• Developmental Biology of Zebrafish and Integration of Transgenic Lines to Study Microglia in Perspective of Glioblastoma

      O'Keefe, Anabelle; McCartney, Katherine; Kandepu, Umasai; Rajpurohit, Surendra; Biological Sciences; Department of Biochemistry and Molecular Biology; Rajpurohit, Surendra; Augusta University (1/31/2020)
      Glioblastoma is a vicious cancer of the brain that is extremely invasive. Our innovative approach to studying glioblastoma utilizes zebrafish as model for scientific study because of their affordable maintenance, transparent body plan during embryo and larval stages, and genomic accessibility. We aim to use zebrafish as an organismal model to study how glioblastoma and microglial cells interact in the neural region. To achieve this, we are developing an all-encompassing in-vivo transgenic and transparent zebrafish modeling system to study microglia function and manipulation in the context of adverse conditions such as glioblastoma and inflammation. Microglia are the resident macrophages found in zebrafish and humans located along the central nervous system in the brain and spinal cord. These cells support the immune system by cleaning any foreign debris. The model will integrate Microglia, NF-kB, and Annexin-5 transgenic lines displaying which genes in the brain are activated via their corresponding fluorescent protein upon the introduction of glioblastoma. Furthermore, a mutant Casper line of zebrafish will introduce a transparent characteristic in adult zebrafish that allows for simpler visualization and observation in the final model. Ultimately, the transgenic model will utilize microglia cells as a mechanism to approach glioblastomas.

      Chakraborty, Ananya; Halder, Bithika; Mondal, Souravi; Gabor Csanyi; Biological Sciences; Vascular Biology Center; Pharmacology and Toxicology; Maria Sabbatini; Augusta University (1/31/2020)
      Pancreatic ductal adenocarcinoma (PDAC) is a type of exocrine cancer that accounts for almost all cases of pancreatic cancer. Many studies show that chronic pancreatitis (CP), a long-term inflammation of the pancreas, is considered as the greatest risk factor for developing pancreatic cancer. We found that reactive oxygen species (ROS) generated by NADPH oxidase 1 (Nox1) in pancreatic stellate cells (PaSCs) mediate the fibrogenic process in CP. PaSCs are a class of pancreatic cells that, in the stroma surrounding pancreatic cancer cells, are known to facilitate cancer cell invasion. We found that the lack of Nox1 in PaSCs decreased the invasion of three different pancreatic cell lines using two approaches: transwell cell invasion and culture wound closure assays. The lack of Nox1 also decreased the expression of matrix metalloproteinase 9, which is an enzyme that breaks down the basal lamina, facilitating cell invasion. Using mass spectroscopy, we will assess the extent to which the lack of Nox1 in PaSCs affects the production of pro-migratory and pro-invasive proteins using mass spectroscopy. These results implicate Nox1 inhibitors as a potential therapeutic drug to impede the progression of CP to PDAC.

      Zimmerman, Matthew; Bennetts, Stacy; Biological Sciences; Bennetts, Stacy; Augusta University (1/31/2020)
      Pediomelum piedmontanum, Dixie Mt. Breadroot, is a rare legume species that was discovered in 2006. Currently, there are only three known populations, which are growing in either serpentine or phyllite soil. Both soil types contain extremely high concentrations of Mg as well as some other heavy metals. Previous experiments have revealed that propagation of P. piedmontanum is unsuccessful in potting soil, with high levels of mortality approximately two months after germination. Since Mg is unusually high in both soil types, it was hypothesized that survivability and growth of seedlings would be greater with Mg enriched soil than in potting soil. In order to test this hypothesis, seedlings from a phyllite population (7 plants/pot with 3 replicate pots/Mg group and 2 pots/control) were transplanted into one of the following potting soil enrichments: 50μM MgSO4, 100μM MgSO4 or controls with no Mg enrichment. During 12 weeks, seedlings in 100μM Mg displayed the greatest survivability and shoot growth, with the lowest survivability in control pots. Atypical Mg requirements have been noted in the literature for some plants adapted to serpentine soil, but this is a unique discovery for a population adapted to phyllite.
    • Diabetes Attenuation of the Estrogen-Mediated Increase in Endothelial Function is Associated with Circulating SIRT1

      O'Bryant, Sinead; Casey Derella; Thomas, Jeff; Looney, Jacob; Bleck, Marie-Rose; Harris, Ryan; Biological Sciences; Department of Medicine; Georgia Prevention Institute; Ryan Harris; et al. (1/15/2020)
      Cardiovascular disease (CVD) is the most prominent killer within Type 1 Diabetes (T1D) with endothelial dysfunction as a major player in the development of CVD. Women with T1D experience an accelerated CVD risk despite the apparent sex-specific cardio-protection by circulating endogenous estrogen experienced by heathy premenopausal women. Animal models have shown the modulation of SIRT1, a NAD+ histone deacetylase, by estrogen as a CVD protector. This study sought to test the hypothesis that lower circulating SIRT1 is associated with reduced endothelial function in T1D women. Change in flow mediated dilation (FMD), a clinical measure of endothelial function, and SIRT1 over the menstrual cycle exhibited contrasting trends between T1D women and healthy women: increases of FMD and SIRT1 as estrogen increases in healthy women and decreases of FMD and SIRT1 as estrogen increases in T1D women, providing evidence that signaling roles by circulating estrogen may be attenuated in T1D and the effects of decreased SIRT1 contributes to endothelial dysfunction, resulting in determinant effects on vascular health in T1D women.