Defective placental vasculogenesis causes embryonic lethality in VHL-deficient mice

Defective placental vasculogenesis causes embryonic lethality in VHL-deficient mice

^*Urologic Oncology Branch, Division of Clinical Sciences, ^‖Laboratory of Pathology, and ^**Office of the Director, National Cancer Institute, Bethesda, MD 20892; ^‡Veterinary and Tumor Pathology Section, Office of Laboratory Animal Science, National Cancer Institute, Frederick, MD 21702-1201; and ^§Inheritable Disorders Branch, and ^¶Laboratory of Mammalian Genes and Development, National Institute of Child Health and Human Development, Bethesda, MD 20892

Contributed by Richard D. Klausner

Abstract

Inheritance of an inactivated form of the VHL tumor suppressor gene predisposes patients to develop von Hippel–Lindau disease, and somatic VHL inactivation is an early genetic event leading to the development of sporadic renal cell carcinoma. The VHL gene was disrupted by targeted homologous recombination in murine embryonic stem cells, and a mouse line containing an inactivated VHL allele was generated. While heterozygous VHL (+/−) mice appeared phenotypically normal, VHL −/− mice died in utero at 10.5 to 12.5 days of gestation (E10.5 to E12.5). Homozygous VHL −/− embryos appeared to develop normally until E9.5 to E10.5, when placental dysgenesis developed. Embryonic vasculogenesis of the placenta failed to occur in VHL −/− mice, and hemorrhagic lesions developed in the placenta. Subsequent hemorrhage in VHL −/− embryos caused necrosis and death. These results indicate that VHL expression is critical for normal extraembryonic vascular development.

Footnotes

↵ † Present address: Department of Biochemistry and Molecular Biology, Stanley S. Scott Cancer Center, Louisiana State University Medical Center, New Orleans, LA 70112.
ABBREVIATIONS:

ES,

embryonic stem;

E,

gestational day;

VEGF,

vascular endothelial cell growth factor