Abstract: TH-PO298

NAD+ Augmentation Ameliorates Cisplatin Toxicity via Enhanced Autophagy

Session Information

Category: Acute Kidney Injury

  • 001 AKI: Basic

Authors

  • Lynch, Matthew R., Beth Israel Deaconess Medical Center, Boston, Massachusetts, United States
  • Ralto, Kenneth M., Beth Israel Deaconess Medical Center, Boston, Massachusetts, United States
  • Tran, Mei T., Beth Israel Deaconess Medical Center, Boston, Massachusetts, United States
  • Parikh, Samir M., Beth Israel Deaconess Medical Center, Boston, Massachusetts, United States
Background

We recently reported that renal NAD+ (nicotinamide adenine dinucleotide) concentrations decline markedly in diverse etiologies of AKI and showed that nutritional NAD+ augmentation can treat experimental post-ischemic AKI. Downstream salutary mechanisms of NAD+ augmentation are incompletely understood. Based on evidence linking impaired autophagy to cisplatin-induced renal tubular injury, we hypothesized that NAD+ augmentation may enhance resistance to cisplatin by increasing autophagy.

Methods

Murine intermedullary collecting duct (IMCD3) cells were pre-treated with the NAD+ precursor NMN (nicotinamide mononucleotide) or vehicle for one hour before cisplatin. Cell survival was assessed by automated trypan blue. RNA and protein were isolated for quantitative PCR measurement of autophagy related genes and autophagocytic flux by western blot, respectively. Acidified lysosomes were imaged using Lysotracker DND-99.

Results

NMN supplementation increased NAD+ levels at baseline and preserved NAD+ levels despite cisplatin exposure. NMN-treated cells better tolerated cisplatin stress whereas the lysosomal inhibitor chloroquine exacerbated cisplatin toxicity. NMN enhanced expression of autophagy genes (p < 0.05). Finally, NMN-supplemented cells maintained lysosomes in a favorable low-pH-state (Figure 1).

Conclusion

Addition of NMN enhanced cell survival after cisplatin exposure. Autophagic gene and protein levels, along with lysosomal imaging, implicate NMN-related increase in autophagy. NAD+ augmentation may therefore counteract cisplatin-induced renal injury by promoting autophagy.

Figure 1. Lysotracker imaging reveals preservation of low pH state of lysosomes with NMN and cisplatin. Representative images (20X).

Funding

  • NIDDK Support