BACKGROUND:It is a mature technology to culture MC3T3-E1 cels in the self-assembling peptide hydrogel, RADA16-NBD. Moreover, it is confirmed that a variety of metal ions, such as Fe, Cu, Zn, Mn, are involved in normal bone metabolism.
OBJECTIVE:To observe the effect of Cu2+and Fe3+ on the proliferation and differentiation of MC3T3-E1 cels cultured in the self-assembling peptide hydrogel, RADA16-NBD.
METHODS: Osteoblasts cultured with RADA16-NBD were divided into three groups and respectively cultured in culture medium containing Cu2+, Fe3+ or serum-free medium (control group), respectively. After 24, 48 and 72 hours, cel proliferation was detected by cel counting kit-8. After 1, 3, 5 days, alkaline phosphatase activity was detected. At 21 days, formation of calcified nodules was observed. Cel migration ability of cels was observed at 24 hours of Transwil chamber culture.
RESULTS AND CONCLUSION:Compared with the control group, the proliferative ability of cels cultured in the Cu2+, Fe3+ groups was significantly higher (P < 0.05,P < 0.01). At 72 hours of culture, there was no difference in the cel proliferation among the three groups. At 1, 3, 5 days of culture, the alkaline phosphatase activity in the Cu2+, Fe3+ groups was significantly higher than that in the control group (P < 0.05); while at 3 and 5 days of culture, the alkaline phosphatase activity in the Cu2+ group was significantly higher than that in the Fe3+ group (P < 0.05). In addition, the number of migrated cels was higher in the Cu2+ group than the Fe3+ group (P < 0.05). These findings indicate that both Cu2+ and Fe3+, especialy the former one, can promote MC3T3-E1 cel proliferation, differentiation and migration.

BACKGROUND:Ligustrazine has been shown to restore the function of the femoral headviathe revascularization, increased blood flow, theabsorption ofnecroticbone, and bone regeneration. OBJECTIVE:To study the effects of ligustrazine on remodeling of periodontal tissues and the expression of osteoprotegerin in the maintenance phase in rats with orthodontic tooth movement. METHODS:Thirty-two healthy male Wistar rats were included and equaly randomized into four groups. Maxilary left first molar mesialization was performed through traction of 50 g force for 21 days to establish the rat model of tooth movement. 5, 10, 15 mg/L ligustrazine (50 μL) were localy injected into the first molar periosteum in model rats on the day before removing the orthodontic forcing device. Same volume of saline was injected in the control group. The injection was administered every other day. At 1 and 4 weeks after injection, the distance of tooth movement, the recurrence distances and percentage were determined and calculated. The pathological changes in periodontal tissues were observed by immunohistochemistry and hematoxylin-eosin staining. The width ofthe parodontium and number of osteoblasts were observed under an optical microscope. RESULTS AND CONCLUSION:The recurrence distance inthecontrol group was increased compared withtheexperimental group, while the number of osteoblasts and osteoprotegerin immunoreactivity were decreased. Good width of the parodontium and smal recurrence trend were found in 10mg/L ligustrazine group. These findings indicate that ligustrazine promotes the proliferation of osteoblasts and enhances the expression of osteoprotegerin, which is beneficial to the retention of teeth after orthodontic surgery.

Objective To investigate the expressions of lung cancer related genes and miRNA in peripheral blood of the residents surrounding the extremely high radon hot springs in Ruoergai County,Sichuan Province. Methods Peripheral blood samples were collected from the local residents.Expressions of lung cancer related genes (p53,k-ras) and miRNA (let-7a,miR-34a/b) were detected by real-time PCR and the protein expressions of p53 and k-ras were detected by Western blot.Results The expressions of p53 and k-ras mRNA of the residents in high radon area were 0.97 and 1.33 times of the control respectively (t =0.13,-1.12,P ＞0.05),and the p53 and k-ras protein levels were 0.70 and 1.23 times of the control respectively (t =0.72,0.46,P ＞ 0.05).The let-7a of the residents in high radon area was lower (t =1.63,P ＞ 0.05 ) while the miR-34a and miR-34b were significantly higher than those of the controls (t =- 3.20,- 3.32,P ＜ 0.05).Conclusions Based on the expressions of p53 and k-ras gene and miRNA,it can be concluded that the residents surrounding the high radon hot springs received radiation damage.

Objective To investigate the influences of miR-34a on the radiosensitivity of H1299 cells.Methods CCK-8 kit was used to examine the viability of H1299 cells which were exposed to different doses (0,2,4,6 and 8 Gy) of 60Co γ-rays after transient transfection of pre-miR-34a.Apoptosis rate and cell cycle were measured with flow cytometry.The expression levels of miR-34a target genes,bcl-2,bax,CDK4,CDK6 and cyclinD1 were analyzed by real-time PCR.Results Compared to the control group of negative transfection,the cell viability in pre-miR-34a transfection group decreased significantly after irradiation at0,2,4,6,8 Gy (t=-2.39,-3.12,-4.98,-4.03,-3.06,P＜0.05) in a dose-dependent manner.After being irradiated with 6 Gy γ-rays,the apoptotic rate in pre-miR-34a transfection group was significantly increased (t =7.06,P ＜ 0.05) together with an accumulation of G0/G1 phase (t =3.94,P ＜ 0.05) and a reduction of S phase (t =6.23,P ＜ 0.05).The gene expression levels of bcl-2,CDK4 and CDK6 in pre-miR-34a transfection group were respectively decreased (t =3.39,12.88,6.21,P ＜ 0.05) of negative control.cyclinD1 was also decreased but no significance,while bax was increased to 1.94 times of negative control (t =-4.35,P ＜ 0.05) together with a decrease of bcl-2/bax.Conclusions miR-34a could promote cell apoptosis,induce G0/G1 phase accumulation,suppress cell activity,and in turn increase the radiosensitivity of H1299 cells.

Objective To explore the expression of GPR30,HRG1 and HER2 including the activation status of HER2 (phosphorylated HER2)in invasive ductal breast cancers and their relationship with lymphatic metastasis.Methods The expres-sion of GPR30,HRG1,HER2 and pHER2 in 72 cases of specimens of invasive ductal breast cancers were examined by immunohis-tochemistry method.Results A moderate correlation between GPR30 and HRG1 was disclosed (r=0.597,P =0.000).There was strong correlation between pHER2 and GPR30 or HRG1(r=0.742,P =0.000;r=0.615,P =0.000).The expression of GPR30 and pHER2 in the lymphatic metastasis group was remarkably higher than in the group without lymphatic metastasis(P <0.05). Conclusion The interaction between GPR30 and HRG1 HER2 signal transduction pathways might be involved in the lymphatic metastasis in breast cancer.Blocking both of GPR30 and HRG1 signaling pathway could be a promising new strategy for breast cancer treatments.

BACKGROUND:Bone tissue transplantation or osteogenic material fil ing is after used for bone defect repair. To remove autologous bone tissues can lead to additional damage and secondary deformity, therefore, it is extremely urgent to search for a new osteogenic material. OBJECTIVE:To construct the porousβ-tricalcium phosphate (β-TCP)/col agen scaffold modified with human bone morphogenetic protein 2 (hBMP2) gene, and to observe its effects on differentiation of MC3T3-E1 cel lines. METHODS:The porousβ-TCP/col agen scaffold modified with hBMP2 gene was prepared. Then in vitro culture system of MC3T3-E1 cel lines with composite scaffold was established. There were scaffold and plate groups, and each group was divided into two subgroups according to the different concentrations of plasmid. Samples were col ected and observed morphological y by scanning electron microscope and light microscope after complex culture. After 1, 3, 7 and 14 days of induction, calcium nodules were observed through alizarin red staining, the cel cycle was detected by real-time PCR, and expressions ofαI-chain col agen type I gene, Osterix and bone sialoprotein were observed. RESULTS AND CONCLUSION:The number of cel s adhered, differentated and distributed on the composite scaffold was significantly higher than that of the single scaffold (P<0.05). Alizarin red staining and real-time PCR detection showed that the osteogenesis ability of MC3T3-E1 cel lines in the scaffold group was stronger than that in the plate group. To conclude, the porousβ-TCP/col agen scaffold modified with hBMP2 gene is an appropriate candidate for bone defect repair.

Objective To evaluate the effects of preventive cardiac pacing on acute inferior wall myocardiac infarction ( AIMI ) . Methods A total of 52 patients were given preventive cardiac pacing before Percutaneous coronary intervention (PCI) (group T),while another 68 patients were not (group N).Heart rate and average blood pressure level before reperfusion, average blood pressure level after reperfusion,TIMI flow grade before and after reperfusion,the incidence of malignant ventricular arrhythmia after reperfusion and adverse cardiovascular events during hospitalization were compared in two groups. Results There were no significant differences in heart rate before reperfusion , average blood pressure levels before and after reperfusion , and the TIMI flow grade before and after reperfusion between two groups. The malignant ventricular arrhythmia after reperfusion in group T was significantly higher than that in group N while heart failure and nonfatal myocardial infarction were no significantly different between them. Mortality rate and mortality rate of cardiovascular disease in group T were higher than those in group N, but there were no significant differences between them. Conclusions The temporary cardiac pacing has no additional preventive effect on hemodynamic , but increases the occurrence of malignant ventricular arrhythmia , and the risk of death and cardiovascular events.

Objective To explore the effects of high background radiation on the expressions of miR-16, miR-106b, miR-449a, miR-34a and let-7g in peripheral blood plasma of the residents .Methods Totally 110 healthy female long-term local residents aged over 50 years were randomly selected from the high background radiation area and the control area , while their age, body mass index(BMI) and other indicators were surveyed .The relative expression levels of miRNAs in peripheral blood plasma of these women were quantitatively detected by real-time fluorescence quantitative PCR ( RT-PCR) .Then t-test was used to analyze the cumulative dose , age and BMI between the high background and control group .Mann-Whitney U-test was used for statistical analysis of miRNA expression levels between two groups , and the multiple regression analysis was used finally .Results Compared with the control group , the cumulative dose of individuals in the high background group was about four times higher (t=42.803, P<0.05), and the levels of miR-16 and miR-106b in plasma of high background group were down-regulated, while the level of miR-449a was up-regulated ( Z =4.180, 2.422, 2.794, P <0.05 ).After controlling of confounding factors such as age and BMI , the expression levels of miR-16 and miR-106b were negatively correlated with the cumulative dose of individuals (P<0.05).On the contrary, no significant correlation was observed between the levels of miR-449a, miR-34a, let-7g and the individual cumulative dose (P>0.05).Conclusions miR-16 and miR-106b may serve as biomarkers for the early stage of low dose radiation health effects .

Objective To analyze the influence of ionizing radiation on the lymphocytes and its regulatory T cells in mice.Methods Mice were administered with whole body irradiation of γ-rays at different doses,and lymphocytes were separated from thymus and spleen,then the number of total cells were counted and the percentages of CD4 + T and CD4 + FOXP3 + CD25 + Treg lymphocytes were analyzed by using FACS.Results The lymphocyte numbers in thymus and spleen decreased in dosedependent manner and reached to the minimum at 4 d after irradiation (F =118.08,144.01,P ＜ 0.05).Exposure to higher dose(more than 1 Gy) decreased Treg number time-dependently in thymus,however increased it in spleen.On the contrary,exposure to lower dose (less than 0.75 Gy) increased Treg number in thymus.Besides,the percentage of Treg cells increased dose-dependently(in thymus,F =5.16,89.44,3.01,P ＜ 0.05 ; in spleen,F =52.02,32.13,27.45,P ＜ 0.05).Conclusions The radiation responses of lymphocytes and their Treg subpopulation vary with the different doses.Treg cells are resistant to high dose irradiation,however,their differentiation could be induced by low dose irradiation.In addition,the different time-dependent responses of lymphocytes and their subpopulation to ionizing radiation indicate the difference of lymphocyte maturation,differentiation and emigration.

Objective To detect the changes of the percentage of micronucleated reticulocytes (MN-RET) in the peripheral blood of mice exposed to 60Co γ-rays,in order to provide evidence for a new biomarker of radiation biodosimetry.Methods ICR mice were irradiated in whole body with 0,0.5,1,2,4 and 8 Gy at a dose rate of 0.24 Gy/min.Peripheral blood was collected for MN-RET assay using a flow cytometry.Results The percentage of peripheral MN-RET increased steadily with irradiation doses up to 2 Gy and then had a downtrend beyond 2 Gy.The changes of MN-RET observed with a microscope were consistent with the results from flow cytometry.The dose response of the MN-RET fitted to a lineal model (R2 =0.9063),and the MN-RET at 2 Gy was significantly higher than that of nonirradiated control (t =-2.856,P ＜ 0.05).Conclusion Percentage of peripheral M N-RET could be an early,rapid and high-throughput radiation bio-dosimeter in certain range of doses.