Forkhead box M1 transcriptional factor is required for smooth muscle cells during embryonic development of blood vessels and esophagus.
The forkhead box m1 (Foxm1 or Foxm1b) transcription factor (previously called HFH-11B, Trident, Win, or MPP2) is expressed in a variety of tissues during embryogenesis, including vascular, airway, and intestinal smooth muscle cells (SMCs). Although global deletion of Foxm1 in Foxm1(-/-) mice is lethal in the embryonic period due to multiple abnormalities in the liver, heart, and lung, the specific role of Foxm1 in SMC remains unknown. In the present study, Foxm1 was deleted conditionally in the developing SMC (smFoxm1(-/-) mice). The majority of smFoxm1(-/-) mice died immediately after birth due to severe pulmonary hemorrhage and structural defects in arterial wall and esophagus. Although Foxm1 deletion did not influence SMC differentiation, decreased proliferation of SMC was found in smFoxm1(-/-) blood vessels and esophagus. Depletion of Foxm1 in cultured SMC caused G(2) arrest and decreased numbers of cells undergoing mitosis. Foxm1-deficiency in vitro and in vivo was associated with reduced expression of cell cycle regulatory genes, including cyclin B1, Cdk1-activator Cdc25b phosphatase, Polo-like 1 and JNK1 kinases, and cMyc transcription factor. Foxm1 is critical for proliferation of smooth muscle cells and is required for proper embryonic development of blood vessels and esophagus.
Ustiyan
Vladimir
V
Divisions of Pulmonary Biology, Perinatal Institute of the Cincinnati Children's Hospital Research Foundation, 3333 Burnet Ave., Cincinnati, OH 45229, USA.
Wang
I-Ching
IC
Ren
Xiaomeng
X
Zhang
Yufang
Y
Snyder
Jonathan
J
Xu
Yan
Y
Wert
Susan E
SE
Lessard
James L
JL
Kalin
Tanya V
TV
Kalinichenko
Vladimir V
VV
D000818:Animals; D001808:Blood Vessels / Q000196:embryology*; D049109:Cell Proliferation; D004947:Esophagus / Q000196:embryology*; D000072278:Forkhead Box Protein M1; D051858:Forkhead Transcription Factors / Q000235:genetics / Q000502:physiology*; D005804:Genes, Lethal; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009130:Muscle, Smooth / Q000166:cytology / Q000196:embryology*; D034741:RNA, Small Interfering
D000072278:Forkhead Box Protein M1; D051858:Forkhead Transcription Factors; C491524:Foxm1 protein, mouse; D034741:RNA, Small Interfering