Laminin α4 (LAMA4) expression promotes trophoblast cell invasion, migration, and angiogenesis, and is lowered in preeclamptic placentas. Issue 8 (August 2015)

• Record Type: Journal Article
• Authors: Shan, N.; Zhang, X.; Xiao, X.; Zhang, H.; Tong, C.; Luo, X.; Chen, Y.; Liu, X.; Yin, N.; Deng, Q.; Qi, H.
• Is Part Of: Placenta. Volume 36:Issue 8(2015:Aug.)
• Page Start: 809
• Page End: 820
• Publication Date: 2015-08
• Subjects: Placenta -- Periodicals; Reproduction -- Periodicals; Placenta -- Periodicals; Placenta -- Périodiques; Reproduction -- Périodiques; 612.63
• DOI: 10.1016/j.placenta.2015.04.008
• Languages: English
• ISSNs: 0143-4004

Abstract

<abstract xml:lang="en" abstract-type="author" id="abs0010"> <title id="sectitle0010">Abstract</title> <sec> <title id="sectitle0015">Introduction</title> <p id="abspara0010">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.</p> </sec> <sec> <title id="sectitle0020">Methods</title> <p id="abspara0015">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.</p> </sec> <sec> <title id="sectitle0025">Results</title> <p id="abspara0020">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.</p> </sec> <sec> <title id="sectitle0030">Conclusions</title> <p id="abspara0025">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.</p> </sec> </abstract>