Interactive effects of cerium oxide and diesel exhaust nanoparticles on inducing pulmonary fibrosis

Cerium compounds have been used as a fuel-borne catalyst to lower the generation of diesel exhaust particles (DEPs), but are emitted as cerium oxide nanoparticles (CeO₂) along with DEP in the diesel exhaust. The present study investigates the effects of the combined exposure to DEP and CeO₂ on the pulmonary system in a rat model. Specific pathogen-free male Sprague–Dawley rats were exposed to CeO₂ and/or DEP via a single intratracheal instillation and were sacrificed at various time points post-exposure. This investigation demonstrated that CeO₂ induces a sustained inflammatory response, whereas DEP elicits a switch of the pulmonary immune response from Th1 to Th2. Both CeO₂ and DEP activated AM and lymphocyte secretion of the proinflammatory cytokines IL-12 and IFN-γ, respectively. However, only DEP enhanced the anti-inflammatory cytokine IL-10 production in response to ex vivo LPS or Concanavalin A challenge that was not affected by the presence of CeO₂, suggesting that DEP suppresses host defense capability by inducing the Th2 immunity. The micrographs of lymph nodes show that the particle clumps in DEP + CeO₂ were significantly larger than CeO₂ or DEP, exhibiting dense clumps continuous throughout the lymph nodes. Morphometric analysis demonstrates that the localization of collagen in the lung tissue after DEP + CeO₂ reflects the combination of DEP-exposure plus CeO₂-exposure. At 4 weeks post-exposure, the histological features demonstrated that CeO₂ induced lung phospholipidosis and fibrosis. DEP induced lung granulomas that were not significantly affected by the presence of CeO₂ in the combined exposure. Using CeO₂ as diesel fuel catalyst may cause health concerns.     

骨桥蛋白反义基因在食管癌浸润与转移中的作用

目的:探讨骨桥蛋白(OPN)反义基因对食管癌细胞增殖和转移的影响,为食管癌基因治疗提供理论依据。方法： PCR扩增获得人OPN基因,连接pcDNA3.1(+)载体,酶切、测序。脂质体介导将pcDNA3.1 -ANOPN基因转入ECA 109,G418筛选获得稳定表达ANOPN基因的转染细胞ECA-ANOPN、表达空载体的ECA-vect细胞及空白对照ECA 。RT-PCR检测ANOPN mRNA、免疫组织化学检测ANOPN基因蛋白表达。体外观察各组细胞生长速度、倍增时间,Transwell小室法检测细胞黏附、侵袭迁移能力的差异。结果：载体构建正确,测序结果与GenBank中公布的序列同源性为100%。与ECA-vect、ECA组比较,ECA-ANOPN细胞OPN的表达率明显降低（P<0.05）,生长速度明显减慢（P<0.05）,倍增时间增加（P<0.05）,透膜细胞数明显降低（P<0.01）。结论：ANOPN基因的稳定表达明显抑制ECA 109细胞的恶性表型。     

Immunodetection of noncollagenous matrix proteins during periodontal tissue regeneration

The interface between denuded dentin and regenerative periodontal tissue was investigated in a rat alveolar bone defect model using morphological and immunocytochemical approaches. The dentin surface was surgically exposed along the palatal roots of maxillary first molars. At 3 weeks post treatment, animals were perfused and treated regions from decalcified mandibles were embedded in Epon for ultrastructural studies or LR White for post-embedding immunogold labeling. Thin tissue sections were incubated with antibodies against noncollagenous matrix (osteopontin, bone sialoprotein, osteocalcin and fibronectin) and plasma (alpha2HS-glycoprotein and albumin) proteins. While in some cases, regenerative events took place directly on the denuded dentin surface, the interface between the denuded dentin and regenerating periodontal tissue was frequently characterized by the presence of an interfacial zone. This zone sometimes showed an electron-dense, cement line-like, planar accumulation of organic material immunoreactive for osteopontin and bone sialoprotein. Immunolabeling for osteocalcin and alpha2HS-glycoprotein was moderate and diffuse throughout the interfacial zone, whereas labeling with antibodies to albumin and fibronectin resulted in a weak reaction. It is concluded that accumulation of bone sialoprotein and osteopontin is a primary event during the formation of regenerative cementum onto denuded root surfaces.     

釉基质蛋白对人牙周膜细胞合成骨桥蛋白、骨涎蛋白的影响

目的:观察釉基质蛋白对体外培养的人牙周膜细胞合成骨桥蛋白、骨涎蛋白能力的影响.方法:乙酸法提取猪釉基质蛋白,改良组织块法原代培养人牙周膜细胞,免疫细胞化学方法和图像分析方法观察细胞合成骨桥蛋白、骨涎蛋白的能力.结果:人牙周膜细胞胞浆骨桥蛋白、骨涎蛋白染色阳性,200、100、50mg/L釉基质蛋白作用下可以使细胞胞浆骨桥蛋白、骨涎蛋白染色不同程度地加深.人牙周膜细胞在釉基质蛋白作用下,最早从第3d开始骨桥蛋白表达增加、从第7d开始骨涎蛋白表达增加.结论:一定浓度的釉基质蛋白在特定的时间可以促进牙周膜细胞合成骨桥蛋白、骨涎蛋白.     

Osteopontin in gingival crevicular fluid

Osteopontin (OPN) is a major glycosylated phosphoprotein in bone matrix and is produced by several cells including osteoblasts, osteoclasts and macrophages. OPN levels increase in active sites of bone metabolism. Recently, several bone-related proteins were identified in gingival crevicular fluid (GCF) to seek markers of alveolar bone resorption in periodontal disease. In this study, we investigated the existence of OPN in GCF and the correlation between OPN level in GCF and probing depth (PD) of sampling sites in 98 periodontitis patients and 35 healthy subjects. An immunoblotting analysis using 10% polyacrylamide gel showed that two forms of OPN with molecular masses of 54 and 66 kDa and several degraded fragments were detected in most GCF samples from diseased sites (PD > 4 mm). In GCF samples from healthy sites (PD < or = 3 mm), only one form (54 kDa) was observed, but any degraded fragments were not detected. When OPN amounts in GCF samples were determined by ELISA, a weak. but significant correlation was observed between OPN amount in GCF and PD (r=0.32, p=0.0013). These results demonstrate that OPN exists in GCF and that OPN level in GCF increases with the progression of periodontal disease.     

肾上腺髓质素对大鼠血管外膜成纤维细胞迁移的影响

目的研究肾上腺髓质素（ADM）对血管紧张素II（Ang II）诱导的大鼠胸主动脉外膜成纤维细胞迁移的影响。方法采用体外培养的大鼠胸主动脉外膜成纤维细胞,运用Transwell技术测定不同浓度ADM对外膜成纤维细胞迁移的影响,用RT-PCR及Western blotting分析Ang II（1×10-6mol/L）及不同浓度ADM干预后大鼠胸主动脉外膜成纤维细胞内骨桥蛋白的表达。结果在Ang II（1×10-6mol/L）趋化作用下,外膜成纤维细胞迁移活性较对照组显著增强,ADM可抑制Ang II刺激的细胞迁移,迁移细胞数目在一定范围内随着ADM浓度增加而减少;Ang II（1×10-6mol/L）诱导骨桥蛋白呈高表达,ADM可下调这种表达,呈一定剂量依赖性。结论ADM明显抑制Ang II刺激的外膜成纤维细胞迁移,并且ADM可以抑制Ang II刺激的骨桥蛋白表达。