Ryoichi Hashida

Effect of PGI2 on transcellular transport of fluorescein dextran through an arterial endothelial monolayer

The effects of prostacyclin (PGI2) and stable derivatives of PGI2, such as isocarbacyclin (PGI2 deriv. (A] and isocarbacyclin methyl ester (PGI2 deriv. (B)), on junctional transport of fluorescein dextran (FD) through cultured porcine arterial endothelial cells were investigated. These PGI2S inhibited the transcellular transport dose-dependently. After the elimination of PGI2, its inhibitory effect persisted for at least 1 hr. A good correlation was found between increase of cAMP and the potency of inhibition. Increase of cAMP after PGI2 treatment seemed to be involved in the inhibition of FD transport.

Gene Expression Analysis of Atopic Dermatitis-Like Skin Lesions Induced in NC/Nga Mice by Mite Antigen Stimulation under Specific Pathogen-Free Conditions

Background: Atopic dermatitis (AD) is a chronic relapsing inflammation characterized by pruritic and eczematous skin lesions usually observed in patients with a familial history of atopic diseases, but its exact etiology is unclear. An animal model is indispensable for the analysis of the pathogenesis and the development of new drugs to treat this disease. Here, we compare changes in gene expression profiles in the AD-like skin lesions of NC/Nga or BALB/c mice stimulated intradermally by mite antigen under specific pathogen-free (SPF) conditions. Methods: Mite Extract-Dp was injected intradermally into the right and left pinnae and into the skin of the back of NC/Nga or BALB/c mice in 2 places once per 3 days, and the clinical symptoms and the ear thickness were measured. On day 14 or day 28 after starting mite extract injection, we collected plasma and pinnae from NC/Nga or BALB/c mice. The amount of total immunoglobulin E (IgE) in plasma was assayed. We analyzed mRNA transcripts in pinnae using real-time quantitative PCR for the murine counterparts of several known allergy-related genes. Moreover, genome-wide gene expression in pinnae from NC/Nga mice was analyzed using high-density oligonucleotide arrays (GeneChip, Affymetrix). Results: From 2 weeks after stimulation, marked skin inflammation was induced in the pinnae of NC/Nga but not BALB/c mice. However, IgE levels in sera rose equally in both strains. Quantitative PCR analysis and comprehensive GeneChip analysis of the AD-like pinna skin lesions revealed that their development was accompanied by changes in expression of more than 1,000 genes. These included cytokines, cytokine receptors, proteases, and adhesion molecules. Furthermore, genes thus far not reported in association with AD were also affected. Conclusion: From these results, the NC/Nga mouse model using mite sensitization under SPF conditions could be useful for elucidating the mechanisms of AD pathogenesis and developing more effective therapy for AD.

Analysis of gene expression in peripheral blood eosinophils from patients with atopic dermatitis and in vitro cytokine-stimulated blood eosinophils

Investigation of differentially expressed genes in eosinophils of patients with allergic diseases such as atopic dermatitis (AD) will provide important information for elucidating possible mechanisms of pathology. To identify novel genes that are expressed in AD, we compared gene expression in samples of peripheral blood eosinophils from AD patients and healthy volunteers. RNA was extracted from peripheral blood eosinophils. The expression of various genes, such as those for cytokine receptors, eosinophil activation marker, platelet activating factor (PAF) receptor, eosinophil‐specific granular proteins and apoptosis‐related genes, was confirmed using real‐time reverse transcription–polymerase chain reaction (RT‐PCR). Peripheral blood eosinophils of healthy volunteers were also isolated and stimulated for introduction of various cytokines. RNA was extracted and gene expression was monitored. Several genes, such as those for cytokine receptors (granulocyte‐macrophage colony‐stimulating factor (GM‐CSF) receptor α and β chain and interleukin (IL)‐3 receptor α chain), CD44 and PAF receptor were expressed at significantly higher levels in AD patients than in healthy volunteers. In addition, the anti‐apoptotic genes, bcl‐2 and bcl‐xL, were expressed at increased levels in AD patients. No single gene expression correlated with clinical markers, such as eosinophil count or IgE levels. Expression of GM‐CSF receptor β chain and IL‐3 receptor α chain in isolated blood eosinophils of healthy volunteers was stimulated by IL‐5, IL‐4, interferon (IFN)‐γ and GM‐CSF. Expression of bcl‐2 and bcl‐xL was also increased after stimulation with IL‐5, IL‐4 or IFN‐γ. The in vitro enhancement of cytokine‐stimulated gene expression correlated well with the enhancement observed in clinical samples of eosinophils, suggesting that cytokines may affect gene expression in vivo in eosinophils of patients with AD.

Cloning and characterization of the highly expressed ETEA gene from blood cells of atopic dermatitis patients.

Analysis of patients with atopic dermatitis (AD) for differential expression of genes, as compared to normal individuals, will be useful for understanding the molecular pathogenesis of AD. We found that the expression of the gene ETEA in human peripheral blood CD3-positive cells from patients with atopic dermatitis was significantly higher than in normal individuals. Eosinophils from AD patients expressed ETEA at a significantly higher level than the healthy controls. The overall sequence of the 445 aa deduced polypeptide from the cloned ETEA cDNA showed homology to human Fas-associated factor 1 (FAF1), which is involved in Fas-mediated apoptosis. However, the interaction of ETEA with the Fas death domain was weaker than that of FAF1, as studied in yeast two-hybrid experiments. The ETEA-EGFP fusion protein was expressed in cytoplasm. During the course of activation-induced cell death of primary T cells, transcription levels of ETEA and FAF1 were upregulated with similar kinetics. The enhanced expression of ETEA may play a role in the regulating the resistance to apoptosis that is observed in T cells and eosinophils of AD patients.

Gene Expression Accompanied by Differentiation of Cord Blood-Derived CD34+ Cells to Eosinophils

To clarify the relation between the expression of genes such as eosinophil-specific granular proteins and cytokine receptors and the pathogenesis of allergic disease, cord blood-derived CD34+ cells were cultured and differentiated into eosinophils. Gene expression in the cells during the differentiation was determined by real-time reverse transcription PCR (ABI PRISM 7700). CD34+ mononuclear cells cultured with stem cell factor, granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-3, and IL-5 in Iscove’s MEM, and proliferated until the 2nd week, when the cell number reached a plateau. Under these conditions, more than 90% of the cells differentiate into mature eosinophils in 3 weeks. The expression of major basic protein and eosinophil-derived neurotoxin in the treated cells increased until week 2 and decreased between week 2 and 3. However, the expression of membrane receptor genes, such as IL-5 receptor (α chain), IL-3 receptor (α chain), GM-CSF-α receptor, GM-CSF-β receptor, CC chemokine receptor 3, interferon-γ receptor, platelet-activating factor receptor and leukotriene D4 receptor, increased until the 3rd week of eosinophil maturation. Our study suggests that the in vitro eosinophil differentiation and maturation model is useful for clarifying the relation between eosinophil-specific gene expression during allergic diseases and the progression of the disease.

NR4A Orphan Nuclear Receptor Family in Peripheral Blood Eosinophils from Patients with Atopic Dermatitis and Apoptotic Eosinophils in vitro

To identify novel genes related to the clinical signs of atopic dermatitis (AD), differentially expressed genes were sought in peripheral blood eosinophils from both AD patients and healthy volunteers. RNA was prepared from eosinophils, expression of various genes was monitored using the Affymetrix GeneChip, and expression was quantified by real-time RT-PCR. Two genes, Nur77 and NOR1, members of NR4A orphan nuclear receptor family, were expressed at a significantly higher level in AD patients than in healthy volunteers. Expression of another gene in the NR4A receptor family, Nurr1, was also higher in AD patients than in healthy volunteers. When peripheral blood leukocytes from healthy volunteers were fractionated, NOR1 expression was highest in eosinophils, but expression of Nur77 and Nurr1 genes was not eosinophil-specific. Extremely intense apoptosis was induced in both eosinophils and an eosinophil cell line, AML14.3D10, by treatment with antibody (Ab) to both CD30 and Fas. Rapid expression of the genes for the NR4A receptor family was observed with anti-CD30 Ab treatment but not with anti-Fas Ab. The NR4A orphan nuclear receptor family gene expression and the subsequent eosinophil apoptosis were downregulated by the MAPK inhibitor, U0126. These results suggest that the expression of the NR4A receptor family genes through CD30 signaling may regulate eosinophil apoptosis in allergic conditions such as AD.

The NR4A nuclear receptor family in eosinophils

AbstractIt is well-known that many members of the family of nuclear receptors have been implicated in human diseases, and metabolic disorders in particular. The NR4A nuclear receptor family consists of three members, Nur77, Nurr1, and NOR1. All of these are orphan receptors, and Nur77 and NOR1 exert possible pathological roles in immune diseases through the modulation of leukocyte functions. CD30 stimulation, which induces eosinophil-specific apoptosis, markedly enhances expression of Nur77 and NOR1 in eosinophils. This suggests the possibility of pharmacological modulation of Nur77- or NOR1-specific apoptotic pathways via receptor-dependent transactivation. In this review, we discuss treatment of allergic diseases by low molecular weight compounds acting through the NR4A receptor family to cause eosinophil apoptosis. NR4A nuclear receptor genes were selected following comprehensive analysis of differentially expressed genes in eosinophils of atopic dermatitis patients compared with healthy volunteers.

Expression of a Human SOCS Protein, HSOCP-1, in Peripheral Blood Eosinophils from Patients with Atopic Dermatitis

To identify new genes related to atopic dermatitis (AD), we screened for differentially expressed genes in peripheral blood eosinophils derived from AD patients and healthy volunteers. RNA was prepared from peripheral blood eosinophils obtained from both AD patients and healthy volunteers, and the expression of various genes was monitored using fluorescent differential display and real-time RT-PCR. One of the expressed sequence tags (ESTs) was expressed at a significantly higher level in AD patients than in healthy volunteers. A full-length cDNA was identified that encoded a human suppressor of cytokine signaling (SOCS) protein, HSOCP-1, also named hASB-8. The expression of HSOCP-1 was increased in cultured peripheral blood eosinophils after IL-4 stimulation, and overexpression of HSOCP-1 caused cell death in an eosinophil cell line, AML14.3D10. p34SEI-1 was identified as a HSOCP-1-interacting protein by a yeast two-hybrid system. It is a protein that also interacts with the cyclin-dependent kinase inhibitor p16INK4, suggesting that HSOCP-1 is involved in cell cycle control and apoptosis.

Effect of PGI2 on platelet binding to partially denuded endothelial monolayer in vitro

We have developed a new model for the investigation of platelet interaction with injured vascular endothelium. This involves the quantitative detection of platelet binding to a partially denuded endothelial cell monolayer in vitro. Porcine arterial endothelial monolayer, cultured on collagen gel containing fibrinogen and fibronectin, was partially denuded and the binding of 51Cr-platelets was measured. A synergistic increase in platelet binding was observed in the presence of fibrinogen and fibronectin. A distinct aggregation of platelets along the edge of the denuded area of the endothelial monolayer was seen. Prostacyclin (PGI2) inhibited platelet aggregation, although adhesive platelets were still present at denuded sites.

Endothelial Injury and Accumulation of Cholesterol Ester Derived from Circulating Lipoproteins

To elucidate the mechanism how lipoproteins transport through the endothelial barrier, an in vitro model of transcellular transport of macromolecules was developed.