Recent developments in the immunopathology of COVID-19.

There has been an important change in the clinical characteristics and immune profile of Coronavirus disease 2019 (COVID-19) patients during the pandemic thanks to the extensive vaccination programs. Here, we highlight recent studies on COVID-19, from the clinical and immunological characteristics to the protective and risk factors for severity and mortality of COVID-19. The efficacy of the COVID-19 vaccines and potential allergic reactions after administration are also discussed. The occurrence of new variants of concerns such as Omicron BA.2, BA.4, and BA.5 and the global administration of COVID-19 vaccines have changed the clinical scenario of COVID-19. Multisystem inflammatory syndrome in children (MIS-C) may cause severe and heterogeneous disease but with a lower mortality rate. Perturbations in immunity of T cells, B cells, and mast cells, as well as autoantibodies and metabolic reprogramming may contribute to the long-term symptoms of COVID-19. There is conflicting evidence about whether atopic diseases, such as allergic asthma and rhinitis, are associated with a lower susceptibility and better outcomes of COVID-19. At the beginning of pandemic, the European Academy of Allergy and Clinical Immunology (EAACI) developed guidelines that provided timely information for the management of allergic diseases and preventive measures to reduce transmission in the allergic clinics. The global distribution of COVID-19 vaccines and emerging severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants with reduced pathogenic potential dramatically decreased the morbidity, severity, and mortality of COVID-19. Nevertheless, breakthrough infection remains a challenge for disease control. Hypersensitivity reactions (HSR) to COVID-19 vaccines are low compared to other vaccines, and these were addressed in EAACI statements that provided indications for the management of allergic reactions, including anaphylaxis to COVID-19 vaccines. We have gained a depth knowledge and experience in the over 2 years since the start of the pandemic, and yet a full eradication of SARS-CoV-2 is not on the horizon. Novel strategies are warranted to prevent severe disease in high-risk groups, the development of MIS-C and long COVID-19.

Effect of Haemophilus influenzae, Streptococcus pneumoniae and influenza vaccinations on infections, immune response and asthma control in preschool children with asthma.

BACKGROUND: Haemophilus influenzae (H. influenzae), Streptococcus pneumoniae (pneumococcus) and influenza vaccines are administered in children to prevent infections caused by these pathogens. The benefits of vaccination for asthma control in children and the elicited immune response are not fully understood. This study aimed to investigate the impact of these vaccinations on respiratory infections, asthma symptoms, asthma severity and control status, pathogen colonization and in vitro immune responses to different stimulants mimicking infections in asthmatic children. METHODS: Children aged 4-6 years were recruited into the multicentre prospective PreDicta study conducted across five European countries. Information about vaccination history, infections, antibiotic use, inhaled corticosteroid (ICS) use and asthma symptoms in the last 12 months were obtained from questionnaires of the study. Nasopharyngeal samples were collected at the first visit to assess bacterial and viral colonization, and venous blood for isolation of peripheral blood mononuclear cells (PBMCs). The PBMCs were stimulated with phytohemagglutinin, R848, Poly I:C and zymosan. The levels of 22 cytokines and chemokines were measured in cell culture supernatants using a luminometric multiplex assay. RESULTS: One-hundred and forty asthmatic preschool children (5.3 ± 0.7 years) and 53 healthy children (5.0 ± 0.8 years) from the PreDicta cohort were included in the current study. Asthmatic children were associated with more frequent upper and lower respiratory infections, and more frequent and longer duration of antibiotic use compared with healthy children. In asthmatic children, sufficient H. influenzae vaccination was associated with a shorter duration of upper respiratory infection (URI) and overall use and average dose of ICS. The airway colonization was characterized by less pneumococcus and more rhinovirus. Pneumococcal vaccination was associated with a reduction in the use rate and average dose of ICS, improved asthma control, and less human enterovirus and more H. influenzae and rhinovirus (RV) airway colonization. Influenza vaccination in the last 12 months was associated with a longer duration of URI, but with a decrease in the occurrence of lower respiratory infection (LRI) and the duration of gastrointestinal (GI) infection and antibiotic use. Asthmatic preschoolers vaccinated with H. influenzae, pneumococcus or influenza presented higher levels of Th1-, Th2-, Th17- and regulatory T cells (Treg)-related cytokines in unstimulated PBMCs. Under stimulation, PBMCs from asthmatic preschoolers with pneumococcal vaccination displayed a predominant anti-inflammatory immune response, whereas PBMCs from asthmatic children with sufficient H. influenzae or influenza vaccination were associated with both pro- and anti-inflammatory immune responses. CONCLUSION: In asthmatic preschoolers, the standard childhood vaccinations to common respiratory pathogens have beneficial effects on asthma control and may modulate immune responses relevant to asthma pathogenesis.

The effect of allergy and asthma as a comorbidity on the susceptibility and outcomes of COVID-19.

The coronavirus disease 2019 (COVID-19) pandemic causes an overwhelming number of hospitalization and deaths with a significant socioeconomic impact. The vast majority of studies indicate that asthma and allergic diseases do not represent a risk factor for COVID-19 susceptibility nor cause a more severe course of disease. This raises the opportunity to investigate the underlying mechanisms of the interaction between an allergic background and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The majority of patients with asthma, atopic dermatitis, allergic rhinitis, chronic rhinosinusitis, food allergies and drug allergies exhibit an over-expression of type 2 immune and inflammatory pathways with the contribution of epithelial cells, innate lymphoid cells, dendritic cells, T cells, eosinophils, mast cells, basophils, and the type 2 cytokines interleukin (IL)-4, IL-5, IL-9, IL-13, and IL-31. The potential impact of type 2 inflammation-related allergic diseases on susceptibility to COVID-19 and severity of its course have been reported. In this review, the prevalence of asthma and other common allergic diseases in COVID-19 patients is addressed. Moreover, the impact of allergic and non-allergic asthma with different severity and control status, currently available asthma treatments such as inhaled and oral corticosteroids, short- and long-acting ß2 agonists, leukotriene receptor antagonists and biologicals on the outcome of COVID-19 patients is reviewed. In addition, possible protective mechanisms of asthma and type 2 inflammation on COVID-19 infection, such as the expression of SARS-CoV-2 entry receptors, antiviral activity of eosinophils and cross-reactive T-cell epitopes, are discussed. Potential interactions of other allergic diseases with COVID-19 are postulated, including recommendations for their management.

Regulatory roles of three miRNAs on allergen mRNA expression in Tyrophagus putrescentiae.

BACKGROUND: Tyrophagus putresecentiae is an important mite species in rural and urban environments, causing sensitization and allergic disease. While evidence suggests that microRNAs (miRNAs) may regulate the expression of allergen-encoding genes, no study has directly investigated this possibility. Here, this gap was addressed by profiling miRNAs and elucidating their target allergen messenger RNAs (mRNAs) in this mite species. METHODS: Small RNA and transcriptome libraries were constructed for eggs, larvae, nymphs, and adults. After deep miRNA and whole-transcriptome sequencing were performed, the miRNA and allergen-encoding mRNA regulatory networks were explored. RESULTS: A total of 540 miRNAs were identified, including 155 with expression levels differing significantly across the four mite developmental stages (p < .01), 59 of which were novel. The mRNA expression for allergens was higher for Tyr p 1 in adults than in other developmental stages; Tyr p 2-5, 7, 10, 13, 33, and 34 in immature stages; and Tyr p 28, 35, and 36 in eggs and adults. A combined miRNA and transcriptome bioinformatics analysis showed that allergen Tyr p 3 was regulated by miRNA PC-5p-5698441_1, Tyr p 4 was regulated by PC-5p-7050653_1, and Tyr p 34 was regulated by PC-5p-5534223_1 and PC-5p-5698441_1. These three allergen mRNA and three miRNAs were identified using qRT-PCR, and their regulatory roles were confirmed by double-fluorescent reporter gene system and site-directed mutagenesis technology. CONCLUSIONS: For the first time, allergen mRNA expression and miRNAs were profiled throughout the life cycle for an allergen-producing mite, and the results showed that miRNAs bind to target allergen mRNAs to regulate their expression.

Physical activity in asthma control and its immune modulatory effect in asthmatic preschoolers.

BACKGROUND: The impact of physical activity on immune response is a hot topic in exercise immunology, but studies involving asthmatic children are scarce. Our aims were to examine whether there were any differences in the level of physical activity and daily TV attendance, to assess its role on asthma control and immune responses to various immune stimulants. METHODS: Weekly physical activity and daily television attendance were obtained from questionnaires at inclusion of the PreDicta study. PBMC cultures were stimulated with phytohemagglutinin (PHA), R848, poly I:C, and zymosan. A panel of cytokines was measured and quantified in cell culture supernatants using luminometric multiplex immunofluorescence beads-based assay. RESULTS: Asthmatic preschoolers showed significantly more TV attendance than their healthy peers (58.6% vs. 41.5% 1-3 h daily and only 25.7% vs. 47.2% ≤1 h daily) and poor asthma control was associated with less frequent physical activity (PA) (75% no or occasional activity in uncontrolled vs. 20% in controlled asthma; 25% ≥3 times weekly vs. 62%). Asthmatics with increased PA exhibited elevated cytokine levels in response to polyclonal stimulants, suggesting a readiness of circulating immune cells for type 1, 2, and 17 cytokine release compared to subjects with low PA and high TV attendance. This may also represent a proinflammatory state in high PA asthmatic children. Low physical activity and high TV attendance were associated with a decrease in proinflammatory cytokines. Proinflammatory cytokines were correlating with each other in in vitro immune responses of asthmatic children, but not healthy controls, this correlation was more pronounced in children with sedentary behavior. CONCLUSION: Asthmatic children show more sedentary behavior than healthy subjects, while poor asthma control is associated with a substantial decrease in physical activity. Our results suggest that asthmatic children may profit from regular exercise, as elevated cytokine levels in stimulated conditions indicate an immune system prepared for responding strongly in case of different types of infections. However, it has to be considered that a hyperinflammatory state in high PA may not be beneficial in asthmatic children.

Store-operated calcium entry-associated regulatory factor regulates airway inflammation and airway remodeling in asthma mice models.

Store-operated calcium entry (SOCE) is involved in the pathogenesis of airway inflammation and remodeling in asthma. Store-operated calcium entry-associated regulatory factor (SARAF) can downregulate SOCE. We sought to investigate the role of SARAF in the regulation of airway inflammation and remodeling in asthma mice models, as well as in the functional regulation of human airway smooth muscle cells (hASMCs). Balb/c mice were sensitized and challenged with ovalbumin to establish the asthma mice models. Mice were transfected with lentivirus, which expressed the SARAF gene + GFP (green fluorescence protein) or the negative control gene + GFP. Airway resistance was measured with the animal pulmonary function system. Airway inflammation and remodeling were evaluated via histological staining. In vitro cultured hASMCs were transfected with scrambled small interfering RNA (siRNA) or SARAF-specific siRNA, respectively. The proliferation, migration rate, hypertrophy, and SOCE activity of hASMCs were examined with Cell Counting Kit-8, wound healing test, bright field imaging, and Ca2+ fluorescence imaging, respectively. SARAF expression was measured by quantitative real-time PCR. Asthma mice models showed decreased SARAF mRNA expression in the lungs. SARAF overexpression attenuated airway inflammation, resistance, and also remodeling. Downregulation of SARAF expression with siRNA promoted the proliferation, migration, hypertrophy, and SOCE activity in hASMCs. SARAF plays a protective role against airway inflammation and remodeling in asthma mice models by blunting SOCE; SARAF may also be a functional regulating factor of hASMCs.

Clinical characteristics of 182 pediatric COVID-19 patients with different severities and allergic status.

BACKGROUND: The pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has made widespread impact recently. We aim to investigate the clinical characteristics of COVID-19 children with different severities and allergic status. METHODS: Data extracted from the electronic medical records, including demographics, clinical manifestations, comorbidities, laboratory and immunological results, and radiological images of 182 hospitalized COVID-19 children, were summarized and analyzed. RESULTS: The median age was 6 years, ranging from 3 days to 15 years, and there were more boys (male-female ratio about 2:1) within the studied 182 patients. Most of the children were infected by family members. Fever (43.4%) and dry cough (44.5%) were common symptoms, and gastrointestinal manifestations accounted for 11.0%, including diarrhea, abdominal discomfort, and vomiting. 71.4% had abnormal chest computed tomography (CT) scan images, and typical signs of pneumonia were ground-glass opacity and local patchy shadowing on admission. Laboratory results were mostly within normal ranges, and only a small ratio of lymphopenia (3.9%) and eosinopenia (29.5%) were observed. The majority (97.8%) of infected children were not severe, and 24 (13.2%) of them had asymptomatic infections. Compared to children without pneumonia (manifested as asymptomatic and acute upper respiratory infection), children with pneumonia were associated with higher percentages of the comorbidity history, symptoms of fever and cough, and increased levels of serum procalcitonin, alkaline phosphatase, and serum interleukins (IL)-2, IL-4, IL-6, IL-10, and TNF-α. There were no differences in treatments, duration of hospitalization, time from first positive to first negative nucleic acid testing, and outcomes between children with mild pneumonia and without pneumonia. All the hospitalized COVID-19 children had recovered except one death due to intussusception and sepsis. In 43 allergic children with COVID-19, allergic rhinitis (83.7%) was the major disease, followed by drug allergy, atopic dermatitis, food allergy, and asthma. Demographics and clinical features were not significantly different between allergic and nonallergic groups. Allergic patients showed less increase in acute phase reactants, procalcitonin, D-dimer, and aspartate aminotransferase levels compared with all patients. Immunological profiles including circulating T, B, and NK lymphocyte subsets, total immunoglobulin and complement levels, and serum cytokines did not show any difference in allergic and pneumonia groups. Neither eosinophil counts nor serum total immunoglobulin E (IgE) levels showed a significant correlation with other immunological measures, such as other immunoglobulins, complements, lymphocyte subset numbers, and serum cytokine levels. CONCLUSION: Pediatric COVID-19 patients tended to have a mild clinical course. Patients with pneumonia had higher proportion of fever and cough and increased inflammatory biomarkers than those without pneumonia. There was no difference between allergic and nonallergic COVID-19 children in disease incidence, clinical features, and laboratory and immunological findings. Allergy was not a risk factor for developing and severity of SARS-CoV-2 infection and hardly influenced the disease course of COVID-19 in children.

Clinical, radiological, and laboratory characteristics and risk factors for severity and mortality of 289 hospitalized COVID-19 patients.

BACKGROUND: The coronavirus disease 2019 (COVID-19) has become a global pandemic, with 10%-20% of severe cases and over 508 000 deaths worldwide. OBJECTIVE: This study aims to address the risk factors associated with the severity of COVID-19 patients and the mortality of severe patients. METHODS: 289 hospitalized laboratory-confirmed COVID-19 patients were included in this study. Electronic medical records, including patient demographics, clinical manifestation, comorbidities, laboratory tests results, and radiological materials, were collected and analyzed. According to the severity and outcomes of the patients, they were divided into three groups: nonsurvived (n = 49), survived severe (n = 78), and nonsevere (n = 162) groups. Clinical, laboratory, and radiological data were compared among these groups. Principal component analysis (PCA) was applied to reduce the dimensionality and visualize the patients on a low-dimensional space. Correlations between clinical, radiological, and laboratory parameters were investigated. Univariate and multivariate logistic regression methods were used to determine the risk factors associated with mortality in severe patients. Longitudinal changes of laboratory findings of survived severe cases and nonsurvived cases during hospital stay were also collected. RESULTS: Of the 289 patients, the median age was 57 years (range, 22-88) and 155 (53.4%) patients were male. As of the final follow-up date of this study, 240 (83.0%) patients were discharged from the hospital and 49 (17.0%) patients died. Elder age, underlying comorbidities, and increased laboratory variables, such as leukocyte count, neutrophil count, neutrophil-to-lymphocyte ratio (NLR), C-reactive protein (CRP), procalcitonin (PCT), D-dimer, alanine aminotransferase (ALT), aspartate aminotransferase (AST), and blood urea nitrogen (BUN) on admission, were found in survived severe cases compared to nonsevere cases. According to the multivariate logistic regression analysis, elder age, a higher number of affected lobes, elevated CRP levels on admission, increased prevalence of chest tightness/dyspnea, and smoking history were independent risk factors for death of severe patients. A trajectory in PCA was observed from "nonsevere" toward "nonsurvived" via "severe and survived" patients. Strong correlations between the age of patients, the affected lobe numbers, and laboratory variables were identified. Dynamic changes of laboratory findings of survived severe cases and nonsurvived cases during hospital stay showed that continuing increase of leukocytes and neutrophil count, sustained lymphopenia and eosinopenia, progressing decrease in platelet count, as well as high levels of NLR, CRP, PCT, AST, BUN, and serum creatinine were associated with in-hospital death. CONCLUSIONS: Survived severe and nonsurvived COVID-19 patients had distinct clinical and laboratory characteristics, which were separated by principle component analysis. Elder age, increased number of affected lobes, higher levels of serum CRP, chest tightness/dyspnea, and smoking history were risk factors for mortality of severe COVID-19 patients. Longitudinal changes of laboratory findings may be helpful in predicting disease progression and clinical outcome of severe patients.

Risk factors for severe and critically ill COVID-19 patients: A review.

The pandemic of coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has caused an unprecedented global social and economic impact, and high numbers of deaths. Many risk factors have been identified in the progression of COVID-19 into a severe and critical stage, including old age, male gender, underlying comorbidities such as hypertension, diabetes, obesity, chronic lung diseases, heart, liver and kidney diseases, tumors, clinically apparent immunodeficiencies, local immunodeficiencies, such as early type I interferon secretion capacity, and pregnancy. Possible complications include acute kidney injury, coagulation disorders, thoromboembolism. The development of lymphopenia and eosinopenia are laboratory indicators of COVID-19. Laboratory parameters to monitor disease progression include lactate dehydrogenase, procalcitonin, high-sensitivity C-reactive protein, proinflammatory cytokines such as interleukin (IL)-6, IL-1ß, Krebs von den Lungen-6 (KL-6), and ferritin. The development of a cytokine storm and extensive chest computed tomography imaging patterns are indicators of a severe disease. In addition, socioeconomic status, diet, lifestyle, geographical differences, ethnicity, exposed viral load, day of initiation of treatment, and quality of health care have been reported to influence individual outcomes. In this review, we highlight the scientific evidence on the risk factors of severity of COVID-19.

Eleven faces of coronavirus disease 2019.

BACKGROUND AND AIMS: The outbreak of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has recently spread worldwide and been declared a pandemic. We aim to describe here the various clinical presentations of this disease by examining eleven cases. METHODS: Electronic medical records of 11 patients with COVID-19 were collected, and demographics, clinical manifestations, outcomes, key laboratory results, and radiological images are discussed. RESULTS: The clinical course of the eleven cases demonstrated the complexity of the COVID-19 profile with different clinical presentations. Clinical manifestations range from asymptomatic cases to patients with mild and severe symptoms, with or without pneumonia. Laboratory detection of the viral nucleic acid can yield false-negative results, and serological testing of virus-specific IgG and IgM antibodies should be used as an alternative for diagnosis. Patients with common allergic diseases did not develop distinct symptoms and severe courses. Cases with a pre-existing condition of chronic obstructive pulmonary disease or complicated with a secondary bacterial pneumonia were more severe. CONCLUSION: All different clinical characteristics of COVID-19 should be taken into consideration to identify patients that need to be in strict quarantine for the efficient containment of the pandemic.

Clinical characteristics of 140 patients infected with SARS-CoV-2 in Wuhan, China.

BACKGROUND: Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has been widely spread. We aim to investigate the clinical characteristic and allergy status of patients infected with SARS-CoV-2. METHODS: Electronic medical records including demographics, clinical manifestation, comorbidities, laboratory data, and radiological materials of 140 hospitalized COVID-19 patients, with confirmed result of SARS-CoV-2 viral infection, were extracted and analyzed. RESULTS: An approximately 1:1 ratio of male (50.7%) and female COVID-19 patients was found, with an overall median age of 57.0 years. All patients were community-acquired cases. Fever (91.7%), cough (75.0%), fatigue (75.0%), and gastrointestinal symptoms (39.6%) were the most common clinical manifestations, whereas hypertension (30.0%) and diabetes mellitus (12.1%) were the most common comorbidities. Drug hypersensitivity (11.4%) and urticaria (1.4%) were self-reported by several patients. Asthma or other allergic diseases were not reported by any of the patients. Chronic obstructive pulmonary disease (COPD, 1.4%) patients and current smokers (1.4%) were rare. Bilateral ground-glass or patchy opacity (89.6%) was the most common sign of radiological finding. Lymphopenia (75.4%) and eosinopenia (52.9%) were observed in most patients. Blood eosinophil counts correlate positively with lymphocyte counts in severe (r = .486, P < .001) and nonsevere (r = .469, P < .001) patients after hospital admission. Significantly higher levels of D-dimer, C-reactive protein, and procalcitonin were associated with severe patients compared to nonsevere patients (all P < .001). CONCLUSION: Detailed clinical investigation of 140 hospitalized COVID-19 cases suggests eosinopenia together with lymphopenia may be a potential indicator for diagnosis. Allergic diseases, asthma, and COPD are not risk factors for SARS-CoV-2 infection. Older age, high number of comorbidities, and more prominent laboratory abnormalities were associated with severe patients.

Advances and recent developments in asthma in 2020.

In this review, we discuss recent publications on asthma and review the studies that have reported on the different aspects of the prevalence, risk factors and prevention, mechanisms, diagnosis, and treatment of asthma. Many risk and protective factors and molecular mechanisms are involved in the development of asthma. Emerging concepts and challenges in implementing the exposome paradigm and its application in allergic diseases and asthma are reviewed, including genetic and epigenetic factors, microbial dysbiosis, and environmental exposure, particularly to indoor and outdoor substances. The most relevant experimental studies further advancing the understanding of molecular and immune mechanisms with potential new targets for the development of therapeutics are discussed. A reliable diagnosis of asthma, disease endotyping, and monitoring its severity are of great importance in the management of asthma. Correct evaluation and management of asthma comorbidity/multimorbidity, including interaction with asthma phenotypes and its value for the precision medicine approach and validation of predictive biomarkers, are further detailed. Novel approaches and strategies in asthma treatment linked to mechanisms and endotypes of asthma, particularly biologicals, are critically appraised. Finally, due to the recent pandemics and its impact on patient management, we discuss the challenges, relationships, and molecular mechanisms between asthma, allergies, SARS-CoV-2, and COVID-19.

A compendium answering 150 questions on COVID-19 and SARS-CoV-2.

In December 2019, China reported the first cases of the coronavirus disease 2019 (COVID-19). This disease, caused by the severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2), has developed into a pandemic. To date, it has resulted in ~9 million confirmed cases and caused almost 500 000 related deaths worldwide. Unequivocally, the COVID-19 pandemic is the gravest health and socioeconomic crisis of our time. In this context, numerous questions have emerged in demand of basic scientific information and evidence-based medical advice on SARS-CoV-2 and COVID-19. Although the majority of the patients show a very mild, self-limiting viral respiratory disease, many clinical manifestations in severe patients are unique to COVID-19, such as severe lymphopenia and eosinopenia, extensive pneumonia, a "cytokine storm" leading to acute respiratory distress syndrome, endothelitis, thromboembolic complications, and multiorgan failure. The epidemiologic features of COVID-19 are distinctive and have changed throughout the pandemic. Vaccine and drug development studies and clinical trials are rapidly growing at an unprecedented speed. However, basic and clinical research on COVID-19-related topics should be based on more coordinated high-quality studies. This paper answers pressing questions, formulated by young clinicians and scientists, on SARS-CoV-2, COVID-19, and allergy, focusing on the following topics: virology, immunology, diagnosis, management of patients with allergic disease and asthma, treatment, clinical trials, drug discovery, vaccine development, and epidemiology. A total of 150 questions were answered by experts in the field providing a comprehensive and practical overview of COVID-19 and allergic disease.

Exchange protein directly activated by cAMP (Epac) protects against airway inflammation and airway remodeling in asthmatic mice.

BACKGROUND: ß2 receptor agonists induce airway smooth muscle relaxation by increasing intracellular cAMP production. PKA is the traditional downstream signaling pathway of cAMP. Exchange protein directly activated by cAMP (Epac) was identified as another important signaling molecule of cAMP recently. The role of Epac in asthmatic airway inflammation and airway remodeling is unclear. METHODS: We established OVA-sensitized and -challenged acute and chronic asthma mice models to explore the expression of Epac at first. Then, airway inflammation and airway hyperresponsiveness in acute asthma mice model and airway remodeling in chronic asthma mice model were observed respectively after treatment with Epac-selective cAMP analogue 8-pCPT-2'-O-Me-cAMP (8pCPT) and Epac inhibitor ESI-09. Next, the effects of 8pCPT and ESI-09 on the proliferation and apoptosis of in vitro cultured mouse airway smooth muscle cells (ASMCs) were detected with CCK-8 assays and Annexin-V staining. Lastly, the effects of 8pCPT and ESI-09 on store-operated Ca2+ entry (SOCE) of ASMCs were examined by confocal Ca2+ fluorescence measurement. RESULTS: We found that in lung tissues of acute and chronic asthma mice models, both mRNA and protein expression of Epac1 and Epac2, two isoforms of Epac, were lower than that of control mice. In acute asthma mice model, the airway inflammatory cell infiltration, Th2 cytokines secretion and airway hyperresponsiveness were significantly attenuated by 8pCPT and aggravated by ESI-09. In chronic asthma mice model, 8pCPT decreased airway inflammatory cell infiltration and airway remodeling indexes such as collagen deposition and airway smooth muscle cell proliferation, while ESI-09 increased airway inflammation and airway remodeling. In vitro cultured mice ASMCs, 8pCPT dose-dependently inhibited, whereas ESI-09 promoted ASMCs proliferation. Interestingly, 8pCPT promoted the apoptosis of ASMCs, whereas ESI-09 had no effect on ASMCs apoptosis. Lastly, confocal Ca2+ fluorescence examination found that 8pCPT could inhibit SOCE in ASMCs at 100 µM, and ESI-09 promoted SOCE of ASMCs at 10 µM and 100 µM. In addition, the promoting effect of ESI-09 on ASMCs proliferation was inhibited by store-operated Ca2+ channel blocker, SKF-96365. CONCLUSIONS: Our results suggest that Epac has a protecting effect on asthmatic airway inflammation and airway remodeling, and Epac reduces ASMCs proliferation by inhibiting SOCE in part.

Comparison of diagnostic efficacy between CLE, tissue sampling, and CLE combined with tissue sampling for undetermined pancreaticobiliary strictures: a meta-analysis.

OBJECTIVE: The accurate diagnosis of undetermined pancreaticobiliary strictures remains challenging. Current ERCP-guided tissue sampling methods are of low sensitivity. Confocal laser endomicroscopy (CLE) is a new procedure and allows real optical biopsies that may improve the diagnosis of undetermined pancreaticobiliary strictures. The aim of this meta-analysis was to determine the diagnostic yield of CLE, tissue sampling, and CLE combined with tissue sampling for undetermined pancreaticobiliary strictures. METHOD: Pubmed, Embase, and the Cochrane Library database were reviewed for relevant studies. Pooled estimates of sensitivity and specificity with 95% confidence intervals (CIs) were calculated using the random-effects meta-analysis model. The summary receiver-operating characteristic (SROC) curve was constructed, and the area under the receiver operating characteristic curve (AUC) was calculated. RESULTS: Twelve studies involving 591 patients were enrolled in our analysis. The overall sensitivity and the specificity estimate of CLE for discriminating benign and malignant pancreaticobiliary strictures were 87% (95%CI, 83-91%) and 76% (95%CI, 70-81%), respectively. The AUC to assess the diagnostic efficacy was 0.8705. For tissue sampling, the overall sensitivity and the specificity estimate were 64% (95%CI, 57-70%) and 94% (95%CI, 90-97%), respectively. The AUC to assess the diagnostic efficacy was 0.8040. A combination of both methods increased the sensitivity (93%; 95%CI, 88-96%) with a specificity of 82% (95%CI, 74-89%). The AUC to assess the diagnostic efficacy was 0.9377. There was no publication bias by Deeks' Funnel Plot with p = .936. CONCLUSIONS: Compared with tissue sampling, CLE may increase the sensitivity for the diagnosis of malignant pancreaticobiliary strictures. A combination of both can effectively diagnose malignant pancreaticobiliary strictures.

Endobronchial one-way valves for treatment of persistent air leaks: a systematic review.

Persistent air leak (PAL) is associated with significant morbidity and mortality, prolonged hospitalization and increased health-care costs. It can arise from a number of conditions, including pneumothorax, necrotizing infection, trauma, malignancies, procedural interventions and complications after thoracic surgery. Numerous therapeutic options, including noninvasive and invasive techniques, are available to treat PALs. Recently, endobronchial one-way valves have been used to treat PAL. We conducted a systematic review based on studies retrieved from PubMed, EMbase and Cochrane library. We also did a hand-search in the bibliographies of relevant articles for additional studies. 34 case reports and 10 case series comprising 208 patients were included in our review. Only 4 patients were children, most of the patients were males. The most common underlying disease was COPD, emphysema and cancer. The most remarkable cause was pneumothorax. The upper lobes were the most frequent locations of air leaks. Complete resolution was gained within less than 24 h in majority of patients. Complications were migration or expectoration of valves, moderate oxygen desaturation and infection of related lung. No death related to endobronchial one-way valves implantation has been found. The use of endobronchial one-way valve adds to the armamentarium for non-invasive treatments of challenging PAL, especially those with difficulties of anesthesia, poor condition and high morbidity. Nevertheless, prospective randomized control trials with large sample should be needed to further evaluate the effects and safety of endobronchial one-way valve implantation in the treatment of PAL.

Th2 cytokine-primed airway smooth muscle cells induce mast cell chemotaxis via secretion of ATP.

OBJECTIVE: Mast cell infiltration into airway smooth muscle (ASM) bundle is an important feature of asthma. Extracellular adenosine triphosphate (eATP) contributes to the initiation of airway inflammation. eATP induces mast cells migration by acting through purinergic receptors. CD39 is an ectonucleotidase that degrades ATP to ADP and AMP. Whether eATP participates in the migration of mast cell towards ASM cells is still unknown. METHODS: Airway smooth muscle cells (ASMCs) were isolated from C57/BL6J mice sensitized and challenged with OVA. ASMCs were in vitro cultured and stimulated with IL-4 + IL-13 in the presence or absence of exogenous CD39 or CD39 inhibitor ARL67156. ATP level in the supernatants was measured with ATP content determination kit. CXCL10 concentration in the ASMCs supernatants was measured by ELISA, the mRNA expression of CXCL10 in ASMCs was determined with real-time PCR. Human mast cell line HMC-1 was cultured in Iscove's-Modified Dubecco's Medium. The expression of CXCR3 in HMC-1 cells was determined with flow cytometry and real-time PCR, respectively. HMC-1 migration rates were determined with transwell system. RESULTS: In the supernatants of Th2 cytokine-stimulated ASMCs, ATP level was higher than that without stimulation. CD39 decreased, whereas ARL67156 increased ATP level in the supernatants. Both ATP and the supernatants of Th2 cytokine-stimulated ASMCs induced migration of HMC-1 cells. The surface and mRNA expression of CXCR3 in HMC-1 cells, and the mRNA expression and secretion of CXCL10 in ASMCs were increased after stimulation with ATP or Th2 cytokines. All these effects were partially inhibited by CD39. CONCLUSION: Our data suggested ASMCs in the asthma microenvironment promoted the migration of mast cells via secretion of ATP and the expression of CXCL10/CXCR3 axis. CD39 could reverse this effect and may be a new target for the treatment of asthma.

Biocatalytic Hydrogen-Borrowing Cascade in Organic Synthesis.

Biocatalytic hydrogen borrowing represents an environmentally friendly and highly efficient synthetic method. This innovative approach involves converting various substrates into high-value-added products, typically via a one-pot, two/three-step sequence encompassing dehydrogenation (intermediate transformation) and hydrogenation processes employing the hydride shuffling between NAD(P)+ and NAD(P)H. Represented key transformations in hydrogen borrowing include stereoisomer conversion within alcohols, conversion between alcohols and amines, conversion of allylic alcohols to saturated carbonyl counterparts, and α,ß-unsaturated aldehydes to saturated carboxylic acids, etc. The direct transformation methodology and environmentally benign characteristics of hydrogen borrowing have contributed to its advancements in fine chemical synthesis or drug developments. Over the past decades, the hydrogen borrowing strategy in biocatalysis has led to the creation of diverse catalytic systems, demonstrating substantial potential for straightforward synthesis as well as asymmetric transformations. This perspective serves as a detailed exposition of the recent advancements in biocatalytic reactions employing the hydrogen borrowing strategy. It provides insights into the potential of this approach for future development, shedding light on its promising prospects in the field of biocatalysis.