Differential expression of PPP1R12A transcripts, including those harbouring alternatively spliced micro-exons, in placentae from complicated pregnancies

Edward Frew, Rebecca Sainty, Louise Chappell-Maor, Caitlin Bone, Dagne Daskeviciute, Sarah Russell, Claudia Buhigas, Isabel Iglesias-Platas, Jon Lartey, David Monk

Research output: Contribution to journalArticlepeer-review

Abstract

Introduction: Placenta-associated pregnancy complications, including pre-eclampsia (PE) and intrauterine growth restriction (IUGR) are conditions postulated to originate from initial failure of placentation, leading to clinical sequelae indicative of endothelial dysfunction. Vascular smooth muscle aberrations have also been implicated in the pathogenesis of both disorders via smooth muscle contractility and relaxation mediated by Myosin Light Chain Phosphatase (MLCP) and the oppositional contractile action of Myosin Light Chain Kinase. PPP1R12A is a constituent part of the MLCP complex responsible for dephosphorylation of myosin fibrils. We hypothesize that alternative splicing of micro-exons result in isoforms lacking the functional leucine zipper (LZ) domain which may give those cells expressing these alternative transcripts a tendency towards contraction and vasoconstriction.

Methods: Expression was determined by qRT-PCR. Epigenetic profiling consisted of bisulphite-based DNA methylation analysis and ChIP for underlying histone modifications.

Results: We identified several novel transcripts with alternative micro-exon inclusion that would produce LZ- PPP1R12A protein. qRT-PCR revealed some isoforms, including the PPP1R12A canonical transcript, are differentially expressed in placenta biopsies from PE and IUGR samples compared to uncomplicated pregnancies.

Discussion: We propose that upregulation of PPP1R12A expression in complicated pregnancies may be due to enhanced promoter activity leading to increased transcription as a response to physiological stress in the placenta, which we show is independent of promoter DNA methylation.
Original languageEnglish
Pages (from-to)1-9
Number of pages9
JournalPlacenta
Volume151
Early online date9 Apr 2024
DOIs
Publication statusE-pub ahead of print - 9 Apr 2024

Keywords

  • DNA methylation
  • Micro-exons
  • PPP1R12A
  • Placenta

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