The epidemiology of amyotrophic lateral sclerosis in Moscow (Russia).

Objectives: To estimate the incidence of amyotrophic lateral sclerosis (ALS) in Moscow by investigating multiple sources of cases. Incidence rates from previous Russian studies ranged from 0.3 to 0.7 per 100,000/year. Methods: A retrospective study of the incidence of ALS was performed in the South district of Moscow (population, 1,760,000, 2015). Several data sources were investigated. The medical records of the calendar year 2015 were examined by an ALS expert who accepted only patients with definite or probable ALS according to the revised El Escorial criteria. Crude and standardized incidence rates were calculated, the latter adjusted to the Russian and the European population. Results: Twenty-two patients were found, accounting for a crude incidence of 1.25/100,000/year (95% CI 0.78-1.89) and a standardized incidence of 1.22 (Russia) and 1.28 (Europe). The sample included 11 men and 11 women aged 36-73 years (mean 56). Five patients (23%) had bulbar onset ALS. The mean diagnostic delay was 12.8 ± 9.2 months (8.5 ± 4.8 in men and 17.2 ± 10.6 in women) (p = 0.02). Family history of ALS was present in two cases. Conclusion: The incidence of ALS in the Russian Federation is higher than previously reported but lower than in other countries. Poor diagnostic ascertainment, particularly in women, and the shorter life expectancy of the Russian population are possible explanations.

Amyloid-ß interrupts canonical Sonic hedgehog signaling by distorting primary cilia structure.

BACKGROUND: Primary cilia are small non-motile microtubule and cell membrane protrusions expressed on most vertebrate cells, including cortical and hippocampal neurons. These small organelles serve as sensory structures sampling the extracellular environment and reprogramming the transcriptional machinery in response to environmental change. Primary cilia are decorated with a variety of receptor proteins and are necessary for specific signaling cascades such as the Sonic hedgehog (Shh) pathway. Disrupting cilia structure or function results in a spectrum of diseases collectively referred to as ciliopathies. Common to human ciliopathies is cognitive impairment, a symptom also observed in Alzheimer's disease (AD). One hallmark of AD is accumulation of senile plaques composed of neurotoxic Amyloid-ß (Aß) peptide. The Aß peptide is generated by the proteolytic cleavage of the amyloid precursor protein (APP). We set out to determine if Aß affects primary cilia structure and the Shh signaling cascade. METHODS: We utilized in vitro cell-based assays in combination with fluorescent confocal microscopy to address our study goals. Shh signaling and cilia structure was studied using two different cell lines, mouse NIH3T3 and human HeLa cells. To investigate how Aß levels affect Shh signaling and cilia structure in these cells, we utilized naturally secreted Aß as well as synthetic Aß. Effects on Shh signaling were assessed by luciferase activity while cilia structure was analyzed by fluorescent microscopy. RESULTS: Here, we report that APP localizes to primary cilia and Aß treatment results in distorted primary cilia structure. In addition, we demonstrate that Aß treatment interrupts canonical Shh signal transduction. CONCLUSIONS: Overall, our study illustrates that Aß can alter primary cilia structure suggesting that elevated Aß levels, like those observed in AD patients, could have similar effects on neuronal primary cilia in the brain. Additionally, our study suggests that Aß impairs the Shh signaling pathway. Together our findings shed light on two novel targets for future AD therapeutics.

Interleukin-6, S-Nitrosothiols, and Neurodegeneration in Different Central Nervous System Demyelinating Disorders: Is There a Relationship?

BACKGROUND AND PURPOSE: A few groups have suggested that activated cytokines and nitrosative stress are closely involved in the pathogenesis of different demyelinating disorders induced by the neuroinflammatory destruction of neurons. The purpose of this study was to elucidate the associations of cytokines and S-nitrosothiols (RSNO) with the severity of neurodegeneration during relapse in demyelinating disorders of the central nervous system. METHODS: We measured levels of interleukin-6 (IL-6), erythropoietin, RSNO, and phosphorylated neurofilament heavy chain (pNfh) in cerebrospinal fluid (CSF) samples obtained from patients with different demyelinating disorders: multiple sclerosis (MS, n=52), acute disseminated encephalomyelitis (ADEM, n=9), and neuromyelitis optica spectrum disorders (NMOSD) with aquaporin-4 immunoglobulin G (AQP4-IgG, n=12). We compared these levels with those measured in a control group (n=24). RESULTS: We found that IL-6 in CSF was elevated in NMOSD with AQP4-IgG and ADEM patients as well as in MS patients after the destruction of soluble IL-6. Erythropoietin levels were lower in MS, while RSNO levels were higher in NMOSD with AQP4-IgG and MS patients than in the control group. CSF pNfh levels were elevated in MS and ADEM patients. CONCLUSIONS: These results confirm that IL-6 is activated in different demyelinating disorders, with this elevation being more prominent in the CSF of NMOSD with AQP4-IgG and ADEM patients. Moreover, S-nitrosylation is activated in demyelinating disorders with spinal-cord injury and neurodegeneration in these patients. However, we found no correlation between these biochemical markers, and so we could not confirm whether IL-6-mediated nitric oxide production is involved in spinal-cord lesions.

The Pathogenesis of the Demyelinating Form of Guillain-Barre Syndrome (GBS): Proteo-peptidomic and Immunological Profiling of Physiological Fluids.

Acute inflammatory demyelinating polyneuropathy (AIDP) - the main form of Guillain-Barre syndrome-is a rare and severe disorder of the peripheral nervous system with an unknown etiology. One of the hallmarks of the AIDP pathogenesis is a significantly elevated cerebrospinal fluid (CSF) protein level. In this paper CSF peptidome and proteome in AIDP were analyzed and compared with multiple sclerosis and control patients. A total protein concentration increase was shown to be because of even changes in all proteins rather than some specific response, supporting the hypothesis of protein leakage from blood through the blood-nerve barrier. The elevated CSF protein level in AIDP was complemented by activization of protein degradation and much higher peptidome diversity. Because of the studies of the acute motor axonal form, Guillain-Barre syndrome as a whole is thought to be associated with autoimmune response against neurospecific molecules. Thus, in AIDP, autoantibodies against cell adhesion proteins localized at Ranvier's nodes were suggested as possible targets in AIDP. Indeed, AIDP CSF peptidome analysis revealed cell adhesion proteins degradation, however no reliable dependence on the corresponding autoantibodies levels was found. Proteome analysis revealed overrepresentation of Gene Ontology groups related to responses to bacteria and virus infections, which were earlier suggested as possible AIDP triggers. Immunoglobulin blood serum analysis against most common neuronal viruses did not reveal any specific pathogen; however, AIDP patients were more immunopositive in average and often had polyinfections. Cytokine analysis of both AIDP CSF and blood did not show a systemic adaptive immune response or general inflammation, whereas innate immunity cytokines were up-regulated. To supplement the widely-accepted though still unproven autoimmunity-based AIDP mechanism we propose a hypothesis of the primary peripheral nervous system damaging initiated as an innate immunity-associated local inflammation following neurotropic viruses egress, whereas the autoantibody production might be an optional complementary secondary process.

Increased S-nitrosothiols are associated with spinal cord injury in multiple sclerosis.

Multiple sclerosis (MS) is an immune-mediated disorder associated with inflammation, demyelination and axonal damage. In search of potential biomarkers of spinal cord lesions in MS related to nitric oxide metabolites, we measured total nitrite and nitrate levels, and protein-bound nitrotyrosine and S-nitrosothiol concentrations in the serum of MS patients at different stages of the disease. Sixty-eight patients and 36 healthy volunteers were included in the study. Total nitrite and nitrate levels were augmented in relapsing-remitting MS, while increased S-nitrosothiol concentrations were found both in relapsing-remitting and secondary-progressive MS. Further analysis demonstrated that S-nitrosothiol levels were selectively increased in patients with spinal cord injury. The data suggest that high S-nitrosothiol concentration may be a potential serum biomarker for spinal cord injury in MS.

Cyclopamine modulates γ-secretase-mediated cleavage of amyloid precursor protein by altering its subcellular trafficking and lysosomal degradation.

Alzheimer disease (AD) is a progressive neurodegenerative disease leading to memory loss. Numerous lines of evidence suggest that amyloid-ß (Aß), a neurotoxic peptide, initiates a cascade that results in synaptic dysfunction, neuronal death, and eventually cognitive deficits. Aß is generated by the proteolytic processing of the amyloid precursor protein (APP), and alterations to this processing can result in Alzheimer disease. Using in vitro and in vivo models, we identified cyclopamine as a novel regulator of γ-secretase-mediated cleavage of APP. We demonstrate that cyclopamine decreases Aß generation by altering APP retrograde trafficking. Specifically, cyclopamine treatment reduced APP-C-terminal fragment (CTF) delivery to the trans-Golgi network where γ-secretase cleavage occurs. Instead, cyclopamine redirects APP-CTFs to the lysosome. These data demonstrate that cyclopamine treatment decreases γ-secretase-mediated cleavage of APP. In addition, cyclopamine treatment decreases the rate of APP-CTF degradation. Together, our data demonstrate that cyclopamine alters APP processing and Aß generation by inducing changes in APP subcellular trafficking and APP-CTF degradation.

Altered levels of STAT1 and STAT3 influence the neuronal response to interferon gamma.

As immune responses in the CNS are highly regulated, cell-specific differences in IFNgamma signaling may be integral in dictating the outcome of host cell responses. In comparing the response of IFNgamma-treated primary neurons to control MEF, we observed that neurons demonstrated lower basal expression of both STAT1 and STAT3, the primary signal transducers responsible for IFNgamma signaling. Following IFNgamma treatment of these cell populations, we noted muted and delayed STAT1 phosphorylation, no detectable STAT3 phosphorylation, and a 3-10-fold lower level of representative IFNgamma-responsive gene transcripts. Moreover, in response to a brief pulse of IFNgamma, a steady increase in STAT1 phosphorylation and IFNgamma gene expression over 48 h was observed in neurons, as compared to rapid attenuation in MEF. These distinct response kinetics in IFNgamma-stimulated neurons may reflect modifications in the IFNgamma negative feedback loop, which may provide a mechanism for the cell-specific heterogeneity of responses to IFNgamma.