Biomedical subjects

Hui Yang

Publications and source records attributed to Hui Yang.

At least 73 records · Page 4Linked to original sources

PubMed2005

Antileukemia activity of the combination of 5-aza-2'-deoxycytidine with valproic acid.

Aberrant DNA methylation of promoter associated CpG islands is a common phenomenon in human leukemias and cooperates with histone code changes in the control of gene expression. 5-Aza-2'-deoxycytidine (DAC) is a hypomethylating agent with significant antileukemia activity in humans. Recently, valproic acid (VPA) has been shown to be a histone deacetylase inhibitor and to have potential antineoplastic activity. In this report, we study the in vitro effects of the combination of DAC and VPA on the leukemic cell lines HL-60 and MOLT4. DAC alone induced growth inhibition and apoptosis at doses of 1 microM, an effect observed with VPA at doses of 1 mM. Each drug alone had the capacity to induce the expression of p57KIP2 and p21CIP1. DAC mediated hypomethylation of p57KIP2 was not required to induce p57KIP2 gene expression, and treatment with DAC resulted in the induction of p21CIP1. VPA induced global histone acetylation, an effect enhanced by the addition of DAC. The combination of DAC and VPA had a synergistic effect in terms of growth inhibition, induction of apoptosis and reactivation of p57KIP2 and p21CIP1. These results suggest that the combination of DAC and VPA could have significant antileukemia activity in vivo.

Antibiotics, Antineoplastic↗

PubMed2005

Aberrant DNA methylation of a cell cycle regulatory pathway composed of P73, P15 and P57KIP2 is a rare event in children with acute lymphocytic leukemia.

Aberrant DNA methylation of multiple promoter associated CpG islands is a frequent phenomenon in acute lymphocytic leukemia (ALL). Recently, methylation of a cell cycle control pathway composed of P73, P15 and P57KIP2 has been shown to confer poor prognosis to adult patients with ALL. Using bisulfite PCR methods, we have explored the prevalence of methylation of this pathway in a cohort of children with ALL (N=20), and compared these results with those observed in a group of adult patients (N=53). P73 was methylated in 4 (20%) pediatric patients, P15 in 3 (15%), and P57KIP2 in 2 (10%). These compared to 14 (26%), p=0.5, 16 (30%), p=0.04 and 20 (37%), p=0.04, respectively in adult patients. Methylation of two or more genes was not observed in any pediatric patient, but in 15 (28%) adult patients (p=0.003). Poor survival of adult patients was associated with methylation of > or =2 genes (p=0.003). These results indicate that differences in DNA methylation of specific molecular pathways may contribute to the prognostic differences known to occur between pediatric and adult patients with ALL.

Adolescent↗

PubMed2005

[Effect of acid suppression therapy for eradicating Helicobacter pylori infection on bismuth absorption from colloidal bismuth pectin].

OBJECTIVE: To investigate whether acid suppression therapy influences the absorption of bismuth from colloidal bismuth pectin (CBP). METHODS: 48 male SD rats were randomly divided into five groups to be administer with different medicines once a day for 14 days: group A1 (administered with CBP only and killed on the cessation day of administration), group B1 (administered with CBP only and killed 8 weeks after the cessation of administration), group A2 [administered with CBP + amoxicillin (AMO) + metronidazole (MTR) + losec and killed on the cessation day of administration], group B2 (administered with CBP + AMO + MTR + losec and killed 8 weeks after the cessation of administration), and control group (administered with distilled water). The kidney issue sections were counterstained after AMG development. The bismuth deposited in tissues was observed by microscopy. The gray level of kidney tissue sections were measured and compared through image processing program. The deposition of bismuth and the degrees of cell organ's impairment were observed by electron microscopy. By using electron probe microanalysis bismuth was identified from the chemical elements in the specimens. RESULTS: Under the light microscopy, black-brown granules were discovered in the cell bodies of the proximal convoluted renal tubule. The amounts of bismuth accumulated in kidney of the 2 quadruple therapy groups were much more than those of the 2 single compound therapy groups (all P < 0.05). The amount of bismuth accumulated in kidney on the cessation day of administration was more than that eight weeks later (both P < 0.01). Under electron microscopy, black-brown granules were observed exclusively in the lysosomes of the proximal convoluted renal tubule cell. Electron microscopy found cell impairment in the quadruple therapy groups. Impairment of these cells could be recovered 8 weeks after the cessation of administration. CONCLUSION: Acid suppression therapy causes an increase of absorption and accumulation of bismuth from CBP in the kidney. Bismuth can be accumulated in the cell bodies of proximal convoluted renal tubule after its absorption. The absorbed bismuth can be discharged out of the body via kidney. Large amounts of bismuth accumulation in kidney can impair the functions of proximal convoluted renal tubule cells.

Amoxicillin↗

PubMed2005

Neural precursor cells differentiated from mouse embryonic stem cells relieve symptomatic motor behavior in a rat model of Parkinson's disease.

Pluripotent embryonic stem (ES) cells are the most versatile cells, with the potential to differentiate into all types of cell lineages including neural precursor cells (NPCs), which can be expanded in large numbers for significant periods of time to provide a reliable cell source for transplantation in neurodegenerative disorders such as Parkinson's disease (PD). In the present study, we used the MESPU35 mouse ES cell line, which expresses enhanced green fluorescent protein that enables one to distinguish between transplanted cells and cells of host origin. Embryoid bodies (EBs) were formed and were induced to NPCs in N2 selection medium plus fibronectin. Praxiology and immunohistochemistry methods were used to observe the survival, differentiation, and therapeutic effect of NPCs after grafted into the striatum of PD rats. We found that mouse ESc were differentiated into nestin-positive NPCs 6 days after the EBs formed and cultured in the N2 selection medium. The number of survival NPCs was increased significantly by fibronectin. About 23.76+/-2.29% of remaining cells were tyrosine hydroxylase (TH)-positive 12 days after NPCs were cultured in N2 selective medium. The survival rates of NPCs were 2.10+/-0.41% and about 90.90+/-3.00% of the engrafted NPCs were TH-positive 6 weeks after transplantation into the striatum of PD rats. The rotation of PD rats was relieved 3 weeks after the NPCs transplantation and this effect was kept for at least 6 weeks. It suggests that most of the survival NPCs derived from ES cells differentiated into TH-positive neurons after grafted into the striatum of PD rats, which produces therapeutic effect on PD.

Animals↗

PubMed2005

Immortalized rat astrocyte strain genetically modified by rat preprogalanin gene.

To construct an immortalized rat astrocyte strain genetically modified by rat preprogalanin gene (IAST/GAL) and detect its galanin (GAL) expression and secretion, a cDNA fragment of rat GAL in plasmid of pBS KS(+)-GAL was inserted into eukaryotic expression vector pcDNA3.1 (+) by DNA recombinant technology, then the restriction enzyme digestion and DNA sequencing were carried out to evaluate the recombinant. The pcDNA3.1 (+)-GAL and pcDNA3.1 (+) construct were transfected into immortalized rat astrocyte strain (IAST) by lipofectamine and the population of cells which stably integrated the construct was selected with 600 microg/mL G418. Individual clones were screened and expanded into clonal cell strains. Detection of Neo gene was used to validate the success of the transfection. Immunocytochemical staining, RT-PCR and radioimmunoassay were used to detect the expression and secretion level of GAL. The recombinant had been successfully constructed by restriction enzyme digestion and DNA sequencing. Detection of Neo gene showed that the pcDNA3.1 (+)-GAL and pcDNA3.1 (+) have been successfully transfected into IAST. After selection by using G418, IAST/GAL and IAST/Neo cell strains were obtained. IAST/GAL, IAST/Neo and IAST were immunostained positively for GAL, but the GAL average optical density of IAST/GAL was significantly higher than that of IAST/Neo and IAST (P< 0.01). The level of GAL mRNA expression and the supernatant concentration of GAL in cultured IAST/GAL were significantly higher than those of IAST and IAST/Neo (P<0.01), but no significant differences were found between the IAST and IAST/Neo (P>0.05). It was concluded that IAST/GAL strain was constructed successfully and it might provide a basis for the further study of pain therapy.

Animals↗

PubMed2005

Adaptive diversification of vomeronasal receptor 1 genes in rodents.

The vomeronasal receptor 1 (V1R) are believed to be pheromone receptors in rodents. Here we used computational methods to identify 95 and 62 new putative V1R genes from the draft rat and mouse genome sequence, respectively. The rat V1R repertoire consists of 11 subfamilies, 10 of which are shared with the mouse, while rat appears to lack the H and I subfamilies found in mouse and possesses one unique subfamily (M). The estimations of the relative divergence times suggest that many subfamilies originated after the split of rodents and primates. The analysis also reveals that these clusters underwent an expansion very close to the split of mouse and rat. In addition, maximum likelihood analysis showed that the nonsynonymous and synonymous rate ratio for most of these clusters was much higher than one, suggesting the role of positive selection in the diversification of these duplicated V1R genes. Because V1R are thought to mediate the process of signal transduction in response to pheromone detection, we speculate that the V1R genes have evolved under positive Darwinian selection to maintain the ability to discriminate between large and complex pheromonal mixtures.

Adaptation, Physiological↗

PubMed2005

Roles of cyclophilins in cancers and other organ systems.

Cyclophilins are originally identified as cellular binding proteins for the immunosuppressive drug cyclosporin A. Many cyclophilins, including CypA, CypB, CypC, CypD, and Cyp40, have been discovered and shown to be ubiquitously distributed in many types of cells and organ systems. Recent investigations have uncovered many important properties and functions for cyclophilins including peptidyle-prolyl-isomerase activity and protein folding/repair; maintaining mitochondrial functions and involvement in apoptosis; roles in regulation of T-cell function and inflammation; interaction with CD147; and pathogenesis of vascular disease, human immunodeficiency virus infection, and rheumatoid arthritis. Furthermore, the expression and functions of cyclophilins may be correlated with tumor biology of several types of cancers including pancreatic carcinoma. Molecular mechanisms of cyclophilin-mediated biologic events and future directions of research are discussed in this review. Understanding the roles of cyclophilins in cancers and other organ systems will be crucial in determining clinical applications for the treatment or diagnosis of human diseases.

Antigens, CD↗

PubMed2005

Roles of thymosins in cancers and other organ systems.

Thymosins are small peptides, originally identified from the thymus, but now known to be more widely distributed in many tissues and cells. Thymosins are divided into three main groups, alpha-, beta-, : and gamma-thymosins, based on their isoelectric points. alpha-thymosins (ProTalpha, Talphal) have nuclear localization and are involved in transcription and/or DNA replications; whereas beta-thymosins (Tbeta4, Tbeta10, Tbetal5) have cytoplasmic localization and show high affinity to G-actin for cell mobility. Furthermore, it is well known that both alpha- and beta-thymosins play important roles in modulating immune response, vascular biology, and cancer pathogenesis. More importantly, thymosins may have significant clinical applications. They may serve as molecular markers for the diagnosis and prognosis of certain diseases. In addition, they could be molecular targets of certain diseases or be used as therapeutic agents to treat certain diseases. However, the molecular mechanisms of action of thymosins are largely unknown. This review not only presents recent advances of basic science research of thymosins and their clinical applications but provides thoughtful views for future directions of investigation on thymosins.

Animals↗

PubMed2005

Roles of neuropilins in neuronal development, angiogenesis, and cancers.

Neuropilin-1 (NRP1) and neuropilin-2 (NRP2) are transmembrane glycoproteins that have been characterized as receptors for both semaphorins for neuronal guidance and vascular endothelial growth factor (VEGF) for angiogenesis. Biologic properties of NRPs have been linked to their unique domain structures. However, molecular interaction among NRPs, VEGF, and VEGF receptors is still not clear. Although several types of cancer cells can express NRPs, the role of NRPs in tumor pathogenesis is largely unknown. Thus, future investigations should include determining the effects and mechanisms of NRPs on proliferation, apoptosis, and migration of neuronal , endothelial, and cancer cells. Study of protein-protein interaction, signal transduction pathways, and NRP-mediated gene expression is particularly important to understand NRPs functions, which may have significant clinical applications in the treatment of neurological disorders, cardiovascular diseases, and certain cancers.

Animals↗

PubMed2005

The assays of activities and function of TH, AADC, and GCH1 and their potential use in ex vivo gene therapy of PD.

In the past decades, there have been numerous studies in the gene therapy for Parkinson's disease (PD), especially in delivering genes of enzymes for dopamine (DA) synthesis. Gene therapy in PD appears to be at the brink of the clinical study phase. However, there are many questions that need to be solved before this approach can be contemplated clinically, especially the question about the control of DA production because too much DA could cause toxicity. Until recently, few studies have investigated the relation between DA production and PD improvement and respective expressed human tyrosine hydroxylase (hTH), human GTP-cyclohydrolase 1 (hGCH1), and human aromatic acid decarboxylase (hAADC) in ex vivo gene therapy for PD. Now, we have developed a simple, fast, and reliable method to assay the activities of TH and AADC and have provided the possibility of ex vivo gene therapy for PD by genetically modifying cells with separate hTH, hGCH1, and hAADC genes. Using the method, we found though hTH, hGCH1, and hAADC genes were expressed, respectively, they could fulfil the function of DA synthesis by incubating together in vitro, and more DA was synthesized in vitro when hTH, hGCH1, and hAADC genes were expressed together rather than hTH and hAADC genes expressed or hTH expressed. The result suggests that we could easily control DA production in ex vivo gene therapy before transplantation. By combining this method and microdialysis, we also could further investigate the DA production in vitro and in vivo and then decide the optimal number and ratio of different transduced cells to improve the therapy of PD. Thus, the method has potential use in ex vivo gene therapy of PD.

Animals↗

PubMed2005

Phylogenetic analysis and developmental expression of brp-like genes in amphioxus and zebrafish.

The brp-like genes in amphioxus (Branchiostoma belcheri tsingtauense) and in zebrafish (Danio rerio) are reported. The putative brp-like proteins are orthologous to the ancestor of the human brain protein 239FB and 239AB. Previous studies showed that human brain protein 239 might play a role in central nervous system development and function. In this study, the transcripts of zebrafish brp-like gene are mainly located in the developing central neural system in embryo and larva similar to its orthologous genes in human. In contrast, the developmental expression pattern of amphioxus brp-like gene suggests that the gene might be involved in the development of the notochord, pharynx, gills and gut in amphioxus embryos and larvae. Phylogenetic analysis shows that the amphioxus brp-like gene is closer to the orthologous genes in vertebrates than those in invertebrates. The results suggest that the function of the brain protein 239 family genes may change in evolution.

Amino Acid Sequence↗

PubMed2005

Identification and expression of the amphioxus Cks1 gene.

A full-length Cks1 homologue gene, AmphiCks1, was identified in amphioxus, Branchiostoma belcheri tsingtauense. Sequence characteristics, phylogeny and patterns of expression during embryonic and larval development were established. The protein predicted from AmphiCks1 showed high sequence identity with vertebrate and invertebrate homologues. Protein structural studies and phylogenetic analysis suggested that Cks homologues are evolutionarily conserved. The AmphiCks1 transcript was detected in most early developmental stages by northern blotting and whole-mount in situ hybridization, suggesting a role for the gene in cell division.

Amino Acid Sequence↗

PubMed2005

Acceleration of endothelial-like cell differentiation from CD14+ monocytes in vitro.

OBJECTIVE: In vitro differentiation of endothelial cells has potential applications in vascular tissue engineering and cell-based therapy for many diseases. The objective of this study was to develop a new strategy that utilizes cytokines and lipopolysaccharide (LPS) to accelerate endothelial-like cell differentiation from peripheral blood CD14(+) monocytes. METHODS: Peripheral blood CD14(+) monocytes were purified with immunobeads and cultured with an angiogenic growth factor-rich growth medium (EGM-2) with or without initial treatment of LPS in combination of granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-4 (IL-4) for 4 days (the day 4 cultures). The cells were then continuously cultured in EGM-2 medium for an additional 4 or 10 days (the day 8 or day 14 cultures). Cell markers were determined by flow cytometry analysis and immunofluorescence staining. Cytokine/chemokine profile was studied by Bio-Plex immunoassay. RESULTS: In the group of initial treatment of LPS in combination with GM-CSF, IL-4, and EGM-2, the majority of suspended CD14(+) monocytes were attached and changed their morphology to endothelial-like cells, which expressed high levels of endothelial cell markers CD31, von Willebrand factor, and vascular endothelial growth factor receptor-1 as well as two major endothelial tight junction proteins zonula occludens -1 and occludin in the day 8 cultures. Endothelial nitric oxide synthase expression was substantially increased. Endothelial-like cells were also able to uptake acetylated low-density lipoprotein and bind to Ulex europeus lectin. In addition, endothelial-like cells showed a unique cytokine/chemokine profile with substantial increases of macrophage inflammatory protein-1beta, IL-6, granulocyte colony-stimulating factor, and IL-8. CONCLUSION: Initial treatment of LPS in combination with GM-CSF, IL-4, and EGM-2 is an effective strategy for acceleration of endothelial-like cell differentiation from peripheral blood CD14(+) monocytes in vitro.

Biomarkers↗

PubMed2005

TNF-alpha decreases expression of somatostatin, somatostatin receptors, and cortistatin in human coronary endothelial cells.

BACKGROUND: The objective of this study was to determine the expression of somatostatin (SST) and its receptors (SSTRs) and their regulation by TNF-alpha as well as cell proliferation in response to SST in human endothelial cells. MATERIALS AND METHODS: Human coronary artery endothelial cells (HCAECs) were cultured without or with TNF-alpha (0.1, 1, or 10 ng/ml) for 24 h. The mRNA levels of SST, SSTR-1-5, as well as a housekeeping gene (beta-actin) were determined by real-time RT-PCR. Expression of SSTR-2 was also demonstrated by immunofluorescence staining. Cell proliferation in response to SST treatment (0.04, 0.2, or 1 ng/ml) was performed by [3H]thymidine incorporation. RESULTS: Without TNF-alpha treatment, HCAECs showed mRNA expression of SST, SSTR-1, SSTR-2, and SSTR-5. The mRNA of SSTR-2 was expressed at a higher level than that of SSTR-1 and SSTR-5. However, SSTR-3 and SSTR-4 were not expressed or were minimally expressed. After treatment with TNF-alpha, the mRNA levels of SST, SSTR-1, SSTR-2, and SSTR-5 were significantly reduced in a dose-dependent fashion. TNF-alpha (1 ng/ml) reduced SST, SSTR-1, SSTR-2, and SSTR-5 by 93, 51, 85, and 99%, respectively, compared to controls (P < 0.001, t test). The immunoreactivity of SSTR-2 was also reduced after TNF-alpha treatment. SST-treated cells showed a significant reduction in [3H]thymidine incorporation in a dose-dependent manner. TNF-alpha treatment decreased SST inhibitory potential in cell proliferation. CONCLUSIONS: HCAECs express SST, SSTR-1, SSTR-2, and SSTR-5, which are all decreased by TNF-alpha treatment. Furthermore, treatment with exogenous SST significantly reduces cell proliferation, and this inhibitory effect is also decreased by TNF-alpha.

Cell Division↗

PubMed2005

Effects of cyclophilin A on cell proliferation and gene expressions in human vascular smooth muscle cells and endothelial cells.

BACKGROUND: Cyclophilin A (CypA) is a cytosolic protein which involves many biological functions including immune modulation, cell growth, tumorigenesis, and vascular disease. The objective of this study was to determine the effect of CypA on cell proliferation and several gene expressions in human endothelial cells and vascular smooth muscle cells. METHODS: Human coronary artery endothelial cells (HCAEC), human lung microvascular endothelial cells (HMVEC-L), and human aorta smooth muscle cells (HAoSMC) were used in this study. Cells were treated with 10 nM CypA for 24 h. The cell proliferation was determined by [3H]thymidine incorporation. The mRNA levels of 13 genes including CD147 (receptor for CypA), PDGF-BB, endothelin-1 (ET-1), vascular endothelial growth factor receptor-1 (VEGFR-1), VEGFR-2, VEGFR-3, neuropilin-1 (NRP-1), NRP-2, eNOS, iNOS, nNOS, ICAM-1, and PECAM-1 were semiquantitatively determined by real time RT-PCR as standardized with a house keeping gene beta-actin. RESULTS: CypA significantly increased cell proliferation of HAoSMC and HMVEC-L by 31% and 45%, respectively, as compared to controls, but had no effect on HCAEC. Blocking CD147 did not affect the mitogenic action of CypA. In addition, CypA also significantly increased the mRNA expression of CD147 by 43% and VEGFR-2 by 65% in HAoSMCs (P < 0.05, t test). HAoSMCs expressed much higher CD147 and neuropilin-1 (NRP-1) mRNA than HMVECs-L and HCAECs (P < 0.017, ANOVA). Furthermore, CypA increased ET-1 mRNA by 22% and VEGFR-1 mRNA by 23% in HMVECs-L, but had limited effects on HCAECs. HMVECs-L had much higher expressions of PDGF-BB, ET-1, VEGFR-2, VEGFR-1, VEGFR-3, and NRP-2 than HAoSMCs and HCAECs (P < 0.017, ANOVA). By contrast, HCAECs had much higher ICAM-1 mRNA levels than HMVECs-L and HAoSMCs (P < 0.017, ANOVA). CONCLUSIONS: These data demonstrate that CypA has a mitogenic effect on HAoSMCs and HMVECs-L, but not HCAECs. CD147 may not mediate the action of CypA. In addition, CypA substantially alters the mRNA levels of several key genes in human vascular cells, indicating potential multifunctional roles of CypA in vascular system. Furthermore, this study provides several new aspects of gene expressions in vascular cells.

Aorta↗

PubMed2005

Synthesis and cofluorescence of Eu(Y) complexes with salicylic acid and o-phenanthroline.

A series of dinuclear complexes of salicylic acid (HSal) and o-phenanthroline (Phen) with different molar ratios of Eu3+ to Y3+ have been synthesized. Their compositions are Eu(x)Y(1-x) (Sal)3(Phen) (x = 0 to approximately 1). Their UV spectra, IR spectra, and fluorescence spectra were studied. The UV spectra of the complexes reflect essentially absorption of the ligands for the fact that no obvious change of wavelength and band shape is found between the spectra of the complexes and that of the ligands except slight red shift. The IR absorption spectra indicate that salicylic acid is coordinated to the rare earth ions and chemical bonds are formed between rare earth ions and nitrogen atoms of o-phenanthroline. The fluorescence spectra of the complexes indicate that the fluorescence emission intensity of europium ion was enhanced by the addition of Y3+, which is referred to as cofluorescence. These facts show that not only the ligands but also the yttrium complex can transfer the absorbed energy to Eu3+ ion in the complexes. Formation of polynuclear complexes appears to be responsible for cofluorescence.

Europium↗

PubMed2005

C-reactive protein decreases expression of thrombomodulin and endothelial protein C receptor in human endothelial cells.

BACKGROUND: C-reactive protein (CRP) is associated with atherosclerosis and thrombosis. However, it is unclear whether CRP has direct effects on the antithrombogenic properties of endothelial cells. The objective of the present study was to determine the effect of CRP on the expression of thrombomodulin (TM) and the endothelial protein C receptor (EPCR) in human endothelial cells. METHODS: Human coronary artery endothelial cells (HCAECs) were treated with CRP in a dose- and time-dependent manner. The messenger RNA levels of TM and EPCR were determined by real-time polymerase chain reaction. Anti-CD32 antibody and curcumin were used to block the potential effects of CRP. RESULTS: In HCAECs, CRP (10 and 25 microg/mL) significantly reduced TM messenger RNA levels by 18 and 30%, respectively, compared with controls (P < .05). This effect was also confirmed in other types of human endothelial cells from umbilical veins and skin microvessels. The cells treated with CRP (10 and 25 microg/mL) showed significant reductions of EPCR mRNA levels by 34% and 33%, respectively (P < .05). Anti-CD32 antibody partially blocked CRP-induced downregulation of TM and EPCR in HCAECs. Furthermore, curcumin (5 and 10 microM) in combination with CRP (10 microg/mL) significantly increased TM mRNA levels by 45 and 100%, respectively, and increased EPCR mRNA levels by 24 and 45%, respectively, compared with those in CRP-treated cells (P < .05). CONCLUSIONS: CRP significantly decreases the expression of TM and EPCR in human endothelial cells, thereby promoting thrombogenic conditions. This effect is partially mediated by CD32. Curcumin completely blocks CRP-induced downregulation of TM and EPCR in HCAECs.

Anti-Inflammatory Agents, Non-Steroidal↗

PubMed2005

Effects of lysophosphatidylcholine on monolayer cell permeability of human coronary artery endothelial cells.

BACKGROUND: Lysophosphatidylcholine (LysoPC) is a product of phosphatidylcholine hydrolysis by phospholipase A2, which is associated with atherosclerosis. However, the underlying molecular mechanisms are still unclear. The purpose of this study was to determine the effects of LysoPC on monolayer permeability of human coronary artery endothelial cells (HCAECs). METHODS: HCAECs were cultured with LysoPC in a dose- and time-dependent manner. Monolayer permeability was studied by using a transwell system with a Texas-Red-labeled dextran tracer. The messenger RNA and protein levels of endothelial tight junction proteins were determined with the use of real-time reverse transcriptase-polymerase chain reaction and Western blot analysis, respectively. Superoxide anion levels were determined with the use of fluorescent dye dihydroethidium-based flow cytometry analysis. Activation of mitogen-activated protein kinases was determined by performing Bio-Plex immunoassay. RESULTS: LysoPC (30 micromol/L) increased monolayer permeability by 53% and decreased the messenger RNA levels of zonula occludens-1, occludin, claudin-1, and junctional adhesion molecule by 44%, 53%, 50%, and 52%, respectively, compared with controls (P < .05). Western blot analysis showed reduced protein levels of these tight junction molecules. LysoPC (15 and 30 micromol/L) also increased superoxide anion production by 54% and 58%, respectively, compared with controls (P < .05). Antioxidant seleno-L-methionine (20 and 30 micromol/L) inhibited LysoPC (30 micromol/L)-induced permeability by 42% and 68%, respectively (P < .05). Furthermore, LysoPC (30 micromol/L) activated c-Jun N-terminal kinase and p38 phosphorylation, but not extracellular signal-related kinase 1/2, within 5 to 10 minutes. CONCLUSIONS: LysoPC increases monolayer permeability and reduces the expression of tight junction molecules in HCAECs through oxidative stress and activation of c-Jun N-terminal kinase and p38 mitogen-activated protein kinase. The antioxidant can effectively block LysoPC-induced endothelial permeability.

Cadherins↗