PDF《Research Communication》

Research Communication Genetic Repression of Mouse VEGF Expression Regulates Coagulation Cascade Xiao Liu1 , Liming Hao2 , Shuzhi Zhang1 , Yan Ji1 , Yuntao Zhang1 , Xiaodan Lu1 , Bo Shi2 , Haihong Pei3 , Yi Wang4 , Dongming Chen5 , Xingang Guan1 and Yaowu Zheng1 *

1 National Engineering Laboratory, Institution of Genetics and Cytology, Northeast Normal University, Changchun 130024, People'

s Republic of China

2 Department of Histology and Embryology, Norman Bethune Medical College of Jilin University, Changchun 130021, People'

s Republic of China

3 Physical Education Center, Jilin University, Changchun 130021, People'

s Republic of China

4 Department of Ophthalmology, Second Af?liated Hospital of Jilin University, Changchun 130000, People'

s Republic of China

5 Nursing Department, First Af?liated Hospital of Jilin University, Changchun 130021, People'

s Republic of China Summary VEGF is an important growth factor in embryonic development and functional maintenance of adult organs.

Single allele inactiva- tion of VEGF leads to embryonic lethality and many conditional disruptions show dramatic phenotypes or reduced viabilities. To overcome this burden, a reversible system, which was used in the regulation of VEGF expression and functional studies of many tis- sues and organs in adult, was developed. VEGF is known for expression in many tissues and high expression in platelets. Repres- sion of VEGF expression showed signi?cant defect in bleeding time and clotting time. In mouse model of LPS-induced blood hypercoa- gulation, signi?cant reduction of plasma thrombin-antithrombin formation was observed in VEGF repressed mice, and tissues expressed different modes of damages. These results indicate that VEGF regulates coagulation cascade and may affect sepsis. This is the ?rst genetic evidence of direct link between VEGF transcription and coagulation cascade. Studies using this system may help us to ?nd out how VEGF regulates coagulation cascade and provide new strategies in treating coagulation related diseases. ?

2010 IUBMB IUBMB Life, 62(11): 819C824,

2010 Keywords VEGF repression;

coagulation cascade;

hypercoagulation;

bleeding time. INTRODUCTION Vascular endothelial growth factor (VEGF) is ?rst identi?ed and characterized as vascular permeability factor (VPF) and subsequently reported to promote proliferation, migration, and sur- vival of endothelial cells (1C3). VEGF (also termed VEGF-A) is a member of a growing family of proteins including VEGF-B, -C, -D, and placental growth factor (4C6). VEGF binds to two trans- membrane receptors, Flt-1 and Flk-1. Flk-1 is selectively expressed in endothelium. Flt-1 is present on both endothelial cells and monocytes (7, 8). In addition to its role in promoting endothelial permeability and proliferation, VEGF may contribute to in?amma- tion and coagulation. For example, VEGF induces the expression of cell adhesion molecules (E-selectin), intercellular adhesion mol- ecule

1 (ICAM-1), and vascular cell adhesion molecule

1 (VCAM-1) in endothelial cells and promotes the adhesion of leu- kocytes (9, 10). Moreover, VEGF signaling upregulates tissue fac- tor mRNA, protein, and procoagulant activity (11). VEGF has been implicated as a pathophysiological mediator in many human diseases, including rheumatoid arthritis, cancer, and in?ammatory bowel disease (3, 12C14). Recently, two independent studies reported an association between human severe sepsis/septic shock and elevated circulating levels of VEGF (15, 16). But the direct link between VEGF expression and coagulation system has never been con?rmed. Our ?ndings indicated that VEGF expression played a role in coagulation cascade. MATERIALS AND METHODS Plasmid Constructs and Generation of Transgenic Mouse VEGFtetO mice were generated by targeted insertion of tet operator sequences into VEGF promoter region. Four copies of tet operator sequences were inserted into unique NruI site to- gether with ?oxed NEO cassette. NEO cassette was removed by transfection of CRE expression plasmid into one of the correctly Address correspondence to: Yaowu Zheng, Institution of Genetics and Cytology, School of Life Science, Northeast Normal University, Changchun 130024, People'