scholarly journals Astrocyte dysfunction in Parkinson's disease: from the perspectives of transmitted α-synuclein and genetic modulation

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Changjing Wang ◽  
Tongtong Yang ◽  
Meiyu Liang ◽  
Junxia Xie ◽  
Ning Song

AbstractParkinson’s disease (PD) is a common neurodegenerative disorder that primarily affects the elderly. While the etiology of PD is likely multifactorial with the involvement of genetic, environmental, aging and other factors, α-synuclein (α-syn) pathology is a pivotal mechanism underlying the development of PD. In recent years, astrocytes have attracted considerable attention in the field. Although astrocytes perform a variety of physiological functions in the brain, they are pivotal mediators of α-syn toxicity since they internalize α-syn released from damaged neurons, and this triggers an inflammatory response, protein degradation dysfunction, mitochondrial dysfunction and endoplasmic reticulum stress. Astrocytes are indispensable coordinators in the background of several genetic mutations, including PARK7, GBA1, LRRK2, ATP13A2, PINK1, PRKN and PLA2G6. As the most abundant glial cells in the brain, functional astrocytes can be replenished and even converted to functional neurons. In this review, we discuss astrocyte dysfunction in PD with an emphasis on α-syn toxicity and genetic modulation and conclude that astrocyte replenishment is a valuable therapeutic approach in PD.

2021 ◽  
pp. 1-15
Author(s):  
Ida Manna ◽  
Andrea Quattrone ◽  
Selene De Benedittis ◽  
Enrico Iaccino ◽  
Aldo Quattrone

Parkinson’s disease (PD) is the second most common neurodegenerative disorder, affecting 5%of the elderly population. Currently, the diagnosis of PD is mainly based on clinical features and no definitive diagnostic biomarkers have been identified. The discovery of biomarkers at the earliest stages of PD is of extreme interest. This review focuses on the current findings in the field of circulating non-coding RNAs in PD. We briefly describe the more established circulating biomarkers in PD and provide a more thorough review of non-coding RNAs, in particular microRNAs, long non-coding RNAs and circular RNAs, differentially expressed in PD, highlighting their potential for being considered as biomarkers for diagnosis. Together, these studies hold promise for the use of peripheral biomarkers for the diagnosis of PD.


2020 ◽  
Author(s):  
Ashok Kumar Pandey ◽  
Saurabh Mishra ◽  
Alka Mishra

Background: Parkinson's disease is a disabling neurodegenerative disorder, mainly affecting the elderly population. Symptoms of Parkinsonism include motor function abnormalities, tremors in hands and legs, postural instability, etc. Side-effect free, long-term management of Parkinsonism is still a challenge. According to Ayurveda, the disease that resembles the symptoms associated with Parkinson's disease is Kampavata (kampa means tremors), which is primarily caused by the imbalance of the Vata Dosha. Various Panchakarma procedures have been found useful in the treatment of different Vata Vyadhis (diseases caused by the imbalance of Vata Dosha).Methodology: Panchakarma therapy was administered for 19 days to a male patient suffering from symptoms of Parkinsonism (Kampavata) since about nine months, as well as other associated ailments. According to Ayurveda, Kampavata is primarily associated with Vata imbalance. Hence, Vata pacifying herbal medicines, that also provide strengthening and nourishing effect to the degenerative tissues of the body, as well as nourishment to the brain, were used.Results: The patient experienced significant relief in the tremors in B/L hands, numbness in B/L big toes, weakness in lower extremity, and lower back pain. The patient also experienced notable relief in the complaints of Constipation, Gastric upset, and Flatus. Overall, the patient reported a satisfactory experience after taking the therapy.Conclusion: Panchakarma therapy showed encouraging results in the management of symptoms associated with Parkinsonism, as well as other associated ailments, in short duration of time.


2021 ◽  
Vol 44 (1) ◽  
pp. 87-108
Author(s):  
Gabriel E. Vázquez-Vélez ◽  
Huda Y. Zoghbi

Parkinson's disease (PD) is a common neurodegenerative disorder characterized by degeneration of the substantia nigra pars compacta and by accumulation of α-synuclein in Lewy bodies. PD is caused by a combination of environmental factors and genetic variants. These variants range from highly penetrant Mendelian alleles to alleles that only modestly increase disease risk. Here, we review what is known about the genetics of PD. We also describe how PD genetics have solidified the role of endosomal, lysosomal, and mitochondrial dysfunction in PD pathophysiology. Finally, we highlight how all three pathways are affected by α-synuclein and how this knowledge may be harnessed for the development of disease-modifying therapeutics.


Author(s):  
Vaibhav Walia ◽  
Ashish Gakkhar ◽  
Munish Garg

Parkinson's disease (PD) is a neurodegenerative disorder in which a progressive loss of the dopaminergic neurons occurs. The loss of the neurons is most prominent in the substantia nigra region of the brain. The prevalence of PD is much greater among the older patients suggesting the risk of PD increases with the increase of age. The exact cause of the neurodegeneration in PD is not known. In this chapter, the authors introduce PD, demonstrate its history, pathogenesis, neurobiology, sign and symptoms, diagnosis, and pharmacotherapy.


2018 ◽  
Vol 19 (11) ◽  
pp. 3573 ◽  
Author(s):  
Małgorzata Kujawska ◽  
Jadwiga Jodynis-Liebert

Parkinson’s disease (PD) is a neurodegenerative disorder resulting from degeneration of dopaminergic neurons in the substantia nigra pars compacta (SNpc). PD is characterized by motor dysfunctions as well as gastrointestinal symptoms and mental impairment. The pathological hallmark of PD is an accumulation of misfolded α-synuclein aggregates within the brain. The etiology of PD and related synucleinopathy is poorly understood, but recently, the hypothesis that α-synuclein pathology spreads in a prion-like fashion originating in the gut has gained much scientific attention. A crucial clue was the appearance of constipation before the onset of motor symptoms, gut dysbiosis and synucleinopathy in PD patients. Another line of evidence, demonstrating accumulation of α-synuclein within the peripheral autonomic nervous system (PANS), including the enteric nervous system (ENS), and the dorsal motor nucleus of the vagus (DMV) support the concept that α-synuclein can spread from the ENS to the brain by the vagus nerve. The decreased risk of PD following truncal vagotomy supports this. The convincing evidence of the prion-like behavior of α-synuclein came from postmortem observations that pathological α-synuclein inclusions appeared in healthy grafted neurons. In this review, we summarize the available data from human subjects’ research and animal experiments, which seem to be the most suggestive for explaining the hypotheses.


2020 ◽  
Vol 40 (19) ◽  
Author(s):  
Yasir H. Qureshi ◽  
Penelope Baez ◽  
Christiane Reitz

ABSTRACT Neuronal ceroid lipofuscinosis (NCL) is one of the most prevalent neurodegenerative disorders of early life, Parkinson’s disease (PD) is the most common neurodegenerative disorder of midlife, while Alzheimer’s disease (AD) is the most common neurodegenerative disorder of late life. While they are phenotypically distinct, recent studies suggest that they share a biological pathway, retromer-dependent endosomal trafficking. A retromer is a multimodular protein assembly critical for sorting and trafficking cargo out of the endosome. As a lysosomal storage disease, all 13 of NCL’s causative genes affect endolysosomal function, and at least four have been directly linked to retromer. PD has several known causative genes, with one directly linked to retromer and others causing endolysosomal dysfunction. AD has over 25 causative genes/risk factors, with several of them linked to retromer or endosomal trafficking dysfunction. In this article, we summarize the emerging evidence on the association of genes causing NCL with retromer function and endosomal trafficking, review the recent evidence linking NCL genes to AD, and discuss how NCL, AD, and PD converge on a shared molecular pathway. We also discuss this pathway’s role in microglia and neurons, cell populations which are critical to proper brain homeostasis and whose dysfunction plays a key role in neurodegeneration.


2020 ◽  
Vol 21 (12) ◽  
pp. 4250
Author(s):  
Yuzuru Imai

Parkinson’s disease (PD) is the second most common neurodegenerative disorder characterized by age-dependent motor dysfunction and degeneration of the midbrain dopaminergic neurons [...]


2021 ◽  
Author(s):  
Merry Chen ◽  
Julie Vincent ◽  
Alexis Ezeanii ◽  
Saurabh Wakade ◽  
Shobha Yerigenahally ◽  
...  

Parkinson's disease (PD) is a debilitating neurodegenerative disorder characterized by progressive motor decline and the aggregation of α-synuclein protein. Growing evidence suggests that α-synuclein aggregates may spread from neurons of the digestive tract to the brain in a prion-like manner. While rodent models have recapitulated gut-to-brain α-synuclein transmission, animal models that are amenable to high-throughput investigations are needed to facilitate the discovery of disease mechanisms. Here we describe the first C. elegans models in which feeding with α-synuclein pre-formed fibrils (PFFs) induced prion-like dopamine neuron degeneration and seeding of aggregation of human α-synuclein expressed in the host. PFF acceleration of α-synuclein aggregation in C. elegans muscle cells was associated with a progressive motor deficit, whereas feeding with α-synuclein monomer produced much milder effects. RNAi-mediated knockdown of the C. elegans syndecan sdn-1, and enzymes involved in heparan sulfate proteoglycan biosynthesis, afforded protection from PFF-induced seeding of aggregation and toxicity, as well as dopaminergic neurodegeneration. This work offers new models by which to investigate gut-derived α-synuclein spreading and propagation of disease.


2018 ◽  
Author(s):  
Pedro D. Maia ◽  
Sneha Pandya ◽  
Justin Torok ◽  
Ajay Gupta ◽  
Yashar Zeighami ◽  
...  

AbstractParkinson’s Disease (PD) is a the second most common neurodegenerative disorder after Alzheimer’s disease and is characterized by cell death in the amygdala and in substructures of the basal ganglia such as the substantia nigra. Since neuronal loss in PD leads to measurable atrophy patterns in the brain, there is clinical value in understanding where exactly the pathology emerges in each patient and how incipient atrophy relates to the future spread of disease. A recent seed-inference algorithm combining an established network-diffusion model with an L1-penalized optimization routine led to new insights regarding the non-stereotypical origins of Alzheimer’s pathologies across individual subjects. Here, we leverage the same technique to PD patients, demonstrating that the high variability in their atrophy patterns also translates into heterogeneous seed locations. Our individualized seeds are significantly more predictive of future atrophy than a single seed placed at the substantia nigra or the amygdala. We also found a clear distinction in seeding patterns between two PD subgroups – one characterized by predominant involvement of brainstem and ventral nuclei, and the other by more widespread frontal and striatal cortices. This might be indicative of two distinct etiological mechanisms operative in PD. Ultimately, our methods demonstrate that the early stages of the disease may exhibit incipient atrophy patterns that are more complex and variable than generally appreciated.


2021 ◽  
Author(s):  
Leo R Quinlan ◽  
Jara Maria Baena-Montes ◽  
Sahar Avazzadeh

α-synuclein is an increasingly prominent player in the pathology of a variety of neurodegenerative conditions. Parkinson’s disease (PD) is a neurodegenerative disorder that affects mainly the dopaminergic neurons in the substantia nigra of the brain. Typical of PD pathology is the finding of protein aggregations termed ‘Lewy bodies’ in the brain regions affected. α-synuclein is implicated in many disease states including dementia with Lewy bodies and Alzheimer’s disease. However, PD is the most common synucleinopathy and continues to be a significant focus of PD research in terms of the α-synuclein Lewy body pathology. Mutations in several genes are associated with PD development including SNCA, which encodes α-synuclein. A variety of model systems have been employed to study α-synuclein physiology and pathophysiology in an attempt to relate more closely to PD pathology. These models include cellular and animal system exploring transgenic technologies, viral vector expression and knockdown approaches, and models to study the potential prion protein-like effects of α-synuclein. The current review focuses on human induced pluripotent stem cell (iPSC) models with a specific focus on mutations or multiplications of the SNCA gene. iPSCs are a rapidly evolving technology with huge promise in the study of normal physiology and disease modeling in vitro. The ability to maintain a patient's genetic background and replicate similar cell phenotypes make iPSCs a powerful tool in the study of neurological diseases. This review focus on the current knowledge about α-synuclein physiological function as well as its role in PD pathogenesis based on human iPSC models.


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