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Huang L, Wang ST, Kuo HP, Delclaux C, Jensen ME, Wood LG, Costa D, Nowakowski D, Wronka I, Oliveira PD, Chen YC, Chen YC, Lee YL. Effects of obesity on pulmonary function considering the transition from obstructive to restrictive pattern from childhood to young adulthood. Obes Rev 2021; 22:e13327. [PMID: 34322972 DOI: 10.1111/obr.13327] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 07/11/2021] [Accepted: 07/11/2021] [Indexed: 12/25/2022]
Abstract
Adults with obesity exhibit a restrictive pattern, whereas children with obesity exhibit an obstructive pattern. However, the transition process remains unclear. We performed a systematic search for studies reporting on body mass index and pulmonary function in children. The main outcomes were forced expiratory volume in 1 s (FEV1 ), forced vital capacity (FVC), and their ratio (FEV1 /FVC). We compared individuals with overweight or with obesity with individuals with normal weight. Random-effects models were used to calculate pooled estimates. A total of 17 studies were included. Individuals with obesity had a lower FEV1 /FVC ratio (mean difference [MD] = -3.61%; 95% confidence interval [CI] = -4.58%, -2.64%) and a higher percent-predicted FVC (MD = 3.33%; 95% CI = 0.79%, 5.88%) than those with normal weight. Obesity impaired pulmonary function in the obstructive pattern during childhood to young adulthood, and the maximum obstruction was observed at the age of 16 years in boys and 20 years in girls. The effects attenuated at approximately 30 years and then shifted to the restrictive pattern after 35 years of age in men and 40 years in women. The effects of obesity on pulmonary function change from the obstructive pattern in childhood to the restrictive pattern in adulthood.
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Pinkerton JW, Kim RY, Brown AC, Rae BE, Donovan C, Mayall JR, Carroll OR, Khadem Ali M, Scott HA, Berthon BS, Baines KJ, Starkey MR, Kermani NZ, Guo YK, Robertson AAB, O'Neill LAJ, Adcock IM, Cooper MA, Gibson PG, Wood LG, Hansbro PM, Horvat JC. Relationship between type 2 cytokine and inflammasome responses in obesity-associated asthma. J Allergy Clin Immunol 2021; 149:1270-1280. [PMID: 34678326 DOI: 10.1016/j.jaci.2021.10.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 09/22/2021] [Accepted: 10/01/2021] [Indexed: 12/13/2022]
Abstract
BACKGROUND Obesity is a risk factor for asthma, and obese asthmatic individuals are more likely to have severe, steroid-insensitive disease. How obesity affects the pathogenesis and severity of asthma is poorly understood. Roles for increased inflammasome-mediated neutrophilic responses, type 2 immunity, and eosinophilic inflammation have been described. OBJECTIVE We investigated how obesity affects the pathogenesis and severity of asthma and identified effective therapies for obesity-associated disease. METHODS We assessed associations between body mass index and inflammasome responses with type 2 (T2) immune responses in the sputum of 25 subjects with asthma. Functional roles for NLR family, pyrin domain-containing (NLRP) 3 inflammasome and T2 cytokine responses in driving key features of disease were examined in experimental high-fat diet-induced obesity and asthma. RESULTS Body mass index and inflammasome responses positively correlated with increased IL-5 and IL-13 expression as well as C-C chemokine receptor type 3 expression in the sputum of subjects with asthma. High-fat diet-induced obesity resulted in steroid-insensitive airway hyperresponsiveness in both the presence and absence of experimental asthma. High-fat diet-induced obesity was also associated with increased NLRP3 inflammasome responses and eosinophilic inflammation in airway tissue, but not lumen, in experimental asthma. Inhibition of NLRP3 inflammasome responses reduced steroid-insensitive airway hyperresponsiveness but had no effect on IL-5 or IL-13 responses in experimental asthma. Depletion of IL-5 and IL-13 reduced obesity-induced NLRP3 inflammasome responses and steroid-insensitive airway hyperresponsiveness in experimental asthma. CONCLUSION We found a relationship between T2 cytokine and NLRP3 inflammasome responses in obesity-associated asthma, highlighting the potential utility of T2 cytokine-targeted biologics and inflammasome inhibitors.
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Althoff MD, Ghincea A, Wood LG, Holguin F, Sharma S. Asthma and Three Colinear Comorbidities: Obesity, OSA, and GERD. THE JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY-IN PRACTICE 2021; 9:3877-3884. [PMID: 34506967 DOI: 10.1016/j.jaip.2021.09.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 08/29/2021] [Accepted: 09/01/2021] [Indexed: 12/18/2022]
Abstract
Asthma is a complex disease with heterogeneous phenotypes and endotypes that are incompletely understood. Obesity, obstructive sleep apnea, and gastroesophageal reflux disease co-occur in patients with asthma at higher rates than in those without asthma. Although these diseases share risk factors, there are some data suggesting that these comorbidities have shared inflammatory pathways, drive the development of asthma, or worsen asthma control. This review discusses the epidemiology, pathophysiology, management recommendations, and key knowledge gaps of these common comorbidities.
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Pathinayake PS, Waters DW, Nichol KS, Brown AC, Reid AT, Hsu ACY, Horvat JC, Wood LG, Baines KJ, Simpson JL, Gibson PG, Hansbro PM, Wark PAB. Endoplasmic reticulum-unfolded protein response signalling is altered in severe eosinophilic and neutrophilic asthma. Thorax 2021; 77:443-451. [PMID: 34510013 DOI: 10.1136/thoraxjnl-2020-215979] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 07/06/2021] [Indexed: 11/04/2022]
Abstract
INTRODUCTION The significance of endoplasmic reticulum (ER) stress in asthma is unclear. Here, we demonstrate that ER stress and the unfolded protein response (UPR) are related to disease severity and inflammatory phenotype. METHODS Induced sputum (n=47), bronchial lavage (n=23) and endobronchial biopsies (n=40) were collected from participants with asthma with varying disease severity, inflammatory phenotypes and from healthy controls. Markers for ER stress and UPR were assessed. These markers were also assessed in established eosinophilic and neutrophilic murine models of asthma. RESULTS Our results demonstrate increased ER stress and UPR pathways in asthma and these are related to clinical severity and inflammatory phenotypes. Genes associated with ER protein chaperone (BiP, CANX, CALR), ER-associated protein degradation (EDEM1, DERL1) and ER stress-induced apoptosis (DDIT3, PPP1R15A) were dysregulated in participants with asthma and are associated with impaired lung function (forced expiratory volume in 1 s) and active eosinophilic and neutrophilic inflammation. ER stress genes also displayed a significant correlation with classic Th2 (interleukin-4, IL-4/13) genes, Th17 (IL-17F/CXCL1) genes, proinflammatory (IL-1b, tumour necrosis factor α, IL-8) genes and inflammasome activation (NLRP3) in sputum from asthmatic participants. Mice with allergic airway disease (AAD) and severe steroid insensitive AAD also showed increased ER stress signalling in their lungs. CONCLUSION Heightened ER stress is associated with severe eosinophilic and neutrophilic inflammation in asthma and may play a crucial role in the pathogenesis of asthma.
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Wood LG. We can do better in COPD: Time for action to preserve body composition. Respirology 2021; 26:828-829. [PMID: 34291542 DOI: 10.1111/resp.14120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 07/15/2021] [Indexed: 11/29/2022]
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Berthon BS, McLoughlin RF, Jensen ME, Hosseini B, Williams EJ, Baines KJ, Taylor SL, Rogers GB, Ivey KL, Morten M, Da Silva Sena CR, Collison AM, Starkey MR, Mattes J, Wark PAB, Wood LG. The effects of increasing fruit and vegetable intake in children with asthma: A randomized controlled trial. Clin Exp Allergy 2021; 51:1144-1156. [PMID: 34197676 DOI: 10.1111/cea.13979] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 06/25/2021] [Indexed: 12/13/2022]
Abstract
BACKGROUND A high fruit and vegetable (F&V) diet reduces asthma exacerbations in adults; this has not been examined in children to date. OBJECTIVE To investigate the effect of a 6-month, high F&V diet on the time to first asthma exacerbation in children with asthma, in a parallel-group, randomized, controlled trial. METHODS Children (aged 3-11 years) with asthma, history of exacerbations and usual low F&V intake (≤3 serves/day) were randomized to the intervention (high F&V diet) or control group (usual diet) for 6 months. The primary outcome was time to first exacerbation requiring medical intervention. Secondary outcomes included exacerbation rate, lung function, plasma TNF-α, CRP, and IL-6, faecal microbiota and peripheral blood mononuclear cell (PBMC) histone deacetylase (HDAC) activity and G-protein coupled receptor (GPR) 41/43 and HDAC (1-11) expression. RESULTS 67 children were randomized between September 2015 and July 2018. F&V intake (difference in change (∆): 3.5 serves/day, 95% CI: [2.6, 4.4] p < 0.001) and plasma total carotenoids (∆: 0.44 µg/ml [0.19, 0.70] p = 0.001) increased after 6 months (intervention vs control). Time to first exacerbation (HR: 0.81, 95% CI: [0.38, 1.69], p = 0.569) and exacerbation rate (IRR: 0.84, [0.47, 1.49], p = 0.553) were similar between groups. In per-protocol analysis, airway reactance z-scores increased (X5 ∆: 0.76 [0.04, 1.48] p = 0.038, X20 ∆: 0.93 [0.23, 1.64] p = 0.009) and changes in faecal microbiota were observed, both in the intervention versus control group, though there was no difference between groups in systemic inflammation or molecular mechanisms. In the control group, CRP and HDAC enzyme activity increased, while GPR41 expression decreased. No adverse events attributable to the interventions were observed. CONCLUSION & CLINICAL RELEVANCE A high F&V diet did not affect asthma exacerbations over the 6-month intervention, though warrants further investigation as a strategy for improving lung function and protecting against systemic inflammation in children with asthma.
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Hosseini B, Berthon BS, Starkey MR, Collison A, McLoughlin RF, Williams EJ, Nichol K, Wark PA, Jensen ME, Da Silva Sena CR, Baines KJ, Mattes J, Wood LG. Children With Asthma Have Impaired Innate Immunity and Increased Numbers of Type 2 Innate Lymphoid Cells Compared With Healthy Controls. Front Immunol 2021; 12:664668. [PMID: 34220812 PMCID: PMC8248177 DOI: 10.3389/fimmu.2021.664668] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 05/17/2021] [Indexed: 12/20/2022] Open
Abstract
Background Asthma is the most frequent cause of hospitalisation among children; however, little is known regarding the effects of asthma on immune responses in children. Objective The present study aimed to evaluate cytokine responses of peripheral blood mononuclear cells (PBMCs), PBMC composition and lung function in children with and without asthma. Methods Using a case-control design, we compared 48 children with asthma aged 3-11 years with 14 age-matched healthy controls. PBMC composition and cytokine production including interferon (IFN)-γ, interleukin (IL)-1β, IL-5 and lL-6 following stimulation with rhinovirus-1B (RV1B), house dust mite (HDM) and lipopolysaccharide (LPS) were measured. Lung function was assessed using impulse oscillometry and nitrogen multiple breath washout. Results The frequency of group 2 innate lymphoid cells were significantly higher in asthmatics and PBMCs from asthmatics had deficient IFN-γ production in response to both RV1B and LPS compared with controls (P<0.01). RV1B-induced IL-1β response and HDM-stimulated IL-5 production was higher in asthmatics than controls (P<0.05). In contrast, IL-1β and IL-6 were significantly reduced in response to HDM and LPS in asthmatics compared to controls (P<0.05). Children with asthma also had reduced pulmonary function, indicated by lower respiratory reactance as well as higher area of-reactance and lung clearance index values compared with controls (P<0.05). Conclusion Our study indicates that children with asthma have a reduced lung function in concert with impaired immune responses and altered immune cell subsets. Improving our understanding of immune responses to viral and bacterial infection in childhood asthma can help to tailor management of the disease.
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Wood LG. Diet and lung disease-Are fruits and vegetables the ideal whole-food intervention? Respirology 2021; 26:527-528. [PMID: 33829597 DOI: 10.1111/resp.14052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 03/14/2021] [Accepted: 03/22/2021] [Indexed: 11/27/2022]
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Thompson CA, Eslick SR, Berthon BS, Wood LG. Asthma medication use in obese and healthy weight asthma: systematic review/meta-analysis. Eur Respir J 2021; 57:13993003.00612-2020. [PMID: 32943399 DOI: 10.1183/13993003.00612-2020] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 08/31/2020] [Indexed: 12/17/2022]
Abstract
BACKGROUND Obesity is a common comorbidity in asthma and associated with poorer asthma control, more frequent/severe exacerbations, and reduced response to asthma pharmacotherapy. OBJECTIVE This review aims to compare use of all classes of asthma medications in obese (body mass index (BMI) ≤30 kg·m-2) versus healthy-weight (BMI <25 kg·m-2) subjects with asthma. DESIGN Databases including CINAHL (Cumulative Index to Nursing and Allied Health Literature), Cochrane, Embase and MEDLINE were searched up to July 2019 for English-language studies that recorded medication use or dose in obese and healthy-weight adults with asthma. A critical appraisal checklist was utilised for scrutinising methodological quality of eligible studies. Meta-analysis was performed and heterogeneity was examined with the use of the Chi-squared test. This review was conducted based on a published protocol (www.crd.york.ac.uk/PROSPERO CRD42020148671). RESULTS Meta-analysis showed that obese subjects are more likely to use asthma medications, including short-acting β2-agonists (OR 1.75, 95% CI 1.17-2.60; p=0.006, I2=41%) and maintenance oral corticosteroids (OR 1.86, 95% CI 1.49-2.31; p<0.001, I2=0%) compared to healthy-weight subjects. Inhaled corticosteroid (ICS) dose (µg·day-1) was significantly higher in obese subjects (mean difference 208.14, 95% CI 107.01-309.27; p<0.001, I2=74%). Forced expiratory volume in 1 s (FEV1) % predicted was significantly lower in obese subjects (mean difference -5.32%, 95% CI -6.75--3.89; p<0.001, I2=42%); however, no significant differences were observed in FEV1/forced vital capacity (FVC) ratio between groups. CONCLUSIONS We found that obese subjects with asthma have higher use of all included asthma medication classes and higher ICS doses than healthy-weight asthma subjects, despite lower FEV1 and a similar FEV1/FVC %. A better understanding of the factors driving increased medication use is required to improve outcomes in this subgroup of asthmatics.
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McLoughlin RF, Berthon BS, Wood LG. Weight loss in obese children with asthma - is it important? Paediatr Respir Rev 2021; 37:10-14. [PMID: 32303450 DOI: 10.1016/j.prrv.2020.02.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 02/28/2020] [Indexed: 12/12/2022]
Abstract
Obesity is a significant public health problem worldwide, and it has been identified as an independent risk factor for asthma in both adults and children. Not only does obesity increase asthma risk, but it is also associated with decreased asthma-related quality of life, worsened symptoms and asthma control, increased frequency and severity of asthma exacerbations and reduced response to asthma medications. In this review we examine the epidemiology and implications of obesity in both children and adults with asthma, and how the obesogenic "western" diet contributes to asthma prevalence and progression. Finally, we summarise the current evidence on the impact of weight loss on asthma outcomes in both adults and children, highlighting the need for further research to be conducted in the paediatric population.
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Bowerman KL, Rehman SF, Vaughan A, Lachner N, Budden KF, Kim RY, Wood DLA, Gellatly SL, Shukla SD, Wood LG, Yang IA, Wark PA, Hugenholtz P, Hansbro PM. Disease-associated gut microbiome and metabolome changes in patients with chronic obstructive pulmonary disease. Nat Commun 2020; 11:5886. [PMID: 33208745 PMCID: PMC7676259 DOI: 10.1038/s41467-020-19701-0] [Citation(s) in RCA: 186] [Impact Index Per Article: 46.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Accepted: 10/19/2020] [Indexed: 02/07/2023] Open
Abstract
Chronic obstructive pulmonary disease (COPD) is the third commonest cause of death globally, and manifests as a progressive inflammatory lung disease with no curative treatment. The lung microbiome contributes to COPD progression, but the function of the gut microbiome remains unclear. Here we examine the faecal microbiome and metabolome of COPD patients and healthy controls, finding 146 bacterial species differing between the two groups. Several species, including Streptococcus sp000187445, Streptococcus vestibularis and multiple members of the family Lachnospiraceae, also correlate with reduced lung function. Untargeted metabolomics identifies a COPD signature comprising 46% lipid, 20% xenobiotic and 20% amino acid related metabolites. Furthermore, we describe a disease-associated network connecting Streptococcus parasanguinis_B with COPD-associated metabolites, including N-acetylglutamate and its analogue N-carbamoylglutamate. While correlative, our results suggest that the faecal microbiome and metabolome of COPD patients are distinct from those of healthy individuals, and may thus aid in the search for biomarkers for COPD. Chronic obstructive pulmonary disease (COPD) is a progressing disease, with lung but not gut microbiota implicated in its etiology. Here the authors compare the stool from patients with COPD and healthy controls to find specific gut bacteria and metabolites associated with active disease, thereby hinting at a potential role for the gut microbiome in COPD.
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Kuszewski JC, Wong RHX, Wood LG, Howe PRC. Effects of fish oil and curcumin supplementation on cerebrovascular function in older adults: A randomized controlled trial. Nutr Metab Cardiovasc Dis 2020; 30:625-633. [PMID: 32127335 DOI: 10.1016/j.numecd.2019.12.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 12/06/2019] [Accepted: 12/19/2019] [Indexed: 01/30/2023]
Abstract
BACKGROUND AND AIMS Chronic conditions such as obesity, which contribute to endothelial dysfunction in older adults, can cause impairments in cerebrovascular perfusion, which is associated with accelerated cognitive decline. Supplementing the diet with bioactive nutrients that can enhance endothelial function, such as fish oil or curcumin, may help to counteract cerebrovascular dysfunction. METHODS AND RESULTS A 16-week double-blind, randomized placebo-controlled trial was undertaken in 152 older sedentary overweight/obese adults (50-80 years, body mass index: 25-40 kg/m2) to investigate effects of fish oil (2000 mg docosahexaenoic acid + 400 mg eicosapentaenoic acid/day), curcumin (160 mg/day) or a combination of both on cerebrovascular function (measured by Transcranial Doppler ultrasound), systemic vascular function (blood pressure, heart rate and arterial compliance) and cardiometabolic (fasting glucose and blood lipids) and inflammatory (C-reactive protein) biomarkers. The primary outcome, cerebrovascular responsiveness to hypercapnia, was not affected by the interventions. However, cerebral artery stiffness was significantly reduced in males following fish oil supplementation (P = 0.007). Furthermore, fish oil reduced heart rate (P = 0.038) and serum triglycerides (P = 0.006) and increased HDL cholesterol (P = 0.002). Curcumin did not significantly affect these outcomes either alone or in combination with fish oil. CONCLUSION Regular supplementation with fish oil but not curcumin improved biomarkers of cardiovascular and cerebrovascular function. The combined supplementation did not result in additional benefits. Further studies are warranted to identify an efficacious curcumin dose and to characterize (in terms of sex, BMI, cardiovascular and metabolic risk factors) populations whose cerebrovascular and cognitive functions might benefit from either intervention. CLINICAL TRIAL REGISTRATION ACTRN12616000732482p.
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Eslick S, Jensen ME, Collins CE, Gibson PG, Hilton J, Wood LG. Characterising a Weight Loss Intervention in Obese Asthmatic Children. Nutrients 2020; 12:nu12020507. [PMID: 32079331 PMCID: PMC7071161 DOI: 10.3390/nu12020507] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 02/06/2020] [Accepted: 02/07/2020] [Indexed: 11/18/2022] Open
Abstract
The prevalence of obesity in asthmatic children is high and is associated with worse clinical outcomes. We have previously reported that weight loss leads to improvements in lung function and asthma control in obese asthmatic children. The objectives of this secondary analysis were to examine: (1) changes in diet quality and (2) associations between the baseline subject characteristics and the degree of weight loss following the intervention. Twenty-eight obese asthmatic children, aged 8–17 years, completed a 10-week diet-induced weight loss intervention. Dietary intake, nutritional biomarkers, anthropometry, lung function, asthma control, and clinical outcomes were analysed before and after the intervention. Following the intervention, the body mass index (BMI) z-score decreased (Δ = 0.18 ± 0.04; p < 0.001), %energy from protein increased (Δ = 4.3 ± 0.9%; p = 0.002), and sugar intake decreased (Δ = 23.2 ± 9.3 g; p= 0.025). Baseline lung function and physical activity level were inversely associated with Δ% fat mass. The ΔBMI z-score was negatively associated with physical activity duration at baseline. Dietary intervention is effective in achieving acute weight loss in obese asthmatic children, with significant improvements in diet quality and body composition. Lower lung function and physical engagement at baseline were associated with lesser weight loss, highlighting that subjects with these attributes may require greater support to achieve weight loss goals.
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Rutting S, Zakarya R, Bozier J, Xenaki D, Horvat JC, Wood LG, Hansbro PM, Oliver BG. Dietary Fatty Acids Amplify Inflammatory Responses to Infection through p38 MAPK Signaling. Am J Respir Cell Mol Biol 2019; 60:554-568. [PMID: 30648905 DOI: 10.1165/rcmb.2018-0215oc] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Obesity is an important risk factor for severe asthma exacerbations, which are mainly caused by respiratory infections. Dietary fatty acids, which are increased systemically in obese patients and are further increased after high-fat meals, affect the innate immune system and may contribute to dysfunctional immune responses to respiratory infection. In this study we investigated the effects of dietary fatty acids on immune responses to respiratory infection in pulmonary fibroblasts and a bronchial epithelial cell line (BEAS-2B). Cells were challenged with BSA-conjugated fatty acids (ω-6 polyunsaturated fatty acids [PUFAs], ω-3 PUFAs, or saturated fatty acids [SFAs]) +/- the viral mimic polyinosinic:polycytidylic acid (poly[I:C]) or bacterial compound lipoteichoic acid (LTA), and release of proinflammatory cytokines was measured. In both cell types, challenge with arachidonic acid (AA) (ω-6 PUFA) and poly(I:C) or LTA led to substantially greater IL-6 and CXCL8 release than either challenge alone, demonstrating synergy. In epithelial cells, palmitic acid (SFA) combined with poly(I:C) also led to greater IL-6 release. The underlying signaling pathways of AA and poly(I:C)- or LTA-induced cytokine release were examined using specific signaling inhibitors and IB. Cytokine production in pulmonary fibroblasts was prostaglandin dependent, and synergistic upregulation occurred via p38 mitogen-activated protein kinase signaling, whereas cytokine production in bronchial epithelial cell lines was mainly mediated through JNK and p38 mitogen-activated protein kinase signaling. We confirmed these findings using rhinovirus infection, demonstrating that AA enhances rhinovirus-induced cytokine release. This study suggests that during respiratory infection, increased levels of dietary ω-6 PUFAs and SFAs may lead to more severe airway inflammation and may contribute to and/or increase the severity of asthma exacerbations.
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Baines KJ, Fricker M, McDonald VM, Simpson JL, Wood LG, Wark PAB, Macdonald HE, Reid A, Gibson PG. Sputum transcriptomics implicates increased p38 signalling activity in severe asthma. Respirology 2019; 25:709-718. [PMID: 31808595 DOI: 10.1111/resp.13749] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 09/12/2019] [Accepted: 10/28/2019] [Indexed: 12/28/2022]
Abstract
BACKGROUND AND OBJECTIVE Severe asthma is responsible for a disproportionate burden of illness and healthcare costs spent on asthma. This study analyses sputum transcriptomics to investigate the mechanisms and novel treatment targets of severe asthma. METHODS Induced sputum samples were collected in a cross-sectional study from participants with severe asthma (n = 12, defined as per GINA criteria), non-severe uncontrolled (n = 21) and controlled asthma (n = 21) and healthy controls (n = 15). Sputum RNA was extracted and transcriptomic profiles were generated (Illumina HumanRef-8 V2) and analysed (GeneSpring). Sputum protein lysates were analysed for p38 activation in a validation study (n = 24 asthma, n = 8 healthy) by western blotting. RESULTS There were 2166 genes differentially expressed between the four groups. In severe asthma, the expression of 1875, 1308 and 563 genes was altered compared to healthy controls, controlled and uncontrolled asthma, respectively. Of the 1875 genes significantly different to healthy controls, 123 were >2-fold change from which four networks were identified. Thirty genes (>2-fold change) were significantly different in severe asthma compared to both controlled asthma and healthy controls. There was enrichment of genes in the p38 signalling pathway that were associated with severe asthma. Phosphorylation of p38 was increased in a subset of severe asthma samples, correlating with neutrophilic airway inflammation. CONCLUSION Severe asthma is associated with substantial differences in sputum gene expression that underlie unique cellular mechanisms. The p38 signalling pathway may be important in the pathogenesis of severe asthma, and future investigations into p38 inhibition are warranted as a 'non-Th2' therapeutic option.
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Williams LM, Scott HA, Wood LG. Soluble fibre as a treatment for inflammation in asthma. JOURNAL OF NUTRITION & INTERMEDIARY METABOLISM 2019. [DOI: 10.1016/j.jnim.2019.100108] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
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Qin L, Gibson PG, Simpson JL, Baines KJ, McDonald VM, Wood LG, Powell H, Fricker M. Dysregulation of sputum columnar epithelial cells and products in distinct asthma phenotypes. Clin Exp Allergy 2019; 49:1418-1428. [PMID: 31264263 DOI: 10.1111/cea.13452] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 06/21/2019] [Accepted: 06/26/2019] [Indexed: 12/22/2022]
Abstract
BACKGROUND Dysfunction of the bronchial epithelium plays an important role in asthma; however, its measurement is challenging. Columnar epithelial cells are often quantified, yet rarely analysed, in induced sputum studies. OBJECTIVE We aimed to test whether sputum columnar epithelial cell proportion and count are altered in asthma, and whether they are associated with clinical and inflammatory variables. We aimed to test whether sputum-based measures could provide a relatively non-invasive means through which to monitor airway epithelial activation status. METHODS We examined the relationship of sputum columnar epithelial cells with clinical and inflammatory variables of asthma in a large retrospective cross-sectional cohort (901 participants with asthma and 138 healthy controls). In further studies, we used flow cytometry, microarray, qPCR and ELISA to characterize sputum columnar epithelial cells and their products. RESULTS Multivariate analysis and generation of 90th centile cut-offs (≥11% or ≥18.1 × 104 /mL) to identify columnar epithelial cell "high" asthma revealed a significant relationship between elevated sputum columnar cells and male gender, severe asthma and non-neutrophilic airway inflammation. Flow cytometry showed viable columnar epithelial cells were present in all sputum samples tested. An epithelial gene signature (SCGB3A1, LDLRAD1, FOXJ1, DNALI1, CFAP157, CFAP53) was detected in columnar epithelial cell-high sputum. CLCA1 mRNA and periostin protein, previously identified biomarkers of IL-13-mediated epithelial activation, were elevated in columnar epithelial cell-high sputum samples, but only when accompanied by eosinophilia. CONCLUSIONS & CLINICAL RELEVANCE Sputum columnar epithelial cells are related to important clinical and inflammatory variables in asthma. Measurement of epithelial biomarkers in sputum samples could allow non-invasive assessment of altered bronchial epithelium status in asthma.
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Tobias TAM, Wood LG, Rastogi D. Carotenoids, fatty acids and disease burden in obese minority adolescents with asthma. Clin Exp Allergy 2019; 49:838-846. [PMID: 30908741 DOI: 10.1111/cea.13391] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 03/05/2019] [Accepted: 03/18/2019] [Indexed: 12/27/2022]
Abstract
BACKGROUND Paediatric obesity-related asthma causes high disease burden, is associated with metabolic abnormalities, has few therapeutic options, and disproportionately affects urban minority children. Although poor diet quality is linked to asthma, the association of nutritional status with disease burden among children with obesity-related asthma is not well understood. OBJECTIVE To quantify nutritional status, defined as concentrations of serum carotenoids and n-3 fatty acids, and its association with pulmonary function and metabolic markers among obese asthmatic children. METHODS We quantified serum carotenoids and fatty acids in a study cohort of 158 urban minority adolescents including 39 obese asthmatics, 39 healthy weight asthmatics, 38 obese controls and 42 healthy weight controls and compared between the groups. We correlated carotenoid and fatty acid levels with pulmonary function indices and with insulin resistance and dyslipidemia. RESULTS Mean total carotenoids were lowest in obese asthmatic children (0.41 μg/mL), lower than healthy weight asthmatics (0.52 μg/mL, P < 0.05) and healthy weight controls (0.60 μg/mL, P < 0.001). n-6/n-3 polyunsaturated fatty acid (PUFA) ratio also differed between the groups (P < 0.05). Total carotenoids positively correlated with per cent-predicted FEV1 and inversely correlated with insulin resistance among obese asthmatics only. n-6/n-3 PUFA ratio inversely correlated with per cent-predicted FEV1 in obese asthmatics. CONCLUSIONS & CLINICAL RELEVANCE Our findings suggest that carotenoids, which are lowest in obese asthmatic children, may have protective effects on metabolic health and pulmonary function among obese asthmatic children. Similarly, n-3 PUFA appear to be protective for pulmonary function.
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Blekkenhorst LC, Lewis JR, Prince RL, Devine A, Bondonno NP, Bondonno CP, Wood LG, Puddey IB, Ward NC, Croft KD, Woodman RJ, Beilin LJ, Hodgson JM. Reply to OM Shannon et al. Am J Clin Nutr 2018; 108:1353-1354. [PMID: 30379994 DOI: 10.1093/ajcn/nqy246] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 09/03/2018] [Indexed: 01/24/2023] Open
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Rutting S, Xenaki D, Malouf M, Horvat JC, Wood LG, Hansbro PM, Oliver BG. Short-chain fatty acids increase TNFα-induced inflammation in primary human lung mesenchymal cells through the activation of p38 MAPK. Am J Physiol Lung Cell Mol Physiol 2018; 316:L157-L174. [PMID: 30407866 DOI: 10.1152/ajplung.00306.2018] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Short-chain fatty acids (SCFAs), produced as by-products of dietary fiber metabolism by gut bacteria, have anti-inflammatory properties and could potentially be used for the treatment of inflammatory diseases, including asthma. The direct effects of SCFAs on inflammatory responses in primary human lung mesenchymal cells have not been assessed. We investigated whether SCFAs can protect against tumor necrosis factor (TNF)α-induced inflammation in primary human lung fibroblasts (HLFs) and airway smooth muscle (ASM) cells in vitro. HLFs and ASM cells were exposed to SCFAs, acetate (C2:0), propionate (C3:0), and butyrate (C4:0) (0.01-25 mM) with or without TNFα, and the release of proinflammatory cytokines, IL-6, and CXCL8 was measured using ELISA. We found that none of the SCFAs suppressed TNFα-induced cytokine release. On the contrary, challenge with supraphysiological concentrations (10-25 mM), as might be used therapeutically, of propionate or butyrate in combination with TNFα resulted in substantially greater IL-6 and CXCL8 release from HLFs and ASM cells than challenge with TNFα alone, demonstrating synergistic effects. In ASM cells, challenge with acetate also enhanced TNFα-induced IL-6, but not CXCL8 release. Synergistic upregulation of IL-6 and CXCL8 was mediated through the activation of free fatty acid receptor (FFAR)3, but not FFAR2. The signaling pathways involved were further examined using specific inhibitors and immunoblotting, and responses were found to be mediated through p38 MAPK signaling. This study demonstrates that proinflammatory, rather than anti-inflammatory effects of SCFAs are evident in lung mesenchymal cells.
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Rutting S, Papanicolaou M, Xenaki D, Wood LG, Mullin AM, Hansbro PM, Oliver BG. Dietary ω-6 polyunsaturated fatty acid arachidonic acid increases inflammation, but inhibits ECM protein expression in COPD. Respir Res 2018; 19:211. [PMID: 30390648 PMCID: PMC6215599 DOI: 10.1186/s12931-018-0919-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 10/21/2018] [Indexed: 02/06/2023] Open
Abstract
Background The obesity paradox in COPD describes protective effects of obesity on lung pathology and inflammation. However, the underlying relationships between obesity, diet and disease outcomes in COPD are not fully understood. In this study we measured the response to dietary fatty acids upon markers of inflammation and remodelling in human lung cells from people with and without COPD. Methods Pulmonary fibroblasts were challenged with ω-3 polyunsaturated fatty acids (PUFAs), ω-6 PUFAs, saturated fatty acids (SFAs) or the obesity-associated cytokine TNFα. After 48–72 h release of the pro-inflammatory cytokines interleukin (IL)-6 and CXCL8 was measured using ELISA and mRNA expression and deposition of the extracellular matrix (ECM) proteins fibronectin, type I collagen, tenascin and perlecan were measured using qPCR or ECM ELISA, respectively. Results Challenge with the ω-6 PUFA arachidonic acid (AA), but not ω-3 PUFAs or SFAs, resulted in increased IL-6 and CXCL8 release from fibroblasts, however IL-6 and CXCL8 release was reduced in COPD (n = 19) compared to non-COPD (n = 36). AA-induced cytokine release was partially mediated by downstream mediators of cyclooxygenase (COX)-2 in both COPD and non-COPD. In comparison, TNFα-induced IL-6 and CXCL8 release was similar in COPD and non-COPD, indicating a specific interaction of AA in COPD. In patients with or without COPD, regression analysis revealed no relationship between BMI and cytokine release. In addition, AA, but not SFAs or ω-3 PUFAs reduced the basal deposition of fibronectin, type I collagen, tenascin and perlecan into the ECM in COPD fibroblasts. In non-COPD fibroblasts, AA-challenge decreased basal deposition of type I collagen and perlecan, but not fibronectin and tenascin. Conclusions This study shows that AA has disease-specific effects on inflammation and ECM protein deposition. The impaired response to AA in COPD might in part explain why obesity appears to have less detrimental effects in COPD, compared to other lung diseases. Electronic supplementary material The online version of this article (10.1186/s12931-018-0919-4) contains supplementary material, which is available to authorized users.
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Wang CS, Wang J, Zhang X, Zhang L, Zhang HP, Wang L, Wood LG, Wang G. Is the consumption of fast foods associated with asthma or other allergic diseases? Respirology 2018; 23:901-913. [PMID: 29974559 DOI: 10.1111/resp.13339] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 02/23/2018] [Accepted: 05/16/2018] [Indexed: 02/05/2023]
Abstract
The associations between the consumption of fast foods and asthma or allergic diseases have not been clarified. The aim of this study was to determine whether fast foods consumption is associated with asthma or allergic diseases. Databases were searched up to February 2018. Studies investigating the associations between fast foods consumption and asthma or allergic diseases were considered eligible. Included studies were assessed for quality using standardized critical appraisal checklists. The quality scores were 5.33 ± 1.16 in case-control studies and 5.69 ± 1.55 in cross-sectional studies. Adjusted odds ratios (aOR) with 95% confidence interval (CI) were pooled. Sixteen studies (13 cross-sectional and 3 case-control studies) were included. The consumption of fast foods was significantly related to current asthma (aOR: 1.58; 95% CI: 1.17-2.13 for case-control study and aOR: 1.58; 95% CI: 1.10-2.26 for cross-sectional studies), severe asthma (aOR: 1.34; 95% CI: 1.23-1.46), asthma ever (aOR: 1.36; 95% CI: 1.06-1.75), current wheeze (aOR: 1.21; 95% CI: 1.16-1.27), wheeze ever (aOR: 1.65; 95% CI: 1.07-2.52), physician-diagnosed allergic rhinitis (odds ratio: 1.43; 95% CI: 1.05-1.95), severe eczema (aOR: 1.51; 95% CI: 1.16-1.96) and severe rhino-conjunctivitis (aOR: 1.54; 95% CI: 1.18-2.00). The consumption of hamburgers was associated with current asthma (aOR: 1.59; 95% CI: 1.13-2.25), severe asthma (aOR: 1.34; 95% CI: 1.23-1.46), asthma ever (aOR: 1.47; 95% CI: 1.13-1.92), severe eczema (aOR: 1.51; 95% CI: 1.16-1.96), severe rhino-conjunctivitis (aOR: 1.54; 95% CI: 1.18-2.00) and rhino-conjunctivitis (aOR: 1.21; 95% CI: 1.15-1.27). The consumption of fast foods, especially hamburgers, ≥3 times/week, was more likely to be associated with severe asthma and current wheeze compared with the consumption of 1-2 times/week (both P < 0.001). In conclusion, the consumption of fast foods, particularly hamburgers, correlates to asthma in a dose-response pattern, which needs to be further validated in longitudinal and interventional studies.
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Hosseini B, Berthon BS, Saedisomeolia A, Starkey MR, Collison A, Wark PAB, Wood LG. Effects of fruit and vegetable consumption on inflammatory biomarkers and immune cell populations: a systematic literature review and meta-analysis. Am J Clin Nutr 2018; 108:136-155. [PMID: 29931038 DOI: 10.1093/ajcn/nqy082] [Citation(s) in RCA: 121] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 03/28/2018] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Inflammation is associated with an increased risk of a range of chronic diseases. A diet high in fruit and vegetables may help to reduce inflammation, as fruit and vegetables are rich sources of antioxidants and other biologically active substances, which may improve immune function. OBJECTIVE To summarize the evidence, we executed a systematic review and meta-analysis examining the effects of fruit and/or vegetable intake on inflammatory biomarkers and immune cells in humans with different diseases and conditions. Design Electronic databases including PubMed, Cochrane, CINAHL, and EMBASE were systematically searched up to March 2018. RESULTS Eighty-three studies were included. Of these, 71 (86%) were clinical trials, and 12 were observational studies (n = 10 cross-sectional and n = 2 cohort). Amongst the observational research, n = 10 studies found an inverse association between intakes of fruit or vegetables and inflammatory biomarkers. Similarly, the majority of the intervention studies (68%, n = 48) reported beneficial effects of fruit or vegetable intake on ≥1 biomarker of systemic or airway inflammation. A meta-analysis of included studies showed that fruit or vegetable intake decreased circulating levels of C-reactive protein and tumor necrosis factor-α (P < 0.05) and increased the γδ-T cell population (P < 0.05). Conclusions In conclusion, this review suggests that higher intakes of fruit and vegetables lead to both a reduction in proinflammatory mediators and an enhanced immune cell profile.
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Blekkenhorst LC, Lewis JR, Prince RL, Devine A, Bondonno NP, Bondonno CP, Wood LG, Puddey IB, Ward NC, Croft KD, Woodman RJ, Beilin LJ, Hodgson JM. Nitrate-rich vegetables do not lower blood pressure in individuals with mildly elevated blood pressure: a 4-wk randomized controlled crossover trial. Am J Clin Nutr 2018; 107:894-908. [PMID: 29868911 DOI: 10.1093/ajcn/nqy061] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Accepted: 03/12/2018] [Indexed: 11/12/2022] Open
Abstract
Background Emerging evidence suggests that increasing intakes of nitrate-rich vegetables may be an effective approach to reduce blood pressure. Objective Our primary aim was to determine whether daily consumption of nitrate-rich vegetables over 4 wk would result in lower blood pressure. Design Thirty participants with prehypertension or untreated grade 1 hypertension were recruited to a randomized controlled crossover trial with 4-wk treatment periods separated by 4-wk washout periods. Participants completed 3 treatments in random order: 1) increased intake (∼200 g/d) of nitrate-rich vegetables [high-nitrate (HN); ∼150 mg nitrate/d], 2) increased intake (∼200 g/d) of nitrate-poor vegetables [low-nitrate (LN); ∼22 mg nitrate/d], and 3) no increase in vegetables (control; ∼6 mg nitrate/d). Compliance was assessed with the use of food diaries and by measuring plasma nitrate and carotenoids. Nitrate metabolism was assessed with the use of plasma, salivary, and urinary nitrate and nitrite concentrations. The primary outcome was blood pressure assessed by using 24-h ambulatory, home, and clinic measurements. Secondary outcomes included measures of arterial stiffness. Results Plasma nitrate and nitrite concentrations increased with the HN treatment in comparison to the LN and control treatments (P < 0.001). Plasma carotenoids increased with the HN and LN treatments compared with the control (P < 0.01). HN treatment did not reduce systolic blood pressure [24-h ambulatory-HN: 127.4 ± 1.1 mm Hg; LN: 128.6 ± 1.1 mm Hg; control: 126.2 ± 1.1 mm Hg (P = 0.20); home-HN: 127.4 ± 0.7 mm Hg; LN: 128.7 ± 0.7 mm Hg; control: 128.3 ± 0.7 mm Hg (P = 0.36); clinic-HN: 128.4 ± 1.3 mm Hg; LN: 130.3 ± 1.3 mm Hg; control: 129.8 ± 1.3 mm Hg (P = 0.49)] or diastolic blood pressure compared with LN and control treatments (P > 0.05) after adjustment for pretreatment values, treatment period, and treatment order. Similarly, no differences were observed between treatments for arterial stiffness measures (P > 0.05). Conclusion Increased intake of nitrate-rich vegetables did not lower blood pressure in prehypertensive or untreated grade 1 hypertensive individuals when compared with increased intake of nitrate-poor vegetables and no increase in vegetables. This trial was registered at www.anzctr.org.au as ACTRN12615000194561.
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Wood LG, Li Q, Scott HA, Rutting S, Berthon BS, Gibson PG, Hansbro PM, Williams E, Horvat J, Simpson JL, Young P, Oliver BG, Baines KJ. Saturated fatty acids, obesity, and the nucleotide oligomerization domain-like receptor protein 3 (NLRP3) inflammasome in asthmatic patients. J Allergy Clin Immunol 2018; 143:305-315. [PMID: 29857009 DOI: 10.1016/j.jaci.2018.04.037] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Revised: 03/29/2018] [Accepted: 04/30/2018] [Indexed: 01/17/2023]
Abstract
BACKGROUND Both obesity and high dietary fat intake activate the nucleotide oligomerization domain-like receptor protein 3 (NLRP3) inflammasome. OBJECTIVE We aimed to examine NLRP3 inflammasome activity in the airways of obese asthmatic patients after macronutrient overload and in immune cells challenged by inflammasome triggers. METHODS Study 1 was a cross-sectional observational study of nonobese (n = 51) and obese (n = 76) asthmatic adults. Study 2 was a randomized, crossover, acute feeding study in 23 asthmatic adults (n = 12 nonobese and n = 11 obese subjects). Subjects consumed 3 isocaloric meals on 3 separate occasions (ie, saturated fatty acid, n-6 polyunsaturated fatty acid, and carbohydrate) and were assessed at 0 and 4 hours. For Studies 1 and 2, airway inflammation was measured based on sputum differential cell counts, IL-1β protein levels (ELISA), and sputum cell gene expression (Nanostring nCounter). In Study 3 peripheral blood neutrophils and monocytes were isolated by using Ficoll density gradient and magnetic bead separation and incubated with or without palmitic acid, LPS, or TNF-α for 24 hours, and IL-1β release was measured (ELISA). RESULTS In Study 1 NLRP3 and nucleotide oligomerization domain 1 (NOD1) gene expression was upregulated, and sputum IL-1β protein levels were greater in obese versus nonobese asthmatic patients. In Study 2 the saturated fatty acid meal led to increases in sputum neutrophil percentages and sputum cell gene expression of Toll-like receptor 4 (TLR4) and NLRP3 at 4 hours in nonobese asthmatic patients. In Study 3 neutrophils and monocytes released IL-1β when challenged with a combination of palmitic acid and LPS or TNF-α. CONCLUSION The NLRP3 inflammasome is a potential therapeutic target in asthmatic patients. Behavioral interventions that reduce fatty acid exposure, such as weight loss and dietary saturated fat restriction, warrant further exploration.
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