TY - JOUR
T1 - Oxalobacter formigenes-derived bioactive factors stimulate oxalate transport by intestinal epithelial cells
AU - Arvans, Donna
AU - Jung, Yong Chul
AU - Antonopoulos, Dionysios
AU - Koval, Jason
AU - Granja, Ignacio
AU - Bashir, Mohamed
AU - Karrar, Eltayeb
AU - Roy-Chowdhury, Jayanta
AU - Musch, Mark
AU - Asplin, John
AU - Chang, Eugene
AU - Hassan, Hatim
N1 - Publisher Copyright:
© 2017 by the American Society of Nephrology.
PY - 2017/3
Y1 - 2017/3
N2 - Hyperoxaluria is a major risk factor for kidney stones and has no specific therapy, although Oxalobacter formigenes colonization is associated with reduced stone risk. O. formigenes interacts with colonic epithelium and induces colonic oxalate secretion, thereby reducingurinary oxalate excretion, via an unknownsecretagogue. The difficulties in sustaining O. formigenes colonization underscore the need to identify the derived factors inducing colonicoxalate secretion.We therefore evaluatedthe effects of O. formigenes culture conditionedmedium(CM) on apical 14C-oxalate uptake by human intestinal Caco-2-BBE cells. Compared with control medium, O. formigenes CM significantly stimulated oxalate uptake (.2.4-fold), whereas CM from Lactobacillus acidophilus did not. Treating the O. formigenes CM with heat or pepsin completely abolished this bioactivity, and selective ultrafiltration of the CMrevealed that the O. formigenes-derived factors have molecular masses of 10-30 kDa. Treatment with the protein kinase A inhibitor H89 or the anion exchange inhibitor 4,4'-diisothiocyano-2,2'- stilbenedisulfonic acid completely blocked the CM-induced oxalate transport. Knockdown of the oxalate transporter SLC26A6 also significantly restricted the induction of oxalate transport byCM. In amousemodel of primary hyperoxaluria type 1, rectal administration of O. formigenes CM significantly reduced (.32.5%) urinary oxalate excretion and stimulated (.42%) distal colonic oxalate secretion. We conclude that O. formigenes-derived bioactive factors stimulate oxalate transport in intestinal cells through mechanisms including PKA activation. The reduction in urinary oxalate excretion in hyperoxaluric mice treated with O. formigenesCMreflects the in vivo retention of biologic activity and the therapeutic potential of these factors.
AB - Hyperoxaluria is a major risk factor for kidney stones and has no specific therapy, although Oxalobacter formigenes colonization is associated with reduced stone risk. O. formigenes interacts with colonic epithelium and induces colonic oxalate secretion, thereby reducingurinary oxalate excretion, via an unknownsecretagogue. The difficulties in sustaining O. formigenes colonization underscore the need to identify the derived factors inducing colonicoxalate secretion.We therefore evaluatedthe effects of O. formigenes culture conditionedmedium(CM) on apical 14C-oxalate uptake by human intestinal Caco-2-BBE cells. Compared with control medium, O. formigenes CM significantly stimulated oxalate uptake (.2.4-fold), whereas CM from Lactobacillus acidophilus did not. Treating the O. formigenes CM with heat or pepsin completely abolished this bioactivity, and selective ultrafiltration of the CMrevealed that the O. formigenes-derived factors have molecular masses of 10-30 kDa. Treatment with the protein kinase A inhibitor H89 or the anion exchange inhibitor 4,4'-diisothiocyano-2,2'- stilbenedisulfonic acid completely blocked the CM-induced oxalate transport. Knockdown of the oxalate transporter SLC26A6 also significantly restricted the induction of oxalate transport byCM. In amousemodel of primary hyperoxaluria type 1, rectal administration of O. formigenes CM significantly reduced (.32.5%) urinary oxalate excretion and stimulated (.42%) distal colonic oxalate secretion. We conclude that O. formigenes-derived bioactive factors stimulate oxalate transport in intestinal cells through mechanisms including PKA activation. The reduction in urinary oxalate excretion in hyperoxaluric mice treated with O. formigenesCMreflects the in vivo retention of biologic activity and the therapeutic potential of these factors.
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U2 - 10.1681/ASN.2016020132
DO - 10.1681/ASN.2016020132
M3 - Article
C2 - 27738124
AN - SCOPUS:85021850916
SN - 1046-6673
VL - 28
SP - 876
EP - 887
JO - Journal of the American Society of Nephrology
JF - Journal of the American Society of Nephrology
IS - 3
ER -