How does particulate air pollution affect barrier functions and inflammatory activity of lung vascular endothelium?

Both particulate matter and gaseous components of air pollution have already been shown to increase cardiovascular mortality in numerous studies. It is, however, important to note that on their way to the bloodstream the polluting agents pass the lung barrier. Inside the alveoli, particles of approximately 0.4-1 µm are most efficiently deposited and commonly undergo phagocytosis by lung macrophages. Not only the soluble agents, but also particles fine enough to leave the alveoli enter the bloodstream in this finite part of the endothelium, reaching thus higher concentrations in close proximity of the alveoli and endothelium. Additionally, deposits of particulate matter linger in direct proximity of the endothelial cells and may induce inflammation, immune responses, and influence endothelial barrier dysfunction thus increasing PM bioavailability in positive feedback. The presented discussion provides an overview of possible components of indoor PM and how endothelium is thus influenced, with emphasis on lung vascular endothelium and clinical perspectives.

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.

Is Atopic Dermatitis Only a Skin Disease?

Atopic dermatitis (AD) is a chronic, pruritic, inflammatory dermatosis that imposes significant patient and population burdens. In addition to the cutaneous signs and symptoms, growing evidence suggests that AD is systemic in nature. Certain diseases can possibly co-occur with AD as a result of coincidental exposure to similar environmental factors. However, it is also suspected that they are linked to the pathogenesis of AD through more complex genetic and immunological mechanisms, but these correlations remain less understood. It is of great need to seek explanations for the higher frequency of the number of cardiovascular, autoimmune, neurological, psychiatric, and metabolic disorders that have been observed in epidemiologic investigations among AD patients. Moreover, analysing the immunology of chronic inflammation and its correction, activation, or suppression may prevent the development of a variety of comorbidities. As comorbid diseases in patients diagnosed with AD may potentially go undetected, physicians should be aware of them.

Evaluation of the Continuous Positive Airway Pressure Effect on Neurotrophins' Gene Expression and Protein Levels.

Neurotrophins (NT) might be associated with the pathophysiology of obstructive sleep apnea (OSA) due to concurrent intermittent hypoxia and sleep fragmentation. Such a relationship could have implications for the health and overall well-being of patients; however, the literature on this subject is sparse. This study investigated the alterations in the serum protein concentration and the mRNA expression of the brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF), neurotrophin-3 (NTF3), and neurotrophin-4 (NTF4) proteins following a single night of continuous positive airway pressure (CPAP) therapy. This study group consisted of 30 patients with OSA. Venous blood was collected twice after a diagnostic polysomnography (PSG) and PSG with CPAP treatment. Gene expression was assessed with a quantitative real-time polymerase chain reaction. An enzyme-linked immunosorbent assay was used to determine the protein concentrations. After CPAP treatment, BDNF, proBDNF, GDNF, and NTF4 protein levels decreased (p = 0.002, p = 0.003, p = 0.047, and p = 0.009, respectively), while NTF3 increased (p = 0.001). Sleep latency was correlated with ΔPSG + CPAP/PSG gene expression for BDNF (R = 0.387, p = 0.038), NTF3 (R = 0.440, p = 0.019), and NTF4 (R = 0.424, p = 0.025). OSA severity parameters were not associated with protein levels or gene expressions. CPAP therapy could have an impact on the posttranscriptional stages of NT synthesis. The expression of different NTs appears to be connected with sleep architecture but not with OSA severity.

Accumulation of Deleterious Effects in Gastric Epithelial Cells and Vascular Endothelial Cells In Vitro in the Milieu of Helicobacter pylori Components, 7-Ketocholesterol and Acetylsalicylic Acid.

The Gastric pathogen Helicobacter pylori (HP) may influence the development of coronary heart disease (CHD). H. pylori induce reactive oxygen species (ROS), which transform cholesterol to 7-ketocholesterol (7-kCh), a CHD risk factor. Acetylsalicylic acid (ASA)-an Anti-aggregation drug used in CHD patients-may increase gastric bleeding and inflammation. We examined whether H. pylori driven ROS effects in the cell cultures of gastric epithelial cells (AGS) and vascular endothelial cells (HUVEC) progress in the milieu of 7-kCh and ASA. Cell cultures, exposed to 7-kCh or ASA alone or pulsed with the H. pylori antigenic complex-Glycine acid extract (GE), urease (UreA), cytotoxin associated gene A (CagA) protein or lipopolysaccharide (LPS), alone or with 7-kCh and ASA-were examined for ROS, apoptosis, cell integrity, interleukin (IL)-8, the activation of signal transducer, the activator of transcription 3 (STAT3), and wound healing. ASA and 7-kCh alone, and particularly in conjunction with H. pylori components, increased the ROS level and the rate of apoptosis, which was followed by cell disintegration, the activation of STAT3, and IL-8 elevation. AGS cells were unable to undergo wound healing. The cell ROS response to H. pylori components may be elevated by 7-kCh and ASA.

The relationship between human coronaviruses, asthma and allergy-An unresolved dilemma.

Human coronaviruses (HCoVs) such as HCoV-229E or OC43 are responsible for mild upper airway infections, whereas highly pathogenic HCoVs, including SARS-CoV, MERS-CoV and SARS-CoV-2, often evoke acute, heavy pneumonias. They tend to induce immune responses based on interferon and host inflammatory cytokine production and promotion of T1 immune profile. Less is known about their effect on T2-type immunity. Unlike human rhinoviruses (HRV) and Respiratory Syncytial Virus (RSV), HCoVs are not considered as a dominant risk factor of severe exacerbations of asthma, mostly T2-type chronic inflammatory disease. The relationship between coronaviruses and T2-type immunity, especially in asthma and allergy, is not well understood. This review aims to summarize currently available knowledge about the relationship of HCoVs, including novel SARS-CoV-2, with asthma and allergic inflammation.

Toll-Like Receptor Agonists Modulate Wound Regeneration in Airway Epithelial Cells.

BACKGROUND: Impaired regeneration of airway epithelium may lead to persistence of inflammation and remodelling. Regeneration of injured epithelium is a complex phenomenon and the role of toll-like receptors (TLRs) in the stimulation of respiratory virus products in this process has not been established. OBJECTIVE: This study was undertaken to test the hypothesis that the wound repair process in airway epithelium is modulated by microbial products via toll-like receptors. METHODS: Injured and not-injured bronchial epithelial cells (ECs) (BEAS-2B line) were incubated with the TLR agonists poly(I:C), lipopolisacharide (LPS), allergen Der p1, and supernatants from virus-infected epithelial cells, either alone or in combination with TLR inhibitors. Regeneration and immune response in injured and not-injured cells were studied. RESULTS: Addition of either poly(I:C) or LPS to ECs induced a marked inhibition of wound repair. Supernatants from RV1b-infected cells also decreased regeneration. Preincubation of injured and not-injured ECs with TLR inhibitors decreased LPS and poly(I:C)-induced repair inhibition. TGF-ß and RANTES mRNA expression was higher in injured ECs and IFN-α, IFN-ß, IL-8, and VEGF mRNA expression was lower in damaged epithelium as compared to not-injured. Stimulation with poly(I:C) increased IFN-α and IFN-ß mRNA expression in injured cells, and LPS stimulation decreased interferons mRNA expression both in not-injured and injured ECs. CONCLUSION: Regeneration of the airway epithelium is modulated by microbial products via toll-like receptors.

Endothelial integrity may be regulated by a specific antigen via an IgE-mediated mechanism.

BACKGROUND: Human vascular endothelial function and integrity may be regulated by many non-specific factors. However, the potential influence of specific antigens via an IgE-mediated mechanism remains unknown. The aim of the study was to determine the expression of the IgE receptors FcεRI and FcεRII in the human vascular endothelium and to assess their relevance in the IgE-mediated regulation of endothelial integrity. MATERIAL/METHODS: FcεRI and FcεRII expression in human umbilical vein endothelial cells (HUVEC) was genetically assessed by PCR with respective primers and sequencing. HUVEC were cultured with IL-4, and changes in FcεRI and FcεRII mRNA expression were analyzed by real-time PCR. Changes in the integrity of endothelium pre-treated with anti-BSA-DNP IgE following exposure to the specific BSA-DNP antigen was assessed using the Real-time Cell Electric Impedance Sensing system (RTCA-DP). RESULTS: PCR and sequencing revealed the expression of FcεRI and FcεRII receptors in the human vascular endothelium. IL-4 caused respective 2- and 3-fold increases in FcεRI and FcεRII mRNA expression. Exposure of endothelium pre-treated with anti-BSA-DNP IgE to specific BSA-DNP antigen led to a 20% increase of endothelial integrity (p<0.05) after 24 hours, but only in cells pre-incubated with IL-4. CONCLUSIONS: The presence of FcεRI and FcεRII may allow the human vascular endothelium to respond to a specific antigen by increasing its integrity via an IgE-mediated mechanism.

Human lung vascular endothelium may limit infection with HRV16 via IFN-ß-dependent mechanisms.

Human rhinovirus 16 (HRV16) may induce inflammatory and antiviral responses in the human lung vascular endothelium (ECs) and impair its barrier functions after infection. However, ECs may regain barrier and metabolic functions. Mechanisms of limitation of HRV16 infection in the lung vascular endothelium are unknown. Human lung vascular endothelium (HMVEC-L) was infected with HRV16. IFN-ß, OAS-1, and PKR expression was assessed by real-time PCR, flow cytometry, and confocal microscope. To prove the significance of IFN-ß in the limitation of HRV16 replication, HMVEC-Ls were preincubated with anti-IFN-ß Abs. To prove the involvement of OAS-1 and PKR in the IFN-dependent limitation of HRV16 replication, HMVEC-Ls were transfected with respective siRNA. HRV16 stimulated IFN-ß production and activated intracellular mechanisms of antiviral immunity based on OAS-1 and PKR activation. Blocking of IFN-ß contributed to the inhibition of intracellular mechanisms of antiviral immunity (OAS-1, PKR) and boosted replication of HRV16. Effective OAS-1 silencing by siRNA caused the increase of HRV16 copy numbers after HRV16 infection. siRNA upregulated the other genes related to the antiviral response. The infected lung vascular endothelium may limit the HRV16 infection. This limitation may be associated with the induction of IFN-ß-dependent intracellular mechanisms based on OAS-1 and PKR activity.

The effect of 7-ketocholesterol and 25-hydroxycholesterol on the integrity of the human aortic endothelial and intestinal epithelial barriers.

OBJECTIVE AND DESIGN: The damage of barrtier tissues, such as the vascular endothelium and intestinal epithelium, may lead to disturbances of local immune homeostasis. The aim of the study was to assess and compare the effect of oxidized cholesterols (7-ketocholesterol and 25-hydroxycholesterol) on the barrier properties of human primary aortic endothelium (HAEC) and intestinal epithelium Caco-2 cells using a realtime cell electric impedance sensing system (RTCA-DP). MATERIALS AND METHODS: HAEC and Caco-2 cells were stimulated with 7-ketocholesterol and 25-hydroxycholesterol by the RTCA-DP system. Apoptosis was assessed by flow cytometry and cell monolayer morphology was assessed under a light microscope. RESULTS: 7-ketocholesterol decreased impedance (nCI) in both the endothelium and epithelium. However, the decrease was more profound in the endothelium. Similarly, although 25-hydroxycholesterol decreased nCI in both the endothelium and epithelium, the effect was weaker than that of 7-ketocholesterol, which caused extensive damage to the endothelial monolayer, while 25-hydroxycholesterol caused partial damage and did not affect the epithelial monolayer. 7-ketocholesterol, but not 25-hydroxycholesterol, increased endothelial cell apoptosis and decreased the viability of endothelial cells. However, 7-ketocholesterol and 25-hydroxycholesterol decreased epithelial cell apoptosis and increased viability. CONCLUSION: Oxidized cholesterols destroy the HAEC, but not the Caco-2 epithelial barrier, via cell apoptosis dependent on the site of oxidation. Damage to the endothelium by oxidized cholesterol may disrupt local homeostasis and provide open access to inner parts of the vascular wall for lipids, other peripheral blood-derived agents, and immune cells, leading to inflammation and atherogenesis.

Inhibition of angiogenesis by IL-32: possible role in asthma.

BACKGROUND: IL-32 is a proinflammatory cytokine involved in various chronic inflammatory diseases. Chronic airway inflammation in asthmatic patients results in structural airway changes, including angiogenesis. Vascular endothelial growth factor (VEGF) is a key inducer of angiogenesis in the airways of asthmatic patients. OBJECTIVE: The aim of the study was to investigate the expression and function of IL-32 in patients with angiogenesis and asthma. METHODS: The expression and regulation of IL-32 in normal human bronchial epithelial (NHBE) cells was analyzed by using RT-PCR, ELISA, Western blotting, immunofluorescent staining, and flow cytometry. After knockdown of IL-32 in NHBE cells by small interfering RNA (siRNA) transfections, VEGF secretion was quantified by means of ELISA. New blood vessel formation was determined with human umbilical vein endothelial cells by culturing with supernatants from IL-32 siRNA-transfected NHBE cells. IL-32 was determined in serum and induced sputum samples of asthmatic patients and healthy control subjects by means of ELISA. RESULTS: IL-32 is expressed in NHBE cells on stimulation with IFN-γ, TNF-α, T(H)1 cells, and rhinovirus. Inhibition of IL-32 expression resulted in significantly increased secretion of the proangiogenic factors VEGF and platelet-derived growth factor by NHBE cells. Human umbilical vein endothelial cells cultured in supernatants from IL-32 siRNA-transfected NHBE cells showed enhanced in vitro angiogenesis. IL-32 is detectable in induced sputum from asthmatic patients. IL-32 serum levels were significantly higher in asthmatic patients compared with those seen in healthy control subjects and correlated with response to asthma treatment. CONCLUSION: IL-32 is induced by IFN-γ, TNF-α, T(H)1 cells, and rhinovirus in bronchial epithelial cells. It inhibits angiogenesis, and its serum levels are associated with a good treatment response in asthmatic patients.

miRNA expression in serum and PBMCs isolated from middle-aged and elderly patients during asthma exacerbation.

microRNAs are short, noncoding RNA molecules involved in many inflammatory processes including bronchial asthma. Rhinoviruses are the main cause of acute asthma attack and may be involved in miRNA profile dysregulation. The aim of the study was to investigate the serum miRNA profile during asthma exacerbation in middle-aged and elderly patients. We also evaluated in this group in vitro response to rhinovirus 1b exposure. Seventeen middle-aged and elderly asthmatics were admitted to an outpatient clinic during asthma exacerbation and within a period of 6-8 weeks later. Blood samples were collected from the subjects and PBMCs were isolated. Cells were cultured in the presence of Rhinovirus 1b and with the medium only, and, after 48 h. miRNA expression (miRNA-19b, -106a, 126a, and -146a) isolated from serum and PBMCs (cultures) was evaluated with RT-PCR. Cytokines (INF-γ, TNF-α, IL6, and Il-10) in culture supernatants were evaluated with flow cytometry. On exacerbation visit patients demonstrated higher expression of serum miRNA-126a and -146a as compared to follow-up visit. There was a positive correlation between asthma control test results and miRNA-19, -126a, -146a. There was no other significant association between patient characteristics and the miRNA profile. Rhinovirus exposure did not changed miRNA expression in PBMCs as compared to medium on both visits. Cytokine production in culture supernatants significantly increased after rhinovirus infection. The group of middle-aged and elderly patients demonstrated changed levels serum miRNA during asthma exacerbation as compared to follow-up visit; however, correlations between their expression and clinical features were hardly noticeable. Rhinovirus did not affect expression of miRNA in PBMCs; yet, it induced cytokine production.

Short-term supplementation with Aronia melanocarpa extract improves platelet aggregation, clotting, and fibrinolysis in patients with metabolic syndrome.

PURPOSE: A diet rich in berries is believed to play a distinct role in the prevention of metabolic diseases associated with obesity. So far, there have been no published clinical observations evaluating the influence of Aronia melanocarpa on hemostasis. The aim of our study was to investigate the effects of A. melanocarpa extract (AM) supplementation on platelet aggregation, clot formation, and lysis in patients with metabolic syndrome (MS). METHODS: Middle-aged non-medicated subjects with MS (n = 38) and 14 healthy volunteers were included in this study. Patients with MS were treated with 100 mg of AM three times daily for 2 months. RESULTS: We observed a significant reduction in the concentration of TC, LDL-C, and TG after AM supplementation. Beneficial changes in coagulation parameters were also observed. After 1 month of AM administration, we noticed significant inhibition of platelet aggregation. However, this effect became less pronounced after 2 months of supplementation. In the case of coagulation induced by endogenic thrombin, a significant decrease in the overall potential for coagulation was induced after 1 or 2 months of supplementation. Moreover, after 1 month of AM extract supplementation, we observed a beneficial reduction in the overall potential for clot formation and fibrinolysis. CONCLUSIONS: We observed the normalization of hemostasis parameters in MS patients after both 1 and 2 months of AM administration. After 1 month of AM supplementation, we found favorable changes in regards to the overall potential for plasma clotting, clot formation, and lysis, as well as in the lipid profiles of subjects.