Kidney Week

Abstract: SA-PO099

Activation of Renal AMP-Activated Protein Kinase (AMPK) Is an Adaptive Response to Sepsis/Inflammation That Can Be Pharmacologically Harnessed to Improve Survival

Session Information

• AKI: Mechanisms - Primary Injury and Repair - II
  November 09, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Acute Kidney Injury

• 103 AKI: Mechanisms

Authors

• Manrique-Caballero, Carlos L., University of Pittsburgh, Pittsburgh, Pennsylvania, United States

Carlos L. Manrique-Caballero,

• Frank, Alicia, University of Pittsburgh, Pittsburgh, Pennsylvania, United States

Alicia Frank,

• Baty, Catherine J., University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States

Catherine J. Baty,

• Kellum, John A., University of Pittsburgh, Pittsburgh, Pennsylvania, United States

John A. Kellum,

• Gomez Danies, Hernando, University of Pittsburgh, Pittsburgh, Pennsylvania, United States

Hernando Gomez Danies,

Background

To determine the role of renal AMPK activation and inhibition in the renal tubular epithelial cells (TEC) metabolic response to sepsis, and to investigate the effects of AMPK signaling on sepsis-induced TEC injury, clinical status and survival

Methods

Animals: Ten-twelve week old C57BL/6 (n=6-10/group) mice were randomized to vehicle, 5-Aminoimidazole-4-carboxamide ribonucleotide (AICAR) or compound C (CC), and underwent cecal ligation and puncture (CLP). Outcome: Survival at 7 days.
Cells: Human kidney 2 (HK2) cells were cultured in serum-containing media at 21% O₂ and were assigned to control, AICAR and CC, and then exposed to inflammatory mix (IM=LPS+HMGB1). Using the Seahorse metabolic analyzer, we measured oxygen consumption rate (OCR) as a surrogate of OXPHOS (mitochondrial respiration) and extracellular acidification rate (ECAR) as a surrogate of glycolysis at 24 hours. Spare respiratory capacity defined as the capacity of the cell to increase ATP production in conditions of increased energetic demands was assessed by comparing OCR at baseline and after uncoupling mitochondria.

Results

Pharmacologic activation of AMPK with AICAR before or after sepsis improves mice survival at 7 days (AICAR+CLP vs CLP; 70% vs 19%; p<0.05), and inhibition with CC before sepsis increases mortality at 7 days (CC+CLP vs CLP; 100% vs 81%; p<0.05). Cells exposed to IM and CC showed a decrease in OCR and spare respiratory capacity at 24 hours by 26% and 90.3% respectively when compared to IM (Fig 1B, C), and limited the recruitment of glycolysis upon blockade of the mitochondrial electron transport chain (Fig 1D).

Conclusion

Enhancement of AMPK with AICAR increases survival, whereas inhibition with CC increases mortality. AMPK inhibition limited the capacity of tubular epithelial cells to recruit OXPHOS and glycolysis, thereby limiting metabolic flexibility. These findings suggest that TEC metabolic response to sepsis is an adaptive mechanism and that maintenance of metabolic flexibility may be key to survival from sepsis

Funding

• Other NIH Support