No Effect of Remote Ischemic Conditioning Strategies on Recovery from Renal Ischemia-Reperfusion Injury and Protective Molecular Mediators

PLoS One. 2015 Dec 31;10(12):e0146109. doi: 10.1371/journal.pone.0146109. eCollection 2015.

Abstract

Ischemia-reperfusion injury (IRI) is the major cause of acute kidney injury. Remote ischemic conditioning (rIC) performed as brief intermittent sub-lethal ischemia and reperfusion episodes in a distant organ may protect the kidney against IRI. Here we investigated the renal effects of rIC applied either prior to (remote ischemic preconditioning; rIPC) or during (remote ischemic perconditioning; rIPerC) sustained ischemic kidney injury in rats. The effects were evaluated as differences in creatinine clearance (CrCl) rate, tissue tubular damage marker expression, and potential kidney recovery mediators. One week after undergoing right-sided nephrectomy, rats were randomly divided into four groups: sham (n = 7), ischemia and reperfusion (IR; n = 10), IR+rIPC (n = 10), and IR+rIPerC (n = 10). The rIC was performed as four repeated episodes of 5-minute clamping of the infrarenal aorta followed by 5-minute release either before or during 37 minutes of left renal artery clamping representing the IRI. Urine and blood were sampled prior to ischemia as well as 3 and 7 days after reperfusion. The kidney was harvested for mRNA and protein isolation. Seven days after IRI, the CrCl change from baseline values was similar in the IR (δ: 0.74 mL/min/kg [-0.45 to 1.94]), IR+rIPC (δ: 0.21 mL/min/kg [-0.75 to 1.17], p > 0.9999), and IR+rIPerC (δ: 0.41 mL/min/kg [-0.43 to 1.25], p > 0.9999) groups. Kidney function recovery was associated with a significant up-regulation of phosphorylated protein kinase B (pAkt), extracellular regulated kinase 1/2 (pERK1/2), and heat shock proteins (HSPs) pHSP27, HSP32, and HSP70, but rIC was not associated with any significant differences in tubular damage, inflammatory, or fibrosis marker expression. In our study, rIC did not protect the kidney against IRI. However, on days 3-7 after IRI, all groups recovered renal function. This was associated with pAkt and pERK1/2 up-regulation and increased HSP expression at day 7.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acute Kidney Injury / metabolism
  • Acute Kidney Injury / physiopathology
  • Animals
  • Aorta, Abdominal / metabolism
  • Aorta, Abdominal / physiopathology
  • Constriction
  • HSP70 Heat-Shock Proteins / metabolism
  • Ischemic Preconditioning / methods
  • Kidney / metabolism
  • Kidney / physiopathology*
  • MAP Kinase Signaling System / physiology
  • Male
  • Proto-Oncogene Proteins c-akt / metabolism
  • Rats
  • Rats, Wistar
  • Reperfusion Injury / metabolism
  • Reperfusion Injury / physiopathology*
  • Up-Regulation / physiology

Substances

  • HSP70 Heat-Shock Proteins
  • Proto-Oncogene Proteins c-akt

Associated data

  • figshare/10.6084/M9.FIGSHARE.1615026
  • figshare/10.6084/M9.FIGSHARE.1615027
  • figshare/10.6084/M9.FIGSHARE.1615028

Grants and funding

This work was supported by the Danish Society of Nephrology Research Foundation, no grant number (www.nephrology.com); the Bjørnows Foundation, no grant number (www.bjoernowsfond.dk); the P.A. Messerschmidt og hustrus Foundation, no grant number (www.bechbruun.com/da/Mennesker/JHW); and the Department of Clinical Medicine, no grant number (www.clin.au.dk). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.