The genetic profile of dysferlinopathy in a cohort of 209 cases: Genotype-phenotype relationship and a hotspot on the inner DysF domain.

Dysferlinopathy is a group of autosomal recessive muscular dystrophies caused by variants in the dysferlin gene (DYSF), with variable proximal and distal muscle involvement. We performed DYSF gene analyses of 200 cases suspected of having dysferlinopathy (Cohort 1), and identified diagnostic variants in 129/200 cases, including 19 novel variants. To achieve a comprehensive genetic profile of dysferlinopathy, we analyzed the variant data from 209 affected cases from unrelated 209 families, including 80 previously diagnosed and 129 newly diagnosed cases (Cohort 2). Among the 90 types of variants identified in 209 cases, the NM_003494.3: c.2997G>T; p.Trp999Cys, was the most frequent (96/420; 22.9%), followed by c.1566C>G; p.Tyr522* (45/420; 10.7%) on an allele base. p.Trp999Cys was found in 70/209 cases (33.5%), including 20/104 cases (19.2%) with the Miyoshi muscular phenotype and 43/82 cases (52.4%) with the limb-girdle phenotype. In the analysis of missense variants, p.Trp992Arg, p.Trp999Arg, p.Trp999Cys, p.Ser1000Phe, p.Arg1040Trp, and p.Arg1046His were located in the inner DysF domain, representing in 113/160 missense variants (70.6%). This large cohort highlighted the frequent missense variants located in the inner DysF domain as a hotspot for missense variants among our cohort of 209 cases (>95%, Japanese) and hinted at their potential as targets for future therapeutic strategies.

Cerebral small-vessel disease protein HTRA1 controls the amount of TGF-ß1 via cleavage of proTGF-ß1.

Cerebral small-vessel disease is a common disorder in elderly populations; however, its molecular basis is not well understood. We recently demonstrated that mutations in the high-temperature requirement A (HTRA) serine peptidase 1 (HTRA1) gene cause a hereditary cerebral small-vessel disease, cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL). HTRA1 belongs to the HTRA protein family, whose members have dual activities as chaperones and serine proteases and also repress transforming growth factor-ß (TGF-ß) family signaling. We demonstrated that CARASIL-associated mutant HTRA1s decrease protease activity and fail to decrease TGF-ß family signaling. However, the precise molecular mechanism for decreasing the signaling remains unknown. Here we show that increased expression of ED-A fibronectin is limited to cerebral small arteries and is not observed in coronary, renal arterial or aortic walls in patients with CARASIL. Using a cell-mixing assay, we found that HTRA1 decreases TGF-ß1 signaling triggered by proTGF-ß1 in the intracellular space. HTRA1 binds and cleaves the pro-domain of proTGF-ß1 in the endoplasmic reticulum (ER), and cleaved proTGF-ß1 is degraded by ER-associated degradation. Consequently, the amount of mature TGF-ß1 is reduced. These results establish a novel mechanism for regulating the amount of TGF-ß1, specifically, the intracellular cleavage of proTGF-ß1 in the ER.

Soluble polyglutamine oligomers formed prior to inclusion body formation are cytotoxic.

Expanded polyglutamine (polyQ) repeats cause neurodegenerative disorders, but their cytotoxic structures remain to be elucidated. Although soluble polyQ oligomers have been proposed as a cytotoxic structure, the cytotoxicity of soluble polyQ oligomers, not inclusion bodies (IBs), has not been proven in living cells. To clarify the cytotoxicity of soluble polyQ oligomers, we carried our fluorescence resonance energy transfer (FRET) confocal microscopy and distinguished oligomers from monomers and IBs in a single living cell. FRET signals were detected when donor and acceptor fluorescent proteins were attached to the same side, not the opposite side, of polyQ repeats, which agrees with a parallel beta-sheet or a head-to-tail cylindrical beta-sheet model. These FRET signals disappeared in semi-intact cells, indicating that these polyQ oligomers are soluble. PolyQ monomers assembled into soluble oligomers in a length-dependent manner, which was followed by the formation of IBs. Notably, survival assay of neuronally differentiated cells revealed that cells with soluble oligomers died faster than those with IBs or monomers. These results indicate that a length-dependent formation of oligomers is an essential mechanism underlying neurodegeneration in polyQ-mediated disorders.

A patient with anti-aquaporin 4 antibody who presented with recurrent hypersomnia, reduced orexin (hypocretin) level, and symmetrical hypothalamic lesions.

Recent studies have demonstrated that hypothalamic lesions associated with brain tumor, head trauma, and encephalopathy can cause symptomatic hypersomnia with a reduced orexin (hypocretin) level in the cerebrospinal fluid (CSF). Aquaporin 4 (AQP4), a member of the AQP superfamily, is strongly expressed in the hypothalamus in which orexin (hypocretin)-containing neurons are primarily concentrated. We report the case of a patient with a serum anti-AQP4 antibody who presented with recurrent hypersomnia, symmetrical hypothalamic lesions with long spinal cord lesions on MRI, and a reduced CSF orexin (hypocretin) level, all of which were improved simultaneously by steroid therapy. Further studies should be performed to determine the roles of anti-AQP4 antibody positivity in patients with hypersomnia associated with orexin (hypocretin) deficiency and hypothalamic lesions.

Visualization of the Intimal Flap in Intracranial Arterial Dissection Using High-Resolution 3T MRI.

BACKGROUND AND PURPOSE: Presence of an intimal flap is a critical imaging finding in diagnosing intracranial artery dissection (ICAD). Recent reports showed that high-resolution magnetic resonance imaging (MRI) was better at identifying intimal flaps as compared with routine MRI techniques used in clinical settings. However, no current standardized sequence for high-resolution MRI without gadolinium enhancement produces images of satisfactory quality with clinically tolerable scanning times. This study evaluated a nonenhanced high-resolution fast spin echo (HR-FSE) MRI sequence for visualizing intimal flaps in patients with ICAD. SUBJECTS AND METHODS: Three patients with ICAD underwent plain MRI examination using a 2-dimensional T2-weighted FSE imaging sequence optimized for our 3T system (in-plane pixel size, .23 mm × .23 mm; slice thickness 3 mm with no interslice gap), as well as scanning with conventional modalities, including CT angiography, magnetic resonance angiography, and digital subtraction angiography. We assessed whether these imaging methods could visualize an intimal flap and/or double lumen sign in the participants and compared the results between HR-FSE and the other modalities. RESULTS: HR-FSE images clearly showed intimal flaps and double lumen signs in all 3 patients, whereas the conventional modalities identified a double lumen sign in only 2 of the 3 patients. CONCLUSIONS: The present method of optimized HR-FSE imaging with a 3T system improved visualization of intimal flaps and should thus be considered for assessing patients with suspected ICAD that cannot be definitively diagnosed by conventional imaging modalities.

Human neurexin-3α antibodies associate with encephalitis and alter synapse development.

OBJECTIVE: To report a novel autoimmune encephalitis in which the antibodies target neurexin-3α, a cell adhesion molecule involved in the development and function of synapses. METHODS: Five patients with encephalitis and antibodies with a similar pattern of brain reactivity were selected. Antigen precipitation and determination of antibody effects on cultured rat embryonic neurons were performed with reported techniques. RESULTS: Immunoprecipitation and cell-based assays identified neurexin-3α as the autoantigen of patients' antibodies. All 5 patients (median age 44 years, range 23-50; 4 female) presented with prodromal fever, headache, or gastrointestinal symptoms, followed by confusion, seizures, and decreased level of consciousness. Two developed mild orofacial dyskinesias, 3 needed respiratory support, and 4 had findings suggesting propensity to autoimmunity. CSF was abnormal in all patients (4 pleocytosis, 1 elevated immunoglobulin G [IgG] index), and brain MRI was abnormal in 1 (increased fluid-attenuated inversion recovery/T2 in temporal lobes). All received steroids, 1 IV immunoglobulin, and 1 cyclophosphamide; 3 partially recovered, 1 died of sepsis while recovering, and 1 had a rapid progression to death. At autopsy, edema but no inflammatory cells were identified. Cultures of neurons exposed during days in vitro (div) 7-17 to patients' IgG showed a decrease of neurexin-3α clusters as well as the total number of synapses. No reduction of synapses occurred in mature neurons (div 18) exposed for 48 hours to patients' IgG. Neuronal survival, dendritic morphology, and spine density were unaffected. CONCLUSION: Neurexin-3α autoantibodies associate with a severe but potentially treatable encephalitis in which the antibodies cause a decrease of neurexin-3α and alter synapse development.

Fibromyalgia in a Patient with Cushing's Disease Accompanied by Central Hypothyroidism.

A 39-year-old woman with a 3-year history of a rounded face developed widespread myalgia. Detailed examinations revealed no disorders that could explain the pain other than concomitant Cushing's disease and central hypothyroidism. Both the hypercortisolemia and hypothyroidism completely resolved after the patient underwent surgery to treat Cushing's disease, but she continued to experience unresolved myalgia and met the diagnostic criteria for fibromyalgia. Few studies have so far investigated patients with fibromyalgia associated with Cushing's syndrome. In our case, the hypothyroidism caused by Cushing's disease probably played an important role in triggering and exacerbating fibromyalgia. This highlights the need to examine the endocrine function in patients with muscle pain.

[A case of polymyalgia rheumatica with improved steroid-responsibility after discontinuing carbamazepine].

A 70-year-old woman under anticonvulsive therapy with carbamazepine and valproate was diagnosed as polymyalgia rheumatica. She responded to the prednisolone therapy so poorly that she required high dose prednisolone and methotrexate, and it was difficult to reduce prednisolone. After discontinuing of carbamazepine, her steroid response improved immediately. Carbamazepine is known to induce hepatic enzyme CYP3A4 and alter metabolism of other drugs. In our case, the effect of prednisolone might have been reduced by carbamazepine. This case suggests more attention should be paid to the interaction between carbamazepine and prednisolone.

Early diagnosis of hepatic intravascular lymphoma: a case report and literature review.

Hepatic intravascular large B-cell lymphoma (IVL) is a rare disease entity that involves invasion into various organs. Due to the aggressive behavior and poor prognosis of the disease and the difficulty in making an early diagnosis, some cases are diagnosed at autopsy. Early suspicion and the use of imaging studies and liver biopsies are key for diagnosing IVL; however, no reports have described the results of imaging studies due to the limited number of cases. We herein report the results of imaging studies of hepatic IVL, including the findings PET-CT, dynamic-CT, EOB-MRI and CEUS. These results may help physicians to make an early diagnosis and improve the prognosis.

Chorea as the first sign in a patient with elderly-onset systemic lupus erythematosus.

The case of an elderly patient who had chorea as an initial symptom of systemic lupus erythematosus (SLE) accompanied by antiphospholipid syndrome (APS) is reported. A 68-year-old woman suddenly developed chorea of her left arm and leg. Magnetic resonance imaging (MRI) of the brain demonstrated a focal lesion in the right caudate head, which showed hyperintensity on fluid-attenuated inversion recovery and diffusion-weighted imaging. This condition was thought to be a common form of vascular chorea, which is likely to occur in elderly individuals; however, the laboratory data of this patient finally fulfilled the diagnostic criteria of SLE and APS. Physicians should be careful in diagnosing elderly individuals simply as having a vascular chorea because this symptom can be the initial manifestation of SLE or APS.

Polyglutamine diseases: where does toxicity come from? what is toxicity? where are we going?

Although the genetic basis of polyglutamine diseases has been recognized for 20 years, their molecular basis is still unclear. We have no therapeutic strategies for these intractable neurodegenerative disorders. To adequately treat patients, we must clarify the molecular basis of polyglutamine diseases. Three main issues address their molecular pathogenesis: whether the specific structure of expanded polyglutamine diseases results in cellular toxicity; what type of dysfunction causes them; and how the toxic structure causes dysfunction, that is, the link between structure and dysfunction. For structures, expanded polyglutamine proteins undergo transformation from monomers to oligomers and inclusions. One can hypothesize that one of these structures might cause the polyglutamine disease. Although the expanded polyglutamine protein is toxic, it does not explain the selective vulnerability of specific neurons in each polyglutamine disease. The normal function of each protein, including protein-protein interaction and modification, might also be crucial for pathogenesis. For dysfunction, various molecular mechanisms have been proposed, including dysregulation of transcription, impairment of the ubiquitin-proteasome system, mitochondrial dysfunction, dysregulation of intracellular Ca(2+) homeostasis, impairment of axonal transport and genotoxic stress. These hypotheses might correlate with each other. In addition, the disease pathogenesis of might not be exclusive to one particular structure or dysfunction. To develop a therapeutic strategy for patients with polyglutamine disease, identifying the most toxic structure and the earliest event in the pathogenesis is important. We review the current understanding of the toxic structure and dysfunction by expanded polyglutamine proteins and suggest directions for future studies of polyglutamine diseases.

Optimum condition of Fourier transform infrared multiple-angle incidence resolution spectrometry for surface analysis.

A novel measurement technique of pure out-of-plane vibrational modes of thin films on a nonmetallic substrate has recently been proposed, which is named multiple-angle incidence resolution spectrometry (MAIRS). Since this technique could not be replaced by other conventional techniques, MAIRS was expected to be a promising tool for analysis of thin soft materials and surface adsorbates. Nevertheless, some experimental conditions have been found to be inappropriate for MAIRS, which yields incorrect results. In the present study, therefore, the problems in the technique have been investigated in terms of optics to improve the accomplishments of MAIRS. The problems have been found to have a strong relationship with optics in FT-IR, which is influenced by refractive index of the sample material and angle of incidence. In particular, optimization of the size matching of the detector surface and the infrared spot at the detector was a key to having MAIRS perform properly. It has been concluded that reliable MAIRS measurements require overfilling of the detector and a substrate with a high-refractive index.