scholarly journals Calcium-responsive transactivator (CREST) toxicity is rescued by loss of PBP1/ATXN2 function in a novel yeast proteinopathy model and in transgenic flies

2018 ◽  
Author(s):  
By Sangeun Park ◽  
Sei-Kyoung Park ◽  
Naruaki Watanabe ◽  
Tadafumi Hashimoto ◽  
Takeshi Iwatsubo ◽  
...  
Keyword(s):  
Amyotrophic Lateral Sclerosis ◽  
Neurodegenerative Diseases ◽  
Neurodegenerative Disease ◽  
Chromatin Remodeling ◽  
Mammalian Cells ◽  
Ganglion Cells ◽  
Yeast Prions ◽  
Wide Range ◽  
Associated Proteins ◽  
Lateral Sclerosis

AbstractProteins associated with familial neurodegenerative disease often aggregate in patients’ neurons. Several such proteins, e.g. TDP-43, aggregate and are toxic when expressed in yeast. Deletion of the ATXN2 ortholog, PBP1, reduces yeast TDP-43 toxicity, which led to identification of ATXN2 as an amyotrophic lateral sclerosis (ALS) risk factor and therapeutic target. Likewise, new yeast neurodegenerative disease models could facilitate identification of other risk factors and targets. Mutations in SS18L1, encoding the calcium-responsive transactivator (CREST) chromatin-remodeling protein, are associated with ALS. We show that CREST is toxic in yeast and forms nuclear and occasionally cytoplasmic foci that stain with Thioflavin-T, a dye indicative of amyloid-like protein. Like the yeast chromatin-remodeling factor SWI1, CREST inhibits silencing of FLO genes. Toxicity of CREST is enhanced by the [PIN+] prion and reduced by deletion of the HSP104 chaperone required for the propagation of many yeast prions. Likewise, deletion of PBP1 reduced CREST toxicity and aggregation. In accord with the yeast data, we show that the Drosophila ortholog of human ATXN2, dAtx2, is a potent enhancer of CREST toxicity. Downregulation of dAtx2 in flies overexpressing CREST in retinal ganglion cells was sufficient to largely rescue the severe degenerative phenotype induced by human CREST. Overexpression caused considerable co-localization of CREST and PBP1/ATXN2 in cytoplasmic foci in both yeast and mammalian cells. Thus, co-aggregation of CREST and PBP1/ATXN2 may serve as one of the mechanisms of PBP1/ATXN2-mediated toxicity. These results extend the spectrum of ALS associated proteins whose toxicity is regulated by PBP1/ATXN2, suggesting that therapies targeting ATXN2 may be effective for a wide range of neurodegenerative diseases.Author summaryMutations in the calcium-responsive transactivator (CREST) protein have been shown to cause amyotrophic lateral sclerosis (ALS). Here we show that the human CREST protein expressed in yeast forms largely nuclear aggregates and is toxic. We also show that the HSP104 chaperone required for propagation of yeast prions is likewise required for CREST toxicity. Furthermore deletion of HSP104 affects CREST aggregation. ATXN2, previously shown to modify ALS toxicity caused by mutations in the TDP-43 encoding gene, also modifies toxicity of CREST expressed in either yeast or flies. In addition, deletion of the yeast ATXN2 ortholog reduces CREST aggregation. These results extend the spectrum of ALS associated proteins whose toxicity is regulated by ATXN2, suggesting that therapies targeting ATXN2 may be effective for a wide range of neurodegenerative diseases.

scholarly journals Cyanobacteria, Cyanotoxins, and Neurodegenerative Diseases: Dangerous Liaisons

2021 ◽  
Vol 22 (16) ◽  
pp. 8726
Author(s):  
Paola Sini ◽  
Thi Bang Chau Dang ◽  
Milena Fais ◽  
Manuela Galioto ◽  
Bachisio Mario Padedda ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Amyotrophic Lateral Sclerosis ◽  
Neurodegenerative Diseases ◽  
Neurodegenerative Disease ◽  
Genetic Susceptibility ◽  
Molecular Mechanisms ◽  
Environmental Influences ◽  
Older Age ◽  
Lateral Sclerosis ◽  
Effective Treatments

The prevalence of neurodegenerative disease (ND) is increasing, partly owing to extensions in lifespan, with a larger percentage of members living to an older age, but the ND aetiology and pathogenesis are not fully understood, and effective treatments are still lacking. Neurodegenerative diseases such as Alzheimer’s disease, Parkinson’s disease, and amyotrophic lateral sclerosis are generally thought to progress as a consequence of genetic susceptibility and environmental influences. Up to now, several environmental triggers have been associated with NDs, and recent studies suggest that some cyanotoxins, produced by cyanobacteria and acting through a variety of molecular mechanisms, are highly neurotoxic, although their roles in neuropathy and particularly in NDs are still controversial. In this review, we summarize the most relevant and recent evidence that points at cyanotoxins as environmental triggers in NDs development.

scholarly journals Therapeutic Assay with the Non-toxic C-Terminal Fragment of Tetanus Toxin (TTC) in Transgenic Murine Models of Prion Disease

2021 ◽  
Author(s):  
Marina Betancor ◽  
Laura Moreno-Martínez ◽  
Óscar López-Pérez ◽  
Alicia Otero ◽  
Adelaida Hernaiz ◽  
...  
Keyword(s):  
Amyotrophic Lateral Sclerosis ◽  
Neurodegenerative Diseases ◽  
Prion Disease ◽  
Tetanus Toxin ◽  
Neuronal Survival ◽  
Prion Diseases ◽  
Cellular Prion Protein ◽  
Murine Models ◽  
Terminal Fragment ◽  
Lateral Sclerosis

AbstractThe non-toxic C-terminal fragment of the tetanus toxin (TTC) has been described as a neuroprotective molecule since it binds to Trk receptors and activates Trk-dependent signaling, activating neuronal survival pathways and inhibiting apoptosis. Previous in vivo studies have demonstrated the ability of this molecule to increase mice survival, inhibit apoptosis and regulate autophagy in murine models of neurodegenerative diseases such as amyotrophic lateral sclerosis and spinal muscular atrophy. Prion diseases are fatal neurodegenerative disorders in which the main pathogenic event is the conversion of the cellular prion protein (PrPC) into an abnormal and misfolded isoform known as PrPSc. These diseases share different pathological features with other neurodegenerative diseases, such as amyotrophic lateral sclerosis, Parkinson’s disease or Alzheimer’s disease. Hitherto, there are no effective therapies to treat prion diseases. Here, we present a pilot study to test the therapeutic potential of TTC to treat prion diseases. C57BL6 wild-type mice and the transgenic mice Tg338, which overexpress PrPC, were intracerebrally inoculated with scrapie prions and then subjected to a treatment consisting of repeated intramuscular injections of TTC. Our results indicate that TTC displays neuroprotective effects in the murine models of prion disease reducing apoptosis, regulating autophagy and therefore increasing neuronal survival, although TTC did not increase survival time in these models.

scholarly journals Mitophagy Modulation, a New Player in the Race against ALS

2021 ◽  
Vol 22 (2) ◽  
pp. 740
Author(s):  
Enrique Madruga ◽  
Inés Maestro ◽  
Ana Martínez
Keyword(s):  
Amyotrophic Lateral Sclerosis ◽  
Protein Aggregation ◽  
Neurodegenerative Disease ◽  
Effective Treatment ◽  
Unknown Etiology ◽  
Drug Candidates ◽  
Relevant Evidence ◽  
Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a lethal neurodegenerative disease that usually results in respiratory paralysis in an interval of 2 to 4 years. ALS shows a multifactorial pathogenesis with an unknown etiology, and currently lacks an effective treatment. The vast majority of patients exhibit protein aggregation and a dysfunctional mitochondrial accumulation in their motoneurons. As a result, autophagy and mitophagy modulators may be interesting drug candidates that mitigate key pathological hallmarks of the disease. This work reviews the most relevant evidence that correlate mitophagy defects and ALS, and discusses the possibility of considering mitophagy as an interesting target in the search for an effective treatment for ALS.

scholarly journals Proline/arginine dipeptide repeat polymers derail protein folding in amyotrophic lateral sclerosis

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Maria Babu ◽  
Filippo Favretto ◽  
Alain Ibáñez de Opakua ◽  
Marija Rankovic ◽  
Stefan Becker ◽  
...  
Keyword(s):  
Amyotrophic Lateral Sclerosis ◽  
Protein Folding ◽  
Neurodegenerative Diseases ◽  
Catalyst Activity ◽  
Coding Region ◽  
Prolyl Isomerase ◽  
X Ray Crystallography ◽  
Hexanucleotide Repeat ◽  
Lateral Sclerosis ◽  
Dipeptide Repeat

AbstractAmyotrophic lateral sclerosis and frontotemporal dementia are two neurodegenerative diseases with overlapping clinical features and the pathological hallmark of cytoplasmic deposits of misfolded proteins. The most frequent cause of familial forms of these diseases is a hexanucleotide repeat expansion in the non-coding region of the C9ORF72 gene that is translated into dipeptide repeat polymers. Here we show that proline/arginine repeat polymers derail protein folding by sequestering molecular chaperones. We demonstrate that proline/arginine repeat polymers inhibit the folding catalyst activity of PPIA, an abundant molecular chaperone and prolyl isomerase in the brain that is altered in amyotrophic lateral sclerosis. NMR spectroscopy reveals that proline/arginine repeat polymers bind to the active site of PPIA. X-ray crystallography determines the atomic structure of a proline/arginine repeat polymer in complex with the prolyl isomerase and defines the molecular basis for the specificity of disease-associated proline/arginine polymer interactions. The combined data establish a toxic mechanism that is specific for proline/arginine dipeptide repeat polymers and leads to derailed protein homeostasis in C9orf72-associated neurodegenerative diseases.

scholarly journals Paraoxonase Role in Human Neurodegenerative Diseases

Antioxidants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 11
Author(s):  
Cadiele Oliana Reichert ◽  
Debora Levy ◽  
Sergio P. Bydlowski
Keyword(s):  
Oxidative Stress ◽  
Multiple Sclerosis ◽  
Amyotrophic Lateral Sclerosis ◽  
Neurodegenerative Diseases ◽  
High Density Lipoprotein ◽  
Density Lipoprotein ◽  
Structural Homology ◽  
Redox Systems ◽  
Genetic Cluster ◽  
Lateral Sclerosis

The human body has biological redox systems capable of preventing or mitigating the damage caused by increased oxidative stress throughout life. One of them are the paraoxonase (PON) enzymes. The PONs genetic cluster is made up of three members (PON1, PON2, PON3) that share a structural homology, located adjacent to chromosome seven. The most studied enzyme is PON1, which is associated with high density lipoprotein (HDL), having paraoxonase, arylesterase and lactonase activities. Due to these characteristics, the enzyme PON1 has been associated with the development of neurodegenerative diseases. Here we update the knowledge about the association of PON enzymes and their polymorphisms and the development of multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), Alzheimer’s disease (AD) and Parkinson’s disease (PD).

scholarly journals Bile Acids Reduce Prion Conversion, Reduce Neuronal Loss, and Prolong Male Survival in Models of Prion Disease

2015 ◽  
Vol 89 (15) ◽  
pp. 7660-7672 ◽  
Author(s):  
Leonardo M. Cortez ◽  
Jody Campeau ◽  
Grant Norman ◽  
Marian Kalayil ◽  
Jacques Van der Merwe ◽  
...  
Keyword(s):  
Amyotrophic Lateral Sclerosis ◽  
Neurodegenerative Diseases ◽  
Bile Acids ◽  
Prion Disease ◽  
Prion Diseases ◽  
Neuronal Loss ◽  
Disease Models ◽  
Orally Bioavailable ◽  
Prion Conversion ◽  
Lateral Sclerosis

ABSTRACTPrion diseases are fatal neurodegenerative disorders associated with the conversion of cellular prion protein (PrPC) into its aberrant infectious form (PrPSc). There is no treatment available for these diseases. The bile acids tauroursodeoxycholic acid (TUDCA) and ursodeoxycholic acid (UDCA) have been recently shown to be neuroprotective in other protein misfolding disease models, including Parkinson's, Huntington's and Alzheimer's diseases, and also in humans with amyotrophic lateral sclerosis. Here, we studied the therapeutic efficacy of these compounds in prion disease. We demonstrated that TUDCA and UDCA substantially reduced PrP conversion in cell-free aggregation assays, as well as in chronically and acutely infected cell cultures. This effect was mediated through reduction of PrPScseeding ability, rather than an effect on PrPC. We also demonstrated the ability of TUDCA and UDCA to reduce neuronal loss in prion-infected cerebellar slice cultures. UDCA treatment reduced astrocytosis and prolonged survival in RML prion-infected mice. Interestingly, these effects were limited to the males, implying a gender-specific difference in drug metabolism. Beyond effects on PrPSc, we found that levels of phosphorylated eIF2α were increased at early time points, with correlated reductions in postsynaptic density protein 95. As demonstrated for other neurodegenerative diseases, we now show that TUDCA and UDCA may have a therapeutic role in prion diseases, with effects on both prion conversion and neuroprotection. Our findings, together with the fact that these natural compounds are orally bioavailable, permeable to the blood-brain barrier, and U.S. Food and Drug Administration-approved for use in humans, make these compounds promising alternatives for the treatment of prion diseases.IMPORTANCEPrion diseases are fatal neurodegenerative diseases that are transmissible to humans and other mammals. There are no disease-modifying therapies available, despite decades of research. Treatment targets have included inhibition of protein accumulation, clearance of toxic aggregates, and prevention of downstream neurodegeneration. No one target may be sufficient; rather, compounds which have a multimodal mechanism, acting on different targets, would be ideal. TUDCA and UDCA are bile acids that may fulfill this dual role. Previous studies have demonstrated their neuroprotective effects in several neurodegenerative disease models, and we now demonstrate that this effect occurs in prion disease, with an added mechanistic target of upstream prion seeding. Importantly, these are natural compounds which are orally bioavailable, permeable to the blood-brain barrier, and U.S. Food and Drug Administration-approved for use in humans with primary biliary cirrhosis. They have recently been proven efficacious in human amyotrophic lateral sclerosis. Therefore, these compounds are promising options for the treatment of prion diseases.

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