Mitochondrial protein OPA mediates osteoporosis induced by radiation through the P38 signaling pathway.

OBJECTIVE: Bone marrow is full of mitochondria. However, the role of bone marrow mitochondrial protein in bone marrow damage and related signal transduction mechanism remains to be further studied. OPA is a newly discovered mitochondrial transmembrane protein. Its expression pattern and function in the physiological and pathological conditions of bone marrow are still elusive. The purpose of this study is to investigate the potential role of OPA in osteoporosis. PATIENTS AND METHODS: A mouse osteoporosis model was established by radiation. The OPA expression was tested by Western blot and qRT-PCR. The P38 signaling activity was evaluated by enzymatic activity kit. The mitochondrial ATP production was determined by flow cytometry. The bone marrow cell apoptosis was detected by flow cytometry. U0126 was used to pretreat mouse before modeling. Bone marrow tissue was collected from patients who received osteoporosis surgery to test the OPA expression, P38 activation and cell apoptosis. The OPA and P38 levels were analyzed by correlation. RESULTS: The mouse osteoporosis model was successfully established by radiation induction. In this osteoporosis model, the expression of OPA was increased. The P38 signaling was activated while the mitochondrial ATP production was reduced, with the increase of apoptosis of bone marrow cells. By contrast, U0126 pretreatment markedly inhibited the OPA expression, restrained the P38 signaling pathway, enhanced mitochondrial ATP production and suppressed the bone marrow cell apoptosis in mouse osteoporosis model. A significantly positive correlation was found between OPA and P38. CONCLUSIONS: The down-regulation of OPA inhibits cell apoptosis and improves osteoporosis via inducing mitochondrial ATP production and suppressing the P38 signaling pathway.

Investigation for TGF-ß1 expression in type 2 diabetes and protective effects of TGF-ß1 on osteoblasts under high glucose environment.

OBJECTIVE: The occurrence rate of delayed fracture healing in diabetes mellitus patients is high. Transforming growth factor ß1 (TGF-ß1) is an important regulatory factor in bone tissue repair and regeneration. However, TGF-ß1 expression and its function in diabetic patient fracture have not been fully elucidated. PATIENTS AND METHODS: Type 2 diabetes fracture patients (T2DM group), fracture patients without diabetes (non-T2DM group), and healthy volunteers (Control group) were selected for the research. TGF-ß1 expression in peripheral blood was detected by using enzyme-linked immunosorbent assay (ELISA). Osteoblast cell line, MG-63 cells, were randomly divided into Control, high glucose group, and TGF-ß1 group. TGF-ß1 expression was evaluated by using Real Time-PCR (RT-PCR). Cell proliferation was evaluated by using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay. Cell apoptosis activity was determined with caspase-3 activity and flow cytometry assay. The effect of TGF-ß1 on NF-κB was detected by using Western blot. RESULTS: TGF-ß1 was significantly reduced in patients of T2DM and non-T2DM groups compared with Control (p<0.05), while it was lower in T2DM group (p<0.05). TGF-ß1 expression was declined, cell proliferation was inhibited, caspase-3 activity was enhanced, cell apoptosis was elevated, and NF-κB expression was reduced in MG-63 cells of high glucose group compared to Control group (p<0.05). TGF-ß1 significantly promoted cell proliferation, suppressed caspase-3 activity, alleviated cell apoptosis, and elevated NF-κB expression in MG-63 cells compared with high glucose group (p<0.05). CONCLUSIONS: TGF-ß1 decreased in diabetes fracture patients. Up-regulation of TGF-ß1 regulates cell apoptosis and caspase-3 activity, and it facilitates osteoblasts proliferation.

[The screening of rubella virus IgG antibody in Kaohsiung area women of successive age groups].

In this study, 961 females subjects were observed and their serum Rubella virus IgG antibody was analyzed by the ELISA method (Abbott Rubazyme commercial kit). The sample included 457 students from junior high school, senior high school and college; 144 female hospital workers; and 360 females 16 weeks or less pregnant. The number of positive results was 605 (63.0%). The positive rate increased when age increased: 29.1% (32/110) for ages 12-14; 52.3% (101/193) for ages 15-19; 61.6% (98/159) for ages 20-24; 68.7% (57/83) for ages 25-29 and 78.6% (44/56) ages above 30. The study also found a positive rate of 29.6% (37/125) in junior high school students, 52.7% (79/150) in senior high school students and 62.6% (114/182) in college students; The mean positive rate for the student group is 50.3% (230/457). The positive rate in the female hospital workers group is 71.5% (103/144). The positive rate for the pregnant women is 75.8% (273/360) the highest among these three groupings. The difference in positive rate between the student group and female hospital workers group or between the student group and the pregnant women's group is statistically significant (p less than 0.001). This study found that, among females whose ages are between 20-30 or who are pregnant, only 67.5% (166/246) had been infected by Rubella virus and had Rubella virus IgG antibody. From the epidemiological stand-point, it is worthwhile to screen those female's serum Rubella virus IgG antibody to give them Rubella vaccination if they test negative before marriage.