Distribution of vitronectin mRNA during murine development

Abstract

Vitronectin (Vn) is not only a major adhesive glycoprotein in plasma but also regulates cell-mediated proteolytic enzyme cascades, including the complement, coagulation, and fibrinolytic systems. This broad functional activity suggests that Vn may also play a critical role in development. To begin to investigate this possibility, we studied Vn gene expression during murine embryogenesis. In situ hybridization analysis of embryonic tissues revealed Vn mRNA primarily in the liver and the central nervous system (CNS). In the liver, Vn mRNA was detected by day 10, the level increasing at later developmental stages. In the CNS, Vn mRNA was also detected as early as day 10 and was confined to the floor plate. However, as development proceeded, high levels of Vn transcripts became prominent in the meninges of the cortex and spinal cord, and in close proximity to brain capillaries. The perikarya of most neurons lacked Vn mRNA. Unexpectedly, high levels of Vn mRNA were associated with capillaries of the CNS, but not with blood vessels of peripheral organs. These results indicate that Vn is expressed in a spatially and temporally distinct pattern during murine embryogenesis, and suggest that the Vn transcript may be a CNS-specific vascular marker. o 1995 WiIey-Liss, Inc.

Vitronectin is not essential for normal mammalian development and fertility.

“…VN is widely distributed in the ECM of many tissues in adult humans (1,2) and during embryogenesis in the mouse (30). Despite extensive prior studies suggesting a major role for VN in the developing embryo, particularly during central nervous system and heart organogenesis (7,8,30), we failed to detect any disturbance of normal growth or development in mice engineered to be completely deficient in VN. These data suggest some degree of overlap or compensation by other ECM proteins in support of these critical developmental functions.…”

Foxa(HNF3) Up-regulates Vitronectin Expression during Retinoic Acid-induced Differentiation in Mouse Neuroblastoma Neuro2a Cells.

“…Up-regulation of vitronectin expression is also observed in notochord and floor plate during mouse and chick neurogenesis (Seiffert et al, 1995;Martinez-Morales et al, 1997;Pons and Marti, 2000). Our previous study showed that Foxa regulates the constitutive expression of vitronectin through site B (Shimizu et al, 2002).…”

“…In this study, we showed that Foxa is involved in the up-regulation of vitronectin expression during the retinoic acid-induced differentiation. Transcription factors Foxa1 and Foxa2, which are members of the Foxa family (Lai et al, 1990;Kaestner, 2000;Kaestner et al, 2000), are expressed in liver, notochord and floor plate (Monaghan et al, 1993;Sasaki and Hogan, 1993;Seiffert et al, 1995). In point of detail, the internal granular layer of the cerebellum and mouse embryonic carcinoma P19 cells express Foxa1 and/or Foxa2 during the neuronal differentiation (Jacob et al, 1997;Dahmane and Ruiz-i-Altaba, 1999).…”

“…In addition, recent studies have shown that vitronectin is expressed in the neural system during embryogenesis and promotes neuronal differentiation of motor neurons (Martinez-Morales et al, 1997;Pons and Marti, 2000) and cerebellar granule cells (Pons et al, 2001). In chick and mouse embryo, vitronectin is transiently expressed in the notochord, floor plate and neural tube (Seiffert et al, 1995;Martinez-Morales et al, 1997;Pons and Marti, 2000). During differentiation of granule cells in the cerebellar cortex, vitronectin is localized at the inner external germinal layer (iEGL) and internal granule layer (IGL) of the chick cerebellar cortex (Pons et al, 2001).…”

Vitronectin's Basic Domain is a Syndecan Ligand which Functionsin transto Regulate Vitronectin Turnover

“…Vitronectin deposition into the matrix is tightly regulated, occurring at specific times during development and disease progression. In the adult animal, vitronectin synthesis occurs primarily in the liver (71,72,78), however, induction of vitronectin synthesis by tissue cells and its increased deposition into surrounding 86 C. E. WILKINS-PORT ET AL. tissues has been observed in association with tumor progression (6,7,26,27,80), atherosclerosis (17,83), rheumatoid arthritis (79), macular degeneration (29,57), and differentiation of neuroectodermal and mesenchymal structures (16,40,48,71). Vitronectin has a relatively short half life in the matrix as it is actively removed by integrin receptor mediated endocytosis and subsequently degraded by lysosomal enzymes (49,59).…”