Systematic Characterization of the Group 2 House Dust Mite Allergen in Dermatophagoides microceras

BackgroundAllergic asthma, a chronic airway inflammatory disease, is a critical public health problem. Indoor house dust mites (HDMs) could cause allergic asthma. The prevalence of sensitization to Dermatophagoides microceras (Der m) was approximately 80% and is related to the immunoglobulin E crossing-reactivity of mites belonging to the same genus, Dermatophagoides pteronyssinus (Der p) and Dermatophagoides farina (Der f). However, studies on Der m are scant.MethodsWe used integrated OMICs approaches to identify and characterize the group 2 mite allergen-like protein in Der m (Der m 2). We established a Der m 2-induced allergic asthma mouse model and treated the mice with a fungal immunomodulatory protein (FIP-fve) isolated from Flammulina veluptipes to evaluate the allergenicity of Der m 2 and the immunomodulatory effects of FIP-fve.ResultsBy performing de novo draft genome assembly and comparative genome analysis, we identified the putative 144-amino acid Der m 2 in silico and further confirmed its existence through liquid chromatography–tandem mass spectrometry. Der m 2 is a lipopolysaccharides (LPS)-binding protein. Thus, we examined the LPS-binding activity of recombinant Der m 2 by performing molecular docking analysis, co-immunoprecipitation (Co-IP), and a pull-down assay. Der m 2 elicited the production of pro-inflammatory cytokines, interleukin (IL)-6, and IL-8 in BEAS-2B cells, a human bronchial epithelial cell line, and induced airway hyperresponsiveness in mice. Furthermore, in mice sensitized with Der m 2, the administration of FIP-fve in either the earlier stage or the late stage, FIP-fve alleviated allergic asthma by moderating airway inflammation and remodeling.ConclusionsDer m 2 induced inflammatory responses in cell and mouse models. FIP-fve alleviated inflammation in Der m 2-induced asthma in mice by exerting an immunomodulatory effect.

Potentials of CCL21 and CBS as therapeutic approaches for breast cancer

Objective: The present research set out to ascertain the roles of CCL21 and CBS in breast cancer (BC) cell biological behaviors and the relationship of CCL21 and CBS expression with the clinicopathological features of patients with BC. Methods: Immunohistochemistry of CCL21 or CBS was performed in 18 intraductal cancer tissues, 124 invasive BC tissues, 50 paraneoplastic tissues, 50 lobular hyperplasia tissues, and 30 normal breast tissues. For cell experiments, two human BC cell lines (MDA-MB-231 and MCF-7) and a human breast epithelial cell line (MCF-10A) were utilized to detect the expression of CCL21 and CBS. After loss- and gain-of-function assays for CCL21 or CBS, the expression of CBS and CCL21 was measured by qRT-PCR and Western blot. Additionally, BC cell proliferation was assessed by MTT assay and EdU staining, and BC cell migration was determined by scratch test and Transwell assay. Results: In the clinical data, the positive rate of CCL21 or CBS was significantly higher in invasive BC tissues than in intraductal BC tissues, lobular hyperplasia tissues, paraneoplastic tissues, and normal breast tissues (P < 0.05 or P < 0.01). CBS or CCL21 expression shared close association with the clinicopathological characteristic and the poor prognosis of BC patients. In cell experiments, overexpression of CCL21 or CBS enhanced the proliferative and migratory abilities of BC cells. Conclusion: CCL21 and CBS promoted BC cell migration and proliferation. CCL21 or CBS expression was strongly related to the poor prognosis of BC patients.

Expression of immune response genes in human corneal epithelial cells interacting with Aspergillus flavus conidia

Background Aspergillus flavus, one of the causative agents of human fungal keratitis, can be phagocytosed by human corneal epithelial (HCE) cells and the conidia containing phagosomes mature into phagolysosomes. But the immunological responses of human corneal epithelial cells interacting with A. flavus are not clear. In this study, we report the expression of immune response related genes of HCE cells exposed to A. flavus spores using targeted transcriptomics. Methods Human corneal epithelial cell line and primary cultures were grown in a six-well plate and used for coculture experiments. Internalization of the conidia was confirmed by immunofluorescence microscopy of the colocalized endosomal markers CD71 and LAMP1. Total RNA was isolated, and the quantity and quality of the isolated RNA were assessed using Qubit and Bioanalyzer. NanoString nCounter platform was used for the analysis of mRNA abundance using the Human Immunology panel. R-package and nSolver software were used for data analysis. KEGG and FunRich 3.1.3 tools were used to analyze the differentially expressed genes. Results Different morphotypes of conidia were observed after 6 h of coculture with human corneal epithelial cells and found to be internalized by epithelial cells. NanoString profiling showed more than 20 differentially expressed genes in immortalized human corneal epithelial cell line and more than ten differentially expressed genes in primary corneal epithelial cells. Distinct set of genes were altered in their expression in cell line and primary corneal epithelial cells. KEGG pathway analysis revealed that genes associated with TNF signaling, NF-KB signaling, and Th17 signaling were up-regulated, and genes associated with chemokine signaling and B cell receptor signaling were down regulated. FunRich pathway analysis showed that pathways such as CDC42 signaling, PI3K signaling, and Arf6 trafficking events were activated by the clinical isolates CI1123 and CI1698 in both type of cells. Conclusions Combining the transcript analysis data from cell lines and primary cultures, we showed the up regulation of immune defense genes in A. flavus infected cells. At the same time, chemokine signaling and B cell signaling pathways are downregulated. The variability in the expression levels in the immortalized cell line and the primary cultures is likely due to the variable epigenetic reprogramming in the immortalized cells and primary cultures in the absence of any changes in the genome. It highlights the importance of using both cell types in host-pathogen interaction studies.

lncRNA PCAT1 might coordinate ZNF217 to promote CRC adhesion and invasion through regulating MTA2/MTA3/Snai1/E-cadherin signaling

LncRNA prostate cancer-associated transcript 1 (PCAT1) is a well-known oncogene, but the mechanisms of exosomes PCAT1 in colorectal cancer (CRC) remain largely unknown. Thus, the mechanisms of exosomes lncRNA PCAT1 were investigated. The expressions of exosomes lncRNA PCAT1 in tissues from stage 0-I and stage II-III CRC patients, and intestinal epithelial cell line FHC and two CRC cell lines, HT29 and HCT8 were measured by real-time quantitative PCR. The effects of lncRNA PCAT1 on adhesion and invasion of two CRC cell lines were investigated by cell-matrix adhesion and transwell assays. In addition, the target of PCAT1 (ZNF217) was validated using an RNA immune precipitation assay. Finally, the protein levels of MTA2, MTA3, SNAI1, and E-cadherin in normal participants, stage 0-I and stage II-III CRC patients, as well as two cell lines with stable ZNF217 knockdown were investigated by western blotting. The plasma exosomal lncRNA PCAT1 was found to be significantly increased in the CRC tissues and cell lines. In addition, lncRNA PCAT1 knockdown significantly inhibited the adhesion and invasion of HT29 and HCT8 cells. RIP assay results showed lncRNA PCAT1 could target ZNF217, and downregulation of lncRNA PCAT1 could decrease the protein expressions of ZNF217 in two CRC cells lines. Moreover, ZNF217 knockdown significantly decreased MTA2, MTA3, and SNAI1 expressions, but increased E-cadherin expressions in both CRC cells lines. Exosomal lncRNA PCAT1 can promote the adhesion and invasion of CRC cells, and PCAT1 overexpression may lead to ZNF217 upregulation that regulates EMT-related MTA2/MTA3/Snai1/E-cadherin signaling

In vitro study on effect of bardoxolone methyl on cisplatin-induced cellular senescence in human proximal tubular cells

Bardoxolone methyl [methyl-2-cyano-3, 12-dioxooleana-1, 9(11)dien-28-oate (CDDO-Me)], an activator of the nuclear factor erythroid-derived 2-related factor2 pathway, is a potential therapeutic candidate for the treatment of kidney diseases. However, its effect against cellular senescence remains unclear. This study aimed to investigate whether CDDO-Me protects cells against cisplatin-induced cellular senescence using an in vitro model. The human renal proximal tubular epithelial cell line HK-2 was treated with cisplatin for 6 h, followed by treatment with or without CDDO-Me (0.1 or 0.2 μmol/L). Senescence markers were analyzed using western blotting and real-time PCR. Apoptosis was evaluated through TUNEL staining. Cisplatin induced changes in the levels of markers specific for proliferation, cell cycle, and senescence in a time- and dose-dependent manner. Furthermore, IL-6 and IL-8 levels in the culture medium increased markedly. These data suggested that cellular senescence-like alterations occurred in HK-2 cells exposed to cisplatin. CDDO-Me treatment reversed the cisplatin-mediated alterations in the levels of cellular senescence markers. The antioxidant enzymes, HO1, NQO1, GPX1, and CAT were upregulated by CDDO-Me treatment. Furthermore, CDDO-Me treatment induced apoptosis in cisplatin-exposed HK-2 cells. Pretreatment with Ac-DEVD-CHO, the caspase inhibitor, suppressed the reversal effect of CDDO-Me against cisplatin-induced cellular senescence-like alterations. This study showed that CDDO-Me attenuated cisplatin-induced premature senescence of HK-2 cells. This beneficial effect may be related to Nrf2 activation. Our findings also showed that CDDO-Me induced apoptosis in cisplatin-treated HK-2 cells, potentially protecting the kidneys from cellular senescence. CDDO-Me appears to be a candidate treatment for acute kidney injury.

Glaucocalyxin A Ameliorates Hypoxia/Reoxygenation-Induced Injury in Human Renal Proximal Tubular Epithelial Cell Line HK-2 Cells

Ischemia-reperfusion injury is one of the major causes of acute kidney injury (AKI), which is increasingly prevalent in clinical settings. Glaucocalxin A (GLA), a biologically ent-kauranoid diterpenoid, has various pharmacological effects like antioxidation, immune regulation, and antiatherosclerosis. In this study, the effect of GLA on AKI and its mechanism were studied in vitro. HK-2 human renal tubular epithelial cells were exposed to hypoxia/reoxygenation (H/R), which were established as an in vitro AKI model. Subsequently, the mRNA expressions of inflammatory and antioxidant factors were determined by quantitative reverse transcription polymerase chain reaction (RT-qPCR). Reactive oxygen species (ROS) production and cell death were detected by fluorescence-activated cell sorting. GLA pre-treatment improved the cell viability of HK-2 cells exposed to H/R. GLA suppressed the H/R-induced ROS production in HK-2 cells. GLA also elevated the activities of superoxide dismutase of HK-2 cells exposed to H/R. Moreover, GLA prevented H/R-induced cell death in HK-2 cells. Furthermore, GLA ameliorated the activation of the protein kinase B (Akt)/nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling pathway in HK-2 cells exposed to H/R. Our findings suggested that GLA protected HK-2 cells from H/R-induced oxidative damage, which was mediated by the Akt/Nrf2/HO-1 signaling pathway. These results indicate that GLA may serve as a promising therapeutic drug for AKI.

MIR-181A-5P Attenuates Ovalbumin-Induced Allergic Inflammation in Nasal Epithelial Cells by Targeting IL-33/P38 MAPK Pathway

Purpose: Chronic inflammation of the nasal mucosal tissues plays an important role in the pathogenesis of allergic rhinitis (AR). Aberrantly-expressed micro ribonucleic acid (miRNA) has been found to have strong associations with the inflammatory reactions in allergic diseases; however, its functional significance and molecular mechanism in AR remains unclear. The purpose of this study is to determine the functional role and mechanism of miR-181a-5p in AR. Methods: Allergic inflammatory reaction was induced by ovalbumin in human nasal epithelial cell line RPMI2650. The anti-inflammatory effects of miR-181a-5p were evaluated by examining pro-inflammatory cytokines (interleukin (IL)-1β, IL-6, tumor necrosis factor-α (TNF-α)) in the culture of RPMI-2650 cells stimulated by ovalbumin, using quantitative real-time reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assay. Luciferase assay and gain-of-function assay were used to investigate the association of miR-181a-5p and IL-33/p38 MAPK axis. Results: MiR-181a-5p was significantly downregulated in mucosal tissues of AR patients and in RPMI-2650 cells treated with ovalbumin. The overexpression of miR-181a-5p showed prominent suppression of inflammatory cytokine production in RPMI-2650 cells with the stimulation of ovalbumin. MiR-181a-5p directly targeted, and negatively regulated IL-33 to suppress the activation of p38 MAPK signalling. Conclusion: The results suggest that miR-181a-5p restricted allergic inflammation through inhibition of IL-33/p38 MAPK pathway, indicating miR-181a-5p may play an anti-inflammatory role in AR.

Oenothein B in Eucalyptus Leaf Extract Suppresses Fructose Absorption in Caco-2 Cells

Inhibition of fructose absorption may suppress adiposity and adiposity-related diseases caused by fructose ingestion. Eucalyptus leaf extract (ELE) inhibits intestinal fructose absorption (but not glucose absorption); however, its active compound has not yet been identified. Therefore, we evaluated the inhibitory activity of ELE obtained from Eucalyptus globulus using an intestinal fructose permeation assay with the human intestinal epithelial cell line Caco-2. The luminal sides of a cell monolayer model cultured on membrane filters were exposed to fructose with or without the ELE. Cellular fructose permeation was evaluated by measuring the fructose concentration in the medium on the basolateral side. ELE inhibited 65% of fructose absorption at a final concentration of 1 mg/mL. Oenothein B isolated from the ELE strongly inhibited fructose absorption; the inhibition rate was 63% at a final concentration of 5 μg/mL. Oenothein B did not affect glucose absorption. In contrast, the other major constituents (i.e., gallic acid and ellagic acid) showed little fructose-inhibitory activity. To our knowledge, this is the first report that oenothein B in ELE strongly inhibits fructose absorption in vitro. ELE containing oenothein B can prevent and ameliorate obesity and other diseases caused by dietary fructose consumption.

sRNAs enriched in outer membrane vesicles of pathogenic Flavobacterium psychrophilum interact with immune genes of rainbow trout

Outer membrane vesicles (OMVs) released by gram-negative bacteria during host-pathogen interactions harbor cargos, such as DNA, RNA, toxins, and virulence factors. We hypothesized that sRNAs carried within OMVs of Flavobacterium psychrophilum interact with host immune genes and affect their expression. OMVs were isolated from F. psychrophilum and visualized using transmission electron microscopy (TEM). RNA-Seq datasets generated from whole-cell F. psychrophilum and their OMVs indicated enrichment of specific sRNAs in the OMVs compared to the parent cell. Fluorescent in situ hybridization (FISH) and confocal microscopy confirmed the expression of a randomly chosen sRNA. Integrated RNA-Seq analyses of host transcriptome and bacterial sRNAs on day 5 post-infection of F. psychrophilum -resistant and -susceptible rainbow trout genetic lines revealed 516 protein-coding, 595 lncRNA, and 116 bacterial sRNA differentially expressed (DE) transcripts. Integrated and network analyses of these DE transcripts revealed immune genes targeted by bacterial sRNAs. On the top of these genes, an isoform encoding anaphase-promoting complex subunit 13 (ANAPC13_1) was highly upregulated and exhibited interaction and reciprocal expression with 21 DE sRNAs enriched in OMVs and/or located in pathogenicity islands (PAIs). In vitro treatment of the rainbow trout epithelial cell line RTgill-W1 with OMVs showed signs of cell autolysis accompanied by dynamic changes in expression of host genes when profiled 24h following treatment. The OMV-enriched sRNAs, soFE013584 and soFE002123, showed high interactions with the protection of telomeres 1 gene (POT1); essential for chromosome stability and cellular viability. Modulation of the host gene expression following OMV-treatment, which favors elements from the phagocytic, endocytic, and antigen presentation pathways in addition to HSP70, HSP90, and cochaperone proteins, provided evidence for a potential role of OMVs in boosting the host immune response. In conclusion, our work identified novel microbial targets and inherent characteristics of OMVs that could open up new avenues of treatment and prevention of fish infections.