Morphometric analysis of dopaminergic neurons (substantia nigra) in the brain of MPTP-treated alpha-synuclein knockout mice

Целью данной работы являлась оценка выживаемости популяции зрелых дофаминергических (ДА-ергических) нейронов чёрной субстанции двух альфа-синуклеин нокаутных линий мышей Abel-KO и ΔFlox-KO, а также бессинуклеиновых животных abg-КО в условиях МФТП-токсического моделирования паркинсонического синдрома. Методы исследования: Водный раствор нейротоксина МФТП вводили 3-месячным мышам внутрибрюшинно в дозе 30 мг/кг ежедневно в течение 5 дней по субхроническому протоколу. Через 21 день после последней инъекции МФТП у животных извлекали головной мозг, фиксировали в холодном растворе Карнуа и парафинизировали для последующего приготовления гистологических препаратов на ротационном микротоме Leica RM2265 (Leica Biosystems, Германия). Иммуногистохимическое окрашивание проводили антителами против тирозингидроксилазы (моноклональные антитела мыши, Sigma, разведение 1:2000). Сравнительный морфометрический анализ популяции ДА-ергических нейронов чёрной субстанции выполнен с учётом поправки Аберкромби. Результаты: Установлено, что в условиях дефицита альфа-синуклеина мыши устойчивы к потере ДА-ергических нейронов в компактной части ЧС после введения МФТП. При генетической делеции всех трёх синуклеинов чувствительность ДА-ергических нейронов ЧС к токсическому действию МФТП не отличается от таковой у животных с немодифицированным геномом. Заключение. На основании проведённого морфометрического анализа предполагается, что особенности чувствительности к нейротоксину МФТП у альфа-синуклеин нокаутных линий мышей обусловлены повышением функциональной активности (замещением) бета-синуклеина, оптимизирующего захват ДА синаптическими везикулами. The aim of this study was to assess survival of mature dopaminergic (DAergic) neuronal population in the substantia nigra pars compacta (SNpc) of two alpha-synuclein knockout mice strains (Abel-KO and ΔFlox-KO) and of non-synuclein animals (abg-KO) in MPTP-induced parkinsonism. Material and methods: MPTP water solution was administered to 3-month-old mice intraperitoneally (30 mg/kg daily for 5 days) according to a subchronic protocol. On the 21st day after the last MPTP injection, the brain was excised, fixed in cold Carnoy’s solution and paraffined for the subsequent preparation of histological samples on a Leica RM2265 rotary microtome (Leica Biosystems, Germany). Immunohistochemical staining was performed with antibodies against tyrosine hydroxylase (mouse monoclonal antibodies, Sigma, dilution 1:2000). A comparative morphometric analysis of substantia nigra dopaminergic neurons was performed using the Abercrombie correction. Results: MPTP-treated alpha-synuclein deficient mice were resistant to the loss of DAergic neurons in the SNpc. Genetic deletion of all three synucleins restored the sensitivity of SNpc DAergic neurons to the MPTP toxicity, which did not differ from the sensitivity of wild type animals. Conclusion: Based on the morphometric analysis, it was assumed that the specific features of MPTP sensitivity in alpha-synuclein knockout mice are due to an increased functional activity (substitution) of beta-synuclein, which optimizes the capture of DA by synaptic vesicles.

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Reduced complement of dopaminergic neurons in the substantia nigra pars compacta of mice with a constitutive “low footprint” genetic knockout of alpha-synuclein

Molecular Brain ◽

10.1186/s13041-020-00613-5 ◽

2020 ◽

Vol 13 (1) ◽

Author(s):

Valeria V. Goloborshcheva ◽

Kirill D. Chaprov ◽

Ekaterina V. Teterina ◽

Ruslan Ovchinnikov ◽

Vladimir L. Buchman

Keyword(s):

Substantia Nigra ◽

Dopaminergic Neurons ◽

Alpha Synuclein ◽

Substantia Nigra Pars Compacta ◽

Genetic Knockout

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Developmental loss and resistance to MPTP toxicity of dopaminergic neurones in substantia nigra pars compacta of gamma-synuclein, alpha-synuclein and double alpha/gamma-synuclein null mutant mice

Journal of Neurochemistry ◽

10.1111/j.1471-4159.2004.02378.x ◽

2004 ◽

Vol 89 (5) ◽

pp. 1126-1136 ◽

Cited By ~ 89

Author(s):

Darren C. Robertson ◽

Oliver Schmidt ◽

Natalia Ninkina ◽

Paul A. Jones ◽

John Sharkey ◽

...

Keyword(s):

Substantia Nigra ◽

Alpha Synuclein ◽

Mutant Mice ◽

Substantia Nigra Pars Compacta ◽

Null Mutant ◽

Mptp Toxicity ◽

Null Mutant Mice

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Association Between Decreased Srpk3 Expression And An Increase In Substantia Nigra Alpha-Synuclein Levels In An MPTP-Induced Parkinson’s Disease Mouse Model

10.21203/rs.3.rs-1207279/v1 ◽

2022 ◽

Author(s):

Min Hyung Seo ◽

Sujung Yeo

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Substantia Nigra ◽

Dopaminergic Neurons ◽

Cell Loss ◽

Alpha Synuclein ◽

Mice Model ◽

Dopaminergic Cell ◽

The Brain

Abstract Parkinson’s disease (PD) is known as the second most common neurodegenerative disease, which is caused by destruction of dopaminergic neurons in the substantia nigra (SN) of the brain; however, the reason for the death of dopaminergic neurons remains unclear. An increase in α-synuclein (α-syn) is considered an important factor in the pathogenesis of PD. In the current study, we investigated the association between PD and serine/arginine-rich protein specific kinase 3 (Srpk3) in MPTP-induced parkinsonism mice model and in SH-SY5Y cells treated with MPP+. Srpk3 expression was significantly downregulated, while tyrosine hydroxylase (TH) decreased and α-synuclein (α-syn) increased after 4 weeks of MPTP intoxication treatment. Dopaminergic cell reduction and α-syn increase were demonstrated by inhibiting Srpk3 expression by siRNA in SH-SY5Y cells. Moreover, a decrease in Srpk3 expression upon siRNA treatment promoted dopaminergic cell reduction and α-syn increase in SH-SY5Y cells treated with MPP+. These results suggest that the decrease in Srpk3 expression due to Srpk3 siRNA caused both a decrease in TH and an increase in α-syn. This raises new possibilities for studying how Srpk3 controls dopaminergic cells and α-syn expression, which may be related to the pathogenesis of PD. Our results provide an avenue for understanding the role of Srpk3 during dopaminergic cell loss and α-syn increase in the SN. Furthermore, this study could support a therapeutic possibility for PD in that the maintenance of Srpk3 expression inhibited dopaminergic cell reduction.

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Protective effect of Curcumin against rotenone-induced Substantia nigra pars compacta neuronal dysfunction

10.21203/rs.3.rs-874598/v1 ◽

2021 ◽

Author(s):

Lilit Vahan Darbinyan ◽

Lilia Eduard Hambardzumyan ◽

Larisa Paylak Manukyan ◽

Karen Vazgen Simonyan ◽

Carlos Augusto Carvalho de Vasconcelos ◽

...

Keyword(s):

Substantia Nigra ◽

Dopaminergic Neurons ◽

Therapeutic Agent ◽

Male Rats ◽

Substantia Nigra Pars Compacta ◽

Nissl Staining ◽

Histological Changes ◽

Naturally Occurring ◽

The Brain

Abstract Rotenone is involved in the degeneration of dopaminergic neurons, and curcumin may prevent or effectively slow the progression of Parkinson disease (PD). Previous research has shown that the naturally occurring phenolic compound curcumin can reduce inflammation and oxidation, making it a potential therapeutic agent for neurodegenerative diseases. The present study involves investigation of rotenone induced histological changes in the brain areas, hippocampus using Nissl staining after 35 day of subcutaneous injection administration of rotenone in adult male rats. In this study, we investigated whether curcumin protects against rotenone-induced dopaminergic neurotoxicity in a rat model by in vivo electrical recording from Substantia nigra pars compacta (SNc). Curcumin treatment significantly improved electrical activity of neurons in the SNc of rotenone-induced PD model rats. The pattern of histological alterations corresponds with electrophysiological manifestations.

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Gender biased neuroprotective effect of Transferrin Receptor 2 deletion in multiple models of Parkinson’s disease

Cell Death and Differentiation ◽

10.1038/s41418-020-00698-4 ◽

2020 ◽

Author(s):

Chiara Milanese ◽

Sylvia Gabriels ◽

Sander Barnhoorn ◽

Silvia Cerri ◽

Ayse Ulusoy ◽

...

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Substantia Nigra ◽

Iron Overload ◽

Transferrin Receptor ◽

Dopaminergic Neurons ◽

Iron Homeostasis ◽

Alpha Synuclein ◽

Substantia Nigra Pars Compacta ◽

Transferrin Receptor 2

AbstractAlterations in the metabolism of iron and its accumulation in the substantia nigra pars compacta accompany the pathogenesis of Parkinson’s disease (PD). Changes in iron homeostasis also occur during aging, which constitutes a PD major risk factor. As such, mitigation of iron overload via chelation strategies has been considered a plausible disease modifying approach. Iron chelation, however, is imperfect because of general undesired side effects and lack of specificity; more effective approaches would rely on targeting distinctive pathways responsible for iron overload in brain regions relevant to PD and, in particular, the substantia nigra. We have previously demonstrated that the Transferrin/Transferrin Receptor 2 (TfR2) iron import mechanism functions in nigral dopaminergic neurons, is perturbed in PD models and patients, and therefore constitutes a potential therapeutic target to halt iron accumulation. To validate this hypothesis, we generated mice with targeted deletion of TfR2 in dopaminergic neurons. In these animals, we modeled PD with multiple approaches, based either on neurotoxin exposure or alpha-synuclein proteotoxic mechanisms. We found that TfR2 deletion can provide neuroprotection against dopaminergic degeneration, and against PD- and aging-related iron overload. The effects, however, were significantly more pronounced in females rather than in males. Our data indicate that the TfR2 iron import pathway represents an amenable strategy to hamper PD progression. Data also suggest, however, that therapeutic strategies targeting TfR2 should consider a potential sexual dimorphism in neuroprotective response.

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Muscarine Reduces Calcium-Dependent Electrical Activity in Substantia Nigra Dopaminergic Neurons

Journal of Neurophysiology ◽

10.1152/jn.2001.86.6.2966 ◽

2001 ◽

Vol 86 (6) ◽

pp. 2966-2972 ◽

Cited By ~ 26

Author(s):

Reese S. Scroggs ◽

Carla G. Cardenas ◽

Joseph A. Whittaker ◽

Stephen T. Kitai

Keyword(s):

Substantia Nigra ◽

Electrical Activity ◽

Dopaminergic Neurons ◽

Brain Slices ◽

Oscillatory Potentials ◽

Substantia Nigra Pars Compacta ◽

Pontine Nucleus ◽

Calcium Dependent ◽

The Brain

The effect of muscarine on Ca2+ dependent electrical activity was studied in dopamine (DA) neurons located in the substantia nigra pars compacta (SNc) in brain slices from young rats, using sharp electrodes. In most DA neurons tested, muscarine (50 μM) reduced the amplitude of spontaneous oscillatory potentials and evoked Ca2+-dependent potentials recorded in the presence of TTX. Muscarine also reduced the amplitude of the slow afterhyperpolarization (sAHP) following action potentials in most DA neurons. These data suggest that muscarine reduces Ca2+ entry in SNc DA neurons. The reduction of the amplitude of the sAHP by muscarine in DA neurons may facilitate bursting initiated by glutamatergic input by increasing the frequency at which DA neurons can fire. The reduction of the sAHP via activation of muscarinic receptors in vivo may provide a mechanism whereby cholinergic inputs to DA neurons from the tegmental peduncular pontine nucleus could modulate dopamine release at dopaminergic targets in the brain.

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Genetic inactivation of alpha-synuclein affects embryonic development of dopaminergic neurons of the substantia nigra, but not the ventral tegmental area, in mouse brain

10.7287/peerj.preprints.26547v2 ◽

2018 ◽

Author(s):

Tatiana V Tarasova ◽

Olga A Lytkina ◽

Valeria V Goloborshcheva ◽

Larisa N Skuratovskaya ◽

Alexandr I Antohin ◽

...

Keyword(s):

Substantia Nigra ◽

Embryonic Development ◽

Ventral Tegmental Area ◽

Knockout Mice ◽

Dopaminergic Neurons ◽

Lewy Bodies ◽

Alpha Synuclein ◽

Nigrostriatal System ◽

Ventral Tegmental

Lesion of the dopaminergic neurons of the nigrostriatal system is a key feature of Parkinson's disease (PD). Alpha-synuclein is a protein that is a major component of Lewy bodies, histopathological hallmarks of PD, and is involved in regulation of dopamine (DA) neurotransmission. Previous studies of knockout mice have shown that inactivation of alpha-synuclein gene can lead to the reduction in number of DA neurons in the substantia nigra (SN). DA neurons of the SN are known to be the most affected in PD patients whereas DA neurons of neighboring ventral tegmental area (VTA) are much less susceptible to degeneration. Here we have studied the dynamics of changes in TH-positive cell numbers in the SN and VTA during a critical period of their embryonic development in alpha-synuclein knockout mice. This precise study of DA neurons during development of the SN revealed that not only is the number of DA neurons reduced by the end of the period of ontogenic selection, but that the way these neurons are formed is altered in alpha-synuclein knockout mice. At the same time, DA neurons in the VTA are not affected. Alpha-synuclein exerts a modulating effect on the formation of DA neurons in the SN and has no effect on the formation of DA neurons in VTA, the structure that is much less susceptible to degeneration in PD brain, suggesting a potential role of alpha-synuclein in the development of the population of DA neurons in substantia nigra.

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Genetic inactivation of alpha-synuclein affects embryonic development of dopaminergic neurons of the substantia nigra, but not the ventral tegmental area, in mouse brain

10.7287/peerj.preprints.26547 ◽

2018 ◽

Author(s):

Tatiana V Tarasova ◽

Olga A Lytkina ◽

Valeria V Goloborshcheva ◽

Larisa N Skuratovskaya ◽

Alexandr I Antohin ◽

...

Keyword(s):

Substantia Nigra ◽

Embryonic Development ◽

Ventral Tegmental Area ◽

Knockout Mice ◽

Dopaminergic Neurons ◽

Lewy Bodies ◽

Alpha Synuclein ◽

Nigrostriatal System ◽

Ventral Tegmental

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Genetic inactivation of alpha-synuclein affects embryonic development of dopaminergic neurons of the substantia nigra, but not the ventral tegmental area, in mouse brain

PeerJ ◽

10.7717/peerj.4779 ◽

2018 ◽

Vol 6 ◽

pp. e4779 ◽

Cited By ~ 2

Author(s):

Tatiana V. Tarasova ◽

Olga A. Lytkina ◽

Valeria V. Goloborshcheva ◽

Larisa N. Skuratovskaya ◽

Alexandr I. Antohin ◽

...

Keyword(s):

Substantia Nigra ◽

Embryonic Development ◽

Ventral Tegmental Area ◽

Knockout Mice ◽

Dopaminergic Neurons ◽

Lewy Bodies ◽

Alpha Synuclein ◽

Nigrostriatal System ◽

Ventral Tegmental

Lesion of the dopaminergic neurons of the nigrostriatal system is a key feature of Parkinson’s disease (PD). Alpha-synuclein is a protein that is a major component of Lewy bodies, histopathological hallmarks of PD, and is involved in regulation of dopamine (DA) neurotransmission. Previous studies of knockout mice have shown that inactivation of alpha-synuclein gene can lead to the reduction in number of DA neurons in the substantia nigra (SN). DA neurons of the SN are known to be the most affected in PD patients whereas DA neurons of neighboring ventral tegmental area (VTA) are much less susceptible to degeneration. Here we have studied the dynamics of changes in TH-positive cell numbers in the SN and VTA during a critical period of their embryonic development in alpha-synuclein knockout mice. This precise study of DA neurons during development of the SN revealed that not only is the number of DA neurons reduced by the end of the period of ontogenic selection, but that the way these neurons are formed is altered in alpha-synuclein knockout mice. At the same time, DA neurons in the VTA are not affected. Alpha-synuclein exerts a modulating effect on the formation of DA neurons in the SN and has no effect on the formation of DA neurons in VTA, the structure that is much less susceptible to degeneration in a brain with PD, suggesting a potential role of alpha-synuclein in the development of the population of DA neurons in substantia nigra.

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