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One cluster of the extrapulmonary manifestations in chronic obstructive pulmonary disease (COPD) is related to the brain, which includes anxiety, depression and cognitive impairment. Brain-related comorbidities are related to worsening of symptoms and increased mortality in COPD patients. In this study, a murine model of COPD was used to examine the effects of emphysema and repetitive pulmonary inflammatory events on systemic inflammatory outcomes and brain function. In addition, the effect of a dietary intervention on brain-related parameters was assessed. Adult male C57Bl/6J mice were exposed to elastase or vehicle intratracheally (i.t.) once a week on three consecutive weeks. Two weeks after the final administration, mice were i.t. exposed to lipopolysaccharide (LPS) or vehicle for three times with a 10 day interval. A dietary intervention enriched with omega-3 PUFAs, prebiotic fibers, tryptophan and vitamin D was administered from the first LPS exposure onward. Behavior and cognitive function, the degree of emphysema and both pulmonary and systemic inflammation as well as blood-brain barrier (BBB) integrity and neuroinflammation in the brain were assessed. A lower score in the cognitive test was observed in elastase-exposed mice. Mice exposed to elastase plus LPS showed less locomotion in the behavior test. The enriched diet seemed to reduce anxiety-like behavior over time and cognitive impairments associated with the presented COPD model, without affecting locomotion. In addition, the enriched diet restored the disbalance in splenic T-helper 1 (Th1) and Th2 cells. There was a trend toward recovering elastase plus LPS-induced decreased expression of occludin in brain microvessels, a measure of BBB integrity, as well as improving expression levels of kynurenine pathway markers in the brain by the enriched diet. The findings of this study demonstrate brain-associated comorbidities – including cognitive and behavioral impairments – in this murine model for COPD. Although no changes in lung parameters were observed, exposure to the specific enriched diet in this model appeared to improve systemic immune disbalance, BBB integrity and derailed kynurenine pathway which may lead to reduction of anxiety-like behavior and improved cognition.

Chronic obstructive pulmonary disease (COPD), often caused by smoking, is a chronic lung disease with systemic manifestations including metabolic comorbidities. This study investigates adaptive and pathological alterations in adipose and skeletal muscle tissue following cigarette smoke exposure using in vivo and in vitro models. Mice were exposed to cigarette smoke or air for 72 days and the pre-adipose cell line 3T3-L1 was utilized as an in vitro model. Cigarette smoke exposure decreased body weight, and the proportional loss in fat mass was more pronounced than the lean mass loss. Cigarette smoke exposure reduced adipocyte size and increased adipocyte numbers. Adipose macrophage numbers and associated cytokine levels, including interleukin-1β, interleukine-6 and tumor necrosis factor-α were elevated in smoke-exposed mice. Muscle strength and protein synthesis signaling were decreased after smoke exposure; however, muscle mass was not changed. In vitro studies demonstrated that lipolysis and fatty acid oxidation were upregulated in cigarette smoke-exposed pre-adipocytes. In conclusion, cigarette smoke exposure induces a loss of whole-body fat mass and adipose atrophy, which is likely due to enhanced lipolysis.

Background: Chronic obstructive pulmonary disease (COPD) is often accompanied by psychiatric problems, such as depression and anxiety, affecting both treatment outcomes and mortality. Evidence for the number of COPD patients using medication for these disorders is sparse. In this study, chronic antidepressant (ATD) and anxiolytic (ANX) drug use – to identify depression and anxiety – among COPD patients was compared with subjects with or without other chronic diseases. Methods: The NControl database containing prescription data of 800 pharmacies including 7 million individuals in The Netherlands was used. Patients of age 55+ years who received frequent prescriptions – at least two/year in 5 out of 6 years – for COPD medication, dermatological drugs, disease-modifying antirheumatic drugs (DMARDs), statins and oral glucose-lowering medication were analyzed for concomitant chronic use of ATDs and ANXs between 1 January 2013 and 1 January 2019. All other subjects aged 55+ years were included as a control group (control group 1). This group was further stratified into a group of subjects that received frequent prescriptions of any kind (control group 2). Results: 15.2% of the patients that receive COPD treatment ( n = 96,319), 15.3% of subjects that are treated for dermatological problems ( n = 62,865), 13.2% of subjects that receive DMARDs ( n = 7900), 11.6% of statins users ( n = 422,376) and 11.4% of oral glucose-lowering medication users ( n = 165,975) are also chronically treated for depression or anxiety, compared with 2.6% (control group 1; n = 3,290,608) and 11.4% (control group 2; n = 757,947). In general, female and 75+ years aged subjects showed a higher risk for using ATDs and ANXs chronically. In the COPD and the dermatological patient group the risk was the highest compared with the other patient groups. Conclusions: The rates of chronic ATD and ANX use and the risk of having depression and/or anxiety are especially high in COPD patients, indicating that psychiatric problems are more common in COPD than in most other chronic diseases. In general, age and gender strongly influence the risk of chronically using ATDs and ANXs. The reviews of this paper are available via the supplemental material section.

The N-terminally truncated pyroglutamate Aβ3−42 (AβpE3−42) and Aβ4−42 peptides are known to be highly abundant in the brain of Alzheimer's disease (AD) patients. Both peptides show enhanced aggregation and neurotoxicity in comparison to full-length Aβ, suggesting that these amyloid peptides may play an important role in the pathogenesis of AD. The aim of the present work was to study the direct effect of the combination of AβpE3−42 and Aβ4−42 on ongoing AD-related neuron loss, pathology, and neurological deficits in transgenic mice. Bigenic mice were generated by crossing the established TBA42 and Tg4-42 mouse models expressing the N-truncated Aβ peptides AβpE3−42 and Aβ4−42, respectively. After generation of the bigenic mice, detailed phenotypical characterization was performed using either immunostainings to evaluate amyloid pathology or quantification of neuron numbers using design-based stereology. The elevated plus maze was used to study anxiety levels. In order to evaluate sensori-motor deficits, the inverted grid, the balance beam and the string suspension tasks were applied. We could demonstrate that co-expression of AβpE3−42 and Aβ4−42 accelerates neuron loss in the CA1 pyramidal layer of young bigenic mice as seen by reduced neuron numbers in comparison to single transgenic homozygous mice expressing either AβpE3−42 or Aβ4−42. This observation coincides with the robust intraneuronal Aβ accumulation observed in the bigenic mice. In addition, loss of anxiety and motor deficits were enhanced in an age-dependent manner. The sensori-motor deficits correlate with the abundant spinal cord pathology, as demonstrated by robust intracellular Aβ accumulation within motor neurons and extracellular Aβ deposition. Our observations demonstrate that a combination of AβpE3−42 and Aβ4−42 has a stronger effect on ongoing AD pathology than the peptides alone. Therefore, AβpE3−42 and Aβ4−42 might represent excellent potential therapeutic targets and diagnostic markers for AD.