scholarly journals Emerging regenerative medicine and tissue engineering strategies for Parkinson’s disease

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
James P. Harris ◽  
Justin C. Burrell ◽  
Laura A. Struzyna ◽  
H. Isaac Chen ◽  
Mijail D. Serruya ◽  
...  

AbstractParkinson’s disease (PD) is the second most common progressive neurodegenerative disease, affecting 1–2% of people over 65. The classic motor symptoms of PD result from selective degeneration of dopaminergic neurons in the substantia nigra pars compacta (SNpc), resulting in a loss of their long axonal projections to the striatum. Current treatment strategies such as dopamine replacement and deep brain stimulation (DBS) can only minimize the symptoms of nigrostriatal degeneration, not directly replace the lost pathway. Regenerative medicine-based solutions are being aggressively pursued with the goal of restoring dopamine levels in the striatum, with several emerging techniques attempting to reconstruct the entire nigrostriatal pathway—a key goal to recreate feedback pathways to ensure proper dopamine regulation. Although many pharmacological, genetic, and optogenetic treatments are being developed, this article focuses on the evolution of transplant therapies for the treatment of PD, including fetal grafts, cell-based implants, and more recent tissue-engineered constructs. Attention is given to cell/tissue sources, efficacy to date, and future challenges that must be overcome to enable robust translation into clinical use. Emerging regenerative medicine therapies are being developed using neurons derived from autologous stem cells, enabling the construction of patient-specific constructs tailored to their particular extent of degeneration. In the upcoming era of restorative neurosurgery, such constructs may directly replace SNpc neurons, restore axon-based dopaminergic inputs to the striatum, and ameliorate motor deficits. These solutions may provide a transformative and scalable solution to permanently replace lost neuroanatomy and improve the lives of millions of people afflicted by PD.

2020 ◽  
Vol 21 (18) ◽  
pp. 6719
Author(s):  
Samuel Ohiomokhare ◽  
Francis Olaolorun ◽  
Amany Ladagu ◽  
Funmilayo Olopade ◽  
Melanie-Jayne R. Howes ◽  
...  

Parkinson’s disease (PD) pathology is characterised by distinct types of cellular defects, notably associated with oxidative damage and mitochondria dysfunction, leading to the selective loss of dopaminergic neurons in the brain’s substantia nigra pars compacta (SNpc). Exposure to some environmental toxicants and heavy metals has been associated with PD pathogenesis. Raised iron levels have also been consistently observed in the nigrostriatal pathway of PD cases. This study explored, for the first time, the effects of an exogenous environmental heavy metal (vanadium) and its interaction with iron, focusing on the subtoxic effects of these metals on PD-like oxidative stress phenotypes in Catecholaminergic a-differentiated (CAD) cells and PTEN-induced kinase 1 (PINK−1)B9Drosophila melanogaster models of PD. We found that undifferentiated CAD cells were more susceptible to vanadium exposure than differentiated cells, and this susceptibility was modulated by iron. In PINK−1 flies, the exposure to chronic low doses of vanadium exacerbated the existing motor deficits, reduced survival, and increased the production of reactive oxygen species (ROS). Both Aloysia citrodora Paláu, a natural iron chelator, and Deferoxamine Mesylate (DFO), a synthetic iron chelator, significantly protected against the PD-like phenotypes in both models. These results favour the case for iron-chelation therapy as a viable option for the symptomatic treatment of PD.


2020 ◽  
Vol 26 (6) ◽  
pp. 333-342 ◽  
Author(s):  
Shoned Jones ◽  
Kelli M. Torsney ◽  
Lily Scourfield ◽  
Katie Berryman ◽  
Emily J. Henderson

SUMMARYHistorically, Parkinson's disease was viewed as a motor disorder and it is only in recent years that the spectrum of non-motor disorders associated with the condition has been fully recognised. There is a broad scope of neuropsychiatric manifestations, including depression, anxiety, apathy, psychosis and cognitive impairment. Patients are more predisposed to delirium, and Parkinson's disease treatments give rise to specific syndromes, including impulse control disorders, dopamine agonist withdrawal syndrome and dopamine dysregulation syndrome. This article gives a broad overview of the spectrum of these conditions, describes the association with severity of Parkinson's disease and the degree to which dopaminergic degeneration and/or treatment influence symptoms. We highlight useful assessment scales that inform diagnosis and current treatment strategies to ameliorate these troublesome symptoms, which frequently negatively affect quality of life.


Author(s):  
Hayrettin Ozan Gulcan

: Similar to other neurodegenerative diseases, Parkinson’s disease (PD) has been extensively investigated with respect to its neuropathological background and possible treatment options. Since the symptomatic outcomes are generally related to dopamine deficiency, the current treatment strategies towards PD mainly employ dopaminergic agonists as well as the compounds acting on dopamine metabolism. These drugs do not provide disease modifying properties; therefore alternative drug discovery studies focus on targets involved in the progressive neurodegenerative character of PD. This study has aimed to present the pathophysiology of PD concomitant to the representation of drugs and promising molecules displaying activity against the validated and non-validated targets of PD.


2020 ◽  
Vol 21 (10) ◽  
pp. 3459 ◽  
Author(s):  
Sandra Barata-Antunes ◽  
Fábio G. Teixeira ◽  
Bárbara Mendes-Pinheiro ◽  
Ana V. Domingues ◽  
Helena Vilaça-Faria ◽  
...  

Parkinson’s disease (PD) is the second most common age-related neurodegenerative disorder. The neurodegeneration leading to incapacitating motor abnormalities mainly occurs in the nigrostriatal pathway due to the loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc). Several animal models have been developed not only to better understand the mechanisms underlying neurodegeneration but also to test the potential of emerging disease-modifying therapies. However, despite aging being the main risk factor for developing idiopathic PD, most of the studies do not use aged animals. Therefore, this study aimed at assessing the effect of aging in the unilateral 6-hydroxydopamine (6-OHDA)-induced animal model of PD. For this, female young adult and aged rats received a unilateral injection of 6-OHDA into the medial forebrain bundle. Subsequently, the impact of aging on 6-OHDA-induced effects on animal welfare, motor performance, and nigrostriatal integrity were assessed. The results showed that aging had a negative impact on animal welfare after surgery. Furthermore, 6-OHDA-induced impairments on skilled motor function were significantly higher in aged rats when compared with their younger counterparts. Nigrostriatal histological analysis further revealed an increased 6-OHDA-induced dopaminergic cell loss in the SNpc of aged animals when compared to young animals. Overall, our results demonstrate a higher susceptibility of aged animals to 6-OHDA toxic insult.


2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Joonsoo Kim ◽  
Govindarajan Karthivashan ◽  
Mee-Hyang Kweon ◽  
Deuk-Hoi Kim ◽  
Dong-Kug Choi

Hyperactivation of microglia, the resident innate immune cells of the central nervous system, exacerbates various neurodegenerative disorders, including Parkinson’s disease (PD). Parkinson’s disease is generally characterized by a severe loss of dopaminergic neurons in the nigrostriatal pathway, with substantial neuroinflammation and motor deficits. This was experimentally replicated in animal models, using neurotoxins, i.e., LPS (lipopolysaccharides) and MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine).Salicornia europaeaL. (SE) has been used as a dietary supplement in Korea and Europe for several years, due to its nutritional and therapeutic value. In this study, we intend to investigate the antineuroinflammatory and anti-PD-like effects of the bioactive fraction/candidate of the SE extract. Initially, we screened various fractions of SE extract using anin vitroantioxidant assay. The optimal fraction was investigated for itsin vitroantineuroinflammatory potential in LPS-stimulated BV-2 microglial cells andin vivoanti-PD-like potential in MPTP-intoxicated mice. Subsequently, to identify the potential candidate responsible for the elite therapeutic potential of the optimal fraction, we conducted antioxidant activity-guided isolation and purification; the bioactive candidate was structurally characterized using nuclear magnetic resonance spectroscopy and chromatographic techniques and further investigated for itsin vitroantioxidative and antineuroinflammatory potential. The results of our study indicate that SE-EA and its bioactive candidate, Irilin B, effectively alleviate the deleterious effect of microglia-mediated neuroinflammation and promote antioxidative effects. Thus, they exhibit potential as therapeutic candidates against neuroinflammatory and oxidative stress-mediated PD-like neurodegenerative complications.


2020 ◽  
Vol 29 (8) ◽  
pp. 1239-1252 ◽  
Author(s):  
Ting-Ting Wu ◽  
Te Liu ◽  
Xuan Li ◽  
Ya-Jing Chen ◽  
Tian-Jiao Chen ◽  
...  

Abstract It has been reported that abnormal epigenetic modification is associated with the occurrence of Parkinson’s disease (PD). Here, we found that a ten-eleven translocation 2 (TET2), a staff of the DNA hydroxylases family, was increased in dopaminergic neurons in vitro and in vivo. Genome-wide mapping of DNA 5-hydroxymethylcytosine (5-hmC)-sequencing has revealed an aberrant epigenome 5-hmC landscape in 1-methyl-4-phenylpyridinium iodide (MPP+)-induced SH-SY5Y cells. The TET family of DNA hydroxylases could reverse DNA methylation by oxidization of 5-methylcytosine (5-mC) to 5-hmC. However, the relationship between modification of DNA hydroxymethylation and the pathogenesis of PD is not clear. According to the results of 5-hmC-sequencing studies, 5-hmC was associated with gene-rich regions in the genomes related to cell cycle, especially gene-cyclin-dependent kinase inhibitor 2A (Cdkn2A). Downregulation of TET2 expression could significantly rescue MPP+-stimulated SH-SY5Y cell damage and cell cycle arrest. Meanwhile, knockdown of Tet2 expression in the substantia nigra pars compacta of MPTP-induced PD mice resulted in attenuated MPTP-induced motor deficits and dopaminergic neuronal injury via p16 suppression. In this study, we demonstrated a critical function of TET2 in PD development via the CDKN2A activity-dependent epigenetic pathway, suggesting a potential new strategy for epigenetic therapy.


2020 ◽  
Author(s):  
Chenyu Zhang ◽  
Miao Zhao ◽  
Bingwei Wang ◽  
Zhijie Su ◽  
Bingbing Guo ◽  
...  

Abstract Background: Parkinson’s disease (PD) is characterized by the loss of dopaminergic neurons in the substantia nigra pars compacta (SNc), accompanied by chronic neuroinflammation, oxidative stress, and widespread accumulation of α-synuclein. Celastrol (Cel), a potent anti-inflammatory and anti-oxidative pentacyclic triterpene, has emerged as a neuroprotective agent. However, the mechanisms by which celastrol is neuroprotective in PD has not yet been elucidated. Methods: The MPTP and AAV-mediated human wild-type α-syn overexpression within SNc induced PD mouse models were employed in this study. By using multiple genetically modified mice (Nrf2-KO, NLRP3-KO and Caspase1-KO), we identified that celastrol effectively inhibited the NLRP3 inflammasome activation, mitigated motor deficits and nigrostriatal dopaminergic degeneration through Nrf2-NLRP3-Caspase1 pathway. Results: Here we show that celastrol protected against the loss of dopaminergic neurons, mitigated the neuroinflammation and motor deficits in both MPTP-induced PD mouse model and AAV-mediated human α-syn overexpression PD model. Whole-genome deep sequencing analysis reveals that Nrf2, NLRP3 and Caspase1 in SNc may be associated with the neuroprotective actions of celastrol in PD. Conclusions: These findings suggest that Nrf2-NLRP3-Caspase1 axis may be a key target of celastrol in PD treatment, and highlight the favorable properties linked to neuroprotection of celastrol, making celastrol as a promising disease-modifying agent for PD.


Author(s):  
Meritxell Pons-Espinal ◽  
Lucas Blasco-Agell ◽  
Antonella Consiglio

AbstractParkinson’s disease (PD) is an incurable age-linked neurodegenerative disease with characteristic movement impairments that are caused by the progressive loss of dopamine-containing neurons (DAn) within the substantia nigra pars compacta. It has been suggested that misfolded protein aggregates together with neuroinflammation and glial reactivity, may impact nerve cell function, leading to neurodegeneration and diseases, such as PD. However, not many studies have been able to examine the role of human glial cells in the pathogenesis of PD. With the advent of induced pluripotent stem cell (iPSC) technology, it is now possible to reprogram human somatic cells to pluripotency and to generate viable human patient-specific DA neurons and glial cells, providing a tremendous opportunity for dissecting cellular and molecular pathological mechanisms occurring at early stages of PD. This reviews will report on recent work using human iPSC and 3D brain organoid models showing that iPSC technology can be used to recapitulate PD-relevant disease-associated phenotypes, including protein aggregation, cell death or loss of neurite complexity and deficient autophagic vacuoles clearance and focus on the recent co-culture systems that are revealing new insights into the complex interactions that occur between different brain cell types during neurodegeneration. Consequently, such advances are the key to improve our understanding of PD pathology and generate potential targets for new therapies aimed at curing PD patients.


2021 ◽  
Vol 22 (13) ◽  
pp. 7135
Author(s):  
Carmela Conte

Parkinson’s disease (PD) is the most common neurodegenerative motor disorder characterized by selective degeneration of dopaminergic neurons in the substantia nigra pars compacta (SNpc) of the midbrain, depletion of dopamine (DA), and impaired nigrostriatal pathway. The pathological hallmark of PD includes the aggregation and accumulation α-synuclein (α-SYN). Although the precise mechanisms underlying the pathogenesis of PD are still unknown, the activation of toll-like receptors (TLRs), mainly TLR4 and subsequent neuroinflammatory immune response, seem to play a significant role. Mounting evidence suggests that viral infection can concur with the precipitation of PD or parkinsonism. The recently identified coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of ongoing pandemic coronavirus disease 2019 (COVID-19), responsible for 160 million cases that led to the death of more than three million individuals worldwide. Studies have reported that many patients with COVID-19 display several neurological manifestations, including acute cerebrovascular diseases, conscious disturbance, and typical motor and non-motor symptoms accompanying PD. In this review, the neurotropic potential of SARS-CoV-2 and its possible involvement in the pathogenesis of PD are discussed. Specifically, the involvement of the TLR4 signaling pathway in mediating the virus entry, as well as the massive immune and inflammatory response in COVID-19 patients is explored. The binding of SARS-CoV-2 spike (S) protein to TLR4 and the possible interaction between SARS-CoV-2 and α-SYN as contributing factors to neuronal death are also considered.


2021 ◽  
Vol 79 (11) ◽  
pp. 989-994
Author(s):  
Mayela Rodríguez-Violante ◽  
Yazmín Ríos-Solís ◽  
Oscar Esquivel-Zapata ◽  
Fanny Herrera ◽  
Susana López-Alamillo ◽  
...  

ABSTRACT Background: Impulse control disorders (ICD) occur frequently in individuals with Parkinson's disease. So far, prevention is the best treatment. Several strategies for its treatment have been suggested, but their frequency of use and benefit have scarcely been explored. Objective: To investigate which strategy is the most commonly used in a real-life setting and its rate of response. Methods: A longitudinal study was conducted. At the baseline evaluation, data on current treatment and ICD status according to QUIP-RS were collected. The treatment strategies were categorized as “no-change”, dopamine agonist (DA) dose lowering, DA removal, DA switch or add-on therapy. At the six-month follow-up visit, the same tools were applied. Results: A total of 132 individuals (58.3% men) were included; 18.2% had at least one ICD at baseline. The therapeutic strategy most used in the ICD group was no-change (37.5%), followed by DA removal (16.7%), DA switch (12.5%) and DA lowering (8.3%). Unexpectedly, in 20.8% of the ICD subjects the DA dose was increased. Overall, nearly 80% of the subjects showed remission of their ICD at follow-up. Conclusions: Regardless of the therapy used, most of the subjects presented remission of their ICD at follow-up Further research with a longer follow-up in a larger sample, with assessment of decision-making processes, is required in order to better understand the efficacy of strategies for ICD treatment.


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