Pim oncogenes are overexpressed in a wide range of tumours from a haematological and epithelial origin. Pim genes encode serine/threonine kinases that have been shown to counteract the increased ...sensitivity to apoptosis induction that is associated with MYC-driven tumorigenesis. Recently, considerable progress has been made in characterizing the pathways of PIM-mediated survival signalling. Given the unique structure of their active site and the minimal phenotype of mice mutant for all Pim family members, these oncogenes might be promising targets for highly specific and selective drugs with favourable toxicity profiles. In this Review, we discuss the physiological functions and oncogenic activities of Pim kinases.
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Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Infection with severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2) leads to coronavirus disease 2019 (COVID‐19), which poses an unprecedented worldwide health crisis, and has been declared a ...pandemic by the World Health Organization (WHO) on March 11, 2020. The angiotensin converting enzyme 2 (ACE2) has been suggested to be the key protein used by SARS‐CoV‐2 for host cell entry. In their recent work, Lindskog and colleagues (Hikmet et al, 2020) report that ACE2 is expressed at very low protein levels—if at all—in respiratory epithelial cells. Severe COVID‐19, however, is characterized by acute respiratory distress syndrome and extensive damage to the alveoli in the lung parenchyma. Then, what is the role of the airway epithelium in the early stages of COVID‐19, and which cells need to be studied to characterize the biological mechanisms responsible for the progression to severe disease after initial infection by the novel coronavirus?
The Angiotensin I converting enzyme 2 (ACE2) has been suggested as the key protein used by SARS‐CoV‐2 for host cell entry. In their recent study, Lindskog and colleagues (Hikmet et al, 2020) report very low ‐if any‐ ACE2 protein expression in respiratory epithelial cells.
Airway epithelial barrier dysfunction is frequently observed in asthma and may have important implications. The physical barrier function of the airway epithelium is tightly interwoven with its ...immunomodulatory actions, while abnormal epithelial repair responses may contribute to remodelling of the airway wall. We propose that abnormalities in the airway epithelial barrier play a crucial role in the sensitization to allergens and pathogenesis of asthma. Many of the identified susceptibility genes for asthma are expressed in the airway epithelium, supporting the notion that events at the airway epithelial surface are critical for the development of the disease. However, the exact mechanisms by which the expression of epithelial susceptibility genes translates into a functionally altered response to environmental risk factors of asthma are still unknown. Interactions between genetic factors and epigenetic regulatory mechanisms may be crucial for asthma susceptibility. Understanding these mechanisms may lead to identification of novel targets for asthma intervention by targeting the airway epithelium. Moreover, exciting new insights have come from recent studies using single‐cell RNA sequencing (scRNA‐Seq) to study the airway epithelium in asthma. This review focuses on the role of airway epithelial barrier function in the susceptibility to develop asthma and novel insights in the modulation of epithelial cell dysfunction in asthma.
Lung disease accounts for every sixth death globally. Profiling the molecular state of all lung cell types in health and disease is currently revolutionizing the identification of disease mechanisms ...and will aid the design of novel diagnostic and personalized therapeutic regimens. Recent progress in high-throughput techniques for single-cell genomic and transcriptomic analyses has opened up new possibilities to study individual cells within a tissue, classify these into cell types, and characterize variations in their molecular profiles as a function of genetics, environment, cell-cell interactions, developmental processes, aging, or disease. Integration of these cell state definitions with spatial information allows the in-depth molecular description of cellular neighborhoods and tissue microenvironments, including the tissue resident structural and immune cells, the tissue matrix, and the microbiome. The Human Cell Atlas consortium aims to characterize all cells in the healthy human body and has prioritized lung tissue as one of the flagship projects. Here, we present the rationale, the approach, and the expected impact of a Human Lung Cell Atlas.
Recent data indicate a role for airway epithelial necroptosis, a regulated form of necrosis, and the associated release of damage-associated molecular patterns (DAMPs) in the development of chronic ...obstructive pulmonary disease (COPD). DAMPs can activate pattern recognition receptors (PRRs), triggering innate immune responses. We hypothesized that cigarette smoke (CS)-induced epithelial necroptosis and DAMP release initiate airway inflammation in COPD. Human bronchial epithelial BEAS-2B cells were exposed to cigarette smoke extract (CSE), and necrotic cell death (membrane integrity by propidium iodide staining) and DAMP release (i.e., double-stranded DNA, high-mobility group box 1, heat shock protein 70, mitochondrial DNA, ATP) were analyzed. Subsequently, BEAS-2B cells were exposed to DAMP-containing supernatant of CS-induced necrotic cells, and the release of proinflammatory mediators C-X-C motif ligand 8 (CXCL-8), IL-6 was evaluated. Furthermore, mice were exposed to CS in the presence and absence of the necroptosis inhibitor necrostatin-1, and levels of DAMPs and inflammatory cell numbers were determined in bronchoalveolar lavage fluid. CSE induced a significant increase in the percentage of necrotic cells and DAMP release in BEAS-2B cells. Stimulation of BEAS-2B cells with supernatant of CS-induced necrotic cells induced a significant increase in the release of CXCL8 and IL-6, in a myeloid differentiation primary response gene 88-dependent fashion. In mice, exposure of CS increased the levels of DAMPs and numbers of neutrophils in bronchoalveolar lavage fluid, which was statistically reduced upon treatment with necrostatin-1. Together, we showed that CS exposure induces necrosis of bronchial epithelial cells and subsequent DAMP release in vitro, inducing the production of proinflammatory cytokines. In vivo, CS exposure induces neutrophilic airway inflammation that is sensitive to necroptosis inhibition.
Human lungs enable efficient gas exchange and form an interface with the environment, which depends on mucosal immunity for protection against infectious agents. Tightly controlled interactions ...between structural and immune cells are required to maintain lung homeostasis. Here, we use single-cell transcriptomics to chart the cellular landscape of upper and lower airways and lung parenchyma in healthy lungs, and lower airways in asthmatic lungs. We report location-dependent airway epithelial cell states and a novel subset of tissue-resident memory T cells. In the lower airways of patients with asthma, mucous cell hyperplasia is shown to stem from a novel mucous ciliated cell state, as well as goblet cell hyperplasia. We report the presence of pathogenic effector type 2 helper T cells (T
2) in asthmatic lungs and find evidence for type 2 cytokines in maintaining the altered epithelial cell states. Unbiased analysis of cell-cell interactions identifies a shift from airway structural cell communication in healthy lungs to a T
2-dominated interactome in asthmatic lungs.
•SNPs in the IL-33 and IL-1RL1 genes play a crucial role in asthma and allergic diseases.•The IL-33/IL-1RL1 pathway modulates several functions in mast cells and basophils under physiological and ...pathological conditions.•Dysregulated activity of the IL-33/IL-1RL1 pathway could contribute to allergic disorders via altered functioning of mast cells and basophils.•Targeting the IL-33/IL-1RL1 pathway could form a novel therapeutic approach to treat allergic diseases.
Interleukin-33 (IL-33) is a recently discovered cytokine that belongs to the IL-1 superfamily and acts as an important regulator in several allergic disorders. It is considered to function as an alarmin, or danger cytokine, that is released upon structural cell damage. IL-33 activates several immune cells, including Th2 cells, mast cells and basophils, following its interaction with a cell surface heterodimer consisting of an IL-1 receptor-related protein ST2 (IL-1RL1) and IL-1 receptor accessory protein (IL-1RAcP). This activation leads to the production of a variety of Th2-like cytokines that mediate allergic-type immune responses. Thus, IL-33 appears to be a double-edged sword because, in addition to its important contribution to host defence, it exacerbates allergic responses, such as allergic rhinitis and asthma. A major purported mechanism of IL-33 in allergy is the activation of mast cells to produce a variety of pro-inflammatory cytokines and chemokines. In this review, we summarize the current knowledge regarding the genetics and physiology of IL-33 and IL-1RL1 and its association with different allergic diseases by focusing on its effects on mast cells and basophils.
Asthma is a complex disease that results from the interaction between genetic predisposition and environmental factors. Recently, genome-wide association studies have identified a number of genes ...that significantly contribute to asthma. Two of these genes, IL33 and IL-1 receptor–like 1 (IL1RL1) , act in one signal transduction pathway. IL33 encodes a cytokine released on damage of cells, whereas IL1RL1 encodes part of the IL-33 receptor complex. Recent progress made in functional studies in human subjects and mouse models of allergic airway disease indicate a central role of IL-33 signaling in driving TH 2 inflammation, which is central to eosinophilic allergic asthma. Here, IL-33 acts on cells of both the adaptive and innate immune systems. Very recently, a novel population of IL-33–responsive innate immune cells, the type 2 innate lymphoid cells, was found to produce hallmark TH 2 cytokines, such as IL-5 and IL-13. The relevance of these cells for asthma is underscored by the identification of retinoic acid–related orphan receptor α (RORA) , the gene encoding the transcription factor critical for their differentiation, as another asthma gene in genome-wide association studies. This review describes the mechanisms through which genetic variation at the IL33 and IL1RL1 loci translates into increased susceptibility for asthma. We propose that genetic variation associated with asthma at the IL33 and IL1RL1 loci can be dissected into independent signals with distinct functional consequences for this pathway that is central to asthma pathogenesis.
A review on the pathophysiology of asthma remission Carpaij, Orestes A.; Burgess, Janette K.; Kerstjens, Huib A.M. ...
Pharmacology & therapeutics (Oxford),
September 2019, 2019-09-00, 20190901, Letnik:
201
Journal Article
Recenzirano
Odprti dostop
Asthma is a chronic respiratory condition, which is highly prevalent worldwide. Although no cure is currently available, it is well recognized that some asthma patients can spontaneously enter ...remission of the disease later in life. Asthma remission is characterized by absence of symptoms and lack of asthma-medication use. Subjects in asthma remission can be divided into two groups: those in clinical remission and those in complete remission. In clinical asthma remission, subjects still have a degree of lung functional impairment or bronchial hyperresponsiveness, while in complete asthma remission, these features are no longer present. Over longer periods, the latter group is less likely to relapse. This remission group is of great scientific interest due to the higher potential to find biomarkers or biological pathways that elicit or are associated with asthma remission.
Despite the fact that the definition of asthma remission varies between studies, some factors are reproducibly observed to be associated with remitted asthma. Among these are lower levels of inflammatory markers, which are lowest in complete remission. Additionally, in both groups some degree of airway remodeling is present. Still, the pathological disease state of asthma remission has been poorly investigated. Future research should focus on at least two aspects: further characterisation of the small airways and airway walls in order to determine histologically true remission, and more thorough biological pathway analyses to explore triggers that elicit this phenomenon. Ultimately, this will result in pharmacological targets that provide the potential to steer the course of asthma towards remission.
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