Abstract: TH-PO592

Autophagy Induction in Mouse Kidneys

Session Information

Category: Genetic Diseases of the Kidney

  • 801 Cystic Kidney Diseases

Authors

  • Brown, Carolyn Nicole, UC Denver Anschutz Medical Campus, Aurora, Colorado, United States
  • Holditch, Sara, UC Denver Anschutz Medical Campus, Aurora, Colorado, United States
  • Edelstein, Charles L., UC Denver Anschutz Medical Campus, Aurora, Colorado, United States
Background

Autophagy occurs in all eukaryotic cells in order to adapt under stressful conditions. Damaged organelles and proteins are sequestered into autophagosomes, which subsequently fuse with lysosomes where cargo is degraded and recycled. The aim of the current study was to determine the effects of autophagy inducers metformin (MET), 2-deoxyglusoce (DOG), and trehalose (TRE) on autophagy in wild type (WT) and RC/RC (PKD) mouse kidneys in vivo.

Methods

WT and PKD mice were treated with MET (250mg/kg IP), DOG (100mg/kg IP), or TRE (2% P.O.) for 6-12 days. At the end of the study, mice received wither vehicle (VEH) or bafilomycin (BAF) (1.75mg/kg IP) to block autophagic flux. P62, an autophagy-specific tag for degradation and a marker of autophagy inhibition, and LC3-II, a marker of autophagome formation, were measured by immunoblot.

Results

WT Kidneys: Significantly reduced LC3-II was detected in the kidneys of MET and DOG mice compared to VEH, suggesting an increase in autophagosome turnover by the lysosome. This was supported by increased LC3-II in MET+BAF vs MET, and DOG+BAF vs DOG, which were notably larger than VEH+BAF vs VEH. TRE had modest effects on LC3-II. PKD Kidneys: LC3-II was increased after BAF treatment in both TRE and MET, but not DOG. Most importantly, in PKD kidneys, MET, DOG, and TRE cleared most p62 protein aggregates, which are characteristic of defective autophagy. Further studies will be performed in PKD kidneys to achieve statistical significance. ImageJ software was used for densitometry (Table 1).

Conclusion

In summary, MET and DOG were both able to successfully induce autophagy in WT and PKD kidneys. Autophagy plays an important role in maintaining kidney homeostasis, and PKD has been described as a case of suppressed autophagy. The effect of autophagy inducers on PKD progression merits further study.

Table 1
 LC3-II/B-actinLC3-II/B-actinp62/B-actin
Group/GenotypeWTPKDPKD
VEH3.3±0.71.8±03.9±0.8
VEH+BAF9.6±2.05.0±0 
MET1.4±0.1 *5.4±0.10.7±0.1†
MET+BAF8.8±4.3 **6.7±1.0 
DOG1.2±0.2 *4.1±0.40.6±0.03†
DOG+BAF11.4±3.1 ***3.8±0.3 
TRE9.7±2.54.8±0.80.6±0.1†
TRE+BAF13.2±3.76.9±0.7 

*p<0.05 vs VEH, **p<0.05 vs MET, ***p<0.06 vs DOG, †p<0.06 vs VEH

Funding

  • Other U.S. Government Support