-
Brain : a Journal of Neurology Jun 2024The relative inability to produce effortful movements is the most specific motor sign of Parkinson's disease, which is primarily characterized by loss of dopaminergic...
The relative inability to produce effortful movements is the most specific motor sign of Parkinson's disease, which is primarily characterized by loss of dopaminergic terminals in the putamen. The motor motivation hypothesis suggests that this motor deficit may not reflect a deficiency in motor control per se, but a deficiency in cost-benefit considerations for motor effort. For the first time, we investigated the quantitative effect of dopamine depletion on the motivation of motor effort in Parkinson's disease. A total of 21 early-stage, unmedicated patients with Parkinson's disease and 26 healthy controls were included. An incentivized force task was used to capture the amount of effort participants were willing to invest for different monetary incentive levels and dopamine transporter depletion in the bilateral putamen was assessed. Our results demonstrate that patients with Parkinson's disease applied significantly less grip force than healthy controls, especially for low incentive levels. Congruously, decrease of motor effort with greater loss of putaminal dopaminergic terminals was most pronounced for low incentive levels. This signifies that putaminal dopamine is most critical to motor effort when the trade-off with the benefit is poor. Taken together, we provide direct evidence that the reduction of effortful movements in Parkinson's disease depends on motivation and that this effect is associated with putaminal dopaminergic degeneration.
PubMed: 38941444
DOI: 10.1093/brain/awae214 -
The Journal of Physical Chemistry. B Jun 2024In recent work we proposed that interdiction in the earliest contact-formation events along the folding pathway of key viral proteins could provide a novel avenue for... (Review)
Review
A Perspective on Interdicting in Protein Misfolding for Therapeutic Drug Design: Modulating the Formation of Nonlocal Contacts in α-Synuclein as a Strategy against Parkinson's Disease.
In recent work we proposed that interdiction in the earliest contact-formation events along the folding pathway of key viral proteins could provide a novel avenue for therapeutic drug design. In this Perspective we explore the potential applicability of the protein folding interdiction strategy in the realm of neurodegenerative diseases with a specific focus on synucleinopathies. In order to fulfill this goal we review the interdiction proposal and its practical challenges, and we present new results concerning design strategies for possible peptide drugs that could be useful in preventing α-synuclein aggregation.
PubMed: 38940731
DOI: 10.1021/acs.jpcb.3c07519 -
Applied and Environmental Microbiology Jun 2024Farnesol salvage, a two-step pathway converting farnesol to farnesyl pyrophosphate (FPP), occurs in bacteria, plants, and animals. This paper investigates the presence...
UNLABELLED
Farnesol salvage, a two-step pathway converting farnesol to farnesyl pyrophosphate (FPP), occurs in bacteria, plants, and animals. This paper investigates the presence of this pathway in fungi. Through bioinformatics, biochemistry, and physiological analyses, we demonstrate its absence in the yeasts and , suggesting a likely absence across fungi. We screened 1,053 fungal genomes, including 34 from , for potential homologs to four genes (, , , and ) known to accomplish farnesol/prenol salvage in other organisms. Additionally, we showed that H-farnesol was not converted to FPP or any other phosphorylated prenol, and exogenous farnesol was not metabolized within 90 minutes at any phase of growth and did not rescue cells from the toxic effects of atorvastatin, but it did elevate the levels of intracellular farnesol (F). All these experiments were conducted with . In sum, we found no evidence for farnesol salvage in fungi.
IMPORTANCE
The absence of farnesol salvage constitutes a major difference in the metabolic capabilities of fungi. In terms of fungal physiology, the lack of farnesol salvage pathways relates to how farnesol acts as a quorum-sensing molecule in and why farnesol should be investigated for use in combination with other known antifungal antibiotics. Its absence is essential for a model (K. W. Nickerson et al., Microbiol Mol Biol Rev 88:e00081-22, 2024), wherein protein farnesylation, protein chaperones, and the unfolded protein response are combined under the unifying umbrella of a cell's intracellular farnesol (F). In terms of human health, farnesol should have at least two different modes of action depending on whether those cells have farnesol salvage. Because animals have farnesol salvage, we can now see the importance of dietary prenols as well as the potential importance of farnesol in treating neurodegenerative diseases such as Parkinson's disease, Alzheimer's disease, and multiple sclerosis.
PubMed: 38940563
DOI: 10.1128/aem.00874-24 -
Movement Disorders : Official Journal... Jun 2024
PubMed: 38940474
DOI: 10.1002/mds.29892 -
ELife Jun 2024Parkinson's disease (PD) is characterized by motor impairments caused by degeneration of dopamine neurons in the substantia nigra pars compacta. In addition to these...
Parkinson's disease (PD) is characterized by motor impairments caused by degeneration of dopamine neurons in the substantia nigra pars compacta. In addition to these symptoms, PD patients often suffer from non-motor comorbidities including sleep and psychiatric disturbances, which are thought to depend on concomitant alterations of serotonergic and noradrenergic transmission. A primary locus of serotonergic neurons is the dorsal raphe nucleus (DRN), providing brain-wide serotonergic input. Here, we identified electrophysiological and morphological parameters to classify serotonergic and dopaminergic neurons in the murine DRN under control conditions and in a PD model, following striatal injection of the catecholamine toxin, 6-hydroxydopamine (6-OHDA). Electrical and morphological properties of both neuronal populations were altered by 6-OHDA. In serotonergic neurons, most changes were reversed when 6-OHDA was injected in combination with desipramine, a noradrenaline (NA) reuptake inhibitor, protecting the noradrenergic terminals. Our results show that the depletion of both NA and dopamine in the 6-OHDA mouse model causes changes in the DRN neural circuitry.
Topics: Animals; Dopaminergic Neurons; Serotonergic Neurons; Dorsal Raphe Nucleus; Mice; Disease Models, Animal; Oxidopamine; Parkinsonian Disorders; Male; Mice, Inbred C57BL; Desipramine; Norepinephrine
PubMed: 38940422
DOI: 10.7554/eLife.90278 -
Epigenomics Jun 2024
PubMed: 38940212
DOI: 10.1080/17501911.2024.2365615 -
Journal of Integrative Neuroscience May 2024The objective of this study is to compare the differences in effective connectivity within the default mode network (DMN) subsystems between patients with Parkinson's...
OBJECTIVE
The objective of this study is to compare the differences in effective connectivity within the default mode network (DMN) subsystems between patients with Parkinson's disease with mild cognitive impairment (PD-MCI) and patients with Parkinson's disease with normal cognition (PD-CN). The mechanisms underlying DMN dysfunction in PD-MCI patients and its association with clinical cognitive function in PD-MCI are aimed to be investigated.
METHODS
The spectral dynamic causal model (spDCM) was employed to analyze the effective connectivity of functional magnetic resonance imaging (fMRI) data in the resting state for the DMN subsystems, which include the medial prefrontal cortex (MPFC), posterior cingulate cortex (PCC), left and right angular gyrus (LAG, RAG) in 23 PD-MCI and 22 PD-CN patients, respectively. The effective connectivity values of DMN subsystems in the two groups were statistically analyzed using a two-sample -test. The Spearman correlation analysis was used to test the correlation between the effective connectivity values of the subsystems with significant differences between the two groups and the clinical cognitive function (as measured by Montreal Cognitive Assessment Scale (MoCA) score).
RESULTS
Statistical analysis revealed significant differences in the effective connections of MPFC-LAG and LAG-PCC between the two patient groups (MPFC-LAG: t = -2.993, < 0.05; LAG-PCC: t = 2.174, < 0.05).
CONCLUSIONS
The study findings suggest that abnormal strength and direction of effective connections between DMN subsystems are found in PD-MCI patients.
Topics: Humans; Parkinson Disease; Cognitive Dysfunction; Male; Female; Default Mode Network; Magnetic Resonance Imaging; Aged; Middle Aged; Prefrontal Cortex; Gyrus Cinguli; Connectome; Nerve Net
PubMed: 38940086
DOI: 10.31083/j.jin2306110 -
Journal of Integrative Neuroscience May 2024Parkinson's disease (PD) is a neurodegenerative disorder characterized by the progressive loss of dopaminergic neurons in the substantia nigra pars compacta region of... (Review)
Review
Parkinson's disease (PD) is a neurodegenerative disorder characterized by the progressive loss of dopaminergic neurons in the substantia nigra pars compacta region of the midbrain and the formation of intracellular protein aggregates known as Lewy bodies, of which a major component is the protein α-synuclein. Several studies have suggested that mitochondria play a central role in the pathogenesis of PD, encompassing both familial and sporadic forms of the disease. Mitochondrial dysfunction is attributed to bioenergetic impairment, increased oxidative stress, damage to mitochondrial DNA, and alteration in mitochondrial morphology. These alterations may contribute to improper functioning of the central nervous system and ultimately lead to neurodegeneration. The perturbation of mitochondrial function makes it a potential target, worthy of exploration for neuroprotective therapies and to improve mitochondrial health in PD. Thus, in the current review, we provide an update on mitochondria-based therapeutic approaches toward α-synucleinopathies in PD.
Topics: Humans; Parkinson Disease; Synucleinopathies; Mitochondria; Animals; alpha-Synuclein
PubMed: 38940084
DOI: 10.31083/j.jin2306109 -
Journal of Integrative Neuroscience Jun 2024Deep brain stimulation (DBS) is a common therapy for managing Parkinson's disease (PD) in clinical practice. However, a complete understanding of its mode of action is... (Review)
Review
Deep brain stimulation (DBS) is a common therapy for managing Parkinson's disease (PD) in clinical practice. However, a complete understanding of its mode of action is still needed. DBS is believed to work primarily through electrical and neurochemical pathways. Furthermore, DBS has other mechanisms of action. This review explores the fundamental concepts and applications of DBS in treating PD, including its mechanisms, clinical implications, and recent research.
Topics: Deep Brain Stimulation; Parkinson Disease; Humans; Brain; Animals
PubMed: 38940083
DOI: 10.31083/j.jin2306114 -
Current Neuropharmacology Jun 2024The human central nervous system (CNS) has a limited capacity for regeneration and repair, as many other organs do. Partly as a result, neurological diseases are the...
The human central nervous system (CNS) has a limited capacity for regeneration and repair, as many other organs do. Partly as a result, neurological diseases are the leading cause of medical burden globally. Most neurological disorders cannot be cured, and primary treatments focus on managing their symptoms and slowing down their progression. Cell therapy for neurological disorders offers several therapeutic potentials and provides hope for many patients. Here we provide a general overview of cell therapy in neurological disorders such as Parkinson's disease (PD), Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), Wilson's disease (WD), stroke and traumatic brain injury (TBI), involving many forms of stem cells, including embryonic stem cells and induced pluripotent stem cells. We also address the current concerns and perspectives for the future. Most studies for cell therapy in neurological diseases are in the pre-clinical stage, and there is still a great need for further research to translate neural replacement and regenerative therapies into clinical settings.
PubMed: 38939990
DOI: 10.2174/1570159X22666240509092903