title: p27(Kip1) and p21(Cip1)-independent proliferative inhibition of vascular smooth muscle cells cultured in type-I collagen matrix honeycombs.
abstract: The proliferation of vascular smooth muscle cells (SMCs) contributes to atherosclerotic plaque formation and restenosis. Cyclin-dependent kinase inhibitors, such as p27(Kip1) and p21(Cip1), are known to play significant roles in the control of the aberrant proliferation of SMCs. Primary cultured SMCs stop proliferating immediately when cultured in three-dimensional matrices of type-I collagen "honeycombs" structures. To clarify whether p27(Kip1) and p21(Cip1) are involved in the proliferative inhibition of SMCs cultured in honeycombs, the characteristics of SMCs derived from the aorta of both wild-type mice (p27[+/+] SMCs) and p27(Kip1) knockout mice (p27[-/-] SMCs) were investigated. Although the growth of p27(-/-) SMCs cultured on plates was faster than that of p27(+/+) SMCs, the number of both p27(+/+) and p27(-/-) SMCs did not change when they were cultured in honeycombs. p21(Cip1) expression was decreased but maintained in p27(-/-) SMCs cultured on plates and in honeycombs. Knockdown of p21(Cip1) in p27(-/-) SMCs promoted proliferation on plates. On the contrary, p21(Cip1) knockdown had no effect on the proliferation of p27(-/-) SMCs cultured in honeycombs. In conclusion, p27(Kip1) and p21(Cip1) are insufficient for the proliferative inhibition of SMCs cultured in honeycombs.
authors.affiliation: Division of Pharmacy, Chiba University Hospital, 1-8-1 Inohana, Chuo-ku, Chiba 260-8677, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Uchida
authors.affiliation: Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8675, Japan.
authors.forename: Saki
authors.initials: S
authors.lastname: Suzuki
authors.affiliation: Division of Pharmacy, Chiba University Hospital, 1-8-1 Inohana, Chuo-ku, Chiba 260-8677, Japan.
authors.forename: Takaaki
authors.initials: T
authors.lastname: Suzuki
authors.affiliation: Division of Pharmacy, Chiba University Hospital, 1-8-1 Inohana, Chuo-ku, Chiba 260-8677, Japan; Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8675, Japan. Electronic address: iishii@faculty.chiba-u.jp.
authors.forename: Itsuko
authors.initials: I
authors.lastname: Ishii
mesh_terms: D000818:Animals; D001011:Aorta / Q000378:metabolism / Q000473:pathology; D049109:Cell Proliferation; D002478:Cells, Cultured; D024042:Collagen Type I / Q000737:chemistry / Q000378:metabolism*; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000235:genetics / Q000378:metabolism*; D050760:Cyclin-Dependent Kinase Inhibitor p27 / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D005260:Female; D005786:Gene Expression Regulation; D005838:Genotype; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009131:Muscle, Smooth, Vascular / Q000378:metabolism* / Q000473:pathology; D032389:Myocytes, Smooth Muscle / Q000378:metabolism* / Q000473:pathology; D010641:Phenotype; D016062:Porosity; D061251:Primary Cell Culture; D034622:RNA Interference; D015398:Signal Transduction; D013997:Time Factors; D014162:Transfection
chemical_list: C493957:Cdkn1a protein, mouse; C493961:Cdkn1b protein, mouse; D024042:Collagen Type I; D050759:Cyclin-Dependent Kinase Inhibitor p21; D050760:Cyclin-Dependent Kinase Inhibitor p27
keywords: Smooth muscle cell; Three-dimensional culture; p21(Cip1); p27(Kip1)