Dataset Information

Cell survival and gene expression under compressive stress in a three-dimensional in vitro human periodontal ligament-like tissue model.

ABSTRACT: This study investigated cell survival and gene expression under various compressive stress conditions mimicking orthodontic force by using a newly developed in vitro model of human periodontal ligament-like tissue (HPdLLT). The HPdLLT was developed by three-dimensional culturing of human periodontal ligament fibroblasts in a porous poly-L-lactide matrix with threefold increased culture media permeability due to hydrophilic modification. In vitro HPdLLTs in experimental groups were subjected to 5, 15, 25 and 35 g/cm(2) compressive stress for 1, 3, 7 or 14 days; controls were cultured over the same periods without compressive stress. Cell morphology and cell apoptosis in the experimental and control groups were investigated using scanning electron microscopy and caspase-3/7 detection. Real-time polymerase chain reaction was performed for seven osteogenic and osteoclastic genes. Similar extracellular matrix and spindle-shaped cells were observed inside or on the surface of in vitro HPdLLTs, with no relation to compressive stress duration or intensity. Similar caspase-3/7 activity indicating comparable apoptosis levels was observed in all samples. Receptor activator of nuclear factor kappa-B ligand and bone morphogenetic protein 2 genes showed characteristic "double-peak" expression at 15 and 35 g/cm(2) on day 14, and alkaline phosphatase and periodontal ligament-associated protein 1 expression peaked at 5 g/cm(2) on day 14; other genes also showed time-dependent and load-dependent expression patterns. The in vitro HPdLLT model system effectively mimicked the reaction and gene expression of the human periodontal ligament in response to orthodontic force. This work provides new information on the effects of compressive stress on human periodontal ligament tissue.

SUBMITTER: Liao W

PROVIDER: S-EPMC4754250 | biostudies-literature | 2016 Mar

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Cell survival and gene expression under compressive stress in a three-dimensional in vitro human periodontal ligament-like tissue model.

Liao Wen W Okada Masahiro M Inami Kaoru K Hashimoto Yoshiya Y Matsumoto Naoyuki N

Cytotechnology 20140803 2

This study investigated cell survival and gene expression under various compressive stress conditions mimicking orthodontic force by using a newly developed in vitro model of human periodontal ligament-like tissue (HPdLLT). The HPdLLT was developed by three-dimensional culturing of human periodontal ligament fibroblasts in a porous poly-L-lactide matrix with threefold increased culture media permeability due to hydrophilic modification. In vitro HPdLLTs in experimental groups were subjected to 5 ...[more]

PMID: 25087076

Similar Datasets

Project description:The periodontal ligament (PDL) is a specialized connective tissue that provides structural support to the tooth and is crucial for oral functions. The mechanical properties of the PDL are mainly derived from the tissue-specific composition and structural characteristics of the extracellular matrix (ECM). The ECM also plays key roles in determining cell fate in the cellular microenvironment thus crucial in the PDL tissue homeostasis. In the present study, we determined the comprehensive ECM profile of mouse molar PDL using laser microdissection and mass spectrometry-based proteomic analysis with ECM-oriented data curation. Additionally, we evaluated changes in the ECM proteome under mechanical loading using a mouse orthodontic tooth movement (OTM) model and analyzed potential regulatory networks using a bioinformatics approach. Proteomic changes were evaluated in reference to the novel second harmonic generation (SHG)-based fiber characterization. Our ECM-oriented proteomics approach succeeded in illustrating the comprehensive ECM profile of the mouse molar PDL. We revealed the presence of type II collagen in PDL, possibly associated with the load-bearing function upon occlusal force. Mechanical loading induced unique architectural changes in collagen fibers along with dynamic compositional changes in the matrisome profile, particularly involving ECM glycoproteins and matrisome-associated proteins. We identified several unique matrisome proteins which responded to the different modes of mechanical loading in PDL. Notably, the proportion of type VI collagen significantly increased at the mesial side, contributing to collagen fibrogenesis. On the other hand, type XII collagen increased at the PDL-cementum boundary of the distal side. Furthermore, a multifaceted bioinformatics approach illustrated the potential molecular cues, including PDGF signaling, that maintain ECM homeostasis under mechanical loading. Our findings provide fundamental insights into the molecular network underlying ECM homeostasis in PDL, which is vital for clinical diagnosis and development of biomimetic tissue-regeneration strategies.

Project description:During orthodontic tooth movement (OTM) mechanical forces trigger pseudo-inflammatory, osteoclastogenic and remodelling processes in the periodontal ligament (PDL) that are mediated by PDL fibroblasts via the expression of various signalling molecules. Thus far, it is unknown whether these processes are mainly induced by mechanical cellular deformation (mechanotransduction) or by concomitant hypoxic conditions via the compression of periodontal blood vessels. Human primary PDL fibroblasts were randomly seeded in conventional six-well cell culture plates with O2-impermeable polystyrene membranes and in special plates with gas-permeable membranes (Lumox®, Sarstedt), enabling the experimental separation of mechanotransducive and hypoxic effects that occur concomitantly during OTM. To simulate physiological orthodontic compressive forces, PDL fibroblasts were stimulated mechanically at 2?g·cm-2 for 48?h after 24?h of pre-incubation. We quantified the cell viability by MTT assay, gene expression by quantitative real-time polymerase chain reaction (RT-qPCR) and protein expression by western blot/enzyme-linked immunosorbent assays (ELISA). In addition, PDL-fibroblast-mediated osteoclastogenesis (TRAP+ cells) was measured in a 72-h coculture with RAW264.7 cells. The expression of HIF-1?, COX-2, PGE2, VEGF, COL1A2, collagen and ALPL, and the RANKL/OPG ratios at the mRNA/protein levels during PDL-fibroblast-mediated osteoclastogenesis were significantly elevated by mechanical loading irrespective of the oxygen supply, whereas hypoxic conditions had no significant additional effects. The cellular-molecular mediation of OTM by PDL fibroblasts via the expression of various signalling molecules is expected to be predominantly controlled by the application of force (mechanotransduction), whereas hypoxic effects seem to play only a minor role. In the context of OTM, the hypoxic marker HIF-1? does not appear to be primarily stabilized by a reduced O2 supply but is rather stabilised mechanically.

Dataset Information

Cell survival and gene expression under compressive stress in a three-dimensional in vitro human periodontal ligament-like tissue model.

Publications

Cell survival and gene expression under compressive stress in a three-dimensional in vitro human periodontal ligament-like tissue model.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets