Intrathecal upregulation of granulocyte colony stimulating factor and its neuroprotective actions on motor neurons in amyotrophic lateral sclerosis

G-CSF prevents the progression of structural disintegration of white matter tracts in amyotrophic lateral sclerosis: a pilot trial

Background

The hematopoietic protein Granulocyte-colony stimulating factor (G-CSF) has neuroprotective and -regenerative properties. The G-CSF receptor is expressed by motoneurons, and G-CSF protects cultured motoneuronal cells from apoptosis. It therefore appears as an attractive and feasible drug candidate for the treatment of amyotrophic lateral sclerosis (ALS). The current pilot study was performed to determine whether treatment with G-CSF in ALS patients is feasible.

Methods

Ten patients with definite ALS were entered into a double-blind, placebo-controlled, randomized trial. Patients received either 10 µg/kg BW G-CSF or placebo subcutaneously for the first 10 days and from day 20 to 25 of the study. Clinical outcome was assessed by changes in the ALS functional rating scale (ALSFRS), a comprehensive neuropsychological test battery, and by examining hand activities of daily living over the course of the study (100 days). The total number of adverse events (AE) and treatment-related AEs, discontinuation due to treatment-related AEs, laboratory parameters including leukocyte, erythrocyte, and platelet count, as well as vital signs were examined as safety endpoints.

Furthermore, we explored potential effects of G-CSF on structural cerebral abnormalities on the basis of voxel-wise statistics of Diffusion Tensor Imaging (DTI), brain volumetry, and voxel-based morphometry.

Results

Treatment was well-tolerated. No significant differences were found between groups in clinical tests and brain volumetry from baseline to day 100. However, DTI analysis revealed significant reductions of fractional anisotropy (FA) encompassing diffuse areas of the brain when patients were compared to controls. On longitudinal analysis, the placebo group showed significant greater and more widespread decline in FA than the ALS patients treated with G-CSF.

Conclusions

Subcutaneous G-CSF treatment in ALS patients appears as feasible approach. Although exploratory analysis of clinical data showed no significant effect, DTI measurements suggest that the widespread and progressive microstructural neural damage in ALS can be modulated by G-CSF treatment. These findings may carry significant implications for further clinical trials on ALS using growth factors.

Trial Registration

ClinicalTrials.gov NCT00298597

Repeated courses of granulocyte colony-stimulating factor in amyotrophic lateral sclerosis: clinical and biological results from a prospective multicenter study

Granulocyte colony-stimulating factor (G-CSF) induces a transient mobilization of hematopoietic progenitor cells from bone marrow to peripheral blood. Our aim was to evaluate safety of repeated courses of G-CSF in patients with amyotrophic lateral sclerosis (ALS), assessing disease progression and changes in chemokine and cytokine levels in serum and cerebrospinal fluid (CSF). Twenty-four ALS patients entered an open-label, multicenter trial in which four courses of G-CSF and mannitol were administered at 3-month intervals. Levels of G-CSF were increased after treatment in the serum and CSF. Few and transitory adverse events were observed. No significant reduction of the mean monthly decrease in ALSFRS-R score and forced vital capacity was observed. A significant reduction in CSF levels of monocyte chemoattractant protein-1 (MCP-1) and interleukin-17 (IL-17) was observed. G-CSF treatment was safe and feasible in a multicenter series of ALS patients. A decrease in the CSF levels of proinflammatory cytokines MCP-1 and IL-17 was found, indicating a G-CSF-induced central anti-inflammatory response.

Exogenous granulocyte colony-stimulating factor exacerbate pain-related behaviors after peripheral nerve injury

Previous studies have demonstrated that inflammatory cells produce several mediators that can effectively counteract pain. This study was designed to test the hypothesis that exogenous administration of recombinant mouse granulocyte-colony-stimulating factor (rmG-CSF) to enhance the recruitment of inflammatory cells to painful inflamed sites could attenuate pain in a chronic neuropathic pain model in mice. Our results indicate that treatment with rmG-CSF increased several cytokines and opioid peptides content; however, it did not attenuate but exacerbate neuropathic pain. Our study highlights the potent pro-inflammatory potential of G-CSF and suggests they may be targets for therapeutic intervention in chronic neuropathic pain.

Interleukin-17 and interleukin-23 are elevated in serum and cerebrospinal fluid of patients with ALS: a reflection of Th17 cells activation?

BACKGROUND

There is evidence that immunological factors may involved in pathogenetic mechanisms of amyotrophic lateral sclerosis (ALS). Th17 cells are characterized by predominant production of IL-17 and are suggested to be crucial in destructive autoimmunity. Interleukin-23 (IL-23) appears to play a supporting role in the continued stimulation and survival of Th17.

PATIENTS AND METHODS

We measured by enzyme-like immunosorbent assay (ELISA) serum and cerebrospinal fluid (CSF) levels of IL-17 and IL-23 in 22 patients with ALS and 19 patients with other non-inflammatory neurological disorders (NIND) studied as a control group. IL-17 and IL-23 serum and CSF levels were also correlated with duration of the disease, the disability level and the clinical subtype of the disease onset in patients with ALS.

RESULTS

IL-17 and IL-23 serum levels were higher in patients with ALS as compared with patients with NIND (P = 0.015 and P = 0.002 respectively). IL-17 and IL-23 CSF levels were also increased in patients with ALS (P = 0.0006 and P = 0.000001 respectively). IL-17 and IL-23 levels were not correlated with disease duration, disability scale or clinical subtype of the disease onset in ALS patients.

CONCLUSIONS

Our findings suggest that these molecules may be involved in the pathogenetic mechanisms acting as potential markers of Th17 cells activation in ALS.

Granulocyte-colony stimulating factor (G-CSF) enhances recovery in mouse model of Parkinson's disease

INTRODUCTION

Granulocyte-colony stimulating factor (G-CSF) is used routinely in clinical practice for the treatment of neutropenia and to increase generation of hematopoietic stem cells in bone marrow donors. A growing body of literature on the neurotrophic effects of G-CSF has led to clinical trials in stroke, Alzheimer's disease (AD) and Parkinson's disease (PD).

OBJECTIVES

The primary objective of this study was to determine if G-CSF administration would rescue the nigro-striatal system and restore locomotor function after completion of a sub-acute course of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) administration (30mg/kg i.p. for 5 days) in 12 month-old mice. A secondary aim was to determine if G-CSF affects the neuro-inflammatory response by modulating microglial activation in striatum and midbrain.

RESULTS

MPTP-treated mice were impaired on the rotometer test after the last dose of the toxicant and remained impaired until euthanasia. MPTP-treated mice that were given an 8-day regimen of G-CSF starting 2 days after the last dose of toxicant enhanced motor performance compared to the MPTP alone group. MPTP treatment depleted striatal DA (DA) levels; G-CSF given after MPTP resulted in a partial, significant repletion of DA levels. Total microglial burden in the striatum was increased significantly in MPTP-treated mice and was reduced after G-CSF rescue.

CONCLUSION

G-CSF enhances recovery of DA nigro-striatal function from MPTP toxicity in part by modulating the microglial response to injury. The G-CSF receptor may provide a novel target for modifying the disease process in Parkinson's disease.

Microglia in ALS: the good, the bad, and the resting

Inflammation, including microglial activation and T cell infiltration, is a neuropathological hallmark of amyotrophic lateral sclerosis (ALS), a rapidly progressing neurodegenerative disease. The identification of mutations in the gene for Cu2+/Zn2+ superoxide dismutase (SOD1) from patients with an inherited form of ALS enabled the creation of transgenic mice overexpressing mutant forms of SOD1 (mSOD1) which develop a motoneuron disease that resembles the disease seen in ALS patients. These transgenic mice display similar inflammatory reactions at sites of motoneuron injury as detected in ALS patients, enabling the observation that this inflammation is not simply a late consequence of motoneuron degeneration, but actively contributes to the balance between neuroprotection and neurotoxicity. The microglial and T cell activation states influence the rate of disease progression. Initially, microglia and T cells can slow disease progression, while they may later contribute to the acceleration of disease. Accumulation of intracellular and extracellular misfolded mSOD1 may be key events regulating the transformation from neuroprotective alternatively activated M2 microglia to cytotoxic classically activated M1 microglia. Intracellular and extracellular mSOD1 utilizing different pathways may enhance the production and release of reactive oxygen species (ROS) and augment the inflammatory cytokine cascade from microglia. These ROS and cytokines may increase the susceptibility of motoneurons to glutamate toxicity and inhibit the function and expression of astrocytic glutamate transporters resulting in further neurotoxicity. Thus, the cumulative evidence suggests that inflammation plays a central role in ALS and manipulating these microglial effector functions may potentially modify the outcome of this devastating disease.

Restoration of microglial function by granulocyte-colony stimulating factor in ALS model mice

We studied the effects of G-CSF on microglial reactions in mutant SOD1 (mSOD1)-Tg (G93A) ALS model mice. Following hypoglossal axotomy, the numbers of neurons and microglia expressing GDNF were significantly lower in mSOD1-Tg mice than in non-transgenic (NTG) littermates. This decrease in the number of neurons after axotomy and a decrease in the number of large myelinated axons in mSOD1-Tg mice over the disease course were improved by G-CSF, which also increased microglial recruitment. Impaired migration of cultured mSOD1-Tg microglia to MCP-1 was recovered following G-CSF treatment. Restoration of microglial responses by G-CSF may contribute to its neuroprotective effects.

The application of biomarkers in clinical trials for motor neuron disease

The interest and research into disease-related biomarkers has greatly accelerated over the last 10 years. The potential clinical benefits for disease-specific biomarkers include a more rapid and accurate disease diagnosis, and potential reduction in size and duration of clinical drug trials, which would speed up drug development. The application of biomarkers into the clinical arena of motor neuron disease should both determine if a drug hits its proposed target and whether the drug alters the course of disease. This article will highlight the progress made in discovering suitable biomarker candidates from a variety of sources, including imaging, neurophysiology and proteomics. For biomarkers to have clinical utility, specific criteria must be satisfied. While there has been tremendous effort to discover biomarkers, very few have been translated to the clinic. The bottlenecks in the biomarker pipeline will be highlighted as well as lessons that can be learned from other disciplines, such as oncology.

CSF chemokine alterations related to the clinical course of amyotrophic lateral sclerosis

We measured the levels of 27 cytokines/chemokines and growth factors in cerebrospinal fluid (CSF) from 42 patients with sporadic amyotrophic lateral sclerosis (ALS), 12 patients with lower motor neuron disease (LMND), and 34 control patients with non-inflammatory neurological diseases (OND), using a multiplexed fluorescent bead-based immunoassay. Among cytokines/chemokines elevated in ALS, CCL2 and CXCL8 levels were negatively correlated with the revised ALS functional rating scale (ALSFRS-R) score, while CCL4 showed a positive correlation with ALSFRS-R score. CCL4 and CXCL10 showed negative correlations with disease progression rate. These chemokine alterations are assumed to somehow correlate with the clinical course of ALS.

Efficacy of thalidomide for the treatment of amyotrophic lateral sclerosis: a phase II open label clinical trial

Neuroinflammation through the cytokine, tumor necrosis factor-alpha (TNF-alpha) is thought to play an important role in the pathogenesis of amyotrophic lateral sclerosis (ALS). We conducted a preliminary phase II trial of thalidomide, which reduces levels of TNF-alpha pre-transcriptionally and post-transcriptionally in vivo and has been shown to prolong disease duration and extend the lifespan of transgenic animal models of ALS. Patients who met diagnostic criteria for ALS received thalidomide at escalating doses to a target dose of 400 mg/day. The primary endpoints in the trial were the ALS Functional Rating Scale (ALSFRS) and pulmonary function testing (PFT) curves after nine months of thalidomide treatment that were compared to historical controls. Secondary endpoints were: survival stratified for newly diagnosed and progressive disease, toxicity, quality of life, and serum cytokine measurements. Twenty-three patients were enrolled, but only 18 were evaluable for the primary outcome. There was no improvement in the ALSFRS or PFT compared to historical controls. Thalidomide had several side-effects in our ALS patients. There was no significant shift in cytokine profile after treatment compared to baseline. In conclusion, treatment of ALS with the TNF-alpha inhibitor, thalidomide, does not appear to effectively modulate disease progression and can cause adverse effects.

Both systemic and local application of granulocyte-colony stimulating factor (G-CSF) is neuroprotective after retinal ganglion cell axotomy

Background

The hematopoietic Granulocyte-Colony Stimulating Factor (G-CSF) plays a crucial role in controlling the number of neutrophil progenitor cells. Its function is mediated via the G-CSF receptor, which was recently found to be expressed also in the central nervous system. In addition, G-CSF provided neuroprotection in models of neuronal cell death. Here we used the retinal ganglion cell (RGC) axotomy model to compare effects of local and systemic application of neuroprotective molecules.

Results

We found that the G-CSF receptor is robustly expressed by RGCs in vivo and in vitro. We thus evaluated G-CSF as a neuroprotectant for RGCs and found a dose-dependent neuroprotective effect of G-CSF on axotomized RGCs when given subcutaneously. As stem stell mobilization had previously been discussed as a possible contributor to the neuroprotective effects of G-CSF, we compared the local treatment of RGCs by injection of G-CSF into the vitreous body with systemic delivery by subcutaneous application. Both routes of application reduced retinal ganglion cell death to a comparable extent. Moreover, G-CSF enhanced the survival of immunopurified RGCs in vitro.

Conclusion

We thus show that G-CSF neuroprotection is at least partially independent of potential systemic effects and provide further evidence that the clinically applicable G-CSF could become a treatment option for both neurodegenerative diseases and glaucoma.

Reduced angiotensin II levels in the cerebrospinal fluid of patients with amyotrophic lateral sclerosis

BACKGROUND

Recent studies suggest that angiotensin II, a major substrate in the renin-angiotensin system, protects neurons through stimulation of its type 2 receptors. However, quite a few clinical studies of angiotensin II levels have shown their relation to disease severity in neurodegenerative disorders, including amyotrophic lateral sclerosis (ALS).

AIMS OF THE STUDY

To clarify the significance of angiotensin II in ALS.

METHODS

We assayed angiotensin II concentrations in cerebrospinal fluid (CSF) samples from 23 patients with ALS, nine patients with spinocerebellar degeneration (SCD) and 24 control individuals. We evaluated the disability levels of patients with ALS using the Revised ALS Functional Rating Scale (ALSFRS-R) and calculated the disease progression rate (DPR).

RESULTS

CSF angiotensin II levels were significantly lower in the ALS group compared with that in the control group (P = 0.00864), and showed a significant positive correlation with scores on the ALSFRS-R, and a significant negative correlation with the DPR.

CONCLUSIONS

In the present study, we reveal for the first time that angiotensin II levels in the CSF from patients with ALS are significantly reduced and significantly associated with disease severity and progression rate. These findings suggest that reduced levels of intrathecal angiotensin II may play a role in ALS.

Intrathecal upregulation of IFN-gamma and MIP-1beta in juvenile muscular atrophy of the distal upper extremity

Juvenile muscular atrophy of the distal upper extremity (JMADUE) is associated with airway allergy and hyperIgEaemia, suggesting the involvement of immunological processes. In this study we aimed to clarify the changes in various cytokines/chemokines in cerebrospinal fluid (CSF) from JMADUE patients. We simultaneously measured 17 cytokines/chemokines in sera and CSF from 6 patients with JMADUE before treatment and from 14 patients with cervical spondylosis (CS) as a disease control (mean age at examination 23+/-7 and. 57+/-16 years, respectively), using a fluorescent bead-based immunoassay. We also assayed CSF from a JMADUE patient before and after plasma exchanges. In sera, only an increase of MIP-1beta (CCL3) in the JMADUE patients had a marginal significance as compared with the CS patients. In the CSF, IFN-gamma and MIP-1beta (CCL3) were significantly elevated in JMADUE patients compared with controls (1.5 and 2-fold increases, respectively), while no other cytokines/chemokines showed any significant differences. Moreover, the upregulated cytokines decreased after plasma exchanges in accord with improvement of distal upper limb weakness. The intrathecal upregulation of proinflammatory Th1 cytokines/chemokines, such as IFN-gamma and MIP-1beta (CCL3), in the CSF of JMADUE patients indicates the possible involvement of intrathecal immunological processes in this condition.

Neural stem cell transplantation can ameliorate the phenotype of a mouse model of spinal muscular atrophy

Spinal muscular atrophy (SMA), a motor neuron disease (MND) and one of the most common genetic causes of infant mortality, currently has no cure. Patients with SMA exhibit muscle weakness and hypotonia. Stem cell transplantation is a potential therapeutic strategy for SMA and other MNDs. In this study, we isolated spinal cord neural stem cells (NSCs) from mice expressing green fluorescent protein only in motor neurons and assessed their therapeutic effects on the phenotype of SMA mice. Intrathecally grafted NSCs migrated into the parenchyma and generated a small proportion of motor neurons. Treated SMA mice exhibited improved neuromuscular function, increased life span, and improved motor unit pathology. Global gene expression analysis of laser-capture-microdissected motor neurons from treated mice showed that the major effect of NSC transplantation was modification of the SMA phenotype toward the wild-type pattern, including changes in RNA metabolism proteins, cell cycle proteins, and actin-binding proteins. NSC transplantation positively affected the SMA disease phenotype, indicating that transplantation of NSCs may be a possible treatment for SMA.

Granulocyte-colony stimulating factor improves outcome in a mouse model of amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease that results in progressive loss of motoneurons, motor weakness and death within 1-5 years after disease onset. Therapeutic options remain limited despite a substantial number of approaches that have been tested clinically. In particular, various neurotrophic factors have been investigated. Failure in these trials has been largely ascribed to problems of insufficient dosing or inability to cross the blood-brain barrier (BBB). We have recently uncovered the neurotrophic properties of the haematopoietic protein granulocyte-colony stimulating factor (G-CSF). The protein is clinically well tolerated and crosses the intact BBB. This study examined the potential role of G-CSF in motoneuron diseases. We investigated the expression of the G-CSF receptor in motoneurons and studied effects of G-CSF in a motoneuron cell line and in the SOD1(G93A) transgenic mouse model. The neurotrophic growth factor was applied both by continuous subcutaneous delivery and CNS-targeted transgenic overexpression. This study shows that given at the stage of the disease where muscle denervation is already evident, G-CSF leads to significant improvement in motor performance, delays the onset of severe motor impairment and prolongs overall survival of SOD1(G93A)tg mice. The G-CSF receptor is expressed by motoneurons and G-CSF protects cultured motoneuronal cells from apoptosis. In ALS mice, G-CSF increased survival of motoneurons and decreased muscular denervation atrophy. We conclude that G-CSF is a novel neurotrophic factor for motoneurons that is an attractive and feasible drug candidate for the treatment of ALS.

Pilot study of granulocyte colony stimulating factor (G-CSF)-mobilized peripheral blood stem cells in amyotrophic lateral sclerosis (ALS)

Amyotrophic lateral sclerosis (ALS) is characterized by degeneration of upper and lower motor neurons in the brain, brainstem, and spinal cord. It has been proposed that bone marrow (BM)-derived cells might supply motor neurons and other cells with a cellular milieu more conducive to survival in ALS. Direct injection of stem cells in ALS is problematic because of the large expanse of the neuraxis that would need to be injected. We reasoned that transiently increasing the number of circulating hematopoietic stem cells might be a useful therapeutic approach. However, agents stimulating the activation and mobilization of hematopoietic stem cells may have adverse effects such as activation of microglial cells. We conducted a small pilot trial of the collection and reinfusion of granulocyte-colony stimulating factor (G-CSF)-mobilized peripheral blood stem cells (PBSC) in ALS patients and found no adverse effects, paving the way for a properly powered therapeutic trial with an optimized regimen of G-CSF.

Cell biology and clinical promise of G-CSF: immunomodulation and neuroprotection

In the light of the enthusiasm to use of recombinant human granulocyte colony-stimulating factor (G-CSF) for immunomodulation and neuroprotection, it should be remembered that the current knowledge is based on a century of laborious research. G-CSF is a pleiotropic cytokine playing a major role as regulator of haematopoiesis. Although the precise mechanisms of G-CSF are not known, there is growing evidence supporting the notion that G-CSF also exerts profound immunoregulatory effect in adaptive immunity and has a neuroprotective role in both cerebral ischemia and neurodegeneration. Here, we describe the immunomodulation and the neuroprotection that can be achieved with G-CSF, and summarize possible mechanisms of G-CSF as a potential therapeutic agent in autoimmune diseases and neurological disorders. Our understanding of these novel sites of action of G-CSF has opened therapeutic avenues for the treatment of autoimmune diseases and neurological disorders, and has translated the beneficial effects of G-CSF from basic experiments to clinical patients.

Increased IL-13-producing T cells in ALS: positive correlations with disease severity and progression rate

We measured the intracellular productions of IFNgamma, IL-2, IL-4, IL-13 and TNFalpha in peripheral blood CD4(+) and CD8(+) T cells from 21 amyotrophic lateral sclerosis (ALS) patients, 14 disease controls (DC) with spinocerebellar degeneration and 16 healthy controls (HC). Only the percentages of CD4(+)IL-13(+) and CD8(+)IL-13(+) T cells were significantly higher in ALS patients than in DC and HC. The CD4(+)IL-13(+) T cell percentages showed a significant negative correlation with the revised ALS functional rating scale scores and significant positive correlation with the disease progression rate, suggesting that IL-13 contributes to ALS.