摘要
BACKGROUND:Due to the sudden release and the rapid removal by proteases,platelet-rich plasma hydrogel leads to shorter residence times of growth factors at the wound site.In recent years,researchers have focused on the use of hydrogels to encapsulate platelet-rich plasma in order to improve the deficiency of platelet-rich plasma hydrogels. OBJECTIVE:To prepare self-assembled polypeptide-platelet-rich plasma hydrogel and to explore its effects on the release of bioactive factors of platelet-rich plasma. METHODS:The self-assembled polypeptide was synthesized by the solid-phase synthesis method,and the solution was prepared by D-PBS.Hydrogels were prepared by mixing different volumes of polypeptide solutions with platelet-rich plasma and calcium chloride/thrombin solutions,so that the final mass fraction of polypeptides in the system was 0.1%,0.3%,and 0.5%,respectively.The hydrogel state was observed,and the release of growth factors in platelet-rich plasma was detected in vitro.The polypeptide self-assembly was stimulated by mixing 1%polypeptide solution with 1%human serum albumin solution,so that the final mass fraction of the polypeptide was 0.1%,0.3%,and 0.5%,respectively.The flow state of the liquid was observed,and the rheological mechanical properties of the self-assembled polypeptide were tested.The microstructure of polypeptide(mass fraction of 0.1%and 0.001%)-human serum albumin solution was observed by scanning electron microscope and transmission electron microscope. RESULTS AND CONCLUSION:(1)Hydrogels could be formed between different volumes of polypeptide solution and platelet-rich plasma.Compared with platelet-rich plasma hydrogels,0.1%and 0.3%polypeptide-platelet-rich plasma hydrogels could alleviate the sudden release of epidermal growth factor and vascular endothelial growth factor,and extend the release time to 48 hours.(2)After the addition of human serum albumin,the 0.1%polypeptide group still exhibited a flowing liquid,the 0.3%polypeptide group was semi-liquid,and the 0.5%polypeptide group stimulated self-assembly to form hydrogel.It was determined that human serum albumin in platelet-rich plasma could stimulate the self-assembly of polypeptides.With the increase of the mass fraction of the polypeptide,the higher the storage modulus of the self-assembled polypeptide,the easier it was to form glue.(3)Transmission electron microscopy exhibited that the polypeptide nanofibers were short and disordered before the addition of human serum albumin.After the addition of human serum albumin,the polypeptide nanofibers became significantly longer and cross-linked into bundles,forming a dense fiber network structure.Under a scanning electron microscope,the polypeptides displayed a disordered lamellar structure before adding human serum albumin.After the addition of human serum albumin,the polypeptides self-assembled into cross-linked and densely arranged porous structures.(4)In conclusion,the novel polypeptide can self-assemble triggered by platelet-rich plasma and the self-assembly effect can be accurately adjusted according to the ratio of human serum albumin to polypeptide.This polypeptide has a sustained release effect on the growth factors of platelet-rich plasma,which can be used as a new biomaterial for tissue repair.
摘要
Objective To investigate the effects of selective COX-2 inhibitor nimesulide on growth inhibition,apoptosis and expression of COX-2 of human esophageal carcinoma Eca-109 cell line; and analyzed the correlation with the anti-oncogene,P277~(kip1). Methods MTT assay was used to detect the proliferation of Eca-109 cell. Apoptosis and cell cycle were determined by electronic microscopy and flow cytometry. The expression of COX-2 mRNA was detected by reverse transcription polymerase chain reaction (RT-PCR),the protein expression of COX-2 and P277~(kip1) were examined by Western blot analysis. Results Nimesulide significantly inhibited the proliferation of Eca-109 cell line in a time-and dose-depenent fashion; increased the proportion of cells in the G_0/G_1 phase and induced apoptosis of the cells in a dose-dependent(manner). Meanwhile,nimesulide can down-regulated the expression of COX-2 and up-regulated the expression of P277~(kip1) protein.Conclusion Nimesulide can inhibit the proliferation of Eca-109 cells,cause G_0/G_1 phase cell cycle arrest and induce apoptosis.The mechanism is probably explained with down-regulation of the expression of COX-2 and up-regulation of P277~(kip1) expression.
摘要
Aim To study the effects of selective cyclooxygenase-2 (COX-2) inhibitor,nimesulide,on COX-2 expression, cell proliferation and apoptosis of human esophageal carcinoma Eca-109 cell lines. Methods MTT assay was used to observe the proliferative effect;COX-2 mRNA expression was evaluated with RT-PCR; COX-2 protein expression,cell cycle and apoptosis were analyzed with flow cytometry;microscope and agarose gel electrophoresis of DNA were also used to observe the apoptosis. Results Nimesulide significantly inhibited the proliferation of Eca-109 cell lines in a time and dose-depenent fashion, down-regulated the expression of COX-2 mRNA and COX-2 protein in a dose-dependent fashion;nimesulide also decreased the proliferation index and the proportion of cells in S phase, meanwhile increased the proportion of cells in G_0/G_1 phase and induced apoptosis. Conclusion COX-2 selective inhibitor nimesulide inhibits proliferation,induces apoptosis and cell cycle arrest of human esophageal cells via down-regulation of COX-2 expression.
摘要
<p><b>OBJECTIVE</b>To explore the molecular events and mechanism in the carcinogenesis of esophageal epithelium in the high incidence area of esophageal carcinoma.</p><p><b>METHODS</b>Epithelial cells collected from the high incidence area of esophageal carcinoma were used to detect DNA content and ploidy by propidium iodide(PI) stain. The expressions of p53, p16 and cyclin D1 were stained by indirect immunofluorescence of fluorescein isothiocyanate(FTTC), which were detected by flow cytometry (FCM).</p><p><b>RESULTS</b>During the process of carcinogenesis, DNA content increased significantly. The diploid cells decreased while heteroploid cells increased sharply, with a heteroploidy rate of 84.2%. At the same time, the p53 protein accumulated and p16 was deleted. The positive rates of p53 and oncogene cyclin D1 were both 100%(5/5, 6/6) in the cancer group.</p><p><b>CONCLUSION</b>In the early carcinogenesis of esophageal epithelium, DNA content and heteroploidy rates increase with tumor suppressor gene p16 deletion and p53 protein accumulation while oncogene cyclin D1 is overexpressed. Multiple molecular events have already occurred when esophageal carcinoma develops.</p>
Subject(s)
Humans , Cyclin D1 , Metabolism , Cyclin-Dependent Kinase Inhibitor p16 , Metabolism , DNA, Neoplasm , Metabolism , Esophageal Neoplasms , Genetics , Metabolism , Pathology , Flow Cytometry , Gene Expression , Precancerous Conditions , Genetics , Tumor Suppressor Protein p53 , Metabolism摘要
Objective To explore the significance of the expression of p53 and bcl- 2 in different cutaneous tumors. Methods The expression of p53 and bcl- 2 were quantitatively detected by Flow Cytometry(FCM) and immunofluorescence in 10 cases of normal skin, 20 cases of squamous cell carcinoma(SCC), 22 cases of basal cell carcinoma(BCC), 18 cases of malignant melanoma(MM) and 18 cases of pigmented nevus (PN). Fluorescence Index(FI) was defined as the expression index of bcl- 2 and p53 protein. Results The FI for bcl- 2 in SCC and BCC was higher than that in normal skin tissues(P
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Cell DNA content in heart, liver, kidney of rats were analysed by flow cytometer at different postmortem interved. The rsults show that mean cellular DNA content is 99.5% at 6 hours, 91.3% at 12 hours, 87.1% at 18 hours, 81.3% at 24 hours, 76.7% at 30 hours, 74.3% at 36 hours, 72.3% 48 hours as compared with that at o hours The results ingicates that the quantitative determination of cell DNA in the tissues, mentioned above may provide an objective and reliable approach for the estimation of postmortem time.
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Aim To investigate the effect and mechanism of valdecoxib on the apoptosis of human esophageal cancer cells.Methods Flow cytometry was used to observe the effect of valdecoxib on apoptosis and the cell cycle distribution of Eca109 cells.Transmission electron microscope was further used to detect the cell apoptosis.The content of LDH was examined using LDH kit.The expressions of p-p38MAPK,Fas and FasL protein were detected using flow cytometry.Results Valdecoxib of 25～400 ?mol?L~(-1) significantly induced the apoptosis of Eca109 cell line,and the rate of apoptosis was increased from(2.95?0.83)% to(48.46?0.73)%,50～400 ?mol?L~(-1) valdecoxib also decreased the proliferation index and the proportion of cells in the S phase,increased the proportion of cells in the G_0/G_1 phase,but had no effect on the proportion of cells in the G_2/M phase.Compared with those in Eca109 cells cultured in the medium with solvent,the expression of p-p38MAPK,Fas and FasL was higher in the Eca109 cells exposed to valdecoxib in a dose-dependent manner in 72 h.Conclusion Valdecoxib can induce apoptosis of Eca109 cell line partly by up-regulating the expression of p-p38MAPK/Fas/FasL.
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Objective:To investigate specific cellular immune response to the HPV16E7 prophylactic vaccine in mice.Methods:BALB/c mice were randomly divided into 3 groups:experimental group (treated with pcDNA3.1-HPV16E7),control group Ⅰ(treated with pcDNA3.1) and control group Ⅱ(treated with N.S.).Mice were injected (i.m.) pcDNA3.1-HPV16E7,pcDNA3.1 and N.S. one time per week,respectively.After three immunization,the blood samples from eye sockets and the supernatant cultured of spleen cells were taken for measurement IFN-? and the number of CD4 +?CD8 +T-lymphocyte by ELISA and FACS assay.Antigen-specific splenocyte proliferation assay in vitro was detected by MTT method.Results:The splenocytes actively proliferated,the number of CD4 +T lymphocyte and the quantitation of IFN-? in spleen and serum in the experimental group were significantly higher than the control group Ⅰ and Ⅱ.Conclusion:The pcDNA3.1-HPV16E7 DNA vaccine can induce specific cellular immune response in BALB/c mice.