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Adhesion molecules play critical roles in maintaining the structural integrity of the airway epithelium in airways under stress. Previously, we reported that catenin alpha-like 1 (CTNNAL1) is downregulated in an asthma animal model and upregulated at the edge of human bronchial epithelial cells (HBECs) after ozone stress. In this work, we explore the potential role of CTNNAL1 in the structural adhesion of HBECs and its possible mechanism. We construct a CTNNAL1‒/‒ mouse model with CTNNAL1-RNAi recombinant adeno-associated virus (AAV) in the lung and a CTNNAL1-silencing cell line stably transfected with CTNNAL1-siRNA recombinant plasmids. Hematoxylin and eosin (HE) staining reveals that CTNNAL1‒/‒ mice have denuded epithelial cells and structural damage to the airway. Silencing of CTNNAL1 in HBECs inhibits cell proliferation and weakens extracellular matrix adhesion and intercellular adhesion, possibly through the action of the cytoskeleton. We also find that the expressions of the structural adhesion-related molecules E-cadherin, integrin β1, and integrin β4 are significantly decreased in ozone-treated cells than in vector control cells. In addition, our results show that the expression levels of RhoA/ROCK1 are decreased after CTNNAL1 silencing. Treatment with Y27632, a ROCK inhibitor, abolished the expressions of adhesion molecules induced by ozone in CTNNAL1-overexpressing HBECs. Overall, the findings of the present study suggest that CTNNAL1 plays a critical role in maintaining the structural integrity of the airway epithelium under ozone challenge, and is associated with epithelial cytoskeleton dynamics and the expressions of adhesion-related molecules via the RhoA/ROCK1 pathway.

The downregulation of adhesion molecule catenin alpha-like 1 (CTNNAL1) in airway epithelial cells of asthma patients and house dust mite (HDM)-induced asthma animal models was illustrated in our previous study. It is assumed to contribute to airway inflammation and mucus hypersecretion. In this work, we further explore the underlying mechanism of CTNNAL1 in asthma. CTNNAL1-silenced female mice exhibit a decreased level of cystic fibrosis transmembrane conductance regulator (CFTR), a cAMP-activated and ATP-gated Cl– channel that correlates with mucus hypersecretion. Our previous study demonstrated that ROCK1 expression decreases but ROCK2 expression increases in the lungs of a CTNNAL1-silenced mouse model. Inhibition of ROCK1 leads to a reduction in CFTR expression in CTNNAL1-overexpressing and CTNNAL1-silenced human bronchial epithelial (HBE) cells. It has been reported that ROCK1 is a downstream target of RhoA and that activation of RhoA increases CFTR expression after CTNNAL1 deficiency in vitro and in vivo. The above results indicate that CTNNAL1 regulates CFTR expression through the ROCK1 pathway. In addition, the expression of CFTR-associated ligand (CAL) is increased after CTNNAL1 silencing, and immunoprecipitation results confirm the interaction between ROCK1 and CAL. Inhibition of CAL does not influence ROCK1 expression but increases CFTR expression in CTNNAL1-silenced HBE cells. These data suggest that CTNNAL1 deficiency decreases CFTR expression in the HDM-induced asthma mouse model through the ROCK1-CAL signaling pathway.

Bombesin receptor‐activated protein (BRAP), encoded by the C6orf89 gene in humans, is expressed in various cells with undefined functions. BC004004, the mouse homologue of C6orf89, has been shown to play a role in bleomycin‐induced pulmonary fibrosis through the use of a BC004004 gene knockout mouse (BC004004−/−). In this study, we investigated the potential involvement of BRAP in renal fibrosis using two mouse models: unilateral ureteral obstruction (UUO) and type 2 diabetes mellitus induced by combination of a high‐fat diet (HFD) and streptozocin (STZ). BRAP or its homologue was expressed in tubular epithelial cells (TECs) in the kidneys of patients with chronic kidney disease (CKD) and in BC004004+/+ mice. Compared to control mice, BC004004−/− mice exhibited attenuated renal injury and renal fibrosis after UUO or after HFD/STZ treatment. Immunohistochemistry and immunoblot analyses of the kidneys of BC004004+/+ mice after UUO surgery showed a more significant decrease in E‐cadherin expression and a more significant increase in both α smooth muscle actin (α‐SMA) and vimentin expression compared to BC004004−/− mice. Additionally, stimulation with transforming growth factor‐β1 (TGF‐β1) led to a more significant decrease in E‐cadherin expression and a more significant increase in α‐SMA and vimentin expression in isolated TECs from BC004004+/+ than in those from BC004004−/− mice. These results suggest that an enhanced epithelial‐mesenchymal transition (EMT) process occurred in TECs in BC004004+/+ mice during renal injury, which might contribute to renal fibrosis. The loss of the BRAP homologue in BC004004−/− mice suppressed EMT activation in kidneys and contributed to the suppression of fibrosis during renal injury. [ABSTRACT FROM AUTHOR]

Background and Purpose: Airway epithelial cells (AECs) regulate the activation of epithelial–mesenchymal trophic units (EMTUs) during airway remodelling through secretion of signalling mediators. However, the major trigger and the intrinsic pathogenesis of airway remodelling is still obscure. Experimental Approach: The differing expressed genes in airway epithelia related to airway remodelling were screened and verified by RNA‐sequencing and signalling pathway analysis. Then, the effects of increased cathepsin K (CTSK) in airway epithelia on airway remodelling and EMTU activation were identified both in vitro and in vivo, and the molecular mechanism was elucidated in the EMTU model. The potential of CTSK as an an effective biomarker of airway remodelling was analysed in an asthma cohort of differing severity. Finally, an inhibitor of CTSK was administered for potential therapeutic intervention for airway remodelling in asthma. Key Results: The expression of CTSK in airway epithelia increased significantly along with the development of airway remodelling in a house dust mite (HDM)‐stressed asthma model. Increased secretion of CTSK from airway epithelia induced the activation of EMTUs by activation of the PAR2‐mediated pathway. Blockade of CTSK inhibited EMTU activation and alleviated airway remodelling as an effective intervention target of airway remodelling. Conclusion and Implications: Increased expression of CTSK in airway epithelia is involved in the development of airway remodelling in asthma through EMTU activation, mediated partly through the PAR2‐mediated signalling pathway. CTSK is a potential biomarker for airway remodelling, and may also be a useful intervention target for airway remodelling in asthma patients. [ABSTRACT FROM AUTHOR]

Acute asthma exacerbation refers to the progressive deterioration of asthma symptoms that is always triggered by virus infection represented by respiratory syncytial virus (RSV). After RSV infection, exaggerated Th2‐mediated pulmonary inflammation is the critical pathological response of asthmatic patients with acute exacerbation. Significantly, airway epithelial cells, being the primary targets of RSV infection, play a crucial role in controlling the pulmonary inflammatory response by releasing airway epithelial cell‐derived exosomes (AEC‐Exos), which potentially influence the development of asthma. However, the specific role of AEC‐Exos in acute asthma exacerbation after RSV infection remains obscure. The purpose of this study was to determine the distinct function of AEC‐Exos in exacerbating acute asthma following RSV infection. Blockade of exosomes by GW reduce the enhanced pulmonary inflammation significantly. Specifically, the enhanced Th2 inflammation was induced by AEC‐Exos thorough transportation of hsa‐miR‐155‐5p–Sirtuin 1 (SIRT1) pathway during acute asthma exacerbation. Targeted inhibition of hsa‐miR‐155‐5p blocks the exaggerated Th2 inflammation effectively in mice with acute asthma exacerbation. In summary, our study showed that during acute asthma exacerbation after RSV infection, AEC‐Exos promote the enhanced Th2 inflammation through transportation of increased hsa‐miR‐155‐5p, which was mediated partly through SIRT1‐mediated pathway. hsa‐miR‐155‐5p is a potential biomarker for early prediction of acute asthma exacerbation. [ABSTRACT FROM AUTHOR]

Both bombesin receptor‐activated protein (BRAP) and its mouse homolog have been found to be expressed in bronchial epithelia but with unclear functions. Using electron microscopy combined with histological assays, we found that BRAP homolog deficiency in mice led to abnormal tracheal cilia. Rab‐3A‐interacting protein (Rabin8), a protein that might play a role in cilia development, was screened by yeast two‐hybrid and further verified to have interaction with human BRAP by co‐immunoprecipitation and pulldown assays. The expression levels of Rabin8, together with acetylated α‐tubulin, a marker of cilia, were either downregulated by knockdown of BRAP or upregulated by overexpression of BRAP in cultured immortalized human bronchial epithelial cells. These results reveal a role for BRAP in airway cilia formation. [ABSTRACT FROM AUTHOR]

Excess reactive oxygen species (ROS) can cause an imbalance between oxidation and anti-oxidation, leading to the occurrence of oxidative stress in the body. The most common product of ROS-induced base damage is 8-hydroxyguanine (8-oxoG). Failure to promptly remove 8-oxoG often causes mutations during DNA replication. 8-oxoG is cleared from cells by the 8-oxoG DNA glycosylase 1 (OGG1)-mediated oxidative damage base excision repair pathway so as to prevent cells from suffering dysfunction due to oxidative stress. Physiological immune homeostasis and, in particular, immune cell function are vulnerable to oxidative stress. Evidence suggests that inflammation, aging, cancer, and other diseases are related to an imbalance in immune homeostasis caused by oxidative stress. However, the role of the OGG1-mediated oxidative damage repair pathway in the activation and maintenance of immune cell function is unknown. This review summarizes the current understanding of the effect of OGG1 on immune cell function. [ABSTRACT FROM AUTHOR]

Airway epithelial cells (AECs) are the first cell barrier of the respiratory system against external stimuli that play a critical role in the development of asthma. It is known that AECs play a key role in asthma susceptibility and severity. ITGB4 is a downregulated adhesion molecule in the airway epithelia of asthma patients, which was involved in the exaggerated lung inflammation after allergy stimulation. Toll-like receptor 4 (TLR4) in AECs has also been shown to play a crucial role in the development of lung inflammation in asthma patients. However, the specific intrinsic regulatory mechanism of TLR4 in AECs are still obscure. In this article, we demonstrated that ITGB4 deficiency in AECs enhances HDM-induced airway inflammation through hyperactivation of the TLR4 signaling pathway, which is mediated by inhibition of FYN phosphorylation. Moreover, TLR4-antagonist treatment or blockade of FYN can inhibit or exaggerate lung inflammation in HDM-stressed ITGB4-deficient mice, separately. Together, these results demonstrated that ITGB4 deficiency in AECs enhances HDM-induced lung inflammatory response through the ITGB4-FYN-TLR4 axis, which may provide new therapeutic approaches for the management of lung inflammation in asthma. [ABSTRACT FROM AUTHOR]

Bombesin receptor-activated protein (BRAP) and its homologous protein in mice, which is encoded by bc004004 gene, were expressed abundantly in brain tissues with unknown functions. We treated bc004004-/- mice with chronic unpredictable mild stress (CUMS) to test whether those mice were more vulnerable to stress-related disorders. The results of forced swimming test, sucrose preference test, and open field test showed that after being treated with CUMS for 28 days or 35 days both bc004004-/- and bc004004+/+ mice exhibited behavioural changes and there was no significant difference between bc004004+/+ and bc004004-/-. However, behavioural changes were observed only in bc004004-/- mice after being exposed to CUMS for 21 days, but not in bc004004+/+ after 21-day CUMS exposure, indicating that lack of BRAP homologous protein may cause vulnerability to stress-related disorders in mice. In addition, bc004004-/- mice showed a reduction in recognition memory as revealed by novel object recognition test. Since memory changes and stress related behavioural changes are all closely related to the hippocampus function we further analyzed the changes of dendrites and synapses of hippocampal neurons as well as expression levels of some proteins closely related to synaptic function. bc004004-/- mice exhibited decreased dendritic lengths and increased amount of immature spines, as well as altered expression pattern of synaptic related proteins including GluN2A, synaptophysin and BDNF in the hippocampus. Those findings suggest that BRAP homologous protein may have a protective effect on the behavioural response to stress via regulating dendritic spine formation and synaptic plasticity in the hippocampus. [ABSTRACT FROM AUTHOR]

Ectopic expression of the gastrin-releasing peptide (GRP) receptor (GRP-R) occurs frequently in human malignancies of the gastrointestinal tract. Owing to paracrine and autocrine interaction with its specific high-affinity ligand GRP, tumor cell proliferation, migration, and invasion might ensue. Here we provide the first insights regarding molecular mechanisms of GRP-R regulation in gastrointestinal cancer cells. We identified by EMSA and chromatin immunoprecipitation assays two cAMP response element (CRE) binding sites that recruited transcription factor CRE binding protein (CREB) to the human GRP-R promoter. Transfection studies with a wild-type human GRP-R promoter reporter and corresponding CRE mutants showed that both CRE sites are critical for basal transcriptional activation in gastrointestinal cancer cells. Forced expression of cAMP-dependent effectors CREB and PKA resulted in robust upregulation of human GRP-R transcriptional activity, and this overexpression strictly required intact wild-type CRE sites. Direct cAMP stimulation with forskolin resulted in enhanced human GRP-R promoter activity only in HuTu-80 cells, but not in Caco-2 cells, coinciding with forskolin-induced CREB phosphorylation occurring only in HuTu-80 but not Caco-2 cells. In summary, CREB is a critical regulator of human GRP-R expression in gastrointestinal cancer and might be activated through different upstream intracellular pathways. regulatory peptide; bombesin; gastrointestinal cancer; cyclic AMP response element

Our previous study indicated that adhesion molecule catenin alpha‐like 1(CTNNAL1) is downregulated in airway epithelial cells of asthma patients and asthma animal model but little is known about how the CTNNAL1 affects asthma pathogenesis. To reveal the direct relationship between asthma and CTNNAL1, CTNNAL1‐deficient mouse model in bronchopulmonary tissue was constructed by introducing CTNNAL1‐siRNA sequence using adeno‐associated virus (AAV) as vector. The mouse model of asthma was established by stimulation of house dust mite (HDM). After HDM‐challenged, there was marked airway inflammation, especially mucus hypersecretion in the CTNNAL1‐deficient mice. In addition, the CTNNAL1‐deficient mice exhibited an increase of lung IL‐4 and IL‐13 levels, as well as a significant increase of goblet cell hyperplasia and MUC5AC after HDM exposure. The expression of Yes‐associated protein (YAP), protein that interacted with α‐catenin, was downregulated after CTNNAL1 silencing and was upregulated due to its overexpression. In addition, the interaction between CTNNAL1 and YAP was confirmed by CO‐IP. Besides, inhibition of YAP could decrease the secretion of MUC5AC, IL‐4 and IL‐13 in CTNNAL1‐deficient 16HBE14o‐cells. Above results indicated us that CTNNAL1 regulated mucus hypersecretion through YAP pathway. In addition, the expression of ROCK2 increased when CTNNAL1 was silenced and decreased after YAP silencing, and inhibition of YAP decreased the expression of ROCK2 in CTNNAL1‐deficient HBE cells. Inhibition of ROCK2 decreased MUC5AC expression and IL‐13 secretion. In all, our study demonstrates that CTNNAL1 plays an important role in HDM‐induced asthma, mediating mucus secretion through the YAP‐ROCK2 pathway. [ABSTRACT FROM AUTHOR]

Background: In children, Langerhans cell histiocytosis (LCH), which is the most prevalent histiocytic disorder, exhibits a wide variety of manifestations and outcomes. There is no standard prognosis evaluation system for LCH. We investigated the combined predictive significance of complete blood counts (CBCs), BRAF V600E and MAP2K1 in childhood LCH. Methods: A cohort of 71 childhood LCH patients was retrospectively studied. The prognosis predictive significance of platelet-to-lymphocyte ratio (PLR), neutrophil-to-lymphocyte ratio (NLR), systemic inflammation response index (SIRI), systemic immune inflammation index (SII), BRAF V600E , and MAP2K1 were analyzed. Results: Histiocyte Society (HS) classification of LCH patients was correlated with NLR, SIRI, and progression free survival (PFS), bone involvement was correlated with SIRI, liver involvement was correlated with NLR, SII, SIRI, and PFS, spleen involvement was correlated with SIRI, lung involvement was correlated with NLR and PFS, CNS involvement was correlated with PFS, while BRAF V600E was correlated with PLR, NLR, SIRI, SII, PFS, and OS (p <0.05). MAP2K1 was correlated with NLR, SIRI, PFS, and OS (p <0.05). Elevated NLR, PLR SIRI, and SII predicted inferior PFS and OS (p < 0.05). PLR, NLE, SIRI, SII, BRAF V600E , and MAP2K1 were used to establish a risk model for stratifying the LCH patients into 3 different risk groups. Respective median PFS for low-, mediate-, and high-risk groups were not reached, 26, and 14 months (p <0.001), and all median OS were not reached (p <0.001). Conclusion: The risk model combined with CBCs, BRAF V600E , and MAP2K1 might be a promising prognostic system for LCH in children. [ABSTRACT FROM AUTHOR]

Respiratory syncytial virus (RSV) infection in airway epithelial cells is the main cause of bronchiolitis in children. Excessive mucus secretion is one of the primary symbols in RSV related lower respiratory tract infections (RSV‐related LRTI). However, the pathological processes of mucus hypersecretion in RSV‐infected airway epithelial cells remains unclear. The current study explores the involvement of miR‐34b/miR‐34c in mucus hypersecretion in RSV‐infected airway epithelial cells by targeting FGFR1. First, miR‐34b/miR‐34c and FGFR1 mRNA were quantified by qPCR in throat swab samples and cell lines, respectively. Then, the luciferase reporters' assay was designed to verify the direct binding between FGFR1 and miR‐34b/miR‐34c. Finally, the involvement of AP‐1 signalling was assessed by western blot. This study identified that miR‐34b/miR‐34c was involved in c‐Jun‐regulated MUC5AC production by targeting FGFR1 in RSV‐infected airway epithelial cells. These results provide some useful insights into the molecular mechanisms of mucus hypersecretion which may also bring new potential strategies to improve mucus hypersecretion in RSV disease. [ABSTRACT FROM AUTHOR]

As the direct contacting site for pathogens and allergens, the mucosal barrier plays a vital role in the lungs and intestines. Innate lymphoid cells (ILCs) are particularly resident in the mucosal barrier and participate in several pathophysiological processes, such as maintaining or disrupting barrier integrity, preventing various pathogenic invasions. In the pulmonary mucosae, ILCs sometimes aggravate inflammation and mucus hypersecretion but restore airway epithelial integrity and maintain lung tissue homeostasis at other times. In the intestinal mucosae, ILCs can increase epithelial permeability, leading to severe intestinal inflammation on the one hand, and assist mucosal barrier in resisting bacterial invasion on the other hand. In this review, we will illustrate the positive and negative roles of ILCs in mucosal barrier immunity. [ABSTRACT FROM AUTHOR]

Severe RSV infection is the main cause of hospitalization to children under the age of five. The regulation of miRNAs on the severity of RSV infection is unclear. The aim of the study was to identify the critical differential expression miRNAs (DE miRNAs) that can regulate the pathological response in RSV‐infected airway epithelial cells. In this study, miRNA and mRNA chips of RSV‐infected airway epithelia from Gene Expression Omnibus (GEO) were screened and analysed, separately. DE miRNAs‐targeted genes were performed for further pathway and process enrichment analysis. DE miRNA‐targeted gene functional network was constructed on the basis of miRNA‐mRNA interaction. The screened critical miRNA was also investigated by bioinformatics analysis. Then, RSV‐infected human bronchial epithelial cells (HBECs) were constructed to verify the expression of the DE miRNAs. Finally, specific synthetic DE miRNAs mimics were used to confirm the effect of DE miRNAs on the RSV‐infected HBECs. 45 DE miRNAs were identified from GEO62306 dataset. Our results showed that hsa‐mir‐34b‐5p and hsa‐mir‐34c‐5p decreased significantly in HBECs after RSV infection. Consistent with the biometric analysis, hsa‐mir‐34b/c‐5p is involved in the regulation of mucin expression gene MUC5AC. In RSV‐infected HBECs, the inducement of MUC5AC production by decreased hsa‐mir‐34b/c‐5p was partly mediated through activation of c‐Jun. These findings provide new insights into the mechanism of mucus obstruction after RSV infection and represent valuable targets for RSV infection and airway obstruction treatment. [ABSTRACT FROM AUTHOR]

Background: Integrin β4 (ITGB4) is a hemi‐desmosome protein which is downregulated in the airway epithelial cells of asthma patients. The proximal promoters and exons of ITGB4 contain CpG islands or multiple CpG sites both in human and mice, which indicated the possible methylation regulation of ITGB4 in airway epithelial cells. Objective: We sought to unveil that DNA methylation regulates the decreased ITGB4 during the pathogenesis of asthma. Methods: Mice were exposed to house dust mite (HDM) extracts to construct an asthma model. 5‐Aza‐2'‐deoxycytidine (5‐AZA) or dexamethasone (DEX) were added in the last two weeks. Besides, the primary human bronchial epithelial (HBE) cells were incubated for the detection of ITGB4 expression and methylation status after HDM stress. Furthermore, DNA methylation of ITGB4 in peripheral blood was measured in asthma patients. Logistic regression was employed to evaluate the association between methylation sites and asthma patients' ages in the control of potential confounders. Moreover, the correlations between differentially methylated sites (DMSs) and clinical parameters in asthma patients were assessed. Finally, the ability of candidate DMSs to predict asthma was evaluated by receiver operating characteristic (ROC) analysis and principal component analysis (PCA). Results: We found that in HDM‐stressed asthma model, DNA methylation regulated the reduced ITGB4 expression in airway epithelial cells. Moreover, alteration in the specific CpG sites (chr17:73717720 and chr17:73717636) of ITGB4 may regulate ITGB4 expression and further may be associated with the clinically phenotypic of asthma. The specific DMSs of ITGB4 in peripheral blood can distinguish asthma patients from healthy controls (HCs) effectively. Conclusions and Clinical Relevance: This study confirmed that DNA methylation regulates the decreased expression of ITGB4 in the airway epithelial cells of asthma patients. These results supply some useful insights to the mechanism of the decreased ITGB4 in asthmatic airway epithelial and provide possible targets for early prediction and screening of asthma. [ABSTRACT FROM AUTHOR]

Lung immune responses to respiratory pathogens and allergens are initiated in early life which will further influence the later onset of asthma. The airway epithelia form the first mechanical physical barrier to allergic stimuli and environmental pollutants, which is also the key regulator in the initiation and development of lung immune response. However, the epithelial regulation mechanisms of early‐life lung immune responses are far from clear. Our previous study found that integrin β4 (ITGB4) is decreased in the airway epithelium of asthma patients with specific variant site. ITGB4 deficiency in adult mice aggravated the lung Th2 immune responses and enhanced airway hyper‐responsiveness (AHR) with a house dust mite (HDM)‐induced asthma model. However, the contribution of ITGB4 to the postnatal lung immune response is still obscure. Here, we further demonstrated that ITGB4 deficiency following birth mediates spontaneous lung inflammation with ILC2 activation and increased infiltration of eosinophils and lymphocytes. Moreover, ITGB4 deficiency regulated thymic stromal lymphopoietin (TSLP) production in airway epithelial cells through EGFR pathways. Neutralization of TSLP inhibited the spontaneous inflammation significantly in ITGB4‐deficient mice. Furthermore, we also found that ITGB4 deficiency led to exaggerated lung allergic inflammation response to HDM stress. In all, these findings indicate that ITGB4 deficiency in early life causes spontaneous lung inflammation and induces exaggerated lung inflammation response to HDM aeroallergen. [ABSTRACT FROM AUTHOR]

Alzheimer's disease (AD), a progressive neurodegenerative disease characterized by impairments of cognitive function as a result of synaptic deficits and neuronal loss, is associated with inflammation. Apelin-13, a predominant neuropeptide with inhibiting effect on inflammation, has beneficial effects on cognition memory and neuronal damage. However, whether apelin-13 can protect neurons to ameliorate cognitive deficits in AD by inhibiting the inflammatory response remains largely unknown. To test this hypothesis, rats were intracerebroventricularly (ICV) injected with streptozotocin (3 mg/kg) alone or in combination with apelin-13 (2 μg). And tyrosine receptor kinase B (TrkB) blocker K252a (200 nM) was administrated 10 min before apelin injection. Furthermore, cognitive performance was assessed by new object recognition (NOR) and Y-maze tests. Protein expression of apelin, APJ, microglial marker (IBA1), astroglia marker (GFAP), interleukin 1 beta (IL-1β), tumor necrosis factor-α (TNF-α), synaptophysin (SYP), brain-derived neurotrophic factor (BDNF), TrkB, phospho-TrkB (p-TrkB) in the hippocampus were examined by western blotting or immunohistochemistry. And the gene expression of IBA1, GFAP, IL-1β, TNF-α, and SYP were detected by real-time quantitative polymerase chain reaction (PCR). Inflammatory disorder in the hippocampus was tested by hematoxylin and eosin (H&E) staining. The enzyme-linked immunosorbent assay (ELISA) was used to study the expression level of acetylcholine. And the activity of acetylcholinesterase was detected by Acetylcholinesterase Assay Kit. We observed that apelin/APJ signaling was downregulated in the hippocampus of rats administrated with STZ. Apelin-13 was found to significantly ameliorate STZ-induced AD-like phenotypes including congnitive deficit, cholinergic disfunction and the damage of neuron and synaptic plasticity. Moreover, apelin-13 inhibited microglia and astrocyte activation, reduced IL-1β and TNF-α expression and hippocampal BDNF/TrkB expression deficit in AD rats. Finally, apelin-13-mediated effects were blocked by TrkB receptor antagonist K252a. These results suggest that apelin-13 upregulates BDNF/TrkB pathway against cognitive deficit in a STZ-induced rat model of sporadic AD by attenuating inflammation. [ABSTRACT FROM AUTHOR]

Aging is characterized by a progressive loss of physiological integrity, leading to impaired organ function and, ultimately, increased vulnerability to death. Many complex diseases are related to aging, including asthma. In the lung, the airway epithelium serves as the first barrier to prevent the access of inspired external stimuli and dictates the initial stress responses. Notably, in the airway mucosa of asthma patients, an increase in senescent airway epithelial cells has been detected. Although it has been speculated that the senescence of airway epithelial cells could increase asthma susceptibility and aggravate asthma severity, the role of cell senescence in the development of asthma remains unclear. Integrin β4 (ITGB4) is a structural adhesion molecule with complex physiological functions that is downregulated in airway epithelial cells of asthma patients. This study demonstrates that the expression of ITGB4 in airway epithelial cells is downregulated significantly under oxidative stress or upon inflammatory stimulation. Moreover, we show that ITGB4 deficiency induces the senescence of airway epithelial cells through the activation of the p53 pathway both in vitro and in vivo. Together, our results demonstrate that airway epithelial senescence induced by ITGB4 deficiency after oxidative stress or inflammatory stimulation may be involved in the pathogenesis of asthma. Understanding the contribution of ITGB4 deficiency to the senescence of airway epithelial cells in asthma patients may provide new therapeutic approaches for the treatment of asthma. Aging is related to many diseases including asthma. Senescence of airway epithelial cells is increased in asthma patients. Here, it is demonstrated that ITGB4 expression in airway epithelia is downregulated under oxidative stress or inflammation stimulation. ITGB4 deficiency induces the senescence of airway epithelia by activating the p53 pathway. These results indicate that oxidative stress or inflammatory stimuli may contribute to the senescence of airway epithelia and could contribute to the pathogenesis of asthma. [ABSTRACT FROM AUTHOR]

In this study we tried to explore whether calcitonin gene-related peptide (CGRP) regulates the potential antigen uptaking ability of human bronchial epithelial cells (HBECs) and promoting the differentiation of Th1/Th2. We found that CGRP increased the uptake of fluorescein isothiocyanate labeled ovalbumin (FITC-OVA) by HBECs using fluorescence microscopy and flow cytometry analysis. MTT assay showed that T cells proliferated in a dose-dependent manner in the presence of OVA-pretreated HBECs and CGRP inhibited the proliferation of T cells. CGRP decreased secretion of IFN-γ, while it had no influence on secretion of IL-4 by ELISA. Our data suggest that CGRP enhanced HBECs antigen uptake ability and inhibits HBECs induced T cells proliferation. [ABSTRACT FROM AUTHOR]

Abstract: Airway epithelial cells play a significant role in the pathogenesis of asthma. Although the structural and functional defects of airway epithelial cells have been postulated to increase asthma susceptibility and exacerbate asthma severity, the mechanism and implication of these defects remain uncertain. Integrin β4 (ITGB4) is a structural adhesion molecule that is downregulated in the airway epithelium of asthma patients. In this study, we demonstrated that ITGB4 deficiency leads to severe allergy‐induced airway inflammation and airway hyper‐responsiveness (AHR) in mice. After house dust mite (HDM) challenge, epithelial cell‐specific ITGB4‐deleted mice showed increased lymphocyte, eosinophil, and neutrophil infiltration into lung compared with that of the wild‐type mice. ITGB4 deficiency also resulted in increased expression of the Th2 cytokine IL‐4, IL‐13, and the Th17 cytokine IL‐17A in the lung tissue and in the T cells after HDM challenge. The aggravated inflammation in ITGB4 defect mice was partly caused by enhanced disrupted epithelial barrier integrity after HDM stress, which induced the increased thymic stromal lymphopoietin secretion from airway epithelial cells. This study therefore demonstrates that ITGB4 plays a pivotal role in containing allergen‐mediated lung inflammation and airway hyper‐responsiveness in allergic asthma. [ABSTRACT FROM AUTHOR]

As the first barrier to the outside environment, airway epithelial cells serve a central role in the initiation and development of airway inflammation. Chemokines are the most direct and immediate cell factors for the recruitment and migration of inflammatory cells. The present review focused on the role of epithelial chemokines in the pathogenesis of airway inflammation in asthma. In addition to traditional CC family chemokines and CXC family chemokines, airway epithelial cells also express other chemokines, including thymic stromal lymphopoietin and interleukin‑33. By expressing and secreting chemokines, airway epithelial cells serve a key role in orchestrating airway inflammation in asthma. [ABSTRACT FROM AUTHOR]

Background: Bombesin receptor subtype-3 (BRS-3) is a member of the bombesin-like peptide receptor family. Our previous studies demonstrated that activation of the human BRS-3 plays a protective role in oxidation-injured human bronchial epithelial cells (HBEC). The present study was designed to determine the role of BRS-3 activation in the antigen-presenting action of HBEC and the corresponding proliferation and differentiation of T cells. Materials and Methods: In vivo, an asthma animal model was established and the expression and distribution of BRS-3 were analyzed by immunocytochemistry. In vitro, 2 kinds of B7 costimulatory molecules, i.e., B7H1 and B7DC, on HBEC were analyzed by flow cytometry. The antigen uptake by HBEC was examined by confocal microscopy and flow cytometry. The antigen-presenting-action-induced proliferation of T cells was determined by MTT assays. IFN-γ and IL-4 levels were measured by ELISA. All studies were performed in the absence or presence of the synthetic peptide P3513. Results: BRS-3 expression was induced in asthma animal models and mainly distributed in bronchial epithelial cells. HBEC express the costimulatory molecules B7H1 and B7DC. BRS-3 activation increased B7H1 expression but decreased B7DC expression on HBEC. BRS-3 activation also increased the antigen uptake by HBEC and the subsequent T cell proliferation. In addition, BRS-3 activation promoted the releases of IFN-γ, but not IL-4, in the supernatant of cocultured HBEC and T cells. Conclusion: These data suggest that HBEC can present antigen to T cells and BRS-3 activation promotes the process of antigen presentation and subsequent T cell proliferation and Th1 differentiation. [ABSTRACT FROM AUTHOR]

Abstract: Precise 3′-end processing of mRNA is essential for correct gene expression, yet in yeast, 3′-processing signals consist of multiple ambiguous sequence elements. Two neighboring elements upstream of the cleavage site are particularly important for the accuracy (positioning element) and efficiency (efficiency element) of 3′-processing and are recognized by the RNA-binding proteins Rna15 and Hrp1, respectively. In vivo, these interactions are strengthened by the scaffolding protein Rna14 that stabilizes their association. The NMR structure of the 34 -kDa ternary complex of the RNA recognition motif (RRM) domains of Hrp1 and Rna15 bound to this pair of RNA elements was determined by residual dipolar coupling and paramagnetic relaxation experiments. It reveals how each of the proteins binds to RNA and introduces a novel class of protein–protein contact in regions of previously unknown function. These interdomain contacts had previously been overlooked in other multi-RRM structures, although a careful analysis suggests that they may be frequently present. Mutations in the regions of these contacts disrupt 3′-end processing, suggesting that they may structurally organize the ribonucleoprotein complexes responsible for RNA processing. [ABSTRACT FROM AUTHOR]

Bombesin and its mammalian homologue gastrin-releasing peptide have been shown to be highly expressed and secreted by neuroendocrine cells in prostate cancer, and are thought to be related to the carcinogenesis and progression of this disease. We found, in this study, bombesin specifically induced mitogen-activated protein (MAP) kinase activation as shown by increased extracellular regulated kinase (ERK) phosphorylation and epidermal growth factor (EGF) receptor transactivation in prostate cancer cells, which express functional gastrin-releasing peptide receptor. The transactivation of EGF receptor was required for bombesin-induced ERK phosphorylation. Furthermore, non-receptor tyrosine kinase Src and cellular Ca2+ were shown to be involved in bombesin-induced EGF receptor transactivation and ERK phosphorylation. Inhibition of either EGF receptor transactivation or ERK activation blocked bombesin-induced DNA synthesis in these cells. Taken together, these data suggest bombesin may act as a mitogen in prostate cancer by activating MAP kinase pathway via EGFR transactivation. [Copyright &y& Elsevier]

Bombesin (BN) and its mammalian homologue gastrin-releasing peptide (GRP) have been shown to play an important role in human cancer as autocrine and paracrine growth factors. Prostatic neuroendocrine cells are thought to secrete these regulatory peptides and they may therefore interact with their specific, aberrantly expressed GRP receptor (GRP-R) in prostate cancer. In this study, we investigated the effect of BN on immediate early gene expression in two androgen-independent prostate cancer cell lines DU-145 and PC-3 with functional GRP receptor. We found that BN induced c-fos mRNA expression in both cell lines in a time-dependent manner. In contrast, c-jun mRNA was only modestly induced in DU-145 cells but not at all in PC-3 cells. On the protein level, we detected BN-induced stimulation of the c-fos gene product but not of c-jun protein. Sustained increase of the c-myc gene product was detectable in PC-3 but not in DU-145 cells. Concurrently, we demonstrated BN-dependent activation of the transcription factor Elk-1 and significant increase of cell proliferation in both prostate cancer cell lines. Taken together, these data suggest that BN acts as a mitogen in prostate cancer and this might be associated with the activation of the transcription factor Elk-1 and the immediate early gene c-fos. [Copyright &y& Elsevier]

The G protein-coupled human gastrin-releasing peptide receptor (hGRP-R) is frequently found aberrantly expressed in human cancers of the colon, stomach, and lung, and its ligand-specific activation has been implicated in cell proliferation and differentiation. Here, we demonstrated hGRP-R activation stimulated sustained cyclic AMP response element binding protein (CREB) phosphorylation and transactivation in duodenal cancer cells through a protein kinase C and partially p38 mitogen-activated protein kinase-dependent pathway. In contrast, intracellular calcium, ERK1/2, protein kinase A, and PI3 kinase were not involved. This novel signaling mechanism might be of importance for regulation of CREB-dependent gene expression in human cancer expressing functional hGRP-R. [Copyright &y& Elsevier]

Persistent injury and the following improper repair in bronchial epithelial cells are involved in the pathogenesis of airway inflammation and airway remodeling of asthma. E-cadherin (ECAD) has been shown to be involved in airway epithelium injury repair, but its underlying mechanisms to this process is poorly understood. Here, we describe a previously undetected function of ECAD in regulating the balance of EMT and MET during injury repair. Injury in mice and human bronchial epithelial cells (HBECs) was induced by successive ozone stress for 4 days at 30 min per day. ECAD overexpression in HBECs was induced by stable transfection. EMT features, transforming growth factor beta1 (TGF-β1) secretion, transcriptional repressor Snail expression, and β-catenin expression were assayed. Ozone exposure and then removal successfully induced airway epithelium injury repair during which EMT and MET occurred. The levels of TGF-β1 secretion and Snail expression increased in EMT process and decreased in MET process. While ECAD overexpression repressed EMT features; enhanced MET features; and decreased TGF-β1 secretion, Snail mRNA level, and β-catenin protein expression. Moreover, activating β-catenin blocked the effects of ECAD on EMT, MET and TGF-β1 signaling. Our results demonstrate that ECAD regulates the balance between EMT and MET, by preventing β-catenin to inhibit TGFβ1 and its target genes, and finally facilitates airway epithelia repair. [ABSTRACT FROM AUTHOR]

Summary: The yeast THO complex and the associated RNA helicase Sub2p are important mRNP maturation factors. Transcripts produced in THO/sub2 mutants are subject to degradation by a surveillance mechanism that involves the nuclear RNA exosome. Here we show that inefficient polyadenylation forms the basis of this accelerated mRNA decay. A genetic screen reveals extensive interactions between deletions of THO subunits and mRNA 3′ end processing mutants. Nuclear run-ons strengthen this link by showing premature transcription termination close to polyadenylation sites in THO/sub2 mutants in vivo. Moreover, in vitro, pre-mRNA substrates are poorly polyadenylated and consequently unstable in extracts from THO/sub2 mutant strains. Decreased polyadenylation correlates with a specific downregulation of the poly(A)-polymerase cofactor Fip1p by the ubiquitin/proteasome pathway. Both polyadenylation defects and Fip1p instability depend on the nuclear exosome component Rrp6p and its activator Trf4p. We suggest that removal of aberrant mRNA is facilitated by direct regulation of polyadenylation activity. [Copyright &y& Elsevier]

An increase in intracellular Cl− concentration ([Cl−] i) may be a general response of airway epithelial cells to various stimuli and may participate in some basic cellular functions. However, whether the basic functional activities of cells, such as proliferation and wound healing, are related to Cl − activities remains unclear. This study aimed to investigate the effects and potential mechanisms of [Cl−] i on the proliferation and wound healing ability of airway epithelial BEAS-2B cells. BEAS-2B cells were treated with four Cl− channel inhibitors (T16Ainh-A01, CFTRinh-172, CaCCinh-A01, and IAA-94), and the Cl− fluorescence probe N-(ethoxycarbonylmethyl)-6-methoxyquinolinium bromide was used. Results showed that all Cl− channel inhibitors could increase [Cl−] i in BEAS-2B cells. The increased [Cl−] i induced by Cl− channel inhibitors or clamping [Cl−] i at high levels enhanced the phosphorylation of focal adhesion kinase (FAK) and subsequently promoted the proliferation and wound healing ability of BEAS-2B cells. By contrast, the FAK inhibitor PF573228 abrogated these effects induced by the increased [Cl−] i. FAK also activated the PI3K/AKT signaling pathway. In conclusion, increased [Cl−] i promotes the proliferation and wound healing ability of BEAS-2B cells by activating FAK to activate the PI3K/AKT signaling pathway. Intracellular Cl− may act as a signaling molecule to regulate the proliferation and wound healing ability of airway epithelial cells. [ABSTRACT FROM AUTHOR]