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The effect of erythromycin on the inflammation caused by exposure to cigarette smoke was investigated in this study. Mice were exposed either to cigarette smoke or to environmental air (control), and some mice exposed to cigarette smoke were treated with oral erythromycin (100 mg/kg/day for 8 days). Pulmonary inflammation was assessed by determining the cellular content of bronchoalveolar lavage (BAL) fluid. The messenger RNA (mRNA) levels of various mediators, including keratinocyte-derived chemokine (KC), macrophage inflammatory protein (MIP)-2, surfactant protein (SP)-D, granulocyte macrophage colony-stimulating factor (GM-CSF), tumor necrosis factor (TNF)-α, interleukin (IL)-6 in lung tissue were determined using quantitative reverse transcription polymerase chain reaction (qRT-PCR) assays. The exposure to cigarette smoke increased significantly the numbers of neutrophils (P = 0.029), macrophages (P = 0.029), and lymphocytes (P = 0.029) recovered in BAL fluid. Moreover, mRNA levels of KC (P = 0.029), MIP-2 (P = 0.029), SP-D (P = 0.029), and GM-CSF (P = 0.057) in the lung tissue were higher in mice exposed to cigarette smoke than in mice exposed to environmental air. In the erythromycin-treated mice that were exposed also to cigarette smoke, both neutrophil and lymphocyte counts were significantly lower in the BAL fluid than those in the vehicle-treated mice (P = 0.029). Erythromycin-treated mice exposed to cigarette smoke showed a trend of lower mRNA levels of KC and TNF-α in the lung tissue than those in the vehicle-treated mice, although the statistical significance was not achieved (P = 0.057). Our data demonstrated that erythromycin prevented lung inflammation induced by cigarette smoke, in parallel to the reduced mRNA levels of KC and TNF-α.

Recently, combination treatment with a macrolide and a steroid for Mycoplasma pneumoniae (Mp) pneumonia has been reported to be effective. Thus, the effect of this combination on a mouse model of lung inflammation associated with Mp extract (the LIMEX mouse) was studied. Interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α) were induced in Mp extract-treated RAW264.7 cells, and this induction was inhibited by dexamethasone, parthenolide, SB203580 or LY294002. This suggested that Mp extract activates nuclear factor κB-, p38- and PI-3K-linked pro-inflammatory signals. The LIMEX mice were then either treated with or without clarithromycin and/or dexamethasone. Clarithromycin administration enhanced the production of IL-6, TNF-α, macrophage inflammatory protein-1α, monocyte chemotactic protein-1 and RANTES, while their production was perfectly suppressed by the combination of clarithromycin and dexamethasone. IL-17, IL-23, keratinocyte-derived chemokine (KC) and interferon-γ levels were not affected by clarithromycin treatment, but they were significantly suppressed by the combination of dexamethasone and clarithromycin. Collectively, some components of Mp extract provoked an inflammatory reaction in the RAW 264.7 cell line and LIMEX mice. Whereas the lung reaction in LIMEX mice was further exacerbated by clarithromycin treatment, it was resolved by the combinational treatment with clarithromycin and dexamethasone.

A 70-year-old man with diabetes mellitus seen for fever, right chest pain, and right-lung field consolidation on chest X-ray was found in thoracoabdominal computed tomography (CT) to have variable-sized nodules in both lung fields and multiple low-density hepatic areas. On physical examination, his pulse was 145 beats per minute and blood pressure 92/68mmHg, indicating a preshock state. Laboratory tests showed elevated WBC of 15,200/microL, serum-C-reactive protein (CRP) of 34.4 mg/dL, and a decreased platelet count of 16,000/microL. Suspecting liver abscesses complicated by a septic pulmonary embolism, we immediately conducted percutaneous transhepatic abscess drainage (PTAD). Liver abscess blood culture and drainage fluid grew the Klebsiella pneumoniae hypermucoviscosity phenotype, carrying the rmpA gene. Although the man had been in critical condition on admission, broad-spectrum antibiotics and PTAD treatment improved his clinical condition to where he could be discharged without problem.

Objective and design:The histone acetylation processes, which are believed to play a critical role in the regulation of many inflammatory genes, are reversible and regulated by histone acetyltransferases (HATs), which promote acetylation, and histone deacetylases (HDACs), which promote deacetylation. We studied the effects of lipopolysaccharide (LPS) on histone acetylation and its role in the regulation of interleukin (IL)-8 expression. Material:A human alveolar epithelial cell line A549 was usedinvitro.Methods:Histone H4 acetylation at the IL-8 promoter region was assessed by a chromatin immunoprecipitation (ChIP) assay. The expression and production of IL-8 were evaluated by quantitative polymerase chain reaction and specific immunoassay. Effects of a HDAC inhibitor, trichostatin A (TSA), and a HAT inhibitor, anacardic acid, were assessed. Results:Escherichia coli-derived LPS showed a dose- and time-dependent stimulatory effect on IL-8 protein production and mRNA expression in A549 cellsin vitro. LPS showed a significant stimulatory effect on histone H4 acetylation at the IL-8 promoter region by ChIP assay. Pretreatment with TSA showed a dose-dependent stimulatory effect on IL-8 release from A549 cells as compared to LPS alone. Conversely, pretreatment with anacardic acid inhibited IL-8 production and expression in A549 cells. Conclusion:These data suggest that LPS-mediated proinflammatory responses in the lungs might be modulated via changing chromatin remodeling by HAT inhibition.

Macrolides are reported to reduce exacerbation of chronic inflammatory respiratory disease, such as chronic obstructive pulmonary disease (COPD), and also show anti-inflammatory effects in vitro and in vivo. However the anti-inflammatory efficacies of current macrolides are relatively weak. Here we found that a novel macrolide/fluoroketolide solithromycin (CEM-101) showed superior anti-inflammatory effects to macrolides in current clinical use. The effects of solithromycin (SOL) on lipopolysaccharide-induced TNFα (tumor necrosis factor α) and/or CXCL8 (C-X-C motif chemokine ligand 8; interleukin-8) release, phorbol 12-myristate 13-acetate-induced MMP9 (matrix metalloproteinase 9) activity and NF-κB (nuclear factor-κB) activity under conditions of oxidative stress have been evaluated and compared with the effects of erythromycin, clarithromycin, azithromycin, and telithromycin in macrophage-like PMA-differentiated U937 cells and peripheral blood mononuclear cells (PBMC) obtained from COPD patients. We also examined effect of SOL on cigarette smoke-induced airway inflammation in mice. SOL exerted superior inhibitory effects on TNFα/CXCL8 production and MMP9 activity in monocytic U937 cells. In addition, SOL suppressed TNFα release and MMP9 activity in PBMC from COPD patients at 10 µM, which is 10 times more potent than the other macrolides tested. Activated NF-κB by oxidative stress was completely reversed by SOL. SOL also inhibited cigarette smoke-induced neutrophilia and pro-MMP9 production in vivo, although erythromycin did not inhibit them. Thus, SOL showed better anti-inflammatory profiles compared with macrolides currently used in the clinic and may be a promising anti-inflammatory and antimicrobial macrolide for the treatment of COPD in future.