SLC26A6 and SLC26A7 Anion Exchangers Have a Distinct Distribution in Human KidneyKujala M. · Tienari J. · Lohi H. · Elomaa O. · Sariola H. · Lehtonen E. · Kere J.
aDepartment of Medical Genetics, University of Helsinki; bDepartment of Urology, Helsinki University Central Hospital, Helsinki; cDepartment of Pathology, Helsinki University Central Hospital/Peijas Hospital and HUSLAB, Vantaa; dInstitute of Biomedicine, Developmental Biology, University of Helsinki, and HUCH Laboratory Diagnostics, Helsinki University Hospital; eDepartment of Pathology, Haartman Institute and Helsinki University Central Hospital, University of Helsinki, Helsinki Finland, and Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, Calif., USA; fDepartment of Biosciences at Novum, Karolinska Institutet, Stockholm, Sweden
Background: The anion transporters SLC26A6 (PAT1) and SLC26A7, transporting at least chloride, oxalate, sulfate and bicarbonate, show a distinct expression and function in different mammalian species. They are expressed in kidney, but their exact localization in human kidney has not been studied. We therefore examined SLC26A6 and A7 expression in human kidneys. Methods: The localization of SLC26A6 and A7 in different segments of human nephrons was studied by RT-PCR and immunohistochemistry by comparing to the tubular markers PNRA, CD10, Tamm-Horsfall antigen, high molecular weight cytokeratin, CK7, AQP2 and H+V-ATPase. Results: In human kidney, SLC26A6 is expressed in distal segments of proximal tubules, parts of the thin and thick ascending limbs of Henle’s loops, macula densa, distal convoluted tubules and a subpopulation of intercalated cells of collecting ducts. SLC26A7 is expressed in extraglomerular mesangial cells and a subpopulation of intercalated cells of collecting ducts. Conclusion: Our results show that in human kidney SLC26A6 and A7 have a distinct, partially overlapping expression in distal segments of nephrons. The distribution partly differs from that found previously in rodent kidneys.