Masato Nakasone1, Kazuhiro Nakaso2, Yosuke Horikoshi3, Takehiko Hanaki1, Yoshinori Kitagawa2, Toru Takahashi2, Yoshimi Inagaki4, Tatsuya Matsura2. 1. Division of Medical Biochemistry, Department of Pathophysiological and Therapeutic Science, School of Medicine, Tottori University Faculty of Medicine, Yonago 683-8503, Japan; †Division of Anesthesiology and Clinical Care Medicine, Department of Surgery, School of Medicine, Tottori University Faculty of Medicine, Yonago 683-8503, Japan. 2. Division of Medical Biochemistry, Department of Pathophysiological and Therapeutic Science, School of Medicine, Tottori University Faculty of Medicine, Yonago 683-8503, Japan. 3. Division of Medical Biochemistry, Department of Pathophysiological and Therapeutic Science, School of Medicine, Tottori University Faculty of Medicine, Yonago 683-8503, Japan; ‡Division of Surgical Oncology, Department of Surgery, School of Medicine, Tottori University Faculty of Medicine, Yonago 683-8503, Japan. 4. †Division of Anesthesiology and Clinical Care Medicine, Department of Surgery, School of Medicine, Tottori University Faculty of Medicine, Yonago 683-8503, Japan.
Abstract
BACKGROUND: Sepsis is a syndrome triggered by endotoxin lipopolysaccharide (LPS) during bacterial infection. Sepsis sometimes recurs, with the second sepsis giving rise to a different phenotype because of disease modification by the preceding sepsis. Such a protective modification is called a preconditioning (PC) effect. PC is an endogenous protective mechanism by which sublethal damage confers tolerance to a subsequent lethal load. Oxidative stress is one of the important pathogenetic mechanisms that occur in sepsis. The nuclear factor erythroid 2 (NF-E2)-related factor-2 (Nrf2) system is a key regulatory transcription factor that protects organs and cells against oxidative stress and may be associated with the PC effect in repeated sepsis. METHODS: The effect of PC induced by low-dose LPS on survival rate and liver injury against subsequent high-dose LPS stimulation was examined using a mouse model of sepsis. In order to understand the detailed mechanism(s) involved in the PC effect within the liver, gene expression array was performed. As a candidate mechanism of PC, the activation of the Nrf2 system was analyzed using Nrf2 reporter mice. Furthermore, the induction of heme oxygenase-1 (HO-1), one of the main targets of Nrf2, in the liver was examined by immunoblotting and immunohistochemistry. The PC effect on liver injury induced by LPS was further examined using Nrf2-deficient mice. RESULTS: PC by LPS (1.7 or 5.0 mg/kg body weight, intraperitoneally) increased the survival rate of mice and decreased liver injury in response to a subsequent injection of a lethal level of LPS (20 mg/kg body weight). DNA array revealed that the gene ontology term "antioxidant activity" as one of the candidate mechanisms of the PC effect by LPS. In Nrf2 reporter mice, PC immediately and intensely enhanced luminescence that indicated Nrf2 activation after subsequent LPS injection. The induction of HO-1 by LPS was also enhanced by preceding PC, and its induction was observed mainly in Kupffer cells of the liver. In Nrf2-deficient mice, the induction of HO-1 in Kupffer cells and the hepatoprotective effect of PC were decreased as compared with wild-type mice. CONCLUSION: Our results suggest that activation of the Nrf2 system is, at least in part, one of the mechanisms of a PC effect in the mouse liver in the case of repeated LPS stimulation.
BACKGROUND:Sepsis is a syndrome triggered by endotoxin lipopolysaccharide (LPS) during bacterial infection. Sepsis sometimes recurs, with the second sepsis giving rise to a different phenotype because of disease modification by the preceding sepsis. Such a protective modification is called a preconditioning (PC) effect. PC is an endogenous protective mechanism by which sublethal damage confers tolerance to a subsequent lethal load. Oxidative stress is one of the important pathogenetic mechanisms that occur in sepsis. The nuclear factor erythroid 2 (NF-E2)-related factor-2 (Nrf2) system is a key regulatory transcription factor that protects organs and cells against oxidative stress and may be associated with the PC effect in repeated sepsis. METHODS: The effect of PC induced by low-dose LPS on survival rate and liver injury against subsequent high-dose LPS stimulation was examined using a mouse model of sepsis. In order to understand the detailed mechanism(s) involved in the PC effect within the liver, gene expression array was performed. As a candidate mechanism of PC, the activation of the Nrf2 system was analyzed using Nrf2 reporter mice. Furthermore, the induction of heme oxygenase-1 (HO-1), one of the main targets of Nrf2, in the liver was examined by immunoblotting and immunohistochemistry. The PC effect on liver injury induced by LPS was further examined using Nrf2-deficient mice. RESULTS:PC by LPS (1.7 or 5.0 mg/kg body weight, intraperitoneally) increased the survival rate of mice and decreased liver injury in response to a subsequent injection of a lethal level of LPS (20 mg/kg body weight). DNA array revealed that the gene ontology term "antioxidant activity" as one of the candidate mechanisms of the PC effect by LPS. In Nrf2 reporter mice, PC immediately and intensely enhanced luminescence that indicated Nrf2 activation after subsequent LPS injection. The induction of HO-1 by LPS was also enhanced by preceding PC, and its induction was observed mainly in Kupffer cells of the liver. In Nrf2-deficient mice, the induction of HO-1 in Kupffer cells and the hepatoprotective effect of PC were decreased as compared with wild-type mice. CONCLUSION: Our results suggest that activation of the Nrf2 system is, at least in part, one of the mechanisms of a PC effect in the mouse liver in the case of repeated LPS stimulation.
Authors: David Bar-Or; Matthew M Carrick; Charles W Mains; Leonard T Rael; Denetta Slone; Edward N Brody Journal: Redox Rep Date: 2015-03-24 Impact factor: 4.412
Authors: Weiqiang Liang; Johannes Greven; Kang Qin; Athanassios Fragoulis; Klemens Horst; Felix Bläsius; Christoph Wruck; Thomas Pufe; Philipp Kobbe; Frank Hildebrand; Philipp Lichte Journal: Front Immunol Date: 2022-02-10 Impact factor: 7.561