Renal expression and localization of SLC9A3 sodium/hydrogen exchanger and its possible role in acid-base regulation in freshwater rainbow trout (Oncorhynchus mykiss)

Abstract

Ivanis G, Braun M, Perry SF. Renal expression and localization of SLC9A3 sodium/hydrogen exchanger and its possible role in acid-base regulation in freshwater rainbow trout (Oncorhynchus mykiss). Am J

Physiological and molecular responses of the goldfish kidney (Carassius auratus) to metabolic acidosis, and potential mechanisms of renal ammonia transport

“…In support of this model, previous work has demonstrated the localization of Rhcg-b to the distal tubule and CD in teleosts (see Introduction), with additional weak expression in the proximal tubules, at least in carp (Wright et al, 2014). HAT has been localized to the apical membranes of the proximal tubules (Perry and Fryer, 1997;Ivanis et al, 2008a). HAT activity was not affected by acidosis in the present study (Table 3), but its activity in the goldfish kidney was much higher than previously reported in the goldfish gill (Sinha et al, 2013) where ammonia excretion rates were ∼20-to 50-fold greater (Maetz, 1972;Sinha et al, 2013) than observed here.…”

“…Cooper et al (2013) demonstrated a similar profile in the distal tubule of the mangrove killifish where Rhcg-b and a Na + /H + exchanger (NHE3) are on the apical membrane with a basolateral NKA. Apical NHE3 also colocalizes with an apical V-type H + -ATPase (HAT) and basolateral NKA in the proximal tubules of rainbow trout (Ivanis et al, 2008a). These observations suggest the presence of a Na + -coupled mechanism of renal ammonia secretion similar to that of the gills ).…”

Rh vs pH: the role of Rhesus glycoproteins in renal ammonia excretion during metabolic acidosis in a freshwater teleost fish

“…Proteins were transferred to Hybond-P ECL membranes and probed overnight with either rabbit anti-zebrafish Rhesus glycoprotein c1 polyclonal (zfRhcg1 Ab740, diluted 1:500) (Nakada et al, 2007), rabbit anti-Na + /K + -ATPase α subunit affinity purified polyclonal (αR1, 1:5000) , mouse anti-Na + :K + :2Cl -cotransporter (NKCC) monoclonal (clone T4, 1:500) (Lytle et al, 1995), rabbit anti-human carbonic anhydrase 2 (CA) polyclonal (1:5000; Abcam, UK), rabbit anti-H + -ATPase B subunit affinity purified polyclonal (B2, 1:1000) , rabbit anti-sodium/proton exchangers 2 (NHE2R15, 1:500) (Ivanis et al, 2008a;Ivanis et al, 2008b) and 3 (NHE3R18, 1:500) (Ivanis et al, 2008a;Ivanis et al, 2008b), mouse anti-heat shock protein 70 (hsp70) monoclonal (clone BRM-22, 1:10,000; Sigma-Aldrich), or mouse anti-α tubulin monoclonal (clone 12G10, 1:500, used as a reference protein; Developmental Studies Hybridoma Bank, University of Iowa, Iowa City, IA, USA, under contract N01-HD-7-3263 from the National Institute of Child Health and Human Development). Following probing with an appropriate horseradish peroxidase conjugated secondary antibody, signal was detected by electrochemiluminescence (Immobilon Millipore) using an imager (LAS4000mini, FujiFilm) and bands quantified using Multi-Gauge software (V3.1, FujiFilm).…”

“…In zebrafish, Danio rerio, Rhcg1 was found to be associated with the apical surface of both distal tubules and collecting ducts using immunofluorescence (IF) microscopy (Nakada et al, 2007). IF microscopy studies also showed that Rhcg1 and NHE3 were co-localized in the apical region of Na + /K + -ATPase (NKA)-positive renal distal tubule cells in mangrove rivulus, Kryptolebias marmoratus (Cooper et al, 2013), whereas in rainbow trout, Oncorhynchus mykiss, NHE3 is colocalized with vacuolar-type H + -ATPase in the apical membrane of proximal tubules (Ivanis et al, 2008a). Gene expression of Rhbg was detected in trout and K. marmoratus kidney homogenates Nawata et al, 2007).…”

Differential expression of Na+-Cl−cotransporter and Na+-K+-Cl−cotransporter 2 in the distal nephrons of euryhaline and seawater pufferfishes

“…In contrast to mammals, fish transporters involved in renal Na ϩ and Cl Ϫ reabsorption have not been identified; the exception is Na ϩ /H ϩ exchanger 3 (NHE3), which has been detected in the apical membrane of the proximal tubule of rainbow trout (25) where it may reabsorb Na ϩ . To identify transporters that mediate Na ϩ and Cl Ϫ reabsorption in the distal nephron and compare their expression profiles in freshwater and seawater fishes, the following experiments were designed to take advantage of two very closely related Takifugu species: mefugu (Takifugu obscurus) and torafugu (tiger pufferfish, Takifugu rubripes) (26,28).…”