The ratio of circulating CD56dim NK cells to follicular T helper cells as a promising predictor for disease activity of relapsing-remitting multiple sclerosis.

Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system primarily mediated by CD4+ T helper cells. This study investigated the dynamic changes of natural killer (NK) cells and follicular T helper (Tfh) cells and their associations in relapsing-remitting MS patients. The findings revealed inverse relationships between NK cells and CD4+ T cells or Tfh cells. Specifically, CD56dim NK cells, not CD56bright NK cells, were negatively correlated with CD4+ T cells and Tfh cells. However, no significant correlations were found between NK cells and sNfL levels or EDSS scores. The ratio of CD56dim NK cells to circulating Tfh (cTfh) cells demonstrated superior discriminatory ability in distinguishing relapsing MS patients from healthy controls (HCs) and remitting patients, as determined by receiver operating characteristic (ROC) analysis. Following treatment with immunosuppressants or disease-modifying therapies (DMTs), a significant increase in the CD56dim NK/cTfh ratio was observed. These findings suggest that the CD56dim NK/cTfh ratio holds promise as a prognostic indicator for clinical relapse and treatment response in MS.

Late-Onset Anti-GABAB Receptor Encephalitis: Clinical Characteristics and Outcomes Differing From Early-Onset Patients.

BACKGROUND AND OBJECTIVES: Existing evidence indicates anti-GABAB receptor encephalitis (GABABR-E) seems to occur more commonly later in life, yet the age-associated differences in clinical features and outcomes are not well determined. This study aims to explore the demographic, clinical characteristics, and prognostic differences between late-onset and early-onset GABABR-E and identify predictors of favorable long-term outcomes. METHODS: This is an observational retrospective study conducted in 19 centers from China. Data from 62 patients with GABABR-E were compared between late-onset (aged 50 years or older) and early-onset (younger than 50 years) groups and between groups with favorable outcomes (modified Rankin scale (mRS) ≤ 2) and poor outcomes (mRS >2). Logistic regression analyses were applied to identify factors affecting long-term outcomes. RESULTS: Forty-one (66.1%) patients experienced late-onset GABABR-E. A greater proportion of males, a higher mRS score at onset, higher frequencies of ICU admission and tumors, and a higher risk of death were demonstrated in the late-onset group than in the early-onset group. Compared with poor outcomes, patients with favorable outcomes had a younger onset age, a lower mRS score at onset, lower frequencies of ICU admission and tumors, and a greater proportion with immunotherapy maintenance for at least 6 months. On multivariate regression analysis, age at onset (OR, 0.849, 95% CI 0.739-0.974, p = 0.020) and the presence of underlying tumors (OR, 0.095, 95% CI 0.015-0.613, p = 0.013) were associated with poorer long-term outcomes, whereas immunotherapy maintenance for at least 6 months was associated with favorable outcomes (OR, 10.958, 95% CI 1.469-81.742, p = 0.020). DISCUSSION: These results demonstrate the importance of risk stratification of GABABR-E according to age at onset. More attention should be paid to older patients especially with underlying tumors, and immunotherapy maintenance for at least 6 months is recommended to achieve a favorable outcome.

Efficacy and safety of repeated low-dose rituximab therapy in relapsing-remitting multiple sclerosis: A retrospective case series study.

BACKGROUND: Rituximab (RTX) is an extensively used off-label drug for multiple sclerosis (MS), whereas the induction and maintenance regimens vary widely among studies. Few data are available on efficacy and safety of repeated low-dose RTX therapy in MS patients. OBJECTIVE: This study aimed to evaluate the efficacy and safety of repeated low-dose RTX therapy for relapsing-remitting MS (RRMS), the most common form of MS affecting approximately 85% of patients. METHODS: Nine RRMS patients were enrolled and the medical records were retrospectively reviewed. RTX at 100 mg per week for three consecutive weeks was used as induction therapy. Maintenance therapy was reinfusions of RTX at 100 mg every 6 months during the first year, followed by 100 mg every 6 to 12 months. Main outcome measures included annualized relapse rate (ARR), expanded disability status scale (EDSS) score, and T2 lesion burden on MRI for evaluating the efficacy of low-dose RTX regimen. Meanwhile, adverse events (AEs) were recorded to assess the safety of repeated RTX infusions. RESULTS: All patients were females with an average onset age of 25.4 ± 6.7 years. The median disease duration before the first RTX infusion was 56 (range, 3-108) months and the median follow-up period was 30 (range, 15-40) months. No relapses were recorded in all patients after RTX therapy. Repeated low-dose RTX therapy resulted in a dramatic reduction of median ARR (pre-RTX vs post-RTX, 1.1 vs 0, p = 0.012), median EDSS score (2.0 vs 0, p = 0.007), and the number of T2 lesions on MRI (35.6 ± 18.0 vs 29.4 ± 18.1, p = 0.001). A total of 35 episodes of AEs occurred during repeated low-dose RTX therapy, and all of them were mild and transient. CONCLUSION: Repeated low-dose RTX therapy is cost-effective for RRMS patients and shows a good safety profile. It may be a promising option for those having no access or poor response to first-line disease-modified drugs (DMDs), particularly in low- or middle-income countries.

Antioxidant activity of mesenchymal stem cell-derived extracellular vesicles restores hippocampal neurons following seizure damage.

Oxidative stress is a critical event in neuronal damage following seizures. Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) have been shown to be promising nanotherapeutic agents in neurological disorders. However, the mechanism underlying MSC-EVs therapeutic efficacy for oxidative stress-induced neuronal damage remains poorly understood. Methods: We investigated the antioxidant and restoration activities of MSC-EVs on hippocampal neurons in response to H2O2 stimulation in vitro and seizures in vivo. We also explored the potential underlying mechanism by injecting adeno-associated virus (AAV)-nuclear factor erythroid-derived 2, like 2 (Nrf2), a key antioxidant mediator, in animal models. Results: MSC-EVs were enriched in antioxidant miRNAs and exhibited remarkable antioxidant activity evident by increased ferric ion-reducing antioxidant ability, catalase, superoxide dismutase, and glutathione peroxidase activities and decreased reactive oxygen species (ROS) generation, DNA/lipid/protein oxidation, and stress-associated molecular patterns in cultured cells and mouse models. Notably, EV administration exerted restorative effects on the hippocampal neuronal structure and associated functional impairments, including dendritic spine alterations, electrophysiological disturbances, calcium transients, mitochondrial changes, and cognitive decline after oxidative stress in vitro or in vivo. Mechanistically, we found that the Nrf2 signaling pathway was involved in the restorative effect of EV therapy against oxidative neuronal damage, while AAV-Nrf2 injection attenuated the antioxidant activity of MSC-EVs on the seizure-induced hippocampal injury. Conclusions: We have shown that MSC-EVs facilitate the reconstruction of hippocampal neurons associated with the Nrf2 defense system in response to oxidative insults. Our study highlights the clinical value of EV-therapy in neurological disorders such as seizures.

Overlapping syndrome of MOG-IgG-associated disease and autoimmune GFAP astrocytopathy.

Antibodies against myelin oligodendrocyte glycoprotein (MOG-IgG) have been considered to be closely relevant to an inflammatory demyelinating disease of the central nervous system (CNS). Glial fibrillary acidic protein (GFAP) immunoglobulin G (IgG) has been identified as a biomarker for a novel autoimmune astrocytopathy. However, coexistence of MOG-IgG and GFAP-IgG is extremely unusual and only one patient has been described with simultaneous presence of MOG-IgG in serum and GFAP-IgG in cerebrospinal fluid (CSF). Herein, we reported the first case of overlapping syndrome of MOG-IgG-associated disease (MOG-AD) and autoimmune GFAP astrocytopathy in whom MOG-IgG and GFAP-IgG were detected both in serum and CSF. A 20-year-old male patient was referred to our department with the presentation of decreased vision, diplopia and weakness of right limb with unknown reasons. Magnetic resonance imaging (MRI) revealed multiple intracranial lesions presenting hypointensity on T1-weighted images, hyperintensity on T2-weighted and FLAIR images and patchy contrast enhancement. MOG-IgG and GFAP-IgG were detected both in serum and CSF, and the titers of both antibodies fluctuated with the severity of disease. Treatment strategy employing intravenous methylprednisolone pulse therapy followed by oral prednisone with slow tapering resulted in an improvement of his symptoms and a sustained remission. Coexistence of MOG-IgG and GFAP-IgG with distinct underlying pathogeneses necessitates the recommendations to screen all recognized pathogenic antibodies against CNS antigens when an autoimmune disease is suspected, since it shows great significance for definite diagnosis of disease and treatment strategy options.

Single-Cell Analysis for Glycogen Localization and Metabolism in Cultured Astrocytes.

Cerebral glycogen is principally localized in astrocytes rather than in neurons. Glycogen metabolism has been implicated in higher brain functions, including learning and memory, yet the distribution patterns of glycogen in different types of astrocytes have not been fully described. Here, we applied a method based on the incorporation of 2-NBDG, a D-glucose fluorescent derivative that can trace glycogen, to investigate glycogen's distribution in the brain. We identified two types of astrocytes, namely, 2-NBDGI (glycogen-deficient) and 2-NBDGII (glycogen-rich) cells. Whole-cell patch-clamp and fluorescence-activated cell sorting (FACS) were used to separate 2-NBDGII astrocytes from 2-NBDGI astrocytes. The expression levels of glycogen metabolic enzymes were analyzed in 2-NBDGI and 2-NBDGII astrocytes. We found unique glycogen metabolic patterns between 2-NBDGI and 2-NBDGII astrocytes. We also observed that 2-NBDGII astrocytes were mainly identified as fibrous astrocytes but not protoplasmic astrocytes. Our data reveal cell type-dependent glycogen distribution and metabolism patterns, suggesting diverse functions of these different astrocytes.

Chronic inflammatory pain decreases the glutamate vesicles in presynaptic terminals of the nucleus accumbens.

Reward system has been proved to be important to nociceptive behavior, and the nucleus accumbens (NAc) is a key node in reward circuitry. It has been further revealed that dopamine system modulates the NAc to influence the pain sensation, whereas the role of glutamatergic projection in the NAc in the modulation of chronic pain is still elusive. In this study, we used a complete Freund's adjuvant-induced chronic inflammatory pain model to explore the changes of the glutamatergic terminals in the NAc, and we found that following the chronic inflammation, the protein level of vesicular glutamate transporter1 (VGLUT1) was significantly decreased in the NAc. Immunofluorescence staining further showed a reduced expression of VGLUT1-positive terminals in the dopamine receptor 2 (D2R) spiny projection neurons of NAc after chronic inflammatory pain. Furthermore, using a whole-cell recording in double transgenic mice, in which dopamine receptor 1- and D2R-expressing neurons can be visualized, we found that the frequency of spontaneous excitatory postsynaptic currents was significantly decreased and paired-pulse ratio of evoked excitatory postsynaptic currents was increased in D2R neurons, but not in dopamine receptor 1 neurons in NAc of complete Freund's adjuvant group. Moreover, the abnormal expression of soluble N-ethylmaleimide-sensitive factor attachment protein receptor complex contributed to the reduced formation of glutamate vesicles. Hence, our results demonstrated that decreased glutamate release in the indirect pathway of the NAc may be a critical mechanism for chronic pain and provided a novel evidence for the presynaptic mechanisms in chronic pain regulation.

From autophagy to mitophagy: the roles of P62 in neurodegenerative diseases.

P62, also called sequestosome1 (SQSTM1), is the selective cargo receptor for autophagy to degenerate misfolded proteins. It has also been found to assist and connect parkin in pink1/parkin mitophagy pathway. Previous studies showed that p62 was in association with neurodegenerative diseases, and one of the diseases pathogenesis is P62 induced autophagy and mitophagy dysfunction. Autophagy is an important process to eliminate misfolded proteins. Intracellular aggregation including α-synuclein, Huntingtin, tau protein and ß-amyloid (Aß) protein are the misfolded proteins found in PD, HD and AD, respectively. P62 induced autophagy failure significantly accelerates misfolded protein aggregation. Mitophagy is the special autophagy, functions as the selective scavenger towards the impaired mitochondria. Mitochondrial dysfunction was confirmed greatly contribute to the occurrence of neurodegenerative diseases. Through assistance and connection with parkin, P62 is vital for regulating mitophagy, thus, aberrant P62 could influence the balance of mitophagy, and further disturb mitochondrial quality control. Therefore, accumulation of misfolded proteins leads to the aberrant P62 expression, aberrant P62 influence the balance of mitophagy, forming a vicious circle afterwards. In this review, we summarize the observations on the function of P62 relevant to autophagy and mitophagy in neurodegenerative diseases, hoping to give some clear and objective opinions to further study.

Striatal Distribution and Cytoarchitecture of Dopamine Receptor Subtype 1 and 2: Evidence from Double-Labeling Transgenic Mice.

As the main input nucleus of the basal ganglion, the striatum executes different functions, including motivation, reward and attention. The functions of the striatum highly rely on its subregions that receive projections from various cortical areas and the distribution of striatonigral neurons that express D1 dopamine (DA) receptors (or D1 medium-sized spiny neurons, D1 MSNs) and striatopallidal neurons that express D2 DA receptors (or D2 MSNs). Using bacterial artificial chromosome (BAC) transgenic mice, several studies have recently been performed on the spatial distribution of D1 and D2 MSNs. However, these studies mainly focused on enumeration of either D1-enhanced fluorescent protein (eGFP) or D2-eGFP in mice. In the present work, we used Drd1a-tdTamato and Drd2-eGFP double BAC transgenic mice to evaluate the spatial pattern of D1 MSNs (red fluorescence) and D2 MSNs (green fluorescence) along the rostro-caudal axis of the dorsal striatum. The dorsal striatum was divided into three subregions: rostral caudoputamen (CPr), intermediate CP (CPi), and caudal CP (CPc) across the rostral-caudal extent of the striatum. The results demonstrate that D1 and D2 MSNs were intermingled with each other in most of these regions. The cell density of D1 MSNs was slightly higher than D2 MSNs through CPr, CPi, and CPc, though it did not reach significance. However, in CPi, the ratio of D1/D2 in the ventromedial CPi group was significantly higher than those in dorsolateral, dorsomedial, and ventrolateral CPi. There was similar proportion of cells that co-expressed D1 and D2 receptors. Moreover, we demonstrated a pathway-specific activation pattern of D1 MSNs and D2 MSNs in a manic like mouse model induced by D-Amphetamine by utilizing this double transgenic mice and c-fos immunoreactivity. Our results may provide a morphological basis for the function or pathophysiology of striatonigral and striatopallidal neurons with diverse cortical inputs to the dorsal striatum.