Knockdown of optineurin controls C2C12 myoblast differentiation via regulating myogenin and MyoD expressions.

Mutations in optineurin (OPTN) have been identified in a small proportion of sporadic and familial amyotrophic lateral sclerosis (ALS) cases. Recent evidences suggest that OPTN would be involved in not only the pathophysiological mechanisms of motor neuron death of ALS but also myofiber degeneration of sporadic inclusion body myositis. However, the detailed role of OPTN in muscle remains unclear. Initially, we showed that OPTN expression levels were significantly increased in the denervated muscles of mice, suggesting that OPTN may be involved in muscle homeostasis. To reveal the molecular role of OPTN in muscle atrophy, we used cultured C2C12 myotubes treated with tumor necrosis factor-like inducer of apoptosis (TWEAK) as an in vitro model of muscle atrophy. Our data showed that OPTN had no effect on the process of muscle atrophy in this model. On the other hand, we found that myogenic differentiation was affected by OPTN. Immunoblotting analysis showed that OPTN protein levels gradually decreased during C2C12 differentiation. Furthermore, OPTN knockdown inhibited C2C12 differentiation, accompanied by reduction of mRNA and protein expression levels of myogenin and MyoD. These findings suggested that OPTN may have a novel function in muscle homeostasis and play a role in the pathogenesis of neuromuscular diseases.

[Valproic acid-induced hyperammonemic encephalopathy in a patient receiving valproic acid monotherapy].

A 79-year-old female was diagnosed with epilepsy because she experienced loss of consciousness twice in January and February and then had a seizure in June 2016. She was treated with 800 mg sodium valproate (sustained release). After 3 days, she experienced loss of appetite, and more than 3 days later, disturbance of consciousness. Serum valproic acid (VPA) concentration was 128.3 µg/ml and serum ammonia was 404 µmol/l. Cerebral edema and status epilepticus occurred. Severe neurological dysfunction remained, even after treatment with continuous hemodiafiltration and levocarnitine. VPA is widely used for the treatment of generalized epilepsy. VPA-induced hyperammonemic encephalopathy is a rare but serious adverse event of VPA. Thus, we must pay attention to serum ammonia levels when using VPA, even VPA monotherapy.

Synphilin-1 has neuroprotective effects on MPP+-induced Parkinson's disease model cells by inhibiting ROS production and apoptosis.

Synphilin-1, a cytoplasmic protein, interacts with α-synuclein which is one of the main constituents of Lewy bodies and plays an important role in the pathology of Parkinson's disease (PD), in neurons. This interaction indicates that synphilin-1 may also play a central role in PD. However, the biological functions of synphilin-1 are not fully understood, and whether synphilin-1 is neurotoxic or neuroprotective remains controversial. This study examined the function of synphilin-1 in a PD model in vitro. We used an inhibitor of mitochondrial complex I, 1-methyl-4-phenylpyridinium (MPP+). We established human neuroblastoma SH-SY5Y cell lines that stably expressed human synphilin-1. We found that overexpression of synphilin-1 increased SH-SY5Y cell viability after MPP+ treatment. We further found that synphilin-1 significantly suppressed apoptotic changes in nuclei, including nuclear condensation and fragmentation, after MPP+ treatment. We showed that synphilin-1 significantly decreased MPP+-induced cleaved caspase-3 and cleaved poly-ADP-ribose polymerase levels by using western blotting. Production of reactive oxygen species (ROS) induced by MPP+ was significantly reduced in cells expressing synphilin-1 compared to those expressing empty vector. Synphilin-1 inhibited MPP+-induced cytochrome c release from mitochondria into the cytosol. These data suggested that synphilin-1 may function to protect against dopaminergic cell death by preserving mitochondrial function and inhibiting early steps in the intrinsic apoptotic pathway. Taken together, our results indicated that synphilin-1 may play neuroprotective roles in PD pathogenesis by inhibiting ROS production and apoptosis.

Screening for Fabry Disease in Japanese Patients with Young-Onset Stroke by Measuring α-Galactosidase A and Globotriaosylsphingosine.

BACKGROUND: Fabry disease is an X-linked lysosomal storage disorder caused by mutations in GLA, which encodes the enzyme α-galactosidase A (α-Gal A). Although the prevalence of Fabry disease in patients with stroke has been reported to range from 0% to 4%, few cohort studies have examined Japanese stroke patients. We aimed to clarify the prevalence of Fabry disease and the frequency of GLA mutations among patients with young-onset stroke in Japan. METHODS: From April 2015 to December 2016, we enrolled patients with young-onset (≤60 years old) ischemic stroke or intracerebral hemorrhage. We measured α-Gal A activity and the concentration of globotriaosylsphingosine in plasma. Genetic evaluations were performed in patients with low α-Gal A activity or high concentrations of globotriaosylsphingosine. RESULTS: Overall, 516 patients (median age of onset, 52 years old; 120 women) were consecutively enrolled in this study. Five patients (4 men and 1 woman) had low α-Gal A activity, and no patients were detected with the screen for plasma globotriaosylsphingosine levels. The genetic analysis did not identify a causative mutation responsible for classic Fabry disease in any of the patients, but 2 patients (.4%) carried the p.E66Q in GLA. CONCLUSIONS: No patient with Fabry disease was detected in our young-onset stroke cohort.

Controlling nutritional status score for predicting 3-mo functional outcome in acute ischemic stroke.

BACKGROUND: Malnutrition is an independent risk factor for poor outcomes in patients with acute ischemic stroke. However, the indicator of malnutrition has not yet been established. We investigated the relationship between the Controlling Nutritional Status score, a useful prognostic measure of malnutrition in patients with cardiovascular diseases and malignant tumors, and functional outcomes in patients with acute ischemic stroke. METHODS: Patients with acute ischemic stroke (n = 264, 71 ± 12 y old) were consecutively evaluated within 7 d of stroke onset. The Controlling Nutritional Status score was calculated from the serum albumin, total peripheral lymphocyte count, and total cholesterol; a Controlling Nutritional Status score of 5 to 12 was defined as malnutrition. Poor functional outcome was defined as a modified Rankin Scale score of 3 to 6 at 3 mo. RESULTS: Of the total cohort, 230 patients (87.1%) were assessed. The patients with poor functional outcome (n = 85) were older; had a lower body mass index; had a higher frequency of atrial fibrillation, chronic heart failure, and anemia; and had a lower frequency of dyslipidemia and a current smoking status. In addition, the Controlling Nutritional Status score and National Institutes of Health Stroke Scale score at admission were significantly higher for the patients with poor functional outcome. After multivariate analysis, adjusted for baseline characteristics, a Controlling Nutritional Status score of 5 to 12 was found to be independently associated with poor outcome (odds ratio: 4.15, 95% confidence interval: 1.52-11.67, P = 0.005). CONCLUSIONS: The Controlling Nutritional Status score at admission could be a useful prognostic marker of 3-mo functional outcomes in patients with acute ischemic stroke.

Alpha-2-macroglobulin as a Promising Biological Marker of Endothelial Function.

AIMS: Alpha-2-macroglobulin (α2MG) is thought to be associated with inflammatory reactions and procoagulant properties that might cause ischemic stroke. Endothelial dysfunction plays an important role in atherosclerosis development and in the occurrence of cardiovascular events. In this study, we investigated whether serum α2MG levels, endothelial function, and endothelial progenitor cell (EPC) number were associated in patients with chronic stroke or cardiovascular risk factors. METHODS: Patients with a history of stroke or any established cardiovascular risk factors were enrolled in this study (n=102; 69 men, 70.1±9.2 years). Endothelial function was assessed by flow-mediated dilation (FMD). EPC numbers (CD34＋/CD133＋) were measured using flow cytometry (n=91). Serum α2MG levels were measured by nephelometry. RESULTS: Patients in the highest tertile of serum α2MG levels were older (P=0.019) and more frequently exhibited dyslipidemia (P=0.021). Univariate-regression analysis revealed that increased α2MG levels were negatively associated with FMD values (r=-0.25; P=0.010), whereas increased EPC numbers were positively associated (r=0.21; P=0.044). Multivariate-regression analysis adjusted for male gender, hypertension, and severe white-matter lesions showed that serum α2MG levels were independently associated with FMD values (standardized partial regression coefficient [ß] -0.185; P=0.033), although not significantly associated with EPC numbers. CONCLUSION: Serum α2MG levels might reflect endothelial dysfunction evaluated by FMD in patients with chronic stroke or cardiovascular risk factors.

Endothelial dysfunction is associated with the severity of cerebral small vessel disease.

The pathogenesis of cerebral small vessel disease, a disease that involves white matter lesions (WMLs) and cerebral microbleeds (CMBs), is thought to be associated with endothelial dysfunction. Flow-mediated dilation (FMD) has been used to measure endothelium-dependent vasodilation. The aim of this study was to investigate the association between endothelial function (as measured by FMD) and cerebral small vessel disease. Patients with a history of cerebrovascular disease and comorbidities were enrolled in this study (n=102; 69 males, 70.1±9.2 years). The patients were divided into two groups according to the severity of WMLs, which were assessed by Fazekas classification; grades 0 to 1 as mild WMLs group and grades 2 to 3 as severe WMLs group. A gradient-echo MRI was performed in 96 patients (94.1%) to evaluate whether CMBs were present. The patients in the severe WMLs group (n=40) were older (P=0.001), more frequently exhibited hypertension (P=0.045) and diabetes mellitus (P=0.026) and possessed lower FMD values (P<0.001) than the patients in the mild WMLs group (n=62). CMBs were observed in 30 patients (31.3%). Using receiver operating characteristic curves, the optimal FMD cutoff values for predicting the presence of severe WMLs and CMBs were 3.9% and 3.7%, respectively. On multivariate logistic analysis, FMD <4.0% (odds ratio 9.50; 95% confidence interval 3.55-28.83) was independently associated with severe WMLs. Additionally, FMD <3.8% (5.82; 2.23-16.50) was also associated with the presence of CMBs. Endothelial dysfunction as evaluated by FMD may be predictive of the severity of cerebral small vessel disease.

Novel compound heterozygous mutations in sacsin-related ataxia.

High prevalence of a form of autosomal recessive spastic ataxia with early onset was originally described among French Canadians in the Charlevoix-Saguenay region, in northeastern Quebec. Since the responsible gene (SACS) was identified, mutations in the SACS gene have been described in Tunisia, Italy, Turkey, and Japan. The mutation sites found outside Quebec are different from the ones in Quebec. All patients outside Quebec, except one Italian patient, have been reported to have homozygous mutations. The authors report here identical twin sisters with novel compound heterozygous mutations (c.[2951_2952delAG]+[3922delT]) in the SACS gene.