Laminin α4 (LAMA4) expression promotes trophoblast cell invasion, migration, and angiogenesis, and is lowered in preeclamptic placentas

N Shan; X Zhang; X Xiao; H Zhang; C Tong; X Luo; Y Chen; X Liu; N Yin; Q Deng; H Qi

doi:10.1016/j.placenta.2015.04.008

Laminin α4 (LAMA4) expression promotes trophoblast cell invasion, migration, and angiogenesis, and is lowered in preeclamptic placentas

Placenta. 2015 Aug;36(8):809-20. doi: 10.1016/j.placenta.2015.04.008. Epub 2015 May 21.

Authors

N Shan¹, X Zhang¹, X Xiao², H Zhang¹, C Tong¹, X Luo¹, Y Chen¹, X Liu¹, N Yin¹, Q Deng¹, H Qi³

Affiliations

¹ Department of Obstetrics and Gynecology, The First Affiliated Hospital, Chongqing Medical University, Chongqing 400016, China.
² Laboratory of Lipid and Glucose Research, The First Affiliated Hospital, Chongqing Medical University, Chongqing 400016, China.
³ Department of Obstetrics and Gynecology, The First Affiliated Hospital, Chongqing Medical University, Chongqing 400016, China. Electronic address: qihongbocq@gmail.com.

PMID: 26059342
DOI: 10.1016/j.placenta.2015.04.008

Abstract

Introduction: The laminin α4 subunit (LAMA4) has been shown to promote migration, proliferation, and survival of various cell types. This study investigated LAMA4's role in trophoblast cells during placental development.

Methods: LAMA4 expression was immunohistochemically assessed in the first trimester and term human placentas. LAMA4 siRNA was applied to silence LAMA4 expression in extravillous explants and HTR8/SVneo cells. Hypoxia-reoxygenation (H/R) conditions were applied to mimic preeclampsia. LAMA4 expression and trophoblast cell invasion, migration, and tube formation (a measure of angiogenesis) were assessed in HTR8/SVneo cells. The p38 mitogen-activated protein kinase (MAPK) inhibitor SB203580 was used to study the mechanism underlying LAMA4 activity. LAMA4 promoter methylation was assessed by bisulfite-sequencing polymerase chain reaction (PCR) or methylation-specific PCR.

Results: LAMA4 levels in preeclamptic placentas were significantly lower than those in controls. LAMA4 silencing significantly inhibited extravillous explant outgrowth as well as HTR8/SVneo cell invasion and migration. H/R conditions significantly lowered LAMA4 expression. Application of either H/R conditions or LAMA4 silencing both significantly decreased HTR8/SVneo cell invasion, migration, and tube formation, decreased MMP2 and MMP9 expression, and increased TIMP2 expression. SB203580 significantly reduced LAMA4 expression. LAMA4 silencing significantly decreased p-p38, p-c-Jun N-terminal kinase (JNK), and p-extracellular signal-regulated kinase (ERK) expressions; by contrast, H/R conditions induced significant upregulation of p-p38 and p-ERK but decreased p-JNK. LAMA4 promoter methylation was not significantly altered in preeclamptic placentas compared to controls.

Conclusions: LAMA4 expression is lowered in preeclamptic placentas and promotes trophoblast cell invasion, migration, and angiogenesis. H/R conditions decrease LAMA4 expression and appear to decouple the positive relationship between LAMA4 expression and p38 and ERK activation.

Keywords: ERK; JNK; LAMA4; Laminin; MAPK; Methylation; Placenta; Preeclampsia; Trophoblast; p38.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Cell Movement / genetics*
Cell Proliferation / genetics*
DNA Methylation
Female
Humans
Laminin / genetics*
Laminin / metabolism
Neovascularization, Physiologic / genetics*
Placenta / metabolism*
Placenta / pathology
Pre-Eclampsia / genetics
Pre-Eclampsia / metabolism*
Pre-Eclampsia / pathology
Pregnancy
Promoter Regions, Genetic
RNA, Small Interfering
Signal Transduction / genetics
Trophoblasts / metabolism*
Trophoblasts / pathology
Up-Regulation

Substances

LAMA4 protein, human
Laminin
RNA, Small Interfering