scholarly journals All Roads Lead to Rome: Different Molecular Players Converge to Common Toxic Pathways in Neurodegeneration

Cells ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 2438
Author(s):  
Shirel Argueti-Ostrovsky ◽  
Leenor Alfahel ◽  
Joy Kahn ◽  
Adrian Israelson

Multiple neurodegenerative diseases (NDDs) such as Alzheimer’s disease (AD), Parkinson’s disease (PD), amyotrophic lateral sclerosis (ALS) and Huntington’s disease (HD) are being suggested to have common cellular and molecular pathological mechanisms, characterized mainly by protein misfolding and aggregation. These large inclusions, most likely, represent an end stage of a molecular cascade; however, the soluble misfolded proteins, which take part in earlier steps of this cascade, are the more toxic players. These pathological proteins, which characterize each specific disease, lead to the selective vulnerability of different neurons, likely resulting from a combination of different intracellular mechanisms, including mitochondrial dysfunction, ER stress, proteasome inhibition, excitotoxicity, oxidative damage, defects in nucleocytoplasmic transport, defective axonal transport and neuroinflammation. Damage within these neurons is enhanced by damage from the nonneuronal cells, via inflammatory processes that accelerate the progression of these diseases. In this review, while acknowledging the hallmark proteins which characterize the most common NDDs; we place specific focus on the common overlapping mechanisms leading to disease pathology despite these different molecular players and discuss how this convergence may occur, with the ultimate hope that therapies effective in one disease may successfully translate to another.

2016 ◽  
Vol 27 (10) ◽  
pp. 1556-1560 ◽  
Author(s):  
James Shorter

Therapeutic agents are urgently required to cure several common and fatal neurodegenerative disorders caused by protein misfolding and aggregation, including amyotrophic lateral sclerosis (ALS), Parkinson’s disease (PD), and Alzheimer’s disease (AD). Protein disaggregases that reverse protein misfolding and restore proteins to native structure, function, and localization could mitigate neurodegeneration by simultaneously reversing 1) any toxic gain of function of the misfolded form and 2) any loss of function due to misfolding. Potentiated variants of Hsp104, a hexameric AAA+ ATPase and protein disaggregase from yeast, have been engineered to robustly disaggregate misfolded proteins connected with ALS (e.g., TDP-43 and FUS) and PD (e.g., α-synuclein). However, Hsp104 has no metazoan homologue. Metazoa possess protein disaggregase systems distinct from Hsp104, including Hsp110, Hsp70, and Hsp40, as well as HtrA1, which might be harnessed to reverse deleterious protein misfolding. Nevertheless, vicissitudes of aging, environment, or genetics conspire to negate these disaggregase systems in neurodegenerative disease. Thus, engineering potentiated human protein disaggregases or isolating small-molecule enhancers of their activity could yield transformative therapeutics for ALS, PD, and AD.


2019 ◽  
Vol 6 (6) ◽  
pp. e631 ◽  
Author(s):  
Marlena Wosiski-Kuhn ◽  
Mac Robinson ◽  
Jane Strupe ◽  
Phonepasong Arounleut ◽  
Matthew Martin ◽  
...  

ObjectiveTo test the hypothesis that patients with amyotrophic lateral sclerosis (ALS) inheriting the common interleukin 6 receptor (IL6R) coding variant (Asp358Ala, rs2228145, C allele) have associated increases in interleukin 6 (IL6) and IL6R levels in serum and CSF and faster disease progression than noncarriers.MethodsAn observational, case-control study of paired serum and CSF of 47 patients with ALS, 46 healthy, and 23 neurologic disease controls from the Northeastern ALS Consortium Biofluid Repository (cohort 1) was performed to determine serum levels of IL6, sIL6R, and soluble glycoprotein 130 and compared across groups and IL6R genotype. Clinical data regarding disease progression from a separate cohort of 35 patients with ALS from the Wake Forest ALS Center (cohort 2) were used to determine change in ALSFRS-R scores by genotype.ResultsPatients with ALS had increased CSF IL6 levels compared with healthy (p < 0.001) and neurologic (p = 0.021) controls. Patients with ALS also had increased serum IL6 compared with healthy (p = 0.040) but not neurologic controls. Additive allelic increases in serum IL6R were observed in all groups (average increase of 52% with the presence of the IL6R C allele; p < 0.001). However, only subjects with ALS had significantly increased CSF sIL6R levels compared with controls (p < 0.001). When compared across genotypes, only patients with ALS inheriting the IL6R C allele exhibit increased CSF IL6. ALSFRS-R scores decreased more in patients with ALS with the IL6R C allele than in those without (p = 0.019).ConclusionsTheses results suggest that for individuals inheriting the IL6R C allele, the cytokine exerts a disease- and location-specific role in ALS. Follow-up, prospective studies are necessary, as this subgroup of patients may be identified as ideally responsive to IL6 receptor–blocking therapies.


Author(s):  
Kristine O’Phelan

The purpose of the Oral Board Examination is to determine a candidate’s competency in neurosurgical disorders, but also neurological disorders, which may mimic neurosurgical conditions. It is not uncommon for a candidate to be presented imaging studies that clearly appear surgical; however, after carefully listening to the history and relevant neurological findings, it will become apparent that the imaging does not explain the patient’s symptoms. Some of the common neurological ailments that the Oral Board examinee needs to be well aware of include amyotrophic lateral sclerosis (ALS), multiple sclerosis (MS), Guillain-Barré syndrome, and Parsonage=Turner syndrome (brachial plexitis), some of which are covered either in this chapter or in other relevant chapters.


Author(s):  
Jeffrey L. Cummings ◽  
Kate Zhong

This chapter describes the common therapeutic targets, approaches to clinical trial design, biomarkers, and therapeutic interventions across neurodegenerative disorders (NDDs). Each unique NDD-Alzheimer’s disease (AD), Parkinson’s disease (PD), amyotrophic lateral sclerosis (ALS), etc.-has a unique phenotype associated with the regional cell population most affected. Each disease, however, is associated with protein misfolding, oxidation, inflammation, apoptosis, and cell death. If vulnerable cell populations include transmitter source nuclei, transmitter deficits also emerge (e.g. cholinergic abnormalities in AD and dopaminergic deficits in PD). Biomarkers show regionally appropriate brain atrophy or process-related cerebrospinal deficits. Clinical trial designs share features for symptomatic interventions (e.g. cholinesterase inhibitors in AD and dopamine agents in PD) and disease-modifying therapies. Biomarkers play similar roles in trials for NDD, including demonstrating target engagement and supporting disease modification. No disease-modifying therapies have been approved for any NDDs; all programs face similar pharmacokinetic, pharmacodynamic, and regulatory challenges in therapeutic development.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Pin-Tse Lee ◽  
Jean-Charles Liévens ◽  
Shao-Ming Wang ◽  
Jian-Ying Chuang ◽  
Bilal Khalil ◽  
...  

ABSTRACT In a subgroup of patients with amyotrophic lateral sclerosis (ALS)/Frontotemporal dementia (FTD), the (G4C2)-RNA repeat expansion from C9orf72 chromosome binds to the Ran-activating protein (RanGAP) at the nuclear pore, resulting in nucleocytoplasmic transport deficit and accumulation of Ran in the cytosol. Here, we found that the sigma-1 receptor (Sig-1R), a molecular chaperone, reverses the pathological effects of (G4C2)-RNA repeats in cell lines and in Drosophila. The Sig-1R colocalizes with RanGAP and nuclear pore proteins (Nups) and stabilizes the latter. Interestingly, Sig-1Rs directly bind (G4C2)-RNA repeats. Overexpression of Sig-1Rs rescues, whereas the Sig-1R knockout exacerbates, the (G4C2)-RNA repeats-induced aberrant cytoplasmic accumulation of Ran. In Drosophila, Sig-1R (but not the Sig-1R-E102Q mutant) overexpression reverses eye necrosis, climbing deficit, and firing discharge caused by (G4C2)-RNA repeats. These results on a molecular chaperone at the nuclear pore suggest that Sig-1Rs may benefit patients with C9orf72 ALS/FTD by chaperoning the nuclear pore assembly and sponging away deleterious (G4C2)-RNA repeats.


Sign in / Sign up

Export Citation Format

Share Document