scholarly journals STEP61 is a substrate of the E3 ligase parkin and is upregulated in Parkinson’s disease

2015 ◽  
Vol 112 (4) ◽  
pp. 1202-1207 ◽  
Author(s):  
Pradeep K. Kurup ◽  
Jian Xu ◽  
Rita Alexandra Videira ◽  
Chimezie Ononenyi ◽  
Graça Baltazar ◽  
...  

Parkinson’s disease (PD) is characterized by the degeneration of dopaminergic neurons in the substantia nigra pars compacta (SNc). The loss of SNc dopaminergic neurons affects the plasticity of striatal neurons and leads to significant motor and cognitive disabilities during the progression of the disease. PARK2 encodes for the E3 ubiquitin ligase parkin and is implicated in genetic and sporadic PD. Mutations in PARK2 are a major contributing factor in the early onset of autosomal-recessive juvenile parkinsonism (AR-JP), although the mechanisms by which a disruption in parkin function contributes to the pathophysiology of PD remain unclear. Here we demonstrate that parkin is an E3 ligase for STEP61 (striatal-enriched protein tyrosine phosphatase), a protein tyrosine phosphatase implicated in several neuropsychiatric disorders. In cellular models, parkin ubiquitinates STEP61 and thereby regulates its level through the proteasome system, whereas clinically relevant parkin mutants fail to do so. STEP61 protein levels are elevated on acute down-regulation of parkin or in PARK2 KO rat striatum. Relevant to PD, STEP61 accumulates in the striatum of human sporadic PD and in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-lesioned mice. The increase in STEP61 is associated with a decrease in the phosphorylation of its substrate ERK1/2 and the downstream target of ERK1/2, pCREB [phospho-CREB (cAMP response element-binding protein)]. These results indicate that STEP61 is a novel substrate of parkin, although further studies are necessary to determine whether elevated STEP61 levels directly contribute to the pathophysiology of PD.

F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 2932 ◽  
Author(s):  
Paul J. Lombroso ◽  
Marilee Ogren ◽  
Pradeep Kurup ◽  
Angus C. Nairn

This commentary focuses on potential molecular mechanisms related to the dysfunctional synaptic plasticity that is associated with neurodegenerative disorders such as Alzheimer’s disease and Parkinson’s disease. Specifically, we focus on the role of striatal-enriched protein tyrosine phosphatase (STEP) in modulating synaptic function in these illnesses. STEP affects neuronal communication by opposing synaptic strengthening and does so by dephosphorylating several key substrates known to control synaptic signaling and plasticity. STEP levels are elevated in brains from patients with Alzheimer’s and Parkinson’s disease. Studies in model systems have found that high levels of STEP result in internalization of glutamate receptors as well as inactivation of ERK1/2, Fyn, Pyk2, and other STEP substrates necessary for the development of synaptic strengthening. We discuss the search for inhibitors of STEP activity that may offer potential treatments for neurocognitive disorders that are characterized by increased STEP activity. Future studies are needed to examine the mechanisms of differential and region-specific changes in STEP expression pattern, as such knowledge could lead to targeted therapies for disorders involving disrupted STEP activity.


2021 ◽  
Vol 22 (13) ◽  
pp. 6646
Author(s):  
Marta del Campo ◽  
Rosalía Fernández-Calle ◽  
Marta Vicente-Rodríguez ◽  
Sara Martín Martínez ◽  
Esther Gramage ◽  
...  

Pleiotrophin (PTN) is a neurotrophic factor that regulates glial responses in animal models of different types of central nervous system (CNS) injuries. PTN is upregulated in the brain in different pathologies characterized by exacerbated neuroinflammation, including Parkinson’s disease. PTN is an endogenous inhibitor of Receptor Protein Tyrosine Phosphatase (RPTP) β/ζ, which is abundantly expressed in the CNS. Using a specific inhibitor of RPTPβ/ζ (MY10), we aimed to assess whether the PTN/RPTPβ/ζ axis is involved in neuronal and glial injury induced by the toxin MPP+. Treatment with the RPTPβ/ζ inhibitor MY10 alone decreased the viability of both SH-SY5Y neuroblastoma cells and BV2 microglial cultures, suggesting that normal RPTPβ/ζ function is involved in neuronal and microglial viability. We observed that PTN partially decreased the cytotoxicity induced by MPP+ in SH-SY5Y cells underpinning the neuroprotective function of PTN. However, MY10 did not seem to modulate the SH-SY5Y cell loss induced by MPP+. Interestingly, we observed that media from SH-SY5Y cells treated with MPP+ and MY10 decreases microglial viability but may elicit a neuroprotective response of microglia by upregulating Ptn expression. The data suggest a neurotrophic role of microglia in response to neuronal injury through upregulation of Ptn levels.


2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Chien-Wei Feng ◽  
Nan-Fu Chen ◽  
Te-Fu Chan ◽  
Wu-Fu Chen

Parkinson’s disease (PD) is one of the most widespread neurodegenerative diseases. However, the currently available treatments could only relieve symptoms. Novel therapeutic targets are urgently needed. Several previous studies mentioned that protein tyrosine phosphatase 1B (PTP1B) acted as a negative regulator of the insulin signal pathway and played a significant role in the inflammation process. However, few studies have investigated the role of PTP1B in the central nervous system. Our study showed that suramin, an inhibitor of PTP1B, could improve neuronal damage. It could significantly attenuate the interferon-gamma-induced upregulation of proinflammatory cytokines, including inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). It enhanced M2 type microglia markers, such as arginase-1 and Ym-1 in BV2 murine microglial cells. PTP1B inhibition also reversed 6-hydroxydopamine- (6-OHDA-) induced downregulation of phospho-cAMP response element-binding protein (p-CREB) and brain-derived neurotrophic factor (BDNF) in SH-SY5Y cells. Besides, we knocked down and overexpressed PTP1B in the SH-SY5Y cells to confirm its role in neuroprotection. We also verified the effect of suramin in the zebrafish PD model. Treatment with suramin could significantly reverse 6-OHDA-induced locomotor deficits and improved tyrosine hydroxylase (TH) via attenuating endoplasmic reticulum (ER) stress biomarkers. These results support that PTP1B could potentially regulate PD via antineuroinflammation and antiapoptotic pathways.


2015 ◽  
Vol 73 (7) ◽  
pp. 616-623 ◽  
Author(s):  
Taysa Bervian Bassani ◽  
Maria A.B.F. Vital ◽  
Laryssa K. Rauh

Parkinson’s disease (PD) is the second most common neurodegenerative disease affecting approximately 1.6% of the population over 60 years old. The cardinal motor symptoms are the result of progressive degeneration of substantia nigra pars compacta dopaminergic neurons which are involved in the fine motor control. Currently, there is no cure for this pathology and the cause of the neurodegeneration remains unknown. Several studies suggest the involvement of neuroinflammation in the pathophysiology of PD as well as a protective effect of anti-inflammatory drugs both in animal models and epidemiological studies, although there are controversial reports. In this review, we address evidences of involvement of inflammatory process and possible therapeutic usefulness of anti-inflammatory drugs in PD.


2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Jialong Chen ◽  
Kanmin Mao ◽  
Honglin Yu ◽  
Yue Wen ◽  
Hua She ◽  
...  

Abstract Background Parkinson’s disease (PD) is characterized by degeneration of dopaminergic neurons in the substantia nigra pars compacta (SNpc), accompanied by accumulation of α-synuclein, chronic neuroinflammation and autophagy dysfunction. Previous studies suggested that misfolded α-synuclein induces the inflammatory response and autophagy dysfunction in microglial cells. The NLRP3 inflammasome signaling pathway plays a crucial role in the neuroinflammatory process in the central nervous system. However, the relationship between autophagy deficiency and NLRP3 activation induced by α-synuclein accumulation is not well understood. Methods Through immunoblotting, immunocytochemistry, immunofluorescence, flow cytometry, ELISA and behavioral tests, we investigated the role of p38-TFEB-NLRP3 signaling pathways on neuroinflammation in the α-synuclein A53T PD models. Results Our results showed that increased protein levels of NLRP3, ASC, and caspase-1 in the α-synuclein A53T PD models. P38 is activated by overexpression of α-synuclein A53T mutant, which inhibited the master transcriptional activator of autophagy TFEB. And we found that NLRP3 was degraded by chaperone-mediated autophagy (CMA) in microglial cells. Furthermore, p38-TFEB pathways inhibited CMA-mediated NLRP3 degradation in Parkinson's disease. Inhibition of p38 had a protective effect on Parkinson's disease model via suppressing the activation of NLRP3 inflammasome pathway. Moreover, both p38 inhibitor SB203580 and NLRP3 inhibitor MCC950 not only prevented neurodegeneration in vivo, but also alleviated movement impairment in α-synuclein A53T-tg mice model of Parkinson’s disease. Conclusion Our research reveals p38-TFEB pathways promote microglia activation through inhibiting CMA-mediated NLRP3 degradation in Parkinson's disease, which could be a potential therapeutic strategy for PD. Graphical abstract p38-TFEB pathways promote microglia activation through inhibiting CMA-mediated NLRP3 degradation in Parkinson's disease. In this model, p38 activates NLRP3 inflammasome via inhibiting TFEB in microglia. TFEB signaling negatively regulates NLRP3 inflammasome through increasing LAMP2A expression, which binds to NLRP3 and promotes its degradation via chaperone-mediated autophagy (CMA). NLRP3-mediated microglial activation promotes the death of dopaminergic neurons.


2018 ◽  
Author(s):  
Michal Wegrzynowicz ◽  
Dana Bar-On ◽  
Laura Calo’ ◽  
Oleg Anichtchik ◽  
Mariangela Iovino ◽  
...  

SUMMARYParkinson’s Disease (PD) is characterized by the presence of α-synuclein aggregates known as Lewy bodies and Lewy neurites, whose formation is linked to disease development. The causal relation between α-synuclein aggregates and PD is not well understood. We generated a new transgenic mouse line (MI2) expressing human, aggregation-prone truncated 1-120 α-synuclein under the control of the tyrosine hydroxylase promoter. MI2 mice exhibit progressive aggregation of α-synuclein in dopaminergic neurons of the substantia nigra pars compacta and their striatal terminals. This is associated with a progressive reduction of striatal dopamine release, reduced striatal innervation and significant nigral dopaminergic nerve cell death starting from 6 and 12 months of age, respectively. Overt impairment in motor behavior was found in MI2 mice at 20 months of age, when 50% of dopaminergic neurons are lost. These changes were associated with an increase in the number and density of 20-500nm α-synuclein species as shown by dSTORM. Treatment with the oligomer modulator anle138b, from 9-12 months of age, restored striatal dopamine release and prevented dopaminergic cell death. These effects were associated with a reduction of the inner density of α-synuclein aggregates and an increase in dispersed small α-synuclein species as revealed by dSTORM. The MI2 mouse model recapitulates the progressive dopaminergic deficit observed in PD, showing that early synaptic dysfunction precedes dopaminergic axonal loss and neuronal death that become associated with a motor deficit upon reaching a certain threshold. Our data also provide new mechanistic insight for the effect of anle138b’s function in vivo supporting that targeting α-synuclein aggregation is a promising therapeutic approach for PD.


Diagnostics ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 402
Author(s):  
Sabyasachi Chakraborty ◽  
Satyabrata Aich ◽  
Hee-Cheol Kim

Parkinson’s Disease is a neurodegenerative disease that affects the aging population and is caused by a progressive loss of dopaminergic neurons in the substantia nigra pars compacta (SNc). With the onset of the disease, the patients suffer from mobility disorders such as tremors, bradykinesia, impairment of posture and balance, etc., and it progressively worsens in the due course of time. Additionally, as there is an exponential growth of the aging population in the world the number of people suffering from Parkinson’s Disease is increasing and it levies a huge economic burden on governments. However, until now no therapeutic method has been discovered for completely eradicating the disease from a person’s body after it’s onset. Therefore, the early detection of Parkinson’s Disease is of paramount importance to tackle the progressive loss of dopaminergic neurons in patients to serve them with a better life. In this study, 3T T1-weighted MRI scans were acquired from the Parkinson’s Progression Markers Initiative (PPMI) database of 406 subjects from baseline visit, where 203 were healthy and 203 were suffering from Parkinson’s Disease. Following data pre-processing, a 3D convolutional neural network (CNN) architecture was developed for learning the intricate patterns in the Magnetic Resonance Imaging (MRI) scans for the detection of Parkinson’s Disease. In the end, it was observed that the developed 3D CNN model performed superiorly by completely aligning with the hypothesis of the study and plotted an overall accuracy of 95.29%, average recall of 0.943, average precision of 0.927, average specificity of 0.9430, f1-score of 0.936, and Receiver Operating Characteristic—Area Under Curve (ROC-AUC) score of 0.98 for both the classes respectively.


2008 ◽  
Vol 413 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Philip A. Robinson

Parkinson's disease (PD), the second most common age-related neurodegenerative disease, results in abnormalities in motor functioning. Many fundamental questions regarding its aetiology remain unanswered. Pathologically, it is not until 70–80% of the dopaminergic neurons from the substantia nigra pars compacta are lost before clinical symptoms are observed. Thus research into PD is complicated by this apparent paradox in that what appears to be the beginning of the disease at the clinical level is really the end point neurochemically. Consequently, we can only second guess when the disease started and what initiated it. The causation is probably complex, with contributions from both genetic and environmental factors. Intracellular proteinaceous inclusions, Lewy bodies and Lewy neurites, found in surviving dopaminergic neurons, are the key pathological characteristic of PD. Their presence points to an inability within these terminally differentiated cells to deal with aggregating proteins. Recent advances in our knowledge of the underlying disease process have come about from studies on models based on genes associated with rare hereditary forms of PD, and mitochondrial toxins that mimic the behavioural effects of PD. The reason that dopaminergic neurons are particularly sensitive may be due to the additional cellular stress caused by the breakdown of the inherently chemically unstable neurotransmitter, dopamine. In the present review, I discuss the proposal that in sporadic disease, interlinked problems of protein processing and inappropriate mitochondrial activity seed the foundation for age-related increased levels of protein damage, and a reduced ability to deal with the damage, leading to inclusion formation and, ultimately, cell toxicity.


2021 ◽  
Vol 12 ◽  
Author(s):  
Yumin Wang ◽  
Luyan Gao ◽  
Jichao Chen ◽  
Qiang Li ◽  
Liang Huo ◽  
...  

Parkinson’s disease (PD) is a complex neurodegenerative disorder featuring both motor and nonmotor symptoms associated with a progressive loss of dopaminergic neurons in the substantia nigra pars compacta. Oxidative stress (OS) has been implicated in the pathogenesis of PD. Genetic and environmental factors can produce OS, which has been implicated as a core contributor to the initiation and progression of PD through the degeneration of dopaminergic neurons. The transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) orchestrates activation of multiple protective genes, including heme oxygenase-1 (HO-1), which protects cells from OS. Nrf2 has also been shown to exert anti-inflammatory effects and modulate both mitochondrial function and biogenesis. Recently, a series of studies have reported that different bioactive compounds were shown to be able to activate Nrf2/antioxidant response element (ARE) and can ameliorate PD-associated neurotoxin, both in animal models and in tissue culture. In this review, we briefly overview the sources of OS and the association between OS and the pathogenesis of PD. Then, we provided a concise overview of Nrf2/ARE pathway and delineated the role played by activation of Nrf2/HO-1 in PD. At last, we expand our discussion to the neuroprotective effects of pharmacological modulation of Nrf2/HO-1 by bioactive compounds and the potential application of Nrf2 activators for the treatment of PD. This review suggests that pharmacological modulation of Nrf2/HO-1 signaling pathway by bioactive compounds is a therapeutic target of PD.


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.


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