Associations between tumor necrosis factor-α and interleukin-6 polymorphisms and unexplained recurrent spontaneous abortion risk: A meta-analysis

Insights into the immunomodulatory regulation of matrix metalloproteinase at the maternal-fetal interface during early pregnancy and pregnancy-related diseases

Trophoblast immune cell interactions are central events in the immune microenvironment at the maternal-fetal interface. Their abnormalities are potential causes of various pregnancy complications, including pre-eclampsia and recurrent spontaneous abortion. Matrix metalloproteinase (MMP) is highly homologous, zinc(II)-containing metalloproteinase involved in altered uterine hemodynamics, closely associated with uterine vascular remodeling. However, the interactions between MMP and the immune microenvironment remain unclear. Here we discuss the key roles and potential interplay of MMP with the immune microenvironment in the embryo implantation process and pregnancy-related diseases, which may contribute to understanding the establishment and maintenance of normal pregnancy and providing new therapeutic strategies. Recent studies have shown that several tissue inhibitors of metalloproteinases (TIMPs) effectively prevent invasive vascular disease by modulating the activity of MMP. We summarize the main findings of these studies and suggest the possibility of TIMPs as emerging biomarkers and potential therapeutic targets for a range of complications induced by abnormalities in the immune microenvironment at the maternal-fetal interface. MMP and TIMPs are promising targets for developing new immunotherapies to treat pregnancy-related diseases caused by immune imbalance.

Associations of serum vitamin D and Fok I polymorphism of receptor gene with unexplained recurrent spontaneous abortion

Background: To investigate the associations of serum vitamin D and Fok I polymorphism of its receptor (VDR) with unexplained recurrent spontaneous abortion (URSA).

Methods: Ninety URSA patients and another 104 healthy pregnant women were selected as URSA and control groups, respectively. 25-Hydroxyvitamin D [25-(OH)D] level was detected by chemiluminescence. VDR gene Fok I polymorphism was analyzed by PCR, and the distribution of genotype frequency was calculated by Hardy-Weinberg equilibrium test. Association between Fok I polymorphism and susceptibility to URSA was investigated by logistic regression analysis.

Results: Gestational age, uterine height, waist circumference, 25-(OH)D level and proportions of Fok I FF and Ff genotypes were significantly lower in the URSA group (P<0.05). Compared with ff genotype, risk of URSA reduced for Ff and FF genotypes. Compared with allele f, risk of URSA was lower for allele F. 25-(OH)D level of ff genotype was significantly lower in the URSA group, which was lower than that of FF genotype (P<0.05). Compared with women with 25-(OH)D level >30 ng/mL and F allele (FF+Ff), the risk of URSA increased 2.45-, 2.43- and 5.34-fold for those with 25-(OH)D level >30 ng/mL and ff genotype, with 25-(OH)D level ≤30 ng/mL, and with ff genotype and 25-(OH)D level ≤30 ng/mL, respectively.

Conclusions: The 25-(OH)D level of the URSA group was significantly lower than that of normal pregnant women. Probably, VDR gene Fok I polymorphism is associated with URSA occurrence, and allele F decreases the risk. The risk of URSA dramatically increases in women with ff genotype and 25-(OH)D deficiency.

Hypoxia-induced DEC1 mediates trophoblast cell proliferation and migration via HIF1α signaling pathway

In early pregnancy, hypoxia is a typical extrinsic factor that regulates EVT functions including proliferation, migration and invasion which are essential for a successful pregnancy. Human differentiated embryonic chondrocyte-expressed gene 1 (DEC1), a hypoxia-regulated gene, has been reported to be overexpressed in several types of cancers. Given that the placenta and the cancer share several similarities with respect to their capacity to proliferate and invade adjacent tissues, we focused on the role of DEC1 on trophoblast function in a physiologically hypoxic environment, which may be associated with unexplained recurrent spontaneous abortion (URSA).In our study, we measured the expression of HIF-1α and DEC1 in first-trimester villi through real-time-PCR (RT-PCR) and immunohistochemical analysis. in vitro, DEC1 expression was downregulated in trophoblast cells via DEC1-specific shRNA plasmid transfection. The expression of DEC1 and HIF-1α was detected via western blotting and RT-PCR analysis. The proliferation and migration of HTR-8/SVneo cells were assayed using CCK-8 and Transwell migration assays, respectively.Our results indicated that the expression of DEC1 was significantly reduced in villi of URSA compared to that in normal pregnant women. in vitro, hypoxia induced the expression of HIF-1ɑ and DEC1 and upregulated proliferation and migration of the HTR-8/SVneo cells. Knockdown of DEC1 inhibited proliferation and migration of HTR-8/SVneo cells exposure to hypoxia. Furthermore, inhibition of HIF1α expression resulted in a significant decrease in DEC1. These findings illustrate that hypoxia-induced DEC1 expression promotes trophoblast cell proliferation and migration through the HIF1α signaling pathway, which plays an important role during placentation.

Prenatal development in Lagostomus maximus (Rodentia, Chinchillidae): A unique case among eutherian mammals of physiological embryonic death

Embryonic death followed by resorption is a conserved process in mammals. Among the polyovular species, Lagostomus maximus (plains viscacha) constitutes a model of early and physiological embryonic death, since out of a total of 10-12 implants, 8-10 are resorbed during early/intermediate gestation, surviving are only the most caudal implantations of each uterine horn. This regular reproductive event is unique to this species, but many characteristics of the implantations during the early gestation of L. maximus, when embryonic death processes begin are unknown. The aim of the present work was to analyze the implantation sites of this species using morphological, morphometric, histochemical, lectinhistochemical, and immunohistochemical techniques to infer the possible causes of this event. Macroscopically, the length and width of the implantation sites significantly increased in a craniocaudal direction. Histochemically, the implantation sites did not differ in the expression of glycoconjugates and glycosidic residues. Furthermore, no variations were observed in cell renewal, hormone receptor expression, and decidualization. Both the glandular and vascular areas of the implantation sites significantly increased in the craniocaudal axis. Some necrotic cells and an inflammatory response with a predominance of lymphocytes and fibrin were observed in the cranial and middle but not in the caudal implantation sites. We conclude that signs of embryonic death and resorption are already observed in the early gestation of L. maximus. Our results reaffirm the hypothesis that postulates the key potential role of uterine glands and blood vessels in the gestation of the species, with emphasis on embryonic death. This pattern of embryonic death in L. maximus makes this species an unconventional mammalian model, which adds to the peculiarities of polyovulation (200-800 oocytes/estrus) and hemochorial placentation.