Adenosinergic Signaling Inhibits Oxalate Transport by Human Intestinal Caco2-BBE Cells Through the A2B Adenosine Receptor.

Adenosinergic Signaling Inhibits Oxalate Transport by Human Intestinal Caco2-BBE Cells Through the A2B Adenosine Receptor. Am J Physiol Cell Physiol. 2018 Jul 18;: Authors: Jung D, Alshaikh A, Ratakonda S, Bashir M, Amin MR, Jeon S, Stevens J, Sharma S, Ahmed W, Musch M, Hassan H Abstract Most kidney stones (KS) are composed of calcium oxalate, and small increases in urine oxalate affect the stone risk. Intestinal oxalate secretion mediated by anion exchanger SLC26A6 (PAT1) plays a crucial role in limiting net absorption of ingested oxalate; thereby preventing hyperoxaluria and related KS, reflecting the importance of understanding regulation of intestinal oxalate transport. We previously showed that ATP and UTP inhibit oxalate transport by human intestinal Caco2-BBE cells (C2). Since ATP is rapidly degraded to adenosine (ADO), we examined whether intestinal oxalate transport is regulated by ADO. We measured 14C-oxalate uptake in the presence of an outward Cl gradient as an assay of Cl-oxalate exchange activity, {greater than or equal to} 49% of which is PAT1-mediated in C2 cells. We found that ADO significantly inhibited oxalate transport by C2 cells, an effect completely blocked by the nonselective ADO receptor antagonist 8-SPT. ADO also significantly inhibited oxalate efflux by C2 cells, which is important since PAT1 mediates oxalate efflux in vivo. Using pharmacological antagonists and A2B adenosine receptor (A2B AR) siRNA knockd...
Source: Am J Physiol Cell Ph... - Category: Cytology Authors: Tags: Am J Physiol Cell Physiol Source Type: research