bims-reprim 2021-10-10 papers

Issue of 2021–10–10
four papers selected by
Iva Filipovic, Karolinska Institutet

JCI Insight. 2021 Oct 08. pii: e146089. [Epub ahead of print]6(19):

Macrophages exert homeostatic actions in pregnancy to protect against preterm birth and fetal inflammatory injury.

Nardhy Gomez-Lopez, Valeria Garcia-Flores, Peck Yin Chin, Holly M Groome, Melanie T Bijland, Kerrilyn R Diener, Roberto Romero, Sarah A Robertson.

Macrophages are commonly thought to contribute to the pathophysiology of preterm labor by amplifying inflammation - but a protective role has not previously been considered to our knowledge. We hypothesized that given their antiinflammatory capability in early pregnancy, macrophages exert essential roles in maintenance of late gestation and that insufficient macrophages may predispose individuals to spontaneous preterm labor and adverse neonatal outcomes. Here, we showed that women with spontaneous preterm birth had reduced CD209+CD206+ expression in alternatively activated CD45+CD14+ICAM3- macrophages and increased TNF expression in proinflammatory CD45+CD14+CD80+HLA-DR+ macrophages in the uterine decidua at the materno-fetal interface. In Cd11bDTR/DTR mice, depletion of maternal CD11b+ myeloid cells caused preterm birth, neonatal death, and postnatal growth impairment, accompanied by uterine cytokine and leukocyte changes indicative of a proinflammatory response, while adoptive transfer of WT macrophages prevented preterm birth and partially rescued neonatal loss. In a model of intra-amniotic inflammation-induced preterm birth, macrophages polarized in vitro to an M2 phenotype showed superior capacity over nonpolarized macrophages to reduce uterine and fetal inflammation, prevent preterm birth, and improve neonatal survival. We conclude that macrophages exert a critical homeostatic regulatory role in late gestation and are implicated as a determinant of susceptibility to spontaneous preterm birth and fetal inflammatory injury.

Keywords: Cytokines; Macrophages; Obstetrics/gynecology; Reproductive Biology

DOI: https://doi.org/10.1172/jci.insight.146089

Reprod Biol Endocrinol. 2021 Oct 02. 19(1): 150

miRNAs in decidual NK cells: regulators worthy of attention during pregnancy.

Liman Li, Ting Feng, Weijie Zhou, Yuan Liu, Hong Li.

The critical immune effectors, including T, B, and natural killer (NK) cells, dendritic cells, and macrophages participate in regulating immune responses during pregnancy. Among these immune cells, decidual NK (dNK) cells are involved in key placental development processes at the maternal-fetal interface, such as uterine spiral artery remodeling, trophoblast invasion, and decidualization. Mechanistically, dNK cells significantly influence pregnancy outcome by secreting cytokines, chemokines, and angiogenic mediators and by their interactions with trophoblasts and other decidual cells. MicroRNAs (miRNAs) are small non-coding RNA molecules that participate in the initiation and progression of human diseases. Although the functions of circulating miRNAs in pathological mechanism has been extensively studied, the regulatory roles of miRNAs in NK cells, especially in dNK cells, have been rarely reported. In this review, we analyze the effects of miRNA regulations of dNK cell functions on the immune system during gestation. We discuss aberrant expressions of certain miRNAs in dNK cells that may lead to pathological consequences, such as recurrent pregnancy loss (RPL). Interestingly, miRNA expression patterns are also different between dNK cells and peripheral NK (pNK) cells, and pNK cells in the first- and third-trimester of gestation. The dysregulation of miRNA plays a pivotal regulatory role in driving immune functions of dNK and pNK cells. Further understanding of the molecular mechanisms of miRNAs in dNK cells may provide new insights into the development of therapeutics to prevent pregnancy failure.

Keywords: Decidual NK cells; Immune regulation; Pregnancy; miRNAs

DOI: https://doi.org/10.1186/s12958-021-00812-2

Epigenetics. 2021 Oct 04. 1-16

CD4+ T-cell DNA methylation changes during pregnancy significantly correlate with disease-associated methylation changes in autoimmune diseases.

Tejaswi V Badam, Sandra Hellberg, Ratnesh B Mehta, Jeannette Lechner-Scott, Rodney A Lea, Jorg Tost, Xavier Mariette, Judit Svensson-Arvelund, Colm E Nestor, Mikael Benson, Göran Berg, Maria C Jenmalm, Mika Gustafsson, Jan Ernerudh.

Epigenetics may play a central, yet unexplored, role in the profound changes that the maternal immune system undergoes during pregnancy and could be involved in the pregnancy-induced modulation of several autoimmune diseases. We investigated changes in the methylome in isolated circulating CD4+ T-cells in non-pregnant and pregnant women, during the 1st and 2nd trimester, using the Illumina Infinium Human Methylation 450K array, and explored how these changes were related to autoimmune diseases that are known to be affected during pregnancy. Pregnancy was associated with several hundreds of methylation differences, particularly during the 2nd trimester. A network-based modular approach identified several genes, e.g., CD28, FYN, VAV1 and pathways related to T-cell signalling and activation, highlighting T-cell regulation as a central component of the observed methylation alterations. The identified pregnancy module was significantly enriched for disease-associated methylation changes related to multiple sclerosis, rheumatoid arthritis and systemic lupus erythematosus. A negative correlation between pregnancy-associated methylation changes and disease-associated changes was found for multiple sclerosis and rheumatoid arthritis, diseases that are known to improve during pregnancy whereas a positive correlation was found for systemic lupus erythematosus, a disease that instead worsens during pregnancy. Thus, the directionality of the observed changes is in line with the previously observed effect of pregnancy on disease activity. Our systems medicine approach supports the importance of the methylome in immune regulation of T-cells during pregnancy. Our findings highlight the relevance of using pregnancy as a model for understanding and identifying disease-related mechanisms involved in the modulation of autoimmune diseases.Abbreviations: BMIQ: beta-mixture quantile dilation; DMGs: differentially methylated genes; DMPs: differentially methylated probes; FE: fold enrichment; FDR: false discovery rate; GO: gene ontology; GWAS: genome-wide association studies; MDS: multidimensional scaling; MS: multiple sclerosis; PBMC: peripheral blood mononuclear cells; PBS: phosphate buffered saline; PPI; protein-protein interaction; RA: rheumatoid arthritis; SD: standard deviation; SLE: systemic lupus erythematosus; SNP: single nucleotide polymorphism; TH: CD4+ T helper cell; VIStA: diVIsive Shuffling Approach.

Keywords: CD4+ T cells; Pregnancy; epigenetics; methylation; module; multiple sclerosis; rheumatoid arthritis; systemic lupus erythematosus

DOI: https://doi.org/10.1080/15592294.2021.1982510

Elife. 2021 Oct 08. pii: e69584. [Epub ahead of print]10

Evolutionary transcriptomics implicates new genes and pathways in human pregnancy and adverse pregnancy outcomes.

Katelyn Mika, Mirna Marinić, Manvendra Singh, Joanne Muter, Jan Joris Brosens, Vincent J Lynch.

Evolutionary changes in the anatomy and physiology of the female reproductive system underlie the origins and diversification of pregnancy in Eutherian ('Placental') mammals. This developmental and evolutionary history constrains normal physiological functions and biases the ways in which dysfunction contributes to reproductive trait diseases and adverse pregnancy outcomes. Here, we show that gene expression changes in the human endometrium during pregnancy are associated with the evolution of human-specific traits and pathologies of pregnancy. We found that hundreds of genes gained or lost endometrial expression in the human lineage. Among these are genes that may contribute to human-specific maternal-fetal communication (HTR2B) and maternal-fetal immunotolerance (PDCD1LG2) systems, as well as vascular remodeling and deep placental invasion (CORIN). These data suggest that explicit evolutionary studies of anatomical systems complement traditional methods for characterizing the genetic architecture of disease. We also anticipate our results will advance the emerging synthesis of evolution and medicine ('evolutionary medicine') and be a starting point for more sophisticated studies of the maternal-fetal interface. Furthermore, the gene expression changes we identified may contribute to the development of diagnostics and interventions for adverse pregnancy outcomes.

Keywords: evolutionary biology

DOI: https://doi.org/10.7554/eLife.69584