scholarly journals Role of neuron specific enolase as a biomarker in Parkinson’s disease

2021 ◽  
Vol 5 (2) ◽  
pp. 061-068
Author(s):  
Dutta Rajib

Parkinson’s disease (PD) is thought to be the most common neurodegenerative disease with movement disorder. The key motor symptoms are rigidity, tremor, akinesis/hypokinesia/bradykinesia, and postural instability. However, in our day-to-day clinical practice we tend to see several other symptoms which may be motor or non-motor. Non-motor symptoms (NMS) are quite common and debilitating. The pathological hallmarks of PD are loss of dopaminergic neurons in the substantia nigra pars compacta (SNPc) and accumulation of unfolded or misfolded alpha-synuclein. Diagnosis of PD is difficult in the pre-motor stage. Late diagnosis renders a substantial loss of dopaminergic neurons in SNPc and spread of disease in other parts of the brain. This may manifest as either full blown symptoms requiring multiple medications or may even lead to life threatening condition due to lack of early diagnostic tools and techniques. Biomarkers are required to diagnose PD at a very early stage when prevention is possible. Hence, we see a lot of interest among researchers involved in finding a biomarker specific to the disease. Biomarkers may be clinical, image based, genetic, and biochemical. Cerebrospinal fluid (CSF) and serum markers which may correlate with disease pathophysiology are of great significance. One such molecule which recently gained a lot of attention is neuron-specific enolase (NSE). The main aim of this paper is to highlight the role of NSE in predicting neurodegeneration and neuroinflammation ultimately reflecting damage of brain cells in PD.

2022 ◽  
Author(s):  
Min Hyung Seo ◽  
Sujung Yeo

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.


Author(s):  
Chiara Milanese ◽  
Sylvia Gabriels ◽  
Sander Barnhoorn ◽  
Silvia Cerri ◽  
Ayse Ulusoy ◽  
...  

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.


2020 ◽  
Vol 17 (10) ◽  
pp. 1261-1269
Author(s):  
Yasir Hasan Siddique ◽  
Rahul ◽  
Mantasha Idrisi ◽  
Mohd. Shahid

Background: Parkinson’s disease is a common neurodegenerative disorder characterized by selective loss of dopaminergic neurons in the substantia nigra pars compacta. Introduction: The effects of alpha synuclein, parkin mutation and pharmacological agents have been studied in the Drosophila model. Methods: The effect of cabergoline was studied on the cognitive impairments exhibited by the transgenic Drosophila expressing human alpha-synuclein in the neurons. The PD flies were allowed to feed on the diet having 0.5, 1 and 1.5 μM of cabergoline. Results and Discussion: The exposure of cabergoline not only showed a dose-dependent significant delay in the cognitive impairments but also prevented the loss of dopaminergic neurons. Molecular docking studies showed the positive interaction between cabergoline and alpha-synuclein. Conclusion: The results suggest a protective effect of cabergoline against the cognitive impairments.


2021 ◽  
Author(s):  
Joana Lama ◽  
Yazead Buhidma ◽  
Edward JR Fletcher ◽  
Susan Duty

Parkinson’s disease (PD) is a complex, multisystem disorder characterised by alpha synuclein pathology, degeneration of nigrostriatal dopaminergic neurons, multifactorial pathogenetic mechanisms and expression of a plethora of motor and non-motor symptoms. Animal models of PD have already been instructive in helping us unravel some of these aspects. However, much remains to be discovered, requiring continued interrogation by the research community. In contrast to the situation for many neurological disorders, PD benefits from of a wide range of available animal models (pharmacological, toxin, genetic and alpha-synuclein) but this makes selection of the optimal one for a given study difficult. This is especially so when a study demands a model that displays a specific combination of features. While many excellent reviews of animal models already exist, this review takes a different approach with the intention of more readily informing this decision-making process. We have considered each feature of PD in turn - aetiology, pathology, pathogenesis, motor dysfunctions and non-motor symptoms - highlighting those animal models that replicate each. By compiling easily accessible tables and figures, we aim to provide the reader with a simple, go-to resource for selecting the optimal animal model of PD to suit their research needs.


2020 ◽  
pp. 10-14
Author(s):  
R. R. Tyutina ◽  
A. A. Pilipovich ◽  
V. L. Golubev ◽  
Al. B. Danilov

Parkinson's disease (PD) is characterized by both motor (hypokinesia, resting tremor, rigidity, postural instability) and non-motor symptoms. It is known that some non-motor manifestations, such as disturbances in smell, sleep, depression, gastrointestinal dysfunction, and others, may precede motor symptoms. Replenishment of dopamine deficiency, which, as known, develops in PD due to the death of dopaminergic neurons of the substantia nigra, makes it possible to influence most motor and some non-motor symptoms of parkinsonism, however many non-motor manifestations remain resistant to this therapy. In addition, it has only a symptomatic effect, and the pathogenetic treatment of PD is currently unavailable, which is primarily due to insufficient knowledge about the etiology and mechanisms of the development of the disease. In particular, it has already been established that alpha synuclein (a pathomorphological marker of PD) begins to be deposited in the intestinal wall, in the enteric nervous system (ENS) long before it appears in neurons of the substantia nigra. Understanding the mechanism of interaction along the axis “intestine – brain”, the role of intestinal wall dysfunction in the onset and development of PD can lead to the development of new directions in the treatment of this disease. Today, the role of microbiota, in particular the intestinal microbiota, in the functioning of the human body, its various systems, including the nervous system, is widely studied in the world. The influence of its imbalance on the activation of inflammatory reactions in the ENS and the possibility of the subsequent development of PD are considered. This review provides some evidence supporting the hypothesis that PD can be initiated in the gut. In addition, the possibilities of influencing the course of BP using pre-, pro-, syn- and metabiotics are considered.


Author(s):  
Yasir Hasan Siddique

: Alpha synuclein (α-synuclein) is a protein which is abundantly found in brain and in lesser amount in heart and muscles. The exact role of α-synuclein is not known but it is consider to control the movement of synaptic vesicles. Its overexpression in the neurons leads to the formation of Lewy bodies which specifically damage the dopaminergic neurons in the subtantianigra of the mid brain and leads to the progression of Parkinson’s disease (PD). There are evidences that aggregates of α-synuclein behaves like prions. The present review is an attempt to put forth the nature of α-synuclein as prions.


2021 ◽  
Vol 13 ◽  
Author(s):  
Xin Liu ◽  
Zhong-Rui Du ◽  
Xiong Wang ◽  
Kar-Him Luk ◽  
Cheuk-Hin Chan ◽  
...  

The role of gut-brain axis in the pathogenesis of Parkinson’s disease (PD) have become a research hotspot, appropriate animal model to study gut-brain axis in PD is yet to be confirmed. Our study employed a classical PD mice model achieved by chronic MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) injection to study concurrent changes of dopaminergic neurons in the midbrain and the colon of mice. Our results showed such a PD model exhibited apparent locomotor deficits but not gastrointestinal dysfunction. Tyrosine hydroxylase expressions and dopamine content reduced greatly in the substantia nigra pars compacta (SNpc) or striatum, but increased in the colon of PD mice. Mechanism investigation indicated autophagy activity and apoptosis were stimulated in the SNpc, but inhibited in the colon of PD mice. Interplay of gut microbiota (GM) and autophagy in response to chronic MPTP injection led to GM dysbiosis and defective autophagy in mice colon. Meanwhile, fecal short chain fatty acids (SCFAs), acetate and propionate in particular, declined greatly in PD mice, which could be attributed to the decreased bacteria abundance of phylum Bacteroidetes, but increased abundance of phylum Firmicutes. GM dysbiosis derived fecal SCFAs might be one of the mediators of downregulated autophagy in the colon of PD mice. In conclusion, colonic dopaminergic neurons changed in the opposition direction with those in the midbrain via GM dysbiosis-mediated autophagy inhibition followed by suppressed apoptosis in response to chronic MPTP injection. Such a chronic PD mice model might not be an ideal model to study role of gut-brain axis in PD progression.


2021 ◽  
Vol 15 ◽  
Author(s):  
Alexandre Iarkov ◽  
Cristhian Mendoza ◽  
Valentina Echeverria

Parkinson’s disease (PD) is a neurodegenerative condition characterized by the loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc) in the midbrain resulting in progressive impairment in cognitive and motor abilities. The physiological and molecular mechanisms triggering dopaminergic neuronal loss are not entirely defined. PD occurrence is associated with various genetic and environmental factors causing inflammation and mitochondrial dysfunction in the brain, leading to oxidative stress, proteinopathy, and reduced viability of dopaminergic neurons. Oxidative stress affects the conformation and function of ions, proteins, and lipids, provoking mitochondrial DNA (mtDNA) mutation and dysfunction. The disruption of protein homeostasis induces the aggregation of alpha-synuclein (α-SYN) and parkin and a deficit in proteasome degradation. Also, oxidative stress affects dopamine release by activating ATP-sensitive potassium channels. The cholinergic system is essential in modulating the striatal cells regulating cognitive and motor functions. Several muscarinic acetylcholine receptors (mAChR) and nicotinic acetylcholine receptors (nAChRs) are expressed in the striatum. The nAChRs signaling reduces neuroinflammation and facilitates neuronal survival, neurotransmitter release, and synaptic plasticity. Since there is a deficit in the nAChRs in PD, inhibiting nAChRs loss in the striatum may help prevent dopaminergic neurons loss in the striatum and its pathological consequences. The nAChRs can also stimulate other brain cells supporting cognitive and motor functions. This review discusses the cholinergic system as a therapeutic target of cotinine to prevent cognitive symptoms and transition to dementia in PD.


Cells ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 1687 ◽  
Author(s):  
Marta Pajares ◽  
Ana I. Rojo ◽  
Gina Manda ◽  
Lisardo Boscá ◽  
Antonio Cuadrado

Parkinson’s disease (PD) is a common neurodegenerative disorder primarily characterized by the death of dopaminergic neurons that project from the substantia nigra pars compacta. Although the molecular bases for PD development are still little defined, extensive evidence from human samples and animal models support the involvement of inflammation in onset or progression. However, the exact trigger for this response remains unclear. Here, we provide a systematic review of the cellular mediators, i.e., microglia, astroglia and endothelial cells. We also discuss the genetic and transcriptional control of inflammation in PD and the immunomodulatory role of dopamine and reactive oxygen species. Finally, we summarize the preclinical and clinical approaches targeting neuroinflammation in PD.


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