RNA-Seq Analyses Reveal Roles of the HVCN1 Proton Channel in Cardiac pH Homeostasis.

The voltage-gated proton channel HVCN1 is a member of the voltage-gated ion channel family. HVCN1 channel controls acid extrusion and regulates pH homeostasis in various cell types. Recent evidence indicated that the HVCN1 channel was associated with cardiac function.

Common food additive carrageenan stimulates Wnt/ β-catenin signaling in colonic epithelium by inhibition of nucleoredoxin reduction.

Exposure to the common food additive carrageenan was previously associated with increased Wnt9A expression and increased cytoplasmic β-catenin in human colonic epithelial cells. In this report, exposure of human colonic epithelial cells in culture and of mouse colonic epithelium in vivo to low concentrations of carrageenan is shown to activate the Wnt/β-catenin signaling pathway, leading to increases in nuclear β-catenin, T-cell factor/lymphoid enhancer factor activation, and cyclin D1 expression and decline in bone morphogenetic protein-4. These effects are mediated through carrageenan-induced reactive oxygen species (ROS), and inhibited by the ROS scavenger Tempol.

Impact of salt exposure on N-acetylgalactosamine-4-sulfatase (arylsulfatase B) activity, glycosaminoglycans, kininogen, and bradykinin.

N-acetylgalactosamine-4-sulfatase (Arylsulfatase B; ARSB) is the enzyme that removes sulfate groups from the N-acetylgalactosamine-4-sulfate residue at the non-reducing end of chondroitin-4-sulfate (C4S) and dermatan sulfate (DS). Previous studies demonstrated reduction in cell-bound high molecular weight kininogen in normal rat kidney (NRK) epithelial cells when chondroitin-4-sulfate content was reduced following overexpression of ARSB activity, and chondroitinase ABC produced similar decline in cell-bound kininogen. Reduction in the cell-bound kininogen was associated with increase in secreted bradykinin.