title: Human Lung Spheroids as In Vitro Niches of Lung Progenitor Cells with Distinctive Paracrine and Plasticity Properties.
abstract: Basic and translational research on lung biology has discovered multiple progenitor cell types, specialized or facultative, responsible for turnover, renewal, and repair. Isolation of populations of resident lung progenitor cells (LPCs) has been described by multiple protocols, and some have been successfully applied to healthy human lung tissue. We aimed at understanding how different cell culture conditions may affect, in vitro, the phenotype of LPCs to create an ideal niche-like microenvironment. The influence of different substrates (i.e., fibronectin, gelatin, laminin) and the impact of a three-dimensional/two-dimensional (3D/2D) culture switch on the biology of LPCs isolated as lung spheroids (LSs) from normal adult human lung biopsy specimens were investigated. We applied a spheroid culture system as the selective/inductive step for progenitor cell culture, as described in many biological systems. The data showed a niche-like proepithelial microenvironment inside the LS, highly sensitive to the 3D culture system and significantly affecting the phenotype of adult LPCs more than culture substrate. LSs favor epithelial phenotypes and LPC maintenance and contain cells more responsive to specific commitment stimuli than 2D monolayer cultures, while secreting a distinctive set of paracrine factors. We have shown for the first time, to our knowledge, how culture as 3D LSs can affect LPC epithelial phenotype and produce strong paracrine signals with a distinctive secretomic profile compared with 2D monolayer conditions. These findings suggest novel approaches to maintain ex vivo LPCs for basic and translational studies. Stem Cells Translational Medicine 2017;6:767-777.
authors.affiliation: Department of Medical-Surgical Sciences and Biotechnology, "Sapienza" University of Rome, Rome, Italy.
authors.forename: Isotta
authors.initials: I
authors.lastname: Chimenti
authors.affiliation: Department of Medical-Surgical Sciences and Biotechnology, "Sapienza" University of Rome, Rome, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Pagano
authors.affiliation: Department of Medical-Surgical Sciences and Biotechnology, "Sapienza" University of Rome, Rome, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Angelini
authors.affiliation: Department of Medical-Surgical Sciences and Biotechnology, "Sapienza" University of Rome, Rome, Italy.
authors.forename: Camilla
authors.initials: C
authors.lastname: Siciliano
authors.affiliation: Department of Medical-Surgical Sciences and Biotechnology, "Sapienza" University of Rome, Rome, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Mangino
authors.affiliation: Department of Medical-Surgical Sciences and Biotechnology, "Sapienza" University of Rome, Rome, Italy.
authors.forename: Vittorio
authors.initials: V
authors.lastname: Picchio
authors.affiliation: Department of Medical-Surgical Sciences and Biotechnology, "Sapienza" University of Rome, Rome, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: De Falco
authors.affiliation: Department of Medical-Surgical Sciences and Biotechnology, "Sapienza" University of Rome, Rome, Italy.
authors.forename: Mariangela
authors.initials: M
authors.lastname: Peruzzi
authors.affiliation: Department of Medical-Surgical Sciences and Biotechnology, "Sapienza" University of Rome, Rome, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Carnevale
authors.affiliation: Department of Medical-Surgical Science and Translational Medicine, "La Sapienza" University of Rome, Rome, Italy.
authors.forename: Mohsen
authors.initials: M
authors.lastname: Ibrahim
authors.affiliation: Department of Medical-Surgical Sciences and Biotechnology, "Sapienza" University of Rome, Rome, Italy.|Department of AngioCardioNeurology, Istituto di Ricovero e Cura a Carattere Scientifico Neuromed, Pozzilli, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Biondi-Zoccai
authors.affiliation: Department of Pediatrics and Neuropsychiatry, "Umberto I" Hospital, Rome, Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: Messina
authors.affiliation: Department of Medical-Surgical Sciences and Biotechnology, "Sapienza" University of Rome, Rome, Italy.|Department of AngioCardioNeurology, Istituto di Ricovero e Cura a Carattere Scientifico Neuromed, Pozzilli, Italy.
authors.forename: Giacomo
authors.initials: G
authors.lastname: Frati
mesh_terms: D000293:Adolescent; D000328:Adult; D000066670:Cell Plasticity; D005260:Female; D006801:Humans; D008168:Lung / Q000166:cytology*; D008297:Male; D019899:Paracrine Communication; D010641:Phenotype; D018874:Spheroids, Cellular / Q000166:cytology* / Q000378:metabolism; D055153:Stem Cell Niche; D013234:Stem Cells / Q000166:cytology* / Q000378:metabolism; D055815:Young Adult
keywords: Epithelial-to-mesenchymal transition; Lung stem cells; Pneumospheres; Stem cell niche; Three-dimensional culture