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

Administration of Δ9-Tetrahydrocannabinol Following Controlled Cortical Impact Restores Hippocampal-Dependent Working Memory and Locomotor Function

Hypothesis: Administration of the phytocannabinoid Δ9-tetrahydrocannabinol (Δ9-THC) will enhance brain repair and improve short-term spatial working memory in mice following controlled cortical impact (CCI) by upregulating granulocyte colony-stimulating factor (G-CSF) and other neurotrophic factors (brain-derived neurotrophic factor [BDNF], glial-derived neurotrophic factor [GDNF]) in hippocampus (HP), cerebral cortex, and striatum. Materials and Methods: C57BL/6J mice underwent CCI and were treated for 3 days with Δ9-THC 3 mg/kg intraperitoneally (i.p.). Short-term working memory was determined using the spontaneous alternations test during exploratory behavior in a Y-maze. Locomotor function was measured as latency to fall from a rotating drum (rotometry). These behaviors were recorded at baseline and 3, 7, and 14 days after CCI. Groups of mice were euthanized at 7 and 14 days. Extent of microgliosis, astrocytosis, and G-CSF, BDNF, and GDNF expression were measured at 7 and 14 days in cerebral cortex, striatum, and HP on the side of the trauma. Levels of the most abundant endocannabinoid (2-arachidonoyl-glycerol [2-AG]) was also measured at these times. Results: Δ9-THC-treated mice exhibited marked improvement in performance on the Y-maze indicating that treatment with the phytocannabinoid could reverse the deficit in working memory caused by the CCI. Δ9-THC-treated mice ran on the rotarod longer than vehicle-treated mice and recovered to normal rotarod performance levels at 2 weeks. Δ9-THC-treated mice, compared with vehicle-treated animals, exhibited significant upregulation of G-CSF as well as BDNF and GDNF in the cerebral cortex, striatum, and HP. Levels of 2-AG were also increased in the Δ9-THC-treated mice. Conclusion: Administration of the phytocannabinoid Δ9-THC promotes significant functional recovery from traumatic brain injury (TBI) in the realms of working memory and locomotor function. This beneficial effect is associated with upregulation of brain 2-AG, G-CSF, BDNF, and GDNF. The latter three neurotrophic factors have been previously shown to mediate brain self-repair following TBI and stroke.

Granulocyte-colony stimulating factor (G-CSF): an emerging therapeutic approach for amyotrophic lateral sclerosis (ALS)

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder characterized by neuronal degeneration and inflammation in the nerves. G-CSF is a 19.6-kDa hematopoietic growth factor which is essential for the proliferation and differentiation of granulocyte hematopoietic progenitors. G-CSF exerts neuroprotective activities by induction of neuronal regeneration, inhibition of neuronal apoptosis, mobilization of Hematopoietic stem cells (HSCs), regulation of pro and anti-inflammatory cytokines, and activation of angiogenesis. Pre-clinical studies have shown significant efficacy of G-CSF therapy in mSOD1^G93A mice models. G-CSF treatments were able to increase the survival of mice. However, clinical studies on ALS patients failed to clone pre-clinical results. Considering the potential role of G-CSF in nervous system regeneration, this study aimed to comprehensively review the clinical and pre-clinical studies addressing G-CSF in ALS treatment.

Drug Repositioning in Friedreich Ataxia

Friedreich ataxia is a rare neurodegenerative disorder caused by insufficient levels of the essential mitochondrial protein frataxin. It is a severely debilitating disease that significantly impacts the quality of life of affected patients and reduces their life expectancy, however, an adequate cure is not yet available for patients. Frataxin function, although not thoroughly elucidated, is associated with assembly of iron-sulfur cluster and iron metabolism, therefore insufficient frataxin levels lead to reduced activity of many mitochondrial enzymes involved in the electron transport chain, impaired mitochondrial metabolism, reduced ATP production and inefficient anti-oxidant response. As a consequence, neurons progressively die and patients progressively lose their ability to coordinate movement and perform daily activities. Therapeutic strategies aim at restoring sufficient frataxin levels or at correcting some of the downstream consequences of frataxin deficiency. However, the classical pathways of drug discovery are challenging, require a significant amount of resources and time to reach the final approval, and present a high failure rate. Drug repositioning represents a viable alternative to boost the identification of a therapy, particularly for rare diseases where resources are often limited. In this review we will describe recent efforts aimed at the identification of a therapy for Friedreich ataxia through drug repositioning, and discuss the limitation of such strategies.

Colony stimulating factors in the nervous system

Although traditionally seen as regulators of hematopoiesis, colony-stimulating factors (CSFs) have emerged as important players in the nervous system, both in health and disease. This review summarizes the cellular sources, patterns of expression and physiological roles of the macrophage (CSF-1, IL-34), granulocyte-macrophage (GM-CSF) and granulocyte (G-CSF) colony stimulating factors within the nervous system, with a particular focus on their actions on microglia. CSF-1 and IL-34, via the CSF-1R, are required for the development, proliferation and maintenance of essentially all CNS microglia in a temporal and regional specific manner. In contrast, in steady state, GM-CSF and G-CSF are mainly involved in regulation of microglial function. The alterations in expression of these growth factors and their receptors, that have been reported in several neurological diseases, are described and the outcomes of their therapeutic targeting in mouse models and humans are discussed.

Ultrarapid Inflammation of the Olfactory Bulb After Spinal Cord Injury: Protective Effects of the Granulocyte Colony-Stimulating Factor on Early Neurodegeneration in the Brain

The correlation among olfactory dysfunction, spinal cord injury (SCI), subjective cognitive decline, and neurodegenerative dementia has been established. Impaired olfaction is considered a marker for neurodegeneration. Hence, there is a need to examine if SCI leads to olfactory dysfunction. In this study, the brain tissue of mice with spinal cord hemisection injury was subjected to microarray analysis. The mRNA expression levels of olfactory receptors in the brain began to decline at 8 h post-SCI. SCI promoted neuroinflammation, downregulated the expression of olfactory receptors, decreased the number of neural stem cells (NSCs), and inhibited the production of neurotrophic factors in the olfactory bulbs at 8 h post-SCI. In particular, the SCI group had upregulated mRNA and protein expression levels of glial fibrillary acidic protein (GFAP; a marker of astrocyte reactivation) and pro-inflammatory mediators [IL-1β, IL-6, and Nestin (marker of NSCs)] in the olfactory bulb compared to levels in the sham control group. The mRNA expression levels of olfactory receptors (Olfr1494, Olfr1324, Olfr1241, and Olfr979) and neurotrophic factors [brain-derived neurotrophic factor (BDNF), glial cell-derived neurotrophic factor (GDNF), and nerve growth factor (NGF)] were downregulated in the olfactory bulb of the SCI group mice at 8 h post-SCI. The administration of granulocyte colony-stimulating factor (G-CSF) mitigated these SCI-induced pathological changes in the olfactory bulb at 8 h post-SCI. These results indicate that the olfactory bulb is vulnerable to environmental damage even if the lesion is located at sites distant from the brain, such as the spinal cord. Additionally, SCI initiated pathological processes, including inflammatory response, and impaired neurogenesis, at an early stage. The findings of this study will provide a basis for future studies on pathological mechanisms of early neurodegenerative diseases involving the olfactory bulb and enable early clinical drug intervention.

Therapeutic Effects of Liraglutide, Oxytocin and Granulocyte Colony-Stimulating Factor in Doxorubicin-Induced Cardiomyopathy Model: An Experimental Animal Study

Doxorubicin-induced (DXR) cardiomyopathy is a serious health issue in oncology patients. Effective treatment of this clinical situation still remains to be discovered. In this experimental animal study, we aimed to define therapeutic effects of liraglutide, oxytocin and granulocyte colony-stimulating factor in DXR-induced cardiomyopathy model. 40 male Sprague-Dawley rats were included to study. 32 rats were given doxorubicin (DXR) for cardiomyopathy model. DXR was administered intraperitonally (i.p.) at every other day of 2.5 mg/kg/day at six times. Eight rats were taken as normal group and no treatment was performed. 32 rats given doxorubicin were divided into 4 groups. Group 1 rats were assigned to a placebo group and was given with a 0.9% NaCl saline solution at a dose of 1 ml/kg/day i.p. (DXR + saline), Group 2 rats were given with 1.8 mg/kg/day of Liraglutide i.p. (DXR + LIR), Group 3 rats were given with 160 μg/kg/day oxytocin i.p. (DXR + OX), Group 4 rats were given with 100 μg/kg/day filgrastim i.p. (DXR + G-CSF). All medications were given for 15 days. On day 16, under anesthesia, ECG was recorded from derivation I. After that, blood samples were taken by tail vein puncture for biochemical analysis. Finally, the animals were euthanized and the heart removed and prepared for immunohistochemical examination. All three treatments were shown to ameliorate the toxic effect of doxorubicin in cardiac tissue with the best results in DXR + OX group. DXR + OX group had the most preserved tissue integrity examined by light microscopy, least immune expression level of CASPASE-3 (5.3 ± 0.9) (p < 0.001) the highest ECG QRS wave voltage amplitude (0.21 ± 0.008 mV) (p < 0.00001) least plasma MDA (115.3 ± 19.8 nm) (p < 0.001), TNF-alpha (26.6 ± 3.05 pg/ml) (p < 0.001), pentraxin-3 (2.7 ± 0.9 ng/ml) (p < 0.001), Troponin T (1.4 ± 0.08 pg/ml) (p < 0.001), pro-BNP (11.1 ± 3.6 pg/ml) (p < 0.001) levels among all three treatment groups. Consistent with previous literature, we found that OX treatment decreased oxidative, apoptotic and inflammatory activity in DXR-induced cardiomyopathy rat model as well as provided better tissue integrity and better results in clinically relevant measures of ECG assessment, plasma Troponin T and pro-BNP levels. LIR and G-CSF treatment caused similar results with less powerful effects. Our findings suggest that with the best results in OX treatment group, all three agents including LIR and G-CSF attenuates DXR-induced cardiomyopathy in this rat model.

Molecular Mechanism of Regulation of MTA1 Expression by Granulocyte Colony-stimulating Factor

Parkinson disease (PD) is a neurodegenerative disorder with loss of dopaminergic neurons of the brain, which results in insufficient synthesis and action of dopamine. Metastasis-associated protein 1 (MTA1) is an upstream modulator of tyrosine hydroxylase (TH), the rate-limiting enzyme in dopamine synthesis, and hence MTA1 plays a significant role in PD pathogenesis. To impart functional and clinical significance to MTA1, we analyzed MTA1 and TH levels in the substantia nigra region of a large cohort of human brain tissue samples by Western blotting, quantitative PCR, and immunohistochemistry. Our results showed that MTA1 and TH levels were significantly down-regulated in PD samples as compared with normal brain tissue. Correspondingly, immunohistochemistry analysis for MTA1 in substantia nigra sections revealed that 74.1% of the samples had a staining intensity of <6 in the PD samples as compared with controls, 25.9%, with an odds ratio of 8.54. Because of the clinical importance of MTA1 established in PD, we looked at agents to modulate MTA1 expression in neuronal cells, and granulocyte colony-stimulating factor (G-CSF) was chosen, due to its clinically proven neurogenic effects. Treatment of the human neuronal cell line KELLY and acute 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine mouse model with G-CSF showed significant induction of MTA1 and TH with rescue of phenotype in the mouse model. Interestingly, the observed induction of TH was compromised on silencing of MTA1. The underlying molecular mechanism of MTA1 induction by G-CSF was proved to be through induction of c-Fos and its recruitment to the MTA1 promoter.

Microglia-Mediated Neuroinflammation and Neurotrophic Factor-Induced Protection in the MPTP Mouse Model of Parkinson's Disease-Lessons from Transgenic Mice

Parkinson's disease (PD) is a neurodegenerative disease characterised by histopathological and biochemical manifestations such as loss of midbrain dopaminergic (DA) neurons and decrease in dopamine levels accompanied by a concomitant neuroinflammatory response in the affected brain regions. Over the past decades, the use of toxin-based animal models has been crucial to elucidate disease pathophysiology, and to develop therapeutic approaches aimed to alleviate its motor symptoms. Analyses of transgenic mice deficient for cytokines, chemokine as well as neurotrophic factors and their respective receptors in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) model of PD have broadened the current knowledge of neuroinflammation and neurotrophic support. Here, we provide a comprehensive review that summarises the contribution of microglia-mediated neuroinflammation in MPTP-induced neurodegeneration. Moreover, we highlight the contribution of neurotrophic factors as endogenous and/or exogenous molecules to slow the progression of midbrain dopaminergic (mDA) neurons and further discuss the potential of combined therapeutic approaches employing neuroinflammation modifying agents and neurotrophic factors.

Effect of Periodic Granulocyte Colony-Stimulating Factor Administration on Endothelial Progenitor Cells and Different Monocyte Subsets in Pediatric Patients with Muscular Dystrophies

Muscular dystrophies (MD) are heterogeneous group of diseases characterized by progressive muscle dysfunction. There is a large body of evidence indicating that angiogenesis is impaired in muscles of MD patients. Therefore, induction of dystrophic muscle revascularization should become a novel approach aimed at diminishing the extent of myocyte damage. Recently, we and others demonstrated that administration of granulocyte colony-stimulating factor (G-CSF) resulted in clinical improvement of patients with neuromuscular disorders. To date, however, the exact mechanisms underlying these beneficial effects of G-CSF have not been fully understood. Here we used flow cytometry to quantitate numbers of CD34+ cells, endothelial progenitor cells, and different monocyte subsets in peripheral blood of pediatric MD patients treated with repetitive courses of G-CSF administration. We showed that repetitive cycles of G-CSF administration induced efficient mobilization of above-mentioned cells including cells with proangiogenic potential. These findings contribute to better understanding the beneficial clinical effects of G-CSF in pediatric MD patients.

Noninvasive tracking of gene transcript and neuroprotection after gene therapy

Gene therapy holds exceptional potential for translational medicine by improving the products of defective genes in diseases and/or providing necessary biologics from endogenous sources during recovery processes. However, validating methods for the delivery, distribution and expression of the exogenous genes from such therapy can generally not be applicable to monitor effects over the long term because they are invasive. We report here that human granulocyte colony-stimulating factor (hG-CSF) cDNA encoded in scAAV-type 2 adeno-associated virus, as delivered through eye drops at multiple time points after cerebral ischemia using bilateral carotid occlusion for 60 min (BCAO-60) led to significant reduction in mortality rates, cerebral atrophy, and neurological deficits in C57black6 mice. Most importantly, we validated hG-CSF cDNA expression using translatable magnetic resonance imaging (MRI) in living brains. This noninvasive approach for monitoring exogenous gene expression in the brains has potential for great impact in the area of experimental gene therapy in animal models of heart attack, stroke, Alzheimer’s dementia, Parkinson’s disorder and amyotrophic lateral sclerosis, and the translation of such techniques to emergency medicine.

G-CSF protects human brain vascular endothelial cells injury induced by high glucose, free fatty acids and hypoxia through MAPK and Akt signaling

Granulocyte-colony stimulating factor (G-CSF) has been shown to play a neuroprotective role in ischemic stroke by mobilizing bone marrow (BM)-derived endothelial progenitor cells (EPCs), promoting angiogenesis, and inhibiting apoptosis. Impairments in mobilization and function of the BM-derived EPCs have previously been reported in animal and human studies of diabetes where there is both reduction in the levels of the BM-derived EPCs and its ability to promote angiogenesis. This is hypothesized to account for the pathogenesis of diabetic vascular complications such as stroke. Here, we sought to investigate the effects of G-CSF on diabetes-associated cerebral vascular defect. We observed that pretreatment of the cultured human brain vascular endothelial cells (HBVECs) with G-CSF largely prevented cell death induced by the combination stimulus with high glucose, free fatty acids (FFA) and hypoxia by increasing cell viability, decreasing apoptosis and caspase-3 activity. Cell ultrastructure measured by transmission electron microscope (TEM) revealed that G-CSF treatment nicely reduced combination stimulus-induced cell apoptosis. The results from fluorescent probe Fluo-3/AM showed that G-CSF greatly suppressed the levels of intracellular calcium ions under combination stimulus. We also found that G-CSF enhanced the expression of cell cycle proteins such as human cell division cycle protein 14A (hCdc14A), cyclinB and cyclinE, inhibited p53 activity, and facilitated cell cycle progression following combination stimulus. In addition, activation of extracellular signal-regulated kinase1/2 (ERK1/2) and Akt, and deactivation of c-Jun N terminal kinase (JNK) and p38 were proved to be required for the pro-survival effects of G-CSF on HBVECs exposed to combination stimulus. Overall, G-CSF is capable of alleviating HBVECs injury triggered by the combination administration with high glucose, FFA and hypoxia involving the mitogen-activated protein kinases (MAPK) and Akt signaling cascades. G-CSF may represent a promising therapeutic agent for diabetic stroke.

Granulocyte colony-stimulating factor provides protection against cardiovascular autonomic neuropathy in streptozotocin-induced diabetes in rats

AIMS

Cardiovascular autonomic neuropathy (CAN) is a relatively common and detrimental complication of diabetes mellitus (DM). Dysregulation of neuropeptides, such as calcitonin gene-related peptide (CGRP) and vasoactive intestinal peptide (VIP), are thought to play significant roles in diabetes-related cardiovascular disease. Accumulating evidence indicates the neuroprotective effects of granulocyte-colony stimulating factor (G-CSF) in different neurological disorders. The purpose of the study is to investigate the role of CGRP and VIP and possible effects of G-CSF on CAN in type I DM model in rats.

METHODS

Diabetes was induced by intraperitoneal injection of streptozotocin (STZ) for 14 rats. Seven rats served as controls and 6 rats were administered G-CSF alone. DM group was randomly divided into 2 groups and received either 1mL/kg saline (DM+saline group) or 100 μg/kg/day G-CSF (DM+G-CSF group) for 4 weeks. Following electrocardiography (ECG), GCRP and VIP levels were measured in plasma samples.

RESULTS

Diabetes promoted a significant prolongation in the corrected QT interval (cQT) (P<0.001) whereas G-CSF administration significantly shortened cQT interval (P<0.05). Plasma VIP and CGRP levels of saline treated DM group were significantly lower than those of control group (P<0.05). G-CSF treatment significantly prevented the reduction in plasma VIP and CGRP levels (P<0.01 and P<0.05, respectively). Also, correlation analysis showed a significant negative correlation between the cQT and neuropeptide levels.

CONCLUSIONS

This study suggests that G-CSF can be effective in CAN by means of neuroprotection, and plasma VIP and CGRP levels can be used for the assessment of autonomic and sensory functions in diabetes.

Granulocyte-colony stimulating factor improves Parkinson's disease associated with co-morbid depression: an experimental exploratory study

Introduction:

The present study was designed to evaluate the effect of granulocyte-colony stimulating factor (G-CSF) in the treatment of Parkinson's disease (PD), the second most common neurodegenerative disease characterized by muscle and movement disorder, often associated with depression. PD is very difficult to treat. Hence, the present study was aimed to evaluate the effect of G-CSF in PD associated with depression.

Materials and Methods:

Adult Wistar male rats weighing about 180-250 g were selected and divided into five groups in parallel designed method namely; control group (n = 5); sham operated group (n = 5); Vehicle group (n = 5); G-CSF group (70 μg/kg, s.c.) (n = 5) and L-DOPA group (n = 5). The rats were treated with 6-hydroxydopamine (6-OHDA) on day 0 and then treatment was continued for 14 day of L-DOPA/carbidopa, whereas G-CSF (70 μg/kg, s.c.) was given from day 1 to 6. Thereafter, adhesive removal and forced swim tests were conducted to evaluate the behavioral outcome of G-CSF treatment. The finding was correlated and analyzed with Nissl staining findings for the final conclusion.

Results:

The behavioral parameters were assessed and found to be ameliorate the symptoms of Parkinson's and reduced the depression like behavior in PD. The histological findings were supported the behavioral findings and showed pathological improvement.

Conclusion:

As a preliminary work, the present study first time suggested that G-CSF have a potential role in PD and associated depression.

Immunization strategies for Parkinson's disease

Parkinson's disease (PD) is the most common neurodegenerative movement disorder. Currently, no curative treatments or treatments that interdict disease progression are available. Over the past decade, immunization strategies were developed in our laboratories to combat disease progression. These strategies were developed in laboratory and animal models of human disease. Induction of humoral immune responses can be elicited against misfolded protein aggregates. Robust cell-mediated immunity against nitrated misfolded protein(s) accelerates disease progression through effector T cell responses that facilitate neuronal death. We propose that shifting the balance between effector and regulatory T cell activity can attenuate neurotoxic inflammatory events. We now summarize our works that support immune regulation in PD with the singular goal of restoring homeostatic glial responses. New methods to optimize immunization schemes and measure their clinical efficacy are discussed.

Neuroprotective cytokines repress PUMA induction in the 1-methyl-4-phenylpyridinium (MPP(+)) model of Parkinson's disease

The hematopoietic cytokines erythropoietin (Epo) and granulocyte-colony stimulating factor (G-CSF) provide neuroprotection in several in vitro and in vivo models of Parkinson's disease (PD). The molecular mechanism by which Epo and G-CSF signals reduce the neuronal death in PD is not clear. Here, we show that in rat pheochromocytoma PC12 cells, Epo and G-CSF efficiently repressed the 1-methyl-4-phenylpyridinium (MPP(+))-induced expression of the proapoptotic protein PUMA (p53 up-regulated modulator of apoptosis). Accordingly, Epo and G-CSF treatment reduced the PC12 cell fraction that underwent apoptosis by MPP(+) treatment and thus improved cell viability. Downregulation of PUMA expression by Epo and G-CSF in MPP(+)-treated PC12 cells seems to be mediated by repression of p53, as the expression of p53 was increased by MPP(+)-treatment and reduced by Epo and G-CSF. Together, these results suggest that the neuroprotective activities of Epo and G-CSF in an experimental model of PD involve the repression of the apoptosis-inducing action of PUMA.