The Apolipoprotein (Apo) family is implicated in lipid metabolism. There are five types of Apo: Apoa, Apob, Apoc, Apod, and Apoe. Apoe has been demonstrated to play a central role in lipoprotein metabolism and to be essential for efficient receptor-mediated plasma clearance of chylomicron remnants and VLDL remnant particles by the liver. Apo e-deficient (Apoe ^−/− ) mice develop atherosclerotic plaques spontaneously, followed by obesity. In this study, we investigated whether lipid deposition caused by Apo e knockout affects reproduction in female mice. The results demonstrated that Apoe ^−/− mice were severely hypercholesterolemic, with their cholesterol metabolism disordered, and lipid accumulating in the ovaries causing the ovaries to be heavier compared with the WT counterparts. In addition, estrogen and progesterone decreased significantly at D 100. Quantitative PCR analysis demonstrated that at D 100 the expression of cytochromeP450 aromatase (Cyp19a1), 3β-hydroxysteroid dehydrogenase (Hsd3b), mechanistic target of rapamycin (Mtor), and nuclear factor-κB (Nfkb) decreased significantly, while that of BCL2-associated agonist of cell death (Bad) and tuberous sclerosis complex 2 (Tsc2) increased significantly in the Apoe ^−/− mice. However, there was no difference in the fertility rates of the Apoe ^−/− and WT mice; that is, obesity induced by Apoe knockout has no significant effect on reproduction. However, the deletion of Apoe increased the number of ovarian follicles and the ratio of ovarian follicle atresia and apoptosis. We believe that this work will augment our understanding of the role of Apoe in reproduction.

MicroRNAs (miRNAs) are non-coding RNA molecules of about 22 nucleotides that involved in post-transcriptional gene regulation. Evidence indicates that miRNAs play essential roles in endometriosis, pre-eclampsia, infertility and other reproductive system diseases. However, whether miRNAs are involved in recurrent spontaneous abortion (RSA) is unclear. In this work, we analysed the miRNA expression profiles in six pairs of villus or decidua from RSA patients and normal pregnancy (NP) women using a human miRNA microarray. Some of the chip results were confirmed by RT-qPCR. In the villi of RSA patients, expression of hsa-miR-184, hsa-miR-187 and hsa-miR-125b-2 was significantly higher, while expression of hsa-miR-520f, hsa-miR-3175 and hsa-miR-4672 was significantly lower, comparing with those of NP control. As well, a total of five miRNAs (hsa-miR-517c, hsa-miR-519a-1, hsa-miR-522, hsa-miR-520h and hsa-miR-184) were upregulated in the decidua of RSA patients. The target genes of these differentially expressed miRNAs were predicted by miRWalk, and we speculate a network of miRNA regulating RSA by target genes function on adhesion, apoptosis and angiogenesis. Our study may help clarify the molecular mechanisms which are involved in the progression of RSA, and provide a reference for future research.

Endometrial cells and microenvironment are two important factors in the pathogenesis of adenomyosis. Our previous study demonstrated that macrophages can induce eutopic epithelial cells of adenomyosis to suffer from epithelial–mesenchymal transition (EMT). The aim of this study is to detect whether macrophages interacting with epithelial cells equally induce the EMT process in normal and eutopic endometria of healthy and adenomyotic patients; and whether macrophages parallelly polarize to M2. We investigated the expression levels of epithelial cadherin (E-cadherin), neural cadherin (N-cadherin), cytokeratin7 (CK7), vimentin, transforming growth factor-β1 (TGFB1), SMAD3 and pSMAD3 using immunohistochemistry and western blot, and then estimated the genetic levels of CD163, IL10 and MMP12 using real-time quantitative polymerase chain reaction (RT-PCR) in macrophages. Eutopic and normal endometrial tissues were obtained from 20 patients with adenomyosis and 11 control patients without adenomyosis, respectively. The immunohistochemical analysis shows distinct EMT in eutopic endometria in secretory phase; the expression levels of TGFB1, SMAD3 and pSMAD3 that indicate signal pathway of EMT were also higher in secretory phase. Macrophages can induce EMT process in primary endometrial epithelial cells derived from normal and eutopic endometria. After co-culturing, THP-1-derived macrophages polarized to M2. Compared with the eutopic endometrium group, further polarization to M2 was observed in the normal endometrium group. These results indicate that adenomyosis may be promoted by the pathologic EMT of epithelial cells, which is induced by macrophages that incapably polarize to M2.

Cell-to-cell contact mediated by cell adhesion is fundamental to the compaction process that ensures blastocyst quality during embryonic development. In this study, we first showed that Rho-associated coiled-coil protein kinases (ROCK1 and ROCK2) were expressed both in porcine oocytes and IVF preimplantation embryos, playing different roles in oocytes maturation and embryo development. The amount of mRNA encoding ROCK1 and the protein concentration clearly increased between the eight-cell and morula stages, but decreased significantly when blastocysts were formed. Conversely, ROCK2 was more abundant in the blastocyst compared with other embryonic stages. Moreover, immunostaining showed that ROCK1 protein distribution changed as the embryo progressed through cleavage and compaction to the morula stage. Initially, the protein was predominantly associated with the plasma membrane but later became cytoplasmic. By contrast, ROCK2 protein was localized in both the cytoplasm and the spindle rotation region during oocyte meiosis, but in the cytoplasm and nucleus as the embryo developed. In addition, ROCK2 was present in the trophectoderm cells of the blastocyst. Treatment with 15 μM Y27632, a specific inhibitor of ROCKs, completely blocked further development of early four-cell stage embryos. Moreover, we did not detect the expression of ROCK1 but did detect ROCK2 expression in blastocysts. Moreover, lysophosphatidic acid an activator of ROCKs significantly improved the rates of blastocyst formation. These data demonstrate that ROCKs are required for embryo development to the blastocyst stage. Together, our results indicate that ROCK1 and ROCK2 may exert different biological functions during the regulation of compaction and in ensuring development of porcine preimplantation embryos to the blastocyst stage.

Many studies have revealed the hazardous effects of cigarette smoking and nicotine exposure on male fertility, but the actual, underlying molecular mechanism remains relatively unclear. To evaluate the detrimental effects of nicotine exposure on the sperm maturation process, two-dimensional gel electrophoresis and mass spectrometry analyses were performed to screen and identify differentially expressed proteins from the epididymal tissue of mice exposed to nicotine. Data mining analysis indicated that 15 identified proteins were mainly involved in the molecular transportation process and the polyol pathway, indicating impaired epididymal secretory functions. Experiments in vitro confirmed that nicotine inhibited tyrosine phosphorylation levels in capacitated spermatozoa via the downregulated seminal fructose concentration. Sord, a key gene encoding sorbitol dehydrogenase, was further investigated to reveal that nicotine induced hyper-methylation of the promoter region of this gene. Nicotine-induced reduced expression of Sord could be involved in impaired secretory functions of the epididymis and thus prevent the sperm from undergoing proper maturation and capacitation, although further experiments are needed to confirm this hypothesis.

This study was designed to examine the effect of Taxol pretreatment on vitrification of porcine oocytes matured in vitro by an open pulled straw (OPS) method. In the first experiment, the effect of Taxol pretreatment and fluorescein diacetate (FDA) staining on parthenogenetic development of oocytes was evaluated. In the second experiment, viability, microtubule organization and embryo development of oocytes were assessed after oocytes were exposed to vitrification/warming solutions or after vitrification with or without Taxol pretreatment. The results showed that Taxol pretreatment and/or FDA staining did not negatively influence the oocyte’s developmental competence after parthenogenetic activation. After being exposed to vitrification/warming solutions, the survival rate (83.3%) of the oocytes was significantly (P < 0.05) reduced as compared with that in the control (100%). Vitrification/warming procedures further reduced the survival rates of oocytes regardless of oocytes being treated with (62.1%) or without (53.8%) Taxol. The proportions of oocytes with normal spindle configuration were significantly reduced after the oocytes were exposed to vitrification/warming solutions (38.5%) or after vitrification with (10.3%) or without (4.1%) Taxol pretreatment as compared with that in control (76.8%). The rates of two-cell-stage (5.6–53.2%) embryos at 48 h and blastocysts (0–3.8%) at 144 h after activation were significantly reduced after exposure to vitrification/warming solutions or after vitrification as compared with control (90.9% and 26.6% respectively). However, the proportion of vitrified oocytes developed to two-cell stage was significantly higher when oocytes were pretreated with (24.3%) than without (5.6%) Taxol. These results indicate that pretreatment of oocytes with Taxol before vitrification helps to reduce the damage induced by vitrification and is a potential way to improve the development of vitrified porcine oocytes.

The present study was designed to investigate the localization and function of cytoplasmic dynein (dynein) during mouse oocyte meiosis and its relationship with two major spindle checkpoint proteins, mitotic arrest-deficient (Mad) 1 and Mad2. Oocytes at various stages during the first meiosis were fixed and immunostained for dynein, Mad1, Mad2, kinetochores, microtubules, and chromosomes. Some oocytes were treated with nocodazole before examination. Anti-dynein antibody was injected into the oocytes at germinal vesicle (GV) stage before the examination of its effects on meiotic progression or Mad1 and Mad2 localization. Results showed that dynein was present in the oocytes at various stages from GV to metaphase II and the locations of Mad1 and Mad2 were associated with dynein’s movement. Both Mad1 and Mad2 had two existing states: one existed in the cytoplasm (cytoplasmic Mad1 or cytoplasmic Mad2), which did not bind to kinetochores, while the other bound to kinetochores (kinetochore Mad1 or kinetochore Mad2). The equilibrium between the two states varied during meiosis and/or in response to the changes of the connection between microtubules and kinetochores. Cytoplasmic Mad1 and Mad2 recruited to chromosomes when the connection between microtubules and chromosomes was destroyed. Inhibition of dynein interferes with cytoplasmic Mad1 and Mad2 transportation from chromosomes to spindle poles, thus inhibits checkpoint silence and delays anaphase onset. These results indicate that dynein may play a role in spindle checkpoint inactivation.

CD9 is a cell surface protein that participates in many cellular processes, such as cell adhesion. Fertilization involves sperm and oocyte interactions including sperm binding to oocytes and sperm–oocyte fusion. Thus CD9 may play an essential role during fertilization in mammals. The present study was conducted to examine whether CD9 is present in porcine gametes and whether it participates in the regulation of sperm–oocyte interactions. The presence of CD9 in ovarian tissues, oocytes and spermatozoa was examined by immunohistochemistry, immunofluorescence and immunoblotting. Sperm binding and penetration of oocytes treated with CD9 antibody were examined by in vitro fertilization. The results showed that CD9 was present on the plasma membrane of oocytes at different developmental stages. A 24 kDa protein was found in oocytes during in vitro maturation by immunoblotting and its quantity was significantly (P < 0.001) increased as oocytes underwent maturation and reached the highest level after the oocytes had been cultured for 44 h. No positive CD9 staining was found in the spermatozoa. Both sperm binding to ooplasma and sperm penetration into oocytes were significantly (P < 0.01) reduced in anti-CD9 antibody-treated oocytes (1.2 ± 0.2 per oocyte and 16.6% respectively) as compared with oocytes in the controls (2.5 ± 0.4 per oocyte and 70.3% respectively). These results indicated that CD9 is expressed in pig oocytes during early growth and meiotic maturation and that it participates in sperm–oocyte interactions during fertilization.

Transforming growth factor β (TGFβ) has been shown to be a multifunctional cytokine required for embryonic development and regulation of trophoblast cell behaviors. In the present study, a non-transformed cell-line representative of normal human trophoblast (NPC) was used to examine the effect of TGFβ1 on trophoblast cell adhesion and invasion. In vitro assay showed that TGFβ1 could significantly promote intercellular adhesion, while inhibiting cell invasion across the collagen I-coated filter. Reverse transcription (RT)-PCR and gelatin zymography demonstrated that TGFβ1 evidently repressed the mRNA expression and proenzyme production of matrix metalloproteinase (MMP)-9, but exerted no effect on mRNA expression and secretion of MMP-2. On the other hand, both the mRNA and protein expression of epithelial-cadherin and β-catenin were obviously upregulated by TGFβ1 in dose-dependent fashion, as revealed by RT-PCR and western-blot analysis. What is more, one of the critical TGFβ signaling molecules – Smad2 was notably phosphorylated in TGFβ1-treated NPC cells. The data indicates that cell invasion and adhesion are coordinated processes in human trophoblasts and that there exists paracrine regulation on adhesion molecules and invasion-associated enzymes in human placenta.

Cryodamage is a major problem in semen cryopreservation, causing changes in the levels of proteins that influence the function and motility of spermatozoa. In this study, protein samples prepared from fresh and frozen–thawed boar spermatozoa were compared using the isobaric tags for relative and absolute quantification (iTRAQ) labeling technique coupled to 2D LC–MS/MS analysis. A total of 41 differentially expressed proteins were identified and quantified, including 35 proteins that were present at higher levels and six proteins that were present at lower levels in frozen–thawed spermatozoa by at least a mean of 1.79-fold (P<0.05). On classifying into ten distinct categories using bioinformatic analysis, most of the 41 differentially expressed proteins were found to be closely relevant to sperm premature capacitation, adhesions, energy supply, and sperm–oocyte binding and fusion. The expression of four of these proteins, SOD1, TPI1, ODF2, and AKAP3, was verified by western blot analysis. We propose that alterations in these identified proteins affect the quality of cryopreserved semen and ultimately lower its fertilizing capacity. This is the first study to compare protein levels in fresh and frozen–thawed spermatozoa using the iTRAQ technology. Our preliminary results provide an overview of the molecular mechanisms of cryodamage in frozen–thawed spermatozoa and theoretical guidance to improve the cryopreservation of boar semen.