BAM15 treats mouse sepsis and kidney injury, linking mortality, mitochondrial DNA, tubule damage, and neutrophils
Naoko Tsuji, Takayuki Tsuji, Tetsushi Yamashita, Naoki Hayase, Xuzhen Hu, Peter S.T. Yuen, Robert A. Star
Naoko Tsuji, Takayuki Tsuji, Tetsushi Yamashita, Naoki Hayase, Xuzhen Hu, Peter S.T. Yuen, Robert A. Star
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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 1

BAM15 treatment improves mortality and AKI in septic mice, even with delayed administration.

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BAM15 treatment improves mortality and AKI in septic mice, even with del...
(A) Kaplan-Meier curves of male mice subjected to sham or CLP surgery treated with vehicle (at 0 hours) and mice subjected to sham or CLP surgery treated with BAM15 (5 mg/kg, at 0 hours) for 7 days. Sham+vehicle/BAM15, n = 4 each; CLP+vehicle/BAM15, n = 20 each. log-rank test. *P < 0.05, CLP+vehicle versus other groups. (B and C) Serum creatinine measured by HPLC. BUN (B), aspartate transferase (AST), alanine transaminase (ALT), lactate dehydrogenase (LDH), amylase, and creatinine kinase (CK) (C) by biochemical examination at 18 hours after mice were subjected to sham or CLP surgery and treated with vehicle (at 0 hours) or BAM15 (5 mg/kg, at 0 hours). Data are represented as mean ± SEM of each group (sham+vehicle, n = 4–6, CLP+vehicle, n = 10–12; sham+BAM15, n = 4–6; CLP+BAM15, n = 10–12). Šidák’s multiple-comparison test following 1-way ANOVA. *Versus sham+vehicle, P < 0.05; †versus sham+BAM15, P < 0.05; ‡versus CLP+vehicle, P < 0.05. (D) Kaplan-Meier curves for 7 days of mice subjected to sham or CLP surgery and treated with vehicle (at 6 hours) or BAM15 (5 mg/kg, at 6 hours). Sham+vehicle/BAM15, n = 4 each; CLP+vehicle (n = 20), BAM15 (n = 19). log-rank test. *CLP+vehicle versus other groups, P < 0.05. (E–F) Serum creatinine measured by HPLC. BUN (E) and AST, ALT, LDH, amylase, and CK (F) measured by biochemical examination at 18 hours after mice subjected to sham or CLP surgery were treated with vehicle (at 6 hours) or BAM15 (5 mg/kg, at 6 hours). Data are represented as mean ± SEM of each group (sham+vehicle, n = 5; CLP+vehicle, n = 13; sham+BAM15, n = 7; CLP+BAM15, n = 17). 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.