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Abstract: SA-PO070

Evaluation of BAM15 on Superoxide Generation in Sepsis AKI by In Vivo Imaging

Session Information

  • AKI: Mechanisms - III
    November 05, 2022 | Location: Exhibit Hall, Orange County Convention Center‚ West Building
    Abstract Time: 10:00 AM - 12:00 PM

Category: Acute Kidney Injury

  • 103 AKI: Mechanisms

Authors

  • Tsuji, Naoko, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland, United States
  • Tsuji, Takayuki, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland, United States
  • Naito, Yoshitaka, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland, United States
  • Hayase, Naoki, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland, United States
  • Woodroofe, Carolyn C., National Heart Lung and Blood Institute, Bethesda, Maryland, United States
  • Swenson, Rolf E., National Heart Lung and Blood Institute, Bethesda, Maryland, United States
  • Yuen, Peter S.T., National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland, United States
  • Star, Robert A., National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland, United States

Group or Team Name

  • Renal Diagnostics and Therapeutics Unit, Kidney Diseases Branch
Background

Non-invasive detection of kidney mitochondrial reactive oxygen species in vivo has been challenging. Recently, Huang et al (2019) developed a fluorescent superoxide molecular renal probe (MRP1) with high renal clearance and rapid detection. The probe enables real-time optical imaging of in vivo renal or ex vivo urinary superoxide by near-infrared fluorescence (NIRF). We previously showed that BAM15, a chemical mitochondrial uncoupler, decreased kidney superoxide generated by septic tubule cells exposed to serum of cecum ligation and puncture (CLP) mice in vitro, and improved survival and AKI in CLP mice (Tsuji et al., under review). Here, we tested if a MRP could detect sepsis induced superoxide generation in kidney or urine, and if BAM15 decreases it in vivo.

Methods

We synthesized a MRP that become fluorescent in the presence of superoxide (tested with KO2 exposure in vitro), and then be rapidly cleared into urine. MRP was injected into mice at 1, 3, or 18 h after CLP or sham surgery, followed by NIRF in vivo imaging at several time points (0-120 min) after MRP probe injection. The fluorescent signal from urine collected 30 min after MRP injection was measured by NIRF imaging. BAM15 (5mg/kg) was administered immediately after CLP. GFR was measured by a transdermal fluorescent detector following IV injection of FITC-sinistrin.

Results

We detected a higher MRP signal in vivo kidney at 1, 3, and 18 h after CLP following MRP injection. MRP uptake was detected in tubular cells and glomeruli in kidney sections by confocal microscopy. MRP signal in urine of CLP treated with BAM15 was lower than that of CLP treated with vehicle at 1h after CLP, even though GFR had not changed at 2-3h after CLP. (Figure 1).

Conclusion

We detected increased kidney and urinary superoxide in a mouse model of sepsis AKI before GFR decreased. The superoxide was decreased in response to a drug (BAM15) that improves mouse and renal survival. BAM15 and MRP might be a drug-companion biomarker pair. More study is needed to determine if superoxide generation measured by MRP is a robust biomarker to ultimately develop it for clinical use.

Funding

  • Government Support – Non-U.S.