scholarly journals AQP2-Induced Acceleration of Renal Cell Proliferation Involves the Activation of a Regulatory Volume Increase Mechanism Dependent on NHE2

2017 ◽  
Vol 118 (5) ◽  
pp. 967-978 ◽  
Author(s):  
Valeria Rivarola ◽  
Gisela Di Giusto ◽  
María José Christensen ◽  
Paula Ford ◽  
Claudia Capurro
2020 ◽  
Author(s):  
Lungwani Muungo

TRIM44 has oncogenic roles in various cancers. However, TRIM44 expression andits function in renal cell carcinoma (RCC) are still unknown. Here in this study, weinvestigated the clinical significance of TRIM44 and its biological function in RCC.TRIM44 overexpression was significantly associated with clinical M stage, histologictype (clear cell) and presence of lymphatic invasion (P = .047, P = .005, and P = .028,respectively). Moreover, TRIM44 overexpression was significantly associated withpoor prognosis in terms of cancer-specific survival (P = .019). Gain-of-function andloss-of-function studies using TRIM44 and siTRIM44 transfection showed thatTRIM44 promotes cell proliferation and cell migration in two RCC cell lines, Caki1and 769P. To further investigate the role of TRIM44 in RCC, we performed integratedmicroarray analysis in Caki1 and 769P cells and explored the data in the Oncominedatabase. Interestingly, FRK was identified as a promising candidate target gene ofTRIM44, which was downregulated in RCC compared with normal renal tissues. Wefound that cell proliferation was inhibited by TRIM44 knockdown and then recoveredby siFRK treatment. Taken together, the present study revealed the associationbetween high expression of TRIM44 and poor prognosis in


1995 ◽  
Vol 105 (4) ◽  
pp. 507-535 ◽  
Author(s):  
F Wehner ◽  
H Sauer ◽  
R K Kinne

We studied the ionic mechanisms underlying the regulatory volume increase of rat hepatocytes in primary culture by use of confocal laser scanning microscopy, conventional and ion-sensitive microelectrodes, cable analysis, microfluorometry, and measurements of 86Rb+ uptake. Increasing osmolarity from 300 to 400 mosm/liter by addition of sucrose decreased cell volumes to 88.6% within 1 min; thereafter, cell volumes increased to 94.1% of control within 10 min, equivalent to a regulatory volume increase (RVI) by 44.5%. This RVI was paralleled by a decrease in cell input resistance and in specific cell membrane resistance to 88 and 60%, respectively. Ion substitution experiments (high K+, low Na+, low Cl-) revealed that these membrane effects are due to an increase in hepatocyte Na+ conductance. During RVI, ouabain-sensitive 86Rb+ uptake was augmented to 141% of control, and cell Na+ and cell K+ increased to 148 and 180%, respectively. The RVI, the increases in Na+ conductance and cell Na+, as well as the activation of Na+/K(+)-ATPase were completely blocked by 10(-5) mol/liter amiloride. At this concentration, amiloride had no effect on osmotically induced cell alkalinization via Na+/H+ exchange. When osmolarity was increased from 220 to 300 mosm/liter (by readdition of sucrose after a preperiod of 15 min in which the cells underwent a regulatory volume decrease, RVD) cell volumes initially decreased to 81.5%; thereafter cell volumes increased to 90.8% of control. This post-RVD-RVI of 55.0% is also mediated by an increase in Na+ conductance. We conclude that rat hepatocytes in confluent primary culture are capable of RVI as well as of post-RVD-RVI. In this system, hypertonic stress leads to a considerable increase in cell membrane Na+ conductance. In concert with conductive Na+ influx, cell K+ is then increased via activation of Na+/K(+)-ATPase. An additional role of Na+/H+ exchange in the volume regulation of rat hepatocytes remains to be defined.


1997 ◽  
Vol 272 (1) ◽  
pp. C191-C202 ◽  
Author(s):  
L. Jiang ◽  
M. N. Chernova ◽  
S. L. Alper

Xenopus oocytes lack volume regulation and Cl/anion-exchange (AE) activity but express endogenous Na+/H+ exchange (NHE). We postulated that expression in oocytes of heterologous anion exchangers might allow regulatory volume increase (RVI) via functional coupling with endogenous NHE. Expression of neither erythroid nor kidney isoforms of AE1 conferred any form of RVI. In contrast, although AE2 expression did not confer primary RVI, it did confer on oocytes secondary RVI, with a requirement for hypotonic swelling before hypertonic shrinkage. This secondary RVI required extracellular Cl- and Na+, was blocked by 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid and amiloride, was bumetanide insensitive, and was blocked by prevention of intracellular alkalinization, all properties consistent with functional coupling of AE2-mediated Cl-/HCO3- exchange and endogenous NHE. RVI was unaffected by CO2-HCO3- or by partial oocyte Cl- depletion and was unrelated to the rate of oocyte shrinkage. Prior hypotonic swelling did not significantly alter subsequent hypertonic stimulation of AE2-mediated 36Cl influx or efflux. We conclude that heterologous AE2 expression suffices to confer volume regulation on Xenopus oocytes that lack intrinsic volume-regulatory mechanisms.


2012 ◽  
Vol 113 (12) ◽  
pp. 3721-3729 ◽  
Author(s):  
Gisela Di Giusto ◽  
Pilar Flamenco ◽  
Valeria Rivarola ◽  
Juan Fernández ◽  
Luciana Melamud ◽  
...  

2018 ◽  
Vol 45 (3) ◽  
pp. 984-992 ◽  
Author(s):  
Lv Yao ◽  
Xiaoqiang Guo ◽  
Yaoting Gui

Background/Aims: Reprogramming energy metabolism is an emerging hallmark of many cancers, and this alteration is especially evident in renal cell carcinomas (RCCs). However, few studies have been conducted on lipid metabolism. This study investigated the function and mechanism of lipid metabolism-related acetyl-CoA synthetase 2 (ACSS2) in RCC development, cell migration and invasion. Methods: Quantitative real-time PCR (qRT-PCR) was used to determine the expression of ACSS2 in cancer tissue and adjacent tissue. The inhibition of ACSS2 expression was achieved by RNA interference, which was confirmed by qRT-PCR and Western blotting. Cell proliferation and apoptosis were detected by a CCK8 assay and a flow cytometry analysis, respectively. Cell migration and invasion were determined by the scratch and transwell assays. Following the knockdown of ACSS2 expression, the expression of the autophagy-related factor LAMP1 was measured by qRT-PCR and Western blotting. Results: Compared to adjacent tissues, ACSS2 expression was upregulated in RCC cancer tissues and positively correlated with metastasis. Inhibition of ACSS2 had no effect on RCC cell proliferation or apoptosis. However, decreased ACSS2 expression was found to inhibit RCC cell migration and invasion. ACSS2 was determined to promote the expression of LAMP1, which can also promote cell migration. This pathway may be considered a potential mechanism through which ACSS2 participates in RCC development. Conclusion: These data suggest that ACSS2 is an important factor for promoting RCC development and is essential for cell migration and invasion, which it promotes by increasing the expression of LAMP1. Taken together, these findings reveal a potential target for the diagnosis and treatment of RCC.


2020 ◽  
Vol 29 (1) ◽  
pp. 39-50
Author(s):  
Kerong Wu ◽  
Linkun Hu ◽  
Xiuyi Lv ◽  
Junfeng Chen ◽  
Zejun Yan ◽  
...  

BACKGROUND: Long non-coding RNAs (lncRNAs) play important roles in cancer development, yet their roles in renal carcinoma remain unclear. OBJECTIVE: We performed this study in order to investigate the expression and roles of lncRNAs in renal cell carcinoma. METHODS: In this study, we investigated the expression of lncRNAs in renal cell carcinoma through microarray analysis. Quantitative real-time PCR was performed to measure the expression of lncRNAs. Gain- or loss-of-function experiments were performed to investigate the roles of lncRNAs in cell proliferation and apoptosis. RNA pull-down and western blotting were performed to explore the underlying mechanism. RESULTS: The microarray analysis identified an upregulated lncRNA MIR4435-1HG in renal carcinoma. The expression level of MIR4435-1HG was correlated with TNM stage, tumor size, and Fuhrman grade. High expression of MIR4435-1HG indicated poor prognosis. MIR4435-1HG knockdown inhibited cell proliferation, and suppressed the migrating and invasive capacity of renal carcinoma cells. RNA pull-down followed by mass spectrometry revealed an interaction between MIR4435-1HG and pyruvate carboxylase, which was later corroborated by western blotting. CONCLUSIONS: MIR4435-1HG plays a critical role in the oncogenesis of renal cell carcinoma and may serve as a potential biomarker for renal cell carcinoma.


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