Zhi-Ling Yan

Xuzhou Medical College, Suchow, Jiangsu Sheng, China

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Publications (13)0 Total impact

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    ABSTRACT: This study was aimed to investigate the effect of Wnt/β-catenin signaling pathway on the biologic behavior of mouse bone marrow mesenchymal stem cells(mBM-MSC) by constructing a RNAi lentiviral vector specific to β-catenin. Three pairs of shRNA coding sequences directed against different sites of β-catenin mRNA were designed and were linked into lentiviral vector plasmid PLB for constructing the PLB-β-catenin/shRNA1, PLB-β-catenin/shRNA2 and PLB-β-catenin/ shRNA3. Those plasimds and lentiviral packaging plasimds were co-transfected into the packaging cells 293FT, then the virus particles were collected and the viral titer was assayed after concentration, and these viral particles were infected to MSC. The flow cytometry was used to sort GFP (+)cells, Western blot and RT-PCR were used to verify the inhibitory effect of those cells on expression of β-catenin gene in cells, CCK-8 method was used to detect the cell proliferation level, Annexin-V/7-AAD was used to determine the cell apoptosis after interference, the cell scratch and transwell tests were used to detect the migration capalbility of MSC. The results showed that the efficient inhibition of β-catenin mRNA and protein expression, and the suppression of MSC proliferation were observed in group of PLB-β-catenin/shRNA2(inteference group), while there was no significant changes of MSC proliferation between negative group(PLB group) and the normal group (control group). The flow cytometric detection indicated that after induced by serum starvation for 72 h, the apoptosis of MSC increased in inteference group, but there was no difference between PLB and control groups(P > 0.05). The cell scratch and transwell tests demonstrated that the migration capability of MSC in inteference group dicreased significantly, while the migration capability of MSC in control group was not changed obvi-ously. It is concluded that the constructed specific RNAi lentivirus can effectively inhibit the expression of β-catenin gene, decrease expression level of β-catenin mRNA and protein. The Wnt/β-catenin signaling pathway plays an important role in biological behavior of BM-MSC.
    Zhongguo shi yan xue ye xue za zhi / Zhongguo bing li sheng li xue hui = Journal of experimental hematology / Chinese Association of Pathophysiology 11/2013; 21(6):1546-51.
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    ABSTRACT: To investigate the sensitivity of imatinib mesylate (IM) on Sup-B15 Ph⁺ acute lymphoblastic leukemia (ALL) cells knockdown of VE-cadherin (CD144), and to further explore its mechanism. CD144 in Sup-B15 leukemia cells was stably knockdowned via lentivirus-mediated RNA interference (named as Sup-B15/shVEC). The inhibitory effects of IM on Sup-B15/shVEC and Sup-B15 leukemia cells were measured by CCK-8 test, and the apoptosis of those cells was determined by AnnexinV/7-AAD dyeing using flow cytomery, the percentage of CD34⁺CD38⁻ leukemia cells also by flow cytomtery. ALDH1 mRNA levels were detected by real-time RT-PCR, and protein levels of CD144, CD133, Bcr-abl and β-catenin by Western blot. IM treatment presented inhibitory effects on Sup-B15/shVEC and Sup-B15 leukemia cells at multiple concentrations of IM. The IC50 of IM on Sup-B15/shVEC and Sup-B15 leukemia cells were 25.1μmol/L and 18.7μmol/L, respectively (P<0.05). After 48h of 20 μmol/L IM treatment, the percentages of apoptosis cell in Sup-B15/shVEC cells and Sup-B15 cell were (13.52±2.06)% and (3.03±0.72) %, respectively (P<0.05). The percentage of CD34⁺CD38⁻ cells in Sup-B15 cells was significantly higher than in Sup-B15/shVEC cells [(2.39±0.28)% vs (0.96±0.07)%, P<0.05). As compared to Sup-B15 cells, the transcription of ALDH1 in Sup-B15/shVEC was remarkably downregulated, and the CD133 protein level was also downregulated in Sup-B15/shVEC cells. Both cytoplamic and nucleic β-catenin protein levels (but not for Bcr-abl levels) decreased in Sup-B15/shVEC cells as compare to Sup-B15 cells. Knockdown of CD144 sensitized Sup-B15 Ph+ ALL cells to IM. The possible mechanisms underlying this phenomenon might be via inhibiting β-catenin nucleic translocation and facilitating β-catenin degradation.
    Zhonghua xue ye xue za zhi = Zhonghua xueyexue zazhi 06/2013; 34(6):522-526.
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    ABSTRACT: To investigate the change of CD4⁺CD25(high)CD127(low) regulatory T cells (Tregs) percentage in patients with primary immune thrombocytopenia (ITP) treated by different methods. One hundred and thirty-eight newly diagnosed adult ITP patients (57 male, median age 40 years, range 18-70 years) were enrolled in this study, who were randomisedly separated into three regiment groups, namely prednisolone (PSL, 1.5 mg/kg for 2-4 weeks and subsequently stepwise reduction) group enrolled 49 patients, dexamethasone [(one course of high-dose dexamethasone (HDD) 40 mg/day, d1-4] 45 patients, and rituximab plus HDD (rituximab 100 mg on days 7, 14, 21, 28 and HDD) group 44 patients. Peripheral blood was taken in ITP patients of each group before treatment, 14 d and 28 d after treatment. The percentages of CD4⁺CD25(high)CD127(low) Tregs in 30 healthy controls and 138 patients were analyzed by flow cytometry. Overall response (OR) rates of PSL, HDD and R+HDD groups at day 28 were 69.4%, 66.7% and 79.5% respectively with no difference. After the following 12 months, sustained response (SR) was more pronounced in R+HDD group compared to the other two groups (R+HDD vs PSL: 66.7% vs 37.8%, P<0.05; R+HDD vs HDD: 66.7% vs 22.7%, P<0.05). The percentage of CD4⁺CD25(high)CD127(low) Tregs in peripheral blood of ITP patients [(1.67±0.70)%] was significantly lower than in healthy control group; After treatment, the percentages of Tregs in peripheral blood of patients both at day 14 and 28 in R+HDD group remarkably decreased compared with before treatment [(4.28±1.09)% vs (1.68±0.68)%, P<0.05; (4.44±0.63)% vs (1.68±0.68)%]. The percentages of Tregs at day 14 in both other two groups decreased notably compared with before treatment. But the Tregs levels measured at day 28 in PSL and HDD groups were similar with before treatment. The percentage of CD4⁺CD25(high)CD127(low) Tregs in peripheral blood of ITP patients was lower than healthy individual. The higher SR of patients treated by R+HDD was related to its ability to up-regulate the percentage of CD4⁺CD25(high)CD127(low) Tregs.
    Zhonghua xue ye xue za zhi = Zhonghua xueyexue zazhi 06/2013; 34(6):478-481.
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    ABSTRACT: OBJECTIVE: To compare the efficacy and safety of low-dose rituximab combined with different dosage of glucocorticoids for immune thrombocytopenia (ITP). METHODS: Seventy-four patients (35 male, median age 34 years, range 18-70 years) including 60 newly-diagnosed, 6 persistent, 5 chronic and 3 refractory patients were enrolled in this study, and separated into control (36 cases) and experimental (38 cases) groups according to the dosage of glucocorticoids. Patients in both groups received dexamethasone 40 mg/day on days 1-4, followed by rituximab 100 mg on days 7, 14, 21, 28. The patients in experimental group also received decrements of prednisone 60, 30, 20, 10 mg/day on days 5-7, 8-14, 15-21, 22-28. The initial, long-term efficacy and safety were evaluated. RESULTS: Platelet counts of all patients at day 4 remarkably increased, with the median platelet count from 11(1-26)×10⁹/L to 84(23-132)×10⁹/L in control group, and 10(2-20)×10⁹/L to 80(22-115)×10⁹/L in experimental group;the platelet counts of patients at day 14 in experimental group [163(19-262)×10⁹/L] was higher than that of control group [98(18-238)×10⁹/L] (P<0.05). The overall response (OR) rates at day 28 in experimental group (84.21%) was significantly higher than that of control group (66.67%, P=0.03). There was no significant difference of sustained response (SR) rates in two groups (63.89%vs 65.79%, 58.33%vs 60.53%, P>0.05) at six and twelve months follow-up points. Both groups showed similar incidence of adverse events, and no patients discontinued the treatment due to side effects. CONCLUSION: Low-dose rituximab and glucocorticoids was an effective method for ITP patients, and maintenance treatment with decrements of prednisone contributed to improving earlier CR rate.
    Zhonghua xue ye xue za zhi = Zhonghua xueyexue zazhi 05/2013; 34(5):409-412.
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    ABSTRACT: OBJECTIVE: To construct mouse CXC chemokine receptor type 4 (Cxcr4) gene overexpressing lentiviral vector and to evaluate its biological effect on mouse mesenchymal stem cells (MSCs). METHODS: Cxcr4 gene was amplified and subcloned into pCR-Blunt vector. Cxcr4 gene and enhanced green fluorescent protein (EGFP) gene expressed bicistronic recombinant lentiviral vector LV-CXCR4-IRES-EGFP and control vector LV-IRES-EGFP were constructed, respectively. Both plasmids were co-transfected into 293FT packaging cell line with packaging plasmid pSPAX2 and enveloping plasmid pMD.2G using Lipofectamine 2000 to produce lentiviral virus, respectively. The recombinant viruses were harvested and the virus titer was determined by limiting dilution. Mouse MSCs were infected with viral supernatant. EGFP expression was visualized using fluorescence microscope and efficiency of infection was determined by flow cytometry (FCM). Cell counting kit-8 (CCK-8) was applied in mixed lymphocyte reaction (MLR) to evaluate the suppressive effect of MSCs on mice splenocyte proliferation in vitro. Wound healing ability of MSCs was measured by scratch experiment and migration capacity by a chemotaxis assay using a transwell assay. RESULTS: The Cxcr4 fragment was amplified by reverse transcription polymerase chain reaction (RT-PCR) and verified by DNA sequencing. The restriction enzyme digestion experiment demonstrated that the recombinant lentiviral vector LV-CXCR4-IRES-EGFP and the control vector LV-IRES-EGFP were successfully constructed. Expression of CXCR4 was detected by fluorescence microscopy, which indicated that the lentiviral particles expressing CXCR4 were packaged. Furthermore,expression of EGFP were detected by fluorescence microscopy in MSCs after infection and the expression of CXCR4 protein on MSCs surface in CXCR4-MSC group was significantly increased comparing to those in the control group(P<0.05).CXCR4-MSCs group and the control group were (90.3±3.37)% and (1.53±0.34)%, respectively. Meanwhile, overexpression of CXCR4 had no effect on their capacity of immune regulation when co-cultured with splenocyte(P>0.05). Moreover, overexpression of CXCR4 can not only accelerated the wound healing after scratch, but also enhanced the migration ability of cells in the transwell induced by high concentration of SDF-1 in a dose-dependent manner compared with the EGFP control group. CONCLUSION: The CXCR4 expressing lentiviral vector LV-CXCR4-IRES-EGFP was successfully constructed. The lentiviral vector can not only efficiently infect mouse MSCs, but also stably express CXCR4 in MSCs. The MSCs modified with CXCR4 have biological characteristic in vitro.
    Zhonghua xue ye xue za zhi = Zhonghua xueyexue zazhi 05/2013; 34(5):440-444.
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    ABSTRACT: This study was aimed to clone the gene coding mouse fibroblast growth factor receptor-1 (fgfr1), to construct the recombinant lentiviral vector of truncated form fgfr-1 (Δfgfr1) carrying enhanced green fluorescence protein (EGFP) and to investigate its expression in eukaryotic cells (293FT cells). The full length fgfr1 gene was cloned by RT-PCR using brain tissue of BALB/c fetal mouse as template and inserted into PCR-Blunt vector, a truncated fgfr1 fragment was produced by site-directed mutagenesis for deleting intraccllular phosphorylated domain, then was subcloned into a lentiviral vector and cotransfected into 293FT packaging cells together with envelope plasmid and packaging plasmid by lipofectamine 2000. Viruses were gathered and concentrated using ultracentrifuge, and then transfected into 293FT cells. Expression of EGFP was detected by fluorescent microscopy and flow cytometry (FCM), and the truncated FGFR1 protein was detected by Western blot. The results demonstrated that mouse fgfr1 gene was cloned and the lentiviral expression vector LV-IRES-EGFP-Δfgfr1 and control vector LV-IRES-EGFP were successfully constructed. The lentiviral particles were correctly packaged, and the virus titers were above 10(8) TU/ml in the supernatant after concentration. Expression of EGFP was detected by fluorescent microscopy in 293FT cells post transfection, and the transfection efficacy was > 95% determined by FCM. Expression of FGFR1 protein detected by Western blot was significantly higher than that in control group. It is concluded that the truncated gene fgfr1 along with the gene coding EGFP is successfully inserted into a lentiviral vector to construct a recombinant lentiviral vector, which can be expressed in eukaryotic cells.
    Zhongguo shi yan xue ye xue za zhi / Zhongguo bing li sheng li xue hui = Journal of experimental hematology / Chinese Association of Pathophysiology 01/2012; 20(1):168-72.
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    ABSTRACT: To explore the functions of TH17 cell in cutaneous graft-versus-host disease (GVHD). A model of acute GVHD (aGVHD) was established with a major histocompatibility complex class I/II-disparate allogeneic bone marrow transplantation (BMT). Bone marrow monocytes and splenic T cells from donor C57/BL6 were enriched. The recipient BABL mice were irradiated ((60)Co source) with 7.5 Gy total body irradiation (TBI) and injected with 5 × 10(6) marrow monocytes and 5 × 10(5) T cells. The experimental mice were divided into 3 groups: lethal total body irradiation (TBI); allogeneic bone marrow transplantation (BMT) and recipients of halofuginone (HF). The symptoms of aGVHD were observed daily and detailed histopathologic analyses of recipient skin were performed at Day 6 post-transplantation. And Tri-color flow cytometry (FCM) was performed at Day 6 post-transplantation to measure the levels of interleukin (IL)-17, interferon (IFN)-γ and TH1/TH17. Clinical GVHD symptoms were observed in recipient mice. The administration of HF to lethally irradiated recipients led to very modest GVHD-induced cutaneous changes manifested predominantly by fur loss. However, the experimental animals receiving only allogeneic BMT showed significant fur loss and pathologic skin conditions. Consistent with the clinical evaluations, the histopathologic results demonstrated significantly increased pathologic cutaneous lesions in recipients undergoing only BMT. The median ratios of TH1/TH17 cells were 17.57 and 5.31 in the HF and BMT groups respectively. The difference had statistical significance (P < 0.05). The serum levels of IL-17 were(1.47 ± 0.18) and (2.81 ± 0.19) pg/ml in the TBI and BMT groups respectively (P < 0.05). But IL-17 could not be detected in the HF group. The serum levels of IFN-γ were (3.86 ± 0.32), (42.97 ± 0.42) and (9.89 ± 0.51) pg/ml in the TBI, BMT and HF groups respectively. The inter-group differences had statistical significance (P < 0.05). An absence of TH17 cell may alleviate the cutaneous GVHD but exacerbate the systemic GVHD.
    Zhonghua yi xue za zhi 07/2011; 91(26):1843-6.
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    ABSTRACT: In order to construct a lentiviral vector carrying human VE-cadherin gene, and to express VE-cadherin in Sup-B15 cells, the VE-cadherin gene was amplified by RT-PCR from the human placenta, and then cloned into pCR-Blunt vector. The VE-cadherin DNA fragment was subcloned into pLB vector to generate a lentiviral vector pLB-VEC. Recombinant lentivirus was generated by co-transfection of three-plasmids into 293FT packing cells using lipofectamine 2000. The Sup-B15 cells were transfected by the lentivirus. The post-transfected Sup-B15 cells were observed by microscopy and flow cytometry. Western blot was used to determine the expression of VE-cadherin. The results showed that the VE-cadherin DNA fragment was amplified from human placenta and was cloned into pCR-Blunt vector, the recombinant lentiviral vector pLB-VEC was successfully constructed. High titer lentivirus was prepared by 3-plasmid packing system, and transfected into Sup-B15 cells in vitro effectively. The obviously morphological changes occurred in transfected cells, the expression of VE-cadherin protein could be detected in Sup-B15 cells via flow cytometry and Western blot. It is concluded that the lentiviral vector pLB-VEC carrying human VE-cadherin gene is successfully constructed; VE-cadherin gene is expressed in Sup-B15 cells via lentiviral vector transfection, which provides an optional tool for further study on the mechanism of VE-cadherin controlling leukemia development.
    Zhongguo shi yan xue ye xue za zhi / Zhongguo bing li sheng li xue hui = Journal of experimental hematology / Chinese Association of Pathophysiology 06/2011; 19(3):574-7.
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    ABSTRACT: To explore the role of Th17 cells in early onset of acute graft-versus-host disease (aGVHD) and its mechanism. Mice aGVHD model was established by irradiated BABL/c mice inoculated with mixed suspension of C57BL/6 bone marrow cells and splenocytes. The mice were divided into 4 groups: (1) normal control, (2) irradiated group, (3) allo-BMT + DMSO group, (4) allo-BMT + halofuginone (HF) group. HF was given intraperitoneally at 5 µg per mouse from -1 d to +10 d after allogeneic bone marrow transplantation(allo-BMT).Mice aGVHD symptoms and survival were observed. Th1/Th17 cells ratio was evaluated by flow cytometry. All the experimental groups (3) and (4) developed aGVHD after transplantation. More severe aGVHD was observed in group (4) than in group (3). HF prevented cutaneous aGVHD in all the mice, but augmented hepatic and small intestine GVHD. The percentage of Th17 cells and the ratio of Th1/Th17 were significantly higher while the percentage of Th1 cells was significantly lower in group (4) at day +6 (P < 0.05). Early blockage of Th17 cell results in increase of Th1 cell percentage, which exacerbates aGVHD.
    Zhonghua xue ye xue za zhi = Zhonghua xueyexue zazhi 05/2011; 32(5):322-5.
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    ABSTRACT: OBJECTIVE: To investigate the proliferation of mouse splenic lymphocytes after shRNA mediated BTLA gene silence. METHODS: Three specific shRNAs and one nonspecific shRNA (scrambled) were ligated to pSilencer3.1-H1-neo plasmid and then subcloned into lentiviral vector pLB. Recombinant viral particles were harvested post-transduction to 293T cells. Mouse lymphocytes were infected with viral supernatant after 24 h incubation and continuously cultured till 4 days. Expression of eGFP was detected by fluorescence microscopy, efficiency of infection and expression of BTLA on lymphocyte cell by FCM. CCK-8 assay was used to detect the proliferation of lymphocytes. RESULTS: Lentiviral expression vectors pLB-shRNA/BTLA were successfully generated. The lentiviral particles were correctly packaged. Expression of BTLA protein in specific shRNA group was significantly decreased comparing to those in control group. O.D. value at A(450) of lymphocytes stimulated by anti-CD3 antibody showed significant difference compared with normal BTLA group (P < 0.05), while there was no difference between ConA stimulated group and control (P > 0.05). CONCLUSION: Gene-specific shRNA can knockdown the expression of BTLA. The proliferation of lymphocytes stimulated by anti-CD3 antibody after RNAi demonstrates significant enhancement as compared to the unstimulated lymphocytes, while stimulated by ConA showed no difference compared to normal lymphocytes.
    Zhonghua xue ye xue za zhi = Zhonghua xueyexue zazhi 12/2010; 31(12):793-797.
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    ABSTRACT: The aim of study was to investigate the injury of bone marrow microenvironment after γ ray irradiation conditioning in mouse allogeneic hematopoietic stem cell transplantation (allo-HSCT). The mononuclear cells collected from mice bone marrow for culture in vitro, were identified by flow cytometry with double staining when cultured for 5 - 7 days. Mice were separated randomly into 4 groups, namely, the control group, irradiation group, endothelial progenitor cell (EPC) transplantation group and irradiation combined EPC transplantation group. Peripheral blood was collected to assay the circulating white blood cells. The histological, electron microscopic and immunofluorescence analyses of bone marrow were performed in the same time, furthermore the distribution of labeled EPC was determined. The results showed that EPC were identified as CD45(low/-)CD133(+)CD31(+), double positive of Dil-Ac-LDL and FITC-UEA-1. The bone marrow microenvironment injury of recipient mice was shown in the irradiation group in which the number of WBC began to decrease after conditioning, and the mice were all died at 8 days (p < 0.05). The intramedullary hemorrhage could be detected by light microscopy at 3 days after irradiation, when the destruction of connection between endothelial cell and the basement membrane was observed by TEM. There were CFSE labeled cells in bone marrow in irradiation combined EPC transplantation group at 18 hours after transplanted cultured EPC in vitro, the number of CFSE(+) cells was 58-folds of EPC transplantation group (p < 0.05). It is concluded that the irradiation can cause the severe endothelium injury that drives extrinsic EPC homing to the injured bone marrow microenvironment.
    Zhongguo shi yan xue ye xue za zhi / Zhongguo bing li sheng li xue hui = Journal of experimental hematology / Chinese Association of Pathophysiology 11/2010; 18(6):1579-84.
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    ABSTRACT: To investigate the effects of conditioning regimen on mice liver injury during hematopoietic stem cell transplantation. Forty healthy 8-10 weeks old female BALB/c mice were randomly divided into control group, non-myeloablative total body irradiation group, myeloablative total body irradiation group, busulfan group and cyclophosphamide group with 8 mice each. The general condition of each mouse was continuously observed. Peripheral white blood cells were counted and pathological changes of liver were examined by hematoxylin and eosin stain under microscope. The ultrastructure changes of hepatocyte and liver vascular endothelium were detected under transmission electron microscope. Compared to control group, each experimental group showed that the count of white blood cells was decreased significantly after conditioning pretreatments (P < 0.05). The conditioning regimen had injury effects on the mice liver in each experimental group. There were various degrees of damage to the hepatocyte and liver vascular endothelium. Total body irradiation, Busulfan and Cyclophosphamide all led to the damage of liver vascular endothelium in hematopoietic stem cell transplantation, and may be the important triggers of hepatic veno-occlusive disease.
    Sichuan da xue xue bao. Yi xue ban = Journal of Sichuan University. Medical science edition 09/2010; 41(5):803-6.
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    ABSTRACT: To investigate the effect of allo-HSCT irradiation preconditioning on the homing of donor endothelial progenitor cells (EPCs). The mononuclear cells were collected form mice bone morrows, then cultured in EGM-2 medium. The cells were identified after 5-7 days and were labeled with CFSE. The mice were divided randomly into four groups, control, EPCs transplantation, irradiation, and irradiation EPCs transplantation. The circulating ECs, circulating EPCs and CFSE positive cells in the peripheral blood, spleen and bone morrows of the mice were measured by FCS. The histological examination, electron microscope and immunofluorescence analyses of those tissues were also performed. The distribution of labeled EPCs was observed. The cells were identified as CD45low, CD133+ CD31+, Dil-ac-LDL+. The number of those cells in the irradiation group increased gradually after preconditioning and reached peak at day 3 or 5 and sustained the peak level for 2 days, which was significantly different from the control (P < 0.05). Under the light microscopy and TEM, damaged endothelium was detected. In the irradiation and EPCs transplantation groups, CFSE labeled cells increased and reached peak at 18 hours, and then decreased till 72 hours. Green fluorescent cells were observed in different tissues at different times, and the strongest fluorescence intensity occurred at 36 hours. The EPCs can be induced from mice bone morrow mononuclear cells, with expressed phenotypic characterization. Irradiation in transplantation preconditioning can cause severe endothelium injury, which can start the mobilization of EPCs. The endothelium injury can induce extrinsic EPCs homing to the tissues which are badly injured. Endothelial progenitor cells
    Sichuan da xue xue bao. Yi xue ban = Journal of Sichuan University. Medical science edition 03/2009; 40(2):250-4.