Increased superoxide radicals generation from alveolar macrophages in immature guinea-pigs

Pre- and Postnatal Lung Development: An Updated Species Comparison

The purpose of this review is to give an outline of respiratory tract morphological and functional development with an emphasis on perinatal and postnatal maturational processes. In view of the rising need for qualitative and quantitative data for the development of pediatric pharmaceuticals, a comparison of the human situation to experimental animal models is made, and functional data as well as suitable models for human airway diseases and functional testing are presented. Birth Defects Research 109:1519-1539, 2017. © 2017 Wiley Periodicals, Inc.

Bioactive Composition of Pig Laryngeal Cartilage Extracts and Their Free Radical-scavenging Activity

This work focused on amino acid and mineral element analysis of pig laryngeal cartilage. Papain and DEAE-Sepharose fast flow ion exchange chromatography were used to hydrolyase cartilage and purify hydrolysate. Further study was performed to compare the free radical-scavenging activity of various fractions. Cartilage is abundant in bioactive amino acids such as glycine, glutamic acid and arginine and minerals such as calcium, magnesium and iron. Four polysaccahrides attached peptides and one peptide were isolated from hydrolysate. Weak 2,2-diphenyl-1-picryhydrazyl free radical scavenging activities of all substances were observed. Other fractions showed hydroxyl free radical and superoxide anion free radical scavenging ability in a concentration-dependent manner except fraction A. The hydroxyl free radical scavenging activity of tested samples decreased in the following order: fraction C crude chondroitin sulphate (ChS) peptide fraction B semi-purified ChS purified ChS. Significant differences were observed between purified ChS and other fractions (P 0.01). For superoxide anion free radical the order was: peptide purified ChS semi-purified ChS crude ChS fraction C fraction B. The peptide was significantly higher than purified ChS (P 0.01), which was significantly higher than the other components (P 0.01). According to the results, polysaccharides, ChS, amino acid and peptide present in cartilage had important bioactivity.

Age-dependent changes in porcine alveolar macrophage function during the postnatal period of alveolarization

During early postnatal ontogeny in most mammals, the lung is structurally and functionally immature. In some species with relatively altricial lung morphology, there is evidence of a coupling between functional maturity of the pulmonary cellular immune system and alveolar maturation. Herein, we examine changes in alveolar macrophage (AM) number and function occurring during alveolarization in a more precocial species, the pig, to determine if heightened oxidative metabolism and phagocytic ability is similarly delayed until completion of lung morphogenesis. We assessed cell differential in lavage fluid and evaluated two main functional parameters of AM phagocytic response, the generation of reactive oxygen species (ROS), and particle internalization. AM functional maturation occurred mainly during the first postnatal week: the proportion of AMs, ROS generation, and phagocytosis all increased significantly. These results suggest maturational improvement of the impaired AM-based pulmonary immune system of the neonate piglet occurs during the postnatal period of rapid alveolarization.

Urinary 8-oxo-7,8-dihydro-2'-deoxyguanosine in patients with parasite infection and effect of antiparasitic drug in relation to cholangiocarcinogenesis

Parasite infection of Opisthorchis viverrini is a major risk factor for cholangiocarcinoma. Our previous immunohistochemical studies showed that O. viverrini infection induced oxidative DNA lesions in the bile duct epithelium during cholangiocarcinoma development. The current study assessed the levels of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), an oxidative DNA lesion, in the urine and leukocytes of O. viverrini-infected subjects and cholangiocarcinoma patients. Forty-nine O. viverrini-infected patients, 55 cholangiocarcinoma patients, and 17 healthy controls were enrolled in the study. We measured 8-oxodG levels in the urine and leukocytes of these subjects using an electrochemical detector coupled to high-performance liquid chromatography. O. viverrini-infected patients were assessed before treatment and 2 months and 1 year after praziquantel treatment. Urinary 8-oxodG levels were significantly higher in cholangiocarcinoma patients (6.83 +/- 1.00 microg/g creatinine) than in O. viverrini-infected patients (4.45 +/- 0.25 mug/g creatinine; P < 0.05) and healthy subjects (3.03 +/- 0.24 microg/g creatinine; P < 0.01) and higher in O. viverrini-infected subjects than in healthy subjects (P < 0.01). The urinary 8-oxodG levels in O. viverrini-infected patients significantly decreased 2 months after praziquantel treatment and were comparable with levels in healthy subjects 1 year after treatment. Urinary 8-oxodG levels were significantly correlated with leukocyte 8-oxodG levels, plasma nitrate/nitrite levels, and aspartate aminotransferase activity. In conclusion, this study, in addition to our previous studies, indicates that 8-oxodG formation by parasite infection may play an important role in cholangiocarcinoma development. Urinary 8-oxodG may be a useful biomarker to monitor not only infection but also carcinogenesis.

Inducible nitric oxide synthase-dependent DNA damage in mouse model of inflammatory bowel disease

Increased cancer risk occurs in inflammatory bowel disease (IBD) undergoing long-term chronic inflammation. To evaluate whether inducible nitric oxide synthase (iNOS)-dependent DNA damage plays a role in the carcinogenic process triggered by IBD, we prepared a mouse model of IBD induced by transfer of CD45RBhighCD4+ T cells lacking regulatory T cells to female severe combined immunodeficiency (SCID) mice. CD45RBhighCD4+ T cells were isolated from mouse spleen after staining with fluorescein isothiocyanate (FITC)-conjugated anti-CD45RB monoclonal antibody, followed by anti-FITC-conjugated microbeads. This IBD mouse model showed that the bodyweight increased with aging to a lesser extent than non-treated controls, and that the intestine was shortened. Pathological findings of this mouse model, which showed severe inflammation in colon tissues, were similar to IBD patients. Double immunofluorescence technique revealed that both 8-nitroguanine and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) were formed mainly in epithelial cells of the IBD mouse model. 8-Nitroguanine was formed in most of 8-oxodG-immunoreactive nuclei of epithelial cells. iNOS, proliferating cell nuclear antigen and p53 protein were also expressed in the colon epithelium. These results indicate that nitrative DNA damage, as well as oxidative DNA damage, is induced in colon epithelial cells of the IBD mouse model followed by proliferation of these cells, which may contribute to colon carcinogenesis.

Mechanism of NO-mediated oxidative and nitrative DNA damage in hamsters infected with Opisthorchis viverrini: a model of inflammation-mediated carcinogenesis

Inflammation mediated by infection is an important factor causing carcinogenesis. Opisthorchis viverrini (OV) infection is a risk factor of cholangiocarcinoma (CHCA), probably through chronic inflammation. Formation of 8-nitroguanine and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), and expression of inducible nitric oxide synthase (iNOS) and heme oxygenase-1 (HO-1) were assessed in the liver of hamsters infected with OV. We newly produced specific anti-8-nitroguanine antibody without cross-reaction. Double immunofluorescence staining revealed that 8-oxodG and 8-nitroguanine were formed mainly in the same inflammatory cells and epithelium of bile ducts from day 7 and showed the strongest immunoreactivity on days 21 and 30, respectively. It is noteworthy that 8-oxodG and 8-nitroguanine still remained in epithelium of bile ducts on day 180, although amount of alanine aminotransferase activity returned to normal level. A time course of 8-nitroguanine was associated with iNOS expression. Furthermore, this study demonstrated that HO-1 expression and subsequent iron accumulation may be involved in enhancement of oxidative DNA damage in epithelium of small bile ducts. In conclusion, nitrative and oxidative DNA damage via iNOS expression in hamsters infected with OV may participate in CHCA carcinogenesis.