title: High glucose alters the secretome of mechanically stimulated osteocyte-like cells affecting osteoclast precursor recruitment and differentiation.
abstract: Diabetes mellitus (DM) induces bone deterioration, while mechanical stimulation promotes osteocyte-driven bone formation. We aimed to evaluate the interaction of acute exposure (24 h) to high glucose (HG) with both the pro-survival effect conferred to osteocytic MLO-Y4 cells and osteoblastic MC3T3-E1 cells by mechanical stimulation and the interaction of these cells with osteoclast precursor RAW264.7 cells. We found that 24 h of HG (25 mM) pre-exposure prevented both cell survival and ERK and β-catenin nuclear translocation upon mechanical stimulation by fluid flow (FF) (10 min) in both MLO-Y4 and MC3T3-E1 cells. However, migration of RAW 264.7 cells was inhibited by MLO-Y4 cell-conditioned medium (CM), but not by MC3T3-E1 cell-CM, with HG or FF. This inhibitory effect was associated with consistent changes in VEGF, RANTES, MIP-1α, MIP-1β MCP-1, and GM-CSF in MLO-Y4 cell-CM. RAW264.7 proliferation was inhibited by MLO-Y4 CM under static or HG conditions, but it increased by FF-CM with or without HG. In addition, both FF and HG abrogated the capacity of RAW 264.7 cells to differentiate into osteoclasts, but in a different manner. Thus, HG-CM in static condition allowed formation of osteoclast-like cells, which were unable to resorb hydroxyapatite. In contrast, FF-CM prevented osteoclastogenesis even in HG condition. Moreover, HG did not affect basal RANKL or IL-6 secretion or their inhibition induced by FF in MLO-Y4 cells. In conclusion, this in vitro study demonstrates that HG exerts disparate effects on osteocyte mechanotransduction, and provides a novel mechanism by which DM disturbs skeletal metabolism through altered osteocyte-osteoclast communication.
authors.affiliation: Laboratorio de Metabolismo Mineral y Óseo, Instituto de Investigación Sanitaria (IIS)-Fundación Jiménez Díaz, UAM, Madrid, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Maycas
authors.affiliation: Facultad de Ciencias Químicas, Departamento de Bioquímica y Biología Molecular I, UCM, Instituto de Investigación Sanitaria San Carlos (IdISSC), Madrid, Spain.
authors.forename: María Teresa
authors.initials: MT
authors.lastname: Portolés
authors.affiliation: Facultad de Ciencias Químicas, Departamento de Bioquímica y Biología Molecular I, UCM, Instituto de Investigación Sanitaria San Carlos (IdISSC), Madrid, Spain.
authors.forename: María Concepción
authors.initials: MC
authors.lastname: Matesanz
authors.affiliation: IMMA- Facultad de Medicina, Universidad San Pablo CEU, Boadilla del Monte, Madrid, Spain.
authors.forename: Irene
authors.initials: I
authors.lastname: Buendía
authors.affiliation: Facultad de Farmacia, Departamento de Química Inorgánica y Bioinorgánica, UCM, Madrid, Spain.|Instituto de Investigación Sanitaria Hospital 12 de Octubre (i + 12) CIBER-BBN, Madrid, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Linares
authors.affiliation: Facultad de Farmacia, Departamento de Química Inorgánica y Bioinorgánica, UCM, Madrid, Spain.|Instituto de Investigación Sanitaria Hospital 12 de Octubre (i + 12) CIBER-BBN, Madrid, Spain.
authors.forename: María José
authors.initials: MJ
authors.lastname: Feito
authors.affiliation: Facultad de Farmacia, Departamento de Química Inorgánica y Bioinorgánica, UCM, Madrid, Spain.|Instituto de Investigación Sanitaria Hospital 12 de Octubre (i + 12) CIBER-BBN, Madrid, Spain.
authors.forename: Daniel
authors.initials: D
authors.lastname: Arcos
authors.affiliation: Facultad de Farmacia, Departamento de Química Inorgánica y Bioinorgánica, UCM, Madrid, Spain.|Instituto de Investigación Sanitaria Hospital 12 de Octubre (i + 12) CIBER-BBN, Madrid, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Vallet-Regí
authors.affiliation: Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, Indiana.|Roudebush Veterans Administration Medical Center, Indianapolis, Indiana.|Indiana Center for Musculoskeletal Health, Indianapolis, Indiana.
authors.forename: Lilian I
authors.initials: LI
authors.lastname: Plotkin
authors.affiliation: Laboratorio de Metabolismo Mineral y Óseo, Instituto de Investigación Sanitaria (IIS)-Fundación Jiménez Díaz, UAM, Madrid, Spain.
authors.forename: Pedro
authors.initials: P
authors.lastname: Esbrit
authors.affiliation: IMMA- Facultad de Medicina, Universidad San Pablo CEU, Boadilla del Monte, Madrid, Spain.
authors.forename: Arancha R
authors.initials: AR
authors.lastname: Gortázar
mesh_terms: D016475:3T3 Cells; D000818:Animals; D002450:Cell Communication / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects*; D002465:Cell Movement / Q000187:drug effects*; D016207:Cytokines / Q000378:metabolism; D005947:Glucose / Q000494:pharmacology*; D040542:Mechanotransduction, Cellular / Q000187:drug effects*; D051379:Mice; D010010:Osteoclasts / Q000187:drug effects* / Q000378:metabolism; D010011:Osteocytes / Q000187:drug effects* / Q000378:metabolism; D010012:Osteogenesis / Q000187:drug effects*; D010812:Physical Stimulation; D000067996:RAW 264.7 Cells; D013234:Stem Cells / Q000187:drug effects* / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: D016207:Cytokines; D042461:Vascular Endothelial Growth Factor A; C467480:vascular endothelial growth factor A, mouse; D005947:Glucose
keywords: diabetes mellitus; mechanotransduction; osteoclast migration; osteoclastogenesis; osteocyte