Cadmium in tobacco smoke may contribute to the development of pulmonary emphysema. However, there is poor understanding of the mechanisms behind the pathogenic role of cadmium in this and other smoking-related lung diseases. The traditional focus on the total body burden of cadmium, estimated through analysis of urine, may not fully reflect the local burden of cadmium, since it is inhaled by smokers. Thus, assessing the local accumulation of cadmium in the lungs appears more relevant, given that there is tissue-specific retention of cadmium.In this review, we outline the principal sources of cadmium exposure and the clinical effects of occupational exposure. In addition, we review evidence on local cadmium and its association with alterations in innate immunity in tobacco smokers. Moreover, we scrutinise the data on cadmium as a cause of lung disease in translational models.We conclude that cadmium may contribute to smoking-related lung diseases, possibly via an altered redox balance and by making macrophages dysfunctional. However, there is a need for new studies on local cadmium levels and their relation to pathology in long-term tobacco smokers, as well as for more indepth studies on cellular and molecular mechanisms, to elucidate the importance of cadmium in smokingrelated lung diseases.

Rationale: Because acute lung injury is a sporadic disease produced by heterogeneous precipitating factors, previous genetic analyses are mainly limited to candidate gene case-control studies. Objectives: To develop a genome-wide strategy in which single nucleotide polymorphism associations are assessed for functional consequences to survival during acute lung injury in mice. Methods: To identify genes associated with acute lung injury, 40 inbred strains were exposed to acrolein and haplotype association mapping, microarray, and DNA-protein binding were assessed. Measurements and Main Results:The mean survival time varied among mouse strains with polar strains differing approximately 2.5-fold. Associations were identified on chromosomes 1, 2, 4, 11, and 12. Seven genes (Acvr1, Cacnb4, Ccdc148, Galnt13, Rfwd2, Rpap2, and Tgfbr3) had single nucleotide polymorphism (SNP) associations within the gene. Because SNP associations may encompass ''blocks'' of associated variants, functional assessment was performed in 91 genes within 6 1 Mbp of each SNP association. Using 10% or greater allelic frequency and 10% or greater phenotype explained as threshold criteria, 16 genes were assessed by microarray and reverse realtime polymerase chain reaction. Microarray revealed several enriched pathways including transforming growth factor-b signaling. Transcripts for Acvr1, Arhgap15, Cacybp, Rfwd2, and Tgfbr3 differed between the strains with exposure and contained SNPs that could eliminate putative transcriptional factor recognition sites. Ccdc148, Fancl, and Tnn had sequence differences that could produce an amino acid substitution. Mycn and Mgat4a had a promoter SNP or 39untranslated region SNPs, respectively. Several genes were related and encoded receptors (ACVR1, TGFBR3), transcription factors (MYCN, possibly CCDC148), and ubiquitin-proteasome (RFWD2, FANCL, CACYBP) proteins that can modulate cell signaling. An Acvr1 SNP eliminated a putative ELK1 binding site and diminished DNA-protein binding. Conclusions: Assessment of genetic associations can be strengthened using a genetic/genomic approach. This approach identified several candidate genes, including Acvr1, associated with increased susceptibility to acute lung injury in mice.

BackgroundCarbonaceous nanoparticles possess an emerging source of human exposure due to the massive release of combustion products and the ongoing revolution in nanotechnology. Pulmonary inflammation caused by deposited nanoparticles is central for their adverse health effects. Epidemiological studies suggest that individuals with favourable lung physiology are at lower risk for particulate matter associated respiratory diseases probably due to efficient control of inflammation and repair process. Therefore we selected a mouse strain C3H/HeJ (C3) with robust lung physiology and exposed it to moderately toxic carbon nanoparticles (CNP) to study the elicited pulmonary inflammation and its resolution.Methods5 μg, 20 μg and 50 μg CNP were intratracheally (i.t.) instilled in C3 mice to identify the optimal dose for subsequent time course studies. Pulmonary inflammation was assessed using histology, bronchoalveolar lavage (BAL) analysis and by a panel of 62 protein markers.Results1 day after instillation of CNP, C3 mice exhibited a typical dose response, with the lowest dose (5 μg) representing the 'no effect level' as reflected by polymorphonuclear leucocyte (PMN), and BAL/lung concentrations of pro-inflammatory proteins. Histological analysis and BAL-protein concentration did not reveal any evidence of tissue injury in 20 μg CNP instilled animals. Accordingly time course assessment of the inflammatory response was performed after 3 and 7 days with this dose (20 μg). Compared to day 1, BAL PMN counts were significantly decreased at day 3 and completely returned to normal by day 7. We have identified protein markers related to the acute response and also to the time dependent response in lung and BAL. After complete resolution of PMN influx on day 7, we detected elevated concentrations of 20 markers that included IL1B, IL18, FGF2, EDN1, and VEGF in lung and/or BAL. Biological pathway analysis revealed these factors to be involved in a closely regulated molecular cascade with IL1B/IL18 as upstream and FGF2/EDN1/VEGF as downstream molecules.ConclusionConsidering the role of VEGF, FGF2 and EDN1 in lung development and morphogenesis together with the lack of any evident tissue damage we suggest a protective/homeostatic machinery to be associated in lungs of stable organisms to counter the CNP challenge as a precautionary measure.

Impaired development and reduced lung capacity are risk factors of asthma and chronic obstructive pulmonary disease. Previously, our genomewide linkage analysis of C3H/HeJ (C3H) and JF1/Msf (JF1) mouse strains identified quantitative trait loci (QTLs) associated with the complex traits of dead space volume (Vd), total lung capacity (TLC), lung compliance (CL), and diffusing capacity for CO (D(CO)). We assessed positional candidate genes by comparing C3H with JF1 lung transcript levels by microarray and by comparing C3H, BALB/cByJ, C57BL/6J, A/J, PWD/PhJ, and JF1 strains, using exon sequencing to predict protein structure. Microarray identified >900 transcripts differing in C3H and JF1 lungs related to lung development, function, and remodeling. Of these, three genes localized to QTLs associated with differences in lung function. C3H and JF1 strains differed in transcript and protein levels of superoxide dismutase 3, extracellular [SOD3; mouse chromosome (mCh) 5: VD] and transcript of trefoil factor 2 (TFF2; mCh 17: TLC and D(CO)), and ectonucleotide pyrophosphatase/phosphodiesterase 2 (ENPP2; mCh 15: TLC and CL). Nucleotide sequencing of Sod3, Tff2, and previously identified Relaxin 1 (Rln1; mCh 19: CL) uncovered polymorphisms that could lead to nonsynonymous amino acid changes and altered predicted protein structure. Gene-targeted Sod3(-/-) mice had increased conducting airway volume (Vd/TLC) compared with strain-matched control Sod3(+/+) mice, consistent with the QTL on mCh 5. Two novel genes (Tff2 and Enpp2) have been identified and two suspected genes (Sod3 and Rln1) have been supported as determinants of lung function in mice. Findings with gene-targeted mice suggest that SOD3 is a contributing factor defining the complex trait of conducting airway volume.

These results confirm the third allele of Crybb2 in the mouse that also affected exon 6 and the fourth Greek key motif. Moreover, expression analysis of Crybb2 identified for the first time distinct regions of expression in the brain, and the differential expression analysis points to the participation of Ca2+ in the corresponding pathologic processes.