Aquaporin 2‐increased renal cell proliferation is associated with cell volume regulation

Giusto, Gisela Di; Flamenco, Pilar; Rivarola, Valeria; Fernández, J. García; Melamud, Luciana; Ford, Paula; Capurro, Claudia

doi:10.1002/jcb.24246

Cited by 21 publications

(22 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Indeed, we demonstrated a few years ago that, in native, isolated perfused, CCDs, induction of PCs to swell by current transfer techniques was immediately followed by cell volume regulation back to control volume states, a process that was dependent upon the Ba 2+ -sensitive apical K + channels [85] that would include ROMK and all K Ca channels. Others have shown that CCD cells in culture undergo regulatory volume decrease upon cell swelling [86] and that cell swelling activates TRP channels to induce Ca 2+ influx in collecting duct cells [43], [86], [87]. Since we have also shown that, in M-1 cells, cell swelling activates TRPV4 and Ca 2+ influx which, in turn, leads to activation of both BK and SK3, it seems reasonable to conclude that swelling states in native CCD and CNT, at least for PCs, leads to activation of both BK and SK3 to effect cell volume regulation.…”

Section: Discussionmentioning

confidence: 99%

Emerging Role of the Calcium-Activated, Small Conductance, SK3 K+ Channel in Distal Tubule Function: Regulation by TRPV4

et al. 2014

View full text Add to dashboard Cite

The Ca2+-activated, maxi-K (BK) K+ channel, with low Ca2+-binding affinity, is expressed in the distal tubule of the nephron and contributes to flow-dependent K+ secretion. In the present study we demonstrate that the Ca2+-activated, SK3 (KCa2.3) K+ channel, with high Ca2+-binding affinity, is also expressed in the mouse kidney (RT-PCR, immunoblots). Immunohistochemical evaluations using tubule specific markers demonstrate significant expression of SK3 in the distal tubule and the entire collecting duct system, including the connecting tubule (CNT) and cortical collecting duct (CCD). In CNT and CCD, main sites for K+ secretion, the highest levels of expression were along the apical (luminal) cell membranes, including for both principal cells (PCs) and intercalated cells (ICs), posturing the channel for Ca2+-dependent K+ secretion. Fluorescent assessment of cell membrane potential in native, split-opened CCD, demonstrated that selective activation of the Ca2+-permeable TRPV4 channel, thereby inducing Ca2+ influx and elevating intracellular Ca2+ levels, activated both the SK3 channel and the BK channel leading to hyperpolarization of the cell membrane. The hyperpolarization response was decreased to a similar extent by either inhibition of SK3 channel with the selective SK antagonist, apamin, or by inhibition of the BK channel with the selective antagonist, iberiotoxin (IbTX). Addition of both inhibitors produced a further depolarization, indicating cooperative effects of the two channels on Vm. It is concluded that SK3 is functionally expressed in the distal nephron and collecting ducts where induction of TRPV4-mediated Ca2+ influx, leading to elevated intracellular Ca2+ levels, activates this high Ca2+-affinity K+ channel. Further, with sites of expression localized to the apical cell membrane, especially in the CNT and CCD, SK3 is poised to be a key pathway for Ca2+-dependent regulation of membrane potential and K+ secretion.

show abstract

Section: Discussionmentioning

confidence: 99%

Emerging Role of the Calcium-Activated, Small Conductance, SK3 K+ Channel in Distal Tubule Function: Regulation by TRPV4

et al. 2014

View full text Add to dashboard Cite

show abstract

“…According to the phylogenetic analysis of Johanson and Gustavsson [18], plant aquaporins are classified into four main subfamilies, widely distributed among higher plants: PIPs (plasma membrane intrinsic proteins), TIPs (tonoplast intrinsic proteins), SIPs (small basic intrinsic proteins), and NIPs (26 kDa intrinsic proteins). The aquaporins are presently and extensively studied, since their importance spans from animal [19] and human physiology [20] to osmo-adaptation of microorganisms [21] and vegetables [22, 23]. The transcripts encoding sugarcane aquaporins have only marginally been described, despite their significant physiological influence and participation in several processes during plant growth and acclimation against biotic and abiotic stresses [24, 25].…”

Section: Introductionmentioning

confidence: 99%

Expression Analysis of Sugarcane Aquaporin Genes under Water Deficit

Silva

Ferreira‐Neto

et al. 2013

Journal of Nucleic Acids

View full text Add to dashboard Cite

The present work is a pioneer study specifically addressing the aquaporin transcripts in sugarcane transcriptomes. Representatives of the four aquaporin subfamilies (PIP, TIP, SIP, and NIP), already described for higher plants, were identified. Forty-two distinct aquaporin isoforms were expressed in four HT-SuperSAGE libraries from sugarcane roots of drought-tolerant and -sensitive genotypes, respectively. At least 10 different potential aquaporin isoform targets and their respective unitags were considered to be promising for future studies and especially for the development of molecular markers for plant breeding. From those 10 isoforms, four (SoPIP2-4, SoPIP2-6, OsPIP2-4, and SsPIP1-1) showed distinct responses towards drought, with divergent expressions between the bulks from tolerant and sensitive genotypes, when they were compared under normal and stress conditions. Two targets (SsPIP1-1 and SoPIP1-3/PIP1-4) were selected for validation via RT-qPCR and their expression patterns as detected by HT-SuperSAGE were confirmed. The employed validation strategy revealed that different genotypes share the same tolerant or sensitive phenotype, respectively, but may use different routes for stress acclimation, indicating the aquaporin transcription in sugarcane to be potentially genotype-specific.

show abstract

“…Due to the sub-second resolution of our method we cannot compare our findings directly with the available literature since both experimental and theoretical approaches involve slow exchange processes or steady state modeling [23,24,25,26]. However, as far as the trafficking of AQP2 is concerned it has already been reported in CD8 cells ( in vitro system as opposed to our ex vivo system) that hypotonic challenge induces internalization of AQP2 [20].…”

Section: Discussionmentioning

confidence: 39%

The Water Permeability Reduction After Successive Hypo-Osmotic Shocks in Kidney Principal Cells is Apically Regulated

Katkova

Baturina

Ilyaskin

et al. 2014

Cell Physiol Biochem

View full text Add to dashboard Cite

Background/Aims: Renal principal cells maintain their intracellular water and electrolyte content despite significant fluctuations of the extracellular water and salt concentrations. Their water permeability decreases rapidly (within a few seconds) after successive hypo-osmotic shocks. Our aim was to investigate the contribution of the apical and basolateral surface to this effect and the potential influence of fast reduction in AQP-2, -3 or -4 plasma membrane content. Methods: Rat principal cells of kidney collecting duct fragments underwent hypo-osmotic challenge applied apically or basolaterally and the regulatory volume decrease (RVD) was measured by the calcein quenching method. The AQP -2, -3 and -4 content of the plasma membrane fraction was quantified by Western blotting. Results: The hypo-osmotic shock applied apically causes rapid swelling with high apparent water permeability and fast RVD. An identical successive shock after 15-20 sec causes significantly lower swelling rate with 3-fold reduction in apparent water permeability. This reaction is accompanied by AQP2 decrease in the plasma membrane while AQP3 and AQP4 are unaffected. The contribution of the basolateral cell surface to RVD is significantly lower than the apical. Conclusion: These results indicate that in principal cells the effective mechanism of RVD is mainly regulated by the apical cell plasma membrane.

show abstract

Aquaporin 2‐increased renal cell proliferation is associated with cell volume regulation

Cited by 21 publications

References 37 publications

Emerging Role of the Calcium-Activated, Small Conductance, SK3 K+ Channel in Distal Tubule Function: Regulation by TRPV4

Emerging Role of the Calcium-Activated, Small Conductance, SK3 K+ Channel in Distal Tubule Function: Regulation by TRPV4

Expression Analysis of Sugarcane Aquaporin Genes under Water Deficit

The Water Permeability Reduction After Successive Hypo-Osmotic Shocks in Kidney Principal Cells is Apically Regulated

Contact Info

Product

Resources

About