metastat and Acute-Lung-Injury

Background: The kidney is the most common extrapulmonary organ injured in sepsis. The current study examines the ability of aerosolized nanochemically modified tetracycline 3 (nCMT-3), a pleiotropic anti-inflammatory agent, to attenuate acute kidney injury (AKI) caused by intratracheal LPS. Methods: C57BL/6 mice received aerosolized intratracheal nCMT-3 (1 mg/kg) or saline, followed by intratracheal LPS (2.5 mg/kg) to induce acute lung injury-induced AKI. Tissues were harvested at 24 h. The effects of nCMT-3 and LPS on AKI were assessed by plasma/tissue levels of serum urea nitrogen, creatinine, neutrophil gelatinase-associated lipocalin, kidney injury molecule 1, and renal histology. Renal matrix metalloproteinase (MMP) level/activity, cytochrome C, Bax, Bcl-2, caspase-3, p38 mitogen-activated protein kinase activation, NLRP3, and caspase-1 were also measured. Apoptotic cells in kidney were determined by TUNEL assay. Renal levels of IL-1β and IL-6 were measured to assess inflammation. Results: Acute lung injury-induced AKI was characterized by increased plasma blood urea nitrogen, creatinine, injury biomarkers (neutrophil gelatinase-associated lipocalin, kidney injury molecule 1), and histologic evidence of renal injury. Lipopolysaccharide-treated mice demonstrated renal injury with increased levels of inflammatory cytokines (IL-1β, IL-6), active MMP-2 and MMP-9, proapoptotic proteins (cytochrome C, Bax/Bcl-2 ratio, cleaved caspase-3), apoptotic cells, inflammasome activation (NLRP3, caspase-1), and p38 signaling. Intratracheal nCMT-3 significantly attenuated all the measured markers of renal injury, inflammation, and apoptosis. Conclusions: Pretreatment with aerosolized nCMT-3 attenuates LPS-induced AKI by inhibiting renal NLRP3 inflammasome activation, renal inflammation, and apoptosis.

Topics: Acute Kidney Injury; Acute Lung Injury; Animals; Apoptosis; bcl-2-Associated X Protein; Caspase 1; Caspase 3; Creatinine; Cytochromes c; Inflammasomes; Inflammation; Interleukin-6; Lipocalin-2; Lipopolysaccharides; Mice; Mice, Inbred C57BL; NLR Family, Pyrin Domain-Containing 3 Protein; Proto-Oncogene Proteins c-bcl-2; Sepsis; Tetracyclines

To investigate the regulatory roles of neutrophil elastase (NE) and matrix metalloproteinase-9 (MMP-9) in lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice.. To construct LPS-induced ALI mouse models, wild-type C57BL/6 mice were administered 5.0 mg/kg of LPS through endotracheal, and/or 1.0 mg/kg of ONO-5046, and/or 20.0 mg/kg of chemically modified tetracycline-3 (CMT-3) by gavage. The levels of MMP-9, tissue inhibitor of metalloprotease-1, interleukin (IL)-6 were detected by real time RT-PCR at 6 h, 24 h and 48 h, and tumor necrosis factor (TNF), lung wet-dry weight ratio, white blood cell (WBC) count and polymorphonuclear (PMN) count in bronchoalveolar lavage fluid (BALF) were tested at 48 h after administration. The 5-day survival analysis of the ALI mice was also performed.. Both ONO-5046 and CMT-3, regardless of being used individually or combined, significantly reduced the levels of MMP-9, IL-6, and TNF in lung tissue as well as in BALF, and the WBC and PMN count in BALF. Combined treatment with ONO-5046 and CMT-3 remarkably improved the survival rate of ALI mice.. Neutrophil elastase synergizes with matrix metalloproteinase-9 to promote and regulate the release of inflammatory mediators and the infiltration of inflammatory cells, consequently affecting the survival of lipopolysaccharide-induced acute lung injury mice.

Topics: Acute Lung Injury; Animals; Bronchoalveolar Lavage Fluid; Disease Models, Animal; Glycine; Inflammation Mediators; Interleukin-6; Leukocyte Count; Leukocyte Elastase; Lipopolysaccharides; Matrix Metalloproteinase 9; Mice, Inbred C57BL; Neutrophils; Sulfonamides; Survival Analysis; Tetracyclines; Time Factors; Tissue Inhibitor of Metalloproteinase-1; Tumor Necrosis Factors