Abstract: SA-PO131
15-Lipoxygenase Alters Inflammation, Metabolism, and Fibrosis in a Model of Renal Injury
Session Information
- AKI: Mechanisms - AKI-CKD Transition
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
- Montford, John Ross, University of Colorado Health Science Center, Aurora, Colorado, United States
- Bauer, Colin D., University of Colorado Health Science Center, Aurora, Colorado, United States
- Faubel, Sarah, University of Colorado Health Science Center, Aurora, Colorado, United States
- Nemenoff, Raphael A., University of Colorado Health Science Center, Aurora, Colorado, United States
- Furgeson, Seth B., University of Colorado Health Science Center, Aurora, Colorado, United States
Background
15-Lipoxygenase (15-LO, ALOX15) is implicated in the pathogenesis of a growing number of inflammatory and fibrotic diseases such as asthma, heart failure, and stroke but its role in renal injury is unexplored. We sought to examine if manipulating 15-LO would influence renal inflammation and fibrosis using a rodent model of unilateral ureteral obstruction (UUO).
Methods
Wild Type (WT) mice (N=18), mice lacking 15-LO (Alox15-/-) (N=11), and mice with transgenic overexpression of 15-LO (N=9) were subjected to UUO and kidneys were collected at 3 and 10 days postoperatively for histology, qRT-PCR, hydroxyproline assessment, and metabolomic and lipidomic analysis of over 200 unique compounds.
Results
At 3 days after UUO, as compared to WT controls, Alox15-/- kidneys had decreased mRNA levels of pro-inflammatory cytokines tumor necrosis factor alpha (TNFα) and fractalkine (CX3CL1) (0.84 vs 1.71 mean fold decrease, p<0.05; and 0.41 vs 1.04 mean fold decrease, p<0.01, respectively). Similar results were obtained 10 days after UUO (0.93 vs 1.39 mean fold decrease, p<0.01, and 2.79 vs 5.32 mean fold decrease, p<0.01, respectively). At 3 days after UUO, injured Alox15-/- mice had reduced levels of toxic reactive eicosanoids including 12(13)- and 9(10)-DiHOMEs, 9- and 13-OxoODEs, and 5(S)-HETE compared with WT specimens. At 10 days after UUO, Alox15-/- mice had evidence of marked oxidative phosphorylation vs. WT mice, which demonstrated a shift towards glycolysis. Also at 10 days after UUO, there was a trend towards reduced fibrosis in the Alox15-/- vs. WT by Picrosirius red staining (p=0.09), but not by mRNA for transforming growth factor beta (TGF-β) and smooth muscle alpha actin (αSMA). Next, we determined if overexpressing 15-LO would promote inflammation and fibrosis 10 days after UUO. As compared with WT mice, 15-LO transgenic mice had increase message for CX3CL1 (4.89 vs 1.69 mean fold increase, p<0.001), TGF-β (6.22 vs 2.35 mean fold increase, p<0.001), and αSMA (4.34 vs 2.52 mean fold increase, p<0.01). Fibrosis was significantly worse among the 15LOTG mice as compared to WT controls by Picrosirius red staining (7.52 vs 4.03 % fibrosis, p<0.05) and cortical hydroxyproline content (4.09 vs 1.99 mcg/mg total protein, p<0.01).
Conclusion
15-Lipoxygenase contributes to inflammation, metabolic changes, and fibrosis in mice undergoing UUO.
Funding
- Veterans Affairs Support