title: Genomic analysis of smooth muscle cells in 3-dimensional collagen matrix.
abstract: The proliferation, differentiation, and protein synthesis of vascular smooth muscle cells (SMCs) play important roles in vascular remodeling. Here, we compared the genetic programming and signaling of SMCs in collagen matrix as a three-dimensional (3-D) environment and on a two-dimensional (2-D) surface. By using DNA microarrays with 9600 genes, we showed that 77 genes were expressed more than twofold and 22 genes were less than one-half in 3-D matrix, when compared with the 2-D condition. The higher expression level of cyclin-dependent kinase inhibitor 1 (p21) in 3-D matrix suggests that p21 may be responsible for the lower proliferation rate in 3-D matrix. The expression level of collagen I was higher in 3-D matrix, suggesting that SMCs in 3-D matrix have increased matrix synthesis. In addition, SMCs in 3-D matrix had less stress fibers and focal adhesions, and a lower level of tyrosine phosphorylation of focal adhesion kinase (FAK). Overexpression of FAK attenuated the expression of p21 and collagen I in 3-D matrix, suggesting that FAK functions as a molecular switch for cell cycle regulation and matrix synthesis. The information generated in this study helps to elucidate the molecular basis of the modulation of SMC phenotypes by the extracellular matrix.
authors.affiliation: Department of Bioengineering and The Whitaker Institute of Biomedical Engineering University of California, San Diego, La Jolla, California, USA.
authors.forename: Song
authors.initials: S
authors.lastname: Li
authors.forename: Jianmin
authors.initials: J
authors.lastname: Lao
authors.forename: Benjamin P C
authors.initials: BP
authors.lastname: Chen
authors.forename: Yi-shuan
authors.initials: YS
authors.lastname: Li
authors.forename: Yihua
authors.initials: Y
authors.lastname: Zhao
authors.forename: Julia
authors.initials: J
authors.lastname: Chu
authors.forename: Kuang-Den
authors.initials: KD
authors.lastname: Chen
authors.forename: Tsui-Chun
authors.initials: TC
authors.lastname: Tsou
authors.forename: Konan
authors.initials: K
authors.lastname: Peck
authors.forename: Shu
authors.initials: S
authors.lastname: Chien
mesh_terms: D018929:Cell Culture Techniques / Q000379:methods; D002455:Cell Division; D002478:Cells, Cultured; D003094:Collagen / Q000096:biosynthesis / Q000494:pharmacology*; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins / Q000096:biosynthesis / Q000235:genetics; D005109:Extracellular Matrix / Q000648:ultrastructure; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; D022001:Focal Adhesions / Q000648:ultrastructure; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D023281:Genomics; D006801:Humans; D008954:Models, Biological; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000378:metabolism* / Q000502:physiology; D010641:Phenotype; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism; D022502:Stress Fibers / Q000648:ultrastructure; D014443:Tyrosine / Q000378:metabolism
chemical_list: C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D014443:Tyrosine; D003094:Collagen; D011505:Protein-Tyrosine Kinases; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; C496050:PTK2 protein, human