Fibroblast Growth Factor-1 Induces Heme Oxygenase-1 via Nuclear FactorErythroid 2-related Factor 2 (Nrf2) in Spinal Cord Astrocytes

Metformin alleviates spinal cord injury by inhibiting nerve cell ferroptosis through upregulation of heme oxygenase-1 expression

JOURNAL/nrgr/04.03/01300535-202409000-00037/figure1/v/2024-01-16T170235Z/r/image-tiff Previous studies have reported upregulation of heme oxygenase-1 in different central nervous system injury models. Heme oxygenase-1 plays a critical anti-inflammatory role and is essential for regulating cellular redox homeostasis. Metformin is a classic drug used to treat type 2 diabetes that can inhibit ferroptosis. Previous studies have shown that, when used to treat cardiovascular and digestive system diseases, metformin can also upregulate heme oxygenase-1 expression. Therefore, we hypothesized that heme oxygenase-1 plays a significant role in mediating the beneficial effects of metformin on neuronal ferroptosis after spinal cord injury. To test this, we first performed a bioinformatics analysis based on the GEO database and found that heme oxygenase-1 was upregulated in the lesion of rats with spinal cord injury. Next, we confirmed this finding in a rat model of T9 spinal cord compression injury that exhibited spinal cord nerve cell ferroptosis. Continuous intraperitoneal injection of metformin for 14 days was found to both upregulate heme oxygenase-1 expression and reduce neuronal ferroptosis in rats with spinal cord injury. Subsequently, we used a lentivirus vector to knock down heme oxygenase-1 expression in the spinal cord, and found that this significantly reduced the effect of metformin on ferroptosis after spinal cord injury. Taken together, these findings suggest that metformin inhibits neuronal ferroptosis after spinal cord injury, and that this effect is partially dependent on upregulation of heme oxygenase-1.

NRF2 signaling cascade in amyotrophic lateral sclerosis: bridging the gap between promise and reality

Amyotrophic lateral sclerosis is a very disabling disease due to the degeneration of motor neurons. Symptoms include muscle weakness and atrophy, spasticity, and progressive paralysis. Currently, there is no treatment to reverse damage to motor neurons and cure amyotrophic lateral sclerosis. The only two treatments actually approved, riluzole and edaravone, have shown mitigated beneficial effects. The difficulty to find a cure lies in the complexity and multifaceted pattern of amyotrophic lateral sclerosis pathogenesis. Among mechanisms, abnormal RNA metabolism, nucleocytoplasmic transport defects, accumulation of unfolded protein, and mitochondrial dysfunction would in fine induce oxidative damage and vice versa. A potent therapeutic strategy will be to find molecules that break this vicious circle. Sharpening the nuclear factor erythroid-2 related factor 2 signaling may fulfill this objective since nuclear factor erythroid-2 related factor 2 has a multitarget profile controlling antioxidant defense, mitochondrial functioning, and inflammation. We here discuss the interest of developing nuclear factor erythroid-2 related factor 2-based therapy in regard to the pathophysiological mechanisms and we provide a general overview of the attempted clinical assays in amyotrophic lateral sclerosis.

Ferroptosis regulation through Nrf2 and implications for neurodegenerative diseases

This article provides an overview of the background knowledge of ferroptosis in the nervous system, as well as the key role of nuclear factor E2-related factor 2 (Nrf2) in regulating ferroptosis. The article takes Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), and amyotrophic lateral sclerosis (ALS) as the starting point to explore the close association between Nrf2 and ferroptosis, which is of clear and significant importance for understanding the mechanism of neurodegenerative diseases (NDs) based on oxidative stress (OS). Accumulating evidence links ferroptosis to the pathogenesis of NDs. As the disease progresses, damage to the antioxidant system, excessive OS, and altered Nrf2 expression levels, especially the inhibition of ferroptosis by lipid peroxidation inhibitors and adaptive enhancement of Nrf2 signaling, demonstrate the potential clinical significance of Nrf2 in detecting and identifying ferroptosis, as well as targeted therapy for neuronal loss and mitochondrial dysfunction. These findings provide new insights and possibilities for the treatment and prevention of NDs.

The Diverse Roles of Reactive Astrocytes in the Pathogenesis of Amyotrophic Lateral Sclerosis

Astrocytes displaying reactive phenotypes are characterized by their ability to remodel morphologically, molecularly, and functionally in response to pathological stimuli. This process results in the loss of their typical astrocyte functions and the acquisition of neurotoxic or neuroprotective roles. A growing body of research indicates that these reactive astrocytes play a pivotal role in the pathogenesis of amyotrophic lateral sclerosis (ALS), involving calcium homeostasis imbalance, mitochondrial dysfunction, abnormal lipid and lactate metabolism, glutamate excitotoxicity, etc. This review summarizes the characteristics of reactive astrocytes, their role in the pathogenesis of ALS, and recent advancements in astrocyte-targeting strategies.

Fibroblast growth factor 5 protects against spinal cord injury through activating AMPK pathway

Excessive productions of inflammatory cytokines and free radicals are involved in spinal cord injury (SCI). Fibroblast growth factor 5 (FGF5) is associated with inflammatory response and oxidative damage, and we herein intend to determine its function in SCI. Lentivirus was instilled to overexpress or knockdown FGF5 expression in mice. Compound C or H89 2HCl were used to suppress AMP-activated protein kinase (AMPK) or protein kinase A (PKA), respectively. FGF5 level was significantly decreased during SCI. FGF5 overexpression mitigated, while FGF5 silence further facilitated inflammatory response, oxidative damage and SCI. Mechanically, FGF5 activated AMPK to attenuate SCI in a cAMP/PKA-dependent manner, while inhibiting AMPK or PKA with pharmacological methods significantly abolished the neuroprotective effects of FGF5 against SCI. More importantly, serum FGF5 level was decreased in SCI patients, and elevated serum FGF5 level often indicate better prognosis. Our study identifies FGF5 as an effective therapeutic and prognostic target for SCI.

Genetic factors affecting survival in Japanese patients with sporadic amyotrophic lateral sclerosis: a genome-wide association study and verification in iPSC-derived motor neurons from patients

BACKGROUND

Several genetic factors are associated with the pathogenesis of sporadic amyotrophic lateral sclerosis (ALS) and its phenotypes, such as disease progression. Here, in this study, we aimed to identify the genes that affect the survival of patients with sporadic ALS.

METHODS

We enrolled 1076 Japanese patients with sporadic ALS with imputed genotype data of 7 908 526 variants. We used Cox proportional hazards regression analysis with an additive model adjusted for sex, age at onset and the first two principal components calculated from genotyped data to conduct a genome-wide association study. We further analysed messenger RNA (mRNA) and phenotype expression in motor neurons derived from induced pluripotent stem cells (iPSC-MNs) of patients with ALS.

RESULTS

Three novel loci were significantly associated with the survival of patients with sporadic ALS-FGF1 at 5q31.3 (rs11738209, HR=2.36 (95% CI, 1.77 to 3.15), p=4.85×10-9), THSD7A at 7p21.3 (rs2354952, 1.38 (95% CI, 1.24 to 1.55), p=1.61×10-8) and LRP1 at 12q13.3 (rs60565245, 2.18 (95% CI, 1.66 to 2.86), p=2.35×10-8). FGF1 and THSD7A variants were associated with decreased mRNA expression of each gene in iPSC-MNs and reduced in vitro survival of iPSC-MNs obtained from patients with ALS. The iPSC-MN in vitro survival was reduced when the expression of FGF1 and THSD7A was partially disrupted. The rs60565245 was not associated with LRP1 mRNA expression.

CONCLUSIONS

We identified three loci associated with the survival of patients with sporadic ALS, decreased mRNA expression of FGF1 and THSD7A and the viability of iPSC-MNs from patients. The iPSC-MN model reflects the association between patient prognosis and genotype and can contribute to target screening and validation for therapeutic intervention.

FGF23 alleviates neuronal apoptosis and inflammation, and promotes locomotion recovery via activation of PI3K/AKT signalling in spinal cord injury

Fibroblast growth factor 23 (FGF23) regulates neuronal morphology, synaptic growth and inflammation; however, its involvement in spinal cord injury (SCI) remains unclear. Therefore, the present study aimed to investigate the effect of FGF23 on neuronal apoptosis, inflammation and locomotion recovery, as well as its underlying mechanism in experimental SCI models. Primary rat neurons were stimulated with H₂O₂ to establish an in vitro model of SCI and were then transfected with an FGF23 overexpression (oeFGF23) or short hairpin RNA (shFGF23) adenovirus-associated virus and treated with or without LY294002 (a PI3K/AKT inhibitor). Subsequently, an SCI rat model was constructed, followed by treatment with oeFGF23, LY294002 or a combination of the two. FGF23 overexpression (oeFGF23 vs. oeNC) decreased the cell apoptotic rate and cleaved-caspase3 expression, but increased Bcl-2 expression in H₂O₂-stimulated neurons, whereas shFGF23 transfection (shFGF23 vs. shNC) exhibited the opposite effect (all P<0.05). Furthermore, FGF23 overexpression (oeFGF23 vs. oeNC) could activate the PI3K/AKT signalling pathway, whereas treatment with the PI3K/AKT inhibitor (LY294002) (oeFGF23 + LY294002 vs. LY294002) attenuated these effects in H₂O₂-stimulated neurons (all P<0.05). In SCI model rats, FGF23 overexpression (oeFGF23 vs. oeNC) reduced the laceration and inflammatory cell infiltration in injured tissue, decreased TNF-α and IL-1β levels, and improved locomotion recovery (all P<0.05); these effects were attenuated by additional administration of LY294002 (oeFGF23 + LY294002 vs. LY294002) (all P<0.05). In conclusion, FGF23 alleviated neuronal apoptosis and inflammation, and promoted locomotion recovery via activation of the PI3K/AKT signalling pathway in SCI, indicating its potential as a treatment option for SCI; however, further studies are warranted for validation.

Astrocytes: Dissecting Their Diverse Roles in Amyotrophic Lateral Sclerosis and Frontotemporal Dementia

Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are fatal neurodegenerative disorders often co-occurring in the same patient, a feature that suggests a common origin of the two diseases. Consistently, pathological inclusions of the same proteins as well as mutations in the same genes can be identified in both ALS/FTD. Although many studies have described several disrupted pathways within neurons, glial cells are also regarded as crucial pathogenetic contributors in ALS/FTD. Here, we focus our attention on astrocytes, a heterogenous population of glial cells that perform several functions for optimal central nervous system homeostasis. Firstly, we discuss how post-mortem material from ALS/FTD patients supports astrocyte dysfunction around three pillars: neuroinflammation, abnormal protein aggregation, and atrophy/degeneration. Furthermore, we summarize current attempts at monitoring astrocyte functions in living patients using either novel imaging strategies or soluble biomarkers. We then address how astrocyte pathology is recapitulated in animal and cellular models of ALS/FTD and how we used these models both to understand the molecular mechanisms driving glial dysfunction and as platforms for pre-clinical testing of therapeutics. Finally, we present the current clinical trials for ALS/FTD, restricting our discussion to treatments that modulate astrocyte functions, directly or indirectly.

Therapeutic Hypothermia after Cardiac Arrest Attenuates Hindlimb Paralysis and Damage of Spinal Motor Neurons and Astrocytes through Modulating Nrf2/HO-1 Signaling Pathway in Rats

Cardiac arrest (CA) and return of spontaneous circulation (ROSC), a global ischemia and reperfusion event, lead to neuronal damage and/or death in the spinal cord as well as the brain. Hypothermic therapy is reported to protect neurons from damage and improve hindlimb paralysis after resuscitation in a rat model of CA induced by asphyxia. In this study, we investigated roles of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) in the lumbar spinal cord protected by therapeutic hypothermia in a rat model of asphyxial CA. Male Sprague-Dawley rats were subjected to seven minutes of asphyxial CA (induced by injection of 2 mg/kg vecuronium bromide) and hypothermia (four hours of cooling, 33 ± 0.5 °C). Survival rate, hindlimb motor function, histopathology, western blotting, and immunohistochemistry were examined at 12, 24, and 48 h after CA/ROSC. The rats of the CA/ROSC and hypothermia-treated groups had an increased survival rate and showed an attenuated hindlimb paralysis and a mild damage/death of motor neurons located in the anterior horn of the lumbar spinal cord compared with those of the CA/ROSC and normothermia-treated groups. In the CA/ROSC and hypothermia-treated groups, expressions of cytoplasmic and nuclear Nrf2 and HO-1 were significantly higher in the anterior horn compared with those of the CA/ROSC and normothermia-treated groups, showing that cytoplasmic and nuclear Nrf2 was expressed in both motor neurons and astrocytes. Moreover, in the CA/ROSC and hypothermia-treated group, interleukin-1β (IL-1β, a pro-inflammatory cytokine) expressed in the motor neurons was significantly reduced, and astrocyte damage was apparently attenuated compared with those found in the CA/ROSC and normothermia group. Taken together, our results indicate that hypothermic therapy after CA/ROSC attenuates CA-induced hindlimb paralysis by protecting motor neurons in the lumbar spinal cord via activating the Nrf2/HO-1 signaling pathway and attenuating pro-inflammation and astrocyte damage (reactive astrogliosis).

Mechanism of SET8 Activates the Nrf2-KEAP1-ARE Signaling Pathway to Promote the Recovery of Motor Function after Spinal Cord Injury

Background

Spinal cord injury (SCI) is a common injury of the central nervous system (CNS), and astrocytes are relatively abundant glial cells in the CNS that impairs the recovery of motor function after SCI. It was confirmed that the oxidative stress of mitochondria leads to the accumulation of reactive oxygen species (ROS) in cells, which plays a key role in the motor function of astrocytes. However, the mechanism by which oxidative stress affects astrocyte motility after SCI is still unexplained. Therefore, this study investigated the influence of SET8-regulated oxidative stress on astrocyte autophagy levels after SCI in rats and the potential mechanisms of action.

Methods

We used real-time quantitative PCR, western blotting, and immunohistochemical staining to analyze SET8, Keap1, and Nrf2 expression at the cellular level and in SCI tissues. ChIP to detect H4K20me1 enrichment in the Keap1 promoter region under OE-SET8 (overexpression of SET8) conditions. Western blotting was used to assess the expression of signature proteins of astrocytes, proteins associated with autophagy, proteins associated with glial scar formation, reactive oxygen species (ROS) levels in cells using DHE staining, and astrocyte number, morphological alterations, and induction of glial scar formation processes using immunofluorescence. In addition, the survival rate of neurons after SCI in rats was examined by using NiSSl staining.

Results

OE-SET8 upregulates the enrichment of H4K20me1 in Keap1, inhibits Keap1 expression, activates the Nrf2-ARE signaling pathway to suppress ROS accumulation, inhibits oxidative stress-induced autophagy and glial scar formation in astrocytes, and leads to reduced neuronal loss, which promoted the recovery and improvement of motor function after SCI in rats.

Conclusion

Overexpression of SET8 alleviated oxidative stress by regulating Keap1/Nrf2/ARE, inhibited astrocyte autophagy levels, and reduced glial scar formation as well as neuronal loss, thereby promoting improved recovery of motor function after SCI. Thus, the SET8/H4K20me1 regulatory function may be a promising cellular therapeutic intervention point after SCI.

FGF1 alleviates LPS-induced acute lung injury via suppression of inflammation and oxidative stress

Background

Acute lung injury (ALI) and its severe form, acute respiratory distress syndrome (ARDS), are devastating clinical disorders with high mortality, and for which more effective therapies are urgently needed. FGF1, the prototype member of the FGF family, is shown to exert protective effects against injurious stimuli in multiple disease models. Here we aimed to evaluate whether FGF1 pretreatment is protective against LPS-induced ALI and elucidate the potential underlying mechanisms.

Methods

For drug-treated groups, C57B/6 mice received a single i.p. injection of FGF1 (1 mg/kg) 1 h before the LPS challenge or not. To induce the ALI model, the mice were treated by intratracheal instillation of LPS (5 mg/kg). Then, histopathological changes in lung tissues were assessed by hematoxylin and eosin staining and transmission electron microscopy. ELISA and qPCR assays were used to detect pro-inflammatory cytokine levels in BALF and lung tissues, respectively. The total number of inflammatory cells (neutrophils and macrophages) in BALF were counted using the Wright-Giemsa method. The expressions of reactive oxygen species (ROS) and malondialdehyde (MDA) were measured using their respective kits. Western blot and immunostaining were used to evaluate the expressions of antioxidants (Nrf-2, HO-1, SOD2, GPX4, and Catalase), as well as the inflammatory and/or apoptosis-related factors (TLR4, NF-κB, and Cleaved- caspase 3).

Results

FGF1 pretreatment significantly ameliorated the LPS-induced histopathological changes, reduced lung wet/dry ratios, ROS and MDA levels, total BALF protein, inflammatory cell infiltration, proinflammatory cytokine levels, and significantly increased the expression of antioxidant proteins (Nrf-2, HO-1, Catalase, and SOD2). In addition, FGF1 pretreatment significantly reduced the expression of TLR4 and cleaved- caspase 3, inhibited NF-κB activation, and reduced LPS-induced cell apoptosis.

Conclusions

Altogether, our results suggest that FGF1 pretreatment is protective against LPS-induced ALI through mediating anti-inflammatory and antioxidant effects, which may be attributed to the downregulation of TLR4 expression and inhibition of NF-κB activation, as well as promotion of antioxidant defenses. Therefore, FGF1 administration may prove beneficial in preventative strategies for ALI/ARDS.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10020-022-00502-8.

Nuclear Localization of Fibroblast Growth Factor Receptor 1 in Breast Cancer Cells Interacting with Cancer Associated Fibroblasts

Cancer-associated fibroblasts (CAFs) represent a major component of the tumor microenvironment and interplay with cancer cells by secreting cytokines, growth factors and extracellular matrix proteins. When estrogen receptor-negative breast cancer MDA-MB-231 cells were treated with the CAF-conditioned medium (CAF-CM), Akt and STAT3 involved in cell proliferation and survival were activated through phosphorylation. CAFs secrete fibroblast growth factor 2 (FGF2), thereby stimulating breast cancer cell progression. Akt activation induced by CAF-CM in MDA-MB-231 cells was abolished when FGF2-neutralizing antibody was added. Treatment of MDA-MB-231 cells directly with FGF2 enhanced the phosphorylation of Akt and the FGF receptor (FGFR) substrate, FRS2α. These events were abrogated by siRNA-mediated silencing of FGFR1. In a xenograft mouse model, co-injection of MDA-MB-231 cells with activated fibroblasts expressing FGF2 dramatically enhanced activation of Akt. Stable knockdown of FGFR1 blunted Akt phosphorylation in xenograft tumors. MDA-MB-231 cells co-cultured with CAFs or directly stimulated with FGF2 exhibited enhanced nuclear localization of FGFR1. Notably, FGF2 stimulation produced reactive oxygen species (ROS) accumulation in MDA-MB-231 cells, and FGF2-induced nuclear accumulation of FGFR1 was abrogated by the ROS scavenging agent, N-acetylcysteine.

NR1D1 downregulation in astrocytes induces a phenotype that is detrimental to cocultured motor neurons

Nuclear receptor subfamily 1 group D member 1 (NR1D1, also known as Rev-erbα) is a nuclear transcription factor that is part of the molecular clock encoding circadian rhythms and may link daily rhythms with metabolism and inflammation. NR1D1, unlike most nuclear receptors, lacks a ligand-dependent activation function domain 2 and is a constitutive transcriptional repressor. Amyotrophic lateral sclerosis (ALS) is the most common adult-onset motor neuron disease, caused by the progressive degeneration of motor neurons in the spinal cord, brain stem, and motor cortex. Approximately 10%-20% of familial ALS is caused by a toxic gain-of-function induced by mutations of the Cu/Zn superoxide dismutase (SOD1). Dysregulated clock and clock-controlled gene expression occur in multiple tissues from mutant hSOD1-linked ALS mouse models. Here we explore NR1D1 dysregulation in the spinal cord of ALS mouse models and its consequences on astrocyte-motor neuron interaction. NR1D1 protein and mRNA expression are significantly downregulated in the spinal cord of symptomatic mice expressing mutant hSOD1, while no changes were observed in age-matched animals overexpressing wild-type hSOD1. In addition, NR1D1 downregulation in primary astrocyte cultures induces a pro-inflammatory phenotype and decreases the survival of cocultured motor neurons. NR1D1 orchestrates the cross talk between physiological pathways identified to be disrupted in ALS (e.g., metabolism, inflammation, redox homeostasis, and circadian rhythms) and we observed that downregulation of NR1D1 alters astrocyte-motor neuron interaction. Our results suggest that NR1D1 could be a potential therapeutic target to prevent astrocyte-mediated motor neuron toxicity in ALS.

Activation of the Nrf2 Pathway as a Therapeutic Strategy for ALS Treatment

Amyotrophic lateral sclerosis is a progressive and fatal disease that causes motoneurons degeneration and functional impairment of voluntary muscles, with limited and poorly efficient therapies. Alterations in the Nrf2-ARE pathway are associated with ALS pathology and result in aberrant oxidative stress, making the stimulation of the Nrf2-mediated antioxidant response a promising therapeutic strategy in ALS to reduce oxidative stress. In this review, we first introduce the involvement of the Nrf2 pathway in the pathogenesis of ALS and the role played by astrocytes in modulating such a protective pathway. We then describe the currently developed activators of Nrf2, used in both preclinical animal models and clinical studies, taking into consideration their potentialities as well as the possible limitations associated with their use.

Impaired antioxidant KEAP1-NRF2 system in amyotrophic lateral sclerosis: NRF2 activation as a potential therapeutic strategy

BACKGROUND

Oxidative stress (OS) is an imbalance between oxidant and antioxidant species and, together with other numerous pathological mechanisms, leads to the degeneration and death of motor neurons (MNs) in amyotrophic lateral sclerosis (ALS).

MAIN BODY

Two of the main players in the molecular and cellular response to OS are NRF2, the transcription nuclear factor erythroid 2-related factor 2, and its principal negative regulator, KEAP1, Kelch-like ECH (erythroid cell-derived protein with CNC homology)-associated protein 1. Here we first provide an overview of the structural organization, regulation, and critical role of the KEAP1-NRF2 system in counteracting OS, with a focus on its alteration in ALS. We then examine several compounds capable of promoting NRF2 activity thereby inducing cytoprotective effects, and which are currently in different stages of clinical development for many pathologies, including neurodegenerative diseases.

CONCLUSIONS

Although challenges associated with some of these compounds remain, important advances have been made in the development of safer and more effective drugs that could actually represent a breakthrough for fatal degenerative diseases such as ALS.

Morin improves functional recovery after spinal cord injury in rats by enhancing axon regeneration via the Nrf2/HO-1 pathway

Spinal cord injury (SCI) is a devastating neurological occurrence that usually leads to a loss of motor and sensory function in patients. Axon regeneration has been reported to be crucial for recovery after trauma to the nervous system. Morin, a natural bioflavonoid obtained from the Moraceae family, has previously been reported to exert neuroprotective effects. In our study, we investigated the protective effects of morin on PC12 cells and primary neurons treated with oxygen-glucose deprivation (OGD) and its function in an SCI model. In vitro experiments showed that treating neuronal cells with morin enhanced axonal regeneration after OGD treatment by regulating microtubule stabilization and protecting mitochondrial function. Mechanistically, morin protected neuronal cells exposed to OGD by activating the nuclear factor (erythroid-derived 2)-like 2 (Nrf2)/heme oxygenase 1 (HO-1) pathway. An in vivo study illustrated that oral morin administration improved microtubule stability and promoted axon regeneration in SCI rats. Taken together, this study showed that treatment with morin improves functional recovery after SCI and that morin may serve as a potential agent for treating SCI.

Challenges and Opportunities of Targeting Astrocytes to Halt Neurodegenerative Disorders

Neurodegenerative diseases are a heterogeneous group of disorders whose incidence is likely to duplicate in the next 30 years along with the progressive aging of the western population. Non-cell-specific therapeutics or therapeutics designed to tackle aberrant pathways within neurons failed to slow down or halt neurodegeneration. Yet, in the last few years, our knowledge of the importance of glial cells to maintain the central nervous system homeostasis in health conditions has increased exponentially, along with our awareness of their fundamental and multifaced role in pathological conditions. Among glial cells, astrocytes emerge as promising therapeutic targets in various neurodegenerative disorders. In this review, we present the latest evidence showing the astonishing level of specialization that astrocytes display to fulfill the demands of their neuronal partners as well as their plasticity upon injury. Then, we discuss the controversies that fuel the current debate on these cells. We tackle evidence of a potential beneficial effect of cell therapy, achieved by transplanting astrocytes or their precursors. Afterwards, we introduce the different strategies proposed to modulate astrocyte functions in neurodegeneration, ranging from lifestyle changes to environmental cues. Finally, we discuss the challenges and the recent advancements to develop astrocyte-specific delivery systems.

Altered expression of clock and clock-controlled genes in a hSOD1-linked amyotrophic lateral sclerosis mouse model

Most physiological processes in mammals are subjected to daily oscillations that are governed by a circadian system. The circadian rhythm orchestrates metabolic pathways in a time-dependent manner and loss of circadian timekeeping has been associated with cellular and system-wide alterations in metabolism, redox homeostasis, and inflammation. Here, we investigated the expression of clock and clock-controlled genes in multiple tissues (suprachiasmatic nucleus, spinal cord, gastrocnemius muscle, and liver) from mutant hSOD1-linked amyotrophic lateral sclerosis (ALS) mouse models. We identified tissue-specific changes in the relative expression, as well as altered daily expression patterns, of clock genes, sirtuins (Sirt1, Sirt3, and Sirt6), metabolic enzymes (Pfkfb3, Cpt1, and Nampt), and redox regulators (Nrf2, G6pd, and Pgd). In addition, astrocytes transdifferentiated from induced pluripotent stem cells from SOD1-linked and FUS RNA binding protein-linked ALS patients also displayed altered expression of clock genes. Overall, our results raise the possibility of disrupted cross-talk between the suprachiasmatic nucleus and peripheral tissues in hSOD1^G93A mice, preventing proper peripheral clock regulation and synchronization. Since these changes were observed in symptomatic mice, it remains unclear whether this dysregulation directly drives or it is a consequence of the degenerative process. However, because metabolism and redox homeostasis are intimately entangled with circadian rhythms, our data suggest that altered expression of clock genes may contribute to metabolic and redox impairment in ALS. Since circadian dyssynchrony can be rescued, these results provide the groundwork for potential disease-modifying interventions.

Omics-based exploration and functional validation of neurotrophic factors and histamine as therapeutic targets in ALS

A plethora of genetic and molecular mechanisms have been implicated in the pathophysiology of the heterogeneous and multifactorial amyotrophic lateral sclerosis (ALS) disease, and hence the conventional "one target-one drug" paradigm has failed so far to provide effective therapeutic solutions, precisely because of the complex nature of ALS. This review intends to highlight how the integration of emerging "omics" approaches may provide a rational foundation for the comprehensive exploration of molecular pathways and dynamic interactions involved in ALS, for the identification of candidate targets and biomarkers that will assist in the rapid diagnosis and prognosis, lastly for the stratification of patients into different subgroups with the aim of personalized therapeutic strategies. To this purpose, particular emphasis will be placed on some potential therapeutic targets, including neurotrophic factors and histamine signaling that both have emerged as dysregulated at different omics levels in specific subgroups of ALS patients, and have already shown promising results in in vitro and in vivo models of ALS. To conclude, we will discuss about the utility of using integrated omics coupled with network-based approaches to provide additional guidance for personalization of medicine applications in ALS.

Decreased Mitochondrial Function, Biogenesis, and Degradation in Peripheral Blood Mononuclear Cells from Amyotrophic Lateral Sclerosis Patients as a Potential Tool for Biomarker Research

Amyotrophic lateral sclerosis (ALS) is a multifactorial and progressive neurodegenerative disease of unknown etiology. Due to ALS’s unpredictable onset and progression rate, the search for biomarkers that allow the detection and tracking of its development and therapeutic efficacy would be of significant medical value. Considering that alterations of energy supply are one of ALS’s main hallmarks and that a correlation has been established between gene expression in human brain tissue and peripheral blood mononuclear cells (PBMCs), the present work investigates whether changes in mitochondrial function could be used to monitor ALS. To achieve this goal, PBMCs from ALS patients and control subjects were used; blood sampling is a quite non-invasive method and is cost-effective. Different parameters were evaluated, namely cytosolic calcium levels, mitochondrial membrane potential, oxidative stress, and metabolic compounds levels, as well as mitochondrial dynamics and degradation. Altogether, we observed lower mitochondrial calcium uptake/retention, mitochondria depolarization, and redox homeostasis deregulation, in addition to a decrease in critical metabolic genes, a diminishment in mitochondrial biogenesis, and an augmentation in mitochondrial fission and autophagy-related gene expression. All of these changes can contribute to the decreased ATP and pyruvate levels observed in ALS PBMCs. Our data indicate that PBMCs from ALS patients show a significant mitochondrial dysfunction, resembling several findings from ALS’ neural cells/models, which could be exploited as a powerful tool in ALS research. Our findings can also guide future studies on new pharmacological interventions for ALS since assessments of brain samples are challenging and represent a relevant limited strategy.

Counteracting role of nuclear factor erythroid 2-related factor 2 pathway in Alzheimer's disease

A salient pathological features in Alzheimer's disease includes redox impairment and neuroinflammation. Nuclear factor erythroid 2-related factor 2 (Nrf2) and Nuclear factor kappa B (NF-ҡB) are the two key transcription factors that regulate cellular responses to redox impairment and neuroinflammation respectively. An effective way to confer neuroprotection in central nervous system (CNS) is the activation of a transcription factor i.e Nuclear factor erythroid 2-related factor 2 (Nrf2). An enhancer element known as Antioxidant Response Element (ARE) mediates the expression of phase II detoxification enzymes. Nrf2 is a nuclear transcription factor that binds to ARE thereby transcribing expression of several antioxidant genes. Kelch ECH associating protein-1 (Keap1), a culin 3-based E3 ligase, polyubiquitinates Nrf2 and targets it for its degradation. Disruption in the interaction between Keap1/Nrf2 can increase the brain's endogenous antioxidant capacity and thereby responsible for cell defence against oxidative stress and neuroinflammation in Alzheimer's disease (AD). The current review discusses about Keap1-Nrf2-ARE structure and function with special emphasis on the various pathways involved in positive and negative modulation of Nrf2, namely Phosphoinositide 3- kinase (PI3K), Glycogen synthase kinase-3β (GSK-3β), Nuclear factor kappa-b (NF-ҡb), Janus kinase/signal transducer and activator of transcription (JAK-STAT),Tumour Necrosis Factor- α (TNF-α), p38Mitogen-activated protein kinases (p38MAPK), Cyclic AMP response element binding protein (CREB) and intrinsic & extrinsic apoptotic pathway. Furthermore, this review highlights the miscellaneous Nrf2 activators as promising therapeutic agents for slowingdown the progression of AD.

Gastrodin Alleviates Oxidative Stress-Induced Apoptosis and Cellular Dysfunction in Human Umbilical Vein Endothelial Cells via the Nuclear Factor-Erythroid 2-Related Factor 2/Heme Oxygenase-1 Pathway and Accelerates Wound Healing In Vivo

Aims: To explore the effect and mechanism of gastrodin (GAS) on human umbilical vein endothelial cells (HUVECs) apoptosis induced by oxidative stress and its function in wound healing.

Main methods: HUVECs were incubated with tert-butyl hydroperoxide (TBHP) to induce endothelial cell dysfunction and GAS was used as a protector. Cell viability was detected by Counting Kit-8 (CCK-8). HUVECs apoptosis was evaluated by TUNEL assay and western blotting for cleaved caspase3 (C-caspase3) and other apoptosis-related proteins. Transwell migration assay, tube formation assay, and cell-matrix adhesion assay were performed to evaluated cell function of HUVECs. Transfection with nuclear factor-erythroid 2-related factor 2 (Nrf2) small interfering ribonucleic acid and western blotting for Nrf2, HO-1, and apoptosis-related proteins were performed to prove that Nrf2/HO-1 pathway is involved in the protective effects of GAS. The skin wound model of rat was used to assess the protective effects of GAS in vivo.

Key Findings: The results show that treating HUVECs with GAS attenuated TBHP-induced apoptosis and cellular dysfunction, including cellular tube formation, migration, and adhesion. Mechanistically, we found that GAS protects HUVECs from TBHP-induced cellular apoptosis by activating the nuclear factor (erythroid-derived 2)-like 2 (Nrf2)/heme oxygenase 1 (HO-1) pathway. An in vivo study illustrated that the oral administration of GAS enhances vascularization in regenerated tissue and facilitates wound healing.

Significance: The findings of this study demonstrated that GAS may serve as a potential agent that accelerates wound healing.

Astrocytes in Motor Neuron Diseases

Motor neuron disorders are highly debilitating and mostly fatal conditions for which only limited therapeutic options are available. To overcome this limitation and develop more effective therapeutic strategies, it is critical to discover the pathogenic mechanisms that trigger and sustain motor neuron degeneration with the greatest accuracy and detail. In the case of Amyotrophic Lateral Sclerosis (ALS), several genes have been associated with familial forms of the disease, whilst the vast majority of cases develop sporadically and no defined cause can be held responsible. On the contrary, the huge majority of Spinal Muscular Atrophy (SMA) occurrences are caused by loss-of-function mutations in a single gene, SMN1. Although the typical hallmark of both diseases is the loss of motor neurons, there is increasing awareness that pathological lesions are also present in the neighbouring glia, whose dysfunction clearly contributes to generating a toxic environment in the central nervous system. Here, ALS and SMA are sequentially presented, each disease section having a brief introduction, followed by a focussed discussion on the role of the astrocytes in the disease pathogenesis. Such a dissertation is substantiated by the findings that built awareness on the glial involvement and how the glial-neuronal interplay is perturbed, along with the appraisal of this new cellular site for possible therapeutic intervention.

Adenovirus vector‑mediated in vivo gene transfer of nuclear factor erythroid‑2p45‑related factor 2 promotes functional recovery following spinal cord contusion

The aim of the present study was to investigate whether nuclear factor erythroid 2p45‑related factor 2 (Nrf2) overexpression by gene transfer may protect neurons/glial cells and the association between neurons/glial cells and axons in spinal cord injury (SCI). In the present study, Nrf2 recombinant adenovirus (Ad) vectors were constructed. The protein levels of Nrf2 in the nucleus and of the Nrf2‑regulated gene products heme oxygenase‑1 (HO‑1) and NAD (P)H‑quinone oxidoreductase‑1 (NQO1), were detected using western blot analysis in PC12 cells following 48 h of transfection. Furthermore, the expression of Nrf2 was localized using an immunofluorescence experiment, and the expression of Nrf2, HO‑1 and NQO1 were detected using an immunohistochemical experiment in the grey matter of spinal cord in rats. Post‑injury motor behavior was assessed via the Basso, Beattie and Bresnahan (BBB) locomotor scale method. In PC12 cells, subsequent to Ad‑Nrf2 transfection, nuclear Nrf2, HO‑1 and NQO1 levels were significantly increased compared with the control (P<0.01). There was statistically significant changes in the PC12‑Ad‑Nrf2 group [Nrf2 (1.146±0.095), HO‑1 (1.816±0.095) and NQO1 (1.421±0.138)] compared with the PC12‑control group [Nrf2 (0.717±0.055), HO‑1 (1.264±0.081) and NQO1 (0.921±0.088)] and PC12‑Ad‑green fluorescent protein group [Nrf2 (0.714±0.111), HO‑1 (1.238±0.053) and NQO1 (0.987±0.045); P<0.01]. The BBB scores of the rats indicated that they had improved functional recovery following the local injection of Ad‑Nrf2. On the third day following the operation, BBB scores in the adenovirus groups (0.167±0.408) were significantly decreased compared with the SCI group (1±0.894; P<0.05). In the injured section of the spinal cord in the rats, the number of positive cells expressing Nrf2, HO‑1 and NQO1 were raised compared with the control and SCI groups, indicating that the adenovirus vector‑mediated gene transfer of Nrf2 promotes functional recovery following spinal cord contusion in rats.

Overview of Lipid Biomarkers in Amyotrophic Lateral Sclerosis (ALS)

Amyotrophic lateral sclerosis (ALS) is a multifactorial neurodegenerative disease involving motor neuron (MN) degeneration in the spinal cord, brain stem and primary motor cortex. The existence of inflammatory processes around MN and axonal degeneration in ALS has been shown. Unfortunately, none of the successful therapies in ALS animal models has improved clinical outcomes in patients with ALS. Therefore, the detection of blood biomarkers to be used as screening tools for disease onset and progression has been an expanding research area with few advances in the development of drugs for the treatment of ALS. In this review, we will address the available data analyzing regarding the relationship of lipid metabolism and lipid derived- products with ALS. We will address the advances on the studies about the role that lipids plays at the onset, progression and lifespan extension of ALS patients.

Mitochondrial Modulation by Dichloroacetate Reduces Toxicity of Aberrant Glial Cells and Gliosis in the SOD1G93A Rat Model of Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by motor neuron (MN) degeneration and gliosis. Neonatal astrocytes obtained from the SOD1G93A rat model of ALS exhibit mitochondrial dysfunction and neurotoxicity that can be reduced by dichloroacetate (DCA), a metabolic modulator that has been used in humans, and shows beneficial effects on disease outcome in SOD1G93A mice. Aberrant glial cells (AbGC) isolated from the spinal cords of adult paralytic SOD1G93A rats exhibit highly proliferative and neurotoxic properties and may contribute to disease progression. Here we analyze the mitochondrial activity of AbGC and whether metabolic modulation would modify their phenotypic profile. Our studies revealed fragmented mitochondria and lower respiratory control ratio in AbGC compared to neonatal SOD1G93A and nontransgenic rat astrocytes. DCA (5 mM) exposure improved AbGC mitochondrial function, reduced their proliferative rate, and importantly, decreased their toxicity to MNs. Furthermore, oral DCA administration (100 mg/kg, 10 days) to symptomatic SOD1G93A rats reduced MN degeneration, gliosis, and the number of GFAP/S100β double-labeled hypertrophic glial cells in the spinal cord. DCA treatment of AbGC reduced extracellular lactate levels indicating that the main recognized DCA action, targeting the pyruvate dehydrogenase kinase/pyruvate dehydrogenase complex, may underlie our findings. Our results show that AbGC metabolic phenotype is related to their toxicity to MNs and indicate that its modulation can reduce glial mediated pathology in the spinal cord. Together with previous findings, these results further support glial metabolic modulation as a valid therapeutic strategy in ALS.

Mini-GAGR, an intranasally applied polysaccharide, activates the neuronal Nrf2-mediated antioxidant defense system

Oxidative stress triggers and exacerbates neurodegeneration in Alzheimer's disease (AD). Various antioxidants reduce oxidative stress, but these agents have little efficacy due to poor blood-brain barrier (BBB) permeability. Additionally, single-modal antioxidants are easily overwhelmed by global oxidative stress. Activating nuclear factor erythroid 2 (NF-E2)-related factor 2 (Nrf2) and its downstream antioxidant system are considered very effective for reducing global oxidative stress. Thus far, only a few BBB-permeable agents activate the Nrf2-dependent antioxidant system. Here, we discovered a BBB-bypassing Nrf2-activating polysaccharide that may attenuate AD pathogenesis. Mini-GAGR, a 0.7-kDa cleavage product of low-acyl gellan gum, increased the levels and activities of Nrf2-dependent antioxidant enzymes, decreased reactive oxygen species (ROS) under oxidative stress in mouse cortical neurons, and robustly protected mitochondria from oxidative insults. Moreover, mini-GAGR increased the nuclear localization and transcriptional activity of Nrf2 similarly to known Nrf2 activators. Mechanistically, mini-GAGR increased the dissociation of Nrf2 from its inhibitor, Kelch-like ECH-associated protein 1 (Keap1), and induced phosphorylation and nuclear translocation of Nrf2 in a protein kinase C (PKC)- and fibroblast growth factor receptor (FGFR1)-dependent manner. Finally, 20-day intranasal treatment of 3xTg-AD mice with 100 nmol of mini-GAGR increased nuclear p-Nrf2 and growth-associated protein 43 (GAP43) levels in hippocampal neurons, reduced p-tau and β-amyloid (Aβ) peptide-stained neurons, and improved memory. The BBB-bypassing Nrf2-activating polysaccharide reported here may be effective in reducing oxidative stress and neurodegeneration in AD.

Improving the protective effects of aFGF for peripheral nerve injury repair using sulfated chitooligosaccharides

Injury to the peripheral nerves can result in temporary or life-long neuronal dysfunction and subsequent economic or social disability. Acidic fibroblast growth factor (aFGF) promotes the growth and survival of neurons and is a possible treatment for peripheral nerve injury. Yet, the actual therapeutic utility of aFGF is limited by its short half-life and instability in vivo. In the present study, we prepared sulfated chitooligosaccharides (SCOS), which have heparin-like properties, to improve the bioactivity of aFGF. We investigated the protective effects of SCOS with or without aFGF on RSC96 cells exposed to Na₂S₂O₄ hypoxia/reoxygenation injury. Cell viability was measured by MTT assay and cytotoxicity induced by Na₂S₂O₄ was assessed by lactate dehydrogenase (LDH) release into the culture medium. Pretreatment with aFGF and SCOS dramatically decreased LDH release after injury compared to pretreatment with aFGF or SCOS alone. We subsequently prepared an aFGF/SCOS thermo-sensitive hydrogel with poloxamer and examined its effects in vivo. Paw withdrawal thresholds and thermal withdrawal latencies were measured in rats with sciatic nerve injury. Local injection of the aFGF/SCOS hydrogels (aFGF: 40, 80 µg/kg) increased the efficiency of sciatic nerve repair compared to aFGF (80 µg/kg) hydrogel alone. Especially aFGF/SCOS thermo-sensitive hydrogel decreased paw withdrawal thresholds from 117.75 ± 8.38 (g, 4 d) to 65.74 ± 3.39 (g, 10 d), but aFGF alone group were 140.58 ± 27.54 (g, 4 d) to 89.12 ± 5.60 (g, 10 d) (aFGF dose was 80 µg/kg, P < 0.05, n = 8). The thermal withdrawal latencies decreased from 11.61 ± 2.26 (s, 4 d) to 2.37 ±0.67 (s, 10 d). However, aFGF alone group were from 17.69 ± 1.47 (s, 4 d) to 4.65 ± 1.73 (s, 10 d) (P < 0.05, n = 8). Furthermore, the aFGF/SCOS hydrogels also exhibited good biocompatibility in mice. In summary, SCOS improved the protective effects of aFGF in RSC96 cells injured with Na₂S₂O₄ and increased the efficiency of nerve repair and recovery of function in rats with sciatic nerve injury. These findings pave an avenue for the development of novel prophylactic and therapeutic strategies for peripheral nerve injury.

Improved Healing after the Co-Transplantation of HO-1 and BDNF Overexpressed Mesenchymal Stem Cells in the Subacute Spinal Cord Injury of Dogs

Abundant expression of proinflammatory cytokines after a spinal cord injury (SCI) creates an inhibitory microenvironment for neuroregeneration. The mesenchymal stem cells help to mitigate the inflammation and improve neural growth and survival. For this purpose, we potentiated the function of adipose-derived mesenchymal stem cells (Ad-MSCs) by transfecting them with brain-derived neurotrophic factor (BDNF) and heme oxygenase-1 (HO-1), through a lentivirus, to produce BDNF overexpressed Ad-MSCs (BDNF-MSCs), and HO-1 overexpressed Ad-MSCs (HO-1-MSCs). Sixteen SCI beagle dogs were randomly assigned into four treatment groups. We injected both HO-1 and BDNF-overexpressed MSCs as a combination group, to selectively control inflammation and induce neuroregeneration in SCI dogs, and compared this with BDNF-MSCs, HO-1-MSCs, and GFP-MSCs injected dogs. The groups were compared in terms of improvement in canine Basso, Beattie, and Bresnahan (cBBB) score during 8 weeks of experimentation. After 8 weeks, spinal cords were harvested and subjected to western blot analysis, immunofluorescent staining, and hematoxylin and eosin (H&E) staining. The combination group showed a significant improvement in hindlimb functions, with a higher BBB score, and a robust increase in neuroregeneration, depicted by a higher expression of Tuj-1, NF-M, and GAP-43 due to a decreased expression of the inflammatory markers interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), and an increased expression of interleukin-10 (IL-10) (P ≤ 0.05). H&E staining showed more reduced intraparenchymal fibrosis in the combination group than in other groups (P ≤ 0.05). It was thus suggested that the cotransplantation of HO-1 and BDNF-MSCs is more effective in promoting the healing of SCI. HO-1-MSCs reduce inflammation, which favors BDNF-induced neuroregeneration in SCI of dogs.

Profile of Arachidonic Acid-Derived Inflammatory Markers and Its Modulation by Nitro-Oleic Acid in an Inherited Model of Amyotrophic Lateral Sclerosis

The lack of current treatments for amyotrophic lateral sclerosis (ALS) highlights the need of a comprehensive understanding of the biological mechanisms of the disease. A consistent neuropathological feature of ALS is the extensive inflammation around motor neurons and axonal degeneration, evidenced by accumulation of reactive astrocytes and activated microglia. Final products of inflammatory processes may be detected as a screening tool to identify treatment response. Herein, we focus on (a) detection of arachidonic acid (AA) metabolization products by lipoxygenase (LOX) and prostaglandin endoperoxide H synthase in SOD1^G93A mice and (b) evaluate its response to the electrophilic nitro-oleic acid (NO₂-OA). Regarding LOX-derived products, a significant increase in 12-hydroxyeicosatetraenoic acid (12-HETE) levels was detected in SOD1^G93A mice both in plasma and brain whereas no changes were observed in age-matched non-Tg mice at the onset of motor symptoms (90 days-old). In addition, 15-hydroxyeicosatetraenoic acid (15-HETE) levels were greater in SOD1^G93A brains compared to non-Tg. Prostaglandin levels were also increased at day 90 in plasma from SOD1^G93A compared to non-Tg being similar in both types of animals at later stages of the disease. Administration of NO₂-OA 16 mg/kg, subcutaneously (s/c) three times a week to SOD1^G93A female mice, lowered the observed increase in brain 12-HETE levels compared to the non-nitrated fatty acid condition, and modified many others inflammatory markers. In addition, NO₂-OA significantly improved grip strength and rotarod performance compared to vehicle or OA treated animals. These beneficial effects were associated with increased hemeoxygenase 1 (HO-1) expression in the spinal cord of treated mice co-localized with reactive astrocytes. Furthermore, significant levels of NO₂-OA were detected in brain and spinal cord from NO₂-OA -treated mice indicating that nitro-fatty acids (NFA) cross brain–blood barrier and reach the central nervous system to induce neuroprotective actions. In summary, we demonstrate that LOX-derived oxidation products correlate with disease progression. Overall, we are proposing that key inflammatory mediators of AA-derived pathways may be useful as novel footprints of ALS onset and progression as well as NO₂-OA as a promising therapeutic compound.

FGF1 improves functional recovery through inducing PRDX1 to regulate autophagy and anti-ROS after spinal cord injury

Fibroblast growth factor 1 (FGF1) is thought to exert protective and regenerative effects on neurons following spinal cord injury (SCI), although the mechanism of these effects is not well understood. The use of FGF1 as a therapeutic agent is limited by its lack of physicochemical stability and its limited capacity to cross the blood‐spinal cord barrier. Here, we demonstrated that overexpression of FGF1 in spinal cord following SCI significantly reduced tissue loss, protected neurons in the ventricornu, ameliorated pathological morphology of the lesion, dramatically improved tissue recovery via neuroprotection, and promoted axonal regeneration and remyelination both in vivo and in vivo. In addition, the autophagy and the expression levels of PRDX1 (an antioxidant protein) were induced by AAV‐FGF1 in PC12 cells after H₂O₂ treatment. Furthermore, the autophagy levels were not changed in PRDX1‐suppressing cells that were treated by AAV‐FGF1. Taken together, these results suggest that FGF1 improves functional recovery mainly through inducing PRDX1 expression to increase autophagy and anti‐ROS activity after SCI.

Gastrodin protects against LPS-induced acute lung injury by activating Nrf2 signaling pathway

Gastrodin (GAS), a phenolic glucoside derived from Gastrodiaelata Blume, has been reported to have anti-inflammatory effect. The aim of this study was to investigate the effects of GAS on LPS-induced acute lung injury in mice. ALI was induced by the intranasal administration of LPS and GAS was given 1 h or 12 h after LPS treatment. The results indicated that GAS treatment markedly attenuated the damage of lung injury induced by LPS. GAS attenuated the activity of myeloperoxidase (MPO) and down-regulated the levels of pro-inflammatory cytokines TNF-α, IL-6 and IL-1β in BALF. LPS-induced lung edema and lung function were also reversed by GAS. Furthermore, GAS was found to inhibit LPS-induced inflammatory cells infiltration. In addition, treatment of GAS inhibited LPS-induced NF-κB activation and up-regulated the expression of Nrf2 and HO-1. In conclusion, our results indicated that GAS had anti-inflammatory effects on LPS-induced acute lung injury. The anti-inflammatory mechanism of GAS was through the inhibition of NF-κB and activation of Nrf2 signaling pathways.

Vein wrapping facilitates basic fibroblast growth factor-induced heme oxygenase-1 expression following chronic nerve constriction injury

The clinical efficacy of autologous vein wrapping for recurrent compressive neuropathy has been demonstrated; however, the underlying mechanisms of this technique remain unclear. Rats were divided into chronic constriction injury (CCI) and CCI + vein wrapping (CCI + VW) groups. Mechanical allodynia was evaluated using von Frey filaments. To identify the neuroprotective factors released from veins, basic fibroblast growth factor (bFGF) mRNA expression in veins was compared to that in the sciatic nerve. The response of heme oxygenase-1 (HO-1) expression to vein wrapping was evaluated by RT-PCR and enzyme-linked immunosorbent assays. The effects of exogenous bFGF on HO-1 expression were evaluated using a sciatic nerve cell culture. Vein wrapping significantly increased the withdraw threshold levels compared to the untreated CCI group. bFGF mRNA expression in veins was higher than that in untreated sciatic nerves. HO-1 mRNA expression was induced at higher levels in sciatic nerve cells in the presence of exogenous bFGF compared to untreated control cells. HO-1 mRNA and protein expression in the sciatic nerve were also higher in the CCI + VW group compared with the CCI group. Our results suggest that vein-derived bFGF contributes to the therapeutic benefit of vein wrapping through the induction of HO-1 in the sciatic nerve. Vein wrapping is a useful technique for reducing neuropathic pain. Further understanding of the neurotrophic factors released from veins may help to optimize current procedures for treating recurrent compressive neuropathy and traumatic peripheral nerve injury, and lead to the development of new therapeutic methods using recombinant neurotrophic factors. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:898-905, 2018.

Fibroblast growth factor-2-mediated protection of cardiomyocytes from the toxic effects of doxorubicin requires the mTOR/Nrf-2/HO-1 pathway

Background

Cardiotoxic side effects impose limits to the use of anti-tumour chemotherapeutic drugs such as doxorubicin (Dox). There is a need for cardioprotective strategies to prevent the multiple deleterious effects of Dox. Here, we examined the ability of administered fibroblast growth factor-2 (FGF-2), a cardioprotective protein that is synthesized as high and low molecular weight (Hi-, Lo-FGF-2) isoforms, to prevent Dox-induced: oxidative stress; cell death; lysosome dysregulation; and inactivation of potent endogenous protective pathways, such as the anti-oxidant/detoxification nuclear factor erythroid-2-related factor (Nrf-2), heme oxygenase-1 (HO-1) axis.

Methods and Results

Brief pre-incubation of neonatal rat cardiomyocyte cultures with either Hi- or Lo-FGF-2 reduced the Dox-induced: oxidative stress; apoptotic/necrotic cell death; lysosomal dysregulation; decrease in active mammalian target of Rapamycin (mTOR). FGF-2 isoforms prevented the Dox-induced downregulation of Nrf-2, and promoted robust increases in the Nrf-2-downstream targets including the cardioprotective protein HO-1, and p62/SQSTM1, a multifunctional scaffold protein involved in autophagy. Chloroquine, an autophagic flux inhibitor, caused a further increase in p62/SQSTM1, indicating intact autophagic flux in the FGF-2-treated groups. A selective inhibitor for HO-1, Tin-Protoporphyrin, prevented the FGF-2 protection against cell death. The mTOR inhibitor Rapamycin prevented FGF-2 protection, and blocked the FGF-2 effects on Nrf-2, HO-1 and p62/SQSTM1.

Conclusions

In an acute setting Hi- or Lo-FGF-2 protect cardiomyocytes against multiple Dox-induced deleterious effects, by a mechanism dependent on preservation of mTOR activity, Nrf-2 levels, and the upregulation of HO-1. Preservation/activation of endogenous anti-oxidant/detoxification defences by FGF-2 is a desirable property in the setting of Dox-cardiotoxicity.

Are Astrocytes the Predominant Cell Type for Activation of Nrf2 in Aging and Neurodegeneration?

Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor that regulates hundreds of antioxidant genes, and is activated in response to oxidative stress. Given that many neurodegenerative diseases including Alzheimer’s disease, Parkinson’s disease, amyotrophic lateral sclerosis, Huntington’s disease and multiple sclerosis are characterised by oxidative stress, Nrf2 is commonly activated in these diseases. Evidence demonstrates that Nrf2 activity is repressed in neurons in vitro, and only cultured astrocytes respond strongly to Nrf2 inducers, leading to the interpretation that Nrf2 signalling is largely restricted to astrocytes. However, Nrf2 activity can be observed in neurons in post-mortem brain tissue and animal models of disease. Thus this interpretation may be false, and a detailed analysis of the cell type expression of Nrf2 in neurodegenerative diseases is required. This review describes the evidence for Nrf2 activation in each cell type in prominent neurodegenerative diseases and normal aging in human brain and animal models of neurodegeneration, the response to pharmacological and genetic modulation of Nrf2, and clinical trials involving Nrf2-modifying drugs.

Can Co-Activation of Nrf2 and Neurotrophic Signaling Pathway Slow Alzheimer's Disease?

Alzheimer’s disease (AD) is a multifaceted disease that is hard to treat by single-modal treatment. AD starts with amyloid peptides, mitochondrial dysfunction, and oxidative stress and later is accompanied with chronic endoplasmic reticulum (ER) stress and autophagy dysfunction, resulting in more complicated pathogenesis. Currently, few treatments can modify the complicated pathogenic progress of AD. Compared to the treatment with exogenous antioxidants, the activation of global antioxidant defense system via Nrf2 looks more promising in attenuating oxidative stress in AD brains. Accompanying the activation of the Nrf2-mediated antioxidant defense system that reduce the AD-causative factor, oxidative stress, it is also necessary to activate the neurotrophic signaling pathway that replaces damaged organelles and molecules with new ones. Thus, the dual actions to activate both the Nrf2 antioxidant system and neurotrophic signaling pathway are expected to provide a better strategy to modify AD pathogenesis. Here, we review the current understanding of AD pathogenesis and neuronal defense systems and discuss a possible way to co-activate the Nrf2 antioxidant system and neurotrophic signaling pathway with the hope of helping to find a better strategy to slow AD.

"Pumping iron"-how macrophages handle iron at the systemic, microenvironmental, and cellular levels

Macrophages reside in virtually every organ. First arising during embryogenesis, macrophages replenish themselves in the adult through a combination of self-renewal and influx of bone marrow-derived monocytes. As large phagocytic cells, macrophages participate in innate immunity while contributing to tissue-specific homeostatic functions. Among the key metabolic tasks are senescent red blood cell recycling, free heme detoxification, and provision of iron for de novo hemoglobin synthesis. While this systemic mechanism involves the shuttling of iron between spleen, liver, and bone marrow through the concerted function of defined macrophage populations, similar circuits appear to exist within the microenvironment of other organs. The high turnover of iron is the prerequisite for continuous erythropoiesis and tissue integrity but challenges macrophages’ ability to maintain cellular iron homeostasis and immune function.

This review provides a brief overview of systemic, microenvironmental, and cellular aspects of macrophage iron handling with a focus on exciting and unresolved questions in the field.

Oligodendroglial fibroblast growth factor receptor 1 gene targeting protects mice from experimental autoimmune encephalomyelitis through ERK/AKT phosphorylation

Fibroblast growth factors (FGFs) exert diverse biological effects by binding and activation of specific fibroblast growth factor receptors (FGFRs). FGFs and FGFRs have been implicated in demyelinating pathologies including multiple sclerosis. In vitro activation of the FGF2/FGFR1 pathway results in downregulation of myelin proteins. FGF1, 2 and 9 have been shown to be involved in the pathology of multiple sclerosis. Recent studies on the function of oligodendroglial FGFR1 in a model of toxic demyelination showed that deletion of FGFR1 led to increased remyelination and preservation of axonal density and an increased number of mature oligodendrocytes. In the present study the in vivo function of oligodendroglial FGFR1 was characterized using an oligodendrocyte-specific genetic approach in the most frequently used model of multiple sclerosis the MOG_35-55 -induced EAE. Oligodendroglial FGFR1 deficient mice (referred to as Fgfr1^ind-/- ) showed a significantly ameliorated disease course in MOG_35-55 -induced EAE. Less myelin and axonal loss, and reduced lymphocyte and macrophage/microglia infiltration were found in Fgfr1^ind-/- mice. The reduction in disease severity in Fgfr1^ind-/- mice was accompanied by ERK/AKT phosphorylation, and increased expression of BDNF and TrkB. Reduced proinflammatory cytokine and chemokine expression was seen in Fgfr1^ind-/- mice compared with control mice. Considering that FGFR inhibitors are used in cancer trials, the oligodendroglial FGFR1 pathway may provide a new target for therapy in multiple sclerosis.

A Thermosensitive Heparin-Poloxamer Hydrogel Bridges aFGF to Treat Spinal Cord Injury

Acidic fibroblast growth factor (aFGF) exerts a protective effect on spinal cord injury (SCI) but is limited by the lack of physicochemical stability and the ability to cross the blood spinal cord barrier (BSCB). As promising biomaterials, hydrogels contain substantial amounts of water and a three-dimensional porous structure and are commonly used to load and deliver growth factors. Heparin can not only enhance growth factor loading onto hydrogels but also can stabilize the structure and control the release behavior. Herein, a novel aFGF-loaded thermosensitive heparin-poloxamer (aFGF-HP) hydrogel was developed and applied to provide protection and regeneration after SCI. To assess the effects of the aFGF-HP hydrogel, BSCB restoration, neuron and axonal rehabilitation, glial scar inhibition, inflammatory response suppression, and motor recovery were studied both in vivo and in vitro. The aFGF-HP hydrogels exhibited sustained release of aFGF and protected the bioactivity of aFGF in vitro. Compared to groups intravenously administered either drug-free HP hydrogel or aFGF alone, the aFGF-HP hydrogel group revealed prominent and attenuated disruption of the BSCB, reduced neuronal apoptosis, reactive astrogliosis, and increased neuron and axonal rehabilitation both in vivo and in vitro. This work provides an effective approach to enhance recovery after SCI and provide a successful strategy for SCI protection.

Role and Therapeutic Potential of Astrocytes in Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is characterized by the progressive degeneration of motor neurons in the spinal cord, brain stem, and motor cortex. The molecular mechanism underlying the progressive degeneration of motor neuron remains uncertain but involves a non-cell autonomous process. In acute injury or degenerative diseases astrocytes adopt a reactive phenotype known as astrogliosis. Astrogliosis is a complex remodeling of astrocyte biology and most likely represents a continuum of potential phenotypes that affect neuronal function and survival in an injury-specific manner. In ALS patients, reactive astrocytes surround both upper and lower degenerating motor neurons and play a key role in the pathology. It has become clear that astrocytes play a major role in ALS pathology. Through loss of normal function or acquired new characteristics, astrocytes are able to influence motor neuron fate and the progression of the disease. The use of different cell culture models indicates that ALS-astrocytes are able to induce motor neuron death by secreting a soluble factor(s). Here, we discuss several pathogenic mechanisms that have been proposed to explain astrocyte-mediated motor neuron death in ALS. In addition, examples of strategies that revert astrocyte-mediated motor neuron toxicity are reviewed to illustrate the therapeutic potential of astrocytes in ALS. Due to the central role played by astrocytes in ALS pathology, therapies aimed at modulating astrocyte biology may contribute to the development of integral therapeutic approaches to halt ALS progression.

Electrophilic nitro-fatty acids prevent astrocyte-mediated toxicity to motor neurons in a cell model of familial amyotrophic lateral sclerosis via nuclear factor erythroid 2-related factor activation

Nitro-fatty acids (NO2-FA) are electrophilic signaling mediators formed in tissues during inflammation, which are able to induce pleiotropic cytoprotective and antioxidant pathways including up regulation of Nuclear factor erythroid 2-related factor 2 (Nrf2) responsive genes. Amyotrophic Lateral Sclerosis (ALS) is a fatal neurodegenerative disease characterized by the loss of motor neurons associated to an inflammatory process that usually aggravates the disease progression. In ALS animal models, the activation of the transcription factor Nrf2 in astrocytes confers protection to neighboring neurons. It is currently unknown whether NO2-FA can exert protective activity in ALS through Nrf2 activation. Herein we demonstrate that nitro-arachidonic acid (NO2-AA) or nitro-oleic acid (NO2-OA) administrated to astrocytes expressing the ALS-linked hSOD1(G93A) induce antioxidant phase II enzyme expression through Nrf2 activation concomitant with increasing intracellular glutathione levels. Furthermore, treatment of hSOD1(G93A)-expressing astrocytes with NO2-FA prevented their toxicity to motor neurons. Transfection of siRNA targeted to Nrf2 mRNA supported the involvement of Nrf2 activation in NO2-FA-mediated protective effects. Our results show for the first time that NO2-FA induce a potent Nrf2-dependent antioxidant response in astrocytes capable of preventing motor neurons death in a culture model of ALS.

Enhancing NAD+ Salvage Pathway Reverts the Toxicity of Primary Astrocytes Expressing Amyotrophic Lateral Sclerosis-linked Mutant Superoxide Dismutase 1 (SOD1)

Nicotinamide adenine dinucleotide (NAD(+)) participates in redox reactions and NAD(+)-dependent signaling pathways. Although the redox reactions are critical for efficient mitochondrial metabolism, they are not accompanied by any net consumption of the nucleotide. On the contrary, NAD(+)-dependent signaling processes lead to its degradation. Three distinct families of enzymes consume NAD(+) as substrate: poly(ADP-ribose) polymerases, ADP-ribosyl cyclases (CD38 and CD157), and sirtuins (SIRT1-7). Because all of the above enzymes generate nicotinamide as a byproduct, mammalian cells have evolved an NAD(+) salvage pathway capable of resynthesizing NAD(+) from nicotinamide. Overexpression of the rate-limiting enzyme in this pathway, nicotinamide phosphoribosyltransferase, increases total and mitochondrial NAD(+) levels in astrocytes. Moreover, targeting nicotinamide phosphoribosyltransferase to the mitochondria also enhances NAD(+) salvage pathway in astrocytes. Supplementation with the NAD(+) precursors nicotinamide mononucleotide and nicotinamide riboside also increases NAD(+) levels in astrocytes. Amyotrophic lateral sclerosis (ALS) is caused by the progressive degeneration of motor neurons in the spinal cord, brain stem, and motor cortex. Superoxide dismutase 1 (SOD1) mutations account for up to 20% of familial ALS and 1-2% of apparently sporadic ALS cases. Primary astrocytes isolated from mutant human superoxide dismutase 1-overexpressing mice as well as human post-mortem ALS spinal cord-derived astrocytes induce motor neuron death in co-culture. Increasing total and mitochondrial NAD(+) content in ALS astrocytes increases oxidative stress resistance and reverts their toxicity toward co-cultured motor neurons. Taken together, our results suggest that enhancing the NAD(+) salvage pathway in astrocytes could be a potential therapeutic target to prevent astrocyte-mediated motor neuron death in ALS.

DNA Demethylation Upregulated Nrf2 Expression in Alzheimer's Disease Cellular Model

Nuclear factor erythroid 2-related factor 2 (Nrf2) is an important transcription factor in the defense against oxidative stress. Cumulative evidence has shown that oxidative stress plays a key role in the pathogenesis of Alzheimer’s disease (AD). Previous animal and clinical studies had observed decreased expression of Nrf2 in AD. However, the underlying regulation mechanisms of Nrf2 in AD remain unclear. Here, we used the DNA methyltransferases (Dnmts) inhibitor 5-aza-2′-deoxycytidine (5-Aza) to test whether Nrf2 expression was regulated by methylation in N2a cells characterizing by expressing human Swedish mutant amyloid precursor protein (N2a/APPswe). We found 5-Aza treatment increased Nrf2 at both messenger RNA and protein levels via downregulating the expression of Dnmts and DNA demethylation. In addition, 5-Aza-mediated upregulation of Nrf2 expression was concomitant with increased nuclear translocation of Nrf2 and higher expression of Nrf2 downstream target gene NAD(P)H:quinone oxidoreductas (NQO1). Our study showed that DNA demethylation promoted the Nrf2 cell signaling pathway, which may enhance the antioxidant system against AD development.

Nrf2--a therapeutic target for the treatment of neurodegenerative diseases

The brain is very sensitive to changes in redox status; thus maintaining redox homeostasis in the brain is critical for the prevention of accumulating oxidative damage. Aging is the primary risk factor for developing neurodegenerative diseases. In addition to age, genetic and environmental risk factors have also been associated with disease development. The primary reactive insults associated with the aging process are a result of oxidative stress (OS) and nitrosative stress (NS). Markers of increased oxidative stress, protein and DNA modification, inflammation, and dysfunctional proteostasis have all been implicated in contributing to the progression of neurodegeneration. The ability of the cell to combat OS/NS and maintain a clearance mechanism for misfolded aggregating proteins determines whether or not it will survive. A critical pathway in this regard is the Nrf2 (nuclear factor erythroid 2-related factor 2)- antioxidant response element (ARE) pathway. Nrf2 activation has been shown to mitigate a number of pathologic mechanisms associated with Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, Huntington's disease, and multiple sclerosis. This review will focus on the role of Nrf2 in these diseases and the potential for Nrf2 activation to attenuate disease progression.

Dual regulation of transcription factor Nrf2 by Keap1 and by the combined actions of β-TrCP and GSK-3

Nuclear factor-erythroid 2 p45 (NF-E2 p45)-related factor 2 (Nrf2) is a master regulator of redox homoeostasis that allows cells to adapt to oxidative stress and also promotes cell proliferation. In this review, we describe the molecular mechanisms by which oxidants/electrophilic agents and growth factors increase Nrf2 activity. In the former case, oxidants/electrophiles increase the stability of Nrf2 by antagonizing the ability of Kelch-like ECH-associated protein 1 (Keap1) to target the transcription factor for proteasomal degradation via the cullin-3 (Cul3)–RING ubiquitin ligase CRLKeap1. In the latter case, we speculate that growth factors increase the stability of Nrf2 by stimulating phosphoinositide 3-kinase (PI3K)−protein kinase B (PKB)/Akt signalling, which in turn results in inhibitory phosphorylation of glycogen synthase kinase-3 (GSK-3) and in doing so prevents the formation of a DSGIS motif-containing phosphodegron in Nrf2 that is recognized by the β-transducin repeat-containing protein (β-TrCP) Cul1-based E3 ubiquitin ligase complex SCFβ-TrCP. We present data showing that in the absence of Keap1, the electrophile tert-butyl hydroquinone (tBHQ) can stimulate Nrf2 activity and induce the Nrf2-target gene NAD(P)H:quinone oxidoreductase-1 (NQO1), whilst simultaneously causing inhibitory phosphorylation of GSK-3β at Ser9. Together, these observations suggest that tBHQ can suppress the ability of SCFβ-TrCP to target Nrf2 for proteasomal degradation by increasing PI3K−PKB/Akt signalling. We also propose a scheme that explains how other protein kinases that inhibit GSK-3 could stimulate induction of Nrf2-target genes by preventing formation of the DSGIS motif-containing phosphodegron in Nrf2.

Elusive roles for reactive astrocytes in neurodegenerative diseases

Astrocytes play crucial roles in the brain and are involved in the neuroinflammatory response. They become reactive in response to virtually all pathological situations in the brain such as axotomy, ischemia, infection, and neurodegenerative diseases (ND). Astrocyte reactivity was originally characterized by morphological changes (hypertrophy, remodeling of processes) and the overexpression of the intermediate filament glial fibrillary acidic protein (GFAP). However, it is unclear how the normal supportive functions of astrocytes are altered by their reactive state. In ND, in which neuronal dysfunction and astrocyte reactivity take place over several years or decades, the issue is even more complex and highly debated, with several conflicting reports published recently. In this review, we discuss studies addressing the contribution of reactive astrocytes to ND. We describe the molecular triggers leading to astrocyte reactivity during ND, examine how some key astrocyte functions may be enhanced or altered during the disease process, and discuss how astrocyte reactivity may globally affect ND progression. Finally we will consider the anticipated developments in this important field. With this review, we aim to show that the detailed study of reactive astrocytes may open new perspectives for ND.

Targeting the heparin-binding domain of fibroblast growth factor receptor 1 as a potential cancer therapy

Background

Aberrant activation of fibroblast growth factor receptors (FGFRs) deregulates cell proliferation and promotes cell survival, and may predispose to tumorigenesis. Therefore, selective inactivation of FGFRs is an important strategy for cancer therapy. Here as a proof-of-concept study, we developed a FGFR1 neutralizing antisera, IMB-R1, employing a novel strategy aimed at preventing the access of essential heparan sulfate (HS) co-receptors to the heparin-binding domain on FGFR1.

Methods

The mRNA and protein expression level of FGFR1 and other FGFRs were examined in several lines of breast cancer and osteosarcoma cells and corresponding normal cells using Taqman real-time quantitative PCR and Western blot analysis. The specificity of IMB-R1 against FGFR1 was assessed with various ELISA-based approaches and Receptor Tyrosine Kinase array. Proliferation assay and apoptosis analysis were performed to assess the effect of IMB-R1 on cancer cell growth and apoptosis, respectively, in comparison with known FGFR1 inhibitors. The IMB-R1 induced alteration of intracellular signaling and gene expression were analysed using Western blot and microarray approaches. Immunohistochemical staining of FGFR1 using IMB-R1 were carried out in different cancer tissues from clinical patients. Throughout the study, statistical differences were determined by Student’s t test where appropriate and reported when a p value was less than 0.05.

Results

We demonstrate that IMB-R1 is minimally cross-reactive for other FGFRs, and that it potently and specifically inhibits binding of heparin to FGFR1. Furthermore, IMB-R1 blocks the interaction of FGF2 with FGFR1, the kinase activity of FGFR1 and activation of intracellular FGFR signaling. Cancer cells treated with IMB-R1 displayed impaired FGF2 signaling, were unable to grow and instead underwent apoptosis. IMB-R1-induced cell death correlated with a disruption of antioxidative defense networks and increased expression of several tumor suppressors and apoptotic proteins, including p53. Immunostaining with IMB-R1 was stronger in human cancer tissues in which the FGFR1 gene is amplified.

Conclusion

Our study suggests that blocking HS interaction with the heparin-binding domains of FGFR1 inhibited cancer cell growth, which can be an attractive strategy to inactivate cancer-related heparin-binding proteins.

Electronic supplementary material

The online version of this article (doi:10.1186/s12943-015-0391-4) contains supplementary material, which is available to authorized users.

Allogeneic Neural Stem/Progenitor Cells Derived From Embryonic Stem Cells Promote Functional Recovery After Transplantation Into Injured Spinal Cord of Nonhuman Primates

: Previous studies have demonstrated that neural stem/progenitor cells (NS/PCs) promote functional recovery in rodent animal models of spinal cord injury (SCI). Because distinct differences exist in the neuroanatomy and immunological responses between rodents and primates, it is critical to determine the effectiveness and safety of allografted embryonic stem cell (ESC)-derived NS/PCs (ESC-NS/PCs) in a nonhuman primate SCI model. In the present study, common marmoset ESC-NS/PCs were grafted into the lesion epicenter 14 days after contusive SCI in adult marmosets (transplantation group). In the control group, phosphate-buffered saline was injected instead of cells. In the presence of a low-dose of tacrolimus, several grafted cells survived without tumorigenicity and differentiated into neurons, astrocytes, or oligodendrocytes. Significant differences were found in the transverse areas of luxol fast blue-positive myelin sheaths, neurofilament-positive axons, corticospinal tract fibers, and platelet endothelial cell adhesion molecule-1-positive vessels at the lesion epicenter between the transplantation and control groups. Immunoelectron microscopic examination demonstrated that the grafted ESC-NS/PC-derived oligodendrocytes contributed to the remyelination of demyelinated axons. In addition, some grafted neurons formed synaptic connections with host cells, and some transplanted neurons were myelinated by host cells. Eventually, motor functional recovery significantly improved in the transplantation group compared with the control group. In addition, a mixed lymphocyte reaction assay indicated that ESC-NS/PCs modulated the allogeneic immune rejection. Taken together, our results indicate that allogeneic transplantation of ESC-NS/PCs from a nonhuman primate promoted functional recovery after SCI without tumorigenicity.

SIGNIFICANCE

This study demonstrates that allogeneic embryonic stem cell (ESC)-derived neural stem/progenitor cells (NS/PCs) promoted functional recovery after transplantation into the injured spinal cord in nonhuman primates. ESC-NS/PCs were chosen because ESC-NS/PCs are one of the controls for induced pluripotent stem cell-derived NS/PCs and because ESC derivatives are possible candidates for clinical use. This translational research using an allograft model of a nonhuman primate is critical for clinical application of grafting NS/PCs derived from various allogeneic pluripotent stem cells, especially induced pluripotent stem cells, into injured spinal cord at the subacute phase.