ABSTRACT
Amyotrophic lateral sclerosis (ALS) is a progressive paralyzing disease characterized by tissue oxidative damage and motor neuron degeneration. This study investigated the in vivo effect of diacetylbis(N(4)-methylthiosemicarbazonato) copper(II) (CuII(atsm)), which is an orally bioavailable, blood-brain barrier-permeable complex. In vitro the compound inhibits the action of peroxynitrite on Cu,Zn-superoxide dismutase (SOD1) and subsequent nitration of cellular proteins. Oral treatment of transgenic SOD1G93A mice with CuII(atsm) at presymptomatic and symptomatic ages was performed. The mice were examined for improvement in lifespan and motor function, as well as histological and biochemical changes to key disease markers. Systemic treatment of SOD1G93A mice significantly delayed onset of paralysis and prolonged lifespan, even when administered to symptomatic animals. Consistent with the properties of this compound, treated mice had reduced protein nitration and carbonylation, as well as increased antioxidant activity in spinal cord. Treatment also significantly preserved motor neurons and attenuated astrocyte and microglial activation in mice. Furthermore, CuII(atsm) prevented the accumulation of abnormally phosphorylated and fragmented TAR DNA-binding protein-43 (TDP-43) in spinal cord, a protein pivotal to the development of ALS. CuII(atsm) therefore represents a potential new class of neuroprotective agents targeting multiple major disease pathways of motor neurons with therapeutic potential for ALS.
Subject(s)
Amyotrophic Lateral Sclerosis/metabolism , Organometallic Compounds/chemistry , Peroxynitrous Acid/metabolism , Superoxide Dismutase/genetics , Thiosemicarbazones/chemistry , Animals , Antioxidants/chemistry , Astrocytes/cytology , Coordination Complexes , Copper/chemistry , DNA-Binding Proteins/pharmacology , Disease Models, Animal , Male , Mice , Mice, Inbred C57BL , Mice, Transgenic , Microglia/cytology , Neurodegenerative Diseases/embryology , Neurons/metabolism , Oxidative Stress , Oxygen/chemistry , Spinal Cord/pathology , Superoxide Dismutase-1 , TransgenesABSTRACT
The administration of MPTP selectively targets the dopaminergic system resulting in Parkinsonism-like symptoms and is commonly used as a mice model of Parkinson's disease. We previously demonstrated that the neuroprotective compound Cu(II)(atsm) rescues nigral cell loss and improves dopamine metabolism in the MPTP model. The mechanism of action of Cu(II)(atsm) needs to be further defined to understand how the compound promotes neuronal survival. Whole genome transcriptomic profiling has become a popular method to examine the relationship between gene expression and function. Substantia nigra samples from MPTP-lesioned mice were evaluated using whole transcriptome sequencing to investigate the genes altered upon Cu(II)(atsm) treatment. We identified 143 genes affected by MPTP lesioning that are associated with biological processes related to brain and cognitive development, dopamine synthesis and perturbed synaptic neurotransmission. Upon Cu(II)(atsm) treatment, the expression of 40 genes involved in promoting dopamine synthesis, calcium signaling and synaptic plasticity were restored which were validated by qRT-PCR. The study provides the first detailed whole transcriptomic analysis of pathways involved in MPTP-induced Parkinsonism. In addition, we identify key therapeutic pathways targeted by a potentially new class of neuroprotective agents which may provide therapeutic benefits for other neurodegenerative disorders.
Subject(s)
Dopamine/biosynthesis , MPTP Poisoning/pathology , Neuroprotective Agents/therapeutic use , Organometallic Compounds/therapeutic use , Parkinson Disease, Secondary/genetics , Parkinson Disease/genetics , Substantia Nigra/metabolism , Synaptic Transmission/genetics , Thiosemicarbazones/therapeutic use , 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine/adverse effects , Animals , Calcium Signaling/genetics , Coordination Complexes , Disease Models, Animal , Dopamine/genetics , Dopaminergic Neurons/metabolism , MPTP Poisoning/genetics , Mice , Mice, Inbred C57BL , Parkinson Disease/pathology , Parkinson Disease, Secondary/chemically induced , Substantia Nigra/drug effectsABSTRACT
Parkinson's disease (PD) is a progressive, chronic disease characterized by dyskinesia, rigidity, instability, and tremors. The disease is defined by the presence of Lewy bodies, which primarily consist of aggregated α-synuclein protein, and is accompanied by the loss of monoaminergic neurons. Current therapeutic strategies only give symptomatic relief of motor impairment and do not address the underlying neurodegeneration. Hence, we have identified Cu(II)(atsm) as a potential therapeutic for PD. Drug administration to four different animal models of PD resulted in improved motor and cognition function, rescued nigral cell loss, and improved dopamine metabolism. In vitro, this compound is able to inhibit the effects of peroxynitrite-driven toxicity, including the formation of nitrated α-synuclein oligomers. Our results show that Cu(II)(atsm) is effective in reversing parkinsonian defects in animal models and has the potential to be a successful treatment of PD.