Initial responses of osteoblasts derived from human alveolar bone to various compressive forces.
Mechanical stress generated by orthodontic force is recognized as a major factor in the modulation of alveolar bone remodeling. During this process, osteoblasts play a crucial role, not only by participating in bone formation but also by promoting osteoclastogenesis. The aim of this study was to investigate how continuous compressive force (CF) affects human primary osteoblasts (HOBs) in terms of cell proliferation, apoptosis, and expression of interleukin-6 (IL-6) and chemokine CXC ligand 8 (CXCL8). Human primary osteoblasts, isolated from human mandibular bone pieces, were cultured with or without CF (1-4 g cm(-2)) for up to 72 h. Cell viability and proliferation were evaluated using the MTT assay. RT-PCR was used to determine the levels of expression of KI67 (a proliferation marker), BAX (a pro-apoptotic marker), BCL2 (an apoptotic inhibitor), IL6, and CXCL8 mRNAs, while a multiplexed bead immunoassay was used to measure the release of IL-6 and CXCL8. The results revealed that CF decreased cell viability and proliferation in a time- and force-dependent manner. After applying CF for 24 h, the mRNA expression of KI67 was markedly inhibited, whereas the mRNA expression of BAX and BCL2 was unaltered. In addition, CF enhanced the levels of IL6 and CXCL8 mRNAs in a force-dependent manner, whereas the levels of the corresponding proteins were reduced in the compressed HOBs.
Department of Clinical Dentistry, Centre for Clinical Dental Research, Faculty of Medicine and Dentistry, University of Bergen, Bergen, Norway.
Polbhat
P
Tripuwabhrut
Kamal
K
Mustafa
Pongsri
P
Brudvik
Manal
M
Mustafa
D000293:Adolescent; D000328:Adult; D017209:Apoptosis; D016723:Bone Remodeling / Q000502:physiology*; D049109:Cell Proliferation; D002478:Cells, Cultured; D006801:Humans; D015850:Interleukin-6 / Q000096:biosynthesis* / Q000378:metabolism; D016209:Interleukin-8 / Q000096:biosynthesis* / Q000378:metabolism; D019394:Ki-67 Antigen / Q000378:metabolism; D008853:Microscopy; D008964:Molar, Third / Q000166:cytology / Q000502:physiology; D010006:Osteoblasts / Q000737:chemistry / Q000166:cytology* / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013314:Stress, Mechanical
D015850:Interleukin-6; D016209:Interleukin-8; D019394:Ki-67 Antigen; D012333:RNA, Messenger