The fully linked HTML version of this article has now been published.
Development ePress online publication date 11 Jan 2006
doi: 10.1242/dev.02237
Research Article: Development and Disease
Human trophoblast survival at low oxygen concentrations requires metalloproteinase-mediated shedding of heparin-binding EGF-like growth factor
D. Randall Armant*,
Brian A. Kilburn,
Anelia Petkova,
Samuel S. Edwin,
Zophia M. Duniec-Dmuchowski,
Holly J. Edwards,
Roberto Romero,
and
Richard E. Leach
* Author for correspondence (e-mail: d.armant{at}wayne.edu)
Heparin-binding EGF-like growth factor (HBEGF), which is expressed in the placenta during normal pregnancy, is downregulated in pre-eclampsia, a human pregnancy disorder associated with poor trophoblast differentiation and survival. This growth factor protects against apoptosis during stress, suggesting a role in trophoblast survival in the relatively low O2 (
2%) environment of the first trimester conceptus. Using a well-characterized human first trimester cytotrophoblast cell line, we found that a 4-hour exposure to 2% O2 upregulates HBEGF synthesis and secretion independently of an increase in its mRNA. Five other expressed members of the EGF family are largely unaffected. At 2% O2, signaling via HER1 or HER4, known HBEGF receptors, is required for both HBEGF upregulation and protection against apoptosis. This positive-feedback loop is dependent on metalloproteinase-mediated cleavage and shedding of the HBEGF ectodomain. The restoration of trophoblast survival by the addition of soluble HBEGF in cultures exposed to low O2 and metalloproteinase inhibitor suggests that the effects of HBEGF are mediated by autocrine/paracrine, rather than juxtacrine, signaling. Our results provide evidence that a post-transcriptional mechanism induced in trophoblasts by low O2 rapidly amplifies HBEGF signaling to inhibit apoptosis. These findings have a high clinical significance, as the downregulation of HBEGF in pre-eclampsia is likely to be a contributing factor leading to the demise of trophoblasts.

CiteULike
Complore
Connotea
Del.icio.us
Digg
Reddit
Technorati
Twitter What's this?
This article has been cited by other articles:

|
 |

|
 |
 
J. Liu, C. D. MacCalman, Y.-l. Wang, and P. C. K. Leung
Promotion of Human Trophoblasts Invasion by Gonadotropin-Releasing Hormone (GnRH) I and GnRH II via Distinct Signaling Pathways
Mol. Endocrinol.,
July 1, 2009;
23(7):
1014 - 1021.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
T. Uetani, H. Nakayama, H. Okayama, T. Okura, J. Higaki, H. Inoue, and S. Higashiyama
Insufficiency of Pro-heparin-binding Epidermal Growth Factor-like Growth Factor Shedding Enhances Hypoxic Cell Death in H9c2 Cardiomyoblasts via the Activation of Caspase-3 and c-Jun N-terminal Kinase
J. Biol. Chem.,
May 1, 2009;
284(18):
12399 - 12409.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
S. M. Nelson and I. A. Greer
The potential role of heparin in assisted conception
Hum. Reprod. Update,
November 1, 2008;
14(6):
623 - 645.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
T.-H. Hung, S.-F. Chen, C.-C. Hsieh, J.-J. Hsu, M.-J. Li, Y.-L. Yeh, and T.-T. Hsieh
Tumor Necrosis Factor--{alpha} Converting Enzyme in the Human Placenta Throughout Gestation
Reproductive Sciences,
February 1, 2008;
15(2):
195 - 209.
[Abstract]
[PDF]
|
 |
|

|
 |

|
 |
 
G. S. Wolff, P. J. Chiang, S. M. Smith, R. Romero, and D. R. Armant
Epidermal Growth Factor-Like Growth Factors Prevent Apoptosis of Alcohol-Exposed Human Placental Cytotrophoblast Cells
Biol Reprod,
July 1, 2007;
77(1):
53 - 60.
[Abstract]
[Full Text]
[PDF]
|
 |
|
© The Company of Biologists Ltd 2006