Perni M et al. (2021) Sci Rep "Exogenous misfolded protein oligomers can cross the intestinal barrier and cause a disease phenotype in C. elegans."

Vendruscolo M, Mannini B, Kumita JR, Perni M, Dobson CM, Chiti F, Xu CK

[Sci Rep, 2021]

Misfolded protein oligomers are increasingly recognized as highly cytotoxic agents in a wide range of human disorders associated with protein aggregation. In this study, we assessed the possible uptake and resulting toxic effects of model protein oligomers administered to C. elegans through the culture medium. We used an automated machine-vision, high-throughput screening procedure to monitor the phenotypic changes in the worms, in combination with confocal microscopy to monitor the diffusion of the oligomers, and oxidative stress assays to detect their toxic effects. Our results suggest that the oligomers can diffuse from the intestinal lumen to other tissues, resulting in a disease phenotype. We also observed that pre-incubation of the oligomers with a molecular chaperone (B-crystallin) or a small molecule inhibitor of protein aggregation (squalamine), reduced the oligomer absorption. These results indicate that exogenous misfolded protein oligomers can be taken up by the worms from their environment and spread across tissues, giving rise to pathological effects in regions distant from their place of absorbance.

Habchi J et al. (2016) Proc Natl Acad Sci U S A "Systematic development of small molecules to inhibit specific microscopic steps of A42 aggregation in Alzheimer's disease."

Habchi J, Vendruscolo M, Knowles TP, Limbocker R, Perni M, Mannini B, Chia S, Arosio P, Linse S, Hansson O, Cohen SI, Dobson CM, Kumita JR, Challa PK, Ahn M

[Proc Natl Acad Sci U S A, 2016]

The aggregation of the 42-residue form of the amyloid- peptide (A42) is a pivotal event in Alzheimer's disease (AD). The use of chemical kinetics has recently enabled highly accurate quantifications of the effects of small molecules on specific microscopic steps in A42 aggregation. Here, we exploit this approach to develop a rational drug discovery strategy against A42 aggregation that uses as a read-out the changes in the nucleation and elongation rate constants caused by candidate small molecules. We thus identify a pool of compounds that target specific microscopic steps in A42 aggregation. We then test further these small molecules in human cerebrospinal fluid and in a Caenorhabditis elegans model of AD. Our results show that this strategy represents a powerful approach to identify systematically small molecule lead compounds, thus offering an appealing opportunity to reduce the attrition problem in drug discovery.

Kaminski Schierle GS et al. (2011) Chemphyschem "A FRET sensor for non-invasive imaging of amyloid formation in vivo."

Schwedler S, Kaminski Schierle GS, Nollen EA, Schlachter S, Kaminski CF, van der Goot AT, Dobson CM, Esposito A, Kumita JR, van Ham T, Chan FT, Skepper J, Bertoncini CW

[Chemphyschem, 2011]

Misfolding and aggregation of amyloidogenic polypeptides lie at the root of many neurodegenerative diseases. Whilst protein aggregation can be readily studied in vitro by established biophysical techniques, direct observation of the nature and kinetics of aggregation processes taking place in vivo is much more challenging. We describe here, however, a Forster resonance energy transfer sensor that permits the aggregation kinetics of amyloidogenic proteins to be quantified in living systems by exploiting our observation that amyloid assemblies can act as energy acceptors for variants of fluorescent proteins. The observed lifetime reduction can be attributed to fluorescence energy transfer to intrinsic energy states associated with the growing amyloid species. Indeed, for a-synuclein, a protein whose aggregation is linked to Parkinson's disease, we have used this sensor to follow the kinetics of the self-association reactions taking place in vitro and in vivo and to reveal the nature of the ensuing aggregated species. Experiments were conducted in vitro, in cells in culture and in living Caenorhabditis elegans. For the latter the readout correlates directly with the appearance of a toxic phenotype. The ability to measure the appearance and development of pathogenic amyloid species in a living animal and the ability to relate such data to similar processes observed in vitro provides a powerful new tool in the study of the pathology of the family of misfolding disorders. Our study confirms the importance of the molecular environment in which aggregation reactions take place, highlighting similarities as well as differences between the processes occurring in vitro and in vivo, and their significance for defining the molecular physiology of the diseases with which they are associated.

Bradford BR et al. (2020) Genetics "Counteracting Environmental Chemicals with Coenzyme Q10: An Educational Primer for Use with "Antioxidant CoQ10 Restores Fertility by Rescuing Bisphenol A-Induced Oxidative DNA Damage in the Caenorhabditis elegans Germline"."

Nowakowski AM, Maurina S, Checchi PM, FitzGibbon TC, Gervasio ED, Kelly M, Bradford BR, Fassnacht N, Benjamin AV, Briand NE

[Genetics, 2020]

Environmental toxicants are chemicals that negatively affect human health. Although there are numerous ways to limit exposure, the ubiquitous nature of certain environmental toxicants makes it impossible to avoid them entirely. Consequently, scientists are continuously working toward developing strategies for combating their harmful effects. Using the nematode <i>Caenorhabditis elegans</i>, a model with many genetic and physiological similarities to humans, researchers in the Colaiacovo laboratory have identified several molecular mechanisms by which the toxic agent bisphenol A (BPA) interferes with reproduction. Here, we address their recent discovery that a widely available compound, Coenzyme Q10 (CoQ10), can rescue BPA-induced damage. This work is significant in that it poses a low-cost method for improving reproductive success in humans. The goal of this primer is to assist educators and students with navigating the paper entitled &quot;Antioxidant CoQ10 Restores Fertility by Rescuing Bisphenol A-Induced Oxidative DNA Damage in the <i>Caenorhabditis elegans</i> Germline.&quot; It is ideally suited for integration into an upper-level undergraduate course such as Genetics, Cell and Molecular Biology, Developmental Biology, or Toxicology. The primer provides background information on the history of BPA, the utility of the <i>C. elegans</i> germ line as a model for studying reproductive toxicity, and research methods including assessment of programmed cell death, fluorescent microscopy applications, and assays to quantify gene expression. Questions for deeper exploration in-class or online are provided.<b>Related article in <i>GENETICS</i>:</b> Hornos Carneiro MF, Shin N, Karthikraj R, Barbosa F Jr, Kannan K, Colaiacovo MP. Antioxidant CoQ10 restores fertility by rescuing bisphenol A-induced oxidative DNA damage in the <i>Caenorhabditis elegans</i> Germline. Genetics 214:381-395.

Perni M et al. (2018) ACS Chem Biol "Multistep Inhibition of -Synuclein Aggregation and Toxicity in Vitro and in Vivo by Trodusquemine."

Vendruscolo M, Heller GT, Barbut D, Chen SW, Cascella R, Zasloff M, Kumita JR, Cecchi C, Chiti F, Mannini B, Limbocker R, Flagmeier P, Cremades N, Knowles TPJ, Perni M, Aprile FA, Cohen SIA, Dobson CM, Kirkegaard JB, Nollen EAA, Galvagnion C, Challa PK, Meisl G

[ACS Chem Biol, 2018]

The aggregation of -synuclein, an intrinsically disordered protein that is highly abundant in neurons, is closely associated with the onset and progression of Parkinson's disease. We have shown previously that the aminosterol squalamine can inhibit the lipid induced initiation process in the aggregation of -synuclein, and we report here that the related compound trodusquemine is capable of inhibiting not only this process but also the fibril-dependent secondary pathways in the aggregation reaction. We further demonstrate that trodusquemine can effectively suppress the toxicity of -synuclein oligomers in neuronal cells, and that its administration, even after the initial growth phase, leads to a dramatic reduction in the number of -synuclein inclusions in a Caenorhabditis elegans model of Parkinson's disease, eliminates the related muscle paralysis, and increases lifespan. On the basis of these findings, we show that trodusquemine is able to inhibit multiple events in the aggregation process of -synuclein and hence to provide important information about the link between such events and neurodegeneration, as it is initiated and progresses. Particularly in the light of the previously reported ability of trodusquemine to cross the blood-brain barrier and to promote tissue regeneration, the present results suggest that this compound has the potential to be an important therapeutic candidate for Parkinson's disease and related disorders.

Limbocker R et al. (2019) Nat Commun "Trodusquemine enhances A42 aggregation but suppresses its toxicity by displacing oligomers from cell membranes."

Cecchi C, Mannini B, Zasloff M, Meisl G, Kloss ND, Kumita JR, Dobson CM, Heller GT, Fernando N, Perni M, Challa PK, Michaels TCT, Casford ST, Vendruscolo M, Knowles TPJ, Ahn M, Limbocker R, Linse S, Xu CK, Chiti F, Cohen SIA, Ruggeri FS, Chia S, Cascella R, Habchi J

[Nat Commun, 2019]

Transient oligomeric species formed during the aggregation process of the 42-residue form of the amyloid- peptide (A₄₂) are key pathogenic agents in Alzheimer's disease (AD). To investigate the relationship between A₄₂ aggregation and its cytotoxicity and the influence of a potentialdrug on both phenomena, we have studied the effects of trodusquemine. This aminosterol enhances the rate of aggregation by promoting monomer-dependent secondary nucleation, but significantly reduces the toxicity of the resulting oligomers to neuroblastoma cells by inhibiting their binding to the cellular membranes. When administered to a C. elegans model of AD, we again observe an increase in aggregate formation alongside the suppression of A₄₂-induced toxicity. In addition to oligomer displacement, the reduced toxicity could also point towards an increased rate of conversion of oligomers to less toxic fibrils. The ability of a small molecule to reduce the toxicity of oligomeric species represents a potential therapeutic strategy against AD.

Perni M et al. (2021) Front Cell Dev Biol "Comparative Studies in the A30P and A53T -Synuclein C. elegans Strains to Investigate the Molecular Origins of Parkinson's Disease."

Chen SW, Xu CK, van Ham TJ, Kirkegaard JB, Cohen SIA, Vendruscolo M, van der Goot A, Kaminski Schierle GS, Knowles TPJ, Seinstra R, Muller MBD, Nollen EAA, Laine RF, Kumita JR, Aprile FA, Perni M, Barbut D, Thijssen K, Kaminski CF, Sormanni P, Dobson CM, Flagmeier P, Ma KY, Limbocker R, Zasloff M, Fusco G, Challa PK, De Simone A, Sinnige T

[Front Cell Dev Biol, 2021]

The aggregation of -synuclein is a hallmark of Parkinson's disease (PD) and a variety of related neurological disorders. A number of mutations in this protein, including A30P and A53T, are associated with familial forms of the disease. Patients carrying the A30P mutation typically exhibit a similar age of onset and symptoms as sporadic PD, while those carrying the A53T mutation generally have an earlier age of onset and an accelerated progression. We report two <i>C. elegans</i> models of PD (PD_A30P and PD_A53T), which express these mutational variants in the muscle cells, and probed their behavior relative to animals expressing the wild-type protein (PD_WT). PD_A30P worms showed a reduced speed of movement and an increased paralysis rate, control worms, but no change in the frequency of body bends. By contrast, in PD_A53T worms both speed and frequency of body bends were significantly decreased, and paralysis rate was increased. -Synuclein was also observed to be less well localized into aggregates in PD_A30P worms compared to PD_A53T and PD_WT worms, and amyloid-like features were evident later in the life of the animals, despite comparable levels of expression of -synuclein. Furthermore, squalamine, a natural product currently in clinical trials for treating symptomatic aspects of PD, was found to reduce significantly the aggregation of -synuclein and its associated toxicity in PD_A53T and PD_WT worms, but had less marked effects in PD_A30P. In addition, using an antibody that targets the N-terminal region of -synuclein, we observed a suppression of toxicity in PD_A30P, PD_A53T and PD_WT worms. These results illustrate the use of these two <i>C. elegans</i> models in fundamental and applied PD research.