Influence of hypoxia on the proliferation and activity of human umbilical vein endothelial cells / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the influence of hypoxia on the proliferation and activity of human umbilical vein vascular endothelial cells (EA. hy926).</p><p><b>METHODS</b>EA. hy926 cells were cultured in vitro and divided into normal control and hypoxia groups. The cells in hypoxia group were placed into hypoxic jar and treated with mixed gases(94% N2 +5% CO2 + 1% O2) for 1,3,6 and 12 hours. Then the total proteins were extracted for the determination of the expression of vascular endothelial growth factor (VEGF) and proliferation cell nuclear antigen (PCNA). The cell cycle and growth curve were determined with flow cytometry and MTT method, respectively.</p><p><b>RESULTS</b>The expression of PCNA protein began to increase at 3 post-hypoxia hour (PHH), peaked at 6 PHH, but without obvious difference compared with that at 12 PHH. The expression of VEGF began to increase at 1 PHH, peaked at 6 PHH, and decreased at 12 PHH, though it was still markedly higher than that of normoxia at 12 PHH. MTT results showed that the cell activity began to increase at 1 PHH, and it was still to increased at 3 PHH, then decreased at 6 PHH, and it was lower than that in control group at 12 PHH. The number of cells in G0/G1 phase was decreased, but the cells in S and G2/M phase was increased at 1, 3, 6 PHH when compared with those in normal controls. The proliferation index (PI) of cells in hypoxia group at 1PHH (43 +/- 9)%, 3PHH (39 +/- 11)%, 6 PHH (40 +/- 11))% were higher than that before hypoxia (32 +/- 9)% and 3 (39 +/- 11) % and 6 hours (40 +/- 11)% after hypoxia (P < 0.05). The PI was obviously lower at 12 PHH (27 +/- 4))% compared with that of cells under normoxic condition (P < 0.05).</p><p><b>CONCLUSION</b>Short-term hypoxia is beneficial to promote the proliferation of the cells, but this effect will be inhibited with the prolongation of hypoxia.</p>

Involvement of JNK signal pathway in hypoxia related upregulation of calcium/calmodulin-dependent serine protein kinase in endothelial cells / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the expression of calcium/calmodulin-dependent serine protein kinase (CASK) induced by short-term hypoxia, and to explore the role of JNK pathway in this signal event.</p><p><b>METHODS</b>EA. hy926 cells were cultured in normoxic condition for 0, 12, 24, 48, 72 h after being exposed to hypoxic condition for 3 h, then the cellular lysates were extracted. CASK promoter luciferase reporter recombinant was constructed and transfected into EA. hy926 cells for 48h. Cellular lysates were extracted 1, 3, 6, 12 h after hypoxia treatment and were used to detect firefly luciferase activity and rinella luciferase activity with luminometer. EA. hy926 cells were cultured under hypoxic condition for 1, 3, 6, 12 h or under normoxic condition, then the cell lysates were extracted and used to detect phospho-JNK with Western blot. EA. hy926 cells were pretreated with different concentrations of JNK specific inhibitor SP 600125 (0, 10, 100 nmol/L and 1,10 micromol/L) 1h before hypoxic treatment of various duration, and the cell lysates were extracted to detect CASK expression with Western blot.</p><p><b>RESULTS</b>CASK expression was obviously elevated by hypoxia, and the high expression sustained for 72 h when the hypoxic cells were cultured in normal conditions, and it was significantly higher than that of normal controls. Dual luciferase reporter assay showed that CASK promoter activity was significantly increased after hypoxia (0.010 +/- 0.003, P < 0.01), and it reached the peak 12 hrs after hypoxia (0.192 +/- 0.023, P < 0.01). The phosphorylation of JNK was enhanced with the prolongation of hypoxic time. CASK protein expression was suppressed by JNK specific inhibitor SP600125 in a dose dependent manner, and it decreased to the lowest level with 10 micromol/L SP600125 pretreatment.</p><p><b>CONCLUSION</b>JNK signal pathway is involved in short-term hypoxia related CASK upregulation.</p>

Inhibition of integrin beta1 expression in human keratinocyte stem cells by vector-1 based interfering RNA strategy / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the influence of integrin beta1 on the proliferation and differentiation of human keratinocyte stem cells (KSCs).</p><p><b>METHODS</b>DNA oligonucleotides targeting integrin beta1 at different locations were synthesized and inserted into BamHI-1 HindIII linearized p Silencer 3.1/H1 plasmids. The inserted sequences were verified by DNA sequencing. The KSCs were divided into control (without transfection), T1 (with transfection of vacant vector), T2 (with transfection of si integrin beta(1-1) vector), T3 (with transfection of si integrin beta(1-1) vector), and T4 (with transfection of si Negative vector) groups. The change in the expression of integrin beta1, was determined with Western blotting. The positive vector with the highest expression of integrin beta1 was selected and named as integrin beta1, and semi-quantitative RT-PCR was employed to detect the change in the expression of integrin beta1 mRNA.</p><p><b>RESULTS</b>The protein expression of integrin beta1, was not suppressed in control and T1 group, but it was suppressed in T2 and T3 groups, especially in T3 group (the suppression rate was 60%-70%, which was named si integrin beta1). The expression of integrin beta1 mRNA was obviously decreased by integrin beta1, transfection (the suppression rate was 70%).</p><p><b>CONCLUSION</b>The expression of integrin beta1, mRNA and protein could be down-regulated with recombinant si integrin P, vector transfection.</p>

Establishment of human endothelial-overexpressed lipopolysaccharide-associated factor 1 compelling expression model and its effects on the proliferation of ECV304 cells / 中华烧伤杂志

<p><b>OBJECTIVE</b>To design and construct the inducible expression vector of endothelial-overexpressed lipopolysaccharide-associated factor 1 (EOLA1), in order to establish EOLA1 compelling expression model, and to observe the effects of EOLA1 compelling expression on the proliferation of ECV304 cells.</p><p><b>METHODS</b>Inducible overexpression vector pOPRSV I-EOLA1 was constructed by amplifying the open reading fragment of EOLA1 and subcloning it into the Not I site and Xho I site of pOPRSV I vector. After sequencing, the pOPRSV I-EOLA1 recombinant vector and pCMVLac I vector were co-transfected into ECV304 cells. The cells resistant to G418 and hygromycin were screened by G418 and hygromycin, so that stable transfected cell strain was obtained. The growth curve of cells with or without isopropyl-beta-D-thiogalactoside (IPTG) induction were graphed with cell counting.</p><p><b>RESULTS</b>The inducible overexpressed EOLA1 vector was constructed successfully. The proliferation of the cells with EOLA1 compelling expression after induction of IPTG (44 +/- 17) x 10(4) was significantly higher than that without IPTG induction (27 +/- 11) x 10(4), (P < 0.01).</p><p><b>CONCLUSION</b>Compelling expression of EOLA1 protein can enhance the proliferation of ECV304 cell.</p>

Purification of human endothelial overexpressed lipopolysaccharide-associated factor 1 protein / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the feasibility of obtaining of a highly pure protein of human endothelial overexpressed lipopolysaccharide-associated factor 1 (EOLA1) with metal chelation chromatography.</p><p><b>METHODS</b>Inclusion bodies of the E. coli transformed with EOLA1 gene were extracted and washed with BugBuster Protein Extraction Reagent. The primary purified products were purified by His. Bind Resin Chromatography under denaturing condition and dialyzed for renaturation, and then were analyzed with SDS-PAGE, Western blotting and peptide mass fingerprinting (PMF).</p><p><b>RESULTS</b>EOLA1 was mainly expressed in E. coli as insoluble inclusion bodies. The protein content in the primary extracted inclusion bodies accounted for over 75%, and it accounted for more than 90% after chromatography and renaturation. It was indicated by PMF that the targeted protein peptide overlaid many of designed protein peptide.</p><p><b>CONCLUSION</b>The method of EOLA1 protein purification and renaturation was convenient and efficient, and by this method sufficient amount of highly pure EOLA1 protein could be obtained for the preparation of EOLA1 monoclonal antibody and for the study of its gene function.</p>

Study on the injurious effect of a self designed micro-skin machine on the epithelia / 中华烧伤杂志

<p><b>OBJECTIVE</b>To observe the injury on micro-skin induced by a self designed micro-skin machine.</p><p><b>METHODS</b>Micro-skin was produced either with the machine or by hand. Cells at the edge of micro-skin were observed by transmission electron microscope. succinic dehydrogenase activity in supernatant of cultivated cells was analyzed, and the cell proliferation of micro-skin was assessed by (3)H-TdR. Twenty patients were enrolled in the study for the observation of the wound healing time between the two groups of micro-skin after being grafted.</p><p><b>RESULTS</b>Transmission electron microscope examination revealed that the cellular injury at the edge of the micro-skin in machine-made group was mild compared with that in man-made group. (3)H-TdR rate was elevated but the activity of succinic dehydrogenase in the supernatant of cultured cells decreased in supernatant of cultured cells of machine produced micro-skin. Wound healing time was shortened in machine made group. (P < 0.05).</p><p><b>CONCLUSION</b>The cellular injury at the edge of micro-skin in the machine made group was mild when compared with that in the man-made group with cell proliferation accelerated and wound healing time shortened.</p>