title: Murine Rankl-/-Mesenchymal Stromal Cells Display an Osteogenic Differentiation Defect Improved by a RANKL-Expressing Lentiviral Vector.
abstract: Autosomal recessive osteopetrosis (ARO) is a severe bone disease characterized by increased bone density due to impairment in osteoclast resorptive function or differentiation. Hematopoietic stem cell transplantation is the only available treatment; however, this therapy is not effective in RANKL-dependent ARO, since in bone this gene is mainly expressed by cells of mesenchymal origin. Of note, whether lack of RANKL production might cause a defect also in the bone marrow (BM) stromal compartment, possibly contributing to the pathology, is unknown. To verify this possibility, we generated and characterized BM mesenchymal stromal cell (BM-MSC) lines from wild type and Rankl-/-mice, and found that Rankl-/-BM-MSCs displayed reduced clonogenicity and osteogenic capacity. The differentiation defect was significantly improved by lentiviral transduction of Rankl-/-BM-MSCs with a vector stably expressing human soluble RANKL (hsRANKL). Expression of Rankl receptor, Rank, on the cytoplasmic membrane of BM-MSCs pointed to the existence of an autocrine loop possibly activated by the secreted cytokine. Based on the close resemblance of RANKL-defective osteopetrosis in humans and mice, we expect that our results are also relevant for RANKL-dependent ARO patients. Data obtained in vitro after transduction with a lentiviral vector expressing hsRANKL would suggest that restoration of RANKL production might not only rescue the defective osteoclastogenesis of this ARO form, but also improve a less obvious defect in the osteoblast lineage, thus possibly achieving higher benefit for the patients, when the approach is translated to clinics. Stem Cells 2017;35:1365-1377.
authors.affiliation: Laboratory of Immunology and Rheumatic Diseases, Pediatrics II, Genova, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Schena
authors.affiliation: Milan Unit, CNR-IRGB, Milan, Italy.|Laboratory of Human Genome, Humanitas Clinical and Research Institute, Rozzano, Italy.
authors.forename: Ciro
authors.initials: C
authors.lastname: Menale
authors.affiliation: Molecular Genetics Laboratory G. Gaslini Children's Hospital, Genova, Italy.
authors.forename: Emanuela
authors.initials: E
authors.lastname: Caci
authors.affiliation: Milan Unit, CNR-IRGB, Milan, Italy.|Laboratory of Human Genome, Humanitas Clinical and Research Institute, Rozzano, Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Diomede
authors.affiliation: Laboratory of Human Genome, Humanitas Clinical and Research Institute, Rozzano, Italy.|Department of Medical Biotechnologies and Translational Medicine, University of Milan, Milan, Italy.
authors.forename: Eleonora
authors.initials: E
authors.lastname: Palagano
authors.affiliation: Mouse and Animal Pathology Laboratory, Fondazione Filarete, Milano, Italy.
authors.forename: Camilla
authors.initials: C
authors.lastname: Recordati
authors.affiliation: ISTEC-CNR, Institute of Science & Technology for Ceramics, National Research Council of Italy, Faenza, Italy.
authors.forename: Monica
authors.initials: M
authors.lastname: Sandri
authors.affiliation: ISTEC-CNR, Institute of Science & Technology for Ceramics, National Research Council of Italy, Faenza, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Tampieri
authors.affiliation: Milan Unit, CNR-IRGB, Milan, Italy.|San Raffaele Telethon Institute for Gene Therapy, San Raffaele Scientific Institute, Milan, Italy.
authors.forename: Ileana
authors.initials: I
authors.lastname: Bortolomai
authors.affiliation: San Raffaele Telethon Institute for Gene Therapy, San Raffaele Scientific Institute, Milan, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Capo
authors.affiliation: Laboratory of Immunology and Rheumatic Diseases, Pediatrics II, Genova, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Pastorino
authors.affiliation: Laboratory of Immunology and Rheumatic Diseases, Pediatrics II, Genova, Italy.|Centre of Excellence for Biomedical Research, University of Genoa, Genova, Italy.
authors.forename: Arinna
authors.initials: A
authors.lastname: Bertoni
authors.affiliation: Laboratory of Immunology and Rheumatic Diseases, Pediatrics II, Genova, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Gattorno
authors.affiliation: Laboratory of Immunology and Rheumatic Diseases, Pediatrics II, Genova, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Martini
authors.affiliation: Milan Unit, CNR-IRGB, Milan, Italy.|Laboratory of Human Genome, Humanitas Clinical and Research Institute, Rozzano, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Villa
authors.affiliation: Laboratory of Immunology and Rheumatic Diseases, Pediatrics II, Genova, Italy.|Novartis Institute for Biomedical Research, Klybeckstrasse, Basel, Switzerland.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Traggiai
authors.affiliation: Milan Unit, CNR-IRGB, Milan, Italy.|Laboratory of Human Genome, Humanitas Clinical and Research Institute, Rozzano, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Sobacchi
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D002454:Cell Differentiation; D002999:Clone Cells; D005822:Genetic Vectors / Q000378:metabolism*; D016130:Immunophenotyping; D016086:Lentivirus / Q000378:metabolism*; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000378:metabolism*; D008810:Mice, Inbred C57BL; D010012:Osteogenesis; D053245:RANK Ligand / Q000172:deficiency* / Q000378:metabolism; D015398:Signal Transduction; D014161:Transduction, Genetic
chemical_list: D015415:Biomarkers; D053245:RANK Ligand
keywords: Bone; Differentiation; Lentiviral transduction; Mesenchymal stromal cell; Osteopetrosis; Rankl