An in vitro assay reveals a role for the diaphragm protein PV-1 in endothelial fenestra morphogenesis.
Fenestrae are small pores in the endothelium of renal glomerular, gastrointestinal, and endocrine gland capillaries and are involved in the bidirectional exchange of molecules between blood and tissues. Although decades of studies have characterized fenestrae at the ultrastructural level, little is known on the mechanisms by which fenestrae form. We present the development of an in vitro assay in which rapid and abundant fenestra induction enables a detailed study of their biogenesis. Through the use of agents that stabilize or disassemble actin microfilaments, we show that actin microfilament remodeling is part of fenestra biogenesis in this model. Furthermore, by using a loss-of-function approach, we show that the diaphragm protein PV-1 is necessary for fenestral pore architecture and the ordered arrangement of fenestrae in sieve plates. Together, these data provide insight into the cell biology of fenestra formation and open up the future study of the fenestra to a combined morphological and biochemical analysis.
Ioannidou
Sofia
S
Eyetech Research Center, OSI Eyetech, 35 Hartwell Avenue, Lexington, MA 02420, USA.
Deinhardt
Katrin
K
Miotla
Jadwiga
J
Bradley
John
J
Cheung
Eunice
E
Samuelsson
Steven
S
Ng
Yin-Shan
YS
Shima
David T
DT
D008841:Actin Cytoskeleton / Q000378:metabolism / Q000648:ultrastructure; D000199:Actins / Q000378:metabolism; D000818:Animals; D002352:Carrier Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D051242:Caveolin 1 / Q000378:metabolism; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism / Q000648:ultrastructure; D003599:Cytoskeleton / Q000378:metabolism / Q000648:ultrastructure; D042783:Endothelial Cells / Q000378:metabolism* / Q000648:ultrastructure*; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D008565:Membrane Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008854:Microscopy, Electron; D034741:RNA, Small Interfering / Q000235:genetics
D000199:Actins; D002352:Carrier Proteins; D051242:Caveolin 1; D008565:Membrane Proteins; C486772:Plvap protein, mouse; D034741:RNA, Small Interfering