A team of researchers in the Haverford Chemistry department are researching Huntington’s Disease, a rare neurodegenerative hereditary disorder that affects motor and cognition. The experiment is led by chemistry professor Leah Seebald and biology professor Robert Fairman. Senior Abby Olivier 25’ is conducting her thesis on it and sophomore Seth Anderson 27’ assists primarily with manual tasks within the lab.
After Olivier graduates this spring with a double major in neuroscience and chemistry, she will begin a PhD in Neurobiology and Anatomy at Drexel University and plans to study the effects of head injuries such as sports-related concussions in children. Seebald praised Olivier by saying “I give Abby full credit for developing this project and taking initiative. She chose to approach her thesis in “challenge mode,” and it’s been exciting to have a clear direction and methodology for measuring the toxicity of future molecules, probes, and inhibitors developed in the lab.” Anderson also plans to major in chemistry with a biochemistry concentration and is still deciding what future work he wants to pursue but has enjoyed his current role.
The researchers are measuring the toxicity of a chemical called methylated azirinomycin (AZ1) in a type of worm called C. Elegans. AZ1 has a similar chemical structure to molecules present in the 2H-Azirine probe, which is a probe with an added fluorescent tag that scientists can use to learn more characteristics about the disease. Although the probe is unlikely to be used in humans, its use in C. Elegans can provide researchers with important insight in regards to the human disease. The researchers chose to use C. Elegans because they share more common gene orthologs and homologs with humans than most other species. Ultimately, they are likely to either show that the chemical is toxic and therefore probes containing similar molecules should only be used in vitro (experiments done outside the living organism with cells and enzymes removed from living organisms) or that the chemical is not toxic and similar probes should continue to be used in living organisms to learn more about Huntington’s disease.
Professor Seebald provided further detail on their choices. “Our lab is interested in the toxicity of azirinomycin and other natural products containing a 2H-azirine moiety. Azirinomycin is the simplest of the nine known natural products that feature this structural motif, yet much remains to be understood about the biological mechanisms of action. Prior work shows that these moieties show promise as covalent probes or covalent inhibitors. By working with C. elegans, we aim to investigate the potential toxicity and other biological effects of 2H-azirine compounds to gain deeper insight into the deleterious effects in living systems.”
To assess toxicity, the group has separated the worms into three random groups and administered them different levels of AZ1: 0.2, 1.0, 5.0 milligrams per milliliter respectively. Given that the worms only live for about three weeks, they administer the molecule during their first week of life and measure the survival rate from there.
The researchers have outlined possible future plans which include to test if AZ1 affects reproduction, test an unclicked probe, and use ABPP to identify more proteins within the disease. Through activity based protein profiling (ABPP), they intend to use click chemistry to track how similarly structured probes and inhibitors interact with proteins in the worms. If the probe can bind with certain disease related proteins, they can better understand the disease at a molecular level. Chemical markers are attached to active proteins, allowing them to be seen under a confocal microscope. Seebald commented further on potential uses of the molecule: “At this stage, it can only be used for toxicity studies, with no further read outs. This is a small piece in a larger puzzle regarding the biological reactivity of 2H-azirine moieties. These studies will lay the groundwork for future probe development by helping us determine whether 2H-azirine-based probes can be used in live systems or if these molecules are limited to in vitro applications.”
Although Olivier will be graduating, Seebald commented on Anderson having a future role in the project: “I’m also thrilled that Seth has shown interest and taken on these demanding tasks and experiments. He has been very hands-on with training, and the project is being passed on to capable hands. It will be interesting to see where the research takes us next.”
The group has yet to come to an official conclusion on the toxicity or additional uses of the probe, as the research is still ongoing but Anderson said that the tests so far (as of April 2nd) have indicated that there is a no significant level of toxicity of the molecule in C elegans, an 100% survival rate among those treated. There were minor effects on egg fertilization, which researchers are still determining the significance of. Anderson says that these are promising signs and that there is a high likelihood that researchers will continue to use the molecule and associated probes and inhibitors in the future.
“I genuinely enjoy working on collaborative projects, and it’s been especially rewarding to work with Rob Fairman. I believe that some of the most impactful scientific discoveries arise when researchers from different fields come together. Collaboration allows us to approach questions from multiple angles, integrate diverse expertise, and develop more innovative solutions. In STEM, meaningful progress often depends on this kind of interdisciplinary partnership,” said Professor Seebald.
“I also really appreciate the initiative Abby showed in developing this project. Without her, I don’t know when we would have started investigating toxicity, but the data she and Seth have gathered so far has been incredibly exciting. Her work has opened up a whole new direction for the lab.”
