title: Microenvironment is involved in cellular response to hydrostatic pressures during chondrogenesis of mesenchymal stem cells.
abstract: Chondrocytes integrate numerous microenvironmental cues to mount physiologically relevant differentiation responses, and the regulation of mechanical signaling in chondrogenic differentiation is now coming into intensive focus. To facilitate tissue-engineered chondrogenesis by mechanical strategy, a thorough understanding about the interactional roles of chemical factors under mechanical stimuli in regulating chondrogenesis is in great need. Therefore, this study attempts to investigate the interaction of rat MSCs with their microenvironment by imposing dynamic and static hydrostatic pressure through modulating gaseous tension above the culture medium. Under dynamic pressure, chemical parameters (pH, pO2, and pCO2) were kept in homeostasis. In contrast, pH was remarkably reduced due to increased pCO2 under static pressure. MSCs under the dynamically pressured microenvironment exhibited a strong accumulation of GAG within and outside the alginate beads, while cells under the statically pressured environment lost newly synthesized GAG into the medium with a speed higher than its production. In addition, the synergic influence on expression of chondrogenic genes was more persistent under dynamic pressure than that under static pressure. This temporal contrast was similar to that of activation of endogenous TGF-β1. Taken altogether, it indicates that a loading strategy which can keep a homeostatic chemical microenvironment is preferred, since it might sustain the stimulatory effects of mechanical stimuli on chondrogenesis via activation of endogenous TGF-β1.
authors.affiliation: State Key Laboratory of Oral Diseases, Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, P.R., China.
authors.forename: Rui
authors.initials: R
authors.lastname: Ye
authors.forename: Jin
authors.initials: J
authors.lastname: Hao
authors.forename: Jinlin
authors.initials: J
authors.lastname: Song
authors.forename: Zhihe
authors.initials: Z
authors.lastname: Zhao
authors.forename: Shanbao
authors.initials: S
authors.lastname: Fang
authors.forename: Yating
authors.initials: Y
authors.lastname: Wang
authors.forename: Juan
authors.initials: J
authors.lastname: Li
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology / Q000378:metabolism / Q000502:physiology; D002454:Cell Differentiation / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D002478:Cells, Cultured; D060833:Cellular Microenvironment / Q000235:genetics / Q000502:physiology*; D019902:Chondrocytes / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D020219:Chondrogenesis / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D015870:Gene Expression / Q000187:drug effects; D006025:Glycosaminoglycans / Q000096:biosynthesis; D006874:Hydrostatic Pressure; D008297:Male; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D017207:Rats, Sprague-Dawley; D013997:Time Factors; D053773:Transforming Growth Factor beta1 / Q000378:metabolism / Q000494:pharmacology
chemical_list: D006025:Glycosaminoglycans; D053773:Transforming Growth Factor beta1
keywords: CHONDROGENESIS; DYNAMIC HYDROSTATIC PRESSURE; MESENCHYMAL STEM CELLS; MICROENVIRONMENT; STATIC HYDROSTATIC PRESSURE