**4.4. Common transcriptomic signature of macrophages, dendritic cells and mast cells**

To identify a common signature of these three placenta immune cells, we performed a retroanalysis of microarray data deposited in Gene Expression Omnibus at the National Center for Biotechnology Information. We evaluated the transcriptomic signatures of macrophages, dendritic cells and mast cells from at term placentas of healthy women and compared them to those of monocytes, monocyte-derived dendritic cells and the cell line HMC-1, respectively. As depicted in **Figure 2A**, the hierarchical clustering reveals two major branches that distinguish cells of placenta origin from the others (ANOVA, p < 0.001). Focusing on common modulated genes, we observed that 479 (**Figure 2B**) and 5671 (**Figure 2C**) genes are up- and down-regulated, respectively. Interestingly, 45% of down-modulated genes are associated with pregnancy versus 10% of up-modulated genes. Thus, these data suggest that innate immune cells express a core of genes that reflect the influence of placenta microenvironment.

**5. Conclusion**

**Acknowledgements**

Infection 10-IAHU-03).

**Author contributions**

**Declaration of interest**

**Author details**

Soraya Mezouar1

The authors declare no competing interests.

\* and Jean-Louis Mege1,2

\*Address all correspondence to: soraya.mezouar@univ-amu.fr

(IHU)—Méditerranée Infection, UF Immunologie, Marseille, France

1 Aix-Marseille University, Institut de Recherche pour le Développement (IRD), Assistance Publique-Hôpitaux de Marseille (AP-HM), Microbes Evolution PHylogeny and Infections (MEPHI), Institut Hospitalo-Universitaire (IHU)—Méditerranée Infection, Marseille, France 2 Assistance Publique-Hôpitaux de Marseille (AP-HM), Institut Hospitalo-Universitaire

Transcriptional analysis of placenta reveals the modulation of a very large number of genes and pathways, allowing a better understanding of tissue and cell mechanisms of normal and pathological pregnancy. The development of RNA-Seq, with a better genomic coverage and more sensitivity than microarray, and single cell technology will permit promises to detect genes with low expression level and to reveal differential new gene expression for normal and complicated pregnancies. Thus, this study reveals only the visible part of an iceberg and

Gene Expression Profiling of Placenta from Normal to Pathological Pregnancies

http://dx.doi.org/10.5772/intechopen.80551

45

We are very thankful to Dr. Christian Capo for his help and councils regarding the redaction of the manuscript. Soraya Mezouar was supported by a "Fondation pour la Recherche Médicale" postdoctoral fellowship (reference: SPF20151234951). This work was supported by the French Government under the "Investissements d'avenir" (investments for the future) program managed by the "Agence Nationale de la Recherche" (reference: Méditerranée

suggests that the immersed part must be further investigated.

Soraya Mezouar and Jean-Louis Mege conceived and wrote the paper.

**Figure 2.** Transcriptomic analysis of dendritic cells, macrophages and mast cells from placenta tissue compared to controls including monocytes-derived dendritic cells, monocytes-derived macrophages and HMC-1 cell line, respectively. (A) Hierarchical clustering of placental cells showing the up- (red) and down- (green) modulated genes. Venn diagrams were realized to show the number of (B) up- and (C) down-modulated genes in common from dendritic cells (green), macrophages (blue) and mast cells (gray) from placenta.
