Tumoral and choroidal vascularization: differential cellular mechanisms involving plasminogen activator inhibitor type I

Am J Pathol. 2007 Oct;171(4):1369-80. doi: 10.2353/ajpath.2007.070074. Epub 2007 Aug 23.

Abstract

An adequate balance between serine proteases and their plasminogen activator inhibitor-1 (PAI-1) is critical for pathological angiogenesis. PAI-1 deficiency in mice is associated with impaired choroidal neovascularization (CNV) and tumoral angiogenesis. In the present work, we demonstrate unexpected differences in the contribution of bone marrow (BM)-derived cells in these two processes regulated by PAI-1. PAI-1(-/-) mice grafted with BM-derived from wild-type mice were able to support laser-induced CNV formation but not skin carcinoma vascularization. Engraftment of irradiated wild-type mice with PAI-1(-/-) BM prevented CNV formation, demonstrating the crucial role of PAI-1 delivered by BM-derived cells. In contrast, the transient infiltration of tumor transplants by local PAI-1-producing host cells rather than by BM cells was sufficient to rescue tumor growth and angiogenesis in PAI-1-deficient mice. These data identify PAI-1 as a molecular determinant of a local permissive soil for tumor angiogenesis. Altogether, the present study demonstrates that different cellular mechanisms contribute to PAI-1-regulated tumoral and CNV. PAI-1 contributes to BM-dependent choroidal vascularization and to BM-independent tumor growth and angiogenesis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bone Marrow Cells / physiology*
  • Bone Marrow Transplantation
  • Carcinoma / blood supply*
  • Choroidal Neovascularization / etiology*
  • Choroidal Neovascularization / metabolism
  • Choroidal Neovascularization / pathology
  • Keratinocytes / pathology
  • Keratinocytes / transplantation
  • Mice
  • Mice, Transgenic
  • Neovascularization, Pathologic / etiology*
  • Neovascularization, Pathologic / metabolism
  • Neovascularization, Pathologic / pathology
  • Plasminogen Activator Inhibitor 1 / genetics
  • Plasminogen Activator Inhibitor 1 / physiology*
  • Skin Neoplasms / blood supply*

Substances

  • Plasminogen Activator Inhibitor 1