Anti-myelin Oligodendrocyte Glycoprotein Antibody-positive Myelitis after Coronavirus Disease 2019.

We herein report a case of anti-myelin oligodendrocyte glycoprotein (MOG) antibody-related myelitis caused by coronavirus disease (COVID-19) infection in 2021. A 22-year-old man with no history of any related illness contracted COVID-19. Eight days later, he developed bladder problems, paraplegia and sensory disturbances. Cervical spinal cord magnetic resonance imaging revealed extensive hyperintensity at T2 and spinal cord lesions extending from C4 to Th1. The patient was diagnosed with transverse myelitis and started on intravenous methylprednisolone, plasma exchange and intravenous immunoglobulin therapy. The symptoms improved only after intravenous methylprednisolone therapy. Anti-MOG antibodies were found in his serum and cerebrospinal fluid during routine screening. As this observation is unusual and could cause serious health problems, we wonder if COVID-19 triggered this autoimmune response.

Axonal growth inhibitors and their receptors in spinal cord injury: from biology to clinical translation.

Axonal growth inhibitors are released during traumatic injuries to the adult mammalian central nervous system, including after spinal cord injury. These molecules accumulate at the injury site and form a highly inhibitory environment for axonal regeneration. Among these inhibitory molecules, myelin-associated inhibitors, including neurite outgrowth inhibitor A, oligodendrocyte myelin glycoprotein, myelin-associated glycoprotein, chondroitin sulfate proteoglycans and repulsive guidance molecule A are of particular importance. Due to their inhibitory nature, they represent exciting molecular targets to study axonal inhibition and regeneration after central injuries. These molecules are mainly produced by neurons, oligodendrocytes, and astrocytes within the scar and in its immediate vicinity. They exert their effects by binding to specific receptors, localized in the membranes of neurons. Receptors for these inhibitory cues include Nogo receptor 1, leucine-rich repeat, and Ig domain containing 1 and p75 neurotrophin receptor/tumor necrosis factor receptor superfamily member 19 (that form a receptor complex that binds all myelin-associated inhibitors), and also paired immunoglobulin-like receptor B. Chondroitin sulfate proteoglycans and repulsive guidance molecule A bind to Nogo receptor 1, Nogo receptor 3, receptor protein tyrosine phosphatase σ and leucocyte common antigen related phosphatase, and neogenin, respectively. Once activated, these receptors initiate downstream signaling pathways, the most common amongst them being the RhoA/ROCK signaling pathway. These signaling cascades result in actin depolymerization, neurite outgrowth inhibition, and failure to regenerate after spinal cord injury. Currently, there are no approved pharmacological treatments to overcome spinal cord injuries other than physical rehabilitation and management of the array of symptoms brought on by spinal cord injuries. However, several novel therapies aiming to modulate these inhibitory proteins and/or their receptors are under investigation in ongoing clinical trials. Investigation has also been demonstrating that combinatorial therapies of growth inhibitors with other therapies, such as growth factors or stem-cell therapies, produce stronger results and their potential application in the clinics opens new venues in spinal cord injury treatment.

Development and optimisation of an animal model for the study of ganglion cells in degenerative diseases of the retina and optic nerve. / Desarrollo y optimización de un modelo animal para el estudio de las células ganglionares en enfermedad degenerativa de la retina y nervio óptico.

INTRODUCTION: Multiple sclerosis is an autoimmune, chronic and inflammatory disease of the central nervous system with axonal demyelination, gliosis and neurodegeneration. It is considered a frequent cause of neurological disability in young adults. In this work, an Experimental Autoimmune Encephalomyelitis (EAE) model was optimised by injecting a myelin oligodendrocyte glycoprotein (MOG35-55). The ophthalmological effects were studied, as well as its use as an experimental model in other studies of retinal ganglion cell degeneration (RGC) and optic nerve (ON). MATERIAL AND METHODS: The study included 16 mice of 10 weeks that were placed into 2 study groups: a control group of 10 animals and another group of 6 animals with EAE that were injected with MOG35-55. The animals of the EAE model were monitored using motor disability scales. The retinas and optic nerves were processed for morphological examination by optical microscopy and ultrastructure studies. RESULTS: The animal models presented with motor symptoms of spinal cord injury, with the first symptoms appearing between the 7th and 19th day post-injection, with a maximum disability mean of 3.5 points. In the retina, the mean RGC in the EAE group was 0.0891µm, compared with 0.1678µm of the control group (p=.0003). The ON was strongly affected with reactive gliosis, increased axonal damage and decreased density axonal (control group 0.38038 axons/µm2 versus EAE group 0.16 axons/µm2, p=.00032). CONCLUSIONS: In this work an animal model of EAE has been characterised and detailed for the study of demyelinating alterations in the retina and the ON. Its characteristics make it an excellent tool for the study of neurodegenerative ophthalmic diseases.

Transplantation of mesenchymal stem cells promotes the functional recovery of the central nervous system following cerebral ischemia by inhibiting myelin-associated inhibitor expression and neural apoptosis.

Cerebral ischemia, which may lead to cerebral hypoxia and damage of the brain tissue, is a leading cause of human mortality and adult disability. Mesenchymal stem cells (MSCs) are a class of adult progenitor cells with the ability to differentiate into multiple cell types. The transplantation of bone marrow-derived MSCs is a potential therapeutic strategy for cerebral ischemia. However, the underlying mechanism has yet to be elucidated. In the present study, primary MSCs were isolated from healthy rats, labeled and transplanted into the brains of middle cerebral artery occlusion rat models. The location of the labeled MSCs in the rat brains were determined by fluorescent microscopy, and the neurological functions of the rats were scored. Immunohistochemical analyses demonstrated that the protein expression levels of myelin-associated inhibitors of regeneration, including Nogo-A, oligodendrocyte myelin glycoprotein and myelin-associated glycoprotein, were decreased following transplantation of the bone marrow-derived MSCs. Furthermore, the mRNA expression levels of Capase-3 and B-cell lymphoma 2, as determined by reverse transcription-quantitative polymerase chain reactions, were downregulated and upregulated, respectively, in the MSC-transplanted rats; thus suggesting that neural apoptosis was inhibited. The results of the present study suggested that the transplantation of bone marrow-derived MSCs was able to promote the functional recovery of the central nervous system following cerebral ischemia. Accordingly, inhibitors targeting myelin-associated inhibitors and apoptosis may be of clinical significance for cerebral ischemia in the future.

Role of neurite outgrowth inhibitor-oligodendrocyte myelin glycoprotein/Ras homologous (Rho)-Rho-associated coiled-coil forming protein kinase signaling pathway in acute brain injury of carbon monoxide poisoning rats and treatment feasibility with hydrochloride fasudil / 中华神经医学杂志

Objective:To investigate the role of neurite outgrowth inhibitor (Nogo)-oligodendrocyte myelin glycoprotein (Omgp)/Ras homologous (Rho)-Rho-associated coiled-coil forming protein kinase (Rock) signaling pathway in acute brain injury of carbon monoxide (CO) poisoning rats and treatment feasibility with Rho kinase inhibitor hydrochloride fasudil.Methods:According to random number table method, 135 healthy male SD rats were divided into three groups: a normal control group, a CO poisoning group and a fasudil treatment group ( n=45). Rat models of acute severe CO poisoning were established in the CO poisoning group and fasudil treatment group by inhalation method in a hyperbaric oxygen chamber. All rats received hyperbaric oxygen therapy for two weeks. Rats in the farsudil treatment group were intraperitoneally injected with hydrochloride farsudil for intervention (15 mg/[kg·d], once a d for 2 weeks), while those in the CO poisoning and normal control groups received the same volume of normal saline. The ultrastructures of rat brain tissues were observed by transmission electron microscopy one week after modeling. Staining intensities of Nogo- and OMgp-positive cells were detected by immunohistochemistry, and those of Rock-positive cells were analyzed by immunofluorescence one d, one week, one month and two months after modeling. The protein expressions of Nogo, OMgp and Rock in brain tissues were detected by Western blotting one d, one week, one month and two months after modeling. Results:In the CO poisoning group, the ultrastructures of brain tissues and blood-brain barrier were damaged obviously, and the changes in nucleus, mitochondria and synaptic structure were obvious; while fasudil treatment could effectively maintain the integrity of ultrastructures and functions of brain tissues, and reduce brain edema. One d, one week, one month and two months after modeling, the staining intensities of Nogo, OMgp and Rock positive cells and protein expression levels of Nogo, OMgp and Rock in the CO poisoning group were significantly higher than those in the normal control group at the same time point ( P<0.05); the staining intensities of Nogo, OMgp and Rock positive cells and protein expression levels of Nogo, OMgp and Rock in the fasudil treatment group were significantly lower than those in the CO poisoning group at the same time point ( P<0.05). Conclusion:The activation of Nogo-OMgp/Rho-Rock signaling pathway related molecules (Nogo, OMgp and Rock) is closely related to acute brain injury caused by CO poisoning; hydrochloride fasudil can effectively down-regulate the protein expressions of Nogo, OMgp and Rock, therefore obviously alleviate brain injury after CO poisoning.

Altered expression of myelin-associated inhibitors and their receptors after traumatic brain injury in the mouse.

PURPOSE: When central nervous system axons are injured, regeneration is partly inhibited by myelin-associated inhibitors (MAIs). Following traumatic brain injury (TBI) in the rat, pharmacological neutralisation of the MAIs Nogo-A and myelin-associated glycoprotein (MAG) resulted in improved functional outcome. In contrast, genetic or pharmacological neutralization of the MAI receptors Nogo-66 receptor 1 (NgR1) or paired-immunoglobulin like receptor-B (PirB) showed an unaltered or impaired outcome following TBI in mice. The aim of the present study was thus to evaluate the MAI expression levels following TBI in mice. METHODS: Quantitative reverse transcriptase PCR (qRT-PCR) was used to measure total RNA isolated from brains of young adult male C57BL/6 mice at one, three or seven days following controlled cortical impact TBI or sham injury. Hippocampal and neocortical tissue ipsi- and contralateral to the injury was analyzed for Nogo-A, oligodendrocyte-myelin glycoprotein (OMgp), MAG, and the MAI receptors PirB and NgR1, including its co-receptor Lingo1. RESULTS: Compared to sham-injured controls, PirB neocortical expression was significantly upregulated at one day and NgR1 expression downregulated at seven days post-TBI. In the hippocampus, transcriptional upregulation was observed in Nogo-A (one day post-injury), MAG and PirB at seven days post-injury. In contrast, the hippocampal transcripts of NgR1 and Lingo1 were decreased at seven days post-injury. The expression of OMgp was unaltered at all time points post-injury. CONCLUSION: These results suggest that early dynamic changes in MAI gene expression occur following TBI in the mouse, particularly in the hippocampus, which may play an inhibitory role for post-injury regeneration and plasticity.

Características de la estructura molecular de las proteínas E del virus del Zika y E1 del virus de la rubéola y posibles implicaciones en el neurotropismo y en las alteraciones del sistema nervioso / E-ZIKV and E1-RV proteins molecular structure and their potential implications in neurotropism and nervous system disorders

Resumen Introducción. El virus del Zika (ZIKV) es un flavivirus con envoltura, transmitido a los seres humanos principalmente por el vector Aedes aegypti. La infección por ZIKV se ha asociado con un gran neurotropismo y con efectos neuropáticos, como el síndrome de Guillain-Barré en el adulto y la microcefalia fetal y posnatal, así como con un síndrome de infección congénita similar al producido por el virus de la rubéola (RV). Objetivo. Comparar las estructuras moleculares de la proteína de envoltura E del virus del Zika (E-ZIKV) y de la E1 del virus de la rubéola (E1-RV), y plantear posibles implicaciones en el neurotropismo y en las alteraciones del sistema nervioso asociadas con el ZIKV. Materiales y métodos. La secuencia de aminoácidos de la proteína E-ZIKV (PDB: 5iZ7) se alineó con la de la glucopreteína E1 del virus de la rubéola (PDB: 4ADG). Los elementos de la estructura secundaria se determinaron usando los programas Vector NTI Advance®, DSSP y POSA, así como herramientas de gestión de datos (AlignX®). Uno de los criterios principales de comparación y alineación fue la asignación de residuos estructuralmente equivalentes, con más de 70 % de identidad. Resultados. La organización estructural de la proteína E-ZIKV (PDB: 5iZ7) fue similar a la de E1-RV (PDB: 4ADG) (70 a 80 % de identidad), y se observó una correspondencia con la estructura definida para las glucoproteínas de fusión de membrana de clase II de los virus con envoltura. E-ZIKV y E1-RV exhibieron elementos estructurales de fusión muy conservados en la región distal del dominio II, asociados con la unión a los receptores celulares de entrada del virus de la rubéola (glucoproteína de mielina del oligodendrocito, Myelin Oligodendrocyte Glycoprotein, MOG), y con los receptores celulares Axl del ZIKV y de otros flavivirus. Conclusión. La comparación de las proteínas E-ZIKV y E1-RV es un paso necesario hacia la definición de otros factores moleculares determinantes del neurotropismo y la patogenia del ZIKV, el cual puede contribuir a generar estrategias de diagnóstico, prevención y tratamiento de las complicaciones neurológicas inducidas por el ZIKV.

Abstract Introduction: Zika virus (ZIKV) is an enveloped flavivirus transmitted to humans mainly by Aedes aegypti. ZIKV infection has been associated with high neurotropism and neuropathic effects such as the Guillain-Barré syndrome in adults, and fetal and postnatal microcephaly and the congenital Zika virus syndrome similar to that produced by rubella virus (VR). Objective: To compare Zika virus membrane protein E (E-ZIKV) and rubella virus membrane protein E1 (E1-RV), and to propose possible implications for neurotropism and nervous system disorders associated with ZIKV infections. Materials and methods: The amino acid sequence of E-ZIKV protein (PDB: 5iZ7) was aligned to that of rubella virus glycoprotein E1 (PDB: 4ADG). The secondary structure elements were determined using the programs Vector NTI Advance®, DSSP, and POSA, and integrated data management tools (AlignX®). One of the main comparison and alignment criteria was the allocation of structurally equivalent residues with more than 70% identity. Results: E-ZIKV structural organization (PDB: 5iZ7) was similar to that of E1-RV (PDB: 4ADG) (70%-80% identity), and it was consistent with relevant structural features of viral membrane class II fusion glycoproteins. E-ZIKV and E1-RV exhibited highly conserved fusion structural elements at the distal region of domain II, which has been associated with the RV myelin oligodendrocyte glycoprotein and Axl cell receptors in ZIKV and other flaviviruses. Conclusion: The comparison of E-ZIKV and E1-RV proteins constitutes an essential step towards the definition of ZIKV neurotropism and pathogenesis molecular determinants, and for the adoption of diagnosis, prevention and treatment strategies against neurological complications induced by ZIKV infection.

Effect of Early Intervention on Oligodendrocyte-Myelin Glycoprotein mRNA Expression of Neonatal Rats with Brain Injury Caused by Intrauterine Infection / 实用儿科临床杂志

Objective To observe the effect of early intervention on the oligodendrocyte-myelin glycoprotein(OMgp) mRNA expression of brain injury neonatal rats caused by intrauterine infection.Methods 1.Twenty-eight Wistar pregnant rats were randomly divided into 2 groups:lipopolysaccharide(LPS)-treated group and saline control group.Pregnant rats were consecutively injected with LPS (450 ?g?kg-1) or saline on the 18th gestation age.After birth,the placentas were taken out and made HE staining to observe intrauterine infection.2.Thirty neonatal rats in the saline control group and 55 rats in the LPS-treated group were randomly selected which were divided into intervention group (n=25) and no-intervention group (n=25).The second post-natal day (P2) rats in intervention group were treated by early touch and enriched environment.The neonatal rats in the no-intervention group and saline control group were fed in a routine way.Five cases of P1 rats were selected respectively from the LPS-treated group and saline control group,and brain tissue pathological section was made to observe the condition of brain injury.3.Five cases of P1,P3,P7,P28 and P42 rats were selected from the saline control group,intervention group and no-intervention group to detect the OMgp mRNA expression levels by using the real time polymerase chain reaction me-thod.Results 1.There were a great number of neurophilic granulocytes in the placentas in the LPS-treated group.2.Brain tissue pathological of P1 in the saline control group had complete substantia alba structure,ordered disposition and lightly stained clear chromatospherite.While in the LPS-treated group, there existed brain tissue looseness,colloid cell aggregation and oligodendrocyte cytoreduction in the position of substantia alba,callositas and capsula interna.Intraventricular hemorrhage,substantia alba blood vessel dilatation and blood capillary angiorrhexis and hemorrhage could also be found.3.There was a higher increase in OMgp mRNA expressions of brain tissue in the LPS-treated group at P1,P3,P7,P28,P42 than those in the saline control group (Pa