Molecular and mechano-biology of collagen gel contraction mediated by human MG-63 cells: involvement of specific intracellular signaling pathways and the cytoskeleton.
Culture of human osteoblast-like MG-63 cells within collagen gels results in the generation of intrinsic stress. Release of such collagen gels from attachment results in gel contraction and enhanced MMP-1, MMP-3, and alpha2 integrin mRNA levels. To understand the potential role of microtubules and signaling pathways involved in MG-63 cell-mediated contraction and gene expression, cells were cultured in collagen gels. After 24 h collagen gels were released, then immediately treated with nocodazole or specific protein kinase inhibitors. Contraction was assessed, RNA isolated, and real-time PCR analysis performed. Treatment with high concentrations of a microtubule depolymerization agent, nocodazole, enhanced early contraction and led to elevated mRNA levels for MMP-3, whereas low concentrations inhibited contraction at later time points and did not affect mRNA levels. ROCK inhibitor treatment (Y27632) inhibited collagen gel contraction and led to depressed mRNA levels. The ERK1/2 inhibitor U0126 did not affect contraction, but treatment led to depressed MMP-1, MMP-3, and alpha2 mRNA levels. The p38MAPK inhibitor SB203580 modestly affected contraction, but did not affect mRNA levels. These results suggest the potential role of cytoskeletal integrity and multiple kinase signaling pathways in specific bone-remodeling events.
Parreno
Justin
J
Department of Laboratory Medicine and Pathobiology, Mount Sinai Hospital, University of Toronto, 600 University Ave., Toronto ON M5X 1G5, Canada.
Hart
David A
DA
D045744:Cell Line, Tumor; D003094:Collagen / Q000378:metabolism*; D003599:Cytoskeleton / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000378:metabolism / Q000494:pharmacology; D048049:Extracellular Signal-Regulated MAP Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D005782:Gels / Q000378:metabolism*; D006801:Humans; D039421:Integrin alpha2 / Q000235:genetics / Q000378:metabolism; D020781:Matrix Metalloproteinase 1 / Q000235:genetics / Q000378:metabolism; D019278:Matrix Metalloproteinase 3 / Q000235:genetics / Q000378:metabolism; D008870:Microtubules / Q000187:drug effects / Q000378:metabolism; D015739:Nocodazole / Q000494:pharmacology; D012516:Osteosarcoma; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology*; D050257:Tubulin Modulators / Q000494:pharmacology; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D054460:rho-Associated Kinases / Q000235:genetics / Q000378:metabolism
D004791:Enzyme Inhibitors; D005782:Gels; D039421:Integrin alpha2; D012333:RNA, Messenger; D050257:Tubulin Modulators; D003094:Collagen; D054460:rho-Associated Kinases; D048049:Extracellular Signal-Regulated MAP Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D019278:Matrix Metalloproteinase 3; D020781:Matrix Metalloproteinase 1; D015739:Nocodazole