Life Sciences Commons^™

Assessment Of Tick Antioxidant Responses To Exogenous Oxidative Stressors And Insight Into The Role Of Catalase In The Reproductive Fitness Of The Gulf Coast Tick, Amblyomma Maculatum, D. Kumar, K. Budachetri, V.C. Meyers, Shahid Karim

Faculty Publications

As obligate blood‐sucking ectoparasites, to avoid tissue damage, ticks must neutralize the reactive oxygen species (ROS) generated from uptake and digestion of a bloodmeal. Consequently, ticks utilize a battery of antioxidant molecules, including catalase (CAT), an enzyme that converts hydrogen peroxide (H₂O₂) into water and oxygen. Here, we investigated the tick antioxidant machinery by exogenous injection of sublethal doses of H₂O₂ or paraquat. The relative transcript levels of selected Amblyomma maculatum antioxidant targets in tissues were determined by quantitative reverse transcriptase PCR following treatment. The results showed 2–16‐fold increases in target antioxidant gene …

Hydrogen Peroxide Induced Loss Of Heterozygosity Correlates With Replicative Lifespan And Mitotic Asymmetry In Saccharomyces Cerevisiae, Emine Guven, Lindsay A. Parnell, Erin D. Jackson, Meighan Parker, Nilin Gupta, Jenny Rodrigues, Hong Qin

Scholarly Works

Cellular aging in Saccharomyces cerevisiae can lead to genomic instability and impaired mitotic asymmetry. To investigate the role of oxidative stress in cellular aging, we examined the effect of exogenous hydrogen peroxide on genomic instability and mitotic asymmetry in a collection of yeast strains with diverse backgrounds. We treated yeast cells with hydrogen peroxide and monitored the changes of viability and the frequencies of loss of heterozygosity (LOH) in response to hydrogen peroxide doses. The mid-transition points of viability and LOH were quantified using sigmoid mathematical functions. We found that the increase of hydrogen peroxide dependent genomic instability often occurs …

Characterization Of Hemerythrin-Like Protein Rv2633c, Michelle D. Cherne

Honors Undergraduate Theses

Hemerythrin-like protein Rv2633c is a small 18 kDa protein that is expressed in Mycobacterium tuberculosis (Mtb). Sequence analysis of Rv2633c predicts the presence of a hemerythrin-like domain, which binds dioxygen using a µ-oxo-bridge (Fe-O-Fe), rather than a heme group. Though it is noticeably upregulated during macrophage infection and during in vitro acidification, the role of Rv2633c in Mtb survival has yet to be elucidated. This project aims to characterize the function of Rv2633c by studying the in vitro response of the recombinant protein to conditions present in the macrophage lysosome, such as reduced oxygen levels or the …

High Glucose Induces Reactivation Of Latent Kaposi’S Sarcoma-Associated Herpesvirus, Fengchun Ye, Yan Zeng, Jingfeng Sha, Tiffany Jones, Kurt Kuhne, Charles Wood, Shou-Jiang Gao

Nebraska Center for Virology: Faculty Publications

High prevalence of Kaposi’s sarcoma (KS) is seen in diabetic patients. It is unknown if the physiological condition of diabetes contributes to KS development. We found elevated levels of viral lytic gene expression when Kaposi’s sarcoma-associated herpesvirus (KSHV) infected cells were cultured in high glucose medium. To demonstrate the association between high glucose and KSHV replication, we xeno29

grafted telomerase-immortalized human umbilical vein endothelial cells that are infected with KSHV (TIVE-KSHV) into hyperglycemic and normal nude mice. The injected cells expressed significantly higher levels of KSHV lytic genes in hyperglycemic mice than in normal mice. We further demonstrated that high …