Search

Glycoprotein nonmetastatic melanoma protein B (GPNMB) aggregates are observed in the spinal cord of amyotrophic lateral sclerosis (ALS) patients, but the detailed localization is still unclear. Mutations of transactive response DNA binding protein 43kDa (TDP-43) are associated with neurodegenerative diseases including ALS. In this study, we evaluated the localization of GPNMB aggregates in the spinal cord of ALS patients and the effect of GPNMB against mutant TDP-43 induced motor neuron cell death. GPNMB aggregates were not localized in the glial fibrillary acidic protein (GFAP)-positive astrocyte and ionized calcium binding adaptor molecule-1 (Iba1)-positive microglia. GPNMB aggregates were localized in the microtubule-associated protein 2 (MAP-2)-positive neuron and neurofilament H non-phosphorylated (SMI-32)-positive neuron, and these were co-localized with TDP-43 aggregates in the spinal cord of ALS patients. Mock or TDP-43 (WT, M337V, and A315T) plasmids were transfected into mouse motor neuron cells (NSC34). The expression level of GPNMB was increased by transfection of mutant TDP-43 plasmids. Recombinant GPNMB ameliorated motor neuron cell death induced by transfection of mutant TDP-43 plasmids and serum-free stress. Furthermore, the expression of phosphorylated ERK1/2 and phosphorylated Akt were decreased by this stress, and these expressions were increased by recombinant GPNMB. These results indicate that GPNMB has protective effects against mutant TDP-43 stress via activating the ERK1/2 and Akt pathways, and GPNMB may be a therapeutic target for TDP-43 proteinopathy in familial and sporadic ALS. © 2016 Wiley Periodicals, Inc., (© 2016 Wiley Periodicals, Inc.)

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by progressive loss of motor neurons and subsequent muscular atrophy. The quality of life of patients with ALS is significantly improved by ameliorating muscular symptoms. We previously reported that glycoprotein nonmetastatic melanoma protein B (GPNMB; osteoactivin) might serve as a target for ALS therapy. In the present study, superoxide dismutase 1/glycine residue 93 changed to alanine (SOD1(G93A) ) transgenic mice were used as a model of ALS. Expression of the C-terminal fragment of GPNMB was increased in the skeletal muscles of SOD1(G93A) mice and patients with sporadic ALS. SOD1(G93A) /GPNMB transgenic mice were generated to determine whether GPNMB expression ameliorates muscular symptoms. The weight and cross-sectional area of the gastrocnemius muscle, number and cross-sectional area of myofibers, and denervation of neuromuscular junctions were ameliorated in SOD1(G93A) /GPNMB vs. SOD1(G93A) mice. Furthermore, direct injection of a GPNMB expression plasmid into the gastrocnemius muscle of SOD1(G93A) mice increased the numbers of myofibers and prevented myofiber atrophy. These findings suggest that GPNMB directly affects skeletal muscle and prevents muscular pathology in SOD1(G93A) mice and may therefore serve as a target for therapy of ALS., (© 2015 Wiley Periodicals, Inc.)

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease. Recently, it has been reported that a mutation in the sigma-1 receptor causes juvenile ALS. Therefore, the function of the sigma-1 receptor may be important in the pathology of ALS. In the present study, we investigated the effect of SA4503, a sigma-1 receptor agonist, against in in vitro and in vivo ALS models. We first investigated whether SA4503, a sigma-1 receptor agonist, prevented superoxide dismutase 1 (SOD1(G93A))- and serum free-induced cell death of mice motor neuron cells (NSC34) in in vitro model of an ALS. At concentrations of 1-10μM, SA4503 reduced SOD1(G93A)-induced cell death in a concentration-dependent manner, and BD1047, a sigma-1 receptor antagonist, inhibited the protective effect of SA4503. Next, we investigated whether SA4503 affected the phosphorylation levels of Akt (Ser 473) and extracellular signal-regulated kinase (ERK) 1/2 and the expression of the sigma-1 receptor. SA4503 promoted the phosphorylation of Akt (Ser 473) and ERK1/2 in a time-dependent manner, but SA4503 did not affect the expression of the sigma-1 receptor. These results suggest that the protective effect of SA4503 might be involved in promoting the phosphorylation of Akt and ERK1/2. We then investigated whether SA4503 suppressed the progression of ALS in an SOD1(G93A) ALS mouse model. SA4503 did not affect the onset time of ALS. However, it significantly extended the survival time in the SOD1(G93A) mice compared with a vehicle-treated group. These findings indicate that SA4503 is effective in suppressing motor neuron degeneration and symptom progression in ALS., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

The diagnosis of amyotrophic lateral sclerosis (ALS) is difficult due to lack of definitive biomarkers. Our aim was to identify characteristic serum protein patterns that could provide candidate biomarkers for ALS. We divided mutant superoxide dismutase-1 (SOD1)(H46R) rats into three groups based on disease progression: pre-symptom (90 days), onset, and end-stage. After separation of serum proteins using two-dimensional electrophoresis, we selected clear protein spots and identified two candidate proteins-inter-alpha-trypsin inhibitor heavy chain H4 (ITIH4) and glutathione peroxidase 3 (Gpx3). The 120 kDa ITIH4 increased at the onset of the disease and the 85 kDa ITIH4, a cleaved form, at the end-stage in the sera of the SOD1(H46R) rats. Expression of the 85 kDa ITIH4 was substantial in ALS compared with controls or patients with muscular dystrophy, Alzheimer diseases, or Parkinson diseases. The Gpx3 protein levels in the sera of SOD1(H46R) rats were upregulated pre-symptom and gradually decreased as the disease progressed. The Gpx3 protein levels were lower in the sera of the patients with ALS than in other diseases. These results indicate that ITIH4 and Gpx3 are potential biomarkers for ALS.

Amyotrophic lateral sclerosis (ALS) is an incurable and fatal neurodegenerative disease characterized by the loss of motor neurons. Despite substantial research, the causes of ALS remain unclear. Glycoprotein nonmetastatic melanoma protein B (GPNMB) was identified as an ALS-related factor using DNA microarray analysis with mutant superoxide dismutase (SOD1(G93A)) mice. GPNMB was greatly induced in the spinal cords of ALS patients and a mouse model as the disease progressed. It was especially expressed in motor neurons and astrocytes. In an NSC34 cell line, glycosylation of GPNMB was inhibited by interaction with SOD1(G93A), increasing motor neuron vulnerability, whereas extracellular fragments of GPNMB secreted from activated astrocytes attenuated the neurotoxicity of SOD1(G93A) in neural cells. Furthermore, GPNMB expression was substantial in the sera of sporadic ALS patients than that of other diseased patients. This study suggests that GPNMB can be a target for therapeutic intervention for suppressing motor neuron degeneration in ALS.

Aims: Amyotrophic lateral sclerosis (ALS) is a fatal motor neuron disease whose mechanism is not understood. Recently, it was reported that apoptosis-inducing factor (AIF) was involved in motor neuronal cell death in ALS model mice, and AIF-induced neuronal cell death by interacting with cyclophilin A (CypA). However, it is unknown whether the CypA and AIF-complex induces chromatinolysis in ALS. Therefore, in the present study, we investigated the process of motor neuron degeneration as the disease progresses and to determine whether the CypA-AIF complex would play a role in inducing motor neuronal cell death in mutant superoxide dismutase 1 (SOD1)(G93A) ALS model mice., Methodology: We prepared the nuclear fractions of spinal cords and demonstrated the nuclear translocation of CypA with AIF in SOD1(G93A) mice by immunoprecipitation. The localization of CypA and AIF in the spinal cords was assessed by immunohistochemistry., Results: In the spinal cords of SOD1(G93A) mice, the expressions of CypA and AIF were detected in the motor neurons, and CypA and AIF cotranslocated to the motor neuronal nuclei with CypA. Furthermore, the expression of CypA was detected in GFAP-positive astrocytes, but not in CD11b-positive microglial cells. On the other hand, these findings were not detected in the spinal cords of wild-type mice., Conclusions: From these results, we suggest that CypA and AIF may play cooperative and pivotal roles in motor neuronal death in the murine ALS model., (© 2010 Blackwell Publishing Ltd.)

Amyotrophic lateral sclerosis (ALS) is the most frequent adult-onset motor neuron disease, and recent evidence has suggested that endoplasmic reticulum (ER) stress signaling is involved in the pathogenesis of ALS. Here we identified a small molecule, SUN N8075, which has a marked protective effect on ER stress-induced cell death, in an in vitro cell-based screening, and its protective mechanism was mediated by an induction of VGF nerve growth factor inducible (VGF): VGF knockdown with siRNA completely abolished the protective effect of SUN N8075 against ER-induced cell death, and overexpression of VGF inhibited ER-stress-induced cell death. VGF level was lower in the spinal cords of sporadic ALS patients than in the control patients. Furthermore, SUN N8075 slowed disease progression and prolonged survival in mutant SOD1 transgenic mouse and rat models of ALS, preventing the decrease of VGF expression in the spinal cords of ALS mice. These data suggest that VGF plays a critical role in motor neuron survival and may be a potential new therapeutic target for ALS, and SUN N8075 may become a potential therapeutic candidate for treatment of ALS.

Endoplasmic reticulum (ER) stress-induced neuronal death may play a critical role in the pathogenesis of amyotrophic lateral sclerosis (ALS). However, whether CCAAT/enhancer binding protein (C/EBP) homologous protein (CHOP), an ER-stress apoptotic mediator, is involved in the pathogenesis of ALS is controversial. Here we demonstrate the expression levels and localization of CHOP in spinal cords of both sporadic ALS patients and ALS transgenic mice by immunohistochemistry. In the spinal cords of sporadic ALS patients, CHOP was markedly up-regulated but typically expressed at low levels in those of the control. Likewise, CHOP expression increased at 14 (symptomatic stage) and 18 to 20 weeks (end stage) in ALS transgenic mice spinal cords. Furthermore, localizations of CHOP were merged in motor neurons and glial cells, such as oligodendrocytes, astrocytes, and microglia. These results indicate that the up-regulation of CHOP in motor neurons and glial cells may play pivotal roles in the pathogenesis of ALS.

The retina is highly sensitive to oxidative stress because of its high consumption of oxygen associated with the phototransductional processes. Recent findings have suggested that oxidative stress is involved in the pathology of age-related macular degeneration, a progressive degeneration of the central retina. A well-known environmental risk factor is light exposure, as excessive and continuous light exposure can damage photoreceptors. Nuclear factor-erythroid 2-related factor 2 (Nrf2) is a transcriptional factor that controls antioxidative responses and phase 2 enzymes. Thus, we hypothesized that RS9, a specific activator of Nrf2, decreases light-induced retinal cell death in vivo and in vitro. Nrf2 was detected in the nucleus of the 661W cells exposed to RS9 and also after light exposure, and the Nrf2-antioxidant response element binding was increased in 661W cells after exposure to RS9. Consequentially, the expression of the phase 2 enzyme's mRNAs of Ho-1, Nqo-1, and Gclm genes was increased in 661W cells after exposure to RS9. Furthermore, RS9 decreased the light-induced death of 661W cells (2500 lux, 24 h), and also reduced the functional damages and the histological degeneration of the nuclei in the outer nuclear layer or the retina in the in vivo studies (8000 lux, 3 h). Heme oxygenase-1 was increased after light exposure, and Nrf2 was translocated into the nucleus after light exposure in vivo. Silencing of Ho-1 reduced the protective effects of RS9 against light-induced death of 661W cells. These findings indicate that RS9 has therapeutic potential for retinal diseases that are aggravated by light exposure. [ABSTRACT FROM AUTHOR]