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Hong J, Tong H, Wang X, Lv X, He L, Yang X, Wang Y, Xu K, Liang Q, Feng Q, Niu T, Niu X, Lu Y. Embryonic diapause due to high glucose is related to changes in glycolysis and oxidative phosphorylation, as well as abnormalities in the TCA cycle and amino acid metabolism. Front Endocrinol (Lausanne) 2023; 14:1135837. [PMID: 38170036 PMCID: PMC10759208 DOI: 10.3389/fendo.2023.1135837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/01/2023] [Accepted: 11/08/2023] [Indexed: 01/05/2024] Open
Abstract
Introduction The adverse effects of high glucose on embryos can be traced to the preimplantation stage. This study aimed to observe the effect of high glucose on early-stage embryos. Methods and results Seven-week-old ICR female mice were superovulated and mated, and the zygotes were collected. The zygotes were randomly cultured in 5 different glucose concentrations (control, 20mM, 40mM, 60mM and 80mM glucose). The cleavage rate, blastocyst rate and total cell number of blastocyst were used to assess the embryo quality. 40 mM glucose was selected to model high glucose levels in this study. 40mM glucose arrested early embryonic development, and the blastocyst rate and total cell number of the blastocyst decreased significantly as glucose concentration was increased. The reduction in the total cell number of blastocysts in the high glucose group was attributed to decreased proliferation and increased cell apoptosis, which is associated with the diminished expression of GLUTs (GLUT1, GLUT2, GLUT3). Furthermore, the metabolic characterization of blastocyst culture was observed in the high-glucose environment. Discussion The balance of glycolysis and oxidative phosphorylation at the blastocyst stage was disrupted. And embryo development arrest due to high glucose is associated with changes in glycolysis and oxidative phosphorylation, as well as abnormalities in the TCA cycle and amino acid metabolism.
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Affiliation(s)
- Jiewei Hong
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| | - Hongxuan Tong
- Institute of Basic Theory of Chinese Medicine, China Academy of Chinese Medical Sciences, Beijing, China
| | - Xuan Wang
- Party Committee Office, Shanxi Health Vocational College, Shanxi, China
| | - Xiaoyan Lv
- Library Collection and Editing Department, Beijing University of Chinese Medicine, Beijing, China
| | - Lijuan He
- Rehabilitation Department, Dongfang Hospital Beijing University of Chinese Medicine, Beijing, China
| | - Xuezhi Yang
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| | - Yingli Wang
- Experimental Management Center, Shanxi University of Traditional Chinese Medicine, Shanxi, China
| | - Kaixia Xu
- School of Basic Medicine, Shanxi University of Traditional Chinese Medicine, Shanxi, China
| | - Qi Liang
- Centre for Marine Bioproducts Development, College of Medicine and Public Health, Flinders University, Bedford Park, SA, Australia
| | - Qianjin Feng
- Experimental Management Center, Shanxi University of Traditional Chinese Medicine, Shanxi, China
| | - Tingli Niu
- Medical Insurance Office, Beijing University of Chinese Medicine Third Affiliated Hospital, Beijing, China
| | - Xin Niu
- School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| | - Yu Lu
- Institute of Information on Traditional Chinese Medicine, China Academy of Chinese Medical Sciences, Beijing, China
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Aragoneses-Cazorla G, Vallet-Regí M, Gómez-Gómez MM, González B, Luque-Garcia JL. Integrated transcriptomics and metabolomics analysis reveals the biomolecular mechanisms associated to the antitumoral potential of a novel silver-based core@shell nanosystem. Mikrochim Acta 2023; 190:132. [PMID: 36914921 PMCID: PMC10011303 DOI: 10.1007/s00604-023-05712-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 02/28/2023] [Indexed: 03/14/2023]
Abstract
A combination of omics techniques (transcriptomics and metabolomics) has been used to elucidate the mechanisms responsible for the antitumor action of a nanosystem based on a Ag core coated with mesoporous silica on which transferrin has been anchored as a targeting ligand against tumor cells (Ag@MSNs-Tf). Transcriptomics analysis has been carried out by gene microarrays and RT-qPCR, while high-resolution mass spectrometry has been used for metabolomics. This multi-omics strategy has enabled the discovery of the effect of this nanosystem on different key molecular pathways including the glycolysis, the pentose phosphate pathway, the oxidative phosphorylation and the synthesis of fatty acids, among others.
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Affiliation(s)
- Guillermo Aragoneses-Cazorla
- Department of Analytical Chemistry, Faculty of Chemical Sciences, Complutense University of Madrid, 28040, Madrid, Spain
| | - María Vallet-Regí
- Department of Chemistry in Pharmaceutical Sciences, Faculty of Pharmacy, Complutense University of Madrid, Instituto de Investigación Sanitaria Hospital, 12 de Octubre (I+12), 28040, Madrid, Spain
- Centro de Investigación Biomédica en Red de Bioingeniería, Biomateriales Y Nanomedicina (CIBER-BBN), Saragossa, Spain
| | - Ma Milagros Gómez-Gómez
- Department of Analytical Chemistry, Faculty of Chemical Sciences, Complutense University of Madrid, 28040, Madrid, Spain
| | - Blanca González
- Department of Chemistry in Pharmaceutical Sciences, Faculty of Pharmacy, Complutense University of Madrid, Instituto de Investigación Sanitaria Hospital, 12 de Octubre (I+12), 28040, Madrid, Spain
- Centro de Investigación Biomédica en Red de Bioingeniería, Biomateriales Y Nanomedicina (CIBER-BBN), Saragossa, Spain
| | - Jose L Luque-Garcia
- Department of Analytical Chemistry, Faculty of Chemical Sciences, Complutense University of Madrid, 28040, Madrid, Spain.
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Ramos-Ibeas P, Gimeno I, Cañón-Beltrán K, Gutiérrez-Adán A, Rizos D, Gómez E. Senescence and Apoptosis During in vitro Embryo Development in a Bovine Model. Front Cell Dev Biol 2020; 8:619902. [PMID: 33392207 PMCID: PMC7775420 DOI: 10.3389/fcell.2020.619902] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 12/01/2020] [Indexed: 12/15/2022] Open
Abstract
According to the World Health Organization, infertility affects up to 14% of couples under reproductive age, leading to an exponential rise in the use of assisted reproduction as a route for conceiving a baby. In the same way, thousands of embryos are produced in cattle and other farm animals annually, leading to increased numbers of individuals born. All reproductive manipulations entail deviations of natural phenotypes and genotypes, with in vitro embryo technologies perhaps showing the biggest effects, although these alterations are still emerging. Most of these indications have been provided by animal models, in particular the bovine species, due to its similarities to human early embryo development. Oocytes and embryos are highly sensitive to environmental stress in vivo and in vitro. Thus, during in vitro culture, a number of stressful conditions affect embryonic quality and viability, inducing subfertility and/or long-term consequences that may reach the offspring. A high proportion of the embryos produced in vitro are arrested at a species-specific stage of development during the first cell divisions. These arrested embryos do not show signs of programmed cell death during early cleavage stages. Instead, defective in vitro produced embryos would enter a permanent cell cycle arrest compatible with cellular senescence, in which they show active metabolism and high reactive oxygen species levels. Later in development, mainly during the morula and blastocyst stages, apoptosis would mediate the elimination of certain cells, accomplishing both a physiological role in to balancing cell proliferation and death, and a pathological role preventing the transmission of damaged cells with an altered genome. The latter would acquire relevant importance in in vitro produced embryos that are submitted to stressful environmental stimuli. In this article, we review the mechanisms mediating apoptosis and senescence during early embryo development, with a focus on in vitro produced bovine embryos. Additionally, we shed light on the protective role of senescence and apoptosis to ensure that unhealthy cells and early embryos do not progress in development, avoiding long-term detrimental effects.
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Affiliation(s)
- Priscila Ramos-Ibeas
- Department of Animal Reproduction, National Institute for Agriculture and Food Research and Technology (INIA), Madrid, Spain
| | - Isabel Gimeno
- Servicio Regional de Investigación y Desarrollo Agroalimentario (SERIDA), Gijón, Spain
| | - Karina Cañón-Beltrán
- Department of Animal Reproduction, National Institute for Agriculture and Food Research and Technology (INIA), Madrid, Spain
| | - Alfonso Gutiérrez-Adán
- Department of Animal Reproduction, National Institute for Agriculture and Food Research and Technology (INIA), Madrid, Spain
| | - Dimitrios Rizos
- Department of Animal Reproduction, National Institute for Agriculture and Food Research and Technology (INIA), Madrid, Spain
| | - Enrique Gómez
- Servicio Regional de Investigación y Desarrollo Agroalimentario (SERIDA), Gijón, Spain
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Zhao J, Hakvoort TBM, Willemsen AM, Jongejan A, Sokolovic M, Bradley EJ, de Boer VCJ, Baas F, van Kampen AHC, Lamers WH. Effect of Hyperglycemia on Gene Expression during Early Organogenesis in Mice. PLoS One 2016; 11:e0158035. [PMID: 27433804 PMCID: PMC4951019 DOI: 10.1371/journal.pone.0158035] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2015] [Accepted: 06/09/2016] [Indexed: 01/01/2023] Open
Abstract
Background Cardiovascular and neural malformations are common sequels of diabetic pregnancies, but the underlying molecular mechanisms remain unknown. We hypothesized that maternal hyperglycemia would affect the embryos most shortly after the glucose-sensitive time window at embryonic day (ED) 7.5 in mice. Methods Mice were made diabetic with streptozotocin, treated with slow-release insulin implants and mated. Pregnancy aggravated hyperglycemia. Gene expression profiles were determined in ED8.5 and ED9.5 embryos from diabetic and control mice using Serial Analysis of Gene Expression and deep sequencing. Results Maternal hyperglycemia induced differential regulation of 1,024 and 2,148 unique functional genes on ED8.5 and ED9.5, respectively, mostly in downward direction. Pathway analysis showed that ED8.5 embryos suffered mainly from impaired cell proliferation, and ED9.5 embryos from impaired cytoskeletal remodeling and oxidative phosphorylation (all P ≤ E-5). A query of the Mouse Genome Database showed that 20–25% of the differentially expressed genes were caused by cardiovascular and/or neural malformations, if deficient. Despite high glucose levels in embryos with maternal hyperglycemia and a ~150-fold higher rate of ATP production from glycolysis than from oxidative phosphorylation on ED9.5, ATP production from both glycolysis and oxidative phosphorylation was reduced to ~70% of controls, implying a shortage of energy production in hyperglycemic embryos. Conclusion Maternal hyperglycemia suppressed cell proliferation during gastrulation and cytoskeletal remodeling during early organogenesis. 20–25% of the genes that were differentially regulated by hyperglycemia were associated with relevant congenital malformations. Unexpectedly, maternal hyperglycemia also endangered the energy supply of the embryo by suppressing its glycolytic capacity.
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Affiliation(s)
- Jing Zhao
- Tytgat Institute for Liver and Intestinal Research, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Theodorus B. M. Hakvoort
- Tytgat Institute for Liver and Intestinal Research, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - A. Marcel Willemsen
- Bioinformatics Laboratory, Department of Bioinformatics, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Aldo Jongejan
- Bioinformatics Laboratory, Department of Bioinformatics, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Milka Sokolovic
- Department of Biochemistry, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Edward J. Bradley
- Department of Genome Analysis, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Vincent C. J. de Boer
- Department of Laboratory Genetic Metabolic Diseases, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Frank Baas
- Department of Genome Analysis, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Antoine H. C. van Kampen
- Bioinformatics Laboratory, Department of Bioinformatics, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
- Biosystems Data Analysis Group, University of Amsterdam, Amsterdam, The Netherlands
| | - Wouter H. Lamers
- Tytgat Institute for Liver and Intestinal Research, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
- * E-mail:
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Zhao X, Hao H, Du W, Zhu H. Effect of vitrification on the microRNA transcriptome in mouse blastocysts. PLoS One 2015; 10:e0123451. [PMID: 25853900 PMCID: PMC4390370 DOI: 10.1371/journal.pone.0123451] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Accepted: 03/03/2015] [Indexed: 12/13/2022] Open
Abstract
Vitrification is commonly used in the cryopreservation of mammalian blastocysts to overcome the temporal and spatial limitations of embryo transfer. Previous studies have shown that the implantation ability of vitrified blastocysts is impaired and that microRNAs (miRNAs) regulate the critical genes for embryo implantation. However, little information is available about the effect of vitrification on the miRNA transcriptome in blastocysts. In the present study, the miRNA transcriptomes in fresh and vitrified mouse blastocysts were analyzed by miRNA Taqman assay based method, and the results were validated using quantitative real-time PCR (qRT-PCR). Then, the differentially expressed miRNAs were assessed using the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases. Overall, 760 known mouse miRNAs were detected in the vitrified and fresh mouse blastocysts. Of these, the expression levels of five miRNAs differed significantly: in the vitrified blastocysts, four miRNAs (mmu-miR-199a-5p, mmu-miR-329-3p, mmu-miR-136-5p and mmu-miR-16-1-3p) were upregulated, and one (mmu-miR-212-3p) was downregulated. The expression levels of all miRNAs measured by the miRNA Taqman assay based method and qRT-PCR were consistent. The four upregulated miRNAs were predicted to regulate 877 candidate target genes, and the downregulated miRNA was predicted to regulate 231 genes. The biological analysis further showed that the differentially expressed miRNAs mainly regulated the implantation of embryos. In conclusion, the results of our study showed that vitrification significantly altered the miRNA transcriptome in mouse blastocysts, which may decrease the implantation potential of vitrified blastocysts.
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Affiliation(s)
- Xueming Zhao
- Embryo Biotechnology and Reproduction Laboratory, Institute of Animal Sciences (IAS), Chinese Academy of Agricultural Sciences (CAAS), Beijing 100193, P. R. China
| | - Haisheng Hao
- Embryo Biotechnology and Reproduction Laboratory, Institute of Animal Sciences (IAS), Chinese Academy of Agricultural Sciences (CAAS), Beijing 100193, P. R. China
| | - Weihua Du
- Embryo Biotechnology and Reproduction Laboratory, Institute of Animal Sciences (IAS), Chinese Academy of Agricultural Sciences (CAAS), Beijing 100193, P. R. China
| | - Huabin Zhu
- Embryo Biotechnology and Reproduction Laboratory, Institute of Animal Sciences (IAS), Chinese Academy of Agricultural Sciences (CAAS), Beijing 100193, P. R. China
- * E-mail:
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Velazquez MA. Impact of maternal malnutrition during the periconceptional period on mammalian preimplantation embryo development. Domest Anim Endocrinol 2015; 51:27-45. [PMID: 25498236 DOI: 10.1016/j.domaniend.2014.10.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Revised: 10/27/2014] [Accepted: 10/28/2014] [Indexed: 02/07/2023]
Abstract
During episodes of undernutrition and overnutrition the mammalian preimplantation embryo undergoes molecular and metabolic adaptations to cope with nutrient deficits or excesses. Maternal adaptations also take place to keep a nutritional microenvironment favorable for oocyte development and embryo formation. This maternal-embryo communication takes place via several nutritional mediators. Although adaptive responses to malnutrition by both the mother and the embryo may ensure blastocyst formation, the resultant quality of the embryo can be compromised, leading to early pregnancy failure. Still, studies have shown that, although early embryonic mortality can be induced during malnutrition, the preimplantation embryo possesses an enormous plasticity that allows it to implant and achieve a full-term pregnancy under nutritional stress, even in extreme cases of malnutrition. This developmental strategy, however, may come with a price, as shown by the adverse developmental programming induced by even subtle nutritional challenges exerted exclusively during folliculogenesis and the preimplantation period, resulting in offspring with a higher risk of developing deleterious phenotypes in adulthood. Overall, current evidence indicates that malnutrition during the periconceptional period can induce cellular and molecular alterations in preimplantation embryos with repercussions for fertility and postnatal health.
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Affiliation(s)
- M A Velazquez
- Centre for Biological Sciences, University of Southampton, Southampton General Hospital, Southampton, UK.
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Ye EA, Steinle JJ. miR-15b/16 protects primary human retinal microvascular endothelial cells against hyperglycemia-induced increases in tumor necrosis factor alpha and suppressor of cytokine signaling 3. J Neuroinflammation 2015; 12:44. [PMID: 25888955 PMCID: PMC4355155 DOI: 10.1186/s12974-015-0265-0] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 02/10/2015] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Mechanisms underlying the pathology of diabetic retinopathy are still not completely understood. Increased understanding of potential cellular pathways responsive to hyperglycemia is essential to develop novel therapeutic strategies for diabetic retinopathy. Emerging evidence shows the impact of microRNA (miR) as a potential novel therapeutic target. The purpose of our study was to test the hypothesis that miR-15b and miR-16 are altered by hyperglycemia in retinal endothelial cells (REC), and that miR-15b/16 play key roles in regulating insulin signaling through a reduction in TNFα- and suppressor of cytokine signaling 3 (SOCS3)-mediated insulin resistance pathways. METHODS Human REC were maintained in normal (5 mM) glucose or transferred to high-glucose medium (25 mM) for 3 days. REC were transfected with miRNA mimics (hsa-miR-15b-5p and hsa-miR-16-5p) 48 h before cell harvest. A final concentration of 30 nM was used when transfected separately (miR-15b and miR-16) and 15 nM was used in combination (miR-15b + miR-16). A negative control group was treated with an equal concentration of a mimic negative control. The levels of miRNA overexpression were verified using quantitative reverse transcription-polymerase chain reaction and real-time PCR. Western blot analyses were performed to study the levels of phosphorylated Akt (Serine 473), Akt, SOCS3, insulin receptor, phosphorylated insulin receptor (tyrosine 1150/1151), and insulin receptor phosphorylated on Tyr960. In addition, ELISA was used to examine cleaved caspase 3 and TNFα. Analyses were done using unpaired Student t test. Data are presented as mean ± S.E.M. RESULTS We demonstrated that the expression of miR-15b and miR-16 was reduced in human REC cultured in hyperglycemia. Overexpression of miR-15b and/or miR-16 reduced TNFα and SOCS3 levels, while increasing insulin-like growth factor binding protein-3 (IGFBP-3) levels and the phosphorylation of insulin receptor (IR)(Tyr1150/1151) in REC cultured in hyperglycemia. These, in turn, led to an increase of Akt phosphorylation and decreased cleavage of caspase 3. CONCLUSIONS miR-15b and miR-16 play a role in the inhibition of insulin resistance via reduced TNFα and SOCS3 signaling and increased IGFBP-3 levels, resulting in REC protection from hyperglycemia-induced apoptosis. This outcome suggests that both miR-15b and miR-16 are potential therapeutic targets for therapeutics for the diabetic retina.
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Affiliation(s)
- Eun-Ah Ye
- Department of Anatomy and Cell Biology, Wayne State University, 9314 Scott Hall, 48201, Detroit, MI, USA.
| | - Jena J Steinle
- Department of Anatomy and Cell Biology, Wayne State University, 9314 Scott Hall, 48201, Detroit, MI, USA. .,Department of Ophthalmology, Wayne State University, 9314 Scott Hall, 48201, Detroit, MI, USA.
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Heselich A, Frohns F, Frohns A, Naumann SC, Layer PG. Near-infrared exposure changes cellular responses to ionizing radiation. Photochem Photobiol 2011; 88:135-46. [PMID: 22053955 DOI: 10.1111/j.1751-1097.2011.01031.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Near infrared (NIR) and X-rays are radiations from different sides of the wavelength spectrum but both are used during medical treatments, as they have severe impacts on cellular processes, including metabolism, gene expression, proliferation and survival. However, both radiations differ strictly in their consequences for exposed patients: NIR effects are generally supposed to be positive, mostly ascribed to a stimulation of metabolism, whereas X-ray leads to genetic instability, an increase of reactive oxygen species (ROS) and DNA damages and finally to cellular death by apoptosis in tumor cells. Since genomic stability after X-irradiation depends on the mitochondrial metabolism, which is well known to be regulated by NIR, we analyzed the impact of NIR on cellular responses of fibroblasts, retinal progenitor cells and keratinocytes to X-radiation. Our data show that previous exposure to naturally occurring doses of nonthermal NIR combined with clinically relevant X-ray doses leads to (1) increased genomic instability, indicated by elevated ratios of mitotic catastrophes, (2) increased ROS, (3) higher amounts of X-irradiated cells entering S-phase and (4) impaired DNA double-strand break repair. Taken together, our data show tremendous effects of NIR on cellular responses to X-rays, probably affecting the results of radiotherapy after NIR exposure during cancer treatment.
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Affiliation(s)
- Anja Heselich
- Developmental Biology and Neurogenetics, TU Darmstadt, Darmstadt, Germany.
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Boumela I, Assou S, Aouacheria A, Haouzi D, Dechaud H, De Vos J, Handyside A, Hamamah S. Involvement of BCL2 family members in the regulation of human oocyte and early embryo survival and death: gene expression and beyond. Reproduction 2011; 141:549-61. [PMID: 21339285 DOI: 10.1530/rep-10-0504] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
In women, up to 99.9% of the oocyte stockpile formed during fetal life is decimated by apoptosis. Apoptotic features are also detected in human preimplantation embryos both in vivo and in vitro. Despite the important consequences of cell death processes to oocyte competence and early embryonic development, little is known about its genetic and molecular control. B cell lymphoma-2 (BCL2) family proteins are major regulators of cell death and survival. Here, we present a literature review on BCL2 family expression and protein distribution in human and animal oocytes and early embryos. Most of the studies focused on the expression of two antagonistic members: the founding and survival family member BCL2 and its proapoptotic homolog BAX. However, recent transcriptomic analyses have identified novel candidate genes related to oocyte and/or early embryonic viability (such as BCL2L10) or commitment to apoptosis (e.g. BIK). Interestingly, some BCL2 proteins appear to be differentially distributed at the subcellular level during oocyte maturation and early embryonic development, a process probably linked to the functional compartmentalization of the ooplasm and blastomere. Assessment of BCL2 family involvement in regulating the survival of human oocytes and embryos may be of particular value for diagnosis and assisted reproductive technology. We suggest that implications of not only aberrant gene expression but also abnormal subcellular protein redistribution should be established in pathological conditions resulting in infertility.
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Affiliation(s)
- Imene Boumela
- CHU Montpellier, Institute for Research in Biotherapy, Hôpital Saint-Eloi, Montpellier F-34000, France
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Perumalsamy A, Fernandes R, Lai I, Detmar J, Varmuza S, Casper RF, Jurisicova A. Developmental consequences of alternative Bcl-x splicing during preimplantation embryo development. FEBS J 2010; 277:1219-33. [PMID: 20136652 DOI: 10.1111/j.1742-4658.2010.07554.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Elevated cell death in human preimplantation embryos is one of the cellular events compromising pregnancy rates after assisted reproductive technology treatments. We therefore explored the molecular pathways regulating cell death at the blastocyst stage in human embryos cultured in vitro. Owing to limited availability of human embryos, these pathways were further characterized in mouse blastocysts. Gene expression studies revealed a positive correlation between the cell death index and the expression of Bcl-x transcript. Cell death activation in human blastocysts was accompanied by changes in Bcl-x splicing, favoring production of Bcl-xS, an activator of cell death. Expression of Bcl-xS was detected in a subset of human blastocysts that show particular clustering in dying and/or dead cells. Altering the Bcl-xL/Bcl-xS ratio in mouse embryos, in antisense experiments, confirmed that upregulation of Bcl-xS, with concomitant downregulation of Bcl-xL, compromised developmental potential and committed a subset of cells to undergoing cell death. This was accompanied by increased accumulation of reactive oxygen species levels without any impact on mtDNA content. In addition, altered Bcl-x splicing in favor of Bcl-xS was stimulated by culture in HTF medium or by addition of excessive glucose, leading to compromised embryo development. Thus, we conclude that inappropriate culture conditions affect Bcl-x isoform expression, contributing to compromised preimplantation embryo development.
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