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Dagilgan S, Dundar-Yenilmez E, Tuli A, Urunsak IF, Erdogan S. Acidosis defense mechanisms in the preimplantation stages of embryos in BALB/c strain mice. Theriogenology 2024; 217:136-142. [PMID: 38277795 DOI: 10.1016/j.theriogenology.2024.01.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 01/17/2024] [Accepted: 01/17/2024] [Indexed: 01/28/2024]
Abstract
Regulation of intracellular pH (pHi) is an important homeostatic function of cells. There are three major pHi regulatory mechanisms: the HCO3-/Cl- exchanger (AE), which alleviates alkalosis, and the Na+/H+ exchanger (NHE) and Na+,HCO3-/Cl- exchanger (NDBCE), both of which counteract acidosis. NHE activity, which is high at the germinal vesicle stage of oocyte, is inhibited during meiotic maturation, while this inhibition is abolished when the oocyte reaches the pronuclear (PN) stage of the zygote. On the other hand, we have previously found that NDBCE performs complementary regulation against acidosis during meiotic maturation. Additionally, we found that AE activity, which is a defense mechanism against alkalosis, gradually decreases during preimplantation period of embryonic development. Considering that NHE activity is inhibited during meiotic maturation and AE activity gradually decreases during embryonic development stages, we investigated whether NHE and NDBCE activities, both of which act against acidosis, functionally change from the PN zygote to the blastocyst stage of the embryo and identified these pH-regulating proteins at the molecular level in mice of the Balb/c strain. PN zygotes, two-cell (2-c), four-cell (4-c), morula and blastocyst stage embryos were obtained from 5-8-week-old, sexually mature female Balb/c mice by using the classical superovulation procedure. pHi was recorded by using the microspectrofluorometric technique on zygotes and embryos simultaneously loaded with the pH-sensitive fluorophore, 2',7'-Bis(2-carboxyethyl)-5(6)-carboxyfluorescein (BCECF). The activities of NHE and NDBCE were determined from the recovery curve of induced-acidosis in bicarbonate-free and bicarbonate-containing media, respectively. Specific inhibitors such as cariporide (1 μM), S3226 (1 and 10 μM), EIPA (1, 5, and 25 μM), and amiloride (1 mM) were used to functionally identify NHE isoforms, and the nonspecific inhibitor 4,4'-diisocyanatostilbene-2,2' disulphonic acid, disodium salt (DIDS) was used to confirm NDBCE activity. The isoforms of the pHi-regulatory proteins were also identified by molecular biology using real-time PCR. We found that NHE activity was high at all embryonic stages, and differences between stages were not significant. Functional and molecular findings indicated that isoforms of NHE 1 and 5 are present in the blastocyst, whereas isoforms of NHE 1, 3, and 4 are functional at earlier embryonic stages. Although the contribution of NDBCE activity to recovery from induced-acidosis was detected at all embryonic stages, it was significant only in the PN zygote and the 2-c embryo. This finding was confirmed by molecular analysis, which detected the expression of SLC4A8 encoding NDBCE at all embryonic stages. In conclusion, NHE is an active and important defense mechanism against acidosis and is encoded by at least two protein isoforms in all stages of the Balb/c strain of mice. NDBCE has a supportive function in all embryonic stages, especially in the PN zygote and the 2-c embryo. Preimplantation stage embryos have effective mechanisms to defend against acidosis in response to their metabolic end products (increased acid load) and the acidic environment in utero.
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Affiliation(s)
- Senay Dagilgan
- Cukurova University Faculty of Medicine, Departments of Physiology, Balcali, 01330, Adana, Turkey
| | - Ebru Dundar-Yenilmez
- Cukurova University Faculty of Medicine, Biochemistry, Balcali, 01330, Adana, Turkey
| | - Abdullah Tuli
- Cukurova University Faculty of Medicine, Biochemistry, Balcali, 01330, Adana, Turkey
| | - Ibrahim Ferhat Urunsak
- Cukurova University Faculty of Medicine, Obstetric and Gynaecology, Balcali, 01330, Adana, Turkey
| | - Seref Erdogan
- Cukurova University Faculty of Medicine, Departments of Physiology, Balcali, 01330, Adana, Turkey.
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Tscherner AK, Macaulay AD, Ortman CS, Baltz JM. Initiation of cell volume regulation and unique cell volume regulatory mechanisms in mammalian oocytes and embryos. J Cell Physiol 2021; 236:7117-7133. [PMID: 33634482 DOI: 10.1002/jcp.30352] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 02/09/2021] [Accepted: 02/17/2021] [Indexed: 11/07/2022]
Abstract
The period beginning with the signal for ovulation, when a fully-grown oocyte progresses through meiosis to become a mature egg that is fertilized and develops as a preimplantation embryo, is crucial for healthy development. The early preimplantation embryo is unusually sensitive to cell volume perturbations, with even moderate decreases in volume or dysregulation of volume-regulatory mechanisms resulting in developmental arrest. To prevent this, early embryos possess mechanisms of cell volume control that are apparently unique to them. These rely on the accumulation of glycine and betaine (N, N, N-trimethylglycine) as organic osmolytes-compounds that can provide intracellular osmotic support without the deleterious effects of inorganic ions. Preimplantation embryos also have the same mechanisms as somatic cells that mediate rapid responses to deviations in cell volume, which rely on inorganic ion transport. Both the unique, embryo-specific mechanisms that use glycine and betaine and the inorganic ion-dependent mechanisms undergo major changes during meiotic maturation and preimplantation development. The most profound changes occur immediately after ovulation is triggered. Before this, oocytes cannot regulate their volume, since they are strongly attached to their rigid extracellular matrix shell, the zona pellucida. After ovulation is triggered, the oocyte detaches from the zona pellucida and first becomes capable of independent volume regulation. A complex set of developmental changes in each cell volume-regulatory mechanism continues through egg maturation and preimplantation development. The unique cell volume-regulatory mechanisms in eggs and preimplantation embryos and the developmental changes they undergo appear critical for normal healthy embryo development.
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Affiliation(s)
- Allison K Tscherner
- Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
- Department of Obstetrics and Gynecology, University of Ottawa, Ottawa, Ontario, Canada
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Angus D Macaulay
- Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
- Department of Obstetrics and Gynecology, University of Ottawa, Ottawa, Ontario, Canada
| | - Chyna S Ortman
- Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
- Department of Obstetrics and Gynecology, University of Ottawa, Ottawa, Ontario, Canada
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Jay M Baltz
- Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
- Department of Obstetrics and Gynecology, University of Ottawa, Ottawa, Ontario, Canada
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada
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Wang C, Guo F, Li H, Xu J, Hu J, Liu H, Wang M. A porous ionic polymer bionic carrier in a mixed matrix membrane for facilitating selective CO2 permeability. J Memb Sci 2020. [DOI: 10.1016/j.memsci.2019.117677] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Dagilgan S, Dundar-Yenilmez E, Tuli A, Urunsak IF, Erdogan S. Evaluation of intracellular pH regulation and alkalosis defense mechanisms in preimplantation embryos. Theriogenology 2015; 83:1075-84. [DOI: 10.1016/j.theriogenology.2014.12.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Revised: 12/02/2014] [Accepted: 12/06/2014] [Indexed: 10/24/2022]
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Zhou C, Fitzharris G, Alper SL, Baltz JM. Na+/H+exchange is inactivated during mouse oocyte meiosis, facilitating glycine accumulation that maintains embryo cell volume. J Cell Physiol 2013; 228:2042-53. [DOI: 10.1002/jcp.24370] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Accepted: 03/20/2013] [Indexed: 11/07/2022]
Affiliation(s)
| | | | - Seth L. Alper
- Renal Division and Molecular and Vascular Medicine Division, Beth Israel Deaconess Medical Center; Department of Medicine, Harvard Medical School; Boston; Massachusetts
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Baltz JM, Zhou C. Cell volume regulation in mammalian oocytes and preimplantation embryos. Mol Reprod Dev 2012; 79:821-31. [DOI: 10.1002/mrd.22117] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Accepted: 09/17/2012] [Indexed: 11/06/2022]
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Erdogan S, Cetinkaya A, Tuli A, Yilmaz ED, Dogan A. Changes in the activity of defense mechanisms against induced acidosis during meiotic maturation in mouse oocytes. Theriogenology 2011; 75:1057-66. [DOI: 10.1016/j.theriogenology.2010.11.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2009] [Revised: 11/08/2010] [Accepted: 11/09/2010] [Indexed: 10/18/2022]
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Hentemann M, Mousavi K, Bertheussen K. Differential pH in embryo culture. Fertil Steril 2010; 95:1291-4. [PMID: 21067724 DOI: 10.1016/j.fertnstert.2010.10.018] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2009] [Revised: 08/30/2010] [Accepted: 10/13/2010] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To determine the optimum pH in sequential media for embryo culture around the fertilization-zygote stage and cleavage stage, with use of a mouse embryo assay. DESIGN Experimental laboratory study. SETTING University Hospital and University Research Unit. ANIMAL(S) F1 hybrids between CD1 female and BDF male mice. INTERVENTION(S) Fertilized, one-cell mouse embryos were cultured 5 days in test media where pH was changed at defined time intervals. MAIN OUTCOME MEASURE(S) Percentage of good-quality embryos, defined by strict morphology. RESULT(S) A significantly improved development was observed when pH was as high as 7.30 before the pronuclear stage and lowered to pH 7.15 during the cleavage period. CONCLUSION(S) Good embryo development is consistent with two different pH values in sequential culture media. This could have important implications for embryo culture in human IVF.
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Affiliation(s)
- Martha Hentemann
- Department of Obstetrics and Gynecology, IVF Unit, University Hospital of Northern Norway, Tromsø, Norway
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Zhou C, Tiberi M, Liang B, Alper SL, Baltz JM. HCO3(-)/Cl(-) exchange inactivation and reactivation during mouse oocyte meiosis correlates with MEK/MAPK-regulated Ae2 plasma membrane localization. PLoS One 2009; 4:e7417. [PMID: 19823673 PMCID: PMC2757902 DOI: 10.1371/journal.pone.0007417] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2009] [Accepted: 09/16/2009] [Indexed: 11/18/2022] Open
Abstract
Background Germinal Vesicle (GV) stage mouse oocytes in first meiotic prophase exhibit highly active HCO3−/Cl− exchange—a class of transport nearly ubiquitously involved in regulation of intracellular pH and cell volume. During meiosis, however, oocyte HCO3−/Cl− exchange becomes inactivated during first metaphase (MI), remains inactive in second metaphase (MII), and is reactivated only after egg activation. Previous work using pharmacological manipulations had indicated that activity of the MEK/MAPK signaling pathway was negatively correlated with HCO3−/Cl− exchange activity during meiosis. However, the mechanism by which the exchanger is inactivated during meiotic progression had not been determined, nor had the role of MEK/MAPK been directly established. Methodology/Principal Findings Expression of a constitutively active form of MEK (MAP kinase kinase), which prevented the normal downregulation of MAPK after egg activation, also prevented reactivation of HCO3−/Cl− exchange. Conversely, suppression of endogenous MAPK activity with dominant negative MEK activated the normally quiescent HCO3−/Cl− exchange in mature MII eggs. A GFP-tagged form of the HCO3−/Cl− exchanger isoform Ae2 (Slc4a2) was strongly expressed at the GV oocyte plasma membrane, but membrane localization decreased markedly during meiotic progression. A similar pattern for endogenous Ae2 was confirmed by immunocytochemistry. The loss of membrane-localized Ae2 appeared selective, since membrane localization of a GFP-tagged human dopamine D1 receptor did not change during meiotic maturation. Conclusions Direct manipulation of MAPK activity indicated that GFP-tagged Ae2 localization depended upon MAPK activity. Inactivation of HCO3−/Cl− exchange during the meiotic cell cycle may therefore reflect the loss of Ae2 from the oocyte plasma membrane, downstream of MEK/MAPK signaling. This identifies a novel role for MEK/MAPK-mediated cytostatic factor (CSF) activity during meiosis in membrane protein trafficking in mouse oocytes, and shows for the first time that selective retrieval of membrane proteins is a feature of meiosis in mammalian oocytes.
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Affiliation(s)
- Chenxi Zhou
- Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
- Division of Reproductive Medicine, Department of Obstetrics and Gynecology, University of Ottawa Faculty of Medicine, Ottawa, Ontario, Canada
| | - Mario Tiberi
- Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
- Department of Cellular and Molecular Medicine, University of Ottawa Faculty of Medicine, Ottawa, Ontario, Canada
- Departments of Psychiatry and Medicine, University of Ottawa Faculty of Medicine, Ottawa, Ontario, Canada
| | - Binhui Liang
- Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
- Department of Cellular and Molecular Medicine, University of Ottawa Faculty of Medicine, Ottawa, Ontario, Canada
- Departments of Psychiatry and Medicine, University of Ottawa Faculty of Medicine, Ottawa, Ontario, Canada
| | - Seth L. Alper
- Molecular and Vascular Medicine Unit and Renal Division, Beth Israel Deaconess Medical Center, and Department of Medicine, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Jay M. Baltz
- Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
- Division of Reproductive Medicine, Department of Obstetrics and Gynecology, University of Ottawa Faculty of Medicine, Ottawa, Ontario, Canada
- Department of Cellular and Molecular Medicine, University of Ottawa Faculty of Medicine, Ottawa, Ontario, Canada
- * E-mail:
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FitzHarris G, Baltz JM. Regulation of intracellular pH during oocyte growth and maturation in mammals. Reproduction 2009; 138:619-27. [PMID: 19520797 DOI: 10.1530/rep-09-0112] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Regulation of intracellular pH (pH(i)) is a fundamental homeostatic process essential for the survival and proliferation of virtually all cell types. The mammalian preimplantation embryo, for example, possesses Na(+)/H(+) and HCO(3)(-)/Cl(-) exchangers that robustly regulate against acidosis and alkalosis respectively. Inhibition of these transporters prevents pH corrections and, perhaps unsurprisingly, leads to impaired embryogenesis. However, recent studies have revealed that the role and regulation of pH(i) is somewhat more complex in the case of the developing and maturing oocyte. Small meiotically incompetent growing oocytes are apparently incapable of regulating their own pH(i), and instead rely upon the surrounding granulosa cells to correct ooplasmic pH, until such a time that the oocyte has developed the capacity to regulate its own pH(i). Later, during meiotic maturation, pH(i)-regulating activities that were developed during growth are inactivated, apparently under the control of MAPK signalling, until the oocyte is successfully fertilized. Here, we will discuss pH homeostasis in early mammalian development, focussing on recent developments highlighting the unusual and unexpected scenario of pH regulation during oocyte growth and maturation.
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Affiliation(s)
- Greg FitzHarris
- Institute for Women's Health, University College London, 86-96 Chenies Mews, London WC1E 6HX, UK
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