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Rüegg AB, Kowalewski MP, Ulbrich SE. Endometrial extracellular matrix components do not change over the course of embryonic diapause and reactivation in the roe deer (Capreolus capreolus). Reprod Domest Anim 2023; 58:594-604. [PMID: 36645739 DOI: 10.1111/rda.14320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2022] [Revised: 11/20/2022] [Accepted: 12/14/2022] [Indexed: 01/17/2023]
Abstract
The modification of the endometrial extracellular matrix (ECM) is a crucial step for embryo implantation in many mammalian species. The embryo of the European roe deer (Capreolus capreolus) displays a 4-5 months long temporary reduction of developmental pace termed embryonic diapause. A reduction of epithelial cell height during diapause has previously been described. Co-occurring ECM modifications may contribute to the changes of the intra-uterine milieu during reactivation at which the embryo regains developmental velocity. We assessed the localization of five ECM proteins (collagen I and IV, fibronectin, laminin, and extracellular matrix protein 1) using immunohistochemistry in animals with early, late, and post-diapause (elongating) embryos. While our results confirmed the reduction of epithelial height during diapause, we only detected marginal differences in localization and staining intensities of the selected ECM proteins. Major ECM remodelling events in the roe deer endometrium are thus likely to occur only at implantation.
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Affiliation(s)
- Anna B Rüegg
- ETH Zurich, Animal Physiology, Institute of Agricultural Sciences, Zurich, Switzerland
| | - Mariusz P Kowalewski
- Vetsuisse Faculty, Institute of Veterinary Anatomy, University of Zurich, Zurich, Switzerland
| | - Susanne E Ulbrich
- ETH Zurich, Animal Physiology, Institute of Agricultural Sciences, Zurich, Switzerland
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2
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Matsuo I, Kimura-Yoshida C, Ueda Y. Developmental and mechanical roles of Reichert's membrane in mouse embryos. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210257. [PMID: 36252218 PMCID: PMC9574627 DOI: 10.1098/rstb.2021.0257] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 02/24/2022] [Indexed: 12/23/2022] Open
Abstract
Embryonic development and growth in placental mammals proceeds in utero with the support of exchanges of gases, nutrients and waste products between maternal tissues and offspring. Murine embryos are surrounded by several extraembryonic membranes, parietal and visceral yolk sacs, and amnion in the uterus. Notably, the parietal yolk sac is the most outer membrane, consists of three layers, trophoblasts and parietal endoderm (PaE) cells, and is separated by a thick basal lamina termed Reichert's membrane (RM). RM is composed of extracellular matrix (ECM) initially formed as the basement membrane of the trophectoderm of pre-implanted embryos and followed by the heavy deposition of ECM mainly produced in PaE cells of post-implanted embryos. In addition to the physiological roles of RM, such as gas and nutrient exchange, it also plays a crucial role in cushioning and dispersing intrauterine pressures exerted on embryos for normal egg-cylinder morphogenesis. Mechanistically, such intrauterine pressures generated by uterine smooth muscle contractions appear to be involved in the elongation of the egg-cylinder shape, along with primary axis formation, as an important biomechanical element in utero. This review focuses on our current views of the roles of RM in properly buffering intrauterine mechanical forces for mouse egg-cylinder morphogenesis. This article is part of the theme issue 'Extraembryonic tissues: exploring concepts, definitions and functions across the animal kingdom'.
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Grants
- Takeda Science Foundation
- a grant-in-aid for challenging Research(Exploratory)from the Ministry of Education, Culture, Sports, Science, and Technology, Japan
- from the Ministry a grant-in-aid for Scientific Research (C) of Education, Culture, Sports, Science, and Technology, Japan
- a grant-in-aid for Transformative Research Areas (A)from the Ministry of Education, Culture, Sports, Science, and Technology, Japan
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Affiliation(s)
- Isao Matsuo
- Department of Molecular Embryology, Research Institute, Osaka Women's and Children's Hospital, Osaka Prefectural Hospital Organization, 840, Murodo-cho, Izumi, Osaka 594-1101, Japan
| | - Chiharu Kimura-Yoshida
- Department of Molecular Embryology, Research Institute, Osaka Women's and Children's Hospital, Osaka Prefectural Hospital Organization, 840, Murodo-cho, Izumi, Osaka 594-1101, Japan
| | - Yoko Ueda
- Department of Molecular Embryology, Research Institute, Osaka Women's and Children's Hospital, Osaka Prefectural Hospital Organization, 840, Murodo-cho, Izumi, Osaka 594-1101, Japan
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3
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Qu H, Khalil RA. Role of ADAM and ADAMTS Disintegrin and Metalloproteinases in Normal Pregnancy and Preeclampsia. Biochem Pharmacol 2022; 206:115266. [PMID: 36191626 DOI: 10.1016/j.bcp.2022.115266] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 09/22/2022] [Accepted: 09/23/2022] [Indexed: 11/16/2022]
Abstract
Normal pregnancy (NP) involves intricate processes starting with egg fertilization, proceeding to embryo implantation, placentation and gestation, and culminating in parturition. These pregnancy-related processes require marked uteroplacental and vascular remodeling by proteolytic enzymes and metalloproteinases. A disintegrin and metalloproteinase (ADAM) and ADAM with thrombospondin motifs (ADAMTS) are members of the zinc-dependent family of proteinases with highly conserved protein structure and sequence homology, which include a pro-domain, and a metalloproteinase, disintegrin and cysteine-rich domain. In NP, ADAMs and ADAMTS regulate sperm-egg fusion, embryo implantation, trophoblast invasion, placental angiogenesis and spiral arteries remodeling through their ectodomain proteolysis of cell surface cytokines, cadherins and growth factors as well as their adhesion with integrins and cell-cell junction proteins. Preeclampsia (PE) is a serious complication of pregnancy characterized by new-onset hypertension (HTN) in pregnancy (HTN-Preg) at or after 20 weeks of gestation, with or without proteinuria. Insufficient trophoblast invasion of the uterine wall, inadequate expansive remodeling of the spiral arteries, reduced uteroplacental perfusion pressure, and placental ischemia/hypoxia are major initiating events in the pathogenesis of PE. Placental ischemia/hypoxia increase the release of reactive oxygen species (ROS), which lead to aberrant expression/activity of certain ADAMs and ADAMTS. In PE, abnormal expression/activity of specific ADAMs and ADAMTS that function as proteolytic sheddases could alter proangiogenic and growth factors, and promote the release of antiangiogenic factors and inflammatory cytokines into the placenta and maternal circulation leading to generalized inflammation, endothelial cell injury and HTN-Preg, renal injury and proteinuria, and further decreases in uteroplacental blood flow, exaggeration of placental ischemia, and consequently fetal growth restriction. Identifying the role of ADAMs and ADAMTS in NP and PE has led to a better understanding of the underlying molecular and vascular pathways, and advanced the potential for novel biomarkers for prediction and early detection, and new approaches for the management of PE.
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Affiliation(s)
- Hongmei Qu
- Vascular Surgery Research Laboratories, Division of Vascular and Endovascular Surgery, Brigham and Women's Hospital, and Harvard Medical School, Boston, MA
| | - Raouf A Khalil
- Vascular Surgery Research Laboratories, Division of Vascular and Endovascular Surgery, Brigham and Women's Hospital, and Harvard Medical School, Boston, MA.
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4
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Yang ZS, Pan HY, Shi WW, Chen ST, Wang Y, Li MY, Zhang HY, Yang C, Liu AX, Yang ZM. Regulation and Function of Laminin A5 during Mouse and Human Decidualization. Int J Mol Sci 2021; 23:199. [PMID: 35008625 PMCID: PMC8745792 DOI: 10.3390/ijms23010199] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 12/20/2021] [Accepted: 12/22/2021] [Indexed: 01/03/2023] Open
Abstract
Decidualization is essential to the establishment of pregnancy in rodents and primates. Laminin A5 (encoding by Laminin α5) is a member of the laminin family, which is mainly expressed in the basement membranes. Although laminins regulate cellular phenotype maintenance, adhesion, migration, growth, and differentiation, the expression, function, and regulation of laminin A5 during early pregnancy are still unknown. Therefore, we investigated the expression and role of laminin A5 during mouse and human decidualization. Laminin A5 is highly expressed in mouse decidua and artificially induced deciduoma. Laminin A5 is significantly increased under in vitro decidualization. Laminin A5 knockdown significantly inhibits the expression of Prl8a2, a marker for mouse decidualization. Progesterone stimulates the expression of laminin A5 in ovariectomized mouse uterus and cultured mouse stromal cells. We also show that progesterone regulates laminin A5 through the PKA-CREB-C/EBPβ pathway. Laminin A5 is also highly expressed in human pregnant decidua and cultured human endometrial stromal cells during in vitro decidualization. Laminin A5 knockdown by siRNA inhibits human in vitro decidualization. Collectively, our study reveals that laminin A5 may play a pivotal role during mouse and human decidualization via the PKA-CREB-C/EBPβ pathway.
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Affiliation(s)
- Zhen-Shan Yang
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; (Z.-S.Y.); (H.-Y.P.); (W.-W.S.); (S.-T.C.); (Y.W.); (M.-Y.L.); (H.-Y.Z.); (C.Y.)
| | - Hai-Yang Pan
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; (Z.-S.Y.); (H.-Y.P.); (W.-W.S.); (S.-T.C.); (Y.W.); (M.-Y.L.); (H.-Y.Z.); (C.Y.)
| | - Wen-Wen Shi
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; (Z.-S.Y.); (H.-Y.P.); (W.-W.S.); (S.-T.C.); (Y.W.); (M.-Y.L.); (H.-Y.Z.); (C.Y.)
| | - Si-Ting Chen
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; (Z.-S.Y.); (H.-Y.P.); (W.-W.S.); (S.-T.C.); (Y.W.); (M.-Y.L.); (H.-Y.Z.); (C.Y.)
| | - Ying Wang
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; (Z.-S.Y.); (H.-Y.P.); (W.-W.S.); (S.-T.C.); (Y.W.); (M.-Y.L.); (H.-Y.Z.); (C.Y.)
| | - Meng-Yuan Li
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; (Z.-S.Y.); (H.-Y.P.); (W.-W.S.); (S.-T.C.); (Y.W.); (M.-Y.L.); (H.-Y.Z.); (C.Y.)
| | - Hai-Yi Zhang
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; (Z.-S.Y.); (H.-Y.P.); (W.-W.S.); (S.-T.C.); (Y.W.); (M.-Y.L.); (H.-Y.Z.); (C.Y.)
| | - Chen Yang
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; (Z.-S.Y.); (H.-Y.P.); (W.-W.S.); (S.-T.C.); (Y.W.); (M.-Y.L.); (H.-Y.Z.); (C.Y.)
| | - Ai-Xia Liu
- Department of Reproductive Endocrinology, Women’s Hospital, School of Medicine, Zhejiang University, Xueshi Road, Hangzhou 310006, China
| | - Zeng-Ming Yang
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; (Z.-S.Y.); (H.-Y.P.); (W.-W.S.); (S.-T.C.); (Y.W.); (M.-Y.L.); (H.-Y.Z.); (C.Y.)
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5
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Li K, Li Q, Bashir ST, Bany BM, Nowak RA. Loss of basigin expression in uterine cells leads to subfertility in female mice†. Biol Reprod 2021; 105:859-875. [PMID: 34106247 PMCID: PMC8511667 DOI: 10.1093/biolre/ioab109] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Revised: 04/07/2020] [Accepted: 05/27/2021] [Indexed: 01/19/2023] Open
Abstract
Basigin (BSG) is a transmembrane glycoprotein involved in cell proliferation, angiogenesis, and tissue remodeling. BSG has been shown to be essential for male and female reproduction although little is known about its role in normal uterine function. To study the potential function of BSG in the female reproductive tract, we generated mice with conditional knockout of Bsg in uterine cells using progesterone receptor-Cre and hypothesized that BSG is required for normal pregnancy in mice. Fertility study data showed that the conditional knockout mice had significantly reduced fertility compared to controls. Ovarian function of the conditional knockout mice appeared normal with no difference in the number of superovulated oocytes collected or in serum progesterone levels between the conditional knockout and the control mice. Uterine tissues collected at various times of gestation showed increased abnormalities in implantation, decidualization, placentation, and parturition in the conditional knockout mice. Uterine cross sections on Day 5 of pregnancy showed implantation failure and abnormal uterine epithelial differentiation in a large proportion of the conditional knockout mice. There was a compromised decidual response to artificial decidualization stimuli and decreased mRNA and protein levels for decidualization genes in the uteri of the conditional knockout mice. We also observed altered protein expression of monocarboxylate transporter 1 (MCT1), as well as impaired angiogenesis in the conditional knockout uteri compared to the controls. These results support that BSG is required for successful pregnancy through its functions in implantation and decidualization.
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Affiliation(s)
- Kailiang Li
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Quanxi Li
- Department of Comparative Biosciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Shah Tauseef Bashir
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Brent M Bany
- Department of Physiology, Southern Illinois University School of Medicine, Carbondale, IL, USA
| | - Romana A Nowak
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA
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6
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Zheng HT, Zhang HY, Chen ST, Li MY, Fu T, Yang ZM. The detrimental effects of stress-induced glucocorticoid exposure on mouse uterine receptivity and decidualization. FASEB J 2020; 34:14200-14216. [PMID: 32918762 DOI: 10.1096/fj.201902911rr] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 07/20/2020] [Accepted: 07/27/2020] [Indexed: 11/11/2022]
Abstract
Glucocorticoids (GCs), stress-induced steroid hormones, are released by adrenal cortex and essential for stress adaptation. Recently, there has been renewed interest in the relationship between GCs and pregnancy following the discovery that glucocorticoid receptor is necessary for implantation. It has been widely recognized that stress is detrimental to pregnancy. However, effects of stress-induced GC exposure on uterine receptivity and decidualization are still poorly understood. This study aims to explore the effects of GCs exposure on uterine receptivity, decidualization, and their underlying mechanisms in mice. Single prolonged stress (SPS) and corticosterone (Cort) injection models were used to analyze effects of GC exposure on early pregnancy, respectively. SPS or Cort injection inhibits embryo implantation by interfering Lif signaling and stimulating the uterine deposition of collagen types I, III, and IV on day 4 of pregnancy. Uterine decidualization is also attenuated by SPS or Cort injection through suppressing Cox-2 expression. Cort-induced collagen disorder also suppresses decidualization through regulating mesenchymal-epithelial transition. Our data should shed lights for a better understanding for the effects of GCs on embryo implantation for clinical research.
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Affiliation(s)
- Hong-Tao Zheng
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Hai-Yi Zhang
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Si-Ting Chen
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Meng-Yuan Li
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Tao Fu
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Zeng-Ming Yang
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
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A hypoxia-induced Rab pathway regulates embryo implantation by controlled trafficking of secretory granules. Proc Natl Acad Sci U S A 2020; 117:14532-14542. [PMID: 32513733 DOI: 10.1073/pnas.2000810117] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Implantation is initiated when an embryo attaches to the uterine luminal epithelium and subsequently penetrates into the underlying stroma to firmly embed in the endometrium. These events are followed by the formation of an extensive vascular network in the stroma that supports embryonic growth and ensures successful implantation. Interestingly, in many mammalian species, these processes of early pregnancy occur in a hypoxic environment. However, the mechanisms underlying maternal adaptation to hypoxia during early pregnancy remain unclear. In this study, using a knockout mouse model, we show that the transcription factor hypoxia-inducible factor 2 alpha (Hif2α), which is induced in subluminal stromal cells at the time of implantation, plays a crucial role during early pregnancy. Indeed, when preimplantation endometrial stromal cells are exposed to hypoxic conditions in vitro, we observed a striking enhancement in HIF2α expression. Further studies revealed that HIF2α regulates the expression of several metabolic and protein trafficking factors, including RAB27B, at the onset of implantation. RAB27B is a member of the Rab family of GTPases that allows controlled release of secretory granules. These granules are involved in trafficking MMP-9 from the stroma to the epithelium to promote luminal epithelial remodeling during embryo invasion. As pregnancy progresses, the HIF2α-RAB27B pathway additionally mediates crosstalk between stromal and endothelial cells via VEGF granules, developing the vascular network critical for establishing pregnancy. Collectively, our study provides insights into the intercellular communication mechanisms that operate during adaptation to hypoxia, which is essential for embryo implantation and establishment of pregnancy.
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Transcriptomic changes in the pre-implantation uterus highlight histotrophic nutrition of the developing marsupial embryo. Sci Rep 2018; 8:2412. [PMID: 29402916 PMCID: PMC5799185 DOI: 10.1038/s41598-018-20744-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 01/23/2018] [Indexed: 12/12/2022] Open
Abstract
Early pregnancy is a critical time for successful reproduction; up to half of human pregnancies fail before the development of the definitive chorioallantoic placenta. Unlike the situation in eutherian mammals, marsupial pregnancy is characterised by a long pre-implantation period prior to the development of the short-lived placenta, making them ideal models for study of the uterine environment promoting embryonic survival pre-implantation. Here we present a transcriptomic study of pre-implantation marsupial pregnancy, and identify differentially expressed genes in the Sminthopsis crassicaudata uterus involved in metabolism and biosynthesis, transport, immunity, tissue remodelling, and uterine receptivity. Interestingly, almost one quarter of the top 50 genes that are differentially upregulated in early pregnancy are putatively involved in histotrophy, highlighting the importance of nutrient transport to the conceptus prior to the development of the placenta. This work furthers our understanding of the mechanisms underlying survival of pre-implantation embryos in the earliest live bearing ancestors of mammals.
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Matsumoto H. Molecular and cellular events during blastocyst implantation in the receptive uterus: clues from mouse models. J Reprod Dev 2017. [PMID: 28638003 PMCID: PMC5649093 DOI: 10.1262/jrd.2017-047] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The success of implantation is an interactive process between the blastocyst and the uterus. Synchronized development of embryos with uterine differentiation to a receptive state is necessary to complete pregnancy. The period of uterine receptivity for implantation is limited and referred to as the “implantation window”, which is regulated by ovarian steroid hormones. Implantation process is complicated due to the many signaling molecules in the hierarchical mechanisms with the embryo-uterine dialogue. The mouse is widely used in animal research, and is uniquely suited for reproductive studies, i.e., having a large litter size and brief estrous cycles. This review first describes why the mouse is the preferred model for implantation studies, focusing on uterine morphology and physiological traits, and then highlights the knowledge on uterine receptivity and the hormonal regulation of blastocyst implantation in mice. Our recent study revealed that selective proteolysis in the activated blastocyst is associated with the completion of blastocyst implantation after embryo transfer. Furthermore, in the context of blastocyst implantation in the mouse, this review discusses the window of uterine receptivity, hormonal regulation, uterine vascular permeability and angiogenesis, the delayed-implantation mouse model, morphogens, adhesion molecules, crosslinker proteins, extracellular matrix, and matricellular proteins. A better understanding of uterine and blastocyst biology during the peri-implantation period should facilitate further development of reproductive technology.
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Affiliation(s)
- Hiromichi Matsumoto
- Laboratory of Animal Breeding and Reproduction, Division of Animal Science, Department of Agrobiology and Bioresources, School of Agriculture, Utsunomiya University, Tochigi 321-8505, Japan.,Center for Bioscience Research and Education, Utsunomiya University, Tochigi 321-8505, Japan
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Liu JL, Zhao M, Peng Y, Fu YS. Identification of gene expression changes in rabbit uterus during embryo implantation. Genomics 2016; 107:216-21. [PMID: 27071951 DOI: 10.1016/j.ygeno.2016.03.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 03/06/2016] [Accepted: 03/29/2016] [Indexed: 11/30/2022]
Abstract
Embryo implantation in the rabbit is unique in that a typical fusion type of implantation is employed, in which trophoblast cells adhere and fuse to the apical surface of uterine epithelial cells. In the present study, we analyzed global gene expression changes in the rabbit uterus during embryo implantation by using RNA-seq. We identified a total of 536 differentially expressed genes (fold change >2 and adjusted p-value <0.01), of which 266 genes were down-regulated and 270 genes were up-regulated at the implantation site compared to the inter-implantation site. Functional clustering revealed that cell adhesion is among top ranked enriched terms from both gene ontology and pathway analysis, highlighting the importance of cell adhesion during embryo implantation in rabbits. Through gene network analysis, we prioritized 9 genes using the hub gene method. Our study provides a valuable resource for in-depth understanding of the mechanism underlying embryo implantation in rabbits.
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Affiliation(s)
- Ji-Long Liu
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.
| | - Miao Zhao
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Ying Peng
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Yong-Sheng Fu
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
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Molecular and cellular events involved in the completion of blastocyst implantation. Reprod Med Biol 2015; 15:53-58. [PMID: 29259421 DOI: 10.1007/s12522-015-0222-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 08/05/2015] [Indexed: 12/19/2022] Open
Abstract
Blastocyst implantation is an interactive process between the embryo and the uterus. The synchronization of embryonic development with uterine differentiation to a receptive state is essential for a successful pregnancy. The period of uterine receptivity for implantation is limited. Although implantation involves the interaction of numerous signaling molecules, our understanding of the hierarchical mechanisms that coordinate with the embryo-uterine dialogue is not yet sufficient to prevent infertility caused by implantation failure. This review highlights our knowledge on uterine receptivity and hormonal regulation of blastocyst implantation in mice. We also discuss the adhesion molecules, cross-linker proteins, extracellular proteins, and matricellular proteins involved in blastocyst implantation. Furthermore, our recent study reveals that selective proteolysis in an activated blastocyst is associated with the completion of blastocyst implantation after embryo transfer. A better understanding of uterine and blastocyst biology during the peri-implantation period would facilitate further development of reproductive technology.
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12
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Paule S, Aljofan M, Simon C, Rombauts LJF, Nie G. Cleavage of endometrial -integrins into their functional forms is mediated by proprotein convertase 5/6. Hum Reprod 2012; 27:2766-74. [DOI: 10.1093/humrep/des203] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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13
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Gürgen SG, Erdoğan D, Coşkun ZK, Cansu A. The effect of valproic acid and oxcarbazepine on the distribution of adhesion molecules in embryo implantation. Toxicology 2012; 292:71-7. [DOI: 10.1016/j.tox.2011.11.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2011] [Revised: 11/17/2011] [Accepted: 11/19/2011] [Indexed: 11/30/2022]
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Inhibition of proprotein convertase 5/6 activity: potential for nonhormonal women-centered contraception. Contraception 2011; 85:602-10. [PMID: 22079608 DOI: 10.1016/j.contraception.2011.10.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Revised: 10/04/2011] [Accepted: 10/05/2011] [Indexed: 11/22/2022]
Abstract
BACKGROUND Proprotein convertase 5/6 (PC6) is critical for endometrial epithelial receptivity and stromal cell decidualization for embryo implantation in women. We hypothesized that inhibiting PC6 could block implantation for contraception. The aim of this study was to prove this concept using human cell models and rabbits. STUDY DESIGN A potential PC6 inhibitor, C1239-PEG-Poly R, was biochemically confirmed to be a potent PC6 inhibitor. The potential contraceptive action of the inhibitor was then tested in decidualization of primary human endometrial stromal cells in a human trophoblast spheroid attachment model and in vivo in rabbits. RESULTS The PC6 inhibitor C1239-PEG-Poly R inhibited in a dose-dependent manner both decidualization and spheroid attachment. Vaginal delivery of 200 μL of the inhibitor at a final concentration of 5 mM to rabbits over a 3-day period starting 6 days after mating resulted in a 60% decrease in implantation and, hence, pregnancy. CONCLUSIONS This study presents proof of concept that PC6 inhibition has the potential to block embryo implantation, providing nonhormonal contraception for women.
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Tinelli A, Malvasi A, Cavallotti C, Dell'Edera D, Tsin DA, Stark M, Mettler L. The management of fibroids based on immunohistochemical studies of their pseudocapsules. Expert Opin Ther Targets 2011; 15:1241-7. [PMID: 21961807 DOI: 10.1517/14728222.2011.616196] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND We examined the presence of collagen IV and laminin in the pseudocapsule of uterine myomata to clarify different ultra-structural characteristics and their possible role in the management of this condition. METHODS Twenty non-pregnant patients underwent laparoscopic intracapsular myomectomies. Samples of the removed fibroids pseudocapsules were analyzed by immunochemical staining for collagen IV, immunohistochemical location of the vascular membrane-bound laminin and quantitative analysis of their images. RESULTS In the blood vessels of the pseudocapsules, a reduction in laminin and increase in collagen IV with increasing diameter of fibroids was noted. These proteins are related to loss of the basal membrane and to ageing of the tissue. The increase of collagen IV is linked to the increase of amorphous substance, including glycosaminoglycans and glycoproteins. CONCLUSION Based on immunohistochemical findings, the authors propose to remove fibroids in women seeking pregnancy whilst respecting the pseudocapsule by neurofibre sparing in the incision site. This is essential for optimal muscular healing and myometrial function in future pregnancies, and also when fibroids remain under 6 cm diameter, especially in young women wishing pregnancies. Fibroid removal should be performed before the myoma reaches a size causing compression of the surrounding tissues, which results in the loss of regenerative potential.
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Affiliation(s)
- Andrea Tinelli
- Vito Fazzi Hospital, Division of Experimental Endoscopic Surgery, Imaging, Minimally Invasive Therapy & Technology, Department of Obstetrics and Gynaecology, Piazza Muratore, 73100 Lecce, Italy.
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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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Affiliation(s)
- Honglu Diao
- Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia, Athens, Georgia 30602, USA
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Igarashi T, Tajiri Y, Sakurai M, Sato E, Li D, Mukai K, Suematsu M, Fukui E, Yoshizawa M, Matsumoto H. Tubulointerstitial nephritis antigen-like 1 is expressed in extraembryonic tissues and interacts with laminin 1 in the Reichert membrane at postimplantation in the mouse. Biol Reprod 2009; 81:948-55. [PMID: 19587330 DOI: 10.1095/biolreprod.109.078162] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Tubulointerstitial nephritis antigen-like 1 (Tinagl1, also known as adrenocortical zonation factor 1 [AZ-1] or lipocalin 7) has been cloned from mouse adrenocortical cells and is known to be closely associated with zonal differentiation of adrenocortical cells. In cell culture systems, TINAGL1 is a matricellular protein that interacts with both structural matrix proteins and cell surface receptors. However, the physiological roles of TINAGL1 and regulation of its expression are still not clearly understood. In the present study, the expression and localization of TINAGL1 in peri-implantation mouse embryos was examined. During preimplantation, the expression of both Tinagl1 mRNA and TINAGL1 protein was increased just prior to implantation. In blastocysts, TINAGL1 expression was localized to the trophectoderm. Using a progesterone-treated, delayed-implantation model, TINAGL1 was found to be upregulated in implantation-competent blastocysts after estrogen treatment. During postimplantation, TINAGL1 expression was restricted to extraembryonic regions. Marked expression was detected in the Reichert membrane on Embryonic Days 6.5 (E6.5) and E7.5. Colocalization of laminin 1 and TINAGL1 was also examined. Using an anti-LAMA1 antibody, colocalization of LAMA1 and TINAGL1 was observed in postimplantation embryos. Colocalization was also detected in the Reichert membrane. Immunoprecipitation analysis determined that LAMA1 and TINAGL1 interact in embryos on E7.5. These results demonstrate that after implantation, TINAGL1 is an extraembryonic tissue-specific protein. In particular, TINAGL1 is a novel component of the Reichert membrane that interacts with laminin 1. These results suggest that TINAGL1 most likely plays a physical and physiological role in embryo development at postimplantation.
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Affiliation(s)
- Tadashi Igarashi
- Laboratory of Animal Breeding and Reproduction, Division of Animal Science, Faculty of Agriculture, Utsunomiya University, Utsunomiya, Japan
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Kimber SJ. Blastocyst implantation:the adhesion cascade. REPRODUCTIVE MEDICINE AND ASSISTED REPRODUCTIVE TECHNIQUES 2008. [DOI: 10.3109/9780203091500.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Kim J, Kang SG, Kim JI, Park JH, Kim SK, Cho DJ, Kim H. Implication of ADAM-8, -9, -10, -12, -15, -17, and ADAMTS-1 in implantational remodeling of a mouse uterus. Yonsei Med J 2006; 47:558-67. [PMID: 16941747 PMCID: PMC2687738 DOI: 10.3349/ymj.2006.47.4.558] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
In the present study, whether the ADAM-8, -9, -10, -12, -15, -17, and ADAMTS-1 proteins might play a role in mouse uterus during periimplantation period was investigated. Immunoblotting analyses demonstrated that all ADAM proteins consistently appeared throughout days 1 to 8 of pregnancy but with a variation depending on the species of ADAM gene, the progression of pregnancy, and the site of the uterus. Immunohistochemical analyses indicated that ADAM proteins were localized in the luminal or glandular epithelial layers with a varying intensity depending on the species of ADAM and the progression of pregnancy. Particularly ADAM-8, -12, and -15, were predominantly located in the implantation site of the uterine tissues, whereas little or no protein was localized in the interimplantation site. Based upon these observations, it is suggested that the ADAMs might play an important role in the remodeling of the mouse uterus during the periimplantation period.
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Affiliation(s)
- Jiyoung Kim
- Department of Biotechnology, College of Natural Sciences, Seoul Women's University, Seoul, Korea
| | - Sung Goo Kang
- School of Biotechnology and Biomedical Science, Inje University, Kimhae, Korea
| | - Jong Il Kim
- Department of Applied Microbiology, College of Natural Sciences, Seoul Women's University, Seoul, Korea
| | - Joo Hyun Park
- Department of Obstetrics and Gynecology, College of Medicine, Yonsei University, Seoul, Korea
| | - Sei Kwang Kim
- Department of Obstetrics and Gynecology, College of Medicine, Yonsei University, Seoul, Korea
| | - Dong Jae Cho
- Department of Obstetrics and Gynecology, College of Medicine, Yonsei University, Seoul, Korea
| | - Haekwon Kim
- Department of Biotechnology, College of Natural Sciences, Seoul Women's University, Seoul, Korea
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20
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Oner H, Oner J, Demir R. Expression of nidogens in rat uterus and embryo during decidualization and implantation. J Morphol 2006; 267:822-30. [PMID: 16607619 DOI: 10.1002/jmor.10449] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The purpose of this study was to demonstrate the expression of nidogen-1 and nidogen-2 and their possible role in decidualization and implantation events during early pregnancy in rats. The tissue samples were examined from pregnant animals between gestational days 1-8 using immunocytochemistry. The uterine luminal epithelium, the glandular epithelium, and the myometrial smooth muscle cells stained strongly from gestational days 1-8 with both nidogen antibodies. At day 4 the decidual reaction areas began to appear in the stromal matrix and immunostaining of both nidogens revealed that the basement membrane of the surface epithelium was discontinuous. The differentiation of stromal cells into decidual cells was seen at gestational day 5 and both nidogens were weakly expressed in the decidualizing cells. At day 6, nidogen-2 immunoreactivity was higher in the primary decidual cells close to the embryo than nidogen-1, and during development of the decidual tissue both nidogens appeared in the endometrial stromal cells. At day 7, while expression of both nidogens declined in the primary decidual cells, their expression was markedly observed in the secondary decidual cells close to the myometrium. At day 8, expression of both nidogens was also observed to increase in the primary decidual cells. While nidogen-2 expression was seen in the parietal endoderm and primary ectoderm of the rat embryos at this developmental stage, nidogen-1 expression was only detected in the parietal endoderm. These results indicate that nidogen-1 and nidogen-2 could play important roles during embryogenesis, decidualization, and implantation in the endometrium of rat uterus.
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Affiliation(s)
- Hakan Oner
- Department of Histology and Embryology, Faculty of Veterinary Medicine, Akdeniz University, 15100 Burdur, Turkey.
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Matalon ST, Blank M, Matsuura E, Inagaki J, Nomizu M, Levi Y, Koike T, Shere Y, Ornoy A, Shoenfeld Y. Immunization of naïve mice with mouse laminin-1 affected pregnancy outcome in a mouse model. Am J Reprod Immunol 2003; 50:159-65. [PMID: 12846680 DOI: 10.1034/j.1600-0897.2003.00068.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
PROBLEM Laminins have important roles during placental and embryonic development. The aim of our study was to determine if active immunization of mice with laminin-1 could elicit an autoimmune response, and induce features of reproductive failure. METHOD OF STUDY BALB/c mice were immunized with mouse laminin-1. Autoantibodies to laminin-1 were measured by enzyme-linked immunosorbent assay. Pregnant mice were killed on day 14 of pregnancy and examined for pregnancy outcome. RESULTS Mice immunized with laminin-1 developed elevated levels of anti-laminin-1 auto-antibodies contrary to the control group. A higher fetal resorption rate was found in the laminin-1 immunized group (23.8%) compared with that of the control group (12.2%), and was even higher in the subgroup of those animals with very high levels of anti-laminin-1 (P < 0.01). Laminin-1 immunized mice also had lower fetal and placental weights. CONCLUSIONS Active immunization with laminin-1 followed by elevated circulating anti-laminin-1 antibodies results in reproductive failure manifested by a higher fetal resorption rate.
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Affiliation(s)
- Shelly Tartakover Matalon
- Research Center for autoimmune diseases, Department of Medicine B Sheba Medical Center, Tel Hashomer, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
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Abstract
This review covers the sequence of cell adhesion events occurring during implantation of the mammalian embryo, concentrating on data from mouse and human. The analogy is explored between initial attachment of trophoblast to the uterine lining epithelium and that of neutrophils to the endothelial lining of blood vessels at sites of inflammation. The possible role of various carbohydrate ligands in initial attachment of the blastocyst is reviewed. The evidence for subsequent stabilization of cell adhesion via integrins or the trophinin-tastin complex is discussed.
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Affiliation(s)
- S J Kimber
- School of Biological Sciences, University of Manchester, 3.239 Stopford Building, Oxford Rd, Manchester, M13 9PT, UK
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Sarani SA, Ghaffari-Novin M, Warren MA, Dockery P, Cooke ID. Morphological evidence for the 'implantation window' in human luminal endometrium. Hum Reprod 1999; 14:3101-6. [PMID: 10601103 DOI: 10.1093/humrep/14.12.3101] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Endometrial tissue was taken from 21 normal fertile women (aged 18-40 years) between 4 and 13 days after the luteinizing hormone (LH) surge. Systematic random samples of luminal epithelium were taken for both light and electron microscopy and examined morphometrically. Throughout the luteal phase there were remarkably few changes in the volume fraction of nucleus, mitochondria, rough endoplasmic reticulum and 'vesicular system' to cell. Nuclear profile dimensions and cell height also did not change over time. Cell and organelle volume (estimated as volume weighted mean volume) did not change significantly, but showed numerically smallest values on day LH + 13. However the ratio of desmosomes to whole cell and both arithmetic mean thickness and harmonic mean thickness of basement membrane were minimal at the time when implantation would be most likely to occur, i.e. approximately 6 days after the LH peak. Therefore it appears that while some morphometric parameters in human luminal epithelial cells change little during the luteal phase, specific cellular changes occur to the basement membrane and desmosomes which may facilitate embryo implantation. These changes occurred around day LH+ 6 and may be a morphological representation of the 'implantation window'.
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Affiliation(s)
- S A Sarani
- Department of Anatomy, Medical University of Zahedan, PO Box 98135-396 Zahedan, Iran
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Pollitt CC, Daradka M. Equine laminitis basement membrane pathology: loss of type IV collagen, type VII collagen and laminin immunostaining. Equine Vet J 1998:139-44. [PMID: 9932105 DOI: 10.1111/j.2042-3306.1998.tb05133.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Disintegration of the basement membrane (BM) of the equine hoof lamellae and failure of the BM to remain attached to the basal cells of the secondary epidermal lamellae (SEL) is one of the earliest pathological events to occur in acute laminitis. Changes in the lamellar basement membrane were investigated by immunolabelling the key structural components of the BM, type IV collagen, type VII collagen and laminin in the lamellar BM of horses 48 h after the induction of laminitis. Lamellar tissues were harvested from 2 normal horses and 2 horses with acute laminitis. Immunostaining with antibody raised against human epitopes for type IV collagen, type VII collagen and laminin successfully stained the basement membranes of horse hoof lamellar tissues. Vascular tissue did not immunostain with type VII collagen antibody. Normal BM stained as a fine dark brown line and the lamellar BM was adhered to the basal cells of the SELs with no evidence of lamellar separation. At least 2 changes to the lamellar BM occurred in acute laminitis: loss of attachment of lamellar epidermal basal cells to their underlying BM and disintegration of the lamellar BM. In some sections from feet affected by acute laminitis, there was widespread separation of the SELs from their BM without loss of BM immunostaining and in others there was extensive loss of BM immunostaining. In lesions characterised by lamellar separation, the epidermal basal cells at the tips of the primary epidermal lamellae appeared to have slipped away from their BM and were an amorphous clump of epidermal cells devoid of immunostained BM. The BM from which they had separated remained in its original position in the dermis and was clearly outlined by all 3 antibodies. In other areas, however, virtually all the BM immunoreactivity at the PEL tips was absent. Only the occasional distorted SEL tip and fragments of BM retained sufficient immunostaining to allow anatomical identification. Numerous polymorphonuclear leucocytes (PMNs) invariably surrounded the tips of lamellae showing large scale loss of immunoreactivity and many PMNs had penetrated the lamellar BM and were within the epidermal compartments. PMNs were less frequent in the midlamellar region. Immunostaining of the BM of many SELs was absent in the midlamellar region. In some lamellae loss of BM immunostaining had occurred only at the bases of the SELs and fragments of immunostained BM were present in the zones of lysed BM suggesting that BM lysis was incomplete at the time of tissue fixation. In other lamellae, lysis of the BM was complete; there was no immunostained BM between SELs and the bulk of the epidermal cells of each PEL were an amorphous column of cells on either side of the central keratinised axis of the PEL. The lamellar BM which remained appeared as immunostained strands of unattached BM along the edges of the PDLs. Activation of BM degrading metalloproteinases (MMPs) occurs in acute laminitis and it seems likely that uncontrolled MMP activity is responsible for the loss and disorganisation of lamellar BM demonstrated in this study.
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Affiliation(s)
- C C Pollitt
- School of Veterinary Science and Animal Production, University of Queensland, Brisbane, Australia
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25
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Singh P, Dai B, Given RL, Lu X, Holthuizen PE. Differential activation of IGF-II promoters P3 and P4 in Caco-2 cells during growth and differentiation. Gastroenterology 1998; 114:1221-9. [PMID: 9609759 DOI: 10.1016/s0016-5085(98)70428-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND & AIMS Insulin-like growth factor (IGF)-II gene is overexpressed in colon cancers. Transcriptional up-regulation may be the major mechanism contributing to its overexpression. IGF-II messenger RNA (mRNA) levels are up-regulated during proliferation followed by a significant decline during differentiation of Caco-2 cells. Mechanisms underlying transcriptional regulation of the IGF-II gene promoters (P1-P4) have yet to be examined in colon cancers, which was the basis for this study. METHODS Ribonuclease protection assay was used to measure IGF-II mRNA derived from P1-P4. To determine if changes in the IGF-II transcripts reflected differences in promoter activity, transient transfection assays with the full-length P1-P4-luciferase expression vectors were performed. RESULTS Both P3- and P4-derived transcripts were significantly up-regulated during the proliferative phase of the cells (days 3-6 in culture) and declined rapidly in cells undergoing differentiation (days 7-10); conversely, P1- and P2-derived transcripts were not detected. Similarly, transcriptional activity of P3 and P4 promoters reached peak levels by days 4-6 and declined rapidly thereafter. P1 and P2 were relatively inactive on all days. CONCLUSIONS The activity of the P3 and P4 promoters may play a selective role in regulating IGF-II mRNA levels during growth and differentiation of colon cancer cells.
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Affiliation(s)
- P Singh
- Department of Anatomy and Neurosciences, University of Texas Medical Branch, Galveston, USA.
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