Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality worldwide. While the primary risk factor for COPD is cigarette smoke exposure, vitamin D deficiency has been epidemiologically implicated as a factor in the progressive development of COPD-associated emphysema. Because of difficulties inherent to studies involving multiple risk factors in the progression of COPD in humans, we developed a murine model in which to study the separate and combined effects of vitamin D deficiency and cigarette smoke exposure. During a 16-week period, mice were exposed to one of four conditions, control diet breathing room air (CD-NS), control diet with cigarette smoke exposure (CD-CSE), vitamin D deficient diet breathing room air (VDD-NS) or vitamin D deficient diet with cigarette smoke exposure (VDD-CSE). At the end of the exposure period, the lungs were examined by a pathologist and separately by morphometric analysis. In parallel experiments, mice were anesthetized for pulmonary function testing followed by sacrifice and analysis. Emphysema (determined by an increase in alveolar mean linear intercept length) was more severe in the VDD-CSE mice compared to control animals and animals exposed to VDD or CSE alone. The VDD-CSE and the CD-CSE mice had increased total lung capacity and increased static lung compliance. There was also a significant increase in the matrix metalloproteinase-9: tissue inhibitor of metalloproteinases-1 (TIMP-1) ratio in VDD-CSE mice compared with all controls. Alpha-1 antitrypsin (A1AT) expression was reduced in VDD-CSE mice as well. In summary, vitamin D deficiency, when combined with cigarette smoke exposure, seemed to accelerate the appearance of emphysemas, perhaps by virtue of an increased protease-antiprotease ratio in the combined VDD-CSE animals. These results support the value of our mouse model in the study of COPD.

Cigarette smoke (CS) exposure is known to increase infection rates, but the mechanisms are not well understood. These studies tested the hypothesis that CS exposure would impair antimicrobial activity of apical conditioned media from human airway (BEAS-2B) cultures by reducing induction and release of the antimicrobial peptide CCL20. BEAS-2B cultures were exposed to CS extract and assayed for temporal and physical characteristics of release as well as for antimicrobial activity. E. coli were exposed to Beas-2B-conditioned media (BCM) and subsequent bacterial colonies were enumerated. In time course studies TLR-agonist-induced CCL20 transcription and release were rapid, of short duration and release was consistently targeted to the apical/luminal compartment. Cells treated with CS extract had diminished release of CCL20 under both constitutive and toll-like receptor (TLR) agonist stimulating conditions. Exposure of the cells to CS significantly reduced the antimicrobial activity in BCM and neutralizing antibodies to CCL20 brought antibacterial activity back to baseline levels demonstrating that antimicrobial activity in this culture system was primarily attributable to CCL20. These studies add to the understanding of CCL20 as a mucosal antimicrobial and improve insight into a likely mechanism linking infection to CS exposure.

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Roughly 90% of socially monogamous bird species exhibit some degree of extra-pair paternity (EPP), although the extent and the underlying mechanisms vary among species. We analyzed spatial and demographic patterns of EPP over a 6 year period (2005–2010) as part of a long-term population study of Canada Warblers (Cardellina canadensis (L., 1766)). We identified 12 microsatellite loci used to assess paternity for 185 nestlings from 61 nests. Extra-pair young (EPY) accounted for 41.6% of all nestlings and 57.4% of nests contained at least one EPY. Fewer than half of EPY were sired by males who shared territorial boundaries, and some males sired young in nests 1 km from their territory. The age of social males did not differ from males who cuckolded them. The majority (83%) of EPY were sired by males in older age classes (2+ years old), while <17% were sired by 1 year olds. Of the young sired by older males, 58.5% were sired by males 3–7 years old. Males that sired more EPY sired fewer within-pair young (WPY); those without EPY sired more WPY suggesting a possible fitness trade-off between these two strategies. Our findings suggest multiple age-based strategies within a single breeding population, as well as potential strategy shifts to maximize lifetime fitness as they age.

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