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Holder BS, Tower CL, Forbes K, Mulla MJ, Aplin JD, Abrahams VM. Immune cell activation by trophoblast-derived microvesicles is mediated by syncytin 1. Immunology 2012; 136:184-91. [PMID: 22348442 DOI: 10.1111/j.1365-2567.2012.03568.x] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
Envelope glycoproteins of human endogenous retrovirus (HERV), such as syncytin 1 (HERV-W), are highly expressed in the placenta and some family members have immunomodulatory properties. Placental microvesicles (MV), which are shed into the maternal circulation during pregnancy, have been demonstrated to induce immune cell activation. Therefore, the aim of this study was to investigate the immunological properties of the highly expressed placental HERV-W protein, syncytin 1, and its potential involvement in placental MV modulation of immune cell activity. The MV shed from first trimester, normal term and pre-eclamptic term placentas, and from the BeWo trophoblast cell line, all contain syncytin 1. Recombinant syncytin 1 and syncytin 1-positive BeWo trophoblast MV both induced peripheral blood mononuclear cell (PBMC) activation, indicated through production of cytokines and chemokines. Reducing syncytin 1 content in BeWo MV inhibited PBMC activation. Recombinant syncytin 1 and syncytin-1-positive BeWo MV dampened PBMC responses to lipopolysaccharide challenge. Our findings suggest that syncytin 1 is shed from the placenta into the maternal circulation in association with MV, and modulates immune cell activation and the responses of immune cells to subsequent lipopolysaccharide stimulation. These studies implicate placental MV-associated HERV in fetal regulation of the maternal immune system.
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Holder BS, Tower CL, Jones CJP, Aplin JD, Abrahams VM. Heightened pro-inflammatory effect of preeclamptic placental microvesicles on peripheral blood immune cells in humans. Biol Reprod 2012; 86:103. [PMID: 22205696 DOI: 10.1095/biolreprod.111.097014] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Normal pregnancy is associated with the presence of circulating placental microvesicles (MVs). Increased MV shedding and altered immune activation are seen in patients with preeclampsia, suggesting that placental MVs may play a role in the pathophysiology of this disease. Therefore, the aim of this study was to investigate the activation of peripheral blood mononuclear cells (PBMCs) by MVs shed by first-trimester, normal term, and preeclamptic term placenta. First-trimester and preeclamptic term, but not normal term, placental-derived MVs activated PBMCs, as evidenced by elevated IL1B. Significant changes were also seen with several other cytokines and chemokines, and in general when compared to normal term MVs, preeclamptic MVs induced a greater pro-inflammatory response in PBMCs. Pretreatment of PBMCs with first-trimester or normal term placental MVs resulted in a dampened IL1B response to a subsequent lipopolysaccharide (LPS) challenge. In contrast, treatment of PBMCs with preeclamptic term placental MVs exacerbated the LPS response. This was also the case for several other cytokines and chemokines. These studies suggest that placental MVs can modulate basal peripheral immune cell activation and responsiveness to LPS during normal pregnancy, and that in preeclampsia this effect is exacerbated.
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Nakamura H, Jasper MJ, Hull ML, Aplin JD, Robertson SA. Macrophages regulate expression of α1,2-fucosyltransferase genes in human endometrial epithelial cells. Mol Hum Reprod 2012; 18:204-15. [PMID: 22053055 DOI: 10.1093/molehr/gar070] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The epithelial cell surface of the endometrium undergoes substantial biochemical changes to allow embryo attachment and implantation in early pregnancy. We hypothesized that tissue macrophages influence these events to promote uterine receptivity. To investigate the role of macrophages in regulating epithelial cell expression of genes linked to glycan-mediated embryo adhesion, Ishikawa, RL95-2 and HEC1A endometrial epithelial cells were cultured alone or with unactivated or lipopolysaccharide-activated monocytic U937 cells, separated using transwell inserts. Expression of mRNAs encoding two α1,2-fucosyltransferases (FUT1, FUT2) was increased in all three epithelial cell lines following co-culture with U937 cells, and was associated with increased fucosylation of cell surface glycoproteins detected using lectins from Ulex europaeus (UEA-1) and Dolichos biflorus (DBA). FUT1 induction by U937 cells also occurred in primary endometrial epithelial cells collected in luteal but not proliferative phase. Activation of the interleukin-6 (IL6)/leukemia inhibitory factor (LIF) cytokine signaling pathway with phosphorylation of STAT3 and elevated SOCS3 mRNA expression was evident in epithelial cells stimulated by U937 co-culture. Several recombinant macrophage-secreted cytokines exerted stimulatory or inhibitory effects on FUT1 and FUT2 mRNA expression, and the macrophage-derived cytokine LIF partially replicated the effects of U937 cells on both FUT1 and FUT2 expression and UEA-1 and DBA lectin reactivity in Ishikawa cells. These results suggest that macrophage-derived factors including LIF might facilitate development of an implantation-receptive endometrium by regulating surface glycan structures in epithelial cells. Abnormal phenotypes or altered abundance of uterine macrophages could contribute to the pathophysiology of primary unexplained infertility in women.
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Holder BS, Tower CL, Abrahams VM, Aplin JD. Syncytin 1 in the human placenta. Placenta 2012; 33:460-6. [PMID: 22381536 DOI: 10.1016/j.placenta.2012.02.012] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2011] [Revised: 01/27/2012] [Accepted: 02/09/2012] [Indexed: 12/27/2022]
Abstract
This study characterises HERV-W (syncytin 1) expression in normal and pathologic placenta and in BeWo cells. HERV-W mRNA levels were higher in the first trimester than at term, and similar patterns were observed with another retrovirally-derived mRNA species, ERV-3. N-glycosylated syncytin 1 precursor (73 kDa) is cleaved to surface-associated (SU) and transmembrane (TM) subunits. Both were evident in villous trophoblast, where perinuclear and punctate cytoplasmic deposits were observed, and linear TM subunit immunoreactivity was seen at the syncytial microvillous membrane. Punctate immunoreactivity was seen in BeWo cells with antibodies to SU and TM, and the two were co-localised. SU immunoreactivity was observed in association with fetal endothelium, and this effect was increased in tissue from pre-eclamptic placentas, which also showed a higher level of total SU protein. Absence of the TM subunit from endothelium suggests it is not a biosynthetic source. We suggest that SU is released from trophoblast into fetal circulation where it may bind vascular endothelium.
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Sood A, Salih S, Roh D, Lacharme-Lora L, Parry M, Hardiman B, Keehan R, Grummer R, Winterhager E, Gokhale PJ, Andrews PW, Abbott C, Forbes K, Westwood M, Aplin JD, Ingham E, Papageorgiou I, Berry M, Liu J, Dick AD, Garland RJ, Williams N, Singh R, Simon AK, Lewis M, Ham J, Roger L, Baird DM, Crompton LA, Caldwell MA, Swalwell H, Birch-Machin M, Lopez-Castejon G, Randall A, Lin H, Suleiman MS, Evans WH, Newson R, Case CP. Signalling of DNA damage and cytokines across cell barriers exposed to nanoparticles depends on barrier thickness. NATURE NANOTECHNOLOGY 2011; 6:824-33. [PMID: 22056725 DOI: 10.1038/nnano.2011.188] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2011] [Accepted: 09/28/2011] [Indexed: 05/28/2023]
Abstract
The use of nanoparticles in medicine is ever increasing, and it is important to understand their targeted and non-targeted effects. We have previously shown that nanoparticles can cause DNA damage to cells cultured below a cellular barrier without crossing this barrier. Here, we show that this indirect DNA damage depends on the thickness of the cellular barrier, and it is mediated by signalling through gap junction proteins following the generation of mitochondrial free radicals. Indirect damage was seen across both trophoblast and corneal barriers. Signalling, including cytokine release, occurred only across bilayer and multilayer barriers, but not across monolayer barriers. Indirect toxicity was also observed in mice and using ex vivo explants of the human placenta. If the importance of barrier thickness in signalling is a general feature for all types of barriers, our results may offer a principle with which to limit the adverse effects of nanoparticle exposure and offer new therapeutic approaches.
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Tilbrook HE, Cox H, Hewitt CE, Kang'ombe AR, Chuang LH, Jayakody S, Aplin JD, Semlyen A, Trewhela A, Watt I, Torgerson DJ. Yoga for chronic low back pain: a randomized trial. Ann Intern Med 2011; 155:569-78. [PMID: 22041945 DOI: 10.7326/0003-4819-155-9-201111010-00003] [Citation(s) in RCA: 154] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Previous studies indicate that yoga may be an effective treatment for chronic or recurrent low back pain. OBJECTIVE To compare the effectiveness of yoga and usual care for chronic or recurrent low back pain. DESIGN Parallel-group, randomized, controlled trial using computer-generated randomization conducted from April 2007 to March 2010. Outcomes were assessed by postal questionnaire. (International Standard Randomised Controlled Trial Number Register: ISRCTN 81079604) SETTING 13 non-National Health Service premises in the United Kingdom. PATIENTS 313 adults with chronic or recurrent low back pain. INTERVENTION Yoga (n = 156) or usual care (n = 157). All participants received a back pain education booklet. The intervention group was offered a 12-class, gradually progressing yoga program delivered by 12 teachers over 3 months. MEASUREMENTS Scores on the Roland-Morris Disability Questionnaire (RMDQ) at 3 (primary outcome), 6, and 12 (secondary outcomes) months; pain, pain self-efficacy, and general health measures at 3, 6, and 12 months (secondary outcomes). RESULTS 93 (60%) patients offered yoga attended at least 3 of the first 6 sessions and at least 3 other sessions. The yoga group had better back function at 3, 6, and 12 months than the usual care group. The adjusted mean RMDQ score was 2.17 points (95% CI, 1.03 to 3.31 points) lower in the yoga group at 3 months, 1.48 points (CI, 0.33 to 2.62 points) lower at 6 months, and 1.57 points (CI, 0.42 to 2.71 points) lower at 12 months. The yoga and usual care groups had similar back pain and general health scores at 3, 6, and 12 months, and the yoga group had higher pain self-efficacy scores at 3 and 6 months but not at 12 months. Two of the 157 usual care participants and 12 of the 156 yoga participants reported adverse events, mostly increased pain. LIMITATION There were missing data for the primary outcome (yoga group, n = 21; usual care group, n = 18) and differential missing data (more in the yoga group) for secondary outcomes. CONCLUSION Offering a 12-week yoga program to adults with chronic or recurrent low back pain led to greater improvements in back function than did usual care. PRIMARY FUNDING SOURCE Arthritis Research UK.
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Salker MS, Christian M, Steel JH, Nautiyal J, Lavery S, Trew G, Webster Z, Al-Sabbagh M, Puchchakayala G, Föller M, Landles C, Sharkey AM, Quenby S, Aplin JD, Regan L, Lang F, Brosens JJ. Deregulation of the serum- and glucocorticoid-inducible kinase SGK1 in the endometrium causes reproductive failure. Nat Med 2011; 17:1509-13. [PMID: 22001908 DOI: 10.1038/nm.2498] [Citation(s) in RCA: 135] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Accepted: 08/30/2011] [Indexed: 11/09/2022]
Abstract
Infertility and recurrent pregnancy loss (RPL) are prevalent but distinct causes of reproductive failure that often remain unexplained despite extensive investigations. Analysis of midsecretory endometrial samples revealed that SGK1, a kinase involved in epithelial ion transport and cell survival, is upregulated in unexplained infertility, most prominently in the luminal epithelium, but downregulated in the endometrium of women suffering from RPL. To determine the functional importance of these observations, we first expressed a constitutively active SGK1 mutant in the luminal epithelium of the mouse uterus. This prevented expression of certain endometrial receptivity genes, perturbed uterine fluid handling and abolished embryo implantation. By contrast, implantation was unhindered in Sgk1-/- mice, but pregnancy was often complicated by bleeding at the decidual-placental interface and fetal growth retardation and subsequent demise. Compared to wild-type mice, Sgk1-/- mice had gross impairment of pregnancy-dependent induction of genes involved in oxidative stress defenses. Relative SGK1 deficiency was also a hallmark of decidualizing stromal cells from human subjects with RPL and sensitized these cells to oxidative cell death. Thus, depending on the cellular compartment, deregulated SGK1 activity in cycling endometrium interferes with embryo implantation, leading to infertility, or predisposes to pregnancy complications by rendering the feto-maternal interface vulnerable to oxidative damage.
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Harris LK, Aljunaidy MM, Robson A, Lash GE, Aplin JD, Baker PN, Bulmer JN. Physiological Transformation of the Uterine Spiral Arteries During Human Pregnancy: Growth Factors Released by Uterine Natural Killer Cells Initiate Vascular Remodeling. Biol Reprod 2011. [DOI: 10.1093/biolreprod/85.s1.184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Jasper MJ, Care AS, Sullivan B, Ingman WV, Aplin JD, Robertson SA. Macrophage-derived LIF and IL1B regulate alpha(1,2)fucosyltransferase 2 (Fut2) expression in mouse uterine epithelial cells during early pregnancy. Biol Reprod 2011; 84:179-88. [PMID: 20864644 DOI: 10.1095/biolreprod.110.085399] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Macrophages accumulate within stromal tissue subjacent to the luminal epithelium in the mouse uterus during early pregnancy after seminal fluid exposure at coitus. To investigate their role in regulating epithelial cell expression of fucosylated structures required for embryo attachment and implantation, fucosyltransferase enzymes Fut1, Fut2 (Enzyme Commission number [EC] 2.4.1.69), and Fut4 (EC 2.4.1.214) and Muc1 and Muc4 mRNAs were quantified by quantitative real-time PCR in uterine epithelial cells after laser capture microdissection in situ or after epithelial cell coculture with macrophages or macrophage-secreted factors. When uterine macrophage recruitment was impaired by mating with seminal plasma-deficient males, epithelial cell Fut2 expression on Day 3.5 postcoitus (pc) was reduced compared to intact-mated controls. Epithelial cell Fut2 was upregulated in vitro by coculture with macrophages or macrophage-conditioned medium (MCM). Macrophage-derived cytokines LIF, IL1B, and IL12 replicated the effect of MCM on Fut2 mRNA expression, and MCM-stimulated expression was inhibited by anti-LIF and anti-IL1B neutralizing antibodies. The effects of acute macrophage depletion on fucosylated structures detected with lectins Ulex europaeus 1 (UEA-1) and Lotus tetragonolobus purpureas (LTP), or LewisX immunoreactivity, were quantified in vivo in Cd11b-dtr transgenic mice. Depletion of macrophages caused a 30% reduction in luminal epithelial UEA-1 staining and a 67% reduction in LewisX staining in uterine tissues of mice hormonally treated to mimic early pregnancy. Together, these data demonstrate that uterine epithelial Fut2 mRNA expression and terminal fucosylation of embryo attachment ligands is regulated in preparation for implantation by factors including LIF and IL1B secreted from macrophages recruited during the inflammatory response to insemination.
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Tower CL, Lui S, Charlesworth NR, Smith SD, Aplin JD, Jones RL. Differential expression of angiotensin II type 1 and type 2 receptors at the maternal–fetal interface: potential roles in early placental development. Reproduction 2010; 140:931-42. [DOI: 10.1530/rep-10-0307] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Angiotensin II (Ang II) is locally generated in the placenta and regulates syncytial transport, vascular contractility and trophoblast invasion. It acts through two receptor subtypes, AGTR1 and AGTR2 (AT1 and AT2), which typically mediate antagonising actions. The objectives of this study are to characterise the cellular distribution of AGTR1 and AGTR2 at the maternal–fetal interface and explore the effects on cytotrophoblast turnover. Low levels ofAGTR2mRNA were detected in first trimester placental homogenates using real-time PCR. Immunohistochemistry using polyclonal antibodies against AGTR1 and AGTR2 detected the receptors in first trimester placenta, decidua basalis and villous tip outgrowths in culture. Serial staining with cytokeratin-7 was used to identify extravillous trophoblasts (EVTs). AGTR1 was found in the syncytiotrophoblast microvillous membrane, in a subpopulation of villous cytotrophoblasts, and in Hofbauer cells. AGTR1 was strongly upregulated in cytotrophoblasts in cell columns and villous tip outgrowths, but was absent in interstitial and endovascular EVTs within the decidua. AGTR2 immunostaining was present in Hofbauer cells and villous cytotrophoblasts, but was absent from syncytiotrophoblast. Faint staining was detected in cell column cytotrophoblasts and villous outgrowths, but not in EVTs within the decidua. Both receptors were detected in placental homogenates by western blotting. Ang II significantly increased proliferation of cytotrophoblasts in both villous explants and villous tip outgrowths, but did not affect apoptosis. Blockade of AGTR1 and AGTR2 together abrogated this effect. This study shows specific expression patterns for AGTR1 and AGTR2 in distinct trophoblast populations at the maternal–fetal interface and suggests that Ang II plays a role in placental development and generation of EVTs.
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Harris LK, Crocker IP, Baker PN, Aplin JD, Westwood M. IGF2 actions on trophoblast in human placenta are regulated by the insulin-like growth factor 2 receptor, which can function as both a signaling and clearance receptor. Biol Reprod 2010; 84:440-6. [PMID: 20980691 DOI: 10.1095/biolreprod.110.088195] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Insulin-like growth factor 2 (IGF2) enhances proliferation and survival of human first-trimester cytotrophoblasts (CTB) by signaling through the insulin-like growth factor 1 receptor (IGF1R). However, the role of the IGF2 receptor (IGF2R) in regulating trophoblast kinetics is unclear: It could act as a clearance receptor for trafficking excess ligand to lysosomes for degradation and/or directly mediate IGF2 signaling. We used an IGF2R knockdown strategy in BeWo cells and placental villous explants to investigate trophoblast proliferation and survival in response to stimulation by IGF. Both IGF1 and IGF2 significantly (P < 0.001) increased mitosis and reduced apoptosis in serum-starved BeWo cells. Small interfering RNA (siRNA)-mediated knockdown of IGF2R further enhanced IGF2-stimulated mitosis (P < 0.01), and IGF2-mediated rescue of apoptosis (P < 0.001) in these cells. Leu(27)IGF2, an IGF2 analogue that binds to IGF2R but not IGF1R, also protected IGF2R-expressing BeWo cells from apoptosis but did not increase mitosis. IGF treatment of term placental villous explants with reduced syncytial expression of IGF2R increased CTB proliferation (P < 0.001) and decreased apoptosis (P < 0.01) compared to untreated controls. Moreover, IGF2-mediated rescue of CTB apoptosis was significantly greater than that in tissue with normal IGF2R expression. Leu(27)IGF2 promoted mitogenesis and survival only in explants with intact IGF2R expression. Given that altered CTB turnover is observed in pregnancies complicated by fetal growth restriction, the development of strategies to manipulate the IGF2R signaling axis in the syncytiotrophoblast may provide a therapeutic avenue for treating this condition.
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Diao H, Aplin JD, Xiao S, Chun J, Li Z, Chen S, Ye X. Altered spatiotemporal expression of collagen types I, III, IV, and VI in Lpar3-deficient peri-implantation mouse uterus. Biol Reprod 2010; 84:255-65. [PMID: 20864640 DOI: 10.1095/biolreprod.110.086942] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Abstract
Lpar3 is upregulated in the preimplantation uterus, and deletion of Lpar3 leads to delayed uterine receptivity in mice. Microarray analysis revealed that there was higher expression of Col3a1 and Col6a3 in the Preimplantation Day 3.5 Lpar3(-/-) uterus compared to Day 3.5 wild-type (WT) uterus. Since extracellular matrix (ECM) remodeling is indispensable during embryo implantation, and dynamic spatiotemporal alteration of specific collagen types is part of this process, this study aimed to characterize the expression of four main uterine collagen types: fibril-forming collagen (COL) I and COL III, basement membrane COL IV, and microfibrillar COL VI in the peri-implantation WT and Lpar3(-/-) uterus. An observed delay of COL III and COL VI clearance in the Lpar3(-/-) uterus may be associated with higher preimplantation expression of Col3a1 and Col6a3. There was also delayed clearance of COL I and delayed deposition of COL IV in the decidual zone in the Lpar3(-/-) uterus. These changes were different from the effects of 17beta-estradiol and progesterone on uterine collagen expression in ovariectomized WT uterus, indicating that the altered collagen expression in Lpar3(-/-) uterus is unlikely to be a result of alterations in ovarian hormones. Decreased expression of several genes encoding matrix-degrading metallo- and serine proteinases was observed in the Lpar3(-/-) uterus. These results demonstrate that pathways downstream of LPA3 are involved in the dynamic remodeling of ECM in the peri-implantation uterus.
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Aplin JD. Embryo implantation: the molecular mechanism remains elusive. Reprod Biomed Online 2010; 14 Spec No 1:49-55. [PMID: 20483399 DOI: 10.1016/s1472-6483(10)61458-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2006] [Accepted: 08/25/2006] [Indexed: 10/01/2022]
Abstract
Low rates of implantation are an impediment to more efficient assisted reproduction techniques. Improved endometrial receptivity and embryo preparation should lead to higher pregnancy rates, lower rates of early pregnancy failure and fewer multiple pregnancies. As the first site of contact between embryo and endometrium, the luminal epithelium (LE) is responsible for the non-receptive status of proliferative and early secretory tissue, and transformation to receptivity in the mid-secretory phase presumably requires alterations in expression, organization or activation of adhesion systems. Luminal cells are less abundant than their glandular counterparts, and are under-represented in global tissue datasets. Furthermore, alterations in cell surface composition can be readily accomplished by mechanisms that do not rely on altered transcription or translation. Current data from in-vitro models are consistent with initial attachment to mucin in the apical glycocalyx, perhaps via a carbohydrate-mediated interaction, after which the epithelial phenotype is modified by a medium- or short-range embryonic signal. A cascade of interactions follows, mediating embryo migration across the epithelium. Strikingly, numerous potential mediators of adhesion at implantation are located in the lateral rather than the apical surface of LE cells. Attached embryos appear to gain rapid access to this highly adhesive lateral membrane domain.
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Harris LK, Smith SD, Keogh RJ, Jones RL, Baker PN, Knöfler M, Cartwright JE, Whitley GSJ, Aplin JD. Trophoblast- and vascular smooth muscle cell-derived MMP-12 mediates elastolysis during uterine spiral artery remodeling. THE AMERICAN JOURNAL OF PATHOLOGY 2010; 177:2103-15. [PMID: 20802175 DOI: 10.2353/ajpath.2010.100182] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
During the first trimester of pregnancy, the uterine spiral arteries are remodeled, creating heavily dilated conduits that lack maternal vasomotor control but allow the placenta to meet an increasing requirement for nutrients and oxygen. To effect permanent vasodilatation, the internal elastic lamina and medial elastin fibers must be degraded. In this study, we sought to identify the elastolytic proteases involved in this process. Primary first-trimester cytotrophoblasts (CTBs) derived from the placenta exhibited intracellular and membrane-associated elastase activity; membrane-associated activity was primarily attributable to matrix metalloproteinases (MMP). Indeed, Affymetrix microarray analysis and immunocytochemistry implicated MMP-12 (macrophage metalloelastase) as a key mediator of elastolysis. Cultured human aortic smooth muscle cells (HASMCs) exhibited constitutive membrane-associated elastase activity and inducible intracellular elastase activity; these cells also expressed MMP-12 protein. Moreover, a specific inhibitor of MMP-12 significantly reduced CTB- and HASMC-mediated elastolysis in vitro, to 31.7 ± 10.9% and 23.3 ± 8.7% of control levels, respectively. MMP-12 is expressed by both interstitial and endovascular trophoblasts in the first-trimester placental bed and by vascular SMCs (VSMCs) in remodeling spiral arteries. Perfusion of isolated spiral artery segments with CTB-conditioned medium stimulated MMP-12 expression in medial VSMCs. Our data support a model in which trophoblasts and VSMCs use MMP-12 cooperatively to degrade elastin during vascular remodeling in pregnancy, with the localized release of elastin peptides and CTB-derived factors amplifying elastin catabolism.
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Singh H, Nardo L, Kimber SJ, Aplin JD. Early stages of implantation as revealed by an in vitro model. Reproduction 2010; 139:905-14. [DOI: 10.1530/rep-09-0271] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Our limited understanding of the processes underlying steroid hormonal control of human endometrial receptivity is largely due to the lack of a relevant model system. To overcome scarcity of material, we have developed a model in which mouse embryos attach to human Ishikawa cells, which express functional steroid hormone receptors. Blastocysts flushed from day 4 pregnant superovulated mice were transferred to confluent Ishikawa cell monolayers. After 48 h of co-culture, 85% of the blastocysts had attached loosely, but only 40% attached stably to the epithelial cell surface. In contrast, 95% of the embryos attached stably to tissue culture plastic. Thus, weak attachment of a majority of the embryos was followed by stronger adhesion of a smaller proportion. Seventeen percent of the transferred blastocysts modified the epithelial cell surface with loss of MUC1 at the attachment site, extending variably to adjacent epithelial cells. Initially, stable attachment occurred without disruption to the integrity of the epithelial monolayer, but at later stages after the embryo had spread laterally, displacement of subjacent cells was observed. A modest increase in stable attachment, but no changes to MUC1 clearance, was observed after assisted hatching. After 24 h priming of Ishikawa cells by 17β-oestradiol (OE2) followed by 72-h incubation with medroxyprogesterone acetate and OE2, stable attachment increased from 40 to 70%. Initial attachment is efficient either in the presence or in the absence of hormone; steroid treatment increased the incidence of stable attachment. Implantation failure is predicted to occur in this model when embryos fail to progress from initial to stable attachment.
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Forbes K, Souquet B, Garside R, Aplin JD, Westwood M. Transforming growth factor-{beta} (TGF{beta}) receptors I/II differentially regulate TGF{beta}1 and IGF-binding protein-3 mitogenic effects in the human placenta. Endocrinology 2010; 151:1723-31. [PMID: 20172969 DOI: 10.1210/en.2009-0896] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Maternal IGFs regulate cytotrophoblast proliferation and, thereby, placental growth and function. IGF bioavailability is controlled by IGF-binding proteins (IGFBPs); in placenta, IGFBP-3 is particularly abundant. In other systems, IGFBP-3 can regulate cellular events independently of IGFs; these effects are thought to be mediated by TGFbeta receptors (TbetaR). We have examined IGFBP-3 regulation of IGF-dependent and -independent cytotrophoblast proliferation in first-trimester placental explants and the role of TbetaRII in mediating these effects. In the presence of IGFBP-3 (50 nm), IGF-induced (10 nm) proliferation (monitored by immunohistochemical analysis of Ki67 expression and bromodeoxyuridine incorporation) was significantly reduced (P < 0.05). IGFBP-3 also reduced basal proliferation independently of IGF receptor signaling. Immunohistochemical analysis demonstrated that TGFbeta signaling molecules [TGFbeta receptor I (TbetaRI), TbetaRII, TbetaRV, Smad-2, and ERK] are expressed in syncytium and/or cytotrophoblast. TGFbeta1 (10 ng/ml) enhanced cytotrophoblast proliferation and activated both Smad-2 and ERK-1/2, whereas IGFBP-3 activated only Smad-2. The function of both TGFbeta1 and IGFBP-3 was attenuated by a TbetaRII function-blocking antibody and by small interfering RNA-mediated knockdown of TbetaRII (P < 0.05); this was accompanied by a reduction in Smad-2 activation. This study demonstrates that both TGFbeta1 and IGFBP-3 signal through TbetaRI/II to influence human cytotrophoblast proliferation. However, downstream pathways are distinct, because IGFBP-3 acts only through Smad-2, whereas TGFbeta1 also phosphorylates ERK, resulting in opposite effects on cytotrophoblast proliferation. The effects of maternal growth signals on placental growth and function therefore depend on the balance of ligands, receptors, and signaling molecules at the syncytiotrophoblast surface. Therapeutic manipulation of this balance might offer a strategy to optimize placental development and pregnancy outcome.
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Ingman K, Cookson VJKW, Jones CJP, Aplin JD. Characterisation of Hofbauer cells in first and second trimester placenta: incidence, phenotype, survival in vitro and motility. Placenta 2010; 31:535-44. [PMID: 20347485 DOI: 10.1016/j.placenta.2010.03.003] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2010] [Revised: 03/01/2010] [Accepted: 03/02/2010] [Indexed: 11/25/2022]
Abstract
Macrophages, known as Hofbauer cells, are most abundant in placental villous stroma in the first and second trimesters. Their functions are not well defined. We have used a combination of in situ and in vitro methods to characterise these cells. Lectin histochemistry and immunohistochemistry were used to identify macrophages in situ. The lectin from Maclura pomifera (MPA) was found to mark cells bearing the CD68 antigen with optimal specificity and selectivity. MPA staining was used to show that they increase in number from mid first to mid second trimester, becoming much less abundant at term. The cells are absent from mesenchymal villi, being associated primarily with villous stroma containing the prominent interstitial channels characteristic of immature intermediate villi. A mixed stromal cell isolate was studied in monolayer culture, including the use of time-lapse microscopy. Cells from first or second trimester tissue contained a subpopulation of about 14-17% of cells that exhibited a macrophage-like morphology and expressed CD68 as well as MPA-binding glycans. These cells were short-lived in monoculture, but could persist in vitro in association with a fibroblast layer for several weeks. They could switch rapidly from a macrophage-like to a fibroblastic morphology, were highly motile and associated in clusters that rapidly formed and dissipated over periods of a few hours. These data suggest that Hofbauer cells play a role in the maturation of mesenchymal into immature intermediate-type stroma. They may be important in the excavation of stromal channels. Their prolonged viability in mixed cultures suggests a paracrine relationship with resident fibroblasts. Their location and migratory behaviour predict an ability to move rapidly around the villous stroma, perhaps within the channel system, and to make transient contacts both with other macrophages and stromal cells.
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Aplin JD. Developmental cell biology of human villous trophoblast: current research problems. THE INTERNATIONAL JOURNAL OF DEVELOPMENTAL BIOLOGY 2010; 54:323-9. [DOI: 10.1387/ijdb.082759ja] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Blankley RT, Robinson NJ, Aplin JD, Crocker IP, Gaskell SJ, Whetton AD, Baker PN, Myers JE. A gel-free quantitative proteomics analysis of factors released from hypoxic-conditioned placentae. Reprod Sci 2009; 17:247-57. [PMID: 19907055 DOI: 10.1177/1933719109351320] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Characterizing the protein factors released from placentae during pathogenesis remains a key objective toward understanding preeclampsia and related pregnancy disorders. Gel-free proteomics technologies applied to placental explant-conditioned media offers the potential of identifying these factors. Relative quantification mass spectrometry using isobaric tagging for relative and absolute quantification (iTRAQ) labeling was employed to compare the ''secretome'' between healthy term placental tissue cultured under both normoxic and hypoxic oxygen tensions. Of the 499 proteins identified, 45 were differentially expressed (P < .01 level), including interleukin 8 (IL-8) which was significantly upregulated under hypoxia. Global protein level changes are suggestive of decreased extracellular matrix remodeling under the same conditions. A significant enrichment of soluble liberated placental factors is achieved using this model system. Identifying these changes resulting from hypoxic conditioning is hypothesis generating and may provide new mechanistic insights into preeclampsia.
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Sanches JCT, Jones CJP, Aplin JD, Iozzo RV, Zorn TMT, Oliveira SF. Collagen fibril organization in the pregnant endometrium of decorin-deficient mice. J Anat 2009; 216:144-55. [PMID: 19900179 DOI: 10.1111/j.1469-7580.2009.01170.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
In the pregnant mouse endometrium, collagen fibrillogenesis is characterized by the presence of very thick collagen fibrils which are topographically located exclusively within the decidualized stroma. This dynamic biological process is in part regulated by the small leucine-rich proteoglycans decorin and biglycan. In the present study we utilized wild-type (Dcn(+/+)) and decorin-deficient (Dcn(-/-)) time-pregnant mice to investigate the evolution of non-decidualized and decidualized collagen matrix in the uterine wall of these animals. Ultrastructural and morphometric analyses revealed that the organization of collagen fibrils in the pregnant endometrium of both non-decidualized and decidualized stroma showed a great variability of shape and size, regardless of the genotype. However, the decidualized endometrium from Dcn(-/-) mice contained fibrils with larger diameter and more irregular contours as compared to the wild-type littermates. In the Dcn(-/-) animals, the proportion of thin (10-50 nm) fibrils was also higher as compared to Dcn(+/+) animals. On day 7 of pregnancy, biglycan was similarly localized in the decidualized endometrium in both genotypes. Lumican immunostaining was intense both in decidualized and non-decidualized stroma from Dcn(-/-) animals. The present results support previous findings suggesting that decorin participates in uterine collagen fibrillogenesis. In addition, we suggest that the absence of decorin disturbs the process of lateral assembly of thin fibrils, resulting in very thick collagen fibrils with irregular profiles. Our data further suggest that decorin, biglycan and lumican might play an interactive role in collagen fibrillogenesis in the mouse endometrium, a process modulated according to the stage of pregnancy.
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Forbes K, West G, Garside R, Aplin JD, Westwood M. The protein-tyrosine phosphatase, SRC homology-2 domain containing protein tyrosine phosphatase-2, is a crucial mediator of exogenous insulin-like growth factor signaling to human trophoblast. Endocrinology 2009; 150:4744-54. [PMID: 19589868 DOI: 10.1210/en.2009-0166] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Adequate fetal growth depends on placental transfer of nutrients and gases from the mother; thus, as pregnancy progresses, the placenta must grow to meet the increasing demands of the developing fetus. IGFs control proliferation, differentiation, and survival of trophoblast in first-trimester placenta via intracellular tyrosine kinase signaling cascades, the activation of which is also regulated by tyrosine phosphatases. The protein-tyrosine phosphatase, Src homology-2 domain containing protein tyrosine phosphatase (SHP)-2, is crucial for mouse placental development and is known to mediate IGF actions in other systems. In this study we examined the role of SHP-2 in regulating IGF-mediated proliferation in human trophoblast. Immunohistochemical analysis demonstrated that SHP-2 is expressed strongly in cytotrophoblast and only weakly in syncytium. After small interfering RNA-mediated knockdown of SHP-2 in BeWo choriocarcinoma cells and human first-trimester placental explants, IGF-induced trophoblast proliferation, examined using immunohistochemical analysis of Ki67 and 5-bromo-2'-deoxyuridine incorporation, was significantly reduced (P < 0.05). Kinase activation assays suggested that SHP-2 interacts with the MAPK pathway to mediate these effects. Markers of trophoblast differentiation were elevated after SHP-2 knockdown. This study demonstrates a role for tyrosine phosphatases in human trophoblast and establishes SHP-2 as a component of the IGF signaling pathway that is required for normal placental growth.
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Singh H, Aplin JD. Adhesion molecules in endometrial epithelium: tissue integrity and embryo implantation. J Anat 2009; 215:3-13. [PMID: 19453302 PMCID: PMC2714633 DOI: 10.1111/j.1469-7580.2008.01034.x] [Citation(s) in RCA: 114] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/14/2008] [Indexed: 12/16/2022] Open
Abstract
Cell adhesion in endometrial epithelium is regulated to maintain the continuity and protectiveness of the luminal covering cell layer while permitting interstitial implantation of the embryo during a restricted period of about 4 days. Many apparently normal embryos fail to implant, and epithelial-embryo adhesion remains a poorly understood phenomenon. After menstruation, epithelial regeneration occurs by epiboly from the basal residues of glands, an activity that requires migration on extracellular matrix as well as cell-cell cohesion. Here we review current knowledge of adhesion molecules in the epithelium.
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Salgado RM, Capelo LP, Favaro RR, Glazier JD, Aplin JD, Zorn TMT. Hormone-regulated expression and distribution of versican in mouse uterine tissues. Reprod Biol Endocrinol 2009; 7:60. [PMID: 19500372 PMCID: PMC2698856 DOI: 10.1186/1477-7827-7-60] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2009] [Accepted: 06/05/2009] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Remodeling of the extracellular matrix is one of the most striking features observed in the uterus during the estrous cycle and after hormone replacement. Versican (VER) is a hyaluronan-binding proteoglycan that undergoes RNA alternative splicing, generating four distinct isoforms. This study analyzed the synthesis and distribution of VER in mouse uterine tissues during the estrous cycle, in ovariectomized (OVX) animals and after 17beta-estradiol (E2) and medroxyprogesterone (MPA) treatments, either alone or in combination. METHODS Uteri from mice in all phases of the estrous cycle, and animals subjected to ovariectomy and hormone replacement were collected for immunoperoxidase staining for versican, as well as PCR and quantitative Real Time PCR. RESULTS In diestrus and proestrus, VER was exclusively expressed in the endometrial stroma. In estrus and metaestrus, VER was present in both endometrial stroma and myometrium. In OVX mice, VER immunoreaction was abolished in all uterine tissues. VER expression was restored by E2, MPA and E2+MPA treatments. Real Time PCR analysis showed that VER expression increases considerably in the MPA-treated group. Analysis of mRNA identified isoforms V0, V1 and V3 in the mouse uterus. CONCLUSION These results show that the expression of versican in uterine tissues is modulated by ovarian steroid hormones, in a tissue-specific manner. VER is induced in the myometrium exclusively by E2, whereas MPA induces VER deposition only in the endometrial stroma.
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Ben-Nagi J, Walker A, Jurkovic D, Yazbek J, Aplin JD. Effect of cesarean delivery on the endometrium. Int J Gynaecol Obstet 2009; 106:30-4. [PMID: 19356756 DOI: 10.1016/j.ijgo.2009.02.019] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2008] [Revised: 01/27/2009] [Accepted: 02/20/2009] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To compare endometrial tissue samples from cesarean scar (CS) sites and from the posterior uterine wall to better understand the pathophysiology of implantation into a CS. METHODS Endometrial samples were taken from both a CS site and the posterior wall in premenopausal women with CSs, and from the posterior wall in premenopausal women who had spontaneous vaginal deliveries (SVDs) only. RESULTS In the secretory phase, there were significantly fewer leukocytes at CS sites than in the endometrium of women who had SVDs only (P<0.05). Significant differences in leukocytic infiltration and cell proliferation between the proliferative and secretory phases were only found in women who had SVDs only (P<0.05). CONCLUSION Leukocyte recruitment to the endometrium during the secretory phase may be affected by the presence of a CS.
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Smith SD, Dunk CE, Aplin JD, Harris LK, Jones RL. Evidence for immune cell involvement in decidual spiral arteriole remodeling in early human pregnancy. THE AMERICAN JOURNAL OF PATHOLOGY 2009; 174:1959-71. [PMID: 19349361 DOI: 10.2353/ajpath.2009.080995] [Citation(s) in RCA: 337] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Decidual artery remodeling is essential for a healthy pregnancy. This process involves loss of vascular smooth muscle cells and endothelium, which are replaced by endovascular trophoblasts (vEVTs) embedded in fibrinoid. Remodeling is impaired during pre-eclampsia, a disease of pregnancy that results in maternal and fetal mortality and morbidity. Early vascular changes occur in the absence of vEVTs, suggesting that another cell type is involved; evidence from animal models indicates that decidual leukocytes play a role. We hypothesized that leukocytes participate in remodeling through the triggering of apoptosis or extracellular matrix degradation. Decidua basalis samples (8 to 12 weeks gestation) were examined by immunohistochemistry to elucidate associations between leukocytes, vEVTs, and key remodeling events. Trophoblast-independent and -dependent phases of remodeling were identified. Based on a combination of morphological attributes, vessel profiles were classified into a putative temporal series of four stages. In early stages of remodeling, vascular smooth muscle cells showed dramatic disruption and disorganization before vEVT presence. Leukocytes (identified as uterine natural killer cells and macrophages) were apparent infiltrating vascular smooth muscle cells layers and were matrix metalloproteinase-7 and -9 immunopositive. A proportion of vascular smooth muscle cells and endothelial cells were terminal deoxynucleotidyl transferase dUTP nick-end labeling positive, suggesting remodeling involves apoptosis. We thus confirm that vascular remodeling occurs in distinct trophoblast-independent and -dependent stages and provide the first evidence of decidual leukocyte involvement in trophoblast-independent stages.
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