Peroxiredoxins (Prxs) are a family of antioxidant proteins that reduce peroxide levels by using reducing agents such as thioredoxin. These proteins were characterized to have a number of cellular functions, including cell proliferation and differentiation and protection of specific proteins from oxidative damage. Thus, it is important to clarify the physiological role of Prxs by generating mouse models deficient in each Prx to better understand the in vivo function of Prxs. We have generated and characterized mice deficient in Prx I and II that are abundantly expressed in almost all types of cells. The Prx II-/- mice were healthy in appearance and fertile, however showed several pathophysiological disorders. Using the mice, we found that Prx II is an essential antioxidant enzyme that prevents oxidative stress in erythropoiesis, protects against endotoxin-induced lethal shock, regulates platelet-derived growth factor signaling and angiogenesis, inhibits cellular senescence, preserves cognitive function against age-linked hippocampal oxidative damage and exacerbates tumorigenesis in a liver cancer mouse model. The Prx I-/- mice were also healthy in appearance and fertile like Prx II-/- mice. With the mice, we found that Prx I suppresses K-ras-driven lung tumorigenesis by opposing the redox-sensitive extracellular-signal-regulated kinase/cyclin D1 pathway and plays concerted action with sulfiredoxin in preventing against alcohol-induced oxidative injury in the mouse liver. The results obtained suggest that Prx I and II are essential antioxidant enzymes for maintaining redox homeostasis in mice.
Animals ; Antioxidants ; Cell Aging ; Cell Proliferation ; Cell Transformation, Neoplastic ; Erythropoiesis ; Homeostasis ; Humans ; Liver ; Liver Neoplasms ; Lung ; Mice ; Mice, Knockout ; Oxidation-Reduction ; Oxidative Stress ; Peroxiredoxins ; Platelet-Derived Growth Factor ; Proteins ; Reducing Agents ; Shock ; Thioredoxins

PURPOSE: Matrix metalloproteinases (MMPs) have been reported to play critical roles in the endothelial cell migration and matrix remodeling during angiogenic process. To investigate the roles of the membrane type MMP (MT1-MMP) by the matrix remodeling of endothelial cells, MT1-MMP expression vector was transfected into bovine aortic endothelial cells (BAECs). Increased ex+pression of MT1-MMP in BAECs enhanced the activation of MMP-2, invasion and migration of BAECs. Moreover, the capacity of tube formation was increased by MT1-MMP transfectants. These observations indicate that MT1-MMP is involved in the angiogenic process of endothelial cells in vitro. In this study, we attempted these effects were confirmed in vivo system. MATERIALS AND METHODS: In this study, we used MT1- MMP or Antisense MT1-MMP stable transfectants in HT1080 human fibrosarcoma cells. Chorioallantoic membrane (CAM) assay was used for the detection of angiogenesis in vivo and modified CAM assay for quantification of invasion of MT1-MMP transfected cells. RESULTS: In CAM assay, the formation of microvessels was stimulated by MT1-MMP transfectants. Invasive capacity of HT1080 cells was also increased in a novel in vivo metastasis model, PCR based CAM assay. CONCLUSION: These results identify the function of MT1- MMP during the neovascularization process.
Chorioallantoic Membrane* ; Endothelial Cells ; Fibrosarcoma ; Humans ; Matrix Metalloproteinase 1* ; Matrix Metalloproteinase 14 ; Matrix Metalloproteinases ; Membranes ; Microvessels ; Neoplasm Metastasis ; Polymerase Chain Reaction

The hepatitis B virus (HBV) infects approximately 240 million people worldwide, causing chronic liver disease (CLD) and liver cancer. Although numerous studies have been performed to date, unfortunately there is no conclusive drug or treatment for HBV induced liver disease. The hepatitis B virus X (HBx) is considered a key player in inducing CLD and hepatocellular carcinoma (HCC). We generated transgenic (Tg) mice expressing HBx protein, inducing HCC at the age of 11–18 months. The incidence of histological phenotype, including liver tumor, differed depending on the genetic background of HBx Tg mice. Fatty change and tumor generation were observed much earlier in livers of HBx Tg hybrid (C57BL/6 and CBA) (HBx-Tg hybrid) mice than in HBx Tg C57BL/6 (HBx-Tg B6) mice. Inflammation was also enhanced in the HBx-Tg B6 mice as compared to HBx-Tg hybrid mice. HBx may be involved in inducing and promoting hepatic steatosis, glycemia, hepatic fibrosis, and liver cancer. Reactive oxygen species (ROS) generation was remarkably increased in livers of HBx Tg young mice compared to young wild type control mice.Previous studies on HBx Tg mice indicate that the HBx-induced ROS plays a role in inducing and promoting CLD and HCC.

The hepatitis B virus (HBV) infects approximately 240 million people worldwide, causing chronic liver disease (CLD) and liver cancer. Although numerous studies have been performed to date, unfortunately there is no conclusive drug or treatment for HBV induced liver disease. The hepatitis B virus X (HBx) is considered a key player in inducing CLD and hepatocellular carcinoma (HCC). We generated transgenic (Tg) mice expressing HBx protein, inducing HCC at the age of 11–18 months. The incidence of histological phenotype, including liver tumor, differed depending on the genetic background of HBx Tg mice. Fatty change and tumor generation were observed much earlier in livers of HBx Tg hybrid (C57BL/6 and CBA) (HBx-Tg hybrid) mice than in HBx Tg C57BL/6 (HBx-Tg B6) mice. Inflammation was also enhanced in the HBx-Tg B6 mice as compared to HBx-Tg hybrid mice. HBx may be involved in inducing and promoting hepatic steatosis, glycemia, hepatic fibrosis, and liver cancer. Reactive oxygen species (ROS) generation was remarkably increased in livers of HBx Tg young mice compared to young wild type control mice.Previous studies on HBx Tg mice indicate that the HBx-induced ROS plays a role in inducing and promoting CLD and HCC.

It has long been known that lactoferrin prevents human beings from infection of virus. To prove this activity of lactoferrin, we evaluated the activities of different lactoferrins to an isolate human rotavirus K-21. Bovine lactoferrin inhibited infection of K-21 to MA-104 cell at the concentration of 25.9 microM whereas bovine hydrolysed lactoferrin prevented rotavirus infection at 103.8 microM. However human lactoferrin prevented infection of K-21 at the concentration of 217.5 microM. These data suggested that lactoferrin activity may be unaffected by the intestinal digestive enzymes and bovine lactoferrin is more active than human lactoferrin with respect to prevention of rotavirus infection.
Humans* ; Lactoferrin* ; Rotavirus Infections ; Rotavirus*

It has long been known that lactoferrin prevents human beings from infection of virus. To prove this activity of lactoferrin, we evaluated the activities of different lactoferrins to an isolate human rotavirus K-21. Bovine lactoferrin inhibited infection of K-21 to MA-104 cell at the concentration of 25.9 microM whereas bovine hydrolysed lactoferrin prevented rotavirus infection at 103.8 microM. However human lactoferrin prevented infection of K-21 at the concentration of 217.5 microM. These data suggested that lactoferrin activity may be unaffected by the intestinal digestive enzymes and bovine lactoferrin is more active than human lactoferrin with respect to prevention of rotavirus infection.
Humans* ; Lactoferrin* ; Rotavirus Infections ; Rotavirus*

PURPOSE: To determine the value of high resolution ultrasonography (US) for the detection of hepatocellular carcinoma in the HBx transgenic mice. MATERIALS AND METHODS: Forty-two HBx transgenic mice aged 8-20 (mean, 14) months underwent high-resolution ultrasound using a 10 -12 MHz linear transducer. US findings indicating the presence or absence, number, size and echogenicity of each hepatic tumor were analyzed, and inaddition, color or power Doppler US was used to analyse tumoral vascularity. In each animal, sacrificed less than five hours after US examination, sonographic and pathologic findings were correlated. RESULT: On gross pathologic examination, 20 hepatocellular carcinomas measuring 1.5 -15 (mean, 4.7) mm in diameter were found in 16 mice; US revealed that 17 of the tumors were homogeneous hypoechoic nodules. With regard to tumor detection, sensitivity was 85%, specificity 96%, positive predictive value 0.944, negative predictive value 0.897, and overall accuracy 90%. Doppler US revealed that in three nodules, intratumoral vessels were present. Inthe other 26 mice, gross examination showed that no mass was present; microscopically, however, four nodules measuring 0.3 -1.2 mm were found in four of these animals. Tumoral vascularity detected by color Doppler US corresponded to the intratumoral vessel within the nodules. One peritoneal nodule, confirmed as a metastatic tumor, was found at the greater omentum. CONCLUSION: In HBx transgenic mice, high-resolution US is valuable for the detection of hepatocellular carcinoma.
Animals ; Carcinoma, Hepatocellular* ; Hepatitis B virus* ; Hepatitis B* ; Hepatitis* ; Liver Neoplasms ; Mice ; Mice, Transgenic* ; Omentum ; Sensitivity and Specificity ; Transducers ; Ultrasonography

Purpose: Expression of organic anion transporting polypeptides (OATPs) 1B1/1B3 in hepatocellular carcinoma (HCC) induces a paradoxical enhancement of gadoxetic acid on liver magnetic resonance imaging (MRI). We examined the expression profile of OATPs with regard to tumor differentiation in a genetically modified H-Ras 12V mouse model of spontaneous HCC that undergoes multistep hepatocarcinogenesis with minimal inter-individual variation. Materials and Methods: Tumor nodules were harvested from transgenic H-Ras 12V mice. Hematoxylin and eosin-stained slides were examined for tumor differentiation and high-grade pathological components (tumor necrosis, thickened trabeculae, or vascular invasion). Immunohistochemistry of OATP 1B1/1B3 was performed, and OATP expression was assessed. Results: We examined well-differentiated HCCs (n=59) in which high-grade pathological components were absent (n=49) or present (n=10). Among the well-differentiated HCCs without high-grade pathological components (n=49), OATP expression was negative, weak positive, and moderate positive in 23, 17, and nine cases, respectively. Among the well-differentiated HCCs with highgrade pathological components (n=10), OATP expression was negative, weak positive, and moderate positive in one, two, and seven cases, respectively. The ratio of positive OATP 1B1/1B3 expressing tumors was higher in HCCs with high-grade pathological components than in those without high-grade pathological components (p=0.004). Conclusion Our findings support those of previous clinical studies that have reported the frequent appearance of gadoxetic acidenhanced MRI in moderately differentiated HCC.

Purpose: Expression of organic anion transporting polypeptides (OATPs) 1B1/1B3 in hepatocellular carcinoma (HCC) induces a paradoxical enhancement of gadoxetic acid on liver magnetic resonance imaging (MRI). We examined the expression profile of OATPs with regard to tumor differentiation in a genetically modified H-Ras 12V mouse model of spontaneous HCC that undergoes multistep hepatocarcinogenesis with minimal inter-individual variation. Materials and Methods: Tumor nodules were harvested from transgenic H-Ras 12V mice. Hematoxylin and eosin-stained slides were examined for tumor differentiation and high-grade pathological components (tumor necrosis, thickened trabeculae, or vascular invasion). Immunohistochemistry of OATP 1B1/1B3 was performed, and OATP expression was assessed. Results: We examined well-differentiated HCCs (n=59) in which high-grade pathological components were absent (n=49) or present (n=10). Among the well-differentiated HCCs without high-grade pathological components (n=49), OATP expression was negative, weak positive, and moderate positive in 23, 17, and nine cases, respectively. Among the well-differentiated HCCs with highgrade pathological components (n=10), OATP expression was negative, weak positive, and moderate positive in one, two, and seven cases, respectively. The ratio of positive OATP 1B1/1B3 expressing tumors was higher in HCCs with high-grade pathological components than in those without high-grade pathological components (p=0.004). Conclusion Our findings support those of previous clinical studies that have reported the frequent appearance of gadoxetic acidenhanced MRI in moderately differentiated HCC.

Rotaviruses belong to Reoviridae causes diarrhea in human beings as well as domestic animals. This study was conducted to see what type of human rotaviruses are distributed in Seoul and Kyung-gi province. Twenty two of 81 patients showed rotavirus positive with diagnostic kit and RNA electropherosis. We isolated all of rotaviruses from the patients. Electropherotypes of 22 isolates showed 4:2:3 :2 patters whereas those migration patterns were long type. All of those isolates belonged to group 4. Twenty out of 22 isolates reacted with monoclonal antibodies specific to G1, P1A and subgroup II, whereas rest of them, 4-29 and K-30 reacted with subgroup I specific monoclonal antibody. The nucleotide sequence of an isolate K-21 showed 98~100% and 90~96% homologies with those of Wa and KU strain, respectively.
Animals, Domestic ; Antibodies, Monoclonal ; Base Sequence ; Diarrhea ; Gyeonggi-do ; Humans* ; Korea* ; Reoviridae ; RNA ; Rotavirus* ; Seoul