title: Bioinformatic analysis of responsive genes in two-dimension and three-dimension cultured human periodontal ligament cells subjected to compressive stress.
abstract: OBJECTIVE
  Analyzing responses of human periodontal ligament cells to mechanical stress and mechanotransduction is important for understanding periodontal tissue physiology and remodeling. It has been shown that the cellular response to mechanical stress can vary according to the type and duration of force and to extracellular attachment conditions. This study investigated the gene-expression profile of human periodontal ligament cells cultured in two-dimension (2D) and three-dimension (3D) conditions after application of compressive stress for 2 and 48 h.
  
  
  METHODS
  Human primary periodontal ligament cells were obtained from premolars extracted for orthodontic purposes. Cells were cultured in a conventional 2D culture dish or in 3D collagen gel and compressive stress was applied for 2 and 48 h. Control cells were cultured under identical conditions but without the application of compressive stress. After the application of compressive stress, total RNA was extracted and a cDNA microarray was performed. Microarray data were analyzed using statistical methods, including david and gene set enrichment analysis to identify significant signaling pathways. Real-time PCR was performed for five mRNAs in order to confirm the cDNA microarray results.
  
  
  RESULTS
  The cDNA microarray analysis revealed that after application of compressive stress for 2 h, 191 and 553 genes showed changes in their expression levels in 2D and 3D cultured cells, respectively. After application of compressive stress for 48 h, 280 and 519 genes showed changes in their expression levels in 2D and 3D cultured cells, respectively. Euclidean clustering method was used to demonstrate the gene-expression kinetics.
  
  
  CONCLUSIONS
  Analysis of the results showed that several signaling pathways, including the MAPK pathway and the focal adhesion kinase pathway are relevant to the compressive force-induced cellular response. 2D and 3D cultured cells showed significantly different gene-expression profiles, suggesting that cellular attachment to extracellular matrix influences cellular responses to mechanical stresses.
authors: Department of Periodontology, Kyunghee University Dental College, Seoul, Korea.
authors: K-L
authors: KL
authors: Kang
authors: S-W
authors: SW
authors: Lee
authors: Y-S
authors: YS
authors: Ahn
authors: S-H
authors: SH
authors: Kim
authors: Y-G
authors: YG
authors: Kang
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D002448:Cell Adhesion / Q000235:genetics; D018929:Cell Culture Techniques; D002874:Chromosome Mapping; D003094:Collagen; D019295:Computational Biology; D005109:Extracellular Matrix / Q000235:genetics; D005260:Female; D051417:Focal Adhesion Kinase 1 / Q000235:genetics; D015870:Gene Expression / Q000235:genetics; D020869:Gene Expression Profiling / Q000379:methods*; D006801:Humans; D020935:MAP Kinase Signaling System / Q000235:genetics; D040542:Mechanotransduction, Cellular / Q000502:physiology*; D020411:Oligonucleotide Array Sequence Analysis; D010513:Periodontal Ligament / Q000166:cytology* / Q000378:metabolism; D012313:RNA / Q000032:analysis; D015398:Signal Transduction / Q000235:genetics; D013314:Stress, Mechanical; D013997:Time Factors; D054457:Tissue Scaffolds; D014158:Transcription, Genetic / Q000235:genetics; D055815:Young Adult
chemical_list: D012313:RNA; D003094:Collagen; D051417:Focal Adhesion Kinase 1; C496050:PTK2 protein, human