The Use of Stem Cells’ Hematopoietic Stimulating Factors Therapy Following Spinal Cord Injury

Granulocyte colony-stimulating factor in traumatic spinal cord injury

Granulocyte colony-stimulating factor (G-CSF) is a cytokine used in pharmaceutical preparations for the treatment of chemotherapy-induced neutropenia. Evidence from experimental studies indicates that G-CSF exerts relevant activities in the central nervous system (CNS) in particular after lesions. In acute, subacute, and chronic CNS lesions, G-CSF appears to have strong anti-inflammatory, antiapoptotic, antioxidative, myelin-protective, and axon-regenerative activities. Additional effects result in the stimulation of angiogenesis and neurogenesis as well as in bone marrow stem cell mobilization to the CNS. There are emerging preclinical and clinical data indicating that G-CSF is a safe and effective drug for the treatment of acute and chronic traumatic spinal cord injury (tSCI), which we summarize in this review.

Progress in Stem Cell Therapy for Spinal Cord Injury

Background

Spinal cord injury (SCI) is one of the serious neurological diseases that occur in young people with high morbidity and disability. However, there is still a lack of effective treatments for it. Stem cell (SC) treatment of SCI has gradually become a new research hotspot over the past decades. This article is aimed at reviewing the research progress of SC therapy for SCI.

Methods

Review the literature and summarize the effects, strategies, related mechanisms, safety, and clinical application of different SC types and new approaches in combination with SC in SCI treatment.

Results

A large number of studies have focused on SC therapy for SCI, most of which showed good effects. The common SC types for SCI treatment include mesenchymal stem cells (MSCs), hematopoietic stem cells (HSCs), neural stem cells (NSCs), induced pluripotent stem cells (iPSCs), and embryonic stem cells (ESCs). The modes of treatment include in vivo and in vitro induction. The pathways of transplantation consist of intravenous, transarterial, nasal, intraperitoneal, intrathecal, and intramedullary injections. Most of the SC treatments for SCI use a number of cells ranging from tens of thousands to millions. Early or late SC administration, application of immunosuppressant or not are still controversies. Potential mechanisms of SC therapy include tissue repair and replacement, neurotrophy, and regeneration and promotion of angiogenesis, antiapoptosis, and anti-inflammatory. Common safety issues include thrombosis and embolism, tumorigenicity and instability, infection, high fever, and even death. Recently, some new approaches, such as the pharmacological activation of endogenous SCs, biomaterials, 3D print, and optogenetics, have been also developed, which greatly improved the application of SC therapy for SCI.

Conclusion

Most studies support the effects of SC therapy on SCI, while a few studies do not. The cell types, mechanisms, and strategies of SC therapy for SCI are very different among studies. In addition, the safety cannot be ignored, and more clinical trials are required. The application of new technology will promote SC therapy of SCI.

Combination of BMSCs-laden acellular nerve xenografts transplantation and G-CSF administration promotes sciatic nerve regeneration

Peripheral nerve gaps often lead to interrupted innervation, manifesting as severe sensory and motor dysfunctions. The repairs of the nerve injuries have not achieved satisfactory curative effects in clinic. The transplantation of bone marrow stromal cells (BMSCs)-laden acellular nerve xenografts (ANX) has been proven more effective than the acellular nerve allografting. Besides, granulocyte colony-stimulating factor (G-CSF) can inhibit inflammation and apoptosis, and thus is conducive to the microenvironmental improvement of axonal regeneration. This study aims to investigate the joint effect of BMSCs-seeded ANX grafting and G-CSF administration, and explore the relevant mechanisms. Adult SD rats were divided into five groups randomly: ANX group, ANX combined with G-CSF group, BMSCs-laden ANX group, BMSCs-laden ANX combined with G-CSF group, and autograft group. Eight weeks after transplantation, the detection of praxiology and neuroelectrophysiology was conducted, and then the morphology of the regenerated nerves was analyzed. The inflammatory response and apoptosis in the nerve grafts as well as the expression of the growth-promoting factors in the regenerated tissues were further assayed. G-CSF intervention and BMSCs implanting synergistically promoted peripheral nerve regeneration and functional recovery following ANX bridging, and the restoration effect was matchable with that of the autologous nerve grafting. Moreover, local inflammation was alleviated, the apoptosis of the seeded BMSCs was decreased, and the levels of the neuromodulatory factors were elevated. In conclusion, the union application of BMSCs-implanted ANX and G-CSF ameliorated the niche of neurotization and advanced nerve regeneration substantially. The strategy achieved the favorable effectiveness as an alternative to the autotransplantation.

Stem cells and their potential clinical applications in psychiatric disorders

The robustness of stem cells is one of the major factors that directly impacts life quality and life span. Evidence has accumulated that changes in the stem cell compartment affect human mental health and serve as an indicator of psychiatric problems. It is well known that stem cells continuously replace differentiated cells and tissues that are used up during life, although this replacement occurs at a different pace in the various organs. However, the participation of local neural stem cells in regeneration of the central nervous system is controversial. It is known that low numbers of stem cells circulate continuously in peripheral blood (PB) and lymph and undergo a circadian rhythm in their PB level, with the peak occurring early in the morning and the nadir at night, and recent evidence suggests that the number and pattern of circulating stem cells in PB changes in psychotic disorders. On the other hand, progress in the creation of induced pluripotent stem cells (iPSCs) from patient somatic cells provides valuable tools with which to study changes in gene expression in psychotic patients. We will discuss the various potential sources of stem cells that are currently employed in regenerative medicine and the mechanisms that explain some of their beneficial effects as well as the emerging problems with stem cell therapies. However, the main question remains: Will it be possible in the future to modulate the stem cell compartment to reverse psychiatric problems?

Safety of granulocyte colony-stimulating factor (G-CSF) administration for postrehabilitated motor complete spinal cord injury patients: an open-label, phase I study

Granulocyte colony-stimulating factor (G-CSF) is a major growth factor in the activation and differentiation of granulocytes. This cytokine has been widely and safely employed in different conditions over many years. In this translational study, G-CSF is administered to 19 patients with chronic motor complete spinal cord injury, and outcomes are reported. All 19 patients received subcutaneous G-CSF (5 µg/kg per day) for 5 days and were followed for at least 6 months. The American Spinal Injury Association (ASIA) scale was used for motor and sensory assessment, and the International Association of Neurorestoratology-Spinal Cord Injury Functional Rating Scale (IANR-SCIFRS) and the Spinal Cord Independence Measure (SCIM) III were used to assess improvements in the ability to perform basic daily tasks. At the 6-month follow-up, upper extremity motor scores improved by 10, which was statistically significant (p = 0.007), whereas there were no significant changes in lower extremity motor scores. Also, the median of light touch sensory scores improved by 5 (p = 0.001). Pinprick sensory scores significantly improved (p = 0.002). The median increment in SCIM III total score was 7 (p = 0.001). The improvements in bladder and bowel management as well as moderate distance mobility subscales were also significant (p < 0.05). Total IANR-SCIFRS scores changed from 17 to 32, which was statistically significant (p = 0.001); again the bladder and bowel management subscale improvements were statistically significant (p < 0.05). Mild side effects of the G-CSF treatment such as bone pain, rash, fever, neuropathic pain, and spasticity were noted in a few patients; all of them resolved after 1 week. Our results indicate that G-CSF administration is a safe process and is associated with neurological as well as functional improvement. This manuscript is published as part of the International Association of Neurorestoratology (IANR) supplement issue of Cell Transplantation.

Flt3 ligand synergizes with granulocyte-colony-stimulating factor in bone marrow mobilization to improve functional outcome after spinal cord injury in the rat

BACKGROUND AIMS

The effect of granulocyte-colony-stimulating factor (G-CSF) and/or the cytokine fms-like thyrosin kinase 3 (Flt3) ligand on functional outcome and tissue regeneration was studied in a rat model of spinal cord injury (SCI).

METHODS

Rats with a balloon-induced compression lesion were injected with G-CSF and/or Flt3 ligand to mobilize bone marrow cells. Behavioral tests (Basso-Beattie-Bresnahan and plantar test), blood counts, morphometric evaluation of the white and gray matter, and histology were performed 5 weeks after SCI.

RESULTS

The mobilization of bone marrow cells by G-CSF, Flt3 ligand and their combination improved the motor and sensory performance of rats with SCI, reduced glial scarring, increased axonal sprouting and spared white and gray matter in the lesion. The best results were obtained with a combination of G-CSF and Flt3. G-CSF alone or in combination with Flt3 ligand significantly increased the number of white blood cells, but not red blood cells or hemoglobin content, during and after the time-course of bone marrow stimulation. The combination of factors led to infiltration of the lesion by CD11b(+) cells.

CONCLUSIONS

The observed improvement in behavioral and morphologic parameters and tissue regeneration in animals with SCI treated with a combination of both factors could be associated with a prolonged time-course of mobilization of bone marrow cells. The intravenous administration of G-CSF and/or Flt3 ligand represents a safe and effective treatment modality for SCI.

Effect of granulocyte-colony stimulating factor on spinal cord tissue after experimental contusion injury

The purpose of this study was to investigate the early effects of granulocyte-colony stimulating factor (G-CSF) on myeloperoxidase (MPO) activity, lipid peroxidation (LPO) and ultrastructural findings in rats after spinal cord injury (SCI). We also compared the effects of G-CSF and methylprednisolone sodium succinate (MPSS). Wistar rats were divided into four groups: control, SCI alone (50 g/cm weight drop trauma), SCI+MPSS (30 mg/kg), and SCI+G-CSF (50 μg/kg). Administration of G-CSF and MPSS significantly decreased LPO (p < 0.05) and MPO activity (p < 0.05) in the first 24 hours. MPSS was more effective than G-CSF in reducing LPO (p < 0.05) and in minimizing ultrastructure changes. The results of this study indicate that G-CSF exerts a beneficial effect by decreasing MPO activity and LPO and may reduce tissue damage in the first 24 hours after SCI. Our findings do not exclude the possibility that G-CSF has a protective effect on spinal cord ultrastructure after the first 24 hours following SCI.

Combination of bone marrow stromal cell transplantation with mobilization by granulocyte-colony stimulating factor promotes functional recovery after spinal cord transection

PURPOSE

Spinal cord injury (SCI) results in severe neurological deficit. However, the functional recovery following SCI is very poor due to the neural lost and limited axonal regeneration. To date, there was no effective treatment. Recent studies have shown that bone marrow stromal cells (BMSCs) transplantated into the central nervous system (CNS) can survive and differentiate into neuronal-like cells. Additionally, granulocyte colony-stimulating factor (G-CSF) can mobilize hematopoietic stem cells and inhibit neural cell apoptosis. Thus, we aimed to evaluate the combined effect of BMSC transplantation and G-CSF administration on rats with traverse spinal cord injury.

METHODS

BMSCs were cultured in vitro, labeled with Hoechst33342, and then transplanted into the lesion site with or without G-CSF administration (50 microg/kg/day) for 5 subsequent days. The groups included an untreated control, along with treatment by G-CSF alone, BMSCs alone, and G-CSF + BMSCs.

RESULTS

In this study, by the end of eighth week after SCI injury, the animals in group treated with G-CSF + BMSCs showed higher BBB scores than the other two groups. Morphometric assessment showed that the lesion areas in the rats of the G-CSF + BMSCs group were much smaller. Compared with the control, BMSC, and G-CSF groups, less expression of apoptosis cells and more neural-cell markers around the spinal cord injury were found in rats treated with G-CSF + BMSCs.

CONCLUSIONS

The animals with the combination treatment achieved a better functional and morphologic recovery, although partial. This synergistic effect between BMSCs and G-CSF may be attributed to extrinsic and endogenous neurogenesis in the traverse spinal cord injury.

Translational research: from benchside to bedside

Translation of the achievements of basic science into everyday clinical practice remains a major issue in contemporary medicine, and is addressed through a new discipline, translational research, which aims to bridge the gap between basic and clinical research. Translational research encompasses laboratory studies, clinical demands, public health and health management, policies and economics; it is crucial in the evolution of contemporary biomedical science; and its interventions follow the political-economic, ethical-social and educational-scientific approaches. Translational research can progress through reorganisation of academic teams in a translational way. New academic posts translationally orientated are urgently needed, particularly in the field of trauma medicine, where lack of awareness of this new evolution is evident.