title: Microarray analysis of in vitro pericyte differentiation reveals an angiogenic program of gene expression.
abstract: The vasculature consists of endothelial cells (ECs) lined by pericyte/vascular smooth muscle cells (vSMCs). Pericyte/vSMCs provide support to the mature vasculature but are also essential for normal blood vessel development. To determine how pericyte-EC communication influences vascular development, we used the well-established in vitro model of TGFbeta-stimulated differentiation of 10T1/2 cells into pericyte/vSMCs. Microarray analysis was performed to identify genes that were differentially expressed by induced vs. uninduced 10T1/2 cells. We discovered that these cells show an angiogenic program of gene expression, with up-regulation of several genes previously implicated in angiogenesis, including VEGF, IL-6, VEGF-C, HB-EGF, CTGF, tenascin C, integrin alpha5, and Eph receptor A2. Up-regulation of some genes was validated by Western blots and immunocytochemistry. We also examined the functional significance of these gene expression changes. VEGF and IL-6 alone and in combination were important in 10T1/2 cell differentiation. Furthermore, we used a coculture system of 10T1/2 and human umbilical vein ECs (HUVECs), resulting in the formation of cordlike structures by the HUVECs. This cordlike structure formation was disrupted when neutralizing antibodies to VEGF or IL-6 were added to the coculture system. The results of these studies show that factors produced by pericytes may be responsible for recruiting ECs and promoting angiogenesis. Therefore, a further understanding of the genes involved in pericyte differentiation could provide a novel approach for developing anti-angiogenic therapies.
authors.affiliation: Division of Nephrology, Center for Study of the Tumor Microenvironment, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02215, USA.
authors.forename: Sujata
authors.initials: S
authors.lastname: Kale
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Hanai
authors.forename: Barden
authors.initials: B
authors.lastname: Chan
authors.forename: Anil
authors.initials: A
authors.lastname: Karihaloo
authors.forename: Gary
authors.initials: G
authors.lastname: Grotendorst
authors.forename: Lloyd
authors.initials: L
authors.lastname: Cantley
authors.forename: Vikas P
authors.initials: VP
authors.lastname: Sukhatme
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000235:genetics*; D002460:Cell Line; D018920:Coculture Techniques; D004622:Embryo, Mammalian / Q000166:cytology; D020869:Gene Expression Profiling / Q000379:methods*; D005786:Gene Expression Regulation / Q000235:genetics*; D005796:Genes / Q000502:physiology; D006801:Humans; D051379:Mice; D008809:Mice, Inbred C3H; D046228:Microarray Analysis / Q000379:methods*; D039902:Multipotent Stem Cells / Q000737:chemistry / Q000166:cytology / Q000378:metabolism; D018919:Neovascularization, Physiologic / Q000235:genetics*; D020286:Pericytes / Q000737:chemistry / Q000166:cytology* / Q000378:metabolism; D014471:Umbilical Veins / Q000737:chemistry / Q000166:cytology / Q000378:metabolism