| First Author | Kim ST | Year | 2012 |
| Journal | PLoS One | Volume | 7 |
| Issue | 7 | Pages | e41348 |
| PubMed ID | 22911783 | Mgi Jnum | J:189883 |
| Mgi Id | MGI:5447211 | Doi | 10.1371/journal.pone.0041348 |
| Citation | Kim ST, et al. (2012) Functional consequences of cell type-restricted expression of laminin alpha5 in mouse placental labyrinth and kidney glomerular capillaries. PLoS One 7(7):e41348 |
| abstractText | The labyrinth is the highly vascularized part of the rodent placenta that allows efficient transfer of gases, nutrients, wastes, and other molecules between the maternal and embryonic circulations. These two blood compartments are separated by blastocyst-derived trophoblasts and endothelial cells with an intervening basement membrane that contains laminin and other typical basement membrane components. Previously we reported that the labyrinth of laminin alpha5 knockout (LMalpha5-/-) embryos exhibits reduced vascularization and detachment of endothelial cells from the basement membrane, which normally contains LMalpha5. As very little is known about the origin of this vascular basement membrane, we investigated the cellular requirements for LMalpha5 expression in the mouse placental labyrinth. By fluorescence-activated cell sorting and RT-PCR we confirmed that both endothelial cells and trophoblasts normally express LMalpha5. Using Cre-loxP technology and doxycycline-mediated gene expression, we generated genetically mosaic placentas in which either the trophoblasts or the endothelial cells, but not both, expressed LMalpha5. We found that the overall architecture of the labyrinth was normal as long as one of these two cell types expressed LMalpha5, even if it was transgene-derived human laminin alpha5. These results suggest that laminin trimers containing alpha5 that are synthesized and secreted by endothelium or by trophoblasts are capable of integrating into the basement membrane and promoting normal vascularization of the placenta. Additional studies showed that endothelium-expressed human LMalpha5 can support vascularization of the kidney glomerulus, consistent with previous studies using a tissue grafting approach. |
