BAM15 treats mouse sepsis and kidney injury, linking mortality, mitochondrial DNA, tubule damage, and neutrophils
Naoko Tsuji, … , Peter S.T. Yuen, Robert A. Star
Naoko Tsuji, … , Peter S.T. Yuen, Robert A. Star
Published February 9, 2023
Citation Information: J Clin Invest. 2023;133(7):e152401. https://doi.org/10.1172/JCI152401.
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Research Article Nephrology

BAM15 treats mouse sepsis and kidney injury, linking mortality, mitochondrial DNA, tubule damage, and neutrophils

Abstract

Sepsis pathogenesis is complex and heterogeneous; hence, a precision-medicine strategy is needed. Acute kidney injury (AKI) following sepsis portends higher mortality. Overproduction of mitochondrial ROS (mtROS) is a potential mediator of sepsis and sepsis-induced AKI. BAM15, a chemical uncoupler, dissipates mitochondrial proton gradients without generating mtROS. We injected BAM15 into mice at 0, 6, or 12 hours after cecal ligation and puncture (CLP), and these mice were treated with fluids and antibiotics. BAM15 reduced mortality, even after 12 hours, when mice were ill, and BAM15 reduced kidney damage and splenic apoptosis. Serial plasma and urinary mitochondrial DNA (mtDNA) levels increased after CLP and decreased after BAM15 administration (at 0 or 6 hours). In vitro septic serum proportionately increased mtROS overproduction and mtDNA release from kidney tubule cells, which BAM15 prevented. BAM15 decreased neutrophil apoptosis and mtDNA release; neutrophil depletion counteracted BAM15 benefits. Further, mtDNA injection in vivo replicated inflammation and kidney injury, which was prevented by BAM15. A large dose of exogenous mtDNA reversed protection by BAM15. We conclude that BAM15 is an effective preventive and therapeutic candidate in experimental sepsis and that BAM15 and mtDNA, a potential drug-companion diagnostic/drug-efficacy pair for clinical sepsis, are mechanistically linked via mtROS.

Authors

Naoko Tsuji, Takayuki Tsuji, Tetsushi Yamashita, Naoki Hayase, Xuzhen Hu, Peter S.T. Yuen, Robert A. Star

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Figure 2

BAM15 reduces injury and oxidative damage via RNS in septic kidney.

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BAM15 reduces injury and oxidative damage via RNS in septic kidney. Peri...
Periodic acid–Schiff staining of cortex and OSOM in kidneys at 18 hours after mice subjected to sham or CLP surgery were treated with vehicle (at 0 hours) or BAM15 (5 mg/kg, at 0 hours). (A) Representative images of cortex and OSOM. Arrows show vacuolization in proximal tubule cells. Original magnification, ×400. (B) Tubular damage score in cortex and OSOM of kidney at 18 hours after being subjected to sham (4 mice each, total 20 fields of ×400) or CLP surgery (8 mice each, total 40 fields of ×400) treated with vehicle (at 0 hours) or BAM15 (5 mg/kg, at 0 hours). Data are represented as mean ± SEM. Dunn’s multiple-comparison test following Kruskal-Wallis test. *Versus sham+vehicle, P < 0.05; †versus sham+BAM15, P < 0.05; ‡versus CLP+vehicle, P < 0.05. (A–D) Representative nitrotyrosine images and positive area rate of cortex (C and D) and OSOM (E and F) in kidney at 2, 6, and 18 hours after being subjected to sham or CLP surgery and treated with vehicle (at 0 hours) or BAM15 (5 mg/kg, at 0 hours). Original magnification, ×400. The positive area rate was calculated by Fiji/ImageJ (NIH) software. Each circle represents the average of positive area of 3 to 4 fields per mouse kidney (3 to 4 mice/group). Bars show mean ± SEM. Tukey’s multiple-comparison test following 2-way ANOVA test. *Versus sham+vehicle, P < 0.05; †versus sham+BAM15, P < 0.05; ‡versus CLP+vehicle, P < 0.05; #comparison between time points, P < 0.05.