title: In search of the elusive lipofibroblast in human lungs.
abstract: Although the pulmonary interstitial lipofibroblast (LF) has been widely recognized in rat and mouse lungs, their presence in human lungs remains controversial. In a recent issue of the Journal, Tahedl and associates (Tahedl D, Wirkes A, Tschanz SA, Ochs M, Mühlfeld C. Am J Physiol Lung Cell Mol Physiol 307: L386-L394, 2014) address this controversy and provide the most detailed stereological analysis of LFs in mammals other than rodents. Strikingly, their observations demonstrate that LFs were only observed in rodents, which contrasts with earlier reports. This editorial reviews the anatomical, physiological, and biochemical characteristics of the LF to better understand the significance of LFs for lung development and disease. Although lipid droplets are a signature of the LF cell type, it remains unclear whether lipid storage is the defining characteristic of LFs, or whether other less overt properties determine the importance of LFs. Are lipid droplets an adaptation to the neonatal environment, or are LFs a surrogate for other properties that promote alveolar development, and do lipid droplets modify physiology or disease in adults?
authors.affiliation: Department of Lung Development and Remodelling, Max Planck Institute for Heart and Lung Research, Bad Nauheim Germany; Department of Internal Medicine (Pulmonology), University of Giessen and Marburg Lung Center (UGMLC), Giessen, Germany; and Katrin.Ahlbrecht@innere.med.uni-giessen.de.
authors.forename: Katrin
authors.initials: K
authors.lastname: Ahlbrecht
authors.affiliation: Department of Veterans Affairs Research Service and Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa.
authors.forename: Stephen E
authors.initials: SE
authors.lastname: McGowan
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D005347:Fibroblasts / Q000166:cytology* / Q000378:metabolism; D006801:Humans; D050356:Lipid Metabolism; D051379:Mice; D011650:Pulmonary Alveoli / Q000166:cytology* / Q000378:metabolism; D051381:Rats