1
|
Skalkos ZMG, Van Dyke JU, Dowland SN, Whittington CM. Paternal protein provisioning to embryos during male seahorse pregnancy. Reproduction 2024; 167:e230420. [PMID: 38377683 DOI: 10.1530/rep-23-0420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Accepted: 02/19/2024] [Indexed: 02/22/2024]
Abstract
In brief Seahorses exhibit male pregnancy and are thus valuable comparative models for the study of the physiology and evolution of pregnancy. This study shows that protein is transported from fathers to developing embryos during gestation, and provides new knowledge about paternal contributions to embryonic development. Abstract Syngnathid embryos (seahorses, pipefishes and seadragons) develop on or in the male in a specialised brooding structure (brood pouch). Seahorse brood pouches supply nutrients, including lipids, to developing embryos (patrotrophy). We tested the hypothesis that proteins, vital for gene regulation and tissue growth during embryogenesis, are also transported from father to embryos, using the Australian pot-bellied seahorse, Hippocampus abdominalis. We used dry masses and total nitrogen content to estimate the total protein content of newly fertilised egg and neonate H. abdominalis. Neonates contained significantly greater protein mass than newly fertilised eggs. This result indicates that paternal protein transport to developing embryos occurs during H. abdominalis pregnancy. This study is the first to show paternal protein transport during pregnancy in seahorses, and furthers our understanding of paternal influence on embryonic development in male pregnant vertebrates.
Collapse
Affiliation(s)
- Zoe M G Skalkos
- The University of Sydney, School of Life and Environmental Sciences, Sydney, NSW, Australia
| | - James U Van Dyke
- La Trobe University, Department of Environment and Genetics, School of Agriculture, Biomedicine and Environment, Wodonga, VIC, Australia
| | - Samson N Dowland
- The University of Sydney, School of Medical Sciences, Sydney, NSW, Australia
| | - Camilla M Whittington
- The University of Sydney, School of Life and Environmental Sciences, Sydney, NSW, Australia
| |
Collapse
|
2
|
Shankie-Williams KN, Ratcliffe SE, Dowland SN, Black K. User interest in a new non-hormonal long-acting reversible contraceptive: what impact does mechanism of action have on past and future contraceptive decision-making? BMJ Sex Reprod Health 2023; 49:43-48. [PMID: 36379701 DOI: 10.1136/bmjsrh-2022-201664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 11/03/2022] [Indexed: 06/16/2023]
Abstract
BACKGROUND We are in the process of developing a new non-hormonal long-acting reversible method of contraception (LARC) in recognition of the fact that a significant minority of users are unhappy with their current method. Our method has a novel (post-fertilisation) mechanism of action (MOA), but little is known about the value users place on this. METHODS Using in-depth interviews, we explored 30 Australian end-users' experiences of contraception, recruited via social media. A thematic approach was taken to examine the influence the MOA has on choice and factors affecting willingness to try current methods and a novel non-hormonal LARC with a post-fertilisation effect. RESULTS We identified two themes that were the most salient across all interviews: that contraceptive decision-making involves a trade-off of priorities, influenced by contraceptive properties (including MOA) and the context in which contraception is used; and views on novel methods of contraception were influenced by willingness to trial new products and interest in non-hormonal options. Side effects, efficacy, and the financial burden of contraceptives were all considered more important than MOA during decision-making. Participants were willing to try a new method if endorsed by trusted sources, including friends and medical practitioners, and were enthusiastic to try a novel LARC with no hormones. CONCLUSION This study found that the MOA had minimal impact on participants' choice of contraception. Rather, avoidance of hormones and side effects influenced willingness to try a novel method over any unacceptable aspects of a post-fertilisation MOA.
Collapse
Affiliation(s)
- Kirsten Norma Shankie-Williams
- School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia
| | - Sarah E Ratcliffe
- Centre for Medical Psychology & Evidence-based Decision-making, School of Psychology, Faculty of Science, The University of Sydney, Sydney, New South Wales, Australia
| | - Samson N Dowland
- School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia
| | - Kirsten Black
- Speciality of Obstetrics, Gynaecology and Neonatology, Faculty of Medicine and Health, Central Clinical School, The University of Sydney, Sydney, New South Wales, Australia
- Royal Prince Alfred Hospital, Sydney Local Health District, Sydney, New South Wales, Australia
| |
Collapse
|
3
|
Shankie-Williams K, Lindsay L, Murphy CR, Dowland SN. Zinc as a non-hormonal contraceptive: an alternative to the copper intrauterine device (IUD). Reproduction 2022; 164:135-142. [PMID: 35929835 DOI: 10.1530/rep-22-0155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Accepted: 08/05/2022] [Indexed: 11/08/2022]
Abstract
Long-acting and reversible contraceptives (LARC) are the most widely used form of female contraception worldwide, however they have significant side-effects that often result in early removal. Most LARCs are hormonal, but the use of exogenous hormones is not suitable for all women and causes side-effects in many others. The copper IUD (CuIUD) is the only non-hormonal LARC, but a large proportion of users suffer severe side effects. This study proposes the use of zinc as a suitable alternative to the CuIUD. A rat intrauterine device (IUD) model was established to test the efficacy of a zinc IUD (ZnIUD) against a CuIUD. The IUD was surgically implanted into one uterine horn while the other remained untreated. Both the ZnIUD and CuIUD resulted in zero implantation sites which was significantly fewer compared to non-treated horns. Histological assessment revealed damage and inflammation in the endometrium of CuIUD treated horns, but only minor epithelial changes in ZnIUD treated horns. This suggests ZnIUDs may not share the side-effect profile of the CuIUD. To test the long-term efficacy of the ZnIUD, rats had a ZnIUD surgically implanted into both horns and cohoused with males for 3 months. These rats mated regularly but did not get pregnant, confirming long-term effectiveness. Reversibility of the ZnIUD was also established, as removal of the ZnIUD after 3 months resulted in no significant difference in the number of implantation sites between treated and untreated horns. This study demonstrated the contraceptive efficacy of zinc and its potential as a LARC.
Collapse
Affiliation(s)
| | - Laura Lindsay
- L Lindsay, School of Medical Sciences, The University of Sydney, Sydney, Australia
| | - Christopher R Murphy
- C Murphy, School of Medical Sciences, The University of Sydney, Sydney, Australia
| | - Samson N Dowland
- S Dowland, School of Medical Sciences, The University of Sydney, Sydney, Australia
| |
Collapse
|
4
|
Dudley JS, Hannaford P, Dowland SN, Lindsay LA, Thompson MB, Murphy CR, Van Dyke JU, Whittington CM. Structural changes to the brood pouch of male pregnant seahorses (Hippocampus abdominalis) facilitate exchange between father and embryos. Placenta 2021; 114:115-123. [PMID: 34517263 DOI: 10.1016/j.placenta.2021.09.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Revised: 08/10/2021] [Accepted: 09/01/2021] [Indexed: 11/16/2022]
Abstract
INTRODUCTION Embryonic growth and development require efficient respiratory gas exchange. Internal incubation of developing young thus presents a significant physiological challenge, because respiratory gas diffusion to embryos is impeded by the additional barrier of parental tissue between the embryo and the environment. Therefore, live-bearing species exhibit a variety of adaptations facilitating respiratory gas exchange between the parent (usually the mother) and embryos. Syngnathid fishes are the only vertebrates to exhibit male pregnancy, allowing comparative studies of the biology and evolution of internal incubation of embryos, independent of the female reproductive tract. Here, we examine the fleshy, sealed, seahorse brood pouch, and provide the first quantification of structural changes to this gestational organ across pregnancy. METHODS We used histological analysis and morphometrics to quantify the surface area for exchange across the brood pouch epithelium, and the structure of the vascular bed of the brood pouch. RESULTS We show dramatic remodelling of gestational tissues as pregnancy progresses, including an increase in tortuosity of the gestational epithelium, an increase in capillary density, and a decrease in diffusion distance between capillaries and the pouch lumen. DISCUSSION These changes produce an increased surface area and expansion of the vascular bed of the placenta that likely facilitates respiratory gas exchange. These changes mirror the remodelling of gestational tissue in viviparous amniotes and elasmobranchs, and provide further evidence of the convergence of adaptations to support pregnancy in live-bearing animals.
Collapse
Affiliation(s)
- J S Dudley
- The University of Sydney, School of Life and Environmental Sciences, Sydney, NSW, Australia; Macquarie University, Department of Biological Sciences, Faculty of Science and Engineering, Macquarie Park, NSW, Australia
| | - P Hannaford
- The University of Sydney, School of Life and Environmental Sciences, Sydney, NSW, Australia
| | - S N Dowland
- The University of Sydney, School of Medical Sciences (Anatomy and Histology), Sydney, NSW, Australia
| | - L A Lindsay
- The University of Sydney, School of Medical Sciences (Anatomy and Histology), Sydney, NSW, Australia
| | - M B Thompson
- The University of Sydney, School of Life and Environmental Sciences, Sydney, NSW, Australia
| | - C R Murphy
- The University of Sydney, School of Life and Environmental Sciences, Sydney, NSW, Australia; The University of Sydney, School of Medical Sciences (Anatomy and Histology), Sydney, NSW, Australia
| | - J U Van Dyke
- La Trobe University, Department of Pharmacy and Biomedical Sciences, School of Molecular Sciences, Wodonga, Victoria, Australia
| | - C M Whittington
- The University of Sydney, School of Life and Environmental Sciences, Sydney, NSW, Australia.
| |
Collapse
|
5
|
Buddle AL, Van Dyke JU, Thompson MB, Simpfendorfer CA, Murphy CR, Dowland SN, Whittington CM. Structure of the paraplacenta and the yolk sac placenta of the viviparous Australian sharpnose shark, Rhizoprionodon taylori. Placenta 2021; 108:11-22. [PMID: 33780667 DOI: 10.1016/j.placenta.2021.03.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 03/08/2021] [Accepted: 03/14/2021] [Indexed: 12/15/2022]
Abstract
INTRODUCTION Viviparity (live-birth) has evolved from oviparity (egg-laying) multiple times in sharks. While most transitions from oviparity to viviparity have resulted in non-placental forms of viviparity, some sharks develop a yolk sac placenta during pregnancy. The Australian sharpnose shark (Rhizoprionodon taylori) is a placental species that suspends embryonic development in a diapause for most of pregnancy. METHODS To identify structures involved in supporting rapid embryonic growth in late pregnancy, we examined uterine and placental morphology by light and electron microscopy. RESULTS Paraplacental uterine regions have morphological specialisations consistent with secretion and fluid transport between uterine tissues and the lumen. Uterine secretions in the lumen may be absorbed by the outgrowths on the embryonic umbilical cord ('appendiculae'), which are densely covered by microvilli. The placenta consists of uterine villi that interdigitate with the yolk sac and enhance the surface area available for fetomaternal exchange. The yolk sac does not invade the uterine epithelium, and the egg capsule remains intact at the placental interface, separating maternal and fetal tissues. Some placental uterine epithelial cells are secretory, and endocytic vesicles in the opposing yolk sac ectodermal cells suggest that nutrient transport is by histotrophic uterine secretion followed by fetal absorption. Respiratory gases, water and possibly small nutrients likely diffuse across the placenta, where maternal and fetal blood vessels are ~2 μm apart. DISCUSSION Placental structure in R. taylori is similar to most other sharks, but there are differences in cellular structures between species that may indicate species-specific placental transport mechanisms.
Collapse
Affiliation(s)
- Alice L Buddle
- School of Life and Environmental Sciences, The University of Sydney, Heydon-Laurence Building (A08), Sydney, NSW, 2006, Australia
| | - James U Van Dyke
- Department of Pharmacy and Biomedical Science, School of Molecular Sciences, La Trobe University, Wodonga, Victoria, Australia
| | - Michael B Thompson
- School of Life and Environmental Sciences, The University of Sydney, Heydon-Laurence Building (A08), Sydney, NSW, 2006, Australia
| | - Colin A Simpfendorfer
- College of Science of Engineering, James Cook University, Townsville, Queensland, Australia
| | - Christopher R Murphy
- School of Medical Sciences (Anatomy and Histology), The University of Sydney, Sydney, New South Wales, Australia
| | - Samson N Dowland
- School of Medical Sciences (Anatomy and Histology), The University of Sydney, Sydney, New South Wales, Australia
| | - Camilla M Whittington
- School of Life and Environmental Sciences, The University of Sydney, Heydon-Laurence Building (A08), Sydney, NSW, 2006, Australia.
| |
Collapse
|
6
|
Bromfield EG, Dowland SN, Dunleavy JEM, Dunning KR, Holland OJ, Houston BJ, Pankhurst MW, Richani D, Riepsamen AH, Rose R, Bertoldo MJ. Fifty years of reproductive biology in Australia: highlights from the 50th Annual Meeting of the Society for Reproductive Biology (SRB). Reprod Fertil Dev 2019; 31:829-836. [PMID: 30636191 DOI: 10.1071/rd18436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 12/03/2018] [Indexed: 11/23/2022] Open
Abstract
The 2018 edition of the Society for Reproductive Biology's (SRB) Annual Meeting was a celebration of 50 years of Australian research into reproductive biology. The past 50 years has seen many important contributions to this field, and these advances have led to changes in practice and policy, improvements in the efficiency of animal reproduction and improved health outcomes. This conference review delivers a dedicated summary of the symposia, discussing emerging concepts, raising new questions and proposing directions forward. Notably, the symposia discussed in this review emphasised the impact that reproductive research can have on quality of life and the health trajectories of individuals. The breadth of the research discussed encompasses the central regulation of fertility and cyclicity, life course health and how the environment of gametes and embryos can affect subsequent generations, significant advances in our understanding of placental biology and pregnancy disorders and the implications of assisted reproductive technologies on population health. The importance of a reliable food supply and protection of endangered species is also discussed. The research covered at SRB's 2018 meeting not only recognised the important contributions of its members over the past 50 years, but also highlighted key findings and avenues for innovation moving forward that will enable the SRB to continue making significant contributions for the next 50 years.
Collapse
Affiliation(s)
- Elizabeth G Bromfield
- Priority Research Centre for Reproductive Science, School of Environmental and Life Sciences, The University of Newcastle, NSW 2308, Australia
| | - Samson N Dowland
- School of Medical Sciences (Discipline of Anatomy and Histology) and The Bosch Institute, F13 Anderson Stuart Building, The University of Sydney, Sydney, NSW 2006, Australia
| | | | - Kylie R Dunning
- Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, University of Adelaide, SA 5005, Australia
| | - Olivia J Holland
- School of Medical Science, Griffith University, Gold Coast Campus, Southport, Qld 5005, Australia
| | - Brendan J Houston
- School of Biological Sciences, Monash University, Clayton, Vic. 3168, Australia
| | - Michael W Pankhurst
- Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin 9054, New Zealand
| | - Dulama Richani
- Fertility and Research Centre, School of Women's and Children's Health, UNSW, Randwick 2052, NSW 4222, Australia
| | - Angelique H Riepsamen
- Fertility and Research Centre, School of Women's and Children's Health, UNSW, Randwick 2052, NSW 4222, Australia
| | - Ryan Rose
- Robinson Research Institute, Adelaide Medical School, University of Adelaide, Adelaide, SA 5005, Australia
| | - Michael J Bertoldo
- Fertility and Research Centre, School of Women's and Children's Health, UNSW, Randwick 2052, NSW 4222, Australia
| |
Collapse
|
7
|
Dowland SN, Madawala RJ, Poon CE, Lindsay LA, Murphy CR. Prominin-1 glycosylation changes throughout early pregnancy in uterine epithelial cells under the influence of maternal ovarian hormones. Reprod Fertil Dev 2018; 29:1194-1208. [PMID: 27166505 DOI: 10.1071/rd15432] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Accepted: 03/17/2016] [Indexed: 12/29/2022] Open
Abstract
In preparation for uterine receptivity, the uterine epithelial cells (UECs) exhibit a loss of microvilli and glycocalyx and a restructuring of the actin cytoskeleton. The prominin-1 protein contains large, heavily glycosylated extracellular loops and is usually restricted to apical plasma membrane (APM) protrusions. The present study examined rat UECs during early pregnancy using immunofluorescence, western blotting and deglycosylation analyses. Ovariectomised rats were injected with oestrogen and progesterone to examine how these hormones affect prominin-1. At the time of fertilisation, prominin-1 was located diffusely in the apical domain of UECs and 147- and 120-kDa glycoforms of prominin-1 were identified, along with the 97-kDa core protein. At the time of implantation, prominin-1 concentrates towards the APM and densitometry revealed that the 120-kDa glycoform decreased (P<0.05), but there was an increase in the 97-kDa core protein (P<0.05). Progesterone treatment of ovariectomised rats resulted in prominin-1 becoming concentrated towards the APM. The 120-kDa glycoform was increased after oestrogen treatment (P<0.0001), whereas the 97-kDa core protein was increased after progesterone treatment (P<0.05). Endoglycosidase H analysis demonstrated that the 120-kDa glycoform is in the endoplasmic reticulum, undergoing protein synthesis. These results indicate that oestrogen stimulates prominin-1 production, whereas progesterone stimulates the deglycosylation and concentration of prominin-1 to the apical region of the UECs. This likely presents the deglycosylated extracellular loops of prominin-1 to the extracellular space, where they may interact with the implanting blastocyst.
Collapse
Affiliation(s)
- Samson N Dowland
- Cell and Reproductive Biology Laboratory, School of Medical Sciences (Discipline of Anatomy and Histology) and The Bosch Institute, Room N364, F13 Anderson Stuart Building, The University of Sydney, NSW 2006, Australia
| | - Romanthi J Madawala
- Cell and Reproductive Biology Laboratory, School of Medical Sciences (Discipline of Anatomy and Histology) and The Bosch Institute, Room N364, F13 Anderson Stuart Building, The University of Sydney, NSW 2006, Australia
| | - Connie E Poon
- Cell and Reproductive Biology Laboratory, School of Medical Sciences (Discipline of Anatomy and Histology) and The Bosch Institute, Room N364, F13 Anderson Stuart Building, The University of Sydney, NSW 2006, Australia
| | - Laura A Lindsay
- Cell and Reproductive Biology Laboratory, School of Medical Sciences (Discipline of Anatomy and Histology) and The Bosch Institute, Room N364, F13 Anderson Stuart Building, The University of Sydney, NSW 2006, Australia
| | - Christopher R Murphy
- Cell and Reproductive Biology Laboratory, School of Medical Sciences (Discipline of Anatomy and Histology) and The Bosch Institute, Room N364, F13 Anderson Stuart Building, The University of Sydney, NSW 2006, Australia
| |
Collapse
|
8
|
Danastas K, Whittington CM, Dowland SN, Combes V, Murphy CR, Lindsay LA. Ovarian Hyperstimulation Reduces Vascular Endothelial Growth Factor-A During Uterine Receptivity. Reprod Sci 2018; 26:259-268. [PMID: 29621956 DOI: 10.1177/1933719118768703] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The angiogenic factor vascular endothelial growth factor-A (VEGFA) plays a critical role during early pregnancy in many species including the rat, and any alterations in VEGFA levels can severely impact blastocyst implantation rates. The rat ovarian hyperstimulation (OH) model is useful in studying how the induction of superovulation affects VEGFA levels and endometrial receptivity to blastocyst implantation. The present study shows that the major isoform in the rat uterus, Vegf188, is reduced at the time of receptivity in OH compared to normal pregnancy, whereas there is no change in Vegf164 and Vegf120 messenger RNA (mRNA). The VEGFA receptor 2 (VEGFR2) protein levels are also reduced at the time of receptivity in OH. Our ovariectomy studies show that Vegf164, Vegf188, and Vegf120 are significantly decreased by estrogen, and, to a lesser extent progesterone, when compared to control animals. Although no change in the percentage of endometrial blood vessels was seen across all stages of pregnancy, at the time of receptivity in OH pregnancies, blood vessels were typically larger compared to other stages. The altered progesterone-estrogen ratio seen in OH, taken together with our ovariectomy studies, explains the changes to Vegfa mRNA in OH at the time of receptivity. Since VEGFA is important during implantation, the changes to Vegfa and VEGFR2 levels in the endometrium may help explain the observed lower endometrial receptivity following OH. This study aimed to analyse how ovarian hyperstimulation alters the levels of vascular endothleial growth factor and its major receptor, VEGFR2 in the uterus in a rat model.
Collapse
Affiliation(s)
- Kevin Danastas
- 1 Anatomy and Histology, School of Medical Sciences, Bosch Institute, University of Sydney, Sydney, New South Wales, Australia
| | - Camilla M Whittington
- 2 School of Life and Environmental Sciences, University of Sydney, Sydney, New South Wales, Australia
| | - Samson N Dowland
- 1 Anatomy and Histology, School of Medical Sciences, Bosch Institute, University of Sydney, Sydney, New South Wales, Australia
| | - Valery Combes
- 3 School of Life Sciences, The University of Technology Sydney, Sydney, New South Wales, Australia
| | - Christopher R Murphy
- 1 Anatomy and Histology, School of Medical Sciences, Bosch Institute, University of Sydney, Sydney, New South Wales, Australia
| | - Laura A Lindsay
- 1 Anatomy and Histology, School of Medical Sciences, Bosch Institute, University of Sydney, Sydney, New South Wales, Australia
| |
Collapse
|
9
|
Dowland SN, Madawala RJ, Poon CE, Lindsay LA, Murphy CR. Prominin-2 Prevents the Formation of Caveolae in Normal and Ovarian Hyperstimulated Pregnancy. Reprod Sci 2017; 25:1231-1242. [PMID: 29113580 DOI: 10.1177/1933719117737842] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
During early pregnancy, uterine epithelial cells (UECs) become less adherent to the underlying basal lamina and are subsequently removed so the blastocyst can invade the underlying stroma. This process involves the removal of focal adhesions from the basal plasma membrane of UECs. These focal adhesions are thought to be internalized by caveolae, which significantly increase in abundance at the time of blastocyst implantation. A recent in vitro study indicated that prominin-2 prevents the formation of caveolae by sequestering membrane cholesterol. The present study examines whether prominin-2 affects the formation of caveolae and loss of focal adhesions in UECs during normal and ovarian hyperstimulation (OH) pregnancy in the rat. At the time of fertilization during normal pregnancy, prominin-2 is distributed throughout the basolateral plasma membrane. However, at the time of implantation and coincident with an increase in caveolae, prominin-2 is lost from the basal plasma membrane. In contrast, prominin-2 remains in the basolateral plasma membrane throughout OH pregnancy. Transmission electron microscopy showed that this membrane contained few caveolae throughout OH pregnancy. Our results indicate that prominin-2 prevents the formation of caveolae. We suggest the retention of prominin-2 in the basal plasma membrane during OH pregnancy prevents the formation of caveolae and is responsible for the retention of focal adhesions in this membrane, thereby contributing to the reduced implantation rate observed after such treatments.
Collapse
Affiliation(s)
- Samson N Dowland
- 1 Cell and Reproductive Biology Laboratory, School of Medical Sciences (Discipline of Anatomy and Histology) and The Bosch Institute, The University of Sydney, Sydney, New South Wales, Australia
| | - Romanthi J Madawala
- 1 Cell and Reproductive Biology Laboratory, School of Medical Sciences (Discipline of Anatomy and Histology) and The Bosch Institute, The University of Sydney, Sydney, New South Wales, Australia
| | - Connie E Poon
- 1 Cell and Reproductive Biology Laboratory, School of Medical Sciences (Discipline of Anatomy and Histology) and The Bosch Institute, The University of Sydney, Sydney, New South Wales, Australia
| | - Laura A Lindsay
- 1 Cell and Reproductive Biology Laboratory, School of Medical Sciences (Discipline of Anatomy and Histology) and The Bosch Institute, The University of Sydney, Sydney, New South Wales, Australia
| | - Christopher R Murphy
- 1 Cell and Reproductive Biology Laboratory, School of Medical Sciences (Discipline of Anatomy and Histology) and The Bosch Institute, The University of Sydney, Sydney, New South Wales, Australia
| |
Collapse
|
10
|
Poon CE, Madawala RJ, Dowland SN, Murphy CR. Nectin-3 Is Increased in the Cell Junctions of the Uterine Epithelium at Implantation. Reprod Sci 2016; 23:1580-1592. [DOI: 10.1177/1933719116648216] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Connie E. Poon
- Cell and Reproductive Biology Laboratory, School of Medical Sciences (Discipline of Anatomy and Histology), The University of Sydney, Sydney, New South Wales, Australia
- The Bosch Institute, The University of Sydney, Sydney, New South Wales, Australia
| | - Romanthi J. Madawala
- Cell and Reproductive Biology Laboratory, School of Medical Sciences (Discipline of Anatomy and Histology), The University of Sydney, Sydney, New South Wales, Australia
- The Bosch Institute, The University of Sydney, Sydney, New South Wales, Australia
| | - Samson N. Dowland
- Cell and Reproductive Biology Laboratory, School of Medical Sciences (Discipline of Anatomy and Histology), The University of Sydney, Sydney, New South Wales, Australia
- The Bosch Institute, The University of Sydney, Sydney, New South Wales, Australia
| | - Christopher R. Murphy
- Cell and Reproductive Biology Laboratory, School of Medical Sciences (Discipline of Anatomy and Histology), The University of Sydney, Sydney, New South Wales, Australia
- The Bosch Institute, The University of Sydney, Sydney, New South Wales, Australia
| |
Collapse
|
11
|
Lindsay LA, Dowland SN, Murphy CR. Uterine focal adhesions are retained at implantation after rat ovarian hyperstimulation. Reproduction 2016; 152:753-763. [PMID: 27651522 DOI: 10.1530/rep-16-0331] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 09/19/2016] [Indexed: 11/08/2022]
Abstract
Controlled ovarian hyperstimulation is an essential component of IVF techniques to ensure proliferation and development of multiple ovarian follicles, but the effects of these hormones on the endometrium are largely unknown. During normal pregnancy in rats, there are significant changes in the basal plasma membrane of uterine epithelial cells (UECs) at the time of receptivity, including loss of focal adhesions. This enables the UECs to be removed from the implantation chamber surrounding the blastocyst, thus allowing invasion into the underlying stroma. This study investigated the influence of ovarian hyperstimulation (OH) on the basal plasma membrane of UECs during early pregnancy in the rat. Immunofluorescence results demonstrate the presence of paxillin, talin, integrin β1 and phosphorylated FAK (Y397FAK) in the basal portion of UECs at the time of implantation in OH pregnancy. TEM analysis demonstrated a flattened basal lamina and the presence of focal adhesions on the basal surface at this time in OH pregnancy. Significantly low full-length paxillin, high paxillin δ and integrin β1 were seen at the time of implantation in OH compared with those in normal pregnancy. The increase in paxillin δ suggests that these cells are less mobile, whereas the increase in integrin β1 and Y397FAK suggests the retention of a stable FA complex. Taken together with the increase in morphological focal adhesions, this represents a cell type that is stable and less easily removed for blastocyst implantation. This may be one mechanism explaining lower implantation rates after fresh embryo transfers compared with frozen cycles.
Collapse
Affiliation(s)
- Laura A Lindsay
- School of Medical Sciences (Anatomy and Histology)The University of Sydney, Sydney, New South Wales, Australia
| | - Samson N Dowland
- School of Medical Sciences (Anatomy and Histology)The University of Sydney, Sydney, New South Wales, Australia
| | - Christopher R Murphy
- School of Medical Sciences (Anatomy and Histology)The University of Sydney, Sydney, New South Wales, Australia
| |
Collapse
|
12
|
Dowland SN, Madawala RJ, Lindsay LA, Murphy CR. The adherens junction is lost during normal pregnancy but not during ovarian hyperstimulated pregnancy. Acta Histochem 2016; 118:137-43. [PMID: 26738975 DOI: 10.1016/j.acthis.2015.12.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Revised: 12/15/2015] [Accepted: 12/15/2015] [Indexed: 12/20/2022]
Abstract
During early pregnancy in the rat, the luminal uterine epithelial cells (UECs) must transform to a receptive state to permit blastocyst attachment and implantation. The implantation process involves penetration of the epithelial barrier, so it is expected that the transformation of UECs includes alterations in the lateral junctional complex. Previous studies have demonstrated a deepening of the tight junction (zonula occludens) and a reduction in the number of desmosomes (macula adherens) in UECs at the time of implantation. However, the adherens junction (zonula adherens), which is primarily responsible for cell-cell adhesion, has been little studied during early pregnancy. This study investigated the adherens junction in rat UECs during the early stages of normal pregnancy and ovarian hyperstimulated (OH) pregnancy using transmission electron microscopy. The adherens junction is present in UECs at the time of fertilisation, but is lost at the time of blastocyst implantation during normal pregnancy. Interestingly, at the time of implantation after OH, adherens junctions are retained and may impede blastocyst penetration of the epithelium. The adherens junction anchors the actin-based terminal web, which is known to be disrupted in UECs during early pregnancy. However, artificial disruption of the terminal web, using cytochalasin D, did not cause removal of the adherens junction in UECs. This study revealed that adherens junction disassembly occurs during early pregnancy, but that this process does not occur during OH pregnancy. Such disassembly does not appear to depend on the disruption of the terminal web.
Collapse
|
13
|
Madawala RJ, Poon CE, Dowland SN, Murphy CR. Actin crosslinking protein filamin A during early pregnancy in the rat uterus. Reprod Fertil Dev 2016; 28:960-968. [DOI: 10.1071/rd14240] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Accepted: 11/13/2014] [Indexed: 02/01/2023] Open
Abstract
During early pregnancy the endometrium undergoes a major transformation in order for it to become receptive to blastocyst implantation. The actin cytoskeleton and plasma membrane of luminal uterine epithelial cells (UECs) and the underlying stromal cells undergo dramatic remodelling to facilitate these changes. Filamin A (FLNA), a protein that crosslinks actin filaments and also mediates the anchorage of membrane proteins to the actin cytoskeleton, was investigated in the rat uterus at fertilisation (Day 1) and implantation (Day 6) to determine the role of FLNA in actin cytoskeletal remodelling of UECs and decidua during early pregnancy. Localisation of FLNA in UECs at the time of fertilisation was cytoplasmic, whilst at implantation it was distributed apically; its localisation is under the influence of progesterone. FLNA was also concentrated to the first two to three stromal cell layers at the time of fertilisation and shifted to the primary decidualisation zone at the time of implantation. This shift in localisation was found to be dependent on the decidualisation reaction. Protein abundance of the FLNA 280-kDa monomer and calpain-cleaved fragment (240 kDa) did not change during early pregnancy in UECs. Since major actin cytoskeletal remodelling occurs during early pregnancy in UECs and in decidual cells, the changing localisation of FLNA suggests that it may be an important regulator of cytoskeletal remodelling of these cells to allow uterine receptivity and decidualisation necessary for implantation in the rat.
Collapse
|