Search

It is well known that embryo implantation is a critical process in which embryo should be able to reach and attach to endometrium. Until now, various types of factors are involved in the regulation of this process. S100 proteins are calcium-binding proteins, which have vital roles in embryo implantation and have been considered as possible candidate markers for endometrial receptivity. However, studies regarding mode of actions of these proteins are scarce and more mechanistic insights are needed to clarify exact roles of each one of the S100 protein family. Understanding of function of these proteins in different compartments, stages, and phases of endometrium, could pave the way for conducting studies regarding the therapeutic significance of these proteins in some disorders such as recurrent implantation failure. In this review, we outlined roles and possible underlying mechanisms of S100 protein family in embryo implantation., (© 2019 Wiley Periodicals, Inc.)

Different strategies are applied for cellular cross-talk and organization in multicellular organisms. Exosomes are a homogenous population of biological nanoparticles (30-100 nm), originated from multivesicular bodies. The exosomes (Exos) could regulate and affect both cellular physiology and pathophysiology in various organs, such as the female reproductive tract, by altering gene pathways and/or epigenetic programming. Besides, engineered Exos have the potential to be used as a novel drug and gene delivery tools. Here in this review, we discussed various aspects of exosome-based intercellular communication in female reproductive microenvironments. Furthermore, we addressed the findings and issues related to Exos in reproductive biology to give a better view of the involved molecular mechanisms. Moreover, clinical applications of the Exos and their isolation source/methods have been considered to throw some light on the progression of new biological, diagnostic, and therapeutic approaches in clinical embryology., (© 2019 Wiley Periodicals, Inc.)

To evaluate the concentration of tumor necrosis factor α (TNF-α) and its soluble receptors (sTNFR I and II) in serum and follicular fluid (FF) at the time of oocyte retrieval and to detect expression of TNF-α and its receptors by luteinized granulosa cells (GCs). In a cross-sectional study and through an in vitro fertilization-intracytoplasmic sperm injection (IVF-ICSI) program, 81 women undergoing oocyte retrieval were recruited. Serum and FF were obtained from 81 women. GCs were pooled from 20 patients (from six different days of oocyte retrievals, 5-16 follicles per patient). TNF-α and its soluble receptors concentration were determined by enzyme-linked immunosorbent assay and also their expression by immune cytochemistry and reverse-transcription polymerase chain reaction analysis. The median TNF-α concentration in serum was 4.06 pg/ml (interquartile range [IQR], 3.71-6.14) and significantly higher than that in FF with 3.50 pg/ml (IQR, 3.05-5.01), p < 0.001. The sTNFR I and II levels in serum were lower and higher than FF, respectively. The TNF-α levels in serum and FF of good responders were higher than low responders (p = 0.017 and 0.021, respectively). TNF-α cut-off level for low responders versus good responders was 4.174 pg/ml in serum with a pregnancy rate of 25.8% and 40% for below and above of this level, respectively (p = 0.19). For FF, the cut-off value was 3.89 pg/ml. TNF-α and its receptors were expressed by GCs. The presence of TNF-α and its soluble receptors in serum and FF and their expression by GCs suggest an important role for this cytokine in ovarian function., (© 2019 Wiley Periodicals, Inc.)

As a critical stage of pregnancy, the implantation of blastocysts into the endometrium is a progressive, excessively regulated local tissue remodeling step involving a complex sequence of genetic and cellular interplay executed within an optimal time frame. For better understanding the causes of infertility and, more importantly, for developing powerful strategies for successful implantations and combating infertility, an increasing number of recent studies have been focused on the identification and study of newly described substances in the reproductive tree. The endothelins (ET), a 21-aminoacidic family of genes, have been reported to be responsible for the contraction of vascular and nonvascular smooth muscles, including the smooth muscles of the uterus. Therefore, this review aims to comprehensively discuss the physiological role of endothelins and signaling through their receptors, as well as their probable involvement in the implantation process., (© 2019 Wiley Periodicals, Inc.)

Coronary artery disease (CAD) is a common cause of morbidity and mortality worldwide. Atherosclerotic plaques, as a hallmark of CAD, cause chronic narrowing of coronary arteries over time and could also result in acute myocardial infarction (AMI). The standard treatments for ameliorating AMI are reperfusion strategies, which paradoxically result in ischemic reperfusion (I/R) injury. Sphingosine 1 phosphate (S1P), as a potent lysophospholipid, plays an important role in various organs, including immune and cardiovascular systems. In addition, high-density lipoprotein, as a negative predictor of atherosclerosis and CAD, is a major carrier of S1P in blood circulation. S1P mediates its effects through binding to specific G protein-coupled receptors, and its signaling contributes to a variety of responses, including cardiac inflammation, dysfunction, and I/R injury protection. In this review, we will focus on the role of S1P in CAD and I/R injury as a potential therapeutic target., (© 2018 Wiley Periodicals, Inc.)

Atherosclerosis is identified as the formation of atherosclerotic plaques, which could initiate the formation of a blood clot in which its growth to coronary artery can lead to a heart attack. N-methyltransferase (NNMT) is an enzyme that converts the NAM (nicotinamide) to its methylated form, N1-methylnicotinamide (MNAM). Higher levels of MNAM have been reported in cases with coronary artery disease (CAD). Further, MNAM increases endothelial prostacyclin (PGI2) and nitric oxide (NO) and thereby causes vasorelaxation. The vasoprotective, anti-inflammatory and anti-thrombotic roles of MNAM have been well documented; however, the exact underlying mechanisms remain to be clarified. Due to potential role of MNAM in the formation of lipid droplets (LDs), it might exert its function in coordination with lipids, and their targets. In this study, we summarized the roles of MNAM in cardiovascular system and highlighted its possible mode of actions., (© 2018 Wiley Periodicals, Inc.)

During embryo implantation, crosstalk between the endometrial epithelium and the blastocyst, especially the trophoblasts, is a prerequisite for successful implantation. During this crosstalk, various molecular and functional changes occur to promote synchrony between the embryo and the endometrium as well as the uterine cavity microenvironment. In the past few years, growing evidence has shown that endometrium-derived exosomes play pivotal roles in the embryonic-maternal crosstalk during implantation, although the exact mechanism of this crosstalk has yet to be determined. The presence of metalloproteinases has been reported in endometrium-derived exosomes, implying the importance of these enzymes in exosome-based crosstalk. Thus, in this review, we describe the potential roles of the metalloproteinases of endometrium-derived exosomes in promoting embryo attachment and implantation. This study could provide a better understanding of the potential roles of exosomal metalloproteinases in embryo implantation and pave the way for developing novel exosome-based regulatory agents to support early pregnancy., (© 2017 Wiley Periodicals, Inc.)

Considering the self-renewal and differentiation ability of pluripotent stem cells, some studies have pointed out the possibility of stem cell-derived sperm production. Most studies that test this hypothesis have been conducted on rodents, with some promising results; however, studies on humans are progressing slowly, and have encountered technical and ethical hurdles. Established methods to differentiate stem cells-including embryoid bodies, co-culturing, and various feeder cells-may provide a niche that is similar to in vivo conditions and resolve epigenetic abnormalities, but a gonadal-like three-dimensional structure is still required to produce germ cells with the correct imprinting. In the last few years, sperm-like cells with fertilizing capacity were produced from mouse embryonic stem cells, and the resulting embryos from these cells yielded live offspring. Future research should move towards the use of adult stem cells, however, owing to the unavailability of embryonic cells in adults. More intensive research and techniques are required since in vitro spermatogenesis provides hope to individuals without mature sperm who cannot be treated, and may be a useful system to study the precise mechanism of spermatogenesis. In this review, we describe recent studies of in vitro spermatogenesis mechanisms and related techniques in mammals. We also discuss the possible cell surface markers and culture conditions that might improve in vitro spermatogenesis., (© 2017 Wiley Periodicals, Inc.)