Mouse anti-Human ITGB6 monoclonal antibody, clone 548322 [APC]

Mouse models are useful for studying cigarette smoke (CS)-induced chronic pulmonary pathologies such as lung emphysema. To enhance translation of large-scale omics data from mechanistic studies into pathophysiological changes, we have developed computational tools based on reverse causal reasoning (RCR). In the present study we applied a systems biology approach leveraging RCR to identify molecular mechanistic explanations of pathophysiological changes associated with CS-induced lung emphysema in susceptible mice. The lung transcriptomes of five mouse models (C57BL/6, ApoE (-/-) , A/J, CD1, and Nrf2 (-/-) ) were analyzed following 5-7 months of CS exposure. We predicted 39 molecular changes mostly related to inflammatory processes including known key emphysema drivers such as NF-kappa B and TLR4 signaling, and increased levels of TNF-alpha, CSF2, and several interleukins. More importantly, RCR predicted potential molecular mechanisms that are less well-established, including increased transcriptional activity of PU.1, STAT1, C/EBP, FOXM1, YY1, and N-COR, and reduced protein abundance of ITGB6 and CFTR. We corroborated several predictions using targeted proteomic approaches, demonstrating increased abundance of CSF2, C/EBP alpha, C/EBP beta, PU.1, BRCA1, and STAT1. These systems biology-derived candidate mechanisms common to susceptible mouse models may enhance understanding of CS-induced molecular processes underlying emphysema development in mice and their relevancy for human chronic obstructive pulmonary disease.

Background: A pig phenotype characterized by juvenile hairlessness, thin skin and age dependent lung emphysema has been discovered in a Danish pig herd. The trait shows autosomal co-dominant inheritance with all three genotypes distinguishable. Since the phenotype shows resemblance to the integrin beta 6(-/-) knockout phenotype seen in mice, the two genes encoding the two subunits of integrin alpha(v)beta(6), i. e. ITGB6 and ITGAV, were considered candidate genes for this trait. Results: The mutated pig phenotype is characterized by hairlessness until puberty, thin skin with few hair follicles and absence of musculi arrectores pili, and at puberty or later localized areas of emphysema are seen in the lungs. Comparative mapping predicted that the porcine ITGB6 andITGAV orthologs map to SSC15. In an experimental family (n = 113), showing segregation of the trait, the candidate region was confirmed by linkage analysis with four microsatellite markers. Mapping of the porcine ITGB6 and ITGAV in the IMpRH radiation hybrid panel confirmed the comparative mapping information. Sequencing of the ITGB6 and ITGAV coding sequences from affected and normal pigs revealed no evidence of a causative mutation, but alternative splicing of the ITGB6 pre-mRNA was detected. For both ITGB6 and ITGAV quantitative PCR revealed no significant difference in the expression levels in normal and affected animals. In a western blot, ITGB6 was detected in lung protein samples of all three genotypes. This result was supported by flow cytometric analyses which showed comparable reactions of kidney cells from affected and normal pigs with an integrin alpha(v)beta(6) monoclonal antibody. Also, immunohistochemical staining of lung tissue with an integrin beta(6) antibody showed immunoreaction in both normal and affected pigs. Conclusion: A phenotype resembling the integrin beta(-/-)(6) knockout phenotype seen in mice has been characterized in the pig. The candidate region on SSC15 has been confirmed by linkage analysis but molecular and functional analyses have excluded that the mutated phenotype is caused by structural mutations in or ablation of any of the two candidate genes.