Human heterochromatin protein 1 isoforms HP1(Hsα) and HP1(Hsβ) interfere with hTERT-telomere interactions and correlate with changes in cell growth and response to ionizing radiation

Telomeres are associated with the nuclear matrix and are thought to be heterochromatic. We show here that in human cells the overexpression of green fluorescent protein-tagged heterochromatin protein 1 (GFP-HP1) or nontagged HP1 isoforms HP1(Hsα) or HP1(Hsβ), but not HP1(Hsγ), results in decreased association of a catalytic unit of telomerase (hTERT) with telomeres. However, reduction of the G overhangs and overall telomere sizes was found in cells overexpressing any of these three proteins. Cells overexpressing HP1(Hsα) or HP1(Hsβ) also display a higher frequency of chromosome end-to-end associations and spontaneous chromosomal damage than the parental cells. None of these effects were observed in cells expressing mutants of GFP-ΔHP1(Hsα), GFP-ΔHP1(Hsβ), or GFP-ΔHP1(Hsγ) that had their chromodomains deleted. An increase in the cell population doubling time and higher sensitivity to cell killing by ionizing radiation (IR) treatment was also observed for cells overexpressing HP1(Hsα) or HP1(Hsβ). In contrast, cells expressing mutant GFP-ΔHP1(Hsα) or GFP-ΔHP1(Hsβ) showed a decrease in population doubling time and decreased sensitivity to IR compared to the parental cells. The effects on cell doubling times were paralleled by effects on tumorigenicity in mice: overexpression of HP1(Hsα) or HP1(Hsβ) suppressed tumorigenicity, whereas expression of mutant HP1(Hsα) or HP1(Hsβ) did not. Collectively, the results show that human cells are exquisitely sensitive to the amount of HP1(Hsα) or HP1(Hsβ) present, as their overexpression influences telomere stability, population doubling time, radioresistance, and tumorigenicity in a mouse xenograft model. In addition, the isoform-specific effects on telomeres reinforce the notion that telomeres are in a heterochromatinized state

Antigenic diversity of Theileria major piroplasm surface protein gene in Jeju black cattle

Piroplasms are tick-transmitted, intracellular, hemoprotozoan parasites that cause anorexia, fever, anemia, and icterus. Theileriosis is caused by Theileria sergenti and causes major economic losses in grazing cattle in Japan and Korea. In May 2003, we examined the antigenic diversity of the major piroplasm surface protein (MPSP) gene in 35 healthy Jeju black cattle that were born and raised at the National Institute of Subtropical Agriculture. On microscopic examination of Giemsa-stained blood smears, 9 of 35 cattle had intra-erythrocytic piroplasms. Hematological data were within normal range for all 35 cattle. Amplification of DNA from all blood samples using universal MPSP gene primers showed mixed infections with C, I, and B type Theileria spp. Type C was identified in 20 of 35 blood samples, and type B was identified in 17 samples. Allelic variation was seen in type B

Radioprotective effects of fucoidan on bone marrow cells: improvement of the cell survival and immunoreactivity

Fucoidan is a sulfated polysaccharide purified from brown algae including Fucus vesiculosus and has a variety of biological effects including mobilization of hematopoietic progenitor cells. Recently, we demonstrated that fucoidan stimulates the antigen-presenting functions of dendritic cells. In this study, we investigated the radioprotective effects of fucoidan on bone marrow cells (BMCs), which are the main cellular reservoir for the hematopoietic and immune system. To evaluate the effects of fucoidan, we assayed cell viability and immune responses. In a viability assay, fucoidan significantly increased the viability of BMCs. Based on the results of flow cytometric analysis, the increased viability of fucoidan-treated BMCs was attributed to the inhibition of radiation-induced apoptosis. Furthermore, fucoidan altered the production of immune-related cytokines from BMCs and increased the capability of BMCs to induce proliferation of allogeneic splenocytes. Taken together, our study demonstrated that fucoidan has radioprotective effects on BMCs with respect to cell viability and immunoreactivity. These results may provide valuable information, useful in the field of radiotherapy

The Effect of Insulin Resistance on Prognosis of Non-Diabetic Patients Who Underwent Percutaneous Coronary Intervention

Insulin resistance is an important risk factor for coronary artery disease. However, there has been no data regarding its clinical effect on the outcomes of percutaneous coronary intervention (PCI) in non-diabetic patients. We analyzed 98 non-diabetic consecutive patients (59±11.5 yr, male:female=63:35) who underwent elective coronary angiography. The patients were divided into two groups: Group I (n=71; the value of HOMA-IR [homeostasis model assessment of insulin resistance] <2.6) and Group II (n=27; the value of HOMA-IR ≥2.6). In-hospital and 30-day major adverse cardiac events (MACE) were compared between the two groups. The concentrations of fasting insulin and triglyceride were significantly higher in Group II than in Group I. Significant correlations were observed between the value of HOMA-IR and body mass index (r=0.489, p<0.001), levels of total cholesterol (r=0.204, p=0.045), triglyceride (r=0.334, p=0.001) and apolipoprotein B (r=0.212, p=0.038). PCI was performed in 59 patients (60.2%). In-hospital and 30-day MACE were higher in Group II than Group I (2.4% vs. 27.8%, p=0.008; 2.4% vs. 27.8%, p=0.008). Multivariate analysis revealed that the value of HOMA-IR ≥2.6 was an independent predictor of MACE. Increased HOMA-IR level is an important prognostic indicator in non-diabetic patients underwent PCI

One-Step Immunochromatography Assay Kit for Detecting Antibodies to Canine Parvovirus

This study was performed to determine the feasibility of using whole serum to detect antibodies to canine parvovirus (CPV) under nonlaboratory conditions and to evaluate the performance characteristics of an immunochromatography assay kit. Precise detection of levels of antibody against CPV in puppies can be used to determine a vaccination schedule, because maternal antibodies frequently result in the failure of protective vaccination, and can also be used to determine the antibody levels of infected puppies. Several methods for the titration of CPV antibodies have been reported, including the hemagglutination inhibition (HI) assay, which is considered the “gold standard.” These methods, however, require intricate and time-consuming procedures. In this study, a total of 386 serum specimens were tested. Compared to the HI assay, the rapid assay had a 97.1% sensitivity and a 76.6% specificity (with a cutoff HI titer of 1:80). This single-step assay could be performed rapidly and easily without special equipment. The kit provides a reliable method for detection of anti-CPV antibody where laboratory support and personnel are limited