The transcription factor XBP1 in dendritic cells promotes the TH2 cell response in airway allergy.

Dendritic cells (DCs) that express T cell immunoglobulin domain molecule-4 (TIM4), a cell surface receptor for phosphatidylserine, induce T helper 2 (TH2) cell responses and allergic reactions. We elucidated the role of the transcription factor X-box-binding protein-1 (XBP1) in the induction of the TH2 cell response through its role in generating TIM4+ DCs. We found that XBP1 was required for TIM4 mRNA and protein expression in airway DCs in response to the cytokine interleukin-2 (IL-2) and that this pathway was required for TIM4 expression on DCs in response to the allergens PM2.5 and Derf1. The IL-2-XBP1-TIM4 axis in DCs contributed to Derf1/PM2.5-induced, aberrant TH2 cell responses in vivo. An interaction between the guanine nucleotide exchange factor Son of sevenless-1 (SOS1) and the GTPase RAS promoted XBP1 and TIM4 production in DCs. Targeting the XBP1-TIM4 pathway in DCs prevented or alleviated experimental airway allergy. Together, these data suggest that XBP1 is required for TH2 cell responses by inducing the development of TIM4+ DCs, which depends on the IL-2-XBP1-SOS1 axis. This signaling pathway provides potential therapeutic targets for the treatment of TH2 cell-dependent inflammation or allergic diseases.

Dexamethasone can attenuate the pulmonary inflammatory response via regulation of the lncH19/miR-324-3p cascade.

OBJECTIVE: To investigate lncRNAs and their roles in regulating the pulmonary inflammatory response under dexamethasone (Dex) treatment. METHODS: IL-1ß (10 ng/mL) and LPS (1 µg/mL) was used to construct inflammatory cell models with A549 cells; IL-1ß performed better against LPS. Different concentrations of Dex were used to attenuate the inflammation induced by IL-1ß, and its effect was assessed via RT-PCR to detect inflammatory cytokine-related mRNA levels, including those of IKß-α, IKKß, IL-6, IL-8, and TNF-α. Furthermore, ELISA was used to detect the levels of the inflammatory cytokines TNF-α, IL-6, and IL-8. RT-PCR was used to quantify the levels of lncRNAs, including lncMALAT1, lncHotair, lncH19, and lncNeat1. LncH19 was most closely associated with the inflammatory response, which was induced by IL-1ß and attenuated by Dex. Among the lncRNAs, the level of lncH19 showed the highest increase following treatment with 1 and 10 µM Dex. Therefore, lncH19 was selected for further functional studies. LncH19 expression was inhibited by shRNA transduced with lentivirus. Cell assays for cell proliferation and apoptosis as well as RT-PCR, western blot, and ELISA for inflammatory genes were conducted to confirm the functions of lncH19. The predicted target miRNAs of lncH19 were hsa-miR-346, hsa-miR-324-3p, hsa-miR-18a-3p, hsa-miR-18b-5p, hsa-miR-146b-3p, hsa-miR-19b-3p, and hsa-miR-19a-3p. Following estimation via RT-PCR, hsa-miR-346, hsa-miR-18a-3p, and hsa-miR-324-3p showed consistent patterns in A549 NC and A549 shlncH19. An miRNA inhibitor was transfected into A549 NC and A549 shlncH19 cells, and the expression levels were determined via RT-PCR. hsa-miR-324-3p was inhibited the most compared with hsa-miR-346 and hsa-miR-18a-3p and was subjected to further functional studies. RT-PCR, ELISA, and western blotting for inflammatory gene detection were conducted to validate the functions of the target hsa-miR-324-3p. RESULTS: Treatment with 1 and 10 µM Dex could effectively attenuate the inflammatory response. During this process, lncH19 expression significantly increased (P < 0.05). Therefore, treatment with 1 µM Dex was used for further study. Under IL-1ß treatment with or without Dex, lncH19 inhibition led to an increase in cell proliferation; a decrease in cell apoptosis; an increase in the protein levels of inflammatory genes; phosphorylation of P65, ICAM-1, and VCAM-1; and increase inflammatory cytokines. Prediction of the targets of lncH19 and validation via RT-PCR revealed that miR-346, miR-18a-3p, and miR-324-3p negatively correlate with lncH19. Additionally, Dex increased the lncH19 expression but reduced that of the miRNAs. Among the miRNAs, miR-324-3p was the most markedly downregulated miRNA following treatment of miRNA inhibitors. The MTS assay and cell apoptosis assay showed that the miR-324-3p inhibitor inhibited cell proliferation and induced cell apoptosis, thereby significantly attenuating the inflammatory response, which reversed the effect of lncH19 in regulating cell proliferation and the secretion of inflammatory cytokines (P < 0.05). Therefore, lncH19 might regulate miR-324-3p in pulmonary inflammatory response under Dex treatment. CONCLUSION: Dex can attenuate the pulmonary inflammatory response by regulating the lncH19/miR-324-3p cascade.

Bcl2L12 Contributes to Th2-Biased Inflammation in the Intestinal Mucosa by Regulating CD4+ T Cell Activities.

The Th2-biased inflammation and immune deregulation play a critical role in the pathogenesis of ulcerative colitis (UC). Recent studies indicate that the Bcl2-like protein 12 (Bcl2L12) is associated with immune deregulation of UC. This study aims to investigate the role of Bcl2L12 in the induction of aberrant Th2-biased inflammation. In this study, peripheral blood samples were collected from patients with inflammatory bowel disease. The Th2 cell activities were analyzed by flow cytometry, real-time quantitative RT-PCR, and Western blotting. Mice with Bcl2L12-knockout CD4+ T cells were used in the experiments. The results showed that the expression of Bcl2L12 was detected in peripheral CD4+ T cells, which was significantly higher in UC patients than in healthy subjects. A positive correlation between the expression of Bcl2L12 and Th2 cytokines was detected in CD4+ T cells from UC patients. Naive CD4+ T cells with Bcl2L12 overexpression were prone to differentiate into Th2 cells. Mice with Bcl2L12 deficiency failed to induce the Th2-biased inflammation in the intestine. Bcl2L12 bound GATA3 to form a complex to enhance the binding between GATA3 and the Il4 promoter to enhance the expression of IL-4 in CD4+ T cells. CD4+ T cells with Bcl2L12 overexpression were resistant to apoptosis. In conclusion, the Bcl2L12 is a critical factor in the induction of aberrant Th2 polarization by upregulating Th2 responses and downregulating Th2 cell apoptosis. Bcl2L12 may be a novel therapeutic target in the management of the disorders with Th2-biased inflammation.

Vitamin D-deficiency induces eosinophil spontaneous activation.

Eosinophils (Eo) play a critical role in immunity and immune inflammation. The maintenance of Eo homeostasis is not fully understood yet. Vitamin D (VitD) is involved in the regulation of a large number of biochemical reactions. This study tests a hypothesis that VitD receptor (VDR) contributes to the homeostasis of Eos. In this study, EoL-1 cells (an Eo cell line) were cultured in the presence or absence of calcitriol. The Eo-mediators, including major basic protein (MBP), Eo peroxidase (EPX), Eo cationic protein (ECP) and Eo-derived neurotoxin (EDN), were assessed in the culture supernatant and in EoL-1 cells. We observed that, in a VitD deficient environment, EoL-1 cells produced high levels of the Eo-mediators, including MBP, EPX, ECP and EDN, which could be suppressed by the addition of calcitriol to the culture. EoL-1 cells expressed VitD receptor (VDR), which was up regulated by exposure to calcitriol. VDR formed complexes with the transcription factors of the Eo-mediators, which prevented the transcription factors to bind to the promoters of the Eo-mediators, and therefore prevented the Eo-mediated gene transcription. The Eo spontaneous activation was also found in the intestinal mucosa of VDR-deficient mice, in which the intestinal epithelial barrier dysfunction was observed. In conclusion, VDR contributes to the maintenance of the homeostasis of Eos by regulating the gene transcription of the Eo mediators. The VDR-deficiency is one of the causative factors inducing Eo spontaneous activation. This phenomenon may be taken into account in the management of the Eo-related diseases.

[Effect of Seasonal Temperature Increasing on Nitrogen Mineralization in Soil of the Water Level Fluctuating Zone of Three Gorge Tributary During the Dry Period].

To reveal the effect of seasonal temperature increasing on nitrogen mineralization in soil of the water level fluctuating soil zone of three gorge reservoir areas in the Yangtze river tributary during the dry period, surface soils were collected from the water level fluctuating zone of Pengxi river crossing two hydrological sections, i.e., upstream and downstream and three water level altitudes, 155 m (low), 165 m (middle) and 175 m (high). We incubated the soil at 25 degrees C and 35 degrees C to determine the transformation rates of nitrogen in soil of Pengxi river basin during the dry period. The result showed that TN and NO3- -N contents in the soil of upstream section and higher (175 m) altitude of water level were higher than those in downstream and low (165 m) altitude of water level, whereas the pattern for NH4+ -N was different, with higher NH4+ -N contents in downstream and low water level. The inorganic nitrogen was dominated by NO3- -N, which accounted for up to 57.4%-84.7% of inorganic nitrogen. Generally, soil ammoniation, nitration and net N mineralization increased with the rising water level altitude and stream sections (P < 0.05). In summary, nitration and net N mineralization significantly increased with increasing temperature, (P < 0.05), while ammoniation showed no difference (P > 0.05).

Characterization of a new subtype of allergen in dermatophagoides farinae-Der f 28.

BACKGROUND: House dust mites (HDMs) are the major sources of indoor allergens which induce asthma, dermatitis, rhinitis, and some other allergic diseases. Close to 30 sub-allergens have been identified. METHODS: Through analyzing the full genome sequence of dust mite, a new allergen whose primary structure belongs to the heat shock protein family was identified. The sequence of this allergen was determined by cDNA cloning. The allergenicity was assayed by skin prick test, Western-blot and enzyme-linked immunosorbent assay (ELISA). RESULTS: r-Der f 28 bound to serum IgE from mite allergic patients. Positive responses to r-Der f 28 were shown in 11.5% by skin prick testing from 26 DM-allergic patients. Airway hyperresponsiveness, serum specific IgE and IL-4 were significantly increased in allergic asthma mouse model sensitized to r-Der f 28. CONCLUSIONS: Der f 28 is a new subtype of allergen in dermatophagoides farinae.

[Percentage of Th17 Cells in Spleen and IL-17 Level in Bronchoalveolar Lavage Fluid in Dermatophagoides farinae Allergic Asthma Mice].

OBJECTIVE: To detect the percentage of Th17 cells in spleen and IL-17 level in bronchoalveolar lavage fluid in Dermatophagoides farinae allergic asthma mice. METHODS: Twenty BALB/c mice were randomly divided into control group (n=10) and asthma group (n=10). Mice in control group were treated with PBS plus 2 mg Al(OH)3 and those in asthma group were sensitized with 200 µl solution [50 µg Dermatophagoides farinae crude extracts plus 2 mg Al (OH)3] on day 0, 7 and 14. One week after the last sensitization, all mice were intranasally challenged with 50 µg Dermatophagoides farinae crude extracts daily for 7 days. Twenty-four hours after the last challenge, mice were sacrificed. The sera, bronchoalveolar lavage fluid (BALF) and spleens were collected. The serum levels of IgE and IgG1, and IL-17 level in BALF were determined by ELISA. The percentage of Th17 cells in spleen was tested by flow cytometry. RESULTS: The serum levels of IgG, and IgE in asthma group were (0.10 ± 0.01) pg/ml and (1.15 ± 0.10) pg/ml, respectively, which were higher than that of the control [(0.06 ± 0.01) pg/ml and (0.04 ± 0.01) pg/ml] (P < 0.05). IL-17 level in asthma group (85.13 ± 2.36) pg/ml was higher than that of the control [(48.27 ± 4.14) pg/ml] (P < 0.01). The percentage of Th17 cells in asthma group [(5.19 ± 0.68)%] was also higher than that of the control [(0.95 ± 0.19)%] (P < 0.01). Meanwhile, the percentage of Thl7 cells in spleen was positively correlated with IL-17 level in BALF (r = 0.851, P < 0.01). CONCLUSION: Compared with healthy mice, both the percentage of Th17 cells in spleen and IL-17 level in BALF have increased significantly in Dermatophagoides farinae allergic asthma mice.

[Bird species diversity and related protection measures in urban park green spaces of Loudi City, Hunan Province of China].

Urban park green space is an important physical part of urban ecosystem, and also, the important habitat and carrier for birds and other animals. Rapid urbanization induces the great change in the spatial pattern of urban park green space, while the patched distribution of urban park green space has the habitat features similar to 'habitat islands', giving obvious effects on urban avian communities. In order to understand the bird species distribution and species diversity in Loudi City and to provide the basic information for the bird conservation, a line transect method and a quadrat sampling method were adopted to investigate the distribution pattern and species richness of the birds across seven urban parks in the Loudi City from November, 2010 to January, 2012. A total of 56 birds species belonging to 11 orders and 27 families were recorded, among which, there were 32, 12 and 12 species belonging to resident birds, summer migrant birds and winter migrant birds, accounting for 57.2%, 21.4% and 21.4%, respectively. As for the fauna, there were 27, 14, and 15 bird species belonging to oriental species, palaearctic species and widely distributed species, accounting for 48.2%, 25.0% and 26.8%, respectively. A total of 7 species belonging to the second class of the national key protected species were recorded, accounting for 12.5% of the total. The Shannon, Pielou and G-F indices of the bird communities in the urban parks in Loudi City were 1.49, 0.85 and 0.62, respectively. Zhushan Park had the highest species number (42), Shannon index (1.41), G index (3.46), F index (6.12) and G-F index (0.43), and Yueqin Hill Park had the highest Pielou index (0.92). The reasons of the poor bird species in Loudi City were analyzed, and some suggestions for preventing the birds were put forward.