文档库

最新最全的文档下载
当前位置:文档库 > Regulation of angiogenesis by a non-canonical Wnt–

Regulation of angiogenesis by a non-canonical Wnt–

LETTER

doi:10.1038/nature10085

Regulation of angiogenesis by a non-canonical Wnt–Flt1pathway in myeloid cells

James A.Stefater III 1,2,Ian Lewkowich 3,Sujata Rao 1,2,Giovanni Mariggi 4,April C.Carpenter 1,2,Adam R.Burr 5,Jieqing Fan 1,2,Rieko Ajima 6,Jeffery D.Molkentin 5,7,Bart O.Williams 8,Marsha Wills-Karp 3,Jeffrey W.Pollard 9,Terry Yamaguchi 6,Napoleone Ferrara 10,Holger Gerhardt 4,11&Richard http://www.wendangku.net/doc/28d220ae7375a417876f8f6d.html ng 1,2

Regulation of angiogenesis by a non-canonical Wnt–

Myeloid cells are a feature of most tissues.Here we show that during development,retinal myeloid cells (RMCs)produce Wnt ligands to regulate blood vessel branching.In the mouse retina,where angio-genesis occurs postnatally 1,somatic deletion in RMCs of the Wnt ligand transporter Wntless 2,3results in increased angiogenesis in the deeper layers.We also show that mutation of Wnt5a and Wnt11results in increased angiogenesis and that these ligands elicit RMC responses via a non-canonical Wnt http://www.wendangku.net/doc/28d220ae7375a417876f8f6d.html ing cultured myeloid-like cells and RMC somatic deletion of Flt1,we show that an effector of Wnt-dependent suppression of angiogenesis by RMCs is Flt1,a naturally occurring inhibitor of vascular endothelial growth factor (VEGF)4–6.These findings indicate that resident myeloid cells can use a non-canonical,Wnt–Flt1pathway to sup-press angiogenic branching.

Regulation of angiogenesis by a non-canonical Wnt–

Regulation of angiogenesis by a non-canonical Wnt–

Myeloid cells have a wide array of biological activities that include immune activation,arteriogenesis 7,and regulation of salt balance and blood pressure 8.Myeloid cells also regulate vascularity.Tumour-associated macrophages influence the growth of blood vessels 9in part because they are a source of VEGFA 10.Myeloid cells also promote angiogenic branching 11and anastamosis 12.Depending on the context,myeloid cells can be either anti-angiogenic 13or pro-angiogenic 14.Here we show that RMCs suppress retinal angiogenesis via a Wnt–Flt1pathway (Supplementary Fig.1).

Regulation of angiogenesis by a non-canonical Wnt–

Retinal angiogenesis begins on the day of birth in the mouse with the formation of a superficial vascular plexus (Fig.1a)that lies within the ganglion cell layer 15.After formation of this superficial plexus by post-partum day 7(P7),angiogenic sprouts descend vertically through the retinal layers from P8to P14(Fig.1a).At the outer edge of the inner nuclear layer (INL)the vertical angiogenic sprouts turn and simulta-neously branch to form a deep vascular plexus (Fig.1a).Using antibodies to the vascular endothelial cell (VEC)marker endomucin and to the green fluorescent protein (GFP)of the c-fms–EGFP (also known as Tg(Csf1r-EGFP)1Hume )transgene that marks RMCs,we show that myeloid cells have a unique spatial relationship with angiogenic tip cells.At the point of turning and branching in the outer INL,myeloid cells and angiogenic sprouts are in close contact (Supplementary Fig.2a).This was confirmed by labelling with isolectin and F4/80(F4/80is also known as Emr1;Supplementary Fig.2b).We then took advantage of high-intensity isolectin labelling of VECs and RMCs and performed a three-dimensional reconstruction with false colouring to illustrate the overall topology of the angiogenic tip cell–RMC interaction (Fig.1b).This showed close contact between the two cell types throughout turn-and-branch angiogenesis in the deep retinal layer.Furthermore,after turning,angiogenic tip cells extend within the plane of the deep retinal layer and remain RMC-associated (Fig.1c).In further defining RMCs,

1

The Visual Systems Group,Divisions of Pediatric Ophthalmology and Developmental Biology,Cincinnati Children’s Hospital Medical Center,Cincinnati,Ohio 45229,USA.2Department of Ophthalmology,University of Cincinnati,Cincinnati,Ohio 45229,USA.3Division of Immunobiology,Cincinnati Children’s Hospital Medical Center,Cincinnati,Ohio 45229,USA.4Vascular Biology Laboratory,London Research Institute,Cancer Research UK,London WC23PX,UK.5Division of Molecular Cardiovascular Biology,Cincinnati Children’s Hospital Medical Center,University of Cincinnati,Ohio 45229,USA.6

Cancer and Developmental Biology Laboratory,National Cancer Institute,Frederick,Maryland 21701,USA.7Howard Hughes Medical Institute,Cincinnati Children’s Hospital Medical Center,University of Cincinnati,Ohio 45229,USA.8Center for Skeletal Disease Research,Van Andel Research Institute,333Bostwick NE,Grand Rapids,Michigan 49503,USA.9Albert Einstein College of Medicine of Yeshiva University,Jack and Pearl Resnick Campus,1300Morris Park Avenue,Bronx,New York 10461,USA.10Genentech Inc.,1DNA Way,South San Francisco,California 94080,USA.11Consultant Group Leader,Vascular Patterning Laboratory,Vesalius Research Center,VIB,Campus Gasthuisberg,B-3000Leuven,

Belgium.

Isolectin vascular endothelial cells Isolectin false-colour myeloid cells

1057-A A D

C D 204

CD11b

F4/80

104

103102102

1031041050

1051041031020

0102

103104105

0HA

HA

z

y

x Superficial layer myeloid cells

Deep layer myeloid cells

E11.5 whole embryo Act WIs

45a

6

111

2

3

5

6

7

810

16

Deep layer RMCs Superficial layer RMCs

Wnt ligands

Fzd receptors

Lrp5Lrp6

Coreceptors

d

e

f

P10

P2

P6

P18

Superficial vascular layer

Superficial vascular layer

Superficial vascular layer

Superficial vascular layer

Deep vascular layer

Deep vascular layer

a

Figure 1|RMCs interact with VECs and express Wnt components.

a ,Schematic of retina at postnatal days (P)2,6,10,and 18.RMCs interacting with descending vertical sprouts are labelled with red arrowheads.Adapted from ref.1.

b ,Isolectin-labelled three-dimensional reconstruction of vertical angiogeni

c sprouts (green)an

d RMCs (false-colour red).c ,As in b but a two-dimensional imag

e in the deep vascular layer.Scale bars,5m m.d ,e ,Flow cytometry o

f deep layer RMCs based on surface markers.7-AAD,

7-aminoactinomycin D.f ,PCR for Wnt pathway components on flow-sorted RMCs.Red arrowheads indicate expected sizes.Act,b -actin.

00M O N T H 2011|V O L 000|N A T U R E |1

Macmillan Publishers Limited. All rights reserved

©2011

免费下载Word文档免费下载: Regulation of angiogenesis by a non-canonical Wnt–

(共6页)