Vayndorf, Elena et al. (2017) International Worm Meeting "C. elegans as a model for age-related phenotyping, compound screening and toxicological assessment."

Hincks, Joshua, Vayndorf, Elena, Taylor, Barbara, Harris, Michael

[International Worm Meeting, 2017]

The C. elegans pharynx is a tubular, bi-lobed, muscular pump encased in a basement membrane. The pharynx muscle contracts and relaxes as the animal feeds, generating a characteristic electrical signal that can be recorded as an "electropharyngeogram". The frequency of pharyngeal pumping decreases with age and is considered a reliable index of overall health. Recently, NemaMetrix has made available a device that easily monitors and quantifies the C. elegans electropharyngeogram. We have designed a two-week teaching module using the NemaMetrix platform in guided undergraduate research. Projects assay a locally relevant environmental toxin, a natural product, and the effect of age in C. elegans. We provide examples of research projects that can be done in a two-week research module as part of a biomedically-related undergraduate course.

Vayndorf, Elena et al. (2013) International Worm Meeting "Protein homeostasis dysregulation drives aberrant morphology of aging mechanosensory neurons."

Neri, Christian, Parker, J. Alex, Toth, Marton, Nichols, Courtney, Vayndorf, Elena, Taylor, Barbara, Driscoll, Monica, Hunter, Skyler, Parker, Cyrena

[International Worm Meeting, 2013]

In both C. elegans and mammals, the aging nervous system is characterized by decreased synaptic activity, deteriorating short-term and long-term memory, and altered neuronal morphology. We sought to elucidate the functional consequences of altered neuronal morphology by focusing on protein homeostasis in individual neurons. We examined the effects of disrupting proteostasis on the integrity of neuronal cytoarchitecture using a transgenic model with an excessively high neuronal protein load. We found that animals expressing the first 57 amino acids of the human huntingtin gene and an expanded polyglutamine CAG tract (128Q) in mechanosensory neurons accumulate significantly more neuronal aberrations and more protein aggregates, and have a significantly greater decline in function with age, compared to animals that express the non-toxic (19Q) number of repeats, or those that express no repeats. We identified specific morphological alterations, in particular extreme outgrowths in the soma of ALM mechanosensory neurons, as well as a wavy phenotype in processes of PLM neurons, as the major aberrant morphological types in this transgenic background. Our RNAi studies suggest that targeting genes expressed in organelles associated with the maintenance of proteostasis, in particular the proteosome, lysosome and endoplasmic reticulum, alters neuronal morphology and accelerates aging in wild-type animals. Taken together, these results suggest that protein homeostasis is critical for maintaining neuronal integrity and that disrupted proteostasis contributes to morphological abnormalities that increase in frequency with age.

Vayndorf, Elena et al. (2015) International Worm Meeting "Protein homeostasis dysregulation is associated with aberrant morphology and reduced function of aging mechanosensory neurons."

Hunter, Skyler, Driscoll, Monica, Toth, Marton, Scerbak, Courtney, Taylor, Barbara, Neri, Christian, Parker, J. Alex, Vayndorf, Elena

[International Worm Meeting, 2015]

In both C. elegans and humans, the aging nervous system is characterized by decreased synaptic activity, deteriorating short-term and long-term memory, and altered neuronal morphology. Given the overwhelming evidence for proteostasis disruption in neuronal aging, we sought to explain the accumulation of neuronal morphological abnormalities by focusing on protein homeostasis in 6 mechanosensory neurons of aging C. elegans nematodes. We examined the effects of disrupted proteostasis on the integrity of neuronal cytoarchitecture using a transgenic model with an excessively high neuronal protein load, and RNAi knock down of specific genes involved in protein turnover. We found that animals expressing the first 57 amino acids of the human huntingtin gene and an expanded polyglutamine CAG tract (Q128) in mechanosensory neurons accumulate more aberrations that are distinct from those found in animals that express the non-toxic (Q19) number of repeats, or those that express no repeats. We scored and tallied these changes in both the soma and processes and found that they are sometimes associated with improved or reduced function. Next, we used an RNAi candidate gene approach to target genes involved in the maintenance of protein homeostasis in wild-type animals. We found that genes involved in protein turnover play an important role in maintaining the integrity of healthy neurons, and that their knockdown leads to distinct morphological changes in both the process and the soma of wild-type mechanosensory neurons. Taken together, these results suggest that protein homeostasis is critical for maintaining neuronal integrity and function, and that disrupted proteostasis contributes to morphological abnormalities that occur more frequently with advanced age.

Hunter, Skyler et al. (2015) International Worm Meeting "Caenorhabditis Sieve: A novel mechanical approach to sorting C. elegans and other nematode species for age-synchronized, large scale assays."

Hunter, Skyler, Scherbak, Courtney, Taylor, Barbara, Vayndorf, Elena

[International Worm Meeting, 2015]

The most common method of C. elegans transfer is to use a fine sterilized "pick" made of hair or wire to move animals individually or in small groups. Many procedures, such as RNA extraction or fluorescent imaging, require a large sample of synchronized animals of reproductive age for accurate results. Without expensive sorting equipment, researchers are left to manually select and transfer individual animals. To address this need, we built a low-cost (under $10), easy-to-make device to efficiently select and move large numbers of nematodes from plate to plate without the use of a pick, FUDR, or high-cost sorting machines. Our transfer procedure uses a filtration device created with common lab supplies, and a standard buffer solution. The conceptual approach is to filter a population of animals through a fine mesh attached to a plastic cap, then rinse off leftover unwanted animals and debris from the mesh into a disposable tube. The device is then flipped over and the selected animals are rinsed off the filter into a collection tube where they can settle by gravity, after which they are pipetted into or onto a fresh media source. We will present data comparing our method to the current pick selection method in terms of percent yield of filtered animals, use in large scale assays, and several health parameters, including motility, pump rate, fecundity, and activation of stress response genes.

Maulik, Malabika et al. (2017) International Worm Meeting "Alaskan Blueberry attenuates alpha-synuclein over expression and improves movement in Parkinson's like model of Caenorhabditis elegans."

Mitra, Swarup, Maulik, Malabika, Taylor, Barbara, Vayndorf, Elena, Hunter, Skyler, Bult-Ito, Abel

[International Worm Meeting, 2017]

Parkinson's disease (PD) is a neurodegenerative disorder characterized by the loss of dopaminergic neurons and aggregation of alpha-synuclein (AS) protein leading to motor and cognitive impairment. The current study investigates the role of Alaskan bog blueberry (Vaccinum uliginosum), on alpha synuclein aggregation using a transgenic model of Caenorhabditis elegans expressing human alpha-synuclein [OW13 (P(unc-54)::alpha-synuclein::YFP+unc-119)].The current study also examines the role of Sirtuin 1, a histone deacetylase, in reducing the toxicity of alpha-synuclein aggregates and whether this effect is mediated via expression of other downstream molecular targets. The Alaskan bog blueberry was chosen for its high phenolic content, because phenolics have been shown to modulate sirtuin-mediated molecular pathways. Our experiments showed that the crude extract of low bog blueberry ( 100 and 400 ug/ml) reduced alpha-synuclein aggregation and improved motility in the worm model. The study also highlights the molecular mechanism through which the botanicals are exerting this beneficial effect. These findings encourage further studies on these Alaskan botanicals as possible therapeutic agents for Parkinson's disease, specifically of interest are the identification of active ingredients within the extracts and their optimal doses.

Nichols, Courtney Rose et al. (2013) International Worm Meeting "A role for the insulin signaling pathway in development of neuronal aging markers in a polyglutamine protein aggregation C. elegans model."

Parker, J. Alex, Nichols, Courtney Rose, Driscoll, Monica, Neri, Christian, Vayndorf, Elena, Taylor, Barbara

[International Worm Meeting, 2013]

Neurodegenerative diseases, such as Huntington's, Alzheimer's, and Parkinson's disease, result in the progressive loss of neuronal structure and function with age. Many neurodegenerative disorders are caused by genetic mutations and characterized by toxic aggregation of proteins within neurons. We explored the mechanism of accelerated neuronal aging in a polyglutamine (polyQ) protein aggregation model through genetic manipulation. Caenorhabditis elegans expressing the first 57 amino acids of human huntingtin protein with a toxic polyglutamine chain (polyQ128) fluorescently labeled with CFP in YFP-labeled mechanosensory neurons (Parker et al, 2001) were used to monitor neuronal aging phenotypes. We found an age-associated increase in aberrant neuronal morphology, protein aggregation, and functional impairment of the mechanosensory neurons expressing toxic 128 polyQ. We also tested the hypothesis that the insulin signaling pathway is involved in morphological and functional health of aging mechanosensory neurons using neuron-specific RNA interference (RNAi). Furthermore, we measured levels of endogenous oxidative stress and lifespan of aging animals that contain toxic polyQ128 repeats following RNAi manipulation of the insulin signaling pathway. Overall, we found that DAF-16/FOXO is neuroprotective in this accelerated aging model, which corroborates previous findings on the role of DAF-16/FOXO in polyQ128 young adults (Parker et al. 2005). To further characterize overall muscle and neuronal health, we measured action potentials of pharyngeal muscle contractions and neurons that innervate the pharynx using microfluidic electropharyngeography (EPG). In total, our observations support that insulin signaling via DAF-16/FOXO is a mechanism through which accelerated aging and neurodegeneration occurs in this model.

Blue, Ben W. et al. (2019) International Worm Meeting "Longevity Over the Counter: Investigating the Effects of Common Dietary Supplements on Aging."

Berry, Faith, Estes, Raja, Blue, Ben W., Pitt, Jason, Kim, Young-Woo, Vayndorf, Elena, Nikjoo, Arash, Kaeberlein, Matt, Pothan, Lincoln

[International Worm Meeting, 2019]

C. elegans has been a workhorse within the field of aging biology due to its short lifespan, easy culturing, and robust genetic tools. However, one major limiting factor in using C. elegans has been that throughput was constrained by the time and effort needed to manually check each worm for signs of life during longitudinal studies. By using the WormBot, a high-throughput robotic image capture platform, we were able to accurately and quickly screen a wide array of compounds for their effects on C. elegans lifespan. A single WormBot can monitor 144 individual experiments at once and, when coupled with an image analysis package, allows for accurate time of death calls. Here we present data generated with the WormBot that includes a screen of compounds from a wide array of natural and synthetic products. Supplements and multivitamin/minerals (MVMs) were a ~36 billion dollar industry in 2014 but are not subject to the same regulatory standards that FDA-approved drugs are. In order to better examine the effects of these widely-used compounds upon the aging process we examined longevity in a wildtype strain of C. elegans (N2) as well as an engineered strain (GMC101) that expresses human A? protein in the body wall muscle. The age-related pathogenesis of the A?-expressing strain is a progressive paralysis. As such, we screened our battery of compounds to determine which compounds have a significant effect on delaying GMC101's A?-associated paralysis. Lastly, using the WormBot's ability to capture video recording alongside time-lapse photography, we examine how each compound affects the healthspan of the different genetic models by using the WormBot's ability to capture high-resolution videos and then analyzing animal motility.