Immunoglobulins G from Sera of Amyotrophic Lateral Sclerosis Patients Induce Oxidative Stress and Upregulation of Antioxidative System in BV-2 Microglial Cell Line

Endogenous retroviruses are dysregulated in ALS

Amyotrophic lateral sclerosis (ALS) is a universally fatal neurodegenerative disease with no cure. Human endogenous retroviruses (HERVs) have been implicated in its pathogenesis but their relevance to ALS is not fully understood. We examined bulk RNA-seq data from almost 2,000 ALS and unaffected control samples derived from the cortex and spinal cord. Using different methods of feature selection, including differential expression analysis and machine learning, we discovered that transcription of HERV-K loci 1q22 and 8p23.1 were significantly upregulated in the spinal cord of individuals with ALS. Additionally, we identified a subset of ALS patients with upregulated HERV-K expression in the cortex and spinal cord. We also found the expression of HERV-K loci 19q11 and 8p23.1 was correlated with protein coding genes previously implicated in ALS and dysregulated in ALS patients in this study. These results clarify the association of HERV-K and ALS and highlight specific genes in the pathobiology of late-stage ALS.

Associations of cerebrospinal fluid profiles with severity and mortality risk of amyotrophic lateral sclerosis

Background

The relationship between routine cerebrospinal fluid (CSF) testing and the disease phenotype of amyotrophic lateral sclerosis (ALS) is unclear, and there are some contradictions in current studies.

Methods

This study aimed to analyze the relationship between CSF profiles and disease phenotype in ALS patients. We collected 870 ALS patients and 96 control subjects admitted to West China Hospital of Sichuan University. CSF microprotein, albumin, IgG, index of IgG (IgGindex), albumin quotient (QALB), and serum IgG were examined.

Results

In ALS patients, CSF IgG, and QALB were significantly increased, while CSF IgGindex was decreased, compared with control subjects. Approximately one-third of ALS patients had higher CSF IgG levels. The multiple linear regression analysis identified that CSF IgGindex was weakly negatively associated with ALS functional rating scale revised (ALSFRS-R) scores (β = -0.062, p = 0.041). This significance was found in male ALS but not in female ALS. The Cox survival analyses found that upregulated CSF IgG was significantly associated with the increased mortality risk in ALS [HR = 1.219 (1.010-1.470), p = 0.039].

Conclusion

In the current study, the higher CFS IgG was associated with increased mortality risk of ALS. CSF IgGindex may be associated with the severity of ALS. These findings may be sex-specific.

Immunology of amyotrophic lateral sclerosis - role of the innate and adaptive immunity

This review aims to summarize the latest evidence about the role of innate and adaptive immunity in Amyotrophic Lateral Sclerosis (ALS). ALS is a devastating neurodegenerative disease affecting upper and lower motor neurons, which involves essential cells of the immune system that play a basic role in innate or adaptive immunity, that can be neurotoxic or neuroprotective for neurons. However, distinguishing between the sole neurotoxic or neuroprotective function of certain cells such as astrocytes can be challenging due to intricate nature of these cells, the complexity of the microenvironment and the contextual factors. In this review, in regard to innate immunity we focus on the involvement of monocytes/macrophages, microglia, the complement, NK cells, neutrophils, mast cells, and astrocytes, while regarding adaptive immunity, in addition to humoral immunity the most important features and roles of T and B cells are highlighted, specifically different subsets of CD4+ as well as CD8+ T cells. The role of autoantibodies and cytokines is also discussed in distinct sections of this review.

A phase II open label clinical study of the safety, tolerability and efficacy of ILB® for Amyotrophic Lateral Sclerosis

Introduction

Amyotrophic lateral sclerosis (ALS) is an invariably lethal progressive disease, causing degeneration of neurons and muscle. No current treatment halts or reverses disease advance. This single arm, open label, clinical trial in patients with ALS investigated the safety and tolerability of a novel modified low molecular weight dextran sulphate (LMW-DS, named ILB^®) previously proven safe for use in healthy volunteers and shown to exert potent neurotrophic effects in pre-clinical studies. Secondary endpoints relate to efficacy and exploratory biomarkers.

Methods

Thirteen patients with ALS were treated with 5 weekly subcutaneous injections of ILB^®. Safety and efficacy outcome measures were recorded weekly during treatment and at regular intervals for a further 70 days. Functional and laboratory biomarkers were assessed before, during and after treatment.

Results

No deaths, serious adverse events or participant withdrawals occurred during or after ILB^® treatment and no significant drug-related changes in blood safety markers were evident, demonstrating safety and tolerability of the drug in this cohort of patients with ALS. The PK of ILB^® in patients with ALS was similar to that seen in healthy controls. The ILB^® injection elicited a transient elevation of plasma Hepatocyte Growth Factor, a neurotrophic and myogenic growth factor. Following the ILB^® injections patients reported increased vitality, decreased spasticity and increased mobility. The ALSFRS-R rating improved from 36.31 ± 6.66 to 38.77 ± 6.44 and the Norris rating also improved from 70.61 ± 13.91 to 77.85 ± 14.24 by Day 36. The improvement of functions was associated with a decrease in muscle atrophy biomarkers. These therapeutic benefits decreased 3–4 weeks after the last dosage.

Conclusions

This pilot clinical study demonstrates safety and tolerability of ILB^® in patients with ALS. The exploratory biomarker and functional measures must be cautiously interpreted but suggest clinical benefit and have a bearing on the mechanism of action of ILB^®. The results support the drug’s potential as the first disease modifying treatment for patients with ALS.

Trial registration

EudraCT 2017-005065-47.

MPO/HOCl Facilitates Apoptosis and Ferroptosis in the SOD1G93A Motor Neuron of Amyotrophic Lateral Sclerosis

Background. Oxidative stress and reactive oxygen species (ROS) are important in the pathogenesis of amyotrophic lateral sclerosis (ALS). Hypochlorous acid (HOCl) is a powerful oxidant of the reactive oxygen species (ROS) family. HOCl’s role in the progress of ALS remains unclear due to the lack of an effective HOCl detection method. Cumulative evidence supports oxidative damage incurred by mutant hSOD1 contributing to motor neuron death; however, whether HOCl as well as its catalytic enzyme myeloperoxidase (MPO) function in the cell death of SOD1G93A ALS remains elusive. Methods. The hSOD1WT and hSOD1G93A NSC-34 cell and SOD1G93A ALS mouse models were employed. With a novel fluorescent HOCl probe, HKOCl-3, we detected the expressions of HOCl and its catalytic enzyme, MPO, in the above models in vitro and in vivo. The regulation of MPO/HOCl by hSOD1G93A mutation and cell deaths by MPO/HOCl were also assayed, including apoptosis, ferroptosis, and autophagy. Results. Our results showed that hSOD1G93A mutation promoted the activation of the MPO/HOCl pathway in SOD1G93A ALS cell models. The activation of MPO/HOCl pathways facilitated apoptosis and ferroptosis through increasing the Bax/Bcl-2 ratio and expression of caspase-3 or inhibiting the expressions of GPX4 and NQO1 and thus leading to irreversible lipid peroxidation. Overexpressed FSP1, a glutathione-independent suppressor, could ameliorate ferroptosis. In vivo, we demonstrated that the activation of the MPO/HOCl pathway occurred differently in motor neurons of the motor cortices, brain stems, and spinal cords in male and female SOD1G93A transgenic mice. In addition, inhibiting MPO improved the motor performance of SOD1G93A transgenic mice, as demonstrated by the rotarod test. Conclusions. We concluded that aggregation of mutant hSOD1 proteins contributed to activation of the MPO/HOCl pathway, triggering apoptosis and ferroptosis in motor neuronal deaths and exerting impaired motor performance.

Passive Transfer of Blood Sera from ALS Patients with Identified Mutations Results in Elevated Motoneuronal Calcium Level and Loss of Motor Neurons in the Spinal Cord of Mice

Introduction: Previously, we demonstrated the degeneration of axon terminals in mice after repeated injections of blood sera from amyotrophic lateral sclerosis (ALS) patients with identified mutations. However, whether a similar treatment affects the cell body of motor neurons (MNs) remained unresolved. Methods: Sera from healthy individuals or ALS patients with a mutation in different ALS-related genes were intraperitoneally injected into ten-week-old male Balb/c mice (n = 3/serum) for two days. Afterward, the perikaryal calcium level was measured using electron microscopy. Furthermore, the optical disector method was used to evaluate the number of lumbar MNs. Results: The cytoplasmic calcium level of the lumbar MNs of the ALS-serum-treated mice, compared to untreated and healthy-serum-treated controls, was significantly elevated. While injections of the healthy serum did not reduce the number of MNs compared to the untreated control group, ALS sera induced a remarkable loss of MNs. Discussion: Similarly to the distant motor axon terminals, the injection of blood sera of ALS patients has a rapid degenerative effect on MNs. Analogously, the magnitude of the evoked changes was specific to the type of mutation; furthermore, the degeneration was most pronounced in the group treated with sera from ALS patients with a mutation in the chromosome 9 open reading frame 72 gene.

Interplay between immunity and amyotrophic lateral sclerosis: Clinical impact

Amyotrophic lateral sclerosis (ALS) is a debilitating and rapidly fatal neurodegenerative disease. Despite decades of research and many new insights into disease biology over the 150 years since the disease was first described, causative pathogenic mechanisms in ALS remain poorly understood, especially in sporadic cases. Our understanding of the role of the immune system in ALS pathophysiology, however, is rapidly expanding. The aim of this manuscript is to summarize the recent advances regarding the immune system involvement in ALS, with particular attention to clinical translation. We focus on the potential pathophysiologic mechanism of the immune system in ALS, discussing local and systemic factors (blood, cerebrospinal fluid, and microbiota) that influence ALS onset and progression in animal models and people. We also explore the potential of Positron Emission Tomography to detect neuroinflammation in vivo, and discuss ongoing clinical trials of therapies targeting the immune system. With validation in human patients, new evidence in this emerging field will serve to identify novel therapeutic targets and provide realistic hope for personalized treatment strategies.

Defining novel functions for cerebrospinal fluid in ALS pathophysiology

Despite the considerable progress made towards understanding ALS pathophysiology, several key features of ALS remain unexplained, from its aetiology to its epidemiological aspects. The glymphatic system, which has recently been recognised as a major clearance pathway for the brain, has received considerable attention in several neurological conditions, particularly Alzheimer's disease. Its significance in ALS has, however, been little addressed. This perspective article therefore aims to assess the possibility of CSF contribution in ALS by considering various lines of evidence, including the abnormal composition of ALS-CSF, its toxicity and the evidence for impaired CSF dynamics in ALS patients. We also describe a potential role for CSF circulation in determining disease spread as well as the importance of CSF dynamics in ALS neurotherapeutics. We propose that a CSF model could potentially offer additional avenues to explore currently unexplained features of ALS, ultimately leading to new treatment options for people with ALS.

Immunity in amyotrophic lateral sclerosis: blurred lines between excessive inflammation and inefficient immune responses

Despite wide genetic, environmental and clinical heterogeneity in amyotrophic lateral sclerosis, a rapidly fatal neurodegenerative disease targeting motoneurons, neuroinflammation is a common finding. It is marked by local glial activation, T cell infiltration and systemic immune system activation. The immune system has a prominent role in the pathogenesis of various chronic diseases, hence some of them, including some types of cancer, are successfully targeted by immunotherapeutic approaches. However, various anti-inflammatory or immunosuppressive therapies in amyotrophic lateral sclerosis have failed. This prompted increased scrutiny over the immune-mediated processes underlying amyotrophic lateral sclerosis. Perhaps the biggest conundrum is that amyotrophic lateral sclerosis pathogenesis exhibits features of three otherwise distinct immune dysfunctions-excessive inflammation, autoimmunity and inefficient immune responses. Epidemiological and genome-wide association studies show only minimal overlap between amyotrophic lateral sclerosis and autoimmune diseases, so excessive inflammation is usually thought to be secondary to protein aggregation, mitochondrial damage or other stresses. In contrast, several recently characterized amyotrophic lateral sclerosis-linked mutations, including those in TBK1, OPTN, CYLD and C9orf72, could lead to inefficient immune responses and/or damage pile-up, suggesting that an innate immunodeficiency may also be a trigger and/or modifier of this disease. In such cases, non-selective immunosuppression would further restrict neuroprotective immune responses. Here we discuss multiple layers of immune-mediated neuroprotection and neurotoxicity in amyotrophic lateral sclerosis. Particular focus is placed on individual patient mutations that directly or indirectly affect the immune system, and the mechanisms by which these mutations influence disease progression. The topic of immunity in amyotrophic lateral sclerosis is timely and relevant, because it is one of the few common and potentially malleable denominators in this heterogenous disease. Importantly, amyotrophic lateral sclerosis progression has recently been intricately linked to patient T cell and monocyte profiles, as well as polymorphisms in cytokine and chemokine receptors. For this reason, precise patient stratification based on immunophenotyping will be crucial for efficient therapies.

Passive Transfer of Sera from ALS Patients with Identified Mutations Evokes an Increased Synaptic Vesicle Number and Elevation of Calcium Levels in Motor Axon Terminals, Similar to Sera from Sporadic Patients

Previously, we demonstrated increased calcium levels and synaptic vesicle densities in the motor axon terminals (MATs) of sporadic amyotrophic lateral sclerosis (ALS) patients. Such alterations could be conferred to mice with an intraperitoneal injection of sera from these patients or with purified immunoglobulin G. Later, we confirmed the presence of similar alterations in the superoxide dismutase 1 G93A transgenic mouse strain model of familial ALS. These consistent observations suggested that calcium plays a central role in the pathomechanism of ALS. This may be further reinforced by completing a similar analytical study of the MATs of ALS patients with identified mutations. However, due to the low yield of muscle biopsy samples containing MATs, and the low incidence of ALS patients with the identified mutations, these examinations are not technically feasible. Alternatively, a passive transfer of sera from ALS patients with known mutations was used, and the MATs of the inoculated mice were tested for alterations in their calcium homeostasis and synaptic activity. Patients with 11 different ALS-related mutations participated in the study. Intraperitoneal injection of sera from these patients on two consecutive days resulted in elevated intracellular calcium levels and increased vesicle densities in the MATs of mice, which is comparable to the effect of the passive transfer from sporadic patients. Our results support the idea that the pathomechanism underlying the identical manifestation of the disease with or without identified mutations is based on a common final pathway, in which increasing calcium levels play a central role.

Serum IgG-induced microglial activation enhances neuronal cytolysis via the NO/sGC/PKG pathway in children with opsoclonus-myoclonus syndrome and neuroblastoma

Background

Opsoclonus-myoclonus syndrome (OMS) is a rare neurological disease. Some children with OMS also have neuroblastoma (NB). We and others have previously documented that serum IgG from children with OMS and NB induces neuronal cytolysis and activates several signaling pathways. However, the mechanisms underlying OMS remain unclear. Here, we investigated whether nitric oxide (NO) from activated microglias and its cascade contribute to neuronal cytolysis in pediatric OMS.

Methods

The activation of cultured cerebral cortical and cerebellar microglias incubated with sera or IgG isolated from sera of children with OMS and NB was measured by the expression of the activation marker, cytokines, and NO. Neuronal cytolysis was determined after exposing to IgG-treated microglia-conditioned media. Using inhibitors and activators, the effects of NO synthesis and its intracellular cascade, namely soluble guanylyl cyclase (sGC) and protein kinase G (PKG), on neuronal cytolysis were evaluated.

Results

Incubation with sera or IgG from children with OMS and NB increased the activation of cerebral cortical and cerebellar microglias, but not the activation of astrocytes or the cytolysis of glial cells. Moreover, the cytolysis of neurons was elevated by conditioned media from microglias incubated with IgG from children with OMS and NB. Furthermore, the expression of NO, sGC, and PKG was increased. Neuronal cytolysis was relieved by the inhibitors of NO signaling, while neuronal cytolysis was exacerbated by the activators of NO signaling but not proinflammatory cytokines. The cytolysis of neurons was suppressed by pretreatment with the microglial inhibitor minocycline, a clinically tested drug. Finally, increased microglial activation did not depend on the Fab fragment of serum IgG.

Conclusions

Serum IgG from children with OMS and NB potentiates microglial activation, which induces neuronal cytolysis through the NO/sGC/PKG pathway, suggesting an applicability of microglial inhibitor as a therapeutic candidate.

The Effects of Oral Rehmannia glutinosa Polysaccharide Administration on Immune Responses, Antioxidant Activity and Resistance Against Aeromonas hydrophila in the Common Carp, Cyprinus carpio L

The effects of the oral administration of Rehmannia glutinosa polysaccharide (RGP-1) on the immunoregulatory properties, antioxidant activity, and resistance against Aeromonas hydrophila in Cyprinus carpio L. were investigated. The purified RGP-1 (250, 500, and 1,000 μg/mL) was co-cultured with the head kidney cells of the common carp. The proliferation and phagocytosis activities of the head kidney cells, and the concentration of nitric oxide (NO) and cytokines in the culture medium were determined. Next, 300 common carps (47.66 ± 0.43 g) were randomly divided into five groups; the two control groups (negative and positive) were administered sterile PBS and the three treatment groups were administered different concentrations of RGP-1 (250, 500, and 1,000 μg/mL) for seven days. Subsequently, the positive and treatment groups were infected with A. hydrophila, and the negative group was administered sterile PBS for 24 h. The concentration of NO, cytokines, lysozyme (LZM), and alkaline phosphatase (AKP) in serum, the total antioxidant capacity (T-AOC), the levels of malonaldehyde (MDA) and glutathione (GSH), and the total activities of superoxide dismutase (T-SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) in the hepatopancreas of the common carp were tested. We observed that RGP-1 could significantly enhance the proliferation and phagocytosis activities (P < 0.05), besides inducing the production of NO, pro-inflammatory cytokines (TNF-α, IL-1β, IL-6, IL-12) and anti-inflammatory cytokines (IL-10, TGF-β) (P < 0.05) in vitro. The in vivo experimental results revealed that RGP-1 significantly enhanced NO production, protein levels of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6, IL-12), LZM and AKP activities, and the antioxidant content (T-AOC, SOD, CAT, GSH, GSH-Px, and MDA) compared to that observed in the negative group prior to A. hydrophila infection (P < 0.05). NO, pro-inflammatory cytokines, LZM and AKP activities were significantly lower than that in the positive group after infection (P < 0.05). However, whether infected or not, the expression of anti-inflammatory cytokines (IL-10, TGF-β) increased significantly in the RGP-1-treated groups (P < 0.05). Therefore, the results suggested that RGP-1 could enhance the non-specific immunity, antioxidant activity and anti-A. hydrophila activity of the common carp, and could be used as a safe and effective feed additive in aquaculture.

SS-31 reduces inflammation and oxidative stress through the inhibition of Fis1 expression in lipopolysaccharide-stimulated microglia

SS-31 is a kind of mitochondrion-targeted peptide. Recent studies indicated significant neuroprotective effects of SS-31. In this study, we investigated that SS-31 protected the murine cultured microglial cells (BV-2) against lipopolysaccharide (LPS)-induced inflammation and oxidative stress through stabilizing mitochondrial morphology. The morphological study showed that SS-31 preserved LPS-induced mitochondrial ultrastructure by reducing the fission protein 1 (Fis1) expression. Flow cytometry and Western blot verified that SS-31 defended the BV-2 cells against LPS-stimulated inflammation and oxidative stress via suppressing Fis1. To sum up, our study represents that SS-31 preserves BV-2 cells from LPS-stimulated inflammation and oxidative stress by down-regulating the Fis1 expression.

Experimental Motor Neuron Disease Induced in Mice with Long-Term Repeated Intraperitoneal Injections of Serum from ALS Patients

In an earlier study, signs of commencing degeneration of spinal motor neurons were induced in mice with short-term intraperitoneal injections of immunoglobulin G (IgG) taken from patients with amyotrophic lateral sclerosis (ALS). Since in that study, neither weakness nor loss of motor neurons was noted, to test whether the ALS IgG in this paradigm has the potential to evoke relentless degeneration of motor neurons, treatment with repeated injections over a longer period was carried out. Mice were systematically injected intraperitoneally with serum taken from ALS patients over a 75-day period. At selected time points, the isometric force of the limbs, number of spinal motor neurons and their intracellular calcium levels were determined. Furthermore, markers of glial activation and the motoneuronal uptake of human IgG were monitored. During this period, gliosis and progressive motoneuronal degeneration developed, which led to gradual loss of spinal motor neurons, more than 40% at day 21, along with decreasing muscle strength in the limbs. The inclusion-like accumulation of IgG appeared in the perikarya with the increase of intracellular calcium in the cell bodies and motor nerve terminals. Our results demonstrate that ALS serum can transfer motor neuron disease to mice.