Romika Shokorzadeh Shokohi
Pronouns: she/her
Research Mentor(s): Ruma Banerjee
Research Mentor School/College/Department: Biological Chemistry / Medicine
Program:
Authors:
Session: Session 7: 4:40 pm – 5:30 pm
Poster: 37
Abstract
Hydrogen sulfide (H2S) is a signaling molecule that regulates many physiological processes in the mammalian cardiovascular, nervous, and gastrointestinal systems. Intestinal cells are routinely exposed to 0.2-2.4 mM sulfide arising from the interplay between dietary intake of sulfur-containing compounds and gut microbial metabolism. Low levels of H2S stimulate respiration at the mitochondrial electron transport chain (ETC). However, high levels of H2S inhibit respiration by binding to a copper-containing site in complex IV of the ETC. Preliminary data from the Banerjee laboratory show that H2S also reduces protein levels of both copper-containing complex IV subunits, namely MTCO1 and MTCO2, in an epithelial colon adenocarcinoma cell line (HT29). Additionally, high levels of H2S increase the abundance of the copper-binding protein Copper Chaperone for Superoxide dismutase (CCS), an indicator of functional copper deficiency. Paradoxically, sulfide increases cellular copper levels. In this study, we test the hypothesis that chronic sulfide exposure induces functional copper deficiency across different cell lines, which is signaled via increased CCS protein levels and results in decreased protein amounts of copper-containing complex IV subunits. Protein amounts in control vs sulfide-treated cells are determined via Western Blotting. First, whole cell protein is extracted and quantified via Bradford analysis. Protein lysates are separated according to size and transferred to a membrane for detection using protein-specific antibodies. Chemiluminescence imaging is used to quantify the amount of protein present in control and sulfide-treated cells. A consistent increase in CCS as well as a decrease in MTCO2 protein was observed in sulfide-treated endothelial cells (EA.hy926), hepatoma cells (HepG2) and osteosarcoma cells (143B). Taken together, our data show that sulfide impacts copper metabolism across different cell lines.
