Extracellular Hsp70 modulates 16HBE cells' inflammatory responses to cigarette smoke and bacterial components lipopolysaccharide and lipoteichoic acid

Cigarette smoke is a major risk factor for chronic obstructive pulmonary disease (COPD), leading to chronic inflammation, while bacterial components lipopolysaccharide (LPS) and lipoteichoic acid (LTA) are often present in airways of COPD patients, especially during exacerbations.We hypothesised that extracellular heat shock protein 70 (eHsp70), a damage-associated molecular pattern elevated in serum of COPD patients, induces inflammation and alters cigarette smoke and LPS/LTA-induced inflammatory effects in the airway epithelium.We used 16HBE cells exposed to recombinant human (rh)Hsp70 and its combinations with cigarette smoke extract (CSE), LPS or LTA to investigate those assumptions, and we determined pro-inflammatory cytokines' secretion as well as TLR2 and TLR4 gene expression.rhHsp70 and CSE alone stimulated IL-6, IL-8 and TNF-α secretion. CSE and rhHsp70 had antagonistic effect on IL-6 secretion, while combinations of LPS or LTA with rhHsp70 showed antagonistic effect on TNF-α release. By using specific inhibitors, we demonstrated that effects of rhHsp70 on cytokines' secretion were mediated via NF-κB and/or MAPK signalling pathways. rhHsp70 increased, and CSE decreased TLR2 gene expression compared to untreated cells, but their combinations increased it compared to CSE alone. LPS and rhHsp70 combinations decreased TLR2 gene expression compared to untreated cells. TLR4 expression was not induced by any of the treatments.In conclusion, we demonstrated that extracellular Hsp70 modulates pro-inflammatory responses of human airway epithelial cells to cigarette smoke and bacterial components LPS and LTA. Simultaneous presence of those compounds and their interactions might lead to inappropriate immune responses and adverse consequences in COPD.

Activation of NLRP3 inflammasome in stable chronic obstructive pulmonary disease

Nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome activation plays an important role in chronic obstructive pulmonary disease (COPD) pathogenesis and might be involved in ongoing chronic inflammation. This study aimed to determine interleukin-1beta (IL-1β) plasma concentration as well as IL1B, NLRP3 and caspase-1 (CASP1) gene expression in the Croatian COPD patients. 109 patients with stable COPD and age- and sex-matched 95 controls were included in the study. Plasma IL-1β concentration was measured by Luminex technology, and gene expression analysis was performed using TaqMan assays. It was shown that COPD patients had increased concentration of IL-1β and enhanced gene expression of IL1B, NLRP3 and CASP1 compared to controls. There was no difference in IL-1β or IL1B, NLRP3 and CASP1 in patients with COPD regarding airflow obstruction severity and smoking history. Finally, the diagnostic potential of the determined parameters was evaluated, and it was found that IL-1β correctly classified 89% of cases in the combination with common inflammatory biomarkers, white blood cell count and fibrinogen, showing a potential in COPD prediction. In conclusion, up-regulation of IL1B, NLRP3, CASP1 and increased IL-1β concentration suggest the activation of NLRP3 inflammasome in the systemic compartment of patients with stable COPD.

Influence of disease severity, smoking status and therapy regimes on leukocyte subsets and their ratios in stable chronic obstructive pulmonary disease

INTRODUCTION

Blood cells are involved in systemic inflammation in chronic obstructive pulmonary disease (COPD). We aimed to assess differences in leukocyte subsets and their ratios between COPD patients and healthy individuals as well as their association with disease severity, smoking status and therapy in COPD.

MATERIAL AND METHODS

One hundred and nine patients in the stable phase of COPD and 95 controls participated in the study. After blood sampling, white blood cells (WBC), neutrophils (NEUTRO), monocytes (MO), lymphocytes (LY) and basophils (BA) were determined on a Sysmex XN-1000 analyser, and ratios were calculated afterwards.

RESULTS

White blood cells, NEUTRO, MO and BA were higher in COPD patients than in controls. Also, COPD patients had increased neutrophil to lymphocyte ratio (NLR), derived NLR (dNLR), monocyte to lymphocyte ratio (MLR), basophil to lymphocyte ratio (BLR), basophil to monocyte ratio (BMR) and monocyte/granulocyte to lymphocyte ratio (M/GLR). Smoking has an impact on leukocyte counts, with BA, BLR and BMR being higher in COPD smokers vs. ex-smokers. Patients with very severe COPD were distinguished from moderate COPD by NLR, dNLR and M/GLR. In addition, those parameters were associated with lung function and dyspnoea, and NLR and dNLR also with multicomponent COPD indices BODCAT and DOSE. Great potential of dNLR, NLR and M/GLR in identifying COPD patients was observed regarding their odds ratios (OR) of 5.07, 2.86, 2.60, respectively (p < 0.001). Common COPD therapy did not affect any of the parameters investigated.

CONCLUSIONS

Leukocyte subsets and their ratios could be implemented in COPD assessment, especially in evaluating disease severity and prediction.

Increased HSP70 and TLR2 Gene Expression and Association of HSP70 rs6457452 Single Nucleotide Polymorphism with the Risk of Chronic Obstructive Pulmonary Disease in the Croatian Population

Heat shock protein 70 (Hsp70) engages Toll-like receptors (TLR) 2 and 4 when found in the extracellular compartment and contributes to inflammation in chronic obstructive pulmonary disease (COPD). Since there is growing evidence for the genetic risk factors for COPD, the gene expression of HSP70, TLR2 and TLR4 was determined, as well as the association between HSP70, TLR2 and TLR4 single nucleotide polymorphisms, (SNPs) and COPD. The gene expression was assessed in peripheral blood cells of 137 COPD patients and 95 controls by a quantitative polymerase chain reaction (qPCR), while a total of nine SNPs were genotyped by TaqMan allelic discrimination real-time PCR. HSP70 and TLR2 gene expression was increased in COPD patients compared to the controls, regardless of the disease severity and smoking status of participants. The rs6457452 SNP of HSP70 was associated with COPD, indicating the protective role of the T allele (OR = 0.46, 95% CI = 0.24–0.89, p = 0.022). Furthermore, COPD C/T heterozygotes showed a decreased HSP70 mRNA level compared to COPD C/C homozygotes. In conclusion, HSP70 and TLR2 may have a role in the pathogenesis of COPD, and the HSP70 rs6457452 variant might influence the genetic susceptibility to COPD in the Croatian population.

Lipid profile and atherogenic indices in patients with stable chronic obstructive pulmonary disease

BACKGROUND AND AIMS

Limited number of studies investigated lipid profile in chronic obstructive pulmonary disease (COPD) with inconsistent results. This study aimed to investigate lipid parameters in sera of patients with stable COPD and their associations with disease severity, smoking, comorbidities and therapy.

METHODS AND RESULTS

The study included 137 COPD patients and 95 controls. Triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) were assessed. Non-HDL-C (NHC), atherogenic coefficient (AC), TG/HDL-C, atherogenic index of plasma (AIP), Castelli's risk index I and II (CRI-I, CRI-II), and monocyte to HDL ratio (MHR) were calculated. HDL-C and MHR were increased, while other lipid parameters and indices were decreased in COPD patients compared to healthy individuals. Smoking did not influence lipid parameters. However, lipid profile was altered only in more severe disease stages. AC, CRI-I and CRI-II showed positive association with lung function parameters in COPD patients, and negative with COPD multicomponent indices (ADO, BODCAT, BODEx, CODEx and DOSE). Combined model that included CRI-II, C-reactive protein, fibrinogen and white blood cells showed great diagnostic performances, and correctly classified 72% of study participants with an AUC of 0.800 (0.742-0.849), P < 0.001. Bronchodilator monotherapy and statins have opposite impact on TC, LDL-C and NHC, while TG, TG/HDL-C and AIP were increased in COPD patients with cardiovascular diseases.

CONCLUSION

Lipid disbalance is present in COPD, and it seems to occur later as the disease progresses. Further studies are needed to illuminate the underlying mechanism of dyslipidaemia.

Combination of Systemic Inflammatory Biomarkers in Assessment of Chronic Obstructive Pulmonary Disease: Diagnostic Performance and Identification of Networks and Clusters

Interleukin (IL)-1α, IL-1β, IL-6, IL-8 and tumor necrosis factor (TNF)α contribute to inflammation in chronic obstructive pulmonary disease (COPD). We wanted to investigate their interrelations and association with disease severity, as well as to combine them with other inflammation-associated biomarkers and evaluate their predictive value and potential in identifying various patterns of systemic inflammation. One hundred and nine patients with stable COPD and 95 age- and sex-matched controls were enrolled in the study. Cytokines’ concentrations were determined in plasma samples by antibody-based multiplex immunosorbent assay kits. Investigated cytokines were increased in COPD patients but were not associated with disease or symptoms severity. IL-1β, IL-6 and TNFα showed the best discriminative values regarding ongoing inflammation in COPD. Inflammatory patterns were observed in COPD patients when cytokines, C-reactive protein (CRP), fibrinogen (Fbg), extracellular adenosine triphosphate (eATP), extracellular heat shock protein 70 (eHsp70) and clinical data were included in cluster analysis. IL-1β, eATP and eHsp70 combined correctly classified 91% of cases. Therefore, due to the heterogeneity of COPD, its assessment could be improved by combination of biomarkers. Models including IL-1β, eATP and eHsp70 might identify COPD patients, while IL-1β, IL-6 and TNFα combined with CRP, Fbg, eATP and eHsp70 might be informative regarding various COPD clinical subgroups.

Cigarette smoke and extracellular Hsp70 induce secretion of ATP and differential activation of NLRP3 inflammasome in monocytic and bronchial epithelial cells

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is an inflammatory disease mainly caused by smoking. Cigarette smoke damages airway epithelium and activates lung macrophages, causing inflammatory responses. It was suggested that nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome might have an important role in COPD development. Study aimed to explore whether cigarette smoke extract (CSE), extracellular heat shock protein 70 (eHsp70) or their combinations induce adenosine triphosphate (ATP) release and NLRP3 inflammasome activation.

METHODS

We detected NLRP3 and interleukin (IL)-1β mRNA expression, extracellular IL-1β and ATP concentrations as well as lactate dehydrogenase (LDH) activity. We used bronchial epithelial (NCI-H292, 16HBE and NHBE) and monocytic cells (monocyte-derived macrophages (MDMs) and THP-1) as representative of local airway and systemic compartments that could be affected in COPD.

RESULTS

CSE and eHsp70 increased NLRP3 and IL-1β mRNA expression as well as IL-1β and ATP secretion in all cells compared to untreated cells. Lytic cell death was observed in cell lines, especially those of bronchial epithelium origin, but not in primary cells (NHBE, MDMs). Regarding LDH activity, eHsp70 did not modulate CSE effects, except in NCI-H292 cell line. However, eHsp70 significantly affected CSE-provoked NLRP3 inflammasome activation by causing mostly antagonistic effects in airway epithelial cells and synergistic effects in MDMs.

CONCLUSION

We demonstrated that both CSE and eHsp70 induce ATP secretion and differential activation of NLRP3 inflammasome in bronchial epithelial and monocytic cells. We suggest that these mechanisms might be involved in pathophysiology of COPD by contributing to the propagation of inflammation.

Pathogen-associated molecular patterns and extracellular Hsp70 interplay in NLRP3 inflammasome activation in monocytic and bronchial epithelial cellular models of COPD exacerbations

During chronic obstructive pulmonary disease (COPD) exacerbations, interplay between pathogen-associated molecular patterns (PAMPs; e.g. lipopolysaccharide (LPS) and lipoteichoic acid (LTA)) and damage-associated molecular patterns (DAMPs; e.g. extracellular heat shock protein 70 (eHsp70) and adenosine triphosphate (ATP)) might influence patient's outcome. Nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome might have a role in dysfunctional immune system in COPD. We hypothesized that LPS, LTA, eHsp70 and their combinations induce NLRP3 inflammasome activation, and we aimed to explore this assumption. We used monocytic (monocyte-derived macrophages (MDMs) and THP-1) and bronchial epithelial cells (NHBE and NCI-H292) to represent systemic and local airway compartments that could be affected in COPD. Bacterial components and eHsp70 stimulated NLRP3 and interleukin (IL)-1β gene expression as well as IL-1β and ATP release from all cells compared to non-treated cells. LDH secretion was induced in cell lines only. eHsp70 had inhibitory (NCI-H292) or stimulatory (NHBE) effects on eATP levels compared to PAMP alone. Regarding NLRP3 inflammasome activation, eHsp70 had mostly antagonistic effects. We demonstrated that bacterial components and eHsp70 activate NLRP3 inflammasome and increase ATP secretion. We suggest that extracellular Hsp70 might modulate immune responses provoked by bacterial infections and affect COPD patients' outcome during acute exacerbations.

Effects of extracellular Hsp70, lipopolysaccharide and lipoteichoic acid on human monocyte-derived macrophages and differentiated THP-1 cells

Extracellular Hsp70 (eHsp70) is elevated in blood of patients with inflammatory diseases (e.g. chronic obstructive pulmonary disease), prone to bacterial infections. It stimulates pro-inflammatory effects in cells via TLR2 and TLR4. The main hypothesis was that eHsp70 induces inflammation and alters inflammatory responses to lipopolysaccharide (LPS) and lipoteichoic acid (LTA). We assessed pro-inflammatory cytokines concentrations, TLR2, TLR4 and Hsp70 mRNA expressions, NF-κB and MAPKs activation, and viability after treatment of monocyte-derived macrophages (MDMs) and THP-1 cells with recombinant human (rh) Hsp70, LPS and LTA. rhHsp70, LPS, LTA and their combinations induced IL-6, IL-8 and TNF-α from MDMs. LPS, LTA, and combinations with rhHsp70 increased TLR2 and decreased TLR4 in both cells. rhHsp70 increased TLR2 and TLR4 in THP-1 cells, and TLR2 in MDMs. rhHsp70, LPS and their combinations up-regulated Hsp70 in MDMs, while down-regulated it in THP-1. LPS and its combinations with rhHsp70 lowered cell viability in THP-1 cells and activated caspases-8 and -9. Involvement of NF-κB and MAPKs in inflammatory and survival mechanisms stimulated by rhHsp70 was demonstrated. eHsp70 alone and in combination with bacterial components could provoke inflammation and affect viability of MDMs and THP-1 cells leading to disturbed inflammatory responses in diseases accompanied with bacterial colonisations or infections.

Association of Plasma Heat Shock Protein 70 with Disease Severity, Smoking and Lung Function of Patients with Chronic Obstructive Pulmonary Disease

Extracellular heat shock protein 70 (eHsp70) might modulate immune responses in chronic obstructive pulmonary disease (COPD). The aim of the study was to explore eHsp70 concentration in stable COPD, its association with disease severity and smoking status as well as its diagnostic performance in COPD assessment. Plasma samples were collected from 137 COPD patients and 95 healthy individuals, and concentration of eHsp70 was assessed by commercially available enzyme-linked immunosorbent assay (ELISA) kit (Enzo Life Science, Farmingdale, NY, USA). COPD patients were subdivided regarding airflow obstruction severity and symptoms severity according to the Global Initiative for COPD (GOLD) guidelines. eHsp70 concentration increased in COPD patients when compared to controls and increased with the severity of airflow limitation as well as symptoms burden and exacerbation history. eHsp70 concentration did not differ among COPD patients based on smoking status, yet it increased in healthy smokers compared to healthy nonsmokers. In addition, eHsp70 negatively correlated with lung function parameters forced expiratory volume in one second (FEV₁) and FEV₁/ forced vital capacity (FVC), and positively with COPD multicomponent indices BODCAT (BMI, airflow obstruction, dyspnea, CAT score), BODEx (BMI, airflow obstruction, dyspnea, previous exacerbations), CODEx (Charlson’s comorbidity index, airflow obstruction, dyspnea, previous exacerbations) and DOSE (dyspnea, airflow obstruction, smoking status, previous exacerbations) With great predictive value (OR = 7.63) obtained from univariate logistic regression, eHsp70 correctly classified 76% of cases. eHsp70 is associated with COPD prediction and disease severity and might have the potential for becoming an additional biomarker in COPD assessment.

Uric acid and uric acid to creatinine ratio in the assessment of chronic obstructive pulmonary disease: Potential biomarkers in multicomponent models comprising IL-1beta

Chronic obstructive pulmonary disease (COPD) is a complex and heterogeneous disease, with oxidative stress and inflammation implicated in its development. Uric acid (UA) could exert anti-oxidative, pro-oxidative or pro-inflammatory effects, depending on the specific context. It was recently shown that soluble UA, and not just its crystals, could activate the nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome, leading to interleukin (IL)-1β secretion. We aimed to assess the differences in blood levels of UA and its ratio with creatinine (UCR) between COPD patients and healthy subjects, as well as their association with disease severity, smoking status, common COPD comorbidities and therapy regimes. The diagnostic characteristics of UA and UCR were also explored. This study included 109 stable COPD patients and 95 controls and measured white blood cells (WBC), C-reactive protein (CRP), fibrinogen (Fbg), IL-1β, creatinine (CREAT) and UA. All of the parameters were increased in COPD patients, except for CREAT. UA and UCR were positively associated with WBC, CRP and IL-1β. COPD smokers had lower UA and UCR values. Common COPD therapy did not affect UA or UCR, while patients with cardiovascular diseases (CVD) had higher UA, but not UCR, levels. Patients with higher UCR values showed worse disease-related outcomes (lung function, symptoms, quality of life, history of exacerbations, BODCAT and BODEx). Also, UCR differentiated patients with different severity of airflow limitation as well as symptoms and exacerbations. The great individual predictive potential of UCR and IL-1β was observed with their odds ratios (OR) being 2.09 and 5.53, respectively. Multiparameter models of UA and UCR that included IL-1β were able to correctly classify 86% and 90% of cases, respectively. We suggest that UA might be a useful biomarker when combined with IL-1β, while UCR might be even more informative and useful in overall COPD assessments.

Platelet indices in stable chronic obstructive pulmonary disease - association with inflammatory markers, comorbidities and therapy

Introduction

Chronic obstructive pulmonary disease (COPD) is a complex inflammatory condition that can affect haemostasis. This study aimed to determine differences in platelet-related parameters between controls and COPD subjects. The hypothesis was that platelet indices are disturbed in COPD patients, and this would be accompanied by increased C-reactive protein (CRP), fibrinogen (Fbg) and white blood cells (WBC). Therefore, platelet count (Plt), platelet-related parameters - mean platelet volume (MPV), platelet distribution width (PDW), plateletcrit (Pct), their ratios (MPV/Plt, MPV/Pct, PDW/Plt, PDW/Pct), platelet to lymphocyte ratio (PLR), Plt index as well as CRP, Fbg and WBC were assessed.

Materials and methods

Study included 109 patients with stable COPD and 95 control subjects, recruited at Clinical Department for Lung Diseases Jordanovac, University Hospital Centre Zagreb (Zagreb, Croatia). Complete blood count was performed on Sysmex XN-1000, CRP on Cobas c501, and Fbg on BCS XP analyser. Data were analysed with MedCalc statistical software.

Results

Platelet (P = 0.007) and PLR (P = 0.006) were increased, while other platelet indices were decreased in COPD patients compared to controls. Combined model that included PLR, PDW and WBC showed great diagnostic performances, and correctly classified 75% of cases with an AUC of 0.845 (0.788 - 0.892), P < 0.001. Comorbidities (cardiovascular or metabolic diseases) had no effect on investigated parameters, while inhaled corticosteroids/long-acting β₂-agonists (ICS/LABA) therapy increased MPV and PDW values in COPD patients.

Conclusion

Platelet indices were altered in COPD patients and they could be valuable as diagnostic markers of COPD development, especially if combined with already known inflammatory markers.

Extracellular adenosine triphosphate is associated with airflow limitation severity and symptoms burden in patients with chronic obstructive pulmonary disease

Extracellular adenosine triphosphate (eATP)-driven inflammation was observed in chronic obstructive pulmonary disease (COPD) but was not investigated in patients’ blood. Therefore, this study aimed to investigate eATP concentration in plasma of COPD patients and its association with disease severity and smoking. Study included 137 patients with stable COPD and 95 control subjects. eATP concentration was determined in EDTA plasma by luminometric method, and mRNA expression of eATP receptors P2X7R and P2Y2R was analysed by quantitative polymerase chain reaction (qPCR). eATP concentration was increased in COPD patients compared to controls (P < 0.001). Moreover, it was increasing with disease severity (GOLD 2–4) as well as symptoms burden and exacerbations history (GOLD A–D) (P < 0.05). eATP in healthy smokers differed from healthy non-smokers (P < 0.05) but was similar to GOLD 2 and GOLD A patients. eATP showed great diagnostic performances (OR = 12.98, P < 0.001) and correctly classified 79% of study participants. It demonstrated association with FEV₁ and multicomponent indices (ADO, BODEx, BODCAT, CODEx, DOSE). Regarding gene expression, P2Y2R was increased in the blood of COPD patients. Plasma eATP could become a diagnostic and/or prognostic biomarker in COPD, as it seems to be associated with patients’ condition, quality of life and disease progression.