Vishwaas Gangeddula
Pronouns: He/Him
Research Mentor(s): Brian Byrd
Co-Presenter: Mughal, Rayan
Research Mentor School/College/Department: Medicine / Cardiology / Medicine
Presentation Date: April 20
Presentation Type: Poster
Session: Session 3 – 1:40pm – 2:30 pm
Room: League Ballroom
Authors: Vishwaas R. Gangeddula, Rayan Mughal, Satish Rao, J. Brian Byrd
Presenter: 45
Abstract
In short-term, controlled studies, the effects of sodium on the human body include an increase in blood pressure. However, the mechanisms of sodium-induced hypertension in humans are only partially understood. Uromodulin, the most abundant glycoprotein in healthy human urine, is produced in the thick ascending loop of Henle cells in the kidney. A small proportion of uromodulin enters the serum. Low serum uromodulin levels correlate with mortality, inversely related to hypertension, and salt affects the aggregation of uromodulin. Therefore, we hypothesize that uromodulin-protein interactions are relevant to the hypertension phenotype and are a function of dietary salt intake. To determine uromodulin’s interactions with serum proteins, we employed Sepharose-immobilized uromodulin as an affinity ligand. Uromodulin isolated from the 24-hour urine of healthy volunteers enrolled in the clinical trial Sodium Diet Effect on Aldosterone and Urinary RNA (SALTY) was immobilized on Sepharose, loaded with serum proteins, washed and eluted using buffers with 250 mM and 500 mM of sodium chloride. Mass spectrometry was used to identify eluted serum proteins that interacted with uromodulin. Metaboanalyst 5.0 and Database for Annotation, Visualization, and Integrated Discovery (DAVID) were used to visualize the proteomic data. A total of 296 proteins were identified, of which 29 proteins were present in higher abundance in the 500 mM NaCl eluates indicating a stronger interaction with uromodulin compared with the other 267 proteins. Alpha-2-macroglobulin, cytoplasmic actin-1, apolipoprotein A-I, apolipoprotein A-II, transthyretin, cathepsin B, and hemopexin were found to be in the highest abundance across all eluates. Further, Protein-glutamine gamma-glutamyltransferase E (TGM3), was the most differentially bound protein – showing up in higher abundance in the 500 mM NaCl eluates. The methods development and the nature of uromodulin interactions with proteins including TGM3 are discussed. We conclude that Sepharose-immobilized uromodulin affinity chromatography provides a reliable tool for the identification of specific, dysregulated pathways that potentially mediate sodium-induced hypertension in presence of excess salt.
Biomedical Sciences, Interdisciplinary
