In vitro study of regulation of IL-6 production in bronchiectasis

Extract of Cimicifuga racemosa (L.) Nutt protects ovarian follicle reserve of mice against in vitro deleterious effects of dexamethasone

The present study aims to investigate if Cimicifuga racemosa (L.) Nutt extract (CIMI) reduces deleterious effects of dexamethasone (DEXA) in ovaries cultured in vitro. Mouse ovaries were collected and cultured in DMEM+ only or supplemented with 5 ng/mL of CIMI, or 4 ng/mL DEXA, or both CIMI and DEXA. The ovaries were cultured at 37.5°C in 5% CO2 for 6 days. Ovarian morphology, follicular ultrastructure, and the levels of mRNA for Bax, Bcl-2, and Caspase-3 were evaluated. The results showed that DEXA reduced the percentage of morphologically normal follicles, while CIMI prevented the deleterious effects caused by DEXA. In addition, DEXA negatively affected the stromal cellular density, while CIMI prevented these adverse effects. Ovaries cultured with DEXA and CIMI showed similar levels of mRNA for Bax, Bcl-2, and Caspase-3 compared to those cultured in control medium, while ovaries cultured with DEXA had increased expression of the above genes. Additionally, the ultrastructure of the ovaries cultured with CIMI was well preserved. Thus, the extract of CIMI was able to prevent the deleterious effects caused by DEXA on cultured mouse ovaries.

Intracellular replication of Inquilinus limosus in bronchial epithelial cells

Inquilinus limosus is an emerging multi-resistant opportunistic pathogen documented mainly in cystic fibrosis patients. Infection with I. limosus is accompanied by either an acute respiratory exacerbation or a progressive loss of pulmonary function. This study examined the interaction of Inquilinus limosus with the bronquial human epithelial cell line 16HBE14o^-. Almost 100% of the bacteria that attached to the bronquial cells were found internalized and located in acidic LAMP2 positive compartments. According to confocal studies combined with antibiotic protection assays, I. limosus is able to survive and eventually replicate in these compartments. I. limosus was found nontoxic to cells and did not induce neither IL-6 nor IL-8 cytokine production, a characteristic that may help the bacteria to evade host immune response. Overall, this study indicates that I. limosus displays pathogenic properties based on its ability to survive intracellularly in epithelial cells eventually leading to antibiotic failure and chronic infection.

Santos C, Baião RA, Costa J, Ferreira JJ, Caldeira D. Risk of SARS-CoV-2 Infection and COVID-19 Severity Associated With Exposure to Nonsteroidal Anti-Inflammatory Drugs: Systematic Review and Meta-Analysis

Nonsteroidal anti-inflammatory drugs (NSAIDs) were thought to increase the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus entrance into cells. Hence, it was suggested in the media that NSAIDs could lead to a higher risk of infection and/or disease severity. To determine the existence or absence of this association, we aimed to systematically evaluate the risk of SARS-CoV-2 infection and mortality and the risk of severe coronavirus disease 2019 (COVID-19) associated with previous exposure to NSAIDs. MEDLINE, Cochrane Central Register of Controlled Trials (CENTRAL), and EMBASE were searched in February 2021 for controlled studies. The results were calculated through random-effect meta-analyses and reported in terms of odds ratios (ORs) with 95% confidence intervals (CIs). Heterogeneity was assessed with I2 test. Eleven studies were included, comprising a total of 683 715 patients. NSAID exposure did not increase the risk of having a positive test for SARS-CoV-2 infection (OR, 0.97; 95%CI, 0.85-1.11, I2 = 24%; 5 studies). The exposure to NSAIDs did not increase the risk of severe/critical COVID-19 disease (OR, 0.92; 95%CI, 0.80-1.05; I2 = 0%; 5 studies) nor all-cause mortality among patients with COVID-19 (OR, 0.86; 95%CI, 0.75-0.99; I2 = 14%, 4 studies). Our data did not suggest that exposure to NSAIDs increases the risk of having SARS-CoV-2 infection or increases the severity of COVID-19 disease. Also, the fragility of the studies included precludes definite conclusions and highlights the need for further robust data.

Non-steroidal anti-inflammatory drug use and outcomes of COVID-19 in the ISARIC Clinical Characterisation Protocol UK cohort: a matched, prospective cohort study

BACKGROUND

Early in the pandemic it was suggested that pre-existing use of non-steroidal anti-inflammatory drugs (NSAIDs) could lead to increased disease severity in patients with COVID-19. NSAIDs are an important analgesic, particularly in those with rheumatological disease, and are widely available to the general public without prescription. Evidence from community studies, administrative data, and small studies of hospitalised patients suggest NSAIDs are not associated with poorer COVID-19 outcomes. We aimed to characterise the safety of NSAIDs and identify whether pre-existing NSAID use was associated with increased severity of COVID-19 disease.

METHODS

This prospective, multicentre cohort study included patients of any age admitted to hospital with a confirmed or highly suspected SARS-CoV-2 infection leading to COVID-19 between Jan 17 and Aug 10, 2020. The primary outcome was in-hospital mortality, and secondary outcomes were disease severity at presentation, admission to critical care, receipt of invasive ventilation, receipt of non-invasive ventilation, use of supplementary oxygen, and acute kidney injury. NSAID use was required to be within the 2 weeks before hospital admission. We used logistic regression to estimate the effects of NSAIDs and adjust for confounding variables. We used propensity score matching to further estimate effects of NSAIDS while accounting for covariate differences in populations.

RESULTS

Between Jan 17 and Aug 10, 2020, we enrolled 78 674 patients across 255 health-care facilities in England, Scotland, and Wales. 72 179 patients had death outcomes available for matching; 40 406 (56·2%) of 71 915 were men, 31 509 (43·8%) were women. In this cohort, 4211 (5·8%) patients were recorded as taking systemic NSAIDs before admission to hospital. Following propensity score matching, balanced groups of NSAIDs users and NSAIDs non-users were obtained (4205 patients in each group). At hospital admission, we observed no significant differences in severity between exposure groups. After adjusting for explanatory variables, NSAID use was not associated with worse in-hospital mortality (matched OR 0·95, 95% CI 0·84-1·07; p=0·35), critical care admission (1·01, 0·87-1·17; p=0·89), requirement for invasive ventilation (0·96, 0·80-1·17; p=0·69), requirement for non-invasive ventilation (1·12, 0·96-1·32; p=0·14), requirement for oxygen (1·00, 0·89-1·12; p=0·97), or occurrence of acute kidney injury (1·08, 0·92-1·26; p=0·33).

INTERPRETATION

NSAID use is not associated with higher mortality or increased severity of COVID-19. Policy makers should consider reviewing issued advice around NSAID prescribing and COVID-19 severity.

FUNDING

National Institute for Health Research and Medical Research Council.

Effects of triptolide and methotrexate nanosuspensions on left ventricular remodeling in autoimmune myocarditis rats

Purpose

This study was carried out to investigate the effects of a triptolide (TP) nanosuspension and methotrexate (MTX) nanosuspension on left ventricular remodeling and cardiac function for autoimmune myocarditis (EAM) in rats. The regulating effects on inflammatory cytokines in the peripheral serum and related mechanisms are also discussed.

Methods

First, TP and MTX were prepared as a nanosuspension, and the EAM model was successfully established in rats with cardiac myosin. Then, the effect of TP and MTX suspensions was tested in an EAM model.

Results

Results revealed that both TP and MTX suspensions could reduce the degree of myocardial fibrosis and delay the remodeling process of the left ventricle which could further improve cardiac function. Finally, it was found that inflammatory cytokines in the peripheral serum were regulated by the nonspecific immune system and the inhibition of nuclear factor-κB signaling might have partly occurred due to this mechanism.

Conclusion

In summary, this study provided a complete foundation for EAM therapy of profound clinical relevance.

The Role of the Immune Response in the Pathogenesis of Bronchiectasis

Bronchiectasis is a prevalent respiratory condition characterised by permanent and abnormal dilation of the lung airways (bronchi). There are a large variety of causative factors that have been identified for bronchiectasis; all of these compromise the function of the immune response to fight infection. A triggering factor may lead to the establishment of chronic infection in the lower respiratory tract. The bacteria responsible for the lower respiratory tract infection are usually found as commensals in the upper respiratory tract microbiome. The consequent inflammatory response to infection is largely responsible for the pathology of this condition. Both innate and adaptive immune responses are activated. The literature has highlighted the central role of neutrophils in the pathogenesis of bronchiectasis. Proteases produced in the lung by the inflammatory response damage the airways and lead to the pathological dilation that is the pathognomonic feature of bronchiectasis. The small airways demonstrate infiltration with lymphoid follicles that may contribute to localised small airway obstruction. Despite aggressive treatment, most patients will have persistent disease. Manipulating the immune response in bronchiectasis may potentially have therapeutic potential.

Chemokine, cytokine and type I interferon production induced by Toll-like receptor activation in common variable immune deficiency

Common variable immunodeficiency (CVID) is the most common symptomatic primary antibody deficiency and is associated with recurrent infections and chronic inflammatory diseases. We evaluated the ability of Toll-like receptor (TLR) ligands to induce secretion of chemokines, cytokines and type I interferons by peripheral blood mononuclear cells (PBMCs) from CVID patients. High levels of CXCL10, CCL2, CXCL9, CCL5, CXCL8, and IL-6 were detected in sera of CVID patients compared with healthy controls. Increased chemokine levels were observed in unstimulated PBMCs, but after stimulation with TLR2 and TLR4 agonists, equivalent chemokine and pro-inflammatory cytokine secretion, as in healthy controls, was observed, whereas TLR4 agonist induced a decreased secretion of CCL2 and CXCL8 and increased secretion of TNF. Decreased IFN-α secretion induced by TLR7/TLR8 activation was observed in CVID, which was recovered with TLR9 signaling. Our findings revealed that TLR9 activation has an adjuvant effect on the altered type I response in CVID.

Airway epithelium stimulates smooth muscle proliferation

Communication between the airway epithelium and stroma is evident during embryogenesis, and both epithelial shedding and increased smooth muscle proliferation are features of airway remodeling. Hence, we hypothesized that after injury the airway epithelium could modulate airway smooth muscle proliferation. Fully differentiated primary normal human bronchial epithelial (NHBE) cells at an air-liquid interface were co-cultured with serum-deprived normal primary human airway smooth muscle cells (HASM) using commercially available Transwells. In some co-cultures, the NHBE were repeatedly (x4) scrape-injured. An in vivo model of tracheal injury consisted of gently denuding the tracheal epithelium (x3) of a rabbit over 5 days and then examining the trachea by histology 3 days after the last injury. Our results show that HASM cell number increases 2.5-fold in the presence of NHBE, and 4.3-fold in the presence of injured NHBE compared with HASM alone after 8 days of in vitro co-culture. In addition, IL-6, IL-8, monocyte chemotactic protein (MCP)-1 and, more markedly, matrix metalloproteinase (MMP)-9 concentration increased in co-culture correlating with enhanced HASM growth. Inhibiting MMP-9 release significantly attenuated the NHBE-dependent HASM proliferation in co-culture. In vivo, the injured rabbit trachea demonstrated proliferation in the smooth muscle (trachealis) region and significant MMP-9 staining, which was absent in the uninjured control. The airway epithelium modulates smooth muscle cell proliferation via a mechanism that involves secretion of soluble mediators including potential smooth muscle mitogens such as IL-6, IL-8, and MCP-1, but also through a novel MMP-9-dependent mechanism.

Upregulation of ICAM-1 expression in bronchial epithelial cells by airway secretions in bronchiectasis

The airway epithelium participates in chronic airway inflammation by expressing adhesion molecules that mediate the transmigration of neutrophils into the inflamed airways. We hypothesize that, in patients with bronchiectasis, cytokines in their bronchial secretions enhance the expression of intercellular cell adhesion molecule (ICAM-1) in the bronchial epithelium and thus contribute to sustained recruitment of neutrophils into the inflamed airways. In the present study, we investigated the effect of bronchial secretions on the regulation of ICAM-1 in bronchial epithelial cells, and its modulation by pharmacologic agents. The expression of ICAM-1 mRNA and protein in human bronchial epithelial cells upon exposure to sputum sol from subjects with bronchiectasis were evaluated by reverse transcription-polymerase chain reaction (RT-PCR) and ELISA, respectively. Modulating effects of dexamethasone, ibuprofen, MK-663 or triptolide on ICAM-1 regulation were investigated in vitro. We demonstrated that changes in ICAM-1 expression correlated with levels of TNF-alpha in the sputum sol, and treatment of sol samples with TNF-alpha antibodies attenuated both the increase in ICAM-1 mRNA and protein. The role of TNF-alpha was further demonstrated when TNF-alpha elicited dose dependent increase in ICAM-1 expression. The sputum effect could also be suppressed dose-dependently by pre-incubation of bronchial epithelial cells with dexamethasone, ibuprofen, MK-663 or triptolide. Evidence is thus provided for the upregulation of bronchial epithelial ICAM-1 expression by airway secretions in bronchiectasis and a specific role for TNF-alpha in the secretions. The success of drug attenuation of this upregulation provides insight into possible therapeutic paradigms in the management of the disease.

Inhaled steroids improve quality of life in patients with steady-state bronchiectasis

BACKGROUND

The effects of inhaled steroids upon the quality of life of patients with bronchiectasis remain unknown.

STUDY OBJECTIVE

To analyze the effect of inhaled fluticasone propionate (FP) for 6 months upon the clinical, functional, microbiological and outcome parameters of patients with steady-state bronchiectasis not due to cystic fibrosis, and its repercussions for patient health-related quality of life (HRQoL).

DESIGN

Prospective, randomized, double-blind (for effective doses) study.

PATIENTS AND INTERVENTIONS

The diagnosis of bronchiectasis was made by high-resolution computed tomography. Ninety-three patients (mean age: 68.5 [8.4]) were randomized to receive 250 microg bid, 500 microg bid or no treatment with inhaled FP for 6 months. Data were collected at baseline and at 1, 3 and 6 months after the start of treatment. HRQoL was assessed using the validated Spanish version of the St. George's Respiratory Questionnaire.

RESULTS

The group administered FP 1000 microg daily showed significant improvement in dyspnea (1.03 [2.1]-1.24 [2.2] points; P = 0.01-0.04), sputum production (P = 0.001), days without cough (P = 0.02) and short-acting beta-2 agonists used (P = 0.01) from the first month of treatment, with no changes in pulmonary function, number or severity of exacerbations, or microbiological profile of the sputum. As a result, an improvement in HRQoL was seen in this group after 3 months of treatment (45.4 [14.2] vs. 40.5 [13.9]; P = 0.01).

CONCLUSIONS

Inhalatory FP 500 microg bid is effective from the first month of treatment for controlling the symptoms of patients with steady-state bronchiectasis-thus ensuring a significant improvement in HRQoL.

Inhibition of pyocyanin-potentiated IL-8 release by steroids in bronchial epithelial cells

Airway epithelial cells are the first targets of environmental stimuli and local cytokines. Pyocyanin-induced synergism with interleukin (IL)-1 or tumour necrosis factor (TNF) in triggering IL-8 release has been documented previously. In this study, IL-8 mRNA and protein expression were examined in cultured human bronchial epithelial cells (BEAS-2B) stimulated with pyocyanin alone, and in combination with IL-1beta or phorbol 12,13-dibutyrate (PDBu) in the absence and presence of a group of glucocorticoids. IL-8 mRNA was measured by RT-PCR, and IL-8 protein by ELISA (cell supernatants). Pyocyanin alone produced no increase in IL-8 mRNA and release. However, pyocyanin upregulated the stimulatory effect of IL-1beta or PDBu on the release of IL-8 in a dose-dependent manner. The stimulatory effect of pyocyanin on the IL-1beta- or PDBu-stimulated IL-8 release was reduced in the presence of dexamethasone, budesonide, and fluticasone. Budesonide and fluticasone were 10-fold more potent than dexamethasone. The protein kinase C (PKC) inhibitor, Go6976, also significantly reduced the stimulatory effect of pyocyanin on IL-1beta, and PDBu increased IL-8 release. In conclusion, this study shows that PKC signal pathway seems to be involved in the pyocyanin-mediated upregulation of the IL-1beta and PDBu-induced IL-8 release in BEAS-2B cells. These findings suggest that a vicious cycle perpetuating inflammation may exist in the biologic milieu of bronchiectatic patients infected with Pseudomonas aeruginosa due to the production of pyocyanin. The priming action of pyocyanin appears to be blocked by glucocorticoids, thus providing in vitro data in support of the clinical efficacy of inhaled glucocorticoids as anti-inflammatory drugs.