Administration methods and dosage of poly(lactic acid)-glycol intervention to myelin oligodendrocyte glycoprotein-induced experimental autoimmune encephalitis mice.

BACKGROUND: Myelin oligodendrocyte glycoprotein-associated disorders (MOGAD) is an autoimmune central nervous system disease. Antigen-specific immune tolerance using nanoparticles such as Polylactic-co-glycolic acid (PLGA) have recently been used as a new therapeutic tolerization approach for CNS autoimmune diseases. We examined whether MOG1-125 conjugated with PLGA could induce MOG-specific immune tolerance in an experimental autoimmune encephalitis (EAE) mouse model. EAE was induced in sixty C57BL/6 J wild-type mice using MOG1-125 peptide with complete Freund's Adjuvant. The mice were divided into 12 groups (n = 5 each) to test the ability of MOG1-125 conjugated PLGA intervention to mitigate the severity or improve the outcomes from EAE with and without rapamycin compared to antigen alone or PLGA alone. EAE score and serum MOG-IgG titers were compared among the interventions.Kindly check and confirm the processed Affiliation “4” is appropriate.I confirmed the Aff 4.Affiliation: Corresponding author information have been changed to present affiliation. Kindly check and confirm.I checked and confirmed the Corresponding author's information. RESULTS: Mice with EAE that were injected intraperitoneally with MOG1-125 conjugated PLGA + rapamycin complex showed dose-dependent mitigation of EAE score. Intraperitoneal and intravenous administration resulted in similar clinical outcomes, whereas 80% of mice treated with subcutaneous injection had a recurrence of clinical score worsening after approximately 1 week. Although there was no significant difference in EAE scores between unconjugated-PLGA and MOG-conjugated PLGA, serum MOG-IgG tended to decrease in the MOG-conjugated PLGA group compared to controls. CONCLUSION: Intraperitoneal administration of PLGA resulted in dose-dependent and longer-lasting immune tolerance than subcutaneous administration. The induction of immune tolerance using PLGA may represent a future therapeutic option for patients with MOGAD.

Upregulated complement receptors correlate with Fc gamma receptor 3A-positive natural killer and natural killer-T cells in neuromyelitis optica spectrum disorder.

BACKGROUND AND OBJECTIVES: Inhibition of terminal complement in neuromyelitis optica spectrum disorder (NMOSD) using eculizumab helps prevent relapses, but the exact mechanism of action of the drug remains unclear. Similarly, genetic variants in the Fc Gamma receptor 3A (FCGR3A), also known as CD16, are correlated with outcomes in NMOSD, but the immune cells expressing those CD16 are unknown. We compared CD16 expression on immune cells modulated by complement activity in natural killer (NK) cells and natural killer-T (NKT) cells in NMOSD to disease and normal-healthy controls. METHODS: Peripheral blood cell (PBMC) samples from 45 patients with NMOSD with aquaporin 4 (AQP4)-IgG, 18 disease controls, and 19 normal controls were analyzed for CD16 expression and complement receptors in vitro. RESULTS: At baseline, the number of NKT cells was increased in NMOSD (p < 0.001), but the proportion that was CD16 positive was lower compared to normal and disease controls (p = 0.0012). NK cell count was normal, but the ratio that was CD16 positive was also significantly lower (p < 0.001). In both NK cells and NKT cells from NMOSD, C5 complement receptor expression was much higher than normal and disease controls (p < 0.001 for both). We also evaluated activation markers CD69 and CD83, which were also significantly higher in NK and NKT cells from NMOSD patients. FCGR3A p158 V/V genotype group in NMOSD patients showed decreased NK cell proportion with activation, and fewer CD16-expressing NKT cells than the F/F genotype group. DISCUSSION: Our results support an immunopathogenesis model in which complement pathway activation in NK/NKT cells upregulates CD16 expression that binds to antibody/antigen complexes. In the context of NMOSD, these complement-sensitive cells may be responsible for the escalating autoimmune activity.

Staging of astrocytopathy and complement activation in neuromyelitis optica spectrum disorders.

Aquaporin 4 (AQP4)-IgG-positive neuromyelitis optica spectrum disorder (AQP4-IgG+NMOSD) is an autoimmune astrocytopathic disease pathologically characterized by the massive destruction and regeneration of astrocytes with diverse types of tissue injury with or without complement deposition. However, it is unknown whether this diversity is derived from differences in pathological processes or temporal changes. Furthermore, unlike for the demyelinating lesions in multiple sclerosis, there has been no staging of astrocytopathy in AQP4-IgG+NMOSD based on astrocyte morphology. Therefore, we classified astrocytopathy of the disease by comparing the characteristic features, such as AQP4 loss, inflammatory cell infiltration, complement deposition and demyelination activity, with the clinical phase. We performed histopathological analyses in eight autopsied cases of AQP4-IgG+NMOSD. Cases comprised six females and two males, with a median age of 56.5 years (range, 46-71 years) and a median disease duration of 62.5 months (range, 0.6-252 months). Astrocytopathy in AQP4-IgG+NMOSD was classified into the following four stages defined by the astrocyte morphology and immunoreactivity for GFAP: (i) astrocyte lysis: extensive loss of astrocytes with fragmented and/or dust-like particles; (ii) progenitor recruitment: loss of astrocytes except small nucleated cells with GFAP-positive fibre-forming foot processes; (iii) protoplasmic gliosis: presence of star-shaped astrocytes with abundant GFAP-reactive cytoplasm; and (iv) fibrous gliosis: lesions composed of densely packed mature astrocytes. The astrocyte lysis and progenitor recruitment stages dominated in clinically acute cases (within 2 months after the last recurrence). Findings common to both stages were the loss of AQP4, a decreased number of oligodendrocytes, the selective loss of myelin-associated glycoprotein and active demyelination with phagocytic macrophages. The infiltration of polymorphonuclear cells and T cells (CD4-dominant) and the deposition of activated complement (C9neo), which reflects the membrane attack complex, a hallmark of acute NMOSD lesions, were selectively observed in the astrocyte lysis stage (98.4% in astrocyte lysis, 1.6% in progenitor recruitment, and 0% in protoplasmic gliosis and fibrous gliosis). Although most of the protoplasmic gliosis and fibrous gliosis lesions were accompanied by inactive demyelinated lesions with a low amount of inflammatory cell infiltration, the deposition of complement degradation product (C3d) was observed in all four stages, even in fibrous gliosis lesions, suggesting the past or chronic occurrence of complement activation, which is a useful finding to distinguish chronic lesions in NMOSD from those in multiple sclerosis. Our staging of astrocytopathy is expected to be useful for understanding the unique temporal pathology of AQP4-IgG+NMOSD.

Hypertrophic Pachymeningitis Development in Eosinophilic Granulomatosis with Polyangiitis at Relapse of Disease: A Case-Based Review.

Hypertrophic pachymeningitis (HP) presents with thickening of the dura mater in the cerebrum and spine, and its symptoms vary depending on the affected location. The association of HP with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis has been recognized, and most cases are complicated by granulomatosis with polyangiitis. We report the case of a 47-year-old man who presented with HP upon relapse of eosinophilic granulomatosis with polyangiitis (EGPA), with literature review. He presented with disturbance of consciousness, and magnetic resonance imaging (MRI) revealed thickening of the dura mater around the left parietal lobe. Although myeloperoxidase (MPO)-ANCA was positive on EGPA diagnosis, the elevation of MPO-ANCA was not documented at the onset of HP. Brain perfusion scintigraphy showed an increase in blood flow in the left parietal lobe and temporal lobe, and electroencephalogram (EEG) revealed slow waves in the left parietal lobe. He was treated with a high dose of corticosteroid and rituximab, and the slow waves on EEG and brain perfusion were normalized. Although the most frequent symptom of HP is headache, disturbance of consciousness can be the manifestation of HP, and inflammation of HP could affect the cerebral parenchyma, which can be documented as abnormal EEG and perfusion scintigraphy. Literature review revealed that most of the HP in EGPA developed when EGPA relapsed, and was observed in patients with MPO-ANCA positivity. HP develops without evidence of other clinical features of EGPA; therefore, adequate imaging, including contrast-enhanced MRI, is necessary. Rituximab may be effective for treating HP complicated with EGPA.

Myelin oligodendrocyte glycoprotein antibody-associated disease: an immunopathological study.

Conformation-sensitive antibodies against myelin oligodendrocyte glycoprotein (MOG) are detectable in patients with optic neuritis, myelitis, opticomyelitis, acute or multiphasic disseminated encephalomyelitis (ADEM/MDEM) and brainstem/cerebral cortical encephalitis, but are rarely detected in patients with prototypic multiple sclerosis. So far, there has been no systematic study on the pathological relationship between demyelinating lesions and cellular/humoral immunity in MOG antibody-associated disease. Furthermore, it is unclear whether the pathomechanisms of MOG antibody-mediated demyelination are similar to the demyelination patterns of multiple sclerosis, neuromyelitis optica spectrum disorders (NMOSD) with AQP4 antibody, or ADEM. In this study, we immunohistochemically analysed biopsied brain tissues from 11 patients with MOG antibody-associated disease and other inflammatory demyelinating diseases. Patient median onset age was 29 years (range 9-64), and the median interval from attack to biopsy was 1 month (range 0.5-96). The clinical diagnoses were ADEM (n = 2), MDEM (n = 1), multiple brain lesions without encephalopathy (n = 3), leukoencephalopathy (n = 3) and cortical encephalitis (n = 2). All these cases had multiple/extensive lesions on MRI and were oligoclonal IgG band-negative. Most demyelinating lesions in 10 of 11 cases showed a perivenous demyelinating pattern previously reported in ADEM (153/167 lesions) and a fusion pattern (11/167 lesions) mainly in the cortico-medullary junctions and white matter, and only three lesions in two cases showed confluent demyelinated plaques. In addition, 60 of 167 demyelinating lesions (mainly in the early phase) showed MOG-dominant myelin loss, but relatively preserved oligodendrocytes, which were distinct from those of AQP4 antibody-positive NMOSD exhibiting myelin-associated glycoprotein-dominant oligodendrogliopathy. In MOG antibody-associated diseases, MOG-laden macrophages were found in the perivascular spaces and demyelinating lesions, and infiltrated cells were abundant surrounding multiple blood vessels in and around the demyelinating lesions, mainly consisting of macrophages (CD68; 1814 ± 1188 cells/mm2), B cells (CD20; 468 ± 817 cells/mm2), and T cells (CD3; 2286 ± 1951 cells/mm2), with CD4-dominance (CD4+ versus CD8+; 1281 ± 1196 cells/mm2 versus 851 ± 762 cells/mm2, P < 0.01). Humoral immunity, evidenced by perivascular deposits of activated complements and immunoglobulins, was occasionally observed in some MOG antibody-associated demyelinating lesions, and the frequency was much lower than that in AQP4 antibody-positive NMOSD. Subpial lesions with perivenous demyelination were observed in both ADEM and cortical encephalitis. Our study suggests that ADEM-like perivenous inflammatory demyelination with MOG-dominant myelin loss is a characteristic finding of MOG antibody-associated disease regardless of whether the diagnostic criteria of ADEM are met. These pathological features are clearly different from those of multiple sclerosis and AQP4 antibody-positive NMOSD, suggesting an independent autoimmune demyelinating disease entity.

CSF cytokine profile in MOG-IgG+ neurological disease is similar to AQP4-IgG+ NMOSD but distinct from MS: a cross-sectional study and potential therapeutic implications.

OBJECTIVE: To evaluate cerebrospinal fluid (CSF) cytokine profiles in myelin oligodendrocyte glycoprotein IgG-positive (MOG-IgG+) disease in adult and paediatric patients. METHODS: In this cross-sectional study, we measured 27 cytokines in the CSF of MOG-IgG+ disease in acute phase before treatment (n=29). The data were directly compared with those in aquaporin-4 antibody-positive (AQP4-IgG+) neuromyelitis optica spectrum disorder (NMOSD) (n=20), multiple sclerosis (MS) (n=20) and non-inflammatory controls (n=14). RESULTS: In MOG-IgG+ disease, there was no female preponderance and the ages were younger (mean 18 years, range 3-68; 15 were below 18 years) relative to AQP4-IgG+ NMOSD (41, 15-77) and MS (34, 17-48). CSF cell counts were higher and oligoclonal IgG bands were mostly negative in MOG-IgG+ disease and AQP4-IgG+ NMOSD compared with MS. MOG-IgG+ disease had significantly elevated levels of interleukin (IL)-6, IL-8, granulocyte-colony stimulating factor and granulocyte macrophage-colony stimulating factor, interferon-γ, IL-10, IL-1 receptor antagonist, monocyte chemotactic protein-1 and macrophage inflammatory protein-1α as compared with MS. No cytokine in MOG-IgG+ disease was significantly different from AQP4-IgG+ NMOSD. Moreover many elevated cytokines were correlated with each other in MOG-IgG+ disease and AQP4-IgG+ NMOSD but not in MS. No difference in the data was seen between adult and paediatric MOG-IgG+ cases. CONCLUSIONS: The CSF cytokine profile in the acute phase of MOG-IgG+ disease is characterised by coordinated upregulation of T helper 17 (Th17) and other cytokines including some Th1-related and regulatory T cells-related ones in adults and children, which is similar to AQP4-IgG+ NMOSD but clearly different from MS. The results suggest that as with AQP4-IgG+ NMOSD, some disease-modifying drugs for MS may be ineffective in MOG-IgG+ disease while they may provide potential therapeutic targets.

Cerebrospinal fluid aquaporin-4 antibody levels in neuromyelitis optica attacks.

To elucidate immunopathogenetic roles of aquaporin-4 antibodies in the cerebrospinal fluid (CSF) of neuromyelitis optica spectrum disorders (NMOSD), we analyzed aquaporin-4 antibody titers, cellular and inflammatory markers in the CSF collected from 11 aquaporin-4 antibody seropositive patients. The CSF aquaporin-4 antibody levels during attacks (but not in sera) closely correlated with pleocytosis, inflammatory cytokines including interleukin-6 that can regulate antibody-producing plasmablasts, and glial fibrillary acidic protein levels in the CSF. The amount of aquaporin-4 antibodies present in the central nervous system may have therapeutic implications, as it is associated with astrocyte injury and inflammatory responses during NMOSD attacks.

Severe demyelination but no astrocytopathy in clinically definite neuromyelitis optica with anti-myelin-oligodendrocyte glycoprotein antibody.

We report a patient with neuromyelitis optica (NMO) presenting anti-myelin-oligodendrocyte glycoprotein (MOG)-seropositive, in whom biomarkers of demyelination and astrocyte damage were measured during an acute attack. A 31-year-old man developed right optic neuritis followed by longitudinally extensive transverse myelitis, fulfilling the criteria for definite NMO. He was anti-MOG-seropositive and anti-aquaporin-4 seronegative. The myelin basic protein level was markedly elevated whereas glial fibrillary acidic protein was not detectable in cerebrospinal fluid during an acute attack. His symptoms quickly improved after high-dose methylprednisolone therapy. This case suggests that NMO patients with anti-MOG may have severe demyelination in the absence of astrocyte injury.

Anti-aquaporin-4 immune complex stimulates complement-dependent Th17 cytokine release in neuromyelitis optica spectrum disorders.

Proinflammatory cytokines, such as (IL: interleukin) IL-6 and IL-17A, and complement fixation are critical in the immunopathogenesis of neuromyelitis optica spectrum disorders (NMOSD). Blocking the IL-6 receptor or the C5 complement pathway reduces relapse risk. However, the role of interleukin (IL)-6 and complement in aquaporin-4 (AQP4) autoimmunity remains unclear. To investigate the role of the anti-AQP4 immunoglobulin (AQP4-IgG)/AQP4 immunocomplex on the induction and profile of ex vivo cytokine and surface marker expression in peripheral blood mononuclear cells (PBMC) culture. Isolated PBMCs obtained from 18 patients with AQP4-IgG-seropositive-NMOSD (8 treatment-naive, 10 rituximab-treated) or ten healthy controls were cultured with AQP4-immunocomplex with or without complement. Changes in PBMC surface markers and cytokine expression were profiled using flow cytometry and ELISA. PBMCs derived from treatment-naive NMOSD patients stimulated with a complex mixture of serum complement proteins produced significant elevations of IL-17A and IL-6. Rituximab-treated patients also exhibited higher IL-6 but not IL-17A release. IL-6 and IL-17A elevations are not observed without complement. Co-stimulation of PBMCs with AQP4-IgG/AQP4 immunocomplex and complement prompts a Th17-biased response consistent with the inflammatory paradigm observed in NMOSD. A possible inflammation model is proposed via antigen-specific autoreactive peripheral blood cells, including NK/NKT cells.

Presence of six different lesion types suggests diverse mechanisms of tissue injury in neuromyelitis optica.

Neuromyelitis optica (NMO) is an autoimmune disease targeting aquaporin 4 (AQP4), localized mainly at the astrocytic foot processes. Loss of AQP4 and glial fibrillary acidic protein (GFAP) was reported, but the pathological significance of astrocytopathy is still controversial. Here we show that active lesions in NMO display a wide spectrum of pathology even within a single tissue block of an individual patient. We have distinguished six different lesion types. The first reflects complement deposition at the surface of astrocytes, associated with granulocyte infiltration and astrocyte necrosis and followed by demyelination, global tissue destruction and the formation of cystic, necrotic lesions (lesion type 2). Such destructive lesions lead to Wallerian degeneration in lesion-related tracts (lesion type 3). Around active NMO lesions AQP4 may selectively be lost in the absence of aquaporin 1 (AQP1) loss or other structural damage (lesion type 4). Another pattern is characterized by clasmatodendrosis of astrocytes, defined by cytoplasmic swelling and vacuolation, beading and dissolution of their processes and nuclear alterations resembling apoptosis, which was associated with internalization of AQP4 and AQP1 and astrocyte apoptosis in the absence of complement activation. Such lesions give rise to extensive astrocyte loss, which may occur in part in the absence of any other tissue injury, such as demyelination or axonal degeneration (lesion type 5). Finally, lesions with a variable degree of astrocyte clasmatodendrosis are found, which show plaque-like primary demyelination that is associated with oligodendrocyte apoptosis, but with preservation of axons (lesion type 6). In active multiple sclerosis (MS) lesions astrocytes reveal changes of reactive protoplasmatic or fibrillary gliosis. Only in a subset of lesions, in patients with aggressive disease, loss of AQP4 is observed in the initial stage of their formation, which is associated with retraction of astrocyte processes in the absence of complement deposition, granulocyte infiltration or loss of AQP1 or astrocytes. Our data underline the primary assault of astrocytes in NMO lesions, but also indicate that different mechanisms of tissue injury operate in parallel in the same patient and even within the same lesion.

Electrophysiological and Histological Correlations of Optic Neuritis in the Dark Agouti Rat Model of Experimental Autoimmune Encephalomyelitis.

Experimental autoimmune encephalomyelitis (EAE) is an animal model of Inflammatory central nervous system (CNS) disease. Dark agouti (DA) rats immunized with full-length myelin oligodendrocyte glycoprotein (MOG1-125) typically develop a relapsing-remitting EAE form characterized by predominant demyelinating involvement of the spinal cord and optic nerve. Visually evoked potentials (VEP) are a useful objective tool to assess the optic nerve function and monitor electrophysiological changes in optic neuritis (ON). The current study aimed to assess the VEP changes in MOG-EAE DA rats using a minimally invasive recording device and to correlate them with histological findings. Twelve MOG-EAE DA rats and four controls underwent VEP recording at day 0, 7, 14, 21, and 28 post-EAE induction. Tissue samples were obtained on days 14, 21, and 28 from two EAE rats and one control. The median VEP latencies were significantly higher on days 14, 21, and 28 compared to baseline, with maximal latencies observed on day 21. The histological analyses on day 14 demonstrated inflammation with largely preserved myelin and axonal structures. Inflammation and demyelination with largely preserved axons were evident on days 21 and 28, which correlated with prolonged VEP latencies. These findings suggest that VEPs may be a reliable biomarker reflecting the optic nerve involvement in EAE. Moreover, the use of a minimally invasive device enables observation of VEP changes over time in MOG-EAE DA rats. Our findings may have important implications for testing the potential neuroprotective and regenerative effects of new therapies for CNS demyelinating diseases.

Progression independent of relapses in aquaporin4-IgG-seropositive neuromyelitis optica spectrum disorder, myelin oligodendrocyte glycoprotein antibody-associated disease, and multiple sclerosis.

OBJECTIVES: To determine whether progression independent of relapse activity (PIRA) is present in Aquaporin4-IgG-seropositive neuromyelitis optica spectrum disorder (AQP4+NMOSD), Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) and relapsing remitting Multiple sclerosis (RRMS). METHODS: We retrospectively studied the change in EDSS, confirmed disability worsening (CDW) (i.e., PIRA), and new MRI lesions in AQP4+NMOSD, and MOGAD and MS patients. Linear mixed-effect regression model was used to compare the longitudinal changes in EDSS, and Cox regression was used to compare changes in MRI. RESULTS: The estimated mean ΔEDSS in the AQP4+NMOSD and matched MS group were +0.06 (95%CI: -0.40, +0.52, p = 0.76), and +0.02 (95%CI: -0.05, +0.08, p = 0.6) respectively. The same estimate was -0.08 (95%CI: -0.18, +0.02, p = 0.12) in MOGAD and +0.05 (95%CI: -0.05, +0.15, p = 0.35) in matched MS group. Comparing groups for the presence of CDW (i.e., PIRA) showed that PIRA is more associated with MS compared to AQP4+NMOSD (p = 0.02) and MOGAD (p<0.001). Compared to their matched MS groups, the annualized rate of PIRA was significantly lower in AQP4 (0.08 vs 0.44; p<0.0001), and MOG groups (0.04 vs 0.13; p<0.0001). New T2 or enhancing lesions on brain MRI were higher in MS compared to AQP4+NMOSD and MOGAD patients. CONCLUSION: Relapse-independent changes in the EDSS, CDW, and MRI activity are not common in AQP4+NMOSD and MOGAD, especially when compared with MS. Since our patients were on relapse prevention therapies at the time of EDSS measurements, our study supports the importance of preventing relapses in AQP4+NMOSD and MOGAD and suggests different pathologic mechanisms of relapse-free neurological damage between MS and AQP4+NMOSD/MOGAD.

Development of Paraneoplastic Neuromyelitis Optica after Lung Resection in a Patient with Squamous Cell Carcinoma.

Neurological paraneoplastic syndrome is a relatively rare condition in patients with malignant tumors. Recently, it has been reported that anti-Aquaporin 4 (AQP4) antibody is highly specific for neuromyelitis optica. The patient was a 76-year-old man. He underwent right upper lobectomy for squamous cell carcinoma of the lung. Although the immediate postoperative course was uneventful, neurological symptoms became apparent from postoperative day (POD) 4. Magnetic resonance imaging showed longitudinally extended edematous lesions in the spinal cord, and a cerebrospinal fluid examination was positive for anti-AQP4 antibody, leading to the diagnosis of paraneoplastic neuromyelitis optica. Despite multiple rounds of steroid pulse therapy and plasma exchange, the neurological symptoms worsened and the patient died on POD 46. The development of neuromyelitis optica in the early postoperative period could be related to the influence of surgical stress or epidural anesthesia.

Peripheral MC1R activation modulates immune responses and is neuroprotective in a mouse model of Parkinson's disease.

Background: Melanocortin 1 receptor (MC1R) is a key pigmentation gene, and loss-of-function of MC1R variants that produce red hair may be associated with Parkinson's disease (PD). We previously reported compromised dopaminergic neuron survival in Mc1r mutant mice and dopaminergic neuroprotective effects of local injection of a MC1R agonist to the brain or a systemically administered MC1R agonist with appreciable CNS permeability. Beyond melanocytes and dopaminergic neurons, MC1R is expressed in other peripheral tissues and cell types, including immune cells. The present study investigates the impact of NDP-MSH, a synthetic melanocortin receptor (MCR) agonist that does not cross BBB, on the immune system and the nigrostriatal dopaminergic system in mouse model of PD. Methods: C57BL/6 mice were treated systemically with MPTP.HCl (20 mg/kg) and LPS (1 mg/kg) from day 1 to day 4 and NDP-MSH (400 µg/kg) or vehicle from day 1 to day 12 following which the mice were sacrificed. Peripheral and CNS immune cells were phenotyped and inflammatory markers were measured. The nigrostriatal dopaminergic system was assessed behaviorally, chemically, immunologically, and pathologically. To understand the role of regulatory T cells (Tregs) in this model, CD25 monoclonal antibody was used to deplete CD25+ Tregs. Results: Systemic NDP-MSH administration significantly attenuated striatal dopamine depletion and nigral dopaminergic neuron loss induced by MPTP+LPS. It improved the behavioral outcomes in the pole test. Mc1r mutant mice injected with NDP-MSH in the MPTP and LPS paradigm showed no changes in striatal dopamine levels suggesting that the NDP-MSH acts through the MC1R pathway. Although no NDP-MSH was detected in the brain, peripheral, NDP-MSH attenuated neuroinflammation as observed by diminished microglial activation in the nigral region, along with reduced TNF-α and IL1ß levels in the ventral midbrain. Depletion of Tregs limited the neuroprotective effects of NDP-MSH. Conclusions: Our study demonstrates that peripherally acting NDP-MSH confers protection on dopaminergic nigrostriatal neurons and reduces hyperactivated microglia. NDP-MSH modulates peripheral immune responses, and Tregs may be involved in the neuroprotective effect of NDP-MSH.

Peripheral MC1R Activation Modulates Immune Responses and is Neuroprotective in a Mouse Model of Parkinson's Disease.

BACKGROUND: Melanocortin 1 receptor (MC1R) is a key pigmentation gene, and loss-of-function of MC1R variants that produce red hair may be associated with Parkinson's disease (PD). We previously reported compromised dopaminergic neuron survival in Mc1r mutant mice and dopaminergic neuroprotective effects of local injection of a MC1R agonist to the brain or a systemically administered MC1R agonist with appreciable central nervous system (CNS) permeability. Beyond melanocytes and dopaminergic neurons, MC1R is expressed in other peripheral tissues and cell types, including immune cells. The present study investigates the impact of NDP-MSH, a synthetic melanocortin receptor (MCR) agonist that does not cross BBB, on the immune system and the nigrostriatal dopaminergic system in mouse model of PD. METHODS: C57BL/6 mice were treated systemically with MPTP.HCl (20 mg/kg) and LPS (1 mg/kg) from day 1 to day 4 and NDP-MSH (400 µg/kg) or vehicle from day 1 to day 12 following which the mice were sacrificed. Peripheral and CNS immune cells were phenotyped and inflammatory markers were measured. The nigrostriatal dopaminergic system was assessed behaviorally, chemically, immunologically, and pathologically. To understand the role of regulatory T cells (Tregs) in this model, CD25 monoclonal antibody was used to deplete CD25 + Tregs. RESULTS: Systemic NDP-MSH administration significantly attenuated striatal dopamine depletion and nigral dopaminergic neuron loss induced by MPTP + LPS. It improved the behavioral outcomes in the pole test. Mc1r mutant mice injected with NDP-MSH in the MPTP and LPS paradigm showed no changes in striatal dopamine levels suggesting that the NDP-MSH acts through the MC1R pathway. Although no NDP-MSH was detected in the brain, peripheral, NDP-MSH attenuated neuroinflammation as observed by diminished microglial activation in the nigral region, along with reduced TNF-α and IL1ß levels in the ventral midbrain. Depletion of Tregs was associated with diminished neuroprotective effects of NDP-MSH. CONCLUSIONS: Our study demonstrates that peripherally acting NDP-MSH confers protection on dopaminergic nigrostriatal neurons and reduces hyperactivated microglia. NDP-MSH modulates peripheral immune responses, and Tregs may be involved in the neuroprotective effect of NDP-MSH.

White blood cell count profiles in anti-aquaporin-4 antibody seropositive neuromyelitis optica spectrum disorder and anti-myelin oligodendrocyte glycoprotein antibody-associated disease.

White blood cell (WBC) count profiles in anti-aquaporin-4 antibody-positive neuromyelitis optica spectrum disorder (AQP4-NMOSD) and anti-myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) are still unknown. This study evaluated the total WBC count, differential WBC counts, monocyte-to-lymphocyte ratio (MLR), and neutrophil-to-lymphocyte ratio (NLR) in patients with these diseases within three months from an attack before acute treatment or relapse prevention and compared the profiles with those in matched volunteers or in multiple sclerosis (MS) patients. AQP4-NMOSD patients (n = 13) had a higher neutrophil count (p = 0.0247), monocyte count (p = 0.0359), MLR (p = 0.0004), and NLR (p = 0.0037) and lower eosinophil (p = 0.0111) and basophil (p = 0.0283) counts than those of AQP4-NMOSD-matched volunteers (n = 65). Moreover, patients with MOGAD (n = 26) had a higher overall WBC count (p = 0.0001), neutrophil count (p < 0.0001), monocyte count (p = 0.0191), MLR (p = 0.0320), and NLR (p = 0.0002) than those of MOGAD-matched volunteers (n = 130). The three demyelinating diseases showed similar levels of the total and differential WBC counts; however, MOGAD and MS showed different structures in the hierarchical clustering and distributions on a two-dimensional canonical plot using differential WBC counts from the other three groups. WBC count profiles were similar in patients with MOGAD and MS but differed from profiles in matched volunteers or patients with AQP4-NMOSD.

[Studying Abroad for Basic Research During the COVID-19 Pandemic].

The COVID-19 pandemic, caused by a new type of coronavirus, has increased the difficulty of studying abroad for basic research. However, the associated system has changed in response to the coronavirus disaster. In addition, a framework has been built to enable research to be conducted even under a new lifestyle. Although there are many differences betwee studying abroad currently and before the pandemic, you should not give up on your dreams; I encourage you to open the door and challenge yourself.