ABSTRACT
Asthma is a chronic inflammatory disease of the airways characterized by reversible airway obstruction, airway hyperreactivity, and remodeling of the airways. Chlorogenic acid (CGA), an ester of caffeic acid with quinic acid, is one of the most abundant polyphenol compounds in various agricultural products. CGA shows various biological properties, such as anti-oxidant, anti-viral, anti-carcinogenic and anti-inflammatory activities. We investigated suppressive effects of CGA on ovalbumin (OVA)-induced allergic asthma in mice and underlying mechanisms of them. CGA significantly reduced pulmonary eosinophilia and expression of IL-4, IL-5 and TNF-α in the lung as well as the serum levels of total and OVA-specific IgE, while CGA enhanced those of total and OVA-specific IgG3, of which isotype switching is down-regulated by IL-4. In vitro IgE production from LPS/IL-4-stimulated splenocytes was remarkably reduced by CGA, while that of IgG3 was enhanced. The Cε germ line transcription, which is necessary for IL-4 mediated IgE isotype switching, was reduced by CGA in LPS/IL-4-stimulated splenocytes. IgE isotype switching is mediated via several transduction pathways, activating several molecules including STAT-6, NF-κB, ERK1/2, and JNK. Among the molecules, which were activated by IL-4/LPS, activation of STAT-6 and JNK was inhibited by CGA.
Subject(s)
Asthma/chemically induced , Chlorogenic Acid/therapeutic use , Cytokines/metabolism , Immunoglobulin E/metabolism , Pulmonary Eosinophilia/prevention & control , STAT6 Transcription Factor/metabolism , Animals , Artemisia/chemistry , Asthma/drug therapy , Asthma/immunology , Chlorogenic Acid/chemistry , Hypersensitivity/drug therapy , JNK Mitogen-Activated Protein Kinases/genetics , JNK Mitogen-Activated Protein Kinases/metabolism , Mice , Mice, Inbred BALB C , Ovalbumin/toxicity , STAT6 Transcription Factor/genetics , Th2 Cells/metabolismABSTRACT
When pregnant mice were exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), the average time to eye opening in the offspring was shortened by about a day. How acceleration of eye opening by TCDD occurs remains unknown. To reveal the underlying mechanisms of the accelerated eye opening, pregnant mice were intraperitoneally injected with corn oil or TCDD at GD (gestation day) 11, and tissues around the eye of neonatal mice were subject to proteome analysis and RT-PCR. Upon TCDD administration, translationally controlled tumor protein (TCTP) and 60S acidic ribosomal protein p2 (RLA2) were reduced, while stathmin 1(STMN1) was increased, at both protein and mRNA levels. One hypothetical mechanism for eye opening is the proliferation of corneal epithelial cells before eye opening. STMN1, but not TCTP and RLA2, was up-regulated in immortalized human corneal epithelial cells (HCE-T) by TCDD, which promoted proliferation of HCE-T probably by accelerating the G1/S transition. Down-regulation of STMN1 by the antisense oligonucleotide technology inhibited proliferation of HCE-T, suggesting that STMN1, of which expression is enhanced by TCDD, may be involved in accelerated eye opening, probably by stimulating proliferation of corneal epithelial cells.
