The change in tenascin expression in mouse uterus during early pregnancy

Uterine Tissue Engineering: Where We Stand and the Challenges Ahead

Tissue engineering is an innovative approach to develop allogeneic tissues and organs. The uterus is a very sensitive and complex organ, which requires refined techniques to properly regenerate and even, to rebuild itself. Many therapies were developed in 20th century to solve reproductive issues related to uterus failure and, more recently, tissue engineering techniques provided a significant evolution in this issue. Herein we aim to provide a broad overview and highlights of the general concepts involved in bioengineering to reconstruct the uterus and its tissues, focusing on strategies for tissue repair, production of uterine scaffolds, biomaterials and reproductive animal models, highlighting the most recent and effective tissue engineering protocols in literature and their application in regenerative medicine. In addition, we provide a discussion about what was achieved in uterine tissue engineering, the main limitations, the challenges to overcome and future perspectives in this research field.

Endometrial gene expression profiling of recurrent implantation failure after in vitro fertilization

Recurrent implantation failure (RIF) is diagnosed when good-quality embryos repeatedly fail to implant after transfer in several in vitro fertilization (IVF) treatment cycles. Different expression profiles in maternal mRNAs could be referring to many diseases including RIF. This study aimed to reveal significantly dysregulated selected genes expression between healthy fertile women and RIF patients in the implantation window days of the natural menstrual cycle. MME, WWC1, TNC, and FOXP3 genes were chosen as target genes regarding their possible relations with the implantation process. Pathways with these genes were identified and the relationship between these pathways and RIF was investigated. In this study, the endometrial biopsy samples were collected in the secretory phase (cycle day 20-24) of the menstrual cycle from RIF patients (n = 34) and healthy fertile controls (n = 34). After "Pathway and network-oriented GWAS analysis" (PANOGA) and "Kyoto Encyclopedia of Genes and Genomes" (KEGG) pathway analysis; "Membrane Metalloendopeptidase" (MME), "WW and C2 Domain Containing 1" (WWC1), "Tenascin C" (TNC) and "Forkhead Box P3" (FOXP3) genes were chosen as target genes by regarding their possible relation with implantation process. Detection of differences in mRNA expressions between the control group and RIF patients has been performed with the droplet digital PCR (ddPCR) method. Results of the study showed that MME and WWC1 genes expression levels are significantly (p < 0,05) up-regulated 4.9 and 5.2 times respectively and TNC gene expression level is significantly (p < 0,05) down-regulated 9 times in the RIF samples compared to the control group. However, no statistically significant difference was observed between the patient group and the control group in the expression of the FOXP3 gene (p < 0.05). Changes are observed in the expression of the renin-angiotensin system pathway in which the MME gene is involved in the implantation process. The increase in MME gene expression can be speculated to cause implantation failure by restricting the invasion of trophoblast cells. Increasing WWC1 gene expression in the Hippo signaling pathway inhibits "Yes-associated protein 1" (YAP) expression, which is a transcriptional cofactor. Inhibition of YAP protein expression may impair the implantation process by causing the failure of endometrial decidualization. The TNC gene is located in the focal adhesion pathway and this pathway reduces cell adhesion on the endometrial surface to facilitate the attachment of the embryo to the endometrium. The reason for implantation failure might be that the intercellular connections are not suitable for implantation as a result of decreased expression of the focal adhesion pathway in which the TNC gene is effective. Considering the relations between the pathways of the target genes and the implantation process, changes in the expression of target genes might be a cause of RIF.

The role of extracellular matrix in normal and pathological pregnancy: Future applications of microphysiological systems in reproductive medicine

IMPACT STATEMENT

Extracellular matrix in the womb regulates the initiation, progression, and completion of a healthy pregnancy. The composition and physical properties of extracellular matrix in the uterus and at the maternal-fetal interface are remodeled at each gestational stage, while maladaptive matrix remodeling results in obstetric disease. As in vitro models of uterine and placental tissues, including micro-and milli-scale versions of these organs on chips, are developed to overcome the inherent limitations of studying human development in vivo, we can isolate the influence of cellular and extracellular components in healthy and pathological pregnancies. By understanding and recreating key aspects of the extracellular microenvironment at the maternal-fetal interface, we can engineer microphysiological systems to improve assisted reproduction, obstetric disease treatment, and prenatal drug safety.

Expression of tenascin-C in stromal cells of the murine uterus during early pregnancy: induction by interleukin-1 alpha, prostaglandin E(2), and prostaglandin F(2 alpha)

Tenascin-C (TN-C), an extracellular matrix glycoprotein, is known to be expressed in uterine stroma in the peri-implantation period. Examination of the spatiotemporal pattern during early pregnancy using immunohistochemistry and in situ hybridization revealed TN-C expression in the stroma beneath the luminal epithelia of the murine endometrium on Days 0 and 1 of pregnancy, subsequent disappearance, and reappearance on Day 4. After decidualization, tissue around the deciduoma was positive. In situ hybridization demonstrated TN-C production by the stromal cells adjacent to the epithelia. To investigate the regulation of TN-C expression in vitro, murine uterine stromal and epithelial cells were isolated and cultured. Addition of interleukin-1 alpha (IL-1 alpha) and prostaglandin E(2) (PGE(2)) and F(2 alpha) (PGF(2 alpha)) induced TN-C expression in the stromal cells at both protein and mRNA levels, while the sex steroid hormones, progesterone and ss-estradiol, exerted little effect. Immunohistochemistry using anti-IL-1 alpha antibody showed epithelial cells to be positive on Days 2-4 of pregnancy, and addition of progesterone but not ss-estradiol enhanced IL-1 alpha expression in epithelial cells in vitro. In a culture insert system, TN-C expression by stromal cells cocultured with epithelial cells was induced by addition of progesterone alone that was blocked by additions of anti-IL-1 alpha antibody. Collectively, these findings indicate that TN-C expression in the preimplantation period is under the control of progesterone, but not directly, possibly by the paracrine and autocrine intervention of IL-1 alpha secreted by epithelial cells and PGE(2) and PGF(2 alpha) secreted by stromal cells.