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Cell Stem Cell Jul 2023Human induced pluripotent stem cells (hiPSCs) offer advantages for disease modeling and drug discovery. However, recreating innate cellular pathologies, particularly in...
Human induced pluripotent stem cells (hiPSCs) offer advantages for disease modeling and drug discovery. However, recreating innate cellular pathologies, particularly in late-onset neurodegenerative diseases with accumulated protein aggregates including Parkinson's disease (PD), has been challenging. To overcome this barrier, we developed an optogenetics-assisted α-synuclein (α-syn) aggregation induction system (OASIS) that rapidly induces α-syn aggregates and toxicity in PD hiPSC-midbrain dopaminergic neurons and midbrain organoids. Our OASIS-based primary compound screening with SH-SY5Y cells identified 5 candidates that were secondarily validated with OASIS PD hiPSC-midbrain dopaminergic neurons and midbrain organoids, leading us to finally select BAG956. Furthermore, BAG956 significantly reverses characteristic PD phenotypes in α-syn preformed fibril models in vitro and in vivo by promoting autophagic clearance of pathological α-syn aggregates. Following the FDA Modernization Act 2.0's emphasis on alternative non-animal testing methods, our OASIS can serve as an animal-free preclinical test model (newly termed "nonclinical test") for the synucleinopathy drug development.
Topics: Humans; alpha-Synuclein; Dopaminergic Neurons; Induced Pluripotent Stem Cells; Neuroblastoma; Optogenetics; Parkinson Disease
PubMed: 37339636
DOI: 10.1016/j.stem.2023.05.015 -
Science Advances Nov 2023Recent studies have identified increasing levels of nanoplastic pollution in the environment. Here, we find that anionic nanoplastic contaminants potently precipitate...
Recent studies have identified increasing levels of nanoplastic pollution in the environment. Here, we find that anionic nanoplastic contaminants potently precipitate the formation and propagation of α-synuclein protein fibrils through a high-affinity interaction with the amphipathic and non-amyloid component (NAC) domains in α-synuclein. Nanoplastics can internalize in neurons through clathrin-dependent endocytosis, causing a mild lysosomal impairment that slows the degradation of aggregated α-synuclein. In mice, nanoplastics combine with α-synuclein fibrils to exacerbate the spread of α-synuclein pathology across interconnected vulnerable brain regions, including the strong induction of α-synuclein inclusions in dopaminergic neurons in the substantia nigra. These results highlight a potential link for further exploration between nanoplastic pollution and α-synuclein aggregation associated with Parkinson's disease and related dementias.
Topics: Mice; Animals; alpha-Synuclein; Parkinson Disease; Microplastics; Inclusion Bodies; Dopaminergic Neurons
PubMed: 37976362
DOI: 10.1126/sciadv.adi8716 -
Nature Neuroscience Oct 2023Dopamine neurons are characterized by their response to unexpected rewards, but they also fire during movement and aversive stimuli. Dopamine neuron diversity has been...
Dopamine neurons are characterized by their response to unexpected rewards, but they also fire during movement and aversive stimuli. Dopamine neuron diversity has been observed based on molecular expression profiles; however, whether different functions map onto such genetic subtypes remains unclear. In this study, we established that three genetic dopamine neuron subtypes within the substantia nigra pars compacta, characterized by the expression of Slc17a6 (Vglut2), Calb1 and Anxa1, each have a unique set of responses to rewards, aversive stimuli and accelerations and decelerations, and these signaling patterns are highly correlated between somas and axons within subtypes. Remarkably, reward responses were almost entirely absent in the Anxa1 subtype, which instead displayed acceleration-correlated signaling. Our findings establish a connection between functional and genetic dopamine neuron subtypes and demonstrate that molecular expression patterns can serve as a common framework to dissect dopaminergic functions.
Topics: Dopaminergic Neurons; Substantia Nigra; Signal Transduction; Axons
PubMed: 37537242
DOI: 10.1038/s41593-023-01401-9 -
Nature Communications Aug 2023Chronic pain causes both physical suffering and comorbid mental symptoms such as anhedonia. However, the neural circuits and molecular mechanisms underlying these...
Chronic pain causes both physical suffering and comorbid mental symptoms such as anhedonia. However, the neural circuits and molecular mechanisms underlying these maladaptive behaviors remain elusive. Here using a mouse model, we report a pathway from vesicular glutamate transporter 3 neurons in the dorsal raphe nucleus to dopamine neurons in the ventral tegmental area (VGluT3→DA) wherein population-level activity in response to innocuous mechanical stimuli and sucrose consumption is inhibited by chronic neuropathic pain. Mechanistically, neuropathic pain dampens VGluT3 → DA glutamatergic transmission and DA neural excitability. VGluT3 → DA activation alleviates neuropathic pain and comorbid anhedonia-like behavior (CAB) by releasing glutamate, which subsequently promotes DA release in the nucleus accumbens medial shell (NAcMed) and produces analgesic and anti-anhedonia effects via D2 and D1 receptors, respectively. In addition, VGluT3 → DA inhibition produces pain-like reflexive hypersensitivity and anhedonia-like behavior in intact mice. These findings reveal a crucial role for VGluT3 → DA → D2/D1 pathway in establishing and modulating chronic pain and CAB.
Topics: Humans; Ventral Tegmental Area; Chronic Pain; Dorsal Raphe Nucleus; Neuralgia; Anhedonia; Dopaminergic Neurons; Glutamic Acid
PubMed: 37612268
DOI: 10.1038/s41467-023-40860-3 -
Cell Stem Cell Oct 2023Cell replacement therapies for Parkinson's disease (PD) based on transplantation of pluripotent stem cell-derived dopaminergic neurons are now entering clinical trials....
Cell replacement therapies for Parkinson's disease (PD) based on transplantation of pluripotent stem cell-derived dopaminergic neurons are now entering clinical trials. Here, we present quality, safety, and efficacy data supporting the first-in-human STEM-PD phase I/IIa clinical trial along with the trial design. The STEM-PD product was manufactured under GMP and quality tested in vitro and in vivo to meet regulatory requirements. Importantly, no adverse effects were observed upon testing of the product in a 39-week rat GLP safety study for toxicity, tumorigenicity, and biodistribution, and a non-GLP efficacy study confirmed that the transplanted cells mediated full functional recovery in a pre-clinical rat model of PD. We further observed highly comparable efficacy results between two different GMP batches, verifying that the product can be serially manufactured. A fully in vivo-tested batch of STEM-PD is now being used in a clinical trial of 8 patients with moderate PD, initiated in 2022.
Topics: Humans; Rats; Animals; Human Embryonic Stem Cells; Parkinson Disease; Tissue Distribution; Cell Differentiation; Stem Cell Transplantation; Dopaminergic Neurons
PubMed: 37802036
DOI: 10.1016/j.stem.2023.08.014 -
Biomolecules Sep 2023Parkinson's disease (PD) is a devastating disease associated with accumulation of α-synuclein (α-Syn) within dopaminergic neurons, leading to neuronal death. PD is... (Review)
Review
Parkinson's disease (PD) is a devastating disease associated with accumulation of α-synuclein (α-Syn) within dopaminergic neurons, leading to neuronal death. PD is characterized by both motor and non-motor clinical symptoms. Several studies indicate that autophagy, an important intracellular degradation pathway, may be involved in different neurodegenerative diseases including PD. The autophagic process mediates the degradation of protein aggregates, damaged and unneeded proteins, and organelles, allowing their clearance, and thereby maintaining cell homeostasis. Impaired autophagy may cause the accumulation of abnormal proteins. Incomplete or impaired autophagy may explain the neurotoxic accumulation of protein aggregates in several neurodegenerative diseases including PD. Indeed, studies have suggested the contribution of impaired autophagy to α-Syn accumulation, the death of dopaminergic neurons, and neuroinflammation. In this review, we summarize the recent literature on the involvement of autophagy in PD pathogenesis.
Topics: Humans; Parkinson Disease; Protein Aggregates; alpha-Synuclein; Autophagy; Dopaminergic Neurons
PubMed: 37892117
DOI: 10.3390/biom13101435 -
Pharmacological Research Jul 2023Oxidative disruption of dopaminergic neurons is regarded as a crucial pathogenesis in Parkinson's disease (PD), eventually causing neurodegenerative progression....
Oxidative disruption of dopaminergic neurons is regarded as a crucial pathogenesis in Parkinson's disease (PD), eventually causing neurodegenerative progression. (-)-Clausenamide (Clau) is an alkaloid isolated from plant Clausena lansium (Lour.), which is well-known as a scavenger of lipid peroxide products and exhibiting neuroprotective activities both in vivo and in vitro, yet with the in-depth molecular mechanism unrevealed. In this study, we evaluated the protective effects and mechanisms of Clau on dopaminergic neuron. Our results showed that Clau directly interacted with the Ser663 of ALOX5, the PKCα-phosphorylation site, and thus prevented the nuclear translocation of ALOX5, which was essential for catalyzing the production of toxic lipids 5-HETE. LC-MS/MS-based phospholipidomics analysis demonstrated that the oxidized membrane lipids were involved in triggering ferroptotic death in dopaminergic neurons. Furthermore, the inhibition of ALOX5 was found to significantly improving behavioral defects in PD mouse model, which was confirmed associated with the effects of attenuating the accumulation of lipid peroxides and neuronal damages. Collectively, our findings provide an attractive strategy for PD therapy by targeting ALOX5 and preventing ferroptosis in dopaminergic neurons.
Topics: Animals; Mice; Dopaminergic Neurons; Ferroptosis; Chromatography, Liquid; Tandem Mass Spectrometry; Parkinson Disease
PubMed: 37121496
DOI: 10.1016/j.phrs.2023.106779 -
Nature Communications Sep 2023Prosaposin (PSAP) modulates glycosphingolipid metabolism and variants have been linked to Parkinson's disease (PD). Here, we find altered PSAP levels in the plasma, CSF...
Prosaposin (PSAP) modulates glycosphingolipid metabolism and variants have been linked to Parkinson's disease (PD). Here, we find altered PSAP levels in the plasma, CSF and post-mortem brain of PD patients. Altered plasma and CSF PSAP levels correlate with PD-related motor impairments. Dopaminergic PSAP-deficient (cPSAP) mice display hypolocomotion and depression/anxiety-like symptoms with mildly impaired dopaminergic neurotransmission, while serotonergic PSAP-deficient (cPSAP) mice behave normally. Spatial lipidomics revealed an accumulation of highly unsaturated and shortened lipids and reduction of sphingolipids throughout the brains of cPSAP mice. The overexpression of α-synuclein via AAV lead to more severe dopaminergic degeneration and higher p-Ser129 α-synuclein levels in cPSAP mice compared to WT mice. Overexpression of PSAP via AAV and encapsulated cell biodelivery protected against 6-OHDA and α-synuclein toxicity in wild-type rodents. Thus, these findings suggest PSAP may maintain dopaminergic lipid homeostasis, which is dysregulated in PD, and counteract experimental parkinsonism.
Topics: Animals; Mice; alpha-Synuclein; Dopamine; Dopaminergic Neurons; Parkinson Disease; Saposins; Sphingolipids
PubMed: 37726325
DOI: 10.1038/s41467-023-41539-5 -
Nature Methods Dec 2023Ventral midbrain dopaminergic neurons project to the striatum as well as the cortex and are involved in movement control and reward-related cognition. In Parkinson's...
Ventral midbrain dopaminergic neurons project to the striatum as well as the cortex and are involved in movement control and reward-related cognition. In Parkinson's disease, nigrostriatal midbrain dopaminergic neurons degenerate and cause typical Parkinson's disease motor-related impairments, while the dysfunction of mesocorticolimbic midbrain dopaminergic neurons is implicated in addiction and neuropsychiatric disorders. Study of the development and selective neurodegeneration of the human dopaminergic system, however, has been limited due to the lack of an appropriate model and access to human material. Here, we have developed a human in vitro model that recapitulates key aspects of dopaminergic innervation of the striatum and cortex. These spatially arranged ventral midbrain-striatum-cortical organoids (MISCOs) can be used to study dopaminergic neuron maturation, innervation and function with implications for cell therapy and addiction research. We detail protocols for growing ventral midbrain, striatal and cortical organoids and describe how they fuse in a linear manner when placed in custom embedding molds. We report the formation of functional long-range dopaminergic connections to striatal and cortical tissues in MISCOs, and show that injected, ventral midbrain-patterned progenitors can mature and innervate the tissue. Using these assembloids, we examine dopaminergic circuit perturbations and show that chronic cocaine treatment causes long-lasting morphological, functional and transcriptional changes that persist upon drug withdrawal. Thus, our method opens new avenues to investigate human dopaminergic cell transplantation and circuitry reconstruction as well as the effect of drugs on the human dopaminergic system.
Topics: Humans; Parkinson Disease; Mesencephalon; Dopamine; Dopaminergic Neurons; Corpus Striatum
PubMed: 38052989
DOI: 10.1038/s41592-023-02080-x -
Nature Communications Nov 2023Mutations in SNCA, the gene encoding α-synuclein (αSyn), cause familial Parkinson's disease (PD) and aberrant αSyn is a key pathological hallmark of idiopathic PD....
Mutations in SNCA, the gene encoding α-synuclein (αSyn), cause familial Parkinson's disease (PD) and aberrant αSyn is a key pathological hallmark of idiopathic PD. This α-synucleinopathy leads to mitochondrial dysfunction, which may drive dopaminergic neurodegeneration. PARKIN and PINK1, mutated in autosomal recessive PD, regulate the preferential autophagic clearance of dysfunctional mitochondria ("mitophagy") by inducing ubiquitylation of mitochondrial proteins, a process counteracted by deubiquitylation via USP30. Here we show that loss of USP30 in Usp30 knockout mice protects against behavioral deficits and leads to increased mitophagy, decreased phospho-S129 αSyn, and attenuation of SN dopaminergic neuronal loss induced by αSyn. These observations were recapitulated with a potent, selective, brain-penetrant USP30 inhibitor, MTX115325, with good drug-like properties. These data strongly support further study of USP30 inhibition as a potential disease-modifying therapy for PD.
Topics: Animals; Mice; alpha-Synuclein; Dopaminergic Neurons; Mice, Knockout; Mitochondria; Parkinson Disease; Ubiquitin-Protein Ligases; Ubiquitination; Thiolester Hydrolases
PubMed: 37957154
DOI: 10.1038/s41467-023-42876-1