Yu Gong1, Lin Zou, Yan Feng, Dan Li, Jiayan Cai, Dunjin Chen, Wei Chao. 1. From the Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts (Y.G., L.Z., Y.F., D.L., J.C., W.C.); and Key Laboratory for Major Obstetric Diseases, Institute of Gynecology and Obstetrics, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, China (Y.G., D.C.).
Abstract
BACKGROUND: Toll-like receptor 2 (TLR2) contributes to sepsis pathogenesis such as deleterious systemic inflammation, cardiac dysfunction, and high mortality in animal studies. Mitochondrial dysfunction is a key molecular event that is associated with organ injury in sepsis. The role of TLR2 in sepsis-induced mitochondrial dysfunction remains unclear. METHODS: Intracellular hydrogen peroxide (H2O2), mitochondrial superoxide (O2), mitochondrial membrane potential (ΔΨm), and intracellular adenosine triphosphate (ATP) were measured in peritoneal leukocytes. A mouse model of polymicrobial sepsis was generated by cecum ligation and puncture (CLP). Wild-type and TLR2-deficient (TLR2) mice were subjected to sham or CLP. Mitochondrial functions including reactive oxygen species (ROS), ΔΨm, intracellular ATP, and complex III activity were measured. RESULTS: TLR2/1 activation by Pam3Cys enhanced intracellular H2O2 and mitochondrial O2 production in leukocytes, but had no effect on mitochondrial ΔΨm and ATP production. The effect was specific for TLR2/1 as TLR3 or TLR9 ligands did not induce ROS production. Polymicrobial sepsis induced mitochondrial dysfunction in leukocytes, as demonstrated by increased H2O2 and mitochondrial O2- production (CLP vs. sham; H2O2: 3,173±498, n=5 vs. 557±38, n=4; O2-: 707±66, n=35 vs. 485±35, n=17, mean fluorescence intensity, mean±SEM), attenuated complex III activity (13±2, n=16 vs. 30±3, n=7, millioptical densities/min), loss of mitochondrial ΔΨm, and depletion of intracellular ATP (33±6, n=11 vs. 296±29, n=4, nmol/mg protein). In comparison, there was significant improvement in mitochondrial function in septic TLR2-/- mice as evidenced by attenuated mitochondrial ROS production, better-maintained mitochondrial ΔΨm, and higher cellular ATP production. CONCLUSIONS: TLR2 signaling plays a critical role in mediating mitochondrial dysfunction in peritoneal leukocytes during polymicrobial sepsis.
BACKGROUND:Toll-like receptor 2 (TLR2) contributes to sepsis pathogenesis such as deleterious systemic inflammation, cardiac dysfunction, and high mortality in animal studies. Mitochondrial dysfunction is a key molecular event that is associated with organ injury in sepsis. The role of TLR2 in sepsis-induced mitochondrial dysfunction remains unclear. METHODS: Intracellular hydrogen peroxide (H2O2), mitochondrial superoxide (O2), mitochondrial membrane potential (ΔΨm), and intracellular adenosine triphosphate (ATP) were measured in peritoneal leukocytes. A mouse model of polymicrobial sepsis was generated by cecum ligation and puncture (CLP). Wild-type and TLR2-deficient (TLR2) mice were subjected to sham or CLP. Mitochondrial functions including reactive oxygen species (ROS), ΔΨm, intracellular ATP, and complex III activity were measured. RESULTS:TLR2/1 activation by Pam3Cys enhanced intracellular H2O2 and mitochondrial O2 production in leukocytes, but had no effect on mitochondrial ΔΨm and ATP production. The effect was specific for TLR2/1 as TLR3 or TLR9 ligands did not induce ROS production. Polymicrobial sepsis induced mitochondrial dysfunction in leukocytes, as demonstrated by increased H2O2 and mitochondrial O2- production (CLP vs. sham; H2O2: 3,173±498, n=5 vs. 557±38, n=4; O2-: 707±66, n=35 vs. 485±35, n=17, mean fluorescence intensity, mean±SEM), attenuated complex III activity (13±2, n=16 vs. 30±3, n=7, millioptical densities/min), loss of mitochondrial ΔΨm, and depletion of intracellular ATP (33±6, n=11 vs. 296±29, n=4, nmol/mg protein). In comparison, there was significant improvement in mitochondrial function in septic TLR2-/- mice as evidenced by attenuated mitochondrial ROS production, better-maintained mitochondrial ΔΨm, and higher cellular ATP production. CONCLUSIONS:TLR2 signaling plays a critical role in mediating mitochondrial dysfunction in peritoneal leukocytes during polymicrobial sepsis.
Authors: Mitchell M Levy; Mitchell P Fink; John C Marshall; Edward Abraham; Derek Angus; Deborah Cook; Jonathan Cohen; Steven M Opal; Jean-Louis Vincent; Graham Ramsay Journal: Crit Care Med Date: 2003-04 Impact factor: 7.598
Authors: Jose C Alves-Filho; Andressa Freitas; Fabricio O Souto; Fernando Spiller; Heitor Paula-Neto; Joao S Silva; Ricardo T Gazzinelli; Mauro M Teixeira; Sergio H Ferreira; Fernando Q Cunha Journal: Proc Natl Acad Sci U S A Date: 2009-02-20 Impact factor: 11.205
Authors: David Brealey; Sekhar Karyampudi; Thomas S Jacques; Marco Novelli; Ray Stidwill; Val Taylor; Ryszard T Smolenski; Mervyn Singer Journal: Am J Physiol Regul Integr Comp Physiol Date: 2003-11-06 Impact factor: 3.619
Authors: Hagir B Suliman; Martha S Carraway; Karen E Welty-Wolf; A Richard Whorton; Claude A Piantadosi Journal: J Biol Chem Date: 2003-08-05 Impact factor: 5.157
Authors: Julie A Pollock; Naina Sharma; Sirish K Ippagunta; Vanessa Redecke; Hans Häcker; John A Katzenellenbogen Journal: ChemMedChem Date: 2018-09-13 Impact factor: 3.466
Authors: Hai Peng Yan; Miao Li; Xiu Lan Lu; Yi Min Zhu; Wen-Xian Ou-Yang; Zheng Hui Xiao; Jun Qiu; Shuang Jie Li Journal: BMC Pediatr Date: 2018-08-09 Impact factor: 2.125
Authors: Erica L Heipertz; Jourdan Harper; Charlie A Lopez; Erol Fikrig; Michael E Hughes; Wendy E Walker Journal: J Immunol Date: 2018-05-14 Impact factor: 5.426
Authors: Russell B Hawkins; Steven L Raymond; Julie A Stortz; Hiroyuki Horiguchi; Scott C Brakenridge; Anna Gardner; Philip A Efron; Azra Bihorac; Mark Segal; Frederick A Moore; Lyle L Moldawer Journal: Front Immunol Date: 2018-07-02 Impact factor: 7.561