Atherosclerosis is readily observed in areas where disturbed flow is formed, while the atheroprotective region is found in areas with steady laminar flow (L-flow). It has been established that L-flow protects endothelial cells against endothelial dysfunction, including apoptosis and inflammation. It has also been reported that extracellular signal-regulated kinase 5 (ERK5) regulated endothelial integrity and protected endothelial cells from vascular dysfunction and disease under L-flow. However, the molecular mechanism by which L-flow-induced ERK5 activation inhibits endothelial apoptosis has not yet been determined. Transcription factor p53 is a major pro-apoptotic factor which contributes to apoptosis in various cell types. In this study, we found that 15-deoxy-Delta(12,14)-prostaglandin J2 induced p53 expression and that endothelial apoptosis was reduced under the L-flow condition. This anti-apoptotic response was reversed by the biochemical inhibition of ERK5 activation. It was also found that activation of ERK5 protected endothelial apoptosis in a C terminus of Hsc70-interacting protein (CHIP) ubiquitin ligase-dependent manner. Moreover, molecular interaction between ERK5-CHIP and p53 ubiquitination were addressed with a CHIP ubiquitin ligase activity assay. Taken together, our data suggest that the ERK5-CHIP signal module elicited by L-flow plays an important role in the anti-apoptotic mechanism in endothelial cells.
Apoptosis ; Atherosclerosis ; Endothelial Cells ; Inflammation ; Mitogen-Activated Protein Kinase 7 ; Prostaglandin D2 ; Transcription Factors ; Ubiquitin ; Ubiquitination

Emodin is an anthraquinone derivative from the roots of Rheum officinale Baill that possesses a variety of biological activities, including inhibition of 5α-reductase and prostaglandin D2. In this study, we investigated whether emodin promotes hair growth. After emodin was topically applied to the shaved dorsal skin of telogenic C57BL/6 N mice, the hair growth rate and morphological analysis were evaluated in dorsal skin for 15 days. After 13 days of treatment, minoxidil or emodin (0.01% or 0.1%)-treated groups showed remarkable regrowth of hairs relative to the vehicle control group. Scoring of the hair growth and rate of hair growth area for 15 days revealed that groups treated with minoxidil and 0.1% emodin were significantly higher than the vehicle control group. Histological examination revealed the emodin and minoxidil groups markedly recovered the number and morphology of hair follicles, including the subcutis depth, relative to the vehicle group. These results suggest that emodin has an excellent promoting effect in hair growth similar to that of minoxidil and might be useful for treatment of baldness or alopecia.
Alopecia ; Animals ; Emodin* ; Hair Follicle ; Hair* ; Mice* ; Minoxidil ; Prostaglandin D2 ; Rheum ; Skin

Heat contact urticaria is very rare and it is characterized by the development of wheal limited to the areas of heat contact. We report a case of heat contact urticaria in a 65-year-old women. The wheal was induced by hot bathing, washing in hot water or leaning on hot radiators. Symptoms started within 5 minutes of exposure and lasted 30 to 60 minutes. She had no systemic symptoms. The clinical diagnosis of localized heat urticaria was confirmed by experimental induction of localized wheals. Our investigation showed that the threshold temperature needed for induction of the heat urticaria was 39 degrees C. We tried to investigate the plasma levels of prostaglandin D2 and blood histamine before and after heat challenge. The patient showed marked improvement after a combination treatment of desensitizing by repeated exposure to heat and indomethacine.
Aged ; Case Report ; Female ; Heat/*adverse effects ; Human ; Prostaglandin D2/blood ; Urticaria/*etiology/therapy

Prostaglandin D2 (PGD2) is a major prostanoid, produced mainly by mast cells, in allergic diseases, including bronchial asthma. PGD2-induced vasodilatation and increased permeability are well-known classical effects that may be involved in allergic inflammation. Recently, novel functions of PGD2 have been identified. To date, D prostanoid receptor (DP) and chemoattractant receptor homologous molecule expressed on TH2 cells (CRTH2) have been shown to be major PGD2-related receptors. These two receptors have pivotal roles mediating allergic diseases by regulating the functions of various cell types, such as TH2 cells, eosinophils, basophils, mast cells, dendritic cells, and epithelial cells. This review will focus on the current understanding of the roles of PGD2 and its metabolites in TH2 inflammation and the pathogenesis of bronchial asthma.
Asthma/*etiology/immunology ; Basophils/physiology ; Eosinophils/physiology ; Humans ; Mast Cells/physiology ; Prostaglandin D2/*physiology ; Receptors, Immunologic/physiology ; Receptors, Prostaglandin/physiology ; Th2 Cells/*immunology

Imperatorin has been known to exert many biological functions including anti-inflammatory activity. In this study, we investigated the inhibitory effects of imperatorin on the production of inflammatory mediators in mouse bone marrow-derived mast cells (BMMC). Imperatorin inhibited degranulation and the generation of eicosanoids (leukotriene C4 (LTC4) and prostaglandin D2 (PGD2)) in IgE/antigen (Ag)-stimulated BMMC. To elucidate the molecular mechanism involved in this process, we investigated the effect of imperatorin on intracellular signaling in BMMC. Biochemical analyses of the IgE/Ag-mediated signaling pathway demonstrated that imperatorin dramatically attenuated degranulation and the production of 5-lipoxygenase-dependent LTC4 and cyclooxygenase-2-dependent PGD2 through the inhibition of intracellular calcium influx/phospholipase Cgamma1, cytosolic phospholipase A2/mitogen-activated protein kinases and/or nuclear factor-kappaB pathways in BMMC. These results suggest that the effects of imperatorin on inhibition of degranulation and eicosanoid generation through the suppression of multiple steps of IgE/Ag-mediated signaling pathways would be beneficial for the prevention of allergic inflammation.
Animals ; Calcium ; Cytosol ; Eicosanoids ; Inflammation ; Leukotriene C4 ; Mast Cells* ; Mice ; Mitogen-Activated Protein Kinases ; Phospholipases ; Prostaglandin D2 ; Protein Kinases

PURPOSE: The mast cell plays a pivotal role in the human immune response. Crosslinking of 2 IgE molecules bound to the high affinity IgE receptor (FcepsilonRI) on the surface of the mast cell results in mast cell degranulation and the release of several proinflammatory mediators. Patients with type-I allergy have increased levels of IgE in the blood compared to healthy individuals. METHODS: In a 6-week culture system of stem cells to human mast cells we investigated the effect of the concentration of IgE. The mast cells were cultured with different concentrations of IgE for the last 10 days of the maturation period. It was observed how the IgE concentration affects the histamine release, FcepsilonRI density on the mast cell surface and the concentration of other mediators. RESULTS: A clear correlation between IgE concentration in culture medium and the release of histamine upon activation was observed. It showed a bell-shaped dose response curve, with maximal response around an IgE-concentration of 250 ng/mL. Furthermore, the sensitivity of the mast cells and surface density of FcepsilonRI on mast cell surface was also influenced by the IgE concentration in the culture medium. CONCLUSIONS: IgE in the culture medium during the last 10 days of mast cell maturation influences the release of the preformed mediator histamine after mast cell activation and the density of FcepsilonRI on the mast cell surface. The release of the de novo synthetized mediator prostaglandin D2 and the expression of chymase and tryptase are not influenced by IgE in culture medium.
Chymases ; Histamine ; Histamine Release ; Humans ; Hygiene Hypothesis ; Hypersensitivity ; Immunoglobulin E ; Mast Cells ; Prostaglandin D2 ; Stem Cells ; Tryptases

PURPOSE: The mast cell plays a pivotal role in the human immune response. Crosslinking of 2 IgE molecules bound to the high affinity IgE receptor (FcepsilonRI) on the surface of the mast cell results in mast cell degranulation and the release of several proinflammatory mediators. Patients with type-I allergy have increased levels of IgE in the blood compared to healthy individuals. METHODS: In a 6-week culture system of stem cells to human mast cells we investigated the effect of the concentration of IgE. The mast cells were cultured with different concentrations of IgE for the last 10 days of the maturation period. It was observed how the IgE concentration affects the histamine release, FcepsilonRI density on the mast cell surface and the concentration of other mediators. RESULTS: A clear correlation between IgE concentration in culture medium and the release of histamine upon activation was observed. It showed a bell-shaped dose response curve, with maximal response around an IgE-concentration of 250 ng/mL. Furthermore, the sensitivity of the mast cells and surface density of FcepsilonRI on mast cell surface was also influenced by the IgE concentration in the culture medium. CONCLUSIONS: IgE in the culture medium during the last 10 days of mast cell maturation influences the release of the preformed mediator histamine after mast cell activation and the density of FcepsilonRI on the mast cell surface. The release of the de novo synthetized mediator prostaglandin D2 and the expression of chymase and tryptase are not influenced by IgE in culture medium.
Chymases ; Histamine ; Histamine Release ; Humans ; Hygiene Hypothesis ; Hypersensitivity ; Immunoglobulin E ; Mast Cells ; Prostaglandin D2 ; Stem Cells ; Tryptases

The aim of this study was to determine whether britanin, isolated from the flowers of Inula japonica (Inulae Flos), modulates the generation of allergic inflammatory mediators in activated mast cells. To understand the biological activity of britanin, the authors investigated its effects on the generation of prostaglandin D2 (PGD2), leukotriene C4 (LTC4), and degranulation in IgE/Ag-induced bone marrow-derived mast cells (BMMCs). Britanin dose dependently inhibited degranulation and the generations of PGD2 and LTC4 in BMMCs. Biochemical analyses of IgE/Ag-mediated signaling pathways demonstrated that britanin suppressed the phosphorylation of Syk kinase and multiple downstream signaling processes, including phospholipase Cgamma1 (PLCgamma1)-mediated calcium influx, the activation of mitogen-activated protein kinases (MAPKs; extracellular signal-regulated kinase 1/2, c-Jun NH2-terminal kinase and p38), and the nuclear factor-kappaB (NF-kappaB) pathway. Taken together, the findings of this study suggest britanin suppresses degranulation and eicosanoid generation by inhibiting the Syk-dependent pathway and britanin might be useful for the treatment of allergic inflammatory diseases.
Calcium ; Family Characteristics ; Flowers ; Inula ; Leukotriene C4 ; Mast Cells* ; Mitogen-Activated Protein Kinases ; Phospholipases ; Phosphorylation ; Phosphotransferases ; Prostaglandin D2

Contribution of prostaglandins D2, E2 and I2 (PGD2, PGE2 and PGI2) on the regulation of ATP-sensitive K+ channel (KATP channel) was investigated in isolated single rat ventricular cardiac myocytes using the patch clamp technique. PGD2, PGE2 and PGI2 did not affect KATP channel activity in the inside-out patch, but increased channel activity in a dose-dependent manner when the channel activities were attenuated by the administration of 100 muM ATP to the internal solution in the inside-out patch. Channel activations by the prostaglandins were abolished by 50 muM glibenclamide, a KATP channel blocker. Dose-response curves of relative channel activity against the ATP concentrations of internal solution in the inside-out patch were shifted to the right in the presence of those three prostaglandins. The rank order of the channel stimulatory potencies (as IC50 for ATP) calculated from the dose-response curves were PGI2 < PGD2 < PGE2. Conductance of the channel was not changed by those three prostaglandins. In conclusion, we suggest that prostaglandins D2, E2 and I2 are involved in the regulation of KATP channel activity in certain circumstances, and that those three prostaglandins may cause myocardial relaxation by opening KATP channels, thus protecting the heart from ischema.
Adenosine Triphosphate ; Animals ; Dinoprostone ; Epoprostenol ; Glyburide ; Heart ; Inhibitory Concentration 50 ; KATP Channels ; Myocytes, Cardiac* ; Prostaglandin D2 ; Prostaglandins* ; Rats* ; Relaxation

Curcumin is naturally occurring polyphenolic compound found in turmeric and has many pharmacological activities. The present study was undertaken to evaluate anti-allergic inflammatory activity of curcumin, and to investigate its inhibitory mechanisms in immunoglobulin E (IgE)/Ag-induced mouse bone marrow-derived mast cells (BMMCs) and in a mouse model of IgE/Ag-mediated passive systemic anaphylaxis (PSA). Curcumin inhibited cyclooxygenase-2 (COX-2) dependent prostaglandin D2 (PGD2) and 5-lipoxygenase (5-LO) dependent leukotriene C4 (LTC4) generation dose-dependently in BMMCs. To probe the mechanism involved, we assessed the effects of curcumin on the phosphorylation of Syk and its downstream signal molecules. Curcumin inhibited intracellular Ca2+ influx via phospholipase Cgamma1 (PLCgamma1) activation and the phosphorylation of mitogen-activated protein kinases (MAPKs) and the nuclear factor-kappaB (NF-kappaB) pathway. Furthermore, the oral administration of curcumin significantly attenuated IgE/Ag-induced PSA, as determined by serum LTC4, PGD2, and histamine levels. Taken together, this study shows that curcumin offers a basis for drug development for the treatment of allergic inflammatory diseases.
Administration, Oral ; Anaphylaxis* ; Animals ; Arachidonate 5-Lipoxygenase ; Curcuma ; Curcumin* ; Cyclooxygenase 2 ; Histamine* ; Immunoglobulin E ; Immunoglobulins* ; Leukotriene C4 ; Mast Cells* ; Mice* ; Mitogen-Activated Protein Kinases ; Phospholipases ; Phosphorylation ; Prostaglandin D2