OBJECTIVEIt is known that Siglec-8 is selectively expressed on human eosinophils at a high level and mediates eosinophil apoptosis when crosslinked with its antibody. The aim of our review is to elucidate the molecular and biological characteristic of Siglec-8 and then discuss the function and possible mechanisms of Siglec-8 in eosinophils. Thereby, we will expand our understanding to the regulation of eosinophil apoptosis, and provide important clues to the treatment of asthma and other hyper-eosinophilic diseases.

DATA SOURCESMost articles were identified by searching of PubMed online resources using the key term Siglecs.

STUDY SELECTIONMainly original milestone articles and critical reviews written by major pioneer investigators in the field were selected.

RESULTSSiglec-8 is selectively expressed on human eosinophil and can specifically induce eosinophil apoptosis.

CONCLUSIONThe restricted expression of Siglec-8 on human eosinophil and the rapid progress in understanding its role as cell signaling and activation of death receptors have made it an attractive target for treatment of asthma and other hyper-eosinophilic diseases.

Apoptosis ; genetics ; physiology ; Asthma ; metabolism ; therapy ; Eosinophils ; cytology ; metabolism ; Humans ; Sialic Acid Binding Immunoglobulin-like Lectins ; metabolism

OBJECTIVETo establish the method of cytological examination and the normal reference values for hypertonic saline solution-induced sputum of healthy children (age range from 5 to 15 years) with physical examination in Guangzhou.

METHODA total of 352 children, 5 to 15 years old, were enrolled from primary school and middle school in Guangzhou from January to December, 2010. All subjects completed a standardized questionnaire on the presence of respiratory, allergic symptoms and family history, the medical history and the physical examination was performed by doctors, lung function (forced expiratory volume at 1 s in predicted normal, FEV(1)%) was determined. There were 266 healthy children (137 males, 129 females) who were selected and undergone hypertonic saline solution induction of sputum, and cytological examination was performed. Hypertonic saline (5%) was nebulized and inhaled for 15 - 30 min. No expectoration within 30 min was defined as failure, and the procedure was terminated. The part of opaque and higher density sputum samples was detected by cytology. The proportion of neutrophils, lymphocytes, eosinophils, macrophages and monocytes was calculated. This study was approved by the institutional Ethics Review Committee of First Affiliated Hospital of Guangzhou Medical College. Informed consent was obtained from the legal guardians of all participants following a detailed description of the purpose and potential benefits of the study.

RESULTThere were 175 subjects' induced sputum specimens (175/266, 65.8%), non-qualified sputum samples were obtained from 16 of the subjects. The proportions of median (IQR) of lymphocytes were 0.012 (0.020), 95%CI were ranged from 0.015 to 0.022; neutrophils 0.207 (0.330), 95%CI 0.266 - 0.356 macrophages 0.761 (0.327), 95%CI 0.607 - 0.699; eosinophils 0.004 (0.019), 95%CI 0.013 - 0.022. There were no significant differences in proportions of cytological findings of female or male, different age groups and second-hand smoking or not (all P > 0.05). The incidence of adverse event was 4.40% (7/159).

CONCLUSIONThe method and the preliminary data may be used for research, diagnosis and treatment of patients with chronic cough and airway inflammation.

Adolescent ; Child ; Child, Preschool ; China ; Cough ; diagnosis ; physiopathology ; Eosinophils ; cytology ; Female ; Forced Expiratory Volume ; Humans ; Leukocyte Count ; Lymphocyte Count ; Lymphocytes ; cytology ; Male ; Monocytes ; cytology ; Neutrophils ; cytology ; Reference Values ; Saline Solution, Hypertonic ; chemistry ; Sputum ; cytology ; metabolism

OBJECTIVE: To study the expression of interleukin-17 (IL-17) in nasal polyps from both atopic and nonatopic patients, and its associations with histological features of polyps tissue. METHOD: Thirty patients with nasal polyps (NP) were included and divided into atopic and nonatopic groups according to the skin prick test. Histological characteristics were assessed by eosinophilic infiltration with HE staining. IL-17 expression in polyps tissue was detected by ELISA and RT-PCR. RESULT: Eosinophilic infiltration was significantly higher in atopic NP patients than in nonatopic NP patients (P < 0.01). IL-17 protein and IL-17 mRNA levels were significantly upregulated in both atopic (P < 0.01) and nonatopic (P < 0.05) patients compared with controls. Furthermore, IL-17 levels were significantly higher in the atopic group than in nonatopic group. Significantly positive correlations were found between IL-17 levels and eosinophilic infiltration in NP patients. CONCLUSION These results indicated that expression of IL-17 was significantly upregulated in NP patients and was especially higher in atopic NP patients, suggesting that IL-17 may play an important role in the pathogenesis of NP and atopy may contribute to NP by stimulating the production of IL-17.
Adult ; Aged ; Eosinophils ; cytology ; Female ; Humans ; Hypersensitivity, Immediate ; metabolism ; pathology ; Interleukin-17 ; metabolism ; Male ; Middle Aged ; Nasal Polyps ; metabolism ; pathology ; Young Adult

Corticosteroids are considered to be one of the most effective medicine for asthma by suppressing airway inflammation. This study was carried out to investigate the effects of prednisolone in the sputum of exacerbated asthmatics. Clinical severity, cell differentials, levels of interleukin (IL)-5, eosinophil cationic protein (ECP), EG2+ eosinophils, and nitric oxide (NO) metabolites were measured. Sputum was examined 2 weeks apart in 13 exacerbated asthmatics before and after prednisolone treatment, and once in 12 stable asthmatics. We used a sandwich ELISA for IL-5, fluoroimmunoassay for ECP, immunohistochemical staining for EG2+ eosinophils, a NO metabolites assay using modified Griess reaction. Exacerbated asthmatics, in comparison with stable asthmatics, had significantly higher proportion of eosinophils, higher level of ECP, higher percentage of EG2+ eosinophils, and NO metabolites. Exacerbated asthmatics after treatment with prednisolone had reduced the proportions of eosinophils, reduced level of IL-5, ECP and percentage of EG2+ eosinophils. FEV1 was correlated with the proportion of eosinophils, ECP, and IL-5 respectively. These findings suggest that prednisolone is considered to be effective medicine for asthma by suppressing eosinophil activation through IL-5.
Administration, Oral ; Adolescence ; Adrenal Cortex/metabolism ; Adult ; Aged ; Anti-Inflammatory Agents, Steroidal/administration & dosage* ; Asthma/metabolism ; Asthma/immunology* ; Asthma/drug therapy* ; Biological Markers ; Blood Proteins/metabolism* ; Eosinophils/metabolism ; Eosinophils/immunology ; Eosinophils/drug effects* ; Female ; Human ; Interleukin-5/metabolism* ; Leukocyte Count ; Male ; Middle Age ; Nitric Oxide/metabolism ; Prednisolone/administration & dosage* ; Sputum/immunology ; Sputum/cytology

OBJECTIVE: To explore the expression of T-bet/GATA-3 in nasal mucosa tissue of allergic rhinitis rat and to investigate the association between the expression of T-bet/GATA-3 and the eosinophil count. METHOD: Twenty SD rats were randomly divided into a control group and an allergic rhinitis group. The allergic rhinitis rat model was induced with ovalbumin. The total eosinophils were counted in the nasal mucosa. The concentrations of IL-4, IL-5 and IFN-gamma in nasal lavage fluid were measured by ELISA. The mRNA and protein expressions of IL-4, IL-5, IFN-gamma, T-bet and GATA-3 in the nasal mucosa were detected by RT-PCR and Western blot respectively. RESULT: The main inflammatory cells were eosinophils in the nasal mucosa of allergic rhinitis rats. The level of IL-4, IL-5 and IFN-gamma in control group was significantly higher than that in allergic rhinitis group (P < 0.01). The mRNA and protein expression of IFN-gamma and T-bet in allergic rhinitis group was significantly higher than that in control group (P < 0.01). While the mRNA and protein expression of IL-4, IL-5 and GATA-3 in control group was significantly higher than that in allergic rhinitis group (P < 0.01). The ratio of protein expression of T-bet and GATA-3 was negatively correlated with the eosinophil count, IL-4 and IL-5, but positively with the concentrations of IFN-gamma. CONCLUSION The imbalance of transcription factor GATA-3 and T-bet has a close correlation with the eosinophil count, and may play a key role in the formation of allergic rhinitis.
Animals ; Cell Count ; Eosinophils ; cytology ; Female ; GATA3 Transcription Factor ; metabolism ; Hypersensitivity ; immunology ; metabolism ; Male ; Rats ; Rats, Sprague-Dawley ; Rhinitis ; immunology ; metabolism ; T-Box Domain Proteins ; metabolism ; Th1 Cells ; metabolism ; Th2 Cells ; metabolism

This study is to investigate the effect of ibudilast on apoptosis of airway eosinophil in asthmatic guinea pigs and its mechanism. Experimental asthma model of guinea pigs was induced with ovalbumin (OVA). Differential count in BALF was examined. The apoptosis of eosinophils (EOS) was labeled with TdT-mediated dUTP nick end labeling (TUNEL) technique. Fas mRNA expression of EOS was detected by reverse transcription-polymerase chain reaction (RT-PCR). The quantification of GM-CSF and IL-5 in BALF was conducted with ELISA. After treatment of ibudilast, the number of EOS and the quantification of GM-CSF and IL-5 decreased significantly. The number of apoptotic cells as well as Fas mRNA expression of EOS obviously increased. The results indicated that anti-asthma mechanisms of ibudilast can antagonize asthma through decreasing the number of EOS, inducing apoptosis of EOS, enhancing Fas mRNA expression of EOS and reducing the content of GM-CSF and IL-5.
Animals ; Anti-Asthmatic Agents ; pharmacology ; Apoptosis ; drug effects ; Asthma ; metabolism ; pathology ; Bronchoalveolar Lavage Fluid ; Eosinophils ; cytology ; drug effects ; metabolism ; Female ; Granulocyte-Macrophage Colony-Stimulating Factor ; metabolism ; Guinea Pigs ; Interleukin-5 ; metabolism ; Male ; Pyridines ; pharmacology ; fas Receptor ; metabolism

OBJECTIVE: To study the role of P-JNK and P-c-Jun of JNK (c-Jun N-terminal kinase) on nasal mucosa remodeling in allergic rhinitis rats. METHOD: Sixty male Wistar rats (weighing about 200-250 g) were randomly divided into AR group (A group) and B group(control group). The rats in A group were sensitized for inducing AR by intraperitoneal injection of ovalbumin and Al(OH)₃. Rats in group A were randomized into A4, A8 and A12 group (each had 10 rats). Ovalbumin was dropped in each nasal cavity of every rat for 4,8,12 weeks, respectively. Rats in group B were sensitized by saline instead of OVA, and were also divided into B4, B8 and B12 group. Each group had 10 rats. Pathological changes of nasal mucosa in each period were observed by hematoxylin and eosin stain dyeing. The phosphorylation of JNK and c-Jun were tested by immunohistochemistry. RESULT: In A8 group, mucosal congestion and edema thickening with inflammatory cells infiltration of eosinophils were observed in the eighth week, and the inflammatory changes were significantly increased as time went on. The mean absorbance values of P-JNK and P-c-Jun in A group were significantly higher than those in the corresponding B group (all P < 0.01). Moreover, the mean absorbance values of A12 group were significantly higher than A4 group and A8 group (all P < 0.01 ). CONCLUSION The expression of P-JNK and P-c-Jun in the process of nasal mucosa remodeling in allergic rhinitis rats were increased, which suggested that P-JNK and P-c-Jun played important roles in nasal mucosa remodeling of the allergic rhinitis rats.
Airway Remodeling ; Animals ; Disease Models, Animal ; Eosinophils ; cytology ; Injections, Intraperitoneal ; JNK Mitogen-Activated Protein Kinases ; metabolism ; Male ; Nasal Mucosa ; metabolism ; Ovalbumin ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Rats, Wistar ; Rhinitis, Allergic ; metabolism ; Signal Transduction

DNA methylation may regulate gene expression by restricting the access of transcription factors. We have previously demonstrated that GATA-1 regulates the transcription of the CCR3 gene by dynamically interacting with both positively and negatively acting GATA elements of high affinity binding in the proximal promoter region including exon 1. Exon 1 has three CpG sites, two of which are positioned at the negatively acting GATA elements. We hypothesized that the methylation of these two CpGs sites might preclude GATA-1 binding to the negatively acting GATA elements and, as a result, increase the availability of GATA-1 to the positively acting GATA element, thereby contributing to an increase in GATA-1-mediated transcription of the gene. To this end, we determined the methylation of the three CpG sites by bisulfate pyrosequencing in peripheral blood eosinophils, cord blood (CB)-derived eosinophils, PBMCs, and cell lines that vary in CCR3 mRNA expression. Our results demonstrated that methylation of CpG sites at the negatively acting GATA elements severely reduced GATA-1 binding and augmented transcription activity in vitro. In agreement, methylation of these CpG sites positively correlated with CCR3 mRNA expression in the primary cells and cell lines examined. Interestingly, methylation patterns of these three CpG sites in CB-derived eosinophils mostly resembled those in peripheral blood eosinophils. These results suggest that methylation of CpG sites at the GATA elements in the regulatory regions fine-tunes CCR3 transcription.
Binding Sites ; Cell Line ; *CpG Islands ; DNA Methylation ; Enhancer Elements, Genetic ; Eosinophils/cytology/*metabolism ; Exons ; Fetal Blood/cytology/metabolism ; GATA1 Transcription Factor/*genetics/metabolism ; Gene Expression Regulation ; Humans ; Promoter Regions, Genetic ; RNA, Messenger/metabolism ; Receptors, CCR3/*genetics/metabolism ; Sequence Analysis, DNA ; *Transcription, Genetic

OBJECTIVE: To discuss the effect of different doses intranasal corticosteroids on remodeling of allergic rhinitis (AR) mice nasal mucosa and expression level of matrix metalloproteinase-9 (MMP-9). METHOD: Thirty BALB/c female mice were divided into five groups randomly and received OVA or normal saline (NS) with intraperitoneal injection or nasal challenge, respectively. The treatment groups received additional different doses of budesonide (0.6 μg/20 g, 3.0 μg/20 g and 15.0 μg/20 g) daily for 16 weeks. We assessed the nasal symptoms at 4 and 16 weeks. Collected the mice nasal tissue, and then stained with hematoxylin-eosin, Masson's Trichrome, and periodic acid-schiff respectively to evaluate airway remodeling at 16 weeks. MMP-9 was measured with enzyme-linked immunosorbent assay (ELISA). Result: Times of rubbing, sneezes and infiltrate of eosinophil increased more in B group than in A group, and subepithelial fibrosis, collagen deposition, goblet cell hyperplasia, and submucosal gland hypertrophy were only observed in B group at 16 weeks. The nasal symptoms and eosinophil infiltration were inhibited by treatment with budesonide from a dose of 0.6 μg onwards, while the prevention of structure changes was only observed with 3.0 μg onwards. In addition, intranasal budesonide reduced MMP-9 in the nasal of AR mice. CONCLUSION The study suggests that higher dose intranasal corticosteroids might inhibit the airway remodeling of nasal mucosa by reducing MMP-9.
Airway Remodeling ; Animals ; Budesonide ; pharmacology ; Disease Models, Animal ; Eosinophils ; cytology ; Female ; Matrix Metalloproteinase 9 ; metabolism ; Mice ; Mice, Inbred BALB C ; Nasal Mucosa ; drug effects ; Rhinitis, Allergic ; drug therapy ; metabolism

OBJECTIVETo study the expression of signal transducer and activator of transcription 6 and its mRNA in rat asthma model and the modulatory effect of dexamethasone (DXM).

METHODSThirty male SD rats were randomly divided into three groups: the control group, asthma group and DXM group. The rats in each group were sacrificed 24 h after the last challenge. In the experiment, the rat model of asthma was established by ovalbumin (OVA) challenge method. The lung tissue was taken from the left lung, and bronchoalveolar lavage fluid (BALF) was collected from the right lung. The total cell numbers, eosinophils (EOS) count and differentiated cell counts in BALF were performed on different count fluids. The concentrations of IL-4 in serum and BALF were measured by using sandwich ELISA. The protein expressions of STAT6 were detected with immunohistochemical techniques. The mRNA expressions of STAT6 were detected with in situ hybridization.

RESULTS(1) The total cell counts in BALF, the absolute counts of EOS, and the ratios of eosinophils to the total cell numbers (EOS%) of asthma group were all significantly higher than those of the control group (P < 0.01). The total cell counts in BALF, the absolute counts of EOS, and EOS% of DXM group were all significantly lower than those of asthma group (P < 0.01). (2) The concentrations of IL-4 in BALF and serum of asthma group [(25.7 +/- 7.4) ng/L, (34.2 +/- 10.5) ng/L] were significantly higher than those of control group [(8.6 +/- 3.0) ng/L, (12.1 +/- 2.9) ng/L] (P < 0.01). The concentrations of IL-4 in BALF and serum of DXM group were significantly lower than those of asthma group. (3) Immunohistochemistry showed that the protein content of STAT6 around the bronchus of asthma group (0.171 +/- 0.025) was significantly higher than that of the control group (0.082 +/- 0.022) (P < 0.01), while that of DXM group (0.114 +/- 0.013) was significantly lower than that of asthma group. The epithelial cells were the cells. In situ hybridization showed that the mRNA expression of STAT6 around the bronchus of asthma group (0.180 +/- 0.013) was significantly higher than that of the control group (0.091 +/- 0.012) (P < 0.01), while that of DXM group (0.114 +/- 0.010) was significantly lower than that of asthma group. (4) There was a significant correlation between the concentration of IL-4 in BALF, the content of STAT6 and STAT6 mRNA, respectively, in the epithelial cells of bronchus. There was a significant correlation between the absolute numbers of EOS and EOS% in BALF, the content of STAT6 and STAT6 mRNA, respectively, in the epithelial cells of bronchus.

CONCLUSIONSSTAT6 protein and STAT6 mRNA were found strongly expressed in rat asthma model and the epithelial cells were the chief expressing cells. Dexamethasone had an inhibitory effect on airway inflammatory cells infiltration. It significantly depressed STAT6 and mRNA expression. Which may be a key process in modulatory mechanism of asthma.

Animals ; Anti-Inflammatory Agents ; pharmacology ; Asthma ; drug therapy ; genetics ; metabolism ; Bronchi ; cytology ; Bronchoalveolar Lavage Fluid ; cytology ; Cell Count ; Dexamethasone ; pharmacology ; Disease Models, Animal ; Enzyme-Linked Immunosorbent Assay ; Eosinophils ; drug effects ; Epithelial Cells ; drug effects ; metabolism ; Glucocorticoids ; pharmacology ; Immunohistochemistry ; In Situ Hybridization ; Interleukin-4 ; metabolism ; Male ; RNA, Messenger ; Rats ; Rats, Sprague-Dawley ; STAT6 Transcription Factor ; genetics ; immunology ; metabolism