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 7

BAM15 decreases neutrophil apoptosis and mtDNA release; neutrophil depletion counteracted BAM15 benefits.

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BAM15 decreases neutrophil apoptosis and mtDNA release; neutrophil deple...
(A–D) Gating of Ly6G+ neutrophils in granulocytes (CD45+CD11b+) of spleen at 18 hours of sham+vehicle (A), sham+BAM15 (B), CLP+vehicle (C), and CLP+BAM15 (5 mg/kg, at 0 hours) (D). (E) Absolute neutrophil number in each group. Sham groups, n = 4 each; CLP groups, n = 8 each. Each circle represents a log-transformed average of duplicated samples. (F–I) Apoptotic cells in neutrophils of spleen at 18 hours of sham+vehicle (F), sham+BAM15 (G), CLP+vehicle (H), and CLP+BAM15 (I), and percentage of these apoptotic neutrophils in each group (J). n = 4 for each sham group; n = 8 for each CLP group. *P < 0.05. (K and L) Extracellular mtDNA in medium of Ly6G+ neutrophils treated with PMA (K) or mtDNA (25 μg/ml) (L) with or without BAM15. Data are represented as mean ± SEM. Holm-Šidák multiple-comparison test following 1-way ANOVA (E, J, K); t test (L). *P < 0.05; **P < 0.001. (M) Study design of CLP with neutrophil depletion. (N–P) Ly6G+ neutrophil population in isotype control–treated (N) or Ly6G Ab–treated (O) spleen at 18 hours after sham surgery, and histogram of Ly6G expression (P). BUN (Q); Serum creatinine (R). Sham groups, n = 3 each; CLP groups, n = 7 each. Data are represented as mean ± SEM. Šidák’s multiple-comparison test following 1-way ANOVA. #P < 0.05, CLP versus sham in each treatment group; *P < 0.05, between CLP groups. (S) Kaplan-Meier curves for 7 days of mice subjected to sham or CLP surgery treated with vehicle or BAM15 (5 mg/kg at 0 hours) following Ly6G Ab or isotype control treatment. Sham groups, n = 3 each; CLP groups, n = 20 each. log-rank test. *P < 0.05, CLP+isotype+vehicle versus CLP+isotype+BAM15. #P < 0.05, CLP+Ly6GAb+BAM15 versus CLP+isotype+BAM15.