15:30 - 17:00
Fri-P2
Planck Lobby & Meitner Hall
Expression of ENaC regulators in δ-ENaC positive cultured adult human fungiform (HBO) taste cells
Fri-P2-122
Presented by: Vijay Lyall
Vijay Lyall 1, Sunila Mahavadi 2, Shobha Mummalaneni 1, Mehmet Hakan Ozdener 3
1 Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, VA., 2 Department of Biology, Center for Biomedical Research, Tuskegee University, Tuskegee, AL., 3 Monell Chemical Senses Center, Philadelphia, PA
In addition to α, β, and γ subunits of ENaC, human salt-sensing taste receptor cells (TRCs) also express the δ-subunit. We used human fungiform taste papillae (HBO) cell culture model along with molecular and imaging techniques to investigate if the expression and function of ENaC δ-subunit in human salt-sensing TRCs is also modulated by the ENaC regulatory hormones and intracellular signaling effectors known to modulate salt responses in rodent TRCs. Our results show that: (i) ENaC subunits are expressed in a subset of type II human taste cells; (ii) TRPV1, ACE2, MASR1, AT1R, GPER1, and CALHM1/3 are expressed in human taste cells; (iii) TRPV1 co-localizes in human taste cells that express the ENaC δ-subunit; (iv) Modulating TRPV1 activity by high salt and capsaicin altered ENaC mRNA expression; (v) Some of the ENaC regulators are most likely present in a complex, and that changes in the expression of one or more regulators can alter the expression of other effectors; We hypothesize that changes in ACE2 expression in human fungiform taste cells can alter the balance between the two major RAAS pathways, ACE1/Ang II/AT1R and ACE2/Ang-(1-7)/MASR, leading to changes in ENaC expression and responses to NaCl. Supported by VCU CCTR and VETAR grants to VL and an independent VETAR grant to SM.