Search Results (59)

Background and Clinical Significance: NMDAR autoimmune encephalitis is a rare but potentially life-threatening autoimmune disorder that can be hard to recognize initially because it has nonspecific symptoms. In the early phase of the disease, clinical presentation is often dominated by psychiatric symptoms, which can be misleading. A diagnosis is established by demonstrating specific anti-NMDA receptor antibodies, with cerebrospinal fluid analysis considered the most reliable diagnostic method. Timely initiation of immunomodulatory therapy, including corticosteroids, intravenous immunoglobulins, and therapeutic plasmapheresis, significantly improves disease outcomes, while second-line therapies are used in refractory cases. Case Presentation: A 21-year-old female patient (M.B.) was admitted to the Psychiatry Clinic at the University Clinical Center of Vojvodina due to the sudden onset of behavioral changes, including social withdrawal, absence of verbal communication, and unusual orofacial grimacing. During hospitalization, the patient was intermittently in a state of severe psychomotor agitation and poorly communicative, with pronounced orofacial dyskinesias and involuntary tongue movements. Anti-NMDA receptor autoantibodies were detected in both serum and cerebrospinal fluid, and the patient was subsequently transferred to the Intensive Care Unit of the Neurology Clinic. Due to the lack of an adequate clinical response to pulse corticosteroid therapy, six cycles of therapeutic plasmapheresis were performed. Following this treatment, significant clinical improvement was observed. Conclusions: Timely recognition of this condition and a multidisciplinary approach allow for early initiation of immunomodulatory therapy and significantly improve treatment outcomes. Full article

Background: Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is an autoimmune disorder frequently associated with ovarian teratomas in young women. Although infectious triggers have been proposed to contribute to immune activation, direct evidence linking viral presence within tumor tissue to disease pathogenesis remains limited. Case Presentation: An 18-year-old woman presented with acute neuropsychiatric symptoms, fever, gastrointestinal prodrome, and rapidly progressive behavioral disturbance progressing to encephalopathy. Cerebrospinal fluid and blood test results, together with clinical features, supported the diagnosis of anti-NMDAR encephalitis. Imaging identified an ovarian mass, and surgical resection was performed. Histopathology confirmed a mature teratoma containing neuroglial elements. Molecular analysis detected parvovirus B19 DNA within the resected teratomatous tissue. No systemic viremia or active central nervous system viral infection was identified. The patient received immunotherapy combined with tumor removal, with subsequent clinical improvement. Discussion: Ovarian teratomas remain a critical etiologic factor in anti-NMDAR encephalitis and mandate prompt surgical management. Detection of B19 viral DNA within teratomatous neuroglial tissue raises the hypothesis that viral persistence could enhance local immune activation and autoantibody generation. However, in this case polymerase chain reaction positivity does not indicate active infection, and the biological significance of this finding remains uncertain. Conclusions: This case documents rare detection of B19V DNA within an ovarian teratomatous tissue in anti-NMDAR encephalitis. The observation is hypothesis-generating rather than causal; established management priorities remain immunotherapy and tumor resection, and viral nucleic acid detection should be interpreted within the broader clinical context. Full article

Objectives: Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is an autoimmune encephalitis that can lead to severe neurological impairments, particularly in pediatric patients. Effective biomarkers for diagnosis and prognosis are crucial for improved treatment outcomes. To evaluate the potential of soluble Triggering Receptor Expressed on Myeloid cells 2 (sTREM2) in cerebrospinal fluid (CSF) and serum as diagnostic and prognostic biomarkers in pediatric patients with anti-NMDAR encephalitis. Methods: The study included 21 children diagnosed with anti-NMDAR encephalitis and 27 children with non-inflammatory neurological disorders (OND) as controls. CSF and serum samples were collected from each patient. sTREM2 levels were measured using enzyme-linked immunosorbent assay (ELISA). Statistical analyses, including Mann–Whitney U test and ROC curve analysis, were performed to assess the diagnostic and prognostic value of sTREM2. Results: sTREM2 levels in CSF and serum were significantly higher in children with anti-NMDAR encephalitis compared to the OND group (p < 0.001). CSF sTREM2 levels showed a positive correlation with modified Rankin Scale (mRS) scores and a negative correlation with Glasgow Coma Scale (GCS) scores, suggesting an association with disease severity. ROC curve analysis demonstrated that CSF sTREM2 had a high diagnostic accuracy (AUC = 0.887, p < 0.001), while serum sTREM2 showed a slightly lower diagnostic accuracy (AUC = 0.848, p < 0.001). Patients with better prognoses had significantly lower CSF sTREM2 levels than those with poorer outcomes (p = 0.029). Conclusions: Elevated CSF sTREM2 levels were associated with increased neuroinflammation and poorer clinical outcomes in children with anti-NMDAR encephalitis. These findings suggest that CSF sTREM2 may serve as a valuable biomarker for the diagnosis and prognosis of pediatric anti-NMDAR encephalitis. Full article

Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is an immune-mediated neurological disorder driven by dysregulated neuroimmune interactions, yet the molecular architecture linking tumor-associated immune activation, peripheral immunity, and neuronal dysfunction remains insufficiently understood. In this study, we established an integrative computational framework that combines multi-tissue transcriptomic profiling, weighted gene co-expression network analysis, immune deconvolution, and machine learning-based feature prioritization to systematically characterize the regulatory landscape of the disease. Joint analysis of three independent GEO datasets spanning ovarian teratoma tissue and peripheral blood transcriptomes identified 2001 consistently dysregulated mRNAs, defining a shared tumor–immune–neural transcriptional axis. Across multiple feature selection algorithms, ACVR2B and MX1 were reproducibly prioritized as immune-associated candidate genes and were consistently downregulated in anti-NMDAR encephalitis samples, showing negative correlations with neutrophil infiltration. Reconstruction of an integrated mRNA-miRNA-lncRNA regulatory network further highlighted a putative core axis (ENSG00000262580–hsa-miR-22-3p–ACVR2B), proposed as a hypothesis-generating regulatory module linking non-coding RNA regulation to immune-neuronal signaling. Pathway and immune profiling analyses demonstrated convergence of canonical immune signaling pathways, including JAK-STAT and PI3K-Akt, with neuronal communication modules, accompanied by enhanced innate immune signatures. Although limited by reliance on public datasets and small sample size, these findings delineate a systems-level neuroimmune regulatory program in anti-NMDAR encephalitis and provide a scalable, network-based multi-omics framework for investigating immune-mediated neurological and autoimmune disorders and for guiding future experimental validation. Full article

Background: Anti-N-methyl-D-aspartate IgM and IgA antibodies (NMDAR1-abs) are associated with unfavorable stroke outcomes and may be risk factors thereof. However, to utilize NMDAR1-abs serostatus for risk assessment in acute stroke, it is crucial to understand the robustness of serostatus during this phase. Therefore, we investigated the robustness of NMDAR1-abs serostatus and titer levels up to seven days after stroke. Methods: In this exploratory analysis of the multicenter STRAWINSKI trial (identifier: NCT01264549), patients with severe ischemic stroke (NIHSS ≥ 9) in the middle cerebral artery territory were included. The first blood sample was taken within 36 h and then daily from day two to seven after stroke. NMDAR1-abs immunoglobulin (Ig)A and IgM were assessed in serum using cell-based assays. We initially measured NMDAR1-abs in the total cohort on day 1. Subsequently, in samples from seropositive and matched seronegative patients, we measured NMDAR1-abs on each following day. Titer dilutions started from 1:10 up to 1:1000. Seropositivity was defined as any titer > 0. Results: Out of 171 patients (mean age = 76 [SD = 11], median NIHSS = 15 [IQR = 12–18]), 16 (9%) individuals were seropositive. Seropositive patients remained seropositive and matched seronegative participants remained seronegative over sequential measurements. Although titer levels remained largely unchanged, some patients showed fluctuating titers. Conclusions: The status of NMDAR1-abs seropositivity is stable during acute stroke, with little to no variation in titer levels. Full article

Background: Agmatine (AG) is an endogenous neurotransmitter discovered in 1910. It acts on imidazoline I1 and I2 receptors, alpha-2 adrenoceptors, N-methyl-D-aspartate receptors (NMDAR), and serotonergic receptors and modulates nitric oxide synthase (NOS) subtypes. It has neuroprotective, anxiolytic, antidepressant, anticonvulsant, and anti-inflammatory properties and is involved in cognitive functions and withdrawal. The cardiovascular effects of AG began to be explored after the hypotensive effect of clonidine, an imidazoline agonist, was demonstrated. The current study aimed to systematize the effects of AG on the cardiovascular system obtained in previous preclinical studies. Methods: We searched three databases, PubMed, Cochrane, and Embase, using the keywords “agmatine” and “cardiac” or “vascular.” Results: Sixty studies were eligible and included in the analysis. Initially identified as Clonidine Displacing Substance (CDS), AG has demonstrated dual effects—an increase or decrease in blood pressure or in heart rate. Conclusions: The effects exerted by AG depend on the dose and route of administration, as well as on the receptors involved and the pathophysiological pathway used. Full article

Autoimmune encephalitis (AE) is an autoantibody-mediated central nervous system disorder with diverse neuropsychiatric and neurological manifestations, and should be considered in the differential diagnosis of acute and subacute neurological or psychiatric syndromes. In this retrospective study, we analyzed 65 patients: 54 with AE (47 antibody-positive, seven antibody-negative) and 11 antibody-positive without AE. The most frequently detected antibodies targeted N-methyl-D-aspartate receptor (NMDAR), leucine-rich glioma-inactivated protein 1 (LGI1), and contactin-associated protein-like 2 (CASPR2)—key synaptic and axonal membrane proteins involved in excitatory neurotransmission, neuronal signaling, and synaptic plasticity. Clinical presentations were heterogeneous, ranging from common neuropsychiatric, cognitive, and seizure manifestations to atypical brainstem or cerebellar features. Symptom distribution analysis further demonstrated distinct patterns among Ab-positive AE, Ab-negative AE, and Ab-positive non-AE groups, with specific symptom–antibody associations providing potential diagnostic clues. Diagnostic complexity was underscored by unusual age at onset, overlap with multiple sclerosis, cases preceded by herpes labialis, and dual-antibody detection. A subset of antibody-positive patients had alternative diagnoses, highlighting the need for careful clinical correlation and cautious interpretation of antibody results. These findings illustrate the diagnostic challenges and broad clinical spectrum of AE, emphasizing the importance of integrating serological, clinical, and imaging data to improve diagnostic accuracy and guide management. Full article

Parkinson’s disease (PD) is a progressive neurological disorder that affects movement, causing symptoms such as tremors, stiffness, slowness, and balance problems due to the degeneration of dopamine-producing neurons in the brain. Nowadays there is no cure for PD. Alpha synuclein (α-syn) aggregates, which are a hallmark of PD, are known to induce microglial activation, specifically the detrimental M1 microglial phenotype, which contributes to neuroinflammation and disease progression. Cannabinoid receptor 2 (CB₂R) activation has been shown to counteract neuroinflammation. CB₂R is able to interact with N-methyl-D-aspartate (NMDA) receptors (NMDAR), which has also attracted attention in PD research due to its role in excitotoxicity. Here we aimed to study the interaction between CB₂R and NMDAR in a PD context in rat tissue. We observed that α-syn fibrils alter CB₂R activation and CB₂R-NMDAR heteromerization in a heterologous expression system. Furthermore, activation of CB₂R counteracted NMDAR signaling. In microglia, α-syn fibrils decreased CB₂R-NMDAR heteromer expression while increasing CB₂R signaling. Importantly, CB₂R activation counteracted the α-syn fibrils-induced increase in M1-activated microglia, while it favored the polarization of microglia to the beneficial M2 phenotype. These results reinforce the idea of using cannabinoids for treating PD, as they provide not only the anti-inflammatory effects of cannabinoids but also counteract the detrimental increase in NMDAR signaling present in this disease. Full article

Temporal lobe epilepsy (TLE) remains pharmacoresistant in 30–40% of patients. Peroxisome proliferator-activated receptor alpha (PPARα) agonists like fenofibrate exhibit anti-inflammatory and neuroprotective properties, but their region-specific effects during epileptogenesis and on behavioral comorbidities are unknown. We investigated fenofibrate (100 mg/kg, 7 days) in the lithium-pilocarpine rat model during the latent phase. Fenofibrate (1) reduced anxiety-like behaviors and improved exploratory deficits; (2) decreased plasma short-chain fatty acids (butyric, pentanoic, hexanoic acids); (3) exerted region-specific modulation of glutamate receptors: restored N-methyl-D-aspartate receptor (NMDAR)/α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) subunit gene expression in temporal cortex but failed to reverse and further exacerbated the downregulation of AMPAR subunits in the dorsal hippocampus; (4) prevented the upregulation of cortical neuroinflammation markers (reduced Nlrp3, Il1rn); and (5) enhanced the A2 astrocyte marker Ptx3 in the hippocampus while reducing the M2 microglial marker Arg1 in the temporal cortex. No effects on astrogliosis (Gfap), microgliosis (Aif1), or trophic factors (Bdnf, Tgfb1) were observed. This first comprehensive study demonstrates that fenofibrate differentially modulates neuroinflammation and synaptic plasticity across brain regions during epileptogenesis, providing behavioral benefits but highlighting potential hippocampal drawbacks. Its PPARα-mediated actions support further investigation as a complementary strategy for TLE, pending optimization of dosing/timing to mitigate regional disparities. Full article

Glutamate is an excitatory neurotransmitter in the central nervous system (CNS) that mediates synaptic transmission. However, glutamate homeostasis among neural cells is broken in cerebral ischemia. Excessive glutamate triggers N-methyl-d-aspartate receptors (NMDARs) in postsynaptic neurons, leading to intracellular calcium (Ca²⁺) overload and excitoneurotoxicity. At this moment, L-lactate may affect NMDARs and play a protective role in cerebral ischemia. This work proposes that L-lactate regulates glutamate signaling among neural cells. But, dysregulation of L-lactate in glutamate signaling cascades contributes to glutamate excitotoxicity in cerebral ischemia. In detail, L-lactate regulates the glutamine(Gln)-glutamate cycle between astrocytes and presynaptic neurons, which triggers the astroglial L-lactate-sensitive receptor (LLR)-cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) pathway, coordinating astroglial glutamate uptake and neuronal glutamate transmission. L-lactate mediates glutamate signaling and synaptic transmission among neural cells. In addition, L-lactate promotes the function of mitochondrial calcium uniporter complex (MCUC), which quickly depletes intracellular Ca²⁺ in postsynaptic neurons. In addition, L-lactate can promote the conversion of microglia from the pro-inflammatory (M1) to anti-inflammatory (M2) phenotype. Therefore, regulation of L-lactate in glutamate signaling in the CNS might become a preventive target for cerebral ischemia. Full article

All human clinical trials evaluating neuroprotective therapeutics in cerebral ischemia have failed, casting a pall over the field which has not recovered. Numerous methodological issues in the performance of these trials were identified, with the result that current trials are now subject to higher degrees of rigor and transparency. Advances in re-canalization technologies now offer the hope that adjunctive neuroprotection can improve patient outcome. The evaluation of neuroprotection in preclinical animal models has also suffered from methodological issues, which has also been addressed, resulting in an improved performance of studies. This leaves the question of how to actually pick the most appropriate neuroprotective therapy for translation. Given the current limitations in resources, and the numerous strategies that have been proposed to take advantage of clinical and preclinical methodological improvements, we suggest that in vitro studies involving subjecting the most sensitive cells—neurons—to oxygen–glucose deprivation (OGD) can be used to resolve among the many possibilities. Specifically, a large body of evidence shows that successive increases in OGD durations (spanning the lethal/supra-lethal continuum) require increasingly ‘strong’ drugs and combinations to adequately protect neurons (criteria not met in clinical trials). Notably, as the OGD duration is lengthened, NMDA receptor (NMDAR) antagonists of increasing potency and dose are required to match this increasing severity. Under supra-lethal OGD conditions, cocktails composed of anti-excitotoxic antagonists with maximal potency and dose are required to achieve neuroprotection. We propose that this approach can serve as a strategy—a neuroprotective framework—to prioritize among the many possibilities that exist for neuroprotective therapeutics for translation. Specifically, utilize the OGD continuum to compare within-, between- and outside-classes of drugs, first alone and then in combinations, to identify the most efficacious drugs (‘head-to-head’ competitions to identify the ‘last man standing’). While the current state of knowledge strongly suggests that anti-excitotoxic approaches are required, this framework allows the integration of testing established and new therapeutics alike. This framework should include new technologies such as multi-electrode arrays (MEAs), which allow the evaluation of adverse effects of drugs alone, as well as if a drug truly provides functional neuroprotection, and not just survival. The neuroprotective framework provides a comprehensive strategy to eliminate ineffectual treatments, leaving only those modalities with the highest therapeutic index to be prioritized for translation. Full article

Chronic pain significantly impacts quality of life and is often accompanied by inflammation, a natural bodily response that can become harmful when excessive. The orofacial region is commonly affected, making effective treatment crucial. However, current drugs often cause undesirable side effects, highlighting the need for new pharmacological alternatives. 4-hydroxycoumarin (4-HC), a natural compound, has shown promising antinociceptive and anti-inflammatory effects, but studies confirming its specific properties are limited. In silico analyses suggest that 4-HC exhibits favorable pharmacokinetic characteristics, not interacting with P-glycoprotein and successfully crossing the blood–brain barrier. Molecular docking studies indicate that its effects may be mediated through NMDA_R or by inhibiting iNOS. Our study assessed the antinociceptive and anti-inflammatory effects of 4-HC in animal models at doses of 25, 50, and 75 mg/kg. 4-HC significantly reduced abdominal contortions induced by acetic acid and decreased nociceptive rubbing in orofacial pain models induced by formalin, glutamate, and capsaicin. Interactions with opioid receptors were not observed, suggesting that 4-HC’s antinociceptive effect does not involve this pathway. Additionally, 4-HC reduced paw edema induced by carrageenan and significantly decreased leukocyte migration and TNF-α levels. These findings highlight the therapeutic potential of 4-HC and warrant further investigation into its mechanisms. Full article

The autoantibodies against the NR1 subunit are well known in the pathomechanism of NMDAR encephalitis. The dysfunction of the NR2 subunit could be a critical factor in this neurological disorder due to its important role in the postsynaptic pathways that direct synaptic plasticity. We report a case of paraneoplastic anti-NMDAR encephalitis presented alongside very severe illness. Computed tomography (CT) of the brain, as well as FLAIR and T2-weighted MRI, was performed to rule out any other acute brain processes. A semi-quantitative method was applied to detect the presence of anti-NMDAR antibodies in the serum and CSF. A CT chest–abdomen–pelvis scan was performed that detected an ovarian teratoma. A histopathological examination was performed after a laparoscopic right-ovary cystectomy. Subsequent immunofluorescence immunohistochemical staining showed the expression of NMDA receptors of type NR2B. Treatment included first-line immunotherapy, second-line immunotherapy, tumor removal, and intrathecal injections with methotrexate and dexamethasone. The histological finding for our patient after tumor removal was ovarian teratoma. Hematoxylin–eosin (HE) staining revealed a characteristic spectrum of elements, including stratified squamous epithelium and fat tissue accompanied by neuroglial cells. Subsequent immunohistochemical staining showed an expression of NMDA receptors of type NR2B in different structures of the teratoma, including the neuroglial cells. The first-line immunotherapy following the tumor removal was insufficient in our patient. The paraneoplastic anti-NMDAR encephalitis with a coexpressed NR2B subunit on the neural cells of the ovarian teratoma may suggest a different inflammation process and could be the key factor in the pathomechanism and treatment of the refractory anti-NMDAR encephalitis. Full article

The MET oncogene, encoding the hepatocyte growth factor (HGF) receptor, plays a key role in tumorigenesis, invasion, and resistance to therapy, yet its full biological functions and activation mechanisms remain incompletely understood. A feature of MET is its extensive interaction network, encompassing the following: (i) receptor tyrosine kinases (RTKs); (ii) co-receptors (e.g., CDCP1, Neuropilin1); (iii) adhesion molecules (e.g., integrins, tetraspanins); (iv) proteases (e.g., ADAM10); and (v) other receptors (e.g., CD44, plexins, GPCRs, and NMDAR). These interactions dynamically modulate MET’s activation, signaling, intracellular trafficking, and degradation, enhancing its functional versatility and oncogenic potential. This review offers current knowledge on MET’s partnerships, focusing on their functional impact on signaling output, therapeutic resistance, and cellular behavior. Finally, we evaluate emerging combination therapies targeting MET and its interactors, highlighting their potential to overcome resistance and improve clinical outcomes. By exploring the complex interplay within the MET network of interacting cell surface proteins, this review provides insights into advancing anti-cancer strategies and understanding the broader implications of RTK crosstalk in oncology. Full article

Objective: To establish a mouse model of anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis and assess the potential therapeutic benefits of D-serine supplementation in mitigating synaptic plasticity impairments induced by anti-NMDAR antibodies. Methods: Anti-NMDAR antibodies were purified from cerebrospinal fluid (CSF) samples of patients diagnosed with anti-NMDAR encephalitis and verified using a cell-based assay. CSF from patients with non-inflammatory neurological diseases served as the control. These antibodies were then injected intraventricularly into C57BL/6 mice. Forty-eight hours following the injection, mice were administered either D-serine (500 mg/kg) or sterile saline intraperitoneally for three consecutive days. Subsequent analyses included Western blotting, immunofluorescence, electrophysiological studies, and a series of behavioral tests to assess pathological changes caused by anti-NMDAR antibodies. Results: Mice injected with anti-NMDAR antibodies exhibited a significant reduction in hippocampal long-term potentiation compared to controls, which was notably ameliorated by D-serine treatment. Additionally, these mice displayed decreased levels of hippocampal membrane NMDAR1 protein and postsynaptic NMDAR1 density. However, D-serine administration did not significantly alter these conditions. Notably, no significant behavioral differences were observed between mice injected with anti-NMDAR antibodies and controls in open fields, elevated plus maze, novel object recognition, or Morris water maze tests. Conclusions: Our findings indicate that exogenous D-serine can improve hippocampal plasticity impairments caused by anti-NMDAR antibodies but does not reverse the decreased expression of NMDAR. Furthermore, a single intraventricular injection of patients’ antibodies was insufficient to induce anti-NMDAR encephalitis-related behaviors in mice. Full article