Biomedical subjects

Z He

Publications and source records attributed to Z He.

At least 19 recordsLinked to original sources

PubMed2006

Potent antitumor efficacy of XAF1 delivered by conditionally replicative adenovirus vector via caspase-independent apoptosis.

XAF1 is a newly identified tumor-suppressor gene that can antagonize XIAP and sensitize cells to other cell death triggers. In this study, we utilized ZD55, a conditionally replicative adenovirus (CRAd) similar to ONYX-015 as the vector to transfer XAF1 into the tumor cells to evaluate its antitumor efficacy in vitro and in vivo. Potent and specific cytopathic effect (CPE) was observed upon infection with ZD55-XAF1 in tumor cell lines. Importantly, ZD55-XAF1 exhibited a superior suppression of tumor growth in an animal model of colorectal carcinoma in nude mice compared with Ad-XAF1 (E1-deleted replication-defective viral) and ONYX-015. Complete eradication of the established tumors was observed in four of eight mice. Our data also showed that infection with ZD55-XAF1 resulted in caspase-independent apoptosis. Although caspase-3, poly(ADP-ribose) polymerase were mildly activated in response to ZD55-XAF1 infection, pretreatment with pan-caspase inhibitor hardly influence its apoptosis-inducing activity. In summary, our study strongly suggested that ZD55-XAF1 could serve as an effective gene-virotherapy strategy and has highly potential against human cancers.

Adaptor Proteins, Signal Transducing↗

PubMed2006

Polymorphisms in the HBB gene relate to individual cardiorespiratory adaptation in response to endurance training.

OBJECTIVE: The crucial role of haemoglobin in endurance performance has been well documented. We examined whether polymorphisms in the HBB gene modified aerobic capacity. METHODS: 102 recruits were trained by running 5000 m three times per week for 18 weeks. Exercise intensity progressively increased from an initial heart rate corresponding to 95% of the individual baseline ventilatory threshold during the first 10 weeks to 105% during the last 8 weeks. The phenotypes measured were running economy and VO(2)max. Running economy was determined by measuring submaximal VO(2) for 5 min at a constant running speed of 12 km.h(-1) and VO(2)max was obtained during an incremental test to exhaustion. Genomic DNA was extracted from white cells of peripheral blood and the -551C/T, intron2,+16C/G and +340 A/T genotypes were examined relative to the TAA site variants by PCR-RFLP. RESULTS: Genotype distributions were in Hardy-Weinberg equilibrium at three loci. None of the running economy and VO(2)max-related traits were associated with the three polymorphisms or haplotypes at baseline, while the training response of running economy was associated with -551C/T and intron2,+16C/G polymorphisms. Subjects homozygous for intron2,+16C/C or -551C/C had decreased oxygen cost of running compared to the other individuals. DISCUSSION: It was concluded that the -551C/C or intron2,+16C/C genotype might explain part of the individual variation in the cardiorespiratory adaptation to endurance training.

Adaptation, Physiological↗

PubMed2006

Microarray applications in microbial ecology research.

Microarray technology has the unparalleled potential to simultaneously determine the dynamics and/or activities of most, if not all, of the microbial populations in complex environments such as soils and sediments. Researchers have developed several types of arrays that characterize the microbial populations in these samples based on their phylogenetic relatedness or functional genomic content. Several recent studies have used these microarrays to investigate ecological issues; however, most have only analyzed a limited number of samples with relatively few experiments utilizing the full high-throughput potential of microarray analysis. This is due in part to the unique analytical challenges that these samples present with regard to sensitivity, specificity, quantitation, and data analysis. This review discusses specific applications of microarrays to microbial ecology research along with some of the latest studies addressing the difficulties encountered during analysis of complex microbial communities within environmental samples. With continued development, microarray technology may ultimately achieve its potential for comprehensive, high-throughput characterization of microbial populations in near real time.

Bacteria↗

PubMed2006

Temporal transcriptomic analysis as Desulfovibrio vulgaris Hildenborough transitions into stationary phase during electron donor depletion.

Desulfovibrio vulgaris was cultivated in a defined medium, and biomass was sampled for approximately 70 h to characterize the shifts in gene expression as cells transitioned from the exponential to the stationary phase during electron donor depletion. In addition to temporal transcriptomics, total protein, carbohydrate, lactate, acetate, and sulfate levels were measured. The microarray data were examined for statistically significant expression changes, hierarchical cluster analysis, and promoter element prediction and were validated by quantitative PCR. As the cells transitioned from the exponential phase to the stationary phase, a majority of the down-expressed genes were involved in translation and transcription, and this trend continued at the remaining times. There were general increases in relative expression for intracellular trafficking and secretion, ion transport, and coenzyme metabolism as the cells entered the stationary phase. As expected, the DNA replication machinery was down-expressed, and the expression of genes involved in DNA repair increased during the stationary phase. Genes involved in amino acid acquisition, carbohydrate metabolism, energy production, and cell envelope biogenesis did not exhibit uniform transcriptional responses. Interestingly, most phage-related genes were up-expressed at the onset of the stationary phase. This result suggested that nutrient depletion may affect community dynamics and DNA transfer mechanisms of sulfate-reducing bacteria via the phage cycle. The putative feoAB system (in addition to other presumptive iron metabolism genes) was significantly up-expressed, and this suggested the possible importance of Fe2+ acquisition under metal-reducing conditions. The expression of a large subset of carbohydrate-related genes was altered, and the total cellular carbohydrate levels declined during the growth phase transition. Interestingly, the D. vulgaris genome does not contain a putative rpoS gene, a common attribute of the delta-Proteobacteria genomes sequenced to date, and the transcription profiles of other putative rpo genes were not significantly altered. Our results indicated that in addition to expected changes (e.g., energy conversion, protein turnover, translation, transcription, and DNA replication and repair), genes related to phage, stress response, carbohydrate flux, the outer envelope, and iron homeostasis played important roles as D. vulgaris cells experienced electron donor depletion.

Bacterial Proteins↗

PubMed2006

Global analysis of heat shock response in Desulfovibrio vulgaris Hildenborough.

Desulfovibrio vulgaris Hildenborough belongs to a class of sulfate-reducing bacteria (SRB) and is found ubiquitously in nature. Given the importance of SRB-mediated reduction for bioremediation of metal ion contaminants, ongoing research on D. vulgaris has been in the direction of elucidating regulatory mechanisms for this organism under a variety of stress conditions. This work presents a global view of this organism's response to elevated growth temperature using whole-cell transcriptomics and proteomics tools. Transcriptional response (1.7-fold change or greater; Z >/= 1.5) ranged from 1,135 genes at 15 min to 1,463 genes at 120 min for a temperature up-shift of 13 degrees C from a growth temperature of 37 degrees C for this organism and suggested both direct and indirect modes of heat sensing. Clusters of orthologous group categories that were significantly affected included posttranslational modifications; protein turnover and chaperones (up-regulated); energy production and conversion (down-regulated), nucleotide transport, metabolism (down-regulated), and translation; ribosomal structure; and biogenesis (down-regulated). Analysis of the genome sequence revealed the presence of features of both negative and positive regulation which included the CIRCE element and promoter sequences corresponding to the alternate sigma factors sigma(32) and sigma(54). While mechanisms of heat shock control for some genes appeared to coincide with those established for Escherichia coli and Bacillus subtilis, the presence of unique control schemes for several other genes was also evident. Analysis of protein expression levels using differential in-gel electrophoresis suggested good agreement with transcriptional profiles of several heat shock proteins, including DnaK (DVU0811), HtpG (DVU2643), HtrA (DVU1468), and AhpC (DVU2247). The proteomics study also suggested the possibility of posttranslational modifications in the chaperones DnaK, AhpC, GroES (DVU1977), and GroEL (DVU1976) and also several periplasmic ABC transporters.

Bacterial Proteins↗

PubMed2005

The formation, role and removal of NO3-N during corona discharge in air for phenol removal.

Pulsed corona discharge carried out in the gas phase has been shown to be a low cost solution for wastewater treatment. In this study, the results show that the nitrogen dissociated during corona discharge in the gas phase formed nitric acid in solution, which resulted in a drop in solution pH. The phenol removal could be described in accordance with a first-order reaction in a basic buffer solution, but not in initial neutral and basic non-buffered solutions. This indicates that basic conditions facilitate phenol removal, whilst the formation of nitric acid in solution resulted in decrease in the phenol removal rate. This study also shows that most of the oxidants used for phenol removal came mainly from the dissociation of water molecules at the surface of the liquid phase and/or the gas phase very close to the liquid surface in discharging conditions, not from the gas dissociation in the bulk gas phase, and therefore, it is more effective to keep the solution basic than to change the component of gas in the reactor when removing phenol from water using corona discharge.

Cost Control↗

PubMed2005

No role of alpha-Gal in human monocyte-endothelial cell interactions in vitro.

Vascularized organ xenografts undergoing acute vascular rejection (AVR) are infiltrated by innate immune cells such as monocytes/macrophages. Herein, human monocyte static and dynamic adhesion to, and migration across, human and porcine aortic endothelial cells (HAEC and PAEC) were investigated. To elucidate the role of Gal alpha1,3Gal (alpha-Gal) epitopes in these processes in the absence of anti-Gal antibodies (Ab), this determinant was aberrantly expressed in HAEC. HAEC were transduced with a lentiviral vector encoding the porcine alpha1,3 galactosyltransferase to express alpha-Gal at high frequencies (75-95%). Alpha-Gal expression on HAEC did not increase their ability to support monocyte transendothelial migration or adhesion under either static or flow conditions. Porcine and human endothelium supported static adhesion and migration of monocytes equally well. However, human monocytes adhered less to PAEC than to HAEC (P = 0.03) under flow following human, but not porcine, tumour necrosis factor-alpha stimulation. In the absence of anti-Gal Ab, the alpha-Gal epitope does not contribute to increased monocyte adhesion to, or migration across, endothelium. Thus, inhibiting adhesion receptor-ligand interactions essential for the adhesion of human monocytes to porcine endothelium may be more important than carbohydrate remodelling of donor pigs to prevent adhesion/infiltration of monocytes into organ xenografts during AVR.

Animals↗

PubMed2004

The predictive value of p16(INK4a) and hybrid capture 2 human papillomavirus testing for high-grade cervical intraepithelial neoplasia.

We performed p16(INK4a) immunocytochemical analysis and Hybrid Capture 2 (HC2; Digene, Gaithersburg, MD) high-risk HPV testing on 210 abnormal SurePath (TriPath Imaging, Burlington, NC) Papanicolaou specimens diagnosed as low-grade squamous intraepithelial lesion (LSIL) or high grade squamous intraepithelial lesion (HSIL). The results were compared with 121 follow-up biopsy specimens. p16(INK4a) was positive in 57.9% of women with LSIL compared with 97.1% of women with HSIL. In contrast, HC2 testing was positive in 85.0% of women with LSIL and 86.4% of women with HSIL. The differences in the positive rates for16(INK4a) between LSIL and HSIL was significant (P < .001), whereas, for HC2, it was not (P = .264). In patients who had cervical biopsies following a cytologic diagnosis of LSIL, the positive predictive value (PPV) of p16(INK4a) for a biopsy of cervical intraepithelial neoplasia grade 2 or 3 (CIN2/3; 33.3%) was significantly higher than the PPV of HC2 results (21.2%) (P < .001). Using liquid-based cytology specimens, p16(INK4a) immunocytochemical analysis has a higher PPV than reflex HC2 HPV testing for identifying CIN2/3 among patients with LSIL and might be useful for selecting patients with LSIL for colposcopy.

Cyclin-Dependent Kinase Inhibitor p16↗

PubMed2004

Removal of polycyclic aromatic hydrocarbons (PAHs) from sewage sludge by anaerobic degradation.

Due to the hydrophobic nature of the polyaromatic hydrocarbons (PAHs) they are mostly bound to the sludge and escape aerobic treatment in a wastewater treatment plant. They therefore proceed directly to the anaerobic post treatment, terminate in the sludge, and can be released to the environment if land spreading is used. PAH degradation in anaerobic methanogenic systems has only recently been shown to occur. In this study we have assessed several factors of anaerobic PAH degradation by evaluating thermodynamic feasibility of degradation, assessing degradation at different temperatures, and investigating the enriched cultures using fluorescent in-situ hybridization (FISH). Thermodynamic calculations indicated that PAH degradation was possible under methanogenic conditions, in the presence of hydrogen utilizing methanogens. Removal of naphthalene and 1-methyl naphthalene depended both on temperature and the initial inoculum. Inocula sourced from contaminated land sites were the most effective. The enrichments were all a mixture of Bacteria, and Archaea, and the Archaea were generally identified as Methanobacteriales, using an order-specific probe. The bacteria were not specifically identified. The results indicate a syntrophic culture, with the bacteria oxidizing the naphthalene, and the Archaea converting the hydrogen produced by oxidation, to methane.

Bacteria, Anaerobic↗

PubMed2002

Ultrapermeable, reverse-selective nanocomposite membranes.

Polymer nanocomposites continue to receive tremendous attention for application in areas such as microelectronics, organic batteries, optics, and catalysis. We have discovered that physical dispersion of nonporous, nanoscale, fumed silica particles in glassy amorphous poly(4-methyl-2-pentyne) simultaneously and surprisingly enhances both membrane permeability and selectivity for large organic molecules over small permanent gases. These highly unusual property enhancements, in contrast to results obtained in conventional filled polymer systems, reflect fumed silica-induced disruption of polymer chain packing and an accompanying subtle increase in the size of free volume elements through which molecular transport occurs, as discerned by positron annihilation lifetime spectroscopy. Such nanoscale hybridization represents an innovative means to tune the separation properties of glassy polymeric media through systematic manipulation of molecular packing.

Journal Article↗

PubMed2001

Inhibitory mechanisms of tea polyphenols on the ultraviolet B-activated phosphatidylinositol 3-kinase-dependent pathway.

In this study, we investigated the effect of tea polyphenols, (-)-epigallocatechin-3-gallate or theaflavins, on UVB-induced phosphatidylinositol 3-kinase (PI3K) activation in mouse epidermal JB6 Cl 41 cells. Pretreatment of cells with these polyphenols inhibited UVB-induced PI3K activation. Furthermore, UVB-induced activation of Akt and ribosomal p70 S6 kinase (p70 S6-K), PI3K downstream effectors, were also attenuated by the polyphenols. In addition to LY294002, a PI3K inhibitor, pretreatment with a specific mitogen-activated protein/extracellular signal-regulated protein kinases (Erks) kinase 1 inhibitor, U0126, or a specific p38 kinase inhibitor, SB202190, blocked UVB-induced activation of both Akt and p70 S6-K. Pretreatment with LY294002 restrained UVB-induced phosphorylation of Erks, suggesting that in UVB signaling, the Erk pathway is mediated by PI3K. Moreover, pretreatment with rapamycin, an inhibitor of p70 S6-K, inhibited UVB-induced activation of p70 S6-K, but UVB-induced activation of Akt did not change. Interestingly, UVB-induced p70 S6-K activation was directly blocked by the addition of (-)-epigallocatechin-3-gallate or theaflavins, whereas these polyphenols showed only a weak inhibition on UVB-induced Akt activation. Because PI3K is an important factor in carcinogenesis, the inhibitory effect of these polyphenols on activation of PI3K and its downstream effects may further explain the anti-tumor promotion action of these tea constituents.

Animals↗

PubMed2001

[Effects of aspirin on ferritin expression and resistance to oxidative damage in endothelial cells].

OBJECTIVE: To explore the mechanism of Aspirin induced ferritin synthesis on resistance to oxidative damage in endothelial cells. METHODS: Using cultured endothelial cells, we measured the effect of aspirin with different incubative time (4 - 24 h) and different concentration (0.1 - 3 mmol/L), salicylic acid and indomethacin induced ferritin expression by ELISA kit, and observed the change of lactate dehydrogenase (LDH) release rate, malondialdehyde (MDA) and cellular viability after preincubating the cell for 8 h with aspirin on resistance to hydrogen peroxide toxicity. Statistical analysis using a one-way analysis of variance. RESULTS: Aspirin at low concentration (0.1 mmol/L) induced significant increase ferritin expression in a concentration-dependent fashion: (5.8 +/- 0.3) ng/10(6) cell (0.1 mmol/L As), (6.4 +/- 0.4) ng/10(6) cell (0.5 mmol/L As), (7.0 +/- 0.7) ng/10(6) cell (1 mmol/L As), (7.4 +/- 0.4) ng/10(6) cell (2 mmol/L As), (7.7 +/- 0.5) ng/10(6) cell (3 mmol/L As), significant for all values: P < 0.05 versus normal control. Induction of ferritin levels by aspirin (1 mmol/L) was also time dependent: (5.8 +/- 1.0) ng/10(6) cell (4 h, but P > 0.05 vs control), (6.5 +/- 1.0) ng/10(6) cell (8 h, P < 0.05 vs control) and (7.8 +/- 0.8) ng/10(6) cell (24 h). Preincubating the cells with aspirin (0.1 mmol/L) reduced LDH release rate by 50%, toxicity reduction by 40%, and significant decrease MDA production. Aspirin induced cytoprotection from H(2)O(2) damage was also in a concentration dependent fashion. The cytoprotection of aspirin was mimicked by exogenous iron-free apo-ferritin but not iron-load ferritin. Salicylic acid and indomethacin failed to increase ferritin expression. CONCLUSION: Aspirin could induce significant increase ferritin synthesis at low concentration (0.1 mmol/L). Ferritin induction by aspirin was specific in nonsteroidal anti-inflammatory drugs.

Antioxidants↗

PubMed2001

Intermolecular hydrogen bonding between carotenoid and bacteriochlorophyll in LH2.

We have studied van der Waals contacts of the carotenoid rhodopin glucoside (RG) with the bacteriochlorophyll pigments absorbing at 800 nm (B800) in the crystal structure of Rhodopseudomonas acidophila, and the hydrogen positions were determined from quantum chemical calculations at the Hartree--Fock (6-31G) level. We have found strong evidence for hydrogen bonding between the B800 BChl and the RG from neighboring protomer units. The binding energy was estimated to be about 2 kcal/mol (700 cm(-1)). CI-singles approach and time-dependent density functional theory calculations of the B800--RG dimer indicate a red-shift (ca 2 nm) of the B800 Q(y) transition, along with a substantial increase of its oscillator strength, probably due to the hydrogen bonding.

Bacteriochlorophylls↗

PubMed2001

Expression, purification, and characterization of human hemoglobins Gower-1 (zeta(2)epsilon(2)), Gower-2 (alpha(2)epsilon(2)), and Portland-2 (zeta(2)beta(2)) assembled in complex transgenic-knockout mice.

Embryonic zeta- and epsilon-globin subunits assemble with each other and with adult alpha- and beta-globin subunits into hemoglobin heterotetramers in both primitive and definitive erythrocytes. The properties of these hemoglobins-Hbs Gower-1 (zeta(2)epsilon(2)), Gower-2 (alpha(2)epsilon(2)), and Portland-2 (zeta(2)beta(2))-have been incompletely described as they are difficult to obtain in quantity from either primary human tissue or conventional expression systems. The generation of complex transgenic-knockout mice that express these hemoglobins at levels between 24% and 70% is described, as are efficient methods for their purification from mouse hemolysates. Key physiological characteristics-including P(50), Hill coefficient, Bohr effect, and affinity for 2,3-BPG-were established for each of the 3 human hemoglobins. The stability of each hemoglobin in the face of mechanical, thermal, and chemical stresses was also determined. Analyses indicate that the zeta-for-alpha exchange distinguishing Hb Portland-2 and Hb A alters hemoglobin O(2)-transport capacity by increasing its P(50) and decreasing its Bohr effect. By comparison, the epsilon-for-beta exchange distinguishing Hb Gower-2 and Hb A has little impact on these same functional parameters. Hb Gower-1, assembled entirely from embryonic subunits, displays an elevated P(50) level, a reduced Bohr effect, and increased 2,3-BPG binding compared to Hb A. The data support the hypothesis that Hb Gower-2, assembled from reactivated epsilon globin in individuals with defined hemoglobinopathies and thalassemias, would serve as a physiologically acceptable substitute for deficient or dysfunctional Hb A. In addition, the unexpected properties of Hb Gower-1 call into question a common hypothesis for its primary role in embryonic development.

2,3-Diphosphoglycerate↗

PubMed2001

Genetic analysis of the Escherichia coli FtsZ.ZipA interaction in the yeast two-hybrid system. Characterization of FtsZ residues essential for the interactions with ZipA and with FtsA.

The recruitment of ZipA to the septum by FtsZ is an early, essential step in cell division in Escherichia coli. We have used polymerase chain reaction-mediated random mutagenesis in the yeast two-hybrid system to analyze this interaction and have identified residues within a highly conserved sequence at the C terminus of FtsZ as the ZipA binding site. A search for suppressors of a mutation that causes a loss of interaction (ftsZ(D373G)) identified eight different changes at two residues within this sequence. In vitro, wild type FtsZ interacted with ZipA with a high affinity in an enzyme-linked immunosorbent assay, whereas FtsZ(D373G) failed to interact. Two mutant proteins examined restored this interaction significantly. In vivo, the alleles tested are significantly more toxic than the wild type ftsZ and cannot complement a deletion. We have shown that a fusion, which encodes the last 70 residues of FtsZ in the two-hybrid system, is sufficient for the interaction with FtsA and ZipA. However, when the wild type sequence is compared with one that encodes FtsZ(D373G), no interaction was seen with either protein. Mutations surrounding Asp-373 differentially affected the interactions of FtsZ with ZipA and FtsA, indicating that these proteins bind the C terminus of FtsZ differently.

Amino Acid Sequence↗

PubMed2001

Application of complementary DNA microarray (DNA chip) technology in the study of gene expression profiles during folliculogenesis.

OBJECTIVE: Using oligonucleotide microarray (DNA chip)-based hybridization analysis to gain a comprehensive view of gene expression and regulation involved in folliculogenesis. DESIGN: Prospective randomized study. SETTING: Academic institution. ANIMAL(S): B6D2F1 female mice. INTERVENTION(S): Superovulation. MAIN OUTCOME MEASURE(S): Preantral follicles isolated from day 14 B6D2F-1 mice were stimulated in vitro to form Graafian follicles. Total RNA extracted from the mouse preantral and Graafian follicles were reverse transcribed, labeled with digoxigenin-11-dUTP, and then hybridized with Clontech Atlas mouse cDNA expression arrays for comparison. RESULT(S): Of 588 known studied genes, 39 and 61 were detected in preantral follicles and in Graafian follicles, respectively, and 17 were highly expressed consistently in both preantral and Graafian follicles. Performing clustering analysis, we found that 15 detected genes were down-regulated and 46 were up-regulated as the follicles advanced to mature stages. CONCLUSION(S): We have successfully developed a sensitive DNA chip technology that is able to simultaneously and quantitatively study gene expression profiles in a small number of follicles (1.5-15 follicles). Several folliculogenesis-related genes have been identified. Some of these genes were expressed, indicating that they may be essential for follicle growth and maturation, whereas others were up-regulated only during late follicular development, indicating stage-specific roles.

Animals↗

PubMed2001

Changes in the marine environment of Port Kembla Harbour, NSW, Australia, 1975-1995: a review.

Data on water quality, sediment quality and aquatic organisms in Port Kembla Harbour from the 1970s to the 1990s are reviewed. In the 1970s, the marine environment of Port Kembla Harbour was in poor condition as a result of pollution from heavy industries. Elevated concentrations of pollutants were found in water, sediment and fish in the harbour; aquatic biodiversity was limited and many fish kills were reported. With the implementation of pollution reduction programs (required by legislation changes) by the industries surrounding the harbour since the 1970s, pollution in the harbour has been reduced dramatically, and the quality of the marine environment of the harbour has noticeably improved. Large reductions in the concentrations of certain toxic wastes and heavy metals in water have occurred. Marine life has returned to the whole harbour (parts were described in 1977 as abiotic). Contaminants in fish have decreased. Despite this achievement, however, there is still considerable room for improvement in the quality of the marine environment of the harbour.

Animals↗

PubMed2001

The in vitro activity and specificity of human endothelial cell-specific promoters in porcine cells.

The chronic shortage of human organs, tissues and cells for transplantation has inspired research on the possibility of using animal donor tissue instead. Transplantation over a species barrier is associated with rejections which are difficult to control. Therefore, it is generally agreed that successful pig to human xenotransplantation requires donor pigs to be genetically modified. Vascular endothelium is the most immediate barrier between the xenogeneic donor organ and host immune and nonimmune defense systems. Thus, these cells are the prime targets for such genetic modifications. Luciferase assays were used to evaluate the activity and specificity of human endothelial-cell specific promoters in porcine aortic-, microvascular- and nonendothelial cells. The promoters for human Flk-1 (fetal liver kinase-1), Flt-1 (fms-like tyrosine kinase), ICAM-2 (intercellular adhesion molecule-2), thrombomodulin and vWf (von Willebrand factor) supported similar levels of luciferase expression in human and porcine aortic endothelial cells, with the Flk-1 promoter being the strongest followed by the thrombomodulin promoter. Relative to the activity of the CMV promoter, the human endothelial cell-specific promoters all showed less activity in porcine kidney microvascular endothelial cells than in liver or brain microvascular endothelial cells. The thrombomodulin and Flk-1 promoters exhibited similar activity in liver and kidney microvascular endothelial cells, whereas the Flk-1 promoter was stronger in aortic and brain microvascular endothelial cells. Human endothelial cell-specific promoters also showed some degree of specificity in pig, because they supported less luciferase activity in porcine nonendothelial cell lines. Based on the in vitro data and previously published in vivo data, the human Flk-1 and thrombomodulin promoters are good candidate promoters for strong endothelial cell-specific gene expression in transgenic pigs.

Animals↗