N-acetylcysteine Protects Mice from Lethal Endotoxemia by Regulating the Redox State of Immune Cells

The excessive production of reactive oxygen species (ROS) associated with inflammation leads to oxidative stress, which is involved with the high mortality from several diseases such as endotoxic shock and can be controlled to a certain degree by antioxidants. The immune cells use ROS in order to support their functions and, therefore, need adequate levels of antioxidant defenses in order to avoid the harmful effect of an excessive ROS production. In the present work, the effect of the administration of the antioxidant N-acetylcysteine (NAC) on the redox state of peritoneal macrophages and lymphocytes from mice with lethal endotoxic shock (100 mg/kg i.p. of lipopolysaccharide, LPS), was studied. In both types of immune cells at 0, 2, 4, 12 and 24 h after LPS injection, an increase of ROS, of the proinflammatory cytokine tumor necrosis factor alpha (TNFα), the lipid peroxidation (malonaldehyde levels, MDA), inducible nitric oxide synthase (iNOS) expression and the oxidized/reduced glutathione (GSSG/GSH) ratio, as well as a decrease of enzymatic antioxidant defenses, such as superoxide dismutase (SOD) and catalase (CAT) activity, was observed. The injection of NAC (150 mg/kg i.p. at 30 min after LPS injection) decreased the ROS, the TNFα the MDA levels, iNOS expression and the GSSG/GSH ratio, and increased the antioxidant defenses in both macrophages and lymphocytes. Moreover, the NAC treatment prevented the activation of nuclear translocation of the nuclear factor κB (NF-κB), which regulates ROS, inflammatory cytokines and antioxidant levels. Our present results provide evidence that both cell types have a relevant role in the pathogenesis of endotoxic shock, and that NAC, by improving the redox state of these immune cells, could increase mouse survival. Thus, antioxidants could offer an alternative treatment of human endotoxic shock.     

Macrophage elastase (MMP-12) in expanding murine adipose tissue

Background

Matrix metalloproteinases (MMPs) are known to play a role in adipose tissue development, but little information is available on the role of individual proteinases. Expansion of adipose tissue is associated with an increased macrophage content. Macrophage elastase (MMP-12) has an important role in macrophage infiltration, which induces pro-inflammatory effects in adipose tissue.

Methods

The role of MMP-12 was investigated in adipose tissues of MMP-12 deficient and wild-type control mice kept on normal chow or on high fat diet for 15 weeks.

Results

MMP-12 deficiency had no significant effect on total body weight or on subcutaneous (SC) or gonadal (GON) adipose tissue mass. Adipocyte and blood vessel size and density in SC and GON adipose tissues of obese mice were also comparable in MMP-12 deficient and control mice. Macrophage infiltration in SC and GON adipose tissues was not affected by MMP-12 deficiency, but the amount of crown-like structures (CLS) was significantly lower. MMP-12 deficiency did not affect elastin content in the extracellular matrix of SC or GON adipose tissue.

Conclusions

Adipose tissue mass and composition in mice with nutritionally induced obesity was not markedly affected by MMP-12 deficiency, except for an apparently lower degree of CLS.

General Significance

MMP-12 does not seem to be essential for macrophage infiltration in adipose tissue, but contributes to the formation of CLS surrounding moribund adipocytes.     

Probiotic Bacillus amyloliquefaciens SC06 Prevents Bacterial Translocation in Weaned Mice

Probiotic is a preparation containing microorganisms that confers beneficial effect to the host. This work assessed whether oral administration of Bacillus amyloliquefaciens SC06 (Ba) could decrease bacterial translocation in weaned mice. Weaned C57BL/6 were randomly allocated into three groups: group I as the control group, group II were treated with 0.85 % NaCl. Group III was administered with probiotic Ba 1 × 10⁹ CFU/day dissolved in 100 μl of 0.85 % NaCl for 30 days. Mice were then sacrificed, and tissue were cultured to determine bacterial translocation. Meanwhile, splenic CD4⁺T cells, CD8⁺T cells, B cells, and macrophages were analysised by FACS. Our results showed that probiotic Ba significantly reduced bacteria translocation compared with the control group and 0.85 % NaCl group (P < 0.05), lower levels of bacteria were detected in the MLN, liver, spleen, and kidney of mice. Moreover, significant increase in percentage and number of macrophages were observed in the spleen of Ba-treated mice compared with the control and 0.85 % NaCl groups. Together, these data indicated that Ba could decrease bacterial translocation in weaned mice. This effect seems to be correlated with the changes of macrophage numbers.     

Cryopreservation induces macrophage colony stimulating factor from human periodontal ligament cells in vitro

Cryopreservation is used to protect vital periodontal ligaments during the transplantation of teeth. We investigated which gene products implicated in root resorption are upregulated in human periodontal ligament cells by cryopreservation, and whether cryopreservation affects the expression of macrophage-colony stimulating factor (M-CSF) in human periodontal ligament cells. We used customized microarrays to compare gene expression in human periodontal ligament cells cultured from teeth immediately after extraction and from cryopreserved teeth. Based on the result of these assays, we examined M-CSF expression in periodontal ligament cells from the immediately extracted tooth and cryopreserved teeth by real-time PCR, enzyme-linked immunosorbent assay (ELISA), Western blot analysis, and immunofluorescence. We also investigated whether human bone marrow cells differentiate into tartrate-resistant acid phosphatase (TRAP) positive osteoclasts when stimulated with RANKL (Receptor Activator for Nuclear Factor κ B Ligand) together with any secreted M-CSF present in the supernatants of the periodontal ligament cells cultured from the various groups of teeth. M-CSF was twofold higher in the periodontal ligament cells from the rapid freezing teeth than in those from the immediately extracted group (p < 0.05). Cryopreservation increased M-CSF expression in the periodontal ligament cells when analyzed by real time PCR, ELISA, Western blotting, and immunofluorescence (p < 0.05). TRAP positive osteoclasts were formed in response to RANKL and the secreted M-CSF present in the supernatants of all the experimental groups except negative control. These results demonstrate that cryopreservation promotes the production of M-CSF, which plays an important role in root resorption by periodontal ligament cells.     

Enhancement of kinase selectivity in a potent class of arylamide FMS inhibitors

Structure–activity relationship (SAR) studies on a highly potent series of arylamide FMS inhibitors were carried out with the aim of improving FMS kinase selectivity, particularly over KIT. Potent compound 17r (FMS IC₅₀ 0.7 nM, FMS cell IC₅₀ 6.1 nM) was discovered that had good PK properties and a greater than fivefold improvement in selectivity for FMS over KIT kinase in a cellular assay relative to the previously reported clinical candidate 4. This improved selectivity was manifested in vivo by no observed decrease in circulating reticulocytes, a measure of bone safety, at the highest studied dose. Compound 17r was highly active in a mouse pharmacodynamic model and demonstrated disease-modifying effects in a dose-dependent manner in a strep cell wall-induced arthritis model of rheumatoid arthritis in rats.     

大鼠骨骼肌损伤后中性粒细胞、巨噬细胞和肌成纤维细胞数量分析研究

目的 研究大鼠骨骼肌损伤后中性粒细胞、巨噬细胞和肌成纤维细胞数量的变化情况,为今后骨骼肌损伤修复的病理学机制研究打下坚实的基础.方法 建立大鼠骨骼肌机械性损伤动物模型,随机分为伤后6h、12h、1d、3d、7d、10d、14d及正常对照组.应用免疫组织荧光染色和免疫组织化学染色,检测大鼠骨骼肌损伤后不同时间点中性粒细胞、巨噬细胞和肌成纤维细胞的数量.结果 伤后6h-12h,损伤区可见中性粒细胞和巨噬细胞浸润,中性粒细胞数量达到高峰.伤后1d,损伤区巨噬细胞数量急剧增加,迅速达到高峰,而中性粒细胞数量开始下降.伤后3d,中性粒细胞和巨噬细胞数量都显著下降.伤后7d,肌成纤维细胞开始出现.到伤后10d-14d,损伤区主要以肌成纤维细胞为主,偶见巨噬细胞.结论 大鼠骨骼肌损伤区中性粒细胞、巨噬细胞和肌成纤维细胞数量呈时间规律性变化,以期为骨骼肌损伤修复的病理学机制研究提供参考资料.     

不同产地雷公藤对巨噬细胞炎性因子的影响

目的:观察不同产地雷公藤对巨噬细胞上清液中炎性因子的影响。方法:收集国内雷公藤药材18批,经提取分离后所得的醇提物经细胞活性检测测定其作用于小鼠骨髓来源巨噬细胞(BMDM)的半数抑制率(IC50),18批样品均以IC50浓度作用BMDM细胞,以Elisa法对各组细胞上清液中的IL-6、IL-10及i NOS的含量进行检测,并通过与柳氮磺吡啶的比较观察各批次对巨噬细胞的影响。结果:安徽亳州产及贵州黔东南自治州雷州县产雷公藤醇提物的巨噬细胞上清液中IL-6及i NOS的含量均显著低于柳氮磺吡啶(P0.05),且其上清液中IL-10的含量均显著高于柳氮磺吡啶(P0.05)。结论:安徽亳州产及贵州黔东南自治州雷州县产雷公藤的醇提物对巨噬细胞的总体抗炎功效优于柳氮磺吡啶,且贵州黔东南自治州雷州县产雷公藤的出膏率最高,可作为雷公藤在治疗类风湿关节炎方面的"道地药材"进行深入的探索与研究。     

Association between high expression macrophage migration inhibitory factor (MIF) alleles and West Nile virus encephalitis

Infection with mosquito-borne West Nile virus (WNV) is usually asymptomatic but can lead to severe WNV encephalitis. The innate cytokine, macrophage migration inhibitory factor (MIF), is elevated in patients with WNV encephalitis and promotes viral neuroinvasion and mortality in animal models. In a case-control study, we examined functional polymorphisms in the MIF locus in a cohort of 454 North American patients with neuroinvasive WNV disease and found patients homozygous for high-expression MIF alleles to be >20-fold (p = 0.008) more likely to have WNV encephalitis. These data indicate that MIF is an important determinant of severity of WNV neuropathogenesis and may be a therapeutic target.