Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.
Retrograde Viral Delivery of IGF-1 Prolongs Survival in a Mouse ALS Model
Brian K. Kaspar,1
Jerònia Lladó,2*
Nushin Sherkat,1
Jeffrey D. Rothstein,2
Fred H. Gage1
Abstract:
Amyotrophic lateral sclerosis (ALS) is a progressive, lethalneuromuscular disease that is associated with the degenerationof spinal and brainstem motor neurons, leading to atrophy oflimb, axial, and respiratory muscles. The cause of ALS is unknown,and there is no effective therapy. Neurotrophic factors arecandidates for therapeutic evaluation in ALS. Although chronicdelivery of molecules to the central nervous system has provendifficult, we recently discovered that adeno-associated viruscan be retrogradely transported efficiently from muscle to motorneurons of the spinal cord. We report that insulin-like growthfactor 1 prolongs life and delays disease progression, evenwhen delivered at the time of overt disease symptoms.
1 Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA. 2 Departments of Neurology and Neuroscience, Johns Hopkins University, 600 North Wolfe Street, Meyer 6-109, Baltimore, MD 21287, USA.
* Present address: Institut Universitari d'Investigacióen Ciències de la Salut (IUNICS), Hospital Son Dureta,C/Andrea Doria 55, Edifici D 1a planta, 07014 Palma, Illes Balears,Spain.
To whom correspondence should be addressed. E-mail: gage{at}salk.edu
Overexpression of superoxide dismutase-1 (SOD1) gene mutationsin mice and rats recapitulates the clinical and pathologicalcharacteristics of amyotrophic lateral sclerosis (ALS) in humans,in which motor neurons (MNs) degenerate and animals die shortlyafter onset of symptoms (1–9). Compounds active in retardingsymptoms in this model have been shown to be predictive forclinical efficacy in patients with ALS (10). Typically, compoundsthat show any level of efficacy must be continuously deliveredwell before symptom onset in order to delay disease or increasesurvival times in the mouse model. Given the lack of preclinicaldiagnostic tools, this approach is unpredictable in the clinic(2–7). Although investigation of these molecules continues,the targeted delivery of a therapy to MNs remains problematic.
We recently discovered that adeno-associated virus (AAV) isretrogradely transported from presynaptic terminals of projectingneurons through the entire length of the axon and can enterthe projecting cell nucleus, providing sustained gene delivery(11–13). We used the retrograde transport ability of AAVin the ALS animal model by injecting AAV into respiratory andmotor limb muscles to directly target the affected MNs and testthe efficacy of two neurotrophic factors (NTFs), insulin growthfactor 1 (IGF-1) and glial cell line–derived neurotrophicfactor (GDNF) (14–16). Our results reveal that IGF-1 delaysthe onset of behavioral symptoms and sustains life in the SOD1mutant to a greater degree than GDNF, even when administeredat the onset of overt clinical symptoms. The importance of retrogradedelivery was accentuated by the finding of the significantlyreduced effects of IGF-1 delivered by lentivirus, a virus thatis not transported efficiently (17), when compared to the effectsof IGF-1 delivered by AAV. The marked effects of IGF-1 on onsetand survival are accompanied by robust survival and preservedmorphology of MNs and decreased gliosis. The actions of IGF-1occur at least in part through an antiapoptotic mechanism, asevidenced by the inhibition of caspase-3 and -9 cleavage andDNA fragmentation.
Retrograde transport from MNs that innervate muscles requiresthe virus to bind to viral receptors on the axon terminal, withsubsequent transport over a long distance to the MN nucleus,allowing sustained gene expression (Fig. 1A). We investigatedthe ability of AAV to target specific subsets of MNs that projectto defined muscles in 90-day-old transgenic mice that expressthe G93A SOD1 transgene, the high-expressing SOD1 mutant mousethat displays disease onset at 90 days and dies 30 days later(8). AAV carrying green fluorescent protein (AAV-GFP) injectedinto the hindlimb quadriceps and intercostal muscles showedGFP expression in choline acetyltransferase (CHAT)–positiveMNs within the ventral horn of the lumbar and thoracic spinalcord, respectively, with no evidence of glial cell transduction(Fig. 1, B and C). Quantification revealed that more than 400MNs were positive for GFP in the spinal cord, and transcriptionof GFP was confirmed by reverse transcription–polymerasechain reaction (PCR) (18). We found a dose response for retrogradetransport to the spinal cord by injecting virus at titers between4 x 107 and 3 x 1010 viral particles into the quadriceps musclesand performing PCR for vector sequences on the lumbar spinalcord. A dose of 1 x 1010 viral particles was required to achievetransport to the lumbar spinal cord; however, in one of threeexperiments, vector sequence was found at 4 x 109 viral particles(Fig. 1D). Up to 1.1% of the virus injected at a dose of 1 x1010 viral particles was transported to the lumbar region ofthe spinal cord, as assessed by quantitative PCR (18).
Fig. 1.. Targeting the spinal cord by retrograde transport to MNs. (A) Schematic of intramuscular AAV injection for retrograde transport to the spinal cord. (B and C) AAV-GFP injected in hindlimb quadriceps and intercostal muscles (1 x 1010 viral particles per injection) expressed GFP in (B) lumbar MNs and (C) thoracic MNs. GFP expression (in green) is restricted to MNs labeled with CHAT (in red). GFP was not expressed in glial cells (labeled with GFAP, in blue). (D) PCR for the presence of the AAV vector genome in the lumbar spinal cord after its injection into the quadricep muscles at varying doses, demonstrating a dose response for retrograde transport. MW, molecular weight marker; CTL, control plasmid; e, exponent. (E) Age of onset of disease symptoms in G93A SOD1 animals injected at 60 days of age with AAV-GFP (green), AAV-GDNF (blue), or AAV–IGF-1 (red). (F) Survival analysis in animals injected at 60 days of age with AAV NTFs. Disease onset and mortality were significantly delayed in G93A SOD1 mice treated with AAV-GDNF (blue) and AAV–IGF-1 (red), compared to AAV-GFP–treated animals (green).
[View Larger Version of this Image (56K GIF file)]
To explore two NTFs that have been reported to have potent effectson MN survival (14–16), AAV vectors expressing GDNF orIGF-1 were injected bilaterally into the hindlimb quadricepsand intercostal muscles of G93A SOD1 animals before diseaseonset at 60 days of age, with a dosage of 1 x 1010 particlesper injection. AAV-GFP was used as control vector. At the ageof 91 days, disease onset was observed in GFP-treated animals(n = 25 mice), as assessed by a decline in hindlimb functionin the rotarod test. IGF-1 treatment (n = 25 mice) delayed theonset by 31 days compared to a 16-day delay of onset in GDNF-treatedanimals (n = 15 mice) (2 = 34.14, P < 0.0001) (Fig. 1E).GDNF-treated animals showed a smaller, 11-day increase in mediansurvival compared to GFP-treated controls (134 days versus 123days, 2 = 29.05, P < 0.0001). IGF-1–treated animalsshowed a larger, significant improvement in life-span, witha 37-day increase in median survival compared to controls (160days versus 123 days, 2 = 19.40, P < 0.0001). The maximallife-span of IGF-1–treated animals was 265 days, comparedto 140 days in the control group (Fig. 1F). Thus, it appearsthat injections of IGF-1 not only delayed the onset but alsoslowed the rate of disease progression. In contrast, GDNF appearsonly to have delayed the onset of symptoms (19).
We next tested the therapeutic potential of the two NTFs atthe time of disease onset, by giving injections into the hindlimbquadriceps and intercostal muscles at 90 days of age. GDNF treatment(n = 20 mice) had minimal effects, with a 7-day median increasein survival compared to control GFP animals (n = 20 mice) (130days versus 123 days, respectively; 2 = 18.92, P < 0.0001).In contrast, IGF-1 treatment (n = 30 mice) extended median life-spanby 22 days compared to the GFP group (n = 30 mice) (146 daysversus 124 days, 2 = 29.40, P < 0.0001) (Fig. 2A). Assessmentof neuromuscular function was performed on IGF-1–treatedanimals by quantitative grip strength and rotarod performance(Fig. 2, B to D). Between 100 and 110 days of age, GFP-treatedanimals showed a marked decrease in performance, whereas theIGF-1–treated animals displayed the greatest deficits20 days later. Additionally, IGF-1–treated animals maintainedtheir weights over a longer period of time, compared to a 15%weight loss in GFP-treated animals (Fig. 2E). IGF-1 treatmenthad hypertrophic and protective effects against muscle atrophy,resulting in a 20% higher muscle mass in IGF-1–treatedanimals compared to GFP-treated animals at 115 days of age (18).These combined results suggest that addition of IGF-1 afterthe onset of overt motor dysfunction results not only in anextension of life but also in a delay in the functional declineassociated with the disease.
Fig. 2.. Delivery of AAV–IGF-1 at disease onset by retrograde transport extends survival and delays motor decline. (A) The cumulative probability of survival in symptomatic G93A SOD1 mice injected with AAV-GDNF (blue), AAV–IGF-1 (red), or AAV-GFP (green) at 90 days of age. (B and C) Grip strength measurements of (B) hindlimb and (C) forelimb in animals injected with AAV–IGF-1 or AAV-GFP. (D) Rotarod evaluation of animals treated with AAV–IGF-1 or AAV-GFP. (E) Weight measurements of animals treated with AAV–IGF-1 or AAV-GFP (error bars represent SEM). (F) Survival analysis of intramuscular delivery of LV–IGF-1 or LV-GFP.
[View Larger Version of this Image (16K GIF file)]
Histological evaluation of the lumbar spinal cord revealed thatIGF-1 treatment prevented the pathological changes typical ofthe transgenic disease model. Neurotrophic factor treatmentproduced a qualitative reduction in neuropil and cellular vacuolizationin animals at 110 days of age (Fig. 3, A and B). Average MNcounts per section in the lumbar spinal cord in IGF-1–treatedanimals injected at 90 days of age (n = 3 mice) were similarto counts in control wild-type animals (n = 3 mice) (26.58 ±1.10 versus 25.5 ± 1.04), whereas GFP-treated animals(n = 3 mice) showed a substantial loss of MNs (14.99 ±0.85). There were no significant differences in MN counts betweenGFP and IGF-1 treatments when animals were classified as end-stage(Fig. 3E). An estimate of the total number of MNs in the lumbarspinal cord showed that IGF-1 promoted a 78% increase in MNsurvival when compared to the GFP group. The most vulnerableMNs in ALS, which are the large MNs, were also significantlypreserved in the IGF-1–treated animals, as analyzed bymorphometric measurements, with a 66% increase in survival ofthis subgroup of neurons when compared to the GFP group (Fig. 3F).At the end-stage, animals treated with IGF-1 continuedto have 34% more large neurons (>250 µm2) as comparedto untreated G93A SOD1 mice (18). Staining for nonphosphorylatedneurofilament by SMI-32 revealed higher numbers of neurons inIGF-1–treated animals than in GFP-treated animals (Fig. 3, C and D).
Fig. 3.. AAV–IGF-1 protects MNs and delays astroglial response in G93A SOD 1 mice. (A and B) Histological evaluation of 110-day-old lumbar spinal cord in (A) AAV-GFP– and (B) AAV–IGF-1–treated animals. (C and D) Immunohistochemistry for neurofilament marker SMI-32(in green) and GFAP (in blue) of (C) AAV-GFP– and (D) AAV–IGF-1–treated animals. (E) Quantification of surviving MNs in wild-type (WT), AAV-GFP–, and AAV–IGF-1–injected animals at 110 days of age and end-stage classification of the disease. (F) Morphometric evaluation of surviving MNs in AAV–IGF-1– and AAV-GFP–treated animals at 110 days of age.
[View Larger Version of this Image (50K GIF file)]
To assess the requirement for retrograde transport of AAV–IGF-1to the spinal cord to achieve therapeutic effects, we used avector that would maintain long-term expression in the muscleonly, i.e., that would not be retrogradely transported to thespinal cord (20). Vesicular stomatitis virus glycoprotein–pseudotypedlentiviral vector (LV) expressing IGF-1 (n = 10 mice) or GFP(n = 6 mice) was injected in a manner similar to that used inthe AAV experiments, without transport to the spinal cord, andsurvival was evaluated. Muscle production of IGF-1 was similarbetween LV- and AAV-injected animals 3 weeks post-injection,on the basis of transcript and protein measurements from musclebiopsies (18, 19). LV–IGF-1 increased median survivalby 9 days over GFP controls (132 days versus 123 days, 2 = 6.863,P = 0.0088), a period significantly shorter than the 22-dayincrease seen with AAV–IGF-1, suggesting that deliveryto both the muscle and spinal cord is the most efficacious deliverymethod (Fig. 2F).
The beneficial effects of IGF-1 treatment were not solely restrictedto neurons. There was also a significantly reduced amount ofastrogliosis, as assessed by glial fibrillary acidic protein(GFAP) staining, suggesting a delayed activation of astrocytesin the IGF-1–treated animals (Fig. 3, C and D). Overexpressionof G93A SOD1 has been shown to be associated with neuropil,neuronal, and astroglial accumulations of ubiquitin-positiveaggregated protein (21). GFP-treated G93A SOD1 animals exhibitedlarge, ubiquitin-positive aggregates in the spinal cord. However,IGF-1 treatment resulted in smaller, focalized inclusions, suggestinga delay in the pathological course of aggregate formation orenhanced degradation of aggregates. Importantly, there wereno significant changes found in the levels of G93A SOD1 proteinin the spinal cord between IGF-1– and GFP-treated animals(18).
Consistent with the finding that apoptosis is involved in ALS(22, 23), GFP-treated animals exhibited large numbers of cellsthat were positive for terminal deoxynucleotide transferase–mediateddeoxyuridine triphosphate nick end labeling (TUNEL) at 110 daysof age, compared to little to no TUNEL reactivity in IGF-1–treatedanimals (Fig. 4A). One reported mechanism of action of IGF-1is to increase the phosphorylated state of Akt, a protein kinaseactivated by insulin and various growth factors that is involvedin blocking proapoptotic pathways through receptor-mediatedphosphatidylinositol 3–kinase signaling (24). We foundthat AAV–IGF-1-treated animals had 38% higher levels ofphosphorylated Akt when compared to GFP controls (Fig. 4D).Phosphorylated Akt has been shown to prevent cleavage of caspase-9,thereby inhibiting apoptosis. Signaling within the apoptoticpathway, including the cleavage of caspase-3 and -9, is a targetfor disease intervention in ALS (23).
Fig. 4.. AAV–IGF-1 inhibits the apoptotic pathway in G93A SOD1 animals. (A) TUNEL staining (in red) with 4',6-diamidino-2-phenylindole (DAPI) nuclear counterstain (in blue) of the lumbar spinal cord in 110-day-old G93 SOD1 mice treated with AAV-GFP (left) or AAV–IGF-1 (right). (B) Active caspase-3 (in green) immunohistochemistry with DAPI nuclear counterstain (in blue) of the lumbar spinal cord in AAV-GFP– (left) or AAV–IGF-1– (right) treated G93A SOD1 animals. (C) Caspase-9 Western blot of lumbar spinal cord lysate of G93A SOD1 mice treated with AAV-GFP (G lanes) or AAV–IGF-1 (I lanes), with an antibody specific for procaspase-9 and its cleaved forms (p39 and p37). (D) Active phosphorylated Akt and Akt Western blot of the lumbar spinal cord.
[View Larger Version of this Image (20K GIF file)]
IGF-1 significantly reduced the amount of caspase-9 cleavage.At 110 days of age, IGF-1 decreased the cleaved 37- and 39-kDsubunits by more than 63% compared to the GFP group, indicatingthat IGF-1 can block caspase activation involved in the apoptoticpathway (Fig. 4C). In addition, cleaved caspase-3 immunohistochemistrywas less evident in IGF-1–treated animals compared tothe GFP group (16 ± 5 cells versus 117 ± 7 cells,respectively; n = 5 mice each, P < 0.001) (Fig. 4B). Furthermore,IGF-1–treated animals showed a 59% decrease in the levelsof tumor necrosis factor– within the lumbar spinal cordcompared to GFP controls (n = 5 mice), indicating that IGF-1also works to delay the associated glial (microglial and astroglial)response seen in ALS.
We describe AAV-NTF delivery in vivo to the hindlimb and intercostalmuscles in a mouse model of ALS, which results in a significantdelay in the decline of motor function, a prolongation of MNsurvival, a decrease in parenchymal gliosis, and most importantly,a prolongation in survival. Furthermore, these effects wereevident even with late delivery of therapy—at the timeof symptom onset—that is comparable to the method andtime of treatment that needs to be used for the human disease.The mechanism of increased survival may be multifactorial, bothclinically and biochemically. Death of the transgenic mice likelyreflects both loss of respiratory function and wasting and weightloss due to muscle weakness, leading to starvation and dehydration.Thus, at the clinical level, delivery of the agent to both limband respiratory MNs is appropriate. At the cellular and biochemicallevel, gliosis is believed to contribute to disease progression,with resultant insults including excitotoxicity, oxidative stress,and initiation of apoptotic cascades (25, 26). Previous in vitrodata have demonstrated that IGF-1 can also prevent excitotoxicMN degeneration (27). AAV– IGF-1 delivery clearly delayedloss of MNs and also increased muscle mass. Those two effectsalone could be responsible for the increased survival in mice.However, lentiviral delivery of IGF-1 to muscle, without retrogradetransport, only produced a modest effect in survival. This findingsuggests that the retrograde transport and MN soma expressionof IGF-1 were responsible for the majority of the neuroprotection.Our studies do not allow us to determine if the protection isdue to effects of the intraneuronal expression of IGF-1 and/orits release to surrounding neuropil. The decrease in gliosisseen with IGF-1 by delivery— either through paracrineeffects of the secreted IGF-1 or through limited neuronal injuryand associated cellular responses—may also be protective.Recent studies using anti-inflammatory agents have also demonstratedincreased survival associated with limited gliosis (28, 29).
Importantly, past studies have suggested that many differenttrophic factors are MN-protective. NTFs such as ciliary neurotrophic factor, GDNF, and brain-derived neurotrophic factorhave been unsuccessful in human trials. However, subcutaneousdelivery of a recombinant growth factor, IGF-1, has had marginalsuccess in one of two human trials (14). Recent studies havedemonstrated that viral muscle and intra parenchymal deliveryof GDNF can increase survival in G93A mice (15, 16, 30–34).Our direct comparison of these two factors clearly demonstratesa superior effect of IGF-1.
The marginal efficacy in these past human trials may be due,in part, to the limited delivery of the protein to the targetneurons and glia in the spinal cord. AAV vectors will providefor long-term muscular secretion of IGF-1, thereby avoidingthe half-life and stability issues seen with protein therapeutics(14, 35). Furthermore, AAV vectors have the useful propertyof retrograde transport, such that spinal MNs can be selectivelytargeted, permitting local secretion of IGF-1 to have a broadereffect on surrounding cells and not be confined only to theMNs that transported the virus.
Our results demonstrate substantial behavioral, functional,and pathological improvements in a clinically relevant modelof MN disease after intramuscular AAV–IGF-1 delivery.A clinical trial testing this approach is being designed.
18"> B. K. Kaspar, J. Lladó, N. Sherkat, J. D. Rothstein, F. H. Gage, unpublished data.
19"> Levels of IGF-1 were determined by enzyme-linked immunosorbent assay specific to human IGF-1 from the plasma, muscle biopsy, and lumbar spinal cord of animals injected with AAV–IGF-1, AAV-GFP, or LV–IGF-1. Circulating levels of IGF-1 in the plasma of animals treated with AAV–IGF-1 were found to be slightly above those in control GFP or non-injected G93A animals; however, the change was not significant (95 ± 22 ng/ml versus 70 ± 38 ng/ml). High levels of human IGF-1 were found in the quadriceps muscle of AAV–IGF-1 and LV–IGF-1 animals (175 ± 18 ng/ml and 195 ± 19 ng/ml, n = 6 mice each, P > 0.05 respectively), compared to IGF-1 levels detected in AAV-GFP– and LV-GFP–treated animals (18 ± 6 ng/ml). Lumbar spinal cord IGF-1 measurements showed increased levels of IGF-1 in the AAV-injected animals compared to LV-injected animals (111 ± 6 ng/ml versus 11.3 ± 6.7 ng/ml, n = 3 mice each, P = 0.001). There was no significant difference in the lumbar spinal cord between animals injected with LV–IGF-1 and GFP-injected animals, n = 3 mice each, P > 0.05).
We thank the Salk Animal Facility, L. Frost, M. Lucero, L. Christian, and M. Dykes-Hoberg for technical assistance; J. Simon and L. Kitabayashi for imaging; and M. L. Gage for critical reading of the manuscript. Grateful thanks to V. Estess (Project A.L.S.) for valuable support and encouragement. This work was supported by Project A.L.S., the Christopher Reeve Paralysis Foundation, and NIH grant nos. NIH AG21876, NIH AG12992, and NS33958.
Subventricular Zone-Derived Neural Stem Cell Grafts Protect Against Hippocampal Degeneration and Restore Cognitive Function in the Mouse Following Intrahippocampal Kainic Acid Administration.
P. Miltiadous, G. Kouroupi, A. Stamatakis, P. N. Koutsoudaki, R. Matsas, and F. Stylianopoulou (2013)
Stem Cells Trans Med
2, 185-198
|Abstract »|Full Text »|PDF »
Myelin Loss Does Not Lead to Axonal Degeneration in a Long-Lived Model of Chronic Demyelination.
C. M. Smith, E. Cooksey, and I. D. Duncan (2013)
J. Neurosci.
33, 2718-2727
|Abstract »|Full Text »|PDF »
Multimodal Actions of Neural Stem Cells in a Mouse Model of ALS: A Meta-Analysis.
Y. D. Teng, S. C. Benn, S. N. Kalkanis, J. M. Shefner, R. C. Onario, B. Cheng, M. B. Lachyankar, M. Marconi, J. Li, D. Yu, et al. (2012)
Science Translational Medicine
4, 165ra164
|Abstract »|Full Text »|PDF »
Upregulation of the E3 ligase NEDD4-1 by Oxidative Stress Degrades IGF-1 Receptor Protein in Neurodegeneration.
Y.-D. Kwak, B. Wang, J. J. Li, R. Wang, Q. Deng, S. Diao, Y. Chen, R. Xu, E. Masliah, H. Xu, et al. (2012)
J. Neurosci.
32, 10971-10981
|Abstract »|Full Text »|PDF »
Impairments to the GH-IGF-I Axis in hSOD1G93A Mice Give Insight into Possible Mechanisms of GH Dysregulation in Patients with Amyotrophic Lateral Sclerosis.
F. J. Steyn, S. T. Ngo, J. D. Lee, J. W. Leong, A. J. Buckley, J. D. Veldhuis, P. A. McCombe, C. Chen, and M. C. Bellingham (2012)
Endocrinology
153, 3735-3746
|Abstract »|Full Text »|PDF »
Human Axonal Survival of Motor Neuron (a-SMN) Protein Stimulates Axon Growth, Cell Motility, C-C Motif Ligand 2 (CCL2), and Insulin-like Growth Factor-1 (IGF1) Production.
D. Locatelli, M. Terao, M. Fratelli, A. Zanetti, M. Kurosaki, M. Lupi, M. M. Barzago, A. Uggetti, S. Capra, P. D'Errico, et al. (2012)
J. Biol. Chem.
287, 25782-25794
|Abstract »|Full Text »|PDF »
The in vivo contribution of motor neuron TrkB receptors to mutant SOD1 motor neuron disease.
J. Zhai, W. Zhou, J. Li, C. R. Hayworth, L. Zhang, H. Misawa, R. Klein, S. S. Scherer, R. J. Balice-Gordon, and R. G. Kalb (2011)
Hum. Mol. Genet.
20, 4116-4131
|Abstract »|Full Text »|PDF »
Increased IGF-1 in muscle modulates the phenotype of severe SMA mice.
M. Bosch-Marce, C. D. Wee, T. L. Martinez, C. E. Lipkes, D. W. Choe, L. Kong, J. P. Van Meerbeke, A. Musaro, and C. J. Sumner (2011)
Hum. Mol. Genet.
20, 1844-1853
|Abstract »|Full Text »|PDF »
Genetic therapy for the nervous system.
W. J. Bowers, X. O. Breakefield, and M. Sena-Esteves (2011)
Hum. Mol. Genet.
20, R28-R41
|Abstract »|Full Text »|PDF »
Global gene expression profiling of somatic motor neuron populations with different vulnerability identify molecules and pathways of degeneration and protection.
E. Hedlund, M. Karlsson, T. Osborn, W. Ludwig, and O. Isacson (2010)
Brain
133, 2313-2330
|Abstract »|Full Text »|PDF »
Collapsin Response Mediator Protein 4a (CRMP4a) Is Upregulated in Motoneurons of Mutant SOD1 Mice and Can Trigger Motoneuron Axonal Degeneration and Cell Death.
L. Duplan, N. Bernard, W. Casseron, K. Dudley, E. Thouvenot, J. Honnorat, V. Rogemond, B. De Bovis, P. Aebischer, P. Marin, et al. (2010)
J. Neurosci.
30, 785-796
|Abstract »|Full Text »|PDF »
Role and Therapeutic Potential of VEGF in the Nervous System.
C. Ruiz de Almodovar, D. Lambrechts, M. Mazzone, and P. Carmeliet (2009)
Physiol Rev
89, 607-648
|Abstract »|Full Text »|PDF »
Schwann cells expressing dismutase active mutant SOD1 unexpectedly slow disease progression in ALS mice.
C. S. Lobsiger, S. Boillee, M. McAlonis-Downes, A. M. Khan, M. L. Feltri, K. Yamanaka, and D. W. Cleveland (2009)
PNAS
106, 4465-4470
|Abstract »|Full Text »|PDF »
Delivery of recombinant follistatin lessens disease severity in a mouse model of spinal muscular atrophy.
F. F. Rose Jr, V. B. Mattis, H. Rindt, and C. L. Lorson (2009)
Hum. Mol. Genet.
18, 997-1005
|Abstract »|Full Text »|PDF »
Efficient gene therapy-based method for the delivery of therapeutics to primate cortex.
A. P. Kells, P. Hadaczek, D. Yin, J. Bringas, V. Varenika, J. Forsayeth, and K. S. Bankiewicz (2009)
PNAS
106, 2407-2411
|Abstract »|Full Text »|PDF »
Insulin-Like Growth Factors in the Peripheral Nervous System.
K. A. Sullivan, B. Kim, and E. L. Feldman (2008)
Endocrinology
149, 5963-5971
|Abstract »|Full Text »|PDF »
Granulocyte-colony stimulating factor improves outcome in a mouse model of amyotrophic lateral sclerosis.
C. Pitzer, C. Kruger, C. Plaas, F. Kirsch, T. Dittgen, R. Muller, R. Laage, S. Kastner, S. Suess, R. Spoelgen, et al. (2008)
Brain
131, 3335-3347
|Abstract »|Full Text »|PDF »
T lymphocytes potentiate endogenous neuroprotective inflammation in a mouse model of ALS.
I. M. Chiu, A. Chen, Y. Zheng, B. Kosaras, S. A. Tsiftsoglou, T. K. Vartanian, R. H. Brown Jr, and M. C. Carroll (2008)
PNAS
105, 17913-17918
|Abstract »|Full Text »|PDF »
IGFBP-5 regulates muscle cell differentiation by binding to IGF-II and switching on the IGF-II auto-regulation loop.
Mesenchymal stromal cells genetically engineered to overexpress IGF-I enhance cell-based gene therapy of renal failure-induced anemia.
T. Kucic, I. B. Copland, J. Cuerquis, D. L. Coutu, L. E. Chalifour, R. F. Gagnon, and J. Galipeau (2008)
Am J Physiol Renal Physiol
295, F488-F496
|Abstract »|Full Text »|PDF »
Mutant SOD1 in cell types other than motor neurons and oligodendrocytes accelerates onset of disease in ALS mice.
K. Yamanaka, S. Boillee, E. A. Roberts, M. L. Garcia, M. McAlonis-Downes, O. R. Mikse, D. W. Cleveland, and L. S. B. Goldstein (2008)
PNAS
105, 7594-7599
|Abstract »|Full Text »|PDF »
Adeno-Associated Virus Transfer of a Gene Encoding SNAP-25 Resistant to Botulinum Toxin A Attenuates Neuromuscular Paralysis Associated with Botulism.
A. Raghunath, F. Perez-Branguli, L. Smith, and J. O. Dolly (2008)
J. Neurosci.
28, 3683-3688
|Abstract »|Full Text »|PDF »
The Neurotrophic Effects of Glial Cell Line-Derived Neurotrophic Factor on Spinal Motoneurons Are Restricted to Fusimotor Subtypes.
T. W. Gould, S. Yonemura, R. W. Oppenheim, S. Ohmori, and H. Enomoto (2008)
J. Neurosci.
28, 2131-2146
|Abstract »|Full Text »|PDF »
Neurodegeneration and cell replacement.
B. K Ormerod, T. D Palmer, and M. A Caldwell (2008)
Phil Trans R Soc B
363, 153-170
|Abstract »|Full Text »|PDF »
Exogenous Delivery of Heat Shock Protein 70 Increases Lifespan in a Mouse Model of Amyotrophic Lateral Sclerosis.
D. J. Gifondorwa, M. B. Robinson, C. D. Hayes, A. R. Taylor, D. M. Prevette, R. W. Oppenheim, J. Caress, and C. E. Milligan (2007)
J. Neurosci.
27, 13173-13180
|Abstract »|Full Text »|PDF »
A Single Injection of an Adeno-Associated Virus Vector into Nuclei with Divergent Connections Results in Widespread Vector Distribution in the Brain and Global Correction of a Neurogenetic Disease.
Interaction between Familial Amyotrophic Lateral Sclerosis (ALS)-linked SOD1 Mutants and the Dynein Complex.
F. Zhang, A.-L. Strom, K. Fukada, S. Lee, L. J. Hayward, and H. Zhu (2007)
J. Biol. Chem.
282, 16691-16699
|Abstract »|Full Text »|PDF »
Concurrent Administration of Neu2000 and Lithium Produces Marked Improvement of Motor Neuron Survival, Motor Function, and Mortality in a Mouse Model of Amyotrophic Lateral Sclerosis.
J. H. Shin, S. I. Cho, H. R. Lim, J. K. Lee, Y. A. Lee, J. S. Noh, I. S. Joo, K.-W. Kim, and B. J. Gwag (2007)
Mol. Pharmacol.
71, 965-975
|Abstract »|Full Text »|PDF »
Cortical area size dictates performance at modality-specific behaviors.
A. Leingartner, S. Thuret, T. T. Kroll, S.-J. Chou, J. L. Leasure, F. H. Gage, and D. D. M. O'Leary (2007)
PNAS
104, 4153-4158
|Abstract »|Full Text »|PDF »
Respiratory impairment in a mouse model of amyotrophic lateral sclerosis.
C. G. Tankersley, C. Haenggeli, and J. D. Rothstein (2007)
J Appl Physiol
102, 926-932
|Abstract »|Full Text »|PDF »
Therapeutic effects of immunization with mutant superoxide dismutase in mice models of amyotrophic lateral sclerosis.
Gene transfer demonstrates that muscle is not a primary target for non-cell-autonomous toxicity in familial amyotrophic lateral sclerosis.
T. M. Miller, S. H. Kim, K. Yamanaka, M. Hester, P. Umapathi, H. Arnson, L. Rizo, J. R. Mendell, F. H. Gage, D. W. Cleveland, et al. (2006)
PNAS
103, 19546-19551
|Abstract »|Full Text »|PDF »
Wild-type microglia extend survival in PU.1 knockout mice with familial amyotrophic lateral sclerosis.
D. R. Beers, J. S. Henkel, Q. Xiao, W. Zhao, J. Wang, A. A. Yen, L. Siklos, S. R. McKercher, and S. H. Appel (2006)
PNAS
103, 16021-16026
|Abstract »|Full Text »|PDF »
The inflammatory NADPH oxidase enzyme modulates motor neuron degeneration in amyotrophic lateral sclerosis mice.
D.-C. Wu, D. B. Re, M. Nagai, H. Ischiropoulos, and S. Przedborski (2006)
PNAS
103, 12132-12137
|Abstract »|Full Text »|PDF »
Neuroprotective agents for clinical trials in ALS: A systematic assessment..
B. J. Traynor, L. Bruijn, R. Conwit, F. Beal, G. O'Neill, S. C. Fagan, and M. E. Cudkowicz (2006)
Neurology
67, 20-27
|Abstract »|Full Text »|PDF »
Informatics-assisted Protein Profiling in a Transgenic Mouse Model of Amyotrophic Lateral Sclerosis.
T. J. Lukas, W. W. Luo, H. Mao, N. Cole, and T. Siddique (2006)
Mol. Cell. Proteomics
5, 1233-1244
|Abstract »|Full Text »|PDF »
Als2-deficient mice exhibit disturbances in endosome trafficking associated with motor behavioral abnormalities.
R. S. Devon, P. C. Orban, K. Gerrow, M. A. Barbieri, C. Schwab, L. P. Cao, J. R. Helm, N. Bissada, R. Cruz-Aguado, T.-L. Davidson, et al. (2006)
PNAS
103, 9595-9600
|Abstract »|Full Text »|PDF »
Risks, benefits, and consent in the age of gene therapy.
J. R. Mendell and K. R. Clark (2006)
Neurology
66, 964-965
|Full Text »|PDF »
Autophagy-mediated clearance of huntingtin aggregates triggered by the insulin-signaling pathway.
A. Yamamoto, M. L. Cremona, and J. E. Rothman (2006)
J. Cell Biol.
172, 719-731
|Abstract »|Full Text »|PDF »
Intracranial Delivery of CLN2 Reduces Brain Pathology in a Mouse Model of Classical Late Infantile Neuronal Ceroid Lipofuscinosis.
M. A. Passini, J. C. Dodge, J. Bu, W. Yang, Q. Zhao, D. Sondhi, N. R. Hackett, S. M. Kaminsky, Q. Mao, L. S. Shihabuddin, et al. (2006)
J. Neurosci.
26, 1334-1342
|Abstract »|Full Text »|PDF »
The Insulin-Like Growth Factor System and Its Pleiotropic Functions in Brain.
V. C. Russo, P. D. Gluckman, E. L. Feldman, and G. A. Werther (2005)
Endocr. Rev.
26, 916-943
|Abstract »|Full Text »|PDF »
Tau Is Hyperphosphorylated in the Insulin-Like Growth Factor-I Null Brain.
C. M. Cheng, V. Tseng, J. Wang, D. Wang, L. Matyakhina, and C. A. Bondy (2005)
Endocrinology
146, 5086-5091
|Abstract »|Full Text »|PDF »
Clinical Trials in Amyotrophic Lateral Sclerosis: The Tenuous Past and the Promising Future.
R. B. Choudry and M. E. Cudkowicz (2005)
J. Clin. Pharmacol.
45, 1334-1344
|Abstract »|Full Text »|PDF »
Intraneuronal {beta}-Amyloid Expression Downregulates the Akt Survival Pathway and Blunts the Stress Response.
J. Magrane, K. M. Rosen, R. C. Smith, K. Walsh, G. K. Gouras, and H. W. Querfurth (2005)
J. Neurosci.
25, 10960-10969
|Abstract »|Full Text »|PDF »
No widespread induction of cell death genes occurs in pure motoneurons in an amyotrophic lateral sclerosis mouse model.
F. E. Perrin, G. Boisset, M. Docquier, O. Schaad, P. Descombes, and A. C. Kato (2005)
Hum. Mol. Genet.
14, 3309-3320
|Abstract »|Full Text »|PDF »
Amelioration of laminin-{alpha}2-deficient congenital muscular dystrophy by somatic gene transfer of miniagrin.
C. Qiao, J. Li, T. Zhu, R. Draviam, S. Watkins, X. Ye, C. Chen, J. Li, and X. Xiao (2005)
PNAS
102, 11999-12004
|Abstract »|Full Text »|PDF »
Molecular Endocrinology and Physiology of the Aging Central Nervous System.
A Rac1/Phosphatidylinositol 3-Kinase/Akt3 Anti-apoptotic Pathway, Triggered by AlsinLF, the Product of the ALS2 Gene, Antagonizes Cu/Zn-superoxide Dismutase (SOD1) Mutant-induced Motoneuronal Cell Death.
K. Kanekura, Y. Hashimoto, Y. Kita, J. Sasabe, S. Aiso, I. Nishimoto, and M. Matsuoka (2005)
J. Biol. Chem.
280, 4532-4543
|Abstract »|Full Text »|PDF »
Muscle expression of a local Igf-1 isoform protects motor neurons in an ALS mouse model.
G. Dobrowolny, C. Giacinti, L. Pelosi, C. Nicoletti, N. Winn, L. Barberi, M. Molinaro, N. Rosenthal, and A. Musaro (2005)
J. Cell Biol.
168, 193-199
|Abstract »|Full Text »|PDF »
Gene transfer for neurologic disease: Agencies, policies, and process.
To whom correspondence should be addressed. E-mail: 
30 days later (
2 = 34.14, P < 0.0001) (
within the lumbar spinal cord compared to GFP controls (n = 5 mice), indicating that IGF-1 also works to delay the associated glial (microglial and astroglial) response seen in ALS. 
