Role of macrophage migration inhibitory factor in age-related lung disease

Airway-derived emphysema-specific alveolar type II cells exhibit impaired regenerative potential in COPD

Emphysema, the progressive destruction of gas exchange surfaces in the lungs, is a hallmark of COPD that is presently incurable. This therapeutic gap is largely due to a poor understanding of potential drivers of impaired tissue regeneration, such as abnormal lung epithelial progenitor cells, including alveolar type II (ATII) and airway club cells. We discovered an emphysema-specific subpopulation of ATII cells located in enlarged distal alveolar sacs, termed asATII cells. Single-cell RNA sequencing and in situ localisation revealed that asATII cells co-express the alveolar marker surfactant protein C and the club cell marker secretaglobin-3A2 (SCGB3A2). A similar ATII subpopulation derived from club cells was also identified in mouse COPD models using lineage labelling. Human and mouse ATII subpopulations formed 80-90% fewer alveolar organoids than healthy controls, indicating reduced progenitor function. Targeting asATII cells or their progenitor club cells could reveal novel COPD treatment strategies.

Lung Cancer: New Directions in Senior Patients Assessment

Age is but one significant prognostic factor in lung cancer, influencing survival, treatment response, and outcomes. This narrative review synthesizes findings from searches of 11 leading databases of research studies, systematic reviews, book chapters, and clinical trial reports on lung cancer in senior patients, with a focus on geriatric assessment as well as biomarkers. Key prognostic factors for lung cancer in seniors include biological age, functional capability, physical and psychological comorbidities, frailty, nutrition, status, and biomarkers like DNA methylation age. We identified the most valuable assessments that balance efficacy with quality of life. Optimizing care and improving outcomes with senior lung cancer patients benefits from a tailored therapeutic approach incorporating a complex geriatric assessment. A multidisciplinary collaboration between geriatricians, oncologists, and pulmonologists is crucial.

Transcriptomics Analysis Identifies the Decline in the Alveolar Type II Stem Cell Niche in Aged Human Lungs

Aging poses a global public health challenge, which is linked to the rise of age-related lung diseases. The precise understanding of the molecular and genetic changes in the aging lung that elevate the risk of acute and chronic lung diseases remains incomplete. Alveolar type II (AT2) cells are stem cells that maintain epithelial homeostasis and repair the lung after injury. AT2 progenitor function decreases with aging. The maintenance of AT2 function requires niche support from other cell types, but little has been done to characterize alveolar alterations with aging in the AT2 niche. To systematically profile the genetic changes associated with age, we present a single-cell transcriptional atlas comprising nearly half a million cells from the healthy lungs of human subjects spanning various ages, sexes, and smoking statuses. Most annotated cell lineages in aged lungs exhibit dysregulated genetic programs. Specifically, the aged AT2 cells demonstrate loss of epithelial identities, heightened inflammaging characterized by increased expression of AP-1 (Activator Protein-1) transcription factor and chemokine genes, and significantly increased cellular senescence. Furthermore, the aged mesenchymal cells display a remarkable decrease in collagen and elastin transcription and a loss of support to epithelial cell stemness. The decline of the AT2 niche is further exacerbated by a dysregulated genetic program in macrophages and dysregulated communications between AT2 and macrophages in aged human lungs. These findings highlight the dysregulations observed in both AT2 stem cells and their supportive niche cells, potentially contributing to the increased susceptibility of aged populations to lung diseases.

Candidate molecular targets uncovered in mouse lifespan extension studies

INTRODUCTION

Multiple interventions have demonstrated an increase in mouse lifespan. However, non-standardized controls, sex or strain-specific factors, and insufficient focus on targets, hinder the translation of these findings into clinical applications.

AREAS COVERED

We examined the effects of genetic and drug-based interventions on mice from databases DrugAge, GenAge, the Mouse Phenome Database, and publications from PubMed that led to a lifespan extension of more than 10%, identifying specific molecular targets that were manipulated to achieve the maximum lifespan in mice. Subsequently, we characterized 10 molecular targets influenced by these interventions, with particular attention given to clinical trials and potential indications for each.

EXPERT OPINION

To increase the translational potential of mice life-extension studies to clinical research several factors are crucial: standardization of mice lifespan research approaches, the development of clear criteria for control and experimental groups, the establishment of criteria for potential geroprotectors, and focusing on targets and their clinical application. Pinpointing the targets affected by geroprotectors helps in understanding species-specific differences and identifying potential side effects, ensuring the safety and effectiveness of clinical trials. Additionally, target review facilitates the optimization of treatment protocols and the evaluation of the clinical feasibility of translating research findings into practical therapies for humans.

Reactive Oxygen Species-Responsive Dual Anti-Inflammatory and Antioxidative Nanoparticles for Anterior Uveitis

Anterior uveitis (AU) is an immune-mediated inflammatory disease that results in iritis, cyclitis, glaucoma, cataracts, and even a loss of vision. The frequent and long-term administration of corticosteroid drugs is limited in the clinic owing to the side effects and patient noncompliance with the drugs. Therefore, specifically delivering drugs to inflammatory anterior segment tissues and reducing the topical application dosage of the drug are still a challenge. Here, we developed dual dexamethasone (Dex) and curcumin (Cur)-loaded reactive oxygen species (ROS)-responsive nanoparticles (CPDC NPs) to treat anterior uveitis. The CPDC NPs demonstrated both anti-inflammatory and antioxidative effects, owing to their therapeutic characteristics of dexamethasone and curcumin, respectively. The CPDC NPs could effectively release dexamethasone and curcumin in the oxidizing physiological environment of the inflammation tissue. The CPDC NPs can effectively internalize by activated macrophage cells, subsequently suppressing the proinflammatory factor expression. Moreover, the CPDC NPs can inhibit ROS and inflammation via nuclear transcription factor E2-related factor 2/heme oxygenase-1 (Nrf2/HO-1) pathway activation. In an endotoxin-induced uveitis rabbit model, the CPDC NPs show a therapeutic effect that is better than that of either free drugs or commercial eye drops. Importantly, the CPDC NPs with a lower dexamethasone dosage could reduce the side effects significantly. Taken together, we believe that the dual-drug-loaded ROS-responsive NPs could effectively target and inhibit inflammation and have the potential for anterior uveitis treatment in clinical practice.

Plant MDL proteins synergize with the cytokine MIF at CXCR2 and CXCR4 receptors in human cells

Mammalian macrophage migration inhibitory factor (MIF) and its paralog, D-dopachrome tautomerase, are multifunctional inflammatory cytokines. Plants have orthologous MIF and D-dopachrome tautomerase-like (MDL) proteins that mimic some of the effects of MIF on immune cells in vitro. We explored the structural and functional similarities between the three Arabidopsis thaliana MDLs and MIF. X-ray crystallography of the MDLs revealed high structural similarity between MDL and MIF homotrimers and suggested a potential explanation for the lack of tautomerase activity in the MDLs. MDL1 and MDL2 interacted with each other and with MIF in vitro, in yeast, and in plant leaves and formed hetero-oligomeric complexes with MIF in vitro. The MDLs stimulated signaling through the MIF receptors CXCR2 or CXCR4 and enhanced the responses to MIF in a yeast reporter system, in human neutrophils, and in human lung epithelial cells. Pharmacological inhibitors that disrupted MIF activity or prevented the formation of MIF-MDL hetero-oligomers blocked the observed synergism. These findings demonstrate that MDLs can enhance cellular responses to MIF, which may have functional implications in tissues exposed to MDLs from the diet or environment.

Utility of a three-gene transcriptomic signature in the diagnosis of tuberculosis in a low-endemic hospital setting

BACKGROUND

Host transcriptomic blood signatures have demonstrated diagnostic potential for tuberculosis (TB), requiring further validation across different geographical settings. Discriminating TB from other diseases with similar clinical manifestations is crucial for the development of an accurate immunodiagnostic tool. In this exploratory cohort study, we evaluated the performance of potential blood-based transcriptomic signatures in distinguishing TB disease from non-TB lower respiratory tract infections in hospitalised patients in a TB low-endemic country.

METHOD

Quantitative real-time polymerase chain reaction qPCR) was used to evaluate 26 previously published genes in blood from 31 patients (14 TB and 17 lower respiratory tract infection cases) admitted to Oslo University Hospital in Norway. The diagnostic accuracies of differentially expressed genes were determined by receiver operating characteristic curves.

RESULTS

A significant difference (p < .01) in the age distribution was observed between patients with TB (mean age, 40 ± 15 years) and lower respiratory tract infection (mean age 59 ± 12 years). Following adjustment for age, ETV7, GBP1, GBP5, P2RY14 and BLK were significantly differentially expressed between patients with TB and those with LRI. A general discriminant analysis generated a three-gene signature (BAFT2, ETV7 and CD1C), which diagnosed TB with an area under the receiver operating characteristic curve (AUC) of 0.86 (95% CI, 0.69 - 1.00), sensitivity of 69.23% (95% CI, 38.57%-90.91%) and specificity of 94.12% (95% CI, 71.31%-99.85%).

CONCLUSION

The three-genes signature may have potential to improve diagnosis of TB in a hospitalised low-burden setting. However, the influence of confounding variables or covariates such as age requires further evaluation in larger studies.

Nematode Orthologs of Macrophage Migration Inhibitory Factor (MIF) as Modulators of the Host Immune Response and Potential Therapeutic Targets

One of the adaptations of nematodes, which allows long-term survival in the host, is the production of proteins with immunomodulatory properties. The parasites secrete numerous homologs of human immune mediators, such as macrophage migration inhibitory factor (MIF), which is a substantial regulator of the inflammatory immune response. Homologs of mammalian MIF have been recognized in many species of nematode parasites, but their role has not been fully understood. The application of molecular biology and genetic engineering methods, including the production of recombinant proteins, has enabled better characterization of their structure and properties. This review provides insight into the current state of knowledge on MIF homologs produced by nematodes, as well as their structure, enzymatic activity, tissue expression pattern, impact on the host immune system, and potential use in the treatment of parasitic, inflammatory, and autoimmune diseases.

A high docosahexaenoic acid diet alters lung inflammation and recovery following repetitive exposure to aqueous organic dust extracts

Agricultural workers, especially those who work in swine confinement facilities, are at increased risk for developing pulmonary diseases including asthma, chronic obstructive pulmonary disease, and chronic bronchitis due to exposures to fumes, vapors, and organic dust. Repetitive exposure to agricultural dust leads to unresolved inflammation, a common underlying mechanism that worsens lung disease. Besides occupational exposure to dusts, diet also significantly contributes to inflammation and disease progression. Since DHA (docosahexaenoic acid), a polyunsaturated omega-3 fatty acid and its bioactive metabolites have key roles in inflammation resolution, we rationalized that individuals chronically exposed to organic dusts can benefit from dietary modifications. Here, we evaluated the role of DHA in modifying airway inflammation in a murine model of repetitive exposure to an aqueous extract of agricultural dust (three-week exposure to swine confinement dust extract, HDE) and after a one-week resolution/recovery period. We found that mice fed a high DHA diet had significantly increased bronchoalveolar lavage fluid (BALF) levels of DHA-derived resolvins and lower TNFα along with altered plasma levels of endocannabinoids and related lipid mediators. Following the one-week recovery we identified significantly reduced BALF cellularity and cytokine/chemokine release along with increased BALF amphiregulin and resolvins in DHA diet-fed versus control diet-fed mice challenged with HDE. We further report observations on the effects of repetitive HDE exposure on lung Ym1+ and Arg-1+ macrophages. Overall, our findings support a protective role for DHA and identify DHA-derived resolvins and endocannabinoids among the potential mediators of DHA in altering airway inflammation in chronic agricultural dust exposure.

Role of Atypical Chemokines and Chemokine Receptors Pathways in the Pathogenesis of COPD

Chronic obstructive pulmonary disease (COPD) represents a heightened inflammatory response in the lung generally resulting from tobacco smoking-induced recruitment and activation of inflammatory cells and/or activation of lower airway structural cells. Several mediators can modulate activation and recruitment of these cells, particularly those belonging to the chemokines (conventional and atypical) family. There is emerging evidence for complex roles of atypical chemokines and their receptors (such as high mobility group box 1 (HMGB1), antimicrobial peptides, receptor for advanced glycosylation end products (RAGE) or toll-like receptors (TLRs)) in the pathogenesis of COPD, both in the stable disease and during exacerbations. Modulators of these pathways represent potential novel therapies for COPD and many are now in preclinical development. Inhibition of only a single atypical chemokine or receptor may not block inflammatory processes because there is redundancy in this network. However, there are many animal studies that encourage studies for modulating the atypical chemokine network in COPD. Thus, few pharmaceutical companies maintain a significant interest in developing agents that target these molecules as potential antiinflammatory drugs. Antibody-based (biological) and small molecule drug (SMD)-based therapies targeting atypical chemokines and/or their receptors are mostly at the preclinical stage and their progression to clinical trials is eagerly awaited. These agents will most likely enhance our knowledge about the role of atypical chemokines in COPD pathophysiology and thereby improve COPD management.

Anti-inflammatory activity of the water extract of Chloranthus serratus roots in LPS-stimulated RAW264.7 cells mediated by the Nrf2/HO-1, MAPK and NF-κB signaling pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Chloranthus serratus is a traditional Chinese medicine for treating arthritis and bruises.

AIM OF THE STUDY

To investigate the dose-effect relationship and molecular mechanisms of the water extract of C. serratus roots (WECR) in lipopolysaccharide (LPS)-stimulated RAW264.7 cells.

MATERIALS AND METHODS

The cell viability was detected by CCK-8 method. One-step method, DCFH-DA fluorescence probe method and immunofluorescence method were used to detect nitric oxide (NO), reactive oxygen species (ROS) and p65 nuclear transcription, respectively. Interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and prostaglandin E₂ (PGE₂) were detected by enzyme linked immunosorbent assay. Inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) mRNA were detected by quantitative real-time PCR. Western blotting was taken to determine the contents of the relevant proteins in the nuclear transcription factor E2 related factor 2/heme oxygenase-1 (Nrf2/HO-1), mitogen-activated protein kinases (MAPK) and nuclear factor-kappa B (NF-κB) pathways.

RESULTS

The concentrations of 3, 30 and 300 μg/mL were optimized as low, medium and high concentrations of the WECR, respectively, and 1 μg/mL was selected as the optimal concentration of LPS to activate macrophages. The dose of the positive drug dexamethasone was 0.13 mg/mL. The WECR could not only inhibit LPS-induced cell differentiation and the overexpression of NO, IL-6, TNF-α, PGE₂ and ROS but also promote the expression of Nrf2 and HO-1, and down-regulate the phosphorylation levels of ERK, JNK, p38 and p65. After the WECR treatment, the expression levels of iNOS and COX-2 mRNA and nuclear translocation of p65 were all inhibited.

CONCLUSIONS

The WECR exerts its anti-inflammatory activity by inhibiting the MAPK and NF-κB pathways, activating the Nrf2/HO-1 pathway and down-regulating inflammatory factor levels in a dose-dependent manner.

Genetic regulation of gene expression of MIF family members in lung tissue

Macrophage migration inhibitory factor (MIF) is a cytokine found to be associated with chronic obstructive pulmonary disease (COPD). However, there is no consensus on how MIF levels differ in COPD compared to control conditions and there are no reports on MIF expression in lung tissue. Here we studied gene expression of members of the MIF family MIF, D-Dopachrome Tautomerase (DDT) and DDT-like (DDTL) in a lung tissue dataset with 1087 subjects and identified single nucleotide polymorphisms (SNPs) regulating their gene expression. We found higher MIF and DDT expression in COPD patients compared to non-COPD subjects and found 71 SNPs significantly influencing gene expression of MIF and DDTL. Furthermore, the platform used to measure MIF (microarray or RNAseq) was found to influence the splice variants detected and subsequently the direction of the SNP effects on MIF expression. Among the SNPs found to regulate MIF expression, the major LD block identified was linked to rs5844572, a SNP previously found to be associated with lower diffusion capacity in COPD. This suggests that MIF may be contributing to the pathogenesis of COPD, as SNPs that influence MIF expression are also associated with symptoms of COPD. Our study shows that MIF levels are affected not only by disease but also by genetic diversity (i.e. SNPs). Since none of our significant eSNPs for MIF or DDTL have been described in GWAS for COPD or lung function, MIF expression in COPD patients is more likely a consequence of disease-related factors rather than a cause of the disease.

Prevention of Oxygen-Induced Inflammatory Lung Injury by Caffeine in Neonatal Rats

Background

Preterm birth implies an array of respiratory diseases including apnea of prematurity and bronchopulmonary dysplasia (BPD). Caffeine has been introduced to treat apneas but also appears to reduce rates of BPD. Oxygen is essential when treating preterm infants with respiratory problems but high oxygen exposure aggravates BPD. This experimental study is aimed at investigating the action of caffeine on inflammatory response and cell death in pulmonary tissue in a hyperoxia-based model of BPD in the newborn rat. Material/Methods. Lung injury was induced by hyperoxic exposure with 80% oxygen for three (P3) or five (P5) postnatal days with or without recovery in ambient air until postnatal day 15 (P15). Newborn Wistar rats were treated with PBS or caffeine (10 mg/kg) every two days beginning at the day of birth. The effects of caffeine on hyperoxic-induced pulmonary inflammatory response were examined at P3 and P5 immediately after oxygen exposure or after recovery in ambient air (P15) by immunohistological staining and analysis of lung homogenates by ELISA and qPCR.

Results

Treatment with caffeine significantly attenuated changes in hyperoxia-induced cell death and apoptosis-associated factors. There was a significant decrease in proinflammatory mediators and redox-sensitive transcription factor NFκB in the hyperoxia-exposed lung tissue of the caffeine-treated group compared to the nontreated group. Moreover, treatment with caffeine under hyperoxia modulated the transcription of the adenosine receptor (Adora)1. Caffeine induced pulmonary chemokine and cytokine transcription followed by immune cell infiltration of alveolar macrophages as well as increased adenosine receptor (Adora1, 2a, and 2b) expression.

Conclusions

The present study investigating the impact of caffeine on the inflammatory response, pulmonary cell degeneration and modulation of adenosine receptor expression, provides further evidence that caffeine acts as an antioxidative and anti-inflammatory drug for experimental oxygen-mediated lung injury. Experimental studies may broaden the understanding of therapeutic use of caffeine in modulating detrimental mechanisms involved in BPD development.

Single-Cell RNA Sequencing of Human Embryonic Stem Cell Differentiation Delineates Adverse Effects of Nicotine on Embryonic Development

Nicotine, the main chemical constituent of tobacco, is highly detrimental to the developing fetus by increasing the risk of gestational complications and organ disorders. The effects of nicotine on human embryonic development and related mechanisms, however, remain poorly understood. Here, we performed single-cell RNA sequencing (scRNA-seq) of human embryonic stem cell (hESC)-derived embryoid body (EB) in the presence or absence of nicotine. Nicotine-induced lineage-specific responses and dysregulated cell-to-cell communication in EBs, shedding light on the adverse effects of nicotine on human embryonic development. In addition, nicotine reduced cell viability, increased reactive oxygen species (ROS), and altered cell cycling in EBs. Abnormal Ca2+ signaling was found in muscle cells upon nicotine exposure, as verified in hESC-derived cardiomyocytes. Consequently, our scRNA-seq data suggest direct adverse effects of nicotine on hESC differentiation at the single-cell level and offer a new method for evaluating drug and environmental toxicity on human embryonic development in utero.

Endothelial cell-secreted MIF reduces pericyte contractility and enhances neutrophil extravasation

Dysregulated neutrophil extravasation contributes to the pathogenesis of many inflammatory disorders. Pericytes (PCs) have been implicated in the regulation of neutrophil transmigration, and previous work demonstrates that endothelial cell (EC)-derived signals reduce PC barrier function; however, the signaling mechanisms are unknown. Here, we demonstrate a novel role for EC-derived macrophage migration inhibitory factor (MIF) in inhibiting PC contractility and facilitating neutrophil transmigration. With the use of micro-ELISAs, RNA sequencing, quantitative PCR, and flow cytometry, we found that ECs secrete MIF, and PCs upregulate CD74 in response to TNF-α. We demonstrate that EC-derived MIF decreases PC contractility on 2-dimensional silicone substrates via reduction of phosphorylated myosin light chain. With the use of an in vitro microvascular model of the human EC-PC barrier, we demonstrate that MIF decreases the PC barrier to human neutrophil transmigration by increasing intercellular PC gap formation. For the first time, an EC-specific MIF knockout mouse was used to investigate the effects of selective deletion of EC MIF. In a model of acute lung injury, selective deletion of EC MIF decreases neutrophil infiltration to the bronchoalveolar lavage and tissue and simultaneously decreases PC relaxation by increasing myosin light-chain phosphorylation. We conclude that paracrine signals from EC via MIF decrease PC contraction and enhance PC-regulated neutrophil transmigration.-Pellowe, A. S., Sauler, M., Hou, Y., Merola, J., Liu, R., Calderon, B., Lauridsen, H. M., Harris, M. R., Leng, L., Zhang, Y., Tilstam, P. V., Pober, J. S., Bucala, R., Lee, P. J., Gonzalez, A. L. Endothelial cell-secreted MIF reduces pericyte contractility and enhances neutrophil extravasation.

A functional macrophage migration inhibitory factor promoter polymorphism is associated with reduced diffusing capacity

Cigarette smoke exposure is the leading modifiable risk factor for chronic obstructive pulmonary disease (COPD); however, the clinical and pathologic consequences of chronic cigarette smoke exposure are variable among smokers. Macrophage migration inhibitory factor (MIF) is a pleiotropic cytokine implicated in the pathogenesis of COPD. Within the promoter of the MIF gene is a functional polymorphism that regulates MIF expression (-794 CATT_5-8 microsatellite repeat) ( rs5844572 ). The role of this polymorphim in mediating disease susceptibility to COPD-related traits remains unknown. We performed a cross-sectional analysis of DNA samples from 641 subjects to analyze MIF-794 CATT_5-8 ( rs5844572 ) polymorphism by standard methods. We generated multivariable logistic regression models to determine the risk of low expressing MIF alleles for airflow obstruction [defined by forced expiratory volume in 1 s (FEV₁)/forced vital capacity ratio <0.70] and an abnormal diffusion capacity [defined by a diffusion capacity for carbon monoxide (DL_CO) percent predicted <80%]. We then used generalized linear models to determine the association of MIF genotypes with FEV₁ percent predicted and DL_CO percent predicted. The MIF-794 CATT₅ allele was associated with an abnormal diffusion capacity in two cohorts [odds ratio (OR): 9.31, 95% confidence interval (CI): 1.97-4.06; and OR: 2.21, 95% CI: 1.03-4.75]. Similarly, the MIF-794 CATT₅ allele was associated with a reduced DL_CO percentage predicted in these two cohorts: 63.5 vs. 70.0 ( P = 0.0023) and 60.1 vs. 65.4 ( P = 0.059). This study suggests an association between a common genetic polymorphism of an endogenous innate immune gene, MIF, with reduced DL_CO, an important measurement of COPD severity.

Streptozotocin-induced β-cell damage, high fat diet, and metformin administration regulate Hes3 expression in the adult mouse brain

Diabetes mellitus is a group of disorders characterized by prolonged high levels of circulating blood glucose. Type 1 diabetes is caused by decreased insulin production in the pancreas whereas type 2 diabetes may develop due to obesity and lack of exercise; it begins with insulin resistance whereby cells fail to respond properly to insulin and it may also progress to decreased insulin levels. The brain is an important target for insulin, and there is great interest in understanding how diabetes affects the brain. In addition to the direct effects of insulin on the brain, diabetes may also impact the brain through modulation of the inflammatory system. Here we investigate how perturbation of circulating insulin levels affects the expression of Hes3, a transcription factor expressed in neural stem and progenitor cells that is involved in tissue regeneration. Our data show that streptozotocin-induced β-cell damage, high fat diet, as well as metformin, a common type 2 diabetes medication, regulate Hes3 levels in the brain. This work suggests that Hes3 is a valuable biomarker helping to monitor the state of endogenous neural stem and progenitor cells in the context of diabetes mellitus.

Macrophage Migration Inhibitory Factor -173 G/C Polymorphism: A Global Meta-Analysis across the Disease Spectrum

Human macrophage migration inhibitory factor (MIF) is a cytokine that plays a role in several metabolic and inflammatory processes. Single nucleotide polymorphism (SNP) -173 G/C (rs755622) on MIF gene has been associated with numerous diseases, such as arthritis and cancer. However, most of the reports concerning the association of MIF with these and other pathologies are inconsistent and remain quite controversial. Therefore, we performed a meta-analysis from 96 case-control studies on -173 G/C MIF SNP and stratified the data according to the subjects geographic localization or the disease pathophysiology, in order to determine a more meaningful significance to this SNP. The polymorphism was strongly associated with an increased risk in autoimmune-inflammatory, infectious and age-related diseases on the dominant (OR: 0.74 [0.58-0.93], P < 0.01; OR: 0.81 [0.74-0.89], P < 0.0001; and OR: 0.81 [0.76-0.87], P < 0.0001, respectively) and the recessive models (OR: 0.74 [0.57-0.095], P < 0.01; OR: 0.66 [0.48-0.92], P < 0.0154; and OR: 0.70 [0.60-0.82], P < 0.0001, respectively). Also, significant association was found in the geographic localization setting for Asia, Europe and Latin America subdivisions in the dominant (OR: 0.76 [0.69-0.84], P < 0.0001; OR: 0.77 [0.72-0.83], P < 0.0001; OR: 0.61 [0.44-0.83], P-value: 0.0017, respectively) and overdominant models (OR: 0.85 [0.77-0.94], P < 0.0001; OR: 0.80 [0.75-0.86], P < 0.0001; OR: 0.73 [0.63-0.85], P-value: 0.0017, respectively). Afterwards, we implemented a network meta-analysis to compare the association of the polymorphism for two different subdivisions. We found a stronger association for autoimmune than for age-related or autoimmune-inflammatory diseases, and stronger association for infectious than for autoimmune-inflammatory diseases. We report for the first time a meta-analysis of rs755622 polymorphism with a variety of stratified diseases and populations. The study reveals a strong association of the polymorphism with autoimmune and infectious diseases. These results may help direct future research on MIF-173 G/C in diseases in which the relation is clearer and thus assist the search for more plausible applications.

Mechanisms and consequences of oxidative stress in lung disease: therapeutic implications for an aging populace

The rapid expansion of the elderly population has led to the recent epidemic of age-related diseases, including increased incidence and mortality of chronic and acute lung diseases. Numerous studies have implicated aging and oxidative stress in the pathogenesis of various pulmonary diseases; however, despite recent advances in these fields, the specific contributions of aging and oxidative stress remain elusive. This review will discuss the consequences of aging on lung morphology and physiology, and how redox imbalance with aging contributes to lung disease susceptibility. Here, we focus on three lung diseases for which aging is a significant risk factor: acute respiratory distress syndrome (ARDS), chronic obstructive pulmonary disease (COPD), and idiopathic pulmonary fibrosis (IPF). Preclinical and clinical development for redox- and senescence-altering therapeutic strategies are discussed, as well as scientific advancements that may direct current and future therapeutic development. A deeper understanding of how aging impacts normal lung function, redox balance, and injury-repair processes will inspire the development of new therapies to prevent and/or reverse age-associated pulmonary diseases, and ultimately increase health span and longevity. This review is intended to encourage basic, clinical, and translational research that will bridge knowledge gaps at the intersection of aging, oxidative stress, and lung disease to fuel the development of more effective therapeutic strategies for lung diseases that disproportionately afflict the elderly.

Proteomic Analysis Shows Constitutive Secretion of MIF and p53-associated Activity of COX-2-/- Lung Fibroblasts

The differential expression of two closelyassociated cyclooxygenase isozymes, COX-1 and COX-2, exhibited functions beyond eicosanoid metabolism. We hypothesized that COX-1 or COX-2 knockout lung fibroblasts may display altered protein profiles which may allow us to further differentiate the functional roles of these isozymes at the molecular level. Proteomic analysis shows constitutive production of macrophage migration inhibitory factor (MIF) in lung fibroblasts derived from COX-2^−/− but not wild-type (WT) or COX-1^−/− mice. MIF was spontaneously released in high levels into the extracellular milieu of COX2^−/− fibroblasts seemingly from the preformed intracellular stores, with no change in the basal gene expression of MIF. The secretion and regulation of MIF in COX-2^−/− was “prostaglandin-independent.” GO analysis showed that concurrent with upregulation of MIF, there is a significant surge in expression of genes related to fibroblast growth, FK506 binding proteins, and isomerase activity in COX-2^−/− cells. Furthermore, COX-2^−/− fibroblasts also exhibit a significant increase in transcriptional activity of various regulators, antagonists, and co-modulators of p53, as well as in the expression of oncogenes and related transcripts. Integrative Oncogenomics Cancer Browser (IntroGen) analysis shows downregulation of COX-2 and amplification of MIF and/or p53 activity during development of glioblastomas, ependymoma, and colon adenomas. These data indicate the functional role of the MIF-COX-p53 axis in inflammation and cancer at the genomic and proteomic levels in COX-2-ablated cells. This systematic analysis not only shows the proinflammatory state but also unveils a molecular signature of a pro-oncogenic state of COX-1 in COX-2 ablated cells.

HO-1 Is Essential for Tetrahydroxystilbene Glucoside Mediated Mitochondrial Biogenesis and Anti-Inflammation Process in LPS-Treated RAW264.7 Macrophages

2,3,5,4'-Tetrahydroxystilbene-2-O-β-D-glucoside (TSG), an important monomer extracted from Polygonum multiflorum, can prevent a number of inflammation associated chronic diseases. However, the mechanism involved in TSG inducing anti-inflammatory role remains unclear. As an inducible antioxidant enzyme, Heme oxygenase-1 (HO-1), is crucial for protecting the mammalian cells against adverse stimuli. Here, we found that the TSG treatment strongly induces the expression of HO-1 in an NRF2-depended manner. Meanwhile, TSG increased the mitochondrial mass through upregulation of the mitochondrial biogenesis activators (PGC-1α, NRF1, and TFAM) as well as the mitochondrial complex IV. Furthermore, TSG attenuated Lipopolysaccharide (LPS) mediated RAW264.7 cells activation and secretion of proinflammatory cytokines, including interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). Zinc Protoporphyrin (ZnPP), a selective inhibitor of HO-1 activity, was able to attenuate TSG mediated mitochondrial biogenesis and anti-inflammatory process. Finally, we observed that LPS induced obvious mtDNA depletion and ATP deficiency, which indicated a severe damage of mitochondria. TSG restored the LPS induced mitochondrial dysfunction via activation of the mitochondrial biogenesis. ZnPP treatment markedly reversed the inhibitory effects of TSG on mitochondrial damage and oxidative stress in LPS stimulated macrophages. Taken together, these findings suggest that TSG enhances mitochondrial biogenesis and function mainly via activation the HO-1. TSG can be developed as a potential drug for treatment of inflammatory diseases.

Pro-Inflammatory and Pro-Fibrogenic Effects of Ionic and Particulate Arsenide and Indium-Containing Semiconductor Materials in the Murine Lung

We have recently shown that the toxicological potential of GaAs and InAs particulates in cells is size- and dissolution-dependent, tending to be more pronounced for nano- vs micron-sized particles. Whether the size-dependent dissolution and shedding of ionic III-V materials also apply to pulmonary exposure is unclear. While it has been demonstrated that micron-sized III-V particles, such as GaAs and InAs, are capable of inducing hazardous pulmonary effects in an occupational setting as well as in animal studies, the effect of submicron particles (e.g., the removal of asperities during processing of semiconductor wafers) is unclear. We used cytokine profiling to compare the pro-inflammatory effects of micron- and nanoscale GaAs and InAs particulates in cells as well as the murine lung 40 h and 21 days after oropharyngeal aspiration. Use of cytokine array technology in macrophage and epithelial cell cultures demonstrated a proportionally higher increase in the levels of matrix metalloproteinase inducer (EMMPRIN), macrophage migration inhibitory factor (MIF), and interleukin 1β (IL-1β) by nanosized (n) GaAs and n-InAs as well as As(III). n-GaAs and n-InAs also triggered higher neutrophil counts in the bronchoalveolar lavage fluid (BALF) of mice than micronscale particles 40 h post-aspiration, along with increased production of EMMPRIN and MIF. In contrast, in animals sacrificed 21 days after exposure, only n-InAs induced fibrotic lung changes as determined by increased lung collagen as well as increased levels of TGF-β1 and PDGF-AA in the BALF. A similar trend was seen for EMMPRIN and matrix metallopeptidase (MMP-9) levels in the BALF. Nano- and micron-GaAs had negligible subacute effects. Importantly, the difference between the 40 h and 21 days data appears to be biopersistence of n-InAs, as demonstrated by ICP-OES analysis of lung tissue. Interestingly, an ionic form of In, InCl₃, also showed pro-fibrogenic effects due to the formation of insoluble In(OH)₃ nanostructures. All considered, these data indicate that while nanoscale particles exhibit increased pro-inflammatory effects in the lung, most effects are transient, except for n-InAs and insoluble InCl₃ species that are biopersistent and trigger pro-fibrotic effects. These results are of potential importance for the understanding the occupational health effects of III-V particulates.

Association of macrophage migration inhibitory factor promoter polymorphism -173G/C with susceptibility to childhood asthma

Introduction

Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine that plays an important role in the pathogenesis of asthma. Polymorphisms associated with inflammatory diseases exist in the promoter region of MIF, which alter its expression. We aimed to study the association of MIF promoter polymorphism –173G/C with childhood asthma.

Material and methods

In this case-control study, we recruited 60 pediatric patients with bronchial asthma and 90 age- and sex-matched healthy controls. MIF-173G/C was genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

Results

Genotype distribution between cases and healthy controls was statistically evaluated. Our results revealed that the frequency of the MIF-173C allele was significantly higher in children with asthma than in the control group (p = 0.002, odds ratio [OR] = 3.61, 95% confidence interval [CI] = 1.63-7.97). The frequency of the MIF-173CC genotype was higher in the asthmatic children than in the controls (p = 0.028, OR = 6.24, 95% CI = 1.24-31.29). Comparing carriage of the MIF-173C allele in pediatric patients with asthma with that observed in healthy controls (GC + CC vs. GG) revealed a positive association with the disease (p = 0.019, OR = 3.12, 95% CI = 1.22-7.99).

Conclusions

These results suggest that MIF-173G/C polymorphism confers an increased risk of susceptibility to the development of childhood asthma in an Egyptian population.

Aging and Lung Disease. Clinical Impact and Cellular and Molecular Pathways

With the expected rapid growth of the aging population worldwide, there is a clear need to understand the complex process of aging to develop interventions that might extend the health span in this group of patients. Aging is associated with increased susceptibility to a variety of chronic diseases, and lung pathologies are no exception. The prevalence of lung diseases such as idiopathic pulmonary fibrosis and chronic obstructive pulmonary disease has been found to increase considerably with age. In October 2014, the Division of Pulmonary, Allergy, and Critical Care of the University of Pittsburgh cohosted the Pittsburgh-Munich Lung Conference focused in aging and lung disease with the Comprehensive Pneumology Center, Institute of Lung Biology and Disease, Ludwig-Maximilians University and Helmholtz Zentrum Munich Germany. The purpose of the conference was to disseminate novel concepts in aging mechanisms that have an impact in lung physiology and pathogenesis of pulmonary diseases that commonly occur in older populations. The conference included 28 presentations on diverse topics, which are summarized in this report. The participants identified priorities for future basic and translational investigations that will assist in the identification of molecular insights involved in the pathogenesis of age-related pulmonary diseases and the design of therapeutic interventions for these lung conditions.

Macrophage migration inhibitory factor, a role in COPD

Macrophage migration inhibitor factor (MIF) is a pluripotent cytokine associated with several different inflammatory conditions, but its role within lung inflammation and chronic obstructive pulmonary disease (COPD) is unclear. This study aimed to examine MIF in both stable COPD and during acute exacerbations (AECOPD). The study included 433 patients with COPD aged 41-76 and 325 individuals from the Bergen COPD cohort study who served as controls. All patients had an FEV1 of <80% predicted, FEV1/FVC ratio of <0.7, and a smoking history >10 pack-years. Serum levels of MIF were compared between the two groups at baseline, and for 149 patients, measurements were also carried out during AECOPD. Linear regression models were fitted with MIF as the outcome variable and adjusted for sex, age, body composition, smoking, and Charlson Comorbidity Score (CCS). Median MIF (interquartile range) in patients with COPD was 20.1 ng/ml (13.5-30.9) compared with 14.9 ng/ml (11.1-21.6) in controls (P < 0.01). MIF was bivariately associated with sex, body composition, and CCS (P < 0.05 for all). In the regression analyses, MIF was significantly higher in patients with COPD, coefficient 1.32 (P < 0.01) and 1.30 (P < 0.01) unadjusted and adjusted, respectively. In addition, in 149 patients during episodes of AECOPD, MIF was significantly elevated, with a median of 23.2 ng/ml (14.1-42.3) compared with measurements at stable disease of 19.3 ng/ml (12.4-31.3, P < 0.01). Serum levels of MIF were significantly higher in patients with COPD compared with controls. We also identified an additional increase in MIF levels during episodes of AECOPD.

Models for preclinical studies in aging-related disorders: One is not for all

Preclinical studies are essentially based on animal models of a particular disease. The primary purpose of preclinical efficacy studies is to support generalization of treatment-effect relationships to human subjects. Researchers aim to demonstrate a causal relationship between an investigational agent and a disease-related phenotype in such models. Numerous factors can muddle reliable inferences about such cause-effect relationships, including biased outcome assessment due to experimenter expectations. For instance, responses in a particular inbred mouse might be specific to the strain, limiting generalizability. Selecting well-justified and widely acknowledged model systems represents the best start in designing preclinical studies, especially to overcome any potential bias related to the model itself. This is particularly true in the research that focuses on aging, which carries unique challenges, mainly attributable to the fact that our already long lifespan makes designing experiments that use people as subjects extremely difficult and largely impractical.