NEMO reshapes the α-Synuclein aggregate interface and acts as an autophagy adapter by co-condensation with p62.

NEMO is a ubiquitin-binding protein which regulates canonical NF-κB pathway activation in innate immune signaling, cell death regulation and host-pathogen interactions. Here we identify an NF-κB-independent function of NEMO in proteostasis regulation by promoting autophagosomal clearance of protein aggregates. NEMO-deficient cells accumulate misfolded proteins upon proteotoxic stress and are vulnerable to proteostasis challenges. Moreover, a patient with a mutation in the NEMO-encoding IKBKG gene resulting in defective binding of NEMO to linear ubiquitin chains, developed a widespread mixed brain proteinopathy, including α-synuclein, tau and TDP-43 pathology. NEMO amplifies linear ubiquitylation at α-synuclein aggregates and promotes the local concentration of p62 into foci. In vitro, NEMO lowers the threshold concentrations required for ubiquitin-dependent phase transition of p62. In summary, NEMO reshapes the aggregate surface for efficient autophagosomal clearance by providing a mobile phase at the aggregate interphase favoring co-condensation with p62.

Subarachnoid hemorrhages and aneurysms during the SARS-CoV2-pandemia at a tertiary medical center - Analysis of incidence and outcome.

Introduction: During the COVID-19-pandemic a significant decrease of up to 13% of all kinds of medical emergencies was reported. Similar trends were expected for aneurysmal subarachnoid hemorrhages (aSAH) and/or symptomatic aneurysms. Research question: To analyze a correlation of the SARS-CoV2-infection and the incidence of aSAH, and to assess the impact of the pandemic-lockdown on the incidence, the outcome and the course of patients suffering from aSAH and/or aneurysms. Material and methods: From March 16th, 2020 (first lockdown in Germany) to January 31st, 2021, all patients admitted to our hospital were screened by polymerase-chain-reaction (PCR) test for genetic material of SARS-CoV2. During this period, aSAH and symptomatic cerebral aneurysms were assessed and retrospectively compared to a historic longitudinal case-cohort. Results: Of 109.927 PCR-tests, 7.856 (7.15%) revealed a SARS-CoV2-infection. None of the patients mentioned above were tested positively. The number of aSAH and symptomatic aneurysms rose by 20.5% (39 vs. 47 cases) (p â€‹= â€‹0.93). Poor grade aSAH, as well as extensive bleeding-patterns were more often observed (p â€‹= â€‹0.63 and p â€‹= â€‹0.40, respectively), with more symptomatic vasospasms diagnosed (5 vs. 9 patients). Mortality rate increased by 8,4%. Discussion and conclusion: A correlation between SARS-CoV2-infection and the incidence of aSAH could not be established. Still, the overall number and the number of poor-grade aSAHs increased as well as symptomatic aneurysms during the pandemic. Therefore, we might conclude that dedicated neurovascular competence should be retained in designated centers to care for these patients even or especially in special situations affecting the global healthcare system.

Neurotrauma Emergencies during the SARS-CoV2 Pandemic at a Tertiary Medical Center: Analysis of Incidence and Outcome.

BACKGROUND: We assess the impact of lockdown in Germany due to the COVID-19 pandemic on the incidence and outcome of neurotrauma emergencies at a tertiary medical center. METHODS: All neurosurgical emergencies from March 16, 2020 (first lockdown in Germany) to January 31, 2021 were included and compared with a longitudinal case-cohort. Cases were descriptively recorded and retrospectively analyzed with respect to incidence and outcome. RESULTS: All emergencies defined as polytrauma referred to our center decreased by 10% during the pandemic (n = 226), whereas neurosurgical emergencies increased by 18.4% (764 vs. 905 cases). The number of specific neurotrauma emergencies increased by 44.4% (63 vs. 91 cases), yet statistically not significant (p = 0.245). The duration of treatment in the intensive care unit (ICU) extended from 621 to 1,056 days (p = 0.34). CONCLUSION: The reasons for the increase in the number of neurotrauma emergencies were the following: (1) many surrounding smaller care providers were canceled during this time and (2) there was a lack of free intensive care capacities in other hospitals, urging primarily maximum care providers to deal with more referrals. Both these facts and the prolonged treatment on ICUs strengthen the necessity for maximum care providers to keep ICU capacities for non-COVID patients. Specialized neurosurgical expertise should maintain in tertiary medical centers, even or particularly in exceptional circumstances such as the current pandemic.

Evidences for Mutant Huntingtin Inducing Musculoskeletal and Brain Growth Impairments via Disturbing Testosterone Biosynthesis in Male Huntington Disease Animals.

Body weight (BW) loss and reduced body mass index (BMI) are the most common peripheral alterations in Huntington disease (HD) and have been found in HD mutation carriers and HD animal models before the manifestation of neurological symptoms. This suggests that, at least in the early disease stage, these changes could be due to abnormal tissue growth rather than tissue atrophy. Moreover, BW and BMI are reported to be more affected in males than females in HD animal models and patients. Here, we confirmed sex-dependent growth alterations in the BACHD rat model for HD and investigated the associated contributing factors. Our results showed growth abnormalities along with decreased plasma testosterone and insulin-like growth factor 1 (IGF-1) levels only in males. Moreover, we demonstrated correlations between growth parameters, IGF-1, and testosterone. Our analyses further revealed an aberrant transcription of testosterone biosynthesis-related genes in the testes of BACHD rats with undisturbed luteinizing hormone (LH)/cAMP/PKA signaling, which plays a key role in regulating the transcription process of some of these genes. In line with the findings in BACHD rats, analyses in the R6/2 mouse model of HD showed similar results. Our findings support the view that mutant huntingtin may induce abnormal growth in males via the dysregulation of gene transcription in the testis, which in turn can affect testosterone biosynthesis.

Positive effect of immunomodulatory therapies on disease progression in Huntington's disease? Data from a real-world cohort.

Background: The role of neuroinflammation and autoimmune processes in neurodegenerative diseases is not fully understood. Activation of microglia with expression of proinflammatory cytokines supports the hypothesis that immune processes may play an important role in the pathophysiology of Huntington's disease (HD) and thus, immunomodulating therapies might have potential neuroprotective properties. Until now, no disease-modifying therapy (DMT) is available for HD. Objective: The aim of this research was to characterize a cohort of patients suffering from both HD and autoimmune demyelinating diseases of the central nervous system (classified as G35-37 in ICD-10; ADD-CNS) in comparison to HD cases without ADD-CNS. In particular, we were interested to investigate potential modulating effects on disease manifestation and progression of HD over time of prescribed immunomodulating medications (DMT). Methods: We analyzed the course of HD regarding motoric, functional, and cognitive aspects, using longitudinal data of up to 2 years from the worldwide registry study ENROLL-HD. Additional cross-sectional data in the largest cohort worldwide of HD patients was analyzed using demographic and molecular genetic parameters. Data were analyzed using analysis of variance (ANOVA) for cross-sectional and repeated-measures ANOVA for longitudinal parameters in IBM SPSS Statistics V.27. Results: Within the ENROLL-HD database, we investigated N = 21,116 participants and identified n = 60 participants suffering from ADD-CNS. Molecular, genetic, and demographic data did not differ between groups. The subgroup of n = 32 participants with motor-manifest HD revealed better cognitive performance in five out of eight cognitive tests at baseline with less progression over time in two tests (all p < 0.05). Differentiation between DMT-treated and untreated patients revealed better cognitive and motor performance in the DMT group; those patients, however, tended to be younger. Pre-manifest HD patients simultaneously diagnosed with ADD-CNS (n = 12) showed lower functional scores and more decline over time when compared with other pre-manifest HD (p < 0.05). Conclusion: Patients suffering from motor-manifest HD and simultaneously from ADD-CNS have better cognitive capacities compared with other motor-manifest HD patients. Moreover, DMTs might have beneficial effects on progression of neurodegeneration including the motor phenotype. However, this effect might have been biased by younger age in DMT-treated patients. Pre-manifest HD patients showed more functional impairment as expected due to their additional ADD-CNS disease.

Non-ischemic neurovascular emergencies at a supra-regional medical center during the SARS-CoV2-pandemia.

OBJECTIVE: To assess the impact of the lockdown in Germany due to the SARS-CoV2-pandemic on the incidence and the outcome of neurovascular emergencies at a tertiary medical center. METHODS: From March 16th, 2020 (first lockdown in Germany) to January 31st, 2021, all neurosurgical emergencies were included and compared to a longitudinal case-cohort. Cases were descriptively recorded and retrospectively analyzed with respect to incidence and outcome. RESULTS: All emergencies referred to our tertiary medical center decreased by 10% during the pandemic, whereas, neurosurgical emergencies increased by 18.4% (764 vs. 905 cases). Number of specific non-ischemic neurovascular emergencies increased by 29% (95 vs. 123 cases). The difference was not statistically significant (p = 0.53). Mortality rate increased dramatically by 40% during the pandemic throughout all neurovascular cases. As all included patients were negative PCR-tested for SARS-CoV2 the observed increase is unrelated to the virus infection. CONCLUSION: Unexpectedly, according to our data neurovascular emergencies raised in number and severity during the pandemic in Germany at our tertiary referral center. Furthermore, the case fatality increased. Even though our data lack proof of evidence for these findings, we might suggest two possible explanations for the absolute increase in numbers: firstly, patients might have refused to seek medical help while suffering only mild symptoms. Furthermore, as numerous lower-level medical centers restricted admissions, the referral times of patients in need of neurosurgical attention increased. We, therefore, suggest that even in a pandemic situation like the SARS-CoV2/COVID-19, it seems of utmost importance to retain dedicated neurovascular competence in designated centers to care for these emergencies.

Germany-wide evaluation of residency in neurological intensive care medicine.

BACKGROUND: Neurointensive medicine is an important subspecialization of neurology. Its growing importance can be attributed to factors such as demographic change and the establishment of new therapeutic options. Part of the neurological residency in Germany is a six-month rotation on an intensive care unit (ICU), which has not yet been evaluated nationwide. The aim of this study was to evaluate kind and feasibility of neurointensive care training in Germany and to discover particularly successful training concepts. METHODS: In a preliminary study, ten residents and ten instructors were interviewed. Using content analysis, two questionnaires were created, which contained questions about specific teaching methods as well as individual satisfaction. The questionnaires were sent to 187 neurological clinics in Germany, and residents and instructors were asked to participate in the study. The data analysis was performed using SPSS and content analysis for the free-text data. RESULTS: Seventy of the 187 clinics contacted did not offer ICU-rotation. At 59,8% (n = 70) of the remaining hospitals, a total of 154 participants (84 residents, 70 educators) could be recruited. General satisfaction with the neurointensive medical training is high in both groups (residents: 3.34 ± 0.54; instructors: 3.79 ± 0.41, evaluated on the basis of a Likert scale from 1 = "not satisfied" to 5 = "fully satisfied"). Specific teaching methods (e.g. simulation trainings, feedback sessions) are perceived as very useful by residents, but rarely take place. Instructors are interested in educational opportunities such as didactic courses. CONCLUSION: This study provides an overview of the ICU-rotation as part of the five-year neurological residency. Neurointensive care rotations usually take place at maximum care hospitals and last at least seven months. Despite frequent time and personnel restrictions, motivation of trainers and residents is high. Nevertheless, teaching methods as simulation training and educational opportunities for instructors must be expanded.

Mechanical thrombectomy for acute ischemic stroke in COVID-19 patients: multicenter experience in 111 cases.

BACKGROUND: Data on the frequency and outcome of mechanical thrombectomy (MT) for large vessel occlusion (LVO) in patients with COVID-19 is limited. Addressing this subject, we report our multicenter experience. METHODS: A retrospective cohort study was performed of consecutive acute stroke patients with COVID-19 infection treated with MT at 26 tertiary care centers between January 2020 and November 2021. Baseline demographics, angiographic outcome and clinical outcome evaluated by the modified Rankin Scale (mRS) at discharge and 90 days were noted. RESULTS: We identified 111 out of 11 365 (1%) patients with acute or subsided COVID-19 infection who underwent MT due to LVO. Cardioembolic events were the most common etiology for LVO (38.7%). Median baseline National Institutes of Health Stroke Scale score and Alberta Stroke Program Early CT Score were 16 (IQR 11.5-20) and 9 (IQR 7-10), respectively. Successful reperfusion (mTICI ≥2b) was achieved in 97/111 (87.4%) patients and 46/111 (41.4%) patients were reperfused completely. The procedure-related complication rate was 12.6% (14/111). Functional independence was achieved in 20/108 (18.5%) patients at discharge and 14/66 (21.2%) at 90 days follow-up. The in-hospital mortality rate was 30.6% (33/108). In the subgroup analysis, patients with severe acute COVID-19 infection requiring intubation had a mortality rate twice as high as patients with mild or moderate acute COVID-19 infection. Acute respiratory failure requiring ventilation and time interval from symptom onset to groin puncture were independent predictors for an unfavorable outcome in a logistic regression analysis. CONCLUSION: Our study showed a poor clinical outcome and high mortality, especially in patients with severe acute COVID-19 infection undergoing MT due to LVO.

Progressive multifocal leukoencephalopathy and immune reconstitution inflammatory syndrome in seven patients with sarcoidosis: a critical discussion of treatment and prognosis.

Progressive multifocal leukoencephalopathy (PML) is a subacute brain infection by the opportunistic John Cunningham (JC) virus. Herein, we describe seven patients with PML, lymphopenia, and sarcoidosis, in three of whom PML was the first manifestation of sarcoidosis. At onset, the clinical picture comprised rapidly progressive spastic hemi- or limb pareses as well as disturbances of vision, speech, and orientation. Cerebral magnetic resonance imaging showed T2-hyperintense, confluent, mainly supratentorial lesions. Four patients developed punctate contrast enhancement as a radiological sign of an immune reconstitution inflammatory syndrome (IRIS), three of them having a fatal course. In the cerebrospinal fluid, the initial JC virus load (8-25,787 copies/ml) did not correlate with interindividual severity; however, virus load corresponded to clinical dynamics. Brain biopsies (n = 2), performed 2 months after symptom onset, showed spotted demyelination and microglial activation. All patients had lymphopenia in the range of 270-1150/µl. To control JC virus, three patients received a combination of mirtazapine and mefloquine, another two patients additionally took cidofovir. One patient was treated with cidofovir only, and one patient had a combined regimen with mirtazapine, mefloquine, cidofovir, intravenous interleukin 2, and JC capsid vaccination. To treat sarcoidosis, the four previously untreated patients received prednisolone. Three patients had taken immunosuppressants prior to PML onset, which were subsequently stopped as a potential accelerator of opportunistic infections. After 6-54 months of follow up, three patients reached an incomplete recovery, one patient progressed, but survived so far, and two patients died. One further patient was additionally diagnosed with lung cancer, which he died from after 24 months. We conclude that the combination of PML and sarcoidosis is a diagnostic and therapeutic challenge. PML can occur as the first sign of sarcoidosis without preceding immunosuppressive treatment. The development of IRIS might be an indicator of poor outcome.

Successful Treatment of Severe Digitoxin Intoxication with CytoSorb® Hemoadsorption.

While several intoxications can be successfully treated with specific antidotes, intoxications with the steroid glycoside digitoxin still represent a major challenge. Besides conventional approaches, CytoSorb® hemoadsorption might be another treatment option. We report on an 81-year-old female patient treated in our intensive care unit (ICU) with severe digitoxin intoxication, acute renal failure, and urinary tract infection (UTI). As physiological digitoxin elimination kinetics are known to appear slow, and also in regard to the renal failure, the decision was made to initiate continuous renal replacement therapy combined with CytoSorb hemoadsorption. The patient was hemodynamically stabilized within the first 4 h of treatment and initially required catecholamines to be stopped within 24 h of treatment. Pre- and post-adsorber drug level measurements showed a rapid elimination of digitoxin. Antibiotic treatment with piperacillin/tazobactam was initiated, and despite CytoSorb hemoadsorption therapy and its known potential to reduce plasma concentrations of several drugs, the UTI was successfully treated. After 3 days of CytoSorb treatment, digitoxin plasma levels were stable and almost normalized, and no clinical signs of intoxication were present. Five days after presentation, the patient was transferred from the ICU in a stable condition. CytoSorb hemoadsorption may be an easily available, efficient, and less cost-intensive therapy option than treatment with the Fab fragment, which is the currently recommended therapy for digitalis intoxications. Therefore, the use of CytoSorb might represent an alternative treatment for life-threatening complications of digitoxin intoxications.

Ocrelizumab Treatment in Patients with Primary Progressive Multiple Sclerosis: Short-term Safety Results from a Compassionate Use Programme in Germany.

OBJECTIVES: In January 2018, the European Union (EU) approved ocrelizumab in relapsing multiple sclerosis (RMS) and as the first disease-modifying therapy (DMT) for patients with primary progressive multiple sclerosis (PPMS) with efficacy proven in a phase 3 randomised controlled trial. Eleven months prior to the European regulatory approval, a compassionate use programme (CUP) made ocrelizumab available to 489 patients with PPMS in Germany, thereby for the first time providing a therapeutic option to patients with PPMS who could not participate in ocrelizumab studies. Here, we report real-world patient characteristics and short-term safety data of patients with PPMS treated with ocrelizumab in this CUP. PATIENTS AND METHODS: This CUP was initiated in February 2017 - shortly before US Food and Drug administration approval in March 2017 - and ended in January 2018, following ocrelizumab approval in the EU. Adult patients (age ≥18 years) with PPMS who had a positive benefit/risk ratio according to the treating physician were eligible for inclusion at German treatment centres. The main exclusion criteria were current/recent treatment with other immune therapies and unresolved/chronic/active infections. Patients received methylprednisolone and an antihistamine before treatment with intravenous ocrelizumab in 6-month cycles. The first ocrelizumab dose was a 300 mg infusion followed by a second 300 mg infusion 2 weeks later; subsequent doses were delivered as a single 600 mg infusion. Adverse events were reported immediately. RESULTS: Of 580 requests received from 104 centres, 525 patients met the eligibility criteria. Thirty-five patients did not participate due to withdrawal by the treating physician, and one due to death prior to treatment. A total of 489 patients received at least one 600 mg dose of ocrelizumab (administered as two 300 mg infusions) and 51 received a second dose. Due to termination of the CUP upon marketing authorisation, the maximum follow-up period was 12 months. Median patient age was 52 years (range: 24-73), and 49% were female. Previous immunomodulatory or immunosuppressive therapies had been received by 41% of patients, with the most commonly used being glucocorticoids, mitoxantrone, interferon-ß and glatiramer acetate. Patients with a previous malignancy, serious disease or infection (42 patients, 9%) had recovered from this prior to the CUP. Nine serious adverse events and 70 non-serious adverse events were reported in 40 patients. Adverse event categories were generally consistent with the known safety profile of ocrelizumab; one patient had carry-over progressive multifocal leukoencephalopathy (PML) due to previous natalizumab treatment. CONCLUSION: This CUP provides first real-world observations of ocrelizumab for the treatment of PPMS in a large patient cohort in Germany, supporting that ocrelizumab is generally well-tolerated in clinical practice. Physicians should be vigilant for early symptoms of PML, as to date, 9 PML cases that were all confounded have been reported in patients treated with ocrelizumab worldwide, with 8 carry-over cases from a prior DMT.

Immunomodulatory and anti-oxidative effect of the direct TRPV1 receptor agonist capsaicin on Schwann cells.

BACKGROUND: Only few studies describe the impact of nutritive factors on chronic inflammatory demyelinating polyneuropathy (CIDP), an inflammatory disease of the peripheral nervous system. The active component of chili pepper, capsaicin, is the direct agonist of the transient receptor potential channel vanilloid subfamily member 1. Its anti-inflammatory effect in the animal model experimental autoimmune neuritis (EAN) has been previously demonstrated. METHODS: In the present study, we describe the anti-inflammatory and anti-oxidative influence of capsaicin on Schwann cells (SCs) in an in vitro setting. Hereby, we analyze the effect of capsaicin on Schwann cells' gene expression pattern, major histocompatibility complex class II (MHC-II) presentation, and H2O2-induced oxidative stress. Furthermore, the effect of capsaicin on myelination was examined in a SC-dorsal root ganglia (DRG) coculture by myelin basic protein staining. Finally, in order to investigate the isolated effect of capsaicin on SCs in EAN pathology, we transplant naïve and capsaicin pre-treated SCs intrathecally in EAN immunized rats and analyzed clinical presentation, electrophysiological parameters, and cytokine expression in the sciatic nerve. RESULTS: In SC monoculture, incubation with capsaicin significantly reduces interferon gamma-induced MHC-II production as well as toll-like receptor 4 and intercellular adhesion molecule 1 mRNA expression. Calcitonin gene-related peptide mRNA production is significantly upregulated after capsaicin treatment. Capsaicin reduces H2O2-induced oxidative stress in SC in a preventive, but not therapeutic setting. In a SC-DRG coculture, capsaicin does not affect myelination rate. After intrathecal transplantation of naïve and capsaicin pre-treated SCs in EAN-immunized rats, naïve, but not capsaicin pre-treated intrathecal SCs, ameliorated EAN pathology in rats. CONCLUSIONS: In conclusion, we were able to demonstrate a direct immunomodulatory and anti-oxidative effect of capsaicin in a SC culture by reduced antigen presentation and expression of an anti-inflammatory profile. Furthermore, capsaicin increases the resistance of SCs against oxidative stress. A primary effect of capsaicin on myelination was not proven. These results are in concordance with previous data showing an anti-inflammatory effect of capsaicin, which might be highly relevant for CIDP patients.

Novel variants in a patient with late-onset hyperprolinemia type II: diagnostic key for status epilepticus and lactic acidosis.

BACKGROUND: Hyperprolinemia type 2 (HPII) is a rare autosomal recessive disorder of the proline metabolism, that affects the ALDH4A1 gene. So far only four different pathogenic mutations are known. The manifestation is mostly in neonatal age, in early infancy or early childhood. CASE PRESENTATION: The 64-years female patient had a long history of abdominal pain, and episode of an acute neuritis. Ten years later she was admitted into the neurological intensive-care-unit with acute abdominal pain, multiple generalized epileptic seizures, a vertical gaze palsy accompanied by extensive lactic acidosis in serum 26.0 mmol/l (reference: 0.55-2.2 mmol/l) and CSF 12.01 mmol/l (reference: 1.12-2.47 mmol/l). Due to repeated epileptic seizures and secondary complications a long-term sedation with a ventilation therapy over 20 days was administered. A diagnostic work-up revealed up to 400-times increased prolin-level in urine CSF and blood. Furthermore, a low vitamin-B6 serum value was found, consistent with a HPII causing secondary pyridoxine deficiency and seizures. The ALDH4A1 gene sequencing confirmed two previously unknown compound heterozygous variants (ALDH4A1 gene (NM_003748.3) Intron 1: c.62 + 1G > A - heterozygous and ALDH4A1 gene (NM_003748.3) Exon 5 c.349G > C, p.(Asp117His) - heterozygous). Under high-dose vitamin-B6 therapy no further seizures occurred. CONCLUSION: We describe two novel ALDH4A1-variants in an adult patient with hyperprolinemia type II causing secondary pyridoxine deficiency and seizures. Severe and potentially life-threatening course of this treatable disease emphasizes the importance of diagnostic vigilance and thorough laboratory work-up including gene analysis even in cases with atypical late manifestation.

Brainstem Encephalitis With Low-Titer Acetylcholine Receptor Antibodies Mimicking Myasthenia Gravis.

Objective: To report a rare case of brainstem encephalitis with low-titer acetylcholine receptor antibodies mimicking myasthenia gravis. Methods: The patient was investigated with repeated brain MRI, CSF examination, repetitive nerve stimulation, thoracic CT, and serologic screening. Our patient passed away and finally autopsy revealed a definitive diagnosis. Written informed consent was obtained from the relatives of the patient for access to clinical files for research purposes and publication. Results: We present a young woman with a subacute bulbar syndrome, who was initially diagnosed with myasthenia gravis based on clinical finding and elevated acetylcholine receptor antibodies. Episodes of numbness in the pharynx and tongue and moderate saccadic horizontal and vertical pursuits were atypical. Despite initial stabilization with intravenous immunoglobulins she developed acute asphyxia after regurgitation of food and had to be resuscitated with ultimately lethal outcome. Autopsy revealed an autoimmune T-cell mediated brainstem encephalitis. Serological screening revealed positive GAD and Ma2 autoantibodies, indicating its probable paraneoplastic nature. Conclusions: Brainstem encephalitis is an important differential diagnosis even in seropositive bulbar myasthenia gravis, as several autoimmune processes often co-occur. Sudden unexpected death must be taken into account in brainstem encephalitis, requiring prolonged monitoring of the patients.

A protein quality control pathway regulated by linear ubiquitination.

Neurodegenerative diseases are characterized by the accumulation of misfolded proteins in the brain. Insights into protein quality control mechanisms to prevent neuronal dysfunction and cell death are crucial in developing causal therapies. Here, we report that various disease-associated protein aggregates are modified by the linear ubiquitin chain assembly complex (LUBAC). HOIP, the catalytic component of LUBAC, is recruited to misfolded Huntingtin in a p97/VCP-dependent manner, resulting in the assembly of linear polyubiquitin. As a consequence, the interactive surface of misfolded Huntingtin species is shielded from unwanted interactions, for example with the low complexity sequence domain-containing transcription factor Sp1, and proteasomal degradation of misfolded Huntingtin is facilitated. Notably, all three core LUBAC components are transcriptionally regulated by Sp1, linking defective LUBAC expression to Huntington's disease. In support of a protective activity of linear ubiquitination, silencing of OTULIN, a deubiquitinase with unique specificity for linear polyubiquitin, decreases proteotoxicity, whereas silencing of HOIP has the opposite effect. These findings identify linear ubiquitination as a protein quality control mechanism and hence a novel target for disease-modifying strategies in proteinopathies.

Author Correction: Laquinimod treatment in the R6/2 mouse model.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.

Peripheral CD19+ B-cell counts and infusion intervals as a surrogate for long-term B-cell depleting therapy in multiple sclerosis and neuromyelitis optica/neuromyelitis optica spectrum disorders.

BACKGROUND: With ocrelizumab another drug is available for the treatment of multiple sclerosis (MS). Little is known on the long-term use of ocrelizumab on immune cell subsets, and no surrogate markers are available. Rituximab (RTX) has been in off-label use for the treatment of MS, neuromyelitis optica (NMO) and neuromyelitis optica spectrum disorder (NMOSD) for > 10 years. OBJECTIVE: We evaluated the long-term depletion and repopulation rate of peripheral CD19+ B-cells as a potential surrogate for the clinical outcome, and whether it may serve for dosage and time-to-infusion decision making. METHODS: We evaluated the CD19+ and CD4+/8+ T-cell counts in n = 153 patients treated with RTX (132 MS, 21 NMO/NMOSD). The dosages ranged from 250 to 2000 mg RTX. Depletion/repopulation rates of CD19+ B-cells as well as long-term total lymphocyte cell counts, were assessed and corroborated with EDSS, ARR (annualized relapse rate), MRI, and time to reinfusion. RESULTS: CD19+ B-cells' repopulation rate significantly varied depending on the dosage applied leading to individualized application intervals (mean 9.73 ± 0.528 months). Low/absent CD19+ B-cell counts were associated with reduced ARR, EDSS, and GD+-MRI-lesions. Long-term B-cell-depleting therapy led to a transiently skewed CD4+/8+ T-cell ratio due to reduced CD4+ T-cells and absolute lymphocyte counts, which recovered after the second cycle. CONCLUSION: Our data suggest that CD19+ B-cell repopulation latency may serve as surrogate marker for individualized treatment strategies in MS and NMO/NMOSD, which proved clinically equally effective in our cohort as evaluated by previous studies.

Tryptophan immunoadsorption during pregnancy and breastfeeding in patients with acute relapse of multiple sclerosis and neuromyelitis optica.

BACKGROUND: Up to every fourth woman with multiple sclerosis (MS) or neuromyelitis optica spectrum disorder (NMOSD) suffers a clinically relevant relapse during pregnancy. High doses of steroids bear some serious risks, especially within the first trimester of pregnancy. Immunoadsorption (IA) is an effective and more selective treatment option in disabling MS relapse than plasma exchange. Data on the use of IA during pregnancy and breastfeeding are scarce. METHODS: In this retrospective multicenter study, we analyzed the safety and efficacy of IA treatment in acute relapses during pregnancy or breastfeeding. The primary outcome parameter - change of acute relapse-related disability after IA - was assessed using Expanded Disability Status Scale (EDSS) and visual acuity (VA) measurements for patients with optic neuritis (ON). RESULTS: A total of 24 patients were analyzed, 23 with relapsing-remitting MS, and 1 with NMOSD. Twenty patients were treated with IA during pregnancy. Four patients received IA postnatally during the breastfeeding period. Treatment was started at a mean 22.5 [standard deviation (SD) 13.9] days after onset of relapse. Patients were treated with a series of 5.8 (mean, SD 0.7) IA treatments within 7-10 days. Sixteen patients received IA because of steroid-refractory relapse, eight were treated without preceding steroid pulse therapy. EDSS improved clinically relevant from 3.5 [median, interquartile range (IQR) 2] before IA to 2.5 (median, IQR 1.1) after IA, p < 0.001. In patients with ON, VA improved in four out of five patients. Altogether, in 83% of patients, a rapid and marked improvement of relapse-related symptoms was observed after IA with either a decrease of ⩾1 EDSS grade or improvement in VA ⩾20%. No clinically relevant side effect was reported in 138 IA treatments. CONCLUSIONS: Tryptophan-IA was found to be effective and well tolerated in MS/NMOSD relapses, both as an escalation option after insufficient response to steroid pulse therapy and as first-line relapse treatment during pregnancy and breastfeeding.

Activation of NPY-Y2 receptors ameliorates disease pathology in the R6/2 mouse and PC12 cell models of Huntington's disease.

Huntington's disease (HD) is a monogenic inherited polyglutamine-mediated neurodegenerative disorder for which effective therapies are currently unavailable. Neuropeptide Y (NPY) has been implicated as a potential therapeutic target in several neurodegenerative diseases, including HD. However, its mechanisms of action in the context of HD pathology remain unknown. Here, we investigated the beneficial effects of Y2 receptor (Y2R) activation with NPY or Y2R selective agonist NPY13-36 in the R6/2 mouse and PC12 cell models of HD. Also, we explored the effects of selective pharmacological blockage of Y2R using selective non-peptide small molecule Y2R antagonist SF31 in vivo and in vitro. Our results showed that activation of Y2R with intranasal NPY or NPY13-36 led to an improved motor function in R6/2 mice as revealed by rotarod performance, vertical pole test, and hindlimb clasping behaviour. Also, intranasal NPY or NPY13-36 led to a decrease in aggregated mHtt and mediated increase in dopamine and cAMP-regulated phosphoprotein, 32kDa (DARPP-32), brain-derived neurotrophic factor (BDNF), and activated extracellular signal-regulated protein kinases (pERK1/2) levels in R6/2 mice. Intranasal NPY or NPY13-36 had no effect on body weight but showed positive effects on survival in R6/2 mice. Furthermore, intranasal NPY or NPY13-36 attenuated induction of proinflammatory cytokine and inflammatory mediators in R6/2 mice. In contrast, antagonizing by using SF31 exacerbates phenotypic severity in R6/2 mice and treatment effects with either intranasal NPY or NPY13-36 were significantly blocked.In vitro, using inducible PC12/HttQ103-EGFP cells, treatment with NPY or NPY13-36 protected against mHtt-mediated neuromorphological defects (neurite length and soma area) and neurotoxicity but had no effect on mHtt inclusion body formation. Conversely, co-treatment with SF31 significantly inhibited these effects. Together, our findings extend previous evidence of the beneficial effects of NPY in R6/2 mice, and more importantly, suggest that targeted activation of Y2R receptor might be a promising disease-modifying target for HD and other neurodegenerative diseases.