10
µg/mL TPCK, and 10 µg/mL TLCK). For immunoprecipitation, 400 µg
of protein extract (
30 to 50 µL) was incubated with 5 µg of
calmodulin rabbit polyclonal antibody (Zymed) in 100 µL
at 4°C with gentle rocking for 1 hour followed by the addition of 50
µL of protein A/G agarose (Santa Cruz) and another hour of incubation
at 4°C. The samples were washed 3 times with 200 µL of
immunoprecipitation buffer and subjected to SDS-PAGE. Immunodetection
was then performed with a calcineurin antibody (Transduction
Laboratories) followed by a calmodulin-specific antibody
(Zymed). Blots were quantified for fluorescence with a Storm
860 PhosphorImager (Molecular Dynamics).
Calcineurin Phosphatase Assay
Left ventricles were homogenized in equal volumes of
cell lysis buffer (50 mmol/L Tris-Cl pH 7.5, 0.1 mmol/L NaCl,
5 mmol/L DTT, 1 mmol/L EDTA, pH 8.0, 1 mmol/L PMSF, 5
µg/mL pepstatin, 5 µg/mL leupeptin, and 5 µg/mL aprotinin) and
sonicated at 4°C. The resulting supernatants (25 µg of
protein) were assayed in buffer consisting of 20 mmol/L Tris-Cl,
pH 7.5, 50 mmol/L NaCl, 6 mmol/L MgCl2,
0.5 mmol/L CaCl2, 1 mmol/L DTT, and 50
µg/mL BSA. Phosphatase activity was measured as the
dephosphorylation rate of a synthetic
[32P]-ATPlabeled phosphopeptide substrate
(R-II peptide; Peninsula Labs) in the presence of 0.5 mmol/L
CaCl2, 1.0 µmol/L calmodulin,
and 1.0 µmol/L okadaic acid as described
previously.18 Activity was blocked with the addition of
500 µmol/L calcineurin autoinhibitory peptide
(Calbiochem), and total activity was determined as the difference
between the blocked and unblocked states.
Quantitative mRNA Analysis
Determination of mRNA levels of a subset of hypertrophic markers
was performed as described previously in detail, including the sequence
of the rat-specific oligonucleotides that were
used.26 Blots were quantified on a PhosphorImager
(Molecular Dynamics). The signal intensity of each RNA dot was
normalized to the corresponding GAPDH signal to account for equal
loading.
Statistics
All data are presented as mean±SEM and were
analyzed by a 1-way ANOVA between the indicated groups by the
use of a Bonferroni multiple comparison test when appropriate or an
unpaired Students t test, and significance was assigned a
value of P<0.05. Tests were performed with the Instat
software package (Graphpad).
| Results |
|---|
|
|
|---|
Rats were subjected to abdominal aortic banding for 6 hours, 1, 3, 7,
14, 21, or 42 days, at which time their hearts were collected for
analysis. Left ventricular and atrial protein
extracts were subjected to calmodulin immunoprecipitation
followed by a calcineurin-specific Western blot (Figure 1A
). Levels of immunoprecipitated
calcineurin were normalized to levels of calmodulin
coprecipitated and are represented graphically below each
Western blot. The data demonstrate calcineurin association with
calmodulin as early as 1 day after aortic banding in the
left ventricle. Association then reached a maximum within 3 days and
was maintained through day 42, whereas calcineurin was not
activated in the atria (Figure 1A
). Atria were included
for control purposes, which did not demonstrate increased
calcineurin-calmodulin association. These results were
consistent across 2 animals each at the indicated time points,
although only 1 is shown for simplicity.
|
Unprecipitated protein was also subjected to Western blotting to quantify absolute levels of calcineurin and calmodulin in each sample. The data demonstrate invariant calmodulin levels but an increase in total calcineurin protein content at days 7 and 14 in the left ventricle and to a lesser extent in the atria. This increase in total calcineurin protein was seen in 4 of 4 samples at day 14 and 2 of 2 at day 7.
Total calcineurin enzymatic activity after 14 days of banding was also
increased 3.2-fold (P<0.05) in the left ventricle as
assayed by dephosphorylation of a
32P-labeled RII peptide (Figure 1B
).
Because the increase in calcineurin activity at day 14 is also
associated with increased calcineurin protein content, it is difficult
to infer an increase in specific activity. However, the
calmodulin-calcineurin immunoprecipitation assay shows
increased association at time points when calcineurin protein content
is invariant, suggesting an increase in specific activity of
calcineurin.
CsA Prevents Pressure-Overload Hypertrophy
To evaluate the effects of calcineurin inhibition on
pressure-overload hypertrophy, Sprague-Dawley rats were
pretreated with CsA (Sandimmune) for 1 day before abdominal aortic
banding and maintained on CsA for 14 additional days (Table
).
Control groups included aortic-banded rats without CsA, sham rats, and
sham rats treated with CsA. Hearttobody weight ratios were
calculated for each group (Figure 2
). The
data demonstrate that aortic banding induced a significant increase in
hearttobody weight ratio after 14 days (34%) (P<0.05),
which was prevented in a dose-dependent manner by CsA treatment
(P<0.05 for each group). At the highest dosage of CsA, a
large attenuation was observed, whereas at a x0.4 dosage a modest
attenuation was still noted (P<0.05). CsA treatment did not
influence the hearttobody weight ratios of sham animals, nor did it
substantially increase the mortality rates of either the sham or banded
groups.
|
|
Aortic-banded animals treated with CsA lost a small percentage of their
body weight during the treatment protocol (Table
). To control
for weight loss, we restricted the diets of either sham rats or
aortic-banded rats to 16.7% of the weight-adjusted daily caloric
requirements (very low caloric diet, VLCD).25 Sham rats on
a caloric-restricted diet lost 28% of their body weight yet maintained
a nearly identical hearttobody weight ratio as ad libitum feed
shams (Table
). More importantly, caloric-restricted,
aortic-banded rats had identical increases in hearttobody weight
ratios compared with ad libitum feed, banded animals despite a
significant weight loss (Figure 2
).
Calcineurin-specific Western blots were performed on protein extracts
derived from nonbanded hearts, 14-day banded hearts, or 14-day banded
hearts treated with CsA. The data show that CsA administration
effectively prevented the increase in total calcineurin protein
content, whereas calmodulin levels did not vary (Figure 3
). It is likely that the total increase
in calcineurin protein content by day 14 is part of a secondary
mechanism that is associated with hypertrophy itself, so
that CsA treatment that attenuates the hypertrophy response
also blocks this increase in calcineurin protein content.
|
Effects of Calcineurin Inhibition on Reversal of
Pressure-Overload Hypertrophy
To determine whether calcineurin inhibition could reverse
pressure-overload hypertrophy, rats were banded for 14 days
and treated with CsA at 10 mg/kg twice daily for an additional 14 days
(Table
). An additional control group included untreated rats
that were subject to aortic banding for 28 days. Analysis of
hearttobody weight ratios demonstrated a partial reversal of
hypertrophy in the CsA-treated rats compared with either
the 14- or 28-day banded, untreated controls (P<0.05)
(Figure 4A
and Table
). These data
indicate that CsA significantly but only partially reverses
pressure-overload hypertrophy caused by abdominal aortic
banding.
|
We extended this analysis to include a longitudinal assessment
of left ventricular wall thickness by
echocardiography within the same animals before and
after CsA treatment. Fourteen-day aortic-banded rats had an average
left ventricular wall thickness of 0.262±0.0099 cm,
whereas these same animals after an additional 14 days of CsA treatment
had an average wall thickness of 0.229±0.0088 (P<0.05)
(Figure 4B
). These data demonstrate a longitudinal reversal of
hypertrophy within the same animals after 14 days of CsA
treatment.
Histological and Molecular Analysis of
CsA-Treated Rats
We performed histological analysis of left
ventricular cardiac tissue to examine myocyte fiber sizes,
organization, and fibrosis. Hematoxylin and eosinstained sections on
gross inspection appeared normal between sham, banded, and banded with
CsA groups, although the banded group appeared to have larger fibers
(Figure 5
, A through C). Trichrome
staining of sections between the 3 treatment groups did not reveal a
qualitative difference in fibrosis after 14 days (Figure 5
, D
through F). To quantify myofiber sizes between treatment groups, wheat
germ agglutinin staining was performed as described
previously28 (Figure 5
, G through I). The data show
a significant increase in myofiber surface area from banded hearts,
which was prevented with CsA (P<0.05) (Figure 5J
).
|
We also assayed for ANF and ß-MHC mRNA levels by quantitative dot
blot analysis to determine whether CsA treatment could prevent
increased expression of hypertrophic markers (Figure 6
). The values were normalized to GAPDH
mRNA levels and demonstrated a statistically significant induction of
ANF and ß-MHC mRNA levels in aortic-banded hearts when compared with
levels in sham animals, which were attenuated with CsA
(P<0.05).
|
| Discussion |
|---|
|
|
|---|
In abdominal aorticbanded rats, 2 separate studies did not report a significant attenuation of pressure-overload hypertrophy with CsA or FK506.19 21 Although these studies failed to identify attenuation with CsA, careful inspection of the data suggests a trend. Luo et al19 reported a 42% increase in hearttobody weight ratio in the banded group and only a 27% increase in the banded, CsA-treated group (highest dose). Zhang et al21 reported a 47% increase in left ventricletobody weight ratio in the banded group but only a 21% and 27% increase in banded animals at 2 different dosages of CsA (4-week study), yet these differences were not interpreted as significant, given the manner is which the data were normalized to blood pressure gradient between the groups.
A potential criticism of our data is that CsA has a nonspecific effect
that diminishes the "health" of the heart or animal. However, sham
animals treated with CsA did not have a decrease in heart weight, nor
did CsA prevent hypertrophy in RAR transgenic
mice18 or NF-AT3 transgenic mice (data not shown). Another
potential variable relates to the observation that banded CsA
groups either lost body weight or failed to gain weight over 14 days of
treatment (Table
). However, the VLCD control group demonstrated
the same degree of relative hypertrophy despite a >30%
loss in body weight (Table
).
Blood CsA levels (3104 ng/mL) in the banded group were 6 to 10 times higher than is achieved clinically in humans.29 However, it is difficult to interpret the relevance of this dosage between rat and humans, given the known differences in physiology and drug metabolism. Indeed, effective immunosuppression in the mouse was reported to require substantially higher CsA blood levels than is required in humans.30 Alternatively, calcineurin protein content is thought to be higher in the heart compared with T cells, necessitating higher doses to achieve inhibition.17
This report also raises the question as to other potential mechanisms (calcineurin independent) whereby CsA might affect cardiac hypertrophy. We previously demonstrated that both CsA and FK506 were capable of preventing cardiac myopathy in tropomodulin transgenic mice.18 The significant biological effects in common to both CsA and FK506, which each bind different immunophilin proteins, have been attributed to their ability to inhibit calcineurin.31 These data suggest that the observed attenuation and partial reversal of cardiac hypertrophy by CsA is primarily due to calcineurin inhibition, although we cannot formally rule out other mechanisms of action.
The calcineurin-inhibitory drugs CsA and FK506 are currently prescribed to prevent allograft tissue rejection after organ transplantation. Anecdotal reports have suggested that calcineurin inhibitors have a negative effect on the heart. Long-term CsA therapy is reported to cause LVH in heart transplantation recipients.32 In addition, 2 separate case report studies found hypertrophic cardiomyopathy in pediatric liver transplantation recipients receiving FK506.33 34
In contrast to these case reports, our analysis of intrinsic and extrinsic animal models of cardiac hypertrophy would suggest that calcineurin inhibitors antagonize cardiac hypertrophy. The reason for these disparate results either reflects a temporally regulated phenomenon or is related to the higher doses required to inhibit cardiac calcineurin activity. The clinical reports represent long-term effects associated with CsA and FK506, whereas our animal studies were preformed in the short term and at high doses. The side effects associated with CsA and FK506 probably exclude these drugs as long-term therapeutics for human heart disease, but it also suggests new avenues for drug discovery with cardiac specificity.
| Acknowledgments |
|---|
Received July 12, 1999; revision received October 1, 1999; accepted October 21, 1999.
| References |
|---|
|
|
|---|
myosin heavy chain gene leads to dosage effects and
functional deficits in the heart. J Clin Invest. 1996;98:19061917.[Medline]
[Order article via Infotrieve]This article has been cited by other articles:
![]() |
X. Loyer, A. M. Gomez, P. Milliez, M. Fernandez-Velasco, P. Vangheluwe, L. Vinet, D. Charue, E. Vaudin, W. Zhang, Y. Sainte-Marie, et al. Cardiomyocyte Overexpression of Neuronal Nitric Oxide Synthase Delays Transition Toward Heart Failure in Response to Pressure Overload by Preserving Calcium Cycling Circulation, June 24, 2008; 117(25): 3187 - 3198. [Abstract] [Full Text] [PDF] |
||||
![]() |
I. Pinz, S. E. Ostroy, K. Hoyer, H. Osinska, J. Robbins, J. D. Molkentin, and J. S. Ingwall Calcineurin-induced energy wasting in a transgenic mouse model of heart failure Am J Physiol Heart Circ Physiol, March 1, 2008; 294(3): H1459 - H1466. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. M. MacDonnell, H. Kubo, D. M. Harris, X. Chen, R. Berretta, M. F. Barbe, S. Kolwicz, P. O. Reger, A. Eckhart, B. F. Renna, et al. Calcineurin inhibition normalizes beta-adrenergic responsiveness in the spontaneously hypertensive rat Am J Physiol Heart Circ Physiol, November 1, 2007; 293(5): H3122 - H3129. [Abstract] [Full Text] [PDF] |
||||
![]() |
V. C. Tu, H. Sun, G. T. Bowden, and Q. M. Chen Involvement of oxidants and AP-1 in angiotensin II-activated NFAT3 transcription factor Am J Physiol Cell Physiol, April 1, 2007; 292(4): C1248 - C1255. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Javadov, D. M. Purdham, A. Zeidan, and M. Karmazyn NHE-1 inhibition improves cardiac mitochondrial function through regulation of mitochondrial biogenesis during postinfarction remodeling Am J Physiol Heart Circ Physiol, October 1, 2006; 291(4): H1722 - H1730. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Heger and G. Euler iNOS - Another cardiac target of calcineurin Cardiovasc Res, September 1, 2006; 71(4): 612 - 614. [Full Text] [PDF] |
||||
![]() |
B. Sanna, E. B. Brandt, R. A. Kaiser, P. Pfluger, S. A. Witt, T. R. Kimball, E. van Rooij, L. J. De Windt, M. E. Rothenberg, M. H. Tschop, et al. Modulatory calcineurin-interacting proteins 1 and 2 function as calcineurin facilitators in vivo PNAS, May 9, 2006; 103(19): 7327 - 7332. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Kilic, A. Velic, L. J. De Windt, L. Fabritz, M. Voss, D. Mitko, M. Zwiener, H. A. Baba, M. van Eickels, E. Schlatter, et al. Enhanced Activity of the Myocardial Na+/H+ Exchanger NHE-1 Contributes to Cardiac Remodeling in Atrial Natriuretic Peptide Receptor-Deficient Mice Circulation, October 11, 2005; 112(15): 2307 - 2317. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Heineke, H. Ruetten, C. Willenbockel, S. C. Gross, M. Naguib, A. Schaefer, T. Kempf, D. Hilfiker-Kleiner, P. Caroni, T. Kraft, et al. Attenuation of cardiac remodeling after myocardial infarction by muscle LIM protein-calcineurin signaling at the sarcomeric Z-disc PNAS, February 1, 2005; 102(5): 1655 - 1660. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. D. Schreiner, K. Kelemen, J. Zehelein, R. Becker, J. C. Senges, A. Bauer, F. Voss, P. Kraft, H. A. Katus, and W. Schoels Biventricular hypertrophy in dogs with chronic AV block: effects of cyclosporin A on morphology and electrophysiology Am J Physiol Heart Circ Physiol, December 1, 2004; 287(6): H2891 - H2898. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. D Molkentin Calcineurin-NFAT signaling regulates the cardiac hypertrophic response in coordination with the MAPKs Cardiovasc Res, August 15, 2004; 63(3): 467 - 475. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. R. McMullen, T. Shioi, W.-Y. Huang, L. Zhang, O. Tarnavski, E. Bisping, M. Schinke, S. Kong, M. C. Sherwood, J. Brown, et al. The Insulin-like Growth Factor 1 Receptor Induces Physiological Heart Growth via the Phosphoinositide 3-Kinase(p110{alpha}) Pathway J. Biol. Chem., February 6, 2004; 279(6): 4782 - 4793. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. J. Wilkins, Y.-S. Dai, O. F. Bueno, S. A. Parsons, J. Xu, D. M. Plank, F. Jones, T. R. Kimball, and J. D. Molkentin Calcineurin/NFAT Coupling Participates in Pathological, but not Physiological, Cardiac Hypertrophy Circ. Res., January 9, 2004; 94(1): 110 - 118. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. B. Vega, R. Bassel-Duby, and E. N. Olson Control of Cardiac Growth and Function by Calcineurin Signaling J. Biol. Chem., September 26, 2003; 278(39): 36981 - 36984. [Full Text] [PDF] |
||||
![]() |
J. Li, A. Yatani, S.-J. Kim, G. Takagi, K. Irie, Q. Zhang, V. Karoor, C. Hong, G. Yang, J. Sadoshima, et al. Neurally-mediated increase in calcineurin activity regulates cardiac contractile function in absence of hypertrophy Cardiovasc Res, September 1, 2003; 59(3): 649 - 657. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Mitsuhashi, N. Saito, K. Watano, K. Igarashi, S. Tagami, H. Shima, and K. Kikuchi Defect of Delta-Sarcoglycan Gene Is Responsible for Development of Dilated Cardiomyopathy of a Novel Hamster Strain, J2N-k: Calcineurin/PP2B Activity in the Heart of J2N-k Hamster J. Biochem., August 1, 2003; 134(2): 269 - 276. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. El Bekay, M. Alvarez, J. Monteseirin, G. Alba, P. Chacon, A. Vega, J. Martin-Nieto, J. Jimenez, E. Pintado, F. J. Bedoya, et al. Oxidative stress is a critical mediator of the angiotensin II signal in human neutrophils: involvement of mitogen-activated protein kinase, calcineurin, and the transcription factor NF-{kappa}B Blood, July 15, 2003; 102(2): 662 - 671. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. J. Lips, L. J. deWindt, D. J.W. van Kraaij, and P. A. Doevendans Molecular determinants of myocardial hypertrophy and failure: alternative pathways for beneficial and maladaptive hypertrophy Eur. Heart J., May 2, 2003; 24(10): 883 - 896. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. R. Sayen, A. B. Gustafsson, M. A. Sussman, J. D. Molkentin, and R. A. Gottlieb Calcineurin transgenic mice have mitochondrial dysfunction and elevated superoxide production Am J Physiol Cell Physiol, February 1, 2003; 284(2): C562 - C570. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. Dong, Y. Duan, J. Guo, D. E Roach, S. L Swirp, L. Wang, J.P Lees-Miller, R.S Sheldon, J. D Molkentin, and H. J Duff Overexpression of calcineurin in mouse causes sudden cardiac death associated with decreased density of K+ channels Cardiovasc Res, February 1, 2003; 57(2): 320 - 332. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. van Rooij, P. A. Doevendans, C. C. de Theije, F. A. Babiker, J. D. Molkentin, and L. J. De Windt Requirement of Nuclear Factor of Activated T-cells in Calcineurin-mediated Cardiomyocyte Hypertrophy J. Biol. Chem., December 6, 2002; 277(50): 48617 - 48626. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. J. Wilkins, L. J. De Windt, O. F. Bueno, J. C. Braz, B. J. Glascock, T. F. Kimball, and J. D. Molkentin Targeted Disruption of NFATc3, but Not NFATc4, Reveals an Intrinsic Defect in Calcineurin-Mediated Cardiac Hypertrophic Growth Mol. Cell. Biol., November 1, 2002; 22(21): 7603 - 7613. [Abstract] [Full Text] [PDF] |
||||