Smoking, telomere length and lung function decline: a longitudinal population-based study

Joint association of systemic immune-inflammation index and phenotypic age acceleration with chronic respiratory disease: a cross-sectional study

BACKGROUND

Chronic respiratory diseases (CRD) represents a series of lung disorders and is posing a global health burden. Systemic inflammation and phenotypic ageing have been respectively reported to associate with certain CRD. However, little is known about the co-exposures and mutual associations of inflammation and ageing with CRD. Here, we aim to systematically elucidate the joint and mutual mediating associations of systemic immune-inflammation index (SII) and phenotypic age acceleration (PhenoAgeAccel) with CRD based on data from National Health and Nutrition Examination Survey (NHANES).

METHODS

Data for this study was obtained from NHANES 2007-2010 and 2015-2018. The single and combined associations of SII and PhenoAgeAccel with CRD were analyzed using multivariable logistic regression models. The dose-response relationship between exposures and outcomes was determined by restricted cubic splines (RCS) regression. Subgroup and mediation analyses were further conducted.

RESULTS

Totally, 15,075 participants were enrolled in this study including 3,587 CRD patients. Compare with controls, CRD patients tended to be older, females and present higher SII and PhenoAgeAccel values. Single-index analysis indicated that either SII or PhenoAgeAccel demonstrated a significantly positive association with CRD via logistic regressions and RCS curves. Furthermore, the joint-indexes analysis revealed that compared to individuals with lower SII and PhenoAgeAccel, those with higher SII and PhenoAgeAccel exhibited remarkably stronger associations with CRD (adjusted OR [aOR], 1.56; 95% CI, 1.31-1.85; P < 0.001), chronic obstructive pulmonary disease (aOR, 1.56; 95% CI, 1.22-2.00; P = 0.001) and asthma (aOR, 1.40; 95% CI, 1.16-1.70; P = 0.001), which were predominant among those aged above 40 years, females and smokers. Eventually, mediation analyses suggested the mutual mediating effects of SII and PhenoAgeAccel on CRD and PhenoAgeAccel mediated SII resulting in CRD more significantly.

CONCLUSION

This study confirmed the coexposure effect and mutual mediation between SII and PhenoAgeAccel on CRD. We recommend that the joint assessment may conduce to the accurate identification for populations susceptible to CRD and early prevention of chronic respiratory diseases.

Unraveling the influence of childhood emotional support on adult aging: Insights from the UK Biobank

BACKGROUND

Exploring the association between Childhood Emotional Support (CES) and the mechanisms of aging is pivotal for understanding its potential to lessen the incidence of age-related pathologies and promote a milieu for healthy aging.

METHODS

Utilizing data from the UK Biobank comprising nearly 160,000 individuals, comprehensive analyses were conducted to explore associations between CES levels and age-related diseases, biological age and aging hallmarks. Cox proportional hazards regression models were used to investigate the relationship between CES and the risk of hospitalization for age-related diseases. Linear regression models were employed to explore the associations between CES and the frailty index (FI), Klemera-Doubal method (KDM) biological age acceleration, homeostatic dysregulation (HD), C-reactive protein (CRP), white blood cell (WBC) count, and telomere length.

RESULTS

The analyses revealed a significant association between higher CES levels and a decreased risk of hospitalization for age-related diseases in later life. After adjustments for covariates, the hazard ratio for age-related diseases was 0.87 (95 % confidence interval, 0.83-0.91, p < 0.001) in those with the highest CES level compared to those with the lowest CES level. Participants with the highest CES level exhibited lower FI scores (coefficient = -0.033, p < 0.001), reduced CRP level (coefficient = -0.097, p < 0.05) and lower WBC counts (coefficient = -0.034, p < 0.05). Stratified analyses based on genetic susceptibility further elucidated the protective role of CES against age-related diseases.

CONCLUSION

These findings underscore the potential of early interventions targeting CES to promote healthy aging and alleviating the burden of age-related diseases.

Leukocyte telomere length and lung function: a mendelian randomization study in European population

Background

The telomere has long been regarded as a dependable biomarker for cellular senescence. The lung function can reflect the function and status of the lungs. As individuals age beyond adulthood, there is a gradual decline in lung function. However, the existence of a associated between leukocyte telomere length (LTL) and lung function remains uncertain.

Methods

A two-sample Mendelian randomization (MR) analysis was used. The Single-nucleotide polymorphisms (SNPs) of LTL from the genome-wide association (GWAS) study were used as exposure instruments variable, and the lung function indicator including Forced expiratory volume in 1-s (FEV1), FEV1 Best measure, FEV1 predicted and Forced vital capacity (FVC) from the Neale Lab and MRC-IEU were used as outcomes. The associated between the exposures and outcomes was assessed using inverse-variance weighted (IVW), MR-Egger, and weighted median methods. Sensitivity analysis was conducted using Cochran's Q-test, MR-Egger intercept test, MR-PRESSO, leave-one-out analysis, and Steriger test.

Results

Using the IVW method, a significant association was identified between genetically determined telomere length extension and enhanced lung function in FEV1, with ukb-a-336 (P = 0.127, OR = 1.028,95CI% = 1.003-1.042) and ukb-b-19657 (P = 7.26E-05, OR = 1.051,95CI% = 1.025-1.077),in FEV1 predicted, ukb-a-234 (P = 0.013, OR = 1.029,95CI% = 1.003-1.042), ukb-b-8428 (P = 0.001, OR = 1.032,95CI% = 1.012-1.052), in FEV1 best measure, ukb-a-231 (P = 7.24E-05, OR = 1.050,95CI% = 1.025-1.075), ukb-b-11141 (P = 1.40E-09, OR = 1.067,95CI% = 1.045-1.090).The sensitivity analysis did not reveal heterogeneity or horizontal pleiotropy.Meanwhile, the Steriger test results also indicate that the directionality between exposure and outcome is correct. Therefore, the results indicated robustness.

Conclusion

There is a correlation between longer LTL and better lung function in the European dataset.

Long-term cadmium exposure induces chronic obstructive pulmonary disease-like lung lesions in a mouse model

Accumulating evidences demonstrate that long-term exposure to atmospheric fine particles and air pollutants elevates the risk of chronic obstructive pulmonary disease (COPD). Cadmium (Cd) is one of the important toxic substances in atmospheric fine particles and air pollutants. In this study, we aimed to establish a mouse model to evaluate whether respiratory Cd exposure induces COPD-like lung injury. Adult male C57BL/6 mice were exposed to CdCl₂ (10 mg/L, 4 h per day) by inhaling aerosol for either 10 weeks (short-term) or 6 months (long-term). The mean serum Cd concentration was 6.26 μg/L in Cd-exposed mice. Lung weight and coefficient were elevated in long-term Cd-exposed mice. Pathological scores and alveolar destructive indices were increased in long-term Cd-exposed mouse lungs. Mean linear intercept and airway wall thickness were accordingly elevated in Cd-exposed mice. Inflammatory cell infiltration was obvious and inflammatory cytokines, including TNF-α, IL-1β, IL-6, IL-8, IL-10 and TGF-β, were up-regulated in Cd-exposed mouse lungs. α-SMA, N-cadherin and vimentin, epithelial-mesenchymal transition markers, and extracellular matrix collagen deposition around small airway, determined by Masson's trichrome staining, were shown in Cd-exposed mouse lungs. COPD-characteristic lung function decline was observed in long-term Cd-exposed mice. These outcomes show that long-term respiratory exposure to Cd induces COPD-like lung lesions for the first time.

[Cell senescence, a new target for respiratory viral infections: From influenza virus to SARS-CoV-2]

The accumulation of senescent cells in tissues is a key process of aging and age-related diseases, including lung diseases such as chronic obstructive pulmonary disease, lung fibrosis, or cancer. In recent years, the spectrum of respiratory diseases associated with cellular senescence has been broadened, in particular acute viral pulmonary infections, foremost among which is coronavirus disease 2019 (COVID19), which is particularly severe in the elderly or in subjects with comorbidities. Influenza virus infection, which strikes more severely at the extreme ages of life, is also associated with severe pulmonary senescence. Cellular senescence potentially represents an original target for attacking these diseases, although its specific mechanisms remain largely misunderstood. New anti-senescent therapeutic approaches are thus proposed during severe viral pulmonary infections, with the aim of preventing acute effects and/or, in the longer term, pulmonary sequelae.

Phospholipase A2 receptor 1 promotes lung cell senescence and emphysema in obstructive lung disease

BACKGROUND

Cell senescence is a key process in age-associated dysfunction and diseases, notably chronic obstructive pulmonary disease (COPD). We previously identified phospholipase A2 receptor 1 (PLA2R1) as a positive regulator of cell senescence acting via Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signalling. Its role in pathology, however, remains unknown. Here, we assessed PLA2R1-induced senescence in COPD and lung emphysema pathogenesis.

METHODS

We assessed cell senescence in lungs and cultured lung cells from patients with COPD and controls subjected to PLA2R1 knockdown, PLA2R1 gene transduction and treatment with the JAK1/2 inhibitor ruxolitinib. To assess whether PLA2R1 upregulation caused lung lesions, we developed transgenic mice overexpressing PLA2R1 (PLA2R1-TG) and intratracheally injected wild-type mice with a lentiviral vector carrying the Pla2r1 gene (LV-PLA2R1 mice).

RESULTS

We found that PLA2R1 was overexpressed in various cell types exhibiting senescence characteristics in COPD lungs. PLA2R1 knockdown extended the population doubling capacity of these cells and inhibited their pro-inflammatory senescence-associated secretory phenotype (SASP). PLA2R1-mediated cell senescence in COPD was largely reversed by treatment with the potent JAK1/2 inhibitor ruxolitinib. Five-month-old PLA2R1-TG mice exhibited lung cell senescence, and developed lung emphysema and lung fibrosis together with pulmonary hypertension. Treatment with ruxolitinib induced reversal of lung emphysema and fibrosis. LV-PLA2R1-treated mice developed lung emphysema within 4 weeks and this was markedly attenuated by concomitant ruxolitinib treatment.

CONCLUSIONS

Our data support a major role for PLA2R1 activation in driving lung cell senescence and lung alterations in COPD. Targeting JAK1/2 may represent a promising therapeutic approach for COPD.

Telomere length dynamics over 10-years and related outcomes in patients with COPD

Background

Chronic obstructive pulmonary disease (COPD) has been proposed as a disease of accelerated aging. Several cross-sectional studies have related a shorter telomere length (TL), a marker of biological aging, with COPD outcomes. Whether accelerated telomere shortening over time relates to worse outcomes in COPD patients, is not known.

Methods

Relative telomere length (T/S) was determined by qPCR in DNA samples from peripheral blood in 263 patients at baseline and up to 10 years post enrolment. Yearly clinical and lung function data of 134 patients with at least two-time measures of T/S over this time were included in the analysis.

Results

At baseline, T/S inversely correlated with age (r = − 0.236; p < 0.001), but there was no relationship between T/S and clinical and lung function variables (p > 0.05). Over 10 years of observation, there was a median shortening of TL of 183 bp/year for COPD patients. After adjusting for age, gender, active smoking and mean T/S, patients that shortened their telomeres the most over time, had worse gas exchange, more lung hyperinflation and extrapulmonary affection during the follow-up, (PaO₂ p < 0.0001; K_CO p = 0.042; IC/TLC p < 0.0001; 6MWD p = 0.004 and BODE index p = 0.009). Patients in the lowest tertile of T/S through the follow-up period had an increased risk of death [HR = 5.48, (1.23–24.42) p = 0.026].

Conclusions

This prospective study shows an association between accelerated telomere shortening and progressive worsening of pulmonary gas exchange, lung hyperinflation and extrapulmonary affection in COPD patients. Moreover, persistently shorter telomeres over this observation time increase the risk for all-cause mortality.

[The effect of air pollution in diffuse interstitial lung disease]

Few studies have examined the effects of air pollution in diffuse interstitial lung disease and they have focused on small numbers of patients. Most data are available in idiopathic pulmonary fibrosis and studies suggest that the level of exposure to pollutants may influence the development of acute exacerbations (ozone and NO₂), their incidence (NO₂), decline in respiratory function (PM₁₀) and death (PM₁₀ and PM_2.5). Several studies show an increase in the incidence of rheumatoid arthritis in people living near busy roads. In systemic scleroderma, hypersensitivity pneumonitis and sarcoidosis although negative effects of pollution have been reported the data are insufficient to be conclusive. Nevertheless, the observed effects of air pollution are consistent with those described for other chronic respiratory diseases. Exposure to pollution induces oxidative stress, chronic inflammation and shortening of telomeres, which are all mechanisms described in fibrogenesis. New epidemiological studies are needed with individual measurements of exposure to outdoor and indoor pollution, as well as fundamental studies to clarify the effect of pollution on fibrogenesis.

Lung Function Decline in Farm and Nonfarm Rural Residents of Saskatchewan

OBJECTIVE

This study aims to assess the annual changes in lung function among farm and nonfarm adult residences in rural Saskatchewan, Canada.

METHODS

Data from the Saskatchewan Rural Health Study survey (2010 to 2014) among 724 adults were used.

RESULTS

For forced expiratory volume in 1 second (FEV1) measurements, estimates of annual decline (in milliliters) were highest in older age male (65+ years) (Mean, SD) (-42.63, 21.16); and among old heavy smokers (-57.79, 24.30). Estimates of annual decline in forced vital capacity (FVC) were highest in current smokers without the use of natural gas (-25.78, 14.78) and among old heavy smokers (-33.88, 20.28). Living on a farm is associated with decreased FEV1 and FVC, but not statistically significant by sex and age.

CONCLUSIONS

A complex mix of personal and contextual factors may affect these estimates.

WGS-based telomere length analysis in Dutch family trios implicates stronger maternal inheritance and a role for RRM1 gene

Telomere length (TL) regulation is an important factor in ageing, reproduction and cancer development. Genetic, hereditary and environmental factors regulating TL are currently widely investigated, however, their relative contribution to TL variability is still understudied. We have used whole genome sequencing data of 250 family trios from the Genome of the Netherlands project to perform computational measurement of TL and a series of regression and genome-wide association analyses to reveal TL inheritance patterns and associated genetic factors. Our results confirm that TL is a largely heritable trait, primarily with mother's, and, to a lesser extent, with father's TL having the strongest influence on the offspring. In this cohort, mother's, but not father's age at conception was positively linked to offspring TL. Age-related TL attrition of 40 bp/year had relatively small influence on TL variability. Finally, we have identified TL-associated variations in ribonuclease reductase catalytic subunit M1 (RRM1 gene), which is known to regulate telomere maintenance in yeast. We also highlight the importance of multivariate approach and the limitations of existing tools for the analysis of TL as a polygenic heritable quantitative trait.

Benchmark dose assessment for coke oven emissions-induced telomere length effects in occupationally exposed workers in China

Telomeres are DNA-protein structures that protect chromosome ends from degradation and fusion, which are shortened by oxidative stress, for example air pollution including benzene, toluene, Coke Oven Emissions (COEs), and so on. As a biomarker of health and disease, telomere length is associated with cardiovascular, diabetes and cancers. The aim of this study was to estimate the effects of COEs exposure on telomere length and the benchmark dose (BMD) of COEs. A total of 542 coke oven workers and 235 healthy controls without exposure to toxicants were recruited. Quantitative PCR was used to determine the telomere length in human peripheral blood leukocytes DNA. Propensity scoring was used to match coke oven workers to healthy controls. Linear regression models and trend tests were used to the relationship between COEs exposure and telomere length. Telomere length in COEs exposed group 0.764 (0.536, 1.092) was significantly shorter than that in the control group 1.064(0.762, 1.438), (P < 0.001). There were significantly dose-response relationships between COEs exposure and telomere damage with telomere length as a biomarker. A BMDL value lower than the present occupational exposure limits (OELs) of COEs exposure was evaluated using the BMD approach in coke oven workers. Our results suggested that shorter telomere length is related to occupational exposure to COEs and the level of COEs exposure lower than the current national OELs in China and many other countries could induce telomere damage.

Telomere length in COPD: Relationships with physical activity, exercise capacity, and acute exacerbations

RATIONALE

Shorter leukocyte telomere length (LTL) is associated with reduced health-related quality of life and increased risk for acute exacerbations (AEs) and mortality in chronic obstructive pulmonary disease (COPD). Increased physical activity and exercise capacity are associated with reduced risk for AEs and death. However, the relationships between LTL and physical activity, exercise capacity, and AEs in COPD are unknown.

METHODS

Data from 3 COPD cohorts were examined: Cohort 1 (n = 112, physical activity intervention trial), Cohorts 2 and 3 (n = 182 and 294, respectively, separate observational studies). Subjects completed a 6-minute walk test (6MWT) and provided blood for LTL assessment using real-time PCR. Physical activity was measured as average daily step count using an accelerometer or pedometer. Number of self-reported AEs was available for 1) the year prior to enrollment (Cohorts 1 and 3) and 2) prospectively after enrollment (all cohorts). Multivariate models examined associations between LTL and average daily step count, 6MWT distance, and AEs.

RESULTS

A significant association between longer LTL and increased 6MWT distance was observed in the three combined cohorts (β = 3x10-5, p = 0.045). No association between LTL and average daily step count was observed. Shorter LTL was associated with an increased number of AEs in the year prior to enrollment (Cohorts 1 and 3 combined, β = -1.93, p = 0.04) and with prospective AEs (Cohort 3, β = -1.3388, p = 0.0003).

CONCLUSIONS

Among COPD patients, increased LTL is associated with higher exercise capacity, but not physical activity. Shorter LTL was associated with AEs in a subgroup of cohorts.

Clinical associations with telomere length in chronic spinal cord injury

STUDY DESIGN

Cross-sectional study OBJECTIVES: To determine clinical factors associated with telomere length in persons with chronic spinal cord injury (SCI).

SETTING

Veterans Affairs Medical Center, Boston, MA.

METHODS

Two hundred seventy-eight participants with chronic SCI provided blood samples for measurement of C-reactive protein (CRP), interleukin-6 (IL-6), and telomere length, completed respiratory health questionnaires, underwent dual X-ray absorptiometry (DXA) to assess body fat, and completed spirometry. High-throughput real-time PCR assays were used to assess telomere length in leukocyte genomic DNA. Linear regression models were used to assess cross-sectional associations with telomere length.

RESULTS

Telomere length was inversely related to age (p < 0.0001). In age-adjusted models, gender, race, injury duration, %-total and %-trunk fat, body mass index (BMI), %-predicted forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV₁), chronic cough or phlegm, CRP, IL-6, wheeze, smoking, diabetes, heart disease, chronic obstructive pulmonary disease (COPD), skin ulcer, urinary tract infection (UTI), or chest illness history were not significantly associated with telomere length. There was a suggestive age-adjusted association between persons with the most severe SCI (cervical motor complete and AIS C) and shorter telomere length (p = 0.055), an effect equivalent to ~8.4 years of premature aging. There were similar age-adjusted associations with telomere length between persons using a wheelchair (p = 0.059) and persons with chronic urinary catheter use (p = 0.082) compared to persons without these characteristics.

CONCLUSIONS

Our results suggest that clinical characteristics such as decreased mobility and bladder dysfunction that are common in individuals with more severe SCI are associated with shorter telomere length.

Accelerated lung aging and chronic obstructive pulmonary disease

INTRODUCTION

The prevalence of chronic obstructive pulmonary disease (COPD) increases exponentially with aging. Its pathogenesis, however, is not well known and aside from smoking cessation, there are no disease-modifying treatments for this disease. Areas covered: COPD is associated with accelerating aging and aging-related diseases. In this review, we will discuss the hallmarks of aging including genomic instability, telomere attrition, epigenetic alteration, loss of proteostasis, mitochondrial dysfunction, deregulated nutrient sensing, cellular senescence, stem cell exhaustion, and altered intercellular communication, which may be involved in COPD pathogenesis. Expert commentary: COPD and the aging process share similar molecular and cellular changes. Aging-related molecular pathways may represent novel therapeutic targets and biomarkers for COPD.

Regulation of Eclipta prostrata L. components on cigarette smoking-induced autophagy of bronchial epithelial cells via keap1-Nrf2 pathway

Cigarette smoking extract (CSE)-induced autophagic injury has been regarded as an important contributor to the pathogenesis of lung cancer. We previously found that Eclipta prostrata L. component (CCE) reduced CSE-induced bronchial epithelial cells damage. However, the mechanism remains unknown. Human normal bronchial epithelial cells (NHBE) were exposed to CSE to establish stress model. Nrf2-siRNA and Keap1-siRNA transfection were performed. mRFP-GFP-LC3 dual fluorescence and transmission electron microscopy were used to observe the autophagic characteristics. CCE prevented CSE-induced Nrf2 transfer into cytoplasm and up-regulated Keap1 level of NHBE cells. Furthermore, CCE significantly increased p-p16, p-p21 and p-p53 phosphorylation levels in Nrf2-siRNA- or Keap1-siRNA-transfected cells. As demonstrated by transmission electron microscopy and mRFP-GFP-LC3 dual fluorescence assays, CCE mitigated autophagic injury, and also down-regulated autophagy-related Beclin-1, LC3II/LC3I ratio, Atg5 and ATF4 levels. Our findings showed the attenuation of CCE on CSE-induced NHBE cells injury was associated with Nrf-2-mediated oxidative signaling pathway.