Neuromyelitis optica (NMO) is clinically characterized by severe optic neuritis and transverse myelitis. In Japan, NMO has been named optic-spinal multiple sclerosis (OSMS) and it has been thought to ...be a subtype of multiple sclerosis (MS). However, several clinical and laboratory findings suggest NMO or OSMS is distinct from MS. Recently, the disease-specific antibody (NMO-IgG) was found in the serum from NMO patients, and its target antigen was identified as aquaporin-4 (AQP4) water channel protein which is mainly expressed in astroglial foot processes. However, the pathogenetic role of AQP4 in NMO remains unknown. We herein report a typical case of NMO in which immunohistochemical analysis showed a lack of AQP4 in the spinal cord lesions. The loss of AQP4 was evident in the central gray matter, especially in the perivascular lesions where immunoglobulins and complements were deposited, and glial fibrillary acidic protein (GFAP) staining was weak in those lesions. However, GFAP was strongly stained at the reactive astrogliosis surrounding the lesions. Myelin basic protein (MBP)-stained myelinated fibers were relatively preserved in the lesions where AQP4 was lost. In contrast to these NMO lesions, AQP4 was expressed predominantly in the gray matter in control spinal cords, and AQP4 was preserved in demyelinating MS lesions. Our findings suggest that astrocytic impairment associated with humoral immunity against AQP4 may be primarily involved in the lesion formation of NMO, and that the pathomechanisms of NMO are different from those of MS in which demyelination is the primary pathology.
Approximately 20% of familial amyotrophic lateral sclerosis (FALS) arises from germ-line mutations in the superoxide dismutase-1 (SOD1) gene. However, the molecular mechanisms underlying the process ...have been elusive. Here, we show that a neuronal homologous to E6AP carboxyl terminus (HECT)-type ubiquitin-protein isopeptide ligase (NEDL1) physically binds translocon-associated protein-δ and also binds and ubiquitinates mutant (but not wild-type) SOD1 proportionately to the disease severity caused by that particular mutant. Immunohistochemically, NEDL1 is present in the central region of the Lewy body-like hyaline inclusions in the spinal cord ventral horn motor neurons of both FALS patients and mutant SOD1 transgenic mice. Two-hybrid screening for the physiological targets of NEDL1 has identified Dishevelled-1, one of the key transducers in the Wnt signaling pathway. Mutant SOD1 also interacted with Dishevelled-1 in the presence of NEDL1 and caused its dysfunction. Thus, our results suggest that an adverse interaction among misfolded SOD1, NEDL1, translocon-associated protein-δ, and Dishevelled-1 forms a ubiquitinated protein complex that is included in potentially cytotoxic protein aggregates and that mutually affects their functions, leading to motor neuron death in FALS.
Cerebral ischemia induces microglial and astroglial activation, which may play a crucial role in the development of ischemic neuronal damage. In this study, we examined the role of cell cycle ...proteins in glial proliferation in the hippocampus following 10
min of global cerebral ischemia in the rat. Proliferating cells were identified with immunostaining for proliferating cell nuclear antigen (PCNA), and glial cells were visualized with immunostaining for microglial response factor-1 (microglia/macrophages) and glial fibrillary acidic protein (astrocytes). Expression of cyclin D1 and cyclin-dependent kinase-4 was also examined with double label immunohistochemistry. Proliferating cells in the CA1 region after ischemia consisted of microglia and much fewer astrocytes. Microglial activation and proliferation (7.6-fold increase in number after 7 days) were preceded by an increase in PCNA-positive microglia; 83% of microglia were PCNA-positive after 2 days. Astrocytes increased by 1.8-fold after 7 days, and only 6% of astrocytes became PCNA-positive by day 7. Cyclin D1 and cyclin-dependent kinase-4 immunoreactivity appeared in these glial cells in parallel with the expression of PCNA. The findings suggest that the accumulation of brain macrophages elicited by transient cerebral ischemia is caused predominantly by activation and proliferation of resident microglia through the upregulation of cell cycle proteins.
Hepatocyte growth factor (HGF) is one of the most potent survival-promoting factors for motor neurons. We showed that introduction of the HGF gene into neurons of G93A transgenic mice attenuates ...motor neuron degeneration and increases the lifespan of these mice. Currently, treatment regimens using recombinant protein are closer to clinical application than gene therapy. To examine its protective effect on motor neurons and therapeutic potential we administered human recombinant HGF (hrHGF) by continuous intrathecal delivery to G93A transgenic rats at doses of 40 or 200 μg and 200 μg at 100 days of age (the age at which pathologic changes of the spinal cord appear, but animals show no clinical weakness) and at 115 days (onset of paralysis), respectively, for 4 weeks each. Intrathecal administration of hrHGF attenuates motor neuron degeneration and prolonged the duration of the disease by 63%, even with administration from the onset of paralysis. Our results indicated the therapeutic efficacy of continuous intrathecal administration of hrHGF in transgenic rats and should lead to the consideration for further clinical trials in amyotrophic lateral sclerosis using continuous intrathecal administration of hrHGF.
8-hydroxy-2′-deoxyguanosine (8-OHdG) or 8-hydroxyguanosine (8-OHG), a product of oxidized DNA or RNA, is a good marker of oxidative cellular damage. In this study, we measured the 8-OHdG/8-OHG levels ...in the serum and cerebrospinal fluid (CSF) of patients with Parkinson's disease (PD) and multiple system atrophy (MSA). Compared to age-matched controls, the mean levels of serum 8-OHdG/8-OHG were significantly higher in PD (P < 0.0001). Although no gender differences were observed in the controls, the mean values of serum 8-OHdG/8-OHG were significantly higher in female PD cases (P < 0.005) than in male patients. 8-OHdG/8-OHG levels in CSF were also increased significantly in patients with PD and MSA, however, their relative values were generally much lower than those in the serum. Together with previous studies showing increased peripheral 8-OHdG levels in Alzheimer's disease and amyotrophic lateral sclerosis, the data presented here suggest that systemic DNA/RNA oxidation is commonly observed in neurodegenerative diseases. Our results also imply that female patients with PD show higher levels of oxidative stress, which may explain the faster progression of this disease in females.
► P188 reduces overload-induced muscle atrophy in dysferlin-deficient mice. ► Phosphorylated p38 was reduced in P188 administered SJL mice. ► Diminished expression of atrogin-1, an E3-ubiquitin ...ligase, is the effector molecule. ► A basis for potential therapeutic strategies for dysferlinopathy.
Dysferlin-deficient SJL mice are commonly used to study dysferlinopathy. We demonstrated that poloxamer 188 (P188), a membrane sealant, is effective in reducing the loss of muscle mass in SJL mice when administered using an osmotic pump for 6 weeks. We did not observe significant changes over a 2-week administration period, suggesting that longthier observation is necessary to determine the effectiveness of P188. We also examined exercise endurance in P188-administered SJL mice using a rolling cage. Phosphorylated p38 was found to be reduced in P188-administered SJL mice; additionally, using microarray analysis, we found diminished expression of atrogin-1, an E3 ubiquitin ligase, as the effector of muscular atrophy. Chronic infusion of P188 to dysferlin-deficient SJL mice reduced muscular atrophy, and administering p38 and atrogin-1 in the gastrocnemius muscle improved its motor function. These results provide a basis for potential treatments for dysferlin-deficient skeletal muscle fibers.
It has been suggested that interleukin-1 (IL-1) is a potent inflammatory mediator and that it is synthesized and secreted into the brain parenchyma. The aim of the present study is to evaluate the ...contribution of IL-1 to brain edema formation after focal brain ischemia.
The brain water content was measured to evaluate postischemic brain injury in rats after 60 minutes of middle cerebral artery occlusion and reperfusion. The effects of exogenous application of recombinant human interleukin-1 beta (rhIL-1 beta), anti-interleukin-1 beta neutralizing antibodies (anti-IL-1 beta), and the IL-1 blocker zinc protoporphyrin (ZnPP) on brain water content were observed, and histological technique was used to measure the infarction size and number of inflammatory cells infiltrated into the brain.
Transient ischemia induced marked increase of brain water content, necrosis, and neutrophilic infiltration in the cortex perfused by the middle cerebral artery and the dorsal and ventral areas of the caudate putamen. Injection of rhIL-1 beta into the left lateral ventricle immediately after reperfusion markedly enhanced ischemic brain edema formation in these three areas in a dose-dependent manner (88.4 +/- 0.7% and 86.6 +/- 0.4% in the dorsal and ventral parts of the caudate putamen, respectively, in rats treated with 10 ng rhIL-1 beta; P < .01). rhIL-1 beta also increased the size of the brain infarction, and it tended to increase the number of infiltrating neutrophils in ischemic areas and the number of neutrophils adherent to the endothelium. In contrast, administration of anti-IL-1 beta and ZnPP into the left cerebral ventricle attenuated the postischemic increase of brain water content and decreased the size of brain infarction (83.5 +/- 2.0% and 79.9 +/- 2.0% in the dorsal and ventral parts of the caudate putamen, respectively, in rats treated with 10 micrograms anti-IL-1 beta; P < .01). The number of neutrophils that infiltrated into ischemic areas also tended to decrease with anti-IL-1 beta or ZnPP treatment.
Application of rhIL-1 beta augmented the increase of brain water content, and application of anti-IL-1 beta depressed the increase of water content. These results tended to correlate with the neutrophilic infiltration into the parenchyma. It thus appears that IL-1 beta may play an important role in ischemic brain damage after reperfusion.
Summary Sarcoidosis is a chronic systemic granulomatous disorder of unknown etiology. The precise mechanism by which granulomatous lesions form is still obscure. Dendritic cells (DCs) are the most ...efficient antigen presenting cells; however, pathologic investigations of dendritic cells in the affected lesions of sarcoidosis are quite limited. We immunohistochemically examined the localization and phenotypes of dendritic cells and the expressions of CD40 and CD40L (CD154), which are key molecules in dendritic cell activation, in the muscles of 5 patients with muscular sarcoidosis, 8 patients with muscular disorders without inflammation, and 4 patients with histologically normal muscles as controls. In muscular sarcoidosis, CD1c-positive myeloid dendritic cells were scattered mainly in the lymphocyte layers of granulomas and the endomysium around the granulomas. Double immunostaining revealed that some CD1c-positive cells expressed the mature dendritic cell marker CD83, but immature dendritic cell marker CD1a-positive cells were not found. Smaller numbers of Blood dendritic cell antigen (BDCA)-2–positive plasmacytoid dendritic cells were found in the lymphocyte layers of granulomas. In the controls, small numbers of CD1c-positive cells were seen in the endomysium, whereas BDCA-2–positive cells were not observed except in 1 case. In muscular sarcoidosis, CD40 was expressed on mononuclear cells, on the interstitium around the muscle fibers and granulomas, and on the endothelium of vessels. CD40L was positive on mononuclear cells scattered within and around granulomas in 3 of 5 patients. In the controls, CD40 was expressed on the endothelium of the vessels and sparse mononuclear cells in the lesions of muscle fiber necrosis, whereas CD40L was not seen in any. In muscular sarcoidosis, recruitment of myeloid dendritic cells and less plasmacytoid dendritic cells and up-regulation of the CD40/CD40L system in affected muscles suggest that myeloid dendritic cells may be mainly involved in granulomatous inflammation through antigen presentation in a Th1 immune milieu.
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