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Myasthenia gravis (MG) is one of the autoantibody-mediated neuroimmunological diseases. Autoantibodies to the muscle-type nicotinic acetylcholine receptor (AChR) were detected in more than 80% of MG patients. The gene structure and pathogenicity of some AChR antibodies produced in MG have already been identified and elucidated, respectively. Therefore, the AChR antibody is similar in nature to innovative drug development targets with respect to MG treatment. Here, we discuss the development of molecular target drugs for AChR antibody-positive MG.

Autoimmune autonomic ganglionopathy (AAG), clinically characterized by gastrointestinal dysmotility, orthostatic hypotension and tonic pupils, is an idiopathic acquired disorder of the autonomic nervous system elicited by antibodies against ganglionic acetylcholine receptor (gAChR). We encountered a 60-year-old man who presented with severe anhidrosis, difficulty in thermoregulation, orthostatic hypotension, gastrointestinal dysmotility, tonic pupils and ptosis. Histologically, an anhidrotic skin sample was normal. Routine laboratory examinations of blood, urine and cerebrospinal fluid returned no abnormal findings. Serological examination revealed antibodies against α3 and β4 subunits of gAChR. The diagnosis was AAG. As sudomotor dysfunction reflects ganglionic neuropathy in AAG, we concluded that his anhidrosis was attributable to AAG. Anhidrosis is an important clue for the diagnosis of AAG, a rare neurological disorder., (© 2017 Japanese Dermatological Association.)

Objectives: Autonomic dysfunction is closely associated with autoimmune diseases (AID) including primary biliary cirrhosis (PBC). The objective of this study was to determine the prevalence of anti-ganglionic (nicotinic) acetylcholine receptor (gAChR) antibodies in patients with AID., Methods: We determined the presence of gAChR antibodies in serum samples from 146 patients (systemic lupus erythematosus [SLE] = 32; rheumatoid arthritis [RA] = 43; systemic sclerosis [SSc] = 38; PBC= 33) without information regarding autonomic symptoms, as well as 34 patients with other neurological diseases [OND], and 73 healthy controls [HC]. We specifically analyzed sera for anti-gAChRα3 and -β4 antibodies using the luciferase immunoprecipitation system (LIPS) assay., Results: LIPS assay detected anti-gAChRα3 and -β4 antibodies in the sera from patients with SLE (12.5%, 4/32), RA (18.6%, 8/43), SSc (13.2%, 5/38), PBC (9.1%, 3/33), OND (2.9%, 1/34), and HC (0.0%, 1/73). There were no significant correlations between the levels of anti-gAChRα3 and -β4 antibodies, and the total titers of autoantibodies in AID., Conclusions: The results demonstrated a significant prevalence of anti-gAChR antibodies in patients with AID, which is independent of the production of other autoantibodies in patients with autoimmune diseases. These anti-gAChR antibodies could mediate the autonomic dysfunction involved in the autoimmune mechanisms of AID.

Consumers have had concerns over the safety of Fukushima-produced foods since the Fukushima-Daiichi nuclear power plant accident. To dispel these concerns, the public administration has distributed the informational leaflets, which guarantee the safety of Fukushima-produced foods in the marketplace. We investigated the effectiveness of the leaflets. Previous research showed that the activation of behavioral immune system exacerbated prejudice toward out-group members. Therefore, we investigated whether reading the leaflets about the safety of foods would increase prejudice toward foreigners. Participants (N = 50) were asked to read a leaflet either relevant or irrelevant to the safety of Fukushima-produced foods and then complete a Japanese-Foreigners Implicit Association Test and Perceived Vulnerability to Disease Scale. As predicted, participants high in chronic germ aversion (GA) were more prejudiced against foreigners when reading the leaflet relevant to the safety of Fukushima-produced foods than when reading the leaflet irrelevant to the issue. No such effect was observed among participants low in GA. These results indicated the possibility that the current leaflet about the safety of Fukushima foods might backfire.

Objectives: To examine anti-KIR4.1 antibodies by 2 different assays in Japanese patients with multiple sclerosis (MS) or neuromyelitis optica (NMO)., Methods: One hundred sixty serum samples from 57 patients with MS, 40 patients with NMO/NMO spectrum disorder (NMOSD), and 50 healthy controls (all were Japanese) were tested with ELISA using a synthetic peptide of the first extracellular portion of human KIR4.1. In addition, we attempted to detect anti-KIR4.1 immunoglobulin G in the serum by the luciferase immunoprecipitation systems (LIPS) with the full length of human KIR4.1 produced in a human cell line, which is highly sensitive to single or multiple epitopes., Results: We failed to detect antibodies to the peptide fragment KIR4.1(83-120) in any case of MS and NMO/NMOSD using ELISA. Antibodies to the recombinant full length of KIR4.1 protein were detected in only 2 patients with MS and none in the patients with NMO/NMOSD by the LIPS assay., Conclusions: We developed 2 different methods (ELISA and LIPS) to measure autoantibodies to KIR4.1 in serum. We detected anti-KIR4.1 immunoglobulin G at a very low frequency in Japanese patients with MS or NMO/NMOSD. Serologic testing for human KIR4.1-specific antibodies is unlikely to improve the diagnosis of MS or NMO/NMOSD in Japanese patients.

Objectives: Although standardized autonomic tests are useful for diagnosing autonomic failure in patients with Guillain-Barré syndrome (GBS), they cannot be used as predictive markers. Thus, serological markers may correctly identify patients with GBS who are at risk for autonomic dysfunction., Methods: We validated a luciferase immunoprecipitation system that detects IgG antibodies in patient serum that specifically bind to the α3 or β4 subunits of ganglionic neuronal nicotinic acetylcholine receptors (gAChR). We then used luciferase-conjugated ligands specific to antibodies against two gAChR subunits to test 79 sera samples from patients with GBS, 34 from subjects with other neurological diseases (OND), and 73 from healthy controls (HC). 1) In the first analysis, patients were classified into two groups according to the presence or absence of autonomic symptoms (AS). We compared the frequency of the anti-gAChR antibodies between these two groups (AS+ and AS-). 2) In the second analysis, furthermore, patients were classified depending on the presence or absence of anti-glycolipid antibodies (AGA). We compared the frequency of the anti-gAChR antibodies between the four categories of GBS (AS+/AGA+, AS+/AGA-, AS-/AGA+, and AS-/AGA-), OND, and HC., Results: Eight subjects with GBS were positive for α3 subunits, while one was positive for β4 subunits. Anti-α3 and -β4 gAChR antibodies were also detected in 13.6% of AS+ GBS group in the first analysis. Two of 35 patients in AS-GBS group were seropositive for the anti-gAChR antibodies and AGA in the second analysis. Patients with GBS that were positive for serum antibodies to the α3 and/or β4 subunits of gAChRs showed a range of clinical features including AS and AGA., Conclusions: Patients with GBS may have circulating antibodies against gAChR, which may contribute to the autonomic dysfunction associated with this disease., (Copyright © 2016 Elsevier B.V. All rights reserved.)

In terms of goal management, this study examined whether progress toward one goal (health goal) leads to goal shifting to another goal (fulfill one's appetite). In the experiment, 47 participants were asked to drink the same quantity of vegetable juice out of either a large or a small cup. Then they rated how hungry they were at that moment. Results showed that participants who drank out of a small cup reported a sense of feeling hungrier than those who drank out of a large cup because the former perceived progress toward a health goal more than the latter. Furthermore, concern with daily intake of vegetables moderated this tendency. Participants who were less concerned with daily intake of vegetables were more likely to report feeling hungrier after drinking out of a small cup (versus a large cup). These results support our hypothesis. We discuss the advantages and disadvantages of these mechanisms for self-regulation.

This research investigated how to overcome temptations and protect high-order goals while pursuing a goal. We hypothesized that in order to promote self-regulation, individuals non-cousciously engage in asymmetric evaluative responses to goal-relevant and temptation-relevant stimuli. In an experiment, we manipulated either diet goal or academic goal. Then, we measured evaluations of either sugary drinks (e.g., Coke, Fanta) or healthy drinks (e.g., Healthya Green Tea, Black Oolong Tea). The results showed that participants who activated a diet goal had significantly more positive evaluations of healthy drinks than sugary drinks. In addition, this tendency was moderated by the means of dieting (i.e., only participants who cut down on sweets when going on a diet). The role of non-consious asymmetric evaluations for self-regulation is discussed.

Background: There is a complex relationship between rhinitis, asthma, and nocturnal cough., Methods: To evaluate whether rhinitis is an important risk factor for nocturnal cough and whether this effect is independent of asthma, we analyzed data collected using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire in a population-based nationwide survey. A child who had experienced a dry cough at night in the past 12 months in the absence of a cold was defined as having nocturnal cough., Results: After excluding 11,475 records with incomplete data, data from 136,506 children were analyzed. Nocturnal cough was significantly more prevalent in children with current rhinitis compared with children without rhinitis. The association between rhinitis and nocturnal cough was significant in children who had current asthma (adjusted OR [95% CI]: 2.26 [2.00-2.56] in children aged 6-7 yr, 1.90 [1.58-2.30] in those aged 13-14 yr, and 1.86 [1.60-2.19] in those aged 16-17 yr), and this association was even higher among children who had no asthma (adjusted OR [95% CI]: 3.65 [3.36-3.97] in children aged 6-7 yr, 3.05 [2.79-3.32] in those aged 13-14 yr, and 2.69 [2.51-2.88] in those aged 16-17 yr)., Conclusions: There was a close association between rhinitis and nocturnal cough in young children through adolescents, and this effect was independent of asthma. Upper airways should be examined in children with nocturnal cough., (© 2012 John Wiley & Sons A/S.)

The neuromuscular junction (NMJ) is a synapse between a motor neuron and skeletal muscle. The contraction of skeletal muscle is controlled by the neurotransmitter acetylcholine (ACh), which is released from the motor nerve terminal. To achieve efficient neuromuscular transmission, acetylcholine receptors (AChRs) must be densely clustered on the muscle membrane of the NMJ. Failure of AChR clustering is associated with disorders of neuromuscular transmission such as congenital myasthenic syndromes (CMS) and myasthenia gravis (MG). Motoneuronal agrin and muscle-specific receptor tyrosine kinase (MuSK) are known to play essential roles in the formation and maintenance of NMJs in the central region of each muscle. However, it had been unclear how agrin activates MuSK. Recent studies have elucidated the roles of several key molecules, including the cytoplasmic adaptor protein Dok-7 and LDL receptor-related protein 4 (Lrp4), in agrin-induced MuSK activation. Moreover, new evidence indicates that cyclin-dependent kinase 5 (Cdk5) regulates postsynaptic differentiation. In this review, we summarize the latest developments in molecular mechanisms underlying NMJ formation in vertebrates.

Myasthenia gravis (MG) is an autoimmune disease of the neuromuscular junction, where acetylcholine receptor (AChR), muscle-specific kinase (MuSK), and low-density lipoprotein (LDL) receptor-related protein 4 (Lrp4) are essential. About 80% and 0% to 10% of patients with generalized MG have autoantibodies to AChR and MuSK, respectively, but pathogenic factors are elusive in others. Here we show that a proportion of AChR antibody-negative patients have autoantibodies to Lrp4. These antibodies inhibit binding of Lrp4 to its ligand and predominantly belong to the immunoglobulin G1 (IgG1) subclass, a complement activator. These findings together indicate the involvement of Lrp4 antibodies in the pathogenesis of AChR antibody-negative MG., (Copyright © 2011 American Neurological Association.)

Background: Foreign body aspiration (FBA) is a common cause for a respiratory emergency in young children and can be a life-threatening event. We, therefore, conducted the first nationwide survey in Japan., Methods: We asked doctors of 261 tertiary hospitals across the nation to fill out a case card of FBA-diagnosed cases they had experienced for the past 2 years. In the case card, age and gender of the patients, elapsed time until being referred to the hospital, presenting symptoms, previous diagnosis, suspected aspiration episode, type and location of aspirated foreign body, and consequences were inquired. This retrospective survey was carried out during 21 months, since January 2005 through September 2006., Results: Replies from 169 hospitals (64.8%) revealed that 163 cases of FBA had been treated in 114 hospitals during the past 2 years. Median age of cases was 1 year (2 months to 15 years), and 66.5% were male. Only 50.9% of the cases were referred to hospitals within 24h. Comparing these early-diagnosed cases, children with delayed diagnosis had similar age and sex distribution. In respect of presenting symptoms, characteristic ones such as choking or dyspnea were observed significantly more often in the early-diagnosed cases, whereas significantly predominant symptoms in children with delayed diagnosis were non-specific ones like coughing and wheezing (both, p<0.05). Although significantly more cases with early diagnosis reported suspected aspiration episodes (p<0.05), even in the delayed diagnosis group more than half cases (65%) had suspected episodes as well. Severe consequences occurred in seven cases (4.3%): four cases of irreversible hypoxic brain damage and one death due to multiorgan failure in the early diagnosis group; one bronchiectasis and one recurrent pneumonia in the delayed diagnosis group., Conclusions: Characteristics of FBA among children in Japan were not substantially different from the reports from other countries. Suspected episodes were important, and there were some differences in presenting symptoms between early and delayed diagnosis cases. However, there are still no key sings to make a prompt diagnosis. In order to prevent FBA and make a timely diagnosis, continuous and extensive educational programs should be provided.

Dok-7 is a cytoplasmic activator of muscle-specific receptor-tyrosine kinase (MuSK). Both Dok-7 and MuSK are required for neuromuscular synaptogenesis. Mutations in DOK7 underlie a congenital myasthenic syndrome (CMS) associated with small and simplified neuromuscular synapses likely due to impaired Dok-7/MuSK signaling. The overwhelming majority of patients with DOK7 CMS have at least one allele with a frameshift mutation that causes a truncation in the COOH-terminal region of Dok-7 and affects MuSK activation. Dok-7 has pleckstrin homology (PH) and phosphotyrosine binding (PTB) domains in the NH2-terminal moiety, both of which are indispensable for MuSK activation in myotubes, but little is known about additional functional elements. Here, we identify a chromosome region maintenance 1-dependent nuclear export signal (NES) in the COOH-terminal moiety and demonstrate that the NES-mediated cytoplasmic location of Dok-7 is essential for regulating the interaction with MuSK in myotubes. The NH2-terminal PH domain is responsible for the nuclear import of Dok-7. We also show that the Src homology 2 target motifs in the COOH-terminal moiety of Dok-7 are active and crucial for MuSK activation in myotubes. In addition, CMS-associated missense mutations found in the PH or PTB domain inactivate Dok-7. Together, these findings demonstrate that, in addition to the NH2-terminal PH and PTB domains, the COOH-terminal NES and Src homology 2 target motifs play key roles in Dok-7/MuSK signaling for neuromuscular synaptogenesis. Ablation or disruption of these functional elements in Dok-7 probably underlies the neuromuscular junction synaptopathy observed in DOK7 CMS.

Congenital myasthenic syndromes (CMSs) are a group of inherited disorders of neuromuscular transmission characterized by fatigable muscle weakness. One major subgroup of patients shows a characteristic "limb girdle" pattern of muscle weakness, in which the muscles have small, simplified neuromuscular junctions but normal acetylcholine receptor and acetylcholinesterase function. We showed that recessive inheritance of mutations in Dok-7, which result in a defective structure of the neuromuscular junction, is a cause of CMS with proximal muscle weakness.

The formation of the neuromuscular synapse requires muscle-specific receptor kinase (MuSK) to orchestrate postsynaptic differentiation, including the clustering of receptors for the neurotransmitter acetylcholine. Upon innervation, neural agrin activates MuSK to establish the postsynaptic apparatus, although agrin-independent formation of neuromuscular synapses can also occur experimentally in the absence of neurotransmission. Dok-7, a MuSK-interacting cytoplasmic protein, is essential for MuSK activation in cultured myotubes; in particular, the Dok-7 phosphotyrosine-binding domain and its target in MuSK are indispensable. Mice lacking Dok-7 formed neither acetylcholine receptor clusters nor neuromuscular synapses. Thus, Dok-7 is essential for neuromuscular synaptogenesis through its interaction with MuSK.

Adaptor proteins are essential in coordinating recruitment and, in a few cases, restraint of various effectors during cellular signaling. Dok-1, Dok-2 and Dok-3 comprise a closely related family of adaptor, which negatively regulates mitogen-activated protein kinase Erk downstream of protein-tyrosine kinases (PTKs). Recruitment of p120 rasGAP, a potent inhibitor of Ras, by Dok-1 and Dok-2 appears critical in the negative regulation of the Ras-Erk pathway. However, as Dok-3 does not bind rasGAP, it has been unclear how Dok-3 inhibits Erk downstream of PTKs. Here, we identified Grb2 as a Dok-3-binding protein upon its tyrosine phosphorylation. This interaction required the intact binding motifs of the Grb2 SH2 domain, and a mutant (Dok-3-FF) having a Tyr/Phe substitution at these motifs failed to inhibit Ras and Erk activation downstream of a cytoplasmic PTK Src. Because Grb2 forms a stable complex with Sos, a crucial activator of Ras, these data suggest that Dok-3 restrains Grb2 and inhibits the ability of the Grb2-Sos complex to activate Ras. Indeed, forced expression of Dok-3, but not Dok-3-FF, inhibited the recruitment of the Grb2-Sos complex to Shc downstream of Src, which is an essential event for activation of the Ras-Erk pathway. These findings indicate that Dok-3 sequesters Grb2 from Shc and inhibits the Ras-Erk pathway downstream of PTKs.

A 31-year-old Japanese woman was referred to our hospital after experiencing a convulsion. Upon radiological examination, a heterogeneously enhanced tumor was found on the anterior skull base. The tumor was surgically removed. On light microscopy, the tumor cells appeared spindle-shaped, forming an interwoven pattern. The nuclei were arranged partially parallel mimicking a palisading pattern. At first, the tumor was thought to be schwannoma. However, it was positive for S-100 and negative for both epithelial membrane antigen (EMA) and Leu7. The final diagnosis was olfactory ensheathing cell (OEC) tumor. OECs are similar to Schwann cells in microscopic appearance and upon immunohistochemical staining. However, the OECs are negative for CD57 (Leu7), while the Schwann cells are positive for it. Our patient's tumor had immunological characteristics identical to those of OEC. In the English and Japanese literature, 21 cases of solitary schwannoma on the anterior skull base have been reported. Although several theories have been suggested, the pathogenesis of subfrontal schwannoma has not been clarified. Also, OECs have never been considered as their origin. However, as in our case, OECs, rather than Schwann cells, are suspected as the origin in some of the cases.

The Wnt signaling pathway is activated in most human colorectal tumors. Mutational inactivation in the tumor suppressor adenomatous polyposis coli (APC), as well as activation of beta-catenin, causes the accumulation of beta-catenin, which in turn associates with the T cell factor/lymphoid enhancer factor (TCF/LEF) family of transcription factors and activates transcription of their target genes. Here we show that beta-catenin activates transcription of the BMP and activin membrane-bound inhibitor (BAMBI)/NMA gene. The expression level of BAMBI was found to be aberrantly elevated in most colorectal and hepatocellular carcinomas relative to the corresponding non-cancerous tissues. Expression of BAMBI in colorectal tumor cell lines was repressed by a dominant-negative mutant of TCF-4 or by an inhibitor of beta-catenin-TCF interaction, suggesting that beta-catenin is responsible for the aberrant expression of BAMBI in colorectal tumor cells. Furthermore, overexpression of BAMBI inhibited the response of tumor cells to transforming growth factor-beta signaling. These results suggest that beta-catenin interferes with transforming growth factor-beta-mediated growth arrest by inducing the expression of BAMBI, and this may contribute to colorectal and hepatocellular tumorigenesis.

We describe an 8-year-old boy who presented with steroid-resistant nephrotic syndrome (SRNS) associated with X-linked ichthyosis (XLI). At birth, the patient exhibited scaly skin, cryptorchidism, and steroid sulfatase (STS) deficiency. DNA analysis showed deletion of exons 1-10 of the STS gene. Proteinuria developed at 6 years and was resistant to steroid therapy. Kidney biopsy findings prior to steroid therapy were compatible with minimal change nephrotic syndrome. By immunofluorescence, glomerular basement membranes exhibited diffuse linear staining for the alpha5 chain of collagen IV, making X-linked Alport syndrome an unlikely explanation for the association of SRNS and ichthyosis. Despite immunosuppressive therapy together with oral prednisolone, no clinical response was achieved. He rapidly reached end-stage renal failure and finally underwent renal transplantation. We propose that SRNS should be considered as one of the highly variable phenotypes associated with XLI.