Author
QIAN, XIAOQIAN - EMORY UNIVERSITY, SCHOOL OF MEDICINE | |
LI, XUECHEN - EMORY UNIVERSITY, SCHOOL OF MEDICINE | |
O ILORI, TITILAYO - COLLABORATOR | |
KLEIN, JANET - EMORY UNIVERSITY, SCHOOL OF MEDICINE | |
HUGHEY, REBECCA - UNIVERSITY OF PITTSBURGH | |
Li, Congjun - Cj | |
ABDEL, ALLI - EMORY UNIVERSITY, SCHOOL OF MEDICINE | |
SONG, XIANG - EMORY UNIVERSITY, SCHOOL OF MEDICINE | |
CHEN, GUANGPING - EMORY UNIVERSITY, SCHOOL OF MEDICINE |
Submitted to: Frontiers in Physiology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 7/28/2015 Publication Date: 9/17/2015 Citation: Qian, X., Li, X., O Ilori, T., Klein, J.D., Hughey, R.P., Li, C., Abdel, A.A., Song, X., Chen, G. 2015. RNA-Seq analysis of glycosylation related gene expression in STZ-induced diabetic rat kidney. Frontiers in Physiology. doi: 10.3389/fphys.2015.00274. Interpretive Summary: The UT-A1 urea transporter is crucial to the kidney’s ability to generate concentrated urine. In diabetes, UT-A1 protein abundance is significantly increased corresponding to an increased urea permeability in perfused kidney inner medulla tubes, which plays an important role in kidney function. Using RNA sequencing, genes involved in the process of UT-A1 protein were analyzed. The key genes identified from RNA-seq were further verified by a quantitative PCR. We conclude that the alteration of these glycosylation related genes may contribute to changing the UT-A1 glycan structure, and therefore modulate kidney urea transport activity under diabetic conditions. Technical Abstract: The UT-A1 urea transporter is crucial to the kidney’s ability to generate the concentrated urine. Native UT-A1 from kidney inner medulla (IM) is a heavily glycosylated protein with two glycosylation forms of 97 and 117 kDa. In diabetes, protein abundance, particularly the 117 kD isoform, is significantly increased corresponding to an increased urea permeability in perfused IM tubes, which plays an important role in preventing the osmotic diuresis caused by glucosuria. In this study, by using sugar-specific binding lectins, we found that the carbohydrate structure of UT-A1 is also changed under the diabetic conditions with increased amounts of sialic acid, fucose and increased glycan branching. These changes were accompanied by an alteration of UT-A1 association with galectin proteins, a group of a-galactoside glycan binding proteins. To explore the molecular basis of the alterations of glycan structures, we sought to employ a highly sensitive next generation sequencing (NGS) technology Illumina RNA-seq to analyze genes involved in the process of UT-A1 glycosylation from streptozotocin (STZ) - induced diabetic rat kidney. A number of important glycosylation related genes have been changed under diabetic conditions. These genes include sialylation enzymes St3gal1, St3gal4, St6Gal1 and Neu1, fucosyltransferase Fut8 and galectin-1, -3, -8 and -9. In contrast, the glycosyltransferase gene Mgat1, Mgat2, Mgat3 and Mgat4b did not show any changes. The key genes identified from RNA-seq were further verified by a quantitative PCR. We conclude that the alteration of these glycosylation related genes may contribute to changing the UT-A1 glycan structure, and therefore modulate kidney urea transport activity under diabetic conditions. |