Anti-apoptotic effect of granulocyte-colony stimulating factor after focal cerebral ischemia in the rat

Effect of granulocyte colony-stimulating factor (G-CSF) in functional outcome of acute spinal cord injury patients: A single-blinded randomized controlled trial

Background

Spinal Cord Injury (SCI) is a major public health issue causing significant disability and economic burden. Current treatments primarily focus on mitigating secondary injury, with limited effective therapies available. This study explores the efficacy of the Granulocyte Colony-Stimulating Factor (G-CSF) in improving functional outcomes in acute SCI patients.

Materials and methods

This single-blinded randomized control trial was conducted at JIPMER's orthopedic department. Patients with acute spinal cord injury (SCI) were enrolled based on specific inclusion and exclusion criteria. Participants were divided into two groups: Group A (n = 16) received a G-CSF injection whereas Group B (n = 18) received a placebo (normal saline) injection. The primary evaluation was based on the changes in the ASIA impairment scale at 1-, 3-, and 6-months post-injury.

Results

The study involved 34 participants, predominantly male. Initial assessments showed significant differences in ASIA scores between the groups. Group A demonstrated marked improvement in neurological status at 1, 3, and 6 months post-treatment compared to Group B. The frequency of adverse events was comparable between the two groups.

Conclusion

G-CSF showed significant improvement in ASIA scores at various time points post-administration compared to placebo. These findings suggest G-CSF as a potential therapeutic agent in acute SCI treatment. However, due to the small sample size, further research is necessary to confirm these results.

Cell death in glioblastoma and the central nervous system

Glioblastoma is the commonest and deadliest primary brain tumor. Glioblastoma is characterized by significant intra- and inter-tumoral heterogeneity, resistance to treatment and dismal prognoses despite decades of research in understanding its biological underpinnings. Encompassed within this heterogeneity and therapy resistance are severely dysregulated programmed cell death pathways. Glioblastomas recapitulate many neurodevelopmental and neural injury responses; in addition, glioblastoma cells are composed of multiple different transformed versions of CNS cell types. To obtain a greater understanding of the features underlying cell death regulation in glioblastoma, it is important to understand the control of cell death within the healthy CNS during homeostatic and neurodegenerative conditions. Herein, we review apoptotic control within neural stem cells, astrocytes, oligodendrocytes and neurons and compare them to glioblastoma apoptotic control. Specific focus is paid to the Inhibitor of Apoptosis proteins, which play key roles in neuroinflammation, CNS cell survival and gliomagenesis. This review will help in understanding glioblastoma as a transformed version of a heterogeneous organ composed of multiple varied cell types performing different functions and possessing different means of apoptotic control. Further, this review will help in developing more glioblastoma-specific treatment approaches and will better inform treatments looking at more direct brain delivery of therapeutic agents.

Potential role of signal transducer and activator of transcription 3 in the amygdala in mitigating stress-induced high blood pressure via exercise in rats

AIM

Chronic stress elevates blood pressure, whereas regular exercise exerts antistress and antihypertensive effects. However, the mechanisms of stress-induced hypertension and preventive effects through exercise remain unknown. Thus, we investigated the molecular basis involved in autonomic blood pressure regulation within the amygdala.

METHODS

The effects of a 3-week restraint stress and daily voluntary exercise against stress on cardiovascular parameters and gene expression profiles in the amygdala were examined using a microarray method. Candidate genes were selected from differentially expressed genes; the localization of their expression within the central nucleus of the amygdala and their roles in cardiovascular regulation were examined using small-interfering RNA transfection and radiotelemetry.

RESULTS

Chronic restraint stress caused an increase in blood pressure levels; however, with voluntary exercise, the blood pressure levels remained comparable to those of the controls. Compared with the controls, chronic restraint stress decreased signal transducer and activator of transcription 3 expression in the amygdala, whereas voluntary exercise improved its expression to normal levels. Immunohistochemical staining revealed the expression of signal transducer and activator of transcription 3 in neurons of the amygdala; inhibition of this expression using small-interfering RNA increased the arterial pressure. However, spontaneous baroreflex gain and low- and high-frequency components of heart rate variability remained unaffected by the inhibition of signal transducer and activator of transcription 3.

CONCLUSION

In the amygdala, signal transducer and activator of transcription 3 regulates the blood pressure levels and is possibly involved in blood pressure elevation in response to chronic stress and its improvement by voluntary exercise.

Granulocyte colony-stimulating factor promotes regeneration of severed facial nerve in rats

Background and aim

The administration of growth and neurotrophic factors has been attempted experimentally as a new therapeutic strategy for severe facial paralysis. Granulocyte colony-stimulating factor (G-CSF) has an effect on the treatment of central nervous system injuries, such as cerebral infarction and spinal cord injury. This study aimed at examining the effects of G-CSF on facial nerve regeneration in rats.

Methods

The left facial nerve of rats was either partially resected (resection group) or severed and sutured (suture group) at the main trunk outside the temporal bone. In each surgical group, saline or G-CSF was administered via the gelatin hydrogel drug delivery system. The suture group was further divided into two subgroups for the late administration of G-CSF (2 weeks after surgical treatment) or immediate administration of G-CSF after surgical treatment. Recovery of the facial nerve was assessed by the evaluation of facial movements (after 12 weeks), complex muscle action potential amplitude measurements (after 2, 4, 8, and 12 weeks), electroneurography values (after 12 weeks), and histological evaluation (comparison of myelinated axon diameters among the groups).

Results

Recovery of the function and morphology of damaged nerves was faster in the suture groups than in the resection group. In the suture groups, recovery was faster for G-CSF-treated rats than for saline-treated rats. Furthermore, recovery was faster in the group that received G-CSF immediately after surgical treatment than in the group that received G-CSF 2 weeks later. However, the group that received G-CSF 2 weeks later also showed faster recovery than did the control group.

Conclusion

G-CSF effectively promoted nerve regeneration during facial nerve paralysis. Thus, G-CSF may be a potential treatment strategy for injured facial nerves as it has been safely administered in clinical treatments for hematological diseases.

Involvement of Calpain in Neurovascular Unit Damage through Up-regulating PARP-NF-κB Signaling during Experimental Ischemic Stroke

Calpain and PARP-NF-κB signaling are reported to participate in the ischemic brain injury. In this study, it was investigated whether calpain was contributed to the neurovascular unit (NVU) damage through up-regulating PARP-NF-κB signaling during experimental ischemic stroke. Male Sprague-Dawley rats were suffered from 90 min of middle cerebral artery occlusion, followed by reperfusion. The NVU damage was evaluated by the permeability of blood-brain barrier (BBB), the degradation of proteins in extracellular matrix and tight junctions, and ultrastructural changes. The inflammatory response was determined by the expression of inflammatory genes driven by PARP-NF-κB signaling and the activities of myeloperoxidase (MPO). Treatment with MDL 28,170, a calpain inhibitor, improved neurological functions, reduced TUNEL staining index, lessened brain swelling, and decreased infarct volume in ischemic rats. Moreover, it reduced the BBB permeability, enhanced the levels of laminin, collagen IV and occludin, and attenuated the ultrastructural damage of NVU in penumbra and core after induction of ischemia. Meanwhile, it enhanced the levels of cytosolic IκBα, lessened the levels of nuclear PARP and NF-κB p65, reduced the levels of ICAM-1, TNF-α, IL-1β, MMP-9, and MMP-2,and suppressed the activities of MPO in penumbra and core. These data showed that calpain inhibition suppressed PARP-NF-κB signaling-mediated inflammatory response, reduced NVU damage, and protected brain against ischemic stroke, suggesting the involvement of calpain in the NVU damage through up-regulating PARP-NF-κB signaling during brain ischemia.

Hematopoietic Growth Factors Regulate the Entry of Monocytes into the Adult Brain via Chemokine Receptor CCR5

Monocytes are circulating macrophage precursors generated from bone marrow hematopoietic stem cells. In adults, monocytes continuously replenish cerebral border-associated macrophages under physiological conditions. Monocytes also rapidly infiltrate the brain in pathological settings. The mechanisms of recruiting monocyte-derived macrophages into the brain under pathological conditions have been extensively studied. However, it remains unclear how monocytes enter the brain to renew border-associated macrophages under physiological conditions. Using both in vitro and in vivo approaches, this study reveals that a combination of two hematopoietic growth factors, stem cell factor (SCF) and granulocyte colony-stimulating factor (G-CSF), complementarily and synergistically enhances the adhesion of monocytes to cerebral endothelial cells in a dose-dependent manner. Cysteine-cysteine chemokine receptor 5 (CCR5) in brain endothelial cells, but not the cell adhesion molecules mediating neuroinflammation-related infiltration of monocyte-derived macrophages, modulates SCF+G-CSF-enhanced monocyte-endothelial cell adhesion. Blocking CCR5 or genetically deleting CCR5 reduces monocyte-endothelial cell adhesion induced by SCF+G-CSF. The SCF+G-CSF-enhanced recruitment of bone marrow-derived monocytes/macrophages into the cerebral perivascular space is also reduced in adult CCR5 knockout mice. This study demonstrates the role of SCF and G-CSF in regulating the entry of monocytes into the adult brain to replenish perivascular macrophages.

Causal Association of Cytokines and Growth Factors with Stroke and Its Subtypes: a Mendelian Randomization Study

Cytokines and growth factors contribute to nerve growth and angiogenesis and are associated with the development of vascular disease. This Mendelian randomization (MR) study was designed to examine the causal relationship between factors associated with stem cell paracrine mechanisms and with stroke and its subtypes. We used pooled statistics on cytokine levels from three studies (INTERIAL, Olink Proseek CVD array, and KORA) encompassing 7795 participants in Europe. Data for stroke and its subtypes were pooled from these European populations (40,585 cases and 406,111 controls) in a multiprogenitor genome-wide association study (GWAS). MR was performed using established analytical methods, including inverse variance weighting (IVW), weighted median (WM), and MR-Egger. Genetically determined high IGF-1 levels were found to associate negatively with risk of stroke, ischemic stroke (large-artery atherosclerosis), and ischemic stroke (cardiogenic embolism). Meanwhile, high IL-13 levels had a positive causal relationship with ischemic stroke (large-artery atherosclerosis). An additional 27 cytokines were found to have a causal association with stroke or its subtypes. However, these results should be interpreted with caution given that the power efficacy was <80%. This MR study supports the concept of a causal relationship of 29 cytokines with stroke or its subtypes. Our genetic analysis provides new insights into stroke prevention and treatment by demonstrating an association of stem cell paracrine-related cytokines with stroke risk.

Hematopoietic growth factors Regulate Entry of Monocytes into the Adult Brain via Chemokine Receptor CCR5

Monocytes are circulating macrophage precursors and are generated from bone marrow hematopoietic stem cells. In the adults, monocytes continuously replenish cerebral border-associated macrophages under a physiological condition. Monocytes also rapidly infiltrate into the brain in the settings of pathological conditions. The mechanisms of recruiting monocyte-derived macrophages into the brain under pathological conditions have been extensively studied. However, it remains unclear how monocytes enter the brain for renewal of border-associated macrophages under the physiological condition. Using both in vitro and in vivo approaches, this study reveals that the combination of two hematopoietic growth factors, stem cell factor (SCF) and granulocyte colony-stimulating factor (G-CSF), complementarily and synergistically enhances adhesion of monocytes to cerebral endothelial cells in a dose dependent manner. Cysteine-cysteine chemokine receptor 5 (CCR5) in brain endothelial cells, but not cell adhesion molecules mediating neuroinflammation-related infiltration of monocyte-derived macrophages, modulates the SCF+G-CSF-enhanced monocyte-endothelial cell adhesion. Blocking CCR5 or genetically deleting CCR5 reduces monocyte-endothelial cell adhesion induced by SCF+G-CSF. SCF+G-CSF-enhanced recruitment of bone marrow-derived monocytes/macrophages in cerebral perivascular space is also reduced in adult CCR5 knockout mice. This study demonstrates the contribution of SCF and G-CSF in regulating the entry of monocytes into the adult brain to replenish perivascular macrophages.

Effect of Granulocyte Colony-Stimulating Factor on the Development of Spermatogenesis in the Adulthood of Juvenile AML Mice Model Treated with Cytarabine

Pediatric acute myeloid leukemia (AML) generally occurs de novo. The treatment of AML includes cytarabine (CYT) and other medications. The granulocyte-colony stimulating factor (GCSF) is used in the clinic in cases of neutropenia after chemotherapies. We show that the administration of GCSF in combination with CYT in AML-diagnosed mice (AML+CYT+GCSF) extended the survival of mice for additional 20 days. However, including GCSF in all treatment modalities does not affect the testis' weight or the histology of the seminiferous tubules (STs). We show that GCSF does not affect normal ST histology from AML-, CYT-, or (AML+CYT)-treated groups compared to the relevant treated group without GCSF 2, 4, and 5 weeks post-injection. However, when comparing the percentages of normal STs between the AML+CYT+GCSF-treated groups and those without GCSF, we observe an increase of 17%-42% in STs at 4 weeks and 5.5 weeks post-injection. Additionally, we show that the injection of GCSF into the normal, AML-alone, or CYT-alone groups, or in combination with AML, significantly decreases the percentage of STs with apoptotic cells compared to the relevant groups without GCSF and to the CT (untreated mice) only 2 weeks post-injection. We also show that injection of GCSF into the CT group increases the examined spermatogonial marker PLZF within 2 weeks post-injection. However, GCSF does not affect the count of meiotic cells (CREM) but decreases the post-meiotic cells (ACROSIN) within 4 weeks post-injection. Furthermore, GCSF not only extends the survival of the AML+CYT-treated group, but it also leads to the generation of sperm (1.2 ± 0.04 × 106/mL) at 5.5 weeks post-injection. In addition, we demonstrate that the injection of GCSF into the CT group increases the RNA expression level of IL-10 but not IL-6 compared to CT 2 weeks post-treatment. However, the injection of GCSF into the AML-treated group reverses the expression levels of both IL-10 and IL-6 to normal levels compared to CT 2 weeks post-injection. Thus, we suggest that the addition of GCSF to the regimen of AML after CYT may assist in the development of future therapeutic strategies to preserve male fertility in AML prepubertal patients.

Neonatal asphyxia as an inflammatory disease: Reactive oxygen species and cytokines

Neonatologists resuscitate asphyxiated neonates by every available means, including positive ventilation, oxygen therapy, and drugs. Asphyxiated neonates sometimes present symptoms that mimic those of inflammation, such as fever and edema. The main pathophysiology of the asphyxia is inflammation caused by hypoxic-ischemic reperfusion. At birth or in the perinatal period, neonates may suffer several, hypoxic insults, which can activate inflammatory cells and inflammatory mediator production leading to the release of larger quantities of reactive oxygen species (ROS). This in turn triggers the production of oxygen stress-induced high mobility group box-1 (HMGB-1), an endogenous damage-associated molecular patterns (DAMPs) protein bound to toll-like receptor (TLR) -4, which activates nuclear factor-kappa B (NF-κB), resulting in the production of excess inflammatory mediators. ROS and inflammatory mediators are produced not only in activated inflammatory cells but also in non-immune cells, such as endothelial cells. Hypothermia inhibits pro-inflammatory mediators. A combination therapy of hypothermia and medications, such as erythropoietin and melatonin, is attracting attention now. These medications have both anti-oxidant and anti-inflammatory effects. As the inflammatory response and oxidative stress play a critical role in the pathophysiology of neonatal asphyxia, these drugs may contribute to improving patient outcomes.

PIM1 attenuates renal ischemia-reperfusion injury by inhibiting ASK1-JNK/P38

Renal ischemia-reperfusion injury (IRI) is the main cause of acute kidney injury (AKI), yet therapeutic approaches to alleviate IRI remain limited. PIM1 (provirus integration site for Moloney murine leukemia virus 1) is a constitutive serine threonine kinase that phosphorylates various substrates to regulate cell death and survival. However, the role of PIM1 in renal IRI remains unclear. This study aims to investigate the effect of PIM1 on renal IRI and explore its downstream regulatory mechanism. In this study, we inhibited or overexpressed PIM1 in mice and cultured proximal tubular cells, and then induced renal IRI model in vivo and hypoxia reoxygenation (HR) model in vitro. Renal function, renal structure injuries and cellular death were assessed to reflect the extent of IRI. The expression of PIM1 and the levels of ASK1, MAPK and their phosphorylated forms were detected by immunoblot. RNA sequencing of kidney cortex was performed to analyze downstream pathway of PIM1 in renal IRI. The results showed that PIM1 expression was significantly upregulated in renal IRI mouse model and in renal tubular cell HR model. AZD1208 (a PIM1 inhibitor) aggravated renal IRI, while PIM1 overexpression ameliorated renal IRI. This was involved in the regulation of the ASK1-MAPK pathway. Moreover, results demonstrated that ASK1 was a downstream target of PIM1 by administering Selonsertib (an inhibitor of ASK1 activity), and inhibiting ASK1 alleviated cell death after HR in PIM1 knockdown cells by reducing JNK/P38 activation. In conclusion, this study elucidated the protective effect of PIM1 on renal IRI, and the underlying mechanism may be related to ASK1-JNK/P38 signaling pathway. Taken together, PIM1 may be a potential therapeutic target for renal IRI.

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.

The role of G-CSF neuroprotective effects in neonatal hypoxic-ischemic encephalopathy (HIE): current status

Hypoxic-ischemic encephalopathy (HIE) is an important cause of permanent damage to central nervous system (CNS) that may result in neonatal death or manifest later as mental retardation, epilepsy, cerebral palsy, or developmental delay. The primary cause of this condition is systemic hypoxemia and/or reduced cerebral blood flow with long-lasting neurological disabilities and neurodevelopmental impairment in neonates. About 20 to 25% of infants with HIE die in the neonatal period, and 25-30% of survivors are left with permanent neurodevelopmental abnormalities. The mechanisms of hypoxia-ischemia (HI) include activation and/or stimulation of myriad of cascades such as increased excitotoxicity, oxidative stress, N-methyl-D-aspartic acid (NMDA) receptor hyperexcitability, mitochondrial collapse, inflammation, cell swelling, impaired maturation, and loss of trophic support. Different therapeutic modalities have been implicated in managing neonatal HIE, though translation of most of these regimens into clinical practices is still limited. Therapeutic hypothermia, for instance, is the most widely used standard treatment in neonates with HIE as studies have shown that it can inhibit many steps in the excito-oxidative cascade including secondary energy failure, increases in brain lactic acid, glutamate, and nitric oxide concentration. Granulocyte-colony stimulating factor (G-CSF) is a glycoprotein that has been implicated in stimulation of cell survival, proliferation, and function of neutrophil precursors and mature neutrophils. Extensive studies both in vivo and ex vivo have shown the neuroprotective effect of G-CSF in neurodegenerative diseases and neonatal brain damage via inhibition of apoptosis and inflammation. Yet, there are still few experimentation models of neonatal HIE and G-CSF's effectiveness, and extrapolation of adult stroke models is challenging because of the evolving brain. Here, we review current studies and/or researches of G-CSF's crucial role in regulating these cytokines and apoptotic mediators triggered following neonatal brain injury, as well as driving neurogenesis and angiogenesis post-HI insults.

Stem Cell Factor in Combination With Granulocyte Colony-Stimulating Factor Protects the Brain From Capillary Thrombosis-Induced Ischemic Neuron Loss in a Mouse Model of CADASIL

Cerebral autosomal dominant arteriopathy with subcortical infarct and leukoencephalopathy (CADASIL) is a Notch3 mutation-induced cerebral small vessel disease, leading to recurrent ischemic stroke and vascular dementia. There is currently no treatment that can stop or delay CADASIL progression. We have demonstrated the efficacy of treatment with combined stem cell factor (SCF) and granulocyte colony-stimulating factor (G-CSF) (SCF+G-CSF) in reducing cerebral small vessel thrombosis in a TgNotch3R90C mouse model of CADASIL. However, it remains unknown whether SCF+G-CSF treatment protects neurons from microvascular thrombosis-induced ischemic damage. Using bone marrow transplantation to track thrombosis, we observed that capillary thrombosis was widely distributed in the cortex, striatum and hippocampus of 22-month-old TgNotch3R90C mice. However, the capillary thrombosis mainly occurred in the cortex. Neuron loss was seen in the area next to the thrombotic capillaries, and severe neuron loss was found in the areas adjacent to the thrombotic capillaries with bifurcations. SCF+G-CSF repeated treatment significantly attenuated neuron loss in the areas next to the thrombotic capillaries in the cortex of the 22-month-old TgNotch3R90C mice. Neuron loss caused by capillary thrombosis in the cerebral cortex may play a crucial role in the pathogenesis of CADASIL. SCF+G-CSF treatment ameliorates the capillary thrombosis-induced ischemic neuron loss in TgNotch3R90C mice. This study provides new insight into the understanding of CADASIL progression and therapeutic potential of SCF+G-CSF in neuroprotection under microvascular ischemia in CADASIL.

The Protective and Reparative Role of Colony-Stimulating Factors in the Brain with Cerebral Ischemia/Reperfusion Injury

Stroke is a debilitating disease and has the ability to culminate in devastating clinical outcomes. Ischemic stroke followed by reperfusion entrains cerebral ischemia/reperfusion (I/R) injury, which is a complex pathological process and is associated with serious clinical manifestations. Therefore, the development of a robust and effective poststroke therapy is crucial. Granulocyte colony-stimulating factor (GCSF) and erythropoietin (EPO), originally discovered as hematopoietic growth factors, are versatile and have transcended beyond their traditional role of orchestrating the proliferation, differentiation, and survival of hematopoietic progenitors to one that fosters brain protection/neuroregeneration. The clinical indication regarding GCSF and EPO as an auspicious therapeutic strategy is conferred in a plethora of illnesses, including anemia and neutropenia. EPO and GCSF alleviate cerebral I/R injury through a multitude of mechanisms, involving antiapoptotic, anti-inflammatory, antioxidant, neurogenic, and angiogenic effects. Despite bolstering evidence from preclinical studies, the multiple brain protective modalities of GCSF and EPO failed to translate in clinical trials and thereby raises several questions. The present review comprehensively compiles and discusses key findings from in vitro, in vivo, and clinical data pertaining to the administration of EPO, GCSF, and other drugs, which alter levels of colony-stimulating factor (CSF) in the brain following cerebral I/R injury, and elaborates on the contributing factors, which led to the lost in translation of CSFs from bench to bedside. Any controversial findings are discussed to enable a clear overview of the role of EPO and GCSF as robust and effective candidates for poststroke therapy.

LXA4 protects against hypoxic-ischemic damage in neonatal rats by reducing the inflammatory response via the IκB/NF-κB pathway

Hypoxia and the resultant decreases in cerebral blood flow in the perinatal period can lead to neonatal hypoxic-ischemic (HI) brain injury, which can, in turn, cause severe disability or even death. However, the efficacy of current treatment strategies remains limited. Several studies have demonstrated that lipoxin A4 (LXA4), as one of the earliest types of endogenous lipid mediators, can inhibit the accumulation of neutrophils, arrest inflammation, and promote the resolution of inflammation. However, research on LXA4 in the nervous system has rarely been carried out. In the present study, we sought to investigate the protective effect of LXA4 on HI brain damage in neonatal rats, as well as the underlying mechanisms. Through experiments conducted using an HI animal model, we found that the LXA4 intervention promoted the recovery of neuronal function and tissue structure following brain injury while maintaining the integrity of the blood-brain barrier in addition to reducing cerebral edema, infarct volume, and inflammatory responses. Our results suggest that LXA4 interfered with neuronal oxygen-glucose deprivation insults, reduced the expression of inflammatory factors, inhibited apoptosis, and promoted neuronal survival in vitro. Finally, the LXA4 intervention attenuated HI-induced activation of inhibitor kappa B (IκB) and degradation of nuclear factor-κB (NF-κB). In conclusion, our data suggest that LXA4 exerts a neuroprotective effect against neonatal HI brain damage through the IκB/NF-κB pathway. Our findings will help inform future studies regarding the effects of LXA4 on neuroinflammation, blood-brain barrier integrity, and neuronal apoptosis.

Granulocyte-colony stimulating factor improves intervertebral disc degeneration in experimental adult male rats: A microscopic and radiological study

Intervertebral disc degeneration (IVDD) is a major contributor to low back pain (LBP). Granulocyte-colony stimulating factor (GCSF) is known to mobilize hematopoietic stem cells (HSCs) that may be implicated in intervertebral disc (IVD) regeneration. Rats were divided into the following three groups: (i) control group; (ii) IVDD group-the rats underwent Co5/Co6 and Co7/Co8 IVDD operation; and (iii) GCSF-treated group-the rats received daily GCSF subcutaneous injections starting 6 weeks after the IVDD operation and continued for 5 days. All of the rats were euthanized after 8 weeks, and IVDs were assessed by tail X-ray and histopathological, immunohistochemical, and transmission electron microscopy (TEM) analyses. The X-rays showed disc narrowing in the IVDD group that was significantly widened in the GCSF-treated rats. Histologically, the IVDD group showed disarrangement of the annulus fibrosis lamellae, complete degeneration of the nucleus pulposus, and loss of proteoglycan content. These changes were improved after GCSF treatment. Vertebral endplate thickness and cellularity were significantly decreased with IVDD and significantly increased after GCSF treatment. Stromal cell-derived factor-1α (SDF-1α) immune expression was significantly increased in the IVDD group but decreased in the GCSF-treated group. However, the caspase-3 expression percentage showed no significant difference among the studied groups. TEM showed excessive collagen deposits around the notochordal cells in the IVDD group, which were attenuated in the GCSF-treated group. These results indicate that GCSF improves IVDD and promotes its recovery based on radiological, histological and TEM findings.

Mitochondrial serine protease Omi/HtrA2 accentuates brain ischemia/reperfusion injury in rats and oxidative stress injury in vitro by modulating mitochondrial stress proteins CHOP and ClpP and physically interacting with mitochondrial fusion protein OPA1

Serine protease Omi/HtrA2, a member of the HtrA family, is closely related to the maintenance of mitochondrial integrity and participates in apoptosis but its role in cerebral ischemia/reperfusion (I/R) injury and cellular oxidative stress response remains unclear. In this study, we found that I/R injury resulted in a time-dependent increase in Omi/HtrA2 expression in rat brain tissue. Inhibition of Omi/HtrA2 significantly inhibited XIAP cleavage in H₂O₂-induced PC12 cells. In addition, inhibition of Omi/HtrA2 significantly inhibited the up-regulation of mitochondrial stress proteins CHOP and ClpP, significantly reduced mitochondrial aggregation, and attenuated the decline of mitochondrial ΔΨm in PC12 cells. Studies show that there is a physical interaction between Omi/HtrA2 and OPA1. We found that Omi/HtrA2 and OPA1 are closely related to the oxidative stress mitochondrial response in PC12 cells. The current study has demonstrated that Omi/HtrA2 is upregulated in brain I/R injury in vivo and is implicated in mitochondrial response to oxidative stress in vitro by regulating mitochondrial stress proteins CHOP and CLpP and by interacting with mitochondrial cristae remodeling protein OPA1. These findings suggest that Omi/HtrA2 could be a candidate molecular target in diseases that involve oxidative stress such as in I/R injury.

Abbreviation: ATP: Adenosine tripHospHate; Bax: BCL2-Associated X; Bcl-2: B-cell lympHoma-2; BSA: Albumin from bovine serum; DMEM: Dulbecco’s Minimum Essential Medium; DMSO: Dimethyl sulfoxide; HSP60: Heat shock protein60, 70; L-OPA1: Long forms of OPA1; Omi/HtrA2: high-temperature-regulated A2; MCAO: Middle cerebral artery occlusion; OPA1: Optic AtropHy; PBS: PHospHate buffered saline; PMSF: pHenylmethyl sulfonylfluoride; ROS: reactive oxygen species; SDS: Sodium dodecyl sulfate; S-OPA1: Short forms of OPA1; TTC: TripHenyltetrazalium chloride; XIAP: X-linked inhibitor apoptosis protein

Hydroxy-α-sanshool Possesses Protective Potentials on H2O2-Stimulated PC12 Cells by Suppression of Oxidative Stress-Induced Apoptosis through Regulation of PI3K/Akt Signal Pathway

Zanthoxylum bungeanum pericarp is a commonly used herbal medicine in China with effects of anti-inflammatory and analgesic, improving learning and memory ability, while hydroxy-α-sanshool (HAS) is the most important active ingredient of Z. bungeanum pericarps. The purpose of this study was to investigate the neuroprotective effect of HAS and its related possible mechanisms using a H₂O₂-stimulated PC12 cell model. CCK-8 assay results showed that HAS had a significant protective effect on H₂O₂-stimulated PC12 cells without obvious cytotoxicity on normal PC12 cells. Flow cytometry and fluorescence microscope (DAPI staining and DCFH-DA staining) indicated that HAS could reduce the H₂O₂-induced apoptosis in PC12 cells via reduction of intracellular ROS and increase of mitochondrial membrane potential (MMP). Subsequently, results of malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) determination suggested that HAS could increase the enzyme activities of SOD, CAT, and GSH-Px whereas it could decrease the MDA contents in H₂O₂-stimulated PC12 cells. Furthermore, the western blotting assays showed that HAS could upregulate the expressions of p-PI3k, Akt, p-Akt, and Bcl-2, while it could downregulate the expressions of cleaved caspase-3 and Bax in H₂O₂-stimulated PC12 cells. Collectively, it could be concluded according to our results that HAS possesses protective potentials on H₂O₂-stimulated PC12 cells through suppression of oxidative stress-induced apoptosis via regulation of PI3K/Akt signal pathway.

The contribution of stem cell factor and granulocyte colony-stimulating factor in reducing neurodegeneration and promoting neurostructure network reorganization after traumatic brain injury

Traumatic brain injury (TBI) is a major cause of death and disability in young adults worldwide. TBI-induced long-term cognitive deficits represent a growing clinical problem. Stem cell factor (SCF) and granulocyte colony-stimulating factor (G-CSF) are involved in neuroprotection and neuronal plasticity. However, the knowledge concerning reparative efficacy of SCF + G-CSF treatment in post-acute TBI recovery remains incomplete. This study aims to determine the efficacy of SCF + G-CSF on post-acute TBI recovery in young adult mice. The controlled cortical impact model of TBI was used for inducing a severe damage in the motor cortex of the right hemisphere in 8-week-old male C57BL mice. SCF + G-CSF treatment was initiated 3 weeks after induction of TBI. Severe TBI led to persistent motor functional deficits (Rota-Rod test) and impaired spatial learning function (water maze test). SCF + G-CSF treatment significantly improved the severe TBI-impaired spatial learning function 6 weeks after treatment. TBI also caused significant increases of Fluoro-Jade C positive degenerating neurons in bilateral frontal cortex, striatum and hippocampus, and significant reductions in MAP2⁺ apical dendrites and overgrowth of SMI312⁺ axons in peri-TBI cavity frontal cortex and in the ipsilateral hippocampal CA1 at 24 weeks post-TBI. SCF + G-CSF treatment significantly reduced TBI-induced neurodegeneration in the contralateral frontal cortex and hippocampal CA1, increased MAP2⁺ apical dendrites in the peri-TBI cavity frontal cortex, and prevented TBI-induced axonal overgrowth in both the peri-TBI cavity frontal cortex and ipsilateral hippocampal CA1.These findings reveal a novel pathology of axonal overgrowth after severe TBI and demonstrate a therapeutic potential of SCF + G-CSF in ameliorating severe TBI-induced long-term neuronal pathology, neurostructural network malformation, and impairments in spatial learning.

G-CSF attenuates neuroinflammation and neuronal apoptosis via the mTOR/p70SK6 signaling pathway in neonatal Hypoxia-Ischemia rat model

BACKGROUND

Hypoxic-ischemic encephalopathy (HIE) is an important cause of permanent damage to the central nervous system, associated with long-lasting neurological disabilities and neurodevelopmental impairment in neonates. Granulocyte-colony stimulating factor (G-CSF) has been shown to have neuroprotective activity in a variety of experimental brain injury models and G-CSF is a standard treatment in chemotherapeutic-induced neutropenia. The underlying mechanisms are still unclear. The mTOR (mammalian target of rapamycin) signaling pathway is a master regulator of cell growth and proliferation in the nervous system. However, the effects of G-CSF treatment on the mTOR signaling pathway have not been elucidated in neonates with hypoxic-ischemic (HI) brain injury. Our study investigated the neuroprotective effect of G-CSF on neonates with hypoxic-ischemic (HI) brain injury and the possible mechanism involving the mTOR/p70S6K pathway.

METHODS

Sprague-Dawley rat pups at postnatal day 7 (P7) were subjected to right unilateral carotid artery ligation followed by hypoxic (8% oxygen and balanced nitrogen) exposure for 2.5 h or sham surgery. Pups received normal saline, G-CSF, G-CSF combined with rapamycin or ethanol (vehicle for rapamycin) intraperitoneally. On postnatal day 9 (P9), TTC staining for infarct volume, and Nissl and TUNEL staining for neuronal cell injury were conducted. Activation of mTOR/p70S6K pathway, cleaved caspase-3 (CC3), Bax and Bcl-2 and cytokine expression levels were determined by western blotting.

RESULTS

The G-CSF treated group was associated with significantly reduced infarction volume and decreased TUNEL positive neuronal cells compared to the HI group treated with saline. The expression levels of TNF-α and IL-1ß were significantly decreased in the G-CSF treated group, while IL-10 expression level was increased. The relative immunoreactivity of p-mTOR and p-p70S6K was significantly reduced in the HI group compared to sham. The HI group treated with G-CSF showed significant upregulated protein expression for p-mTOR and p-p70S6K levels compared to the HI group treated with saline. Furthermore, G-CSF treatment increased Bcl-2 expression levels and decreased CC3 and Bax expression levels in the ipsilateral hemispheres of the HI brain. The effects induced by G-CSF were all reversed by rapamycin.

CONCLUSION

Treatment with G-CSF decreases inflammatory mediators and apoptotic factors, attenuating neuroinflammation and neuronal apoptosis via the mTOR/p70S6K signalling pathway, which represents a potential target for treating HI induced brain damage in neonatal HIE.

Antiapoptotic and Anti-Inflammatory Effects of CPCGI in Rats with Traumatic Brain Injury

BACKGROUND

Compound porcine cerebroside and ganglioside injection (CPCGI) has been used for the treatment of certain brain disorders. Apoptosis and inflammation were reported to be involved in the pathogenesis of traumatic brain injury (TBI). Therefore, this study primarily investigated the effects of CPCGI on mitochondrial apoptotic signaling and PARP/NF-κB inflammatory signaling in a rat model of controlled cortical impact (CCI).

MATERIALS AND METHODS

CPCGI (0.6 mL/kg) was administered intraperitoneally 30 min after the induction of CCI. Mitochondrial apoptotic signaling and PARP/NF-κB inflammatory signaling were evaluated 24 h after CCI, and apoptotic cell death, neutrophil infiltration, and astrocyte and microglial activation were determined by TUNEL and immunofluorescent staining 3 days after CCI.

RESULTS

1) CPCGI markedly enhanced cytosolic and mitochondrial Bcl-xL levels, the mitochondrial Bcl-xL/Bax ratio, and mitochondrial cytochrome (cyt) c levels and reduced cytosolic cyt c levels, caspase-3 activity, and nuclear AIF levels in brain tissues after traumatic injury; however, CPCGI had no significant effects on cytosolic or mitochondrial Bax levels, the cytosolic Bcl-xL/Bax ratio, or mitochondrial AIF levels. Moreover, CPCGI markedly reduced the TUNEL staining score in the contusion region. 2) CPCGI markedly reduced cytosolic and nuclear PARP levels and nuclear NF-κB p65 levels in brain tissues after traumatic injury but had no significant effect on cytosolic NF-κB p65 levels. In addition, CPCGI markedly reduced caspase-1 activity and the levels of caspase-1, ICAM-1, TNF-α, and IL-1β in brain tissues after traumatic injury and decreased the immunoreactivities of neutrophils, GFAP and Iba-1 in the region of CCI-induced contusion.

CONCLUSION

These data suggest that CPCGI can reduce brain injury due to trauma by suppressing both mitochondrial apoptotic signaling and PARP/NF-κB inflammatory signaling.

CPCGI Reduces Gray and White Matter Injury by Upregulating Nrf2 Signaling and Suppressing Calpain Overactivation in a Rat Model of Controlled Cortical Impact

BACKGROUND

Compound porcine cerebroside and ganglioside injection (CPCGI), which involves injection of a neurotrophic drug, has been widely used to treat certain brain disorders in the clinic; however, the detailed mechanism is unknown. This study investigated whether CPCGI protects the brain from trauma by stimulating antioxidative nuclear factor erythroid-2-related factor 2 (Nrf2) signaling and suppressing calpain overactivation in a rat model of controlled cortical impact (CCI).

MATERIALS AND METHODS

The rat model of CCI was used. Neurological deficits, contusion, and white matter damage were evaluated 3 days after CCI. Calpain activation, Nrf2 signaling and oxidative stress were determined 24 h after CCI.

RESULTS

CPCGI dose-dependently reduced neurological deficits, attenuated axonal and myelin sheath injury, and decreased contusion volume 3 days post-CCI. Moreover, CPCGI reduced calpain activity, and enhanced the cytosolic levels of calpastatin, αII-spectrin, microtubule-associated protein 2 (MAP2), neurofilament heavy chain (NF-H) and myelin basic protein (MBP) in traumatic tissues 24 h post-CCI. Furthermore, CPCGI reduced the levels of nuclear Kelch-like ECH-associated protein 1 (Keap1) and thioredoxin interacting protein (TXNIP); increased the levels of cytosolic Nrf2 and thioredoxin 1 (Trx 1) and nuclear Nrf2; increased the cytosolic and nuclear Nrf2/Keap1 and Trx 1/TXNIP ratios; enhanced the levels of heme oxygenase 1 (HO-1), glutathione (GSH), superoxide dismutase activity, and total antioxidative capacity; and reduced the levels of malondialdehyde in TBI tissues.

CONCLUSION

These data confirm the neuroprotective effect of CPCGI against gray and white matter damage due to CCI and suggest that activating Nrf2 signaling and alleviating oxidative stress-mediated calpain activation could be one mechanism by which CPCGI protects against brain trauma.

Antiepileptic Effects of Protein-Rich Extract from Bombyx batryticatus on Mice and Its Protective Effects against H2O2-Induced Oxidative Damage in PC12 Cells via Regulating PI3K/Akt Signaling Pathways

Bombyx batryticatus is a known traditional Chinese medicine (TCM) utilized to treat convulsions, epilepsy, cough, asthma, headaches, and purpura in China for thousands of years. This study is aimed at investigating the antiepileptic effects of protein-rich extracts from Bombyx batryticatus (BBPs) on seizure in mice and exploring the protective effects of BBPs against H₂O₂-induced oxidative stress in PC12 cells and their underlying mechanisms. Maximal electroshock-induced seizure (MES) and pentylenetetrazole- (PTZ-) induced seizure in mice and the histological analysis were carried out to evaluate the antiepileptic effects of BBPs. The cell viability of PC12 cells stimulated by H₂O₂ was determined by MTT assay. The apoptosis and ROS levels of H₂O₂-stimulated PC12 cells were determined by flow cytometry analysis. Furthermore, the levels of malondialdehyde (MDA), superoxide dismutase (SOD), lactate dehydrogenase (LDH), and glutathione (GSH) in PC12 cells were assayed by ELISA and expressions of caspase-3, caspase-9, Bax, Bcl-2, PI3K, Akt, and p-Akt were evaluated by Western blotting and quantitative real-time polymerase chain reaction (RT-qPCR) assays. The results revealed that BBPs exerted significant antiepileptic effects on mice. In addition, BBPs increased the cell viability of H₂O₂-stimulated PC12 cells and reduced apoptotic cells and ROS levels in H₂O₂-stimulated PC12 cells. By BBPs treatments, the levels of MDA and LDH were reduced and the levels of SOD and GSH-Px were increased in H₂O₂-stimulated PC12 cells. Moreover, BBPs upregulated the expressions of PI3K, Akt, p-Akt, and Bcl-2, whereas they downregulated the expressions of caspase-9, caspase-3, and Bax in H₂O₂-stimulated PC12 cells. These findings suggested that BBPs possessed potential antiepileptic effects on MES and PTZ-induced seizure in mice and protective effects on H₂O₂-induced oxidative stress in PC12 cells by exerting antioxidative and antiapoptotic effects via PI3K/Akt signaling pathways.

Effect of long non-coding RNA growth arrest-specific 5 on apoptosis in renal ischaemia/reperfusion injury

AIM

Long non-coding RNA (lncRNAs) have been shown to play a critical role in a variety of pathophysiological processes, such as cell proliferation, apoptosis and migration. However, there were few studies addressing the function of lncRNAs in renal ischaemia/reperfusion (I/R) injury. Apoptosis is an important pathogenesis during I/R injury. Here, we identified the effect of hypoxia-responsive lncRNA growth arrest-specific 5 (GAS5) on apoptosis in renal I/R injury.

METHODS

Ischaemia/reperfusion injury in mice or hypoxia/re-oxygenation (H/R) in human proximal renal tubular epithelial cells (HK-2) was practiced to induce apoptosis. The kidneys and blood were collected at 24 h after reperfusion. The GAS5 messenger RNA (mRNA) expression and apoptosis-related gene mRNA and protein levels, including p53, cellular inhibitor of apoptosis protein 2 (cIAP2) and thrombospondin-1 (TSP-1), were analysed. GAS5 small-interfering RNA was transfected with H/R induced cells. Over-expression of GAS5 was performed by plasmid transfection.

RESULTS

Apoptotic cells significantly increased in I/R-injured kidneys. GAS5 could be up-regulated in kidneys at 24 h after reperfusion and 3 h after re-oxygenation, combined with increased expression of its downstream apoptosis-related proteins p53 and cIAP2. GAS5 small-interfering RNA treatment down-regulated the mRNA and protein levels of p53 and TSP-1, and attenuated apoptosis induced by H/R in HK-2 cells. Conversely, over-expression of GAS5 up-regulated the mRNA and protein levels of p53 and TSP-1, and promoted apoptosis in HK-2 cells.

CONCLUSION

Long non-coding RNA GAS5 induced by I/R injury could promote apoptosis in kidney. TSP-1 might be one of the downstream effectors of GAS5, which will be explored in the future.

Bone Marrow Stromal Cells with the Granulocyte Colony-Stimulating Factor in the Management of Chemotherapy-Induced Ovarian Failure in a Rat Model

BACKGROUND

Bone marrow stromal cells (BMSCs), as a type of mesenchymal stem cells, and the granulocyte colony-stimulating factor (G-CSF), as a type of growth factor, may recover damaged ovaries. The aim of the present study was to investigate the effects of the coadministration of BMSCs and the G-CSF on damaged ovaries after creating a chemotherapy model with cyclophosphamide (CTX) in rats.

METHODS

The present study was performed in Semnan, Iran, in the late 2016 and the early 2017. BMSCs were cultured and were confirmed using the CD markers of stromal cells. Forty female Wistar rats were randomly divided into 4 groups. The rats were injected intraperitoneally with CTX for 14 days to induce chemotherapy and ovarian destruction. Then, the BMSCs were injected into bilateral ovaries and the G-CSF was injected intraperitoneally, individually and together. Four weeks later, the number of ovarian follicles using H&E staining, the number of apoptotic granulosa cells using the TUNEL assay, the number of produced oocytes from the ovaries, and the levels of serum E2 and FSH using an ELISA reader were assessed. Statistical analysis was done using one-way ANOVA with SPSS, version 16.0.

RESULTS

The results showed that the effects of the coadministration of 2×10⁶ BMSCs and 70 µg/kg of the G-CSF were significantly more favorable than those in the control group (P<0.001), the BMSC group (P=0.016), and the G-CSF group (P<0.001) on the recovery of damaged ovaries.

CONCLUSION

The efficacy of the coadministration of BMSCs and the G-CSF in the recovery of ovaries damaged by chemotherapy was high by comparison with the administration of either of them separately.

Pim-1 Expression in Rat Retina and its Changes after Optic Nerve Crush

Pim-1 is a proto-oncogene which has been discovered to involve in cell proliferation, differentiation, and survival. In this study, we observed the expression of Pim-1 in neonatal and adult rat retina and the changes in rat retina following optic nerve crush (ONC) in order to explore the relationship between Pim-1 and the survival of retinal ganglion cells (RGC). We discovered that Pim-1 was distributed mainly in retinal pigment epithelial cells (RPE) and retinal ganglion cell layer (GCL) in normal newborn rats, and it appeared in RPE, cone rod cell layer and GCL in normal adult rats by immunohistochemistry. Our double immunofluorescent staining of Pim-1 and γ-synuclein further confirmed that Pim-1 was localized in 80% of RGC. Moreover, we found that the amount of Pim-1 mRNA and protein in adult rat retina was transiently increased after ONC and then decreased 2 weeks after ONC, and the expression level was lower than that of neonatal rat retina under all conditions. We also discovered that Pim-1 expression in GCL detected by immunohistochemistry was upregulated at Day 1 and Day 3 after ONC, but downregulated at Day 14 after ONC when the survival of RGC was decreased and the apoptotic cells in GCL were increased by hematoxylin-eosin staining, immunohistochemistry, and TUNEL detection. We suggest that the overexpression of Pim-1 in the RGC is related to the optic nerve repair while the low expression of Pim-1 in RGC may be associated with apoptosis and weak intrinsic regeneration ability of RGC. Anat Rec, 301:1968-1976, 2018. © 2018 Wiley Periodicals, Inc.

Granulocyte-colony stimulating factor and umbilical cord blood cell transplantation: Synergistic therapies for the treatment of traumatic brain injury

Traumatic brain injury (TBI) is now characterized as a progressive, degenerative disease and continues to stand as a prevalent cause of death and disability. The pathophysiology of TBI is complex, with a variety of secondary cell death pathways occurring which may persist chronically following the initial cerebral insult. Current therapeutic options for TBI are minimal, with surgical intervention or rehabilitation therapy existing as the only viable treatments. Considering the success of stem-cell therapies in various other neurological diseases, their use has been proposed as a potential potent therapy for patients suffering TBI. Moreover, stem cells are highly amenable to adjunctive use with other therapies, providing an opportunity to overcome the inherent limitations of using a single therapeutic agent. Our research has verified this additive potential by demonstrating the efficacy of co-delivering human umbilical cord blood (hUCB) cells with granulocyte-colony stimulating factor (G-CSF) in a murine model of TBI, providing encouraging results which support the potential of this approach to treat patients suffering from TBI. These findings justify ongoing research toward uncovering the mechanisms which underlie the functional improvements exhibited by hUCB + G-CSF combination therapy, thereby facilitating its safe and effect transition into the clinic. This paper is a review article. Referred literature in this paper has been listed in the reference section. The datasets supporting the conclusions of this article are available online by searching various databases, including PubMed. Some original points in this article come from the laboratory practice in our research center and the authors’ experiences.

Effect of docosahexaenoic acid on traumatic brain injury in rats

The present study aimed to investigate the protective effects of docosahexaenoic acid (DHA) on traumatic brain injury (TBI) in rats. A model of TBI was induced by lateral fluid percussion injury in adult rats and rats were randomly divided into the TBI-model group, TBI-low DHA group and TBI-high DHA group, while other healthy rats were assigned to the sham-operated group. Motor recovery was tested with beam-walking trials at 2, 7 and 15 days post-TBI. Cognitive recovery was tested with Morris water maze trials at 15 days post-TBI. The expression levels of caspase-3, B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X protein (Bax) were measured by western blotting. DHA protected against motor deficits induced by TBI in beam walking tests. All TBI-model groups had longer escape latency and swimming distances than the sham groups. Compared with the TBI-low DHA group, the TBI-high DHA group demonstrated shorter escape latency and swimming distances. DHA inhibited the expression of caspase-3 and the inhibition effect was more obvious at a high dosage. Furthermore, DHA dose-dependently rescued neurons by upregulating the Bcl-2:Bax ratio. DHA supplementation was a viable strategy to mitigate injury from TBI.

Effects of an Inhibitor of Monocyte Recruitment on Recovery from Traumatic Brain Injury in Mice Treated with Granulocyte Colony-Stimulating Factor

Administration of the hematopoietic growth factor granulocyte-colony stimulating Factor (G-CSF) has been reported to enhance recovery from controlled cortical impact (CCI) in rodent models. G-CSF exerts actions in both the periphery (stimulation of hematopoiesis) and in the brain, where it serves as a neurotrophic factor, promoting neuronal survival and stimulating neural stem/progenitor cell proliferation in the hippocampus. In order to distinguish the direct CNS actions of G-CSF from its peripheral actions, experiments were designed to block the recruitment of peripheral monocytes to the site of the lesion produced by CCI. The selective C-C motif receptor 2 (CCR2) antagonist (RS504303) was co-administered with G-CSF for three days after CCI in a chimeric mouse previously transplanted with GFP-expressing (GFP+) blood stem-progenitor cells. Results: The drug significantly impaired infiltration of GFP+ bone marrow-derived cells to the frontal cortex and striatum without impeding recovery performance and hippocampal neurogenesis in the behavioral test, the Radial Arm Water Maze (RAWM). Administration of the CCR2 antagonist alone, without G-CSF, was effective in promoting recovery in RAWM. These results support the hypothesis that the direct action of G-CSF on neural cells, independent of its hematopoietic effects, is primarily responsible for enhanced recovery from CCI. In addition, this study confirms the importance of CCR2 and its ligand, monocyte chemotactic protein-1 (MCP-1), in mediating the inflammatory response following CCI.

Intervention action of total flavonoids from root of Ilex pubescens in cerebral ischemic tolerance with blood stasis

The aim of this study was to explore the action characters of total flavonoids from MDQ on cerebral ischemic tolerance with blood stasis. Fully understanding the mechanism of action of total flavonoids from MDQ is helpful for the development of new drugs and the utilization of resources. Male Wistar rat model of blood stasis was established by injecting dexamethasone into the intramuscular side of the thigh. Then they were given related drugs via an intragastric administration for a successive 10 days. After 7 days, the following occurred: firstly, the method of blocking the bilateral common carotid artery (CCA) was used for 10 min, followed by a restoration of perfusion. After 72 h, we performed a temporary occlusion of the rat’s middle cerebral artery for 2 h with an intraluminal thread method. This was followed by reperfusion for 24 h, respectively, to establish the rat model of cerebral ischemic tolerance with blood stasis. Viscosity of the whole blood was measured after the last administration was given blood. Brain was removed, and then the activity of ATP enzyme and T-SOD was determined. To observe the pathological changes of the hippocampus area by HE staining, and the expression of Bcl-2 and Bax were observed by immunohistochemical method. The rat model of cerebral ischemic tolerance with blood stasis was copied successfully. The whole blood viscosity, the activity of NOS, the content of Gluin in the ischemic brain in the IPC model group and the ischemia–reperfusion group were increased significantly. The activity of ATPase was decreased significantly. Compared with the ischemia–reperfusion model group, the activity of ATPase and the whole blood viscosity in the ischemic preconditioning (IPC) group were increased significantly. The activity of NOS and the content of Gluin were decreased significantly. The degree of pathological injury of the brain tissue was also relieved significantly. Total flavonoids of MDQ were used, improving blood circulation, improving energy metabolism, activating endogenous anti-oxidative capability, enhancing the antiapoptotic effect, and relieving the injury of the nerve cell. Hence, the use of MDQ flavonoids improves the tolerance ability of cerebral ischemia.

G-CSF administration attenuates brain injury in rats following carbon monoxide poisoning via different mechanisms

Acute severe carbon monoxide (CO) poisoning induces hypoxia that leads to cardiovascular and nervous systems disturbances. Different complex mechanisms lead to CO neurotoxicity including lipid peroxidation, inflammatory and immune-mediated reactions, myelin degeneration and finally neuronal apoptosis and necrosis. Granulocyte colony-stimulating factor (G-CSF) is considered to be a novel neuroprotective agent. In this study, we evaluated the efficacy of G-CSF therapy on CO neurotoxicity in rats with acute CO poisoning. Rats were exposed to 3000 ppm CO in air (0.3%) for 1 h, and then different doses (50,100, and 150 µg/kg) of G-CSF or normal saline were administrated intraperitoneally. Water content of brain as an indicator for total edema and blood brain barrier integrity (Evans blue extravasation) were evaluated. Malondialydehyde was determined in order to evaluate the effect of G-CSF on CO-induced lipid peroxidation in brain tissues. Also, the effect of G-CSF on myeloperoxidase activity in the brain tissue was evaluated. The effect of G-CSF administration on induced apoptosis in the brain was measured using TUNEL method. To evaluate the level of MBP, STAT3 and pSTAT3 and HO-1 proteins and the effect of G-CSF on these proteins Western blotting was carried out. G-CSF reduced water content of the edematous poisoned brains (100 µg/kg) and BBB permeability (100 and 150 µg/kg) (P < 0.05). G-CSF (150 µg/kg) reduced the MDA level in the brain tissues (P < 0.05 as compared to CO poisoned animals). G-CSF did not decrease the MPO activity after CO poisoning in any doses. G-CSF significantly reduced the number of apoptotic neurons and Caspase 3 protein levels in the brain. Western blotting results showed that G-CSF treatment enhanced expression of HO-1 and MBP, STAT3 and pSTAT3 proteins in the brain tissues. Based on our results, a single dose of G-CSF immediately after CO poisoning significantly attenuates CO neurotoxicity via different mechanisms. © 2015 Wiley Periodicals, Inc. Environ Toxicol 32: 37-47, 2017.

Hypocretin/orexin loss changes the hypothalamic immune response

Hypocretin, also known as orexin, maintains the vigilance state and regulates various physiological processes, such as arousal, sleep, food intake, energy expenditure, and reward. Previously, we found that when wild-type mice and hypocretin/ataxin-3 littermates (which are depleted of hypothalamic hypocretin-expressing neurons postnatally) were administered lipopolysaccharide (LPS), the two genotypes exhibited significant differences in their sleep/wake cycle, including differences in the degree of increase in sleep periods and in recovery from sickness behaviour. In the present study, we examined changes in the hypothalamic vigilance system and in the hypothalamic expression of inflammatory factors in response to LPS in hypocretin/ataxin-3 mice. Peripheral immune challenge with LPS affected the hypothalamic immune response and vigilance states. This response was altered by the loss of hypocretin. Hypocretin expression was inhibited after LPS injection in both hypocretin/ataxin-3 mice and their wild-type littermates, but expression was completely abolished only in hypocretin/ataxin-3 mice. Increases in the number of histidine decarboxylase (HDC)-positive cells and in Hdc mRNA expression were found in hypocretin/ataxin-3 mice, and this increase was suppressed by LPS. Hypocretin loss did not impact the change in expression of hypothalamic inflammatory factors in response to LPS, except for interferon gamma and colony stimulating factor 3. The number of c-Fos-positive/HDC-positive cells in hypocretin/ataxin-3 mice administered LPS injections was elevated, even during the rest period, in all areas, suggesting that there is an increase in the activity of histaminergic neurons in hypocretin/ataxin-3 mice following LPS injection. Taken together, our results suggest a novel role for hypocretin in the hypothalamic response to peripheral immune challenge. Our findings contribute to the understanding of the pathophysiology of narcolepsy.

Translating G-CSF as an Adjunct Therapy to Stem Cell Transplantation for Stroke

Among recently investigated stroke therapies, stem cell treatment holds great promise by virtue of their putative ability to replace lost cells, promote endogenous neurogenesis,and produce behavioral and functional improvement through their "bystander effects." Translating stem cell in the clinic, however, presents a number of technical difficulties. A strategy suggested to enhance therapeutic utility of stem cells is combination therapy, i.e., co-transplantation of stem cells or adjunct treatment with pharmacological agents and substrates,which is assumed to produce more profound therapeutic benefits by circumventing limitations of individual treatments and facilitating complementary brain repair processes. We previously demonstrated enhanced functional effects of cotreatment with granulocyte-colony stimulating factor (GCSF)and human umbilical cord blood cell (hUCB) transplantation in animal models of traumatic brain injury (TBI). Here,we suggest that the aforementioned combination therapy may also produce synergistic effects in stroke. Accordingly, G-CSF treatment may reduce expression of pro-inflammatory cytokines and enhance neurogenesis rendering a receptive microenvironment for hUCB engraftment. Adjunct treatment of GCSF with hUCB may facilitate stemness maintenance and guide neural lineage commitment of hUCB cells. Moreover, regenerative mechanisms afforded by G-CSF-mobilized endogenous stem cells, secretion of growth factors by hUCB grafts and G-CSF-recruited endothelial progenitor cells(EPCs), as well as the potential graft–host integration that may promote synaptic circuitry re-establishment could altogether produce more pronounced functional improvement in stroked rats subjected to a combination G-CSF treatment and hUCB transplantation. Nevertheless, differences in pathology and repair processes underlying TBI and stroke deserve consideration when testing the effects of combinatorial G-CSF and hUCB cell transplantation for stroke treatment. Further studies are also required to determine the safety and efficacy of this intervention in both preclinical and clinical stroke studies.

Quercetin ameliorates ischemia/reperfusion-induced cognitive deficits by inhibiting ASK1/JNK3/caspase-3 by enhancing the Akt signaling pathway

Cerebral ischemia/reperfusion (I/R) is a major cause of severe disability and death all worldwide. However, therapeutic options to minimize the detrimental effects of cerebral I/R injury are limited. Recent research has demonstrated that quercetin mediates neuroprotective effects associated with the activation of the Akt signaling pathway in the cerebral I/R brain. Therefore, the aim of this study was to further investigate the mechanisms of cognitive deficits induced by cerebral I/R injury and the effects of quercetin on these mechanisms. First, we assessed anxiety-like behavioral and cognitive impairment using the open field test and the Morris water maze test, respectively. Next, we examined the severity of apoptosis by staining hippocampal neurons by the Cresyl violet method. Third, we used western blot analysis to investigate the expression of total and phosphorylated Akt, ASK1, JNK3, c-Jun and caspase-3 after I/R injury. Our results revealed that mice subjected to bilateral common carotid occlusion exhibited severe anxiety-like behavior, learning and memory impairment, cell damage and apoptosis. These severe effects were attenuated by administration of quercetin. Further, western blot analysis revealed that quercetin increased p-Akt expression and decreased p-ASK1, p-JNK3 and cleaved caspase-3 expression after cerebral I/R injury and led to inhibition of neuronal apoptosis. Conversely, treatment with LY294002 (a selective inhibitor of Akt1) reversed the effects of quercetin. In conclusion, these findings highlight the important role of quercetin in protecting against cognitive deficits and inhibiting neuronal apoptosis via the Akt signaling pathway. We believe that quercetin might prove to be a useful therapeutic component in treating cerebral I/R diseases in the near future.

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.

Protective effects of PARP inhibitor, PJ34, is related to down-regulation of calpain and NF-κB in a mouse model of TBI

BACKGROUND

Poly(ADP-ribose) polymerase (PARP), calpain and nuclear factor-κB (NF-κB) are reported to participate in inflammatory reactions in pathological conditions and are involved in traumatic brain injury. The objective of this study was to investigate whether PARP participated in inflammation related to calpain and NF-κB in a mouse model of controlled cortical impact (CCI).

MATERIALS AND METHODS

PJ34 (10 mg kg-1), a selective PARP inhibitor, was administered intraperitoneally 5 minutes and 8 hours after experimental CCI. A neurobehavioural evaluation and a histopathological analysis were then performed and the contusion volume, calpain activity and protein levels were measured in all animals.

RESULTS

Treatment with PJ34 markedly reduced neurological deficits, decreased contusion volume and attenuated necrotic and apoptotic neuronal cell death 24 hours after CCI. The data showed that the cytosolic and nuclear fractions of calpain and NF-κB were up-regulated in the injured cortex and that these changes were reversed by PJ34. Moreover, PJ34 significantly enhanced the calpastatin and IκB levels and decreased the levels of inflammatory mediators.

CONCLUSIONS

PARP inhibition by PJ34 suppresses the over-activation of calpain and the production of inflammatory factors that are caused by NF-κB activation and it improves neurological functioning, decreases the contusion volume and attenuates neuronal cell death in a mouse model of CCI.

The Effects of Granulocyte-Colony Stimulating Factor on Regeneration in Nerve Crush Injuries in Rats

Granulocyte-colony stimulating factor (G-CSF) is widely known to have a neuroprotective effect, but its effects on function and morphology in mechanical nerve injury are not well understood. The aim of this study was to confirm the time course of the functional changes and morphological effects of G-CSF in a rat model of nerve crush injury. Twelve-eight rats were divided into three group: sham-operated control group, G-CSF-treated group, and saline treated group. 2 weeks after the nerve crush injury, G-CSF was injected for 5 days. After 4 weeks, functional tests such as motor nerve conduction velocity (MNCV), mechanical and cold allodynia tests, and morphological studies were performed. G-CSF-treated rats had significantly improved nerve function including MNCV and mechanical and cold allodynia. In addition, G-CSF-treated rats had significantly higher the density of myelinated fibers than saline-treated rats. In conclusion, we found that 100 μg/kg administration of G-CSF promoted long-term functional recovery in a rat model of nerve crush injury.

Control of Cell Survival in Adult Mammalian Neurogenesis

The fact that continuous proliferation of stem cells and progenitors, as well as the production of new neurons, occurs in the adult mammalian central nervous system (CNS) raises several basic questions concerning the number of neurons required in a particular system. Can we observe continued growth of brain regions that sustain neurogenesis? Or does an elimination mechanism exist to maintain a constant number of cells? If so, are old neurons replaced, or are the new neurons competing for limited network access among each other? What signals support their survival and integration and what factors are responsible for their elimination? This review will address these and other questions regarding regulatory mechanisms that control cell-death and cell-survival mechanisms during neurogenesis in the intact adult mammalian brain.

G-CSF attenuates neuroinflammation and stabilizes the blood-brain barrier via the PI3K/Akt/GSK-3β signaling pathway following neonatal hypoxia-ischemia in rats

OBJECTIVE

Neonatal hypoxia occurs in approximately 60% of premature births and is associated with a multitude of neurological disorders. While various treatments have been developed, translating them from bench to bedside has been limited. We previously showed G-CSF administration was neuroprotective in a neonatal hypoxia-ischemia rat pup model, leading us to hypothesize that G-CSF inactivation of GSK-3β via the PI3K/Akt pathway may attenuate neuroinflammation and stabilize the blood-brain barrier (BBB).

METHODS

P10 Sprague-Dawley rat pups were subjected to unilateral carotid artery ligation followed by hypoxia for 2.5h. We assessed inflammation by measuring expression levels of IKKβ, NF-κB, TNF-α, IL-1β, IL-10, and IL-12 as well as neutrophil infiltration. BBB stabilization was evaluated by measuring Evans blue extravasation, and Western blot analysis of Claudin-3, Claudin-5, ICAM-1, and VCAM-1.

MEASUREMENTS AND MAIN RESULTS

First, the time course study showed that p-β-catenin/β-catenin, IKKβ, and NF-κB expression levels peaked at 48h post-HI. The knockdown of GSK-3β with siRNA prevented the HI-induced increase of p-β-catenin/β-catenin, IKKβ, and NF-κB expression levels 48h after HI. G-CSF treatment reduced brain water content and neuroinflammation by downregulating IKKβ, NF-κB, TNF-α, IL-1β, and IL-12 and upregulating IL-10, thereby reducing neutrophil infiltration. Additionally, G-CSF stabilizes the BBB by downregulating VCAM-1 and ICAM-1, as well as upregulating Claudins 3 and 5 in endothelial cells. G-CSFR knockdown by siRNA and Akt inhibition by Wortmannin reversed G-CSF's neuroprotective effects.

CONCLUSIONS

We demonstrate G-CSF plays a pivotal role in attenuating neuroinflammation and BBB disruption following HI by inactivating GSK-3β through the PI3K/Akt pathway.

Neuroprotective effects of quercetin in a mouse model of brain ischemic/reperfusion injury via anti-apoptotic mechanisms based on the Akt pathway

The present study provided experimental evidence for the neuroprotective effects of quercetin using a rat model of global brain ischemic/reperfusion (I/R) injury. Pre‑treatment with quercetin (5 or 10 mg/kg orally (p.o.); once daily) induced a dose‑dependent reduction in I/R‑induced hippocampal neuron cell loss, with 10 mg/kg/day being the lowest dose that achieved maximal neuroprotection. Administration of 10 mg/kg quercetin over at least 3 days prior to I/R was required to improve the survival rate of I/R rats. Fluorescence‑assisted cell sorting, hematoxylin and eosin staining and terminal deoxynucleotidyl transferase dUTP nick end labeling indicated neuronal cell loss in the CA1 hippocampus. Rats that had undergone transient global cerebral ischemia for 15 min followed by 1 h of reperfusion exhibited a significant increase in reactive oxygen species (ROS) production in the hippocampus. The I/R‑induced ROS overproduction in the hippocampus at 1, 12 and 24 h following I/R was significantly decreased by quercetin pre‑treatment. Western blot analysis revealed that the neuroprotective effects of quercetin (5 and 10 mg/kg/day, p.o.) were associated with an upregulation of the I/R‑induced suppression of B‑cell lymphoma‑2 (Bcl‑2), Bcl extra large and survivin expression as well as phosphorylation of Bcl‑2‑associated death promoter. Furthermore, the neuroprotective effects of quercetin (5, 10 mg/kg/day) in the brain were associated with an upregulation of Akt signaling. These findings suggested that the inhibition of I/R‑induced brain injury by quercetin likely involves a transcriptional mechanism to enhance anti‑apoptotic signaling.

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.

Protective actions of PJ34, a poly(ADP-ribose)polymerase inhibitor, on the blood-brain barrier after traumatic brain injury in mice

Poly(ADP-ribose) polymerase (PARP) is activated by oxidative stress and plays an important role in traumatic brain injury (TBI). The objective of this study was to investigate whether PARP activation participated in the blood-brain barrier (BBB) disruption and edema formation in a mouse model of controlled cortical impact (CCI). N-(6-oxo-5,6-dihydrophenanthridin-2-yl)-N,N-dimethylacetamide (PJ34) (10 mg/kg), a selective PARP inhibitor, was administered intraperitoneally at 5 min and 8 h after experimental CCI. After 6 h and 24 h of CCI, the permeability of the cortical BBB was determined after Evans Blue administration. The water content of the brain was also measured. Treatment with PJ34 markedly attenuated the permeability of the BBB and decreased the brain edema at 6 h and 24 h after CCI. Our data showed the up-regulation of nuclear factor-κB in cytosolic fractions and nuclear fractions in the injured cortex, and these changes were reversed by PJ34. Moreover, PJ34 significantly lessened the activities of myeloperoxidase and the levels of matrix metalloproteinase-9, enhanced the levels of occludin, laminin, collagen IV and integrin β1, reduced neurological deficits, decreased the contusion volume, and attenuated the necrotic and apoptotic neuronal cell death. These data suggest the protective effects of PJ34 on BBB integrity and cell death during acute TBI.

G-CSF as an adjunctive therapy with umbilical cord blood cell transplantation for traumatic brain injury

Traumatic brain injury (TBI), a major contributor to deaths and permanent disability worldwide, has been recently described as a progressive cell death process rather than an acute event. TBI pathophysiology is complicated and can be distinguished by the initial primary injury and the subsequent secondary injury that ensues days after the trauma. Therapeutic opportunities for TBI remain very limited with patients subjected to surgery or rehabilitation therapy. The efficacy of stem cell-based interventions, as well as neuroprotective agents in other neurological disorders of which pathologies overlap with TBI, indicates their potential as alternative TBI treatments. Furthermore, their therapeutic limitations may be augmented when combination therapy is pursued instead of using a single agent. Indeed, we demonstrated remarkable combined efficacy of human umbilical cord blood (hUCB) cell therapy and granulocyte-colony-stimulating factor (G-CSF) treatment in TBI models, providing essential evidence for the translation of this approach to treat TBI. Further studies are warranted to determine the mechanisms underlying therapeutic benefits exerted by hUCB + G-CSF in order to enhance its safety and efficacy in the clinic.