HELLP babies link a novel lincRNA to the trophoblast cell cycle
Marie van Dijk, … , Augusta M.A. Lachmeijer, Cees B.M. Oudejans
Marie van Dijk, … , Augusta M.A. Lachmeijer, Cees B.M. Oudejans
Published October 24, 2012
Citation Information: J Clin Invest. 2012;122(11):4003-4011. https://doi.org/10.1172/JCI65171.
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Research Article

HELLP babies link a novel lincRNA to the trophoblast cell cycle

Abstract

The HELLP syndrome is a pregnancy-associated disease inducing hemolysis, elevated liver enzymes, and low platelets in the mother. Although the HELLP symptoms occur in the third trimester in the mother, the origin of the disease can be found in the first trimester fetal placenta. A locus for the HELLP syndrome is present on chromosome 12q23 near PAH. Here, by multipoint nonparametric linkage, pedigree structure allele sharing, and haplotype association analysis of affected sisters and cousins, we demonstrate that the HELLP locus is in an intergenic region on 12q23.2 between PMCH and IGF1. We identified a novel long intergenic noncoding RNA (lincRNA) transcript of 205,012 bases with (peri)nuclear expression in the extravillous trophoblast using strand-specific RT-PCR complemented with RACE and FISH. siRNA-mediated knockdown followed by RNA-sequencing, revealed that the HELLP lincRNA activated a large set of genes that are involved in the cell cycle. Furthermore, blocking potential mutation sites identified in HELLP families decreased the invasion capacity of extravillous trophoblasts. This is the first large noncoding gene to be linked to a Mendelian disorder with autosomal-recessive inheritance.

Authors

Marie van Dijk, Hari K. Thulluru, Joyce Mulders, Omar J. Michel, Ankie Poutsma, Sandra Windhorst, Gunilla Kleiverda, Daoud Sie, Augusta M.A. Lachmeijer, Cees B.M. Oudejans

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Figure 5

Blocking potential mutation sites decreases extravillous trophoblast invasion.

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Blocking potential mutation sites decreases extravillous trophoblast inv...
(A) 3 potential mutations were investigated in detail. RW18-5 (C→T at position 101,120,459) occurred in family 9401; the mutation on the other allele has not yet been identified. HAPLO378 (A→G at position 101,319,702) and HAPLO215Rev (G→C at position 101,241,930) occurred as compound heterozygous mutations in family 9265. HAPLO378 was also present in family 93113. Women affected by HELLP are indicated by black symbols; children born of HELLP pregnancies are indicated by gray symbols. Potential mutagenic alleles are also shaded gray. (B) Morpholinos at a concentration of 5 μM blocking the potential mutagenic sites upregulated expression of the HELLP lincRNA in SGHPL-5 cells. (C) Upregulation of the HELLP lincRNA led to upregulation of downstream effector genes that showed downregulation after siRNA-mediated knockdown of the transcript when the RW18-5 or HAPLO215Rev morpholino was used at a concentration of 5 μM. The combination of HAPLO378 and HAPLO215Rev (2.5 μM each) also upregulated the downstream effector genes. (D) Invasion of SGHPL-5 cells significantly decreased when RW18-5 morpholinos were introduced, whereas HAPLO215Rev trended toward a significant decrease in invasion. HAPLO378 did not affect invasion. The combination of HAPLO215Rev and HAPLO378 (2.5 μM each) significantly decreased the amount of invaded cells. *P < 0.05; **P < 0.01.