Week 10 Summer Undergraduate Research Showcase AMGEN 1- 3:30
Wednesday, August 30 3:30PM – 5:00PM
Location: Online - Live
The Zoom event has ended.
Presentation 1
CHARLOTTE G. GEORGE, Pratiti Dasgupta, Yuka McGrath, Amjad Askary
Identifying Developmentally Distinct Classes of Retinal Progenitors using Spatial Gene Expression Profiling
Glaucoma, one of the leading causes of vision loss, is a disorder principally caused by progressive degeneration of retinal ganglion cells (RGCs) in the eye. Developing methods to regenerate RGCs could be a key to treating glaucoma and other retinal degenerative disorders, but it is currently unclear how to reliably generate RGCs. Retinal progenitor cells (RPCs) are responsible for producing all retinal neurons in a spatially and temporally coordinated manner to form the retina during embryonic development. Based on previous lineage tracing results, we hypothesize that there are subpopulations of RPCs with distinct fate biases, characterized by a combination of their gene expression profile and spatial context. Identifying these subpopulations could allow us to generate different retinal cell types more efficiently. Using sequential Fluorescence In Situ Hybridization (seqFISH), we aim to map spatial patterns of 33 candidate genes with highly variable expression in RPCs in the embryonic mouse retina. seqFISH provides both transcript counts and spatial features of individual RPCs, enabling identification of subpopulations that may not be evident based on gene expression profile alone. Our seqFISH results show that many of the candidate genes have distinct spatial distribution across the retina. This suggests that RPCs with specific transcriptional profiles could also have specific positional tendencies, which could be sufficient to delineate RPC subtypes. If RPC subpopulations are characterized and subsequently associated with the generation of specific retinal cell types, this discovery could be crucial in improving cell replacement therapies for glaucoma as well as other optic neuropathies.
Presentation 2
ELISE TAHTI, Moe Ishihara, Aimee Wu, Tala Ayoub, Lily Wu
The Inhibitory Effects of Statins on Triple-Negative Breast Cancer
Triple-negative breast cancer (TNBC) makes up 15-20% of all breast cancer diagnoses and is associated with a lower survival rate and higher levels of metastasis, in part due to its resistance to typical methods of targeted therapy. TNBC – alongside other cancers like neuroendocrine prostate cancer and clear cell renal cell carcinoma (ccRCC) – has been shown to be inhibited by statins, drugs that target HMG CoA reductase (HMGCR) to treat hypercholesterolemia. The mechanism of action of statins in the context of cancer is unclear in the current literature. In this study, we investigated the impacts of eight statins on four human breast cancer cell lines to determine which is the most effective and better understand their mechanism by comparing it to our previous work with statins and ccRCC. As expected, cell growth of all TNBC cell lines was selectively inhibited by statin treatment over other less aggressive breast cancer types in MTS assays, with Pitavastatin imparting the largest effect. We also observed the impact of hypoxia on statin sensitivity, as our past model has shown the hypoxia program to be connected to statin response. Lastly, we profiled various markers for epithelial-to-mesenchymal transition, hypoxia, metastasis, and HMGCR expression in these cell lines with qPCR and Western Blotting. These results were relatively inconclusive and will require further investigation. This study overall provides more insight into the inhibitory action of statins in TNBC, as well as serving as a wider collective resource for future therapeutic development.
Presentation 3
ARDEN W. CLAUSS, Niko W. Vlahakis, Jose A. Rodriguez
Improving Electron Diffraction Methods by Accounting for Beam-Induced Lattice Reorientation
Electron diffraction presents a new approach to the determination of high-resolution bimolecular structures. Atomic resolution structures determined from microcrystals by electron diffraction (MicroED) offer new perspectives into biochemical processes such as the interactions between enzymes and inhibitors, including the conformation and binding behaviors at inhibitor-enzyme interfaces. In particular, microED of inhibitor-soaked crystals has potential as a high throughput method due to more facile diffusion and lower crystal size thresholds than analogous x-ray diffraction (XRD) methods. However, conformational analysis of small inhibitors in large proteins is greatly limited by lower data quality and higher errors than in XRD. While dynamical scattering and radiation damage are the conventional concerns in microED, there are many factors to consider. We hypothesize that identifying and accounting for conventionally overlooked phenomena that limit apparent diffraction data quality will minimize error and lead to more accurate resolution of interesting structural qualities of molecules. Using a wide range of test samples, we studied a physical variation in diffraction patterns consistent with a changing orientation of a subset of the crystal lattice induced in stationary crystals by incident electrons. The results of this analysis will present a roadmap for improvement of MicroED data and the more accurate determination of biologically relevant molecular structures.
Presentation 4
MATTHEW R. WILLIAMS, James X. Brown, Bo Li and Lili Yang
The Effects of Creatine Supplementation on Dendritic Cell Activation
The depletion of metabolic precursors within the tumor microenvironment (TME) is a major obstacle for responding immune cells in the suppression of tumor progression. Tumors evolve to take advantage of cellular processes and signaling pathways that lead to cellular exhaustion; however it’s been shown that creatine supplementation can regulate the activation of CD8 T cells by creating an intracellular energy buffer and can result in decreased tumor growth in mouse melanoma models. We hypothesize that creatine also plays a role in the activation of dendritic cells, therefore providing a strategy for increasing the efficiency of tumor detection and antitumor response. We monitored dendritic cell activation by looking at common activation markers at both the transcriptional and translational level in order to determine whether creatine is a viable method for activation, which we propose results from an increase in ATP availability. Our early results show encouraging trends in the enhancement of DC activation in response to creatine supplementation, which follows those observed in ATP-supplemented cells. These findings suggest promise in our continued investigation into the role that creatine plays as a regulator in immune activation in the TME and beyond.
Presentation 5
ZILI QIU, Jielu Hao, and Jinghua Hu
A Novel Role for HNF-1β in Cilia-mediated Senescence Initiation in Stressed Renal Tubular Proximal Epithelial Cells
Cellular senescence is a permanent growth arrest process that diminishes the regenerative capability of injured organs, including the kidneys. Senescent cells can aggravate kidney injury by releasing uncontrolled pro-inflammatory senescent-associated-secretory phenotype (SASP). How cellular senescence is initiated in mammalian cells remain poorly understood. We previously demonstrated that the translocation of a ciliary protein, FBF1, to promyelocytic leukemia nuclear bodies (PML-NBs) is crucial for inducing senescence in stressed human kidney epithelial cells. If and how FBF1-mediated senescence is implicated in kidney injury and repair remain unclear. In this research, we established an in vitro kidney injury model by exposing mouse kidney proximal tubular epithelial cells (BUMPT) to various stressors, including irradiation, cisplatin, or hypoxia, to induce injury and cellular senescence. We observed significant upregulation of HNF1β, a transcription factor known to be important in the development and maintenance of renal tubular epithelial cells. Intriguingly, HNF1β was found to colocalize with PML-NBs and interact with FBF1 in stressed cells. We further confirmed that HNF1β regulates the expression of senescence marker genes p16, p21, and RB1. Depleting FBF1 disrupted the stress-induced transcriptional activity of HNF1β and the initiation of senescence. In summary, these discoveries unveil a direct communication between sensory cilia and the nuclear HNF1β pathway during kidney injury-induced senescence. This highlights the potential of targeting cilia as a promising therapeutic approach for managing senescence-related kidney diseases in the future.