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Kidney Week

Abstract: FR-PO1106

Angiotensin-(1–7) Attenuates Tacrolimus-Induced Apoptosis in Human Renal Proximal Tubular Epithelial Cells

Session Information

  • Transplantation: Basic
    November 08, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
    Abstract Time: 10:00 AM - 12:00 PM

Category: Transplantation

  • 1901 Transplantation: Basic

Authors

  • Kim, Chang Seong, Chonnam National University Medical School , Gwangju, Korea (the Republic of)
  • Choi, Hong sang, Chonnam National University Hospital, Gwangju, Korea (the Republic of)
  • Bae, Eun Hui, Chonnam National University Hospital, Gwangju, Korea (the Republic of)
  • Ma, Seong Kwon, Chonnam National University Medical School , Gwangju, Korea (the Republic of)
  • Kim, Soo Wan, Chonnam National University Medical School , Gwangju, Korea (the Republic of)
Background

Tacrolimus (FK-506) is used clinically to reduce the rejection rate in patients with kidney transplantation; however, the nephrotoxicity induced by tacrolimus remains serious clinical problem. Although tacrolimus-induced nephrotoxicity might be involved renin-angiotensin system, but the role of angiotensin-(1–7) [Ang-(1–7)] has not been completely understood. The present study was aimed to investigate the renoprotective effects of Ang-(1–7) in tacrolimus-induced renal tubular injury.

Methods

To investigate the molecular mechanisms underlying tacrolimus-induced renal tubular cell injury, human proximal tubular epithelial (HK-2) cells were treated with tacrolimus (75 μM) in the presence or absence of Ang-(1–7) (1 μM) and Mas receptor antagonist A779 (1 μM). Cell viability was examined using WST-1 assay. Cell cycle arrest was assessed by the protein expression of cyclin B1, phospho-Cdc2 (Tyr 15) and phospho-Histone H3 (Ser 10).

Results

Treatment of tacrolimus decreased cell viability in a dose or time-dependent manner in HK-2 cells. In addition, treatment of tacrolimus decreased the protein expression of cyclin B1, phospho-cdc2 and phospho-Histone H3 in cytosol and nuclear fraction compared with control, indicating that cells arrested at G0/G1 phase. Moreover, tacrolimus induced the expression of nuclear factor-κB (NF-κB) signaling, pro-apoptotic markers Bax and cleaved caspase-3 and necrotic cell death marker cleaved PARP1, as well as attenuated the anti-apoptotic marker Bcl-2 in HK-2 cells. However, these changes were attenuated by pretreatment with Ang-(1–7), while co-treatment with A779 abolished the effect of Ang-(1–7). In addition, tacrolimus increased tumor necrosis factor-α converting enzyme (TACE) and decreased angiotensin-converting enzyme 2 (ACE2) expression in HK-2 cells, while pretreatment with Ang-(1–7) or A779 significantly inhibited or enhanced these effects, respectively.

Conclusion

NF-κB signaling and cell cycle arrest at G0/G1 phase might be mediated in tacrolimus-induced apoptosis. Also, tacrolimus increased TACE expression, which could mediate the vicious cycle of decreasing ACE2. However, Ang-(1–7) protects the cell viability by suppressing apoptosis and necrosis via Mas receptor in tacrolimus-induced HK-2 cells.