Elevation of Sema4A implicates Th cell skewing and the efficacy of IFN-ß therapy in multiple sclerosis.

Multiple sclerosis (MS) is a demyelinating autoimmune disease of the CNS and a leading cause of lasting neurologic disabilities in young adults. Although the precise mechanism remains incompletely understood, Ag presentation and subsequent myelin-reactive CD4(+) T cell activation/differentiation are essential for the pathogenesis of MS. Although semaphorins were initially identified as axon guidance cues during neural development, several semaphorins are crucially involved in various phases of immune responses. Sema4A is one of the membrane-type class IV semaphorins, which we originally identified from the cDNA library of dendritic cell (DC). Sema4A plays critical roles in T cell activation and Th1 differentiation during the course of experimental autoimmune encephalomyelitis, an animal model of MS; however, its pathological involvement in human MS has not been determined. In this study, we report that Sema4A is increased in the sera of patients with MS. The expression of Sema4A is increased on DCs in MS patients and shed from these cells in a metalloproteinase-dependent manner. DC-derived Sema4A is not only critical for Th1 but also for Th17 cell differentiation, and MS patients with high Sema4A levels exhibit Th17 skewing. Furthermore, patients with high Sema4A levels have more severe disabilities and are unresponsive to IFN-ß treatment. Taken together, our results suggest that Sema4A is involved in the pathogenesis of MS by promoting Th17 skewing.

Plexin-A1 and its interaction with DAP12 in immune responses and bone homeostasis.

Semaphorins and their receptors have diverse functions in axon guidance, organogenesis, vascularization and/or angiogenesis, oncogenesis and regulation of immune responses. The primary receptors for semaphorins are members of the plexin family. In particular, plexin-A1, together with ligand-binding neuropilins, transduces repulsive axon guidance signals for soluble class III semaphorins, whereas plexin-A1 has multiple functions in chick cardiogenesis as a receptor for the transmembrane semaphorin, Sema6D, independent of neuropilins. Additionally, plexin-A1 has been implicated in dendritic cell function in the immune system. However, the role of plexin-A1 in vivo, and the mechanisms underlying its pleiotropic functions, remain unclear. Here, we generated plexin-A1-deficient (plexin-A1(-/-)) mice and identified its important roles, not only in immune responses, but also in bone homeostasis. Furthermore, we show that plexin-A1 associates with the triggering receptor expressed on myeloid cells-2 (Trem-2), linking semaphorin-signalling to the immuno-receptor tyrosine-based activation motif (ITAM)-bearing adaptor protein, DAP12. These findings reveal an unexpected role for plexin-A1 and present a novel signalling mechanism for exerting the pleiotropic functions of semaphorins.

Roles of Sema4D-plexin-B1 interactions in the central nervous system for pathogenesis of experimental autoimmune encephalomyelitis.

Although semaphorins were originally identified as axonal guidance molecules during neuronal development, it is emerging that several semaphorins play crucial roles in various phases of immune responses. Sema4D/CD100, a class IV semaphorin, has been shown to be involved in the nervous and immune systems through its receptors plexin-B1 and CD72, respectively. However, the involvement of Sema4D in neuroinflammation still remains unclear. We found that Sema4D promoted inducible NO synthase expression by primary mouse microglia, the effects of which were abolished in plexin-B1-deficient but not in CD72-deficient microglia. In addition, during the development of experimental autoimmune encephalomyelitis (EAE), which was induced by immunization with myelin oligodendrocyte glycoprotein-derived peptides, we observed that the expression of Sema4D and plexin-B1 was induced in infiltrating mononuclear cells and microglia, respectively. Consistent with these expression profiles, when myelin oligodendrocyte glycoprotein-specific T cells derived from wild-type mice were adoptively transferred into plexin-B1-deficient mice or bone marrow chimera mice with plexin-B1-deficient CNS resident cells, the development of EAE was considerably attenuated. Furthermore, blocking Abs against Sema4D significantly inhibited neuroinflammation during EAE development. Collectively, our findings demonstrate the role of Sema4D-plexin-B1 interactions in the activation of microglia and provide their pathologic significance in neuroinflammation.

Complementation of a defect in the asparagine-linked glycosylation of a mouse FM3A mutant G258 cell line by spheroplast fusion of a human mega YAC clone 923f5.

Mouse G258 mutant stopped both cell growth and the synthesis of lipid-linked oligosaccharide at the Man(3)GlcNAc(2)-P-P-Dolichol at a restricted temperature with a single gene mutation. To clarify the lesion in the G258 mutant, we isolated human genomic DNA transformants of the G258 mutant, which recovered from both defects by way of cell hybridization with X-ray irradiated HeLa cells. We detected a common 1.3-kb product by inter-human specific sequence in the L1 (L1Hs) PCR in the transformants (Kataoka et al., Somat. Cell Mol. Genet., 24, 235-243 (1998)). In the present study, we screened a human mega yeast artificial chromosome (YAC) library by PCR with primers designed according to the 1.3-kb DNA, and selected YAC clone 923f5. Moreover, we found by spheroplast fusion that YAC clone 923f5 complemented both defects of the G258 mutant. Since the human counterpart of the yeast ALG11 gene is localized in the region, the G258 mutant might have a defect in the mouse ALG11 gene.

[A case of adult-onset Sturge-Weber syndrome type III without intracranial calcification, presenting with transient homonymous hemianopia].

Sturge-Weber syndrome (SWS) is a rare neurocutaneous disorder. Almost all cases of SWS are diagnosed in children, but some are diagnosed in adults. We describe a case of isolated leptomeningeal angiomatosis without intracranial calcification. A 33-year-old woman was admitted because of sudden-onset right homonymous hemianopia with headache and nausea. These symptoms disappeared by the next morning. She had no history of seizure or mental retardation. No facial angioma was found on physical examination. Brain CT showed no intracranial calcification or atrophic cortex. The blood and cerebrospinal fluid analyses yielded normal results. The findings in the electroencephalogram were unremarkable. MRI with susceptibility weighting (SWI) revealed dilated transmedullary veins in the left occipital lobe. Contrast-enhanced T1-weighted imaging (CE-T1WI) illustrated abnormal leptomeningeal enhancement in the left occipitoparietal cortex and enhancement and enlargement of the choroid plexus in the left lateral ventricle. Post-gadolinium contrast-enhanced f FLAIR imaging demonstrated more extensive enhancement of the leptomeningeal lesions than did CE-T1WI. The symptoms and the findings on these images were suggestive of a diagnosis of SWS type III. Clinicians should keep in mind that some cases of SWS manifest with only minor symptoms, such as migraine. If SWS is suspected, SWI and contrast-enhanced MRI should be performed.

Thrombolysis and Mechanical Thrombectomy for Acute Ischemic Stroke in Pregnancy: A Case Report.

Objective: Intravenous (IV) recombinant tissue plasminogen activator (rt-PA) and mechanical thrombectomy (MT) are effective treatments for acute ischemic stroke (AIS). However, the treatment for AIS in pregnancy is not established because no clinical trials have included pregnant patients. We present a case of middle cerebral artery (MCA) M2 segment occlusion in pregnancy treated with IV thrombolysis and endovascular therapy. Case Presentation: A 36-year-old woman being 6 weeks pregnant presented with right-sided hemiparesis and aphasia. MRI showed a high-intensity area on diffusion-weighted imaging of the left parietal lobe, and MRA showed left MCA M2 segment occlusion. She underwent IV rt-PA and MT and achieved thrombolysis in cerebral infarction 2b revascularization without complications. The protein S concentration was lower than that in the physiological changes during pregnancy. She was diagnosed with embolic stroke related to coagulopathy in pregnancy, and she underwent anticoagulation. At the 3-month follow-up, the modified Rankin Scale was 0. She miscarried at 4 months, and the fetal death was presumed to be obstetric cause. Conclusion: IV rt-PA and MT may be effective and safe treatments for pregnant patients. Estimated fetal radiation exposure during MT is low and is presumed not to affect fetal development. We should mitigate the radiation dose and reduce the dose of iodinated contrast agents, particularly in pregnant patients.

Mechanical Thrombectomy for Acute Middle Cerebral Artery Occlusion Caused by Tumor Embolism: A Case Report.

Objective: We report a case of acute middle cerebral artery (MCA) occlusion caused by tumor embolism. Case Presentation: A 64-year-old man with lung cancer presented with sudden onset left-sided hemiparesis and sensory disturbance. Diffusion-weighted imaging (DWI) revealed hyper-intense foci in the right MCA territory and magnetic resonance angiography (MRA) demonstrated right MCA M2 segment occlusion. Mechanical thrombectomy (MT) was performed with Thrombolysis in Cerebral Infarction 2B recanalization. On histopathology, thrombus composed of fibrin and squamous cell carcinoma was observed. We diagnosed him with tumor embolism from lung cancer that invaded the pulmonary vein and the left atrium. Conclusion: Tumor cells may be confirmed by pathological examination regardless of the morphology of the embolus. Pathological examination of the cerebral embolus is useful for the accurate diagnosis of ischemic stroke subtypes.

Anti-aquaporin-4 antibody induces astrocytic cytotoxicity in the absence of CNS antigen-specific T cells.

Neuromyelitis optica (NMO) is an inflammatory demyelinating disease of the central nervous system (CNS). Anti-aquaporin-4 antibody (AQP4-Ab) is a highly specific serum autoantibody that is detected in patients with NMO. Several lines of evidence indicate that AQP4-Ab not only serves as a disease marker but also plays a pivotal role in the pathogenesis of NMO. Although the pathogenicity of AQP4-Ab in vivo has recently been demonstrated, the presence of CNS antigen-specific T cells is recognized as a prerequisite for the antibody to exert pathogenic effects. Thus, it remains unclear whether AQP4-Ab is the primary cause of the disease or a disease-modifying factor in NMO. Here we report that pre-treatment with complete Freund's adjuvant (CFA) alone is sufficient for AQP4-Ab to induce astrocytic damage in vivo. Our results show the primary pathogenic role of AQP4-Ab in the absence of CNS antigen-specific T cells, and suggest that danger signals provided by nonspecific inflammation can be a trigger for those who harbor the autoantibody to develop NMO.

Neuromyelitis optica: Passive transfer to rats by human immunoglobulin.

Recurrent attacks of optic neuritis and myelitis are the hallmarks of both neuromyelitis optica (NMO) and multiple sclerosis (MS). NMO immunoglobulin G (NMO-IgG), which recognizes astrocytic aquaporin-4 (AQP4) water channels, is a specific serum autoantibody that distinguishes NMO from MS. The pathogenic role of the anti-AQP4 antibody (AQP4-Ab, NMO-IgG) in NMO has been speculated based on several studies in vitro. The aim of this study was to demonstrate the pathogenicity of AQP4-Ab in vivo. We obtained IgG from patients who underwent therapeutic plasmapheresis, and developed an animal model by passive transfer of IgG to rats. The active lesions of the rats exhibited pathological characteristics strikingly similar to those of NMO, marked by astrocytic loss and perivascular deposition of immunoglobulin and complements. These findings provide the first evidence of the pathogenicity of AQP4-Ab in vivo and support the therapeutic efficacy of eliminating the antibodies by plasmapheresis.

Edaravone, a free radical scavenger, ameliorates experimental autoimmune encephalomyelitis.

Reactive oxygen species (ROS) are implicated in the pathogenesis of multiple sclerosis (MS) and its murine model experimental autoimmune encephalomyelitis (EAE). The effect of edaravone, a free radical scavenger, on EAE was investigated in this study. Treatment with edaravone significantly ameliorated the clinical severity of EAE, and a reduced infiltration of lymphocytes was observed based on a histological analysis. The expression of inducible NO synthase (iNOS) in the spinal cords appeared to be reduced by the treatment with edaravone and this effect was confirmed in vitro. A reduction of both the cellular infiltration and the expression of iNOS may therefore underlie the mechanisms of the beneficial effect of edaravone on EAE.

'Crystal lattice engineering,' an approach to engineer protein crystal contacts by creating intermolecular symmetry: crystallization and structure determination of a mutant human RNase 1 with a hydrophobic interface of leucines.

A protein crystal lattice consists of surface contact regions, where the interactions of specific groups play a key role in stabilizing the regular arrangement of the protein molecules. In an attempt to control protein incorporation in a crystal lattice, a leucine zipper-like hydrophobic interface (comprising four leucine residues) was introduced into a helical region (helix 2) of the human pancreatic ribonuclease 1 (RNase 1) that was predicted to form a suitable crystallization interface. Although crystallization of wild-type RNase 1 has not yet been reported, the RNase 1 mutant having four leucines (4L-RNase 1) was successfully crystallized under several different conditions. The crystal structures were subsequently determined by X-ray crystallography by molecular replacement using the structure of bovine RNase A. The overall structure of 4L-RNase 1 is quite similar to that of the bovine RNase A, and the introduced leucine residues formed the designed crystal interface. To characterize the role of the introduced leucine residues in crystallization of RNase 1 further, the number of leucines was reduced to three or two (3L- and 2L-RNase 1, respectively). Both mutants crystallized and a similar hydrophobic interface as in 4L-RNase 1 was observed. A related approach to engineer crystal contacts at helix 3 of RNase 1 (N4L-RNase 1) was also evaluated. N4L-RNase 1 also successfully crystallized and formed the expected hydrophobic packing interface. These results suggest that appropriate introduction of a leucine zipper-like hydrophobic interface can promote intermolecular symmetry for more efficient protein crystallization in crystal lattice engineering efforts.

Vitamin K2 ameliorates experimental autoimmune encephalomyelitis in Lewis rats.

Vitamin K2 (VK2), which has been in wide use for the management of hypoprothrombinemia and osteoporosis in Japan, was tested for its efficacy on experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). The severity of EAE was significantly ameliorated by the prophylactic administration of VK2, though it was not effective when given after the onset. Inflammatory cellular infiltration and the expression of both MHC class II and inducible nitric oxide synthase (iNOS) were reduced in the spinal cords of VK2-treated rats with EAE. The inhibitory effect of VK2 on the iNOS expression in glial cells was also observed in vitro. Considering the long use of VK2 without noticeable untoward effects, it may be applicable to the patients with MS.

[A case of cholesterol embolization syndrome with cognitive impairment and pulmonary hemorrhage].

A seventy-year-old man developed color change in his left toes and was treated for frostbite. Eight months later, he developed cognitive impairment and was admitted to our hospital. A remarkable increase of eosinophils was observed in peripheral blood. Brain MRI revealed abnormal lesions in the fornix, corpus callosum, basal ganglia and frontal lobe. Steroid therapy ameliorated his symptom temporarily, but he suddenly developed cardiopulmonary arrest. His autopsy revealed severe pulmonary hemorrhage with alveolar vasculitis and cholesterol crystals in the brain, kidneys, liver, and the other organs. It was possible that cholesterol embolization to multiple organs including the brain induced systemic vasculitis that caused pulmonary hemorrhage and his critical prognosis. Cholesterol embolization should be considered when we see a patient with brain lesions accompanied with eosinophilia.

Microsomal enzyme induction and clinical aggravation of porphyria: the evaluation of human urinary 6beta-hydroxycortisol/cortisol ratio as the index of hepatic CYP3A4 activity.

The clinical aspect of porphyria has been investigated, and it is well known that porphyrinogens such as estrogens and alcohol or other inducers of P450 isoenzymes exacerbate the porphyric state. However, there can be a delay in diagnosing porphyria and a difficulty in selecting safe medicine for it even today. A 21-year-old woman developed epilepsy, disturbance of mental state, and spastic tetraparesis during the convalescent period after acute viral encephalitis. She was diagnosed with porphyria after the fifth hospitalization. In the course of modifying her anticonvulsant regimen, the authors examined the 6beta-hydroxycortisol/cortisol ratio (6beta-OHF/F) in her urine, which can be the index of hepatic CYP3A4 activity, with electrospray ionization/mass spectrometry/mass spectrometry (ESI/MS/MS). Generalized and partial complex seizures, other neurological signs and symptoms, and laboratory data were improved after modification of her anticonvulsant regimen. This is the first report of evaluating the urinary 6beta-hydroxycortisol/cortisol ratio in a case of porphyria.

[A case of possible neuro-Sweet disease with prolonged disturbance of consciousness and no dermal lesion during the course of dementia].

The patient was a 58-year-old man with 1-year history of cognitive decline, which was diagnosed as Alzheimer's disease in another hospital. He was admitted to our hospital for extreme fatigue, weight loss, and dysphagia, subsequent to the left peripheral facial paresis. Brain magnetic resonance (MR) imaging showed bilateral diffuse white matter lesions and hippocampal atrophy. After admission, he presented with sudden high fever, recurrent exacerbations of consciousness, and increased C-reactive protein level with marked neutrophilia, with the result that he underwent mechanical ventilation. Routine cerebrospinal fluid findings at the exacerbation were normal i.e. 4.7 cells/mm(3), 40 mg/dl of protein, but IL-6 concentration was mildly elevated to 22.2 pg/ml. After confirming the positivity of HLA (human leukocyte antigen) B54 and Cw1, we administered steroid to him and his physical activity and state of consciousness significantly improved. During the course of treatment, dermal lesion characterisitic of Sweet disease was absent. We diagnosed this case was possible neuroSweet disease proposed by Hisanaga in 2005.

Sema4A inhibits the therapeutic effect of IFN-ß in EAE.

Approximately one-third of patients with multiple sclerosis (MS) respond poorly to interferon-beta (IFN-ß) therapy. Serum Sema4A is increased in MS patients, and those who have high Sema4A do not respond to IFN-ß therapy. In this study, we investigated whether recombinant Sema4A abrogates the efficacy of IFN-ß in mice with experimental autoimmune encephalomyelitis (EAE), an animal model of MS. Administration of Sema4A concurrently with IFN-ß diminished the efficacy of IFN-ß in EAE. These effects of Sema4A were attributed to promote Th1 and Th17 differentiation and to increase adhesive activation of T cells to endothelial cells, even in the presence of IFN-ß.

[Brain abscess mediated through a pulmonary arteriovenous malformation in a patient with hereditary hemorrhagic telangiectasia].

The patient is a 66-year-old man with hereditary telangiectasia. He was diagnosed with pulmonary arteriovenous malformation (PAVM), which was revealed by contrast-enhanced chest computed tomography at the age of 65. He developed headache, right homonymous hemianopsia, and right hemiparesis and was admitted to our hospital. Contrast-enhanced magnetic resonance imaging revealed multiple lesions in the left hemisphere, which indicates brain abscesses. Thus, the diagnosis of brain abscess mediated through PAVM was established. Following management with drainage and coil embolization, all neurological symptoms resolved. Therefore, coil embolization should be considered for PAVM at an early stage to prevent brain abscess, even if it is asymptomatic.

The lactic acid bacterium Pediococcus acidilactici suppresses autoimmune encephalomyelitis by inducing IL-10-producing regulatory T cells.

BACKGROUND: Certain intestinal microflora are thought to regulate the systemic immune response. Lactic acid bacteria are one of the most studied bacteria in terms of their beneficial effects on health and autoimmune diseases; one of which is Multiple sclerosis (MS) which affects the central nervous system. We investigated whether the lactic acid bacterium Pediococcus acidilactici, which comprises human commensal bacteria, has beneficial effects on experimental autoimmune encephalomyelitis (EAE), an animal model of MS. METHODOLOGY/PRINCIPAL FINDINGS: P. acidilactici R037 was orally administered to EAE mice to investigate the effects of R037. R037 treatment suppressed clinical EAE severity as prophylaxis and therapy. The antigen-specific production of inflammatory cytokines was inhibited in R037-treated mice. A significant increase in the number of CD4(+) Interleukin (IL)-10-producing cells was observed in the mesenteric lymph nodes (MLNs) and spleens isolated from R037-treated naive mice, while no increase was observed in the number of these cells in the lamina propria. Because only a slight increase in the CD4(+)Foxp3(+) cells was observed in MLNs, R037 may primarily induce Foxp3(-) IL10-producing T regulatory type 1 (Tr1) cells in MLNs, which contribute to the beneficial effect of R037 on EAE. CONCLUSIONS/SIGNIFICANCE: An orally administered single strain of P. acidilactici R037 ameliorates EAE by inducing IL10-producing Tr1 cells. Our findings indicate the therapeutic potential of the oral administration of R037 for treating multiple sclerosis.