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.

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.