Objective To construct inducible lentiviral vector containing human bone morphogenetic protein 2 (hBMP-2) gene and to study its expression in human umbil ical cord blood mesenchymal stem cells (HUMSCs). Methods hBMP-2 gene was ampl ified by PCR from a plasmid and was cloned into pDown by BP reaction. pLV/EXPN2-Neo-TRE-hBMP-2 and pLV/EXPN2-Puro-EF1A-reverse transactivator (rtTA) were obtained with GATEWAY technology, and then were sequenced and analyzed by PCR. The recombinant vectors were transfected into 293FT cells respectively through l ipofectamine, and the lentiviral viruses were harvested from 293FT cells, then the titer was determined. Viruses were used to infect HUMSCs in tandem. In order to research the influence of induction time and concentration, one group of HUMSCs was induced by different doxycl ine concentrations (0, 10, 100 ng/mL, and 1, 10, 100 μg/mL) in the same induction time (48 hours), and the other by the same concentration (10 μg/mL) in different time points (12, 24, 48, and 72 hours). The expression of target gene hBMP-2 was indentified by ELISA method. After 2-week osteogenic induction of transfected HUMSCs, the mineral ization nodes were detected with Al izarin bordeaux staining method. Results Therecombinant inducible lentiviral vectors (pLV/EXPN2-Neo-TRE-hBMP-2 and pLV/EXPN2-Puro-EF1A-rtTA) were successfully constructed. The lentiviruses were also obtained and mediated by 293FT cells, and the virus titers were 3.5 × 108 TU/mL and 9.5 × 107 TU/mL respectively. HUMSCs could expression hBMP-2 by induction of doxycycl ine. The expression of hBMP-2 reached the peak at 10 μg/mL doxycl ine at 48 hours of induction. After 2-week osteogenic induction, a lot of mineral ization nodes were observed. Conclusion The recombinant inducible lentiviral vectors containing hBMP-2 gene can be successfully constructed, which provide an effective and simple method for the further study of stem cells and animal experiment in vivo.
Objective To investigate the results of human amniotic membrane(HAM) which are loaded with marrow mesenchymal stem cells(MSCs) and epidermis cells in treating fullthickness skin defect combined with radiation injury. Methods Eight minipigs were used in this study. Three round fullthickness wounds（Ф3.67cm）, which combined with radiation injury, were created on the dorsum of each side close to the vertebral column in each animal. Among 48 wounds, 24 left side wounds were treated with HAM loaded with MSCs and epidermis cells as experimental group (group A), 16 right side wounds with simple HAM (HAM group, group B) and 8 right side wounds with oil gauze as control (group C). The granulation tissue, reepithelization and wound area were observed after 1,2 and 3 weeks. Immunohistochemistry was performed using vWF as a marker for blood vessels.Image analysis was employed to test new area of wound at different interval time and healing rate of wound.Results The healing time of group A was 6 to 7 days faster than that of group C and 5 to 6 days faster than that of group B. After 15-17 days of graft, there were significant differences in new area of wound and healing rate between group A and groups B,C(Plt;001). New epidermis fully covered whole wound surface in group A, and their granulation tissue, which contained a lot of vWF, fibroblasts, capillaries and collagen, grew well. Many inflammatory cells still were seen in groups B and C, and their contents of vWF, fibroblasts, capillaries and collagen in granulation tissue were smaller than that in group A.Conclusion The graft of HAM loaded with MSCs and epidermis cells played an effective role in promoting healing of wound combined radiation injury with high quality.
Objective To provide references for the rational allocation of health personnel in rural hospitals through understanding the status of health human resources of rural hospitals in remote and poor areas of Sichuan Province. Methodes This study used cluster sampling method, combined with questionnaire survey and qualitative interviews. A total of 711 health workers of 29 rural hospitals in Pengzhou and Baoxing of Sichuan Province were interviewed. SPSS16.0 was used for descriptive analysis.Results The average age of rural hospitals health personnel in remote and poor areas of Sichuan Province was 30 years old. Post-secondary education accounted for 58.12%, and Bachelor degree or above accounted for 7.2%. The number of medium and senior professional titles account for 8.4 %. The ratio of doctors to nurses was 1:0.55. In the survey of health workers, those doctors with practice (assistant) license accounted for 38.5%, and those without any qualification occupied 27.1 %. Conclusions The professional titles of medical personnel of rural hospitals in remote and poor areas in Sichuan province are generally low. The distribution of professional categories is irrational. The staff in charge of prevention and care are inadequate. There exist a large number of unqualified medical workers. Therefore, the government should increase the investment in rural health and take measures to stabilize the team structure, introduce the talented, and strengthen the training for health personnel of rural hospitals to improve their overall quality.
Objective To study whether the porcine endothelial cells (PECs) lines transfected by HLA-G1 can alter the lysis mediated by human peripheral blood mononuclear cell (PBMC) and natural killer cell 92(NK-92). Methods By use of liposomes pack, the pcDNA3.0 eukaryotic expression vector carrying HLA-G1 was transfected into PECs. Using indirect immunofluorescence and RT-PCR assays, the HLA-G1 expression in PECs was detected. The alteration of the lysis mediated by PBMC and NK-92 was detected by51Cr-release assays. Results HLA-G1 expression could be detected in PECs after transfection of HLA-G1 at the levels of protein andRNA. It also could be found that the survival rate of transfected PECs was muchhigher than that of non-transfected PECs, when both of them faced the lysismediated by human PBMC and NK-92.After transfecting the expression of HLA-G1 could be found in the transfected PECs and the lysis mediated by PBMC and NK-92 to PECs decreased obviously (Plt;0.05). Conclusion The PECs- transfected by HLAG1 can decrease the NK lysis, so that it may provide us a new thought to inhibit the xeno-cell-rejection.
Objective To construct human brain-derived neurotrophic factor retroviral vector-pLXSN (hBDNFpLXSN), and to evaluate the bioactivity of hBDNF. Methods The genome mRNA was extracted from embryonic brain tissue of a 5-month-old infant, the hBDNF gene sequence was obtained with RT-PCR technology, and hBDNF-pLXSN constructed in vitro was used to infect the fibroblasts (NIH/3T3). The expression of hBDNF was identfied by the immunohistochemistry method, and the NIH/3T3 and BDNF biological activities were determined by culture of the PC12 cells and dorsal root gangl ia. Results The hBDNF-pLXSN was constructed successfully by sequencing analyses. The infected NIH/3T3 showed positive expression of hBDNF. The infected NIH/3T3 could product hBDNF. Bioactivity of the products could support the PC12cell survival and neurite growth in the primary cultures of dorsal root gangl ia neurons of mice. Conclusion hBDNF-pLXSNvirus has the abil ity to infect NIH/3T3 and make it expressed and secreted hBDNF with the biological activity. It can be used to treat facial paralysis as a gene therapy.
Objective To study the biological activity of recombinant adeno-associated virus vector (rAAV) coexpressing human vascular endothel ial growth factor165 (hVEGF165) and human bone morphogenetic protein 7 (hBMP-7) genes in vitro so as to provide a new method for the therapeutics of osteonecrosis. Methods The 3rd passage rabbit bone marrow mesenchymal stem cells (BMSCs) were transfected with rAAV-hVEGF165-internal ribosome entry site (IRES)-hBMP-7(experimental group) and green fluorescent protein (GFP) labeled rAAV-IRES-GFP (control group). The expressions ofhVEGF165 and hBMP-7 were detected by ELISA assay at the 1st, 2nd, 3rd, 7th, 14th days and Western blot assay at the14th day after transfection. The expression consistencies of hVEGF165 and hBMP-7 were observed by immunofluorescence assay at the 14th day after transfection. The biological activity of hVEGF165 was assessed by angiopoiesis experiment of the 3rd passage human umbil ical vein endothel ial cells (HUVEC). The biological activity of hBMP-7 was assessed by mineral ization of BMSCs detected by ALP staining and al izarin red staining. Results With infecting time, the hVEGF165 and hBMP-7 expressions increased gradually in two groups, showing significant difference between two groups (P lt; 0.05). The expressions of hVEGF165 and hBMP-7 were positive in experimental group and negative in control group, respectively. Immunofluorescence assay showed positive expressions of hVEGF165 and hBMP-7 in the exprimental group and negative expression in the control group, the expression of hVEGF165 and hBMP-7 had good consistencies. hVEGF165 secreted from BMSCs enhanced HUVEC migration, prol iferation and tube formation in experimental group. There was significant difference in the number of blood vessel between two groups (P lt; 0.05). The ALP staining showed more bly stained granules in experimental group than in control group. There was significant difference in the number of the mineral ized nodules between two groups (P lt; 0.05). Conclusion The rAAV-hVEGF165-IRES-hBMP-7 has good biological activity in vitro.
We compared the sensitivities of human embryo conjtmctival fihroblasts(HECF)and rabbit conjunctival fibroblasts(RCF)m five anlineoplasties in vitro.When the concentration of vincrismum and doxorubicin was 0.001~10mg/L.5-FU was 1~1000mg/L and cisplatin was 0.01~10mg/L,the sensitivities of HECF to tile drugs were lower than that of RCF (Plt;0.01).while the difference of the sensitivilics be;ween HECF and RCF to VP-16 was not significant (P＜0.05). The results suggested that the selection of therapeutic agents for intraocular proliferative disease wilh'hunmn conjunctiva fihroblasts may be more valuable than that with RCF. （Chin J Ocul Fundus Dis,1994,10:223-225）
Objective To investigate the effect of the serum from severe burn patients on the biology characteristics of human umbilical cord mesenchymal stem cells (hUCMSCs) in vitro, so as to explore the feasibility of hUCMSCs transplantation for treating severe burn. Methods The 3rd passage of hUCMSCs were randomly divided into 3 groups: 10% fetal bovine serum group (group A), 10% normal serum group (group B), and 10% burn serum group (group C). At 24 hours, 72 hours, and 6 days after culture, the cell morphology and density were observed by inverted microscope; the cell proliferation was assessed by MTT; after 6 days of culture, the cell cycle by propidium iodide staining and flow cytometry, the apoptosis by acridine orange/ethidium bromide staining, and the cell senescence by β-galactosidase staining; the levels of tumor necrosis factor α (TNF-α), interleukin 1 (IL-1), platelet-derived growth factor (PDGF), and insulin-like growth factor 1 (IGF-1) in serum were detected by a double-antibody sandwich ELISA kit. Results hUCMSCs were long spindle/polygon in 3 groups. The cell fusion of group C was obviously faster than that in group A and group B. The cell proliferation curves showed that the velocity and number of cell proliferation in group C were significantly higher than those in group A and group B at 2-6 days after culture (P lt; 0.05). The rates of proliferation period (S) of hUCMSCs were 9.21% ± 1.02%, 11.79% ± 1.87%, and 20.54% ± 2.03%, respectively in groups A, B, and C at 6 days, and group C was significantly higher than that of group A and group B (P lt; 0.05). The hUCMSCs showed normal morphology and structure in 3 groups, and no apoptosis cells was observed. The positive cells percentage of group C (2.6% ± 0.1%) was significantly lower than that of group A (4.8% ± 0.2%) and group B (3.8% ± 0.4%) (P lt; 0.05). The levels of TNF-α, IL-1, PDGF, and IGF-1 in group C were significantly higher than those in group B (P lt; 0.05). Conclusion The higher levels of cytokines in serum from the severe burn patients can significantly stimulate hUCMSCs proliferation, prevent cells apoptosis, and reduce cells senescence. Therefore, it is feasible to use hUCMSCs transplantation for treating severe burn patients.
ObjectiveTo summarize the progress in mechanisms of resistance to trastuzumab in treating human epidermal growth factor receptor 2 (HER2)-positive breast cancer. MethodsBy searching Pubmed and CNKI, the literatures of mechanisms of resistance to trastuzumab in treating HER2-positive breast cancer were reviewed. ResultsThe possible mechanism of resistance to trastuzumab are thought to include HER2 gene amplification and high protein expression; impaired access of trastuzumab to HER2; bidirectional crosstalk between ER and HER2; HER2 downstream signal transduction pathway activation; expansion expression of other RTKs and membrane-associated receptors; alterations in apoptosis and cell cycle control as well as multi-gene mutation, etc. ConclusionsMechanisms of trastuzumab resistance in HER2-positive breast cancer is complicated, a better understanding will be achieved by comprehensive analysis of existing possible mechanisms. The outcome of HER2-positive breast cancer patients who developed resistance to trastuzumab will be improved by appropriate multi-target regime.
【Abstract】Objective To investigate the effects of human interlukin-13 (hIL-13) on the expression of E-selectin and intercellular adhesion molecule-1(ICAM-1) on bovine aortic endothelial cells(BAECs) stimulated by tumor necrosis factor alpha(TNF-α), and to provide experimental basis for hIL-13 inducing immunity endure and relieving the repulsion reaction of xenograft. Methods BAECs were co-cultured with different concentrations of hIL-13 for 2 h and followed by co-cultured with 4 ng/ml TNF-α for 6 h or 18 h. The expressions of E-selectin and ICAM-1 on BAECs were detected by Cell-ELISA. The effect of hIL-13 on activity of BAECs was detected by MTT colorimetry.Results BAECs pretreateded with hIL-13 could inhibit the expression of E-selectin and ICAM-1 induced by TNF-α, and showed a doesdependent manner from 5 ng/ml to 20 ng/ml of hIL-13 (P＜0.01). The experimental result of BAECs activity measured by MTT proved no significant difference in the activities of BAECs in every experimental groups compared with control group’s. Conclusion hIL-13 could inhibit the expression of E-selectin and ICAM-1 on BAECs induced by TNF-α, which may contribute to the xenotransplant immune tolerance.