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.

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 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 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.

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.

BACKGROUND:Bone morphogenetic protein-2 (BMP-2) is a key to bone formation and repair.However,it has some disadvantages such as easy to lose and degrade and difficult to sustain continuous effect.OBJECTIVE:To study the preparation and properties of silk fibroin/chitosan/nano-hydroxyapatite (SF/CS/nHA) scaffold loading BMP-2.METHODS:After silk degumming,dissolution and purification,2％ SF solution was obtained.BMP-2 was dissolved in 2％ CS solution,and then fully mixed with equal volume of SF solution and proper amount of nHA.At last,the SF/CS/nHA scaffold loading BMP-2 was prepared using freeze-drying method as experimental group.The SF/CS/nHA scaffold was soaked in the BMP-2 solution as control group.The scaffold porosity was measured by Archimedes method,the surface morphology of the scaffold was observed by scanning electron microscope,the compressive strength was measured by universal testing machine.Scaffolds in the two groups were soaked in PBS,and the release of BMP-2 was measured by ELISA method at different time points.RESULTS AND CONCLUSION:(1) The scaffolds in the two groups had irregular porous structure,interconnected pores and uneven pore wall.There was no significant difference between the two groups in mean pore diameter,porosity and maximum compressive strength.(2) On the 1st day,the release rate of BMP-2 was 4.63％ in the experimental group,and the release curve increased slowly.After 28 days,the release curve of BMP-2 was transferred to the plateau stage.But in the control group,the release rate of BMP-2 on the 1stday was 58.84％,and it was a significant initial burst release.The release curve increased rapidly,and was transferred to the platform stage on the 10th day.The release rate of BMP-2 release was significantly different between the two groups at days 1,2,4,10 (P ＜ 0.05).These results show that the SF/CS/nHA scaffold loading BMP-2 could sustainably and slowly release BMP-2.

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.

Objective To investigate if the administration of CORM-2 can provide protection against renal ischemia-reperfusion injury (IRI).Method Murine renal ischemia was induced by clamping left renal pedicles for 40 min with vascular micro damps at 32 C,then the contralateral kidney was removed.CORM-2 or vehicle was administered via intravenous infusion 1 h before the onset of ischemia.The blood plasma and renal samples were obtained at 24 h after reperfusion to assess renal function and cellular injury.Plasma Cr and BUN levels,HE and TUNEL were performed to estimate the magnitude of renal damage.Kidneys were retrieved from indicated animals at various time points after renal IRI,and the sections were prepared for histological evaluation.MPO staining procedures were performed to assess the neutrophils infiltration in the renal IRI.Besides,Immunofluorescent stain of TNF-α was performed on the kidneys which were retrieved from indicated animals to determine the production of inflammatory mediators in renal I/R.Results The plasma Cr and BUN were significantly increased at 24 h after reperfusion in IRI control mice,and CORM-2 treatment could markedly diminish the increase of plasma Cr and BUN in mice subjected to I/R.In parallel,histological analysis demonstrated that CORM2 treatment markedly reduced apoptosis of the renal tubular epithelium cells and hemorrhage.IRI caused marked infiltration and accumulation of the MPO-positive neutrophils in renal interstitium.Administration of CORM-2 before ischemia dramatically inhibited neutrophils infiltration as compared with IRI or iCORM-2 group.Furthermore,we confirmed that CORM-2 markedly decreased production of TNF-α.Conclusion Carbon monoxidereleasing molecule CORM-2 could ameliorate inflammation to protect against the renal IRI in mice.