P4-173: Cytoplasmic gelsolin, a beta-amyloid binding protein, is induced by oxidative stress in Pc-12 cells

The accumulation of α-synuclein (αSyn) has been implicated as a causal factor in the pathogenesis of Parkinson’s disease (PD). There is growing evidence that supports mitochondrial dysfunction as a potential primary cause of dopaminergic neuronal death in PD. Here, we focused on reciprocal interactions between αSyn aggregation and mitochondrial injury induced by oxidative stress. We further investigated whether epidermal fatty acid-binding protein 5 (FABP5) is related to αSyn oligomerization/aggregation and subsequent disturbances in mitochondrial function in neuronal cells. In the presence of rotenone, a mitochondrial respiratory chain complex I inhibitor, co-overexpression of FABP5 with αSyn significantly decreased the viability of Neuro-2A cells compared to that of αSyn alone. Under these conditions, FABP5 co-localized with αSyn in the mitochondria, thereby reducing mitochondrial membrane potential. Furthermore, we confirmed that pharmacological inhibition of FABP5 by its ligand prevented αSyn accumulation in mitochondria, which led to cell death rescue. These results suggested that FABP5 is crucial for mitochondrial dysfunction related to αSyn oligomerization/aggregation in the mitochondria induced by oxidative stress in neurons.

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The Interplay of RNA Binding Proteins, Oxidative Stress and Mitochondrial Dysfunction in ALS

Antioxidants ◽

10.3390/antiox10040552 ◽

2021 ◽

Vol 10 (4) ◽

pp. 552

Author(s):

Jasmine Harley ◽

Benjamin E. Clarke ◽

Rickie Patani

Keyword(s):

Oxidative Stress ◽

Gene Expression ◽

Mitochondrial Dysfunction ◽

Binding Proteins ◽

Rna Binding ◽

Rna Binding Proteins ◽

Binding Protein ◽

Rna Binding Protein ◽

Therapeutic Strategies ◽

Lateral Sclerosis

RNA binding proteins fulfil a wide number of roles in gene expression. Multiple mechanisms of RNA binding protein dysregulation have been implicated in the pathomechanisms of several neurodegenerative diseases including amyotrophic lateral sclerosis (ALS). Oxidative stress and mitochondrial dysfunction also play important roles in these diseases. In this review, we highlight the mechanistic interplay between RNA binding protein dysregulation, oxidative stress and mitochondrial dysfunction in ALS. We also discuss different potential therapeutic strategies targeting these pathways.

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Fatty acid-binding protein 7 triggers α-synuclein oligomerization in glial cells and oligodendrocytes associated with oxidative stress

Acta Pharmacologica Sinica ◽

10.1038/s41401-021-00675-8 ◽

2021 ◽

Author(s):

An Cheng ◽

Yi-fei Wang ◽

Yasuharu Shinoda ◽

Ichiro Kawahata ◽

Tetsunori Yamamoto ◽

...

Keyword(s):

Oxidative Stress ◽

Fatty Acid ◽

Glial Cells ◽

Fatty Acid Binding Protein ◽

Binding Protein ◽

Fatty Acid Binding ◽

Acid Binding Protein

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The Interplay between S-glutathionylation and Phosphorylation of Cardiac Troponin I and Myosin Binding Protein C in End-Stage Human Failing Hearts

Antioxidants ◽

10.3390/antiox10071134 ◽

2021 ◽

Vol 10 (7) ◽

pp. 1134

Author(s):

Heidi Budde ◽

Roua Hassoun ◽

Melina Tangos ◽

Saltanat Zhazykbayeva ◽

Melissa Herwig ◽

...

Keyword(s):

Oxidative Stress ◽

Protein C ◽

Troponin I ◽

Reduced Glutathione ◽

Binding Protein ◽

Enzyme Treatment ◽

Myosin Binding Protein ◽

Myosin Binding Protein C ◽

Myosin Binding ◽

End Stage

Oxidative stress is defined as an imbalance between the antioxidant defense system and the production of reactive oxygen species (ROS). At low levels, ROS are involved in the regulation of redox signaling for cell protection. However, upon chronical increase in oxidative stress, cell damage occurs, due to protein, DNA and lipid oxidation. Here, we investigated the oxidative modifications of myofilament proteins, and their role in modulating cardiomyocyte function in end-stage human failing hearts. We found altered maximum Ca2+-activated tension and Ca2+ sensitivity of force production of skinned single cardiomyocytes in end-stage human failing hearts compared to non-failing hearts, which was corrected upon treatment with reduced glutathione enzyme. This was accompanied by the increased oxidation of troponin I and myosin binding protein C, and decreased levels of protein kinases A (PKA)- and C (PKC)-mediated phosphorylation of both proteins. The Ca2+ sensitivity and maximal tension correlated strongly with the myofilament oxidation levels, hypo-phosphorylation, and oxidative stress parameters that were measured in all the samples. Furthermore, we detected elevated titin-based myocardial stiffness in HF myocytes, which was reversed by PKA and reduced glutathione enzyme treatment. Finally, many oxidative stress and inflammation parameters were significantly elevated in failing hearts compared to non-failing hearts, and corrected upon treatment with the anti-oxidant GSH enzyme. Here, we provide evidence that the altered mechanical properties of failing human cardiomyocytes are partially due to phosphorylation, S-glutathionylation, and the interplay between the two post-translational modifications, which contribute to the development of heart failure.

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Developmental Expression of Calcium-Binding Protein-Containing Neurons in Neocortical Transplants

Cell Transplantation ◽

10.1177/096368979800700207 ◽

1998 ◽

Vol 7 (2) ◽

pp. 121-129 ◽

Cited By ~ 2

Author(s):

Jeffrey M. Rosenstein ◽

Newton S. More ◽

Nina Mani ◽

Janette M. Krum

Keyword(s):

Oxidative Stress ◽

Cortical Neurons ◽

Calcium Binding ◽

Binding Protein ◽

Substantial Reduction ◽

Qualitative Change ◽

Afferent Input ◽

Calcium Binding Protein ◽

Developmental Expression ◽

Parvalbumin Neurons

The present study examined the development of calcium binding protein-containing neurons in a timed series of fetal neocortical transplants. The immunoexpression of parvalbumin and calbindin, which are subpopulations of GABAergic neurons, have been widely studied in normal development and in disease and injury states. Because of their purported resistance to oxidative injury by their ability to buffer Ca++ influx, these neurons have been particularly studied following ischemia. Because it is likely that oxidative stress is associated with the grafting procedure, we sought to determine if these neurons displayed enhanced survival characteristics. Normally, parvalbumin and calbindin represent about 5-10% of cortical neurons. Within 2-4 wk after grafting the expression of both proteins increased markedly in that a relatively larger number of neurons (27% for parvalbumin) were immunopositive. This increase was transitory, however, and by 4 mo and beyond, confocal microscopic data showed a reduction of over 50% of parvalbumin (+) neurons and processes. Calbindin (+) processes showed a qualitative change in that they were smaller with less terminal branching. Electron microscopy confirmed a substantial reduction in parvalbumin synaptic contacts. Interestingly, in older grafts, remaining parvalbumin neurons were those that were strongly NSE (+) suggesting a link between normal metabolism and Ca++ buffering in grafted neurons. It is possible that in early grafts certain neuronal populations transiently upregulated calcium binding proteins as a defensive mechanism against Ca++ influx associated with oxidative stress. Over time, however, following physiological normalization within grafts, the calcium binding protein (+) neurons are diminished, possibly due to lack of appropriate afferent input to the interneuronal pool.

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RBM45 Modulates the Antioxidant Response in Amyotrophic Lateral Sclerosis through Interactions with KEAP1

Molecular and Cellular Biology ◽

10.1128/mcb.00087-15 ◽

2015 ◽

Vol 35 (14) ◽

pp. 2385-2399 ◽

Cited By ~ 12

Author(s):

Nadine Bakkar ◽

Arianna Kousari ◽

Tina Kovalik ◽

Yang Li ◽

Robert Bowser

Keyword(s):

Oxidative Stress ◽

Spinal Cord ◽

Amyotrophic Lateral Sclerosis ◽

Motor Neurons ◽

Rna Binding ◽

Binding Protein ◽

Rna Binding Protein ◽

Antioxidant Response ◽

Cytoplasmic Inclusions ◽

Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by the selective loss of motor neurons. Various factors contribute to the disease, including RNA binding protein dysregulation and oxidative stress, but their exact role in pathogenic mechanisms remains unclear. We have recently linked another RNA binding protein, RBM45, to ALS via increased levels of protein in the cerebrospinal fluid of ALS patients and its localization to cytoplasmic inclusions in ALS motor neurons. Here we show RBM45 nuclear exit in ALS spinal cord motor neurons compared to controls, a phenotype recapitulatedin vitroin motor neurons treated with oxidative stressors. We find that RBM45 binds and stabilizes KEAP1, the inhibitor of the antioxidant response transcription factor NRF2. ALS lumbar spinal cord lysates similarly show increased cytoplasmic binding of KEAP1 and RBM45. Binding of RBM45 to KEAP1 impedes the protective antioxidant response, thus contributing to oxidative stress-induced cellular toxicity. Our findings thus describe a novel link between a mislocalized RNA binding protein implicated in ALS (RBM45) and dysregulation of the neuroprotective antioxidant response seen in the disease.

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