Synuclein Proteins in MPTP-Induced Death of Substantia Nigra Pars Compacta Dopaminergic Neurons.

Parkinson's disease (PD) is one of the key neurodegenerative disorders caused by a dopamine deficiency in the striatum due to the death of dopaminergic (DA) neurons of the substantia nigra pars compacta. The initially discovered A53T mutation in the alpha-synuclein gene was linked to the formation of cytotoxic aggregates: Lewy bodies in the DA neurons of PD patients. Further research has contributed to the discovery of beta- and gamma-synucleins, which presumably compensate for the functional loss of either member of the synuclein family. Here, we review research from 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) toxicity models and various synuclein-knockout animals. We conclude that the differences in the sensitivity of the synuclein-knockout animals compared with the MPTP neurotoxin are due to the ontogenetic selection of early neurons followed by a compensatory effect of beta-synuclein, which optimizes dopamine capture in the synapses. Triple-knockout synuclein studies have confirmed the higher sensitivity of DA neurons to the toxic effects of MPTP. Nonetheless, beta-synuclein could modulate the alpha-synuclein function, preventing its aggregation and loss of function. Overall, the use of knockout animals has helped to solve the riddle of synuclein functions, and these proteins could be promising molecular targets for the development of therapies that are aimed at optimizing the synaptic function of dopaminergic neurons.

Proteomic Analysis of Cerebral Cortex Extracts from Sus scrofa with Induced Hemorrhagic Stroke.

Cerebrovascular diseases, including stroke and micro stroke, are the main causes of death in contemporary society. Hemorrhagic stroke is the fast emerging defficiency in the brain function resulting from disturbance of blood supply to the brain caused by the rapture of blood vessels (Lopez et al. in Proteomics Clin Appl 6:190-200, 2012). The influence of a model hemorrhagic stroke on white pigs with the change in the protein profile of their cortical samples 24 h and 2 months after the stroke was examined using mass-spectrometric analysis. Different proteins (n = 30) were identified, and their content was elevated. These proteins are involved in the mechanisms of neuroprotection, including compensation of oxidative stress (TXN, SNCA, PRDX6, ENO1), prevention of unwanted protein aggregation and apoptosis (PTMA, SNCA, SNCB), release of neurotransmitters (GAPDH, PEBP1) and assembly of the cytoskeleton (ACTA2, PTMA, TUBA4A, TUBA1D), etc. Also, a group of seven Ras family proteins involved in the regulation of cell proliferation and differentiation was found in the samples taken 24 h following the stroke. The relative concentrations of most of the proteins in the samples taken 2 months after the stroke demonstrate intermediate values between the control sample and the sample taken in 24 h, indicating the extinction of change in the protein profile with time. During the first 24 h after the stroke, there is an increase in protein fractions participating in exocytosis, synaptic plasticity/signaling, and support of neurotransmitter transport. Such shift in the weight of protein functional clusters can be attributed to activation of compensatory mechanisms in the body focused on neuroprotection.

Relative Abundance of Proteins in Blood Plasma Samples from Patients with Chronic Cerebral Ischemia.

A comparative protein profile analysis of 17 blood plasma samples from patients with ischemia and 20 samples from healthy volunteers was carried out using ultra-high resolution mass spectrometry. The analysis of measurements was performed using the proteomics search engine OMSSA. Normalized spectrum abundance factor (NSAF) in the biological samples was assessed using SearchGUI. The findings of mass spectrometry analysis of the protein composition of blood plasma samples demonstrate that the depleted samples are quite similar in protein composition and relative abundance of proteins. By comparing them with the control samples, we have found a small group of 44 proteins characteristic of the blood plasma samples from patients with chronic cerebral ischemia. These proteins contribute to the processes of homeostasis maintenance, including innate immune response unfolding, the response of a body to stress, and contribution to the blood clotting cascade.