Overexpression of RGPR-p117 suppresses apoptotic cell death and its related gene expression in cloned normal rat kidney proximal tubular epithelial NRK52E cells

  • Authors:
    • Masayoshi Yamaguchi
    • Susumu Tomono
    • Taeko Nakagawa
  • View Affiliations

  • Published online on: October 1, 2007     https://doi.org/10.3892/ijmm.20.4.565
  • Pages: 565-571
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Abstract

The novel protein RGPR-p117 was discovered as a regucalcin gene promoter region-related protein that binds to the TTGGC motif using a yeast one-hybrid system. The role of RGPR-p117 in cell function has not been fully clarified. This study was undertaken to determine whether overexpression of RGPR-p117 regulates various types of signaling factor-induced apoptotic cell death in the cloned normal rat kidney proximal tubular epithelial NRK52E cells. NRK52E cells (wild-type) or stable RGPR-p117/phCMV2-transfected cells (transfectant) were cultured in Dulbecco's modified Eagle's medium containing 5% bovine serum (BS). NRK52E cells with subconfluent monolayers were cultured for 24-72 h in a medium without BS. The presence of tumor necrosis factor-α (TNF-α; 1.0 or 10 ng/ml of medium), lipopolysaccharide (LPS; 0.1 or 1.0 µg/ml), Bay K 8644 (10−6 or 10−5 M), or thapsigargin (10−8 or 10−7 M) caused a significant decrease in the number of NRK52E wild-type cells or phCMV2-transfected (mock-type) cells. The effect of TNF-α, LPS, Bay K 8644, or thapsigargin in decreasing cell number was significantly suppressed in the presence of the caspase-3 inhibitor (10−8 M) in wild-type cells cultured for 48 h. The effect of TNF-α, LPS, or Bay K 8644 in decreasing cell number was significantly inhibited in the transfectants, while the effect of thapsigargin on cell death was not inhibited in the transfectants. Culture with TNF-α or LPS caused DNA fragmentation in wild-type cells. These effects were significantly suppressed in the transfectants. The result of reverse transcription-polymerase chain reaction analysis using specific primers for the genes of apoptotic cell death-related proteins showed that IAP-1, FADD, caspase-8, caspase-9, and caspase-3 mRNA levels were significantly decreased in the transfectants, while Akt-1, Bid, Apaf-1, and glyceroaldehyde-3-phosphate dehydrogenase mRNA levels were not significantly altered in the transfectants. Culture with TNF-α, LPS, Bay K 8644, or thapsigargin caused a significant increase in Apaf-1 or caspase-3 mRNA levels. Such an effect was not seen in the transfectants. This study demonstrates that overexpression of RGPR-p117 has a suppressive effect on cell death and apoptosis induced by TNF-α, LPS, or Bay K 8644 whose actions are mediated through intracellular signaling pathways. This study also demonstrates that RGPR-p117 regulates the gene expression of apoptosis-related proteins.

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October 2007
Volume 20 Issue 4

Print ISSN: 1107-3756
Online ISSN:1791-244X

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Spandidos Publications style
Yamaguchi M, Tomono S and Nakagawa T: Overexpression of RGPR-p117 suppresses apoptotic cell death and its related gene expression in cloned normal rat kidney proximal tubular epithelial NRK52E cells. Int J Mol Med 20: 565-571, 2007.
APA
Yamaguchi, M., Tomono, S., & Nakagawa, T. (2007). Overexpression of RGPR-p117 suppresses apoptotic cell death and its related gene expression in cloned normal rat kidney proximal tubular epithelial NRK52E cells. International Journal of Molecular Medicine, 20, 565-571. https://doi.org/10.3892/ijmm.20.4.565
MLA
Yamaguchi, M., Tomono, S., Nakagawa, T."Overexpression of RGPR-p117 suppresses apoptotic cell death and its related gene expression in cloned normal rat kidney proximal tubular epithelial NRK52E cells". International Journal of Molecular Medicine 20.4 (2007): 565-571.
Chicago
Yamaguchi, M., Tomono, S., Nakagawa, T."Overexpression of RGPR-p117 suppresses apoptotic cell death and its related gene expression in cloned normal rat kidney proximal tubular epithelial NRK52E cells". International Journal of Molecular Medicine 20, no. 4 (2007): 565-571. https://doi.org/10.3892/ijmm.20.4.565