 |
 Previous Article | Next Article 
The Journal of Neuroscience, June 15, 2000, 20(12):4389-4397
Neuroprotective Effects of Creatine in a Transgenic Mouse Model
of Huntington's Disease
Robert J.
Ferrante1, 2, 3,
Ole A.
Andreassen4, 5,
Bruce
G.
Jenkins6, 7,
Alpaslan
Dedeoglu4, 5,
Stefan
Kuemmerle2,
James K.
Kubilus1, 3,
Rima
Kaddurah-Daouk8,
Steven M.
Hersch9, and
M. Flint
Beal4, 5, 10
1 Geriatric Research Education and Clinical Center,
Bedford Veteran's Administration Medical Center, Bedford,
Massachusetts 01730, 2 Neurology, Pathology, and Psychiatry
Departments, and 3 Boston University School of Medicine,
Boston, Massachusetts 02118, 4 Neurochemistry Laboratory,
Neurology Service, Massachusetts General Hospital, and
5 Harvard Medical School, Boston, Massachusetts 02114, 6 Department of Radiology, Massachusetts General
Hospital-Nuclear Magnetic Resonance Center, Massachusetts General
Hospital, and 7 Harvard Medical School, Charlestown,
Massachusetts 02114, 8 The Avicena Group, Inc., Cambridge,
Massachusetts 02139, 9 Neurology Department, Emory
University School of Medicine, Atlanta, Georgia 30322, and
10 Department of Neurology and Neuroscience, Weill Medical
College of Cornell University and the New York Hospital-Cornell
Medical Center, New York, New York 10021
 |
ABSTRACT |
Huntington's disease (HD) is a progressive neurodegenerative
illness for which there is no effective therapy. We examined whether
creatine, which may exert neuroprotective effects by increasing phosphocreatine levels or by stabilizing the mitochondrial permeability transition, has beneficial effects in a transgenic mouse model of HD
(line 6/2). Dietary creatine supplementation significantly improved
survival, slowed the development of brain atrophy, and delayed atrophy
of striatal neurons and the formation of huntingtin-positive aggregates
in R6/2 mice. Body weight and motor performance on the rotarod
test were significantly improved in creatine-supplemented R6/2
mice, whereas the onset of diabetes was markedly delayed. Nuclear
magnetic resonance spectroscopy showed that creatine supplementation significantly increased brain creatine concentrations and delayed decreases in N-acetylaspartate concentrations. These
results support a role of metabolic dysfunction in a transgenic mouse
model of HD and suggest a novel therapeutic strategy to slow the
pathological process.
Key words:
creatine; mitochondria; Huntington's disease; transgenic
mice; diabetes; N-acetylaspartate
| |
INTRODUCTION |
Huntington's disease (HD) is an
autosomal dominant progressive neurodegenerative disease that starts in
midlife and inexorably leads to death. The mean survival after onset is
15-20 years, and at present there is no known effective treatment for
HD. The mutation that causes the illness is an expanded
CAG/polyglutamine repeat stretch that has been postulated to confer
toxic effects by several different mechanisms (The Huntington's
Disease Collaborative Research Group, 1993 ). The protein product of the
HD gene, huntingtin, is expressed ubiquitously in both the nervous
system and peripheral tissues (Strong et al., 1993; Landwehrmeyer et
al., 1995; Sharp et al., 1995; Ferrante et al., 1997).
A breakthrough in HD research was the development of transgenic mouse
models. Transgenic mice expressing exon 1 of the human HD gene with an
expanded CAG repeat develop a progressive neurological disorder
(Mangiarini et al., 1996). These mice (line R 6/2) have CAG repeat
lengths of 141-157 (normal, <35), under the control of the human HD
promoter. At ~6 weeks of age the R6/2 mice show loss of brain and
body weight, and at 9-11 weeks they develop an irregular gait, abrupt
shuddering, stereotypic movements, resting tremors, and epileptic
seizures. The mice show an early decrease of several neurotransmitter
receptors (Cha et al., 1998). The brains of R6/2 mice appear normal in
most respects, however, neuronal intranuclear inclusions that are
immunopositive for huntingtin and ubiquitin are detected in the
striatum at 4.5 weeks (Davies et al., 1997). Neuropil, cytoplasmic, and
neuronal inclusions are also found in human HD (DiFiglia et al., 1997;
Gutekunst et al., 1999; Kuemmerle et al., 1999).
A secondary effect of the gene defect may be impaired energy metabolism
that may contribute to neuronal death. Consistent with this hypothesis,
we and others found that: (1) lactate is elevated in the cerebral
cortex and basal ganglia of patients with HD, (2) there is reduced
phosphocreatine/inorganic phosphate in resting muscle of HD patients,
(3) mitochondrial toxins produce selective damage in the striatum of
animals, which closely resembles the pathology of HD, and (4) there are
reductions in mitochondrial electron transport enzymes in HD postmortem
tissue (Jenkins et al., 1993; Brouillet et al., 1995; Gu et al., 1996;
Browne et al., 1997; Koroshetz et al., 1997). Recent studies show
increased susceptibility of mitochondria to depolarization in HD
lymphoblasts and fibroblasts (Gutekunst et al., 1996; Sawa et al.,
1999). Our studies in R6/2 mice show that they develop marked decreases
in N-acetylaspartate (NAA) concentrations before neuronal
loss (Jenkins et al., 2000) and increased vulnerability to the
mitochondrial toxin 3-nitropropionic acid (Bogdanov et al., 1998). This
may be a consequence of mitochondrial dysfunction (Bates et al.,
1996).
If mitochondrial impairment plays a role in neuronal dysfunction in
the R6/2 mice, then buffering intracellular energy levels may
ameliorate the neurodegenerative process in these animals. Creatine
kinase and its substrates creatine and phosphocreatine constitute an
intricate cellular energy buffering and transport system connecting
sites of energy production (mitochondria) with sites of energy
consumption (Hemmer and Wallimann, 1993). Creatine administration
increases brain concentrations of PCr and inhibits activation of the
mitochondrial permeability transition (MPT), both of which may exert
neuroprotective effects (Hemmer and Wallimann, 1993; O'Gorman et al.,
1996). We previously showed that creatine administration is
neuroprotective in mitochondrial toxin models of HD (Matthews et al.,
1998). In the present study, we examined whether creatine
administration exerts beneficial effects on survival as well as the
behavioral and neuropathological phenotype in R6/2 mice.
| |
MATERIALS AND METHODS |
Transgenic HD mice of the R6/2 strain and littermate controls
were obtained from Jackson Laboratories (Bar Harbor, ME). The male R6/2
mice were bred with females from their background strain (B6 CBAFI/J).
The offspring were genotyped by PCR assay of DNA obtained from tail
tissue. CAG repeat length, using a PCR radioassay method (Wheeler et
al., 1999), was examined to ensure that a drift in number of CAG
repeats did not play a role in the outcome of the studies (courtesy of
Dr. Marcy MacDonald, Massachusetts General Hospital). The repeat length
remained stable within a 151-154 range. Transgenic mice were housed in
microisolator cages in a modified barrier facility. A 12 hr light/dark
cycle was maintained, and animals were given ad libitum
access to food and water. Groups (n = 25) of transgene
negative and positive R6/2 mice from the same "f" generation were
placed on either unsupplemented diets or diets supplemented with 1, 2, or 3% creatine at 21 d of age (Avicena Group, Cambridge, MA).
Approximately 200 mice were used in the survival studies.
Behavioral testing (rotarod). Mice were given 2 d to become acquainted with the rotarod apparatus (Columbus
Instruments, Columbus, OH). Testing commenced on day 23. Mice were
placed on a rod that was rotating at 10 rpm. Each mouse was given three
trials for a maximum of 180 sec for each trial. The length of time at
which the mouse fell off the rotating rod was used as the measure of competency on this task. Mice were tested twice weekly until the R6/2
mice were unable to perform the task.
Body weights. Mice were weighed twice a week at the same
time of day.
Survival. Mice were observed twice daily, in the morning and
late afternoon. The criterion for killing was the point in time when the mice were unable to initiate movement after being gently prodded for 10 min. Two independent observers confirmed this criterion, and this point was used as the time of death.
NMR spectroscopy. We performed in vivo
spectroscopy at 4.7 T (GE Omega CSI; GE, Freemont, CA) using a
sinusoidal bird cage coil (diameter, 20 mm). Mice were anesthetized
using halothane/N2O/O2 anesthesia (1.5% halothane; 2:1
O2/N2O). Body temperature
was maintained using two water blankets surrounding the body at 38°C. Localized proton spectroscopy was run using a PRESS sequence
(Bottomley, 1987), with an echo time (TE) of 136 msec and a repetition
time (TR) of 2 sec. Spectral width was 2 kHz with 1024 complex
points. Six hundred averages were acquired for each spectrum. The
transmitter frequency was placed between the NAA and creatine
resonances. Voxels were placed symmetrically around both basal ganglia
with an average voxel size of 6 × 3.5 × 3 µm (63 µl).
Spectra were analyzed using the NMR1 software program (New Methods
Research, Syracuse, NY). Spectra were integrated, and the choline peak
was normalized to the signal-to-noise of a water spectrum run from the
same voxel without water suppression, but with a TR/TE of 10,000/20
msec and eight averages. The NAA and total creatine values were then
taken as a ratio to the choline peak.
Histological evaluation. At 21 d, R6/2 transgenic mice
and negative littermate controls were fed 2% creatine-supplemented and
unsupplemented diets. Groups of 20 animals were deeply anesthetized and
then transcardially perfused with 4% buffered paraformaldehyde at 21, 28, 42, 63, and 90 d. The brains were removed, post-fixed with the
perfusant for 2 hr, weighed, cryoprotected in a graded series of 10 and
20% glycerol/2% DMSO solution, subsequently serially frozen sectioned
at 50 µm, stored in six well tissue collection clusters, and stained
for Nissl substance (cresyl violet). Serially cut tissue sections were
immunostained for huntingtin using an antibody (EM48; dilution,
1:1,000) that recognizes the first 256 amino acids of human huntingtin
lacking the polyglutamine and polypeptide stretches (courtesy of Dr.
Xiao-Jiang Li) (Gutekunst et al., 1999). The antibody reacts with
N-terminal fragments of huntingtin expressed by transfection. It is a
sensitive marker of huntingtin aggregation. An antibody to ubiquitin
(dilution, 1:200; Dako, Carpinteria, CA) was used in tissue sections to
confirm the presence of aggregates.
Stereology and quantitation. Serial-cut coronal tissue
sections from the rostral segment of the neostriatum to the level of the anterior commissure (interaural 5.34 mm/bregma 1.54 mm to interaural 3.7 mm/bregma  0.10 mm) (Franklin and Paxinos, 1997), including the primary motor cortex, were used for neuronal and huntingtin aggregate analysis. Unbiased stereological counts of huntingtin-positive aggregates ( 1.0 µm) were obtained from the neostriatum and layer 6 of the neocortex in 10 animals from
unsupplemented and 2% creatine-supplemented R6/2 mice at 28, 42, 63, and 90 d using Neurolucida Stereo Investigator software
(Microbrightfield, Colchester, VT). The total areas of the neostriatum
and motor cortex were defined in serial sections in which counting
frames were randomly sampled. The dissector counting method was used in
which huntingtin-positive aggregates were counted in an unbiased selection of serial sections in a defined volume of the neostriatum and
neocortex. Striatal neuron areas were analyzed by microscopic videocapture using a Windows-based image analysis system for area measurement (Optimas; Bioscan Incorporated, Edmonds, WA). The software
automatically identifies and measures profiles. All computer-identified cell profiles were manually verified as neurons and exported to Microsoft Excel. Cross-sectional areas were analyzed using Statview.
Glucose tolerance test. After 6-7 hr of fasting,
baseline levels of glucose were measured. The mice were lightly
anesthetized with isoflurane gas, and tail vein blood was collected.
The mice were subsequently given a bolus injection of glucose (1.5 gm/kg, i.p.), and plasma glucose levels were measured 30 and 60 min
later with Lifescan One Touch basic glucose monitoring system (Johnson & Johnson) and validated by semiautomatic glucose oxidase enzyme assay (Beckman).
Statistics. Statistical comparisons for survival were made
by the Mantel-Cox log-rank test. Statistical comparisons of other parameters were made by ANOVA or repeated measures ANOVA of other parameters followed by the Fisher's least significant difference test.
| |
RESULTS |
The effects of oral administration of creatine in the diet on
survival in HD transgenic mice are shown in Table
1. Oral administration of 1% creatine or
2% creatine in the diet dose-dependently improved survival.
Administration of 3% creatine significantly improved survival, but was
not as effective as either 1 or 2% creatine. Oral administration of
2% creatine was significantly more efficacious than 3% creatine
(p < 0.0001). The mean survival in controls
increased from 97.6 ± 0.7 d to 106.6 ± 0.5 d with
1% creatine (p < 0.0001), to 114.6 ± 0.9 d with 2% creatine (p < 0.0001), and
101.9 ± 1.0 d with 3% creatine (p < 0.0002). The percentage increase in survival for 1, 2, and 3% creatine
was 9.4, 17.4, and 4.4%, respectively.
The effects of oral administration of creatine in the diet on rotarod
performance between 21 and 90 d are shown in Figure 1. There was a dose-dependent effect of
creatine supplementation. Oral administration of 2% creatine
significantly improved rotarod performance throughout the entire
measured (4-13 weeks) life span of the R6/2 mice in contrast to
unsupplemented R6/2 mice (2% creatine, 156 ± 20 sec;
unsupplemented, 88 ± 39 sec, p < 0.001, data
represents combined means and SDs from 5 to 12.5 weeks). Dietary
supplementation with 1% creatine resulted in significant motor
improvement from 5 to 10 weeks (1% creatine, 161 ± 14 sec;
unsupplemented, 114 ± 28 sec, p < 0.001, data
represents combined means and SDs from 5 to 10 weeks), with no
significance observed after 10 weeks. Oral supplementation using 3%
creatine had no significant effect on rotarod performance. The percent
increase in rotarod performance for 1, 2, and 3% creatine was 25, 33, and 6.5%, respectively.
View larger version (19K):
[in this window]
[in a new window]
|
Figure 1.
Effects of 1, 2, and 3% creatine on rotarod
performance. There was significantly improved performance in R6/2 HD
transgenic mice with 2% creatine supplementation throughout the
temporal sequence of the experiment (4-13 weeks)
(B), from 5-10 weeks in 1% creatine-treated
mice (A), with significance only occurring at 6 weeks in the 3% creatine-treated R6/2 mice
(C).
|
|
The effects of oral administration of creatine on body weight in HD
transgenic mice are shown in Figure 2.
Whereas all creatine regimens resulted in significant improvement of
body weight in comparison to unsupplemented R6/2 mice, 2% dietary
creatine supplementation resulted in a significantly greater body
weight gain in R6/2 mice (p < 0.01) than either
1 or 3% creatine supplementation (p < 0.02). Significantly greater body weight measurements were present throughout the temporal sequence of measurements (5-13 weeks) in 1 and 2% supplemented R6/2 mice, but were only found from 10-13 weeks in the
3% supplemented group. The total percentage of increase in body weight
from 4 to 13 weeks for 1, 2, and 3% creatine-fed R6/2 animals in
comparison to unsupplemented R6/2 mice was 6.8, 10.3, and 6.5%,
respectively. In comparison to transgene-negative littermate control
mice, significant body weight loss in 2% creatine-supplemented mice
was delayed until 10 weeks of age. In contrast, significant body weight
loss began after 6 weeks in untreated R6/2 mice (data not shown).
View larger version (19K):
[in this window]
[in a new window]
|
Figure 2.
Effects of 1, 2, and 3% creatine on body weight
in R6/2 HD transgenic mice. Whereas significantly greater body weight
was observed throughout the measured temporal sequence in 1%
(except 6 weeks) and 2% creatine-supplemented R6/2 mice,
significance was present only from 10 to 13 weeks in the 3% treated
mice.
|
|
Gross brain weights of unsupplemented R6/2 mice decreased significantly
over time until death in comparison to both transgene-negative littermate control mice and 2% creatine-supplemented R6/2 mice at all
time points (Table 2). By 90 d,
there was a 20.4% reduction in brain weight in contrast to littermate
control mice. In comparison, there was no significant decrease in brain
weight in the 2% dietary creatine-supplemented R6/2 mice as compared
to controls until end stage measurements at 90 d. At that time
there was a 6.8% difference in brain weight (Table 2). Coincident with
brain weight loss, progressive marked gross atrophy was present in the
unsupplemented R6/2 brains, especially within the neostriatum (Fig.
3). The striatal atrophy was reminiscent
of the neuropathological grading we observed in Huntington's disease
(Vonsattel et al., 1985), such that there was bilateral ventricular
enlargement with a flattening of the medial aspect of the striatum in
the late stages of the illness. Dietary 2% creatine supplementation
reduced gross brain atrophy in R6/2 mice in comparison to the untreated
R6/2 mice (Fig. 3).
View larger version (135K):
[in this window]
[in a new window]
|
Figure 3.
Photomicrographs of coronal sections through the
rostral neostriatum at the level of the anterior commissure in R6/2 HD
transgenic mice at 42 (A), 63 (B), and 90 (C) d. Note the
generalized gross atrophy of the brain over time along with enlargement
of the lateral ventricles. In contrast, a 2% creatine-supplemented
R6/2 mouse at 90 d (D) shows significantly
less atrophy and ventricular enlargement than the unsupplemented mouse
(C). Scale bar, 2 mm.
|
|
Consistent with the gross brain weight loss and striatal atrophy, there
was significant progressive atrophy of striatal neurons from 21 to
90 d in the unsupplemented R6/2 mice with a 37.9% overall decrease in area measurements (striatal neurons R6/2 at 28 d, 88.8 ± 10.7 µm2; striatal neurons
R6/2 at 90 d, 55.1 ± 16.8 µm2; p < 0.001) (Figs.
4, 5). The
cytoprotective effect of 2% creatine significantly delayed striatal
neuron atrophy. There were no significant differences in neuronal areas
in 2% creatine-supplemented R6/2 mice until endstage measurements at
90 d of age (Fig. 4).
View larger version (46K):
[in this window]
[in a new window]
|
Figure 4.
Neuronal areas of 2% creatine-supplemented and
unsupplemented R6/2 mice in comparison to littermate transgene-negative
mice at 28, 42, 63, and 90 d; *p < 0.001.
|
|
View larger version (140K):
[in this window]
[in a new window]
|
Figure 5.
Photomicrographs of Nissl-stained tissue sections
from the dorsomedial aspect of the neostriatum (A, C, E,
G) and 2% creatine-supplemented (B, D, F,
H) R6/2 HD transgene mice at 4 (A, B), 6 (C, D), 9 (E, F), and 13 (G, H) weeks. Note the progressive loss in
neuronal size in the unsupplemented R6/2 group, with delayed neuronal
atrophy in the 2% creatine-supplemented R6/2 mice. Scale bar, 100 µm.
|
|
We examined six mice fed with 2% creatine and eight unsupplemented
mice using NMR spectroscopy at 51-57 d of age. As compared with
unsupplemented mice, there was a significantly higher NAA/choline ratio
in the creatine-fed mice (0.37 ± 0.06 vs 0.48 ± 0.03;
p < 0.05). The creatine/choline was significantly
increased from 0.67 ± 0.04 to 0.83 ± 0.07 (p < 0.01). In a total of 13 mice fed creatine compared to 14 mice on unsupplemented diets, including mice
older than 70 d of age, the NAA/choline ratio was 0.54 ± 0.03 vs 0.45 ± 0.04 (p = 0.09). In the
total group the creatine/choline was 0.85 ± 0.04 vs 0.72 ± 0.03 (p < 0.01). When normalized to a water
standard, there was a significant 21.3 ± 3.8% increase in brain
creatine concentrations. In the creatine-treated mice there was a
significant correlation between NAA/choline and Cr/choline (p < 0.01) that was not seen in the
unsupplemented mice (Fig. 6).
View larger version (20K):
[in this window]
[in a new window]
|
Figure 6.
Correlation between creatine and NAA levels in HD
transgenic R6/2 mice. Correlation between NAA and CR in unsupplemented
mice was not significant.
|
|
An analysis of the formation of aggregates in the neostriatum and
cortex of R6/2 mice showed an early and progressive accumulation of
huntingtin-positive aggregates, as well as an increase in aggregate size, from 21 d of age to the data collection end point at 90 d. Aggregates were much more prominent within the cortex in comparison to the neostriatum. Dietary supplementation with 2% creatine resulted in a significant reduction in striatal aggregate number throughout treatment at each measured time point (Figs.
7, 8). At
28, 42, 63, and 90 d, the percentage of decrease in aggregate
number as compared with unsupplemented mice was 60, 51, 35, and 39%,
respectively. A similar trend toward decreased aggregate number was
present within the cortex in 2% creatine-treated R6/2 mice, however
these decreases were not significant (Figs. 7,
9).
View larger version (29K):
[in this window]
[in a new window]
|
Figure 7.
Graphs of the temporal sequence in the number of
huntingtin-positive aggregates in the neostriatum
(A) and motor neocortex (B)
at 4, 6, 9, and 13 weeks. There was a significant delay in the
formation of aggregates within the striatum in 2%
creatine-supplemented R6/2 mice, in comparison to unsupplemented R6/2
mice. Although a similar trend was observed in the neocortex,
significance was not obtained.
|
|
View larger version (86K):
[in this window]
[in a new window]
|
Figure 8.
Photomicrographs of huntingtin-immunostained
tissue sections from dorsomedial aspect of the neostriatum at the level
of the anterior commissure in 2% creatine-supplemented (A, C,
E, G) and unsupplemented (B, D, F, H)
R6/2 HD transgene mice at 4 (A, B), 6 (C,
D), 9 (E, F), and 13 (G,
H) weeks. There is a progressive increase in number and
size of huntingtin aggregates over time in the unsupplemented R6/2 mice
in comparison to the delay in aggregate formation in the 2%
creatine-supplemented R6/2 mice. Scale bar, 50 µm.
|
|
View larger version (151K):
[in this window]
[in a new window]
|
Figure 9.
Photomicrographs of huntingtin-immunostained
tissue sections from layer 6 of the motor cortex at the level of the
anterior commissure in unsupplemented (A, C, E) and 2%
creatine-supplemented (B, D, F) R6/2 HD transgene
mice at 4 (A, B), 9 (C, D), and 13 (E, F) weeks. There is a progressive increase in
number and size of huntingtin aggregates over time in the
unsupplemented R6/2 mice in comparison to the delay in aggregate
formation in the 2% creatine-supplemented R6/2 mice. Scale bar, 100 µm.
|
|
In the unsupplemented R6/2 mice, there was an increase of
huntingtin-positive aggregates in the pancreatic Islets of Langerhan over time that was first observed at 42 d and became most
prominent at 90 d (Fig. 10).
Little or no detectable huntingtin-positive aggregates were observed in
the pancreatic stroma. Dietary 2% creatine significantly reduced
aggregate number in the pancreas of 90-d-old R6/2 mice (2% creatine,
57 ± 12/field; unsupplemented, 139 ± 15/field;
p < 0.001) (Fig. 10). Furthermore, administration of
2% creatine significantly delayed the onset of diabetes as assessed by a glucose tolerance test at 8.5 weeks of age (Fig. 11).
View larger version (108K):
[in this window]
[in a new window]
|
Figure 10.
Photomicrographs of islets of Langerhan in the
pancreas of 90-d-old unsupplemented (A) and 2%
creatine-supplemented (B) R6/2 HD transgenic mice
immunostained with EM48 antibody. There is a marked reduction in the
huntingtin aggregates within the treated mouse. Scale bar, 50 µm.
|
|
View larger version (20K):
[in this window]
[in a new window]
|
Figure 11.
Effects of 2% creatine supplementation on
glucose tolerance in 8.5-week-old R6/2 mice. Creatine administration
significantly attenuated abnormal glucose tolerance.
*p < 0.05; **p < 0.01.
|
|
| |
DISCUSSION |
The development of transgenic mouse models of neurodegenerative
diseases provides a major advance for studying disease pathogenesis and
for developing therapeutics. If therapeutic effects in the transgenic
mice are shown to be predictive of beneficial effects in man, then this
will allow rapid screening for new therapies. As discussed above, there
is substantial evidence that energy dysfunction occurs in HD, and that
this may play a role in cell death. Creatine administration, as
discussed below, has several potential neuroprotective effects,
including buffering of intracellular energy reserves, stabilizing
intracellular calcium, and inhibiting activation of the MPT, all of
which have been linked to excitotoxic and apoptotic cell death
(O'Gorman et al., 1997; Leist and Nicotera, 1998; Lipton and Nicotera,
1998).
The brain isoform of creatine kinase along with the mitochondrial
isoform and the substrates creatine and phosphocreatine constitute a
system that appears to be critical in regulating energy homeostasis in
the brain (Hemmer and Wallimann, 1993). There is evidence for a direct
functional coupling of creatine kinase with sodium potassium ATPase,
neurotransmitter release, maintenance of membrane potentials, and
restoration of ion gradients after depolarization (Dunant et al., 1988;
Hemmer and Wallimann, 1993). An important role of creatine kinase in
the adult brain is supported by in vivo
31P NMR transfer measurements. These show
that creatine kinase flux correlates with brain activity as measured by
the EEG, as well as with amounts of 2-deoxyglucose uptake in the brain
(Sauter and Rudin, 1993; Corbett and Laptook, 1994). We previously
showed that administration of creatine increases brain phosphocreatine concentrations and buffers against toxin-induced depletions (Matthews et al., 1998).
Creatine kinase also appears to be coupled directly or indirectly to
energetic processes required for calcium homeostasis (Wallimann et al.,
1992; Steeghs et al., 1997). Creatine pretreatment delays increases in
intracellular calcium produced by 3-nitropropionic acid in cortical and
striatal astrocytes in vitro (Deshpande et al., 1997).
Another potential neuroprotective mechanism is the ability of
phosphocreatine to stimulate synaptic glutamate uptake and thereby
reduce extracellular glutamate (Xu et al., 1996).
Lastly, creatine may protect against activation of the MPT, which is
associated with both apoptotic and necrotic cell death (Bernardi et
al., 1998). The MPT is a Ca2+-dependent
increase of the inner membrane permeability to ions and solutes of up
to 1500 Da. Mitochondrial creatine kinase is implicated in a functional
interaction between the outer membrane voltage-dependent anion channel
and the inner membrane adenylate translocator, which are components of
the MPT (Brdiczka et al., 1998). Creatine administration can stabilize
mitochondrial creatine kinase in an octomeric form, which inhibits
activation of the MPT (O'Gorman et al., 1997). Mitochondrial creatine
kinase is also a prime target for peroxynitrite-induced damage, which
results in dissociation of mitochondrial creatine kinase octomers into dimers (Soboll et al., 1999). Creatine administration inhibits peroxynitrite-induced modification and inactivation (Stachowiak et al.,
1998). Creatine administration may also increase ADP concentrations, which inhibits activation of the MPT (Bernardi et al., 1998).
Previous studies showed neuroprotective effects of creatine in
vitro and in vivo. Creatine reduces anoxic damage to
hippocampal slices in vitro (Carter et al., 1995). We have
found that creatine administration exerts neuroprotective effects
against animal models of Huntington's disease produced by
administration of the mitochondrial toxins malonate and
3-nitropropionic acid (Matthews et al., 1998). Creatine administration
also attenuates 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced dopamine depletions and substantia nigra neuronal loss (Matthews et al., 1999). In addition, creatine administration increases survival and improves motor performance in a transgenic mouse
model of amyotrophic lateral sclerosis and results in marked neuroprotective effects against the loss of anterior horn motor neurons
and substantia nigra dopaminergic neurons (Klivenyi et al., 1999).
In the present study, we therefore investigated whether creatine could
exert neuroprotective effects in a transgenic mouse model of HD. We
found that creatine dose-dependently improved survival in these mice.
The increased survival results are comparable to the report of Ona et
al. (1999) in which R6/2 mice were crossed with mice with a
dominant-negative inhibitor of caspase 1. In that study the maximal
increase in survival was 20 d or 20%, whereas in our study 2%
creatine increased survival by 17 d or 17.5%. The effect with 3%
creatine, however, was less than that seen with either 1% or 2%
creatine, consistent with an inverted dose-response curve. We have
made similar observations with malonate and MPTP toxicity (Matthews et
al., 1998, 1999). The explanation for the inverted dose-response curve
is unclear, and at very high concentrations creatine may be toxic,
similar to observations with cyclocreatine (Matthews et al., 1998).
Creatine administration resulted in improved rotarod performance and
reduced weight loss in the R6/2 mice. Similar to effects on survival,
2% creatine was most efficacious, with 1% creatine more effective
than 3% creatine. Interestingly, the administration of creatine also
delayed the onset of diabetes that has been demonstrated in these mice
(Hurlbert et al., 1999). Administration of creatine delayed the
development of both striatal and pancreatic huntingtin-positive aggregates, consistent with other recent observations that experimental manipulations can slow the development of nuclear intraneuronal inclusions (Ona et al., 1999). Cross-sectional areas of striatal neurons in R6/2 and other transgenic models of HD have been recently reported to be reduced (Reddy et al., 1998; Hodgson et al., 1999; Levine et al., 1999). Consistent with these findings, we found that
administration of 2% creatine significantly delayed the development of
both neuronal shrinkage, as well as gross atrophy of the brain. Using
NMR spectroscopy we showed that 2% creatine significantly increased
brain creatine concentrations by 21% and that it significantly attenuated early decreases in N-acetylaspartate
concentrations. The increases in creatine peak may largely
reflect PCr consistent with our earlier biochemical
measurements (Matthews et al., 1998). We recently found a 53% decrease
in N-acetylaspartate concentrations in the R6/2 mice
starting at 6 weeks of age (Jenkins et al., 2000). N-acetylaspartate is a neuronal marker that decreases in HD
(Jenkins et al., 1998), however it may also reflect mitochondrial
function (Bates et al., 1996). NMR spectroscopy could therefore be
useful in monitoring therapeutic effects of creatine in patients.
These results provide further evidence that creatine is neuroprotective
in animal models of neurodegenerative diseases. Creatine administration
is well tolerated in man, results in increased PCr levels, and may have
benefits in pathological conditions (Balsom et al., 1994; Dawson et
al., 1995; Greenhaff, 1997). Long-term administration to patients with
gyrate atrophy of the choroid in the retina prevented visual field
constriction and resulted in improvement of muscle biopsy findings
(Sipila et al., 1981). Several pediatric patients with creatine
deficiency accompanied by an extrapyramidal movement disorder showed
partial restoration of cerebral creatine concentrations and clinical
improvement after oral creatine administration (Stockler et al., 1994,
1996). Creatine administration has also resulted in significant
improvement of patients with the mitochondrial disorder mitochondrial
encephalopathy lactic acidosis and strokes (Tarnopolsky et al., 1997),
as well as in patients suffering from neuromuscular disorders
(Tarnopolsky and Martin, 1999). The present findings support a role for
metabolic dysfunction in a transgenic mouse model of HD and provide
further evidence that treatment with creatine might be a novel
therapeutic strategy to slow or halt the progression of
neurodegeneration in HD.
| |
FOOTNOTES |
Received Feb. 1, 2000; revised March 21, 2000; accepted March 24, 2000.
This work was supported by National Institutes of Health Grants NS38180
(M.F.B.), NS35255 (R.J.F. and S.M.H.), NS37102 and AG13846 (R.J.F.),
and AG12992 (M.F.B. and R.J.F.), the Hereditary Disease Foundation, the
Huntington's Disease Society of America, and the Veteran's
Administration. The secretarial assistance of Sharon Melanson is
gratefully acknowledged.
Correspondence should be addressed to Dr. M. Flint Beal, Chairman,
Neurology Department, New York Hospital-Cornell Medical Center, 525 East 68th Street, New York, NY 10021. E-mail:
fbeal{at}mail.med.cornell.edu or Dr. Robert J. Ferrante, GRECC Unit,
182B, Bedford VA Medical Center, 200 Springs Road, Bedford, MA 01730. E-mail: rjferr{at}bu.edu.
| |
REFERENCES |
-
Balsom PD,
Soderlund K,
Ekblom B
(1994)
Creatine in humans with special reference to creatine supplementation.
Sports Med
18:268-280[Web of Science][Medline].
-
Bates TE,
Strangward M,
Keelan J,
Davey GP,
Munro PMG,
Clark JB
(1996)
Inhibition of N-acetylaspartate production: implications for 1H MRS studies in vivo.
NeuroReport
7:1397-1400[Web of Science][Medline].
-
Bernardi P,
Basso E,
Colonna R,
Costantini P,
Di Lisa F,
Eriksson O,
Fontaine E,
Forte M,
Ichas F,
Massari S,
Nicolli A,
Petronilli V,
Scorrano L
(1998)
Perspectives of the mitochondrial permeability transition.
Biochim Biophys Acta
1365:200-206.
-
Bogdanov MB,
Ferrante RJ,
Kuemmerle S,
Klivenyi P,
Beal MF
(1998)
Increased vulnerability to 3-nitropropionic acid in an animal model of Huntington's disease.
J Neurochem
71:2652-2644.
-
Bottomley PA
(1987)
Spatial localization in NMR spectroscopy in vivo.
Ann NY Acad Sci
508:333-348[Web of Science][Medline].
-
Brdiczka D,
Beutner G,
Ruck A,
Dolder M,
Wallimann T
(1998)
The molecular structure of mitochondrial contact sites. Their role in regulation of energy metabolism and permeability transition.
Biofactors
8:235-242[Web of Science][Medline].
-
Brouillet E,
Hantraye P,
Ferrante RJ,
Dolan R,
Leroy-Willig A,
Kowall NW,
Beal MF
(1995)
Chronic mitochondrial energy impairment produces selective striatal degeneration and abnormal choreiform movements in primates.
Proc Natl Acad Sci USA
92:7105-7109[Abstract/Free Full Text].
-
Browne SE,
Bowling AC,
MacGarvey U,
Baik MJ,
Berger SC,
Muqit MMK,
Bird ED,
Beal MF
(1997)
Oxidative damage and metabolic dysfunction in Huntington's disease: selective vulnerability of the basal ganglia.
Ann Neurol
41:646-653[Web of Science][Medline].
-
Carter AJ,
Muller RE,
Pschorn U,
Stransky W
(1995)
Preincubation with creatine enhances levels of creatine phosphate and prevents anoxic damage in rat hippocampal slices.
J Neurochem
64:2691-2699[Web of Science][Medline].
-
Cha J-HJ,
Kosinski CM,
Kerner JA,
Alsdorf SA,
Mangiarini L,
Davies SW,
Penney JB,
Bates GP,
Young AB
(1998)
Altered brain neurotransmitter receptors in transgenic mice expressing a portion of an abnormal human Huntington disease gene.
Proc Natl Acad Sci USA
95:6480-6485[Abstract/Free Full Text].
-
Corbett RJT,
Laptook AR
(1994)
Age-related changes in swine brain creatine kinase-catalyzed 31P exchange measured in vivo using 31P NMR magnetization transfer.
J Cereb Blood Flow Metab
14:1070-1077[Web of Science][Medline].
-
Davies SW,
Turmaine M,
Cozens BA,
DiFiglia M,
Sharp AH,
Ross CA,
Scherzinger E,
Wanker EE,
Mangiari L,
Bates GP
(1997)
Formation of neuronal intranuclear inclusions underlies the neurological dysfunction in mice transgenic for the HD mutation.
Cell
90:537-548[Web of Science][Medline].
-
Dawson TM,
Hung K,
Dawson VL,
Steiner JP,
Snyder SH
(1995)
Neuroprotective effects of gangliosides may involve inhibition of nitric oxide synthase.
Ann Neurol
37:115-118[Web of Science][Medline].
-
Deshpande SB,
Fukuda A,
Nishino H
(1997)
3-Nitropropionic acid increases the intracellular Ca2+ in cultured astrocytes by reverse operation of the Na+-Ca2+ exchanger.
Exp Neurol
145:38-45[Web of Science][Medline].
-
DiFiglia M,
Sapp E,
Chase KO,
Davies SW,
Bates GP,
Vonsattel JP,
Aronin N
(1997)
Aggregation of huntingtin in neuronal intranuclear inclusions and dystrophic neurites in brain.
Science
277:1990-1993[Abstract/Free Full Text].
-
Dunant Y,
Loctin F,
Marsal J,
Muller D,
Parducz A,
Rabasseda X
(1988)
Energy metabolism and quantal acetylcholine release: effects of botulinum toxin, 1-fluoro-2,4-dinitrobenzene, and diamide in the Torpedo electric organ.
J Neurochem
50:431-439[Web of Science][Medline].
-
Ferrante RJ,
Gutekunst CA,
Persichetti F,
McNeil SM,
Kowall NW,
Gusella JF,
MacDonald ME,
Beal MF,
Hersch SM
(1997)
Heterogeneous topographic and cellular distribution of huntingtin expression in the normal human neostriatum.
J Neurosci
17:3052-3063[Abstract/Free Full Text].
-
Franklin KBJ,
Paxinos G
(1997)
In: The mouse brain in stereotaxic coordinates. New York: Academic.
-
Greenhaff PL
(1997)
The nutritional biochemistry of creatine.
J Nutr Biochem
8:610-618[Web of Science].
-
Gu M,
Gash MT,
Mann VM,
Javoy-Agid F,
Cooper JM,
Schapira AHV
(1996)
Mitochondrial defect in Huntington's disease caudate nucleus.
Ann Neurol
39:385-389[Web of Science][Medline].
-
Gutekunst C-A,
Peng T-I,
Whaley WL,
Rock B,
Hersch SM,
Greenamyre JT
(1996)
Mitochondrial calcium homeostasis in Huntington's disease fibroblasts.
Soc Neurosci Abstr
22:227.
-
Gutekunst CA,
Li SH,
Yi H,
Mulroy JS,
Kuemmerle S,
Jones R,
Rye D,
Ferrante RJ,
Hersch SM,
Li XJ
(1999)
Nuclear and neuropil aggregates in Huntington's disease: relationship to neuropathology.
J Neurosci
19:2522-2534[Abstract/Free Full Text].
-
Hemmer W,
Wallimann T
(1993)
Functional aspects of creatine kinase in brain.
Dev Neurosci
15:249-260[Web of Science][Medline].
-
Hodgson JG,
Agopyan N,
Gutekunst CA,
Leavitt BR,
LePiane F,
Singaraja R,
Smith DJ,
Bissada N,
McCutcheon K,
Nasir J,
Jamot L,
Li XJ,
Stevens ME,
Rosemond E,
Roder JC,
Phillips AG,
Rubin EM,
Hersch SM,
Hayden MR
(1999)
A YAC mouse model for Huntington's disease with full-length mutant huntingtin, cytoplasmic toxicity, and selective striatal neurodegeneration.
Neuron
23:181-192[Web of Science][Medline].
-
Hurlbert MS,
Zhou W,
Wasmeier C,
Kaddis FG,
Hutton JC,
Freed CR
(1999)
Mice transgenic for an expanded CAG repeat in the Huntington's disease gene develop diabetes.
Diabetes
48:649-651[Abstract].
-
Jenkins B,
Koroshetz W,
Beal MF,
Rosen B
(1993)
Evidence for an energy metabolism defect in Huntington's disease using localized proton spectroscopy.
Neurology
43:2689-2695[Abstract/Free Full Text].
-
Jenkins BG,
Rosas HD,
Chen YC,
Makabe T,
Myers R,
MacDonald M,
Rosen BR,
Beal MF,
Koroshetz WJ
(1998)
1H NMR spectroscopy studies of Huntington's disease: correlations with CAG repeat numbers.
Neurology
50:1357-1365[Abstract/Free Full Text].
-
Jenkins BG,
Klivenyi P,
Kustermann E,
Andreassen OA,
Ferrante RJ,
Rosen BR,
Beal MF
(2000)
Non-linear decrease over time in N-acetylaspartate levels in the absence of neuronal loss and increases in glutamine and glucose in transgenic Huntington's disease mice.
J Neurochem
74:2108-2119[Web of Science][Medline].
-
Klivenyi P,
Ferrante RJ,
Matthews RT,
Bogdanov MB,
Klein AM,
Andreassen OA,
Mueller G,
Wermer M,
Kaddurah-Daouk R,
Beal MF
(1999)
Neuroprotective effects of creatine in a transgenic animal model of ALS.
Nat Med
5:347-350[Web of Science][Medline].
-
Koroshetz WJ,
Jenkins BG,
Rosen BR,
Beal MF
(1997)
Energy metabolism defects in Huntington's disease and possible therapy with coenzyme Q10.
Ann Neurol
41:160-165[Web of Science][Medline].
-
Kuemmerle S,
Gutekunst CA,
Klein AM,
Li XJ,
Li SH,
Beal MF,
Hersch SM,
Ferrante RJ
(1999)
Huntingtin aggregates may not predict neuronal death in Huntington's disease.
Ann Neurol
46:842-849[Web of Science][Medline].
-
Landwehrmeyer GB,
McNeil SM,
Dure I, LS,
Ge P,
Aizawa H,
Huang Q,
Ambrose CM,
Duyao MP,
Bird ED,
Bonilla E,
de Young M,
Avila-Gonzales AJ,
Wexler NS,
DiFiglia M,
Gusella JF,
MacDonald ME,
Penney JB,
Young AB,
Vonsattel J-P
(1995)
Huntington's disease gene: regional and cellular expression in brain of normal and affected individuals.
Ann Neurol
37:218-230[Web of Science][Medline].
-
Leist M,
Nicotera P
(1998)
Apoptosis, excitotoxicity, and neuropathology.
Exp Cell Res
239:183-201[Web of Science][Medline].
-
Levine MS,
Klapstein GJ,
Koppel A,
Gruen E,
Cepeda C,
Vargas ME,
Jokel ES,
Carpenter EM,
Zanjani H,
Hurst RS,
Efstratiadis A,
Zeitlin S,
Chesselet MF
(1999)
Enhanced sensitivity to N-methyl-D-aspartate receptor activation in transgenic and knockin mouse models of Huntington's disease.
J Neurosci Res
58:515-532[Web of Science][Medline].
-
Lipton SA,
Nicotera P
(1998)
Excitotoxicity, free radicals, necrosis, and apoptosis.
Neuroscientist
4:345-352[Abstract/Free Full Text].
-
Mangiarini L,
Sathasivam K,
Seller M,
Cozens B,
Harper A,
Hetherington C,
Lawton M,
Trottier Y,
Lehrach H,
Davies SW,
Bates GP
(1996)
Exon 1 of the HD gene with an expanded CAG repeat is sufficient to cause a progressive neurological phenotype in transgenic mice.
Cell
87:493-506[Web of Science][Medline].
-
Matthews RT,
Yang L,
Jenkins BG,
Ferrante RJ,
Rosen BR,
Kaddurah-Daouk R,
Beal MF
(1998)
Neuroprotective effects of creatine and cyclocreatine in animal models of Huntington's disease.
J Neurosci
18:156-163[Abstract/Free Full Text].
-
Matthews RT,
Ferrante RJ,
Klivenyi P,
Yang L,
Klein AM,
Mueller G,
Kaddurah-Daouk R,
Beal MF
(1999)
Creatine and cyclocreatine attenuate MPTP neurotoxicity.
Exp Neurol
157:142-149[Web of Science][Medline].
-
O'Gorman E,
Beutner G,
Wallimann T,
Brdiczka D
(1996)
Differential effects of creatine depletion on the regulation of enzyme activities and on creatine-stimulated mitochondrial respiration in skeletal muscle, heart, and brain.
Biochim Biophys Acta
1276:161-170[Medline].
-
O'Gorman E,
Beutner G,
Dolder M,
Koretsky AP,
Brdiczka D,
Wallimann T
(1997)
The role of creatine kinase inhibition of mitochondrial permeability transition.
FEBS Lett
414:253-257[Web of Science][Medline].
-
Ona VO,
Li M,
Vonsattel JPG,
Andrews LJ,
Khan SQ,
Chung WM,
Frey AS,
Menon AS,
Li X-J,
Stieg PE,
Yuan J,
Penney JB,
Young AB,
Cha J-HJ,
Friedlander RM
(1999)
Inhibition of caspase-1 slows disease progression in a mouse model of Huntington's disease.
Nature
399:263-267[Medline].
-
Reddy PH,
Williams M,
Charles V,
Garrett L,
Pike-Buchanan L,
Whetsell Jr WO,
Miller G,
Tagle DA
(1998)
Behavioural abnormalities and selective neuronal loss in HD transgenic mice expressing mutated full-length HD cDNA.
Nat Genet
20:198-202[Web of Science][Medline].
-
Sauter A,
Rudin M
(1993)
Determination of creatine kinase parameters in rat brain by NMR magnetization transfer: correlation with brain function.
J Biol Chem
268:13166-13171[Abstract/Free Full Text].
-
Sawa A,
Wiegand GW,
Cooper J,
Margolis RL,
Sharp AH,
Lawler Jr JF,
Greenamyre JT,
Snyder SH,
Ross CA
(1999)
Increased apoptosis of Huntington disease lymphoblasts associated with repeat length-dependent mitochondrial depolarization.
Nat Med
5:1194-1198[Web of Science][Medline].
-
Sharp NH,
Loev SJ,
Schilling G,
Li S-H,
Li X-J,
Bao J,
Wagster MV,
Kotzuk JA,
Steiner JP,
Lo A,
Hedreen J,
Sisodia S,
Snyder SH,
Dawson TM,
Ryugo DK,
Ross CA
(1995)
Widespread expression of the Huntington's disease gene (IT-15) protein product.
Neuron
14:1065-1074[Web of Science][Medline].
-
Sipila I,
Rapola J,
Simell O,
Vannas A
(1981)
Supplementary creatine as a treatment for gyrate atrophy of the choroid and retina.
N Engl J Med
304:867-870[Abstract].
-
Soboll S,
Brdiczka D,
Jahnke D,
Schmidt A,
Schlattner U,
Wendt S,
Wyss M,
Wallimann T
(1999)
Octamer-dimer transitions of mitochondrial creatine kinase in heart disease.
J Mol Cell Cardiol
31:857-866[Web of Science][Medline].
-
Stachowiak O,
Dolder M,
Wallimann T,
Richter C
(1998)
Mitochondrial creatine kinase is a prime target of peroxynitrite- induced modification and inactivation.
J Biol Chem
273:16694-16699[Abstract/Free Full Text].
-
Steeghs K,
Benders A,
Oerlemans F,
de Haan A,
Heerschap A,
Ruitenbeek W,
Jost C,
van Deursen J,
Perryman B,
Pette D,
Bruckwilder M,
Koudijs J,
Jap P,
Veerkamp J,
Wieringa B
(1997)
Altered Ca2+ responses in muscles with combined mitochondrial and cytosolic creatine kinase deficiencies.
Cell
89:93-103[Web of Science][Medline].
-
Stockler S,
Holzbach U,
Hanefeld F,
Marquardt I,
Helms G,
Requart M,
Hanicke W,
Frahm J
(1994)
Creatine deficiency in the brain: a new, treatable inborn error of metabolism.
Pediatr Res
36:409-413[Web of Science][Medline].
-
Stockler S,
Hanefeld F,
Frahn J
(1996)
Creatine replacement therapy in quanidinoacetate methyltransferase deficiency, a novel inborn error of metabolism.
Lancet
348:789-790[Web of Science][Medline].
-
Strong TV,
Tagle DA,
Valdes JM,
Elmer LW,
Boehm K,
Swaroop M,
Kaatz KW,
Collins FS,
Albin RL
(1993)
Widespread expression of the human and rat Huntington's disease gene in brain and nonneural tissues.
Nat Genet
5:259-265[Web of Science][Medline].
-
Tarnopolsky M,
Martin J
(1999)
Creatine monohydrate increases strength in patients with neuromuscular disease.
Neurology
52:854-857[Abstract/Free Full Text].
-
Tarnopolsky MA,
Roy BD,
MacDonald JR
(1997)
A randomized, controlled trial of creatine monohydrate in patients with mitochondrial cytopathies.
Muscle Nerve
20:1502-1509[Web of Science][Medline].
-
The Huntington's Disease Collaborative Research Group
(1993)
A novel gene containing a trinucleotide repeat that is expanded and unstable on Huntington's disease chromosomes.
Cell
72:971-983[Web of Science][Medline].
-
Vonsattel JP,
Myers RH,
Stevens TJ,
Ferrante RJ,
Bird ED,
Richardson EP
(1985)
Neuropathological classification of Huntington's disease.
J Neuropathol Exp Neurol
44:559-577[Web of Science][Medline].
-
Wallimann T,
Wyss M,
Brdiczka D,
Nicolay K,
Eppenberger HM
(1992)
Intracellular compartmentation, structure and function of creatine kinase isoenzymes in tissues with high and fluctuating energy demands: the `phosphocreatine circuit' for cellular energy homeostasis.
Biochem J
281:21-40.
-
Wheeler VC,
Auerbach W,
White JK,
Srinidhi J,
Auerbach A,
Ryan A,
Duyao MP,
Vrbanac V,
Weaver M,
Gusella JF,
Joyner AL,
MacDonald ME
(1999)
Length-dependent gametic CAG repeat instability in the Huntington's disease knock-in mouse.
Hum Mol Genet
8:115-122[Abstract/Free Full Text].
-
Xu CJ,
Klunk WE,
Kanfer JN,
Xiong Q,
Miller G,
Pettegrew JW
(1996)
Phosphocreatine-dependent glutamate uptake by synaptic vesicles.
J Biol Chem
271:13435-13440[Abstract/Free Full Text].
Copyright © 2000 Society for Neuroscience 0270-6474/00/20124389-09$05.00/0
This article has been cited by other articles:
|
|
|
|
 
Y. Dai, N. L. Dudek, Q. Li, S. C. Fowler, and N. A. Muma
Striatal Expression of a Calmodulin Fragment Improved Motor Function, Weight Loss, and Neuropathology in the R6/2 Mouse Model of Huntington's Disease
J. Neurosci.,
September 16, 2009;
29(37):
11550 - 11559.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
H. Wang, P. J. Lim, M. Karbowski, and M. J. Monteiro
Effects of overexpression of Huntingtin proteins on mitochondrial integrity
Hum. Mol. Genet.,
February 15, 2009;
18(4):
737 - 752.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
P Cancela, C Ohanian, E Cuitino, and A C Hackney
Creatine supplementation does not affect clinical health markers in football players
Br. J. Sports Med.,
September 1, 2008;
42(9):
731 - 735.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
J. Shao, W. J. Welch, N. A. DiProspero, and M. I. Diamond
Phosphorylation of Profilin by ROCK1 Regulates Polyglutamine Aggregation
Mol. Cell. Biol.,
September 1, 2008;
28(17):
5196 - 5208.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
A. Safdar, N. J. Yardley, R. Snow, S. Melov, and M. A. Tarnopolsky
Global and targeted gene expression and protein content in skeletal muscle of young men following short-term creatine monohydrate supplementation
Physiol Genomics,
January 17, 2008;
32(2):
219 - 228.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
V. Chopra, J. H. Fox, G. Lieberman, K. Dorsey, W. Matson, P. Waldmeier, D. E. Housman, A. Kazantsev, A. B. Young, and S. Hersch
A small-molecule therapeutic lead for Huntington's disease: Preclinical pharmacology and efficacy of C2-8 in the R6/2 transgenic mouse
PNAS,
October 16, 2007;
104(42):
16685 - 16689.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
E. C. Stack, S. J. Del Signore, R. Luthi-Carter, B. Y. Soh, D. R. Goldstein, S. Matson, S. Goodrich, A. L. Markey, K. Cormier, S. W. Hagerty, et al.
Modulation of nucleosome dynamics in Huntington's disease
Hum. Mol. Genet.,
May 15, 2007;
16(10):
1164 - 1175.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
J. L. McBride, S. Ramaswamy, M. Gasmi, R. T. Bartus, C. D. Herzog, E. P. Brandon, L. Zhou, M. R. Pitzer, E. M. Berry-Kravis, and J. H. Kordower
Viral delivery of glial cell line-derived neurotrophic factor improves behavior and protects striatal neurons in a mouse model of Huntington's disease
PNAS,
June 13, 2006;
103(24):
9345 - 9350.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
The NINDS NET-PD Investigators
A randomized, double-blind, futility clinical trial of creatine and minocycline in early Parkinson disease
Neurology,
March 14, 2006;
66(5):
664 - 671.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
S. M. Hersch, S. Gevorkian, K. Marder, C. Moskowitz, A. Feigin, M. Cox, P. Como, C. Zimmerman, M. Lin, L. Zhang, et al.
Creatine in Huntington disease is safe, tolerable, bioavailable in brain and reduces serum 8OH2'dG
Neurology,
January 24, 2006;
66(2):
250 - 252.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
S. J. Tabrizi, A. M. Blamire, D. N. Manners, B. Rajagopalan, P. Styles, A.H.V. Schapira, and T. T. Warner
High-dose creatine therapy for Huntington disease: A 2-year clinical and MRS study
Neurology,
May 10, 2005;
64(9):
1655 - 1656.
[Full Text]
[PDF]
|
|
|
|
|
|
|
J.-S. Ju, J. L. Smith, P. J. Oppelt, and J. S. Fisher
Creatine feeding increases GLUT4 expression in rat skeletal muscle
Am J Physiol Endocrinol Metab,
February 1, 2005;
288(2):
E347 - E352.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. J. Calkins, R. J. Jakel, D. A. Johnson, K. Chan, Y. W. Kan, and J. A. Johnson
Protection from mitochondrial complex II inhibition in vitro and in vivo by Nrf2-mediated transcription
PNAS,
January 4, 2005;
102(1):
244 - 249.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
D. Spano, I. Branchi, A. Rosica, M. T. Pirro, A. Riccio, P. Mithbaokar, A. Affuso, C. Arra, P. Campolongo, D. Terracciano, et al.
Rhes Is Involved in Striatal Function
Mol. Cell. Biol.,
July 1, 2004;
24(13):
5788 - 5796.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
S. Zhu, M. Li, B. E. Figueroa, A. Liu, I. G. Stavrovskaya, P. Pasinelli, M. F. Beal, R. H. Brown Jr, B. S. Kristal, R. J. Ferrante, et al.
Prophylactic Creatine Administration Mediates Neuroprotection in Cerebral Ischemia in Mice
J. Neurosci.,
June 30, 2004;
24(26):
5909 - 5912.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
R. J. Ferrante, J. K. Kubilus, J. Lee, H. Ryu, A. Beesen, B. Zucker, K. Smith, N. W. Kowall, R. R. Ratan, R. Luthi-Carter, et al.
Histone Deacetylase Inhibition by Sodium Butyrate Chemotherapy Ameliorates the Neurodegenerative Phenotype in Huntington's Disease Mice
J. Neurosci.,
October 15, 2003;
23(28):
9418 - 9427.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
P. Verbessem, J. Lemiere, B. O. Eijnde, S. Swinnen, L. Vanhees, M. Van Leemputte, P. Hespel, and R. Dom
Creatine supplementation in Huntington's disease: A placebo-controlled pilot trial
Neurology,
October 14, 2003;
61(7):
925 - 930.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. A. Tarnopolsky, J. M. Bourgeois, R. Snow, S. Keys, B. D. Roy, J. M. Kwiecien, and J. Turnbull
Histological assessment of intermediate- and long-term creatine monohydrate supplementation in mice and rats
Am J Physiol Regulatory Integrative Comp Physiol,
October 1, 2003;
285(4):
R762 - R769.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
S.J. Tabrizi, A.M. Blamire, D.N. Manners, B. Rajagopalan, P. Styles, A.H.V. Schapira, and T.T. Warner
Creatine therapy for Huntington's disease: Clinical and MRS findings in a 1-year pilot study
Neurology,
July 8, 2003;
61(1):
141 - 142.
[Full Text]
[PDF]
|
|
|
|
|
|
|
E. J. Slow, J. van Raamsdonk, D. Rogers, S. H. Coleman, R. K. Graham, Y. Deng, R. Oh, N. Bissada, S. M. Hossain, Y.-Z. Yang, et al.
Selective striatal neuronal loss in a YAC128 mouse model of Huntington disease
Hum. Mol. Genet.,
July 1, 2003;
12(13):
1555 - 1567.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
R. M. Friedlander
Apoptosis and Caspases in Neurodegenerative Diseases
N. Engl. J. Med.,
April 3, 2003;
348(14):
1365 - 1375.
[Full Text]
[PDF]
|
|
|
|
|
|
|
E. Hockly, V. M. Richon, B. Woodman, D. L. Smith, X. Zhou, E. Rosa, K. Sathasivam, S. Ghazi-Noori, A. Mahal, P. A. S. Lowden, et al.
Suberoylanilide hydroxamic acid, a histone deacetylase inhibitor, ameliorates motor deficits in a mouse model of Huntington's disease
PNAS,
February 18, 2003;
100(4):
2041 - 2046.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
V. C. Wheeler, L.-A. Lebel, V. Vrbanac, A. Teed, H. te Riele, and M. E. MacDonald
Mismatch repair gene Msh2 modifies the timing of early disease in HdhQ111 striatum
Hum. Mol. Genet.,
February 1, 2003;
12(3):
273 - 281.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. Lesort, M. Lee, J. Tucholski, and G. V. W. Johnson
Cystamine Inhibits Caspase Activity. IMPLICATIONS FOR THE TREATMENT OF POLYGLUTAMINE DISORDERS
J. Biol. Chem.,
January 31, 2003;
278(6):
3825 - 3830.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
S. Wendt, U. Schlattner, and T. Wallimann
Differential Effects of Peroxynitrite on Human Mitochondrial Creatine Kinase Isoenzymes. INACTIVATION, OCTAMER DESTABILIZATION, AND IDENTIFICATION OF INVOLVED RESIDUES
J. Biol. Chem.,
January 3, 2003;
278(2):
1125 - 1130.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
L. Djousse, B. Knowlton, L. A. Cupples, K. Marder, I. Shoulson, and R. H. Myers
Weight loss in early stage of Huntington's disease
Neurology,
November 12, 2002;
59(9):
1325 - 1330.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
A. Dedeoglu, J. K. Kubilus, T. M. Jeitner, S. A. Matson, M. Bogdanov, N. W. Kowall, W. R. Matson, A. J. L. Cooper, R. R. Ratan, M. F. Beal, et al.
Therapeutic Effects of Cystamine in a Murine Model of Huntington's Disease
J. Neurosci.,
October 15, 2002;
22(20):
8942 - 8950.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
C. D. Keene, C. M. P. Rodrigues, T. Eich, M. S. Chhabra, C. J. Steer, and W. C. Low
Tauroursodeoxycholic acid, a bile acid, is neuroprotective in a transgenic animal model of Huntington's disease
PNAS,
August 6, 2002;
99(16):
10671 - 10676.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
A. H. Nemeth
The genetics of primary dystonias and related disorders
Brain,
April 1, 2002;
125(4):
695 - 721.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
R. J. Ferrante, O. A. Andreassen, A. Dedeoglu, K. L. Ferrante, B. G. Jenkins, S. M. Hersch, and M. F. Beal
Therapeutic Effects of Coenzyme Q10 and Remacemide in Transgenic Mouse Models of Huntington's Disease
J. Neurosci.,
March 1, 2002;
22(5):
1592 - 1599.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
A H V Schapira
The "new" mitochondrial disorders
J. Neurol. Neurosurg. Psychiatry,
February 1, 2002;
72(2):
144 - 149.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
R. O. S. Mejia and R. M. Friedlander
Caspases in Huntington's Disease
Neuroscientist,
December 1, 2001;
7(6):
480 - 489.
[Abstract]
[PDF]
|
|
|
|
|
|
|
A. Petersen, K. E. Larsen, G. G. Behr, N. Romero, S. Przedborski, P. Brundin, and D. Sulzer
Expanded CAG repeats in exon 1 of the Huntington's disease gene stimulate dopamine-mediated striatal neuron autophagy and degeneration
Hum. Mol. Genet.,
June 1, 2001;
10(12):
1243 - 1254.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
A. M. Persky and G. A. Brazeau
Clinical Pharmacology of the Dietary Supplement Creatine Monohydrate
Pharmacol. Rev.,
May 11, 2001;
(2001)
1.
[Abstract]
[Full Text]
|
|
|
|
|
|
|
N. R. Jana, E. A. Zemskov, G.-h. Wang, and N. Nukina
Altered proteasomal function due to the expression of polyglutamine-expanded truncated N-terminal huntingtin induces apoptosis by caspase activation through mitochondrial cytochrome c release
Hum. Mol. Genet.,
May 1, 2001;
10(10):
1049 - 1059.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. F. Beal and P. Hantraye
Novel therapies in the search for a cure for Huntington's disease
PNAS,
January 2, 2001;
98(1):
3 - 4.
[Full Text]
[PDF]
|
|
|
|
|
|
|
B. O.'t Eijnde, B. Ursø, E.A. Richter, P.L. Greenhaff, and P. Hespel
Effect of Oral Creatine Supplementation on Human Muscle GLUT4 Protein Content After Immobilization
Diabetes,
January 1, 2001;
50(1):
18 - 23.
[Abstract]
[Full Text]
|
|
|
|
|
|
|
A. M. Persky and G. A. Brazeau
Clinical Pharmacology of the Dietary Supplement Creatine Monohydrate
Pharmacol. Rev.,
June 1, 2001;
53(2):
161 - 176.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
TOP
ABSTRACT
INTRODUCTION
