Insulin potentiates AVP-induced AQP2 expression in cultured renal collecting duct principal cells

2005 ◽  
Vol 288 (2) ◽  
pp. F334-F344 ◽  
Author(s):  
Mauro Bustamante ◽  
Udo Hasler ◽  
Olga Kotova ◽  
Alexander V. Chibalin ◽  
David Mordasini ◽  
...  
Keyword(s):  
Protein Expression ◽  
Collecting Duct ◽  
Basal Medium ◽  
Mrna Levels ◽  
Kinase Activation ◽  
Principal Cells ◽  
Inhibitor Analysis ◽  
Mrna And Protein Expression ◽  
Renal Collecting Duct ◽  
Aqp2 Gene

In the renal collecting duct (CD), water reabsorption depends on the presence of aquaporin-2 (AQP2) in the apical membrane of principal cells. AQP2 expression and subcellular repartition are under the control of AVP. Some pieces of experimental evidence indicate that additional hormonal factors, including insulin, may also control AQP2 expression and thereby CD water permeability. We have previously shown that AVP induces endogenous AQP2 expression in cultured mouse mpkCCDcl4 CD principal cells ( 23 ). In the present study, we investigated the effect of insulin on AQP2 expression in mpkCCDcl4 cells. Addition of insulin to the basal medium of cells grown on filters slightly increased AQP2 mRNA and protein expression, whereas insulin potentiated the effect of AVP. The potentiation of AVP-induced AQP2 expression by insulin was abolished by actinomycin D, a transcriptional inhibitor. Analysis of AQP2 protein expression under conditions of AVP washout and/or in the presence of chloroquine, a lysosomal degradation inhibitor, revealed that insulin did not significantly alter AQP2 protein degradation. Inhibition of ERK, p38 kinase, and phosphatidylinositol 3′-kinase (PI 3-kinase) activities prevented the insulin-induced stimulation of AQP2 expression, whereas inhibition of PKC has no effect. Taken together, our results indicate that insulin increased AQP2 protein expression mostly through increased AQP2 mRNA levels in cultured mpkCCDcl4 cells. This effect most likely relies on increased AQP2 gene transcription in response to MAPK and PI 3-kinase activation.

scholarly journals Molecular mechanisms of angiotensin II stimulation on aquaporin-2 expression and trafficking

2011 ◽  
Vol 300 (5) ◽  
pp. F1255-F1261 ◽  
Author(s):  
Chunling Li ◽  
Weidong Wang ◽  
Christopher J. Rivard ◽  
Miguel A. Lanaspa ◽  
Sandra Summer ◽  
...  
Keyword(s):  
Protein Expression ◽  
Signaling Pathways ◽  
Collecting Duct ◽  
Mrna Levels ◽  
Camp Accumulation ◽  
Ang Ii ◽  
Principal Cells ◽  
Aquaporin 2 ◽  
Renal Collecting Duct ◽  
Sodium Regulation

ANG II plays a major role in renal water and sodium regulation. In the immortalized mouse renal collecting duct principal cells (mpkCCDcl4) cell line, we treated cells with ANG II and examined aquaporin-2 (AQP2) protein expression, trafficking, and mRNA levels, by immunoblotting, immunofluorescence, and RT-PCR. After 24-h incubation, ANG II-induced AQP2 protein expression was observed at the concentration of 10−10 M and increased in a dose-dependent manner. ANG II (10−7 M) increased AQP2 protein expression and mRNA levels at 0.5, 1, 2, 6, and 24 h. Immunofluorescence studies showed that ANG II increased the apical membrane targeting of AQP2 from 30 min to 6 h. Next, the signaling pathways underlying the ANG II-induced AQP2 expression were investigated. The PKC inhibitor Ro 31–8220 (5 × 10−6 M) and the PKA inhibitor H89 (10−5 M) blocked ANG II-induced AQP2 expression, respectively. Calmodulin inhibitor W-7 markedly reduced ANG II- and/or dDAVP-stimulated AQP2 expression. ANG II (10−9 M) and/or dDAVP (10−10 M) stimulated AQP2 protein levels and cAMP accumulation, which was completely blocked by pretreatment with the vasopressin V2 receptor (V2R) antagonist SR121463B (10−8 M). Pretreatment with the angiotensin AT1 receptor (AT1R) antagonist losartan (3 × 10−6 M) blocked ANG II (10−9 M)-stimulated AQP2 protein expression and cAMP accumulation, and partially blocked dDAVP (10−10 M)- and dDAVP+ANG II-induced AQP2 protein expression and cAMP accumulation. In conclusion, ANG II regulates AQP2 protein, trafficking, and gene expression in renal collecting duct principal cells. ANG II-induced AQP2 expression involves cAMP, PKC, PKA, and calmodulin signaling pathways via V2 and AT1 receptors.

scholarly journals Systems-level analysis of cell-specific AQP2 gene expression in renal collecting duct

2009 ◽  
Vol 106 (7) ◽  
pp. 2441-2446 ◽  
Author(s):  
M.-J. Yu ◽  
R. L. Miller ◽  
P. Uawithya ◽  
M. M. Rinschen ◽  
S. Khositseth ◽  
...  
Keyword(s):  
Gene Expression ◽  
Collecting Duct ◽  
Renal Collecting Duct ◽  
Aqp2 Gene ◽  
Level Analysis

scholarly journals NADPH Oxidase 4 Deficiency Reduces Aquaporin-2 mRNA Expression in Cultured Renal Collecting Duct Principal Cells via Increased PDE3 and PDE4 Activity

PLoS ONE ◽  
2014 ◽  
Vol 9 (1) ◽  
pp. e87239 ◽  
Author(s):  
Eric Féraille ◽  
Eva Dizin ◽  
Isabelle Roth ◽  
Jean-Paul Derouette ◽  
Ildiko Szanto ◽  
...  
Keyword(s):  
Nadph Oxidase ◽  
Mrna Expression ◽  
Collecting Duct ◽  
Principal Cells ◽  
Aquaporin 2 ◽  
Nadph Oxidase 4 ◽  
Renal Collecting Duct

Aquaporin-2 abundance in the renal collecting duct: new insights from cultured cell models

2009 ◽  
Vol 297 (1) ◽  
pp. F10-F18 ◽  
Author(s):  
Udo Hasler ◽  
Valérie Leroy ◽  
Pierre-Yves Martin ◽  
Eric Féraille
Keyword(s):  
Gene Transcription ◽  
Collecting Duct ◽  
Mrna Translation ◽  
Osmotic Gradient ◽  
Thick Ascending Limb ◽  
Whole Cell ◽  
Cell Abundance ◽  
Principal Cells ◽  
Aquaporin 2 ◽  
Aqp2 Gene

The renal cortico-papillary osmotic gradient is generated by sodium reabsorption in the thick ascending limb. The antidiuretic hormone arginine vasopressin (AVP) increases collecting duct water permeability by enhancing aquaporin-2 (AQP2) water channel insertion in the apical membrane of principal cells, allowing water to passively flow along the osmotic gradient from the tubule lumen to the interstitium. In addition to short-term AQP2 redistribution between intracellular compartments and the cell surface, AQP2 whole cell abundance is tightly regulated. AVP is a major transcriptional activator of the AQP2 gene, and stimulation of insulin- and calcium-sensing receptors respectively potentiate and reduce its action. Extracellular tonicity is another key factor that determines the levels of AQP2 abundance. Its effect is dependent on activation of the tonicity-responsive enhancer binding protein that reinforces AVP-induced AQP2 transcriptional activation. Conversely, activation of the NF-κB transcriptional factor by proinflammatory factors reduces AQP2 gene transcription. Aldosterone additionally regulates AQP2 whole cell abundance by simultaneously reducing AQP2 gene transcription and stimulating AQP2 mRNA translation. These examples illustrate how cross talk between various stimuli regulates AQP2 abundance in collecting duct principal cells and consequently contributes to maintenance of body water homeostasis.

Increased galectin-3 levels are associated with abdominal aortic aneurysm progression and inhibition of galectin-3 decreases elastase-induced AAA development

2017 ◽  
Vol 131 (22) ◽  
pp. 2707-2719 ◽  
Author(s):  
Carlos-Ernesto Fernandez-García ◽  
Carlos Tarin ◽  
Raquel Roldan-Montero ◽  
Diego Martinez-Lopez ◽  
Monica Torres-Fonseca ◽  
...  
Keyword(s):  
Abdominal Aortic Aneurysm ◽  
Aortic Aneurysm ◽  
Protein Expression ◽  
Potential Role ◽  
Control Group ◽  
Mrna Levels ◽  
Abdominal Aortic ◽  
Stat3 Phosphorylation ◽  
Galectin 3 ◽  
Mrna And Protein Expression

Abdominal aortic aneurysm (AAA) evolution is unpredictable and no specific treatment exists for AAA, except surgery to prevent aortic rupture. Galectin-3 has been previously associated with CVD, but its potential role in AAA has not been addressed. Galectin-3 levels were increased in the plasma of AAA patients (n=225) compared with the control group (n=100). In addition, galectin-3 concentrations were associated with the need for surgical repair, independently of potential confounding factors. Galectin-3 mRNA and protein expression were increased in human AAA samples compared with healthy aortas. Experimental AAA in mice was induced via aortic elastase perfusion. Mice were treated intravenously with the galectin-3 inhibitor modified citrus pectin (MCP, 10 mg/kg, every other day) or saline. Similar to humans, galectin-3 serum and aortic mRNA levels were also increased in elastase-induced AAA mice compared with control mice. Mice treated with MCP showed decreased aortic dilation, as well as elastin degradation, vascular smooth muscle cell (VSMC) loss, and macrophage content at day 14 postelastase perfusion compared with control mice. The underlying mechanism(s) of the protective effect of MCP was associated with a decrease in galectin-3 and cytokine (mainly CCL5) mRNA and protein expression. Interestingly, galectin-3 induced CCL5 expression by a mechanism involving STAT3 activation in VSMC. Accordingly, MCP treatment decreased STAT3 phosphorylation in elastase-induced AAA. In conclusion, increased galectin-3 levels are associated with AAA progression, while galectin-3 inhibition decreased experimental AAA development. Our data suggest the potential role of galectin-3 as a therapeutic target in AAA.

scholarly journals TRPV4 is a mechanotransducer of fluid flow in principal cells (PC) and intercalated cells (IC) of the renal collecting duct system

2012 ◽  
Vol 26 (S1) ◽  
Author(s):  
Jonathan Berrout ◽  
Min Jin ◽  
Mykola Mamenko ◽  
Oleg L Zaika ◽  
Oleh Pochynyuk ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Collecting Duct ◽  
Intercalated Cells ◽  
Duct System ◽  
Principal Cells ◽  
Renal Collecting Duct

scholarly journals Yiqi Huoxue Recipe Improves Liver Regeneration in Rats after Partial Hepatectomy via JNK Pathway

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Wen-cong Li ◽  
Su-xian Zhao ◽  
Wei-guang Ren ◽  
Hui-juan Du ◽  
Yu-guo Zhang ◽  
...  
Keyword(s):  
Protein Expression ◽  
Liver Regeneration ◽  
Partial Hepatectomy ◽  
Underlying Mechanism ◽  
Mrna Levels ◽  
Protective Effects ◽  
Jnk Pathway ◽  
Expression Levels ◽  
Protein Levels ◽  
Mrna And Protein Expression

The liver is the only visceral organ that exhibits a remarkable capability of regenerating in response to partial hepatectomy (PH) or chemical injury. Improving liver regeneration (LR) ability is the basis for the favourable treatment outcome of patients after PH, which can serve as a potential indicator for postoperative survival. The present study aimed to investigate the protective effects of Yiqi Huoxue recipe (YQHX) on LR after PH in rats and further elucidate its underlying mechanism. A two-thirds PH rat model was used in this study. Wistar rats were randomly divided into four groups: sham-operated, PH, YQHX + PH, and Fuzheng Huayu decoction (FZHY) + PH groups. All rats were sacrificed under anesthesia at 24 and 72 h after surgery. The rates of LR were calculated, and the expression levels of cyclin D1 and c-jun were determined by immunohistochemical staining. The protein levels of p-JNK1/2, JNK1/2, p-c-jun, c-jun, Bax, and Bcl-2 were detected by Western blotting, while the mRNA levels of JNK1, JNK2, c-jun, Bax, and Bcl-2 were examined by real-time polymerase chain reaction (RT-PCR). At the corresponding time points, YQHX and FZHY administration dramatically induced the protein levels of p-JNK1/2 compared to the PH group p<0.05, while FZHY + PH group showed prominently increase in p-JNK1/2 protein levels compared to the YQHX + PH group p<0.05. A similar trend was observed for the expression levels of p-c-jun. Compared to the PH group, YQHX and FZHY markedly reduced the mRNA and protein expression levels of Bax at 24 h after PH, while those in the FZHY + PH group decreased more obviously p<0.05. Besides, in comparison with the PH group, YQHX and FZHY administration predominantly upregulated the mRNA and protein expression levels of Bcl-2 at 24 and 72 h after PH p<0.05. In conclusion, YQHX improves LR in rats after PH by inhibiting hepatocyte apoptosis via the JNK signaling pathway.

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