Candidate mediators of chondrocyte mechanotransduction via targeted and untargeted metabolomic measurements.
Chondrocyte mechanotransduction is the process by which cartilage cells transduce mechanical loads into biochemical and biological signals. Previous studies have identified several pathways by which chondrocytes transduce mechanical loads, yet a general understanding of which signals are activated and in what order remains elusive. This study was performed to identify candidate mediators of chondrocyte mechanotransduction using SW1353 chondrocytes embedded in physiologically stiff agarose. Dynamic compression was applied to cell-seeded constructs for 0-30min, followed immediately by whole-cell metabolite extraction. Metabolites were detected via LC-MS, and compounds of interest were identified via database searches. We found several metabolites which were statistically different between the experimental groups, and we report the detection of 5 molecules which are not found in metabolite databases of known compounds indicating potential novel molecules. Targeted studies to quantify the response of central energy metabolites to compression found a transient increase in the ratio of NADP+ to NADPH and a continual decrease in the ratio of GDP to GTP, suggesting a flux of energy into the TCA cycle. These data are consistent with the remodeling of cytoskeletal components by mechanically induced signaling, and add substantial new data to a complex picture of how chondrocytes transduce mechanical loads.
Department of Mechanical and Industrial Engineering, Montana State University, PO Box 173800, Bozeman, MT 59717-3800, United States.
Aaron A
AA
Jutila
Department of Mechanical and Industrial Engineering, Montana State University, PO Box 173800, Bozeman, MT 59717-3800, United States.
Donald L
DL
Zignego
Department of Mechanical and Industrial Engineering, Montana State University, PO Box 173800, Bozeman, MT 59717-3800, United States.
Bradley K
BK
Hwang
Department of Chemistry and Biochemistry, Montana State University, PO Box 173800, Bozeman, MT 59717-3800, United States.
Jonathan K
JK
Hilmer
Department of Chemistry and Biochemistry, Montana State University, PO Box 173800, Bozeman, MT 59717-3800, United States.
Timothy
T
Hamerly
Department of Mechanical and Industrial Engineering, Montana State University, PO Box 173800, Bozeman, MT 59717-3800, United States.
Cody A
CA
Minor
Department of Immunology and Microbiology, Montana State University, PO Box 173800, Bozeman, MT 59717-3800, United States.
Seth T
ST
Walk
Department of Cell Biology and Neuroscience, Montana State University, PO Box 173800, Bozeman, MT 59717-3800, United States. Electronic address: rjune@me.montana.edu.
Ronald K
RK
June
D002460:Cell Line; D019902:Chondrocytes / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D040542:Mechanotransduction, Cellular; D055442:Metabolome; D055432:Metabolomics / Q000379:methods; D013314:Stress, Mechanical
Cartilage; Chondrocyte; Joint biology; Mechanotransduction; Metabolomics; Osteoarthritis