title: Autocrine signaling is a key regulatory element during osteoclastogenesis.
abstract: Osteoclasts are responsible for bone destruction in degenerative, inflammatory and metastatic bone disorders. Although osteoclastogenesis has been well-characterized in mouse models, many questions remain regarding the regulation of osteoclast formation in human diseases. We examined the regulation of human precursors induced to differentiate and fuse into multinucleated osteoclasts by receptor activator of nuclear factor kappa-B ligand (RANKL). High-content single cell microscopy enabled the time-resolved quantification of both the population of monocytic precursors and the emerging osteoclasts. We observed that prior to induction of osteoclast fusion, RANKL stimulated precursor proliferation, acting in part through an autocrine mediator. Cytokines secreted during osteoclastogenesis were resolved using multiplexed quantification combined with a Partial Least Squares Regression model to identify the relative importance of specific cytokines for the osteoclastogenesis outcome. Interleukin 8 (IL-8) was identified as one of RANKL-induced cytokines and validated for its role in osteoclast formation using inhibitors of the IL-8 cognate receptors CXCR1 and CXCR2 or an IL-8 blocking antibody. These insights demonstrate that autocrine signaling induced by RANKL represents a key regulatory component of human osteoclastogenesis.
authors: Merrimack Pharmaceuticals, One Kendall Square, Suite B7201, Cambridge, MA 02139, USA.
authors: Paul
authors: P
authors: Kopesky
authors: Shriners Hospital for Children - Canada, 1529 Cedar Avenue, Montreal, QC H3G IA6, Canada Faculty of Dentistry, McGill University, 3640 rue University, Montreal, QC H3A 0C7, Canada.
authors: Kerstin
authors: K
authors: Tiedemann
authors: Merrimack Pharmaceuticals, One Kendall Square, Suite B7201, Cambridge, MA 02139, USA.
authors: Dahlia
authors: D
authors: Alkekhia
authors: Merrimack Pharmaceuticals, One Kendall Square, Suite B7201, Cambridge, MA 02139, USA.
authors: Christoph
authors: C
authors: Zechner
authors: Merrimack Pharmaceuticals, One Kendall Square, Suite B7201, Cambridge, MA 02139, USA.
authors: Bjorn
authors: B
authors: Millard
authors: Merrimack Pharmaceuticals, One Kendall Square, Suite B7201, Cambridge, MA 02139, USA.
authors: Birgit
authors: B
authors: Schoeberl
authors: Shriners Hospital for Children - Canada, 1529 Cedar Avenue, Montreal, QC H3G IA6, Canada Faculty of Dentistry, McGill University, 3640 rue University, Montreal, QC H3A 0C7, Canada svetlana.komarova@mcgill.ca.
authors: Svetlana V
authors: SV
authors: Komarova
keywords: Cytokine; High content imaging; Interleukin-8; Osteoclastogenesis; PLSR