Keming Chen

Fourth Military Medical University, Xi’an, Liaoning, China

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Publications (10)5.86 Total impact

  • Article: [Study on estrogenic effect of genistein and apigenin in vitro].
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    ABSTRACT: To detect the estrogenic activity of genistein and apigenin with ER-positive cell line MCF-7 human breast cancer cells. MTT method was adopted to study the impact of genistein and apigenin on MCF-7 proliferation in vitro. Real-time RT-PCR method was used to detect their impact on ERalpha, ERbeta, PR and PS2 mRNA expression levels. Genistein and apigenin promoted the proliferation of MCF-7. Genistein 1 x 10(-10) mol x L(-1) group showed a significant increase in the expression of ERa mRNA levels or a 17. 76 times more than the control group and a 1.75 times more than the E2 group. Apigenin notably promoted the PR mRNA expression or a 4. 57 times more than the control group and a 1.11 times more than the E2 group. Both of them had different effect in promoting ERalpha, ERbeta, PR or PS2 mRNA. Both genistein and apigenin have a strong estrogen-like effect. Although they have different effect in promoting estrogenic response genes (such as ERa, ERbeta, PR and PS2 mRNA), genistein shows a stronger activity than apigenin. It also suggests that the signaling pathways of phytoestrogens showing estrogen-like effect are not completely identical with estrogen pathways. The B-cycle position of flavonoids is one of the key sites to estrogen-like activity, and isoflavones (cycle B on site 3) show stronger estrogen-like activity than flavones (B-cycle lies in site 2).
    Zhongguo Zhong yao za zhi = Zhongguo zhongyao zazhi = China journal of Chinese materia medica 08/2012; 37(15):2317-22.
  • Article: [Protective effect of genistein on hypoxic injuries of osteoblasts cultivated in vitro].
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    ABSTRACT: To investigate the effect of genistein on osteoblast proliferation, cellular cycle, apoptosis and differentiation of osteoblasts cultivated under hypoxia conditions. Rat osteoblasts were isolated from calvarias by enzyme digestion and a hypoxic model was established by in a triple-gas incubator. Rat osteoblasts were grouped into the normoxic control group, the hypoxia control group and the hypoxia administration group which was subdivided into Ge-6 group, Ge-5 group and Ge-4 group, to which genistein was administered at doses of 1 x 10(-6), 1 x 10(-5), 1 x 10(-4) mol x L(-1). The cell survival rate, lactic dehydrogenase leakage rate, apoptosis and differentiation of osteoblasts were observed for each group at 3 h after hypoxia, and the gene expression of HIF-1alpha, Bcl-2, Caspase-3 was detected by Real time RT-PCR. Forty-eight hours after hypoxia, osteogenic differentiation markers including alkaline phosphatase activity and nodules were detected. Compared with the hypoxia control group, the hypoxia administration group displays a significant increase in the survival rate and a decreased in LDH leakage rate, apoptosis rate and percentage of S + G2 phases. Besides, the mRNA level of HIF-1alpha and Bcl-2 were enhanced, the mRNA level of Caspase-3 was inhibited. Genistein has an effect on protecting osteoblasts from hypoxia.
    Zhongguo Zhong yao za zhi = Zhongguo zhongyao zazhi = China journal of Chinese materia medica 02/2012; 37(3):338-43.
  • Article: [Time effect of sinusoidal electromagnetic field on enhancing the maturation and mineralization of osteoblasts in vitro].
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    ABSTRACT: The present research was to investigate the time effect of sinusoidal electromagnetic fields (SEMFs) at different exposure time on the proliferation and differentiation of osteoblasts (OB) in vitro. The newborn rat calvarial OB were isolated by enzyme digestion and divided randomly into 7 groups after one passage. The exposure times of the SEMFs were 0.5 h, 1.0 h, 1.5 h, 2.0 h, 2.5 h and 3.0 h, respectively, and the frequency was 50 Hz. The cells were exposed in the SEMFs of 1.8 mT. Those without SEMFs exposure were used as the control group. They were observed under the contrast phase microscope each day. After 48 h, cell proliferation was assayed by MTT method. The alkaline phosphatase (Alkaline Phosphatase, ALP) activities were measured after the exposure of SEMFs for 3 d, 6 d, 9 d and 12 d, respectively. The calcified nodules were stained by Alizarin Bordeaux after 10 d. The cells exposed in the SEMFs were arranged in Spiral appearance after 8 d. The SEMFs exposure time at 2.0 h, 2.5 h and 3.0 h significantly inhibited cell proliferation (P < 0.01) and 0.5 h, 1.0 h, 1.5 h groups more significantly than control groups (P < 0.05). When the 3 d, 6 d and 12 d the ALP activities of the 0.5 h, 1.0 h, 1.5 h and 2.0 h, times group were significantly higher than those in the control group (P < 0.05), and after 9 d the 1.0 h, 1.5 h and 2.0 h activity of ALP higher significantly than control and other groups (P < 0.01). Other groups had no effect on the ALP activity. Alizarin Bordeaux staining result showed the amounts of calcified nodules 1.0 h, 1.5 h and 2.0 h higher than control groups. The SEMFs at 50 Hz, 1.8 mT different time exposure groups inhibits the proliferation of OB, but they enhances the maturation and mineralization of the OB and SEMFs at 1.8 mT of the 1.5 h has the strongest activity.
    Sheng wu yi xue gong cheng xue za zhi = Journal of biomedical engineering = Shengwu yixue gongchengxue zazhi 12/2011; 28(6):1085-8.
  • Article: [Effects of isopsoralen on bone marrow stromal stem cells differentiate and proliferate in vitro].
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    ABSTRACT: To investigated the effects of isopsoralen on bone marrow stromal stem cells (BMSCs) differentiate and proliferate in vitro. The stratum of mononuclear cells were separated and collected from the rat bone marrow sample by the all bone marrow cell culture methods. The cells were cultured in DMEM contained 10% fetal bovine serum. The culture medium was changed after three days. Nine days later, cells were treatment by isopsoralen with the concentration 1 x 10(-5), 1 x 10(-4), 1 x10(-6), 1 x 10(-7) mol x L(-1). MTT method was used for the proliferated analyzing. Under the induced condition, the alkaline phosphatase (ALP) activity, calcium salt sediment yield and osteocalcin were measured at the 4, 8, 12, 16 d. At the fifteenth day, histochemistry dyeing for calcified tubercle and ALP was proceeded. Total RNA was isolated and the gene expression of bFGF, IGF-1, Osterix and Runx-2 were investigated by Real Time PCR. The BMSCs proliferation refrained by isopsoralen with dose dependent. But it significantly enhanced osteogenesis, which was represented by the promotion of the ALP activity, calcium salt sediment yield, osteocalcin, and calcified tubercle amount. Besides, it also enhanced the mRNA level of bFGF, IGF-1, Osterix and Runx-2. The isopsoralen with the concentration 1 x 10(-5) mol x L(-1) can promote BMSCs differentiation to osteoblasts. It demonstrated the isopsoralen can prevent antiosteoporotic, which is an active part of the traditional Chinese medicine psoralea corylifolia.
    Zhongguo Zhong yao za zhi = Zhongguo zhongyao zazhi = China journal of Chinese materia medica 08/2011; 36(15):2124-8.
  • Article: [Comparative study on effect of icariin and genistein on proliferation and mineralization of osteoblasts in vitro].
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    ABSTRACT: To investigated the effect of icariin and genistein on proliferation and mineralization of cultured rat osteoblasts (rat calvarial osteoblasts, ROB). And to contrast the pharmacological activity of icariin and genistein. Bone cells were obtained by enzyme digestion from the segregated neonatal SD rat skull, and were cultured in MEM containing 10% FBS which was changed after three days later. Serial subcultivation was proceeded when cells covered with 90% culture dish. The final action concentration of icariin and genistein were both 1 x 10(-5) mol x L(-1). Proliferation was analyzed by MTT on 96-well plates, while differentiation was analyzed on 24-well plates. Under the induced condition, the alkaline phosphatase activity, calcium salt sediment yield and osteocalcin were measured at the 3, 6, 9, 12 d. At 12th day, ALP staining, alizarin red staining and calcified nodule count were preceded. Total RNA was isolated at 0, 6, 12, 24, 48, 72 h. The gene expression of bFGF, IGF-1, Osterix and Runx-2 was analyzed by Real-time RT-PCR. With the concentration of 1 x 10(-5) mol x L(-1), icariin and genistein have no significant effect on the ROB' s proliferation. The osteogenesis, ALP activity, calcium salt sediment yield and osteocalcin, calcified tubercle amount were significantly increased. And they enhanced the mRNA level of bFGF, IGF-1, Osterix and Runx-2. On the level of osteoblasts, the activity of icariin is stronger than that of genistein. When the final concentration of icariin and genistein is 1 x 10(-5) mol x L(-1), they can significantly promoted ROB maturation. And on the level of osteoblasts, the activity of icariin is stronger than that of genistein.
    Zhongguo Zhong yao za zhi = Zhongguo zhongyao zazhi = China journal of Chinese materia medica 08/2011; 36(16):2240-5.
  • Article: [Enhancement of osteoblastic differentiation of bone marrow mesenchymal stem cells in rats by sinusoidal electromagnetic fields].
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    ABSTRACT: The present research was aimed to investigate the effects of sinusoidal electromagnetic fields (SEMFs) on the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells in rats (rBMSCs) and to find out the intensity with the best therapeutic efficacy. Primary rat bone marrow mesenchymal stem cells were obtained from Wistar rats and screened by the adhesive method. The rBMSCs were exposed to sinusoidal electromagnetic fields with 50Hz frequency and intensities of 0 mT, 1.4 mT, 1.6 mT, 1.8 mT, 2.0 mT, and 2.2 mT respectively, 30 min per day. The proliferation of the rBMSCs was analyzed by MTT reduction assay. The osteogenic differentiation markers including ALP activity, calcium deposition, mineralized bone modulus and collagen I expression were compared between the rats in the exposed groups and those in the control group. The total cellular RNA was extracted after 6, 12, 24 and 48 hours, respectively. The gene expression of Osterix and IGF-1 was examined by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The absorbance of exposed groups was suppressed significantly in comparison with that in the control group. The exposure to the rBMSCs with intensity of 1.8 mT strongly enhances the osteogenic differentiation of rBMSCs, indicated by remarkably improved ALP activity, calcium deposition, collagen I expression and the number of mineralized bone nodules compared to that in the control group and other groups. Osterix and IGF-1 were also significantly improved (P < 0.05). The SEMFs with frequency and 50Hz and 1.4-2.2 mT intensities enhanced the osteogenic differentiation of rBMSCs, but inhibited their proliferation in the presence of 0.1% serum culture. Among the rBMSCs used in the tests, the one with 1.8 mT had the strongest activity, indicating that it could be the optimal intensity for the clinical application.
    Sheng wu yi xue gong cheng xue za zhi = Journal of biomedical engineering = Shengwu yixue gongchengxue zazhi 08/2011; 28(4):683-8.
  • Article: Sinusoidal electromagnetic field stimulates rat osteoblast differentiation and maturation via activation of NO-cGMP-PKG pathway.
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    ABSTRACT: Nitric oxide (NO) is an important intracellular and intercellular messenger, critically affecting bone metabolism. The purpose of this research is to investigate whether the effect of sinusoidal electromagnetic field (SEMF) on the differentiation and maturation of osteoblasts is mediated by the NO-cGMP-PKG signal pathway. We examined the impact of SEMF on nitric oxide synthase (NOS) activity, and found that L-NAME, nitric oxide synthase's inhibitor, prevents SEMF-mediated increase in NOS activity and NO levels. We showed that an inhibitor of soluble guanylyl cyclase (ODQ) blocks the increase in cGMP levels triggered by exposure to SEMF. The inhibitor PDE5, which hydrolyzes 3',5'-cyclic-GMP to 5'-GMP, prevents the SEMF's stimulation of PKG activity. We also blocked the NO-cGMP-PKG pathway to determine whether the maturation and mineralization of osteoblasts, stimulated by SEMF, would be inhibited. This was evaluated by measuring alkaline phosphatase (ALP) activity, osterix gene expression and mineralized bone modulus. After treatment with SEMF, the NOS activity increases in comparison with the control group (P<0.01), reaching the highest level after 0.5h. Osterix gene expression, ALP activity and mineralized bone nodules in the SEMF experimental group also increase significantly. However, these effects are partially blocked in the L-NAME treated cultures. Surprisingly, all the osteogenic markers in the SEMF+L-NAME group were slightly higher than in the control culture, but lower than in the cells exposed to SEMF only. We conclude that the NO-cGMP-PKG signal pathway is activated by SEMF treatment, the stimulatory effect of SEMF on the differentiation and mineralization of osteoblasts is attenuated when the pathway is blocked.
    Nitric Oxide 06/2011; 25(3):316-25. · 3.55 Impact Factor
  • Article: [Icariin promotes osteogenic differentiation of rat bone marrow stromal cells in vitro].
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    ABSTRACT: To investigate the effects of icariin on the osteogenic differentiation of rat bone marrow stromal cells (rBMSCs). rBMSCs were cultured by adherence screening method. Icariin was supplemented into the culture at 1 x 10(-5) mol x L(-1). The osteogenic differentiation markers including alkaline phosphatase (ALP) activity, CFU-F(ALP) and mineralized bone modulus were compared between the icariin-supplemented group and the control group. Total RNA was isolated and the gene expression of bFGF, IGF-1, Osterix(OSX) and Runx-2 was investigated by RT Real-time PCR. Icariin significantly improved ALP activity, CFU-F(ALP) amounts and mineralized modulus. It also can enhance the mRNA level of bFGF, IGF-1, Osterix and Runx-2. Icariin enhances the osteogenic differentiation of rBMSCs significantly, which suggested that icariin has the potentiality to be a new drug of anti-osteoporosis or fracture healing.
    Zhongguo Zhong yao za zhi = Zhongguo zhongyao zazhi = China journal of Chinese materia medica 12/2010; 35(23):3219-22.
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    Article: [Magnetic resonance imaging and pathological evaluation of vacuum sealing drainage efficacy of early treated limb gunshot].
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    ABSTRACT: Gunshot wound spreads to the surrounding tissues and organs, it is difficult to debride and easy to infect. The conventional treatment is thorough, extensive debridement, fully open drainage, which often causes normal tissue damage and complications. To evaluate the effectiveness of vacuum sealing drainage (VSD) treating the penetrating wound in porcine extremity by MRI and pathological methods so as to provide theoretical basis for future clinical use. Eight healthy adult pigs, weighing (45 +/- 5) kg, were selected. Eight pairs of hind limb penetrating wounds (16 wounds) were made by using Chinese-made 95-type rifle at 25 meters distance, which were randomly divided into experimental group (left side, n=8) and the control group (right side, n=8). After debriding and disinfecting the penetrating wounds at 6 hours after injury, wounds were treated with VSD in experimental group. The ballistics exports of the wounds were covered with single-layer gauze and imports were directly sutured and covered with sterile gauze in control group. The trajectory and the general condition of the adjacent skin were observed. MRI and histological observation were taken at 5, 24, 48, and 72 hours after injury, bacterial counting analysis was done at 0, 12, 24, 48, and 72 hours after injury. The aperture of the trajectory exit and entry were (5.00 +/- 2.50) cm and (0.30 +/- 0.15) cm immediately after injury. The wound surface was clean, rosy without leakage and swelling after 72 hours in experimental group; wound and adjacent tissue were swelling obviously, pus, muscle necrosis and exfoliative tissue was observed, and deep defect cavity at the trajectory exit could be seen in control group. MRI showed that pairs of linear low signal in T1WI and T2WI was seen in trajectory of experimental group at 5 hours after injury, and signal in T1WI gradually increased at disrupted area and tissue deformation area at 24, 48, and 72 hours; in control group, low signal in T1WI was observed at 5 hours after injury, and signal in T2WI gradually increased and a clear boundary between edema and surrounding tissue, and the increase of signal in T1WI was not obvious at 24, 48, and 72 hours. The histological observation showed that wound was dominated by effusion at 5 hours after injury, granulation tissue gradually increased, muscle tissue dissolved and inflammatory cell infiltration was not obvious at 24, 48, and 72 hours in experimental group; in control group, the gradual dissolution of muscle fibers and inflammatory cell infiltration were observed at 5, 24, and 48 hours, muscle tissue became swelling, dissolving and degeneration and a large number of inflammatory cell infiltration gathered into the bacteria group at 72 hours. There was no significant difference in the number of bacteria per gram of tissue (P > 0.05) between experimental group and control group at 0 hour after injury; the numbers of bacteria in control group were significantly higher than those in experimental group at 12, 24, 48, and 72 hours (P < 0.05). MRI combined with pathology show diagnostic meaning in treatment of gunshot wound with VSD. MRI can accurately reflect the scope of limb gunshot wound 72 hours after injury. VSD may be an approach to delay infective time, shorten wound healing time, and promote the growth of healthy granulation tissue.
    Zhongguo xiu fu chong jian wai ke za zhi = Zhongguo xiufu chongjian waike zazhi = Chinese journal of reparative and reconstructive surgery 03/2010; 24(3):335-9.
  • Article: Creation of macroporous calcium phosphate cements as bone substitutes by using genipin-crosslinked gelatin microspheres.
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    ABSTRACT: Macroporous calcium phosphate cements (CPCs) were developed using genipin-crosslinked gelatin microspheres (GMs) with two weight ratios (2.5 wt% and 5 wt%). The initial setting time of the composite was prolonged by GMs. After GMs/CPCs were soaked in phosphate-buffered saline (PBS) for several weeks, macropores appeared as a result of the degradation of GMs. The presence of GMs accelerated the setting reaction and improved the structure of the composite. The compressive strength increased up to 12 MPa (2.5 wt% GMs/CPCs) and 14 MPa (5 wt% GMs/CPCs) after one week of PBS soaking, then gradually decreased to 9 MPa (2.5 wt% GMs/CPCs) and 7 MPa (5 wt% GMs/CPCs) after three weeks of soaking, and further to 6 MPa (2.5 wt% GMs/CPCs) and 2 MPa (5 wt% GMs/CPCs) after five weeks of soaking. CPCs with 2.5 wt% GMs were the most favorable composite in the tested samples. Cell experiments showed that rat osteoblasts displayed normal morphologies when exposed to the 2.5 wt% GMs/CPCs, and proliferation of the cells was also enhanced. An in vivo study showed that new bone tissue was able to grow into the pores that resulted from GM degradation. This study suggests that the new composite could be a promising candidate for use as a bone substitute under non-compression-loaded circumstances.
    Journal of Materials Science Materials in Medicine 01/2009; 20(4):925-34. · 2.32 Impact Factor