Buried alive : how osteoblasts become osteocytes

• Published in: Developmental Dynamics
• Main Authors: Franz-Odendaal, Tamara A., Hall, Brian K., Witten, Paul Eckhard
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2006
• Subjects: Biology and Life Sciences; Developmental Biology; osteoblast; osteocyte; osteogenesis; intramembranous ossification; preosteoblast; osteoid-osteocyte; preosteocyte; TRABECULAR BONE PACKETS; MEAN WALL THICKNESS; ORYZIAS-LATIPES TELEOSTEI; SALMON SALMO-SALAR; GROWTH-FACTOR-I; RAT BONE; MESSENGER-RNA; HYPERTROPHIC CHONDROCYTES; SKELETAL DEVELOPMENT; CELL-PROLIFERATION; Salmo salar
• Online Access: https://biblio.ugent.be/publication/8646034; http://hdl.handle.net/1854/LU-8646034; https://doi.org/10.1002/dvdy.20603; https://biblio.ugent.be/publication/8646034/file/8646035

During osteogenesis, osteoblasts lay down osteoid and transform into osteocytes embedded in mineralized bone matrix. Despite the fact that osteocytes are the most abundant cellular component of bone, little is known about the process of osteoblast-to-osteocyte transformation. What is known is that osteoblasts undergo a number of changes during this transformation, yet retain their connections to preosteoblasts and osteocytes. This review explores the osteoblast-to-osteocyte transformation during intramembranous ossification from both morphological and molecular perspectives. We investigate how these data support five schemes that describe how an osteoblast could become entrapped in the bone matrix (in mammals) and suggest one of the five scenarios that best fits as a model. Those osteoblasts on the bone surface that are destined for burial and destined to become osteocytes slow down matrix production compared to neighbouring osteoblasts, which continue to produce bone matrix. That is, cells that continue to produce matrix actively bury cells producing less or no new bone matrix (passive burial). We summarize which morphological and molecular changes could be used as characters (or markers) to follow the transformation process.