scholarly journals Optogenetic delivery of trophic signals in a genetic model of Parkinson’s disease

PLoS Genetics ◽  
2021 ◽  
Vol 17 (4) ◽  
pp. e1009479
Author(s):  
Alvaro Ingles-Prieto ◽  
Nikolas Furthmann ◽  
Samuel H. Crossman ◽  
Alexandra-Madelaine Tichy ◽  
Nina Hoyer ◽  
...  

Optogenetics has been harnessed to shed new mechanistic light on current and future therapeutic strategies. This has been to date achieved by the regulation of ion flow and electrical signals in neuronal cells and neural circuits that are known to be affected by disease. In contrast, the optogenetic delivery of trophic biochemical signals, which support cell survival and are implicated in degenerative disorders, has never been demonstrated in an animal model of disease. Here, we reengineered the human andDrosophila melanogasterREarranged during Transfection (hRET and dRET) receptors to be activated by light, creating one-component optogenetic tools termed Opto-hRET and Opto-dRET. Upon blue light stimulation, these receptors robustly induced the MAPK/ERK proliferative signaling pathway in cultured cells. In PINK1B9flies that exhibit loss of PTEN-induced putative kinase 1 (PINK1), a kinase associated with familial Parkinson’s disease (PD), light activation of Opto-dRET suppressed mitochondrial defects, tissue degeneration and behavioral deficits. In human cells with PINK1 loss-of-function, mitochondrial fragmentation was rescued using Opto-dRETviathe PI3K/NF-кB pathway. Our results demonstrate that a light-activated receptor can ameliorate disease hallmarks in a genetic model of PD. The optogenetic delivery of trophic signals is cell type-specific and reversible and thus has the potential to inspire novel strategies towards a spatio-temporal regulation of tissue repair.

2020 ◽  
Author(s):  
Álvaro Inglés-Prieto ◽  
Nikolas Furthmann ◽  
Samuel Crossman ◽  
Nina Hoyer ◽  
Meike Petersen ◽  
...  

AbstractOptogenetics has been harnessed to shed new mechanistic light on current therapies and to develop future treatment strategies. This has been to date achieved by the correction of electrical signals in neuronal cells and neural circuits that are affected by disease. In contrast, the optogenetic delivery of trophic biochemical signals, which support cell survival and thereby may modify progression of degenerative disorders, has never been demonstrated in an animal disease model. Here, we reengineered the human and Drosophila melanogaster REarranged during Transfection (hRET and dRET) receptors to be activated by light, creating one-component optogenetic tools termed Opto-hRET and Opto-dRET. Upon blue light stimulation, these receptors robustly induced the MAPK/ERK proliferative signaling pathway in cultured cells. In PINK1B9 flies that exhibit loss of PTEN-induced putative kinase 1 (PINK1), a kinase associated with familial Parkinson’s disease (PD), light activation of Opto-dRET suppressed mitochondrial defects, tissue degeneration and behavioral deficits. In human cells with PINK1 loss-of-function, mitochondrial fragmentation was rescued using Opto-dRET via the PI3K/NF-кB pathway. Our results demonstrate that a light-activated receptor can ameliorate disease hallmarks in a genetic model of PD. The optogenetic delivery of trophic signals is cell type-specific and reversible and thus has the potential to overcome limitations of current strategies towards a spatio-temporal regulation of tissue repair.Significance StatementThe death of physiologically important cell populations underlies of a wide range of degenerative disorders, including Parkinson’s disease (PD). Two major strategies to counter cell degeneration, soluble growth factor injection and growth factor gene therapy, can lead to the undesired activation of bystander cells and non-natural permanent signaling responses. Here, we employed optogenetics to deliver cell type-specific pro-survival signals in a genetic model of PD. In Drosophila and human cells exhibiting loss of the PINK1 kinase, akin to autosomal recessive PD, we efficiently suppressed disease phenotypes using a light-activated tyrosine kinase receptor. This work demonstrates a spatio-temporally precise strategy to interfere with degeneration and may open new avenues towards tissue repair in disease models.


2012 ◽  
Vol 153 (52) ◽  
pp. 2060-2069 ◽  
Author(s):  
András Guseo

Parkinson’s disease is one of the most frequent progressive degenerative disorders with unknown origin of the nervous system. The commutation of the disease on Guam led to the discovery of a neurotoxin which was also found in other continents. This neurotoxin was identified in the common cyanobacteria (blue-green algae). Early clinical observations suggested some loose correlations with gastric and duodenal ulcer and Parkinson’s disease, while recent studies revealed a toxin, almost identical to that found in cyanobacteria in one strain of Helicobacter pylori, which proved to cause Parkinson like symptoms in animals. Therefore, it cannot be ruled out that there is a slowly progressive poisoning in Parkinson’s disease. The disease specific alpha-sinuclein inclusions can be found in nerve cells of the intestinal mucosa far before the appearance of clinical symptoms indicating that the disease may start in the intestines. These results are strengthened by the results of Borody’s fecal transplants, after which in Parkinson patients showed a symptomatic improvement. Based on these observations the Parkinson puzzle is getting complete. Although these observations are not evidence based, they may indicate a new way for basic clinical research, as well as a new way of thinking for clinicians. These new observations in psycho-neuro-immunology strengthen the fact that immunological factors may also play a critical factor facilitating local cell necrosis which may be influenced easily. Orv. Hetil., 2012, 153, 2060–2069.


2021 ◽  
pp. 1-16
Author(s):  
Alison Fellgett ◽  
C. Adam Middleton ◽  
Jack Munns ◽  
Chris Ugbode ◽  
David Jaciuch ◽  
...  

Background: Inherited mutations in the LRRK2 protein are the common causes of Parkinson’s disease, but the mechanisms by which increased kinase activity of mutant LRRK2 leads to pathological events remain to be determined. In vitro assays (heterologous cell culture, phospho-protein mass spectrometry) suggest that several Rab proteins might be directly phosphorylated by LRRK2-G2019S. An in vivo screen of Rab expression in dopaminergic neurons in young adult Drosophila demonstrated a strong genetic interaction between LRRK2-G2019S and Rab10. Objective: To determine if Rab10 is necessary for LRRK2-induced pathophysiological responses in the neurons that control movement, vision, circadian activity, and memory. These four systems were chosen because they are modulated by dopaminergic neurons in both humans and flies. Methods: LRRK2-G2019S was expressed in Drosophila dopaminergic neurons and the effects of Rab10 depletion on Proboscis Extension, retinal neurophysiology, circadian activity pattern (‘sleep’), and courtship memory determined in aged flies. Results: Rab10 loss-of-function rescued LRRK2-G2019S induced bradykinesia and retinal signaling deficits. Rab10 knock-down, however, did not rescue the marked sleep phenotype which results from dopaminergic LRRK2-G2019S. Courtship memory is not affected by LRRK2, but is markedly improved by Rab10 depletion. Anatomically, both LRRK2-G2019S and Rab10 are seen in the cytoplasm and at the synaptic endings of dopaminergic neurons. Conclusion: We conclude that, in Drosophila dopaminergic neurons, Rab10 is involved in some, but not all, LRRK2-induced behavioral deficits. Therefore, variations in Rab expression may contribute to susceptibility of different dopaminergic nuclei to neurodegeneration seen in people with Parkinson’s disease.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Abeer Dagra ◽  
Douglas R. Miller ◽  
Min Lin ◽  
Adithya Gopinath ◽  
Fatemeh Shaerzadeh ◽  
...  

AbstractPathophysiological damages and loss of function of dopamine neurons precede their demise and contribute to the early phases of Parkinson’s disease. The presence of aberrant intracellular pathological inclusions of the protein α-synuclein within ventral midbrain dopaminergic neurons is one of the cardinal features of Parkinson’s disease. We employed molecular biology, electrophysiology, and live-cell imaging to investigate how excessive α-synuclein expression alters multiple characteristics of dopaminergic neuronal dynamics and dopamine transmission in cultured dopamine neurons conditionally expressing GCaMP6f. We found that overexpression of α-synuclein in mouse (male and female) dopaminergic neurons altered neuronal firing properties, calcium dynamics, dopamine release, protein expression, and morphology. Moreover, prolonged exposure to the D2 receptor agonist, quinpirole, rescues many of the alterations induced by α-synuclein overexpression. These studies demonstrate that α-synuclein dysregulation of neuronal activity contributes to the vulnerability of dopaminergic neurons and that modulation of D2 receptor activity can ameliorate the pathophysiology. These findings provide mechanistic insights into the insidious changes in dopaminergic neuronal activity and neuronal loss that characterize Parkinson’s disease progression with significant therapeutic implications.


Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1874
Author(s):  
Suwei Chen ◽  
Sarah J. Annesley ◽  
Rasha A. F. Jasim ◽  
Paul R. Fisher

Mitochondrial dysfunction has been implicated in the pathology of Parkinson’s disease (PD). In Dictyostelium discoideum, strains with mitochondrial dysfunction present consistent, AMPK-dependent phenotypes. This provides an opportunity to investigate if the loss of function of specific PD-associated genes produces cellular pathology by causing mitochondrial dysfunction with AMPK-mediated consequences. DJ-1 is a PD-associated, cytosolic protein with a conserved oxidizable cysteine residue that is important for the protein’s ability to protect cells from the pathological consequences of oxidative stress. Dictyostelium DJ-1 (encoded by the gene deeJ) is located in the cytosol from where it indirectly inhibits mitochondrial respiration and also exerts a positive, nonmitochondrial role in endocytosis (particularly phagocytosis). Its loss in unstressed cells impairs endocytosis and causes correspondingly slower growth, while also stimulating mitochondrial respiration. We report here that oxidative stress in Dictyostelium cells inhibits mitochondrial respiration and impairs phagocytosis in an AMPK-dependent manner. This adds to the separate impairment of phagocytosis caused by DJ-1 knockdown. Oxidative stress also combines with DJ-1 loss in an AMPK-dependent manner to impair or exacerbate defects in phototaxis, morphogenesis and growth. It thereby phenocopies mitochondrial dysfunction. These results support a model in which the oxidized but not the reduced form of DJ-1 inhibits AMPK in the cytosol, thereby protecting cells from the adverse consequences of oxidative stress, mitochondrial dysfunction and the resulting AMPK hyperactivity.


Brain ◽  
2019 ◽  
Vol 142 (8) ◽  
pp. 2380-2401 ◽  
Author(s):  
Saurav Brahmachari ◽  
Saebom Lee ◽  
Sangjune Kim ◽  
Changqing Yuan ◽  
Senthilkumar S Karuppagounder ◽  
...  

Abstract α-Synuclein misfolding and aggregation plays a major role in the pathogenesis of Parkinson’s disease. Although loss of function mutations in the ubiquitin ligase, parkin, cause autosomal recessive Parkinson’s disease, there is evidence that parkin is inactivated in sporadic Parkinson’s disease. Whether parkin inactivation is a driver of neurodegeneration in sporadic Parkinson’s disease or a mere spectator is unknown. Here we show that parkin in inactivated through c-Abelson kinase phosphorylation of parkin in three α-synuclein-induced models of neurodegeneration. This results in the accumulation of parkin interacting substrate protein (zinc finger protein 746) and aminoacyl tRNA synthetase complex interacting multifunctional protein 2 with increased parkin interacting substrate protein levels playing a critical role in α-synuclein-induced neurodegeneration, since knockout of parkin interacting substrate protein attenuates the degenerative process. Thus, accumulation of parkin interacting substrate protein links parkin inactivation and α-synuclein in a common pathogenic neurodegenerative pathway relevant to both sporadic and familial forms Parkinson’s disease. Thus, suppression of parkin interacting substrate protein could be a potential therapeutic strategy to halt the progression of Parkinson’s disease and related α-synucleinopathies.


Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 283
Author(s):  
Daniel Aghaie Madsen ◽  
Sissel Ida Schmidt ◽  
Morten Blaabjerg ◽  
Morten Meyer

Parkin and α-synuclein are two key proteins involved in the pathophysiology of Parkinson’s disease (PD). Neurotoxic alterations of α-synuclein that lead to the formation of toxic oligomers and fibrils contribute to PD through synaptic dysfunction, mitochondrial impairment, defective endoplasmic reticulum and Golgi function, and nuclear dysfunction. In half of the cases, the recessively inherited early-onset PD is caused by loss of function mutations in the PARK2 gene that encodes the E3-ubiquitin ligase, parkin. Parkin is involved in the clearance of misfolded and aggregated proteins by the ubiquitin-proteasome system and regulates mitophagy and mitochondrial biogenesis. PARK2-related PD is generally thought not to be associated with Lewy body formation although it is a neuropathological hallmark of PD. In this review article, we provide an overview of post-mortem neuropathological examinations of PARK2 patients and present the current knowledge of a functional interaction between parkin and α-synuclein in the regulation of protein aggregates including Lewy bodies. Furthermore, we describe prevailing hypotheses about the formation of intracellular micro-aggregates (synuclein inclusions) that might be more likely than Lewy bodies to occur in PARK2-related PD. This information may inform future studies aiming to unveil primary signaling processes involved in PD and related neurodegenerative disorders.


2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Shigeto Sato ◽  
Nobutaka Hattori

The cellular abnormalities in Parkinson's disease (PD) include mitochondrial dysfunction and oxidative damage, which are probably induced by both genetic predisposition and environmental factors. Mitochondrial dysfunction has long been implicated in the pathogenesis of PD. The recent discovery of genes associated with the etiology of familial PD has emphasized the role of mitochondrial dysfunction in PD. The discovery and increasing knowledge of the function of PINK1 and parkin, which are associated with the mitochondria, have also enhanced the understanding of cellular functions. The PINK1-parkin pathway is associated with quality control of the mitochondria, as determined in cultured cells treated with the mitochondrial uncoupler carbonyl cyanide m-chlorophenylhydrazone (CCCP), which causes mitochondrial depolarization. To date, the use of mitochondrial toxins, for example, 1-methyl-4-phynyl-tetrahydropyridine (MPTP) and CCCP, has contributed to our understanding of PD. We review how these toxins and familial PD gene products are associated with and have enhanced our understanding of the role of mitochondrial dysfunction in PD.


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