title: Effects of vibration and hyaluronic acid on activation of three-dimensional cultured chondrocytes.
abstract: OBJECTIVE
  To investigate the effects of vibration (Vib) and hyaluronic acid (HA) on 3-dimensional cultured cartilage.
  
  
  METHODS
  Chondrocytes were obtained from metatarsophalangeal joints of freshly killed 6-month-old pigs. Twenty-four-well plates containing type I collagen sponge disks were used to culture samples. The frequency and the amplitude of the vibration of the well plate were 100 Hz and 0.5 nm, respectively. We produced 3-dimensional cartilage tissue using HA and vibration with collagen sponge as a carrier. Four different culture conditions were examined: a control HA-Vib- group, an HA-Vib+ group, an HA+Vib- group, and an HA+Vib+ group. Each group was cultured for 2 weeks. After culture days 3, 7, 10, and 14 (every 3.5 days), the levels of chondroitin 4-sulfate (C4S) and chondroitin 6-sulfate (C6S) isomers synthesized in each culture medium were measured. Histologic analysis, immunohistochemical analysis, and electron microscopic examination were performed.
  
  
  RESULTS
  Mean C4S and C6S synthesis had increased rapidly after 7 days of culture and continued to increase thereafter. There were significant differences among the 4 groups (P < 0.01). Synthesis of both C4S and C6S was most abundant in the HA+Vib+ group and the lowest in the HA-Vib- group. After 1 and 2 weeks of culture, the chondrocytes had formed stratified structures on the collagen sponges in all groups, although the thickest structure was observed in the HA+Vib+ group and the thinnest in the HA-Vib- group. Under immunofluorescence, the HA+Vib+ group exhibited the strongest chromatic features. Under electron microscopy, the chondrocytes in the HA+Vib+ group exhibited many long and slender prominences on their surface, and extracellular substance could be observed associated with the cells.
  
  
  CONCLUSIONS
  Our results indicate that the combination of vibration and HA activates the production of proteoglycan in 3-dimensional cultured chondrocytes and stimulates MAPK and beta-catenin. This suggests that some mechanoreceptors for vibration exist on the plasma membrane of chondrocytes and activate the intracellular signal transduction system.
authors.affiliation: Yokohama City University School of Medicine, Yokohama, Japan. take0822@hotmail.com
authors.forename: Ryohei
authors.initials: R
authors.lastname: Takeuchi
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Saito
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ishikawa
authors.forename: Hidetake
authors.initials: H
authors.lastname: Takigami
authors.forename: Mari
authors.initials: M
authors.lastname: Dezawa
authors.forename: Chizuka
authors.initials: C
authors.lastname: Ide
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Itokazu
authors.forename: Mitsugu
authors.initials: M
authors.lastname: Ikeda
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Shiraishi
authors.forename: Shin
authors.initials: S
authors.lastname: Morishita
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D019902:Chondrocytes / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D002809:Chondroitin Sulfates / Q000096:biosynthesis; D003584:Cytological Techniques / Q000379:methods; D005455:Fluorescent Antibody Technique; D006820:Hyaluronic Acid / Q000494:pharmacology*; D007150:Immunohistochemistry; D008854:Microscopy, Electron; D020928:Mitogen-Activated Protein Kinases / Q000502:physiology; D013552:Swine; D014732:Vibration; D051176:beta Catenin / Q000502:physiology
chemical_list: D051176:beta Catenin; D006820:Hyaluronic Acid; D002809:Chondroitin Sulfates; D020928:Mitogen-Activated Protein Kinases