Paraoxonase 1 Activity in Patients with Chronic Obstructive Pulmonary Disease

Plasma Proteomics Study Between the Frequent Exacerbation and Infrequent Exacerbation Phenotypes of Chronic Obstructive Pulmonary Disease

Background

Frequent exacerbation (FE) and infrequent exacerbation (IE) are two phenotypes of chronic obstructive pulmonary disease (COPD), of which FE is associated with a higher incidence of exacerbation and a serious threat to human health. Because the pathogenesis mechanisms of FE are unclear, this study aims to identify FE-related proteins in the plasma via proteomics for use as predictive, diagnostic, and therapeutic biomarkers of COPD.

Methods

A cross-sectional study was conducted in which plasma protein profiles were analyzed in COPD patients at stable stage, and differentially expressed proteins (DEPs) were screened out between the FE and IE patients. FE-related DEPs were identified using data-independent acquisition-based proteomics and bioinformatics analyses. In addition, FE-related candidates were verified by enzyme-linked immunosorbent assay.

Results

In this study, 47 DEPs were screened out between the FE and IE groups, including 20 upregulated and 27 downregulated proteins. Key biological functions (eg, neutrophil degranulation, extracellular exosome, protein homodimerization activity) and signaling pathways (eg, arginine and proline metabolism) were enriched in association with the FE phenotype. Receiver operating characteristic (ROC) analysis of the 11 combined DEPs revealed an area under the curve of 0.985 (p <0.05) for discriminating FE from IE. Moreover, correlation and ROC curve analyses indicated that creatine kinase, M-type (CKM) and fat storage-inducing transmembrane protein 1 (FITM1) might be clinically significant in patients with the FE phenotype. In addition, plasma expression levels of CKM and FITM1 were validated to be significantly decreased in the FE group compared with the IE group (CKM: p <0.01; FITM1: p <0.05).

Conclusion

In this study, novel insights into COPD pathogenesis were provided by investigating and comparing plasma protein profiles between the FE and IE patients. CKM, FITM1, and a combinative biomarker panel may serve as useful tools for assisting in the precision diagnosis and effective treatment of the FE phenotype of COPD.

Paraoxonase 1 and Chronic Obstructive Pulmonary Disease: A Meta-Analysis

Oxidative stress is a driving factor in the pathophysiology of chronic obstructive pulmonary disease (COPD). While paraoxonase 1 (PON1) is an antioxidant enzyme and a potential biomarker of this disease, data regarding the status of PON-1 in COPD are inconclusive. In this regard, to shed light on this issue, we performed a meta-analysis of data on PON1 activity in COPD. Electronic databases (MEDLINE, Embase and CENTRAL) were searched for available studies on PON1 activity in patients with stable COPD published before October 2021. A meta-analysis was performed using random-effects models. Twelve studies (12 studies on paraoxonase and three on arylesterase) were identified. Patients with COPD had lower levels of paraoxonase activity (standard mean difference [SMD] -0.77, 95% confidence interval [CI] -1.35 to -0.18) and arylesterase activity (SMD -1.15, 95% CI -1.95 to -0.36) in comparison to healthy controls. In subgroup analyses, paraoxonase activity was lower in patients of studies as consisted of mainly non-severe COPD (SMD -1.42, 95% CI -2.04 to -0.79) and, by contrast, slightly higher in patients of studies including severe COPD (SMD 0.33, 95% CI 0.02 to 0.64) in comparison to healthy controls. Arylesterase activity showed a similar trend. Overall, PON1 activity was lower in patients with COPD, suggesting that PON1-related antioxidant defense is impaired in COPD. Future studies are warranted.

Diagnosis, prevalence, and clinical impact of sarcopenia in COPD: a systematic review and meta-analysis

Sarcopenia prevalence and its clinical impact are reportedly variable in chronic obstructive pulmonary disease (COPD) due partly to definition criteria. This review aimed to identify the criteria used to diagnose sarcopenia and the prevalence and impact of sarcopenia on health outcomes in people with COPD. This review was registered in PROSPERO (CRD42018092576). Five electronic databases were searched to August 2018 to identify studies related to sarcopenia and COPD. Study quality was assessed using validated instruments matched to study designs. Sarcopenia prevalence was determined using authors' definitions. Comparisons were made between people who did and did not have sarcopenia for pulmonary function, exercise capacity, quality of life, muscle strength, gait speed, physical activity levels, inflammation/oxidative stress, and mortality. Twenty-three studies (70% cross-sectional) from Europe (10), Asia (9), and North and South America (4) involving 9637 participants aged ≥40 years were included (69.5% men). Sarcopenia criteria were typically concordant with recommendations of hEuropean and Asian consensus bodies. Overall sarcopenia prevalence varied from 15.5% [95% confidence interval (CI) 11.8-19.1; combined muscle mass, strength, and/or physical performance criteria] to 34% (95%CI 20.6-47.3; muscle mass criteria alone) (P = 0.009 between subgroups) and was greater in people with more severe [37.6% (95%CI 24.8-50.4)] versus less severe [19.1% (95%CI 10.2-28.0)] lung disease (P = 0.020), but similar between men [41.0% (95%CI 26.2-55.9%)] and women [31.9% (95%CI 7.0-56.8%)] (P = 0.538). People with sarcopenia had lower predicted forced expiratory volume in the first second (mean difference -7.1%; 95%CI -9.0 to -5.1%) and poorer exercise tolerance (standardized mean difference -0.8; 95%CI -1.4 to -0.2) and quality of life (standardized mean difference 0.26; 95%CI 0.2-0.4) compared with those who did not (P < 0.001 for all). No clear relationship was observed between sarcopenia and inflammatory or oxidative stress biomarkers. Incident mortality was unreported in the literature. Sarcopenia is prevalent in a significant proportion of people with COPD and negatively impacts upon important clinical outcomes. Opportunities exist to optimize its early detection and management and to evaluate its impact on mortality in this patient group.

NOVEL antioxidant and oxidant biomarkers related to sarcopenia in COPD

BACKGROUND

The relation between oxidative stress (OS) and sarcopenia in COPD remains unknown.

OBJECTIVE

To analyze OS levels and its association with sarcopenia in COPD.

METHODS

Thirty-nine individuals with COPD (69±7years; 41%female) and thirty-five for the control group (69±7years; 43%female) were included. Advanced oxidation protein products (AOPP), paraoxonase-1 (PON1), superoxide dismutase activity (SOD), catalase dismutase activity (CAT), sulfhydryl group (SH), nitric oxide metabolites (NOX), total radical trapping antioxidant parameter (TRAP) were analysed. OS markers were correlated with handgrip and quadriceps strength, gait speed, skeletal muscle mass index, fat-free mass index, maximum inspiratory and expiratory pressure. European criteria were used to identify sarcopenia.

RESULTS

In COPD, antioxidant capacity was correlated with muscle mass and strength (r from 0.5 to 0.64) P<0.05 for all. TRAP≤ 850 μM/trolox and AOPP≤65 μM/l were associated with sarcopenia (OR:8.3; 95% CI: 1.4-49.6 and OR:14; 95%CI: 2.2-87.1, respectively; P<0.05 for both).

CONCLUSION

OS is associated with sarcopenia in COPD.

Paraoxonase Activity and Phenotype Distribution in Patients with Chronic Obstructive Pulmonary Disease

OBJECTIVE

Paraoxonase 1 (PON1) and arylesterase (ARE) enzymes have an important role in the prevention of oxidative stress which is related to the pathogenesis of chronic obstructive pulmonary disease (COPD). PON1 levels vary widely among individuals and ethnic groups, which is in part associated with polymorphisms.

MATERIALS AND METHODS

We investigated PON1 and ARE activity and phenotype distribution in COPD patients and healthy individuals. Sixty six COPD patients and 59 control subjects were involved in the study. Serum PON1 and ARE activities were detected by spectrophotometric method. The ratio of salt-induced PON1 to ARE activity was used to determine phenotypes as QQ, QR, and RR.

RESULTS

COPD patients exhibited higher PON1 activity (199.1 vs 129.2, p=0.002) but lower ARE activity compared to control (21.3 vs 33.5, p=0.021). There was a significant difference between COPD and control group with respect to PON1 phenotype characteristics. RR phenotypic distribution was more common in the COPD group than in control (60.6% [95% CI: 48.8 - 72.3] versus 22.0 % [95% CI: 12.0 - 31.9], p=0.001). We also found that smoking (95.0% CI: 0.001-0.036, p<0.001) and RR phenotype (95.0% CI: 0.006 - 0.59, p=0.016) are independent determinants in COPD.

CONCLUSION

We found that RR phenotype was more common in COPD patients compared to control. Smoking and RR phenotype may be defined as independent factors associated with COPD.

Total oxidant and antioxidant status and paraoxonase 1 levels of children with noncystic fibrosis bronchiectasis

Background/aim

To evaluate total oxidant status (TOS), total antioxidant capacity (TAC), and paraoxonase 1 (PON1) levels in children with noncystic fibrosis (CF) bronchiectasis (BE), and to compare these levels with those of healthy controls. The study parameters were also evaluated according to some demographic, anthropometric, and clinical characteristics, as well as lung functions.

Materials and methods

Enrolled in the study were 118 children with non-CF BE and 68 healthy controls. Serum TOS, TAC, and PON1 levels were determined. Lung function tests were performed by spirometry.

Results

Serum TOS was higher in the patients [median 9.54 (IQR 25–75 = 7.05–13.30) μmol H2O2 Eq/L] than in the healthy subjects [6.64 (5.45–9.53) μmol H2O2 Eq/L] (P < 0.001). TAC was higher in patients with non-CF BE [1.07 (1.0–1.07) mmol Trolox Eq/L] than in the healthy controls [0.87 (0.77–0.98) mmol Trolox Eq/L] (P < 0.001). In addition, serum PON1 levels were significantly higher in the patients [106.5 (42.5–154.2) U/L] than in the controls [47.7 (27.5–82.1) U/L] (P < 0.001). The patients with low FEV1 had decreased TAC when compared to those who had normal FEV1 in non-CF BE.

Conclusion

The present study demonstrated that compared with the control group the children with non-CF BE had elevated oxidative status, antioxidant defenses parameters, and PON1 values.

Is oxidative stress associated with disease severity, pulmonary function and metabolic syndrome in chronic obstructive pulmonary disease?

OBJECTIVE

To investigate associations between oxidant/antioxidant biomarkers with the disease severity, pulmonary function and diagnosis of metabolic syndrome (MetS) in patients with COPD.

METHODS

Seventy-four subjects were included, 39 with COPD (age 69±7 years; female 41%) and 35 for control group (age 69±7 years; female 43%). They were diagnosed with MetS and allocated in one of 4 subgroups: COPD and control, with and without MetS, respectively. Advanced oxidation protein products (AOPP), paraoxonase-1, catalase activity, sulfhydryl group and total lipid hydroperoxide were assayed. Pulmonary function was performed with a plethysmograph.

RESULTS

COPD severity (GOLD≥3) and pulmonary function were associated with sulfhydryl group and AOPP (P≤.03 for all). The prevalence of MetS was associated with AOPP in COPD (P=.04). Individuals with COPD and MetS showed higher AOPP compared to COPD without MetS (P<.0001).

CONCLUSION

COPD severity, worse pulmonary function and presence of metabolic syndrome are associated with oxidative stress in individuals with COPD.

PON1 gene polymorphisms in patients with chronic obstructive pulmonary disease

Aims

Chronic obstructive pulmonary disease (COPD) is characterised with oxidative stress. Paraoxonase 1 (PON1) is an enzyme, coded by PON1 gene, with distinctive antiatherogenic and antioxidative roles. We aimed to investigate the frequencies of Q192R, L55M and −108C>T polymorphisms and association of those polymorphisms with paraoxonase and arylesterase activities in patients with COPD.

Methods

PON1 genotype was determined by PCR–restriction fragment length polymorphism method. PON1 activity was measured by paraoxon and phenylacetate.

Results

Only −108C>T polymorphism resulted in significantly different distribution of genotypes and alleles, with higher frequency of TT genotype and T allele in patients compared with control subjects. Moreover, T allele (OR 2.29 (95% CI 1.54 to 3.41); p<0.001) as well as TT genotype (OR 5.00 (95% CI 2.19 to 11.43); p<0.001) showed an association with the disease. −108C>T polymorphism was suggested as a significant diagnostic predictor for the disease (OR (95% CI) 2.65 (1.53 to 4.59), p=0.001), with an area under the receiver operating characteristic curve of 0.90 (95% CI 0.84 to 0.93) and with 83.90% of correctly classified cases.

Conclusions

Higher frequency of TT genotype and T allele could contribute to the observed reduction of PON1 activity in patients with COPD. T allele and TT genotype are associated with COPD, and the PON1−108C>T polymorphism could be a potential predictor of the disease.

Systemic redox imbalance in stable chronic obstructive pulmonary disease

CONTEXT

Increased oxidative burden is found in chronic obstructive pulmonary disease (COPD).

OBJECTIVE

To assess the association of ceruloplasmin, albumin, bilirubin, transferrin, thiols and malondialdehyde (MDA) with stable COPD.

MATERIALS AND METHODS

Oxidative stress markers measured in 106 COPD patients and 45 healthy subjects were evaluated.

RESULTS

Higher ceruloplasmin and MDA, and lower albumin, transferrin and thiols in COPD patients were found. Ceruloplasmin was the strongest single predictor of COPD. The model combining ceruloplasmin, albumin and thiols improved their individual diagnostic performances.

CONCLUSIONS

Diagnostic characteristics of ceruloplasmin, albumin, transferrin, thiols and MDA suggest their potential value as additional tools in disease diagnosis.

Advances in high-density lipoprotein physiology: surprises, overturns, and promises

Emerging evidence strongly supports that changes in the HDL metabolic pathway, which result in changes in HDL proteome and function, appear to have a causative impact on a number of metabolic disorders. Here, we provide a critical review of the most recent and novel findings correlating HDL properties and functionality with various pathophysiological processes and disease states, such as obesity, type 2 diabetes mellitus, nonalcoholic fatty liver disease, inflammation and sepsis, bone and obstructive pulmonary diseases, and brain disorders.