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Macrophages play a key role in ozone-induced lung injury by regulating both the initiation and resolution of inflammation. These distinct activities are mediated by pro-inflammatory and anti-inflammatory/proresolution macrophages which sequentially accumulate in injured tissues. Macrophage activation is dependent, in part, on intracellular metabolism. Herein, we used RNA-sequencing (seq) to identify signaling pathways regulating macrophage immunometabolic activity following exposure of mice to ozone (0.8 ppm, 3 h) or air control. Analysis of lung macrophages using an Agilent Seahorse showed that inhalation of ozone increased macrophage glycolytic activity and oxidative phosphorylation at 24 and 72 h post-exposure. An increase in the percentage of macrophages in S phase of the cell cycle was observed 24 h post ozone. RNA-seq revealed significant enrichment of pathways involved in innate immune signaling and cytokine production among differentially expressed genes at both 24 and 72 h after ozone, whereas pathways involved in cell cycle regulation were upregulated at 24 h and intracellular metabolism at 72 h. An interaction network analysis identified tumor suppressor 53 (TP53), E2F family of transcription factors (E2Fs), cyclin-dependent kinase inhibitor 1A (CDKN1a/p21), and cyclin D1 (CCND1) as upstream regulators of cell cycle pathways at 24 h and TP53, nuclear receptor subfamily 4 group a member 1 (NR4A1/Nur77), and estrogen receptor alpha (ESR1/ERα) as central upstream regulators of mitochondrial respiration pathways at 72 h. To assess whether ERα regulates metabolic activity, we used ERα-/- mice. In both air and ozone-exposed mice, loss of ERα resulted in increases in glycolytic capacity and glycolytic reserve in lung macrophages with no effect on mitochondrial oxidative phosphorylation. Taken together, these results highlight the complex interaction between cell cycle, intracellular metabolism, and macrophage activation which may be important in the initiation and resolution of inflammation following ozone exposure., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Recent studies have identified exposure to environmental levels of ozone as a risk factor for the development of acute respiratory distress syndrome (ARDS), a severe form of acute lung injury (ALI) that can develop in humans with sepsis. The aim of this study was to develop a murine model of ALI to mechanistically explore the impact of ozone exposure on ARDS development. Mice were exposed to ozone (0.8 ppm, 3 h) or air control followed 24 h later by intravenous administration of 3 mg/kg lipopolysaccharide (LPS) or PBS. Exposure of mice to ozone + LPS caused alveolar hyperplasia; increased BAL levels of albumin, IgM, phospholipids, and proinflammatory mediators including surfactant protein D and soluble receptor for advanced glycation end products were also detected in BAL, along with markers of oxidative and nitrosative stress. Administration of ozone + LPS resulted in an increase in neutrophils and anti-inflammatory macrophages in the lung, with no effects on proinflammatory macrophages. Conversely, the numbers of resident alveolar macrophages decreased after ozone + LPS; however, expression of Nos2, Arg1, Cxcl1, Cxcl2, Ccl2 by these cells increased, indicating that they are activated. These findings demonstrate that ozone sensitizes the lung to respond to endotoxin, resulting in ALI, oxidative stress, and exacerbated pulmonary inflammation, and provide support for the epidemiologic association between ozone exposure and ARDS incidence., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Exposure to ozone causes decrements in pulmonary function, a response associated with alterations in lung lipids. Pulmonary lipid homeostasis is dependent on the activity of peroxisome proliferator activated receptor gamma (PPARγ), a nuclear receptor that regulates lipid uptake and catabolism by alveolar macrophages (AMs). Herein, we assessed the role of PPARγ in ozone-induced dyslipidemia and aberrant lung function in mice. Exposure of mice to ozone (0.8 ppm, 3 h) resulted in a significant reduction in lung hysteresivity at 72 h post exposure; this correlated with increases in levels of total phospholipids, specifically cholesteryl esters, ceramides, phosphatidylcholines, phosphorylethanolamines, sphingomyelins, and di- and triacylglycerols in lung lining fluid. This was accompanied by a reduction in relative surfactant protein-B (SP-B) content, consistent with surfactant dysfunction. Administration of the PPARγ agonist, rosiglitazone (5 mg/kg/day, i.p.) reduced total lung lipids, increased relative amounts of SP-B, and normalized pulmonary function in ozone-exposed mice. This was associated with increases in lung macrophage expression of CD36, a scavenger receptor important in lipid uptake and a transcriptional target of PPARγ. These findings highlight the role of alveolar lipids as regulators of surfactant activity and pulmonary function following ozone exposure and suggest that targeting lipid uptake by lung macrophages may be an efficacious approach for treating altered respiratory mechanics., (© The Author(s) 2023. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Inflammatory macrophages are known to contribute to ozone toxicity. Farnesoid X receptor (FXR) is a nuclear receptor involved in regulating bile acid and lipid homeostasis; it also exerts anti-inflammatory activity by suppressing macrophage NF-κB. Herein, we analyzed the role of FXR in regulating macrophage activation in the lung following ozone exposure. Treatment of wild-type (WT) mice with ozone (0.8 ppm, 3 h) resulted in increases in proinflammatory (F4/80+CD11c+CD11b+Ly6CHi) and anti-inflammatory (F4/80+CD11c+CD11b+Ly6CLo) macrophages in the lung. The accumulation of proinflammatory macrophages was increased in FXR-/- mice compared with WT mice; however, anti-inflammatory macrophage activation was blunted as reflected by reduced arginase and mannose receptor expression, a response correlated with decreased Nur77. This was associated with prolonged oxidative stress, as measured by 4-hydroxynonenal-modified proteins in the lung. Loss of FXR was accompanied by protracted increases in lung NF-κB activity and its target, inducible nitric oxide synthase in response to ozone. Levels of Tnf-α, Il-1β, Ccr2, Ccl2, Cx3cr1, and Cx3cl1 were also increased in lungs of FXR-/- relative to WT mice; conversely, genes regulating lipid homeostasis including Lxrα, Apoe, Vldlr, Abcg1, and Abca1 were downregulated, irrespective of ozone exposure. In FXR-/- mice, ozone caused an increase in total lung phospholipids, with no effect on SP-B or SP-D. Dyslipidemia was correlated with blunting of ozone-induced increases in positive end-expiratory pressure-dependent quasi-static pressure volume curves indicating a stiffer lung in FXR-/- mice. These findings identify FXR as a regulator of macrophage activation following ozone exposure suggesting that FXR ligands may be useful in mitigating inflammation and oxidative stress induced by pulmonary irritants., (© The Author(s) 2020. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Nitrogen mustard (NM) is a vesicant known to target the lung, causing acute injury which progresses to fibrosis. Evidence suggests that activated macrophages contribute to the pathologic response to NM. In these studies, we analyzed the role of lung lipids generated following NM exposure on macrophage activation and phenotype. Treatment of rats with NM (0.125 mg/kg, i.t.) resulted in a time-related increase in enlarged vacuolated macrophages in the lung. At 28 days postexposure, macrophages stained positively for Oil Red O, a marker of neutral lipids. This was correlated with an accumulation of oxidized phospholipids in lung macrophages and epithelial cells and increases in bronchoalveolar lavage fluid (BAL) phospholipids and cholesterol. RNA-sequencing and immunohistochemical analysis revealed that lipid handling pathways under the control of the transcription factors liver-X receptor (LXR), farnesoid-X receptor (FXR), peroxisome proliferator-activated receptor (PPAR)-ɣ, and sterol regulatory element-binding protein (SREBP) were significantly altered following NM exposure. Whereas at 1-3 days post NM, FXR and the downstream oxidized low-density lipoprotein receptor, Cd36, were increased, Lxr and the lipid efflux transporters, Abca1 and Abcg1, were reduced. Treatment of naïve lung macrophages with phospholipid and cholesterol enriched large aggregate fractions of BAL prepared 3 days after NM exposure resulted in upregulation of Nos2 and Ptgs2, markers of proinflammatory activation, whereas large aggregate fractions prepared 28 days post NM upregulated expression of the anti-inflammatory markers, Il10, Cd163, and Cx3cr1, and induced the formation of lipid-laden foamy macrophages. These data suggest that NM-induced alterations in lipid handling and metabolism drive macrophage foam cell formation, potentially contributing to the development of pulmonary fibrosis., (© The Author(s) 2019. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Nitrogen mustard (NM) is a vesicant known to cause acute pulmonary injury which progresses to fibrosis. Macrophages contribute to both of these pathologies. Surfactant protein (SP)-D is a pulmonary collectin that suppresses lung macrophage activity. Herein, we analyzed the effects of loss of SP-D on NM-induced macrophage activation and lung toxicity. Wild-type (WT) and SP-D-/- mice were treated intratracheally with PBS or NM (0.08 mg/kg). Bronchoalveolar lavage (BAL) fluid and tissue were collected 14 days later. In WT mice, NM caused an increase in total SP-D levels in BAL; multiple lower molecular weight forms of SP-D were also identified, consistent with lung injury and oxidative stress. Flow cytometric analysis of BAL cells from NM treated WT mice revealed the presence of proinflammatory and anti-inflammatory macrophages. Whereas loss of SP-D had no effect on numbers of these cells, their activation state, as measured by proinflammatory (iNOS, MMP-9), and anti-inflammatory (MR-1, Ym-1) protein expression, was amplified. Loss of SP-D also exacerbated NM-induced oxidative stress and alveolar epithelial injury, as reflected by increases in heme oxygenase-1 expression, and BAL cell and protein content. This was correlated with alterations in pulmonary mechanics. In NM-treated SP-D-/-, but not WT mice, there was evidence of edema, epithelial hypertrophy and hyperplasia, bronchiectasis, and fibrosis, as well as increases in BAL phospholipid content. These data demonstrate that activated lung macrophages play a role in NM-induced lung injury and oxidative stress. Elucidating mechanisms regulating macrophage activity may be important in developing therapeutics to treat mustard-induced lung injury.

Nitrogen mustard (NM)-induced lung injury is associated with an accumulation of proinflammatory/cytotoxic M1 and antiinflammatory/wound repair M2 macrophages, which have been implicated in tissue injury and repair. Herein, we analyzed the effects of valproic acid (VPA), a histone deacetylase (HDAC) inhibitor with antiinflammatory and antioxidant activity, on lung macrophages responding to NM. Treatment of rats with NM (0.125 mg/kg, i.t.) resulted in structural alterations in the lung and a macrophage-rich inflammatory cell infiltrate, at 3 d and 7 d. This was accompanied by expression of PCNA, a marker of proliferation, and CYPb5, HO-1, and MnSOD, markers of oxidative stress. Administration of VPA (300 mg/kg/day; i.p.), beginning 30 min after NM, reduced increases in PCNA, CYPb5, HO-1, and MnSOD. This was associated with increases in immature CD11b+CD43+ M1 macrophages in the lung, and decreases in mature CD11b+CD43- M2 macrophages 3 d post NM, suggesting delayed maturation and phenotypic switching. VPA also attenuated NM-induced increases in lung iNOS+ and CCR2+ M1 macrophages, a response correlated with downregulation of NOS2, IL12B, PTGS2, MMP-9, and CCR2 expression. Conversely, numbers of CD68+, CD163+ , and ATR-1α+ M2 macrophages increased after VPA, along with the expression of IL10, ApoE, and ATR-1A. NM exposure resulted in increased HDAC activity and upregulation of HDAC2 and acetylated H3K9 in the lung. Whereas VPA blunted the effects of NM on HDAC2 expression, histone H3K9 acetylation increased. These data suggest that alterations in the balance between histone acetylases and deacetylases contribute to lung macrophage maturation and activation following NM exposure., (© The Author 2017. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)

Macrophages and inflammatory mediators have been implicated in ozone toxicity. In these studies, we used splenectomized (SPX) mice to assess the contribution of splenic monocytes to pulmonary inflammation and injury induced by ozone. Cells and tissue were collected 24-72 h after exposure of mice to air or ozone (0.8 ppm, 3 h). Following ozone exposure, increased numbers of pro-inflammatory CD11b  +  Ly6C Hi and anti-inflammatory CD11b  +  Ly6C Lo monocytes were observed in spleens of control (CTL) mice. CD11b  +  Ly6C Hi and MMP-9 +  pro-inflammatory macrophages were also observed in lungs of CTL mice after ozone, along with CD11b  +  Ly6C Lo and mannose receptor (MR) + anti-inflammatory macrophages. This was accompanied by increased lung expression of proteins involved in monocyte/macrophage trafficking including CCL3, CCL4, CCR1, and AT1R. Splenectomy resulted in decreases in pro-inflammatory macrophages in the lung and down regulation of CCR2, CCL2, and CCL4, but increases in CD11b  +  Ly6C Lo anti-inflammatory macrophages. CD11b + Ly6G + Ly6C + granulocytic (G)- and monocytic (M)-myeloid derived suppressor cells (MDSC)s were also detected in the lungs and spleens of CTL mice; these increased after ozone exposure. Splenectomy was associated with a decrease in G-MDSCs in the lung, with no effect on M-MDSCs. Changes in lung macrophage subpopulations and MDSCs in SPX mice were correlated with reduced ozone toxicity, as measured by decreases in bronchoalveolar lavage protein content and reduced 4-hydroxynonenal expression in the lung. These data suggest that the spleen is a source of pro-inflammatory/cytotoxic macrophages that contribute to ozone-induced lung injury, inflammation, and oxidative stress., (© The Author 2016. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)

Background: to examine associations between social resources and cognitive ageing over 30 years., Methods: participants in the Glostrup 1914 Cohort, a year of birth sample, completed a standardarised battery of cognitive ability tests every 10 years from age 50 to 80, summarised as general cognitive ability. Participants also provided information concerning a range of social resources, including marital status and living arrangements from age 50, and from age 70, details regarding social support, social contact and loneliness., Results: across the follow-up, participants were less likely to be married, falling from 85.0 to 40.4% between ages 50 and 80, while the proportion of those living alone increased from 13.1 to 54.2%. In separate growth curve models, being married, living with others and not feeling lonely were all associated with higher cognitive ability level, while more telephone contact had a negative association. Marital status (at ages 50 and 60) and loneliness at age 70 were the only social resources associated with cognitive change; married individuals and those not feeling lonely experienced less cognitive decline. When the social resources showing significant associations were considered together (and accounting for sex, education and social class), loneliness was associated with lower cognitive ability level and greater cognitive decline, while married individuals experienced less decline., Conclusions: in a relatively large cohort followed for up to 30 years, marital status and loneliness were associated with cognitive ability or change. Interventions designed to reduce loneliness in older adults might be supported as one avenue to reduce cognitive ageing., (© The Author 2016. Published by Oxford University Press on behalf of the British Geriatrics Society. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Background: while sexual behaviours are potentially important for quality of life in older adults, they are under-researched. The current study examined associations between frequency and importance of sexual behaviours and quality of life in older adults., Method: one hundred and thirty-three participants (mean 74 years, SD = 7.1) provided information about the frequency with which they participated in six sexual behaviours and the perceived importance of these: touching/holding hands, embracing/hugging, kissing, mutual stroking, masturbating and intercourse. Participants also completed the WHO Quality of Life scale, providing an overall quality of life score, in addition to the domains of physical health, psychological health, social relationships and environment. Participants provided information on their marital status, living arrangements and self-reported health., Results: both the frequency and importance of sexual behaviours were moderately positively correlated with quality of life (r = 0.52 and 0.47, respectively, both P < 0.001). In separate regression analyses, the frequency of sexual behaviours was a significant predictor of quality of life in the social relationships domain (β = 0.225, P < 0.05), and the importance of sexual behaviours was associated with the psychological domain (β = 0.151, P < 0.05), independent of the presence of a spouse/partner and self-reported health., Conclusions: with ageing trends, a broader understanding of the factors that influence quality of life in older adults is increasingly important. The current findings suggest that aspects of sexual behaviour and quality of life were positively associated. Researchers are encouraged to consider aspects of sex and sexuality when exploring determinants of well-being in later life., (© The Author 2015. Published by Oxford University Press on behalf of the British Geriatrics Society. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Reactive nitrogen species (RNS) generated after exposure to radiation have been implicated in lung injury. Surfactant protein D (SP-D) is a pulmonary collectin that suppresses inducible nitric oxide synthase (iNOS)-mediated RNS production. Herein, we analyzed the role of iNOS and SP-D in radiation-induced lung injury. Exposure of wild-type (WT) mice to γ-radiation (8 Gy) caused acute lung injury and inflammation, as measured by increases in bronchoalveolar lavage (BAL) protein and cell content at 24 h. Radiation also caused alterations in SP-D structure at 24 h and 4 weeks post exposure. These responses were blunted in iNOS(-/-) mice. Conversely, loss of iNOS had no effect on radiation-induced expression of phospho-H2A.X or tumor necrosis factor (TNF)-α. Additionally, at 24 h post radiation, cyclooxygenase expression and BAL lipocalin-2 levels were increased in iNOS(-/-) mice, and heme oxygenase (HO)-1(+) and Ym1(+) macrophages were evident. Loss of SP-D resulted in increased numbers of enlarged HO-1(+) macrophages in the lung following radiation, along with upregulation of TNF-α, CCL2, and CXCL2, whereas expression of phospho-H2A.X was diminished. To determine if RNS play a role in the altered sensitivity of SP-D(-/-) mice to radiation, iNOS(-/-)/SP-D(-/-) mice were used. Radiation-induced injury, oxidative stress, and tissue repair were generally similar in iNOS(-/-)/SP-D(-/-) and SP-D(-/-) mice. In contrast, TNF-α, CCL2, and CXCL2 expression was attenuated. These data indicate that although iNOS is involved in radiation-induced injury and altered SP-D structure, in the absence of SP-D, it functions to promote proinflammatory signaling. Thus, multiple inflammatory pathways contribute to the pathogenic response to radiation., (© The Author 2014. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)

In these studies, we analyzed the effects of ozone on bronchiolar epithelium. Exposure of rats to ozone (2 ppm, 3 h) resulted in rapid (within 3 h) and persistent (up to 72 h) histological changes in the bronchiolar epithelium, including hypercellularity, loss of cilia, and necrotizing bronchiolitis. Perivascular edema and vascular congestion were also evident, along with a decrease in Clara cell secretory protein in bronchoalveolar lavage, which was maximal 24 h post-exposure. Ozone also induced the appearance of 8-hydroxy-2'-deoxyguanosine, Ym1, and heme oxygenase-1 in the bronchiolar epithelium. This was associated with increased expression of cleaved caspase-9 and beclin-1, indicating initiation of apoptosis and autophagy. A rapid and persistent increase in galectin-3, a regulator of epithelial cell apoptosis, was also observed. Following ozone exposure (3-24 h), increased expression of cyclooxygenase-2, inducible nitric oxide synthase, and arginase-1 was noted in bronchiolar epithelium. Ozone-induced injury and oxidative stress in bronchiolar epithelium were linked to methacholine-induced alterations in pulmonary mechanics. Thus, significant increases in lung resistance and elastance, along with decreases in lung compliance and end tidal volume, were observed at higher doses of methacholine. This indicates that ozone causes an increase in effective stiffness of the lung as a consequence of changes in the conducting airways. Collectively, these studies demonstrate that bronchiolar epithelium is highly susceptible to injury and oxidative stress induced by acute exposure to ozone; moreover, this is accompanied by altered lung functioning.

This cohort profile describes the origins, tracing, recruitment, testing and follow-up of the University of Edinburgh-based Lothian Birth Cohorts of 1921 (LBC1921; N = 550) and 1936 (LBC1936; N = 1091). The participants undertook a general intelligence test at age 11 years and were recruited for these cohorts at mean ages of 79 (LBC1921) and 70 (LBC1936). The LBC1921 have been examined at mean ages of 79, 83, 87 and 90 years. The LBC1936 have been examined at mean ages of 70 and 73 years, and are being seen at 76 years. Both samples have an emphasis on the ageing of cognitive functions as outcomes. As they have childhood intelligence test scores, the cohorts' data have been used to search for determinants of lifetime cognitive changes, and also cognitive change within old age. The cohorts' outcomes also include a range of physical and psycho-social aspects of well-being in old age. Both cohorts have a wide range of variables: genome-wide genotyping, demographics, psycho-social and lifestyle factors, cognitive functions, medical history and examination, and biomarkers (from blood and urine). The LBC1936 participants also have a detailed structural magnetic resonance imaging (MRI) brain scan. A range of scientific findings is described, to illustrate the possible uses of the cohorts.

Introduction: Age-associated cognitive decline-or normal (non-pathological, normative, usual) cognitive ageing-is an important human experience which differs in extent between individuals. The determinants of the differences in age-related cognitive decline are not fully understood. Progress in the field is taking place across many areas of biomedical and psychosocial sciences., Areas of Agreement and Controversy: The phenotype of normal cognitive ageing is well described. Some mental capabilities are well maintained into old age. From early adulthood, there are declines in mental domains such as processing speed, reasoning, memory and executive functions, some of which is underpinned by a decline in a general cognitive factor. There are contributions to understanding individual differences in normal cognitive ageing from genetics, general health and medical disorders such as atherosclerotic disease, biological processes such as inflammation, neurobiological changes, diet and lifestyle. Many of these effect sizes are small; some are poorly replicated; and in some cases, there is the possibility of reverse causation, with prior cognitive ability causing the supposed 'cause' of cognitive ability in old age., Emerging Areas for Developing Research: Genome-wide scans are a likely source to establish genetic contributions. The role of vascular factors in cognitive ageing is increasingly studied and understood. The same applies to diet, biomarkers such as inflammation and lifestyle factors such as exercise. There are marked advances in brain imaging, affording better in vivo studies of brain correlates of cognitive changes. There is growing appreciation that factors affecting general bodily ageing also influence cognitive functions in old age.

Surfactant protein-D (SP-D), a member of the "collectin" family, has been shown to play a role in innate immunity through modulation of inflammation and clearance of organisms. The role of SP-D in host defense against Pneumocystis carinii pneumonia was assessed using SP-D knockout (KO) mice. When inoculated with P. carinii, both wild-type (wt) and SP-D KO mice required CD4 cell depletion to develop infection. In CD4 cell-depleted models, 2 weeks after infection with P. carinii, SP-D KO mice developed increased intensity of infection, compared with wt mice, despite higher lung-inflammation scores and increased amounts of alveolar inflammatory cells. The increased inflammation seen in SP-D KO mice was accompanied by increases in lung weight, expression of inducible nitric oxide (NO) synthase, total NO levels, and 3-nitrotyrosine levels in lung tissue. These results indicate that SP-D plays a role in host defense against P. carinii in vivo by modulating clearance of organisms, lung inflammation, and metabolism of NO.