Blockade of the N-Methyl-D-Aspartate Glutamate Receptor Ameliorates Lipopolysaccharide-Induced Renal Insufficiency

PLoS One. 2015 Jul 2;10(7):e0132204. doi: 10.1371/journal.pone.0132204. eCollection 2015.

Abstract

N-methyl-D-aspartate (NMDA) receptor activation in rat kidney reduces renal perfusion and ultrafiltration. Hypoperfusion-induced ischemia is the most frequent cause of functional insufficiency in the endotoxemic kidney. Here, we used non-hypotensive rat model of lipopolysaccharide-induced endotoxemia to examine whether NMDA receptor hyperfunction contributes to acute kidney injury. Lipopolysaccharide-induced renal damage via increased enzymuria and hemodynamic impairments were ameliorated by co-treatment with the NMDA receptor blocker, MK-801. The NMDA receptor NR1 subunit in the rat kidney mainly co-localized with serine racemase, an enzyme responsible for synthesizing the NMDA receptor co-agonist, D-serine. The NMDA receptor hyperfunction in lipopolysaccharide-treated kidneys was demonstrated by NR1 and serine racemase upregulation, particularly in renal tubules, and by increased D-serine levels. Lipopolysaccharide also induced cell damage in cultured tubular cell lines and primary rat proximal tubular cells. This damage was mitigated by MK-801 and by small interfering RNA targeting NR1. Lipopolysaccharide increased cytokine release in tubular cell lines via toll-like receptor 4. The release of interleukin-1β from these cells are the most abundant. An interleukin-1 receptor antagonist not only attenuated cell death but also abolished lipopolysaccharide-induced NR1 and serine racemase upregulation and increases in D-serine secretion, suggesting that interleukin-1β-mediated NMDA receptor hyperfunction participates in lipopolysaccharide-induced tubular damage. The results of this study indicate NMDA receptor hyperfunction via cytokine effect participates in lipopolysaccharide-induced renal insufficiency. Blockade of NMDA receptors may represent a promising therapeutic strategy for the treatment of sepsis-associated renal failure.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acute Kidney Injury / chemically induced
  • Acute Kidney Injury / physiopathology*
  • Acute Kidney Injury / prevention & control
  • Animals
  • Cells, Cultured
  • Dizocilpine Maleate / pharmacology
  • Dizocilpine Maleate / therapeutic use*
  • Dogs
  • Endotoxemia / chemically induced
  • Endotoxemia / pathology
  • Endotoxemia / physiopathology*
  • Excitatory Amino Acid Antagonists / pharmacology
  • Excitatory Amino Acid Antagonists / therapeutic use*
  • Hemodynamics / drug effects
  • Interleukin-1beta / physiology
  • Kidney Function Tests
  • Kidney Tubules, Distal / drug effects
  • Kidney Tubules, Distal / metabolism*
  • Kidney Tubules, Distal / pathology
  • Kidney Tubules, Proximal / drug effects
  • Kidney Tubules, Proximal / metabolism*
  • Kidney Tubules, Proximal / pathology
  • LLC-PK1 Cells / drug effects
  • LLC-PK1 Cells / metabolism
  • Lipopolysaccharides / toxicity
  • Madin Darby Canine Kidney Cells / drug effects
  • Madin Darby Canine Kidney Cells / metabolism
  • Male
  • RNA Interference
  • RNA, Messenger / biosynthesis
  • RNA, Small Interfering / genetics
  • Racemases and Epimerases / metabolism
  • Rats
  • Rats, Wistar
  • Receptors, N-Methyl-D-Aspartate / antagonists & inhibitors*
  • Receptors, N-Methyl-D-Aspartate / biosynthesis
  • Receptors, N-Methyl-D-Aspartate / physiology
  • Serine / analysis
  • Swine
  • Toll-Like Receptor 4 / physiology

Substances

  • Excitatory Amino Acid Antagonists
  • Interleukin-1beta
  • Lipopolysaccharides
  • NR1 NMDA receptor
  • RNA, Messenger
  • RNA, Small Interfering
  • Receptors, N-Methyl-D-Aspartate
  • Tlr4 protein, rat
  • Toll-Like Receptor 4
  • lipopolysaccharide, E coli O55-B5
  • Serine
  • Dizocilpine Maleate
  • Racemases and Epimerases
  • serine racemase

Grants and funding

This study was supported by the Far Eastern Memorial Hospital (100FJU-FEMH-03), the Chi-Mei Medical Center (CMFJ10009; CMFJ10203), and the Ministry of Science and Technology (NSC101-2314-B-030-002-MY3).