Cortisol Regulation of Aquaglyceroporin HC-3 Protein Expression in Erythrocytes from the Freeze Tolerant Tree Frog Dryophytes chrysoscelis
Dryophytes chrysoscelis, commonly known as Cope’s gray treefrog, is a freeze tolerant anuran that freezes up to 65% of extracellular fluid during winter to survive. Glycerol is presumably used as a cryoprotectant during a period of cold-acclimation to protect cells from permanent damage due to hypoosmotic stress upon freezing and thawing. The transmembrane movement of glycerol and water is likely mediated through aquaglyceroporin (GLP) 3 ortholog HC-3 in the nucleated erythrocytes (RBCs) of D. chrysoscelis. This thesis analyzes the mechanisms in which D. chrysoscelis prepares for cold-acclimation and glycerol synthesis. Cortisol, a neuroendocrine steroid hormone, is a stress hormone previously shown to respond to osmolarity challenges and regulate aquaporins in teleost fish; however, the role of cortisol in regulating anuran HC-3 protein expression and membrane subcellular localization is yet to be known, and the implications for mediating anticipatory glycerol synthesis and freeze tolerance remain to be determined. We hypothesize that cortisol exposure contributes to enhanced HC-3 protein expression and subcellular localization in the membrane of RBCs from D. chrysoscelis. RBCs were cultured in vitro using complete cell culture media (CCCM) and cortisol for 0, 2, 4, 6, and 8 hours at two separate concentrations, 1.0 μg/ml and 0.1 μg/ml. Another group of RBCs was incubated with CCCM for 24 hours before the 0, 4, and 8-hour incubation with cortisol concentrations of 1.0 μg/ml and 0.1 μg/ml. Western blotting was utilized for quantifying HC-3 protein expression and immunocytochemistry was used to visualize the subcellular localization of the HC-3 protein from the cultured RBCs. The findings gleaned from this thesis provide insight to support human tissue cryoprotection and transplantation.
Carissa M Krane
Primary Advisor's Department
Stander Symposium poster
"Cortisol Regulation of Aquaglyceroporin HC-3 Protein Expression in Erythrocytes from the Freeze Tolerant Tree Frog Dryophytes chrysoscelis" (2019). Stander Symposium Posters. 1758.